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Sample records for Permian Basin

  1. Exploratory shaft facility preliminary designs - Permian Basin

    International Nuclear Information System (INIS)

    The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables

  2. Permian Basin location recommendation report

    International Nuclear Information System (INIS)

    Candidate study areas are screened from the Palo Duro and Dalhart Basin areas using data obtained from studies to date and criteria and specifications that consider: rock geometry; rock characteristics; human intrusion potential; surface characteristics; and environmental and socioeconomic conditions. Two preferred locations are recommended from among these areas for additional characterization to identify potential National Waste Terminal Storage (NWTS) salt repository sites. One location, in northeastern Deaf Smith County and southeastern Oldham County, is underlain by two salt units that meet the adopted screening specifications. The other location, in northcentral Swisher County, is underlain by one salt unit that meets the adopted screening specifications. Both locations have several favorable features, relative to surrounding areas, and no obviously undesirable characteristics. Both lie wholly on the Southern High Plains surface, are in relatively sparsely populated areas, contain no unique land use conflicts, and comprise large enough geographic areas to provide flexibility in site selection. Data gathered to date indicate that these locations contain salt units sufficient in thickness and in depth for the safe construction and operation of the underground facilities under consideration. 93 references, 34 figures, 6 tables

  3. Faunal migration into the Late Permian Zechstein Basin

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Håkansson, Eckart; Stemmerik, Lars

    2007-01-01

    northern margin of Pangea is used to test hypotheses concerning Late Palaeozoic evolution of the North Atlantic region. During the Permian, the Atlantic rift system formed a seaway between Norway and Greenland from the boreal Barents Shelf to the warm and arid Zechstein Basin. This seaway is considered to...

  4. Characteristics and exploration prospects of Middle Permian reservoirs in the Sichuan Basin

    OpenAIRE

    Guang Yang; Hua Wang; Hao Shen; Yuran Yang; Song Jia; Wen Chen; Hua Zhu; Yi Li

    2015-01-01

    In recent years, encouraging progress has been made in the Middle Permian natural gas exploration in the Sichuan Basin – numerous wells have obtained high-yield industrial gas flows in the dolomite porous reservoir sections in the Middle Permian Maokou Formation and the Qixia Formation, making the Middle Permian one of the most realistic replacement strata at present. In order to clarify the further exploration prospect of the basin, the Middle Permian depositional settings and prospective re...

  5. Structure of the Anayet Permian basin (Axial Zone, Central Pyrenees)

    Science.gov (United States)

    Rodriguez, L.; Cuevas, J.; Tuba, J. M.

    2012-04-01

    The Anayet Permian basin was generated by strike-slip tectonics that opened subsident basins with pull-apart geometries in the western Spanish Axial Zone (between the Aragon and Tena valleys). A continental succession of Permian age, that represents the first post-variscan deposits in the area, fills the basin and covers discordantly Devonian to Carboniferous limestones, sandstones and slates. Permian deposits have been classically divided in four main detrital groups, with three basic volcanic episodes interbedded (Gisbert, 1984, Bixel, 1987): the Grey Unit (50-120 m, Estefanian to Kungurian) with slates, conglomerates, tobaceous slates, coal and pyroclastic deposits, the Transition Unit (50 m maximum) showing grey and red sandstones and lutites with oolitic limestones intercalated, the Lower Red Unit (250 m) composed of cross-bedded red sandstones and andesitic volcanic rocks at the top, and finally the Upper Red Unit (400 m minimum, top eroded) formed by three fining up megasequences of carbonates, red sandstones and lutites with lacustrine carbonates intercalated and alkali basalts at the top. Increasingly older rocks are found towards the western part of the basin, where its depocenter is located. South-vergent angular folds deform the Permian sedimentary succession. Fold axes are N115 E-trending, almost horizontal and are characterized by a remarkably constant orientation. Folds exhibit a long limb dipping slightly to the north and a short vertical limb, occasionally reversed. In the Anayet basin four main folds, with a wavelength of 400 m, can be distinguished, two anticlines and two synclines, with minor folds associated. Related to the angular folds an axial plane foliation, E-trending and dipping 40 to 60 to the north, is developed in the lutites. The more competent rocks, conglomerates and breccias, only locally show a spaced fracture cleavage. No main thrusts have been detected in Permian rocks. However, minor scale decollements, usually low angle to bedding-parallel, have been identified along low-dipping limbs of the folds. They can be recognized due to the high colour contrast between the red-coloured Permian beds and the concentration of calcite veins in the decollements. The development of the structures above described has to be linked to the Alpine compressional tectonics. This interpretation is supported by the good correlation in geometry and orientation between the structures observed in the Permian basin and in southernmost areas of the South Pyrenean Zone, where the deformation is imprinted in Cretaceous to Tertiary rocks. In this regard, the southern border of the Anayet basin, at least in the western part, can be interpreted as a normal fault reactivated as a high-angle reverse fault during the positive inversion tectonics induced by the Alpine Orogeny. Bixel, F., 1987. Le volcanisme stephano-permien des Pyrenees petrographie, mineralogie, geochimie. Cuadernos de Geologa Ibrica 11, 41-55. Gisbert, J., 1984. Las molasas tardihercnicas del Pirineo, in: Geologa de Espaa. Libro Jubilar de J. M. Ros, Comba, J.A. (Ed.), IGME, Madrid, 168-186.

  6. Reservoir engineering continuing education course for the Permian Basin Section

    Energy Technology Data Exchange (ETDEWEB)

    Edgar, A.L.; Eddy, R.E.; Caudle, B.H.

    1967-01-01

    A questionnaire sent to members of the Permian Basin Section of the Society of Petroleum Engineers of AIME resulted in the development of a 2-semester course in reservoir engineering. This first semester was devoted to the basic law of fluid flow in porous media and the mathematics for those solutions used in modern reservoir engineering. The second semester consisted of the application of the laws to reservoir engineering problems in well testing, gas cycling, waterflooding, and other secondary recovery methods. The main objective of the program was to increase the ability of the practicing petroleum engineer to understand and use the reservoir engineering methods now being developed and described in the literature. A survey of those attending indicated general satisfaction with the program. The section intends to continue its education program by repeating the reservoir engineering course in 1967-1968 and also introducing a second course covering principles of management.

  7. Feasibility study of heavy oil recovery in the Permian Basin (Texas and New Mexico)

    International Nuclear Information System (INIS)

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production. Each report covers select areas of the United States. The Permian Basin of West Texas and Southeastern New Mexico is made up of the Midland, Delaware, Val Verde, and Kerr Basins; the Northwestern, Eastern, and Southern shelves; the Central Basin Platform, and the Sheffield Channel. The present day Permian Basin was one sedimentary basin until uplift and subsidence occurred during Pennsylvanian and early Permian Age to create the configuration of the basins, shelves, and platform of today. The basin has been a major light oil producing area served by an extensive pipeline network connected to refineries designed to process light sweet and limited sour crude oil. Limited resources of heavy oil (10'' to 20'' API gravity) occurs in both carbonate and sandstone reservoirs of Permian and Cretaceous Age. The largest cumulative heavy oil production comes from fluvial sandstones of the Cretaceous Trinity Group. Permian heavy oil is principally paraffinic and thus commands a higher price than asphaltic California heavy oil. Heavy oil in deeper reservoirs has solution gas and low viscosity and thus can be produced by primary and by waterflooding. Because of the nature of the resource, the Permian Basin should not be considered a major heavy oil producing area

  8. Characteristics and exploration prospects of Middle Permian reservoirs in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2015-11-01

    Full Text Available In recent years, encouraging progress has been made in the Middle Permian natural gas exploration in the Sichuan Basin – numerous wells have obtained high-yield industrial gas flows in the dolomite porous reservoir sections in the Middle Permian Maokou Formation and the Qixia Formation, making the Middle Permian one of the most realistic replacement strata at present. In order to clarify the further exploration prospect of the basin, the Middle Permian depositional settings and prospective reservoir types were analyzed. The results show that: (1 the depositional environment was predominately open, shallow water; the paleogeomorphology was high in the west and low in the east, with bioclastic flat reservoirs more extensive in the middle-west part than the east part; crustal extension made Middle Permian deposits have good conditions for thermal water deposition and hydrothermal alteration; and (2 the prospect reservoirs for exploration were shoal facies dolomite porous reservoir of the Qixia Formation, thermal water dolomite porous reservoir and karst reservoir of the Maokou Formation, thus, dolomite porous reservoir was the most perspective target in the Middle Permian. It is concluded that Middle Permian limestone source rocks have large hydrocarbon generation intensity in the northern part of Western and Central Sichuan Basin and have the material basis for the formation of large-medium gas fields; the thick dolomite reservoir of the Qixia Formation in the Western Sichuan Basin is the most prospective reservoir in the Middle Permian; three types of reservoirs are distributed in the Central Sichuan Basin, and they are superimposed vertically with large exploration potential; Jiange–Nanchong–Fengdu region is located in the thermal sub-basin zone, where the thermal water dolomite reservoir of the Maokou formation is pervasive and superimposed on the karst reservoir of the Maokou Formation, showing good natural gas exploration prospects.

  9. Sedimentary features and exploration targets of Middle Permian reservoirs in the SW Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guoming Xu

    2015-11-01

    Full Text Available The exploration direction and targets for the large-scale Middle Permian gas reservoirs in the Sichuan Basin are hot spots and challenges in current exploration researches. The exploration successes of large gas field of Cambrian Longwangmiao Formation in Gaoshiti-Moxi region, Central Sichuan Basin, indicated that prospective sedimentary facies belt was the basis for the formation of large gas fields. In this paper, based on seismic data, outcrop data and drilling data, the tectonic framework and sedimentary features of the Middle Permian in the SW Sichuan Basin were comprehensively studied. The following conclusions were reached from the perspective of sedimentary facies control: (1 during the Middle Permian, this region was in shallow water gentle slope belts with high energy, where thick reef flat facies were deposited; (2 the basement was uplifted during Middle Permian, resulting in the unconformity weathering crust at the top of Maokou Formation due to erosion; the SW Sichuan Basin was located in the karst slope belt, where epigenic karstification was intense; and (3 reef flat deposits superimposed by karst weathering crust was favorable for the formation of large-scale reef flat karst reservoirs. Based on the combination of the resources conditions and hydrocarbon accumulation conditions in this region, it was pointed out that the Middle Permian has great potential of large-scale reef flat karst gas reservoir due to its advantageous geological conditions; the Middle Permian traps with good hydrocarbon accumulation conditions were developed in the Longmen Mountain front closed structural belt in the SW Sichuan Basin and Western Sichuan Basin depression slope belt, which are favorable targets for large-scale reef flat karst reservoirs.

  10. Early Permian volcano-sedimentary successions, Beishan, NW China: Peperites demonstrate an evolving rift basin

    Science.gov (United States)

    Chen, Shi; Guo, Zhaojie; Qi, Jiafu; Zhang, Yuanyuan; Pe-Piper, Georgia; Piper, David J. W.

    2016-01-01

    The Lower Permian volcano-sedimentary Zhesi Group has been investigated in the Hongliuhe and Liuyuan areas in Beishan, China, which is significant for the reconstruction of Late Paleozoic evolution in the southern part of the Central Asian Orogenic Belt. A variety of volcanic facies were distinguished in the Upper Zhesi Group: pillow basalt with interstitial limestone, thin-interbedded limestone and basalt, closely packed pillows, pillow-fragmented hyaloclastite breccia, and peperite. Laser 40Ar/39Ar whole-rock dating of the basalt yielding an age of 277 ± 11 Ma, as well as Early Permian brachiopod fossils in the limestone interbedded with the basalt, indicate that basalt was erupted in the Early Permian. The identification of the peperite and other facies originating from magma-sediment mingling reveals that the basaltic lava flows were derived from autochthonous basaltic magmatism and formed as part of the Lower Permian succession. The peperite also indicates that these subaqueous basaltic lava flows are not dismembered ophiolitic components, but formed in an autochthonous extensional setting in the Early Permian. The clastic rocks in the Lower Zhesi Group underlying the basaltic flows and peperites in the Hongliuhe and Liuyuan areas show a general fining-upwards sequence, indicating that they were deposited in a progressively deepening basin overlying the Devonian Hongliuhe suture zone. Subaqueous volcanism in a rift basin or basins, accompanied by coeval deposition of carbonate sediment and mud, built up the peperite-bearing volcanogenic-sedimentary successions. From among the various tectonic hypotheses for the Beishan region, this study demonstrates that by Early Permian the region was developing post-collisional rift basins.

  11. The not so simple relationship between seismicity and oil production in the Permian Basin, west Texas

    Science.gov (United States)

    Doser, D. I.; Baker, M. R.; Luo, M.; Marroquin, P.; Ballesteros, L.; Kingwell, J.; Diaz, H. L.; Kaip, G.

    1992-09-01

    We have relocated seismicity occurring in the Permian Basin of west Texas between 1975 and 1979 using three-dimensional velocity models constructed from well log information and compared the locations to detailed geological and geophysical models of specific oil fields. The seismicity appears to be related to a variety of causes including migration of naturally occurring overpressured fluids, tectonic activity, reservoir production, and enhanced recovery operations. Many earthquakes may represent a combination of these effects. Although the Permian Basin is the site of numerous oil and gas fields, only a limited number of fields appears to be associated with seismicity. We find that there are similarities in the structural setting in the fields associated with seismicity. Furthermore, fields within the Delaware Basin that are associated with seismicity are located in regions of high vertical and lateral fluid pressure gradients related to an overpressured zone within the Delaware Basin.

  12. Inversion tectonics in the Anayet Permian basin (Axial Zone, Central Pyrenees)

    Science.gov (United States)

    Rodriguez, L.; Cuevas, J.; Tuba, J. M.

    2012-04-01

    During Permian times the Pyrenees were characterized by extensional tectonics that opened subsident basins with pull-apart geometries. The Anayet Permian basin crops out in the western Spanish Axial Zone between the Aragon and Tena valleys. It is WNW-trending and it is filled by a continental Permian succession that represents the first post-variscan deposits in the area. Permian deposits rest discordantly over Devonian to Carboniferous limestones, sandstones and slates. In the Anayet basin, Permian deposits have been classically divided in four main detrital groups, mainly composed of sandstones and conglomerates, with three basic volcanic episodes interbedded (Gisbert, 1984, Bixel, 1987). Due to the lithological characteristics of the Permian rocks in this region, there are almost no accurate age constraints for these units. A detailed structural study of the area, including mapping and balanced cross-sections, shows increasingly older rocks to the west of the Anayet basin. Moreover, it can be deduced a mean slope of around 11 % to the west for the basin. These data confirm that the basin depocenter was located to the west and that the Anayet basin was partitioned by N10 E-trending normal faults. Although the contacts between the Permian and the Devono-Carboniferous rocks are covered by quaternary deposits in most of its extent, a fault contact can also be recognized. The fault contact is a 3 m thick shear zone oriented N120 E and dipping 60 to the North. It develops breccias, fault gouges and sigmoidal S-C tectonites indicating a reverse motion. The contact places Permian slates and sandstones over Carboniferous limestones and is almost parallel to the alpine cleavage deforming Permian rocks. The slope of the contact together with the presence of younger rocks in the hangingwall of the reverse fault points out that the original contact was a normal fault reactivated as a high-angle reverse fault during the positive inversion tectonics induced by the Alpine Orogeny. The high dip of the contact produced a buttressing effect during the alpine compression that concentrated the deformation near the fault zone and generated the cleavage of the hangingwall. Moreover, the higher abundance of fractures and calcite veins near the contact in the Carboniferous limestones of the footwall can be interpreted as an incipient stage to the formation of a short-cut-fault related with the buttressing effect. This process can explain the uncommon thickness of the fault zone, if we compare it with other alpine thrusts in this region. The structural features described above support the interpretation of the southern limit of the Anayet Permian basin as a normal fault originated during the Permian rifting and inverted during the compressional tectonics due to the Alpine Orogeny. Bixel, F., 1987. Le volcanisme stephano-permien des pyrenees petrographie, mineralogie, geochimie. Cuadernos de Geologa Ibrica 11, 41-55. Gisbert, J., 1984. Las molasas tardihercnicas del Pirineo, in: Geologa de Espaa. Libro Jubilar de J. M. Ros, Comba, J.A. (Ed.). IGME, Madrid, 168-186.

  13. 78 FR 16569 - Iowa Pacific Holdings, LLC, Permian Basin Railways, and San Luis & Rio Grande Railroad-Corporate...

    Science.gov (United States)

    2013-03-15

    ... Holdings, LLC (IPH), its wholly owned subsidiaries Permian Basin Railways (PBR) and San Luis & Rio Grande..., IPH is a noncarrier that wholly owns PBR, which directly controls seven Class III railroads.\\1\\...

  14. Carbon Capture and Storage in the Permian Basin, a Regional Technology Transfer and Training Program

    Energy Technology Data Exchange (ETDEWEB)

    Rychel, Dwight

    2013-09-30

    The Permian Basin Carbon Capture, Utilization and Storage (CCUS) Training Center was one of seven regional centers formed in 2009 under the American Recovery and Reinvestment Act of 2009 and managed by the Department of Energy. Based in the Permian Basin, it is focused on the utilization of CO2 Enhanced Oil Recovery (EOR) projects for the long term storage of CO2 while producing a domestic oil and revenue stream. It delivers training to students, oil and gas professionals, regulators, environmental and academia through a robust web site, newsletter, tech alerts, webinars, self-paced online courses, one day workshops, and two day high level forums. While course material prominently features all aspects of the capture, transportation and EOR utilization of CO2, the audience focus is represented by its high level forums where selected graduate students with an interest in CCUS interact with Industry experts and in-house workshops for the regulatory community.

  15. The problems of Paleozoic beds and reconstruction of the Middle Permian sedimentary basin in western Slovenia

    Directory of Open Access Journals (Sweden)

    Ivan Mlakar

    2003-06-01

    Full Text Available In the first part of paper geologic data from smaller outcrops of Val Gardena Formation in west Slovenia are assembled. Together with the already published information from larger outcrops they permit the reconstruction of the Middle Permian sedimentary basin on which the accent of paper is based. Attention is drawn to general problems of Upper Paleozoic beds, and conclusions regarding lithologic, stratigraphic and structural control of uranium and copper deposits in this part of Slovenia are given.

  16. Volatile-organic molecular characterization of shale-oil produced water from the Permian Basin.

    Science.gov (United States)

    Khan, Naima A; Engle, Mark; Dungan, Barry; Holguin, F Omar; Xu, Pei; Carroll, Kenneth C

    2016-04-01

    Growth in unconventional oil and gas has spurred concerns on environmental impact and interest in beneficial uses of produced water (PW), especially in arid regions such as the Permian Basin, the largest U.S. tight-oil producer. To evaluate environmental impact, treatment, and reuse potential, there is a need to characterize the compositional variability of PW. Although hydraulic fracturing has caused a significant increase in shale-oil production, there are no high-resolution organic composition data for the shale-oil PW from the Permian Basin or other shale-oil plays (Eagle Ford, Bakken, etc.). PW was collected from shale-oil wells in the Midland sub-basin of the Permian Basin. Molecular characterization was conducted using high-resolution solid phase micro extraction gas chromatography time-of-flight mass spectrometry. Approximately 1400 compounds were identified, and 327 compounds had a >70% library match. PW contained alkane, cyclohexane, cyclopentane, BTEX (benzene, toluene, ethylbenzene, and xylene), alkyl benzenes, propyl-benzene, and naphthalene. PW also contained heteroatomic compounds containing nitrogen, oxygen, and sulfur. 3D van Krevelen and double bond equivalence versus carbon number analyses were used to evaluate molecular variability. Source composition, as well as solubility, controlled the distribution of volatile compounds found in shale-oil PW. The salinity also increased with depth, ranging from 105 to 162 g/L total dissolved solids. These data fill a gap for shale-oil PW composition, the associated petroleomics plots provide a fingerprinting framework, and the results for the Permian shale-oil PW suggest that partial treatment of suspended solids and organics would support some beneficial uses such as onsite reuse and bio-energy production. PMID:26802271

  17. Socioeconomic impact of infill drilling recovery from carbonate reservoirs in the Permian Basin, West Texas.

    OpenAIRE

    Jagoe, Bryan Keith

    1994-01-01

    This investigative study presents results on the socioeconomic impact of infill drilling recovery from carbonate reservoirs in the Permian Basin. The amount of incremental oil and gas production from infill drilling in 37 carbonate reservoir units is established using decline curve analysis. The increase in incremental recovery is used to compute the amount of increased revenue and taxes (local, state and federal). A job market analysis is performed to determine the impact of thes...

  18. Phreatomagmatic Pipes of the Tunguska basin (Siberia): Improvement of End-Permian Mass Extinction Model

    Science.gov (United States)

    Polozov, Alexander; Svensen, Henrik; Planke, Sverre; Jerram, Dougal

    2014-05-01

    Formation of the Siberian Traps Large Igneous Province is regarded as key phenomena responsible for the end-Permian mass extinction. Extinct event was accelerating due to release of enormous amount of gases throughout numerous basalt pipes, originated from contact aureoles of dolerite sills intruded into Tunguska Basin. Tunguska sedimentary basin consists of Precambrian and Paleozoic evaporites, carbonates and terrigenous rocks including Late Paleozoic coal-bearing strata. Precambrian and early Paleozoic oil source rocks contain numerous high potential oil and gas fields. Paleozoic evaporites contain rock and potassium salts deposits of commercial grade. Tunguska Basin evaporites are considered as a regional seal for the mineralizing brines. Permian-Triassic volcaniclastic rocks overlie this sequence and intrusive rocks have the numerous evidences of magma-sediment interaction result in basalt pipes formation. Compilation of available Russian literature gives us a chance to make a conclusion that hundreds of basalt pipes occur in the Tunguska Basin. The basalt pipes cross over all known dolerite intrusions and are filled with breccias of magmatic, volcaniclastic and sedimentary rocks altered to varying extents. Pipes from the Tunguska Basin south have a phreatomagmatic origin that is supported by ubiquitous occurrence of altered sedimentary clasts and volcaniclastic lapilli, corroded by brine during initial stages of magma-evaporite (brine) interaction. Corroded lapilli rimmed by diopside, chlorine-bearing hornblende, apatite and magnetite. Our recent study of magnetite-rich coarse lapilli tuffs revealed the garnet lapilli rimmed with magnetite cemented by altered clay groundmass enriched by native metals (Cu, Sn, Zn). This result corroborates our hypothesis about magnetite formation during initial stage of magma-sediment-brine interaction. We suggest that these observations could shed light on end-Permian aerosol flux originated from basalt pipes and could provide new information for improvement of our model.

  19. Socioeconomic data base report for the Permian Basin

    International Nuclear Information System (INIS)

    This report presents the data base of socioeconomic characteristics of 14 counties and 13 key cities that surround the two locations in the Palo Duro Basin. The information describes the demographic features, economic base, community facilities and services, and governmental and fiscal structure. The land use patterns and zoning requirements for selected cities of varying sizes and complexities and the general social characteristics of the region as a whole are described also. Extensive references, 23 figures, 92 tables

  20. The volcanism overprint in the Permian filling of the Lodeve basin. Petrographical and geochemical study, metallogenic implication

    International Nuclear Information System (INIS)

    This study reports on a detail petrological and geochemical study of the Lodeve basin Permian sediments. The petrographical study shows the important contribution of volcanism to the sedimentary components. In the grey, the grey-red, and the lower red Permian, well characterized ash beds are present, whereas in the upper red Permian, tuffite beds are present. In addition, most sediments have a constant fine component of volcanic origin. The volcanic components are of rhyolitic composition. The continuous availability of volcanic debris and discrete beds attributable to explosive volcanic activity indicate that volcanic centers existed nearby during Permian sedimentation in the Lodeve basin. The major and trace element geochemical study of volcanic products shows an evolution of the activity from a calk-alkaline trend corresponding to the grey and grey-red Permian to an alkaline trend later on. These trends are similar to what has been found for this period in Corsica and Esterel. Zircon typology is in agreement with the geochemical trends. The volcanic component of sedimentation in the Lodeve basin as a whole is estimated at approximately 30 %. The abundant, easily altered, fine vitreous component of the volcanic products largely contribute to mineralogic and chemical transformations of the sediments. This volcanic apport, synchronous with sedimentation, would be the source of an important stock of uranium in the Lodeve basin. The reworking of this uranium by different phases of alterations and hydrothermal circulations would have driven to uranium ore deposits today in production in the Lodeve basin. (author)

  1. Significance of new breakthrough in and favorable targets of gas exploration in the Middle Permian system, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Ping Shen

    2015-11-01

    Full Text Available The Middle Permian system in the Sichuan Basin represents favorable conditions for the formation of natural gas reservoirs. However, only fracture-vuggy limestone gas reservoirs were discovered in early exploration, whose scales and results were limited. In 2014, a high-yield industrial gas flow was produced there in Well Shuangtan 1, the major risk-exploration well, which means a great breakthrough in natural gas exploration in the Middle Permian system, Sichuan Basin. This plays a strategically important and guiding role in oil and gas exploration in ultra-deep marine formations. This paper illustrates the deployment background of Well Shuangtan 1, major exploration achievements and its significance in the gas exploration in the Middle Permian system, Sichuan Basin. Moreover, exploration potential and subsequent exploration targets of Middle Permian are analyzed in terms of its hydrocarbon source conditions, sedimentary characteristics, reservoir characteristics and areal extension, resources and favorable exploration zones. It is concluded that the Middle Permian system in the Sichuan Basin is a continent-connected carbonate platform with carbonate deposits being dominant. There are three types of reservoirs, including pore dolomite, karst fracture-vuggy, and fracture, which present considerable natural gas resources and huge exploration potential. Favorable exploration zones classification of Middle Permian in the Sichuan Basin indicates that the most favorable exploration zones are mainly distributed in the central-western Sichuan Basin. In particular, the northwestern Sichuan Basin is the most favorable exploration area which is characterized by the most excellent hydrocarbon source conditions, developed dolomite reservoirs and zonal distribution of structures.

  2. Regional summary and recommended study areas for the Texas Panhandle portion of the Permian Basin

    International Nuclear Information System (INIS)

    This report summarizes the regional geologic and environmental characterizations that have been completed for the Permian region of study, and describes the procedure used to identify study areas for the next phase of investigation. The factors evaluated in the Permian region fall into three broad areas: health and safety, environmental and socioeconomic, and engineering and economic considerations. Health and safety considerations included salt depth and thickness, faults, seismic activity, groundwater, salt dissolution, energy and mineral resources, presence of boreholes, and interactive land uses. Salt depth and thickness was the key health and safety factor, and when mapped, provded to be a discriminator. The evaluation of environmental and socioeconomic conditions focused primarily on the presence of urban areas and on designated land uses such as parks, wildlife areas, and historic sites. Engineering and economic considerations centered primarily on salt depth, which was already evaluated in the health and safety area. The Palo Duro and Dalhart basins are recommended for future studies on the basis of geology. In these two basins, salt depth and thickness appear promising, and there is less likelihood of past or future oil and gas exploratory holes. Environmental and socioeconomic factors did not preclude any of the basins from further study. 66 references, 16 figures, 2 tables

  3. Distribution, Mineralogy, Petrography, Provenance and Significance of Permian Ash-Carrying Deposits in the Paraná Basin

    Directory of Open Access Journals (Sweden)

    José Moacyr Vianna Coutinho

    Full Text Available The study of thin sections taken from drill core samples and outcrops in southern Brazil has demonstrated the occurrenceof repeated ash fall episodes during the Permian period between 280 and 245 Ma. Scattered or concentrated altered volcanicglass shards were detected in strata of Permian sedimentary rocks of the Rio Bonito and Tatui Formations. The shardcarryingsediment is usually a silty or cherty mudstone with variable amounts of calcrete calcite. Burial and alteration ofunstable glass debris led to the development of analcite and less commonly, calcite, silica minerals, zeolites or montmorillonite.Sources of explosive Permian volcanism, responsible for ample ash falls have been sought in South Africa, in the AndeanCordillera and along the Paraná Basin margin. A swarm of rhyolitic centers described in the Cordillera Frontal and in theCentral Argentinian Provincia de La Pampa (Patagonia is here proposed as the most adequate Permian source. In that area,volcanoes must have expelled ashes that traveled thousands of kilometers before settling in deltaic or shallow marineenvironments. Twenty-three occurrences of Permian shard-carrying sediments have been plotted in a Paraná Basin map. Thenumber of ash-carrying sediments decreases northeastward. The authors envisage dense clouds originated in Patagoniatraveling NE, depositing progressively smaller quantities of ashes but reaching Australia in pre-drift Gondwana. Shardcarrying sediments must be distinguished from “tonstein”, ash fall or ash flow tuffs, also recorded in the Permian Gondwana,which would indicate closer ash source area.

  4. Evolution of groundwater from Permian and Triassic aquifers in the Thuringian basin, Germany

    Science.gov (United States)

    Lonschinski, Martin; Merten, Dirk; Büchel, Georg

    2014-05-01

    The hydrochemical properties of shallow and deep groundwater with special emphasis on stable isotopes (2H, 18O, 34SSO4, 18OSO4) as well as rare earth elements (REE) are investigated to study the evolution of groundwater in the edge areas of the Thuringian basin (central Germany). The Thuringian basin is a syncline structure with an extension of 160 km in northwest-southeast and 100 km in northeast-southwest direction. It consists of sandstones, limestones, clays, gypsum and salts, that were deposited from the Late Permian until the Early Jurassic (approximately 250 to 180 million years ago). At the edge areas of the basin, sediments of Zechstein (Permian) and Bunter Sandstone (Early Triassic) are cropping out over a wide area being the catchment areas for ground water recharge of the main aquifers in Bunter Sandstone and Zechstein formations. In addition to the infiltration of atmospheric water, highly mineralized ascending groundwater occurs at fault systems leading to interactions between the aquifers. The isotope data of dissolved sulfates (34SSO4) indicate a terrestrial origin of sulfates in Early Bunter Sandstone as well as marine conditions for sulfate formation in Late Bunter Sandstone and Late Zechstein. Thus, sulfate isotopes can be used to identify the origin of water and to estimate the proportions of sulfates of different sources in mixing water. The isotopic composition of water in Bunter Sandstone aquifers in the eastern part of the basin indicate an increasing influence of sulfates from Late Bunter Sandstone in aquifers of Middle Bunter Sandstone along the groundwater flow towards the center of the basin. On the other hand there is no indication for mixing with Zechstein associated water in these aquifers. In contrast, in the northern part of the Thuringian basin and southward of the basin (south of the Thuringian forest) an interaction of Zechstein and Bunter Sandstone aquifers bound on fault systems becomes evident. The fractionations of rare earth elements in groundwater were determined after an enrichment procedure based on the method of Shabani (1992). Positive and negative Ce anomalies on PAAS (Post Achaean Australian shale) normalized REE fractionation pattern give hints on different redox conditions during groundwater evolution. Positive Ce anomalies were identified only on samples originated at Zechstein aquifers, whereas groundwaters in Bunter Sandstone aquifers with high redox potential show negative Ce anomalies, generally. References: Shabani, M.B., T. Akagi, and A. Masuda (1992): Preconcentration of trace rare earth elements in seawater by complexation with (2-ethylhexyl) hydrogen phosphate and 2-ethylhexyl dihydrogen phosphate adsorbed on a C18 cardridge and determination by inductively coupled plasma mass spectrometry: Anal. Chem. 64, 737-743.

  5. Climatic and biotic changes around the Carboniferous/Permian boundary recorded in the continental basins of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Opluštil, S.; Šimůnek, Z.; Zajíc, Jaroslav; Mencl, V.

    2013-01-01

    Roč. 119, č. 1 (2013), s. 114-151. ISSN 0166-5162 Institutional research plan: CEZ:AV0Z30130516 Institutional support: RVO:67985831 Keywords : biotic change * Bohemian Massif * Carboniferous-Permian transition * continental basin Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.313, year: 2013

  6. Investigation of deep permeable strata in the permian basin for future geothermal energy reserves

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.; Swift, Douglas B.

    1999-09-23

    This project will investigate a previously unidentified geothermal energy resource, opening broad new frontiers to geothermal development. Data collected by industry during oil and gas development demonstrate deep permeable strata with temperatures {ge} 150 C, within the optimum window for binary power plant operation. The project will delineate Deep Permeable Strata Geothermal Energy (DPSGE) assets in the Permian Basin of western Texas and southeastern New Mexico. Presently, geothermal electrical power generation is limited to proximity to shallow, high-temperature igneous heat sources. This geographically restricts geothermal development. Delineation of a new, less geographically constrained geothermal energy source will stimulate geothermal development, increasing available clean, renewable world energy reserves. This proposal will stimulate geothermal reservoir exploration by identifying untapped and unrealized reservoirs of geothermal energy. DPSGE is present in many regions of the United States not presently considered as geothermally prospective. Development of this new energy source will promote geothermal use throughout the nation.

  7. Geological environment of the uranium deposits in the Permian of Lodeve Basin, France

    International Nuclear Information System (INIS)

    The Permian rocks of the Lodeve Basin are characterized by a biorhexistasic cycle which produced fine alternating sequences of organic-rich sedimentary deposits in a basin ranging from lacustrine to a confined briny lagoon. The erosion of the Hercynian massifs, source for the sediments, along with the constant arrival of volcanic ash, provided metallic ions, particularly uranium. A continual subsidence permitted a regular influx of sediments and a burial compatible with a genesis of hydrocarbons. Post-sedimentary tectonic extension as well as the fine bedding of certain layers, created permeable zones that facilitated the circulation of fluids: the oils migrated, concentrated in petroleum-type traps by fault zones and the finely bedded layers. The interstitial waters flushed by compaction were carriers of metallic ions in solution. They used the same permeable zones as the oil, and the uranium was precipitated in the hydrocarbon traps which were strong reducing agents. During diagenesis, an important physical and mineralogical evolution affected the surroundings and certainly played a role of prime importance in the ''recycling'' and precipitation of the uranium. In the meantime, oxidizing and carbonate-bearing meteoric water rose within the rock formations along the principal faults, flushing and transporting uranium to the traps, developing a complementary accretion process. Classified into three principal types, the mineralizations developed within the framework of a dynamic basin system in which several factors - sedimentary, tectonic and diagenetic - operated. (author)

  8. Radiometric age determination of tonsteins and stratigraphic constraints for the Lower Permian coal succession in southern Parana Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Sommer, Margot; Cazzulo-Klepzig, Miriam; Hartmann, Leo Afraneo; Formoso, Milton Luis Laquintinie [Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves, 9500, 91501-970 Porto Alegre, Rio Grande do Sul (Brazil); Santos, Joao Orestes Schneider [Centre for Global Targeting, University of Western Australia, Crawley, Perth 6009, WA (Australia); Ketzer, Joao Marcelo [Instituto de Meio Ambiente, Pontificia Universidade Catolica, Avenida Ipiranga, Porto Alegre, Rio Grande do Sul (Brazil)

    2008-03-03

    Ion microprobe (SHRIMP II) dating of zircons from tonsteins interbedded with coal seams from the Candiota and Faxinal coalfields (Early Permian, Rio Bonito Formation, Parana Basin, Brazil) is presented. The mean ages obtained (290.6 {+-} 1.5 Ma) are more precise than previously published intervals. Calibrations of chronostratigraphic data with radiometric ages show that the main coal succession from the southern Basin is constrained to the Middle Sakmarian. The {+-} 2 Ma time interval of deposition supports the hypothesis that the coal-generating process was quite rapid in terms of geological time. In a general context, Faxinal and Candiota coals are assigned, into the Protohaploxypinus goraiensis Subzone, besides some paleocological differences evidenced by palynological studies. This bio-interval does not correspond to a consistent palynostratigraphic tool and more accurate biostratigraphic zonation for the Carboniferous-Permian interval must be delineated. The new results have far-reaching significance for correlations of the Basin with sequences of the Argentinian Paganzo Basin (302 {+-} 6 Ma and 288 {+-} 7 Ma) and also with the Karoo Basin, with the lowermost Ecca Group (288 {+-} 3 Ma and 289.6 {+-} 3.8 Ma). This new evidence supports the presence of an active and widespread Lower Permian explosive volcanic event in western Gondwana, which is interpreted as the same volcanism which produced the Choiyoi Group in western Argentina. According to this correlation the ash-fall source is located about 1400 km to the southwest of their area of deposition. (author)

  9. Phreatomagmatic Pipes of the Tunguska basin (Siberia): Aerosols Flux into End-Permian atmosphere

    Science.gov (United States)

    Polozov, A. G.; Svensen, H.; Planke, S.; Jerram, D. A.

    2013-12-01

    The Tunguska Basin sedimentary sequence consists of Precambrian and Paleozoic evaporites, carbonates and terrigenous rocks including Late Paleozoic coal-bearing strata. Precambrian and early Paleozoic oil source rocks contain numerous high potential oil and gas fields. Paleozoic evaporites contain rock and potassium salts deposits of commercial grade. Tunguska Basin evaporites are considered as a regional seal for the mineralizing brines. Permian-Triassic volcaniclastic rocks overlie this sequence and intrusive rocks have the numerous evidences of magma-sediment interaction. The Siberian Traps dolerites have intruded the Tunguska Basin sequence at different levels of emplacement and magma-sediment-brine interaction result in basalt pipes formation. Intrusions are surrounded by contact aureoles of thicknesses dependent upon sediment composition, dolerite thickness, depth of emplacement and the number of intrusive bodies. The basalt pipes cutting all intrusive bodies are filled with breccias of magmatic, volcaniclastic and sedimentary rocks altered to varying extents. The age of the pipes is geologically well constrained and related to Siberian Traps intrusion emplacement. A dolerite sill intruded into rock salt sequences of the Nepa potash deposit has a U-Pb zircon age of 252 × 0.4 Ma. Basalt pipe cutting all known dolerite intrusions, revealed here during prospecting survey. The phreatomagmatic origin of the basalt pipes is supported by ubiquitous occurrence of altered sedimentary clasts and volcaniclastic lapilli, corroded by brine during initial stages of magma-evaporite (brine) interaction. Corroded lapilli have rims of diopside, chlorine-bearing hornblende, apatite and magnetite. Iron rich garnet is present on the tuff and glass fragments. Our recent study of magnetite-rich coarse lapilli tuffs revealed the specific garnet lapilli rimmed with magnetite cemented by altered clay groundmass. This result corroborates our hypothesis about magnetite formation during initial stage of magma-sediment-brine interaction. We suggest that such conclusion requires a re-examination of lapilli tuff size and composition from basalt pipes of the Tunguska Basin. We suppose that this study could shed light on our understanding of aerosols flux from the Siberian phreatomagmatic pipes and its influence on End-Permian atmosphere.

  10. Tectonics, basin analysis and organic geochemical attributes of Permian through Mesozoic deposits and their derivative oils of the Turpan-Hami basin, northwestern China

    Science.gov (United States)

    Greene, Todd Jeremy

    The Turpan-Hami basin is a major physiographic and geologic feature of northwest China, yet considerable uncertainty exists as to the timing of its inception, its late Paleozoic and Mesozoic tectonic history, and the relationship of its petroleum systems to those of the nearby Junggar basin. Mesozoic sedimentary fades, regional unconformities, sediment dispersal patterns, and sediment compositions within the Turpan-Hami and southern Junggar basins suggest that these basins were initially separated between Early Triassic and Early Jurassic time. Prior to separation, Upper Permian profundal lacustrine and fan-delta fades and Triassic coarse-grained braided-fluvial/alluvial fades were deposited across a contiguous Junggar-Turpan-Hami basin. Permian through Triassic fades were derived mainly from the Tian Shan to the south as indicated by northward-directed paleocurrent directions and geochemical provenance of granitoid cobbles. Lower through Middle Jurassic strata begin to reflect ponded coal-forming, lake-plain environments within the Turpan-Hami basin. A sharp change in sedimentary-lithic-rich Lower Jurassic sandstone followed by a return to lithic volcanic-rich Middle Jurassic sandstone points to the initial uplift and unroofing of the largely andesitic Bogda Shan range, which first shed its sedimentary cover as it emerged to become the partition between the Turpan-Hami and southern Junggar basins. In Turpan-Hami, source rock age is one of three major statistically significant discriminators of effective source rocks in the basin. A newly developed biomarker parameter appears to track conifer evolution and can distinguish Permian rocks and their correlative oils from Jurassic coals and mudrocks, and their derivative oils. Source fades is a second key control on petroleum occurrence and character. By erecting rock-to-oil correlation models, the biomarker parameters separate oil families into end-member groups: Group 1 oils---Lower/Middle Jurassic peatland/swamp fades, Group 2 oils---Lower/Middle Jurassic marginal lacustrine fades, and Group 3 oils---Upper Permian lacusbine fades. Burial history exercises a third major control on petroleum in the Turpan-Hami basin. While relatively uninterrupted deep burial in the Tabei Depression exhausted Upper Permian source rocks and brought Lower/Middle Jurassic rocks well into the oil generative window, Late Jurassic uplift in the Tainan Depression eroded much of the Lower/Middle Jurassic section and preserved Upper Permian sourced oils as biodegraded, relict, heavy oils.* *This dissertation includes a CD that is multimedia (contains text and other applications that are not available in a printed format). The CD requires the following applications: Adobe Acrobat, UNIX.

  11. Dolomitized cells within chert of the Permian Assistência Formation, Paraná Basin, Brazil

    Science.gov (United States)

    Calça, Cléber P.; Fairchild, Thomas R.; Cavalazzi, Barbara; Hachiro, Jorge; Petri, Setembrino; Huila, Manuel Fernando Gonzalez; Toma, Henrique E.; Araki, Koiti

    2016-04-01

    Dolomitic microscopic structures in the form of microspheres, "horseshoe- shaped" objects, and thin botryoidal crusts found within microfossiliferous chert within stromatolites of the Evaporite Bed (EB) of the Permian Assistência Formation, Irati Subgroup, Paraná Basin, Brazil, have been investigated by means of optical microscopy, X-ray fluorescence, scanning electron microscopy, Raman spectrometry and energy-dispersive X-ray spectrometry. The microspheres were identified as dolomitized coccoidal cyanobacteria based on similarity in size, spheroidal and paired hemispheroidal morphologies and colonial habit to co-occurring silicified organic-walled cyanobacteria embedded within the same microfabric and rock samples. The co-occurrence of dolomite, pyrite framboids, and abundant dispersed carbonaceous material and silicified cells is consistent with a hypersaline depositional environment with abundant cyanobacterial mats and elevated Mg2 +/Ca2 + ratios and reducing conditions with active anoxic microbial processes near the water-(bio)sediment interface. The abundance of extracellular polymeric substances facilitated anoxic microbial processes (sulfate reduction), providing essential conditions for possible primary microbially induced dolomitization. In most of the dolomitized cells dolomite occurs only as an external layer; in fully dolomitized cells magnesium is richest in the outermost layer. Presumably, the dolomitization process was favored by the presence of anoxic microbial degraders and negatively charged functional groups at the surface of the cyanobacterial cells. Botryoidal dolomite rims of silica-filled fenestrae formed by a similar process and inherited the botryoidal morphology of the cell as originally lining the fenestrae. Silicification interrupted the dolomitization of the largely organic biosediment, mostly by permineralization, but locally by substitution, thereby preserving not only dolomitic microspheres, but also huge numbers of structurally well-preserved organic-walled cyanobacteria and portions of microbial mat. Clearly, dolomitization began very early in the microbial mats, prior to compaction of the sediment or full obliteration of cellular remains, followed very closely by silicification thereby impeding continued degradation and providing a window onto very well-preserved Permian microbial mats.

  12. Assessment of Undiscovered Oil and Gas Resources of the Permian Basin Province of West Texas and Southeast New Mexico, 2007

    Science.gov (United States)

    Schenk, Christopher J.; Pollastro, Richard M.; Cook, Troy A.; Pawlewicz, Mark J.; Klett, Timothy R.; Charpentier, Ronald R.; Cook, Harry E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the Permian Basin Province of west Texas and southeast New Mexico. The assessment was geology based and used the total petroleum system concept. The geologic elements of a total petroleum system are petroleum source rocks (quality, source rock maturation, generation, and migration), reservoir rocks (sequence stratigraphy, petrophysical properties), and traps (trap formation and timing). This study assessed potential for technically recoverable resources in new field discoveries only; field growth (or reserve growth) of conventional oil and gas fields was not included. Using this methodology, the U.S. Geological Survey estimated a mean of 41 trillion cubic feet of undiscovered natural gas and a mean of 1.3 billion barrels of undiscovered oil in the Permian Basin Province.

  13. Rock mechanics evaluation of potential repository sites in the Paradox, Permian, and Gulf Coast Basins: Volume 1

    International Nuclear Information System (INIS)

    Thermal and thermomechanical analyses of a conceptual radioactive waste repository containing commercial and defense high-level wastes and spent fuel have been performing using finite element models. The thermal and thermomechanical responses of the waste package, disposal room, and repository regions were evaluated. four bedded salt formations, in Davis and Lavender Canyons in the Paradox Basin of southeastern Utah and in Deaf Smith and Swisher counties in the Permian Basin of northwestern Texas, and three salt domes, Vacherie Dome in northwestern Louisiana and Richton and Cypress Creek Domes in southeastern Mississippi, located in the Gulf Coast Basin, were examined. In the Paradox Basin, the pressure exerted on the waste package overpack was much greater than the initial in situ stress. The disposal room closure was less than 10 percent after 5 years. Surface uplift was nominal, and no significant thermomechanical perturbation of the aquitards was observed. In the Permian Basin, the pressure exerted on the waste package overpack was greater than the initial in situ stress. The disposal room closures were greater than 10 percent in less than 5 years. Surface uplift was nominal, and no significant thermomechanical perturbation of the aquitards was observed. In the Gulf Coast Basin, the pressure exerted on the waste package overpack was greater than the initial in situ stress. The disposal room closures were greater than 10 percent in less than 5 years. No significant thermomechanical perturbation of the overlying geology was observed. 40 refs., 153 figs., 32 tabs

  14. Progress on the palynostratigraphy of the Permian strata in Rio Grande do Sul State, Paraná Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Souza Paulo A.

    2005-01-01

    Full Text Available A review of published papers and results of analysis of new material have allowed improvements on the palynostratigraphy of the Permian strata of the Paraná Basin in Rio Grande do Sul State. Based on first and last occurrences of certain species of pollen taxa, two palynozones are formalized, these are the Vittatina costabilis and Lueckisporites virkkiae Interval Zones, in ascending order. The Vittatina costabilis Interval Zone is subdivided into two units, in ascending order the Protohaploxypinus goraiensis and the Hamiapollenites karrooensis Subzones, and is recognized from the glacial (Itararé Group and post-glacial sequence (Rio Bonito Formation and the base of the Palermo Formation. The Lueckisporites virkkiae Interval Zone occurs from the uppermost Rio Bonito Formation, through the Palermo and Irati formations, and into the Serra Alta and Teresina formations. The main characteristics and reference sections are established, as well as additional criteria to recognize biostratigraphical units, in accordance with the International Stratigraphic Guide. Palynostratigraphical correlation suggests that the Vittatina costabilis Zone concerns the Early Permian (early Cisuralian, while the Lueckisporites virkkiae is regarded as late Early Permian to early Middle Permian (late Cisularian to early Guadalupian.

  15. High precision radiometric ages from the northern Sydney Basin and their implication for the Permian time interval and sedimentation rates

    International Nuclear Information System (INIS)

    Three pyroclastic samples that bracket the coal-bearing Permian System of the northern Sydney Basin have been dated using the zircon U/Pb and hornblende K/Ar methods. The Matthews Gap Dacitic Tuff Member, situated 170 m below the base of the Permian System, gives a best estimate of 309 3 Ma. Its age correlates well with the Paterson Volcanics which suggests that the immediately overlying clastic sediments are equivalent to the Seaham Formation. The Awaba Tuff, which is located 50 m below the top of the Permian System, gives a best estimate of 256 4 Ma. An intervening horizon, the Thornton Claystone of the Tomago Coal Measures, gives a best estimate of 266 0.4 Ma. The ages indicate an earlier beginning ? 299 Ma BP), an earlier termination (? 255 Ma BP) and slightly longer duration (4413 Ma) of the Permian System in the Hunter Valley than previously suggested. Sedimentation rates of 65m/Ma, calculated from proximal sequence thicknesses, are only half the rate calculated from the closest maximum thicknesses. Both are considerably lower than previously quoted rates. The estimated time interval of 10 Ma between the Thornton Claystone and the Awaba Tuff is more than twice the length of time previously attributed to accumulation of the combined Tomago and Newcastle Coal Measures. 38 refs., 5 tabs., 2 figs

  16. Thermal conductivity and diffusivity of Permian Basin bedded salt at elevated pressure and temperature

    International Nuclear Information System (INIS)

    Measurements of thermal conductivity and diffusivity were made on five core samples of bedded rock salt from the Permian Basin in Texas to determine its suitability as an underground nuclear waste repository. The sample size was 100 mm in diameter by 250 mm in length. Measurements were conducted under confining pressures ranging from 3.8 to 31.0 MPa and temperatures from room temperature to 473 K. Conductivity showed no dependence on confining pressure but evidenced a monotonic, negative temperature dependence. Four of the five samples showed conductivities clustered in a range of 5.6 +- 0.5 W/m.K at room temperature, falling to 3.6 +- 0.3 W/m.K at 473 K. These values are approximately 20% below those for pure halite, reflecting perhaps the 5 to 20%-nonhalite component of the samples. Diffusivity also showed a monotonic, negative temperature dependence, with four of the five samples clustered in a range of 2.7 +- 0.4 x 10-6 m2/s at room temperature, and 1.5 +- 0.3 x 10-6 m2/s at 473 K, all roughly 33% below the values for pure halite. One sample showed an unusually high conductivity (it also had the highest diffusivity), about 20% higher than the others; and one sample showed an unusually low diffusivity (it also had the lowest conductivity), roughly a factor of 2 lower than the others. 27 references, 8 figures, 4 tables

  17. Paleomagnetism of the Lower Permian redbeds of the Abadla Basin (Algeria)

    Science.gov (United States)

    Merabet, N.; Bouabdallah, H.; Henry, B.

    1998-07-01

    One of the reference Permian paleomagnetic poles for the African Apparent Polar Wander Path (APWP) was determined by (Morel et al., 1981, Earth Planet. Sci. Lett. 55, 65-74) in the upper unit of the 2000 m thick Abadla redbeds formation (31.2°N, 2.7°W). Unfortunately, this upper unit remains undated, although its age was presumed to be Autunian, whereas microflora fossils characteristic of the Autunian were discovered in the lower unit of the same formation. The paleomagnetic data ( N=11, D=130.1°, I=13.0°, k=138, α95=3.6° and pole: 29.1°S, 57.8°E, A95=2.0°) obtained from the better dated Autunian levels must take the place of the previous Abadla pole for the Autunian part of the African APWP. This new pole is very close to the Morel et al.'s pole determined from the unfossiliferous upper unit of the Abadla formation, giving an Autunian age for this upper unit. Consequently, the subsidence of the Abadla basin and the deposition of the whole succession occurred during a period not longer than 20-25 Myr.

  18. Composition of fluid inclusions in Permian salt beds, Palo Duro Basin, Texas, U.S.A.

    Science.gov (United States)

    Roedder, E.; d'Angelo, W. M.; Dorrzapf, A.F., Jr.; Aruscavage, P. J.

    1987-01-01

    Several methods have been developed and used to extract and chemically analyze the two major types of fluid inclusions in bedded salt from the Palo Duro Basin, Texas. Data on the ratio K: Ca: Mg were obtained on a few of the clouds of tiny inclusions in "chevron" salt, representing the brines from which the salt originally crystallized. Much more complete quantitative data (Na, K, Ca, Mg, Sr, Cl, SO4 and Br) were obtained on ??? 120 individual "large" (mostly ???500 ??m on an edge, i.e., ??? ??? 1.6 ?? 10-4 g) inclusions in recrystallized salt. These latter fluids have a wide range of compositions, even in a given piece of core, indicating that fluids of grossly different composition were present in these salt beds during the several (?) stages of recrystallization. The analytical results indicating very large inter-and intra-sample chemical variation verify the conclusion reached earlier, from petrography and microthermometry, that the inclusion fluids in salt and their solutes are generally polygenetic. The diversity in composition stems from the combination of a variety of sources for the fluids (Permian sea, meteoric, and groundwater, as well as later migrating ground-, formation, or meteoric waters of unknown age), and a variety of subsequent geochemical processes of dissolution, precipitation and rock-water interaction. The compositional data are frequently ambiguous but do provide constraints and may eventually yield a coherent history of the events that produced these beds. Such an understanding of the past history of the evaporite sequence of the Palo Duro Basin should help in predicting the future role of the fluids in the salt if a nuclear waste repository is sited there. ?? 1987.

  19. Pumping test and fluid sampling report, Mansfield No. 1 well, Palo Duro Basin: Report of the Geologic Project Manager, Permian Basin

    International Nuclear Information System (INIS)

    This report describes pumping test and fluid sampling activities performed at the Mansfield No. 1 well in Oldham County about 10 miles north of Vega, Texas. The well site was selected by TBEG and is located along the northern margin of the Palo Duro Basin in an area of active dissolution with the Permian salt sections. The objectives of the pumping test and fluid sampling program were to collect data to determine the hydrologic characteristics (formation pressure and permeability) of deep water bearing formations, and to obtain formation fluid samples for analyses (gas and fluid chemistry) in order to evaluate fluid migration and age relationships in the Permian Basin. 4 refs., 8 figs., 2 tabs

  20. Thermal properties of Permian Basin evaporites to 493 K temperature and 30 MPa confining pressure

    International Nuclear Information System (INIS)

    Laboratory measurements of the thermal conductivity and diffusivity of four rock salts, two anhydrites, and two dolomites bordering Cycle 4 and Cycle 5 bedded salt formations in the Permian Basin in Deaf Smith County, Texas, were made in conditions ranging from 303 to 473 K in temperature and 0.1 to 31.0 MPa in hydrostatic confining pressure. Within the +-5% measurement resolution neither conductivity nor diffusivity showed a dependence upon pressure in any of the rocks. Conductivity and diffusivity in all rocks had a negative temperature dependence. For the Cycle 4 salt samples, conductivity fell from 5.5 to 3.75 W/m . K, and diffusivity fell from about 2.7 to 1.7 x 10-6 m2/s. One Cycle 5 salt was a single crystal with anomalous results, but the other had a low conductivity with very weak temperature dependence and a high diffusivity. In the nonsalts, conductivity and diffusivity decreased 10 to 20% over the temperature range explored. In measurements of the coefficient of thermal linear expansion for Cycle 5 salt and nonsalts, the coefficient typically varied from about 12 x 10-6 K-1 at P = 3.0 MPa to 4 x 10-6 K-1 at P = 30 MPa for both nonsalt rocks. In anhydrite, it decreased with increasing temperature. In dolomite, the coefficient increased at roughly the same rate. Expansion of the salt ranged from 33 to 38 x 10-6 K-1 and was independent of pressure and temperature

  1. Thermal properties of Permian Basin evaporites to 493 K and 30 MPa confining pressure

    International Nuclear Information System (INIS)

    Laboratory measurements have been made of the thermal conductivity and diffusivity of four rock salts, two anhydrites, and two dolomites bordering the Cycle 4 and Cycle 5 bedded salt formations in the Permian Basin in Deaf Smith County, Texas. Measurement conditions ranged from 303 to 473 K in temperature, and 0.1 to 31.0 MPa in hydrostatic confining pressure. Within the +-5% measurement resolution neither conductivity nor diffusivity showed a dependence upon pressure in any of the rocks. Conductivity and diffusivity in all rocks had a negative temperature dependence. For the two Cycle 4 salt samples, conductivity over the temperature range explored fell from 5.5 to 3.75 W/m.K, and diffusivity fell from about 2.7 to 1.7 x 10-6 m2/s. One of the Cycle 5 salts was a single crystal which had anomalous results, but the other had a low conductivity, about 3.4 W/m.K, with very weak temperature dependence, and a high diffusivity, 3.8 to 2.5 x 10-6 m2/s over the temperature range. In the nonsalts, conductivity and diffusivity decreased 10 to 20% over the temperature range explored, which was 308 -6 m2/s for the anhydrites and 1.4 x 10-6 m2/s for both the dolomites. The coefficient of thermal linear expansion was measured for the Cycle 5 salt and nonsalts over 308 -6 K-1 at P = 3.0 MPa to 4 x 10-6 K-1 at P = 30 MPa for both nonsalt rocks. In anhydrite, it decreased with increasing temperature at a rate of roughly 5 x 10-8 K-2 at all pressures. In dolomite, the coefficient increased at roughly the same rate. Expansion of the salt ranged from 33 to 38 x 10-6 K-1 and was independent of pressure and temperature

  2. Natural gas qualities in the Southern Permian basin; Die Erdgasqualitaeten im suedlichen Permbecken

    Energy Technology Data Exchange (ETDEWEB)

    Gerling, P.; Kockel, F. [BGR, Hannover (Germany); Lokhorst, A.; Geluk, M.C. [TNO, Haarlem (Netherlands); Nicholson, R.A. [British Geological Survey, Nottingham (United Kingdom); Laier, T. [Danmarks og Groenlands Geologiske Undersoegelse, Kopenhagen (Denmark); Pokorski, J. [Panstwowy Instytut Geologiczny, Warsaw (Poland)

    1998-12-31

    There is a substantial amount of molecular and isotopic gas data in the literature but mostly in the archives of companies and geological services. As the geological services of most European countries traditionally contain (confidential and non-confidential) data on geology and resources these institutions from Great Britain, the Netherlands, Denmark, Poland and Germany decided to compile molecular and isotopic natural gas data from the area of the Southern European Permian basin. The partially EU-subsidised project was carried out between 1994 and 1997 (LOKHORST ed. 1998) The atlas is based on existing data and also on newly determined molecular and isotopic gas parameters. Ring analyses of national and international standard gases ensure the quality and comparability of the data thus obtained. The aim of the ``stocktaking`` of natural gas was to describe the gas qualities from the Southern North Sea in the West to the Eastern borders of Poland, to characterise them genetically and to relate the to the geological environment. (orig.) [Deutsch] Ein substantieller Anteil von molekularen und isotopischen Gasdaten existiert, teilweise in der Literatur, vor allem aber in den Archiven der Firmen und der geologischen Dienste. Da die geologischen Dienste der meisten europaeischen Laender traditionell (oeffentliche und vertrauliche) Daten ueber die Geologie und Rohstoffe vorhalten, haben sich diese Institutionen aus Grossbritanien, den Niederlanden, Daenemark, Polen und Deutschlands entschlossen, molekulare und isotopische Erdgasdaten aus dem Bereich des suedlichen europaeischen Permbeckens zu kompilieren. Das partiell von der EU gefoerderte Projekt wurde in den Jahren 1994 bis 1997 durchgefuehrt (LOKHORST ed. 1998). Ausser auf bereits vorhandenen Daten beruht der Atlas auf etwa 200 Neu-Bestimmungen molekularer und isotopischer Gasparameter. Ringanalysen nationaler und internationeler Standardgase gewaehrleisteten die Qualitaet und die Vergleichbarkeit der gewonnenen Daten. Ziele dieser `Erdgas-Inventur` waren, die Gasqualitaeten in ihrer raeumlichen Verteilung von der suedlichen Nordsee im Westen bis nahezu an die Ostgrenze Polens darzustellen, sie genetisch zu charakterisieren und eine Beziehung zu den geologischen Rahmenbedingungen herzustellen. (orig.)

  3. Fibers and cylinders of cryptomelane-hollandite in Permian bedded salt, Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    Fibers and thin-walled, hollow cylinders of cryptomelane-hollandite have been found in both the chevron and the clear salt from various drill cores in Permian bedded salt from the Palo Duro Basin, Texas. The authors have found fibers or cylinders from only the lower San Andres Formation units 4 and 5, the upper San Andres Formation, and the Salado-Transill salt. The fibers are inorganic, light to dark reddish brown, pleochroic, highly birefringent, filamentary single crystals, < 1 to ∼ 5 μm in diameter, with length-to-diameter ratios of at least 20:1. The fibers can be straight and/or curved, can bifurcate, can form loops, waves or spirals, and can be isolated or in parallel groups. Detailed petrographic analyses show no evidence for recrystallization or deformation of the enclosing salt after fiber formation. Although the authors observations do not provide a definitive explanation for fiber origin, they suggest that the fibers grew in situ by a solid-state diffusional process at low temperatures. The cylinders are pleochroic, highly birefringent, light to dark reddish brown, hollow, thin-walled, open-ended right cylinders, having a 1- to 2-μm wall thickness and variable lengths and diameters. There also appear to be single crystals of cryptomelane-hollandite, but these are found almost entirely in fluid inclusions in the chevron and clear salt. Their presence in the primary halite suggests that they were formed contemporaneously with the chevron structure and were accidentally trapped in the fluid inclusions. The observation of cylinders partially or completely enclosed by salt stratigraphically above large fluid inclusions suggests that natural downward fluid-inclusion migration has occurred, in response to the geothermal gradient

  4. Late Permian to Late Triassic basin evolution of North Vietnam: geodynamic implications for the South China and Indochina blocks

    Science.gov (United States)

    Rossignol, Camille; Bourquin, Sylvie; Hallot, Erwan; Poujol, Marc; Roger, Françoise

    2015-04-01

    The core of South East Asia is composed of a mosaic of continental blocks, among which the Indochina and the South China blocks (present day northern Vietnam), amalgamated during the Permian and/or the Triassic. Late Permian to Late Triassic geodynamic evolution of these two blocks remains controversial. The main discussion points concern the existence and the closure of an oceanic domain separating the Indochina and the South China blocks during this period. Especially, the polarity and the timing of the subduction zone that led to the collision between the blocks as well as the present location of the suture delimiting them are a matter of debate. Despite the valuable information they can provide, the sedimentary basins from northern Vietnam have been neglected in the previous studies dealing with the geodynamic evolution of South East Asia. To determine the geodynamic evolution of the area, the basins of Sam Nua and Song Da, presently located in North Vietnam, have been investigated using a combined approach involving sedimentology, geochronology (U-Pb/zircon) and geochemistry (whole-rock major and trace elements composition of both volcanic and volcaniclastic rocks). The palaeoenvironment evolution, the main unconformities, their age and the tectonic affinities of the interbedded volcanic and volcaniclastics series have been characterized for these two basins. Our results demonstrate (i) that the Song Da Basin exhibits a palaeogeographic affinity with the South China block, (ii) the occurrence of extensive calk-alkaline volcanism and associated volcaniclastic deposits in the Sam Nua Basin, related to the existence of an active magmatic arc during the Early and the lower Middle Triassic, (iii) a South dipping (present day coordinate) oceanic lithosphere beneath the Indochina block, deduced from the location of the magmatic arc south of the potential suture zones, (iv) that an angular unconformity postdates the lower Middle Triassic volcaniclastic deposits in the Sam Nua basin. This unconformity, crosscutting the subduction related deposits, is interpreted as the result of the collision between the Indochina and the South China blocks.

  5. Shallow lacustrine system of the Permian Pedra de Fogo Formation, Western Gondwana, Parnaíba Basin, Brazil

    Science.gov (United States)

    Araújo, Raphael Neto; Nogueira, Afonso César Rodrigues; Bandeira, José; Angélica, Rômulo Simões

    2016-04-01

    The Permian Period of the Parnaíba Basin, northern Brazil, represented here by deposits from the Pedra de Fogo Formation, records important events that occurred in Western Gondwana near its boundary with the Mesozoic Era. The analysis of outcrop based facies from the Permian Pedra de Fogo Formation, which is 100 m thick, carried out along the eastern and western borders of the Parnaiba Basin, allowed the identification of eleven sedimentary facies, which were grouped into three distinct facies associations (FA), representative of a shallow lacustrine system associated with mudflats and ephemeral rivers. Bioturbation, desiccation cracks, silcretes and various siliceous concretions characterize the Pedra de Fogo deposits. The FA1 mudflat deposits occur predominantly at the base of the Pedra de Fogo Formation and consist of laminated claystone/mudstone, mudcrack-bearing sandstones/mudstones and sandstones exhibiting cross-lamination, massive and megaripple bedding. Popcorn-like silicified nodules and casts indicate evaporite deposits. Other common features are silica concretions, silicified tepees and silcretes. FA2 represents nearshore deposits and consists of fine-grained sandstones with evenly parallel lamination, climbing ripple cross-lamination, massive and megaripple bedding and mudstone/siltstone showing evenly parallel lamination. FA3 refers to wadi/inundite deposits, generally organized as fining-upward cycles of metric size, composed of conglomerates and medium-grained pebbly sandstones showing massive bedding and cross-stratification, as well as claystone/siltstone showing evenly parallel to undulate lamination. Scour-and-fill features are isolated in predominantly tabular deposits composed of mudstones interbedded with fine to medium-grained sandstones showing planar to slightly undulate lamination. Silicified plant remains previously classified as belonging to the Psaronius genus found in the uppermost levels of the Pedra de Fogo Formation, near the contact with the Motuca Formation, are considered here as excellent biostratigraphic markers. Fish remains, ostracods, bryozoans and scolecodonts represent other fossils that are present in the succession. Mudflat deposits developed in an arid and hot climate probably in the Early Permian. Semi-arid conditions prevailed in the Middle Permian allowing the proliferation of fauna and flora in adjacent humid regions and onto the lake margin. The climate variation was responsible for the contraction and expansion phases of the lake, fed by sporadic sheet floods carrying plant remains. The reestablishment of the arid climate, at the end of Permian, marks the final sedimentation of the Pedra de Fogo Formation, linked to the consolidation of the Pangaea Supercontinent. This last event was concomitant with the deposition of the Motuca Formation red beds and the development of extensive ergs related to the Triassic Sambaíba Formation in Western Gondwana.

  6. Regulatory Project Manager for Salina and Permian Basins for the NWTS [National Waste Terminal Storage] Program: Final techical report

    International Nuclear Information System (INIS)

    The identification of candidate sites for nuclear waste repositories involves geological and environmental studies to characterize potential sites. These investigations include the collection and analysis of detailed geological and environmental data and comparison of the data against predetermined site performance criteria, i.e., geologic characteristics, environmental protection, and socioeconomic impacts. The work summarized in this final technical report encompasses mainly ''environmental characterization'' studies in the Permian Basin in the Texas Panhandle during the period of 1977-86; in the earlier phase of the contract, regional environmental work was also done in the Salina Basin (1977-79) and certain licensing support activities and safety analyses were conducted (1977-82). Considerable regulatory support work was also performed during 1986. 9 figs., 2 tabs

  7. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; William Raatz; Cari Breton; Stephen C. Ruppel; Charles Kerans; Mark H. Holtz

    2003-04-01

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest petroleum-producing basin in the US. Approximately 1300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl of oil through 2000. Of these major reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. On a preliminary basis, 32 geologic plays have been defined for Permian Basin oil reservoirs and assignment of each of the 1300 major reservoirs to a play has begun. The reservoirs are being mapped and compiled in a Geographic Information System (GIS) by play. Detailed studies of three reservoirs are in progress: Kelly-Snyder (SACROC unit) in the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play, Fullerton in the Leonardian Restricted Platform Carbonate play, and Barnhart (Ellenburger) in the Ellenburger Selectively Dolomitized Ramp Carbonate play. For each of these detailed reservoir studies, technologies for further, economically viable exploitation are being investigated.

  8. Problems and challenges in detection of pre-Mesozoic maar volcanoes: example from the Principálek Volcano in the Permian Krkonoše Piedmont Basin

    Czech Academy of Sciences Publication Activity Database

    Valenta, Jan; Rapprich, V.; Stárková, M.; Skácelová, Z.; Fojtíková, Lucia; Staněk, František; Balek, Jan

    2014-01-01

    Roč. 59, č. 3 (2014), s. 169-181. ISSN 1802-6222 Institutional support: RVO:67985891 Keywords : diatreme * geophysics * volcanology * Permian * Krkonoše Piedmont Basin Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.405, year: 2014 http://www.jgeosci.org/detail/jgeosci.170

  9. Integrated Synthesis of the Permian Basin: Data and Models for Recovering Existing and Undiscovered Oil Resources from the Largest Oil-Bearing Basin in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    John Jackson; Katherine Jackson

    2008-09-30

    Large volumes of oil and gas remain in the mature basins of North America. This is nowhere more true than in the Permian Basin of Texas and New Mexico. A critical barrier to recovery of this vast remaining resource, however, is information. Access to accurate geological data and analyses of the controls of hydrocarbon distribution is the key to the knowledge base as well as the incentives needed by oil and gas companies. The goals of this project were to collect, analyze, synthesize, and deliver to industry and the public fundamental information and data on the geology of oil and gas systems in the Permian Basin. This was accomplished in two ways. First we gathered all available data, organized it, and placed it on the web for ready access. Data include core analysis data, lists of pertinent published reports, lists of available cores, type logs, and selected PowerPoint presentations. We also created interpretive data such as type logs, geological cross sections, and geological maps and placed them in a geospatially-registered framework in ARC/GIS. Second, we created new written syntheses of selected reservoir plays in the Permian basin. Although only 8 plays were targeted for detailed analysis in the project proposal to DOE, 14 were completed. These include Ellenburger, Simpson, Montoya, Fusselman, Wristen, Thirtyone, Mississippian, Morrow, Atoka, Strawn, Canyon/Cisco, Wolfcamp, Artesia Group, and Delaware Mountain Group. These fully illustrated reports include critical summaries of published literature integrated with new unpublished research conducted during the project. As such these reports provide the most up-to-date analysis of the geological controls on reservoir development available. All reports are available for download on the project website and are also included in this final report. As stated in our proposal, technology transfer is perhaps the most important component of the project. In addition to providing direct access to data and reports through the web, we published 29 papers dealing with aspects of Permian Basin and Fort Worth Basin Paleozoic geology, and gave 35 oral and poster presentations at professional society meetings, and 116 oral and poster presentations at 10 project workshops, field trips, and short courses. These events were attended by hundreds of scientists and engineers representing dozens of oil and gas companies. This project and the data and interpretations that have resulted from it will serve industry, academic, and public needs for decades to come. It will be especially valuable to oil and gas companies in helping to better identify opportunities for development and exploration and reducing risk. The website will be continually added to and updated as additional data and information become available making it a long term source of key information for all interested in better understanding the Permian Basin.

  10. Evolution of a Permian Arid Lake System, Upper Pedra de Fogo Formation, Western Border of the Parnaiba Basin

    Directory of Open Access Journals (Sweden)

    Luiz Saturnino de Andrade

    2014-12-01

    Full Text Available Stratigraphic and facies analysis in the Filadlfia region, TO, BR, at the western of the Parnaba Basin, allowed redefine the paleoenvironment of the upper portion of the Pedra de Fogo Formation of Permian age. The studied deposits are a series of approximately 100 m thick, predominantly siliciclastic, with subordinate carbonates and evaporites, where were defined 21 sedimentary facies that could be grouped into six facies associations (AF: AF1 Lacustrine with ephemeral river deposits; AF2 Storm wave-influenced lake deposits; AF3 Continental sabkha deposits; AF4 Central lake deposits; AF5 Eolian dunes field deposits; and AF6 Lake/oasis deposits with inunditos. These associations indicate that during Permian, an extensive lacustrine arid system developed adjacent to eolian dunes fields and continental sabkha, as well as with contributions from ephemeral rivers. Fluvial incursions into lakes propitiated the formation of suspension lobes and sheet flows (AF1. Sabkha plains (AF3 were formed in the marginal portions of the lake that eventually were influenced by storms waves (AF2, while central zone were site of intense pelitic deposition (AF4. The low supply of eolian sand in this system resulted in the formation of restricted dune fields (AF5, with development of interdune lakes (oasis, where proliferating giant ferns, sporadically flooded by ephemeral rivers (AF6. The facies associations data, corroborated by the paleogeography of the region during the Late Permian, indicate that settling of the top part of the Pedra de Fogo Formation was laid during a hot and arid climate.

  11. Depositional cyclicity and paleoecological variability in an outcrop of Rio Bonito Formation, Early Permian, Parana Basin, Rio Grande do Sul, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, A.; Menegat, R.; Guerra-Sommer, M.; Cazzulo-Klepzig, M.; de Souza, P.A. [UNIVATES, Lajeado (Brazil)

    2006-07-15

    This article integrates faciological, paleobotanical, and palynological analyses to establish the relationship between depositional cyclicity and paleoecological patterns for the (Early Permian) Quiteria outcrop, Rio Bonito Formation, southern Parana Basin, Rio Grande do Sul state. The record in some coal palynofloras of Striadopodocarpites fusus, a component of the Hamiapollenites karrooensis subzone, as defined in the palynostratigraphic framework for the Parana Basin, indicates a Kungurian age for the palynoflora.

  12. Shallow burial dolomitisation of Middle–Upper Permian paleosols in an extensional tectonic context (SE Iberian Basin, Spain): Controls on temperature of precipitation and source of fluids

    OpenAIRE

    Benito Moreno, María Isabel; Horra del Barco, Raúl de la; López Gómez, José; Fernández Barrenechea, José María, ed. lit; Luque del Villar, Francisco Javier, ed. lit; Arche, Alfredo

    2011-01-01

    This work is focused on carbonate paleosols developed in three stratigraphic sections (Landete, Talayuelas and Henarejos) of theMiddle–Late Permian Alcotas Formation in the SE Iberian Basin. The Alcotas Formation, of alluvial origin, was deposited in semi-connected half-grabens developed during the early stages of the Permian–Triassic rifting stage that affected the Iberian Basin. The studied sections were located in two of these half-grabens, the Henarejos section being much clos...

  13. A New Permian Bivalve (Megadesmidae, Plesiocyprinellinae from the Serrinha Member, Rio do Rasto Formation, Paran Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Anelli

    2010-07-01

    Full Text Available During a recent inspection in the Paleontological Collection of the Institute of Geosciences, University of So Paulo,we have identified some specimens of undescribed mollusk bivalves. These called our attention for the following reasons:a all specimens are internal molds of conjugated and closed articulated valves, some of them presenting fragments ofsilicified shells; b all internal molds have similar general shape and internal characters, representing specimens of thesame taxon; c the internal molds and silicified valves are well preserved, including fragile structures, which are hardlypreserved, such as the internal mold of the external ligament and muscle scars; d and equally important, according tothe labels of all specimens, they were collected from rocks of the Passa Dois Group (Permian, Serrinha Member of theRio do Rasto Formation. Although who collected the shells and the precise geographic location of the specimens are stillunknown, the detailed study of these fossils brings us to the conclusion that they are morphologically distinct from anyheretofore published genus of the endemic fauna of bivalves from Passa Dois Group. Based in its general shape, hingestructure and muscles scars, the new form can be classified under the Family Megadesmidae Vokes, 1967, the most diversegroup of Permian bivalves of the Paran Basin. The specimens are referred as Beurlenella elongatella new gen. and sp. Theshell shape and taphonomy indicate that this bivalve was a shallow, rapid, active burrower, suspension feeder, probablypreserved in situ, in event deposits.

  14. Environmental characterization of bedded salt formations and overlying areas of the Permian Basin

    International Nuclear Information System (INIS)

    This report constitutes one input to the first stage of site qualification studies. It presents a general environmental characterization of the region that is underlain by the Permian bedded salt formation. The formation covers portions of Colorado, Kansas, New Mexico, Oklahoma, and Texas. The Permian bedded salt formation is one of a number of deep, stable geologic formations being studied for potential locations for nuclear waste repositories. These studies will not necessarily lead to selection of a site. They are intended only to provide information necessary to evaluate the suitability of locations for repositories. The report is intended as a general characterization of the existing environmental setting of the Permian Region with emphasis on land, water, and air characteristics; resources; plant and animal life; and man's organizations and activities. The report provides background information about the role that this regional study will play in the overall plan for environmental impact assessments and statements deemed necessary as input to the decision-making process. Background information on the present concept of nuclear waste repository design and function is also included. The information presented in this report has been summarized from open literature readily accessible to the public. No field work was conducted nor new data used in developing the descriptions contained herein

  15. Play Analysis and Digital Portfolio of Major Oil Reservoirs in the Permian Basin: Application and Transfer of Advanced Geological and Engineering Technologies for Incremental Production Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-01-13

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest onshore petroleum-producing basin in the United States. Approximately 1,300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of oil through 2000. Of these significant-sized reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. There are 32 geologic plays that have been defined for Permian Basin oil reservoirs, and each of the 1,300 major reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. The final reservoir shapefile for each play contains the geographic location of each reservoir. Associated reservoir information within the linked data tables includes RRC reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are smaller than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. Oil production from the reservoirs in the Permian Basin having cumulative production of >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl [5.25 x 10{sup 8} m{sup 3}]), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres Platform Carbonate play (2.15 Bbbl [3.42 x 10{sup 8} m{sup 3}]). Detailed studies of three reservoirs are in progress: Kelly-Snyder (SACROC unit) in the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play, Fullerton in the Leonard Restricted Platform Carbonate play, and Barnhart (Ellenburger) in the Ellenburger Selectively Dolomitized Ramp Carbonate play. For each of these detailed reservoir studies, technologies for further, economically viable exploitation are being investigated.

  16. Basin-scale distribution of sill intrusions in the Tunguska Basin, East Siberia, and the implications for the end-Permian environmental crisis

    Science.gov (United States)

    Svensen, Henrik H.; Frolov, Sergei; Akhmanov, Grigorii G.; Polozov, Alexander G.; Planke, Sverre

    2015-04-01

    The emplacement of the Siberian Traps Large igneous province through the Tunguska Basin is regarded as the main processes behind the end-Permian environmental crisis. Still, the lack of data from the Tunguska Basin represents one of the main uncertainties in understanding this link. Degassing from contact metamorphic aureoles in evaporites is suggested as key to the continental mass extinction, but very little is known about the actual distribution of sills within these lithologies. We present results from a unique borehole database with more than 700 boreholes, where 293 boreholes are studied in detail and presented here. The boreholes cover large parts of the basin, from Norilsk in the north (N69) to Bratsk in the south (N55), with a bias towards petroleum-bearing regions. In total, 93.5% of the selected boreholes contain sill intrusions. The sill thicknesses vary considerably from kilometer-scale intrusive complexes to individual thin sills of a few tens of meters. Locally, thick sills (up to 900 meters in thickness) occur in the upper part of the sedimentary succession, affecting the coal-rich Tunguska Series sediments. However, on average, the thickest sills in the basin are emplaced within the vast Cambrian salt formations, with average thicknesses in the 115-130 meter range. Accompanying petrographic investigations of metamorphic sediments demonstrate that widespread high temperature devolatilization took place. Degassing to the atmosphere took place via explosive pipe degassing and seepage. We show that depending on the specific location within the province and the emplacement depth, the potential for degassing of both greenhouse gases (CH4, CO2), aerosols (SO2), and ozone destructive gases (CH3Cl, CH3Br) was substantial and can explain the end-Permian mass extinction.

  17. Late- to Post-Variscan magmatism and sedimentation within Late Carboniferous to Late Permian basins in the Balkan Terrane (Bulgaria): geodynamic bearings

    Science.gov (United States)

    Cortesogno, L.; Gaggero, L.; Ronchi, A.; Yanev, S.

    2003-04-01

    Between Late Carboniferous and Late Permian in the Balkan sector of Bulgaria the late to post-Variscan evolution developed through tectono- and volcano-sedimentary polycyclic steps: 1) the first cycle, Namurian-Westphalian in age, is bounded by two unconformities (respectively "Sudetian" and "Asturian" tectonic phases?). Fluviolacustrine deposits infill several fault-bounded narrow basins, whose opening and subsidence are to be referred to crustal weakness and transtensile, frequently transpressional, tectonics. The magmatism, with intermediate composition, issues explosive eruptions from submersed centres, and flows outpoured within emerged areas; 2) a second cycle developed between Upper Stephanian and Lower Permian. The unconformity in the middle of this cycle (German "Saalian" phase?) could separate the Lower and the Upper Rotliegend. The tectonic regime is still transtensional, but developed over wider depositional areas. The volcanism associated with the sedimentary deposition began at the topmost Carboniferous but mostly occurred during the Early Permian (mainly in the "Lower Rotliegend"). The igneous activity is represented by dacite subvolcanic bodies and by later rhyolite ignimbrites, deposited in subaerial environment, and by tuffs and tuffites interbedded to the sediments. At places, volcanic breccias and volcanoclastic deposits derived from the dacite bodies are alternated with conglomerates and were almost in part, reworked into the alluvial deposits. 3) the third cycle, from the latest Early Permian to the beginning of the Late Permian, comprises the "Upper Rotliegend" clastic deposits; in the Balkan region the Lower Permian proluvial sedimentation deposited over the Permian sequences, or directly covering the basement, as wide continental basins; the cycle is also characterized by the disappearance of both intrusive and extrusive production, and by reworking of older igneous fragments. 4) a further unconformity separates the fourth, Late Permian cycle, represented by more widespread "Saxonian"-type red beds. This new tectono-sedimentary succession accompanied by a marked extensional tectonic regime is likely related to the Variscan crustal attenuation as well as to a main plate boundary reorganization. The Early-to-Late Permian stratigraphic and palaeogeographic turnpoint could also represent the onset of a rift system.

  18. Seismic valve as the main mechanism for sedimentary fluid entrapment within extensional basin: example of the Lodve Permian Basin (Hrault, South of France).

    Science.gov (United States)

    Laurent, D.; Lopez, M.; Chauvet, A.; Imbert, P.; Sauvage, A. C.; Martine, B.; Thomas, M.

    2014-12-01

    During syn-sedimentary burial in basin, interstitial fluids initially trapped within the sedimentary pile are easily moving under overpressure gradient. Indeed, they have a significant role on deformation during basin evolution, particularly on fault reactivation. The Lodve Permian Basin (Hrault, France) is an exhumed half graben with exceptional outcrop conditions providing access to barite-sulfides mineralized systems and hydrocarbon trapped into rollover faults of the basin. Architectural studies shows a cyclic infilling of fault zone and associated S0-parallel veins according to three main fluid events during dextral/normal faulting. Contrasting fluid entrapment conditions are deduced from textural analysis, fluid inclusion microthermometry and sulfide isotope geothermometer: (i) the first stage is characterized by an implosion breccia cemented by silicifications and barite during abrupt pressure drop within fault zone; (ii) the second stage consists in succession of barite ribbons precipitated under overpressure fluctuations, derived from fault-valve action, with reactivation planes formed by sulphide-rich micro-shearing structures showing normal movement; and (iii) the third stage is associated to the formation of dextral strike-slip pull-apart infilling by large barite crystals and contemporary hydrocarbons under suprahydrostatic pressure values. Microthermometry, sulfide and strontium isotopic compositions of the barite-sulfides veins indicate that all stages were formed by mixing between deep basinal fluids at 230C, derived from cinerite dewatering, and formation water from overlying sedimentary cover channelized trough fault planes. We conclude to a polyphase history of fluid trapping during Permian synrift formation of the basin: (i) a first event, associated with the dextral strike-slip motion on faults, leads to a first sealing of the fault zone; (ii) periodic reactivations of fault planes and bedding-controlled shearing form the main mineralized ore bodies by the single action of fluid overpressure fluctuations, undergoing changes in local stress distribution and (iii) a final tectonic activation of fault linked to last basinal fluid and hydrocarbon migration during which shear stress restoration on fault plane is faster than fluid pressure build-up.

  19. Thermal and cementation histories of Permian shelf-edge carbonate rocks in the Nanpanjiang Basin, South China

    Science.gov (United States)

    Halley, Robert B.; Parrish, Judith T.; Zahn, Xie; Wenhai, Hu; Scholle, Peter A.; Zhongrui, Su; Yirong, Zhang; Yunming, Huang; Guangxuan, Li

    1989-01-01

    As of 1984, the Nanpanjiang Basin of South China has had almost no exploration by drilling although oil seeps exist among its margins and producing wells occur in adjacent basins.  however, cooperative studies by petroleum geologists and geochemists of the United States and the People's Republic of China (1982-1984) show that calcite-cemented reef and fore-reef carbonate rocks near Ziyun contain bitumen in Upper Permian shelf-edge sediment.  the cementation history consists of three episodes: (1)precipitation of syndepositional marine cement (formerly botryoidal aragonnite and fibrous magnesian calcite); (2)precipitation of post-depositional early cement (radiaxial calcite); and (3)precipitation of late burial cement (white calcite spar).  Hydrocarbons were introduced into the rocks between cementation episodes 2 and 3.  Fluid inclusion analysis of secondary inclusions in the burial cement indicates that the rocks were heated to nearly 200 C after hydrocarbon migration and cementation episode 3.  Bitumen remains in the rocks as evidence of the earlier presence of liquid hydrocarbons.

  20. Geology of permian basin in the northeast of Uruguay: Sedimentology exam about uranium trace

    International Nuclear Information System (INIS)

    The Uranium project was prepared from BRGM to DINAMIGE. Its has got three zones of investigation: zone 1 composed by precambrian basin in the N W; zone 2 the precambrian insular shelf and rocks belts; zone 3 wich include parts of the basin Cretaceous in Salto and Santa Lucia

  1. Origin, distribution, and movement of brine in the Permian Basin (U.S.A.). A model for displacement of connate brine

    International Nuclear Information System (INIS)

    Na-Cl, halite Ca-Cl, and gypsum Ca-Cl brines with salinities from 45 to >300 g/L are identified and mapped in four hydrostratigraphic units in the Permian Basin area beneath western Texas and Oklahoma and eastern New Mexico, providing spatial and lithologic constraints on the interpretation of the origin and movement of brine. Na-Cl brine is derived from meteoric water as young as 5-10 Ma that dissolved anhydrite and halite, whereas Ca-Cl brine is interpreted to be ancient, modified-connate Permian brine that now is mixing with, and being displaced by, the Na-Cl brine. Displacement fronts appear as broad mixing zones with no significant salinity gradients. Evolution of Ca-Cl brine composition from ideal evaporated sea water is attributed to dolomitization and syndepositional recycling of halite and bittern salts by intermittent influx of fresh water and sea water. Halite Ca-Cl brine in the evaporite section in the northern part of the basin differs from gypsum Ca-Cl brine in the south-central part in salinity and Na/Cl ratio and reflects segregation between halite- and gypsum-precipitating lagoons during the Permian. Ca-Cl brine moved downward through the evaporite section into the underlying Lower Permian and Pennsylvanian marine section that is now the deep-basin brine aquifer, mixing there with pre-existing sea water. Buoyancy-driven convection of brine dominated local flow for most of basin history, with regional advection governed by topographically related forces dominant only for the past 5 to 10 Ma. 71 refs., 11 figs

  2. CO2 source-sink matching in the lower 48 United States, with examples from the Texas Gulf Coast and Permian Basin

    Science.gov (United States)

    Ambrose, W. A.; Breton, C.; Holtz, M. H.; Nez-Lpez, V.; Hovorka, S. D.; Duncan, I. J.

    2009-06-01

    Documenting geographic distribution and spatial linkages between CO2 sources and potential sinks in areas with significant levels of CO2 emissions is important when considering carbon-management strategies such as geologic sequestration or enhanced oil recovery (EOR). For example, the US Gulf Coast overlies a thick succession (>6,000 m [>20,000 ft]) of highly porous and permeable sandstone formations separated by thick, regionally extensive shale aquitards. The Gulf Coast and Permian Basin also have a large potential for EOR, in which CO2 injected into suitable oil reservoirs could be followed by long-term storage of CO2 in nonproductive formations below reservoir intervals. For example, >6 billion barrels (Bbbl) of oil from 182 large reservoirs is technically recoverable in the Permian Basin as a result of miscible-CO2 flooding. The Gulf Coast also contains an additional 4.5 Bbbl of oil that could be produced by using miscible CO2. Although the CO2 pipeline infrastructure is well-developed in the Permian Basin, east Texas and the Texas Gulf Coast may have a greater long-term potential for deep, permanent storage of CO2 because of thick brine-bearing formations near both major subsurface and point sources of CO2.

  3. The Permian basin geology in the north of Uruguay.Sedimentology exam about the uranium signs

    International Nuclear Information System (INIS)

    The basin is located in the Precambrian insular shelf limited to the North. East and South. The North (Brazil) and south (Uruguay) edge are constituted by the insular shelf ancient nucleus which dates from 2000 million years.

  4. Preliminary study of uranium in Pennsylvanian and lower Permian strata in the Powder River Basin, Wyoming and Montana, and the Northern Great Plains

    International Nuclear Information System (INIS)

    Persistent and widespread radiometric anomalies occur in Pennsylvanian and Lower Permian strata in the subsurface of the northern Great Plains and the Powder River Basin. The primary host lithology of these anomalies is shale interbedded with sandstone, dolomite, and dolomitic sandstone. Samples from the project area indicate that uranium is responsible for some anomalies. In some samples there seems to be a correlation between high uranium content and high organic-carbon content, which possibly indicates that carbonaceous material acted as a trapping mechanism in some strata. The Pennsylvanian and Permian rocks studied are predominantly marine carbonates and clastics, but there are rocks of fluvial origin in the basal Pennsylvanian of Montana, North Dakota, and South Dakota and in the Pennsylvanian and Permian deposits on the east flank of the Laramie Mountains. Fine-grained clastic rocks that flank the Chadron arch in western Nebraska are possibly of continental origin. The trend of the Chadron arch approximately parallels the trend of radiometric anomalies in the subsurface Permian-Pennsylvanian section. Possible source areas for uranium in the sediments studied were pre-Pennsylvanian strata of the Canadian Shield and Precambrian igneous rocks of the Ancestral Rocky Mountains

  5. When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa.

    Science.gov (United States)

    Day, Michael O; Ramezani, Jahandar; Bowring, Samuel A; Sadler, Peter M; Erwin, Douglas H; Abdala, Fernando; Rubidge, Bruce S

    2015-07-22

    A mid-Permian (Guadalupian epoch) extinction event at approximately 260 Ma has been mooted for two decades. This is based primarily on invertebrate biostratigraphy of Guadalupian-Lopingian marine carbonate platforms in southern China, which are temporally constrained by correlation to the associated Emeishan Large Igneous Province (LIP). Despite attempts to identify a similar biodiversity crisis in the terrestrial realm, the low resolution of mid-Permian tetrapod biostratigraphy and a lack of robust geochronological constraints have until now hampered both the correlation and quantification of terrestrial extinctions. Here we present an extensive compilation of tetrapod-stratigraphic data analysed by the constrained optimization (CONOP) algorithm that reveals a significant extinction event among tetrapods within the lower Beaufort Group of the Karoo Basin, South Africa, in the latest Capitanian. Our fossil dataset reveals a 74-80% loss of generic richness between the upper Tapinocephalus Assemblage Zone (AZ) and the mid-Pristerognathus AZ that is temporally constrained by a U-Pb zircon date (CA-TIMS method) of 260.259 ± 0.081 Ma from a tuff near the top of the Tapinocephalus AZ. This strengthens the biochronology of the Permian Beaufort Group and supports the existence of a mid-Permian mass extinction event on land near the end of the Guadalupian. Our results permit a temporal association between the extinction of dinocephalian therapsids and the LIP volcanism at Emeishan, as well as the marine end-Guadalupian extinctions. PMID:26156768

  6. Geology and taphonomy of the base of the Taquaral Member, Irati Formation (Permian, Paran Basin), Brazil

    Science.gov (United States)

    Chahud, Artur; Petri, Setembrino

    2015-09-01

    The taphonomy of Early Permian vertebrates from a sandy facies at the base of the Taquaral Member, Irati Formation, was surveyed in order to acquire data for the interpretation of the sedimentary processes and paleoenvironment of deposition. Six outcrops from the Rio Claro municipality and surrounding areas, from the Brazilian State of So Paulo, were investigated. The vertebrate groups are Chondrichthyes (Xenacanthiformes, Ctenacanthiformes and Petalodontiformes), Osteichthyes (Actinopterygii and Sarcopterygii) and Tetrapodomorpha. They occur as loose teeth, scales, spines and bone remains. The sandy facies is characterized by fining upward deposition. The coarser sandstone immediately above the underlying Tatu Formation is rich in Chondrichthyes. However, the fine sandstone above, immediately beneath the silty shale facies, is devoid of Chondrichthyes, though Osteichthyes scales, teeth and bones were present. The taphonomy is important for inferring sedimentary processes and then the paleoenvironments. The poor sorting of the sandstone and the presence of fossils that are mostly abraded or worn are indicative of a high energy environment. In contrast, the presence of fossils in a good state of preservation, some without abrasion and breakages are indicative of only limited transport. Differences of fossil spatial density, numbers of specimens and taxa may be explained by the dynamics of deposition, from details of the palaeoenvironment can be obtained.

  7. Variability of the Rotliegend sandstones in the Polish part of the Southern Permian Basin - permeability and porosity relationships

    Directory of Open Access Journals (Sweden)

    Jadwiga JARZYNA

    2009-01-01

    Full Text Available The Flow Zone Index, FZI, applied to order relations between the effective porosity and permeability of the Rotliegend sandstones in the Polish part of the Southern Permian Basin turns out to be a useful and effective factor to evaluate ability of media flow in a rock formation. A dataset of over 2000 samples from 78 wells was analysed. Based only on porosity and permeability, FZI includes all non-parameterized features of rocks as tortuosity and diameters of porous channels, volume of trapped parts of capillary roads, specific surface of pore space, and others. When FZI increases, the ability of fluid to move through the porous space increases. In most cases, the Rotliegend sandstones reveal FZI in the range of 0.5-2.0. The highest FZI, ca. 100, is related to fractured part of the studied formation. The combination of FZI and facies information from several wells in the study area (over 1200 samples showed a good correlation. On the basis of FZI we can divide a set of samples of the Rotliegend sandstone into groups of defined fluid flow abilities and relate them to facies. Also, we show the way of estimation of the reliable values of permeability in full geological log of a borehole on the basis of FZI, and the total porosity determined from well logging interpretation.

  8. Evidence of lacustrine sedimentation in the Upper Permian Bijori Formation, Satpura Gondwana basin: Palaeogeographic and tectonic implications

    Indian Academy of Sciences (India)

    Tapan Chakraborty; Soumen Sarkar

    2005-06-01

    The Upper Permian Bijori Formation of the Satpura Gondwana basin comprising fine- to coarsegrained sandstone, carbonaceous shale/mudstone and thin coal bands was previously interpreted as the deposits of meandering rivers. The present study documents abundance of wave ripples, hummocky and swaley cross-stratification and combined flow bedforms in the Bijori Formation, suggesting that a significant part of the formation was deposited in a wave-agitated environment. Evidence of near-emergent depositional conditions provided by repeated occurrence of rootlet beds and hydromorphic paleosols, local flooding surfaces denoting rapid fluctuation of water level, occurrences of temnospondyl vertebrate fossils, and absence of tidal signatures and marine fossils suggest a lacustrine rather than marine depositional regime. Five facies associations recognised within the Bijori Formation are inferred to represent fluvial channels and associated floodplains (FA1), lake shorelines (FA2), subaqueous distributary channels and associated levees (FA3), wave- and storm-affected delta front (FA4), and open lacustrine/lower shoreface (FA5) deposits. The planoconcave fluvial channel-fill sandbodies with unidirectional cross-beds are clearly distinguishable from the delta front bars that show a convexo-plan or bi-convex sandbody geometry and dominance of wave and combined flow bedforms. Some of the distributary channels record interaction of fluvial and wave-dominated basinal processes. Major distributary sandbodies show a north to northwest flow direction while wave-affected delta front sandbodies show very complex flow patterns reflecting interaction between fluvial discharge and wave processes. Wave ripple crest trends show that the lake shoreline had an overall eastnortheast to westsouthwest orientation. The lack of documented contemporaneous lacustrine or marine sediments in the Satpura Gondwana basin posed a major problem of basin-scale palaeogeographic reconstruction. The existence of Bijori lake solves the problem and the lake is inferred to have acted as repository for the contemporaneous alluvial drainage. Development of the large Bijori lake body implies generation of accommodation space exceeding the rate of sediment supplied and thus represents locus of high tectonic subsidence. Transition of fluvial sediments with red mudstone and calcareous soil profile in the lower part of the succession to carbonaceous shale and coal-bearing lacustrine sediments in the upper part, denote a change from a warm semi-arid climate with seasonal rainfall to a more humid one.

  9. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-05-01

    The Permian Basin of west Texas and southeast New Mexico has produced >30 Bbbl (4.77 x 10{sup 9} m{sup 3}) of oil through 2000, most of it from 1,339 reservoirs having individual cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}). These significant-sized reservoirs are the focus of this report. Thirty-two Permian Basin oil plays were defined, and each of the 1,339 significant-sized reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. Associated reservoir information within linked data tables includes Railroad Commission of Texas reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are <1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. This report contains a summary description of each play, including key reservoir characteristics and successful reservoir-management practices that have been used in the play. The CD accompanying the report contains a pdf version of the report, the GIS project, pdf maps of all plays, and digital data files. Oil production from the reservoirs in the Permian Basin having cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 from these significant-sized reservoirs was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl 5.25 x 10{sup 8} m{sup 3}), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres Platform Carbonate play (2.15 Bbbl [3.42 x 10{sup 8} m{sup 3}]).

  10. Ichnology of the non-marine deposits of the Boskovice Basin (Carboniferous-Permian, Czech Republic

    Directory of Open Access Journals (Sweden)

    Mikul R

    2006-03-01

    Full Text Available In the area of the Boskovice Basin, simple ichnoassemblages and ichnofabric patterns characterize a suite of lacustrine and fluvial deposits. The succession of ichnofabrics enables us to correlate several sections in the northern part of the basin, supporting the correlation of the previously recognized Ba?ov, Mchov and Obora horizons. The mostly finegrained lacustrine deposits below bituminous limestones contain Planolites beverleyensis, Planolites montanus, amphibian footprints, and rare Cruziana problematica. Reddish sandstones, which can be interpreted as alluvial plain deposits, contain Planolites, Scoyenia, 'star-like traces', and Diplocraterion. In the southern part of the basin, the coal-bearing strata are characterized by generally poor bioturbation, with isolated levels of 'root spots' and Planolites. The lowermost strata of the overlying red-bed unit show intensive and rhythmical Planolites ichnofabric, the intensity and uniformity of which decrease upwards.

  11. Radiometric dating of ochoan (permian) evaporites, WIPP site, Delaware basin, New Mexico, USA

    International Nuclear Information System (INIS)

    The authors have attempted radiometric dating of halide-sulfate salts and clay minerals from the Delaware Basin, New Mexico, USA, as part of geochemical study of the stability of the evaporite sequence at the WIPP (Waste Isolation Pilot Plant - a US DOE facility) site. They undertook this dating to determine: (1) primary age of evaporite genesis or time(s) of recrystallization, (2) if previously undated evaporite minerals (leonite, polyhalite, kieserite) give useful data, and (3) if the detrital clay minerals have been radiometrically reset at any time following their incorporation into the evaporite medium. They have shown earlier that polyhalites can indeed be successfully dated by the K-Ar method, and once corrections are applied for admixed halide minerals, dates of 210-230 Ma for the Delaware Basin are obtained. Rb-Sr isochrons from early stage sylvites-polyhalites-anhydrites yield 220 +/- 10 Ma, even when some sylvites yield lower K-Ar dates due to loss of 40Ar*. K-Ar dates on leonites and kieserites are also low due to 40Ar* loss, but their Rb-Sr dates are higher. Detrital clay minerals from the Delaware Basin collectively yield a highly scattered isochron (390 +/- 77 Ma), but samples from a local area, such as the WIPP Site, give a much better age of 428 +/- 7 Ma. These dates show that the interaction between the clay minerals and the evaporitic brines was insufficient to reset the clay minerals Rb-Sr systematics. In a related study, they note that a dike emplaced into the evaporite at 34 Ma had only very limited effect on the intruded rocks; contact phenomena were all within 2 m of the dike. All of their geochemical (radio-metric and trace element) studies of the WIPP site argue for preservation of the isotopic and chemical integrity of the major minerals for the past 200 Ma. 19 references, 1 figure, 5 tables

  12. Stratigraphy and Geochemistry of the Lower Permian Esayoo Volcanics, Northwest Ellesmere Island: Insights into Sverdrup Basin Paleogeography

    Science.gov (United States)

    Morris, N. J.; Beauchamp, B.; Cuthbertson, J. P.; Chau, Y.

    2012-12-01

    The Esayoo Volcanics consist of altered Lower Permian basalts that outcrop on northwest Ellesmere Island and northeast Axel Heiberg, within the Sverdrup Basin, Arctic Canada. Rifting in the Sverdrup Basin initiated in the Early Carboniferous and ceased during the Early Permian. The Esayoo volcanics geochemically classify as alkaline to transitional within-plate-basalts, with high Ti/Y and Zr/Y ratios. Eruptions are coincident with two rifting pulses of Sakmarian and Kungurian age. During the 2011 July field season, ten stratigraphic sections of the Esayoo Volcanics were measured at four locations on northwest Ellesmere Island: Borup Fiord Pass, Oobloyah Bay, Ricker Glacier and Mount Leith. The Esayoo Volcanics reach a maximum thickness of 450 m near Oobloyah Bay, and thin west, east and north of Oobloyah Bay with respective thicknesses of 140 m, 69 m and 75 m. At Oobloyah Bay, volcanic rocks occur at two stratigraphic levels. The lower Esayoo unit lies within the Raanes Formation, a mixed clastic-carbonate, and further west at Ricker Glacier within the upper Hare Fiord Formation, a black siliceous shale-siltstone. The upper Esayoo unit is below the Assistance Formation, carbonate-rich to clean quartz sandstone, and below the Sabine Bay Formation, a clean quartz sandstone with abundant cross-beds. Thin 1 to 2 m shales that indicate maximum flooding surfaces overlie both the upper and lower Esayoo units. Each measured section was divided into individual flow units that averaged 7 m thick. Dominant textures observed within individual flow units include: thin 2-3 cm thick amygdule-rich bases transitioning into thick 2-10 m thick massive flow interiors; frothy, amygdule-rich flow tops 1-3 m thick; and chaotic vesicular units with amygdules ranging from 0.5-3 cm in width and pervasive cross-cutting calcite veins and stringers. The lower level at Oobloyah Bay is composed of a laminated volcaniclastic rock that is rich in heterozoan marine bioclasts, with associated pillow basalts and a capping peperite- a mix of carbonates clasts and juvenile igneous material. The volcanic textures and facies observed within the lower Esayoo level suggest explosive, submarine volcanism. Within the upper Esayoo level, thin vesicle-rich bases within flow units; vesicle pipes, peperites and conglomerates suggest these volcanics were effusive flows that underwent volatile segregation and rapid degassing. These textures suggest volcanic-water interaction during eruption. Along with the extensive cross bedding within the Sabine Bay and Assistance Formations, a likely depositional environment for the upper Esayoo level is a fluvial-deltaic environment. Litho-sequence stratigraphic cross sections constructed representative of measured Esayoo sections indicate that the lower and upper Esayoo levels are bounded within transgressive sequences. In addition to these physical observations, seventy Esayoo Volcanic samples were analyzed for whole rock geochemistry and seven samples are being prepared for Samarian - Neodymium isotope analyses. The geochemistry of these volcanics will further develop the differences and similarities of the source rock between the lower and upper levels, and constrain the tectonic implications the Esayoo Volcanics indicate.

  13. Stratigraphy, structure, and lithofacies relationships of Devonian through Permian sedimentary rocks: Paradox Basin and adjacent areas - southeastern Utah. Technical report

    International Nuclear Information System (INIS)

    Geophysical well log analysis, literature review, and field work were conducted to develop isopach, structure contour, outcrop, and facies maps and cross sections for the Devonian through Permian strata of a 14,586-km2 (5632-square-mile) area in southeastern Utah. The study area includes part of the Paradox Basin, the salt deposits of which are of interest in siting studies for a nuclear waste repository. For this reason hydrologic models of this area are needed. This study, part of which included the development of a three-dimensional stratigraphic computer model utilizing Geographic Information System software, can serve as a base for hydrologic or other models for this area. Within and adjacent to the study area, 730 wells were screened to select the 191 wells analyzed for the study. It was found that the Elbert through Molas formations did not exhibit noticeable facies changes within the study area. The Pinkerton Trail Formation exhibits moderate changes: anhydrite and shale become somewhat more abundant toward the northeast. Facies changes in the Paradox Formation are more dramatic. Thick saline facies deposits are present in the northeast, grading to thinner anhydrite and then to carbonate facies in the south and west. The lithology of the Honaker Trail Formation appears to be fairly uniform throughout the area. Facies changes in the Cutler Group are numerous and sometimes dramatic, and generally correspond to the named formations of the group. Other factors that could affect groundwater flow, such as stratigraphic cover of fine-grained rocks, area of formation outcrops, and fracturing and faulting are discussed and delineated on maps

  14. Facies pattern of the middle Permian Barren Measures Formation, Jharia basin, India: The sedimentary response to basin tectonics

    Indian Academy of Sciences (India)

    Prabir Dasgupta

    2005-06-01

    In the Lower Gondwana succession of the Jharia basin of eastern India, the Barren Measures Formation is characterized by the cyclic disposition of fine-grained lacustrine deposits and relatively coarse-grained fluvial deposits. The cyclic variation in the rate of coarse clastic input is attributed to the sedimentary response to basin tectonics. The sandstone–shale alternations of the Barren Measures succession can be correlated with the tectonic cyclothems developed on the hangingwall dip-slope and adjoining trough in a continental half-graben setting. Enhancement of the gradient of the hangingwall dip-slope during reactivation of the basin margin faults led to progradation of the existing fluvial system towards the half-graben trough and deposition of the coarser clastics on the fine-grained lacustrine deposits of the trough. Peneplanation of the hangingwall slope and slow increase in the lake level caused lacustrine transgression and retrogration of the fluvial system on the hangingwall block. The fluvial sediments were onlapped by the fine-grained lacustrine deposits. Episodic rejuvenation of the basin margin faults thus caused development of tectonic cyclothem on the hangingwall block. The paleocurrent pattern indicates that a persistent northward paleoslope was maintained during Barren Measures sedimentation. The inferred depositional settings were much more extensive than the present limit of the outcrop. The faults, presently defining the northern limit of the Barren Measures Formation, were possibly emplaced after Barren Measures sedimentation. The final movement along these fault planes caused preservation of the downthrown hangingwall block and the Barren Measures sediments on the footwall block were eroded during subsequent denudation. The Southern Boundary Fault came into existence after the deposition of the Barren Measures sediments.

  15. Radionuclides distribution in blooming of the permian sediments from the Irati Formation of the Parana Basin

    International Nuclear Information System (INIS)

    The objective of this work is to study natural radionuclides in sedimentary rocks. The concentration of them reflects the origin of the sediments, the depositional environment as well as some mineralogical characteristics of the rock matrix, and also more recent events as weathering and erosion. Using gamma ray high resolution spectrometry, the profile of activity concentration of the natural radionuclides was assessed for 226Ra, 238U, 32Th and 40K in rocks of the Irati Formation belonging to Parana Sedimentary Basin. The samples were collected at a limestone abandoned mine, in the city of Sapopema, (PR). 24 samples were collected, eleven from the exposed vertical profile with approximately 5.50 m, whose stratigraphy is represented by an alternation among decimetrics layers of limestones, bituminous shales, and some rhythmits layers (milimetric sheets of limestone and bituminous shales), 9 repetitions of a sample to study the variability, and three rigolits samples in sequential apprenticeships of weathering. Each sample was dried in the sun during about 48 hours, broken, drizzled in a sieve of 4 mesh and put, in a cylindrical container. The measures were accomplished using a Germanium Hyper Pure detector (HPGe) with relative efficiency of 66%, connected to a standard spectrometry electronic chain. The measured concentrations of activity of 238U were smaller for the limestones (17.80 ±0.09 Bq.Kg-1), larger for the bituminous shales (125.5 ± 2.6 Bq.Kg-1 with enrichment of uranium in the sample (200), 548 ± 16 Bq.Kg-1, upper part of the column), and intermediate for the rhythmits (23.0 ± 1,3 Bq.Kg-1. The ratio eTh/K obtained for the studied profiles has equivalent values, indicating similar mineralogical characteristics for the limestones, bituminous shales, rhythmits and studied rigolits. On the other hand, to the ratio eTh/eU showed that two of the three regolits samples belong to oxidizer atmospheres, favoring the leaching of uranium, what can be causing the enrichment of the sample (200), once these soils are above the column. The average measured doses were 16 nGy.h-1 for the limestones and rhythmits, 79.5 nGy.h-1 for the bituminous shales and 329.5 nGy.h-1 for the enriched bituminous shales of the top of the column. These results supply data to estimate the contribution of these products for the radiation dose received by the public in general, besides of database for mineralogical and geophysical studies of the Parana Basin. (author)

  16. The Carboniferous-Permian boundary in the central western Argentinean basins: paleontological evidences / El lmite Carbonfero-Prmico en las cuencas del centro oeste de Argentina: evidencias paleontolgicas

    Scientific Electronic Library Online (English)

    Gabriela A, Cisterna; Andrea F, Sterren; Pedro R, Gutirrez.

    2011-07-01

    Full Text Available Las cuencas del centro oeste de Argentina, Ro Blanco, Calingasta-Uspallata y el sector oeste de la cuenca Paganzo, contienen las secuencias marinas ms completas para el estudio del lmite Carbonfero-Prmico en Gondwana. Un estudio detallado de secciones estratigrficas claves ha permitido la iden [...] tificacin de las asociaciones megaflo-rsticas NBG y de Intervalo, y de la palinozona DM (Raistrickia densa-Convolutispora muriornata), del Carbonfero Tardo, en la parte inferior de dichas secciones; en tanto, en la parte media superior de las secciones estudiadas, se han identificado la biozona de invertebrados T-S (Tivertonia jachalensis-Streptorhynchus inaequiornatus) y la palinozona FS (Pakhapites fusus-Vittatina subsaccata), ambas asignadas al Prmico Temprano. El registro de estas asociaciones diagnsticas de mega/microflora e invertebrados marinos provee un esquema bioestratigrfico integrado que permite ubicar el lmite Carbonfero-Prmico en las cuencas del centro oeste de Argentina. Abstract in english The central western Argentinean basins of Ro Blanco, Calingasta-Uspallata and western Paganzo, enclose the most complete marine successions used for examining the Carboniferous-Permian boundary in Gondwana. A detailed review of the key stratigraphical sections has allowed the identification of the [...] latest Carboniferous assemblages; NBG, Interval megafloristic Zone and DM (Raistrickia densa-Convolutispora muriornata) Palynological Zone in the lower part, and the earliest Permian T-S (Tivertonia jachalensis-Streptorhynchus inaequiornatus) invertebrate Zone and FS (Pakhapitesfusus-Vittatina subsaccata) Palynological Zone in the upper part. This diagnostic mega/microflora and marine invertebrate paleontological evidence provides a biostratigraphical framework for the definition of the Carboniferous-Permian boundary inside the basins of central western Argentina.

  17. Dispersal Syndromes of fossil Seeds from the Lower Permian of Paran Basin, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Juliane M. Souza

    2012-03-01

    Full Text Available The morphological analysis of seeds has been an important subject in modern ecological studies, once it provides evidence about the biology and adaptations of the parent plant. However, this kind of study has been restricted to the ecology of modern plants and is rarely used in interpretations of Paleozoic data. From the understanding of dispersal syndromes analysis as an important tool to paleoecological reconstruction, this study provides a first approach using this tool with seeds from the Lower Permian strata of southern Paran Basin in Rio Grande do Sul. Based on previously classified seeds and using their biological and taphonomic data, the syndrome of dispersal was interpreted, and their placement in successional groups (pioneer, early-successional and later-successional was suggested. Seven morphospecies were analyzed: Samaropsis gigas, representing a later-successional species living in water bodies with hydrochory as its dispersal syndrome; Samaropsis kurtzii, typical of early-successional species showing anemochory as its dispersal syndrome and living in distal areas in relation to water bodies; Samaropsis aff. S. millaniana, Cordaicarpus aff. C. brasilianus, Cordaicarpus cerronegrensis and Cordaicarpus truncata have typical characteristics of pioneer plants, exhibiting barochory as their primary dispersal syndrome with other syndromes associated.A Anlise morfolgica das sementes tem sido um importante objeto em estudos ecolgicos modernos, uma vez que fornece evidncias sobre a biologia e as adaptaes das plantas-me de sementes. Entretanto, este tipo de estudo tem sido restrito a ecologia de plantas modernas e raramente utilizado em interpretaes de dados paleozicos. A partir do entendimento da anlise das sindromes de disperso como uma importante ferramenta para reconstrues paleoecolgicas, este estudo oferece uma primeira abordagem utilizando essa ferramenta com sementes do Permiano Inferior do Sul da Bacia do Paran, no Rio Grande do Sul. Baseado em sementes previamente classificadas e utilizando seus dados biolgicos e tafonmicos, a sndrome de disperso foi interpretada, e a classificao das sementes nos grupos successionais (pioneira, secundria inicial ou secundria tardia foi sugerida. Sete morfoespcies foram analisadas: Samaropsis gigas, representando uma espcie de secundria-tardia, vivendo prximo a corpos d'gua, com sndrome de dispeso hidrocrica; Samaropsis kurtzii, tpica espcie de sucesso secundria inicial, apresentando a anemocoria como sndrome de disperso e habitando reas distantes em relao a corpos d'gua; Samaropsis aff. S. millaniana, Cordaicarpus aff. C. brasilianus, Cordaicarpus cerronegrensis e Cordaicarpus truncata com caractersticas tpicas de plantas pioneiras, sendo a barocoria sua principal sndrome de disperso com outras sndromes associadas.

  18. No Abrupt Changes in redox conditions associated with the end-Permian marine ecosystem collapse in the east Greenland basin

    DEFF Research Database (Denmark)

    Nielsen, Jesper K.; Shen, Y; Piasecki, Stefan; Stemmerik, Lars

    is not indicative of an abrupt change of redox chemistry in water columns, in contrast to previous claims. The integration of isotope and framboidal pyrite data provides a nearly continuous record of ocean chemistry evolution and new insights into the end-Permian extinction and delayed biotic...

  19. Sequence stratigraphic features of the Middle Permian Maokou Formation in the Sichuan Basin and their controls on source rocks and reservoirs

    Directory of Open Access Journals (Sweden)

    Wang Su

    2015-11-01

    Full Text Available Well Shuangyushi 1 and Well Nanchong l deployed in the NW and central Sichuan Basin have obtained a high-yield industrial gas flow in the dolomite and karst reservoirs of the Middle Permian Maokou Formation, showing good exploration prospects of the Maokou Formation. In order to identify the sequence stratigraphic features of the Maokou Formation, its sequence stratigraphy was divided and a unified sequence stratigraphic framework applicable for the entire basin was established to analyze the stratigraphic denudation features within the sequence framework by using the spectral curve trend attribute analysis, together with drilling and outcrop data. On this basis, the controls of sequence on source rocks and reservoirs were analyzed. In particular, the Maokou Formation was divided into two third-order sequences – SQ1 and SQ2. SQ1 was composed of members Mao 1 Member and Mao 3, while SQ2 was composed of Mao 4 Member. Sequence stratigraphic correlation indicated that the Maokou Formation within the basin had experienced erosion to varying extent, forming “three intense and two weak” denuded regions, among which, the upper part of SQ2 was slightly denuded in the two weak denuded regions (SW Sichuan Basin and locally Eastern Sichuan Basin, while SQ2 was denuded out in the three intense denuded regions (Southern Sichuan Basin–Central Sichuan Basin, NE and NW Sichuan Basin. The development of source rocks and reservoirs within sequence stratigraphic framework was significantly affected by sequence boundary; the grain banks that can form effective reservoir were predominately distributed in SQ1 highstand systems tract (HST, while effective source rocks were predominately distributed in SQ1 transgressive system tract (TST. It is concluded that the sequence division method is objective and reasonable, which can effectively guide oil and gas exploration in this region.

  20. Deformation bands in carboniferous-permian sandstones of the Parana Basin; Bandas de deformacao em arenitos permocarboniferos da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Trzaskos, Barbara [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P. Gerencia de Geologia Estrutural e Analise Tectonica]. E-mail: barbara.t@petrobras.com.br; Rostirolla, Sidnei Pires; Bocardi, Luciane Bergamin

    2006-11-15

    Deformation bands developed on Carboniferous-Permian sandstones in the eastern portion of the Parana Basin are analyzed. Emphasis was made on their geologic evolution and possible impacts on fluid circulation within naturally fractured reservoirs. Sub vertical fractures and fault zones prevail in the studied area and were generated and/or reactivated in at least three major deformation events during Permian, Jurassic-Cretaceous and Cenozoic times. Micro structurally, two types of deformation bands can be recognized: one type characterized by grain fracturing and a second type showing gouge zone formation due to intense grain comminution. According to hydraulic properties of deformation bands and temporal relationship with hydrocarbon generation and migration, fractures within the sandstones can act as permeability barriers or conduits for fluid flow. In the studied sandstones, deformation bands with gouge zones were potential seals because grain comminution is closely related to permeability decrease. Alternatively, it is probable that marginal damaged zones should have acted as permeability pathways laterally along the gouge zones. Fractured deformation bands were conduits for fluid flow at least during a short time interval in the mesodiagenesis. Carbonate and anhydrite cementation along fractures from core samples suggest that these potential conduits were subsequently sealed still during mesodiagenesis. (author)

  1. Aromatized arborane/fernane hydrocarbons as molecular indicators of floral changes in Upper Carboniferous/Lower Permian strata of the Saar-Nahe Basin, southwestern Germany

    Science.gov (United States)

    Vliex, M.; Hagemann, H. W.; Püttmann, W.

    1994-11-01

    Thirty-seven coal samples of Upper Carboniferous and Lower Permian age from three boreholes in the Saar-Nahe Basin, Germany, have been studied by organic geochemical and coal petrological methods. The investigations were aimed at the recognition of floral changes in the Upper Carboniferous and Lower Permian strata. The results show that compositional changes in the extracts are only partly caused by variations in coalification. Specific aromatic hydrocarbons appear in Upper Westphalian D coal seams and increase in concentration up to the Rotliegendes. The dominant compound has been identified by mass spectrometry and NMR-spectroscopy as 5-methyl-10-(4-methylpentyl)-des- A-25-norarbora(ferna)-5,7,9-triene (MATH) and always occurs associated with 25-norarbora(ferna)-5,7,9-triene. Both compounds are thought to originate from isoarborinol, fernene-3β-ol, or fernenes. The strongly acidic conditions during deposition of the coals might have induced the 4,5-cleavage combined with a methyl-shift in an arborane/fernane-type pentacyclic precursor yielding the MATH. Based on petrological investigations, palynomorphs related to early Gymnospermopsida such as Pteridospermales and Coniferophytes ( Cordaitales and Coniferales) increased in abundance in the strata beginning with the Upper Westphalian D concomitant with the above mentioned biomarkers. The results suggest the arborane/fernane derivatives originate from the plant communities producing these palynomorphs.

  2. Paleobiology of a unique vertebrate coprolites concentration from Rio do Rasto Formation (Middle/Upper Permian), Paran Basin, Brazil

    Science.gov (United States)

    Dentzien-Dias, Paula C.; de Figueiredo, Ana Emilia Q.; Horn, Bruno; Cisneros, Juan Carlos; Schultz, Cesar L.

    2012-12-01

    A large number of coprolites were collected in one outcrop in the lacustrine facies of Rio do Rasto Formation (Middle/Upper Permian) in Southern Brazil. The material ranges from 0.6 cm to 11 cm in length. Their mineralogy, inclusions and morphology were studied to infer their biological source and taphonomy. All of them contain fragments of bones and fish scales, as well as crystalline apatite, and therefore are assigned to carnivores. A wide variety of morphotypes is described, including the knots and the well-known spiral coprolites (heteropolar and amphipolar), as well as a new kind of heteropolar coprolite we called as "edge", that has the whorls grouped in the very end of one pole. These data allow us to instead that a wide variety of vertebrates lived in the lakes of the Middle/Upper Permian in southern Brazil.

  3. Geochemical Variability and the Potential for Beneficial Use of Waste Water Coproduced with Oil from Permian Basin of the Southwest USA

    Science.gov (United States)

    Khan, N. A.; Holguin, F. O.; Xu, P.; Engle, M.; Dungan, B.; Hunter, B.; Carroll, K. C.

    2014-12-01

    The U.S. generates 21 billion barrels/year of coproduced water from oil and gas exploration, which is generally considered waste water. Growth in unconventional oil and gas production has spurred interest in beneficial uses of produced water, especially in arid regions such as the Permian Basin of Texas and New Mexico, the largest U.S. tight oil producer. Produced waters have variable chemistries, but generally contain high levels of organics and salts. In order to evaluate the environmental impact, treatment, and reuse potential, there is a need to characterize the compositional variability of produced water. In the present study, produced water samples were collected from 12 wells across the Permian Basin. Compositional analyses including coupled gas chromatography-time of flight-mass spectrometry and inductively coupled plasma-optical emission spectroscopy were conducted. The samples show elevated benzene, ethylbenzene, toluene, xylene, alkyl benzenes, propyl-benzene, and naphthalene compared to other heteroaromatics; they also contain complex hydrocarbon compounds containing oxygen, nitrogen, and sulfur. Van Krevelen diagrams show an increase in the concentration of heteroaromatic hydrocarbons with increasing well depth. The salinity, dominated by sodium-chloride, also increases with depth, ranging from 37-150 g/L TDS. Depth of wells (or producing formation) is a primary control on predicting water quality for treatment and beneficial use. Our results suggest that partial treatment by removing suspended solids and organic contaminants would support some beneficial uses such as onsite reuse, bioenergy production, and other industrial uses. Due to the high salinity, conventional desalination processes are not applicable or very costly, making beneficial uses requiring low salinity not feasible.

  4. tats de contraintes et mcanismes d'ouverture et de fermeture des bassins permiens du Maroc hercynien. L'exemple des bassins des Jebilet et des RhamnaStates of stresses and opening/closing mechanisms of the Permian basins in Hercynian Morocco. The example of the Jebilet and Rhamna Basins

    Science.gov (United States)

    Saidi, Amal; Tahiri, Abdelfatah; Ait Brahim, Lahcen; Saidi, Maraim

    The fracturing analysis in the Permian basins of Jebilet and Rehamna (Hercynian Morocco) and the underlying terranes allowed us to suggest a model for their opening. Three tectonic episodes are distinguished: a transtensional episode NNE-SSW-trending (Permian I), occurring during the opening along sinistral wrench faults N70-110-trending, associated with synsedimentary normal faults; a transpressive episode ESE-WNW-trending (Permian II), initiating the closure, the normal faults playing back reverse faults and the N70 trending faults dextral wrench faults; a compressional episode NNW-SSE (post-Permian, ante-Triassic), accentuating the closure and the deformation and putting an end to the Tardi-Hercynian compressive movements. To cite this article: A. Saidi et al., C. R. Geoscience 334 (2002) 221-226.

  5. Fluvial facies characteristics of the Sunan formation of the later period of upper permian in Binggoumen basin

    International Nuclear Information System (INIS)

    Two types of paleochannels wewe developed in the Sunan Formation of the later period of Upper Permian (P2s) in Binggoumen anomalous area, Gansu province. The braided tributary river represented by the Daciyao River has a low uranium abundance in the area of erosion and steep gradient of the river bed, short water course and rapid water flow which are not favourable for the formation of uranium mineralization. During the middle to late stage of the development of the Guliyuan River, low-high sinuosity meandering rivers were formed where point bars had developed in a moderate size (river width<300m). Uranium source was abundant, and the river water was enriched with organic matters such as plant debris. During the period of deposition-diagenesis, uranium accumulated at the river bend and at the intersecting part between main channel and tributary channel providing a good prerequiste for the economic uranium concentration in the epigenetic period

  6. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities for geothermal resources have been hindered. To increase the effective regional implementation of geothermal resources as an energy source for power production requires meeting several objectives. These include: 1) Expand (oil and gas as well as geothermal) industry awareness of an untapped source of geothermal energy within deep permeable strata of sedimentary basins; 2) Identify and target specific geographic areas within sedimentary basins where deeper heat sources can be developed; 3) Increase future geothermal field size from 10 km2 to many 100’s km2 or greater; and 4) Increase the productive depth range for economic geothermal energy extraction below the current 4 km limit by converting deep depleted and abandoned gas wells and fields into geothermal energy extraction wells. The first year of the proposed 3-year resource assessment covered an eight county region within the Delaware and Val Verde Basins of West Texas. This project has developed databases in Excel spreadsheet form that list over 8,000 temperature-depth recordings. These recordings come from header information listed on electric well logs recordings from various shallow to deep wells that were drilled for oil and gas exploration and production. The temperature-depth data is uncorrected and thus provides the lower temperature that is be expected to be encountered within the formation associated with the temperature-depth recording. Numerous graphs were developed from the data, all of which suggest that a log-normal solution for the thermal gradient is more descriptive of the data than a linear solution. A discussion of these plots and equations are presented within the narrative. Data was acquired that enable the determination of brine salinity versus brine density with the Permian Basin. A discussion on possible limestone and dolostone thermal conductivity parameters is presented with the purpose of assisting in determining heat flow and reservoir heat content for energy extraction. Subsurface maps of temperature either at a constant depth or within a target geothermal reservoir are discussed, but have yet to be completed.

  7. The Carboniferous - Permian basins of Central and Western Bohemia, the Krkonoše Mt. foreland and the Bohemian Massif, Czech Republic : part I

    Czech Academy of Sciences Publication Activity Database

    Opluštil, S.; Martínek, K.; Lojka, R.; Rosenau, N.; Zajíc, Jaroslav; Šimůnek, Z.; Drábková, J.; Štamberg, S.

    2014-01-01

    Roč. 46, č. 1 (2014), s. 14-54. ISSN 1433-1284. [Field Meeting on Carboniferous and Permian Nonmarine – Marine Correlation. Freiberg, 21.07.2014-27.07.2014] Institutional support: RVO:67985831 Keywords : Carboniferous * Permian * excursion guide Subject RIV: DB - Geology ; Mineralogy

  8. A Middle Permian-Middle Triassic accretionary complex and a Late Triassic foredeep basin: Forerunners of an Indosinian (Late Triassic) thrust complex in the Thailand-Malaysia border area

    Science.gov (United States)

    Ridd, Michael F.

    2013-10-01

    The Semanggol Formation of NW Peninsular Malaysia is a Middle Permian-Late Triassic sequence of predominantly radiolarian chert, sandstone and mudstone (including turbidites), and conglomerate. The belt of country occupied by this unit extends into Thailand where various names including Na Thawi formation have been applied to its correlatives. Fossil evidence, particularly radiolarian, has established its age but also revealed that it is tectonically complex, with numerous out-of-sequence slices interpreted here to be caused by thrusting. The model proposed here involves, initially, in the Middle Permian, accumulation in the oceanward part of an accretionary complex as Palaeotethys began subducting beneath Indochina/East Malaya. This regime, it is proposed, continued until about the end of the Middle Triassic when Sibumasu collided with Indochina/East Malaya bringing an end to subduction. But as crustal shortening continued into the Late Triassic a foredeep basin formed in front of the now-inactive subduction zone and accretionary complex, and the youngest part of the Semanggol Formation was deposited. During this final stage the whole package of rocks comprising those in the accretionary complex and those deposited in the foredeep basin underwent lateral compression resulting in a thrust complex. The Semanggol Formation and its Thailand correlatives occupy part of a N-S belt of imbricately-thrust, deeper-water, sediments which include slope-deposited Carboniferous and Lower Permian beds. That belt is interpreted as a series of thrust slices juxtaposing rocks of different ages, referred to here as the Songkhla-Semanggol terrane. Its western boundary is a N-S line of inferred thrusting which coincides with a major westward facies change to platform carbonates of Middle Permian to Late Triassic age, called here the Rattaphum-Kodiang tectonic line.

  9. Shahejie-Shahejie/Guantao/Wumishan and Carboniferous/Permian Coal-Paleozoic Total Petroleum Systems in the Bohaiwan Basin, China (based on geologic studies for the 2000 World Energy Assessment Project of the U.S. Geological Survey)

    Science.gov (United States)

    Ryder, Robert T.; Qiang, Jin; McCabe, Peter J.; Nuccio, Vito F.; Persits, Felix

    2012-01-01

    This report discusses the geologic framework and petroleum geology used to assess undiscovered petroleum resources in the Bohaiwan basin province for the 2000 World Energy Assessment Project of the U.S. Geological Survey. The Bohaiwan basin in northeastern China is the largest petroleum-producing region in China. Two total petroleum systems have been identified in the basin. The first, the Shahejie&ndashShahejie/Guantao/Wumishan Total Petroleum System, involves oil and gas generated from mature pods of lacustrine source rock that are associated with six major rift-controlled subbasins. Two assessment units are defined in this total petroleum system: (1) a Tertiary lacustrine assessment unit consisting of sandstone reservoirs interbedded with lacustrine shale source rocks, and (2) a pre-Tertiary buried hills assessment unit consisting of carbonate reservoirs that are overlain unconformably by Tertiary lacustrine shale source rocks. The second total petroleum system identified in the Bohaiwan basin is the Carboniferous/Permian Coal–Paleozoic Total Petroleum System, a hypothetical total petroleum system involving natural gas generated from multiple pods of thermally mature coal beds. Low-permeability Permian sandstones and possibly Carboniferous coal beds are the reservoir rocks. Most of the natural gas is inferred to be trapped in continuous accumulations near the center of the subbasins. This total petroleum system is largely unexplored and has good potential for undiscovered gas accumulations. One assessment unit, coal-sourced gas, is defined in this total petroleum system.

  10. Paleomagnetism of an uppermost Permian section in the Lootsberg Pass area, central Karoo Basin: What remanence signal is recorded in the Permo-Triassic boundary sequences in the Karoo Basin?

    Science.gov (United States)

    Geissman, J. W.; Gastaldo, R.; Neveling, J.; Prevec, R.; Kamo, S.; Spencer, K.; Langwenya, M.

    2012-12-01

    The end Permian is associated with the greatest mass extinction in Earth history, with some 80 percent of genus-level extinctions and a range of 75 to 96 percent specie- level extinction in the marine environment, depending upon clade. Although most of our understanding of the Permian-Triassic boundary (PTB) and extinction are based on information from marine sequences in Europe and Asia, a growing body of observations from continental sequences demonstrates a similar extinction event. Yet, the synchronicity of marine and terrestrial events is far from clear. As part of an ongoing, multifaceted effort to better understand one of the best-preserved terrestrial sequences deposited across the PTB, we have collected paleomagnetic data from part of the Beaufort Group of the central Karoo Basin in South Africa with the goal of identifying a magnetic polarity record that can be correlated with the now well-established polarity record across the PTB. We sampled a total of 40 distinct beds (typically each bed was sampled with 8 to 16 cores) at a 127 m thick section near Lootsberg Pass and five sites along the R61 at New Wapadsburg Pass; at both of these localities the PTB has been reported or interpreted to be exposed. Sampled beds at both localities are in siltstone, fine grained sandstone, and carbonate concretions in mudstone intervals. Intensities of NRM typically range from 10 to 50 mA/m. Most materials respond favorably to both progressive alternating field and thermal demagnetization; thermal treatment typically yields a more complete definition of the NRM, with laboratory unblocking temperatures up to about 580 C. NRM directions in all samples are of normal polarity, and most samples yield a well-defined magnetization of NNW declination and moderate negative inclination (normal polarity). At laboratory unblocking temperatures above ~450 C, some samples indicate the possible preservation of a reverse polarity remanence, but it is poorly defined in further demagnetization. The prevailing remanence in these rocks is very comparable to characteristic magnetizations from the ca. 184 to 178 Ma mafic sills of the Karoo Large Igneous Province (e.g., Decl = 336.9, Inc=-55.7, a95=3.8, k=66.2, N = 22 sites; Geissman et al., 2010), which are common throughout the central Karoo Basin. We tentatively question whether the Beaufort Group strata in the central Karoo Basin retain a primary magnetization and, thus, a magnetic polarity stratigraphy across the PTB.

  11. Radiometric dating of Ochoan (Permian) evaporites, WIPP [Waste Isolation Pilot Plant] site, Delaware Basin, New Mexico, USA

    International Nuclear Information System (INIS)

    We have attempted radiometric dating of halide-sulfate salts and clay minerals from the Delaware Basin, New Mexico, USA, as part of geochemical study of the stability of the evaporite sequence at the WIPP (Waste Isolation Pilot Plant - a US DOE facilty) site. We undertook this dating to determine: (1) primary age of evaporite genesis or time(s) of recrystallization; (2) if previously undated evaporite minerals (leonite, polyhalite, kieserite) give useful data; and (3) if the detrital clay minerals have been radiometrically reset at any time following their incorporation into the evaporite medium. We have shown earlier that polyhalites can indeed be successfully dated by the K-Ar method, and once corrections are applied for admixed halide minerals, dates of 210-230 Ma for the Delaware Basin are obtained. Rb-Sr isochrons from early stage sylvites-polyhalites- anhydrites yield 220 +- 10 Ma, even when some sylvites yield lower K-Ar dates due to loss of *40-Ar. K-Ar dates on leonites and kieserities are also low due to *40-Ar loss, but their Rb-Sr dates are higher. Detrital clay minerals from the Delaware Basin collectively yield a highly scattered isochron (390 +- 77 Ma), but samples from a local area, such as the WIPP Site, give a much better age of 428 +- 7 Ma. These dates show that the interaction between the clay minerals and the evaporitic brines was insufficient to reset the clay minerals Rb-Sr systematics. In a related study, we note that a dike emplaced into the evaporite at 34 Ma had only very limited effect on the intruded rocks; contact phenomena were all within 2 m of the dike. All of our geochemical (radio-metric and trace element) studies of the WIPP site argue for preservation of the isotopic and chemical integrity of the major minerals for the past 200 Ma

  12. Permian bivalves of the Taciba Formation, Itararé Group, Paraná Basin, and their biostratigraphic significance

    Directory of Open Access Journals (Sweden)

    Marcello Guimarães Simões

    2012-04-01

    Full Text Available A small and poorly diversified bivalve fauna from Taciba Formation, Itararé Group, Paraná Basin (State of Santa Catarina,Mafra Municipality, is described in this paper for the first time, based on new findings. The fauna is recorded in a 30 cmthick interval of fine sandstone locally at the top of Taciba Formation, in the Butiá quarry. The studied fossil-bearing sandstonebed is a marine intercalation recording a brief eustatic rise in sea-level, probably following glacier retreat and climateamelioration at the end of a broad glacial scenario. The fauna is mainly dominated by productid brachiopods, which are notdescribed here, and rare mollusk shells (bivalves and gastropods. Two bivalve species were identified: Myonia argentinensis(Harrington, 1955, and Aviculopecten multiscalptus (Thomas, 1928. The presence of Myonia argentinensis is noteworthysince this species is also present in the Baitaca assemblage found in marine siltstones (Baitaca assemblage of theRio do Sul Formation, cropping out at the Teixeira Soares region, Paraná State. This species is also recorded in the bivalvefauna from the Bonete Formation, Pillahinco Group, Sauce Grande Basin, Buenos Aires Province, in Argentina. Hence, themarine bivalves of the Taciba Formation are associated with the transgressive event that characterizes the Eurydesma fauna,indicating a Late Asselian-Sakmarian age for the bivalve fauna. Presence of the Myonia argentinensis megadesmid speciesreinforces the Gondwanic nature of the studied fauna.

  13. Geochemical effects of CO2 injection on produced water chemistry at an enhanced oil recovery site in the Permian Basin of northwest Texas, USA: Preliminary geochemical and Li isotope results

    Science.gov (United States)

    Pfister, S.; Gardiner, J.; Phan, T. T.; Macpherson, G. L.; Diehl, J. R.; Lopano, C. L.; Stewart, B. W.; Capo, R. C.

    2014-12-01

    Injection of supercritical CO2 for enhanced oil recovery (EOR) presents an opportunity to evaluate the effects of CO2 on reservoir properties and formation waters during geologic carbon sequestration. Produced water from oil wells tapping a carbonate-hosted reservoir at an active EOR site in the Permian Basin of Texas both before and after injection were sampled to evaluate geochemical and isotopic changes associated with water-rock-CO2 interaction. Produced waters from the carbonate reservoir rock are Na-Cl brines with TDS levels of 16.5-34 g/L and detectable H2S. These brines are potentially diluted with shallow groundwater from earlier EOR water flooding. Initial lithium isotope data (?7Li) from pre-injection produced water in the EOR field fall within the range of Gulf of Mexico Coastal sedimentary basin and Appalachian basin values (Macpherson et al., 2014, Geofluids, doi: 10.1111/gfl.12084). Pre-injection produced water 87Sr/86Sr ratios (0.70788-0.70795) are consistent with mid-late Permian seawater/carbonate. CO2 injection took place in October 2013, and four of the wells sampled in May 2014 showed CO2 breakthrough. Preliminary comparison of pre- and post-injection produced waters indicates no significant changes in the major inorganic constituents following breakthrough, other than a possible drop in K concentration. Trace element and isotope data from pre- and post-breakthrough wells are currently being evaluated and will be presented.

  14. Sr evolution in the Upper Permian and Lower Triassic carbonates, northeast Sichuan basin, China: Constraints from chemistry, isotope and fluid inclusions

    International Nuclear Information System (INIS)

    Petrographic features, C, O and Sr isotopes, rare earth and trace elements were determined, and fluid inclusions were analyzed on various stages of interparticle cements and vug-fillings from the Upper Permian and Lower Triassic sour reservoirs in northeastern Sichuan basin. The aim was to assess the origin and evolution of palaeo-waters in the carbonates. The original water was contemporary seawater, from which marine cements precipitated with slightly high Sr contents (mean 1911 ppm), 87Sr/86Sr ratios from 0.7067 to 0.7082 and nonluminescent CL. The palaeo-seawater was diluted by meteoric water, as indicated by bright cathodoluminescence (CL) and Sr-depletion (0–516 ppm) in low-temperature calcite. When buried to temperatures of about 60–90 °C during Middle to Late Triassic, the palaeo-water was enriched in Sr released from the transformation of precursor aragonite and calcite to dolomite, resulting in precipitation of substantial pre-bitumen Sr-rich minerals (SrSO4 and SrCO3). For un-dolomitized limestone sections, aragonite neomorphism may have contributed Sr to the precipitation of small amounts of Sr-bearing minerals and calcite crystals with elevated homogenization temperatures (HTs, mainly from 90 to 130 °C) and wide Sr contents (from 34 to 3825 ppm), as recorded in stage III calcite. Since the Middle Jurassic, almost all of the early stage celestite and significant amounts of solid CaSO4 have been consumed by reactions with hydrocarbons (i.e., TSR), resulting in water enriched in isotopically light CO2 and HCO3-,Sr2+,Ba2+ and Eu2+, as recorded in calcite with low δ13C values (down to −18.9‰), 87Sr/86Sr ratios from 0.7072 to 0.7076, high HTs (mainly 110–198 °C), positive Eu anomalies and high Sr and Ba contents. Subsequently, the water was uplifted and cooled down to about 115 °C, celestite and strontianite were precipitated with the occurrence of natural elemental S immiscible inclusions. TSR may have produced significant amounts of freshwater, which brought down Sr concentrations and salinities of the palaeo-waters to not more than about 6.0 wt.% NaCl equivalent.

  15. Palynological resolution of Permian sequence in Ib-River coalfield, Orissa and its environmental significance

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, S. [Fakir Mohan University, Vyasa Vihar (India). PG Dept. of Environmental Science

    2007-07-15

    The Ib-River coalfield, a part of Mahanadi Master Basin has rich deposit of Lower Permian Barakar coal. The palynological analysis of sediments from this coalfield has revealed the presence of distinct palynoassemblages. These assemblages represent Permian sequence from Lower Barakar (Early Permian) to Lower Kamthi (Late Permian) sediments. The present palynological studies help in redefining the status of Barakar and Kamthi Formations and in classifying them. Here the palynological assessment has been compared with the megafossil work of the author. Based on the palaeobotanical data, the stratigraphy of this coalfield has been proposed and the environment during Permian time has been discussed in this paper.

  16. SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism Geocronologa SHRIMP del basamento de la Cuenca de Magallanes, Tierra del Fuego: plutonismo Cmbrico y metamorfismo Prmico de alto grado

    Directory of Open Access Journals (Sweden)

    Francisco Herv

    2010-07-01

    Full Text Available Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC, obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (5237 Ma, 5226 Ma and 5386 Ma, interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770C event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobfera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.Cinco nuevas edades radiomtricas logradas mediante anlisis U-Pb en circn utilizando el SHRIMP, fueron determinadas en gneises y rocas plutnicas foliadas obtenidas desde el fondo de pozos de sondajes en la Cuenca de Magallanes y pertenecientes al denominado Complejo gneo y Metamr-fico de Tierra del Fuego. En tres de las muestras fueron calculadas edades del Cmbrico Temprano (5237 Ma, 5226 Ma y 5386 Ma, interpretadas como edades de cristalizacin gnea de las rocas estudiadas. Un gneis migmattico presenta 'peaks' de circones heredados de ca. 950-1.100 Ma y de 560-650 Ma adems de dos granos de edades de 525 Ma, indicando la participacin de material Grenviliano y Brasiliano en el protolito de la migmatita cmbrica. Un gneiss de cordierita-sillimanita-granate presenta una poblacin de circones gneos de edad cmbrica y otro grupo de circones metamrficos, ricos en U, de edad prmica, indicando que en el Prmico un evento metamrfico del alto grado acompaado de anatexis (P=2-3 kbar, T=730-770C afect a rocas gneas cmbricas y/o a rocas sedimentarias derivadas de ellas. Rocas plutnicas cmbricas/ediacaranas han sido descritas en el NW de Argentina, en los basamentos de la Sierra de la Ventana y del Cinturn Plegado del Cabo (en el sur de frica, y en el Orgeno de Ross en Antartica. El evento metamrfico Prmico es contemporneo con la deformacin y metamorfismo de bajo grado, registrado en las sucesiones sedimentarias que sobreyacen el basamento en muchas de estas areas. Siguiendo al episodio Prmico de metamorfismo de alto grado, en Tierra del Fuego fueron removidos al menos 8 a 12 km de rocas de cobertura antes de la depositacin de las rocas volcnicas de la Formacin Tobfera en el Jursico Medio y Superior. Las rocas erosionadas representan una fuente importante de material para las sucesiones conglomerdicas prmicas y trisicas? ubicadas en las regiones vecinas de Amrica del Sur, frica y Antartica.

  17. SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism / Geocronologa SHRIMP del basamento de la Cuenca de Magallanes, Tierra del Fuego: plutonismo Cmbrico y metamorfismo Prmico de alto grado

    Scientific Electronic Library Online (English)

    Francisco, Herv; Mauricio, Caldern; C. Mark, Fanning; Stefan, Kraus; Robert J, Pankhurst.

    2010-07-01

    Full Text Available Cinco nuevas edades radiomtricas logradas mediante anlisis U-Pb en circn utilizando el SHRIMP, fueron determinadas en gneises y rocas plutnicas foliadas obtenidas desde el fondo de pozos de sondajes en la Cuenca de Magallanes y pertenecientes al denominado Complejo gneo y Metamr-fico de Tierra [...] del Fuego. En tres de las muestras fueron calculadas edades del Cmbrico Temprano (5237 Ma, 5226 Ma y 5386 Ma), interpretadas como edades de cristalizacin gnea de las rocas estudiadas. Un gneis migmattico presenta 'peaks' de circones heredados de ca. 950-1.100 Ma y de 560-650 Ma adems de dos granos de edades de 525 Ma, indicando la participacin de material Grenviliano y Brasiliano en el protolito de la migmatita cmbrica. Un gneiss de cordierita-sillimanita-granate presenta una poblacin de circones gneos de edad cmbrica y otro grupo de circones metamrficos, ricos en U, de edad prmica, indicando que en el Prmico un evento metamrfico del alto grado acompaado de anatexis (P=2-3 kbar, T=730-770C) afect a rocas gneas cmbricas y/o a rocas sedimentarias derivadas de ellas. Rocas plutnicas cmbricas/ediacaranas han sido descritas en el NW de Argentina, en los basamentos de la Sierra de la Ventana y del Cinturn Plegado del Cabo (en el sur de frica), y en el Orgeno de Ross en Antartica. El evento metamrfico Prmico es contemporneo con la deformacin y metamorfismo de bajo grado, registrado en las sucesiones sedimentarias que sobreyacen el basamento en muchas de estas areas. Siguiendo al episodio Prmico de metamorfismo de alto grado, en Tierra del Fuego fueron removidos al menos 8 a 12 km de rocas de cobertura antes de la depositacin de las rocas volcnicas de la Formacin Tobfera en el Jursico Medio y Superior. Las rocas erosionadas representan una fuente importante de material para las sucesiones conglomerdicas prmicas y trisicas? ubicadas en las regiones vecinas de Amrica del Sur, frica y Antartica. Abstract in english Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ag [...] es (5237 Ma, 5226 Ma and 5386 Ma), interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770C) event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobfera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.

  18. A new Permian bivalve-dominated assemblage in the Rio do Rasto Formation, Paraná Basin, Brazil: Faunal turnover driven by regional-scale environmental changes in a vast epeiric sea

    Science.gov (United States)

    Simões, Marcello Guimarães; Matos, Suzana Aparecida; Anelli, Luiz Eduardo; Rohn, Rosemarie; Warren, Lucas Veríssimo; David, Juliana Machado

    2015-12-01

    The basal portion of the Permian Rio do Rasto Formation (Serrinha Member), Passa Dois Group, Paraná Basin, Brazil, records an entirely new bivalve fauna intercalated between the underlying Pinzonella neotropica assemblage (uppermost portion of the Teresina Formation) and the overlying Leinzia similis assemblage (Rio do Rasto Formation). Mollusks of these assemblages lived in marginal shallow-water habitats of an immense epeiric sea and were dominated by endemic bivalve species. Taxonomic analysis revealed the presence of Terraia curvata (60.61%), Astartellopsis prosoclina (19.70%), Cowperesia emerita (10.61%), Leinzia curta (4.55%), Terraia bipleura (3.03%) and Beurlenella elongatella (1.52%), which are associated with conchostracans and plant remains. Species composition, abundance, and dominance in this novel assemblage differ notably from the preceding ones, suggesting a substantial evolutionary turnover. Regional-scale environmental changes recognized based on taphonomy, facies analysis, and geochemical data consist of progressive freshening of the marginal habitats of the Paraná Basin and taxic changes that include the following: (a) loss of genera, (b) decrease in bivalve abundance and ecological guilds, (c) disappearance of the dominant bivalve group (Pinzonellinae) and (d) diversification of Terrainae bivalves. The ecological signature also changed notably because only infaunal suspension-feeding bivalves are present, indicating a significant loss of functional diversity at the regional scale. Likely stressor factors (among others) are tied to freshening events, suggesting profound changes in (a) salinity, (b) primary productivity and (c) a lack of coarse, stable substrates coupled with high bioturbation rates. Hence, our regional example could offer valuable clues to benthic (bivalve) community responses in a habitat subjected to (a) rapid climate changes and (b) freshening events in shallow-water settings. Finally, the stratigraphic range of the dominant species (T. curvata) appears to be restricted to the basal portion of the Rio do Rasto Formation. Based on the presence of this species and of C. emerita, the novel assemblage is tentatively correlated with that of the Permian Gai-As Formation in the Huab region of Namibia, thus supporting previous assumptions of a seaway connecting both basins during the Guadalupian Epoch.

  19. News Palynology data of the basal section of Formacion San Gregorio located in Paso de las Bochas (I lower permian north basin, Uruguay

    International Nuclear Information System (INIS)

    Samples from outcrops and concretions of the locality of Paso de las Bochas on the Negro River, provided new palynologycal data to the basal section of the San Gregorio Formation. At least 10 new ta xa are added for San Gregorio concretions, and some of the cited palynomorphs are mentioned for the first time for Uruguay (Rattiganispora minor, Waltzispora pol ita). Moreover, some of the found ta xa have been mentioned for glacial deposits related to the Carboniferous-Permian boundary in other Gondwana regions (p.e. Psomospora detect a, Waltzispora pol ita). The preliminary results reached here allow to admit the hypothesis of the existence of carboniferous dee posits on the Uruguayan territory whose were eroded or not yet recognized. Keywords: San Gregorio Formation, Carboniferous

  20. Petrographic report on clay-rich samples from Permian Unit 4 salt, G. Friemel No. 1 well, Palo Duro Basin, Deaf Smith County, Texas: unanalyzed data

    International Nuclear Information System (INIS)

    This report presents the results of mineralogic and petrographic analyses performed on five samples of clay-rich rock from salt-bearing Permian strata sampled by drill core from G. Friemel No. 1 Well, Deaf Smith County, Texas. Five samples of clay-rich rock from depths of about 2457, 2458, 2521, 2548, and 2568 feet were analyzed to determine the amounts of soluble phase (halite) and the amounts and mineralogy of the insoluble phases. The amounts of halite found were 59, 79, 47, 40, and 4 weight percent, respectively, for the samples. The insoluble minerals are predominately clay (20 to 60 volume percent) and anhydrite (up to 17 volume percent), with minor (about 1.0%) and trace amounts of quartz, dolomite, muscovite, and gypsum. The clays include illite, chlorite, and interstratified chlorite-smectite. The results presented in this petrographic report are descriptive, uninterpreted data. 2 references, 7 tables

  1. Petrographic report on clay-rich samples from Permian Unit 4 salt, G. Friemel No. 1 well, Palo Duro Basin, Deaf Smith County, Texas: unanalyzed data

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, L M

    1983-09-01

    This report presents the results of mineralogic and petrographic analyses performed on five samples of clay-rich rock from salt-bearing Permian strata sampled by drill core from G. Friemel No. 1 Well, Deaf Smith County, Texas. Five samples of clay-rich rock from depths of about 2457, 2458, 2521, 2548, and 2568 feet were analyzed to determine the amounts of soluble phase (halite) and the amounts and mineralogy of the insoluble phases. The amounts of halite found were 59, 79, 47, 40, and 4 weight percent, respectively, for the samples. The insoluble minerals are predominately clay (20 to 60 volume percent) and anhydrite (up to 17 volume percent), with minor (about 1.0%) and trace amounts of quartz, dolomite, muscovite, and gypsum. The clays include illite, chlorite, and interstratified chlorite-smectite. The results presented in this petrographic report are descriptive, uninterpreted data. 2 references, 7 tables.

  2. The Permian system in Kansas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Rocks of Permian age in Kansas were first recognized in 1895, and by the early 21st century the internationally accepted boundary between the Permian and the...

  3. Role of sea-level change in deep water deposition along a carbonate shelf margin, Early and Middle Permian, Delaware Basin: implications for reservoir characterization

    Science.gov (United States)

    Li, Shunli; Yu, Xinghe; Li, Shengli; Giles, Katherine A.

    2015-04-01

    The architecture and sedimentary characteristics of deep water deposition can reflect influences of sea-level change on depositional processes on the shelf edge, slope, and basin floor. Outcrops of the northern slope and basin floor of the Delaware Basin in west Texas are progressively exposed due to canyon incision and road cutting. The outcrops in the Delaware Basin were measured to characterize gravity flow deposits in deep water of the basin. Subsurface data from the East Ford and Red Tank fields in the central and northeastern Delaware Basin were used to study reservoir architectures and properties. Depositional models of deep water gravity flows at different stages of sea-level change were constructed on the basis of outcrop and subsurface data. In the falling-stage system tracts, sandy debris with collapses of reef carbonates are deposited on the slope, and high-density turbidites on the slope toe and basin floor. In the low-stand system tracts, deep water fans that consist of mixed sand/mud facies on the basin floor are comprised of high- to low-density turbidites. In the transgression and high-stand system tracts, channel-levee systems and elongate lobes of mud-rich calciturbidite deposits formed as a result of sea level rise and scarcity of sandy sediment supply. For the reservoir architecture, the fan-like debris and high-density turbidites show high net-to-gross ratio of 62 %, which indicates the sandiest reservoirs for hydrocarbon accumulation. Lobe-like deep water fans with net-to-gross ratio of 57 % facilitate the formation of high quality sandy reservoirs. The channel-levee systems with muddy calciturbidites have low net-to-gross ratio of 30 %.

  4. Palynostratigraphy of Permian succession in the MandRaigarh Coalfield, Chhattisgarh, India and phytogeographical provincialism

    Indian Academy of Sciences (India)

    Srikanta Murthy; Ram-Awatar; Saurabh Gautam

    2014-12-01

    Palynofloras have been recorded from the Barakar Formation in the Borehole MBKW-3, BarpaliKarmitikra Block, MandRaigarh Coalfield, Chhattisgarh. Three distinct palynoassemblages have been identified and referred to the following palynoassemblage zones Gondisporites raniganjensis (Latest Permian); Faunipollenites varius (latest Early Permian), and Scheuringipollenites barakarensis (late Early Permian). It is inferred that these deposits contain the representative palynoassamblages of Early to Late Permian in age. The First Appearance Datum (FAD)s of Arcuatipollenites pellucidus, A. ovatus, Guttulapollenites hannonicus, Lundbladispora microconata, Alisporites opii, Klausipollenites sp., and Goubinispora indica (at 41.95, 45.90, 98.35 m depths), indicate the closing phase of Permian, as these elements are the key species that mark a transition from Permian to the Lower Triassic. An attempt has been made here to reconstruct the phytogeographical provincialism on the basis of Guttulapollenites recorded in this basin.

  5. Sill-induced evaporite- and coal-metamorphism in the Tunguska Basin, Siberia, and the implications for end-Permian environmental crisis

    Science.gov (United States)

    Svensen, Henrik; Polozov, Alexander G.; Planke, Sverre

    2014-05-01

    The emplacement of the Siberian Traps Large igneous province is regarded as the main processes behind the end-Permian environmental crisis. The details of this link are however still under investigation. Among the suggestions are lava degassing of mantle- and crustal-derived gases, explosive lava and phreatomagmatic eruptions, and gas release from contact metamorphism related to the sub-volcanic sill complex. Whereas the lava pile is relatively well studied and investigated, the sub-volcanic sills, dikes, and contact aureoles are poorly studied and documented. We present borehole and field data of sills and contact aureoles from across the Siberian Traps, from Norilsk in the north to Bratsk in the south. The data have been compiled during three field campaigns in 2004, 2006, and 2010. The sill geometries and thicknesses vary considerably from kilometer-scale intrusive complexes to individual thin sills of a few tens of meters. In contrast to several other LIPs, sills are also emplaced within the extrusive pile. Thick sills (up to 900 meters in thickness) occur in high abundance in the upper part of the sedimentary succession, affecting the coal-rich Tungusska Series sediments. Moreover, very thick sills (100-300 meters) are also emplaced within the vast Cambrian salt formations. Petrographic investigations of the metamorphic sediments demonstrate that widespread high temperature devolatilization took place. We show that depending on the specific location within the province and the emplacement depth, the potential for degassing of both greenhouse gases (CH4, CO2), aerosols (SO2), and ozone destructive gases (CH3Cl, CH3Br) was substantial and can explain the crisis.

  6. Characterization of an Upper Permian tight aas reservoir : a multidisciplinary, multiscale analysis from the Rotliegend, Northern Germany

    OpenAIRE

    Antrett, Philipp

    2011-01-01

    This thesis describes a multidisciplinary, multiscale approach to the analysis of tight gas reservoirs. It focused initially on the facies architecture of a Permian tight gas field in the Southern Permian Basin (SPB), East Frisia, Northern Germany. To improve field development, 3D seismic data, wireline and core data were compared to a reservoir analogue in the Panamint Valley, California, United States. Depositional environments of the Permian Upper Rotliegend II included perennial saline la...

  7. Extinguishing a Permian World

    OpenAIRE

    Schneebeli-Hermann, E.

    2012-01-01

    At the end of the Permian, ca. 252 Ma ago, marine and terrestrial fauna were facing the most extensive mass extinction in Earth history (Raup and Sepkoski, 1982). 80%–95% of all species on Earth, on land and in the oceans, became extinct (Benton et al., 2004) within an estimated time interval of less than 200 k.y. to 700 k.y. (Huang et al., 2011; Shen et al., 2011). Among the prominent Paleozoic animal groups that vanished are fusulinid foraminifera, rugose and tabulate cora...

  8. Permian potentiometric analysis

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory (PNL) was requested to analyze potentiometric data from the Wolfcamp Formation of the Permian System to evaluate the recommendations by the University of Texas/Bureau of Economic Geology (UT/BEG) that additional geohydrologic boreholes be drilled into the Wolfcamp. The UT/BEG recommended that two stratigraphic and two geohydrologic borings be drilled into the Permian System during FY83 and that several shallow hydrologic tests be made in the Dockum Formation. A geostatistical technique known as kriging was applied to objectively evaluate these geohydrologic borehole recommendations. The Deaf Smith County location appears to be an excellent choice for a borehole. No high quality potentiometric data are available from Deaf Smith County and a borehole location immediately upgradient from the candidate repository site is needed. Adding this borehole location to the potentiometric data base will significantly reduce field data uncertainty near the location being studied. The Swisher County location does not appear to be the best choice. High quality data values H2206 and H2360 are located immediately upgradient from the proposed repository site. The best placement of additional geohydrological boreholes in the Wolfcamp Formation depends strongly upon the proposed repository location. The variability of the potentiometric data causes estimation errors to rapidly increase away from locations of field measurements. Suggested locations for additional boreholes for the Deaf Smith investigations are in northwest Randall or central Potter Counties. Ideal borehole locations for the Swisher county studies appear to be in southeast Randall and Armstrong Counties

  9. Middle-Late Permian mass extinction on land

    Energy Technology Data Exchange (ETDEWEB)

    Retallack, G.J.; Metzger, C.A.; Greaver, T.; Jahren, A.H.; Smith, R.M.H.; Sheldon, N.D. [University of Oregon, Eugene, OR (United States). Dept. of Geological Science

    2006-11-15

    The end-Permian mass extinction has been envisaged as the nadir of biodiversity decline due to increasing volcanic gas emissions over some 9 million years. We propose a different tempo and mechanism of extinction because we recognize two separate but geologically abrupt mass extinctions on land, one terminating the Middle Permian (Guadalupian) at 260.4 Ma and a later one ending the Permian Period at 251 Ma. Our evidence comes from new paleobotanical, paleopedological, and carbon isotopic studies of Portal Mountain, Antarctica, and comparable studies in the Karoo Basin, South Africa. Extinctions have long been apparent among marine invertebrates at both the end of the Guadalupian and end of the Permian, which were also times of warm-wet greenhouse climatic transients, marked soil erosion, transition from high- to low-sinuosity and braided streams, soil stagnation in wetlands, and profound negative carbon isotope anomalies. Both mass extinctions may have resulted from catastrophic methane outbursts to the atmosphere from coal intruded by feeder dikes to flood basalts, such as the end-Guadalupian Emeishan Basalt and end-Permian Siberian Traps.

  10. Lower Permian brachiopods from Oman : their potential as climatic proxies

    OpenAIRE

    Angiolini, L.; D. P. F. Darbyshire; Stephenson, Michael; Leng, Melanie; Brewer, T. S.; F. Berra; F. Jadoul

    2008-01-01

    The Lower Permian of the Haushi basin, Interior Oman (Al Khlata Formation to Saiwan Formation/lower Gharif member) records climate change from glaciation, through marine sedimentation in the Haushi sea, to subtropical desert. To investigate the palaeoclimatic evolution of the Haushi sea we used O, C, and Sr isotopes from 31 brachiopod shells of eight species collected bed by bed within the type-section of the Saiwan Formation. We assessed diagenesis by scanning electron microscopy of ultrastr...

  11. Early Permian Pangea `B' to Late Permian Pangea `A'

    Science.gov (United States)

    Muttoni, Giovanni; Kent, Dennis V.; Garzanti, Eduardo; Brack, Peter; Abrahamsen, Niels; Gaetani, Maurizio

    2003-10-01

    The pre-drift Wegenerian model of Pangea is almost universally accepted, but debate exists on its pre-Jurassic configuration since Ted Irving introduced Pangea 'B' by placing Gondwana farther to the east by 3000 km with respect to Laurasia on the basis of paleomagnetic data. New paleomagnetic data from radiometrically dated Early Permian volcanic rocks from parts of Adria that are tectonically coherent with Africa (Gondwana), integrated with published coeval data from Gondwana and Laurasia, again only from igneous rocks, fully support a Pangea 'B' configuration in the Early Permian. The use of paleomagnetic data strictly from igneous rocks excludes artifacts from sedimentary inclination error as a contributing explanation for Pangea 'B'. The ultimate option to reject Pangea 'B' is to abandon the geocentric axial dipole hypothesis by introducing a significant non-dipole (zonal octupole) component in the Late Paleozoic time-averaged geomagnetic field. We demonstrate, however, by using a dataset consisting entirely of paleomagnetic directions with low inclinations from sampling sites confined to one hemisphere from Gondwana as well as Laurasia that the effects of a zonal octupole field contribution would not explain away the paleomagnetic evidence for Pangea 'B' in the Early Permian. We therefore regard the paleomagnetic evidence for an Early Permian Pangea 'B' as robust. The transformation from Pangea 'B' to Pangea 'A' took place during the Permian because Late Permian paleomagnetic data allow a Pangea 'A' configuration. We therefore review geological evidence from the literature in support of an intra-Pangea dextral megashear system. The transformation occurred after the cooling of the Variscan mega-suture and lasted 20 Myr. In this interval, the Neotethys Ocean opened between India/Arabia and the Cimmerian microcontinents in the east, while widespread lithospheric wrenching and magmatism took place in the west around the Adriatic promontory. The general distribution of plate boundaries and resulting driving forces are qualitatively consistent with a right-lateral shear couple between Gondwana and Laurasia during the Permian. Transcurrent plate boundaries associated with the Pangea transformation reactivated Variscan shear zones and were subsequently exploited by the opening of western Neotethyan seaways in the Jurassic.

  12. Residual basins

    International Nuclear Information System (INIS)

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author)

  13. Palaeoenvironmental significance of Late Permian palaeosols in the South-Eastern Iberian Ranges, Spain

    OpenAIRE

    Horra del Barco, Raúl de la; Benito Moreno, María Isabel; López Gómez, José; Arche, Alfredo; Fernández Barrenechea, José María, ed. lit; Luque del Villar, Francisco Javier, ed. lit

    2008-01-01

    The Late Permian (Wuchiapingian) Alcotas Formation in the SE Iberian Ranges consists of one red alluvial succession where abundant soil profiles developed. Detailed petrographical and sedimentological studies in seven sections of the Alcotas Formation allow six different types of palaeosols, with distinctive characteristics and different palaeogeographical distribution, to be distinguished throughout the South-eastern Iberian Basin. These characteristics are, in turn, relate...

  14. Permian depositional and environmental development in Svalbard

    OpenAIRE

    Dustira, Anna Marie

    2013-01-01

    The main objective of this thesis is to improve the knowledge on the depositional and environmental development of Svalbard during the Permian (299–252 Ma), with a primary focus on the Early to Late Permian Kapp Starostin Formation (Tempelfjorden Group). Thirteen localities of Permian sedimentary strata were investigated with respect to their sedimentological and geochemical properties. Sediments from this period reflect mostly marine deposition on a broad epicontinental shelf at the northern...

  15. Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistncia Formation (Irati Subgroup), Paran Basin, Brazil: implications for the exploration model / Maturao permotrissica e os vrios estgios de migrao de hidrocarbonetos na Formao Assistncia (Subgrupo Irati), Bacia do Paran: implicaes para os modelos exploratrios

    Scientific Electronic Library Online (English)

    Antnio, Mateus; Claudio, Riccomini; Ezequiel J. E. C. B., Ferreira; Colombo C. G., Tassinari.

    2014-09-01

    Full Text Available Novas linhas de evidncias geolgicas sugerem fortemente que o principal perodo de maturao de hidrocarbonetos na Formao Assistncia teria ocorrido no Permotrissico, estimulado por um gradiente geotrmico elevado que tambm sustentou vrias manifestaes de atividade hidrotermal. Trs fases pri [...] ncipais de migrao de fluidos e hidrocarbonetos tambm podem ser inferidas a partir de observaes em multiescala: fluxo confinado no final do Permiano ao Trissico, dependente do acmulo local de presses de fluidos; fluxo heterogneo no Cretceo Inferior, desencadeado por um gradiente de temperatura rejuvenescido, assistido pelas condies de permeabilidade antes desenvolvidas; e um fluxo tardio, possivelmente impulsionado por gradientes de presso locais, posteriormente ao esfriamento dos diques e soleiras de diabsio. A maturao precoce e a existncia de vrios estgios de migrao de hidrocarbonetos apresentam implicaes significativas na concepo de modelos exploratrios a serem aplicados na Bacia do Paran. Abstract in english New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistncia Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarb [...] on migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paran Basin.

  16. Palynology of Permian Gondwana sequence of Umrer coalfield, Maharashtra

    Energy Technology Data Exchange (ETDEWEB)

    Jha, N.; Tewari, R.; Rajanikanth, A. [Birbal Sahni Institute of Paleobotany, Lucknow (India)

    2007-04-15

    Quantitative and qualitative palynological analysis of Early Permian sediments, Umrer Coalfield, Wardha Basin has been carried out. The microspore assemblage consists of 22 genera and 40 species. It is characterized by dominance of radial monosaccates chiefly, Parasacciles and subdominance of non-striate disaccates chiefly, Scheuringipollenites. Presence of Crucisaccites and Caheniasaccites suggests Upper Karharbari (Late Sakmarian-Early Artinskian) affinity. The presence of the Karharbari palynozone has been demarcated in lithologically designated Barakar Formation. The present finding corroborates the earlier studies by Bharadwaj and Anand Prakash (1974).

  17. Growth and demise of Permian biogenic chert along northwest Pangea: evidence for end-Permian collapse of thermohaline circulation

    OpenAIRE

    Beauchamp Benoît; Baud Aymon

    2002-01-01

    The Permian Chert Event (PCE) was a 30 Ma long episode of unusual chert accumulation along the northwest margin of Pangea, and possibly worldwide. The onset of the PCE occurred at about the Sakmarian-Artinskian boundary in the Sverdrup Basin, Canadian Arctic, where it coincides with a maximum flooding event, the ending of high-frequency/high-amplitude shelf cyclicity, the onset of massive biogenic chert deposition in deep-water distal areas, and a long-term shift from warm- to cool-water carb...

  18. New Permian fauna from tropical Gondwana.

    Science.gov (United States)

    Cisneros, Juan C; Marsicano, Claudia; Angielczyk, Kenneth D; Smith, Roger M H; Richter, Martha; Fröbisch, Jörg; Kammerer, Christian F; Sadleir, Rudyard W

    2015-01-01

    Terrestrial vertebrates are first known to colonize high-latitude regions during the middle Permian (Guadalupian) about 270 million years ago, following the Pennsylvanian Gondwanan continental glaciation. However, despite over 150 years of study in these areas, the biogeographic origins of these rich communities of land-dwelling vertebrates remain obscure. Here we report on a new early Permian continental tetrapod fauna from South America in tropical Western Gondwana that sheds new light on patterns of tetrapod distribution. Northeastern Brazil hosted an extensive lacustrine system inhabited by a unique community of temnospondyl amphibians and reptiles that considerably expand the known temporal and geographic ranges of key subgroups. Our findings demonstrate that tetrapod groups common in later Permian and Triassic temperate communities were already present in tropical Gondwana by the early Permian (Cisuralian). This new fauna constitutes a new biogeographic province with North American affinities and clearly demonstrates that tetrapod dispersal into Gondwana was already underway at the beginning of the Permian. PMID:26537112

  19. First evidence for Permian-Triassic boundary volcanism in the Northern Gemericum: geochemistry and U-Pb zircon geochronology

    Directory of Open Access Journals (Sweden)

    Vozárová Anna

    2015-10-01

    Full Text Available Several magmatic events based on U-Pb zircon geochronology were recognized in the Permian sedimentary succession of the Northern Gemeric Unit (NGU. The Kungurian magmatic event is dominant. The later magmatism stage was documented at the Permian-Triassic boundary. The detrital zircon assemblages from surrounding sediments documented the Sakmarian magmatic age. The post-orogenic extensional/transtensional faulting controlled the magma ascent and its emplacement. The magmatic products are represented by the calc-alkaline volcanic rocks, ranging from basaltic metaandesite to metarhyolite, associated with subordinate metabasalt. The whole group of the studied NGU Permian metavolcanics has values for the Nb/La ratio at (0.44–0.27 and for the Nb/U ratio at (9.55–4.18, which suggests that they represent mainly crustal melts. Magma derivation from continental crust or underplated crust is also indicated by high values of Y/Nb ratios, ranging from 1.63 to 4.01. The new 206U–238Pb zircon ages (concordia age at 269 ± 7 Ma confirm the dominant Kungurian volcanic event in the NGU Permian sedimentary basin. Simultaneously, the Permian-Triassic boundary volcanism at 251 ± 4 Ma has been found for the first time. The NGU Permian volcanic activity was related to a polyphase extensional tectonic regime. Based on the new and previous U-Pb zircon ages, the bulk of the NGU Permian magmatic activity occurred during the Sakmarian and Kungurian. It was linked to the post-orogenic transpression/transtension tectonic movements that reflected the consolidation of the Variscan orogenic belt. The Permian-Triassic boundary magmatism was accompanied by extension, connected with the beginning of the Alpine Wilson cycle.

  20. From rift to drift in South Pamir (Tajikistan): Permian evolution of a Cimmerian terrane

    Science.gov (United States)

    Angiolini, L.; Zanchi, A.; Zanchetta, S.; Nicora, A.; Vuolo, I.; Berra, F.; Henderson, C.; Malaspina, N.; Rettori, R.; Vachard, D.; Vezzoli, G.

    2015-04-01

    Here, we describe the Permian-Lower Triassic sedimentary succession of South Pamir and the associated biota of conodonts, foraminifers and brachiopods. The studied succession comprises the Carboniferous-Lower Permian siliciclastic Uruzbulak and Tashkazyk formations (Bazar Dara Group), which are unconformably covered by upper Lower to Upper Permian units, deposited both in platform settings (Kurteke Formation), and on the slope and basin (Kochusu Formation, Shindy Formation, Kubergandy Formation, Gan Formation, and Takhtabulak Formation). These formations comprise bioclastic limestones, cherty limestones, shales, volcaniclastic rocks, basalts, sandstones and conglomerates, and are locally very rich in fossils (fusulinids, ammonoids, brachiopods, corals and conodonts). The Permian succession is then overlain by shallow water carbonates of the Induan to Anisian Karatash Group. Subsidence analysis and volcanics of the Permian and overlying Triassic successions constrains the timing of rifting of South Pamir from Gondwana in the Early Permian (=Cisuralian), and its docking to Central Pamir, the Eurasian margin and the interposed volcanic arcs at the end of the Triassic. The sedimentary successions of the Pamirs represent a key-point to refine the correlations between the Tethyan regional scale and the International Time Scale. The analyses of the fusulinids and conodonts of the Kubergandian and Murgabian stratotypes of SE Pamir suggest that: (1) the upper Bolorian and the lower part of the Kubergandian correlate to the upper Kungurian; (2) the upper Kubergandian and the lower Murgabian correlate to the Roadian; (3) the mid-upper Murgabian correlates to the Wordian; (4) possibly the uppermost Murgabian and the lower Midian correlate to the lower Capitanian. The Kubergandian is thus a defined regional stage, based on fusulinids, ammonoids and conodonts and can be correlated to the Kungurian and the Roadian; still problematic remains the Murgabian correlation which needs to be investigated and resolved in other Tethyan sections.

  1. The global Devonian, Carboniferous and Permian Correlation Project: a review of the contribution from Great Britain

    OpenAIRE

    Warrington, G.; Barclay, W.J.; Leveridge, B.E.; C. N. Waters

    2012-01-01

    A contribution on the lithostratigraphy and palaeoenvironments of Devonian, Carboniferous and Permian successions onshore in Great Britain, prepared for an international project, is summarised with particular reference to south-west England. Devonian and Carboniferous successions present in that region occur in the Rhenohercynian Tectonic Zone, to the south of the Variscan Front (VF), and their complexity reflects formation in six composite basins. They differ substantially from contempora...

  2. The Permian and Triassic in the Albanian Alps

    Science.gov (United States)

    Gaetani, Maurizio; Meo, Selam; Rettori, Roberto; Henderson, Charles M.; Tulone, Accursio

    2015-09-01

    The sedimentary succession of the Permian to Middle Triassic of the Albanian Alps is described, as part of the eastern Adria passive margin towards the Tethys. A carbonate ramp deepening towards NE in present day coordinates developed during the Middle Permian and was affected by block faulting with the deposition of carbonate breccia. The Early Triassic was characterized by intense terrigenous deposition with several cobble conglomerate units up to 80 m-thick, and by oolitic carbonate shoals. The fine clastic deposition ended gradually during the earliest Anisian and a wide calcarenitic ramp occupied the area, with small local carbonate mounds. Basinward, the red nodular limestone of the Han Bulog Formation was interbedded with calcarenitic material exported from the ramp. Drowning to more open conditions occurred towards the end of the Pelsonian. Subsequently, cherty limestone and tuffitic layers spread over the entire area. Towards the end of the Ladinian, with the end of the volcanic activity, red pelagic limestone was deposited locally for a short period. By the latest Ladinian most of the area returned to shallow-water conditions, with a peritidal carbonate platform. In the Theth area, in contrast, a basin with black organic-rich dolostone and limestone developed which seems to be unique in that part of the Adria passive margin. The occurrence of cobble conglomerate units in the Lower Triassic testifies to very active block faulting and high accommodation, not yet described for the area.

  3. Mineralogical and isotopic data on two hydrothermal uranium deposits located in the Permian volcano-sedimentary basin of Collio Orobico (Bergamasc Alps): occurrence of a Cretaceous U mobilization phase

    International Nuclear Information System (INIS)

    The U deposits of Novazza and Val Vedello are located close to the unconformity with the South-Alpine basement. The ignimbrites adjacent to the Novazza deposit have undergone a pervasive hydrothermal alteration. For this deposit, the study of the micas provides crystallization temperatures ranging from 5400C to 3500C. These micas do not show a zonal distribution with respect to the mineralized bodies. In the neighbouring barren basin, the mica crystallization temperatures at 2000C suggest a post-magmatic evolution very different. The U-Pb data on zircons were made for ignimbrites collected in the Novazza mine and in the barren basin. They allow to propose a multi-episodic evolution model taking into account a mixing of two populations of zircons: a small amount of Precambrian zircons located in basement xenoliths within the ignimbrites, and a large proportion of zircons having crystallized in the ignimbrites, which are supposed to have been emplaced about 280 My ago. The U-Pb data suggest a phase of U concentration, during Cretaceous times. For each deposit, this age does not seem to be related to the ages of fault motions. Different hypothesis concerning the genesis of Novazza and Val Vedello deposits are discussed which take into account the paleotemperature data on micas, the ore paragenesis and the U-Pb data obtained on U-mineralizations

  4. Paleomagnetism of the Independencia Group, Eastern Paraguay: A New Late Permian Pole for Stable South America

    Science.gov (United States)

    Rapalini, A. E.; Fazzito, S.; Orue, D.

    2005-05-01

    The late Permian segment of the South American apparent polar wander path (APWP) is poorly defined due to scarce and unreliable paleomagnetic poles, justifying the need for further paleomagnetic efforts on suitable rocks of such age from stable areas of South America. A study was carried out on the Late Permian Independencia Group, which is discontinuously exposed along Eastern Paraguay and consists of several hundred meters of flat lying continental pink to reddish sandstones and siltstones, deposited on the western margin of the Parana basin. Thirteen sites (83 samples) were collected on the top unit of the Group (the latest Permian Tacuary Fm) from outcrops distributed over 1000 square kms. Detailed AF and thermal demagnetization permitted the isolation of within-site consistent characteristic remanence in eleven sites, being generally hematite the main carrier of the remanence. Excluding one outlier, a paleomagnetic pole was computed by averaging 10 virtual geomagnetic poles of mixed polarities (6 reversed, 4 normal), yielding a position at: 80.7 S, 7.0 E, A95: 6.6. The new pole may be considered as key for a better definition of the South American APWP by filling a gap between recently obtained and reliable Early Permian poles and an older and less reliable Early-Middle Triassic group of poles.

  5. A new Late Permian paleomagnetic pole for stable South America: The Independencia group, eastern Paraguay

    Science.gov (United States)

    Rapalini, Augusto E.; Fazzito, Sabrina; Orué, Delio

    2006-10-01

    The Late Permian segment of the South American apparent polar wander path (APWP) is poorly defined and further paleomagnetic efforts on suitable rocks of such age from stable areas of South America are needed. A study was carried out on the Late Permian Independencia Group, which is discontinuously exposed along Eastern Paraguay and consists of several hundred meters of flat lying continental white, pink and reddish sandstones and siltstones, deposited on the western margin of the Paraná basin. Thirteen sites (83 samples) were collected on the top unit of the Group (the latest Permian Tacuary Fm) from outcrops distributed over 1000 square kms. Detailed AF and thermal demagnetization permitted the isolation of within-site consistent characteristic remanence in eleven sites, being generally hematite the main carrier of the remanence. Excluding one outlier, a paleomagnetic pole was computed by averaging 10 virtual geomagnetic poles of mixed polarities (6 reversed, 4 normal), yielding a position at: 80.7°S, 7.0°E, A95: 6.6°. The new pole may be considered key for a better definition of the South American APWP by filling a gap between a relatively reliable Early Permian and a poorly defined Early-Middle Triassic groups of poles.

  6. Provincialization of terrestrial faunas following the end-Permian mass extinction.

    Science.gov (United States)

    Sidor, Christian A; Vilhena, Daril A; Angielczyk, Kenneth D; Huttenlocker, Adam K; Nesbitt, Sterling J; Peecook, Brandon R; Steyer, J Sébastien; Smith, Roger M H; Tsuji, Linda A

    2013-05-14

    In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence on the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether the end-Permian mass extinction (252.3 Ma) affected the distribution of tetrapod faunas within the southern hemisphere and apply quantitative methods to analyze four components of biogeographic structure: connectedness, clustering, range size, and endemism. For all four components, we detected increased provincialism between our Permian and Triassic datasets. In southern Pangea, a more homogeneous and broadly distributed fauna in the Late Permian (Wuchiapingian, ∼257 Ma) was replaced by a provincial and biogeographically fragmented fauna by Middle Triassic times (Anisian, ∼242 Ma). Importantly in the Triassic, lower latitude basins in Tanzania and Zambia included dinosaur predecessors and other archosaurs unknown elsewhere. The recognition of heterogeneous tetrapod communities in the Triassic implies that the end-Permian mass extinction afforded ecologically marginalized lineages the ecospace to diversify, and that biotic controls (i.e., evolutionary incumbency) were fundamentally reset. Archosaurs, which began diversifying in the Early Triassic, were likely beneficiaries of this ecological release and remained dominant for much of the later Mesozoic. PMID:23630295

  7. Atmospheric circulation in a Permian climate

    Science.gov (United States)

    Schneider, Steven; Tost, Holger

    2015-04-01

    At the beginning of the Permian (299-251 mya) the formation of the supercontinent Pangaea that comprised all of the present-day continents was completed. This configuration with a single landmass stretching from North to South Pole provides a special case of land-sea distribution for analysing its effect on climate and atmospheric circulation. This work uses a coupled system to represent Permian climate, including an explicit formulation for meridional heat transport in both atmosphere and ocean. The simulations are done with a topography of the early Late Permian (approx. 262 mya). During the Permian the Earth turned from an icehouse world with preindustrial carbon dioxide concentration to a hothouse world with an atmosphere containing up to ten times as much of carbon dioxide as before. Therefore centurial time-slice experiments with different carbon dioxide concentrations are performed, allowing for adjusted equilibrium climate states. Our simulation results are compared to alternative modelling studies, but also to sedimental and phytogeographic data. Analysing the Permian atmosphere, special interest is given on convectional processes to study atmospheric circulation in comparison with the present-day situation.

  8. Radionuclides distribution in blooming of the permian sediments from the Irati Formation of the Parana Basin; Distribuicao de radionuclideos em um afloramento de sedimentos permianos da Formacao Irati na Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ademar de Oliveira

    2008-02-15

    The objective of this work is to study natural radionuclides in sedimentary rocks. The concentration of them reflects the origin of the sediments, the depositional environment as well as some mineralogical characteristics of the rock matrix, and also more recent events as weathering and erosion. Using gamma ray high resolution spectrometry, the profile of activity concentration of the natural radionuclides was assessed for {sup 226}Ra, {sup 238}U, {sup 32}Th and {sup 40}K in rocks of the Irati Formation belonging to Parana Sedimentary Basin. The samples were collected at a limestone abandoned mine, in the city of Sapopema, (PR). 24 samples were collected, eleven from the exposed vertical profile with approximately 5.50 m, whose stratigraphy is represented by an alternation among decimetrics layers of limestones, bituminous shales, and some rhythmits layers (milimetric sheets of limestone and bituminous shales), 9 repetitions of a sample to study the variability, and three rigolits samples in sequential apprenticeships of weathering. Each sample was dried in the sun during about 48 hours, broken, drizzled in a sieve of 4 mesh and put, in a cylindrical container. The measures were accomplished using a Germanium Hyper Pure detector (HPGe) with relative efficiency of 66%, connected to a standard spectrometry electronic chain. The measured concentrations of activity of {sup 238}U were smaller for the limestones (17.80 {+-}0.09 Bq.Kg{sup -1}), larger for the bituminous shales (125.5 {+-} 2.6 Bq.Kg{sup -1} with enrichment of uranium in the sample (200), 548 {+-} 16 Bq.Kg{sup -1}, upper part of the column), and intermediate for the rhythmits (23.0 {+-} 1,3 Bq.Kg{sup -1}. The ratio eTh/K obtained for the studied profiles has equivalent values, indicating similar mineralogical characteristics for the limestones, bituminous shales, rhythmits and studied rigolits. On the other hand, to the ratio eTh/eU showed that two of the three regolits samples belong to oxidizer atmospheres, favoring the leaching of uranium, what can be causing the enrichment of the sample (200), once these soils are above the column. The average measured doses were 16 nGy.h{sup -1} for the limestones and rhythmits, 79.5 nGy.h{sup -1} for the bituminous shales and 329.5 nGy.h{sup -1} for the enriched bituminous shales of the top of the column. These results supply data to estimate the contribution of these products for the radiation dose received by the public in general, besides of database for mineralogical and geophysical studies of the Parana Basin. (author)

  9. Carbon isotope variations in the upper Carboniferous - Permian Mallemuk Mountain Group, eastern North Greenland

    International Nuclear Information System (INIS)

    Isotope data from Late Palaeozoic limestones of the Wandel Sea Basin in eastern North Greenland show a variation of ?13C from 0.0 0/00 to 5.7 0/00 vs PDB. Carbonates depleted in 13C occur in the basal part of lower Moscovian, upper Moscovian and middle Gzhelian transgressive sequences. 13C enriched limestones occur later in the cycles. The most 13C enriched limestones occur in the youngest (late Early Permian-early Late Permian) part of the sequence in Amdrup Land. The isotopic data is believed to represent changes in the global carbon cycle. Thus 13C enriched carbonates correlate to periods of burial of organic carbon mostly as coal, while 13C depleted carbonates formed as the result of erosion and oxidation of organic carbon during sea-level low stands. (author)

  10. Grain-rimming kaolinite in Permian Rotliegend reservoir rocks

    Science.gov (United States)

    Waldmann, Svenja; Gaupp, Reinhard

    2016-04-01

    Upper Rotliegend sediments of Permian age from the northeast Netherlands show moderate to good reservoir qualities. The predominant control is by the presence of authigenic grain-rimming kaolinite, which has a negative, but in some parts also a positive, effect on reservoir quality. To better understand the formation and distribution of grain-rimming kaolinite, reservoir rocks were studied in terms of composition and diagenetic processes. Petrographic evidence, summarized as a paragenetic sequence, is integrated with geochemical modeling results to identify early mesodiagenetic water-rock interactions under the participation of gases, i.e., CO2 and H2S, released from underlying Carboniferous source rocks. The sediments investigated were deposited at varying distance from the southern flank of the Southern Permian Basin. Sediments near the basin margin are mainly attributed to a fluvial environment and comprise medium to coarse-grained sandstones and conglomerates. There, vermicular kaolinite occurs with a lath-like structure. Distal to the basin margin, mainly in sandstones intercalated with fine-grained playa sediments, comparatively high amounts of grain-rimming kaolinite occur. There, the presence of this mineral has a significant influence on the rock properties and the reservoir quality. Geochemical modeling suggests that the formation of such kaolinites cannot be explained exclusively by in situ feldspar dissolution. The modeling results support evidence that kaolinite can be formed from precursor clay minerals under the presence of CO2-rich formation waters. Such clay minerals could be corrensite, smectite-chlorite mixed-layer minerals, or chlorite that is potentially present in Rotliegend sediments during early diagenesis. Furthermore, the geochemical modeling can reflect several mineral reactions that were identified from petrographic analysis such as the formation of illite and kaolinite at the expense of feldspar dissolution and consequent silica precipitation. Under the presence of sulfate (SO42 -), partial hematite dissolution and the reduction of Fe3 + to Fe2 + occur, where the latter is further incorporated in Fe-Mg-rich carbonates. The sulfate is bonded in anhydrite. The results of this study are relevant for reservoir quality predictions in kaolinite-dominated systems, as well as for CO2 storage projects and the prediction of long-term fluid-rock interactions under the participation of carbon dioxide and/or other gases.

  11. Paleoecological and paleoenvironmental changes during the continental Middle-Late Permian transition at the SE Iberian Ranges, Spain

    Science.gov (United States)

    De la Horra, R.; Galán-Abellán, A. B.; López-Gómez, J.; Sheldon, N. D.; Barrenechea, J. F.; Luque, F. J.; Arche, A.; Benito, M. I.

    2012-08-01

    The Middle and Late Permian are characterized by a pair of mass-extinction events that are recorded in both marine and continental environments. Here, we present the first continental western peri-Tethyan record of an extinction event located in the Middle-Late interval. In the SE Iberian Ranges, Central Spain, the transition between the Lower and Middle subunits of the Middle Permian Alcotas Formation indicates a significant paleoclimatic change from arid and semiarid conditions towards more humid conditions. Coincident with the onset of humid conditions there were changes in the sedimentology, mineralogy, and geochemistry that indicate significant environmental changes including a shift in weathering intensity and a change of fluvial style from braided to meandering systems. Near the top of the Middle Subunit, a local biotic crisis is recorded by palynomorph assemblages. Following this crisis, there is a total absence of coal beds, plant remains, and microflora that defines a barren zone in the uppermost part of the Alcotas Formation which is recorded throughout the basin. The barren zone is accompanied by a shift back to braided stream systems, but not by a return to carbonate-bearing paleosols indicative of arid or semi-arid conditions. This combination of features is consistent with other Middle-Late continental basins related with mass extinctions, so the barren zone is interpreted as the extinction interval. The regional character of the extinction interval and its proximity with the Middle-Late Permian transition could be related with the global mid-Capitanian biotic turnover described in this period of time in other marine basins. However, the common difficulties of dating with precision non-marine rocks make this relationship difficult to probe in the Iberian Basin and in other Middle-Late Permian basins. Further work, including high resolution carbon-isotope analyses and complete studies of the magnetostratigraphy, should be desirable in order to obtain a better age constraint and to produce reliable comparisons with marine sections.

  12. A Review on Permian to Triassic Active or Convergent Margin in Southeasternmost Gondwanaland: Possibility of Exploration Target for Tin and Hydrocarbon Deposits in the Eastern Indonesia

    Directory of Open Access Journals (Sweden)

    Amiruddin Amiruddin

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no1.20094An active convergence of continental margin is probably generated in Gondwanaland during Permian to Triassic period which is characterized by the presence of magmatic and volcanic belts and back-arc ba- sins occupied respectively by Permian to Triassic rocks. The magmatic belt is occupied by peraluminous granitic plutons showing characteristics of S- type granite and is considered as tin-bearing granites. The back-arc basins are occupied by the Southern Papua and Galille-Bowen-Gunnedah-Sydney Basins. Those large basins are respectivelly filled by fluvial, fluvio- deltaic to marine Permian-Triassic sediments, which are unconformably overlain by the Jurrassic-Cretaceous marine succession. The paleomagnetic data, confirmed by flora content found in Australia and Papua, indicate that those areas initially belong to the Gondwanaland before part of them were drifted and rotated into the present day position. Tectonically, the presence of those Permian-Triassic magmatic-volcanic belts and back-arc basins in behind, indicates that at the time there were huge compressive activities: convergence of paleo-oceanic Pasific Plate moving westward, collided and subducted into the Southeastern Gondwana Continental Plate, moved relatively eastwards. This phenomenon resembles to the formation of Sumatera Tertiary tectonic zones producing back-arc basins, i.e. South Sumatera, Central, and North Sumatera Basins including the Tertiary Magmatic Arc. Concerning the similarity of Permian-Triassic geological condition of the magmatic arc and back-arc basins in Eastern Indonesia and Eastern Australia including paleoposition, paleotectonic setting, strati- graphic succession, and lithologic composition, it is suggested to carry out an increase in a more intens- ive tin exploration in the Eastern Indonesia, e.g. Bird Head area and Banggai Sula Island, and also for hydrocarbon target (coal, coalbed methane, oil and gas, and oil shale in the Southern Papua Basin, East Indonesia. This suggestion is confirmed by cassiterite and hydrocarbon discoveries and exploitation activ- ity in the Eastern Australia and also a new seismic data of the Semai Basin a part of Southern Papua Basin. This seismic record shows a more complete stratigraphic sucession and a number of large structure traps of stratigraphic levels in which the Permian-Triassic units are included within the sequence.  

  13. Diagenesis and reservoir quality of deeply buried Permian sandstones in the Central Graben : a mineralogical, petrographical and petrophysical approach

    OpenAIRE

    2012-01-01

    The study deals with the diagenesis and reservoir quality prediction of deeply buried Rotliegend sandstone from Northern Permian Basin (NPB) in the Central Graben. Cored intervals from two wells (1/3-5 and 2/10-2) have been investigated by petrographical and petrophysical analysis. Quartz cementation is the main process destroying porosity in deeply buried quartz rich sandstone reservoirs of the North Sea. Quartz cement precipitation takes place as syntaxial overgrowths, which starts at t...

  14. Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darn Hill

    OpenAIRE

    Kiss, Gabriella; Zaccarini, Federica

    2013-01-01

    The NE Hungarian Darn Hill has a complex geology; it is built up by an accrtionary mlange complex, which contains Permian, Triassic and Jurassic sedimentary and magmatic blocks too. The succession can be well correlated with the NW Dinarides, and evidences of the different evolutionary stages of the Neotethyan Ocean (rifting, marginal basin opening, closure) were described too. Several ore indications are known from this area, but their genesis was by far not well re...

  15. Raining lead around 250mya : a smoking gun for an Australian impact origin of the Permian Extinction

    OpenAIRE

    Standard, J. C.; Angell, C. A.

    2003-01-01

    Recent documentation of extreme atmospheric sulfur and methane contents at the time of the vast Permo-Triassic (P-T) extinction makes it possible to interpret an observation that has lain unnoticed in the geological literature for 40 years. This is the finding of microscopic metallic lead tear drops in the fluvial strata of the early Triassic sandstones that overlie Permian coal beds and other sedimentary deposits in the Sydney basin of Australia. Elemental lead is almost unknown in nature, s...

  16. Permian Basin, Texas: Volume 1, Text: Final preliminary design report

    International Nuclear Information System (INIS)

    This report is a description of the preliminary design for an Exploratory Shaft Facility (ESF) at the proposed 49 acre site located 21 miles north of Hereford, Texas in Deaf Smith County. Department of Energy must conduct in situ testing at depth to ascertain the engineering and environmental suitability of the site for further consideration for nuclear waste repository development. The ESF includes the construction of two 12-ft diameter engineered shafts for accessing the bedded salt horizon to conduct in situ tests to ascertain if the site should be considered a candidate site for the first High Level Nuclear Waste Repository. This report includes pertinent engineering drawings for two shafts and all support facilities necessary for shaft construction and testing program operation. Shafts will be constructed by conventional drill-and-blast methods employing ground freezing prior to shaft construction to stabilize the existing groundwater and soil conditions at the site. A watertight liner and seal system will be employed to prevent intermingling of aquifers and provide a stable shaft throughout its design life. 38 refs., 37 figs., 14 tabs

  17. Acritarchs from the Number 5 Seam in the Permian Vryheid Formation, Witbank Coalfield, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Venter, M.E.; Cairncross, B. [Rand Afrikaans University, Auckland Park (South Africa). Dept. of Geology

    1995-12-01

    Two species of marine acritarchs, Mehlisphaeridium fibratum and Mehlisphaeridium gondwanaensis, are described from a shale parting near the top of the No. 5 Seam at Greenside Colliery, Witbank Coalfield, Republic of South Africa. The sedimentary sequence containing this coal seam consists of fine- to very coarse-grained sandstone, siltstone, shale, and coal which constitute part of the Early Permian Vryheid Formation (Karoo Supergroup). The paleoenvironmental implications of the discovery of acritarchs imply that marine conditions prevailed in the basin at the time of deposition of this particular shale unit. 56 refs., 6 figs., 1 tab.

  18. Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China

    Science.gov (United States)

    Metcalfe, I.; Foster, C. B.; Afonin, S. A.; Nicoll, R. S.; Mundil, R.; Xiaofeng, Wang; Lucas, S. G.

    2009-11-01

    Measured lithostratigraphic sections of the classic Permian-Triassic non-marine transitional sequences covering the upper Quanzijie, Wutonggou, Guodikeng and lower Jiucaiyuan Formations at Dalongkou and Lucaogou, Xinjiang Province, China are presented. These measured sections form the framework and reference sections for a range of multi-disciplinary studies of the P-T transition in this large ancient lake basin, including palynostratigraphy, vertebrate biostratigraphy, chemostratigraphy and magnetostratigraphy. The 121 m thick Wutonggou Formation at Dalongkou includes 12 sandstone units ranging in thickness from 0.5 to 10.5 m that represent cyclical coarse terrigenous input to the lake basin during the Late Permian. The rhythmically-bedded, mudstone-dominated Guodikeng Formation is 197 m and 209 m thick on the north and south limbs of the Dalongkou anticline, respectively, and 129 m thick at Lucaogou. Based on limited palynological data, the Permian-Triassic boundary was previously placed approximately 50 m below the top of this formation at Dalongkou. This boundary does not coincide with any mappable lithologic unit, such as the basal sandstones of the overlying Jiucaiyuan Formation, assigned to the Early Triassic. The presence of multiple organic ?13C-isotope excursions, mutant pollen, and multiple algal and conchostracan blooms in this formation, together with Late Permian palynomorphs, suggests that the Guodikeng Formation records multiple climatic perturbation signals representing environmental stress during the late Permian mass extinction interval. The overlap between the vertebrates Dicynodon and Lystrosaurus in the upper part of this formation, and the occurrence of late Permian spores and the latest Permian to earliest Triassic megaspore Otynisporites eotriassicus is consistent with a latest Permian age for at least part of the Guodikeng Formation. Palynostratigrahic placement of the Permian-Triassic boundary in the Junggar Basin remains problematic because key miospore taxa, such as Aratrisporites spp. are not present. Palynomorphs from the Guodikeng are assigned to two assemblages; the youngest, from the upper 100 m of the formation (and the overlying Jiucaiyuan Formation), contains both typical Permian elements and distinctive taxa that elsewhere are known from the Early Triassic of Canada, Greenland, Norway, and Russia. The latter include spores assigned to Pechorosporites disertus, Lundbladisporafoveota, Naumovaspora striata, Decussatisporites mulstrigatus and Leptolepidites jonkerii. While the presence of Devonian and Carboniferous spores and Early Permian pollen demonstrate reworking is occurring in the Guodikeng assemblages, the sometimes common occurrence of Scutasporites sp. cf. Scutasporites unicus, and other pollen, suggests that the Late Permian elements are in place, and that the upper assemblage derives from a genuine transitional flora of Early Triassic aspect. In the Junggar Basin, biostratigraphic data and magnetostratigraphic data indicate that the Permian-Triassic boundary (GSSP Level) is in the middle to upper Guodikeng Formation and perhaps as high as the formational contact with the overlying Jiucaiyuan Formation.

  19. First record of shared species of Late Permian small foraminiferids in Australia and Russia: Time correlations and plate reconstructions

    Science.gov (United States)

    Palmieri, V.; Foster, C. B.; Bondareva, E. V.

    At least 12 species of small calcareous foraminiferids known from early Late Permian assemblages from Arctic Russia and adjacent areas also occur in assemblages from the earstern Australian Ingelara Formation of the Bowen Basin (Queensland). A key species is Pseudonodosaria borealis (Gerke 1952), newly recognized in Australia. The shared species allow direct correlation with Late Permian Russian assemblages of Kazanian age. This is the first microfaunal evidence of correlative strata in Gondwana; previous chronologic ties in this region have relied on rate and geographically scattered records of ammonoids from both eastern and western Australia. Other shared foraminiferids from the Ingelara Formation include taxa described in 1914 by Tscherdynzev (Nodosaria krotovi, N. noinskii and N. netchajevi, Lenticulina (Astacolus) rotaliaeformis); and by Gerke in 1952 and 1961 (Frondicularia inflata, F. bella, F. prima, F. tijanica, F. dilemma, Tristix permiana, Nodosaria cuspidulata). A brief synonymy shows that almost all of these Russian taxa may have been recognized previously in Australian assemblages, but under different names. Pseudonodosaria serocoldensis (Crespin 1945) is considered an ancestor of P. borealis and its appearance in older assemblages in both Spitsbergen (Kungurian) and Australia (Bowen Basin, late Artinskian) suggests that similar evolutionary developments of the faunas occurred throughout a continuous seaway that connected these areas since the early Permian. Migration of these benthic forms is presumed to have occurred via deep ocean currents and suggests that either Arctic Russia (Nordvik Basin, Siberia: parts of Novaya Zemlya) and Spitsbergen were in closer proximity to Australia than is generally accepted in modern plate reconstructions for the Late Permian or, most likely, that new oceanic dispersal patterns are required to explained their distributions.

  20. Permian polar forests: deciduousness and environmental variation.

    Science.gov (United States)

    Gulbranson, E L; Isbell, J L; Taylor, E L; Ryberg, P E; Taylor, T N; Flaig, P P

    2012-11-01

    Forests are expected to expand into northern polar latitudes in the next century. However, the impact of forests at high latitudes on climate and terrestrial biogeochemical cycling is poorly understood because such forests cannot be studied in the modern. This study presents forestry and geochemical analyses of three in situ fossil forests from Late Permian strata of Antarctica, which grew at polar latitudes. Stem size measurements and stump spacing measurements indicate significant differences in forest density and canopy structure that are related to the local depositional setting. For forests closest to fluvial systems, tree density appears to decrease as the forests mature, which is the opposite trend of self-thinning observed in modern forests. We speculate that a combination of tree mortality and high disturbance created low-density mature forests without understory vegetation near Late Permian river systems. Stable carbon isotopes measured from permineralized wood in these forests demonstrate two important points: (i) recently developed techniques of high-resolution carbon isotope studies of wood and mummified wood can be applied to permineralized wood, for which much of the original organic matter has been lost and (ii) that the fossil trees maintained a deciduous habit at polar latitudes during the Late Permian. The combination of paleobotanical, sedimentologic, and paleoforestry techniques provides an unrivaled examination of the function of polar forests in deep time; and the carbon isotope geochemistry supplements this work with subannual records of carbon fixation that allows for the quantitative analysis of deciduous versus evergreen habits and environmental parameters, for example, relative humidity. PMID:22845834

  1. Triassic deformation of Permian Early Triassic arc-related sediments in the Beishan (NW China): Last pulse of the accretionary orogenesis in the southernmost Altaids

    Science.gov (United States)

    Tian, Zhonghua; Xiao, Wenjiao; Sun, Jimin; Windley, Brian F.; Glen, Richard; Han, Chunming; Zhang, Zhiyong; Zhang, Ji'en; Wan, Bo; Ao, Songjian; Song, Dongfang

    2015-11-01

    The Beishan orogenic collage (BOC) in the southernmost Altaids provides evidence of the final stage of evolution of the Paleo-Asian Ocean. However, the closure time of the Paleo-Asian Ocean in the BOC is controversial. From field mapping, and structural analysis of mesoscale, superposed folds in Early Triassic sediments in the Hongyanjing Basin in the central BOC, we define at least two phases of deformation, which we can bracket in age as end-Permian to Early-Late Triassic. The sandstones in the basin are poorly sorted with angular clasts, which indicates immaturity characteristic of proximal and rapid deposition. Geochemical data indicate that the Hongyanjing Basin probably developed in an arc-related setting near an active continental margin or mature island arc. Combined with published regional geological data, we interpret the Hongyanjing Basin as a Permian-Early Triassic inter-arc basin between the Carboniferous Mazongshan arc to the north and the Ordovician to Permian Huaniushan-Dundunshan arc to the south. In addition, the age distribution of our sediments shows that the active continental margin or continental arc on which the Hongyanjing arc-related basin sat was somehow independently distributed in the Paleo-Asian Ocean without any major contribution of provenance from the Tarim Craton and Dunhuang Block to the south and Southern Mongolia accretionary system to the north. Deformation of the superposed folds began in the end-Permian, continued in the Early Triassic, and ended before the middle Late Triassic (219 Ma). Therefore the accretionary orogenesis in the Beishan part of the southernmost Altaids was still ongoing in the early to middle Triassic, and it finished in the Late Triassic, which might have been the last pulse of the accretionary orogenesis in the southernmost Altaids. We correlate this terminal event with tectonic developments in the Kunlun and Qinling orogens in the Tethyan domain.

  2. Problems and advances in exploration: Masamba, French permian and Rirang areas(summary)

    International Nuclear Information System (INIS)

    The results of this prospection in Masamba, based on 705 stream sediments samples, 362 heavy minerals samples, 98 rock samples, and a maximum of 0.85 % uranium were particularly positive. Exploration of the Permian basin of Lodeve, near Montpellier in the south of France contains actually about 18,000 tonnes of economic uranium, which the half is already exploited, and about 750 supplementary tonnes of uranium were found and exploited. Radioactive boulders, uranium and rare earths rich, are known since 1974 in the Rirang valley, in the Kalan Basin, In 1986 and 1988 the main activity is to collect rock and ores samples for complementary studies and to test an emanometric survey.(IR)

  3. Pumping test and fluid sampling report - Mansfield No. 1 (PD-4) well, Palo Duro Basin, Texas: unanalyzed data

    International Nuclear Information System (INIS)

    This report contains pumping test and fluid sampling data collected at Mansfield No. 1 well, located in Oldham County, in the Permian Basin of Texas. These data were collected by Stone and Webster Engineering Corporation to support studies of fluid migration and age relationships in the Permian Basin. The testing and sampling took place between October 1981 and October 1982. These data are preliminary. They have been neither analyzed nor evaluated. 4 references, 8 figures, 2 tables

  4. Aeolian Delivery of Organic Matter to a Middle Permian Deepwater Ramp

    Science.gov (United States)

    Artan, S.; Herbert, B. E.; Tice, M. M.

    2010-12-01

    Windblown dust is a significant source of sediment and nutrients for many basins, but its influence on ancient basins can be difficult to detect and quantify. Quantification of organic biological markers, including biomarker ratios and n-alkane distributions, were used to demonstrate the significance of windblown dust in delivery of sediment and terrestrial organic matter to the Middle Permian Delaware Basin. Ramp siltstones of the basin have been interpreted as either the deposits of unconfined low-density turbidity currents or aeolo-marine sediments. We analyzed the organic contents of five samples of channel-confined turbiditic sandstones and siltstones and of five samples of ramp siltstones outcropping in the Guadalupe Mountains National Park, west Texas to estimate the relative proportions of terrestrial and marine organic matter in the two types of host rocks. The total organic carbon content of all samples varied from 0.1% - 2.04%. The abundunce of high molecular weight n-alkanes (n-C27 and greater) suggests that terrestrial organic matter was present in nearly all samples. Terrestrial organic content was quantified using a crossplot of pristane/n-C17 versus phytane/n-C18. Ramp siltstones showed ~10-fold greater variation in terrestrial content than did turbiditic sandstones and siltstones. This observation is more consistent with the aeolo-marine interpretation of ramp siltstones, and suggests that terrestrial organic matter was delivered to the Delaware Basin by wind transport during deposition of the Brushy Canyon Formation.

  5. Summary of the stratigraphy, sedimentology, and mineralogy of Pennsylvanian and permian rocks of Oklahoma in relation to uranium-resource potential

    International Nuclear Information System (INIS)

    Pennsylvanian-Permian strata in Oklahoma were deposited in environments which ranged from deep marine to alluvial fan. The former was most common in the Ouachita geosyncline during Early Pennsylvanian, but parts of the Anadarko basin were also relatively deep water during Middle and Late Pennsylvanian. Alluvial-fan deposits in Oklahoma are related primarily to the Amarillo-Wichita-Criner, Arbuckle, and Ouachita uplifts. As a result of erosion of the Wichita and Arbuckle areas during the Pennsylvanian-Permian, Precambrian and Cambrian felsic igneous rocks were exposed and became sources of significant quantities of feldspar in the sandstones and conglomerates, especially those on the flanks of the uplifts, and possibly sources of significant uranium concentrations in basinal waters. The Ouachita uplift, Sierra Grande-Apishapa uplift to the northwest, and possibly the Appalachian system also furnished feldspar to form the rather common subarkoses in the Upper Pennsylvanian-Permian. Feldspar is an apparent source of uranium which is present in the alluvial-fan deposits associated with the Wichita and Arbuckle uplifts, the Permian sandstones on oil-producing structures in southern Oklahoma, the lenticular sandstones on the Muenster-Waurika arch, and the tidal-flat sandstone-siltstones in western Oklahoma and possibly in north-central Oklahoma. Radioactive anomalies associated with Cherokee sandstones may be related to the Desmoinesian phosphatic shales, local depositional environments of deltaic complexes which influenced diagenetic conditions, and/or the pre-Pennsylvanian unconformity with respect to the radioactive Woodford Shale

  6. XII international congress on Carboniferous and Permian geology and stratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Contains abstracts of papers and posters presented at the 12th international congress. Various aspects of Carboniferous and Permian geology and stratigraphy throughout the world are covered, including coal seams and oil shales.

  7. Petroleum geology of the Palo Duro Basin, Texas Panhandle

    International Nuclear Information System (INIS)

    The Palo Duro Basin, Permian Basin, Texas is an asymmetric, relatively shallow, intracratonic basin in the southern Texas Panhandle filled mostly by Mississippian, Pennsylvanian, and Permian sedimentary rocks. Although deeper and prolific prolific petroleum-producing basins adjoin it on the north (Anadarko Basin), south (Midland Basin), and east (Hardeman Basin), the Palo Duro Basin has produced remarkably small amounts of oil and gas to date. This is all the more noteworthy because the sedimentary sequence and rock types of the basin are similar to those of the adjacent basins. Analyses of the stratigraphic succession and structural configuration of the Palo Duro Basin suggest that adequate reservoir rocks, top-seals, and geologic structures are present. Most of the structures formed early enough to have trapped hydrocarbons if they were migrating in the rock column. Although additional work is under way to properly address the question of the petroleum source rocks, generation, and migration, the general absence of production in the basin may relate to an overall deficiency in hydrocarbon generation within the basin. Geologic information in this report will form part of the basis for further analysis and conclusions on hydrocarbon potential in the Palo Duro Basin

  8. Catastrophic dispersion of coal fly ash into oceans during the latest Permian extinction

    Energy Technology Data Exchange (ETDEWEB)

    Grasby, S.E.; Sanei, H.; Beauchamp, B. [Geological Survey Canada Calgary, Calgary, AB (Canada)

    2011-02-15

    During the latest Permian extinction about 250 Myr ago, more than 90% of marine species went extinct, and biogeochemical cycles were disrupted globally. The cause of the disruption is unclear, but a link between the eruption of the Siberian Trap flood basalts and the extinction has been suggested on the basis of the rough coincidence of the two events. The flood basalt volcanism released CO{sub 2}. In addition, related thermal metamorphism of Siberian coal measures and organic-rich shales led to the emission of methane, which would have affected global climate and carbon cycling, according to model simulations. This scenario is supported by evidence for volcanic eruptions and gas release in the Siberian Tunguska Basin, but direct indicators of coal combustion have not been detected. Here we present analyses of terrestrial carbon in marine sediments that suggest a substantial amount of char was deposited in Permian aged rocks from the Canadian High Arctic immediately before the mass extinction. Based on the geochemistry and petrology of the char, we propose that the char was derived from the combustion of Siberian coal and organic-rich sediments by flood basalts, which was then dispersed globally. The char is remarkably similar to modern coal fly ash, which can create toxic aquatic conditions when released as slurries. We therefore speculate that the global distribution of ash could have created toxic marine conditions.

  9. Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana.

    Science.gov (United States)

    Cisneros, Juan Carlos; Abdala, Fernando; Jashashvili, Tea; de Oliveira Bueno, Ana; Dentzien-Dias, Paula

    2015-07-01

    Anomodontia was a highly successful tetrapod clade during the Permian and the Triassic. New morphological information regarding two bizarre basal anomodonts is provided and their palaeoecological significance is explored. The osteology of the recently discovered Tiarajudens eccentricus Cisneros et al. 2011, from the Brazilian Permian, is described in detail. The taxon exhibits unusual postcranial features, including the presence of gastralia. Additional preparation and computed tomography scans of the holotype of Anomocephalus africanus Modesto et al. 1999 discovered in the Karoo Basin of South Africa allow a reappraisal of this genus. Anomocephalus is similar to Tiarajudens with regard to several traits, including a battery of large, transversally expanded, palatal teeth. Molariform teeth are present in the mandible of the African taxon, providing additional insight into the function of the earliest tooth-occlusion mechanism known in therapsids. At least two waves of tooth replacement can be recognized in the palate of Anomocephalus. The outsized, blade-like caniniforms of the herbivorous Tiarajudens allow several non-exclusive ecological interpretations, among which we favour intraspecific display or combat. This behaviour was an alternative to the head-butting practised by the contemporary dinocephalians. Combat specializations that are considered typical of Cenozoic herbivores likely evolved during the Middle Permian, at the time the first communities with diverse, abundant tetrapod herbivores were being assembled. PMID:26587266

  10. Provenance of Permian Malužiná Formation sandstones (Hronicum, Western Carpathians: evidence from monazite geochronology

    Directory of Open Access Journals (Sweden)

    Vozárová Anna

    2014-10-01

    Full Text Available The Permian Malužiná Formation and the Pennsylvanian Nižná Boca Formation are Upper Paleozoic volcano- sedimentary complexes in the Hronicum nappe system. Sandstones, shales and conglomerates are the dominant lithological members of the Malužiná Formation sequence. Detrital monazites were analysed by electron microprobe, to obtain Th-U-Pb ages of the source areas. The majority of detrital monazites showed Devonian-Mississippian ages, ranging from 330 to 380 Ma with a weighted average of 351 ± 3.3 (2σ, that correspond well with the main phase of arcrelated magmatic activity in the Western Carpathians. Only a small portion of detrital monazites displayed Permian ages in the range of 250-280 Ma, with a significant maximum around 255 Ma. The weighted average corresponds to 255 ± 6.2 Ma. These monazites may have been partially derived from the synsedimentary acid volcanism that was situated on the margins of the original depositional basin. However, some of the Triassic ages (230-240 Ma, reflect, most likely, the genetic relationship with the overheating connected with Permian and subsequent Triassic extensional regime. Detrital monazite ages document the Variscan age of the source area and also reflect a gradual development of the Hronicum terrestrial rift, accompanied by the heterogeneous cooling of the lithosphere.

  11. Oceanographic restriction and deposition of the Permian Park City and Phosphoria formations, northeastern Utah and western Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Whalen, M.T. (Syracuse Univ., NY (United States))

    1991-03-01

    Detailed lithofacies analyses of the Permian Park City Formation, in northeastern Utah and western Wyoming, reveal that it was deposited in both open and restricted continental shelf and slope environments bordering the Oquirrh and Sublett basins. The Park City and the intercalated Phosphoria Formation document the interplay between carbonate, clastic, evaporite, and organic-rich sedimentation, fluctuating sea-level and bottom water oxygenated, and oceanic upwelling. New data from the Park City and Phosphoria formations imply that paleoceanographic models for the deposition of these units must be revised. Both physical and chemical restriction, resulting from paleogeographic constraints, regressive conditions, and the decay of organic matter produced in nutrient-rich upwelled waters, were important to the development of lithofacies patterns. Evidence of restriction includes massive and bedded anhydrite deposits and calcite replaced anhydrite nodules, carbonate facies with low levels of bioturbation and significant quantities of authigenic pyrite, and laminated black, organic-rich shales indicating low oxygen conditions. Park City and Phosphoria lithofacies imply that upwelling began during regression that resulted from a glacio-eustatic drop in sea level. This was accompanied by a greater pole-to-equator temperature gradient and intensified atmospheric circulation that induced eastern ocean basin upwelling. Physical and chemical restriction of marginal Permian basins was important in the development of dysaerobic to anaerobic conditions that facilitated the preservation of organic matter.

  12. Molecular distributions and geochemical implications of pyrrolic nitrogen compounds in the Permian Phosphoria Formation derived oils of Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Silliman, J.E.; Li, M.; Yao, H. [Geological Survey of Canada, Calgary, Alberta (Canada); Hwang, R. [Chevron Petroluem Technology Company, Richmond, CA (United States)

    2002-05-01

    Crude oils from the Laramide structures of Wyoming were studied with respect to their geochemical compositions. The sampling areas include the Greater Green River, Wind River and Big Horn basins, and the Casper Arch region. Based on pristane/phytane ratio and various hopane and sterane parameters, the Permian Phosphoria Formation derived oils can be readily differentiated from oils with different origins. Within the Phosphoria Formation derived oils, three subgroups can be identified using T{sub s}/(T{sub s} + T{sub m}) and diasterane/regular sterane ratios, corresponding to sources with subtle variation in organic facies and/or thermal maturity of the Phosphoria Formation. Differences in source organic input, depositional environments, and thermal maturity were observed to greatly influence the saturated hydrocarbon compositions of the Permian Phosphoria Formation derived oils. However, the distributions of pyrrolic nitrogen compounds in these oils do not appear as diagnostic as the conventional hydrocarbon parameters commonly used as indicators of these geological factors. This fact may be related to the more significant role of oil migration in the modification of pyrrolic nitrogen compound distributions in foreland basins as compared to that in rift basins. The recognition of possible source and maturity effects on pyrrolic nitrogen compounds suggests that all of these factors should be taken into proper consideration before the pyrrolic nitrogen compounds are used as indicators for any specific geological process. (Author)

  13. Nitrogen isotope chemostratigraphy across the Permian-Triassic boundary at Chaotian, Sichuan, South China

    Science.gov (United States)

    Saitoh, M.; Ueno, Y.; Nishizawa, M.; Isozaki, Y.; Takai, K.; Yao, J.; Ji, Z.

    2014-12-01

    Nitrogen isotopic compositions of upper Permian to lowermost Triassic rocks were analyzed at Chaotian, Sichuan, China, to clarify changes in the oceanic N cycle around the Permian-Triassic boundary (P-TB) including the entire Changhsingian (Late Late Permian) prior to the extinction. The analyzed ca. 40 m thick interval across the P-TB at Chaotian consists of three stratigraphic units: the upper Wujiaping Formation, the Dalong Formation, and the lowermost Feixianguan Formation, in ascending order. The upper Wujiaping Formation is composed of dark gray limestone with diverse shallow-marine fossils, such as calcareous algae, deposited on the shallow shelf. In contrast, the overlying Dalong Formation, ca. 25 m thick, is mainly composed of thinly bedded black mudstone and siliceous mudstone containing abundant radiolarians, deposited on the relatively deep slope/basin. Absence of bioturbation, substantially high TOC contents, and abundant occurrence of pyrite framboids in the Dalong Formation indicate deposition under anoxic conditions. The lowermost Feixianguan Formation is composed of thinly bedded gray marl and micritic limestone with minor fossils, deposited on the relatively shallow slope. δ15N values are in positive values around +1 to +2‰ in the upper Wujiaping Formation implying denitrification and/or anammox in the ocean. δ15N values gradually decrease to -1‰ in the lower Dalong Formation and are consistently low (around 0‰) in the middle Dalong to lowermost Feixianguan Formation. No clear δ15N shift is recognized across the extinction horizon. The consistently low δ15N values suggest the enhanced N fixation in the ocean during the Changhsingian at Chaotian. Composite profiles based on previous and the present studies demonstrate the substantial δ15N variation on a global scale in the late Permian to earliest Triassic; a systematic δ15N difference by low and high latitudes is particularly clarified. Although the enhanced N fixation throughout the Changhsingian at Chaotian was likely a regional event in northwestern South China, the composite δ15N profiles imply that the sea area in which fixed N is depleted has gradually developed worldwide in the Changhsingian, possibly acting as a prolonged stress to the shallow-marine biota.

  14. Ocean anoxia did not cause the Latest Permian Extinction

    Science.gov (United States)

    Proemse, Bernadette C.; Grasby, Stephen E.; Wieser, Michael E.; Mayer, Bernhard; Beauchamp, Benoit

    2014-05-01

    The Latest Permian Extinction (LPE, ~252 million years ago) was a turning point in the history of life on Earth with a loss of ~96% of all marine species and ~70% of all terrestrial species. While, the event undoubtedly shaped the evolution of life its cause remains enigmatic. A leading hypothesis is that the global oceans became depleted in oxygen (anoxia). In order to test this hypothesis we investigated a proxy for marine oxygen levels (molybdenum isotopic composition) in shale across the LPE horizon located on the subtropical northwest margin of Pangea at that time. We studied two sedimentary records in the Sverdrup basin, Canadian High Arctic: Buchanan Lake (eastern Axel Heiberg Island; 79° 26.1'N, 87° 12.6'W), representing a distal deep-water slope environment, and West Blind Fiord (southwest Ellesmere Island; 78° 23.9'N, 85° 57.2'W), representing a deep outer shelf environment (below storm wave base). The molybdenum isotopic composition (δ98/95Mo) of sediments has recently become a powerful tool as a paleo-oceanographic proxy of marine oxygen levels. Sample preparation was carried out in a metal-free clean room facility in the isotope laboratory of the Department of Physics and Astronomy, University of Calgary, Canada, that is supplied by HEPA-filtered air. Molybdenum isotope ratios were determined on a Thermo Scientific multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) with an uncertainty better than ±0.10o for δ98/95Mo values. Results from the Buchanan Lake section show a large shift in δ98/95Mo values from 2.02o to +2.23o at the extinction horizon, consistent with onset of euxinic conditions. In contrast, West Blind Fiord shales, representing the sub-storm wave base shelf environment, show little change in the molybdenum isotopic composition (1.34o to +0.05), indicating ongoing oxic conditions across the LPE (Proemse et al., 2013). Our results suggest that areas of the Pangea continental shelf (North West Pangea) experienced oxic conditions throughout the LPE event, while anoxic conditions developed in the deep ocean. Hence, anoxic marine waters did not extend globally onto shelf environments and as such ocean anoxia cannot have been the main driver of the extinction event. While global systems were stressed by anoxia, the anoxic conditions may better represent a symptom of Siberian Trap eruptions that had catastrophic impact on the environment, potentially through nutrient loading and deposition of toxic substances into marine and terrestrial systems. Proemse et al., 2013: Molybdenum isotopic evidence for oxic marine conditions during the latest Permian extinction. Geology 41, 967-970.

  15. An upwelling model for the Phosphoria sea: A Permian, ocean-margin sea in the northwest United States

    Science.gov (United States)

    Piper, D.Z.; Link, P.K.

    2002-01-01

    The Permian Phosphoria Formation, a petroleum source rock and world-class phosphate deposit, was deposited in an epicratonic successor basin on the western margin of North America. We calculate the seawater circulation in the basin during deposition of the lower ore zone in the Meade Peak Member from the accumulation rates of carbonate fluorapatite and trace elements. The model gives the exchange rate of water between the Phosphoria sea and the open ocean to the west in terms of an upwelling rate (84 m yr-1) and residence time (4.2 yr) of seawater in the basin. These hydrographic properties supported a mean rate of primary productivity of 0.87 g m-2 d-1 of carbon in the uppermost few tens of meters of the water column (the photic zone) and denitrifying redox conditions in the bottom water (below approximately 150 m depth). High rain rates, onto the sea floor, of the organic matter that hosted the phosphate and several trace elements contributed to the accumulation of phosphorite, chert, and black shales and mudstones. Evaporation in the Goose Egg basin to the east of the Phosphoria basin ensured the import of surface seawater from the Phosphoria sea. Budgets of water, salt, phosphate, and oxygen, plus the minor accumulation of the biomarker gammacerane, show that exchange of water between the two basins was limited, possibly by the shallow carbonate platform that separated the two basins.

  16. ?13Corg chemostratigraphy of the Permian-Triassic boundary in the Maitai Group, New Zealand : evidence for high-latitudinal methane release

    International Nuclear Information System (INIS)

    Carbon isotopic studies from marine organic matter of the Permian-Triassic Maitai Group, New Zealand, reveal a significant ?13Corg shift toward more negative values within the Little Ben Sandstone Formation. These isotopic data chemostratigraphically define the previously debated position of the Permian-Triassic boundary in the Maitai Group. The Permian-Triassic record of the Maitai Group is also important because of its high paleolatitudinal setting and the deposition at intermediate depths in the ocean (c. 400 m) within a volcanic arc-related basin. Marine Permian-Triassic strata deposited at water depths deeper than shelf areas are rare. High latitude Permian-Triassic boundary sections document a significantly larger isotopic offset across the boundary compared with lower latitude settings. Carbon isotopic values decreased rapidly by an average of 7 per thousand from homogeneous values (x-25 per thousand) in the Tramway and lower Little Ben Sandstone formation to highly fluctuating and very depleted values (x-32 per thousand) within the Little Ben Sandstone Formation. The lowermost Big Ben and Tramway Formations are considered to be Permian in age, based on their homogeneous and comparatively heavier carbon isotope values and supported by fossil atomodesmatinid bivalves. Based on the distinct ?13Corg excursion towards negative values and the concurrent onset of strong isotopic fluctuations, the Permian-Triassic boundary is placed in the lower half of the Little Ben Sandstone Formation. Very depleted ?13Corg values in the Little Ben Sandstone Formation of -38 per thousand indicate a contribution from isotopically light methane. A possible methane source is clathrates, released by large submarine slides or warming-induced melting of permafrost. The Little Ben Sandstone Formation has been interpreted as a massive event deposit from a submarine slide. This hypothetical methane release could have been in part responsible for the larger Permian-Triassic isotopic shift in high latitudes compared with low latitudes because large volumes of clathrates are trapped in continental shelves and high-latitude permafrost. (author). 89 refs., 6 figs., 1 tab

  17. Basin fill evolution and paleotectonic patterns along the Samfrau geosyncline: the Sauce Grande basin-Ventana foldbelt (Argentina) and Karoo basin-Cape foldbelt (South Africa) revisited

    Science.gov (United States)

    López-Gamundí, O. R.; Rossello, E. A.

    As integral parts of du Toit's (1927) ``Samfrau Geosyncline'', the Sauce Grande basin-Ventana foldbelt (Argentina) and Karoo basin-Cape foldbelt (South Africa) share similar paleoclimatic, paleogeographic, and paleotectonic aspects related to the Late Paleozoic tectono-magmatic activity along the Panthalassan continental margin of Gondwanaland. Late Carboniferou-earliest Permian glacial deposits were deposited in the Sauce Grande (Sauce Grande Formation) and Karoo (Dwyka Formation) basins and Falkland-Malvinas Islands (Lafonia Formation) during an initial (sag) phase of extension. The pre-breakup position of the Falkland (Malvinas) Islands on the easternmost part of the Karoo basin (immediately east of the coast of South Africa) is supported by recent paleomagnetic data, lithofacies associations, paleoice flow directions and age similarities between the Dwyka and the Lafonia glacial sequences. The desintegration of the Gondwanan Ice Sheet (GIS) triggered widespread transgressions, reflected in the stratigraphic record by the presence of inter-basinally correlatable, open marine, fine-grained deposits (Piedra Azul Formation in the Sauce Grande basin, Prince Albert Formation in the Karoo basin and Port Sussex Formation in the Falkland Islands) capping glacial marine sediments. These early postglacial transgressive deposits, characterised by fossils of the Eurydesma fauna and Glossopteris flora, represent the maximum flooding of the basins. Cratonward foreland subsidence was triggered by the San Rafael orogeny (ca. 270 Ma) in Argentina and propogated along the Gondwanan margin. This subsidence phase generated sufficient space to accommodate thick synorogenic sequences derived from the orogenic flanks of the Sauce Grande and Karoo basins. Compositionally, the initial extensional phase of these basins was characterized by quartz-rich, craton-derived detritus and was followed by a compressional (foreland) phase characterized by a paleocurrent reversal and dominance of arc/foldbelt-derived material. In the Sauce Grande basin, tuffs are interbedded in the upper half of the synorogenic, foldbelt-derived Tunas Formation (Early-early Late? Permian). Likewise, the first widespread appearance of tuffs in the Karoo basin is in the Whitehill Formation, of late Early Permian (260 Ma) age. Silicic volcanism along the Andes and Patagonia (Choiyoi magmatic province) peaked between the late Early Permian and Late Permian. A link between these volcanics and the consanguineous airborne tuffs present in the Sauce Grande and Karoo basins is suggested on the basis of their similar compositions and ages.

  18. Permian paleoclimate data from fluid inclusions in halite

    Science.gov (United States)

    Benison, K.C.; Goldstein, R.H.

    1999-01-01

    This study has yielded surface water paleotemperatures from primary fluid inclusions in mid Permian Nippewalla Group halite from western Kansas. A 'cooling nucleation' method is used to generate vapor bubbles in originally all-liquid primary inclusions. Then, surface water paleotemperatures are obtained by measuring temperatures of homogenization to liquid. Homogenization temperatures ranged from 21??C to 50??C and are consistent along individual fluid inclusion assemblages, indicating that the fluid inclusions have not been altered by thermal reequilibration. Homogenization temperatures show a range of up to 26??C from base to top of individual cloudy chevron growth bands. Petrographic and fluid inclusion evidence indicate that no significant pressure correction is needed for the homogenization temperature data. We interpret these homogenization temperatures to represent shallow surface water paleotemperatures. The range in temperatures from base to top of single chevron bands may reflect daily temperatures variations. These Permian surface water temperatures fall within the same range as some modern evaporative surface waters, suggesting that this Permian environment may have been relatively similar to its modern counterparts. Shallow surface water temperatures in evaporative settings correspond closely to local air temperatures. Therefore, the Permian surface water temperatures determined in this study may be considered proxies for local Permian air temperatures.

  19. Anomalous carbonate precipitates: is the Precambrian the key to the Permian?

    Science.gov (United States)

    Grotzinger, J. P.; Knoll, A. H.

    1995-01-01

    Late Permian reefs of the Capitan complex, west Texas; the Magnesian Limestone, England; Chuenmuping reef, south China; and elsewhere contain anomalously large volumes of aragonite and calcite marine cements and sea-floor crusts, as well as abundant microbial precipitates. These components strongly influenced reef growth and may have been responsible for the construction of rigid, open reefal frames in which bryozoans and sponges became encrusted and structurally reinforced. In some cases, such as the upper biostrome of the Magnesian Limestone, precipitated microbialites and inorganic crusts were the primary constituents of the reef core. These microbial and inorganic reefs do not have modern marine counterparts; on the contrary, their textures and genesis are best understood through comparison with the older rock record, particularly that of the early Precambrian. Early Precambrian reefal facies are interpreted to have formed in a stratified ocean with anoxic deep waters enriched in carbonate alkalinity. Upwelling mixed deep and surface waters, resulting in massive seafloor precipitation of aragonite and calcite. During Mesoproterozoic and early Neoproterozoic time, the ocean became more fully oxidized, and seafloor carbonate precipitation was significantly reduced. However, during the late Neoproterozoic, sizeable volumes of deep ocean water once again became anoxic for protracted intervals; the distinctive "cap carbonates" found above Neoproterozoic tillites attest to renewed upwelling of anoxic bottom water enriched in carbonate alkalinity and 12C. Anomalous late Permian seafloor precipitates are interpreted as the product, at least in part, of similar processes. Massive carbonate precipitation was favored by: 1) reduced shelf space for carbonate precipitation, 2) increased flux of Ca to the oceans during increased continental erosion, 3) deep basinal anoxia that generated upwelling waters with elevated alkalinities, and 4) further evolution of ocean water in the restricted Delaware, Zechstein, and other basins. Temporal coincidence of these processes resulted in surface seawater that was greatly supersaturated by Phanerozoic standards and whose only precedents occurred in Precambrian oceans.

  20. Palynological records of the Early Permian icehouse-greenhouse transition (Ecca Group, South Africa)

    Science.gov (United States)

    Götz, Annette E.; Ruckwied, Katrin

    2013-04-01

    The Permian coal-bearing formations of the South African Karoo Basin play a crucial role in the study and interpretation of Gondwana's climate history and biodiversity in this time of major global changes in terrestrial and marine ecosystems. Here, we report on new palynological data from the No. 2 coal seam of the northern Witbank coal field, documenting the switch from Icehouse to Greenhouse conditions in the Early Permian (Lower Ecca Group). The studied postglacial fluvio-deltaic deposits of a highly proximal setting comprise coarse-grained to pebbly sandstones, partially with an abrupt upward transition into fine-grained sediments and coal, trough cross-stratified medium- to coarse-grained sandstones, and horizontally laminated fine- to medium-grained sandstones and siltstones. The sedimentary organic matter content clearly documents stratal changes in the palynomorph assemblage and variations in the amount and in the type, size and shape of plant debris. Generally, palynofacies is characterized by a high amount of opaque phytoclasts. Amorphous organic matter is characteristic of laminated siltstones and coals. The palynological record indicates a cold climate, fern wetland community, characteristic of lowland alluvial plains, and an upland conifer community in the lower part of the coal seam. Up section, these communities are replaced by a cool-temperate cycad-like lowland vegetation and gymnospermous upland flora. Ongoing studies focus on the cyclic architecture of the coal seam, applying palynofacies analysis as high-resolution correlation tool with respect to decipher signatures of prominent climate amelioration on basin-wide, intercontinental and intra-Gondwanic scales.

  1. The Permian mega floras of Uruguay.A synthesis

    International Nuclear Information System (INIS)

    The Permian megafloras of Uruguay. A synthesis. An analysis of the impression and fossil wood floras from the Permian of Uruguay is given through a series of Tables. These show : (1) the list of taxa, (2) anatomical characters of the woods, (3) data on the microfloral associations, (4) paleoenvironmental information and (5) comparisons with contemporaneous Gondwana floras. The evolutionary degree of the woods is briefly analyzed where they correspond to the so-called ''transition xilotaphofloras'' as they present typical Paleozoic anatomical characters but with secondary xylem of more advanced characteristics. (author)

  2. Spectral gamma-ray signature of fluvial deposits: a case study from the Late Permian Rio do Rasto Formation, Parana Basin, Brazil; Assinatura gamaespectrometrica de depositos fluviais: estudo de caso na Formacao do Rio do Rasto, Permiano Superior da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Sowek, Guilherme Arruda, E-mail: arruda@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Programa de Pos-graduacao em Geologia; Ferreira, Francisco Jose Fonseca; Vesely, Fernando Farias, E-mail: francisco.ferreira@ufpr.br, E-mail: vesely@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Setor de Ciencias da Terra; Berton, Fabio, E-mail: fabioberton1@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2013-09-15

    Fluvial channel-fill deposits form highly heterogeneous hydrocarbon reservoirs. The study of outcrop analogs can help in the characterization of these heterogeneities, which are usually not detected by subsurface geophysical methods. The aim of this research is to compare outcrop log signatures with grain size trends and depositional elements of the fluvial deposits of the Late Permian Rio do Rasto Formation. A series of vertical gamma-ray logs were assembled in two outcrops in order to: 1) characterize log-facies in a succession composed of alternated flood plain, channel fill and eolian strata; 2) define within-channel spectral gamma-ray variability of a mixed-load composite point bar deposit and its relationship with grain size trends and lithofacies; 3) correlate log signatures observed in the outcrop sections with deep exploratory wells drilled several tens of kilometers from the study area. The results of this study show that gamma-ray logs have good correlation with grain size trends and that different depositional elements have distinct signatures. On the other hand, point bar deposits exhibit strong lateral changes in log signature due variations in grain size and mud content within lateral accretion strata. Although frequent, the classic bell-shaped log motif was not always detected, which means that the amount of fluvial channel-fill deposits recognized in subsurface can be underestimated. Similar log signatures were detected in the boreholes, at least in the closest ones, helping in paleoenvironmental interpretation in the subsurface. (author)

  3. Carboniferous and permian noeggerathialean plants and their spores; preliminary report

    Czech Academy of Sciences Publication Activity Database

    Bek, Jiří; Wang, J.

    Prague : National Museum, 2006. ISBN 80-7036-198-0. [European Palaeobotany- Palynology Conference /7./. 06.09.2006-11.09.2006, Prague] R&D Projects: GA AV ČR IAA3013902 Institutional research plan: CEZ:AV0Z30130516 Keywords : Noeggerathiales * in situ spores * Palaeozoic-Permian Subject RIV: EF - Botanics

  4. Gas hydrate contribution to Late Permian global warming

    Czech Academy of Sciences Publication Activity Database

    Majorowicz, J.; Grasby, S. E.; Šafanda, Jan; Beauchamp, B.

    2014-01-01

    Roč. 393, May (2014), s. 243-253. ISSN 0012-821X Institutional support: RVO:67985530 Keywords : Latest Permian extinction * gas hydrates * carbon isotope shift Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 4.734, year: 2014

  5. Geology and total petroleum systems of the Paradox Basin, Utah, Colorado, New Mexico, and Arizona

    Science.gov (United States)

    Whidden, Katherine J.; Lillis, Paul G.; Anna, Lawrence O.; Pearson, Krystal M.; Dubiel, Russell F.

    2014-01-01

    The geological model for the development of the Total Petroleum Systems (TPSs) within the Paradox Basin formed the foundation of the recent U.S. Geological Survey assessment of undiscovered, technically recoverable resources in the basin. Five TPSs were defined, of which three have known production and two are hypothetical. These TPSs are based on geologic elements of the basin and the potential development of Precambrian, Devonian, Pennsylvanian, Permian-Mississippian, and Cretaceous source rock intervals.

  6. Ground-water hydraulics of the deep-basin brine aquifer, Palo Duro Basin, Texas panhandle

    International Nuclear Information System (INIS)

    The Deep-Basin Brine aquifer of the Palo Duro Basin (Texas Panhandle) underlies thick Permian bedded evaporites that are being evaluated as a potential high-level nuclear waste isolation repository. Potentiometric surface maps of 5 units of the Deep-Basin Brine aquifer were drawn using drill-stem test (DST) pressure data, which were analyzed by a geostatistical technique (kriging) to smooth the large variation in the data. The potentiometric surface maps indicate that the Deep-Basin Brine aquifer could be conceptually modeled as 5 aquifer units; a Lower Permian (Wolfcamp) aquifer, upper and lower Pennsylvanian aquifers, a pre-Pennsylvanian aquifer, and a Pennsylvanian to Wolfcampian granite-wash aquifer. The hydraulic head maps indicate that ground-water flow in each of the units is west to east with a minor northerly component near the Amarillo Uplift, the northern structural boundary of the basin. The Wolfcamp potentiometric surface indicates the strongest component of northerly flow. Inferred flow direction in Pennsylvanian aquifers is easterly, and in the pre-Pennsylvanian aquifer near its pinch-out in the basin center, flow is inferred to be to the north. In the granite-wash aquifer the inferred flow direction is east across the northern edge of the basin and southeast along the Amarillo Uplift

  7. Lipid Biomarker Records Across the Permian-Triassic Boundary from Kap Stosch, Greenland

    Science.gov (United States)

    Hays, L. E.; Love, G. D.; Foster, C. B.; Grice, K.; Summons, R. E.

    2006-12-01

    The end-Permian extinction was the most severe in the past 500 million years of the Earth's history and evidence that an oceanic anoxic event (OAE) occurred contemporaneously has been presented previously [1,2]. OAEs have, therefore, been proposed as responsible for the mass mortality, and if the anoxic ocean was also euxinic, the release of hydrogen sulfide during upwelling and/or transgression provides an extinction agent in the ocean as well as on land. Chlorobiaceae, as indicators of photic zone euxinia (PZE), utilize hydrogen sulfide as an electron donor for anoxygenic photosynthesis. The detection of isorenieratane and a series of short-chain monoaromatic aryl isoprenoids, biomarkers for Chlorobiaceae, in sediments indicates the presence of hydrogen sulfide in the photic zone of the water column during sediment deposition. The Kap Stosch area in Eastern Greenland was identified as a Permian-Triassic boundary (PTB) outcrop of homogeneous shale, silty shale, and siltstone facies [3]. Another late Permian section in Eastern Greenland, the Ravnefjeld Formation, has framboidal pyrites indicative of sulfidic deep water [4]. A sample suite from the Kap Stosch region was studied using standard organic geochemistry methods including stable isotopic analyses of organic carbon, Rock-Eval pyrolysis, and biomarker hydrocarbon analysis. Aryl isoprenoids, including isorenieratane, were present in all samples studied and the concentrations were observed to fluctuate in tandem with TOC, similar to other Mesozoic OAEs. The molecular ratios of pristane/phytane and hopanes/steranes as well as the 2-methyl-hopane index (2-MHI) fluctuated dramatically through this section as they do at the type section at Meishan and in the Perth Basin [5]. The 2-MHI shows an inverse pattern to the total aryl isoprenoids, perhaps indicative of instability in the form of primary productivity in the water column during euxinic episodes. This can result in nitrogen limitation and a competitive advantage of cyanobacteria over microalgae for nutrient resources [6]. Overall, the biomarker patterns in these samples indicate the presence of PZE at this location leading up to and continuing through the PTB. 1. Isozaki Y., 1997. Science 276, 235. 2. Wignall P. and R. Twichett, 1996. Science 272, 1155. 3. Teichert C. and B. Kummel, 1972. Bull. Canadian Petrol. Geol. 20, 659. 4. Nielsen J. and Y. Shen, 2004. Geology 32, 1037. 5. Grice K., et al., 2005. Science 307, 706. 6. Kuypers M., et al., 2004. Geology 32, 853.

  8. Parent brine of the castile evaporites (Upper Permian), Texas and New Mexico

    Science.gov (United States)

    Kirkland, Douglas W.; Denison, Rodger E.; Dean, Walter E.

    2000-01-01

    The Upper Permian (lower Ochoan) Castile Formation is a major evaporite sequence (∼10,000 km3) of calcite, anhydrite, and halite in west Texas and southeastern New Mexico. Traditionally the Castile brine has been considered to have been derived from seawater. This tradition has recently been challenged by two versions of the closed-basin drawdown model. They call for deposition from a mixed brine, in part marine and in large part nonmarine. They propose drawdown of as much as 500 m to form a major sink for ground water issuing from the surrounding Capitan reef complex. A large fraction of the solute in the brine body is inferred to have been recycled from older Permian evaporites on the surrounding shelf. Strontium-isotope analyses show no evidence that meteoric ground water was contributed to the Castile brine. From a stratigraphic, geographic, and lithologic array of 65 samples of anhydrite, gypsum, and calcite, 59 have an 87Sr/86Sr ratio of 0.706923 (Δsw of -225.0), a ratio that is the same as that of strontium in early Ochoan ocean water. If considerable (>15%) influx of meteoric water had occurred, enough continental strontium would have been introduced to have resulted in higher ratios. Low bromide values (20-40 ppm) in Castile halite, which have been used to argue for meteoric influx and for recycled salt, probably resulted from diagenesis. During shallow burial by halite, centimeter-size, bottom-grown crystals of gypsum were altered to nodular anhydrite. The rising water of dehydration caused the halite to recrystallize. During the recrystallization, some bromide was expelled. Despite the large volume of water that evaporated annually from its surface (∼52 km3/yr, assuming an evaporation rate of 2 m/yr), the Castile brine body never completely desiccated. The surrounding shelf was flat, hot, and generally dry. It probably could not have supplied a significant volume of meteoric spring water to the basin over tens of thousands of years. More likely, during the entire history of the evaporite sequence, influx was dominantly marine. Marine ground water flowed through the Capitan Formation into the evaporite basin along its southern and possibly western margin probably with a rate of flow that was usually fast enough to prevent major drawdown of the brine surface.

  9. Permian Triassic palynofloral transition in Chintalapudi area, Godavari Graben, Andhra Pradesh, India

    Indian Academy of Sciences (India)

    Neerja Jha; M Basava Chary; Neha Aggarwal

    2012-10-01

    The entire 606 m-thick sedimentary sequence in borecore MCP-7 from Chintalapudi area, Chintalapudi sub-basin has been lithologically designated as Kamthi Formation. However, the palynological investigation revealed five distinct palynoassemblages, which essentially fall under two groups, one group (Palynoassemblage-I, II and III) having dominance of striate disaccates along with presence of some stratigraphically significant taxa, belongs to Late Permian (Raniganj) palynoflora, while the other group (Palynoassemblages IV and V) shows sharp decline in percentage of characteristic taxa of first group, i.e., striate disaccates, and consequent rise or dominance of taeniate and cingulate cavate spores, belongs to Early Triassic (Panchet) palynoflora. Palynoassemblage-I, II and III (Group I) are characterized by dominance of striate disaccates chiefly, Striatopodocarpites spp. and Faunipollenites spp. Along with presence of rare but stratigraphically significant taxa, viz., Gondisporites raniganjensis, Falcisporites nuthaliensis, Klausipollenites schaubergeri, Chordasporites sp., Striomonosaccites, ovatus, Crescentipollenites multistriatus, Verticipollenites debiles, Strotersporites crassiletus, Guttulapollenites hannonicus, G. gondwanensis, Hamiapollenites insolitus, Corisaccites alutus, Lunatisporites ovatus, Weylandites spp. and Vitreisporites pallidus. Palynoassemblage-I is distinguished by significant presence of Densipollenites spp. while Palynoassemblage-II shows significant presence of Crescentipollenites spp. and Palynoassemblage-III differs from the above two assemblages in having significant presence of Guttulapollenites hannonicus. Palynoassemblage-IV (Group II) is characterized by high percentage of taeniate disaccates chiefly Lunatisporites spp., while Palynoassemblage-V (Group II) is characterized by cingulate-cavate trilete spores chiefly, Lundbladispora spp. and Densoisporites spp. Striate disaccates show a sharp decline in these two assemblages. In Chintalapudi area Late Permian and Early Triassic palynoflora has been recorded for the first time indicating existence of Raniganj and Panchet sediments as well. The study further supports the earlier studies of Jha and Srivastava (1996) that Kamthi Formation represents Early Triassic (=Panchet Formation) overlying Raniganj equivalent sediments with a gradational contact.

  10. Sedimentology and stratigraphic architecture of the Late Permian Betts Creek Beds, Queensland, Australia

    Science.gov (United States)

    Allen, Jonathan P.; Fielding, Christopher R.

    2007-11-01

    The Late Permian Betts Creek Beds form a succession of coal-bearing alluvial-coastal plain sediments in a basin marginal setting within the northeastern Galilee Basin, Queensland, Australia. The unit is ˜ 50-60 m in thickness at Porcupine Creek National Park where outcrop is laterally continuous for several kilometers. Eight facies have been identified within the formation and can be grouped into 2 facies associations: (A) channel deposits and (B) floodbasin deposits. The channel association consists of conglomerate (A1) and trough cross-bedded multistorey sandstone facies (A2), both interpreted as deposits of low-sinuosity river systems, tidally influenced fluvial channels (A3), interbedded sandstone and siltstone (A4) interpreted as the abandonment fill of the alluvial systems, and diamictite (A5) interpreted as debris flows. The floodbasin facies association is composed of sandy siltstone (B1; proximal-distal floodbasin), carbonaceous siltstone (B2; mire), and bioturbated siltstone (B3; estuarine) facies. The overall sediment body architecture can be resolved into 6 unconformity-bounded cycles interpreted as sequences in the genetic sense, which are sheet-like in geometry and, in general, consist of amalgamated multistorey, multilateral braided fluvial deposits at the base overlain by extensive sheet-like overbank mudstones, carbonaceous shales, and coals. Sea-level change is interpreted as the primary control on the sequence architecture of the formation, while the internal stratigraphic architecture, however, varies between sequences and is a function of a combination of sea level, tectonic, and autogenic controls.

  11. Paleotectonic reconstruction of the central Tethys domain since the Late Permian: the DARIUS Maps

    Science.gov (United States)

    Barrier, Eric; Vrielynck, Bruno; Brunet, Marie-Françoise; Robertson, Alastair; Sosson, Marc; Zanchi, Andrea; Brouillet, Jean-françois; Kaveh, Frédéric

    2014-05-01

    The DARIUS Programme is a 4-years consortium sponsored by Major Oil Companies and Research Organizations. DARIUS drive together a group of academic scientific teams whose expertise includes several domains of tectonics (structural analysis, paleotectonic reconstructions, basin analysis, subsidence modeling), stratigraphy (paleontology, sequence stratigraphy, organic matter analysis), modeling, kinematics, and geophysics. The main objective is characterizing the tecto-stratigraphic evolution of a vast domain around Central Tethys extending from Black-Sea Anatolia in the west to western Central Asia in the east. One of the final products of the DARIUS Programme is a set of 20 paleotectonic maps of the DARIUS domain ranging in age from the Late Permian to Pliocene. In these maps we propose paleotectonic reconstructions of the south-central Eurasian and north African-Arabian plates starting after the Late Paleozoic Hercynian orogeny. These palinspastic maps are based on an up-to-date kinematics reconstruction of the African, Indian and Arabian plates with respect to Eurasia. For each map we depict the major tectonic-geodynamic features (i.e. the rifts, different types of basins, major orogens and fold belts, main transcurrent faults, subduction zones, accretionary prisms...) as well as the main paleofacies. Our reconstructions are based on an accurate timing of the tectonic events that have succeeded in the central Tethyan margins since the Late Paleozoic. These events include both the main orogenies resulting from collisions of major plates and blocks and the series of openings and inversions of basins that developed in the northern and southern Tethyan margins between the main collisions. Following the Variscian orogeny that ended in the Early Permian, the Mid to Late Triassic Eo- and Mid-Cimmerian orogenies are related to the collision of Gondwanian blocs with the Pangea margin after closure of the Paleo-Tethys oceanic domain. Then, for the rest of the Mesozoic and Early Cenozoic mainly developed: (1) a northward subduction of the Neo-Tethys oceanic lithosphere beneath the southern Eurasian margin, and (2) a passive margin bordering the African-Arabian plate to the North. In this latter plate, riftings and basins developed until Late Cretaceous when the Neo-tethys ophiolites were obducted onto the Arabian passive margin. On the contrary, the North Tethys active margin recorded a complex tectonic evolution characterized by: (1) the opening of back-arc and marginal basins during the Triassic to Early-Mid Cretaceous times (e.g. Black Sea, Great Caucasus, South Caspian, Central Iran, Amu-Darya and Tadjik basins), and (2) regional compressions associated with the inversions and/or closure of these basins. The main inversions are Mid-Jurassic, Early Cretaceous, and uppermost Cretaceous-Paleogene in age. The first collision between major plates began in the Early Eocene when the northern Indian and southern Eurasian margins collided. The second one is the Arabia-Eurasia collision, which initiated in the Late Eocene. Both developed until Present, originating the Himalaya and Tien-Shan ranges and the Alpine chains respectively. After the complete closure of the remnant Tethyan oceanic domain, at the beginning of Neogene, the continent-continent collisions were developing all along the southern Eurasian active margin.

  12. Gondwana basins and their coal resources in Bangladesh

    International Nuclear Information System (INIS)

    Fault bounded five Gondwana basins have been discovered in the north western Bangladesh. Among these basins show considerable amount of coal deposits. The Gondwana rocks are highly formed during the Permo-carboniferous diastrophism and later on acquired dynamic characters. In almost all basins, the Permian rocks overlie the Precambrian basement and underlie either the Tertiary or the Cretaceous sediments, structural, stratigraphic, and depositional history of these basins is more or less similar. The sedimentary sequences are composed of light to dark gray, fine to very coarse grained, sub angular to sub rounded felspathic sandstone, dark grey carbonaceous shale and sandstone, variegated conglomerate and thick coal seams (single seam max. 42.38m). The rocks are often alternated and bear the characteristics of cyclic sedimentation. The depositional environments varied from restricted drainage to open fluvial dominated low to moderate sinuous drainage system. The coal bearing basins were flanked by vegetated and swampy over bank. Age of these coals is suggested to be the late permian. Proved and probable reserves of coal in Jamalganj-Paharpur basin are 670 and 1,460 million metric tons, in Barapukuria basin 303 and 3899 million metric tons; in Barapukuria basin 303 and 389 million metric tons; and in Khalaspir basin 143 and 685 million metric tons respectively. The coal is high volatile, low sulphur, bituminous type. It can be used for different forms of thermal conversion. (author)

  13. Palynostratigraphy and age correlation of subsurface strata within the sub-basins in Singrauli Gondwana Basin, India

    Indian Academy of Sciences (India)

    Vijaya; Archana Tripathi; A Roy; Saibal Mitra

    2012-08-01

    In the study area, changes in the facies of sediments and spores-pollen content appear to be all causally linked with the depositional set-up. Here, the qualitative and quantitative changes observed in the spores-pollen assemblages have led to recognize 10 Assemblage-zones representing from that earliest Permian in the Talchir Formation to that latest Late Triassic in the Parsora Formation. These sporespollen assemblages are obtained from the wider parts in the Singrauli Gondwana Basin that includes (i) Moher sub-basin (boreholes SSM-1 and 2), and (ii) Singrauli main sub-basin (boreholes SMJS-2, 3 and SMBS-1). The progressively changing spores-pollen content infer the hiatuses of varied magnitude in the sedimentary sequences during the extended time interval of Permian and Triassic.

  14. Petrified peat from a permian coal bed in Antarctica

    Science.gov (United States)

    Schopf, J.M.

    1970-01-01

    Petrified plant remains that composed a Permian peat deposit occur at a coal horizon in a local area of Mount Augusta near the Beardmore Glacier in Antarctica. This discovery is the first in the entire Gondwana area that yields plant materials as exquisitely preserved as the materials of the well-known coal-ball localities of the Northern Hemisphere. A sampling of anatomical details is illustrated.

  15. Oceanic Anoxia and the End Permian Mass Extinction

    Science.gov (United States)

    Wignall; Twitchett

    1996-05-24

    Data on rocks from Spitsbergen and the equatorial sections of Italy and Slovenia indicate that the world's oceans became anoxic at both low and high paleolatitudes in the Late Permian. Such conditions may have been responsible for the mass extinction at this time. This event affected a wide range of shelf depths and extended into shallow water well above the storm wave base. PMID:8662450

  16. SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism Geocronología SHRIMP del basamento de la Cuenca de Magallanes, Tierra del Fuego: plutonismo Cámbrico y metamorfismo Pérmico de alto grado

    OpenAIRE

    Francisco Hervé; Mauricio Calderón; C. Mark Fanning; Stefan Kraus; Pankhurst, Robert J.

    2010-01-01

    Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (523±7 Ma, 522±6 Ma and 538±6 Ma), interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inh...

  17. The permian sequence reconstructed from reworked carbonate clasts in the Batain Plain (northeastern Oman)

    Science.gov (United States)

    Hauser, Marc; Vachard, Daniel; Martini, Rossana; Matter, Albert; Peters, Tjerk; Zaninetti, Louisette

    2000-02-01

    An almost complete Permian sequence is reworked in the conglomerates and sandstones of the Aseelah Unit forming the lower part of the Batain Croup. This series of Late Permian to Earliest Triassic age overlies conformably the Qarari Unit, dated as Middle Permian by ammonoids. The bioclastic limestone pebbles and boulders deposited on shallow marine-shelf environments yield diversified assemblages of dasyclads, red algae, fusulinids and smaller foraminifers, indicating Yakhtashian, Bolorian, Kubergandian, Early Murgabian, Midian and Dzhulfian ages (systematic work in progress).

  18. The Triassic dicynodont Kombuisia (Synapsida, Anomodontia) from Antarctica, a refuge from the terrestrial Permian-Triassic mass extinction

    Science.gov (United States)

    Fröbisch, Jörg; Angielczyk, Kenneth D.; Sidor, Christian A.

    2010-02-01

    Fossils from the central Transantarctic Mountains in Antarctica are referred to a new species of the Triassic genus Kombuisia, one of four dicynodont lineages known to survive the end-Permian mass extinction. The specimens show a unique combination of characters only present in this genus, but the new species can be distinguished from the type species of the genus, Kombuisia frerensis, by the presence of a reduced but slit-like pineal foramen and the lack of contact between the postorbitals. Although incomplete, the Antarctic specimens are significant because Kombuisia was previously known only from the South African Karoo Basin and the new specimens extend the taxon’s biogeographic range to a wider portion of southern Pangaea. In addition, the new finds extend the known stratigraphic range of Kombuisia from the Middle Triassic subzone B of the Cynognathus Assemblage Zone into rocks that are equivalent in age to the Lower Triassic Lystrosaurus Assemblage Zone, shortening the proposed ghost lineage of this taxon. Most importantly, the occurrence of Kombuisia and Lystrosaurus mccaigi in the Lower Triassic of Antarctica suggests that this area served as a refuge from some of the effects of the end-Permian extinction. The composition of the lower Fremouw Formation fauna implies a community structure similar to that of the ecologically anomalous Lystrosaurus Assemblage Zone of South Africa, providing additional evidence for widespread ecological disturbance in the extinction’s aftermath.

  19. Palynological evidence for the age of the Permian Karoo coal deposits near Vereeniging, northern Orange Free State, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Millsteed, B.D. (Geological Survey of South Africa, Pretoria (South Africa))

    1994-03-01

    Palynological investigations of the coal-bearing strata of the Vereeniging area, Orange Free State Coalfield, have led to an interpretation of the age of the northern coal measures of the Main Karoo Basin. The sequence, part of the Vryheid Formation, is composed of three major coal seams, these being the Bottom, Middle, and Top Seams. The well-preserved palynoflora obtained from the sequence allows correlation of the Vereeniging coal seams with the coal-bearing sequence of the Witbank/Highveld coalfields. The age determination of the sequence is dependent upon comparison of the ranges of [ital Granulatisporites trisinus] Balme and Hennelly, 1956, [ital Pseudoreticulatispora pseudoreticulata] (Balme and Hennelly) Bharadwaj and Srivastava, 1969 and [ital Praecolpatites sinuosus] (Balme and Hennelly) Bharadwaj and Srivastava, 1969 with their distribution in the better understood Australian Permian sequences. An Artinskian (Aktastinian to lower Baigendzhinian) age for the Vryheid Formation is suggested. The determination of the age and correlation of these strata is important as they are associated with historically significant plant macrofossil deposits, which were important in the development of the Permian chronostratigraphy of South Africa and Gondwana. 48 refs., 4 figs.

  20. FUSULINID SEQUENCE EVOLUTION AND SEQUENCE EXTINCTIONIN WOLFCAMPIAN AND LEONARDIAN SERIES (LOWER PERMIAN,GLASS MOUNTAINS, WEST TEXAS

    Directory of Open Access Journals (Sweden)

    CHARLES A. ROSS

    2003-07-01

    Full Text Available In the Permian Wolfcampian and Leonardian Series of West Texas, sequence evolution and sequence extinction record the appearance and disappearance of morphological species in stratigraphic successions that show repeated sea level fluctuations and associated depositional hiatuses. The lower Wolfcampian Nealian Stage includes 16 relatively short term sea-level fluctuations (fourth-order depositional sequences and contains a diverse fusulinid fauna of more than 39 species and eight genera.  Most Nealian species range through three or four fourth-order cycles before becoming extinct and none extends into the overlying upper Wolfcampian Lenoxian Stage.  The succeeding Lenox Hills Formation overlies a tectonic unconformity (and hiatus and includes three third-order depositional sequences.  Four Lenoxian species are restricted to the lower sequence, 16 to the middle sequence, and six to the upper sequence. In the Leonardian Series, at the base, the Hessian Stage includes seven third-order depositional sequences and numerous minor fourth-order and smaller parasequences.  Hessian carbonate platform facies have low fusulinid species diversity and high abundances.  The lower four Hessian lowstand clastic wedges of the shelf margin and basin include at least six species of schwagerinids.  The three upper wedges include only three species of Parafusulina. The Cathedralian (upper Stage has one main third-order depositional sequence, and perhaps a second, which is mostly missing on the platform below the Mid-Permian unconformity below the Middle Permian Guadalupian Series. Suggested correlations of the Wolfcampian and Leonardian with the Tethyan succession in Darvas and the Pamirs of Middle Asia place the Nealian as equivalent to the Asselian and Sakmarian. The Lenoxian is probably equivalent to the lower and middle parts of the Yakhtashian.  The Hessian is equivalent to the upper part of the Yakhtashian and the Bolorian. The Cathedralian seems to be equivalent to the Kubergandian. There is little evidence that the upper part of the Kubergandian extends higher into the Middle Permian Roadian Stage. 

  1. Depositional evolution of permo-triassic karoo basins in Tanzania with reference to their economic potential

    Science.gov (United States)

    Kreuser, T.; Wopfner, H.; Kaaya, C. Z.; Markwort, S.; Semkiwa, P. M.; Aslandis, P.

    The Karoo basins of Tanzania contain in excess of 3000 m of sediments which were preserved in several NNE-NE striking half grabens or other structural basin conditions. They are all intracratonic basins, most of which filled with terrestrial sediments. In some basins situated nearer the coastal region short marine incursions occurred in the Late Permian. The Ruhuhu Rasin in SW Tanzania provides a typical depositional sequence of a Karoo basin in eastern Africa. Sedimentation commenced with glacigene deposits. These are of Late Carboniferous to Early Permian age and may be equated with other glacial successions in Africa and elsewhere in Gondwana. The glacigene beds are overlain by fluvial-deltaic coal-bearing deposits succeeded by arkoses and continental red beds. A transitionary formation of carbonaceous shales with impure coals gradually develops into thick lacustrine series which are topped by Late Permian bone bearing beds. The Triassic is characterized by a very thick fluvio-deltaic succession of siliciclastics resting with regional unconformity on the Permian. This Early Triassic sequence exhibits well-developed repetitive depositional cycles. Current azimuth measurements indicate fluctuating flow regimes in the Early Permian but relative stable source areas to the west of the basin later on. The depositional evolution of the Ruhuhu Basin is controlled by both tectonic and climatic factors. During basin evolution important energy resources were deposited such as considerable reserves of coal and source rocks of moderate potential for hydrocarbon generation. Uranium enrichment is observed in the Triassic arenaceous series where diagenetic alterations and subsequent cementation processes led to the formation of laumontite. Post Karoo dykes and plugs had only local effect on thermal evolution of potential source rocks. Enrichments of elements, i.e., Nb, Zr, Rb, Cr, and V present additional exploration targets. A comparison with the Karoo basins of the coastal region indicates possible lithological correlation by the application of sequence stratigraphy. No early Permian deposits are exposed in the coastal Karoo basins but their existence within the deeper parts of these basins cannot be ruled out. There, composition of organic matter analysed so far suggests subsidence and heat exposure exceeding post maturity stage.

  2. Sequence stratigraphy and basin analysis of the Tarfaya-Laâyoune Basins Morocco, on- and offshore Morocco

    OpenAIRE

    Wenke, Axel Adrian Oliver

    2014-01-01

    With the initiation of rifting in the Late Permian (Kazanian; 259.3 Ma) and the onset of drifting in the Early Jurassic (Pliensbachian/Toarcian 189.6 Ma), the Tarfaya-Laâyoune Basins are part of the oldest passive continental margin segments in the Atlantic domain. A basin analysis of the Tarfaya-Laâyoune Basins has been performed based outcrop data, well data, and a multi 2D-seismic survey dataset. Present organo-geochemical, heavy mineral, and thermochronological studies have been consid...

  3. The Lower Permian coal seams from Singrauli coalfield (M. P. ), India: petrochemical nature, rank, age and sedimentation

    Energy Technology Data Exchange (ETDEWEB)

    Misra, B.K.; Singh, B.D. (Birbal Sahni Institute of Palaeobotany, Lucknow (India))

    1990-04-01

    Biopetrographic and chemical investigations carried out on the Lower Permian (Barakar Formation) coal seams encountered in two bore-holes (NCSM-3 and CMSA-111) from the Singrauli coalfield, Son Valley, reveal that they are, in general, rich in inertinite and mineral matter towards the eastern part. Whereas, towards the western part they are rich in vitrinite with subordinate amounts of inertinite and mineral matter. The Turra and Purewa Top seams, in the eastern part, consist chiefly of mixed and fusic coal types and the Turra and Purewa Merged seams, in the western part of the basin, are characterized dominantly by vitric and mixed coal types. The basin of deposition was shallower in its major part but deepened towards west. Consequently frequent oxic fluctuations are most common in the coal seams of the eastern part. The rank of these coal seams ranges between subbituminous-A to high-volatile bituminous-C stages. They show normal increase in rank with depth. The coal seams in the western part of the area are higher in rank than their counterparts in the east. The Purewa Bottom seam (NCSM-3) is petro-palynologically correlatable with the Turra seam (CMSA-111) of the western part. It has been presumed that Glossopteridophyta (a complex group of gymnospermous plants), arthrophytes and ferns were the vegetal source for the formation of Barakar coal seams. These plants during the Early Permian grew as thick forests along river valleys and as upland and subaquatic vegetation, and experienced a warm, humid and windy temperate climate. The coal seams were presumably deposited in backwater and lacustrine swamps in fluvial environment from hypoautochthonous source material. An attempt has been made to explain reasons for the high incidence of mineral matter and its apparent relationship with inertinite content in the coal seams while also discussing the depositional history. 25 refs., 8 figs., 11 tabs.

  4. Organic richness and gas generation potential of Permian Barren Measures from Raniganj field, West Bengal, India

    Indian Academy of Sciences (India)

    Annapurna Boruah; S Ganapathi

    2015-07-01

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin were analysed to evaluate their gas generation potential using Rock–Eval pyrolysis techniques. Petrographic analysis brings out the lithofacies of Barren Measures as carbonaceous silty shale, iron rich claystone and sand-shale intercalation. The total organic content (TOC) of the shale units of Barren Measures ranges from 3.75 to 20.9 wt%, whereas hydrogen index (HI) ranges from 58.45 to 125.34 mg HC/g TOC. Present study suggests early to late maturated (0.6–1%) organic matters in Barren Measures with gas prone type III kerogen. The study analysed the effect of burial history on the preservation and maturation of organic matters. The organic richness, kerogen type, thermal maturity and petrographic properties of Barren Measures signify fair to excellent gas generation potential.

  5. Permian ultrafelsic A-type granite from Besar Islands group, Johor, peninsular Malaysia

    International Nuclear Information System (INIS)

    The granitic rocks of the peninsula have traditionally been divided into two provinces, i.e., Western and Eastern provinces, corresponding to S- and I-type granite respectively. The Western Province granite is characterised by megacrystic and coarse-grained biotite, tin-mineralised, continental collision granite, whereas, the Eastern Province granite is bimodal I-type dominated by granodiorite and associated gabbroic of arc type granite. This paper reports the occurrence of an A-type granite from peninsular Malaysia. The rocks occur in the Besar, Tengah, and Hujung islands located in the southeastern part of the peninsula. The granite is highly felsic with SiO2 ranging from 75.70% to 77.90% (differentiation index = 94.2-97.04). It is weakly peraluminous (average ACNK =1.02), has normative hypersthene (0.09-2.19%) and high alkali content (8.32-8.60%). The granites have many A-type characteristics, among them are shallow level of emplacement, high Ga, FeT/MgO and low P, Sr, Ti, CaO and Nb. Calculated zircon saturation temperatures for the Besar magma ranging from 793° to 806℃ is consistent with high temperature partial melting of a felsic infracrustal source which is taken as one of the mechanisms to produce A-type magma. The occurrence of the A-type granite can be related to the extensional back arc basin in the Indo-China terrane during the earliest Permian. (author)

  6. Permian ultrafelsic A-type granite from Besar Islands group, Johor, peninsular Malaysia

    Indian Academy of Sciences (India)

    Azman A Ghani; Fatin Izzani Hazad; Azmiah Jamil; Quek Long Xiang; Wan Nur Atiqah Wan Ismail; Sun-Lin Chung; Yu-Ming Lai; Muhammad Hatta Roselee; Nur Islami; Kyaw Kyaw Nyein; Meor Hakif Amir Hassan; Mohd Farid Abu Bakar; Mohd Rozi Umor

    2014-12-01

    The granitic rocks of the peninsula have traditionally been divided into two provinces, i.e., Western and Eastern provinces, corresponding to S- and I-type granite respectively. The Western Province granite is characterised by megacrystic and coarse-grained biotite, tin-mineralised, continental collision granite, whereas, the Eastern Province granite is bimodal I-type dominated by granodiorite and associated gabbroic of arc type granite. This paper reports the occurrence of an A-type granite from peninsular Malaysia. The rocks occur in the Besar, Tengah, and Hujung islands located in the southeastern part of the peninsula. The granite is highly felsic with SiO2 ranging from 75.70% to 77.90% (differentiation index = 94.297.04). It is weakly peraluminous (average ACNK=1.02), has normative hypersthene (0.092.19%) and high alkali content (8.328.60%). The granites have many A-type characteristics, among them are shallow level of emplacement, high Ga, FeT/MgO and low P, Sr, Ti, CaO and Nb. Calculated zircon saturation temperatures for the Besar magma ranging from 793 to 806C is consistent with high temperature partial melting of a felsic infracrustal source which is taken as one of the mechanisms to produce A-type magma. The occurrence of the A-type granite can be related to the extensional back arc basin in the Indo-China terrane during the earliest Permian.

  7. Organic richness and gas generation potential of Permian Barren Measures from Raniganj field, West Bengal, India

    Science.gov (United States)

    Boruah, Annapurna; Ganapathi, S.

    2015-07-01

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin were analysed to evaluate their gas generation potential using Rock-Eval pyrolysis techniques. Petrographic analysis brings out the lithofacies of Barren Measures as carbonaceous silty shale, iron rich claystone and sand-shale intercalation. The total organic content (TOC) of the shale units of Barren Measures ranges from 3.75 to 20.9 wt%, whereas hydrogen index (HI) ranges from 58.45 to 125.34 mg HC/g TOC. Present study suggests early to late maturated (0.6-1%) organic matters in Barren Measures with gas prone type III kerogen. The study analysed the effect of burial history on the preservation and maturation of organic matters. The organic richness, kerogen type, thermal maturity and petrographic properties of Barren Measures signify fair to excellent gas generation potential.

  8. Upper Cisuralian palynology and palaeoclimate of Manuguru area Godavari basin, India and their global correlation

    Science.gov (United States)

    K, Pauline Sabina; Jha, Neerja

    2014-10-01

    The Permian system of the Palaeozoic Erathem is divided into three series, the Early Permian Cisuralian Series, the Middle Permian Guadalupian Series, and the Late Permian Lopingian Series. The Cisuralian Series encompasses the Asselian to Kungurian stages which constitute the basal part of the Gondwana supersequence I. In India, they are represented lithostratigraphically by the Talchir, Karharbari, and Barakar formations. This paper presents the palynological results from the Barakar Formation of the Upper Cisuralian Series from Manuguru which lies in the southeastern part of the Godavari basin. The succession studied comprises 35 subsurface samples from bore hole 1007 represented by clay, shale, sandstone, and coal. The palynofloras in this sequence have a homogenous composition demonstrating that not many significant floral changes took place through the considered stratigraphic range. The entire sequence is characterized by the dominance of nonstriate bisaccate genus Scheuringipollenites and sub-dominance of striate bisaccate genus Faunipollenites(= Protohaploxypinus). The other pollen genera among the nonstriate bisaccates are Rhizomaspora, Primuspollenites, Ibisporites, and Platysaccus. The striate bisaccates include Striatites, Striatopodocarpites, and Stroterosporites. The taeniate taxa are represented by Lueckisporites and Lunatisporites. The common monosaccate genera include Caheniasaccites, Potoniesporites, and Barakarites. Spores are less common and include Latosporites, Brevitriletes, Horriditriletes, Microbaculispora, and Callumispora. They characterize the palynofloral composition of the Lower Barakar Formation. The correlation of this assemblage with some of the biostratigraphic palynozones proposed previously for the Cisuralian sequences of the Paraná Basin of South America, Kalahari Karoo Basin of South Africa, Ruhuhu Basin of Tanzania, East Africa as well as palynoassemblages from South Victoria Land and Dronning Maud Land, Antarctica and Collie Basin of west Australia point out to their Early Permian (Late Sakmarian-Early Artinskian) age. Palynomorphs such as Botryococcus sp., Tetraporinia sp., Balmeela sp. and Leiosphaeridia sp. are also recorded which suggest that these sediments were deposited during post-glacial near shore, cool and humid environment.

  9. Upper Cisuralian palynology and palaeoclimate of Manuguru area Godavari basin, and their global correlation

    Indian Academy of Sciences (India)

    Pauline Sabina K; Neerja Jha

    2014-10-01

    The Permian system of the Palaeozoic Erathem is divided into three series, the Early Permian Cisuralian Series, the Middle Permian Guadalupian Series, and the Late Permian Lopingian Series. The Cisuralian Series encompasses the Asselian to Kungurian stages which constitute the basal part of the Gondwana supersequence I. In India, they are represented lithostratigraphically by the Talchir, Karharbari, and Barakar formations. This paper presents the palynological results from the Barakar Formation of the Upper Cisuralian Series from Manuguru which lies in the southeastern part of the Godavari basin. The succession studied comprises 35 subsurface samples from bore hole 1007 represented by clay, shale, sandstone, and coal. The palynofloras in this sequence have a homogenous composition demonstrating that not many significant floral changes took place through the considered stratigraphic range. The entire sequence is characterized by the dominance of nonstriate bisaccate genus Scheuringipollenites and subdominance of striate bisaccate genus Faunipollenites (=Protohaploxypinus). The other pollen genera among the nonstriate bisaccates are Rhizomaspora, Primuspollenites, Ibisporites, and Platysaccus. The striate bisaccates include Striatites, Striatopodocarpites, and Stroterosporites. The taeniate taxa are represented by Lueckisporites and Lunatisporites. The common monosaccate genera include Caheniasaccites, Potoniesporites, and Barakarites. Spores are less common and include Latosporites, Brevitriletes, Horriditriletes, Microbaculispora, and Callumispora. They characterize the palynofloral composition of the Lower Barakar Formation. The correlation of this assemblage with some of the biostratigraphic palynozones proposed previously for the Cisuralian sequences of the Paraná Basin of South America, Kalahari Karoo Basin of South Africa, Ruhuhu Basin of Tanzania, East Africa as well as palynoassemblages from South Victoria Land and Dronning Maud Land, Antarctica and Collie Basin of west Australia point out to their Early Permian (Late Sakmarian–Early Artinskian) age. Palynomorphs such as Botryococcus sp., Tetraporinia sp., Balmeela sp. and Leiosphaeridia sp. are also recorded which suggest that these sediments were deposited during post-glacial near shore, cool and humid environment.

  10. Flourishing ocean drives the end-Permian marine mass extinction.

    Science.gov (United States)

    Schobben, Martin; Stebbins, Alan; Ghaderi, Abbas; Strauss, Harald; Korn, Dieter; Korte, Christoph

    2015-08-18

    The end-Permian mass extinction, the most severe biotic crisis in the Phanerozoic, was accompanied by climate change and expansion of oceanic anoxic zones. The partitioning of sulfur among different exogenic reservoirs by biological and physical processes was of importance for this biodiversity crisis, but the exact role of bioessential sulfur in the mass extinction is still unclear. Here we show that globally increased production of organic matter affected the seawater sulfate sulfur and oxygen isotope signature that has been recorded in carbonate rock spanning the Permian-Triassic boundary. A bifurcating temporal trend is observed for the strata spanning the marine mass extinction with carbonate-associated sulfate sulfur and oxygen isotope excursions toward decreased and increased values, respectively. By coupling these results to a box model, we show that increased marine productivity and successive enhanced microbial sulfate reduction is the most likely scenario to explain these temporal trends. The new data demonstrate that worldwide expansion of euxinic and anoxic zones are symptoms of increased biological carbon recycling in the marine realm initiated by global warming. The spatial distribution of sulfidic water column conditions in shallow seafloor environments is dictated by the severity and geographic patterns of nutrient fluxes and serves as an adequate model to explain the scale of the marine biodiversity crisis. Our results provide evidence that the major biodiversity crises in Earth's history do not necessarily implicate an ocean stripped of (most) life but rather the demise of certain eukaryotic organisms, leading to a decline in species richness. PMID:26240323

  11. Numerical modeling of regional ground-water flow in the deep-basin brine aquifer of the Palo Duro Basin, Texas Panhandle

    International Nuclear Information System (INIS)

    Bedded Permian-age evaporite sequences in the Palo Duro Basin are being considered for a permanent nuclear waste repository by the U.S. Department of Energy. The purpose of this modeling study is to provide an understanding of regional ground-water flow in the formations beneath the Permian evaporite section. From this understanding, more detailed, smaller scale studies can be designed. This study is also intended to provide a better understanding of the boundary conditions and permeabilities of the aquifer and aquitard system as well as provide estimates of ground-water travel times across the basin. Numerical simulations were made of the Wolfcamp aquifer modeled as a single layer and of the entire Deep-Basin Brine aquifer system, including the Wolfcamp aquifer, modeled as a single layer

  12. Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume I. Dalhart Basin

    International Nuclear Information System (INIS)

    This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and highly variable prcipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

  13. Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran

    Science.gov (United States)

    Shadan, Mahdi; Hosseini-Barzi, Mahboubeh

    2010-05-01

    Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran M. Shadan & M. Hosseini-Barzi Geology Department, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran shadangeo@gmail.com Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian) have been studied in two sections (Chahroof with 197 m thick in north and Cheshmeh Bakhshi with 204 m thick in south) along basement Kalmard fault in Posht-e-Badam block, Central Iran. Siliciclastic units are characterized by well sorted, fine to medium grain quartzarenites with laterite interbeds, deposited in shoreline zone (foreshore, upper and lower shoreface) influencing wave and longshore currents. Longshore sands which have been transported along the coast made the sand bars in the shoreface. Further along the coast, returning of these currents as rip currents produced erosive channel inlets and caused to carry fine grain into the deeper regions of the basin. Based on this sedimentary model we introduced longshore currents as a probable agent for mixing, by transporting some volumes of sands into the adjacent carbonate environments. Vertically, clastic units of Khan Formation underlined by carbonate units of a tidal flat and high-energy inner ramp system. Repeating of this pattern produced 3 cycles in each section. Cyclic evolution, in studied sections, is accompanied with discrepancy in erosion and sedimentation. These factors caused to disperse local sub-aerial exposures in successions which are recognizable by laterite and conglomerate interbeds. These horizons of sub-aerial exposures are more often in Chahroof section than in Cheshmeh Bakhshi section and indicate more fluctuations of relative sea level probably due to more local tectonic activity in the northern part of the Kalmard fault than in the southern part of it. Also, thicker siliciclastic units in Chahroof section show higher rate of sediment supply and/or more accommodation space there. Moreover, the late Paleozoic glacial conditions in Gondwana lands supported the large volume of clastic supply into the basin by intense weathering and erosion of vast exposed regions in Posht-e-Badam block. Also, tectonic activity along Kalmard basement fault mainly controlled local sea level changes and lithology of outcrops in the hinterlands. Therefore, interplay of these factors during lowstand of relative sea level, with lower accommodation space and higher gradient led to high rate of sediment input and distribution of siliciclastics in the base of each cycles. In contrast, relative sea level rises have been corresponded to the more accommodation space and reducing of siliciclastic entrance into the sedimentary basin that made a suitable condition for carbonate production. Therefore, during relative sea level rise, verities of carbonate-producing organisms tend to more rates of biogenic carbonate products and eventually formation of carbonate units upon the preexistence silisiclastics. Therefore, mixing of siliciclastics with carbonate deposits in Khan Formation have mainly been controlled temporally by sea level fluctuations due to local and/or eustatic sea level changes and spatially by variations in local tectonic activities and lateral facies mixing by longshore currents.

  14. DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN: A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

    Directory of Open Access Journals (Sweden)

    CRISTIANO LARGHI

    2005-11-01

    Full Text Available The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian bivalve fauna from the Saiwan Formation in the Huqf area, informally named "Dickinsartella Fauna", is described in the present paper. The specimens examined were collected from the "Pachycyrtella Bed" (Auctorum, the basal bed of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella, which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species. The bivalve fauna from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus  mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ?Oriocrassatella sp., and indeterminable aviculopectinids. This fauna shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament.  The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors.The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia,  indicates a wider distribution of the Dickinsartella Fauna and confirms the correlation between Arabian and Australian series already remarked by previous authors. The "Dickinsartella fauna" is the first bivalve fauna testifying to the climatic amelioration gradually affecting the North-Eastern Gondwanan fringe at the end of the Early Permian glacial events. This pioneer fauna spread out, probably in a cool-temperate climate, on the substrate provided by the mid-Sakmarian (basal Sterlitamakian transgression, connected with the final stages of the Gondwanan deglaciation and/or with initial sea-floor spreading in the Neotethys. In the present paper some remarks on the autecology of the new species from the "Pachycyrtella bed" are also discussed.

  15. Repository site data and information in bedded salt: Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    This report is a compilation of data from the literature on the Palo Duro Basin. The Palo Duro Basin is a structural basin, about 150 miles long and 80 miles wide, that is a part of the much larger Permian Basin. The US Department of Energy is investigating the Palo Duro Basin as a potentially suitable area for the site of a repository for the disposal of high-level radioactive waste. Sediments overlying the Precambrian basement range from about 5000 to about 11,000 ft in thickness and from Cambrian to Holocene in age. The strata in the Palo Duro Basin that are of primary interest to the Department of Energy are the bedded salts of the Permian San Andres Formation. The total thickness of the bedded salts is about 2000 ft. The geology of the Palo Duro Basin is well understood. A great deal of information exists on the properties of salt, although much of the available information was not collected in the Palo Duro Basin. Mineral resources are not currently being exploited from the center of the Palo Duro Basin at depth, although the possibility of exploration for and development of such resources can not be ruled out. The continued existence of salts of Permian age indicates a lack of any large amount of circulating ground water. The hydrology of the pre-Tertiary rocks, however, is currently too poorly understood to carry out detailed, site-specific hydrologic modeling with a high degree of confidence. In general, ground water flows from west to east in the Basin. There is little or no hydraulic connection between aquifers above and below the salt sequences. Potable water is pumped from the Ogallala aquifer. Most of the other aquifers yield only nonpotable water. More extensive hydrological data are needed for detailed future modeling in support of risk assessment for a possible repository for high-level waste in the Palo Duro Basin. 464 references

  16. CARBONIFEROUS-PERMIAN STRATIGRAPHY AND FUSULINIDS OF EASTERNIRAN. THE PERMIAN IN THE BAG-E-VANG SECTION (SHIRGESHT AREA

    Directory of Open Access Journals (Sweden)

    ERNST JA. LEVEN

    2004-07-01

    Full Text Available The Jamal Formation of the Bag-e-Vang section near Shirgesht is described. The lower part of the formation (Bag-e-Vang Member is composed of shales and marls with interbeds of hallow water bioclastic limestones. It contains abundant fusulinids indicative of the uppermost Yakhtashian-basal Kubergandian. The upper part of the Jamal Formation is represented by micritic and finely detrital limestones and dolomites. The age of this part of the formation is based on rare fusulinids and smaller foraminifers and cannot be defined more precisely than the Kubergandian-Dorashamian of the Upper Permian. The formation has visible conformable contacts with the underlying Sardar and overlying Sorkh Shale Formations. However, there may be unobservable stratigraphic hiatuses of indefinite scope at the formation boundaries. Forty-one species and subspecies, which belong to 27 genera and subgenera and 9 families of fusulinids, were identified in the Permian of the section described. Among them, two genera (Iranella, Paraleeina, one subgenus (Cuniculina and 8 species, i. e. Yangchienia compressaeformis,Paradoxiella insueta, Darvasites minutus, Skinnerella chusenellaeformis, Iranella bella, I. longa, I. orbiculata, and I. pauca, are new.

  17. Geochemical evidence from Lower Permian volcanic rocks of northeast New South Wales for asthenospheric upwelling following slab breakoff

    International Nuclear Information System (INIS)

    The ca 280 Ma Alum Mountain Volcanics and Werrie Basalt were erupted in northeast New South Wales, Australia, during Early Permian lithospheric extension that separated discrete episodes of subduction of Carboniferous and Late Permian - Triassic age. The Alum Mountain rocks, which are preserved in two major synclines in the southeast Tamworth Belt, are mostly basalt, but andesite and rhyolite are also present. The Werrie Basalt found further north in the Tamworth Belt and in the floor of the Gunnedah Basin is composed mainly of basalt, but includes more evolved rocks in the vicinity of several eruptive centres. The Alum Mountain rocks have REE abundances similar to N-MORB, with flat REE patterns, (La/Sm)N ratios ranging from 0.54 to 1.07, and (La/Yb)N ratios from 0.94 to 2.78, suggesting an origin by large degrees of partial melting of asthenosphere at a depth Nd values, ranging from +2.05 to +6.00, suggesting an asthenospheric origin for these rocks. Spider diagrams show a clear negative Nb anomaly, typical of subduction zones, but LREE/HREE [(La/Sm)N = 1.61 to 2.20; (La/Yb)N = 5.07 to 8.81], Ti/Zr, and Ti/P ratios are close to OIB values. The enriched character of the Werrie Basalt has resulted from either asthenospheric melts being progressively modified during ascent of fractionating magmas through the lithosphere, or by partial melting of a mantle metasomatised by subduction. The presence of a significant depleted-mantle component in the signature of the Lower Permian volcanic rocks indicates rise of the local mantle geotherm to allow extensive melting. We therefore propose a model of asthenospheric upwelling and lateral flow following breakoff of the Carboniferous subducting slab. Our model of asthenospheric convection as derived from eastern Australia suggests a major role for the asthenosphere in subduction zones: not only is the asthenosphere the reservoir from which magmatic arc melts originate, but we surmise that the behaviour of asthenospheric mantle at subduction zones may have far-reaching implications for the overall thermal state of the planet. Copyright (2001) Geological Society of Australia

  18. Characterization of an upper Permian tight gas reservoir. A multidisciplinary, multiscale analysis from the rotliegend, northern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Antrett, Philipp [RWTH Aachen Univ. (Germany). Energy and Mineral Resources Group

    2013-06-01

    Outstanding Ph.D. thesis nominated for a Springer Theses Prize by the RWTH Aachen University, Germany. Uses various approaches and covers a broad range of disciplines. Integrated study, carried out on multiple scales with state of the art technical equipment, that only few laboratories can offer worldwide. ''The thesis of Philipp Antrett is focused on reservoir properties, petrography, lithofacies and sedimentology, core analysis and nanoporosity studies. It will be of major interest for colleagues involved in the exploration and production of tight gas reservoirs in Northern Europe and elsewhere.'' - Francois Roure, August 2012 This thesis describes a multidisciplinary, multiscale approach to the analysis of tight gas reservoirs. It focused initially on the facies architecture of a Permian tight gas field in the Southern Permian Basin (SPB), East Frisia, northern Germany. To improve field development, 3D seismic data, wireline and core data were compared to a reservoir analogue in the Panamint Valley, California, United States. In addition to the large scale approach, a work flow that investigates microporosity by combining Scanning Electron Microscopy-Broad Ion Beam (SEM-BIB) and optical microscopy was developed. For a better understanding of the depositional environment and reservoir rock distribution in the SPB, a sedimentary facies analysis of four cores from the tight gas field in East Frisia was compared to a second study area in northern central Germany. This study demonstrates that tight gas exploration and production requires multidisciplinary, multiscale approaches beyond standard seismic interpretation work flows to better understand the temporal and spatial evolution of these complex reservoirs.

  19. Ocean redox change at the Permian-Triassic mass extinction

    DEFF Research Database (Denmark)

    Ruhl, Micha; Bjerrum, Christian J.; Canfield, Donald Eugene; Stemmerik, Lars

    (anoxic but not euxinic) coinciding with the main extinction event. Molybdenum enrichments, often indicative for freely available sulfide in the water-column, only occur dur¬ing the second phase of euxinia. This pattern of ocean redox-change in Svalbard direct¬ly reflects similar trends in Greenland and...... ocean redox change over the largest mass extinction event in Earth history, at the Permian-Tri¬assic boundary (at ~252 Ma). This event is marked by a major perturbation in the global exogenic carbon cycle (and associated major negative carbon isotope excursion (CIE)), likely initiated by carbon...... oceanographic changes to similar observations for the Triassic-Jurassic mass extinction and discuss environmental forcing, poten¬tially inherent to major volcanic events and leading to global environmental change and extinction...

  20. Cretaceous stem chondrichthyans survived the end-Permian mass extinction.

    Science.gov (United States)

    Guinot, Guillaume; Adnet, Sylvain; Cavin, Lionel; Cappetta, Henri

    2013-01-01

    Cladodontomorph sharks are Palaeozoic stem chondrichthyans thought to go extinct at the end-Permian mass extinction. This extinction preceded the diversification of euselachians, including modern sharks. Here we describe an outer-platform cladodontomorph shark tooth assemblage from the Early Cretaceous of southern France, increasing the fossil record of this group by circa 120 million years. Identification of this material rests on new histological observations and morphological evidence. Our finding shows that this lineage survived mass extinctions most likely by habitat contraction, using deep-sea refuge environments during catastrophic events. The recorded gap in the cladodontomorph lineage represents the longest gap in the fossil record for an extinct marine vertebrate group. This discovery demonstrates that the deep-sea marine diversity, poorly known during most of the fish evolutionary history, contains essential data for a complete understanding of the long-term evolution of marine fish paleobiodiversity. PMID:24169620

  1. The Cordon del Portillo Permian magmatism, Mendoza, Argentina, plutonic and volcanic sequences at the western margin of Gondwana

    Science.gov (United States)

    Gregori, Daniel; Benedini, Leonardo

    2013-03-01

    The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks, parts of the Cordillera Frontal Composite Batholith, cropping out in the Cordón del Portillo, records the Gondwana magmatic development of the Cordillera Frontal of Mendoza, in western Argentina. In this area, the San Rafael Orogenic phase, that represents the closure of the Late Carboniferous-Early Permian marine basins, begins at 284 Ma, and ceased before 276 Ma. The Cerro Punta Blanca, Cerro Bayo and Cerro Punta Negra stocks represent a post-orogenic magmatism and are equivalents to the Choiyoi Group. The Gondwana magmatic activity in the Cordón del Portillo area can be divided into two stages. The Cerro Punta Blanca stock (c.a. 276 Ma) represents an early post-orogenic, subduction-related magmatism similar to the basic-intermediate section of the Choiyoi Group (c.a. 277 Ma). The late post-orogenic second event was recorded by the Cerro Bayo (262 Ma) and Cerro Punta Negra stocks which represent a transition between subduction-related and intra-plate magmatism. This event represents the intrusive counterpart of the acidic facies of the upper section of the Choiyoi Group (c.a. 273 Ma). This extensional condition continued during the Triassic when the Cacheuta basin developed.

  2. A modern vs. Permian black shale - the hydrography, primary productivity, and water-column chemistry of deposition

    Science.gov (United States)

    Piper, D.Z.; Perkins, R.B.

    2004-01-01

    The sediment currently accumulating in the Cariaco Basin, on the continental shelf of Venezuela, has an elevated organic-carbon content of approximately 5%; is accumulating under O2-depleted bottom-water conditions (SO42- reduction); is composed dominantly of foraminiferal calcite, diatomaceous silica, clay, and silt; and is dark greenish gray in color. Upon lithification, it will become a black shale. Recent studies have established the hydrography of the basin and the level of primary productivity and bottom-water redox conditions. These properties are used to model accumulation rates of Cd, Cr, Cu, Mo, Ni, V, and Zn on the seafloor. The model rates agree closely with measured rates for the uppermost surface sediment.The model is applied to the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, a phosphate deposit of Permian age in the northwest United States. It too has all of the requisite properties of a black shale. Although the deposit is a world-class phosphorite, it is composed mostly of phosphatic mudstone and siltstone, chert, limestone, and dolomite. It has organic-carbon concentrations of up to 15%, is strongly enriched in several trace elements above a terrigenous contribution and is black. The trace-element accumulation defines a mean primary productivity in the photic zone of the Phosphoria Basin as moderate, at 500 g m-2 year-1 organic carbon, comparable to primary productivity in the Cariaco Basin. The source of nutrient-enriched water that was imported into the Phosphoria Basin, upwelled into the photic zone, and supported primary productivity was an O2 minimum zone of the open ocean. The depth range over which the water was imported would have been between approximately 100 and 600 m. The mean residence time of bottom water in the basin was approximately 4 years vs. 100 years in the Cariaco Basin. The bottom water was O2 depleted, but it was denitrifying, or NO3- reducing, rather than SO42- reducing. Published by Elsevier B.V.

  3. Fungal event and palynological record of ecological crisis and recovery across the Permian-Triassic boundary

    Science.gov (United States)

    Eshet, Yoram; Rampino, Michael R.; Visscher, Henk

    1995-11-01

    The end of the Permian Period was marked by the most severe mass extinction in the geologic record. Detailed quantitative study of pollen and spores from shallow-marine deposits spanning the Permian-Triassic (P-Tr) boundary in Israel reveals a sequence of palynological-ecological stages reflecting a major crisis among land plants. The disappearance of the gymnosperm-dominated palynoflora of the Late Permian Lueckisporites virkkiae Zone is recorded at a claystone horizon containing almost exclusively abundant fungal remains and carbonized terrestrial plant debris. This fungal spike is followed by a zone dominated by marine acritarchs and a succession showing ecological recovery with abundant lycopod spores and eventual reappearance of bisaccate gymnosperm pollen in the Early Triassic. The latest Permian proliferation of fungi is recognizable worldwide and can be correlated with other paleontological and geochemical markers of a global ecological disaster.

  4. Evolution and extinction of Permian fusulinid fauna in the Khao Tham Yai Limestone in NE Thailand

    Science.gov (United States)

    Hada, Shigeki; Khosithanont, Somboon; Goto, Hiroya; Fontaine, Henri; Salyapongse, Sirot

    2015-05-01

    The first detailed biostratigraphic investigation of a single limestone unit within the Khao Tham Yai Limestone shows it was deposited continuously in a shelf setting without any intercalation of clastic beds. It ranges from the Wordian (middle Middle Permian) up to the Wuchiapingian (lower Upper Permian). The limestone unit is divided in ascending order into three fusulinid zones, i.e. Colania, Lepidolina and Codonofusiella zones. The middle zone is characterized by an abundance of large-tested fusulinids characteristic of the Lepidolina Zone. Shell sizes of the fusulinid species in this zone display continuous rapid morphological change along a one-way evolutionary path from small, primitive species with simple structure to large, highly evolved species having a complicated wall structure. Fusulinid biostratigraphy in a single limestone unit elucidates evolution and extinction patterns of Permian fusulinids of the shallow-water Tethyan shelf area in the Indochina Block. Our study reveals that the boundary between the Guadalupian (Middle Permian) and Lopingian (Upper Permian) in the Khao Tham Yai Limestone is clearly defined as an abrupt change in the fusulinid assemblages from the elimination of large-tested Verbeekinids and Schwagerinids to the domination of small-shelled Schubertellids. The Schubertellids underwent slower evolutionary morphological change than earlier fusulinids and were decreasingly dominant through the Permian. A similar pattern of fusulinid evolution and extinction at the Guadalupian-Lopingian boundary occurs in shallow-water Tethyan shelf areas and mid-oceanic shallow-water environments in mid-Panthalassa. Eventually, even smaller fusulinids abruptly become extinct. Clastic deposits finally replace previous carbonate formations characterized by algae-foraminifera biota. It starts in the upper Middle Permian in the southern parts and spreads throughout the whole area in the lower Upper Permian in NE Thailand. These observations suggest possible correlation between the turning points of fusulinid evolution and global environmental change such as worldwide sea-level drop and its consequent effects.

  5. A Major Unconformity Between Permian and Triassic Strata at Cape Kekurnoi, Alaska Peninsula: Old and New Observations on Stratigraphy and Hydrocarbon Potential

    Science.gov (United States)

    Blodgett, Robert B.; Sralla, Bryan

    2008-01-01

    A major angular unconformity separates carbonates and shales of the Upper Triassic Kamishak Formation from an underlying unnamed sequence of Permian agglomerate, volcaniclastic rocks (sandstone), and limestone near Puale Bay on the Alaska Peninsula. For the first time, we photographically document the angular unconformity in outcrop, as clearly exposed in a seacliff ~1.3 mi (2.1 km) west of Cape Kekurnoi in the Karluk C?4 and C?5 1:63,360-scale quadrangles. This unconformity is also documented by examination of core chips, ditch cuttings, and (or) open-hole electrical logs in two deep oil-and-gas-exploration wells (Humble Oil & Refining Co.?s Bear Creek No. 1 and Standard Oil Co. of California?s Grammer No. 1) drilled along the Alaska Peninsula southwest of Puale Bay. A third well (Richfield Oil Corp.?s Wide Bay Unit No. 1), south of and structurally on trend with the other two wells, probed deeply into the Paleozoic basement, but Triassic strata are absent, owing to either a major unconformity or a large fault. Here we briefly review current and newly acquired data on Permian and Triassic rocks of the Puale Bay-Becharof Lake-Wide Bay area on the basis of an examination of surface and subsurface materials. The resulting reinterpretation of the Permian and Triassic stratigraphy has important economic ramifications for oil and gas exploration on the Alaska Peninsula and in the Cook Inlet basin. We also present a history of petroleum exploration targeting Upper Triassic reservoirs in the region.

  6. Rare-earths in size fractions and sedimentary rocks of Pennsylvanian-Permian age from the mid-continent of the U.S.A

    International Nuclear Information System (INIS)

    The REE (rare-earth) contents of sixty-three <2μ fractions of Pennsylvanian and Permian platform sediment from the mid-continent of the U.S.A. vary considerably (ΣREE = 46 to 439 ppm: La/Lu = 5.2 to 15.7; correlation coefficient of REE with La Lu = 0.89), but the Eu/Sm ratios are nearly constant even in reducing environments that concentrate U (0.16 to 0.22). There is no correlation of REE content to clay mineralogy. Lower Permian <2μ fractions from continental to nearshore marine sediment in Oklahoma have higher REE content (244 to 261 ppm) than marine facies in Kansas (46 to 140 ppm) but <2μ Upper Permian fractions in an evaporite basin have constant but high REE content (288 to 281 ppm; one = 153 ppm). All Pennsylvanian <2μ fractions from Oklahoma have high REE content (209 to 439 ppm), and fractions from Kansas cyclothems have variable REE content (86 to 438 ppm). REE content in the <2μ fractions is inherited from the provenance, but is modified by ion exchange during weathering, transportation or deposition. Exchangable REE tend to be concentrated in clay minerals in basic environments, but removed in acid environments. Sand and gravel-size fractions consist mostly of quartz or chert so their REE content is low (7.9 to 40.6 ppm) although heavy minerals may contribute a large fraction of the REE content. Unexpectedly silt-size fractions have REE contents (74 to 355 ppm) that are usually lower but similar to their <2μ fractions, and the REE contents do not correlate to clay mineral/quartz ratios. (author)

  7. Oxidoreduction processus in a uranium deposit (Aumance - Cerilly Permian basin, Allier (France))

    International Nuclear Information System (INIS)

    Stratigraphic and tectonic data are briefly reviewed. Then a method giving the oxidoreducing properties of elements and using the chemical oxygen demand is exposed. The study of secondary textures shows the effects of the oxidoreducing process. Three pyrite textures were identified at Cerilly by petrographic observations. They are always bound to a secondary enrichment in uranium and they can be used as an exploration guide. Application of factor analysis confirms the studied phenomenon

  8. Declining Petroleum Production and the Effect Upon Communities in New Mexico's Permian Basin

    Science.gov (United States)

    Tipton, Ryan D.

    The petroleum industry, a vital component of New Mexico's economy, is in a gradual decline. As petroleum production is primarily focused in the southeastern corner of the state, this decline phenomenon is particularly relevant to area residents. The problem addressed in this study was that little information is available regarding the lived experiences of business and community leaders concerning this phenomenon, particularly in terms of future economic sustainability. The purpose of this qualitative phenomenological study was to interview a purposive sample of business and community leaders regarding their lived experiences and perceptions relating to the economic sustainability of the region. Research questions asked about the general awareness of the decline of oil production---data collected from federal and state databases---and potential options for alternative economic development. Coded data were analyzed and themes and patterns were identified. Findings included a general lack of awareness of area residents regarding a decline of production, assumed economic stability, and resistance to change based on a lack of incentive. Included in the findings were potential options for strategic economic diversification. Recommendations included a campaign to promote awareness of the decline of oil, provide incentives for change, and economic diversification as method of moving the local economy away from dependence upon the petroleum industry. Implications for positive social change were that the affected region can use the findings to identify sustainable alternative industries to support the communities into the future.

  9. Waterflood improvement in the Permian Basin: Impact of in-situ-stress evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Nolen-Hoeksema, R.C.; Avasthi, J.M. (Chevron Petroleum Technology Co., Houston, TX (United States)); Pape, W.C. (West Australian Petroleum Pty. Ltd., Perth (Australia)); El Rabaa, A.W. (Mobil E and P Technical Center, Dallas, TX (United States))

    1994-11-01

    The authors evaluated in-situ-stress magnitudes and directions to support waterflood improvement programs in McElroy field and North Westbrook Unit. In-situ-stress and hydraulic-fracture directions coincided with directional floodwater effects. This information contributed to successful waterflood realignment programs.

  10. Problems for Evaluation of the Scenario of the Permian-Triassic Boundary Biotic Crisis and of Its Causes

    OpenAIRE

    H. W. Kozur

    1998-01-01

    Determination of the causes of the Permian-Triassic boundary (PTB) biotic crisis is hindered primarily by the diachronous nature of the used PTB, poor stratigraphic control of compared Upper Permian and Lower Triassic faunas, especially in continental biotopes, poor knowledge of the lower and middle Scythian faunas from many environments, and by interpolation of the unknown (lower and middle) Scythian diversity from the known Upper Permian and Middle Triassic diversity data in many major foss...

  11. Youngest dinocephalian fossils extend the Tapinocephalus Zone, Karoo Basin, South Africa

    Scientific Electronic Library Online (English)

    Michael O., Day; Saniye, Gven; Fernando, Abdala; Sifelani, Jirah; Bruce, Rubidge; John, Almond.

    2015-04-01

    Full Text Available The dinocephalians (Synapsida, Therapsida) were one of the dominant tetrapod groups of the Middle Permian (Guadalupian Epoch, ~270-260 million years ago) and are most abundantly recorded in the Tapinocephalus Assemblage Zone (AZ) of the Main Karoo Basin, South Africa. Dinocephalians are thought to h [...] ave become extinct near the top of the Abrahamskraal Formation of the Beaufort Group and their disappearance is one criterion used to define the base of the overlying Pristerognathus AZ. Because of the abundance of fossils in the Karoo, the Beaufort Group biozones form the biostratigraphic standard for later Permian terrestrial tetrapod ecosystems, so their stratigraphic delineation is of great importance to Permian palaeobiology. We report two new specimens of the rare tapinocephalid dinocephalian Criocephalosaurus from the lowermost Poortjie Member, which makes them the youngest dinocephalians known from the Main Karoo Basin and extends the Tapinocephalus AZ from the Abrahamskraal Formation up into the Teekloof Formation. The extension of the Tapinocephalus AZ relative to the lithostratigraphy potentially affects the biozone or biozones to which a fossil species can be attributed; this extension has implications for biostratigraphic correlations within the Main Karoo Basin as well as with other basins across Gondwana. These discoveries also indicate that a population of herbivorous tapinocephalids survived as rare constituents of the tetrapod fauna after most generic richness within the clade had already been lost.

  12. An Early Permian fusuline fauna from southernmost Peninsular Thailand: Discovery of Early Permian warming spikes in the peri-Gondwanan Sibumasu Block

    Science.gov (United States)

    Ueno, Katsumi; Arita, Michiko; Meno, Satomi; Sardsud, Apsorn; Saesaengseerung, Doungrutai

    2015-05-01

    An Early Permian fusuline fauna is reported from the Tarn To Formation of the Yala area in southernmost Peninsular Thailand, which geotectonically belongs to the peri-Gondwanan Sibumasu Block. The fauna consists of Pseudofusulina and Praeskinnerella? species, including forms closely resembling Tethyan and Panthalassan Pseudofusulina fusiformis and Pseudofusulina ex gr. kraffti. A Yakhtashian-Bolorian age is estimated for this fauna. In Sibumasu, shallow-marine biotas showing similar Tethyan affinities, such as the fusulines Misellina and alatoconchid bivalves, also occur in the Early Permian succession of the Kinta Valley area in western Peninsular Malaysia. These unusual Tethyan faunas within Early Permian peri-Gondwanan fossil records suggest episodic influences from paleo-tropical Tethyan biotas. They are here interpreted as showing short-term warming spikes during the late Yakhtashian-Bolorian transgression, which would facilitate sporadic migration and temporal inhabitation of warm-water dwellers into the eastern Cimmerian areas. The Yala and Kinta Valley fusuline and other invertebrate faunas would give us a new insight for the Permian geohistory and environmental change of the peri-Gondwanan Sibumasu Block.

  13. Distribution and origin of natural gas leakage in the Colorado Basin, offshore Argentina Margin, South America : seismic interpretation and 3D basin modelling

    OpenAIRE

    Anka, Z.; Loegering, M. J.; di Primio, R.; Marchal, D.; Rodríguez, J.F.; Vallejo, E.

    2014-01-01

    The detailed analysis of a dense 2D seismic reflection dataset and data from 8 exploration wells, allowed us to identify, map out and characterize possible indications of past and present-day hydrocarbon leakage (i.e. gas chimneys, gas pockets, and seafloor mounds and pockmarks) on the continental shelf and slope of the Colorado Basin, offshore Argentina, where Permian, Jurassic and Early Cretaceous source rocks are potentially present and may be currently mature. Identified gas leakage feat...

  14. Radon in the Creswell Crags Permian limestone caves

    International Nuclear Information System (INIS)

    An investigation of radon levels in the caves of Creswell Crags, Derbyshire, an important Site of Special Scientific Interest (SSSI) shows that the Lower Magnesian Limestone (Permian) caves have moderate to raised radon gas levels (27-7800 Bq m-3) which generally increase with increasing distance into the caves from the entrance regions. This feature is partly explained in terms of cave ventilation and topography. While these levels are generally below the Action Level in the workplace (400 Bq m-3 in the UK), they are above the Action Level for domestic properties (200 Bq m-3). Creswell Crags has approximately 40,000 visitors per year and therefore a quantification of effective dose is important for both visitors and guides to the Robin Hood show cave. Due to short exposure times the dose received by visitors is low (0.0016 mSv/visit) and regulations concerning exposure are not contravened. Similarly, the dose received by guides is fairly low (0.4 mSv/annum) due in part to current working practice. However, the risk to researchers entering the more inaccessible areas of the cave system is higher (0.06 mSv/visit). This survey also investigated the effect of seasonal variations on recorded radon concentration. From this work summer to winter ratios of between 1.1 and 9.51 were determined for different locations within the largest cave system

  15. Simulated warm polar currents during the middle Permian

    Energy Technology Data Exchange (ETDEWEB)

    Winguth, A.M.E.; Kutzbach, J.E. [Wisconsin Univ., Madison, WI (USA). Center for Climatic Research; Heinze, C.; Maier-Reimer, E.; Mikolajewicz, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Rowley, D.; Rees, A.; Ziegler, A.M. [Chicago Univ., IL (United States). Dept. of Geophysical Sciences

    2001-05-01

    During Permian Stage 6 (Wordian, Kazanian) the Pangaean supercontinent was surrounded by a superocean - Panthalassa. An ocean general circulation model has been coupled to an atmospheric energy balance model to simulate the sensitivity of the Wordian climate ({proportional_to}265 million years ago) to changes in greenhouse gas concentrations, high latitude geography, and Earth orbital configurations. The model shows a high sensitivity of the ocean circulation to changes in the greenhouse gas forcing, ranging from a forceful southern circulation at low CO{sub 2} concentration (present level) to a more symmetric circulation cell with deep water formation in both hemispheres at high CO{sub 2} concentration (8 x present level). The simulated climate with 4 x present level CO{sub 2} concentration agrees generally well with climate-sensitive sediments and phytogeographic patterns. In this experiment, the model simulates strong subtropical gyres with similarities to the modern South Pacific circulation and moderate surface temperatures on the southern continent Gondwana, resulting from a strong poleward heat transport in the ocean. An even more moderate climate can be generated if high latitude land is removed so that ocean currents can penetrate into the polar regions or if orbital configurations favor high summer insolation over Gondwana. (orig.)

  16. Electrokinetic transport behavior of phenol in upper Permian soils

    Energy Technology Data Exchange (ETDEWEB)

    Haus, R.; Zorn, R.; Czurda, K.; Ruthe, H. [Dept. of Applied Geology, Univ. Karlsruhe (Germany)

    2001-07-01

    Electrokinetic experiments with upper Permian, phenol contaminated soils ('Solaris'-area Chemnitz) were performed. Bench scale results show the successful removal of phenol. The developing soil-pH during electroremediation tests is found to affect the transport behavior of phenol strongly. If buffer solutions are used at the electrode compartments, phenol could be removed from the soils. By neutralizing the generating hydrogen ions at the anode reservoir the hydroxyl ions developing at the cathode by the electrolysis of water enter the soil and propagate to the anode by increasing the soil pH. The pH dependent dehydroxylation of phenol promotes the electromigration of negative charged phenolate ions from the cathode to the anode. At the anode the coupling of phenoxyl-radicals supports the formation of non toxic, water insoluble polyoxyphenylene by electro-polymerization. In the case of buffering the pH at the cathode uncharged phenol is transported by electroosmosis from the anode to the cathode because of the nonexisting base front and the unhindered production of hydrogen ions at the anode. (orig.)

  17. The Alashan Terrane did not amalgamate with North China block by the Late Permian: Evidence from Carboniferous and Permian paleomagnetic results

    Science.gov (United States)

    Yuan, Wei; Yang, Zhenyu

    2015-05-01

    Rock magnetic and paleomagnetic studies have been carried out on the early Carboniferous limestones and the Late Permian purple sandstones sampled in the eastern Alashan Terrane (ALT), northwest of China. Two components were isolated from the Early Carboniferous limestone by thermal progressive demagnetisation: a low unblocking temperature component (LTC) of recent origin; a pre-folding medium temperature component (MTC) (the paleomagnetic pole is ? = 13.1N, ? = 11.0E, A95 = 7.0) that is probably the result of the hydrothermal fluids from the Qilian Orgenic Belt acquired during the Late Carboniferous-Early Permian. Also, two components were separated from the Late Permian purple sandstone by thermal progressive demagnetisation: the LTC with the recent viscous remanent magnetisation, and the higher temperature component (HTC) revealed from three sections which has passed a regional fold test at the 95% probability level and reversal test, suggesting a primary characteristic magnetisation. The corresponding paleomagnetic pole is ? = 27.2 N, ? = 18.8 E, A95 = 12.0. The apparent polar wander path (including early Carboniferous, late Carboniferous-Early Permian, Late Permian and Early-middle Triassic poles) of the ALT is significantly different with those of the NCB. Comparison of the APWPs between the ALT and NCB shows a strong similarity. If the APWP of Hexi Corridor-Alashan rotated counterclockwise around an Euler pole at 44N, 84E by 32, then the coeval APW path of the ALT overlaps to that of the NCB. This result indicates that the ALT migrated to the NCB after the Early-Middle Triassic along a tectonic boundary located between Helanshan Mountain and Zhuozishan Mountain, and finally amalgamated to the NCB before the Early Cretaceous.

  18. Late Permian global coal hiatus linked to {sup 13}C depleted CO{sub 2} flux into the atmosphere during the final consolidation of Pangea

    Energy Technology Data Exchange (ETDEWEB)

    Faure, K.; Dewit, M.J.; Willis, J.P. [University of Cape Town, Rondesbosch (South Africa). Dept. of Geological sciences

    1995-06-01

    At a time when all continents were finally arrayed in their Pangea supercontinental configuration (250 {+-} 50 Ma), Earth`s stratigraphy records a global and very abrupt coal discontinuity. From the Tartarian stage of the Late Permian to the Middle Triassic, reduced coal productivity and/or preservation overlaps with a period of anomalous oceanic and atmospheric decrease in {sup 13}C, as recorded in marine carbonates and organic matter, and terrestrial plant and animal fossils from the Northern and Southern hemispheres. During the same short period, the peripheral margin of the entire supercontinent Pangea, except for the southern shores of Tethys, was effectively under compressive stress. This unique tectonic state caused deformation and uplift of coal-bearing foreland basins and oxidation of Pangea`s vast peat deposits. The latter resulted in a rapid, massive {sup 13}C-depleted CO{sub 2} flux into the atmosphere, which in turn may have forced global warming.

  19. Bioessential element-depleted ocean following the euxinic maximum of the end-Permian mass extinction

    Science.gov (United States)

    Takahashi, Satoshi; Yamasaki, Shin-ichi; Ogawa, Yasumasa; Kimura, Kazuhiko; Kaiho, Kunio; Yoshida, Takeyoshi; Tsuchiya, Noriyoshi

    2014-05-01

    We describe variations in trace element compositions that occurred on the deep seafloor of palaeo-superocean Panthalassa during the end-Permian mass extinction based on samples of sedimentary rock from one of the most continuous Permian-Triassic boundary sections of the pelagic deep sea exposed in north-eastern Japan. Our measurements revealed low manganese (Mn) enrichment factor (normalised by the composition of the average upper continental crust) and high cerium anomaly values throughout the section, suggesting that a reducing condition already existed in the depositional environment in the Changhsingian (Late Permian). Other redox-sensitive trace-element (vanadium [V], chromium [Cr], molybdenum [Mo], and uranium [U]) enrichment factors provide a detailed redox history ranging from the upper Permian to the end of the Permian. A single V increase (representing the first reduction state of a two-step V reduction process) detected in uppermost Changhsingian chert beds suggests development into a mildly reducing deep-sea condition less than 1 million years before the end-Permian mass extinction. Subsequently, a more reducing condition, inferred from increases in Cr, V, and Mo, developed in overlying Changhsingian grey siliceous claystone beds. The most reducing sulphidic condition is recognised by the highest peaks of Mo and V (second reduction state) in the uppermost siliceous claystone and overlying lowermost black claystone beds, in accordance with the end-Permian mass extinction event. This significant increase in Mo in the upper Changhsingian led to a high Mo/U ratio, much larger than that of modern sulphidic ocean regions. This trend suggests that sulphidic water conditions developed both at the sediment-water interface and in the water column. Above the end-Permian mass extinction horizon, Mo, V and Cr decrease significantly. On this trend, we provide an interpretation of drawdown of these elements in seawater after the massive element precipitation event during the end-Permian maximum development of the reducing water column. A decrease in the Mo/U ratio despite enrichment of Mo and U also supports that of Mo. Calculations of the total amounts of these elements precipitated compared with the global seawater inventory suggest that when more than 6-10% of the global ocean became euxinic as much as the study section, most of the dissolved elements would precipitate into sediments, resulting in a global element-depleted seawater condition. Mo, V, and Cr act as bioessential elements for both primary producers and animals. The continuing reducing water column and the lack of bioessential elements could have had a considerable effect on primary producer turnover and marine life metabolism not only in the pelagic environment, but also in surrounding marine environments.

  20. Evolución tectono-magmática durante el Pérmico al Jurásico temprano en la Cordillera del Viento (37°05´S - 37°15´S: nuevas evidencias geológicas y geoquímicas del inicio de la cuenca Neuquina Tectono-magmatic evolution during the Permian to the Early Jurassic in the Cordillera del Viento (37°05´S - 37°15´S: new geological and geochemical evidences for the early stages of the Neuquén basin

    Directory of Open Access Journals (Sweden)

    E.J. Llambías

    2007-06-01

    Full Text Available El extremo sur de la cordillera del Viento está constituido en mayor parte por las secuencias volcánicas que conforman el basamento de la cuenca Neuquina. Las rocas más antiguas corresponden a sedimentitas de la Formación Huaraco del Grupo Andacollo de edad carbonífera superior. Después de haber sido plegadas por la fase orogénica San Rafael en el Pérmico Temprano, estas sedimentitas fueron intruidas por plutones pérmicos de granodiorita y monzogranito junto con diques y domos de riolita. Las sedimentitas también fueron cubiertas en discordancia angular por ignimbritas riolíticas cogenéticas con los intrusivos. Se ha denominado a este conjunto de rocas ígneas como complejo volcánico-plutónico Huingancó, y por su edad pérmica se lo correlaciona con el Grupo Choiyoi, expuesto en las provincias geológicas de Cordillera Frontal y Bloque de San Rafael. El Complejo Huingancó fue intensamente erosionado en el Triásico Temprano a Medio, labrándose una superficie de erosión ondulada (discordancia huárpica y exhumándose las cúpulas de los plutones pérmicos. Sobre esta superficie de erosión se depositó la Formación Cordillera del Viento (ex Choiyoilitense de Groeber, compuesta por una secuencia mayormente volcánica, con composición andesítica a riolítica y espesores de hasta 1.300 metros. A continuación se depositó en discordancia la Formación Milla Michicó, constituida por basaltos, andesitas basálticas y escasas riolitas, dispuestos en mantos bien estratificados con un espesor de hasta 200 metros. Seguidamente se acumuló la Formación La Primavera de edad pliensbachiana, sobre una superficie irregular que se relaciona con la fase diastrófica Río Atuel. La Formación La Primavera, que es la unidad más antigua del Grupo Cuyo, está compuesta por sedimentitas marinas y lavas basálticas en la base e ignimbritas riolíticas en los niveles superiores. El espesor de esta unidad varía desde unos pocos metros hasta 400 metros. Esta última unidad es cubierta en aparente concordancia por la Formación Los Molles, constituida en la base por calizas que son cubiertas por pelitas negras y areniscas depositadas en un régimen turbidítico. En la base de esta unidad se intercalan lentes de lahares andesíticos y otros depósitos producidos por flujos hiperdensos. La discordancia huárpica marca la transición entre la etapa de pos-orogénesis, durante la cual se desarrolló el Complejo Huingancó, y la etapa de rifting triásica, cuya fracturación permitió el rápido ascenso del magma desde la astenósfera. La finalización de la etapa de rifting se corresponde con la discordancia rioatuélica, que marca el comienzo de la ingresión marina cuyana. Las discordancias comprendidas entre la Huárpica y la Rioatuélica son de menor jerarquía y sólo representan cambios en la velocidad de apertura del rift. Los atributos químicos de las volcanitas estudiadas corresponden a las series calcoalcalinas con moderado a alto contenido de Mg# y pobres en potasio. El enriquecimiento de elementos incompatibles es muy bajo, indicando que el grado de fusión fue moderado a alto y la contaminación con elementos corticales fue pobre. Por estas características se propone que las volcanitas triásicas formaron parte del arco volcánico correspondiente a los complejos de subducción-acreción triásicos situados en la cordillera de la Costa de Chile al sur de los 38° S. Durante el Jurásico Temprano el volcanismo migró hacia el oeste, pasando de la etapa de rifting a la etapa de extensión en retroarco, tiempo en el cual se produjo la extendida ingresión marina del Grupo Cuyo. El grado moderado a alto de fusión que originó el arco volcánico puede explicarse por la presencia de una anomalía geotérmica elevada que favoreció la ruptura de la litósfera en extensión e incrementó la magnitud del grado de fusión por descompresión. La disminución del gradiente geotérmico a partir del Pliensbachiano podría explicar la forma no lineal de la cuenca Neuquina en la provincia del Neuquén.The southern extremity of the Cordillera del Viento is mainly composed of volcanic sequences, which form the basement of the Neuquén basin. The oldest rocks are the sediments in the Huaraco Formation, Andacollo Group, of Upper Carboniferous age. After being folded by the San Rafael orogenic phase during the Lower Permian, these sediments were intruded by granodioritic and monzogranitic plutons along with dikes and domes of rhyolitic nature. They were then covered in angular unconformity by rhyolitic ignimbrites, which are co-genetic with the intrusives. The resulting volcanic-plutonic complex is suggested to be correlative with the Permian Choiyoi Group exposed in the Cordillera Frontal and the Bloque de San Rafael geological provinces. This volcanic-plutonic complex was subjected to strong erosion during the Early to Middle Triassic. The development of an undulated erosion surface (Huarpican unconformity resulted in the exposure of the cupolas of the plutons. This surface support the Cordillera del Viento Formation (ex Groeber's Choiyoilitense, which consists of a volcanic sequence of andesitic to rhyolitic composition up to 1.300 meters thick. The next unit, the Milla Michicó Formation, was also deposited unconformably. This unit is composed of bedded flows of basalts, andesitic basalts and rhyolites with thickness up to 200 meters. The succession continued with the unconformable deposition of the La Primavera Formation, which is the oldest unit of the Cuyo Group. It is composed of marine sediments interbedded with basaltic flows at the base and rhyolitic ignimbrites in the upper levels. The thickness varies from a few meters up to 400 meters. The La Primavera Formation is covered in apparent conformity by the Los Molles Formation, which has limestones at the base and contains pelites with andesitic lahar intercalations deposited in a turbiditic regime. Regionally, the Huarpican unconformity marks the transition between the post-orogenic stage when the Permian volcano-plutonic complex was formed, and the Triassic rifting stage when extension allowed magmas to ascend rapidly from sublithospheric levels. The unconformities that followed the Huarpican diastrophic phase are considered to be of minor hierarchy, and to only represent changes in the velocity of the rift opening. Chemicaly, the volcanic rocks belong to the calc-alkalines series, displaying moderate to high Mg# numbers and the less altered rocks are potassium-poor. The very low incompatible elements enrichments indicate that the mantle melting percentages were moderate to high and that crustal contamination was minimal. Taking these characteristics into account, Triassic volcanic rocks are proposed to have a volcanic arc associated with the subduction-related Triassic accretionary complexes found in the Chilean Cordillera de la Costa at these latitudes. During the Early Jurassic, this volcanic arc migrated westward as the region passed from a rifting to a backarc extension stage, at the time in which the huge marine ingression of the Cuyo Group took place. The moderate to high amount of mantle melting that gave rise to the volcanic arc magmas can be explained by an anomalous high geothermal gradient. Cooling of the area affected by this gradient could explain the non-lineal shape of the Neuquén basin at this latitude.

  1. A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from the Permian of China.

    Science.gov (United States)

    Reisz, Robert R; Liu, Jun; Li, Jin-Ling; Müller, Johannes

    2011-05-01

    Captorhinids, a clade of Paleozoic reptiles, are represented by a rich fossil record that extends from the Late Carboniferous into the Late Permian. Representatives of this clade dispersed from the equatorial regions of Laurasia into the temperate regions of Pangea during the Middle and Late Permian. This rich fossil record shows that there was an evolutionary trend from faunivorous to omnivorous and herbivorous feeding habits within this clade. The discovery of well-preserved captorhinid materials in the Middle Permian of China allows us to determine that the new taxon, Gansurhinus qingtoushanensis, gen. et sp. nov, is a member of Moradisaurinae, a clade of captorhinids with multiple tooth rows arranged in parallel. The presence of this moradisaurine in the Middle Permian of south central Asia leads us to suggest that paleogeographic changes during the Permian, with part of what is today China becoming a large peninsula of Pangea, allowed these early reptiles as well as other terrestrial vertebrates to extend their geographic ranges to this region of the Late Paleozoic supercontinent. PMID:21484260

  2. Pumping test and fluid sampling report - Sawyer No. 1 well, Palo Duro Basin, Texas: unanalyzed data

    International Nuclear Information System (INIS)

    This report describes pumping test and fluid sampling activities performed at the Sawyer No. 1 well, Donley County, Texas. Sawyer No. 1 well is located along the eastern margin of the Palo Duro Basin in an area of active dissolution within the Permian salt section. These data were collected by Stone and Webster Engineering Corporation working in conjunction with the Texas Bureau of Economic Geology as part of a nationwide program to identify potential locations for a nuclear waste repository. These data support studies to determine the hydrologic characteristics of deep water-bearing formations. Formation fluid studies samples were analyzed in order to evaluate fluid migration and age relationships in the Permian Basin. These data were collected from June until October, 1981. Zone isolation for pump testing was accomplished in November, 1981. These data are preliminary. They have been neither analyzed nor evaluated

  3. Application of Markov chain and entropy analysis to lithologic succession – an example from the early Permian Barakar Formation, Bellampalli coalfield, Andhra Pradesh, India

    Indian Academy of Sciences (India)

    Ram Chandra Tewari; D P Singh; Z A Khan

    2009-10-01

    A statistical approach by a modified Markov process model and entropy function is used to prove that the early Permian Barakar Formation of the Bellampalli coal field developed distinct cyclicities during deposition.From results,the transition path of lithological states typical for the Bellampalli basin is as:coarse to medium-grained sandstone $\\longrightarrow $ interbedded fine-grained sandstone/shale $\\longrightarrow $ shale $\\longrightarrow $ coal and again shale.The majority of cycles are symmetrical but asymmetrical cycles are present as well.The chi-square stationarity test implies that these cycles are stationary in space and time.The cycles are interpreted in terms of in-channel,point bar and overbank facies association in a fluvial system.The randomness in the occurrence of facies within a cycle is evaluated in terms of entropy,which can be calculated from the Markov matrices.Two types of entropies are calculated for every facies state;entropy after deposition (post)and entropy before deposition (pre),which together form entropy set;the entropy for the whole system is also calculated.These values are plotted and compared with Hattori ’s idealized plots,which indicate that the sequence is essentially a symmetrical cycle (type-B of Hattroi). The symmetrical cyclical deposition of early Permian Barakar Formation is explained by the lateral migration of stream channels in response to varying discharge and rate of deposition across the alluvial plain.In addition,the fining upward cycles in the upper part enclosing thick beds of fine clastics,as well as coal may represent differential subsidence of depositional basin.

  4. Raining lead around 250mya a smoking gun for an Australian impact origin of the Permian Extinction

    CERN Document Server

    Standard, J C

    2003-01-01

    Recent documentation of extreme atmospheric sulfur and methane contents at the time of the vast Permo-Triassic (P-T) extinction makes it possible to interpret an observation that has lain unnoticed in the geological literature for 40 years. This is the finding of microscopic metallic lead tear drops in the fluvial strata of the early Triassic sandstones that overlie Permian coal beds and other sedimentary deposits in the Sydney basin of Australia. Elemental lead is almost unknown in nature, so its occurrence in these graphite-loaded sandstones is a provocative finding. While climate change and vulcanism could explain the carbon and sulfur anomalies, the only way to account for metallic lead aerodynamic droplets is by massive impact and vaporization of lead mineral-containing formations. Since lead occurs geologically as the sulfide and since lead is an easily reduced element, its occurrence in conjunction with sulfur and carbon count anomalies suggests a bolide impact on carbon-loaded strata in a sulfide mine...

  5. Sedimentary facies reconstruction and kinematic restoration of tight gas fields. Studies from the Upper Permian in Northwestern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Vackiner, Anna Alexandra [RWTH Aachen Univ. (Germany). Energy and Mineral Resources Group

    2013-11-01

    Outstanding Ph.D. thesis nominated for a Springer Theses Prize by the RWTH Aachen University, Germany. A multi-disciplinary study with application in the oil and gas industry. Approx. 60 color figures. The thesis of Anna Alexandra Vackiner focuses on the geometric architecture and tectonic evolution of the Permian series, combining seismic interpretation (3D block), field studies in an analogue basin (Panamint Valley in California), as well as 2D restoration of representative cross sections through time in order to illustrate the complex interaction between multiphase extension, inversion and salt diapirism. It will be of major interest for exploration geologists involved in tectonically complex areas. - Francois Roure, August 2012 This thesis improves the understanding and localization of the Upper Rotliegend II tight gas reservoir rock facies. It provides insights into the detailed Upper Rotliegend II palaeo-topography and local tectonically induced sediment thickness changes prior to a multi-phase tectonic overprinting. The research presented in this study further focuses on the tectonically induced synsedimentary facies distribution in transtensional continental settings on the basis of a comparison with a modern field analogue, which enables a detailed analysis of the reservoir rock's distribution and its properties. The study is rounded off with an analysis of the influence of the multiphase tectonic overprinting on the mature Upper Rotliegend II reservoir rocks.

  6. Plant fossil distributions in some Australian Permian non-marine sediments

    Energy Technology Data Exchange (ETDEWEB)

    McLoughlin, S. (Western Australia University, Nedlands, WA (Australia). Dept. of Geology)

    1993-05-01

    Plant remains occur in all post-Devonian, lowland, terrestrial depositional systems, with distinctive assemblages characterizing discrete environments. Glossopterid gymnospherms dominate most Australian Permian coal-bearing sediments. Herbaceous pteridophytes, sphenophytes, and lycophytes are best represented in lower deltaic lacustrine and paludal deposits. Non-glossopterid gymnosperms mostly colonized drier flood plain and upland environments and are poorly represented in Australian Permian sequences. Fresh- and brackish-water algae are abundantly preserved in paludal and lacustrine facies in both alluvial and delta plain environments. Seasonal productivity and taphonomic factors undoubtedly influenced the composition of interseam compression/impression floras but integration of information from these assemblages with that from permineralized peats, in-situ coalified plants, and coal maceral and palynological analyses can assist in the interpretation of Australian Permian coal-forming environments and the structure of plant communities.

  7. Shallow marine ecosystem feedback to the Permian/Triassic mass extinction

    Science.gov (United States)

    Wang, Yongbiao; Meng, Zheng; Liao, Wei; Weng, Zeting; Yang, Hao

    2011-03-01

    Late Permian reefs developed widely on shallow marine carbonate platforms in South China but disappeared far below the main mass extinction level of the latest Permian. The collapse of reef ecosystem may be related to the enhanced volcanism at the end of Late Permian. Notably, some colony corals and reef-building sponges were found to occur near the mass extinction boundary, inferring the eclipse of reef ecosystem is ahead of the disappearance of reef-building organisms, and the triggers would be present long before the main mass extinction. As the primary producers, the calcareous algae are rich in platform limestones of Late Permian and played a very important role in maintaining the shallow benthic ecosystems. The calcareous algae were found to disappear synchronously with the great reduction of foraminifers, which were ecologically associated with these algae. The extinction of Late Permian calcareous algae greatly reduced the biodiversity of primary producers in the shallow marine environment and destroyed in part the structure and the base of the shallow marine ecosystems, which in turn cause the extinction of ecologically associated metazoan. Microbialites developed on carbonate platforms immediately after the end-Permian mass extinction, representing a simple and unique microbial ecosystem. Widespread occurrence of microbialites symbolized the deterioration of marine environmental conditions and the dramatic revolution of marine ecosystems. As the new primary producers instead of the extinguished calcareous algae, cyanobacteria in the microbialites were an important base of this peculiar ecosystem and contributed greatly to the survival of the remnant faunas after the mass extinction. Widespread occurrence of microbialites in shallow marine environment is suggested to be related to the elevated level of volcanism-induced greenhouse gases and enhanced evaporation and hypersaline condition in addition to the decrease of metazoan grazing pressure. The change from calcareous algae and reef ecosystem to the cyanobacteria-dominated microbial ecosystem documented in the shallow marine sequences in South china is the ecological feedback to the deterioration of the marine environmental conditions probably induced by volcanism.

  8. NEW FINDINGS OF PERMIAN FUSULINIDS AND CORALS FROM WESTERN KARAKORUM AND E HINDU KUSH (PAKISTAN

    Directory of Open Access Journals (Sweden)

    ERNST JA. LEVEN

    2007-07-01

    Full Text Available Additional findings of fusulinids and corals from Permian rocks of Western Karakorum and Eastern Hindu Kush are reported. The Lashkargaz Fm. of Western Karakorum (Sakmarian - Kubergandian in age, is redefined in its uppermost part. A new unit of sucrosic dolostone, the Ini Sar Fm., of early Murgabian age in its basal part, is established for a level previously attributed to the Ailak Fm. The Ailak Fm. is confirmed to be Late Permian in its lower part. A rich fusulinid fauna of early Kubergandian age was found in a carbonate nappe previously unidentified, along the Pakistan-Afghanistan border in the Eastern Hindu Kush. 

  9. Anoxia duirng the Late Permian Binary Mass Extinction and Dark Matter

    CERN Document Server

    Abbas, S; Mohanty, S; Abbas, Samar; Abbas, Afsar; Mohanty, Shukadev

    2000-01-01

    Recent evidence quite convincingly indicates that the Late Permian biotic crisis was in fact a binary extinction with a distinct end-Guadalupian extinction pulse preceding the major terminal end-Permian Tartarian event by 5 million years. In addition anoxia appears to be closely associated with each of these end-Paleozoic binary extinctions. Most leading models cannot explain both anoxia and the binary characteristic of this crisis. In this paper we show that the recently proposed volcanogenic dark matter scenario succeeds in doing this.

  10. Magnetostratigraphic and geochronological age constraints on the lowermost Beaufort Group, Karoo Basin, South Africa

    Science.gov (United States)

    Tohver, E.; Lanci, L.; Wilson, A.; Flint, S.

    2011-12-01

    The Karoo Basin of South Africa is a classic foreland basin sequence, with sedimentation putatively linked to Gondwanide orogenesis in the Cape Fold Belt. Biostratigraphic data for the fluvial to lacustrine sediments of the Beaufort Group have traditionally assigned a late Permian age to these foreland basin sediments on the basis of Glossopteris flora and Dicynodont fauna findings. This age conflicts with recently published U-Pb zircon age data from below the Beaufort Group that suggested a latest Permian, early Triassic age for those rocks. In order to resolve this discrepancy, we undertook a coupled magnetostratigraphic and geochronological study of the lowermost Beaufort Group of South Africa. Volcanic zircons from various tuffaceous horizons were analyzed for U-Pb age by SHRIMP. The youngest population of late Permian zircons are interpreted as the age of volcanic ashfall and sedimentation, with inheritance from pre-existing crust recognized from the presence of ca. 500 Ma and 1000-1100 Ma zircons. The possibility of Pb loss from these youngest grains will be assessed by CA-TIMS work. Magnetostratigraphic sampling was carried out in two separate sedimentary profiles, 169 m and 549 m thick, that are separated by roughly 85 km across depositional strike. Diagnostic patterns of normal and reversed magnetozones allow for the close correlation of these two sections. This pattern, anchored by the U-Pb zircon ages, can be correlated to the Global Polarity Timescale of Ogg et al. (2008), and supports a late Guadalupian age for these sediments.

  11. Digital data in support of studies and assessments of coal and petroleum resources in the Appalachian basin: Chapter I.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Trippi, Michael H.; Kinney, Scott A.; Gunther, Gregory; Ryder, Robert T.; Ruppert, Leslie F.

    2014-01-01

    The Appalachian basin is a mature basin containing abundant oil, gas, and coal resources. Its fossil-fuel-bearing strata range in age from Cambrian to Permian and extend over the States of New York, Pennsylvania, Maryland, Ohio, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. The basin has provided abundant fossil fuels to support the Nations economic growth for at least 150 years and U.S. Geological Survey (USGS) assessments suggest that substantial untapped resources remain. A merger of new and old geologic data and ideas is required to locate and extract those remaining resources.

  12. Characterization of trace elements in sulphur-rich Late Permian coals in the Heshan coal field, Guangxi, South China

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Rongshu; Xu, Wendong [Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China); Zhuang, Xinguo [Faculty of Earth Resources (China); Koukouzas, N. [Centre for Research and Technology Hellas/Institute of Solid Fuels Technology and Applications, (CERTH/ISFTA), IPTA-NRCPS Demokritos, GR-15310 Ag. Paraskevi-Athens (Greece)

    2005-01-18

    The concentration of trace elements and their distribution in the late Permian coal in the Heshan coal field, Guangxi Autonomous Region, were analysed in this paper. The late Permian coal of the Heshan mining district was developed in a low energy and shallow, confined carbonate platform. Heshan coal is a low volatile bituminous coal characterized by a high sulphur content, ranging between 2.0% and 8.2%. Compared with the worldwide average content of the trace elements in coal, the content of some trace element in the study coal is markedly high (Bi, Ce, Cr, Cs, Cu, Ga, Hf, Sr, Ta, Th, U, V, W, Y, Zr, La, Mo, Nb and Sc). The trace element associations were investigated by means of intracorrelation analysis. Some elements, such as Cl, F and Sr are found in coal in association with the carbonate minerals. V, Cr, Zn, Mo, Ni and As contents in coal vary significantly amongst the coal samples. They are mainly concentrated in the lower part of the coal no.4 upper of Suhe and Lilan mines and the coal no.4 lower of Dong mine, and these possibly occurring in minerals such as arsenide and sulphide. The content of U in Heshan coal is high and is mainly concentrated at the upper and the lower parts of the coal seam and it is associated with mineral assemblages with Ba, Mo, V, Ni, Zn, Rb and Cr. Furthermore, La and Ce are highly correlated with those found in phosphate minerals and Pb, Sc, Ga, Th, Y and Sn to those in aluminosilicate minerals. The enrichment of some elements such as V, Cr, Zn, Mo, Ni, Rb as well as total sulphur and iron in the lower part of most coal seams might be associated with the formation of soil horizon before the accumulation of peat in the basin. Some other elements such as Cl, F, Sr and Ca are locally concentrated in the top of specific coal seams as a result of the leaching from overlying carbonates.

  13. Tectonic evolution of the Colorado Basin, offshore Argentina, inferred from seismo-stratigraphy and depositional rates analysis

    OpenAIRE

    J. Loegering, Markus; Anka, Z.; Autin, Julia; Di Primio, Rolando; Marchal, Denis; F. Rodriguez, Jorge; Franke, D.; Vallejo, Eduardo

    2013-01-01

    Based on a dense 2D seismic reflection dataset and information from 8 exploration wells, we reinterpreted the stratigraphic evolution of the Colorado Basin. The basin is located on the continental shelf and slope within 50 to 2250 m of bathymetry. The total sediment fill can be up to 16,000 m. Seismic-to-well log correlations provide a chrono-stratigraphic framework for the interpreted seismic sequences. We show that the Colorado Basin records the development of a Permian pre-rift period, a T...

  14. Avalonian crustal controls on basin evolution: implications for the Mesozoic basins of the southern North Sea

    Science.gov (United States)

    Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

    2015-04-01

    Little is known of the Southern North Sea Basin's (SNSB) Pre-Permian basement due to a lack of outcrop and cores. The nature and structure of the East Avalonian crust and lithosphere remain even less constrained in the absence of deep seismic (refraction) lines. However, various studies have hinted at the importance of the Reactivation of the Early Carboniferous fault network during each consecutive Mesozoic and Cenozoic tectonic phase, demonstrating the key role of weak zones from the Early Carboniferous structural grain in partitioning of structural deformation and vertical basin motions at various scales. Although the older basin history and the basement attract increasing attention, the Pre-Permian tectonics of the SNSB remains little studied with most attention focused on the Permian and younger history. The strong dispersal of existing constraints requires a comprehensive study from Denmark to the UK, i.e. the East Avalonian microplate, bordered by the Variscan Rheïc suture, the Atlantic and Baltica. Based on an extensive literature study and the reinterpretation of publicly available data, linking constraints from the crust and mantle to stratigraphic-sedimentological information, we complement the map of Early Carboniferous rifting of East Avalonia and propose a new tectonic scenario. From the reinterpretation of the boundary between Avalonia and Baltica we propose a new outline for the Avalonian microplate with implications for the tectonics of the North German Basin. Furthermore, we highlight the nature and extent of the major crustal/lithospheric domains with contrasting structural behaviour and the major boundaries that separate them. Results shed light on the effects of long lived differences in crustal fabric that are responsible for spatial heterogeneity in stress and strain magnitudes and zonations of fracturing, burial history and temperature history. The geomechanical control of large crustal-scale fault structures will provide the constraints and geometrical and compositional input for local models of stress and strain. Results will be further used to validate and to test inferred erosion patterns and the potential effect on stress differentiation, in view of the exploration and production of (un)conventional hydrocarbons.

  15. Anatomy of a Permian Erg sequence: the De La Cuesta Formation (northwestern Argentina)

    International Nuclear Information System (INIS)

    This work is about the Permian red beds of the La Cuesta Formation (Sierra de Narvaez, northwestern Argentina) which is composed of sandstones associated with mud stones and subordinate conglomerates. The sediments obtained from the interaction between aeolian and ephemeral fluvial systems, are represented by aeolian dune, dry aeolian inter dune and aeolian sand sheet, mud flat, wet aeolian inter dune, and fluvial deposits

  16. Taeniopterid lamina on Phasmatocycas megasporophylls (Cycadales) from the Lower Permian of Kansas, U.S.A.

    Science.gov (United States)

    Gillespie, W.H.; Pfefferkorn, H.W.

    1986-01-01

    New specimens of Phasmatocycas and Taeniopteris from the original Lower Permian locality in Kansas demonstrate organic attachment of the two and corroborate Mamay's hypothesis that Phasmatocycas and Taeniopteris were parts of the same plant. These forms also suggest that cycads evolved from taxa with entire leaves; i.e. Taeniopteris, rather than from pteridosperms with compound leaves. ?? 1986.

  17. Marine anoxia and delayed Earth system recovery after the end-Permian extinction.

    Science.gov (United States)

    Lau, Kimberly V; Maher, Kate; Altiner, Demir; Kelley, Brian M; Kump, Lee R; Lehrmann, Daniel J; Silva-Tamayo, Juan Carlos; Weaver, Karrie L; Yu, Meiyi; Payne, Jonathan L

    2016-03-01

    Delayed Earth system recovery following the end-Permian mass extinction is often attributed to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains poorly constrained. Here we use paired records of uranium concentrations ([U]) and (238)U/(235)U isotopic compositions (δ(238)U) of Upper Permian-Upper Triassic marine limestones from China and Turkey to quantify variations in global seafloor redox conditions. We observe abrupt decreases in [U] and δ(238)U across the end-Permian extinction horizon, from ∼3 ppm and -0.15‰ to ∼0.3 ppm and -0.77‰, followed by a gradual return to preextinction values over the subsequent 5 million years. These trends imply a factor of 100 increase in the extent of seafloor anoxia and suggest the presence of a shallow oxygen minimum zone (OMZ) that inhibited the recovery of benthic animal diversity and marine ecosystem function. We hypothesize that in the Early Triassic oceans-characterized by prolonged shallow anoxia that may have impinged onto continental shelves-global biogeochemical cycles and marine ecosystem structure became more sensitive to variation in the position of the OMZ. Under this hypothesis, the Middle Triassic decline in bottom water anoxia, stabilization of biogeochemical cycles, and diversification of marine animals together reflect the development of a deeper and less extensive OMZ, which regulated Earth system recovery following the end-Permian catastrophe. PMID:26884155

  18. Integrated Sr isotope variations and global environmental changes through the Late Permian to early Late Triassic

    Science.gov (United States)

    Song, Haijun; Wignall, Paul B.; Tong, Jinnan; Song, Huyue; Chen, Jing; Chu, Daoliang; Tian, Li; Luo, Mao; Zong, Keqing; Chen, Yanlong; Lai, Xulong; Zhang, Kexin; Wang, Hongmei

    2015-08-01

    New 87Sr/86Sr data based on 127 well-preserved and well-dated conodont samples from South China were measured using a new technique (LA-MC-ICPMS) based on single conodont albid crown analysis. These reveal a spectacular climb in seawater 87Sr/86Sr ratios during the Early Triassic that was the most rapid of the Phanerozoic. The rapid increase began in Bed 25 of the Meishan section (GSSP of the Permian-Triassic boundary, PTB), and coincided closely with the latest Permian extinction. Modeling results indicate that the accelerated rise of 87Sr/86Sr ratios can be ascribed to a rapid increase (>2.8×) of riverine flux of Sr caused by intensified weathering. This phenomenon could in turn be related to an intensification of warming-driven runoff and vegetation die-off. Continued rise of 87Sr/86Sr ratios in the Early Triassic indicates that continental weathering rates were enhanced >1.9 times compared to those of the Late Permian. Continental weathering rates began to decline in the middle-late Spathian, which may have played a role in the decrease of oceanic anoxia and recovery of marine benthos. The 87Sr/86Sr values decline gradually into the Middle Triassic to an equilibrium values around 1.2 times those of the Late Permian level, suggesting that vegetation coverage did not attain pre-extinction levels thereby allowing higher runoff.

  19. The Saint Martin de Belleville syncline and its uraniferous permian sandstone

    International Nuclear Information System (INIS)

    This dissertation (these de specialite) is a study of the geology of the St.Martin d.B. syncline and the uranium prospect 'le Cochet' in the Carboniferous Brianconnais Zone of Savoy. Stratigraphy and sedimentology: This syncline presents continental detrital sediments ranging from U.Carboniferous to L.Triassic. In the U.Carboniferous, magmatic activity begins with the Moriaz Layers acid volcanics that are considered as a lateral equivalent of the Stephanian Courchevel Conglomerates. In Permian times, parts of an alluvial fan seem to occupy the north of the study area (gray and green conglomeratic sandstone). Southwards these inter-finger with flood plain sediments (red slate) including a locally oolitic limestone. Volcanic detritus is important in the Permian. Tourmalinite pebbles are frequent and seem to be related to the regional Permian magmatism. Albitization of feldspars is general in the Carboniferous and the Permian. The Permo-triassic typically shows microcline bearing dolomitic sandstones. In the Scythian quartzites orthoclase is the dominant feldspar. The quartzites are overlain by L.Triassic evaporites identified by the sulfur isotope ratio of their gypsum. The morphology of the zircons in the sandstones has been investigated using the typological method of J.P. Pupin. Regional Permian magmatism apparently produces volcanics of the calc-alkalic and tholeiitic series as well as a high level granitic intrusion of anatectic origin. The uranium occurrences are strata-bound on a kilometric and hecto-metric scale. They are developed almost exclusively in the gray variety of the Permian sandstones whose gray and red varieties are always barren. Within this unit, the mineralization impregnates irregularly distributed lenses and pods of coal material. Uranium is accompanied by vanadium occurring as roscoelite. The association U-V, of bio-philic character, reflects the concentration in the sedimentary environment and argues for a quite indirect relation with the source rocks. The mineralization is regarded as syn-genetic or more probably early epigenetic of Permian age, related to surface or groundwater flow that precipitated its metal content on wooden debris ('trash piles') in the host rocks. Alpine deformation resulted in folds and strong schistosity striking N2O that almost obliterate north verging transverse folds. The deformation caused plastic flow of the mineralized carbonaceous material on a metric scale. This material is now commonly found in lenses parallel to schistosity. Metamorphism is at the epizone/anchizone limit with a barrovian to high pressure gradient. It had practically no effect on the mineralization. (author)

  20. The western basins : relative economics and supply potential : three short stories

    International Nuclear Information System (INIS)

    A review of the major producing oil and gas basins of the Rocky Mountains, San Juan and Permian basins was presented. This paper dealt with how much gas is available and at what cost given the technical challenges associated with extraction. It was predicted that the historical and projected gas demand patterns as well as new pipeline capacity expansions will impact the basis. This paper referred to the Dynegy Deal (market power), the Basis Squash (pipeline expansions) and the Power River Bomb (significant new production). 4 tabs., 5 figs

  1. Stratigraphic and palaeoenvironmental framework of the Early Permian sequence in the Salt Range, Pakistan

    Indian Academy of Sciences (India)

    Shahid Ghazi; Nigel P Mountney; Aftab Ahmad Butt; Sadaf Sharif

    2012-10-01

    The Early Permian Gondwana regime succession of the Nilawahan Group is exposed only in the Salt Range of Pakistan. After a prolonged episode of non-deposition that spanned much of the Palaeozoic, the 350 m thick predominantly clastic sequence of the Nilawahan Group records a late glacial and post-glacial episode in which a range of glacio-fluvial, marine and fluvial environments evolved and accumulated. The Early Permian succession of the Salt Range has been classified into four formations, which together indicates a changing climatic regime during the Early Permian in the Salt Range region. The lower-most, Tobra Formation unconformably overlies a Cambrian sequence and is composed of tillite, diamictite and fresh water facies, which contain a floral assemblage (Gangamopteris and Glossopteris) that confirms an Asselian age. The Tobra Formation is overlain by marginal marine deposits of the Dandot Formation (Sakmarian), which contain an abundant brachiopods assemblage (Eurydesma and Conularia). Accumulation of the Dandot Formation was terminated by a regional sea-level fall and a change to the deposition of the fluvial deposits of the Warchha Sandstone (Artinskian). The Warchha Sandstone was deposited by high sinuosity meandering, avulsion prone river with well developed floodplains. This episode of fluvial sedimentation was terminated by a widespread marine transgression, as represented by the abrupt upward transition to the overlying shallow marine Sardhai Formation (Kungurian). The Early Permian Gondwana sequence represented by the Nilawahan Group is capped by predominantly shallow shelf carbonate deposits of the Tethyan realm. The sedimentologic and stratigraphic relationship of these four lithostratigraphic units in the Salt Range reveals a complex stratigraphic history for the Early Permian, which is mainly controlled by eustatic sea-level change due to climatic variation associated with climatic amelioration at the end of the major Gondwana glacial episode, and the gradual regional northward drift to a lower latitude of the Indian plate.

  2. Ostracods (Crustacea associated with microbialites across the Permian-Triassic boundary in Dajiang (Guizhou Province, South China

    Directory of Open Access Journals (Sweden)

    Marie-Beatrice FOREL

    2012-08-01

    Full Text Available 26 samples were processed for a taxonomic study of ostracods from the Upper Permian (Changhsingian - Lower Triassic (Griesbachian interval of the Dajiang section, Guizhou Province, South China. 112 species belonging to 27 genera are recognized. Five new species are described: Acratia candyae sp. nov, Bairdia adelineae sp. nov., Bairdia? huberti sp. nov., Bairdia jeromei sp. nov., Orthobairdia jeanlouisi sp. nov. The unexpected survival faunas associated with microbial formations in the aftermath of the end-Permian extinction are documented for the first time. Ostracod biodiversity variations and palaeo-environmental modifications associated with microbial growth through the Permian-Triassic boundary (PTB are discussed.

  3. Detrital zircon geochronology in blueschist-facies meta-conglomerates from the Western Alps: implications for the late Carboniferous to early Permian palaeogeography

    Science.gov (United States)

    Manzotti, Paola; Poujol, Marc; Ballèvre, Michel

    2015-04-01

    In the Western Alps, the Money Complex of the Gran Paradiso Massif, metamorphosed under blueschist facies during the Alpine cycle, is considered to be Permo-Carboniferous in age, but no palaeontological or radiometric data constrain this interpretation. A revision of the lithostratigraphy of the Money Complex allows recognizing a polygenic (graphite-rich) and a monogenic (graphite-poor) meta-sedimentary formation. Detrital zircon U-Pb geochronology in both meta-sedimentary formations shows that (i) the main population is Cambrian and Ordovician in age, (ii) the youngest grains are Silurian and Lower Devonian, and (iii) Carboniferous zircon grains are lacking. A careful study of the age distributions in the Alps suggests that potential source for the detrital material in the Money Complex is the Briançonnais basement. Late Carboniferous magmatism is widespread in the Helvetic Zone of the Alps. Permian magmatism is dominant in the Briançonnais, the Austroalpine and the Southalpine basements. The lack of Carboniferous zircons in the Money Complex suggests that the detritus was not shed from the Helvetic zone, which was separated from the Money basin by the Zone Houillère basin, where the main drainage pattern was developed from south to north and where the depocenters migrated northwards from the Upper Missisippian to Upper Pennsylvanian. We suggest that the Money Complex may had been located to the east of the main river drainage inside the Zone Houillère basin or alternatively may represent a small basin, located on the east of the Zone Houillère.

  4. Pteridophytes from Lower Gondwana formations of the Ib River Coalfield, Orissa and their diversity and distribution in the Permian of India

    Science.gov (United States)

    Goswami, Shreerup; Jeet Singh, Kamal; Chandra, Shaila

    2006-12-01

    Recent extensive investigations carried out in the Ib River Coalfield, Mahanadi Master Basin, Orissa, identified numerous fossiliferous beds in the lower Gondwana deposits. Six exposures of the Barakar and lower Kamthi formations yielded diverse and abundant plant remains. The flora includes twenty-three genera representing nine groups viz., Lycopodiales, Equisetales, Sphenophyllales, Filicales, Cordaitales, Coniferales, Ginkgoales, Cycadales and Glossopteridales. Systematic descriptions of the pteridophyte taxa namely Cyclodendron (Lycopodiales), Schizoneura, Raniganjia, Bengalia, equisetaceous stems (Equisetales), Trizygia, Benlightfootia (Sphenophyllales), Neomariopteris, and Dichotomopteris (Filicales) are presented in this paper. Pteridophytic leaves comprising nine taxa viz., Cyclodendron leslii, Schizoneura gondwanensis, Raniganjia bengalensis, Bengalia raniganjensis, Trizygia speciosa, Benlightfootia indica, Neomariopteris hughesii, N. talchirensis, and Dichotomopteris sp. together with equisetaceous stems constitute about 7.88% (72 specimens) of the total plant assemblage collected from this coalfield. Among the pteridophytes, equisetaceous stems are most abundant (40.3%; 29 specimens) followed by Schizoneura gondwanensis (20.8%, 15 specimens) and Trizygia speciosa (13.9%, 10 specimens). A summary of the known diversity of pteridophytes in the Indian Permian as a whole is provided. Barakar Formation exposures have been assigned to a lower and upper series based on possession of different floristic assemblages. Pteridophytes do not occur in the lower series. On this basis the beds of Lajkura, Jurabaga collieries, Ratanpur Fireclay Quarry and the locality near Belpahar Railway Station with pteridophyte fossils are assigned to the upper Barakar Formation (late Artinskian). Based on assemblages containing different pteridophytes, beds exposed at Sitaram and Dungri Pahar are assigned to the lower Kamthi Formation (Lopingian). The floristic composition suggests a palaeoclimatic shift from temperate warm moist to warm dry conditions during the late Artinskian and warm and humid during Lopingian. The Permian pteridophytes grew in semi-aquatic conditions, i.e. in marshy places around small ponds, lakes and river-banks.

  5. Late Palaeozoic palynomorph assemblages from the Karoo Supergroup and their potential for biostratigraphic correlation, Kalahari Karoo Basin, Botswana

    OpenAIRE

    Modie B N; Le Hriss A

    2009-01-01

    Late Carbonifeous to Permian core samples from two borehole sections, STRAT 1 and CKP 6, that penetrate the glacial to postglacial and coal-bearing Lower Karoo sequence, Kalahari Karoo Basin, Botswana, contain well preserved pollen and spore palynomorphs. The palynomorph assemblages comprise 165 species of spores and pollen, and few acritarchs and chlorophycean algae. This paper presents a local biozonation of three succeeding assemblage zones, recognisable in each borehole section. The assem...

  6. The Siberian Traps and the end-Permian event: Geology, geochemistry and atmospheric modeling of gas release

    Science.gov (United States)

    Svensen, Henrik; Stordal, Frode; Roscher, Marco; Sokalska, Ewa; Planke, Sverre

    2013-04-01

    The Siberian Traps were emplaces through sedimentary basins covering the Siberian Craton, passing thick accumulations of carbonates and evaporites. Contact metamorphism of the sedimentary rocks around dolerite sills and dikes generated greenhouse gases and halocarbons to such an extent that the process could be responsible for both the end-Permian carbon isotope excursion and the mass extinction. The key processes are suggested to be 1) metamorphism of oil-saturated rock salt sequences (halocarbon production), 2) methane generation from metamorphism of organic-rich shales (methane production), and 3) decarbonation of dolostones (carbon dioxide production). We have analyzed the petrography and geochemistry (including carbon isotopes) of contact metamorphic carbonates from outcrops, and can document the devolatilization processes. In addition, we have explored the potential global warming effects of CO2 and CH4 emissions to the end-Permian atmosphere from the volatile generation. We have constrained the effect of century scale degassing events using the atmospheric lifetime of CH4 and CO2, the pre-event atmospheric composition in terms of methane and carbon-dioxide as well as H2S, the gas flux to the atmosphere, the IR absorption efficiency, the radiative forcing and the climate sensitivity. Assuming rapid emplacement of one single major sill intrusion into the Tunguska Basin, and 100 year gas release with 60% CH4 and 40% CO2, the global annual mean temperature could rise by 2-5°C (best estimate ~3.5°C). In contrast, degassing from subaerial lava flows with the same magma volume as a sill has one order of magnitude lower influence on the global climate, resulting in a warming of about 0.1°C. Per molecule CH4 is much more efficient in absorbing and re-emitting IR radiation than CO2, yielding a much stronger greenhouse effect in the Earth's atmosphere. Considering that the heat trapped in the atmosphere over a 100 year period resulting from an emission of CH4 is, under current conditions, about 25 times larger than from a similar mass of CO2, i.e. the Global Warming Potential (GWP) is ~25, the climate impact of a mixture containing 60% CH4 is strongly dominated by this compound. This effect increases with the amount of available H2S as it strongly influences the lifetime of CH4 in the atmosphere by reducing the oxidation potential. The method and geological model can be applied to other boundary events with LIPs, such as the Triassic-Jurassic boundary (~3.1°C), the Toarcian event (~2.9°C), and the Palaeocene-Eocene Thermal Maximum (~3.5°C).

  7. Basin analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, I. (Univ. of South Carolina, Columbia, SC (US))

    1989-01-01

    The exploration for oil is a high-risk game. Worldwide drilling success is around 5-10%, the average cost of drilling is around $1000 a foot, and the average well is now around 15,000 feet deep. Over the years, two fundamental avenues of attack have been developed: methods designed to locate oil in situ from direct measurement ahead of the drill and methods focusing on the dynamic evolution of a sedimentary basin in relation to the timing of hydrocarbon generation, migration, and accumulation to provide an assessment of which areas in a basin might be the most prospective for oil accumulations today. This volume addresses the problem of quantitative basin analysis in relation to oil accumulations. Emphasis is placed on the uncertainties and resolution limits of basin analysis given constraints derived from surface and downhole data and the sensitivity to model input parameters and assumptions.

  8. Life crises on land across the Permian-Triassic boundary in South China

    Science.gov (United States)

    Peng, Yuanqiao; Shi, G. R.

    2009-02-01

    The western Guizhou and eastern Yunnan area of southwest China commands a unique and significant position globally in the study of Permian-Triassic boundary (PTB) events as it contains well and continuously exposed PTB sections of marine, non-marine and marginal-marine origin in the same area. By using a range of high-resolution stratigraphic methods including biostratigraphy, eventostratigraphy, chronostratigraphy and chemostratigraphy, not only are the non-marine PTB sections correlated with their marine counterparts in the study area with high-resolution, the non-marine PTB sections of the study area can also be aligned with the PTB Global Stratotype Section and Point (GSSP) at Meishan in eastern China. Plant megafossils ("megaplants") in the study area indicate a major loss in abundance and diversity across the PTB, and no coal beds and/or seams have been found in the non-marine Lower Triassic although they are very common in the non-marine Upper Permian. The megaplants, however, did not disappear consistently across the whole area, with some elements of the Late Permian Cathaysian Gigantopteris flora surviving the PTB mass extinction and locally even extending up to the Lower Triassic. Palynomorphs exhibit a similar temporal pattern characterized by a protracted stepwise decrease from fern-dominated spores in the Late Permian to pteridosperm and gymnosperm-dominated pollen in the Early Triassic, which was however punctuated by an accelerated loss in both abundance and diversity across the PTB. Contemporaneous with the PTB crisis in the study area was the peculiar prevalence and dominance of some fungi and/or algae species. The temporal patterns of megaplants and palynomorphs across the PTB in the study area are consistent with the regional trends of plant changes in South China, which also show a long-term decrease in species diversity from the Late Permian Wuchiapingian through the Changhsingian to the earliest Triassic, with about 48% and 77% losses of species occurring respectively in the end-Wuchiapingian and end-Changhsingian. Such consistent patterns, at both local and regional scales, contradict the hypothesis of a regional isochronous extinction of vegetation across the PTB, and hence call into question the notion that the end-Permian mass extinction was a one-hit disaster. Instead, the data from the study area and South China appears more consistent with a scenario that invokes climate change as the main driver for the observed land vegetation changes across the PTB in South China.

  9. Euxinia prior to end-Permian main extinction at Xiaojiaba section, Sichuan Province, South China

    Science.gov (United States)

    Wei, H.; Algeo, T. J.; Chen, D.; Yu, H.

    2013-12-01

    Redox conditions in the global ocean prior to, during, and following the end-Permian mass extinction at 252.28 Ma remain contentious. Previous studies in western Australia, South China, and East Greenland have shown that photic-zone euxinia was present at least intermittently from the early Changhsingian through the Dienerian1-3. Here we report a study of organic carbon isotopes, pyrite sulfur isotopes, TOC, pyritic sulfur content, REE, and major and trace elements from the Upper Permian Xiaojiaba section in the Chaotian district of Guangyuan City, Sichuan Province, China. During the Permian-Triassic transition, this section was located on the northwestern margin of the South China Block, facing the Paleo-Tethys Ocean. Our results indicate that suboxic conditions prevailed during the Wuchiapingian and suboxic to anoxic conditions with several pulses of euxinia during the Changhsingian. δ13Corg values are mostly -28‰ to -26‰ but show three positive excursions (to -22‰) prior to the end-Permian mass extinction horizon. These positive excursions are associated with higher Spy concentrations (to ~1%). δ34Spy values are variable (from -41‰ to +5‰) but show a sharp negative excursion in the late Changhsingian (to -43.4‰) that coincided with the most positive δ13Corg values. This horizon is also associated with increases in Eu/Eu*, Baxs, ∑REE, Si, and redox-sensitive metals such as V. These patterns reflect linkage of the C and S cycles during the latest Permian, possibly in response to redox controls. The observed positive excursions in δ13Corg may be due to organic inputs from green sulfur bacteria, which exhibit a smaller photosynthetic fractionation (-12.5‰4) than eukaryotic algae. The pronounced negative excursion of δ34Spy corresponds to a sulfate-sulfide S isotope fractionation of about -60‰, suggesting a large flux of syngenetic framboidal pyrite, which would be indicative of euxinic water-column conditions. We infer that the euxinia prior to the main extinction horizon may have been caused by oceanic oxygen-minimum zone expansion and upward movement of the chemocline5. The coupled increases in Eu/Eu* and Baxs may record hydrothermal influence, possibly accompanied by increased ocean acidity and high seawater temperatures. Collectively, our results document major changes in seawater chemistry during the Changhsingian prior to the main end-Permian crisis.

  10. Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana

    OpenAIRE

    Cisneros, Juan Carlos; Abdala, Fernando; Jashashvili, Tea; de Oliveira Bueno, Ana; Dentzien-Dias, Paula

    2015-01-01

    Anomodontia was a highly successful tetrapod clade during the Permian and the Triassic. New morphological information regarding two bizarre basal anomodonts is provided and their palaeoecological significance is explored. The osteology of the recently discovered Tiarajudens eccentricus Cisneros et al. 2011, from the Brazilian Permian, is described in detail. The taxon exhibits unusual postcranial features, including the presence of gastralia. Additional preparation and computed tomography sca...

  11. Reworked calcretes: their significance in the reconstruction of alluvial sequences (Permian and Triassic, Minorca, Balearic Islands, Spain)

    OpenAIRE

    Gómez Gras, D.; Alonso-Zarza, Ana María

    2003-01-01

    The Permian and Triassic of Minorca (Balearic Islands) consists of a 670-m-thick, red, alluvial succession that includes in situ calcrete profiles and reworked calcrete material. In the Permian succession, the calcretes vary from laminar forms developed on the Carboniferous basement to weakly developed nodular calcretes in fluvial sediments. The palaeosols in the Triassic are mostly dolomitic, and the profiles reach up to Stage III of soil development (Spec. Pap.-Geol. Surv. Am. 203,...

  12. Permianpolysulphide-sideritebaritehaematite deposit Rude in Samoborska Gora Mts., ZagorjeTransdanubian zone of the Inner Dinarides

    OpenAIRE

    Borojevic Sostaric, Sibila; Palinka, Ladislav Antun; Strmi? Palinka, Sabina; Prochaska, Walter; Spangenberg, Jorge; Cuna, Stella; inkovec, Boris

    2010-01-01

    Samoborska Gora Mts. is situated within westernmost part of the ZagorjeMidTransdanubian zone of the Inner Dinarides. The Samoborska Gora Mts. consists dominantly of Permian unmetamorphosed siliciclastic sediments and evaporites, overlain by Lower Triassic sediments. Rude mineralization is hosted by Permian siliciclastic sediments, beneath gypsum and anhydrite strata. Central part of the deposit consists of 1.5 km long stratabound mineralization, grading laterally into ferruginou...

  13. Late Permian continental sediments in the SE Iberian Ranges, eastern Spain: Petrological and mineralogical characteristics and palaeoenvironmental significance

    OpenAIRE

    Benito Moreno, María Isabel; Horra del Barco, Raúl de la; Fernández Barrenechea, José María, ed. lit; López Gómez, José; Rodas, Magdalena; Alonso Azcárate, Jacinto; Arche, Alfredo; Luque del Villar, Francisco Javier, ed. lit

    2005-01-01

    A detailed mineralogical and petrological study and the analysis of paleosol profiles in continental alluvial sediments of the Late Permian in the SE Iberian Ranges (Spain) allow us to infer the significant environmental changes that occurred during this time period. Three parts have been distinguished in the Late Permian sediments (Alcotas Formation). The lower part includes abundant and well-preserved carbonate paleosol profiles and fine-grained sediments made up by quartz, feldspa...

  14. World class Devonian potential seen in eastern Madre de Dios basin

    Energy Technology Data Exchange (ETDEWEB)

    Peters, K.E.; Wagner, J.B. [Mobil Technology Co., Dallas, TX (United States); Carpenter, D.G. [Mobil New Business Development, Americas, Dallas, TX (United States); Conrad, K.T. [Mobil Exploration Norway, Stavanger (Norway)

    1997-02-17

    The Madre de Dios basin in northern Bolivia contains thick, laterally extensive, organic-rich Upper Devonian source rocks that reached the oil-generative stage of thermal maturity after trap and seal formation. Despite these facts, less than one dozen exploration wells have been drilled in the Madre de Dios basin, and no significant reserves have been discovered. Mobil geoscientists conducted a regional geological, geophysical, and geochemical study of the Madre de Dios basin. The work reported here was designed to assess the distribution, richness, depositional environment, and thermal maturity of Devonian source rocks. It is supported by data from over 3,000 m of continuous slimhole core in two of the five Mobil wells in the basin. Source potential also exists in Cretaceous, Mississippian, and Permian intervals. The results of this study have important implications for future exploration in Bolivia and Peru.

  15. Physiological implications of the abnormal absence of the parietal foramen in a late Permian cynodont (Therapsida)

    Science.gov (United States)

    Benoit, Julien; Abdala, Fernando; Van den Brandt, Marc J.; Manger, Paul R.; Rubidge, Bruce S.

    2015-12-01

    The third eye (pineal eye), an organ responsible for regulating exposure to sunlight in extant ectotherms, is located in an opening on the dorsal surface of the skull, the parietal foramen. The parietal foramen is absent in extant mammals but often observed in basal therapsids, the stem-group to true mammals. Here, we report the absence of the parietal foramen in a specimen of Cynosaurus suppostus, a Late Permian cynodont from South Africa (SA). Comparison with Procynosuchus delaharpeae, a contemporaneous non-mammalian cynodont from SA, demonstrates that the absence of this foramen is an abnormal condition for such a basal species. Because seasonality was marked during the Late Permian in SA, it is proposed that the third eye was functionally redundant in Cynosaurus, possibly due to the acquisition of better thermoregulation or the evolution of specialized cells in the lateral eyes to compensate for the role of the third eye.

  16. Physiological implications of the abnormal absence of the parietal foramen in a late Permian cynodont (Therapsida).

    Science.gov (United States)

    Benoit, Julien; Abdala, Fernando; Van den Brandt, Marc J; Manger, Paul R; Rubidge, Bruce S

    2015-12-01

    The third eye (pineal eye), an organ responsible for regulating exposure to sunlight in extant ectotherms, is located in an opening on the dorsal surface of the skull, the parietal foramen. The parietal foramen is absent in extant mammals but often observed in basal therapsids, the stem-group to true mammals. Here, we report the absence of the parietal foramen in a specimen of Cynosaurus suppostus, a Late Permian cynodont from South Africa (SA). Comparison with Procynosuchus delaharpeae, a contemporaneous non-mammalian cynodont from SA, demonstrates that the absence of this foramen is an abnormal condition for such a basal species. Because seasonality was marked during the Late Permian in SA, it is proposed that the third eye was functionally redundant in Cynosaurus, possibly due to the acquisition of better thermoregulation or the evolution of specialized cells in the lateral eyes to compensate for the role of the third eye. PMID:26538062

  17. Trace elemental analysis of permian gondwana coals in Bangladesh by PIXE technique

    International Nuclear Information System (INIS)

    The study of trace elements level in coal arouses much interest days to assess and evaluate the environmental impact related to its benefit and usage in applying it to the problem of mining site. Further, it is more important during the coal combustion in thermal power stations particularly in relation to the emission of air toxic, disposal and utilization of fly ash. The paper describes the level of nineteen environmentally significant trace elements found in recently discovered Permian Gondwana coals in Barapukuria and Khalaspir of Northwestern Bangladesh using Proton Induced X-ray Emission (PIXE) spectroscopy. Both the mineral species and trace elements are expected to be due to sedimentary and aerobic environmental condition where the Permian coals have been generated depending on their degree of evolution. (author)

  18. The fossil record of early tetrapods: worker effort and the end-Permian mass extinction

    OpenAIRE

    Bernard, Emma L.; Ruta, Marcello; Tarver, James E.; Michael J. Benton

    2010-01-01

    It is important to understand the quality of the fossil record of early tetrapods (Tetrapoda. minus Lissamphibia and Amniota) because of their key role in the transition of vertebrates from water to land, their dominance of terrestrial faunas for over 100 million years of the late Palaeozoic and early Mesozoic, and their variable fates during the end-Permian mass extinction. The first description of an early tetrapod dates back to 1824, and since then discoveries have occurred at a rather irr...

  19. Organic geochemistry across the Permian-Triassic transition at the Idrijca Valley, Western Slovenia

    International Nuclear Information System (INIS)

    Bulk and molecular stable C isotopic compositions and biomarker distributions provide evidence for a diverse community of algal and bacterial organisms in the sedimentary organic matter of a carbonate section throughout the Permian-Triassic (P/Tr) transition at the Idrijca Valley, Western Slovenia. The input of algae and bacteria in all the Upper Permian and Lower Scythian samples is represented by the predominance of C15-C22 n-alkanes, odd C-number alkylcyclohexanes, C27 steranes and substantial contents of C21-C30 acyclic isoprenoids. The occurrence of odd long-chain n-alkanes (C22-C30) and C29 steranes in all the samples indicate a contribution of continental material. The decrease of Corg and Ccarb contents, increase of Rock-Eval oxygen indices, and 13C-enrichment of the kerogen suggest a decrease in anoxia of the uppermost Permian bottom water. The predominance of odd C-number alkylcycloalkanes, C27 steranes, and C17 n-alkanes with δ13C values ∼-30%o, and 13C-enrichment of the kerogens in the lowermost Scythian samples are evidence of greater algal productivity. This increased productivity was probably sustained by a high nutrient availability and changes of dissolved CO2 speciation associated to the earliest Triassic transgression. A decrease of Corg content in the uppermost Scythian samples, associated to a 13C-depletetion in the carbonates (up to 4%o) and individual n-alkanes (up to 3.4%o) compared to the Upper Permian samples, indicate lowering of the primary productivity (algae, cyanobacteria) and/or higher degradation of the organic matter

  20. Anoxia/high temperature double whammy during the Permian-Triassic marine crisis and its aftermath

    OpenAIRE

    Wignall, PB; Chu, D.; Tong, J.; Y. Sun; Song, H; He, W.; Tian, L.

    2014-01-01

    The Permian-Triassic mass extinction was the most severe biotic crisis in the past 500 million years. Many hypotheses have been proposed to explain the crisis, but few account for the spectrum of extinction selectivity and subsequent recovery. Here we show that selective losses are best accounted for by a combination of lethally warm, shallow waters and anoxic deep waters that acted to severely restrict the habitable area to a narrow mid-water refuge zone. The relative tolerance of groups to ...

  1. Subsidence hazards caused by the dissolution of Permian gypsum in England : geology, investigation and remediation

    OpenAIRE

    Cooper, A.H.

    1998-01-01

    About every three years natural catastrophic subsidence, caused by gypsum dissolution, occurs in the vicinity of Ripon, North Yorkshire, England. Holes up to 35 m across and 20 m deep have appeared without warning. In the past 150 years, 30 major collapses have occurred, and in the last ten years the resulting damage to property is estimated at about £1000000. Subsidence, associated with the collapse of caves resulting from gypsum dissolution in the Permian rocks of eastern England, occurs in...

  2. Reproductive biology of the Permian Glossopteridales and their suggested relationship to flowering plants.

    OpenAIRE

    Taylor, E. L.; Taylor, T.N.

    1992-01-01

    The discovery of permineralized glossopterid reproduction organs from Late Permian deposits in the Beard-more Glacier region (central Transantarctic Mountains) of Antarctica provides anatomical evidence for the adaxial attachment of the seeds to the megaasporophyll in this important group of Late Paleozoic seed plants. The position of the seeds is in direct contradiction to many earlier descriptions, based predominatly on impression/compression remains. The attachement of the ovules on the ad...

  3. Brachiopods, fusulines and palynomorphs of the Mengkarang Formation (Early Permian, Sumatra) and their palaeobiogeographical significance

    Science.gov (United States)

    Crippa, G.; Angiolini, L.; Van Waveren, I.; Crow, M. J.; Hasibuan, F.; Stephenson, M. H.; Ueno, K.

    2014-01-01

    Brachiopods, fusulines and palynomorphs from the Lower Permian Mengkarang Formation (Sumatra, Indonesia) have been studied in order to establish the palaeogeographical position and the palaeolatitude of the West Sumatra Block. The position of the West Sumatra Block within the Palaeo-Tethys and Panthalassa oceans and its relationships to their marginal landmasses, in particular the Gondwana supercontinent and the Cathaysian palaeogeographical area, currently is uncertain.

  4. Geochemical anomalies near the Eocene-Oligocene and Permian-Triassic boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Asaro, F.; Alvarez, L.W.; Alvarez, W.; Michel, H.V.

    1981-10-01

    Evidence is presented to support the theory that several mass extinctions, i.e., those that define the Permian-Triassic boundary, the Cretaceous-Tertiary boundary, and the Eocene-1 Oligocene boundary, were caused by impact on the earth of extraterrestrial objects having the composition of carbonaceous chondrites and diameters of about 10 km. The evidence consists of anomalously high concentrations of iridium and other siderophile elements at the stratigraphic levels defining the extinctions. (ACR)

  5. Permian Palaeotemperature and Ice Volumes History: Evidence from Carbon and Oxygen isotopes

    OpenAIRE

    Chen, Bo

    2012-01-01

    High-resolution oxygen isotope record based on 356 measurements of conodont apatite from several low latitudinal sections in South China, USA and Iran was composed in order to unravel Permian palaeotemperature and ice volume history. Oxygen isotope analyses of different conodont taxa suggest that Streptognathodus and Hindeodus lived in near-surface seawater and recorded surface waters temperature, whereas the habitat of gondolellid genera was variable depending on sea level, with both near-su...

  6. Climatic and biotic upheavals following the end-Permian mass extinction

    OpenAIRE

    C. Romano; Goudemand, N.; Vennemann, T. W.; Ware, D.; Schneebeli-Hermann, E.; P. A. Hochuli; Brühwiler, T; Brinkmann, W.; Bucher, H.

    2013-01-01

    Recovery from the end-Permian mass extinction is frequently described as delayed, with complex ecological communities typically not found in the fossil record until the Middle Triassic epoch. However, the taxonomic diversity of a number of marine groups, ranging from ammonoids to benthic foraminifera, peaked rapidly in the Early Triassic. These variations in biodiversity occur amidst pronounced excursions in the carbon isotope record, which are compatible with episodes of massive CO2 outgassi...

  7. Ocean Acidification and the End-Permian Mass Extinction: To What Extent does Evidence Support Hypothesis?

    OpenAIRE

    Marie-Batrice Forel; Pierre-Yves Collin; Yue Li; Stephen Kershaw; Sylvie Crasquin

    2012-01-01

    Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO2, raising concern about marine diversity, food security and ecosystem services. Proxy evidence for acidification during past crises may help predict future change, but three issues limit confidence of comparisons between modern and ancient ocean acidification, illustrated from the end-Permian extinction, 252 million years ago: (1) problems with evidence for ocean acidification preserved in sedimentary rocks, wh...

  8. Provincialization of terrestrial faunas following the end-Permian mass extinction

    OpenAIRE

    Sidor, Christian A.; Vilhena, Daril A.; Angielczyk, Kenneth D.; Adam K. Huttenlocker; Nesbitt, Sterling J.; Peecook, Brandon R.; Steyer, J. Sébastien; Smith, Roger M H; Tsuji, Linda A.

    2013-01-01

    In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence on the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether the end-Permian mass extinction (252.3 Ma) affected the distribution of tetrapod faunas within the southern hemisphere and apply quantitative methods to analyze four components of biogeographic structure: connectedness, clustering, range size, and endemism. For all four ...

  9. FORAMINIFERA, ALGAE AND CARBONATE MICROPROBLEMATICA FROM THE LATE WUCHIAPINGIAN/DZHULFIAN (LATE PERMIAN) OF PELOPONNESUS (GREECE)

    OpenAIRE

    DANIEL VACHARD; ALEXANDRA ZAMBETAKIS-LEKKAS; EMMANUEL SKOURTSOS; ROSSANA MARTINI; LOUISETTE ZANINETTI

    2003-01-01

    The origin of late Permian olistoliths found in the Glypia Cenozoic flysch must be seeked in regions located to the east of the Parnon Mountain and in units that were more internal to Pindos Unit, especially in the islets of Karavia in the Argolis Gulf, and the Episkopi Formation in Hydra Island, that display probably the largest outcrops of this age. The most interesting olistolith is a bioclastic grainstone. It yields about forty taxa of algae, microproblematica, smaller foraminifers and fu...

  10. Evidence for a western extension of the Angaran phytogeographic province in the Early Permian

    Energy Technology Data Exchange (ETDEWEB)

    Sunderlin, David [Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637 (United States)

    2010-08-01

    A newly described Early Permian fossil plant assemblage in the Mt. Dall conglomerate in the Farewell terrane (Alaska Range, USA) is analyzed from a paleobiogeographic perspective. These data constitute the youngest paleontological dataset yet discovered in this terrane, represent the terrane's only predominantly terrestrial fossil assemblage, and are the only plant macrofossil remains of Early Permian age within a > 1500 km radius today. A suite of multivariate statistical analyses comparing the Mt. Dall paleoflora to similar age (Asselian-Artinskian) collections from the Angaran, Euramerican, and Cathaysian Permian phytogeographic provinces reveals that the Mt. Dall paleoflora has a paleobiogeographic affinity with Sub-Angaran plant fossil assemblages collected from Mongolia and the Primorye region of southeastern Russia. The paleoflora has dual importance in the construction and testing of hypotheses for which there are geographically and temporally few controls. First, these data may be used in association with other faunal and floral remains to test models of the assembly of Alaska, which seek, in part, an understanding of the paleogeographic and lithological origins of accreted terranes. That the Mt. Dall paleoflora indicates mixed Eurasia-North America paleobiogeographic affinity among individual taxa and plots in multivariate space with mid-latitude assemblages on northern Pangea may suggest deposition in that latitudinal belt. Second, contrary to the well-sampled fossil plant-bearing Permo-Carboniferous of the paleotropics and the northeastern temperate Pangean regions (Angaraland), terrestrial biome structure and vegetation type of northwestern Pangea are poorly known. This lack of understanding is due to the paucity of paleofloral collections from this region in this time period and the paleogeographic uncertainty of their position along the ancient active margin of Laurentia. The Mt. Dall paleoflora's phytogeographic affinity to paleobotanical collections from the northeastern Pangea therefore suggests that the Angaran province extended meridionally westward in the Early Permian into what is now northern North America. (author)

  11. PERMIAN CRINOIDS FROM THE SAIWAN AND KHUFF FORMATIONS,SOUTHEASTERN OMAN

    OpenAIRE

    GARY D. WEBSTER; ANDREA TINTORI; LUCIA ANGIOLINI

    2009-01-01

    Early Permian (Sakmarian) crinoids are described from six horizons in the Saiwan Formation of the Huqf area of southeastern Oman. Each horizon yielded only one to three taxa. All specimens lived in a shallow water environment characterized by mixed siliciclastic or siliciclastic-carbonate sedimentation. Disarticulated arm plates of an indeterminate articulate crinoid are described from a tempestite bed in the Khuff Formation (Wordian) of the Haushi area.The Saiwan Sakmarian crinoids are some ...

  12. Palynostratigraphy of Permian succession from Binja Block, South Karanpura Coalfield, Jharkhand, India

    Indian Academy of Sciences (India)

    Srikanta Murthy; Archana Tripathi; B Chakraborti; U P Singh

    2014-12-01

    Palynological investigations are carried out on approximately 538.00-m thick Gondwana strata from borehole SKB-1, Binja Block, South Karanpura Coalfield in Jharkhand. Based on the distribution pattern of age marker palynotaxa, two distinct palynoassemblages are identified. Palynoassemblage-I in the lithologically designated Barren Measures and Barakar formations, between 552.00 and 53.20 m depth show dominance of striate bisaccate (Striatopodocarpites, Crescentipollenites, and Faunipollenites) and abundance of nonstriate bisaccate (Scheuringipollenites). Upward the Palynoassemblage-II (39.5013.80 m depth) is rich in striate bisaccate (Striatopodocarpites and Crescentipollenites) and significant enveloping monosaccate Densipollenites magnicorpus pollen. These strata have been equated with Raniganj Formation of Latest Permian age. The First Appearance Datum (FAD) of Arcuatipollenites pellucidus, Playfordiaspora cancellosa, Alisporites sp., Falcisporites sp. and Krempipollenites indicus observed at 13.80 and 39.50 m depth, mark the transition of Permian into the Lower Triassic. The FADs of Guttulapollenites spp. at 49.10 and 504.70 m, Goubinispora morondavensis at 415.90 m, Alisporites ovalis and Arcuatipollenites sp. at 526.70 m is observed and suggest that these sediments are equivalent to Raniganj Formation, Late Permian in age.

  13. Modern Pearl River Delta and Permian Huainan coalfield, China: A comparative sedimentary facies study

    Science.gov (United States)

    Suping, P.; Flores, R.M.

    1996-01-01

    Sedimentary facies types of the Pleistocene deposits of the Modern Pearl River Delta in Guangdong Province, China and Permian Member D deposits in Huainan coalfield in Anhui Province are exemplified by depositional facies of anastomosing fluvial systems. In both study areas, sand/sandstone and mud/mudstone-dominated facies types formed in diverging and converging, coeval fluvial channels laterally juxtaposed with floodplains containing ponds, lakes, and topogenous mires. The mires accumulated thin to thick peat/coal deposits that vary in vertical and lateral distribution between the two study areas. This difference is probably due to attendant sedimentary processes that affected the floodplain environments. The ancestral floodplains of the Modern Pearl River Delta were reworked by combined fluvial and tidal and estuarine processes. In contrast, the floodplains of the Permian Member D were mainly influenced by freshwater fluvial processes. In addition, the thick, laterally extensive coal zones of the Permian Member D may have formed in topogenous mires that developed on abandoned courses of anastomosing fluvial systems. This is typified by Seam 13-1, which is a blanket-like body that thickens to as much as 8 in but also splits into thinner beds. This seam overlies deposits of diverging and converging, coeval fluvial channels of the Sandstone D, and associated overbank-floodplain deposits. The limited areal extent of lenticular Pleistocene peat deposits of the Modern Pearl River Delta is due to their primary accumulation in topogenous mires in the central floodplains that were restricted by contemporaneous anastomosing channels.

  14. Permian to tertiary faunas and paleogeography: Somalia, Kenya Tanzania, Mozambique, Madagascar, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Kamen-Kaye, M.

    1978-07-01

    Permian to Tertiary faunas along the eastern margin of Africa, and on Madagascar, are presented, described, and discussed. Presentation of the faunas is made in four charts: Permo-Triassic, Jurassic, Cretaceous, and Tertiary. A correlation chart provides tentative time-rock units. Paleogeography northeast and east of Africa is derived from the writer's analysis of marine invertebrate fauna, and is delineated in sketches for Late Permian, Jurassic, and Cretaceous times. Limitations exist on the conclusions that can be drawn from fauna alone. Pelagic waters can be indicated, but their extent cannot be specified, and lack of diversification in some of the pelagic genera results in unavoidable ambiguities of interpretation. Nothing in the faunal evidence so far available, however, disproves unequivocally the existence of an ancestral Indian Ocean from Late Permian onward. Even if such an ancestral ocean did not exist the pattern of pelagic waters that can be inferred from marine invertebrate fauna constitutes an impediment to models that suture Australia or India to Africa or Madagascar. Peninsular India, on readings of its own geology across the foreland-orogen boundary, may have occupied its present position through the whole of geologic time. 9 figures.

  15. Far-travelled Permian chert of the North Fork terrane, Klamath Mountains, California

    Science.gov (United States)

    Mankinen, Edward A.; Irwin, William P.; Blome, Charles D.

    1996-04-01

    Permian chert in the North Fork terrane and correlative rocks of the Klamath Mountains province has a remanent magnetization that is prefolding and presumably primary. Paleomagnetic results indicate that the chert formed at a paleolatitude of 8.6° ± 2.5° but in which hemisphere remains uncertain. This finding requires that these rocks have undergone at least 8.6° ± 4.4° of northward transport relative to Permian North America since their deposition. Paleontological evidence suggests that the Permian limestone of the Eastern Klamath terrane originated thousands of kilometers distant from North America. The limestone of the North Fork terrane may have formed at a similar or even greater distance as suggested by its faunal affinity to the Eastern Klamath terrane and more westerly position. Available evidence indicates that convergence of the North Fork and composite Central Metamorphic-Eastern Klamath terranes occurred during Triassic or Early Jurassic time and that their joining together was a Middle Jurassic event. Primary and secondary magnetizations indicate that the new composite terrane containing these and other rocks of the Western Paleozoic and Triassic belt behaved as a single rigid block that has been latitudinally concordant with the North American craton since Middle Jurassic time.

  16. Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

    Science.gov (United States)

    Ketner, Keith B.

    2009-01-01

    The Phosphoria Sea extended at least 500 km westward and at least 700 km southwestward from its core area centered in southeastern Idaho. Throughout that extent it displayed many characteristic features of the core: the same fauna, the same unique sedimentary assemblage including phosphate in mostly pelletal form, chert composed mainly of sponge spicules, and an association with dolomite. Phosphoria-age sediments in Nevada display ample evidence of deposition in shallow water. The chief difference between the sediments in Nevada and those of the core area is the greater admixture of sandstone and conglomerate in Nevada. Evidence of the western margin of the Phosphoria Sea where the water deepened and began to lose its essential characteristics is located in the uppermost part of the Upper Devonian to Permian Havallah sequence, which has been displaced tectonically eastward an unknown distance. The relatively deep water in which the mid-Permian part of the Havallah was deposited was a sea of probably restricted east-west width and was floored by a very thick sequence of mainly terrigenous sedimentary rocks. The phosphate content of mid-Permian strata in western exposures tends to be relatively low as a percentage, but the thickness of those strata tends to be high. The core area in and near southeastern Idaho where the concentration of phosphate is highest was separated from any possible site of upwelling oceanic waters by a great expanse of shallow sea.

  17. Permian vegetational Pompeii from Inner Mongolia and its implications for landscape paleoecology and paleobiogeography of Cathaysia.

    Science.gov (United States)

    Wang, Jun; Pfefferkorn, Hermann W; Zhang, Yi; Feng, Zhuo

    2012-03-27

    Plant communities of the geologic past can be reconstructed with high fidelity only if they were preserved in place in an instant in time. Here we report such a flora from an early Permian (ca. 298 Ma) ash-fall tuff in Inner Mongolia, a time interval and area where such information is filling a large gap of knowledge. About 1,000 m(2) of forest growing on peat could be reconstructed based on the actual location of individual plants. Tree ferns formed a lower canopy and either Cordaites, a coniferophyte, or Sigillaria, a lycopsid, were present as taller trees. Noeggerathiales, an enigmatic and extinct spore-bearing plant group of small trees, is represented by three species that have been found as nearly complete specimens and are presented in reconstructions in their plant community. Landscape heterogenity is apparent, including one site where Noeggerathiales are dominant. This peat-forming flora is also taxonomically distinct from those growing on clastic soils in the same area and during the same time interval. This Permian flora demonstrates both similarities and differences to floras of the same age in Europe and North America and confirms the distinct character of the Cathaysian floral realm. Therefore, this flora will serve as a baseline for the study of other fossil floras in East Asia and the early Permian globally that will be needed for a better understanding of paleoclimate evolution through time. PMID:22355112

  18. Further paleomagnetic results for lower Permian basalts of the Baoshan Terrane, southwestern China, and paleogeographic implications

    Science.gov (United States)

    Xu, Yingchao; Yang, Zhenyu; Tong, Ya-Bo; Wang, Heng; Gao, Liang; An, Chunzhi

    2015-05-01

    The Baoshan Terrane of southwestern China is considered to have been part of the Cimmerian block during the late Paleozoic; consequently, knowledge of its paleoposition and geological evolution can provide constraints on the Permian breakup of northern East Gondwana. Therefore, we conducted paleomagnetic and rockmagnetic studies on lower Permian basalts from four localities in the Baoshan Terrane. The basalts hold a stable characteristic remanent magnetization (ChRM) at high temperatures (300-680 °C) that is carried by magnetite, maghemite, and hematite with both pseudo-single and multiple domains. To test the reliability of data from these volcanic rocks, we analyzed the geomagnetic secular variation (GSV) and reliability of both the present data and previous paleomagnetic data. The results from 23 sites yield a single reversed polarity directed downwards to the southwest, giving a site-mean direction of Dg/Ig = 156.7°/56.6° (kg = 8.0, α95 = 11.4°) before tilt correction, and Ds/Is = 218.3°/60.1° (ks = 14.1, α95 = 8.4°) after tilt correction. The result passed the fold test, but the GSV was able to be averaged out in only two sections. All available data were examined section-by-section using the angular dispersion (SB) of virtual geomagnetic poles (VGPs) to ensure that the GSV was completely averaged out. Because the dispersion in declinations is likely to have been affectedby subsequent tectonic deformation, the paleosecular variation (PSV) could not be evaluated from all the data amassed from different sections, and the PSV was able to be removed from only four (combined) sections. A small-circle fit of these VGPs gives an averaged paleocolatitude of 51.9° ± 3.7° (N = 31 sites) centered on 24°N, 99°E. The result indicates that the sampled area of the Baoshan Terrane was located at a latitude of 38°S ± 3.7° during the late early Permian. A comparison of this result with early Permian data from Gondwanan blocks suggests that the Baoshan Terrane was situated near the junction of northern India and northwestern Australia, and that it broke away from western Australia after the early Permian.

  19. Late Permian Tsunamites in Guryul Ravine (Kashmir, India) - revisited and rejected

    Science.gov (United States)

    Krystyn, Leopold; Horacek, Micha; Brandner, Rainer; Parcha, Suraj

    2014-05-01

    Recent claims for tsunami-related event beds induced by the Siberian Trap basalts in this section (Brookfield et al., 2013) have to be questioned. Identical storm generated carbonate beds occur not only during a short interval close to the Permian-Triassic (P-T) boundary but through a major part of the late Permian (Changhsingian) succession there - as low as 26 m below the so-called tsunami beds. Moreover, during our recent study in a closely neighbouring place called Mandakpal (less than 10 km to the southeast), no signs of tsunamites have been detected in time-correlative finegrained sediments. Based on sedimentary and trace fossil evidence we interpret the late Permian of Guryul as relatively shallow, neritic and delta-influenced. The so-called tsunamites are shelly-enriched discontinuous carbonate lenses fed downslope through local channels. Judging from the distinct facies change from the storm related "tsunamites" to thinly bedded mud turbidites above, the sudden deepening may be explained by local and still rift-related tectonics along the NIM (North-Indian Gondwana Margin) which led to episodic seismic induced sediment redeposition in the area of Guryul. Synsedimentary tectonic activity with tilting and eventual Horst and Graben structure building along the large NIM is indicated by margin inversion during the P-T boundary interval leading to sedimentary breaks and 20 times thinner, condensed limestone deposits far offshore from Guryul in Spiti (Krystyn et al., 2004) and Tibet (Orchard et al., 1994). Thus, local seismic activity seems to be a far more logic explanation of the Guryul "tsunamites" than the eruption of the Siberian Traps more than 6000 km away. References Brookfield, M. E., Algeo, T. J., Hannigan, R., Williams, J and Bhat, G. M., 2013: Shaken and Stirred: Seismites and Tsunamites at the Permian-Triassic boundary, Guryul Ravine, Kashmir, India. Palaios, v. 28, 568-582. Krystyn, L., Balini, M. and Nicora, A., 2004: Lower and Middle Triassic stage boundaries in Spiti. Albertiana, v. 30, 40-53. Orchard, M.J., Nassichuk, W.W., Rui Lin, 1994: Conodonts from the lower Griesbachian Otoceras latilobatum Bed of Selong, Tibet and the position of the Permian-Triassic boundary. In: Pangea: Global Environments and Resources, Memoirs of the Canadian Society of Petroleum Geologists, vol. 17, 823-843.

  20. Vinna Basin

    Czech Academy of Sciences Publication Activity Database

    Honěk, J.; Franců, J.; Mikuláš, Radek; Pešek, J.; Sýkorová, Ivana; Tomanová-Petrová, P.

    Prague : Czech Geological Survey, 2014, s. 223-241 ISBN 978-80-7075-862-5 R&D Projects: GA ČR GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  1. On the origin of the ultradeep East Barents Sea basin

    Science.gov (United States)

    Gac, SéBastien; Huismans, Ritske S.; Podladchikov, Yuri Y.; Faleide, Jan Inge

    2012-04-01

    Very large subsidence, with up to 20 km thick sediment layers, is observed in the East Barents Sea basin. Subsidence started in early Paleozoic, accelerated in Permo-Triassic times, finished during the middle Cretaceous, and was followed by moderate uplift in Cenozoic times. The observed gravity signal suggests that the East Barents Sea is at present in isostatic balance and indicates that a mass excess is required in the lithosphere to produce the observed large subsidence. Several origins have been proposed for the mass excess. We use 1-D thermokinematic modeling and 2-D isostatic density models of continental lithosphere to evaluate these competing hypotheses. The crustal density in 2-D thermokinematic models resulting from pressure-, temperature-, and composition-dependent phase change models is computed along transects crossing the East Barents Sea. The results indicate the following. (1) Extension can only explain the observed subsidence provided that a 10 km thick serpentinized mantle lens beneath the basin center is present. We conclude that this is unlikely given that this highly serpentinized layer should be formed below a sedimentary basin with more than 10 km of sediments and crust at least 10 km thick. (2) Phase changes in a compositionally homogeneous crust do not provide enough mass excess to explain the present-day basin geometry. (3) Phase change induced densification of a preexisting lower crustal gabbroic body, interpreted as a mafic magmatic underplate, can explain the basin geometry and observed gravity anomalies. The following model is proposed for the formation of the East Barents Sea basin: (1) Devonian rifting and extension related magmatism resulted in moderate thinning of the crust and a mafic underplate below the central basin area explaining initial late Paleozoic subsidence. (2) East-west shortening during the Permian and Triassic resulted in densification of the previously emplaced mafic underplated body and enhanced subsidence dramatically, explaining the present-day deep basin geometry.

  2. Late Palaeozoic palynomorph assemblages from the Karoo Supergroup and their potential for biostratigraphic correlation, Kalahari Karoo Basin, Botswana

    Directory of Open Access Journals (Sweden)

    Modie B N

    2009-06-01

    Full Text Available Late Carbonifeous to Permian core samples from two borehole sections, STRAT 1 and CKP 6, that penetrate the glacial to postglacial and coal-bearing Lower Karoo sequence, Kalahari Karoo Basin, Botswana, contain well preserved pollen and spore palynomorphs. The palynomorph assemblages comprise 165 species of spores and pollen, and few acritarchs and chlorophycean algae. This paper presents a local biozonation of three succeeding assemblage zones, recognisable in each borehole section. The assemblage zones are named: the Hamiapollenites bullaeformis Biozone, the Cyclogranisporites gondwanensis Biozone and the Platysaccus papilionis-Striatopodocarpites fusus Biozone, in ascending order of stratigraphy. Assemblages are compared and correlated with assemblages described from other Gondwana areas of Africa, Australia, Arabia, South America and Antarctica. A general analysis of taxa from the Kalahari Karoo Basin indicates a distinct similarity with assemblages from the Paran Basin of South America. The Hamiapollenites bullaeformis Biozone is comparable with the Vittatina costabilis Interval Zone of the Paran Basin. Assemblages from the Cyclogranisporites gondwanensis and the Platysaccus papilionis-Striatopodocarpites fusus zones are comparable with the Lueckisporites virkkiae Interval Zone. Age determination for the assemblages in the Kalahari Karoo Basin is inferred from comparison with similar assemblages from previous Gondwana studies, and ranges from the Late Carboniferous (Kasimovian-Gzhelian to latest Early or possibly earliest Middle Permian (Late Cisularian to Early Guadalupian.

  3. Integrated Vitrinite Reflectance and Apatite Fission Track Thermocronology of the Lower Karoo rocks in the Moatize Basin, Tete Province, Mozambique.

    Science.gov (United States)

    Fernandes, Paulo; Cogné, Nathan; Rodrigues, Bruno; Jorge, Raul; Marques, João

    2014-05-01

    The Karoo in Mozambique is represented by Late Carboniferous to Late Triassic sediments that were deposited in rift basins that fringe or developed between Proterozoic cratons. In Tete Province, central-west Mozambique, the Karoo is well represented along the Zambezi river valley forming several intra-cratonic basins separated by horsts consisting of igneous and high grade metamorphic Proterozoic rocks. One of the main horst blocks is located between the Cahora Bassa region and Tete city, separating the Middle Zambezi Basin and the Lower Zambezi Basin. The area of study is located in the Moatize Basin, one of many small basins that form the Lower Zambezi Basin. The stratigraphy of this basin consists of several sedimentary formations that record changes in depositional environment and palaeoclimate from glacial (Vúzi Formation - Lower Permian) at the base, through wet to temperate in the middle (Moatize Formation - Lower Permian), to warm arid at the top of the succession (Matinde and Cádzi formations - Middle to Upper Permian). The Upper Karoo volcanics of Early Jurassic age do not crop out in the Moatize Basin. One of the most remarkable characteristics of the Moatize Basin is the richness of coal deposits present in the Lower Permian Moatize Formation. Two coal exploration boreholes (DW123 - T.D. 489 m and DW132 - T.D. 516 m) drilled in the Moatize Basin were studied by means of vitrinite reflectance (VR) and apatite fission track analysis (AFTA), in order to assess their burial and uplift histories. The two boreholes intersected only Moatize Formation lithologies. VR increases in the two borehole sections from ca. 1.30-1.32 % Ro at the top to ca. 1.52-1.69 % Ro at the bottom, indicating medium to low volatile coal rank. Modelled VR data from the two boreholes indicate palaeogeothermal gradients between 40 and 56ºC/km, possible related to basin forming processes. Fission track ages increase from 84 Ma and 102 Ma at the bottom to 138 Ma and 146 Ma at the top of the DW132 and DW123 wells respectively. The Mean Track Length is approximately 11.7±0.2 μm for the four samples studied. Inverse modelling of both VR and fission track data have been undertaken with QTQt software. The results are consistent for the two boreholes. Thermal histories indicate that samples have been heated to a maximum temperature of 150 to 180 °C following deposition. Maximum temperature was reached at 260 Ma., then a first phase of cooling occurred between 255 and 230 Ma, related to post Lower Karoo exhumation. The sections subsequently cooled very slowly until Neogene time. At 7 Ma, a second, fast cooling episode reduced rock temperatures from 50 - 60 °C to present day temperature. This second cooling episode is possibly related to exhumation caused by the uplift and erosion of the East-African rift shoulders. The thermal reconstruction indicates that the present coal rank was attained shortly after deposition. Following this burial under a thick sedimentary sequence of approximately 4 km, two main pulse of exhumation affected the Moatize Basin during the Triassic and Pliocene, eroding ca. 2.5 km of Upper Permian strata in the first and 1.5 km in the latter.

  4. CONODONT BIOSTRATIGRAPHY AND LITHOSTRATIGRAPHY ACROSS THE PERMIAN-TRIASSIC BOUNDARY AT THE LUKAC SECTION IN WESTERN SLOVENIA

    Directory of Open Access Journals (Sweden)

    TEA KOLAR-JURKOVSEK

    2011-03-01

    Full Text Available Detailed conodont biostratigraphy and lithostratigraphy of the Late Permian and Early Triassic beds were studied at the LukaC section in western Slovenia. The analyzed section is composed of the Bellerophon Formation ("evaporite-dolomite member" and the newly introduced Lukaè Formation ("transitional beds", "streaky limestone member" and "carbonate-clastic beds member". The Permian-Triassic boundary interval is represented by "transitional beds" of carbonate facies deposited in shallow restricted marine conditions. The presence of H. parvus in sample L1 in the "transitional beds" marks the systemic boundary between Permian and Triassic. The studied interval is characterized by a diverse microfauna that contain conodonts, foraminifers, ostracods and gastropods. Six conodont zones have been recognized, in ascending order, the latest Changhsingian (uppermost Permian praeparvus Zone, and the Griesbachian (lowermost Triassic parvus, lobata, staeschei-isarcica, postparvus and anceps zones. This faunal succession represents the first known and the most complete conodont biozonation across the Permian-Triassic interval from the entire Dinaric region. The recognized conodont biozones can be correlated with the biozonation of the Southern Alps and of the GSSP Meishan D section. 

  5. Internal anatomy of an erg sequence from the aeolian-fluvial system of the De La Cuesta Formation (Paganzo Basin, northwestern Argentina)

    OpenAIRE

    Spallett, L.A.; C. O Limarino; Colombo Piol, F.

    2010-01-01

    Permian red beds of the De La Cuesta Formation in the Sierra de Narvez (Paganzo Basin, northwestern Argentina) are essentially composed of sandstones associated with mudstones and subordinate conglomerates. Facies distributions and stacking patterns indicate that these sediments resulted from the interaction between aeolian and ephemeral fluvial systems, and are represented by aeolian dune, dry aeolian interdune and Aeolian sand sheet, mudflat, wet aeolian interdune, and fluvial deposits. Th...

  6. Pteridophytes from Lower Gondwana formations of the Ib River Coalfield, Orissa and their diversity and distribution in the Permian of India

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, S.; Singh, K.J.; Chandra, S. [Fakir Mohan University, Balasore (India). PG Dept. of Environmental Science

    2006-12-15

    Recent extensive investigations carried out in the Ib River Coalfield, Mahanadi Master Basin, Orissa, identified numerous fossiliferous beds in the lower Gondwana deposits. Six exposures of the Barakar and lower Kamthi formations yielded diverse and abundant plant remains. The flora includes twenty-three genera representing nine groups viz., Lycopodiales, Equisetales, Sphenophyllales, Filicales, Cordaitales, Coniferales, Ginkgoales, Cycadales and Glossopteridales. Systematic descriptions of the pteridophyte taxa namely Cyclodendron (Lycopodiales), Schizoneura, Raniganjia, Bengalia, equisetaceous stems (Equisetales), Trizygia, Benlightfootia (Sphenophyllales), Neomariopteris, and Dichotomopteris (Filicales) are presented in this paper. Pteridophytic leaves comprising nine taxa viz., Cyclodendron leslii, Schizoneura gondwanensis, Raniganjia bengalensis, Bengalia raniganjensis, Trizygia speciosa, Benlightfootia indica, Neomariopteris hughesii, N. talchirensis, and Dichotomopteris sp. together with equisetaceous stems constitute about 7.88% (72 specimens) of the total plant assemblage collected from this coalfield. Among the pteridophytes, equisetaceous stems are most abundant (40.3%; 29 specimens) followed by Schizoneura gondwanensis (20.8%, 15 specimens) and Trizygia speciosa (13.9%, 10 specimens). A summary of the known diversity of pteridophytes in the Indian Permian as a whole is provided.

  7. A calcium isotope test of end-Permian ocean acidification using biogenic apatite

    Science.gov (United States)

    Hinojosa, J.; Brown, S. T.; DePaolo, D. J.; Paytan, A.; Shen, S.; Chen, J.; Payne, J.

    2011-12-01

    Submarine erosional truncation of uppermost Permian carbonate strata has been interpreted to reflect ocean acidification coincident with the end-Permian mass extinction. Although this scenario is consistent with carbon isotope and paleontological data, several alternative scenarios, such as ocean overturn or collapse of the biological pump, can also account for the carbon isotope and paleontological evidence. Calcium isotopes provide a geochemical proxy to test between acidification and alternative scenarios. Specifically, a negative shift in the calcium isotope composition (δ44/40Ca) of seawater is predicted under the acidification scenario but not the alternatives. The δ44/40Ca of carbonate rocks from south China exhibits a negative excursion of approximately 0.3%, but this shift could result from either a change in the δ44/40Ca of seawater or a change in carbonate mineralogy because calcite and aragonite exhibit substantially different fractionation factors relative to seawater. To test whether the negative shift in δ44/40Ca reflects seawater δ44/40Ca or carbonate mineralogy, we measured the δ44/40Ca of conodont microfossils (calcium hydroxyapatite) from the global stratotype section for the Permian-Triassic boundary at Meishan, China. The conodont δ44/40Ca record shows a negative excursion similar in stratigraphic position and magnitude to that previously observed in carbonate rocks. Parallel negative excursions in the δ44/40Ca of carbonate rocks and conodont microfossils cannot be accounted for by a change in carbonate mineralogy but are consistent with a negative shift in the δ44/40Ca of seawater. These data add further support for the ocean acidification scenario, pointing toward strong similarities between the greatest catastrophe in the history of animal life and anticipated global change during the 21st century.

  8. End-Permian Mass Extinction in the Oceans: An Ancient Analog for the Twenty-First Century?

    Science.gov (United States)

    Payne, Jonathan L.; Clapham, Matthew E.

    2012-05-01

    The greatest loss of biodiversity in the history of animal life occurred at the end of the Permian Period (˜252 million years ago). This biotic catastrophe coincided with an interval of widespread ocean anoxia and the eruption of one of Earth's largest continental flood basalt provinces, the Siberian Traps. Volatile release from basaltic magma and sedimentary strata during emplacement of the Siberian Traps can account for most end-Permian paleontological and geochemical observations. Climate change and, perhaps, destruction of the ozone layer can explain extinctions on land, whereas changes in ocean oxygen levels, CO2, pH, and temperature can account for extinction selectivity across marine animals. These emerging insights from geology, geochemistry, and paleobiology suggest that the end-Permian extinction may serve as an important ancient analog for twenty-first century oceans.

  9. Rare earth element geochemistry of the Upper Permian limestone: the Kanigorgeh mining district, NW Iran

    OpenAIRE

    Abedini, Ali; CALAGARI, Ali Asghar

    2015-01-01

    The limestone of the Ruteh Formation of Upper Permian age in the Kanigorgeh district (northeast of Bukan, NW Iran) contains several layers and lenses of bauxitic ores. Mineralogical data show that this limestone consists of calcite and quartz as major and plagioclase, kaolinite, and hematite as minor mineral phases. Geochemical analyses reveal that the proportions of ?REEs (La-Lu) in this limestone vary from 35.28 to 160.78 ppm. The values of Eu and Ce anomalies (normalized to PAAS) of the li...

  10. Palynology and stratigraphy preliminary study and the perforation 313/1, lower Permian. Uruguay

    International Nuclear Information System (INIS)

    The palynomorphs in the bore 313/1 of the Direccion Nacional de Mineria y Geologia are analyzed. Twenty three samples were processed, and only 9 were fertile. The lithologies correspond to sandstones of variable grain size, to mudstone and to diamictite, all of them assigned to the San Gregorio and Tres Islas Fms. The most abundant genera of sporare are essentially represented by monosaccate grains. Bisaccate and striated grains are very scare. The palynoflora is comparable with those studied in Brazil in the Fm Rio Bonito. Therefore, it is proposed that the sediments studied were deposited in the early Permian. (author)

  11. Early Permian intrusions in the Paleozoic sediments of the Eastern North Sea area

    DEFF Research Database (Denmark)

    Clausen, O.R.; Andresen, Katrine Juul; Rasmussen, Jens Andreas

    a sill complex, which in certain areas resembles a poorly outlined composite cone. The intrusions are not observed in the syn-tectonic sedimentary wedges and this combined with the general age of the intrusions suggests that the syn-tectonic wedges are of latest early Permian or earliest late...... characterizes the study area and causes rotation of older probably Paleozoic sediments and creates syn-tectonic sediment wedges. The syn-tectonic wedges most probably contain volcaniclastic sediments of the Karl Formation or sandstones of the Auk Formation, but it cannot be excluded that the earliest late...

  12. Permian vegetational Pompeii from Inner Mongolia and its implications for landscape paleoecology and paleobiogeography of Cathaysia

    OpenAIRE

    Wang, Jun; Pfefferkorn, Hermann W.; ZHANG Yi; Feng, Zhuo

    2012-01-01

    Plant communities of the geologic past can be reconstructed with high fidelity only if they were preserved in place in an instant in time. Here we report such a flora from an early Permian (ca. 298 Ma) ash-fall tuff in Inner Mongolia, a time interval and area where such information is filling a large gap of knowledge. About 1,000 m2 of forest growing on peat could be reconstructed based on the actual location of individual plants. Tree ferns formed a lower canopy and either Cordaites, a conif...

  13. Geohydrology surrounding a potential high level nuclear waste repository in the Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    The Palo Duro Basin of the Texas Panhandle is being investigated as a potential high level nuclear waste repository site. As groundwater is the most likely mechanism for radionuclide movement, it is desirable to locate a repository in a hydrologic regime which is favorable for waste isolation and containment. The Palo Duro Basin consists of deep brine aquifers of low regional permeability underlying a thick Permian age evaporite section. The overlying Permian age evaporites are the Dockum and Ogallala fresh water aquifiers. Observed potentiometric data in the principal aquifers indicate a potential for downward flow from the surficial aquifiers to the deep brine aquifers. Groundwater movement in these deep aquifers is very slow. Modeling efforts indicate flow times of hundreds of thousands to over a million years for groundwater to reach the basin margins. Investigative methods have included drill-stem testing similar to oil field methodology, modified drill-stem testing with tools developed for low-permeability formations and long term production tests similar to conventional water well pumping tests. Testing has generally indicated permeability of .1-10 millidarcies in the water transmitting units

  14. The volcano-sedimentary evolution of a post-Variscan intramontane basin in the Swiss Alps (Glarus Verrucano) as revealed by zircon U-Pb age dating and Hf isotope geochemistry

    Science.gov (United States)

    Letsch, Dominik; Winkler, Wilfried; von Quadt, Albrecht; Gallhofer, Daniela

    2015-01-01

    The Late Palaeozoic Glarus Verrucano basin (GVB, Glarus Alps, eastern Switzerland) formed as an intramontane graben in the aftermath of the Variscan orogeny. Its fill, the Glarus Verrucano, consists of immature alluvial fan and playa lake deposits with intercalated bimodal volcanics (basalts and rhyolites). Despite its importance for local and regional geology, no modern sedimentologic or stratigraphic studies on the GVB exist. By means of sedimentologic and geochronologic studies, we reconstruct the volcano-sedimentary evolution of the GVB: it developed at the Carboniferous/Permian boundary and experienced a first (bimodal) volcanic phase around 285 Ma. For the same time, indications for temporarily humid climate in the otherwise rather arid Early Permian are demonstrated (e.g. pyrite-bearing sandstones). During the Middle and Early Late Permian, increasing aridity is indicated by playa deposits, fanglomerates and subaerial ignimbrites, which mark a second (silicic) volcanic phase at 268 Ma. The detrital zircon age spectra are dominated by Late Variscan ages and thus demonstrate that older sedimentary and metamorphic rocks once forming the Variscan nappe edifice were already mostly eroded at that time. Finally, some larger-scale speculations are given which could indicate a causal connection between the widespread tectono-magmatic Mid-Permian Episode and the local development of the Glarus Verrucano basin.

  15. Neopaleozoic biostratigraphy of the Parana Basin; Bioestratigrafia do neopaleozoico da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Daemon, Roberto Ferreira; Quadros, Luiz Padilha de

    2006-11-15

    Surface samples and cores from 31 exploratory wells were chosen as being the most representative among those drilled by PETROBRAS across the Parana Sedimentary Basin, from Mato Grosso and Goias to Rio Grande do Sul. Their analysis yielded a large amount or Saccites, Monoletes and Monocolpates spores, in addition to representatives of Tasmanales. From the great number of identified forms, 40 species - characterized by their wide geographical distribution allied to a short vertical range - were selected and used as a basis for the biostratigraphical subdivision of the Gondwana section of this sedimentary basin. This biostratigraphic column was divided into six main intervals, designated by the letters G to L, some with further subdivisions. The comparison of the species with those described from other regions provided sufficient geochronological data for the dating of the different intervals. It also demonstrated that the Upper Paleozoic sedimentary sequence in the Parana Basin ranges from the Upper Pennsylvanian (Stephanian C) to the Upper Permian (Kazanian). To complete the paleogeologic data the previously established zonation of the Devonian section was also included. The correlation of the biostratigraphic intervals across the basin and their relationship with the rock-stratigraphic units are demonstrated in several sections. The interpretation of these sections and of the biostratigraphic interval isopachous maps provided important information on the paleogeographic development of the basin. Among the more significant results is evidence of the start of the Permo-Carboniferous sedimentation in the northern regional depression, of a subsequent southward tilting of the basin accompanied by the progressive advance of the deposits toward the Rio Grande do Sul shield and of a Lower Permian lacuna in eastern Parana indicating the beginning of the epeirogenic process which culminated with the rise of the Ponta Grossa arch. The paper also presents some paleoecological considerations and the concluding chapter deals with the systematic discussion of the sporomorphs accompanied by illustrations of the described species. (author)

  16. Evolution of calc-alkaline to alkaline magmatism through Carboniferous convergence to Permian transcurrent tectonics, western Chinese Tianshan

    OpenAIRE

    Wang, Bo; Cluzel, Dominique; Shu, Liangshu S.; Faure, Michel; Charvet, Jacques; Chen, Yan; Meffre, Sébastien; De Jong, Koenraad

    2009-01-01

    Continuous magmatic activity occurred in the western Chinese Tianshan, Central Asia, from the Carboniferous to the Permian, i.e. before and after the Late Carboniferous amalgamation of Junggar and the Yili Blocks. Zircon U–Pb LA-ICPMS and Ar–Ar data reveal a coincidence in time between regional wrench faulting and granitoid emplacement. Permian post-collisional granitoids crop out within or at the margins of large-scale dextral strike-slip shear zones, some of them show synkinematic fabrics. ...

  17. Palynodating of subsurface sediments, Raniganj Coalfield, Damodar Basin, West Bengal

    Indian Academy of Sciences (India)

    Srikanta Murthy; B Chakraborti; M D Roy

    2010-10-01

    The Gondwana sediments comprising ?ne-grained shales,carbonaceous shales,sandstones and the coal horizon in borecore RT-4 (approximately 547.00 m thick)from Tamra block,Raniganj Coal ?eld,Damodar Basin,are analyzed palynologically.Based on the distribution pattern of marker palynotaxa,two assemblage zones are identi ?ed.In the Barren Measures Formation,dominance of enveloping monosaccate (Densipollenites) along with striate bisaccate (Striatopodocarpites,Fauni- pollenites) pollen taxa,and the FAD s of Kamthisaccites and Arcuatipollenites observed at 30.75, have equated this strata (30.75 227.80 m thick)with the Raniganj Formation of Late Permian in age.Downwards in the Barakar Formation,between 423.80 577.70 m depths,an abundance of non-striate (Scheuringipollenites )and striate(Faunipollenites and Striatopodocarpites )bisaccate pollen taxa is observed,that dates late Early Permian in age. Fair occurrences of hyaline,distorted and blackish-brown plant matter is observed within 231.00 408.40 m depths.Present study infers the existence of the Raniganj Formation in the lithologically delimited Barren Measures Formation in the study area,and the underlying unproductive strata (approx.177.40 m)might represent the part of the Barren Measures Formation.

  18. The origin and early evolution of Sauria: reassessing the permian Saurian fossil record and the timing of the crocodile-lizard divergence.

    Science.gov (United States)

    Ezcurra, Martín D; Scheyer, Torsten M; Butler, Richard J

    2014-01-01

    Sauria is the crown-group of Diapsida and is subdivided into Lepidosauromorpha and Archosauromorpha, comprising a high percentage of the diversity of living and fossil tetrapods. The split between lepidosauromorphs and archosauromorphs (the crocodile-lizard, or bird-lizard, divergence) is considered one of the key calibration points for molecular analyses of tetrapod phylogeny. Saurians have a very rich Mesozoic and Cenozoic fossil record, but their late Paleozoic (Permian) record is problematic. Several Permian specimens have been referred to Sauria, but the phylogenetic affinity of some of these records remains questionable. We reexamine and review all of these specimens here, providing new data on early saurian evolution including osteohistology, and present a new morphological phylogenetic dataset. We support previous studies that find that no valid Permian record for Lepidosauromorpha, and we also reject some of the previous referrals of Permian specimens to Archosauromorpha. The most informative Permian archosauromorph is Protorosaurus speneri from the middle Late Permian of Western Europe. A historically problematic specimen from the Late Permian of Tanzania is redescribed and reidentified as a new genus and species of basal archosauromorph: Aenigmastropheus parringtoni. The supposed protorosaur Eorasaurus olsoni from the Late Permian of Russia is recovered among Archosauriformes and may be the oldest known member of the group but the phylogenetic support for this position is low. The assignment of Archosaurus rossicus from the latest Permian of Russia to the archosauromorph clade Proterosuchidae is supported. Our revision suggests a minimum fossil calibration date for the crocodile-lizard split of 254.7 Ma. The occurrences of basal archosauromorphs in the northern (30°N) and southern (55°S) parts of Pangea imply a wider paleobiogeographic distribution for the group during the Late Permian than previously appreciated. Early archosauromorph growth strategies appear to be more diverse than previously suggested based on new data on the osteohistology of Aenigmastropheus. PMID:24586565

  19. Relationship of present saline fluid with paleomigration of basinal brines at the basement/sediment interface (Southeast basin – France)

    International Nuclear Information System (INIS)

    This paper investigates the isotopic composition (O, D, Sr, OSO4, SSO4, Cl, He) of a present saline fluid sample collected at the sediment/basement interface in the Permian continental formation at 634 m depth in the SE margin of the Massif Central shield (Ardèche margin of the Southeast basin of France). The fluid sample shows clear water–rock interaction processes, such as feldspar dissolution and kaolinite precipitation, which have led to high Na concentrations and water stable isotopes above the local meteoric water line. The geological formations of the SE margin of the Massif Central shield show that intensive fluid circulation phases occurred across the margin from the late Triassic to the middle Jurassic. The fluids most probably originated from fluid expulsion during burial of the thick Permo-Carboniferous sedimentary succession. These circulation phases were responsible for cementation of the margin and for the solutes in the matrix microporosity which were extracted by leaching core samples. The chemical and isotopic composition of the saline fluid sample at 634 m in the Permian rock is very similar to that of fluids in the microporosity of the rock matrix. Their SSO4, OSO4 and Sr isotopic compositions are close to those of cements investigated in fracture fillings in the same geological formations. Simple diffusion computations and comparison of the chemical composition of the present free fluid sample with matrix porosity fluids indicate that the solutes in the present free fluid sample are related to solutes originating from fluid circulation events which occurred 160–200 Ma ago through their diffusion from the matrix microporosity. A two-stage fluid flow regime is proposed to interpret the chemistry of present and paleo-fluids. (1) During the extensional context (Permian to Cretaceous), basinal brines migrated along the basement/sediment interface after expulsion from the subsiding basin. This fluid migration would be responsible for the solutes in the rock matrix microporosity and the solutes in the present free fluid sample. (2) Following the Alpine and Pyrenean compressive phases, gravity-driven meteoritic fluids slowly migrated from the surface down to the basement along major faults. This fluid regime would be responsible for the meteoric water collected in the present free fluid sample. Several investigations in Europe have shown that the existence of other saline fluids sampled elsewhere could be explained by these phases of fluid circulation related to specific geodynamic events.

  20. 77 FR 49863 - Iowa Pacific Holdings, LLC and Permian Basin Railways-Continuance in Control Exemption-Santa Cruz...

    Science.gov (United States)

    2012-08-17

    ... becoming a Class III rail carrier.\\1\\ \\1\\ PBR and SCMB are wholly owned subsidiaries of IPH. In a... Northern Railway its lease and operating rights over a 31.0-mile rail line (the Line) owned by...

  1. Dispersal Syndromes of fossil Seeds from the Lower Permian of Paran Basin, Rio Grande do Sul, Brazil

    OpenAIRE

    Juliane M. Souza; Roberto Iannuzzi

    2012-01-01

    The morphological analysis of seeds has been an important subject in modern ecological studies, once it provides evidence about the biology and adaptations of the parent plant. However, this kind of study has been restricted to the ecology of modern plants and is rarely used in interpretations of Paleozoic data. From the understanding of dispersal syndromes analysis as an important tool to paleoecological reconstruction, this study provides a first approach using this tool with seeds from the...

  2. Report of liquid permeability measurements on rock core samples from Mansfield No. 1 Well, Permian Basin project

    International Nuclear Information System (INIS)

    This report presents the results of the measurements on specimens from the Mansfield No. 1 Well, and it describes in some detail the apparatus and procedure used for the measurements to assist the reader in understanding how they were made. Where unusual specimen responses were encountered, the data reflecting the responses are presented and explanations offered. Finally, evaluations are made of both the results and the apparatus and procedure. 4 refs., 13 figs

  3. Report of liquid permeability measurements on rock core samples from Detten No. 1 Well, Permian Basin Project

    International Nuclear Information System (INIS)

    This report presents the results of the measurements on specimens from the Detten No. 1 Well. It also describes in some detail the apparatus and procedure used for the measurements to assist in understanding how they were made. Laboratory measurements of permeability to the flow of saturated brine were made on specimens of rack core from several depths in the Detten No. 1 Well. Brine was used for the permeant to preclude the dissolution of any crystalline salt in the rock. The cylindrical specimens were prepared with axes both vertical and horizontal at each depth wherever this was possible. Measurements were made in a special rock permeameter by confining the specimen under pressure within a membrane consisting of a length of rubber tubing. A pressure difference was then created across the length of the specimen, thus causing permeant to flow through the pores of the specimen. Permeabilities were determined by either measuring the rate of flow under the constant pressure difference (constant-head method) or closing the inflow of permeant to one end of the specimen (with continued outflow of permeant from the other end) and measuring the rate of decrease of the pressure difference (falling-head method). 5 refs, 5 figs, 1 tab

  4. Geochronological data from the Faxinal coal succession, southern Parana Basin, Brazil: A preliminary approach combining radiometric U-Pb dating and palynostratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Sommer, M.; Cazzulo-Klepzig, M.; Menegat, R.; Formoso, M.L.L.; Basei, M.A.; Barboza, E.; Simas, M.W. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

    2008-03-15

    A radiometric zircon age of 285.4 {+-} 8.6 Ma (IDTIMS U-Pb) is reported from a tonstein layer interbedded with coal seams in the Faxinal coalfield, Rio Grande do Sul, Brazil. Calibration of palynostratigraphic data with the absolute age shows that the coal depositional interval in the southern Parana Basin is constrained to the Sakmarian. Consequently, the basal Gondwana sequence in the southern part of the basin should lie at the Carboniferous-Permian boundary, not within the Sakmarian as previously considered. The new results are significant for correlations between the Parana Basin and the Argentinian Paganzo Basin (302 {+-} 6 Ma and 288 {+-} 7 Ma) and with the Karoo Basin, specifically with the top of the Dwyka Tillite (302 {+-} 3 Ma and 299.2 {+-} 3.2 Ma) and the lowermost Ecca Group (288 {+-} 3 Ma and 289.6 {+-} 3.8 Ma). The evidence signifies widespread latest Carboniferous volcanic activity in western Gondwana.

  5. Thermal evolution of inverted basins: Constraints from apatite fission track thermochronology in the Cuyo Basin, Argentine Precordillera

    International Nuclear Information System (INIS)

    Apatite fission track thermochronology (AFTT) was applied to derive the thermal history of formation and inversion of the oil-bearing Triassic-Cretaceous Cuyo Basin, Argentine Precordillera. The obtained central fission track ages range from 13 to 163Ma, and the mean track lengths from 8.2 to 13.1μm. Based on the integration of AFTT, stratigraphic and structural data, five evolutionary phases are here proposed for the studied area: I-Late Permian cooling related to the extrusion of basement volcanics, and initial extensional regime responsible for the Cuyo Basin formation, II-Triassic-Jurassic heating linked with the filling, and consequent burial, of the Cuyo Basin, III-Jurassic-Paleogene tectonic stabilization, IV-Early Miocene heating related to the load of foreland sedimentation, V-Late Miocene rapid cooling related to the Cuyo Basin inversion. During the Late Miocene, rock units formed in different crustal levels were juxtaposed through thrust, reverse and normal faulting, resulting in contrasting old and very young central fission track ages in closely spaced samples

  6. Hydrocarbon habitat of San Martin and Cashiriari gas/condensate discoveries, southern Ucayali basin of Peru

    Energy Technology Data Exchange (ETDEWEB)

    Mohler, H.P.

    1989-03-01

    Fifteen trillion ft/sup 3/ of wet gas in place containing some 800 million bbl of associated liquids have been discovered in the San Martin and Cashiriari anticlines, which are located in the Subandean thrusted foldbelt of the Southern Ucayali basin of Peru. Ultimate recoverable volumes are estimated at 10 trillion ft/sup 3/ of gas and 500 million bbl of liquids including condensate (C5+) and LPG (C3/C4). Most of these potentially recoverable reserves are located in the Cashiriari structure (80% of the gas and 70% of the liquids). They were encountered in fair-excellent sandstone reservoirs of Early Permian and Late Cretaceous age and are thought to be derived from Carboniferous coaly shale source rocks. The Paleozoic (pre-Andean) sedimentary megacycle is represented by deeper shallow marine clastics of Ordovician to Early Carboniferous age (5000 m maximum), including Silurian glaciomarine deposits, overlain by up to 1200 m of Permian-Carboniferous platform carbonates and 600-1000( ) m of Lower Permian-lower Upper Permian coastal-continental clastics. The Mesozoic-Tertiary (Andean) megacycle is represented by a Campanian-Maastrichtian transgressive marine clastic/carbonate and overlying regressive clastic sequence (450 m maximum), followed by several thousand meters of Molasse-type continental infill of the Tertiary foredeep, which was created by the crustal loading in the wake of the compressional Andean orogeny (Peru, Inca, and Quechua phases). Late Tertiary folding and thrusting of the sub-Andean belt was superseded by regional Pleistocene uplift, and parts of the foreland continue to subside.

  7. Supai salt karst features: Holbrook Basin, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Neal, J.T.

    1994-12-31

    More than 300 sinkholes, fissures, depressions, and other collapse features occur along a 70 km (45 mi) dissolution front of the Permian Supai Formation, dipping northward into the Holbrook Basin, also called the Supai Salt Basin. The dissolution front is essentially coincident with the so-called Holbrook Anticline showing local dip reversal; rather than being of tectonic origin, this feature is likely a subsidence-induced monoclinal flexure caused by the northward migrating dissolution front. Three major areas are identified with distinctive attributes: (1) The Sinks, 10 km WNW of Snowflake, containing some 200 sinkholes up to 200 m diameter and 50 m depth, and joint controlled fissures and fissure-sinks; (2) Dry Lake Valley and contiguous areas containing large collapse fissures and sinkholes in jointed Coconino sandstone, some of which drained more than 50 acre-feet ({approximately}6 {times} 10{sup 4} m{sup 3}) of water overnight; and (3) the McCauley Sinks, a localized group of about 40 sinkholes 15 km SE of Winslow along Chevelon Creek, some showing essentially rectangular jointing in the surficial Coconino Formation. Similar salt karst features also occur between these three major areas. The range of features in Supai salt are distinctive, yet similar to those in other evaporate basins. The wide variety of dissolution/collapse features range in development from incipient surface expression to mature and old age. The features began forming at least by Pliocene time and continue to the present, with recent changes reportedly observed and verified on airphotos with 20 year repetition. The evaporate sequence along interstate transportation routes creates a strategic location for underground LPG storage in leached caverns. The existing 11 cavern field at Adamana is safely located about 25 miles away from the dissolution front, but further expansion initiatives will require thorough engineering evaluation.

  8. Calcium and calcium isotope changes during carbon cycle perturbations at the end-Permian

    Science.gov (United States)

    Komar, N.; Zeebe, R. E.

    2016-01-01

    Negative carbon and calcium isotope excursions, as well as climate shifts, took place during the most severe mass extinction event in Earth's history, the end-Permian (˜252 Ma). Investigating the connection between carbon and calcium cycles during transient carbon cycle perturbation events, such as the end-Permian, may help resolve the intricacies between the coupled calcium-carbon cycles, as well as provide a tool for constraining the causes of mass extinction. Here we identify the deficiencies of a simplified calcium model employed in several previous studies, and we demonstrate the importance of a fully coupled carbon cycle model when investigating the dynamics of carbon and calcium cycling. Simulations with a modified version of the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir model, which includes a fully coupled carbon-calcium cycle, indicate that increased weathering rates and ocean acidification (potentially caused by Siberian Trap volcanism) are not capable of producing trends observed in the record, as previously claimed. Our model results suggest that combined effects of carbon input via Siberian Trap volcanism (12,000 Pg C), the cessation of biological carbon export, and variable calcium isotope fractionation (due to a change in the seawater carbonate ion concentration) represents a more plausible scenario. This scenario successfully reconciles δ13C and δ44Ca trends observed in the sediment record, as well as the proposed warming of >6°C.

  9. Larval cases of caddisfly (Insecta: Trichoptera) affinity in Early Permian marine environments of Gondwana.

    Science.gov (United States)

    Mouro, Lucas D; Zatoń, Michał; Fernandes, Antonio C S; Waichel, Breno L

    2016-01-01

    Caddisflies (Trichoptera) are small, cosmopolitan insects closely related to the Lepidoptera (moths and butterflies). Most caddisflies construct protective cases during their larval development. Although the earliest recognisable caddisflies date back to the early Mesozoic (Early and Middle Triassic), being particularly numerous and diverse during the Late Jurassic and Early Cretaceous, the first records of their larval case constructions are known exclusively from much younger, Early to Middle Jurassic non-marine deposits in the northern hemisphere. Here we present fossils from the Early Permian (Asselian-Sakmarian) marine deposits of Brazil which have strong morphological and compositional similarity to larval cases of caddisflies. If they are, which is very probable, these finds not only push back the fossil record of true caddisflies, but also indicate that their larvae constructed cases at the very beginning of their evolution in marine environments. Since modern caddisflies that construct larval cases in marine environments are only known from eastern Australia and New Zealand, we suggest that this marine ecology may have first evolved in western Gondwana during the Early Permian and later spread across southern Pangea. PMID:26765261

  10. Voluminous silicic eruptions during late Permian Emeishan igneous province and link to climate cooling

    Science.gov (United States)

    Yang, Jianghai; Cawood, Peter A.; Du, Yuansheng

    2015-12-01

    Silicic eruptive units can constitute a substantive component in flood-basalts-dominated large igneous provinces, but usually constitute only a small proportion of the preserved volume due to poor preservation. Thus, their environmental impact can be underestimated or ignored. Establishing the original volume and potential climate-sensitive gas emissions of silicic eruptions is generally lacking for most large igneous provinces. We present a case study for the ˜260 Ma Emeishan province, where silicic volcanic rocks are a very minor component of the preserved rock archive due to extensive erosion during the Late Permian. Modal and geochemical data from Late Permian sandstones derived from the province suggest that silicic volcanic rocks constituted some ˜30% by volume of the total eroded Emeishan volcanic source rocks. This volume corresponds to > 3 ×104 km3 on the basis of two independent estimate methods. Detrital zircon trace element and Hf isotopic data require the silicic source rocks to be formed mainly by fractional crystallization from associated basaltic magmas. Based on experimental and theoretical calculations, these basalt-derived ˜104 km3 silicic eruptions released ˜1017 g sulfur gases into the higher atmosphere and contribute to the contemporaneous climate cooling at the Capitanian-Wuchiapingian transition (˜260 Ma). This study highlights the potentially important impact on climate of silicic eruptions associated with large igneous province volcanism.

  11. Dissolution of the Upper Seven Rivers and Salado salt in the interior Palo Duro Basin, Texas: Revision: Topical report

    International Nuclear Information System (INIS)

    The Upper Seven Rivers and Salado Formations contain the uppermost salts within the interior Palo Duro Basin, Stratigraphic and structural evidence based on geophysical well logs indicate that both dissolution and facies change have influenced the thickness of these uppermost salts. The magnitude of vertical salt loss due to dissolution is interminable at this time because original salt thickness is unknown. Gradual thinning of the Upper Seven Rivers Formation is recognized from south to north across the Palo Duro Basin. Anhydrites within the formation pinch out toward the basin margins, indicating that section loss is in part depositionally controlled. Additionally, informal subdivision of the Upper Seven Rivers Formation suggests that salt dissolution has occurred in the uppermost salt. A northeast-trending zone of thin Upper Seven Rivers Formation in portions of Deaf Smith, Randall, Castro, and Parmer Counties is possibly related to Tertiary dissolution. In New Mexico, local thinning of the Upper Seven Rivers Formation may be associated with faulting. Triassic erosion on uplifted fault blocks has affected the Upper Permian section. The Salado salt margin is located within the interior Palo Duro Basin. Geophysical well logs and core evidence indicate that the salt margin has migrated basinward as a result of dissolution. Permian dissolution probably contributed to some salt loss. 106 refs., 31 figs., 2 tabs

  12. PermianTriassic palynostratigraphy in Mailaram area, Godavari Graben, Andhra Pradesh, India

    Indian Academy of Sciences (India)

    Neerja Jha; Neha Aggarwal

    2012-10-01

    Palynological investigations of five borecores, viz., GAM-3, GAM-6, GAM-7, GAM-8 and GAM-10 from Mailaram area have suggested the occurrence of complete Lower Gondwana succession in Mailaram area. Total nine palynozones have been identified on the basis of dominance, sub-dominance and appearance of various palynotaxa. These palynozones belong to Talchir, Upper Karharbari and Barakar (Early Permian), Raniganj (Late Permian) and Panchet (Early Triassic) palynofloras of Indian Gondwana. The oldest Palynozone-1 demonstrated in borecore GAM-6 (331.4500 m) and borecore GAM-10 (505.66581.55 m), is characterized by the dominance of Parasaccites and sub-dominance of Plicatipollenites belongs to Talchir Palynoflora; Palynozone-2 identified in borecore GAM-7 (667749 m) and borecore GAM-8 (89.75 m) is characterized by the dominance of Parasaccites and sub-dominance of Scheuringipollenites which belongs to Upper Karharbari Palynoflora. Palynozone-3, identified in borecore GAM-6 (149.7240.05 m) and borecore GAM-8 (84.95 m), is characterized by the dominance of Scheuringipollenites akin to Scheuringipollenites zone of Barakar palynoflora; Palynozone-4, recorded in borecores GAM-3 (294437.98 m), GAM-7 (453640.5 m) and GAM-8 (35.35 m) is characterized by the dominance of Faunipollenites and sub-dominance of Striatopodocarpites along with certain stratigraphically significant taxa, viz., Weylandites, Guttulapollenites, Corisaccites, Aurangapollenites and Osmundacidites. Palynozone-5, demarcated in borecore GAM-3 (144.86221.3 m) and borecore GAM-10 (35.35 m), is distinguished by the dominance of striate disaccates along with at least 30% pollen assigned to Striasulcites; Palynozone-6, identified in borecore GAM-3 (35.173.08 m) and borecore GAM-7 (231423 m), is characterized by the dominance of striate disaccates along with 2030% of Densipollenites; Palynozone-7, recorded in borecore GAM-7 (206 m), is distinguished by the dominance of Crescentipollenites along with striate disaccates; Palynozone-8, identified in borecore GAM-7 (178.4 m), is characterized by the distinguished presence of taeniate pollen Guttulapollenites. Palynozones 48 belong to Raniganj Palynoflora. Palynozone-9, identified in borecore GAM-7 (166 m), is discriminated by the dominance of trilete spore Verrucosisporites and sub-dominance of taeniate pollen Lunatisporites which belongs to Triassic palynoflora. On the basis of palynological data Palynozone-1 (= Talchir palynoflora), Palynozone-2 and Palynozone-3 have been assigned to Early Permian age; Palynozones 48 (= Raniganj palynoflora) have been assigned to Late Permian age and Palynozone-9 (= Triassic palynoflora) has been assigned to Early Triassic age. With the aim of correlating the Permian and Triassic sediments of Mailaram area palynological investigations of five borecores were carried out.

  13. Subsidence of the West Siberian Basin: Geophysical evidence for eclogitization

    Science.gov (United States)

    Cherepanova, Yulia; Artemieva, Irina M.

    2013-04-01

    The West Siberian basin is the world's largest intracratonic sedimentary basin. The basin basement consists of complexes of island arcs, terranes, micro-continents, and relict ocean basins which amalgamated during late Proterozoic-Paleozoic orogenic events up to the formation of the Pangea super-continent. The basin was affected by rifting and flood basalt eruption in the Permian-early Triassic (ca 250 Ma), which was floowed by rapid late Triassic (190 Ma) subsidence, as observed in borehole data from the axial part of the Ob rift (Saunders, 2005). Widely distributed subsidence of the north and central parts of the basin took place in the Jurassic with accumulation of 1,5- 3 km sediments. Two other subsidence episodes in the early Cretaceous and in the Late Cretaceous to Cenozoic led to deposition of 2-3 km of sediment in the north-eastern and axial parts. (Rudkevich, 1976). Most of the present-day West Siberian basin lacks surface topography, whereas the reliefs of the Moho and the top of the basement have amplitudes of ca. 20 km and 15 km, respectively (Cherepanova et al., 2012). Modeling suggests that the thermal lithosphere is 130km thick in the West Siberian basin, up-to 260 km in the Siberian craton further east, and 90 km in the axial part of the basin under the Ob rift (Artemieva and Mooney, 2001). Assuming local isostatic equilibrium and no effect of dynamic topography (which probably is a valid approximation for most of the region, except for the southern margin and the Urals), we examine the relative contributions of the crust and the lithospheric mantle to maintaining the surface topography. Lithosphere buoyancy is controlled by thicknesses and densities of the crust and the lithospheric mantle, and therefore by composition, metamorphic state, and temperature. Crustal thickness and density are constrained by our new regional crustal model, which is based on a quality-controlled compilation of all seismic models published in international and Russian literature, theses and reports since the 1970s (Cherepanova et al., 2012). Lithosphere thickness and temperature (which are interrelated parameters) are constrained by the thermal model. Our results indicate the presence of a large high-density anomaly in the upper mantle below the axial part of the basin. This result is supported by the seismic velocity variation in the mantle along two ultra-deep Soviet PNE reflection/refraction profiles and with the regional subsidence history and stretching factors. We suggest that this density anomaly is caused by eclogitization, and that the density increase from this process may explain a substantial part of the subsidence of the West Siberian Basin.

  14. Widespread inclination shallowing in Permian and Triassic paleomagnetic data from Laurentia: Support from new paleomagnetic data from Middle Permian shallow intrusions in southern Illinois (USA) and virtual geomagnetic pole distributions

    Science.gov (United States)

    Domeier, M.; Van Der Voo, R.; Denny, F.B.

    2011-01-01

    Recent paleomagnetic work has highlighted a common and shallow inclination bias in continental redbeds. The Permian and Triassic paleomagnetic records from Laurentia are almost entirely derived from such sedimentary rocks, so a pervasive inclination error will expectedly bias the apparent polar wander path of Laurentia in a significant way. The long-standing discrepancy between the apparent polar wander paths of Laurentia and Gondwana in Permian and Triassic time may be a consequence of such a widespread data-pathology. Here we present new Middle Permian paleomagnetic data from igneous rocks and a contact metamorphosed limestone from cratonic Laurentia. The exclusively reversed Middle Permian magnetization is hosted by low-Ti titanomagnetite and pyrrhotite and yields a paleomagnetic pole at 56.3??S, 302.9??E (A95=3.8, N=6). This pole, which is unaffected by inclination shallowing, suggests that a shallow inclination bias may indeed be present in the Laurentian records. To further consider this hypothesis, we conduct a virtual geomagnetic pole distribution analysis, comparing theoretical expectations of a statistical field model (TK03.GAD) against published data-sets. This exercise provides independent evidence that the Laurentian paleomagnetic data is widely biased, likely because of sedimentary inclination shallowing. We estimate the magnitude of this error from our model results and present and discuss several alternative corrections. ?? 2011 Elsevier B.V.

  15. Geologic evolution and hydrocarbon prospects in the Chotts Basin, Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Johns, C. [Scott Pickford Group, Surrey (United Kingdom); Chine, A. [Entreprise Tunisienne d`Activites Petrolieres (ETAP), Tunis (Tunisia)

    1995-08-01

    The Chotts Basin, running east-west across central Tunisia, is a complex Late Paleozoic to Mesozoic graben system with a sediment thickness reaching over 5000m. It covers an area of over 15,000 km{sup 2} but is underexplored. It has been drilled by only a few wells; several of which gave oil and gas shows. A number of oil and condensate fields lie immediately south. ETAP, the national oil company, has undertaken a detailed investigation of the basin, greatly improving our understanding of its evolution and prospectivity. The basin is floored by Lower Paleozoic sediments. These occur at shallow depth on the southern flank where they were affected by periodic contemporary tectonism. The succession includes Ordovician clastics with good reservoir potential and both Ordovician and uppermost Silurian source rocks. Locally, the latter unconformably overlie Ordovician reservoir sections. The basin developed into a major, east-west trending, intracratonic wrench basin during the late Permian. Carbonate facies dominate the southern shelf area and, although lithofacies distributions are poorly constrained, the existence of quality source rocks is a strong possibility. The graben complex was inverted and partly eroded prior to deposition of Upper Triassic volcanics and sandstones. The sandstones are a proven reservoir and several leads are identified. Substantial subsidence occurred in the northern part of the basin from the Middle Jurassic to Early Cretaceous. Jurassic carbonates provide numerous reservoir sections, while Callovian shales constitute a proven, mature source rock. Large fault- and fold- related traps were formed during latest Cretaceous to Paleocene and Mio-Pliocene orogeny; they provide promising objectives.

  16. New data on Upper Carboniferous–Lower Permian deposits of Bol'shevik Island, Severnaya Zemlya Archipelago

    Directory of Open Access Journals (Sweden)

    Victoria B. Ershova

    2015-05-01

    Full Text Available We present here a detailed study of the Upper Carboniferous–Lower Permian stratigraphy of Bol'shevik Island in the Severnaya Zemlya Archipelago, consisting of the analysis of sedimentary structures and lithostratigraphy, U/Pb detrital zircon dating and structural studies. The preserved sedimentary structures suggest that the studied strata were deposited in a relatively small meandering fluvial system. U/Pb dating of detrital zircons reveals that the Upper Carboniferous–Lower Permian sandstones contain a primary age population ranging from 450 to 570 millions of years, with a predominance of Early–Middle Ordovician zircons. This detrital zircon distribution indicates that the studied formations were derived locally from the erosion of Lower Ordovician deposits of Bol'shevik Island or elsewhere in the archipelago. Our structural studies suggest that Upper Carboniferous–Lower Permian deposits are deformed into a series of west–north-west verging open asymmetric folds, suggesting a west–north-west direction of tectonic transport and that deformation across the island is post-Early Permian in age.

  17. Lithostratigraphy and depositional environments of the Pyeongan Supergroup (Carboniferous Permian) in the Taebaek area, mid-east Korea

    Science.gov (United States)

    Lee, H. S.; Chough, S. K.

    2006-03-01

    The Pyeongan Supergroup (Carboniferous-Permian) consists of a thick siliciclastic sequence (1700 m thick). Recent sedimentological work in the Taebaek area has refined the lithostratigraphic units: Manhang, Geumcheon-Jangseong, Hambaeksan, Dosagok, Gohan and Donggo formations in ascending order. The entire sequence is represented by thirteen sedimentary facies, which can be organized into seven facies associations (FA). The lower part of the Manhang Formation (FA 1) (Moscovian) consists of crudely cross-stratified conglomerate, massive sandstone and gray homogeneous siltstone, formed in shoreface off river mouth, whereas purple siltstone and grainstone of the upper part (FA 2) probably formed in a coastal plain environment. The Geumcheon-Jangseong Formation (Moscovian-Artinskian) consists of dark gray sandstone, dark gray shale, coal and bioturbated wackestone (FA 3) formed in a lagoonal environment. The Hambaeksan Formation (Kungurian) comprises milky white, crudely stratified, conglomerate, gray coarse sandstone and partly laminated black shale (FA 4), representing a shoreface progradation. The Dosagok Formation (Late Permian) is characterized by an alternation of purple fine sandstone and conglomerate (FA 5), formed in a bedload-dominated fluvial system. The Gohan Formation (Late Permian) is mostly composed of upward-fining units (massive sandstone to dark gray siltstone) (FA 6), suggesting a restricted inter-distributary bay environment. The Donggo Formation (?Late Permian) consists of cross-stratified coarse sandstone and purple sandstone (FA 7), interpreted as deposits of perennial, sandy braided river system.

  18. Geohydrologic framework of the Roswell ground-water basin, Chaves and Eddy Counties, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Welder, G.E.

    1983-01-01

    This report describes the geohydrology of the Roswell ground-water basin and shows the long-term hydrostatic-head changes in the aquifers. The Roswell ground-water basin consists of a carbonate artesian aquifer overlain by a leaky confining bed, which, in turn is overlain by an alluvial water-table aquifer. The water-table aquifer is hydraulically connected to the Pecos River. Ground-water pumpage from about 1500 wells in the basin was about 378,000 acre-feet in 1978. Irrigation use on about 122,000 acres accounted for 95% of that pumpage. Permeable zones in the artesian aquifer are generally controlled by lithologic changes in the Permian San Andres Limestone and Grayburg Formation and by fractures in the carbonate rock. The thickness of the artesian aquifer in the more heavily pumped part of the basin ranges from 260 to 460 feet. The confining bed is composed of slightly to moderately permeable rocks of the Permian Grayburg, Queen, and Seven Rivers Formations. The shallow aquifer is composed of permeable beds of sand and gravel in the valley-fill alluvium, which is Pliocene, Pleistocene, and Holocene in age. In 1975, the maximum saturated thickness of the valley fill was about 250 feet in depressions northeast of Roswell, south of Dexter, and at Artesia. Hydrostatic heads in the artesian aquifer declined 230 feet in the south part of the basin from 1905 to 1975. The maximum decline in the head of the shallow aquifer from 1938 to 1975 was 120 feet. The chloride concentration of ground-water samples collected in 1978 ranged from 15 to 7000 milligrams per liter for the artesian aquifer and from 20 to 3700 milligrams per liter for the shallow aquifer. The chloride content has gradually increased through the years in the eastern parts of both aquifers. 31 refs., 28 figs., 1 tab.

  19. Paleogeography of the upper Paleozoic basins of southern South America: An overview

    Science.gov (United States)

    Limarino, Carlos O.; Spalletti, Luis A.

    2006-12-01

    The paleogeographic evolution of Late Paleozoic basins located in southern South America is addressed. Three major types of basins are recognized: infracratonic or intraplate, arc-related, and retroarc. Intraplate basins (i.e., Paraná, Chaco-Paraná, Sauce Grande-Colorado, and La Golondrina) are floored by continental or quasi-continental crust, with low or moderate subsidence rates and limited magmatic and tectonic activity. Arc-related basins (northern and central Chile, Navidad-Arizaro, Río Blanco, and Calingasta-Uspallata basins and depocenters along Chilean Patagonia) show a very complex tectonic history, widespread magmatic activity, high subsidence rates, and in some cases metamorphism of Late Paleozoic sediments. An intermediate situation corresponds to the retroarc basins (eastern Madre de Dios, Tarija, Paganzo, and Tepuel-Genoa), which lack extensive magmatism and metamorphism but in which coeval tectonism and sedimentation rates were likely more important than those in the intraplate region. According to the stratigraphic distribution of Late Paleozoic sediments, regional-scale discontinuities, and sedimentation pattern changes, five major paleogeographic stages are proposed. The lowermost is restricted to the proto-Pacific and retroarc basins, corresponds to the Mississippian (stage 1), and is characterized by shallow marine and transitional siliciclastic sediments. During stage 2 (Early Pennsylvanian), glacial-postglacial sequences dominated the infracratonic (or intraplate) and retroarc basins, and terrigenous shallow marine sediments prevailed in arc-related basins. Stage 3 (Late Pennsylvanian-Early Cisuralian) shows the maximum extension of glacial-postglacial sediments in the Paraná and Sauce Grande-Colorado basins (intraplate region), whereas fluvial deposits interfingering with thin intervals of shallow marine sediments prevailed in the retroarc basins. To the west, arc-related basins were dominated by coastal to deep marine conditions (including turbiditic successions). In the Late Cisuralian (stage 4), important differences in sedimentation patterns are registered for the western arc-related basins and eastern intraplate basins. The former were locally dominated by volcaniclastic sediments or marine deposits, and the intraplate basins are characterized by shallow marine conditions punctuated by several episodes of deltaic progradation. Finally, in the Late Permian (stage 5), volcanism and volcaniclastic sedimentation dominated in basins located along the western South American margin. The intraplate basins in turn were characterized by T-R cycles composed of shallow marine, deltaic, and fluvial siliciclastic deposits.

  20. Gradients in seasonality and seawater oxygen isotopic composition along the early Permian Gondwanan coast, SE Australia

    Science.gov (United States)

    Beard, J. Andrew; Ivany, Linda C.; Runnegar, Bruce

    2015-09-01

    Oxygen isotope compositions of marine carbonates are commonly employed for understanding ancient temperatures, but this approach is complicated in the very distant past due to uncertainties about the effects of diagenesis and the isotopic composition of seawater, both locally and globally. Microsampled accretionary calcite from two species of the fossil bivalve Eurydesma Sowerby and Morris 1845 collected from sediments of Cisuralian age in high latitude marine sediments along the SE coast of Australia records cyclic seasonal fluctuations in shell ?18O values during growth, demonstrating the primary nature of the isotope signal and thus allowing investigation of early Permian seawater isotopic composition and water temperature in the high southern latitudes. The mean and seasonal range of ?18Ocarb decreases poleward across about 10 of paleolatitude (?67S-77S). The presence of co-occurring dropstones and stratigraphically associated glendonites constrains winter temperatures across the region to near-freezing, thus permitting calculation of realistic estimates of water composition and summer temperatures. Summer ?18Ocarb values indicate water temperatures between 5 C and 12 C, with warmer values at lower latitudes. The decrease in both mean sea surface temperature and seasonal amplitude with increasing latitude on the Gondwanan coast is much like that observed along high-latitude coastlines today. Calculated ?18Owater decreases toward the pole, likely associated with an increasing contribution of isotopically light fresh water derived from summer snow-melt. The gradient in ?18Owater is similar to that documented over a similar span of latitude on the modern SE Greenland coast. We infer the presence of a north-flowing coastal current of cold, O18-depleted water that entrains progressively greater amounts of more typical seawater as it moves away from the pole. ?18O values in SE Australia, however, are about 3 lower than those off Greenland, suggesting comparatively lower salinity water or more O18-depleted glacial ice/runoff in the Permian Gondwanan high latitudes, perhaps augmented by more depleted (negative) global average seawater. Conditions in southeastern Australia during the largest of the Permian deglaciations were warmer than present-day Antarctica at similar latitudes, but may approximate those of early-mid Miocene Antarctica, with frozen winters but summers closer to 10 C.

  1. WILDFIRES IN THE LATE PALAEOZOIC AND MESOZOIC OF THE SOUTHERN ALPS THE LATE PERMIAN OF THE BLETTERBACH-BUTTERLOCH AREA (NORTHERN ITALY

    Directory of Open Access Journals (Sweden)

    DIETER UHL

    2012-07-01

    Full Text Available For the first time fossil macroscopic remains of charcoal as direct evidence of palaeo-wildfires from the Late Permian Gröden Formation of the Bletterbach-Butterloch area in Northern Italy is described. The charcoal consists of pycnoxylic wood and originates from gymnosperms, but a more specific affiliation is not possible due to the fragmentary nature of the material. On a global scale our knowledge about Late Permian fire-ecology is still rather scarce and this finding helps to fill one of the numerous geographical gaps in our current knowledge about Late Permian wildfires. 

  2. Deposition and alteration of carbonaceous series within a Neotethyan rift at the western boundary of the Arabian plate: The late Permian Um Irna Formation, NW Jordan, a petroleum system

    Energy Technology Data Exchange (ETDEWEB)

    Dill, H.G.; Kus, J. [Federal Institute for Geosciences and Natural Resources, P.O. Box 51 01 53 D-30631 Hannover (Germany); Bechtel, A.; Gratzer, R. [Department of Applied Geosciences and Geophysics, University of Leoben, Peter Tunner Strasse 5, A-8700 Leoben (Austria); Abu Hamad, A.M.B. [Geology Department, University of Jordan, Amman 11942 (Jordan)

    2010-01-07

    During the late Permian (Kungurian to Kazanian) a Neotethyan rift basin evolved at the western boundary of the Arabian Plate, in what is called today the Dead Sea Valley of western Jordan. The break-up of Pangaea was accompanied by low-sinuosity sandy braided- to meandering-fluvial drainage systems which were fed by the uplift of the Arabian Shield and by poorly aerated swamps and ponds that concentrated plant debris of the Cathaysian floral province in the Um Irna Formation. These proximal wet fan sediments are overlain by a dry fan characterized by extensive reddish floodplain deposits, anastomosing channel systems and paleosols. The wet fan is underlain by Cambrian sandstones. These units serve as the top and bottom seals of the OM-bearing system of the Um Irna Formation. The sedimentary rocks of the OM-bearing Um Irna Formation underwent supergene, diagenetic and epigenetic hydrothermal alteration under an elevated geothermal gradient. The temperature increased from the time of deposition of the wet to the time of deposition of the dry fan and caused remobilization of manganese already pre-concentrated in the Cambrian footwall rocks of the rift basin. The anomalous heat regime may be accounted for as a predecessor stage of the Dead Sea Rift which is still active today. Oil seeps are found along faults and fractures near this deep-seated lineamentary fault zone. The deposition and alteration of the organic matter in this late Permian rift are of great consequence for oil generation in the region. Organic petrographic investigations revealed that organic-rich terrestrial carbonaceous and coal rich sediments of mainly of type III kerogen are dominant in the Um Irna Formation. In addition, aquatic liptinite rich sedimentary input (fresh water lake and/or lacustrine swamp) of type I kerogen is also noted. Coal derived organic matter occurs in the form of coaly particles with ranks from subbituminous A to high volatile bituminous C. Higher plant-derived macerals as sporinite and cutinite with an oil generation potential typical of type II kerogen contribute to the source rock potential of the Um Irna Formation which is equivalent to the Khuff Formation in the oil provinces of Iraq, Kuwait and Saudi Arabia (thermal maturity of dispersed OM ranges between 0.48 and 0.55% R{sub r} giving rise to the mature stage of oil generation). Additionally, Botryococcus-type algae point towards the presence of type I kerogen. Moreover the presence of solid bitumen and oil droplets (petroleum fluid expulsions) in the sediments of the Um Irna Formation indicates formation of hydrocarbons. Organic chemistry not only supported the coal petrographic findings but also indicated inhospitable aquatic conditions near the P/Tr boundary evidenced by PAHs present in the sample and by lots of charcoal. The tropical areas were affected by vast wildfires raging in the forest and swamps during the late Permian. They contributed to a highly toxic atmosphere, a decrease of the oxygen contents speeded up by dead OM spilled into the water and creating anoxia approaching the P/Tr boundary. The elevated geothermal gradient sparking hydrothermal alteration in the OM-bearing Um Irna Formation during the Late Permian may be accounted for as related to a precursor stage of the Dead Sea Rift, which is still active today in terms of migration of hot brines and hydrocarbons. (author)

  3. Evaluating the evolution of deep groundwaters in a sedimentary basin by means of environmental isotopes

    Science.gov (United States)

    Geyer, S.; Rehberg, K.; Glaesser, W.

    2003-04-01

    The Weisselster River Basin, a sedimentary basin with a Permian and Triassic bedrock basement filled with fluvial tertiary and glacial sediments shows a very complex hydrogeological situation as a result of basin formation by fault controlled dissolution processes in the basement. Objectives of this ongoing study is the determination of the mean residence times, the assessment of sulfate sources and the chemical evolution of the groundwaters from recharge area to points of discharge. Along with major cations/anions, environmental isotopes ^3H, 14C / ?13C DIC, ?^2H / ?18O, ?34S SO_4 were investigated. Predominating water type in the Permian aquifer is Ca-Mg-SO_4-(HCO_3). Along with elevated DOC-concentration (3--6 mg/l) and high conductivities 700--3000 ?S/cm temperatures up to 17.5^oC are conspicuous. Latter seem to coincide with zones of ascending groundwater from deeper sources within the Permian sequence. This is supported by low 14C concentrations (7--30 pmC), no detectable tritium and clearly elevated Strontium values (2.7--4.0 mg/l). 14C concentrations from samples upgradient are near the 14C input value while downgradient a constant decrease is notable. This is in good correlation to tritium data which indicate young groundwater components. Few samples away from the recharge area do contain ^3H and higher 14C concentrations implying local infiltration from overlying aquifers. From ?13C data ( --14 ppm PDB) and calcite saturation indices > 1 recharge under open system conditions can be assumed. Mean residence time calculated applying various correcting methods reaches maximum values of 10.000 years at locations with high discharge. However, without a suitable correction for carbonate dissolution apparent ages are far to high. Also ?^2H/?18O data give a clear indication for recharge under Holocene climatic conditions. Interpretation of ?34S data is somewhat problematic. So far two sulfate sources can be delineated, values > 10 ppm CDT are most likely dissolved Permian anhydrite, whereas values < 7 ppm CDT would represent a terrestrial environment. Both sources seem to occur in the studied aquifer suggesting a mixing with groundwaters from overlying tertiary aquifers.

  4. Resultados paleomagnticos preliminares en las sedimentitas neo-paleozoicas de la Formacin El Imperial, bloque de San Rafael, Mendoza Preliminary paleomagnetic results from the Carboniferous-Permian El Imperial Formation sedimentary rocks in the San Rafael Block, Mendoza province

    Directory of Open Access Journals (Sweden)

    R.N. Tomezzoli

    2006-09-01

    Full Text Available Durante el Prmico Temprano se desarroll, en el margen sudoccidental del Gondwana, una extensa faja de deformacin contraccional conocida con el nombre de cordn de las Gondwnides. En el extremo occidental de esta faja se instal, durante el Carbonfero Tardo-Prmico Temprano, una cuenca de antepas cuyo relleno se encuentra representado por las sedimentitas de la Formacin El Imperial aflorante en el bloque de San Rafael. Esta unidad presenta una seccin superior que registra una inversin de las paleopendientes, la cual ha sido interpretada como la primera evidencia de la migracin del frente de deformacin hacia el antepas. Se ha encarado un estudio paleomagntico de esta unidad en busca de elementos que permitan acotar la deformacin en el tiempo para poder evaluar as el posible carcter diacrnico de la misma. Se presentan y discuten los primeros resultados paleomagnticos obtenidos en sedimentitas del miembro inferior (Represa Agua del Toro y superior (Puesto La Josefa de la Formacin El Imperial. Estas rocas son portadoras de magnetizaciones remanentes reversas portadas principalmente por hematita, de posible edad prmica. Las posiciones paleopolares obtenidas en ambas localidades no coinciden con las esperadas segn la edad de estas rocas, lo que se podra explicar o bien por que no se ha cancelado correctamente la variacin secular, por rotaciones segn ejes verticales en los bloques de las localidades de muestreo, o bien por la combinacin de algunos o de todos estos factores.During the Early Permian an extensive deformation belt well-known as Gondwnides developed in the southwest Gondwana margin. A foreland basin has been settled during the Late Carboniferous - Early Permian in the western end of this strip, and is represented by the El Imperial Formation, which crops out in the San Rafael Block. The upper section of this unit records an inversion of the ancient slopes, which has been interpreted as the first evidence of the migration of the orogenic front towards the foreland. Therefore, a paleomagnetic study has been carried out on this unit, searching for elements that allow to constraint the deformation age to evaluate the possible diachronism of it. First paleomagnetic results obtained in El Imperial Formation, from the lower member in the Represa Agua del Toro and from the upper member in the Puesto La Josefa, are presented and discussed. These rocks have reverse magnetizations carried by hematite, of possible Permian age. Pole positions are discordant with the apparent polar wander path from South America. These differences could be explained because: secular variation was not properly averaged; rotations about vertical axes of the sampling localities; or the combination of these factors.

  5. Tectonic and climatic controls on sedimentation during deposition of the Sinakumbe Group and Karoo Supergroup, in the mid-Zambezi Valley Basin, southern Zambia

    Science.gov (United States)

    Nyambe, Imasiku A.

    1999-02-01

    Sediments of the Ordovician to Devonian Sinakumbe Group (˜210 m thick) and overlying Upper Carboniferous to Lower Jurassic Karoo Supergroup (˜4.5 km thick) were deposited in the mid-Zambezi Rift Valley Basin, southern Zambia. The Sinakumbe-Karoo succession represents deposition in a extensional fault-controlled basin of half-graben type. The basin-fill succession incorporates two major fining-upward cycles that resulted from major tectonic events, one event beginning with Sinakumbe Group sedimentation, possibly as early as Ordovician times, and the other beginning with Upper Karoo Group sedimentation near the Permo-Triassic boundary. Minor tectonic pulses occurred during deposition of the two major cycles. In the initial fault-controlled half-graben, a basin slope and alluvial fan system (Sikalamba Conglomerate Formation), draining southeastward, was apparently succeeded, without an intervening transitional facies, by a braided river system (Zongwe Sandstone Formation) draining southwestward, parallel to the basin margin. Glaciation followed by deglaciation resulted in glaciofluvial and glacio-lacustrine deposits of the Upper Carboniferous to Lower Permian Siankondobo Sandstone Formation of the Lower Karoo Group, and isostatic rebound eventually produced a broad flood plain on which the coal-bearing Lower Permian Gwembe Coal Formation was deposited. Fault-controlled maximum subsidence is represente by the lacustrine Upper Permian Madumabisa Mudstone Formation. Block-faulting and downwarping, probably due to the Gondwanide Orogeny, culminated with the introduction of large quantities of sediment through braided fluvial systems that overwhelmed and terminated Madumabisa Lake sedimentation, and is now represented by the Triassic Escarpment Grit and Interbedded Sandstone and Mudstone Formations of the Upper Karoo Group. Outpourings of basaltic flows in the Early Jurassic terminated Karoo sedimentation.

  6. Methanogenic Blow-up in the End-Permian Carbon Cycle

    Science.gov (United States)

    Rothman, D.; Fournier, G.; French, K. L.; Alm, E.; Boyle, E. A.; Cao, C.; Summons, R. E.

    2012-12-01

    The end-Permian extinction is associated with a mysterious disruption to Earth's carbon cycle. Here we identify causal mechanisms via three observations. First, we show that geochemical signals indicate an incipient singular blow-up of the marine inorganic carbon reservoir, coincident with the extinction and consistent with the evolutionary expansion of a new microbial metabolic pathway. Second, we show that the fast acetoclastic pathway in Methanosarcina, limited by nickel and responsible for most modern biogenic methane, emerged at a time statistically indistinguishable from the extinction. Finally, we show that nickel concentrations in South China sediments increased sharply at the extinction, probably as a consequence of massive Siberian volcanism and enabling the blow-up. Collectively, these results suggest that a specific microbial innovation instigated Earth's greatest mass extinction.

  7. Reproductive biology of the Permian Glossopteridales and their suggested relationship to flowering plants.

    Science.gov (United States)

    Taylor, E L; Taylor, T N

    1992-12-01

    The discovery of permineralized glossopterid reproduction organs from Late Permian deposits in the Beard-more Glacier region (central Transantarctic Mountains) of Antarctica provides anatomical evidence for the adaxial attachment of the seeds to the megaasporophyll in this important group of Late Paleozoic seed plants. The position of the seeds is in direct contradiction to many earlier descriptions, based predominatly on impression/compression remains. The attachement of the ovules on the adaxial surface of a leaf-like megasporophyll, combined with other features, such as megaga-reproductive biology in this group than has previously been hypothesized. The findings confirm the classification of the Glossopteridales as seed ferns and are important considerations in disscussion of the phylogeny of group, including their suggested role as close relatives or possible ancestors of the angiosperms. PMID:11607341

  8. Restoration of marine ecosystems following the end-Permian mass extinction: pattern and dynamics

    Science.gov (United States)

    Chen, Z.

    2013-12-01

    Life came closest to complete annihilation during the end-Permian mass extinction (EPME). Pattern and cause of this great dying have long been disputed. Similarly, there is also some debate on the recovery rate and pattern of marine organisms in the aftermath of the EPME. Some clades recovered rapidly, within the first 1-3 Myr of the Triassic. For instance, foraminiferal recovery began 1 Myr into the Triassic and was not much affected by Early Triassic crises. Further, some earliest Triassic body and trace fossil assemblages are also more diverse than predicted. Others, ie. Brachiopods, corals etc., however, did not rebound until the Middle Triassic. In addition, although ammonoids recovered fast, reaching a higher diversity by the Smithian than in the Late Permian, much of this Early Triassic radiation was within a single group, the Ceratitina, and their morphological disparity did not expand until the end-Spathian. Here, I like to broaden the modern ecologic network model to explore the complete trophic structure of fossilized ecosystems during the Permian-Triassic transition as a means of assessing the recovery. During the Late Permian and Early Triassic, primary producers, forming the lowest trophic level, were microbes. The middle part of the food web comprises primary and meso-consumer trophic levels, the former dominated by microorganisms such as foraminifers, the latter by opportunistic communities (i.e. disaster taxa), benthic shelly communities, and reef-builders. They were often consumed by invertebrate and vertebrate predators, the top trophic level. Fossil record from South China shows that the post-extinction ecosystems were degraded to a low level and typified by primary producers or opportunistic consumers, which are represented by widespread microbialites or high-abundance, low-diversity communities. Except for some opportunists, primary consumers, namely foraminifers, rebounded in Smithian. Trace-makers recovered in Spathian, which also saw biodiversity increases of some clades. However, benthic communities were still of low diversity and high abundance and did not recover until middle-late Anisian when reef ecosystems have also constructed. The mid-Anisian ecosystems were characterized by the diverse reptile and fish faunas such as the Luoping biota from Yunnan, Southwest China, in which marine reptiles diversified as top predators. Thus, ecosystems were constructed step by step from low level to top trophic level through the Griesbachian to late Anisian, some 8-9 Myr after the crisis. Moreover, although some top predators also rebounded spoarically in Early Triassic, they constructed incomplete and unstable ecosystems, which could not develop sustainably and thus did not occur repetitedly in younger strata. The contrast between the extrinsic and intrinsic models exemplifies a wider debate about macroevolution -- whether the key driver is the physical environment or biotic interactions. Case studies on microbe-metazoan interactions in matground ecosystems reveal that microbial bloom seems to have set an agenda for metazoan diversification in Early Triassic, implying that intrinsic dynamics may have played a crucial role driving ecosystem's restoration following the EPME.

  9. Synchronism of the Siberian Traps and the Permian-Triassic boundary

    Science.gov (United States)

    Campbell, I. H.; Czamanske, G. K.; Fedorenko, V. A.; Hill, R. I.; Stepanov, V.

    1992-12-01

    Uranium-lead ages from an ion probe were taken for zircons from the ore-bearing Noril'sk I intrusion that is comagmatic with, and intrusive to, the Siberian Traps. These values match, within an experimental error of +/- 4 million years, the dates for zircons extracted from a tuff at the Permian-Triassic (P-Tr) boundary. The results are consistent with the hypothesis that the P-Tr extinction was caused by the Siberian basaltic flood volcanism. It is likely that the eruption of these magmas was accompanied by the injection of large amounts of sulfur dioxide into the upper atmosphere, which may have led to global cooling and to expansion of the polar ice cap. The P-Tr extinction event may have been caused by a combination of acid rain and global cooling as well as rapid and extreme changes in sea level resulting from expansion of the polar ice cap.

  10. Eopolydiexodina (Middle Permian giant fusulinids) from Afghanistan: Biometry, morphometry, paleobiogeography, and end-Guadalupian events

    Science.gov (United States)

    Colpaert, Clémentine; Monnet, Claude; Vachard, Daniel

    2015-04-01

    The most spectacular macroevolutionary trend presented by the genera of schwagerinoid fusulinids, during the Pennsylvanian -Permian, is an enormous increase in size, which culminated in the Middle Permian with Eopolydiexodina. However, this potential major biogeographic marker, during the Kubergandian-early Midian time interval, is as yet hampered by its poor taxonomic characterization. Hence, Eopolydiexodina is revised here using biometric and morphometric methods applied to large collections from Afghanistan and selected taxa in the literature. These multivariate analyses consist of classical linear test parameters, as well as new area parameters acquired by computer image analysis. The Afghan species are re-defined, and some other species, occasionally described as Cimmerian, are re-discussed. These methods, combined with classical morphological analyses, also permit to conclude that the largest Eopolydiexodina of Afghanistan are microspheric specimens (probably agamonts) of E. afghanensis and E. bithynica. Two megalospheric groups of individuals (probably gamonts and schizonts) are represented in both species, as well as in E. persica and E. darvasica. Due to this presence of gamonts, agamonts and schizonts in several species, Eopolydiexodina is probably the oldest identified trimorphic genus among the large benthic foraminifers. Biostratigraphically, Eopolydiexodina appears restricted to the late Kubergandian to early Midian. The associated Afghan fusulinids (Dunbarula, Kahlerina, Afghanella, Yangchienia, Sumatrina, and Codonofusiella) allow proposing an accurate biostratigraphy of the Eopolydiexodina species in the Murgabian-Midian boundary interval. Paleobiogeographically, Eopolydiexodina was essentially located in the Laurentian and Perigondwanan borders of the Tethys. The possible presence of Eopolydiexodina in the Cimmerian Continent and in some regions of China has never been irrefutably demonstrated. This paleobiological revision of Eopolydiexodina and the biostratigraphic revision of other large Capitanian fusulinids, permit to suggest that the end-Guadalupian event is most probably a protracted succession of last appearance data of giant genera rather than an instantaneous Lilliput effect at the Capitanian/Wuchiapingian boundary.

  11. Cadmium-isotopic evidence for increasing primary productivity during the Late Permian anoxic event

    Science.gov (United States)

    Georgiev, Svetoslav V.; Horner, Tristan J.; Stein, Holly J.; Hannah, Judith L.; Bingen, Bernard; Rehkämper, Mark

    2015-01-01

    Earth's most extreme extinction event near the end of the Late Permian decimated more than 90% of all extant marine species. Widespread and intensive oceanic anoxia almost certainly contributed to the catastrophe, though the driving mechanisms that sustained such conditions are still debated. Of particular interest is whether water column anoxia was a consequence of a 'stagnant ocean', or if it was controlled by increases in nutrient supply, primary productivity, and subsequent heterotrophic respiration. Testing these competing hypotheses requires deconvolving sedimentary/bottom water redox conditions from changes in surface water productivity in marine sediments. We address this issue by studying marine shales from East Greenland and the mid-Norwegian shelf and combining sedimentary redox proxies with cadmium-isotopic analyses. Sedimentary nitrogen-isotopic data, pyrite framboid analyses, and organic and inorganic shale geochemistry reveal sulfidic conditions with vigorous upwelling, and increasingly anoxic conditions with a strengthening upwelling in the Greenland and Norwegian sections, respectively. Detailed analysis of sedimentary metal budgets illustrates that Cd is primarily associated with organic carbon and records primary geochemical signatures, thus enabling reconstruction of surface water nutrient utilization. Cadmium-isotopic analyses of the authigenic shale fraction released by inverse aqua regia digestion yield an average δ114Cd110 of + 0.15 ± 0.01 ‰ (2 SE, n = 12; rel. NIST SRM 3108), indicative of incomplete surface water nutrient utilization up-section. The constant degree of nutrient utilization combined with strong upwelling requires increasing primary productivity - and not oceanic stagnation - to balance the larger nutrient fluxes to both study sites during the development of the Late Permian water column anoxia. Overall, our data illustrate that if bottom water redox and upwelling can be adequately constrained, Cd-isotopic analyses of organic-rich sediments can be used to provide valuable information on nutrient utilization and therefore past productivity.

  12. Paleoceanographic conditions following the end-Permian mass extinction recorded by giant ooids (Moyang, South China)

    Science.gov (United States)

    Li, Fei; Yan, Jiaxin; Algeo, Thomas; Wu, Xia

    2013-06-01

    Early Triassic oceans were characterized by deposition of a number of "anachronistic facies", including microbialites, seafloor carbonate cement fans, and giant ooids. Giant ooids were particularly prevalent in Lower Triassic sections across South China and exhibit unusual features that may provide insights into marine environmental conditions following the end-Permian mass extinction. The section at Moyang (Guizhou Province) contains abundant giant ooids ranging in size between 2 and 6 mm (maximum 12 mm) and exhibiting various cortical structures, including regular, deformed, compound, regenerated and "domed". Preservation of ooid cortical structure is generally good as indicated by petrographic observations, and trace element and carbon isotope analyses suggest that diagenesis occurred in a closed diagenetic system. All ooids exhibit fine concentric laminae, frequently alternating between light-colored coarsely crystalline and dark-colored finely crystalline layers probably reflecting variation in organic content or original mineralogy. Under scanning electron microscope, biomineralized filaments or biofilms and tiny carbonate fluorapatite (CFA) crystals are commonly found in the finely crystalline layers. We infer that the precipitation of CFA was related to adsorption of P via microbial activity on the surfaces of ooids following episodic incursions of deep waters rich in CO2, H2S and phosphate into shallow-marine environments. Giant ooid precipitation may have been promoted in shallow ramp settings during these events by increased watermass agitation and supersaturation with respect to CaCO3, as well as reduced carbonate removal rates through biotic skeletal formation. Spatio-temporal distribution data reveal that giant ooids were widespread in the Tethyan region during the Early Triassic, and that they were most abundant immediately after the end-Permian crisis and disappeared gradually as metazoans repopulated marine environments.

  13. Facies architecture and stratigraphic evolution of aeolian dune and interdune deposits, Permian Caldeirão Member (Santa Brígida Formation), Brazil

    Science.gov (United States)

    Jones, Fábio Herbert; Scherer, Claiton Marlon dos Santos; Kuchle, Juliano

    2016-05-01

    The Permian Caldeirão Member (Santa Brígida Formation), located in the Tucano Central Basin, northeast region of Brazil, is characterized by a sandstone succession of aeolian origin that comprises the preserved deposits of dunes and interdunes. Grainflow and translatent wind-ripple strata, and frequent presence of reactivation surface, compose the cross-bedding of crescent aeolian dune deposits. The aeolian cross-strata show a mean dip toward the ENE. In places, interlayered with dune cross-beds, occur interdune units composed of facies indicative of dry, damp and wet condition of the substrate, suggesting spatial and/or temporal variations in the moisture content of the interdune accumulation surface. The presence of NNW current ripple cross-lamination in wet interdune areas indicates streamflows confined to interdune corridors and oriented perpendicular to aeolian transport direction. Lenses of damp and wet interdune strata exhibit mainly interdigitated and transitional relationships with the toe-sets of overlying aeolian dune units in sections parallel to aeolian transport, indicating that dune migration was contemporaneous with accumulation in adjacent interdunes. Lateral variations in the preserved thickness of the interdune units and the associated rare occurrence of abrupt and erosive contacts between interdune and overlying dune sets, suggest temporal variations in the angle of dune and interdune climb that may be related to high-frequency changes in water table position. Four stratigraphic intervals in the Caldeirão Member can be identified, two intervals showing cross-bedding of aeolian dunes without wet interdune areas and two intervals exhibiting aeolian dunes separated by wet interdune areas, marking the transition between dry aeolian systems (Intervals I and III) and wet aeolian systems (Intervals II and IV). The temporal alternations between dry and wet aeolian systems reflect changes in the availability of dry sand and/or the rate in the water table rise, possibly controlled by orbitally-driven climatic fluctuations.

  14. Regional well-log correlation in the New Mexico portion of the Delaware Basin

    Energy Technology Data Exchange (ETDEWEB)

    Borns, D.J.; Shaffer, S.E.

    1985-09-01

    Although well logs provide the most complete record of stratigraphy and structure in the northern Delaware Basin, regional interpretations of these logs generate problems of ambiguous lithologic signatures and on-hole anomalies. Interpretation must therefore be based on log-to-log correlation rather than on inferences from single logs. In this report, logs from 276 wells were used to make stratigraphic picks of Ochoan horizons (the Rustler, Salado, and Castile Formations) in the New Mexico portion of the Delaware Basin. Current log correlation suggests that: (1) the Castile is characterized by lateral thickening and thinning; (2) some Castile thinnings are of Permian age; (3) irregular topography in the Guadalupian Bell Canyon Formation may produce apparent structures in the overlying Ochoan units; and (4) extensive dissolution of the Salado is not apparent in the area of the Waste Isolation Pilot Project (WIPP) site. 13 refs., 37 figs.

  15. Regional well-log correlation in the New Mexico portion of the Delaware Basin

    International Nuclear Information System (INIS)

    Although well logs provide the most complete record of stratigraphy and structure in the northern Delaware Basin, regional interpretations of these logs generate problems of ambiguous lithologic signatures and on-hole anomalies. Interpretation must therefore be based on log-to-log correlation rather than on inferences from single logs. In this report, logs from 276 wells were used to make stratigraphic picks of Ochoan horizons (the Rustler, Salado, and Castile Formations) in the New Mexico portion of the Delaware Basin. Current log correlation suggests that: (1) the Castile is characterized by lateral thickening and thinning; (2) some Castile thinnings are of Permian age; (3) irregular topography in the Guadalupian Bell Canyon Formation may produce apparent structures in the overlying Ochoan units; and (4) extensive dissolution of the Salado is not apparent in the area of the Waste Isolation Pilot Project (WIPP) site. 13 refs., 37 figs

  16. Sedimentary and tectonic environments for uranium mineralization on the Parana Basin, Brazil

    International Nuclear Information System (INIS)

    The Parana Basin is an isolated intracratonic basin in Southeastern South America and is characterized by Paleozoic and Mesozoic clastic sediments and by the location of one of the world's largest lava flows. Uranium mineralization occurs mainly in lower Devonian epineritic feldsphatic sandstones and in fluvio-deltaic channels developed in middle Permian mudstones and sandstones. Stratigraphic and sedimentologic conditions plus tectonic barriers in association with underground water controlled the mineralization. Two uranium deposits with 4250 and 6800 tonnes U of RAR plus EAR were found containing primary (pitchblende and coffinite) and secondary (autunite, sabugalite, uranocircite) minerals. A paleochannel model for the Permo-carboniferous mineralization is quite well established whereas many questions are still open for the confirmation of a model for the Devonian occurrences. Host rock sedimentary environment, ore-forming conditions and source rocks are discussed. (author)

  17. Characterization of bedded salt for storage caverns -- A case study from the Midland Basin, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hovorka, Susan D.; Nava, Robin

    2000-06-13

    The geometry of Permian bedding salt in the Midland Basin is a product of interaction between depositional facies and postdepositional modification by salt dissolution. Mapping high-frequency cycle patterns in cross section and map view using wireline logs documents the salt geometry. Geologically based interpretation of depositional and dissolution processes provides a powerful tool for mapping and geometry of salt to assess the suitability of sites for development of solution-mined storage caverns. In addition, this process-based description of salt geometry complements existing data about the evolution of one of the best-known sedimentary basins in the world, and can serve as a genetic model to assist in interpreting other salts.

  18. WILDFIRES IN THE LATE PALAEOZOIC AND MESOZOIC OF THE SOUTHERN ALPS THE LATE PERMIAN OF THE BLETTERBACH-BUTTERLOCH AREA (NORTHERN ITALY)

    OpenAIRE

    DIETER UHL; RAINER BUTZMANN; THILO C. FISCHER; BARBARA MELLER; EVELYN KUSTATSCHER

    2012-01-01

    For the first time fossil macroscopic remains of charcoal as direct evidence of palaeo-wildfires from the Late Permian Grden Formation of the Bletterbach-Butterloch area in Northern Italy is described. The charcoal consists of pycnoxylic wood and originates from gymnosperms, but a more specific affiliation is not possible due to the fragmentary nature of the material. On a global scale our knowledge about Late Permian fire-ecology is still rather scarce and this finding helps to fill one of ...

  19. The Permian-Triassic transition: Historical review of the most important ecological crises with special emphasis on the Iberian Peninsula and Western-Central Europe.

    OpenAIRE

    Virgili, C.

    2008-01-01

    One of the most important climatic and biological crises of the history of the Earth occurred 250 m.a. ago, during the transition from the Permian to the Triassic. During the Permian, all of the continental blocks were covering one hemisphere forming the Pangea supercontinent, while the other was covered by the Panthalasa ocean. General conditions for living on land were very precarious. The exuberant vegetation of the Carboniferous period had disappeared almost completely, as well as the ...

  20. The Permian-Triassic transition: Historical review of the most important ecological crises with special emphasis on the Iberian Peninsula and Western-Central Europe

    OpenAIRE

    Virgili, Carmina

    2008-01-01

    [EN] One of the most important climatic and biological crises of the history of the Earth occurred 250 m.a. ago, during the transition from the Permian to the Triassic. During the Permian, all of the continental blocks were covering one hemisphere forming the Pangea supercontinent, while the other was covered by the Panthalasa ocean. General conditions for living on land were very precarious. The exuberant vegetation of the Carboniferous period had disappeared almost completely, as w...

  1. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    International Nuclear Information System (INIS)

    This report presents the results of a small-scale pilot study of the mineralogy and alteration characteristics of unusual sheet-like native copper occurring together with uraniferous and vanadiferous concretions in mudstones and siltstones of the Permian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The host mudstones and siltstones are smectitic and have been compacted through deep Mesozoic burial. The occurrence of native copper within these rocks represents a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of high-level radioactive waste by the SKB. The study was undertaken by the British Geological Survey (BGS) on behalf of SKB between November 1999 and June 2000. The study was based primarily on archived reference material collected by the BGS during regional geological and mineralogical surveys of the area in the 1970's and 1980's. However, a brief visit was made to Littleham Cove in January 2000 to try to examine the native copper in situ and to collect additional material. Unfortunately, recent landslips and mudflows obscured much of the outcrop, and only one new sample of native copper could be collected. The native copper occurs as thin plates, up to 160 mm in diameter, which occur parallel to bedding in the Permian Littleham Mudstone Formation at Littleham Cove (near Budleigh Salterton) in south Devon. Each plate is made up of composite stacks of individual thin copper sheets each 1-2 mm thick. The copper is very pure (>99.4% Cu) but is accompanied by minor amounts of native silver (also pure - >99%) which occurs as small inclusions within the native copper. Detailed mineralogical and petrological studies of the native copper sheets, using optical petrography, backscattered scanning electron microscopy, X-ray diffraction analysis and electron probe microanalytical techniques, reveal a complex history of mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30-80% of the original thickness) of the copper sheets has been preserved in the saturated compacted clay environment of the Littleham Mudstone for many millions of years, at least since the end of the Lower Jurassic. Apart from the recent weathering effects due to exposure at outcrop, most of the observed corrosion and alteration of the native copper is geologically old and also occurred before the end of the Lower Jurassic. This demonstrates that the native copper can remain stable in a saturated and compacted clay environment for geological timescales (over 176 Ma) well in excess of the timescales considered for Performance Assessment. Since the copper sheets found in the Littleham Mudstone Formation are very thin (1-2 mm) and have survived over this long time, waste canisters - which will be made from much thicker copper - would be expected (by comparison) to show greater performance

  2. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Styles, M.T.; Hards, V.L. [Natural Environment Research Council (United Kingdom). British Geological Survey

    2000-08-01

    This report presents the results of a small-scale pilot study of the mineralogy and alteration characteristics of unusual sheet-like native copper occurring together with uraniferous and vanadiferous concretions in mudstones and siltstones of the Permian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The host mudstones and siltstones are smectitic and have been compacted through deep Mesozoic burial. The occurrence of native copper within these rocks represents a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of high-level radioactive waste by the SKB. The study was undertaken by the British Geological Survey (BGS) on behalf of SKB between November 1999 and June 2000. The study was based primarily on archived reference material collected by the BGS during regional geological and mineralogical surveys of the area in the 1970's and 1980's. However, a brief visit was made to Littleham Cove in January 2000 to try to examine the native copper in situ and to collect additional material. Unfortunately, recent landslips and mudflows obscured much of the outcrop, and only one new sample of native copper could be collected. The native copper occurs as thin plates, up to 160 mm in diameter, which occur parallel to bedding in the Permian Littleham Mudstone Formation at Littleham Cove (near Budleigh Salterton) in south Devon. Each plate is made up of composite stacks of individual thin copper sheets each 1-2 mm thick. The copper is very pure (>99.4% Cu) but is accompanied by minor amounts of native silver (also pure - >99%) which occurs as small inclusions within the native copper. Detailed mineralogical and petrological studies of the native copper sheets, using optical petrography, backscattered scanning electron microscopy, X-ray diffraction analysis and electron probe microanalytical techniques, reveal a complex history of mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30-80% of the original thickness) of the copper sheets has been preserved in the saturated compacted clay environment of the Littleham Mudstone for many millions of years, at least since the end of the Lower Jurassic. Apart from the recent weathering effects due to exposure at outcrop, most of the observed corrosion and alteration of the native copper is geologically old and also occurred before the end of the Lower Jurassic. This demonstrates that the native copper can remain stable in a saturated and compacted clay environment for geological timescales (over 176 Ma) well in excess of the timescales considered for Performance Assessment. Since the copper sheets found in the Littleham Mudstone Formation are very thin (1-2 mm) and have survived over this long time, waste canisters - which will be made from much thicker copper - would be expected (by comparison) to show greater performance.

  3. Permian depositional age of metaturbidites of the Duque de York Complex, southern Chile: U-Pb SHRIMP data and palynology

    International Nuclear Information System (INIS)

    The Duque de York Complex (DYC) is part of the low grade metamorphic accretionary complexes of the pre-Andean Patagonian 'basement'. It is a sedimentary succession exposed along the western margin of southernmost South America. New U-Pb zircon ages and palynological data restrict the maximum depositional age of the DYC to the limit between the early Permian (Kungurian) and the middle Permian (Roadian). The palynological association recorded in the DYC, characterized mainly by Gymnospermopsida pollen, indicates a humid environment of forest with an under-growth of ferns. Regional paleogeographic correlations point out that an interpretation of DYC as an autochthonous terrane cannot be discarded, contrasting with previous hypotheses which suggest an allochthonous character for this complex

  4. Impact of Zn-Pb mining in the Olkusz ore district on the Permian aquifer (SW Poland).

    Science.gov (United States)

    Motyka, Jacek; Postawa, Adam

    2013-11-01

    Long-term extensive mining of Zn-Pb ores in the Olkusz area resulted in significant changes of water table levels and chemical composition of water in all aquifers in this area. Within the Permian aquifer, hydrochemical type of water evolved in two general stages. Short-term effect was freshening in the zones of contact with overlying the Triassic limestones and dolomites. Long-term effect was a change in flow pattern and, as a consequence, an inflow of naturally altered and antropogenically contaminated water from the Triassic aquifer into the Permian complex. This was especially intensive in densely fissured and fault zones. As a result of all these processes, hydrochemical type of water shifted from multi-ion types with various combinations of ions towards higher shares of sulphates, calcium and magnesium. PMID:23633000

  5. FUSULINID SEQUENCE EVOLUTION AND SEQUENCE EXTINCTIONIN WOLFCAMPIAN AND LEONARDIAN SERIES (LOWER PERMIAN),GLASS MOUNTAINS, WEST TEXAS

    OpenAIRE

    CHARLES A. ROSS; JUNE R. P. ROSS

    2003-01-01

    In the Permian Wolfcampian and Leonardian Series of West Texas, sequence evolution and sequence extinction record the appearance and disappearance of morphological species in stratigraphic successions that show repeated sea level fluctuations and associated depositional hiatuses. The lower Wolfcampian Nealian Stage includes 16 relatively short term sea-level fluctuations (fourth-order depositional sequences) and contains a diverse fusulinid fauna of more than 39 species and eight genera. ...

  6. Genesis of Pb-Zn-Cu-Ag Deposits within Permian Carboniferous-Carbonate Rocks in Madina Regency, North Sumatra

    OpenAIRE

    Bhakti Hamonangan Harahap; Hamdan Zainal Abidin; Wahyu Gunawan; Rum Yuniarni

    2015-01-01

    Strong mineralized carbonate rock-bearing Pb-Zn-Cu-Ag-(Au) ores are well exposed on the Latong River area, Madina Regency, North Sumatra Province. The ore deposit is hosted within the carbonate rocks of the Permian to Carboniferous Tapanuli Group. It is mainly accumulated in hollows replacing limestone in the forms of lensoidal, colloform, veins, veinlets, cavity filling, breccia, and dissemination. The ores dominantly consist of galena (126 000 ppm Pb) and sphalerite (2347 ppm Zn). The other...

  7. Septarian carbonate concretions in the Permian Rio do Rasto Formation: Birth, growth and implications for the early diagenetic history of southwestern Gondwana succession

    Science.gov (United States)

    Alessandretti, Luciano; Warren, Lucas Veríssimo; Machado, Rômulo; Novello, Valdir Felipe; Sayeg, Isaac Jamil

    2015-08-01

    Between the Late Carboniferous and Early Triassic, the southwestern Gondwana supercontinent was characterized by the development of a huge intracratonic basin. A large confined epeiric sea and the accumulation of a transgressive-regressive sequence were formed by continuous subsidence related to tectonic effects caused by the Sanrafaelic Orogeny and the consequent generation of accommodation space. The Permian Rio do Rasto Formation documents the last progradational cycle related to the complete continentalization of this epeiric sea. The basal member of the Rio do Rasto Formation (Serrinha) is believed to have been deposited in a shallow epicontinental water body subjected to storms and influenced by episodic deltaic incursions. One of the most remarkable characteristics of the Serrinha Member is the presence of carbonate concretions hosted in mudstones and very fine sandstones. Here, we combine sedimentological and petrographic descriptions coupled with geochemical and stable carbon and oxygen isotopic data to elucidate the nature of these carbonate concretions. The non-deformed internal structure, decreasing proportion of carbonate cements relative to detrital grains toward the concretion edges, core-to-rim isotopic variations, and perhaps most importantly, the preservation of a well-developed cardhouse fabric support an early diagenetic origin for these structures at shallow burial depths of tens of meters. Stable isotope analyses of micritic calcite cements and calcites filling the septarian fractures reveal major negative excursions in both δ18O and δ13C values. Oxygen isotope ratios obtained for the micritic calcite cements vary between - 12.1 and - 2.6‰. The calcite filling septarian fractures also exhibit negative values of δ18O (- 14.2 to - 13.8‰), with an average of - 14‰. The δ13C values of micritic calcite cements range from - 5.0-0.2‰. The carbon isotopic data from the calcite-filling septarian fractures are also negative (- 4.4 to - 3.3‰). The δ18O signatures suggest that the early diagenetic carbonate concretions precipitated in a shallow freshwater environment rather than in a marine setting. The δ13C values suggest that the carbon isotopes were derived from a source with slightly depleted 13C, supporting at least a partial organogenic contribution with weak sulfate reduction rates typical of freshwater systems. Sedimentological analysis shows that the epicontinental water body in which the Serrinha Member was deposited was constantly supplied by rivers and meteoric waters, which suggests that an enormous freshwater basin with restricted marine connections to the Panthalassa Ocean once existed.

  8. Reserves in Western Basins

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, R.H.; Cotton, B.W.

    1993-12-31

    The objective of this project is to investigate the reserves potential of overpressured tight (OPT) gas reservoirs in three Rocky Mountain basins. These are the Greater Green River Basin (GGRB), Uinta Basin and Piceance Basin. By documenting productive characteristics in these basins and characterizing the nature of the vast gas resources in place, the reserves potential may be understood and quantified. Through this understanding, it is hoped that the oil and gas industry will be encouraged to pursue exploitation of this resource. At this point in time, the GGRB work has been completed and the final report submitted for publication. Work on the Uinta basin has just commenced and work on the Piceance basin will commence next year. Since the GGRB portion of this project has been completed, further discussion centers upon this Basin.

  9. Structure of Charnockitic basement in a part of the KrishnaGodavari basin, Andhra Pradesh

    Indian Academy of Sciences (India)

    I V Radhakrishna Murthy; S Bangaru Babu

    2006-08-01

    A regional magnetic survey was carried out over an area of 8000 km2 in Godavari districts of Andhra Pradesh,India,which is covered by the rocks of Eastern Ghat Mobile Belt (EGMB) viz., the Khondalitic series and Charnockites in the northern half and Permian to Mesozoic and Cenozoic sediments in the southern half,and forms a part of the Krishna Godavari (K G)basin. The survey brought out a strong NE SW trending anomaly in the area covered by the rocks of Eastern Ghat Mobile Belt (EGMB),and a mild ENE WSW trending anomaly in the area covered by the sediments of the Krishna Godavari (K G)basin.The NE SW trending anomaly in the northern half could be attributed to the exposed/near surface Charnockite basement that has come closer to the surface as a result of Eastern Ghat Mobile Belt (EGMB)tectonics.Explanation of the mild ENE WSW trending anomaly over the sediments of the Krishna Godavari (K G)basin required a faulted magnetic basement at depth downthrown towards the south.It is therefore concluded that the Charnockitic basement together with the Khondalite group of rocks which are folded and faulted during the different phases of tectonics of Eastern Ghat Mobile Belt (EGMB) extend into the Krishna Godavari (K G)basin and further,were involved in faulting during the phases of formation and sedimentation in the Krishna Godavari (K G)basin.

  10. Kerogen morphology and geochemistry at the Permian-Triassic transition in the Meishan section, South China: Implication for paleoenvironmental variation

    Science.gov (United States)

    Sawada, Ken; Kaiho, Kunio; Okano, Kazuki

    2012-08-01

    Detailed fluorescent microscopic observations and organic geochemical analyses for insoluble sedimentary organic matter (kerogens) are conducted on the end-Permian to earliest Triassic sediments in the Meishan section A of South China. The main objectives of the present study are to reconstruct variations of marine and terrestrial environments, and to evaluate bulk characteristics of terrestrial input in the palaeo-Tethys ocean for the Permian-Triassic boundary (PTB). Most of kerogens in the Meishan section are mainly composed of marine algae-derived amorphous organic matter, while terrestrial plant-derived amorphous organic matter is remarkably dominant in the mass extinction horizon reported previously. The relative abundances of marine organic matter may vary depending on marine production rather than terrestrial input in the palaeo-Tethys associated with changing terrestrial vegetation. We also identified aromatic furans as major compounds in kerogen pyrolysate of all layers. It is possible that sources of aromatic furans with alkyl group, fungi and lichen, proliferated as disaster biota in terrestrial ecosystem through the PTB. Higher abundances of herbaceous organic matter are observed in the layers above the mass extinction horizon. However, the conifer biomarker retene can be identified in kerogen pyrolysates of all layers. These results imply that the productions of herbaceous plants increased as dominant pioneer biota in early stage of recovery for terrestrial ecosystem after its collapse, but also that woody plant potentially continued to be produced in land area throughout the end-Permian and earliest-Triassic.

  11. Australian-derived detrital zircons in the Permian-Triassic Gympie terrane (eastern Australia): Evidence for an autochthonous origin

    Science.gov (United States)

    Li, Pengfei; Rosenbaum, Gideon; Yang, Jin-Hui; Hoy, Derek

    2015-05-01

    The Tasmanides in eastern Australia record accretionary processes along the eastern Gondwana margin during the Phanerozoic. The Gympie terrane is the easternmost segment of the Tasmanides, but whether its origin was autochthonous or allochthonous is a matter of debate. We present U-Pb ages of detrital zircons from Permian and Triassic sedimentary rocks of the Gympie terrane with the aim of tracing the source of the sediments and constraining their tectonic relationships with the Tasmanides. Our results show that the Permian stratigraphic units from the Gympie terrane mainly contain Carboniferous and Permian detrital zircons with dominant age peaks at ~263 Ma, ~300 Ma, ~310 Ma, and ~330 Ma. The provenance ages of the Triassic sedimentary units are similar (~256 Ma, ~295 Ma, and ~328 Ma) with an additional younger age peak of ~240 Ma. This pattern of provenance ages from the Gympie terrane is correlative to episodes of magmatism in the adjacent component of the Tasmanides (New England Orogen), indicating that the detrital zircons were dominantly derived from the Australian continent. Given the widespread input of detrital zircons from the Tasmanides, we think that the sedimentary sequence of the Gympie terrane was deposited along the margin of the eastern Australian continent, possibly in association with a Permo-Triassic continental arc system. Our results do not show evidence for an exotic origin of the Gympie terrane, indicating that similarly to the vast majority of the Tasmanides, the Gympie terrane was genetically linked to the Australian continent.

  12. The armoured dissorophid Cacops from the Early Permian of Oklahoma and the exploitation of the terrestrial realm by amphibians.

    Science.gov (United States)

    Reisz, Robert R; Schoch, Rainer R; Anderson, Jason S

    2009-07-01

    Cacops, one of the most distinctive Paleozoic amphibians, is part of a clade of dissorophoid temnospondyls that diversified in the equatorial region of Pangea during the Late Carboniferous and Early Permian, persisting into the Late Permian in Central Russia and China. Dissorophids were a successful group of fully terrestrial, often spectacularly armoured predators, the only amphibians apparently able to coexist with amniotes when the latter started to dominate terrestrial ecosystems. In this paper, we describe excellent new skulls from the Early Permian of Oklahoma attributed to Cacops, Cacops morrisi sp. nov. and provide for the first time detailed information about this iconic dissorophid. These specimens show anatomical and ontogenetic features that will impact on future studies on the evolution of terrestriality in tetrapods. For example, the large, posteriorly closed tympanic embayment has fine striations on an otherwise smooth surface, documenting the oldest known clear evidence for the presence of a tympanic membrane in the fossil record, a structure that is used for hearing airborne sound in extant tetrapods. The skull of C. morrisi also has several features associated with predatory behaviour, indicating that this dissorophid may have been one of the top terrestrial predators of its time. PMID:19347261

  13. Mineralogical and Geochemical Characteristics of Late Permian Coals from the Mahe Mine, Zhaotong Coalfield, Northeastern Yunnan, China

    Directory of Open Access Journals (Sweden)

    Xibo Wang

    2015-07-01

    Full Text Available This paper reports the mineralogical and geochemical compositions of the Late Permian C2, C5a, C5b, C6a, and C6b semianthracite coals from the Mahe mine, northeastern Yunnan, China. Minerals in the coals are mainly made up of quartz, chamosite, kaolinite, mixed-layer illite/smectite (I/S, pyrite, and calcite; followed by anatase, dolomite, siderite, illite and marcasite. Similar to the Late Permian coals from eastern Yunnan, the authigenic quartz and chamosite were precipitated from the weathering solution of Emeishan basalt, while kaolinite and mixed-layer I/S occurring as lenses or thin beds were related to the weathering residual detrital of Emeishan basalt. However, the euhedral quartz and apatite particles in the Mahe coals were attributed to silicic-rock detrital input. It further indicates that there has been silicic igneous eruption in the northeastern Yunnan. Due to the silicic rock detrital input, the Eu/Eu* value of the Mahe coals is lower than that of the Late Permian coals from eastern Yunnan, where the detrital particles were mainly derived from the basalt. The high contents of Sc, V, Cr, Co, Ni, Cu, Ga, and Sn in the Mahe coals were mainly derived from the Kangdian Upland.

  14. Rare-earth elements in the Permian Phosphoria Formation: Paleo proxies of ocean geochemistry

    Science.gov (United States)

    Piper, D.Z.; Perkins, R.B.; Rowe, H.D.

    2007-01-01

    The geochemistry of deposition of the Meade Peak Member of the Phosphoria Formation (MPM) in southeast Idaho, USA, a world-class sedimentary phosphate deposit of Permian age that extends over 300,000 km2, is ascertained from its rare earth element (REE) composition. Ratios of REE:Al2O3 suggest two sources-seawater and terrigenous debris. The seawater-derived marine fraction identifies bottom water in the Phosphoria Sea as O2-depleted, denitrifying (suboxic) most of the time, and seldom sulfate-reducing (anoxic). This interpretation is supported by earlier research that showed progressively greater ratios in the marine sediment fraction of Cr:Ni>V:Ni???Mo:Ni, relative to their ratios in seawater; for which marine Cr, V, and Mo can have a dominantly O2-depleted bottom-water source and Ni a photic-zone, largely algal, source. The water chemistry was maintained by a balance between bacterial oxidation of organic matter settling through the water column, determined largely by primary productivity in the photic zone, and the flux of oxidants into the bottom water via advection of seawater from the open ocean. Samples strongly enriched in carbonate fluorapatite, the dominant REE host mineral, have variable Er/Sm, Tm/Sm, and Yb/Sm ratios. Their distribution may represent greater advection of seawater between the Phosphoria Sea and open ocean during deposition of two ore zones than a center waste and greater upwelling of nutrient-enriched water into the photic zone. However, the mean rate of deposition of marine Ni, a trace nutrient of algae, and PO43-, a limiting nutrient, indicate that primary productivity was probably high throughout the depositional history. An alternative interpretation of the variable enrichments of Er, Tm, and Yb, relative to Sm, is that they may reflect temporally variable carbonate alkalinity of open-ocean seawater in Permian time. A more strongly negative Ce anomaly for all phosphatic units than the Ce anomaly of modern pelletal phosphate is further indicative of an elevated O2 concentration in the Permo-Carboniferous open ocean, as proposed by others, in contrast to the depletion of O2 in the bottom water of the Phosphoria Sea itself. The oceanographic conditions under which the deposit accumulated were likely similar to conditions under which many sedimentary phosphate deposits have accumulated and to conditions under which many black shales that are commonly phosphate poor have accumulated. A shortcoming of several earlier studies of these deposits has resulted from a failure to examine the marine fraction of elements separate from the terrigenous fraction. ?? 2007 Elsevier Ltd. All rights reserved.

  15. Origins of microspherules from the Permian-Triassic boundary event layers in South China

    Science.gov (United States)

    Zhang, Hua; Shen, Shu-zhong; Cao, Chang-qun; Zheng, Quan-feng

    2014-09-01

    Volcanism and impact scenarios are two of the most plausible ways of interpreting the causes of the largest biological mass extinction at the end-Permian. Microspherules have previously been widely reported from tens of different Permian-Triassic boundary (PTB) sections in South China and some other regions. These microspherules have been interpreted as either the product of volcanic eruptions or an impact event. In order to test these scenarios, we collected 60 samples from 12 intensively-studied PTB sections in South China. In addition, four soil samples close to these PTB layers were also collected for comparison. Our investigation indicates that abundant microspherules with mosaic or dot shape crystals on rounded surface are present in the surface samples in the PTB layers at Meishan, Meili, and Shatian sections and most soil background samples in South China. Those microspherules consist of four different types based on their main chemical composition, surface features, and internal structure including iron, magnetite-silicate, glassy, pyrite microspherules and framboids. In contrast, microspherules have not been found in a few sections in remote areas such as the Selong Xishan section in Tibet and the Dalongkou section in Xinjiang, Northwest China, in the deeply-excavated samples at the Shangsi section and the hard tuff layers around the PTB at the Xiaochehe Section in Guiyang. Microspherules decrease in abundance with depth in PTB clay beds. All these microspherules except the pyrite microspherules and framboids are found in both the PTB layers and the nearby soil background samples. The iron microspherules are pure iron oxides such as magnetite, hematite or maghemite and contain low concentrations of nickel and chromium, and lack an Ni-Fe core and general extraterrestrial mineral wstite. All these external and chemical characteristics suggest that most of iron microspherules previously reported from PTB sections in South China are modern industrial fly ashes. A low ratio of Fe3 +/FeTotal in crystals of magnetite-silicate microspherules and high ZnO contents can identify them as industrial contaminants. The pyrite microspherules and framboidal pyrite found from bed 24e and bed 26 at the Meishan sections are of depositional or/and diagenetic origins, and only the rounded quartz and the fragments containing extremely high SiO2 and TiO2 are possibly of volcanic origin.

  16. The northwestern Argentina Tarija Basin: Stratigraphy, depositional systems, and controlling factors in a glaciated basin

    Science.gov (United States)

    Starck, Daniel; Papa, Cecilia del

    2006-12-01

    The Tarija Basin, shared by Bolivia and Argentina, was subjected to glacial conditions during the Late Carboniferous and Early Permian. The Macharetí and Mandiyutí groups deposited during these times record in their facies advances and retreats of the Gondwanan ice cap. The lithostratigraphic subdivision of these groups presents stages with minor glacial influence in the basal formations of each group (Tupambi and Escarpment formations), whereas in the upper units, glacially related deposition prevails (Tarija and San Telmo formations). Typical facies deposited in relation to glacial settings are diamictites and mudstones mainly related to proglacial, lacustrine environments. During the stages of main ice retreat, deposition was dominated by fluvial and deltaic sandstones. Significant erosion and deep valley incision characterize the basal surfaces of both groups. Conversely, the stratigraphic surface that separates the sandy formations from the overlying diamictites tends to be rather flat. The dynamics of the glacial cap are not only reflected in the facies distribution but also were a key factor in creating accommodation space; the changes in the glacial-driven subsidence linked to the advance and retreat of the ice were its main control.

  17. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  18. Enhanced recycling of organic matter and Os-isotopic evidence for multiple magmatic or meteoritic inputs to the Late Permian Panthalassic Ocean, Opal Creek, Canada

    Science.gov (United States)

    Georgiev, Svetoslav V.; Stein, Holly J.; Hannah, Judith L.; Henderson, Charles M.; Algeo, Thomas J.

    2015-02-01

    The geochemical record for the Permian-Triassic boundary in northern latitudes is essential to evaluation of global changes associated with the most profound extinction of life on Earth. We present inorganic and organic geochemical data, and Re-Os isotope systematics in a critical stratigraphic interval of pre- and post-extinction Upper Permian-Lower Triassic sediments from Opal Creek, western Canada (paleolatitude of ?30N). We document significant and long-lived changes in Panthalassa seawater chemistry that were initiated during the first of four magmatic or meteoritic inputs to Late Permian seawater, evidenced by notable decreases of Os isotopic ratios upsection. Geochemical signals indicate establishment of anoxic bottom waters shortly after regional transgression reinitiated sedimentation in the Late Permian. Euxinic signals are most prominent in the Upper Permian sediments with low organic carbon and high sulfur contents, and gradually wane in the Lower Triassic. The observed features may have been generated in a strongly euxinic ocean in which high bacterioplankton productivity sustained prolific microbial sulfate reduction in the sediment and/or water column, providing hydrogen sulfide to form pyrite. This scenario requires nearly complete anaerobic decomposition of predominantly labile marine organic matter (OM) without the necessity for a complete collapse of primary marine productivity. Similar geochemical variations could have been achieved by widespread oxidation of methane by sulfate reducers after a methanogenic burst in the Late Permian. Both scenarios could have provided similar kill mechanisms for the latest Permian mass extinction. Despite the moderate thermal maturity of the section, OM in all studied samples is dominantly terrestrial and/or continentally derived, recycled and refractory ancient OM. We argue that, as such, the quantity of the OM in the section mainly reflects changes in terrestrial vegetation and/or weathering, and not in marine productivity. At Opal Creek, a pyrite layer and pulses recorded by low initial Os isotopes followed the main extinction.

  19. Revisiting platinum group elements of Late Permian coals from western Guizhou Province, SW China

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Liang [State Key Lab of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China); Gao, Jianfeng [Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China)

    2008-08-05

    Twenty five coal samples from the Late Permian coal-bearing strata in Weining, Nayong, and Zhijin, western Guizhou Province, SW, China, were analyzed for platinum group elements (PGEs). The coal ashes were digested by the Carius tube technique and accurately measured by isotope dilution-inductively coupled plasma mass spectrometry (ID-ICP-MS) for all PGEs. The results are much lower than the previous reported values. Our study suggested that the previously reported PGE values are incorrect and may due to the polyatomic interferences in ICP-MS measurements. In our study, samples from the Weining coalfield have the lowest PGE contents (from 0.019 Ir to 0.42 ng/g Pd), which represent the PGE background value in coal in western Guizhou province. Some of the coals have Pt and Pd contents about 20-times higher than the background value, indicating PGEs are concentrated. We also reported new and reliable PGE data and background value of coal in western Guizhou province, SW, China, and suggested to rework the PGE background values of Chinese coals. (author)

  20. Ocean Acidification and the End-Permian Mass Extinction: To What Extent does Evidence Support Hypothesis?

    Directory of Open Access Journals (Sweden)

    Marie-Béatrice Forel

    2012-09-01

    Full Text Available Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO2, raising concern about marine diversity, food security and ecosystem services. Proxy evidence for acidification during past crises may help predict future change, but three issues limit confidence of comparisons between modern and ancient ocean acidification, illustrated from the end-Permian extinction, 252 million years ago: (1 problems with evidence for ocean acidification preserved in sedimentary rocks, where proposed marine dissolution surfaces may be subaerial. Sedimentary evidence that the extinction was partly due to ocean acidification is therefore inconclusive; (2 Fossils of marine animals potentially affected by ocean acidification are imperfect records of past conditions; selective extinction of hypercalcifying organisms is uncertain evidence for acidification; (3 The current high rates of acidification may not reflect past rates, which cannot be measured directly, and whose temporal resolution decreases in older rocks. Thus large increases in CO2 in the past may have occurred over a long enough time to have allowed assimilation into the oceans, and acidification may not have stressed ocean biota to the present extent. Although we acknowledge the very likely occurrence of past ocean acidification, obtaining support presents a continuing challenge for the Earth science community.

  1. Age of the Emeishan flood magmatism and relations to Permian-Triassic boundary events

    Science.gov (United States)

    Lo, Ching-Hua; Chung, Sun-Lin; Lee, Tung-Yi; Wu, Genyao

    2002-05-01

    The Permian-Triassic (P-T) mass extinction, the greatest biological mortality event in the Earth's history, was probably caused by dramatic and global forcing mechanisms such as the Siberian flood volcanism. Here we present the first set of high-precision 40Ar/ 39Ar dating results of volcanic and intrusive rocks from the Emeishan Traps, South China, which define a main stage of the flood magmatism at 251-253 Ma and a subordinate precursory activity at 255 Ma. This time span is generally coeval with, or slightly older than, the age of the P-T boundary estimated by the ash beds in the Meishan stratotype section and the main eruption of the Siberian Traps. Our data reinforces the notion that the eruption of the Emeishan Traps, rather than eruption of the Siberian Traps, accounted for the formation of the P-T boundary ash beds in South China. The Emeishan flood magmatism, which occurred in the continental margin comprising thick marine limestone formations, moreover, may have triggered rapid release of large volumes of methane and carbon dioxide that could have been responsible for the global ? 13C excursion and associated environmental crisis leading to the mass extinction at the P-T boundary.

  2. Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing, southwestern China

    Energy Technology Data Exchange (ETDEWEB)

    Dai, S.F.; Zhou, Y.P.; Ren, D.Y.; Wang, X.B.; Li, D.; Zhao, L. [China University of Mining & Technology, Beijing (China)

    2007-05-15

    Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using inductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF), cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, and rare earth elements. The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identified in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The alkaline volcanic ashes were the dominant factors for the enrichment of alkaline elements, Nb, Ta, Zr, Hf, and rare earth elements, and the sulfide minerals are the main carriers of Ga, Cu, and Hg in the No. 11 Coal.

  3. Triassic actinopterygian fishes: the recovery after the end-Permian crisis.

    Science.gov (United States)

    Tintori, Andrea; Hitij, Tomaž; Jiang, Dayong; Lombardo, Cristina; Sun, Zuoyu

    2014-08-01

    In the last 15 years, the discovery of several new actinopterygian fish faunas from the Early and Middle Triassic of the Tethys, cast new light on the timing, speed and range of their recovery after the end-Permian crisis. In addition to several new taxa having been described, the stratigraphical and geographical record of many others have been greatly extended. In fact, most of the new fossiliferous sites are in southern China, thus at the Eastern end of the Tethys, and furthermore a few are somewhat older (Chaohu, Panxian, Luoping) than the major classical Western Tethys sites (Monte San Giorgio). Following these new finds, it is possible to have a better definition of the Triassic recovery stages. Indeed, after a quite short phase till the end of the Smithian (Olenekian, Early Triassic) in which a rather consistent fauna was present all around the Pangea coasts, a major radiation occurred in the Early-Middle Anisian after the new Middle Triassic fish fauna already appeared in the late Early Triassic, thus occuring well before what was previously supposed from the Alps localities. Furthermore, the new assemblages from southern China point to an early broader differentiation among the basal neopterygians rather than in the 'subholosteans', the group that was then dominant in the Western Tethys since the Late Anisian. It stands that during the Norian a new basal neopterygian radiation gave rise to several new branches that dominated the remaining part of the Mesozoic. PMID:24148549

  4. Explosive eruption of coal and basalt and the end-Permian mass extinction.

    Science.gov (United States)

    Ogden, Darcy E; Sleep, Norman H

    2012-01-01

    The end-Permian extinction decimated up to 95% of carbonate shell-bearing marine species and 80% of land animals. Isotopic excursions, dissolution of shallow marine carbonates, and the demise of carbonate shell-bearing organisms suggest global warming and ocean acidification. The temporal association of the extinction with the Siberia flood basalts at approximately 250Ma is well known, and recent evidence suggests these flood basalts may have mobilized carbon in thick deposits of organic-rich sediments. Large isotopic excursions recorded in this period are potentially explained by rapid venting of coal-derived methane, which has primarily been attributed to metamorphism of coal by basaltic intrusion. However, recently discovered contemporaneous deposits of fly ash in northern Canada suggest large-scale combustion of coal as an additional mechanism for rapid release of carbon. This massive coal combustion may have resulted from explosive interaction with basalt sills of the Siberian Traps. Here we present physical analysis of explosive eruption of coal and basalt, demonstrating that it is a viable mechanism for global extinction. We describe and constrain the physics of this process including necessary magnitudes of basaltic intrusion, mixing and mobilization of coal and basalt, ascent to the surface, explosive combustion, and the atmospheric rise necessary for global distribution. PMID:22184229

  5. FORAMINIFERA, ALGAE AND CARBONATE MICROPROBLEMATICA FROM THE LATE WUCHIAPINGIAN/DZHULFIAN (LATE PERMIAN OF PELOPONNESUS (GREECE

    Directory of Open Access Journals (Sweden)

    DANIEL VACHARD

    2003-07-01

    Full Text Available The origin of late Permian olistoliths found in the Glypia Cenozoic flysch must be seeked in regions located to the east of the Parnon Mountain and in units that were more internal to Pindos Unit, especially in the islets of Karavia in the Argolis Gulf, and the Episkopi Formation in Hydra Island, that display probably the largest outcrops of this age. The most interesting olistolith is a bioclastic grainstone. It yields about forty taxa of algae, microproblematica, smaller foraminifers and fusulinids, that are briefly described. Three markers generally not co-occurring are locally associated: Paradunbarula (Shindella shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. The age of the Paradunbarula (Shindella biozone is most probably late Wuchiapingian/Dzhulfian, although other datings have been proposed from late Capitanian to late Changhsingian. Due to this dating of the Shindella zone, the coexistence of the first Colaniella with the last Hemigordiopsis are not late Capitanian/Midian in age, but late Wuchiapingian. The similarities of the Greek microfauna with that of South China and southeastern Pamirs, are incompatible with a larger Paleotethys but support the paleogeographic reconstructions which indicate a close location of these geographic units (Pangea B. 

  6. Provenance of the Lower Triassic Bunter Sandstone Formation: implications for distribution and architecture of aeolian vs. fluvial reservoirs in the North German Basin

    DEFF Research Database (Denmark)

    Olivarius, Mette; Weibel, Rikke; Friis, Henrik; Boldreel, Lars Ole; Keulen, Nynke; Thomsen, Tonny B.

    2016-01-01

    Zircon U–Pb geochronometry, heavy mineral analyses and conventional seismic reflection data were used to interpret the provenance of the Lower Triassic Bunter Sandstone Formation. The succession was sampled in five Danish wells in the northern part of the North German Basin. The zircon ages found...... analysis is an invaluable tool of correlation and subdivision of the Bunter Sandstone in this marginal basin setting. This is because the succession includes many hiatuses so the cyclo-, magneto-, and bio-stratigraphic frameworks established elsewhere in the basin cannot readily be applied here. Zircon......-grade metamorphism, whereas a secondary age population with a peak at 300 Ma matches the timing of volcanism and magmatism at the Carboniferous/Permian boundary in the northern Variscan belt. The Ringkøbing-Fyn High also supplied some sediment tothe Volpriehausen Member. The zircon ages obtained from the Solling...

  7. Organic geochemistry of oils and condensates in the Kekeya field, southwest depression of the Tarim Basin (China)

    Energy Technology Data Exchange (ETDEWEB)

    Maowen Li; Snowdon, L.R. [Geological Survey of Canada, Calgary (Canada); Renzi Lin; Peirong Wang [Jianghan Petroleum Institute, Hubei (China); Yongsheng Liao; Peilong Li [Shengli Petroleum Administrative Bureau, Shandong (China)

    1999-07-01

    This study shows that the oils and condensates in the Kekeya Field in the Tarim Basin, NW China, belong to a single family, most likely derived from marine shale source rocks deposited under oxic-suboxic conditions with mixed terrigenous and algal-bacterial organic inputs. The maturity data clearly indicate that the paraffinic condensates were not formed by thermal cracking of oil during late catagenesis (R{sub o} > 1.2%). Both the oils and condensates were generated within the normal oil window, whereas addition of gaseous hydrocarbons from a separate source resulted in migration fractionation and hence spuriously high heptane indices. Age specific biomarkers show that the oils and condensates were not generated from the Mesozoic-Cenozoic strata, but from the Carboniferous-Permian sections. 1D basin modelling results are consistent with this interpretation, suggesting that the Mesozoic-Eocene strata are currently immature with respect to hydrocarbon generation and expulsion. Deep-seated faults may have provided routes for upward fluid migration at the time of active deformation during several pulses of the Himalayan orogeny. The favoured targets for further petroleum exploration in front of the Kunlun Mountains include the deep structures within the Carboniferous-Permian strata for indigenous petroleum accumulations and anticlines and stratigraphic traps within the Mesozoic-Cenozoic sections that are cut by deep-seated thrust faults where secondary petroleum accumulations most likely occurred. (author)

  8. Permian to late Cenozoic evolution of northern Patagonia: Main tectonic events, magmatic activity, and depositional trends

    Science.gov (United States)

    Uliana, M. A.; Biddle, K. T.

    The late Paleozoic to late Cenozoic evolution of northern Patagonia was influenced significantly by events that occurred while the area was part of the South American sector of Gondwanaland. Late Paleozoic to Middle Triassic subduction along the edge of the supercontinent formed a broad convergent-margin system that is the underpinning of northern Patagonia. Deformation (Gondwanidian orogeny) associated with the subduction is recognized in both the forearc and the convergent backarc areas. Regional extension, accompanied by bimodal volcanism, began in the Late Triassic and led to the formation of a number of north-northwest trending rift basins in Patagonia, which generally followed the Gondwanidian basement grain. Continued extension in the Jurassic and Early Cretaceous led to the opening of the Rocas Verdes marginal basin in southern Chile and, ultimately, to the opening of the South Atlantic Ocean. Once oceanic crust began to form, faulting and volcanism declined in Patagonia. During the late Early Cretaceous to the Late Cretaceous, sags over the rift basins coalesced to form a broad backarc basin behind the volcanic arc to the west. These sags are suggestive of thermally driven subsidence. Subsidence of the evolving Atlantic margin allowed extensive marine transgressions to take place from the east. The stratigraphic record of northern Patagonia reflects these events. The upper Paleozoic to upper Mesozoic sedimentary sequences were deposited in basins directly associated with convergent activity along the margin of Gondwanaland or in rift basins created during its breakup. Even though the Tertiary evolution of Patagonia was dominated by events along the western margin of South America, the patterns of sediment transport, thickness, and general shoreline position were still influenced by the locations of the Mesozoic rifts formed during the breakup of Gondwanaland.

  9. Permian basic magmatism, Upper Eocene and Lower Oligocene metamorphism in the Furgg zone (Western Alps)

    Science.gov (United States)

    Liati, A.; Gebauer, D.; Froitzheim, N.

    2003-04-01

    The Furgg zone (Western Alps) separates the Monte Rosa nappe from the Bernhard and Zermatt nappes. It consists mainly of a schist-, leucocratic gneiss-, quartzite- and metacarbonate-matrix containing boudins of amphibolitised eclogites. Controversial views exist on the nature, origin and extent of the Furgg zone (cf. Dal Piaz, 2001). We dated by SHRIMP (GSC, Ottawa) magmatic and metamorphic zircon domains of a metabasite in the area of Stockknubel (north of the western part of the Monte Rosa nappe). This metabasite is a strongly retrogressed eclogite occurring in form of a boudin, ca. 1 m long, within leucocratic schists. Based on cathodoluminescence (CL)-imaging, zircons from this rock consist of large oscillatory zoned (magmatic) domains surrounded by metamorphic (recrystallisation) rims, bright in CL, with ghost oscillatory zoning. Bright CL-domains are irregularly dispersed also inside the magmatic domains, due to fluid circulation along fractures during metamorphism(s). Eight spot analyses on the magmatic domains yield a Permian weighted mean age at 269 3 Ma (95% c.l.), corresponding to the crystallisation time of the gabbroic protolith of this metabasite. This age is in agreement with a ca. 272 Ma age reported for the crystallisation of an orthogneiss at Mattmark (farther east in the Furgg zone; Liati et al., 2001), as well as for Monte Rosa granites. The new Permian protolith age of the metabasic rock in Stockknubel, together with a 510 5 Ma age reported for an eclogite boudin from the eastern part of the Furgg zone, is in agreement with the 'mlange hypothesis' for the origin of the Furgg zone (e.g. Froitzheim, 2001). 11 spot analyses on metamorphic domains indicate a strong influence of the Lepontine event at 31.5 1.0 Ma (weighted mean of 8 analyses), accompanied by influx of high amounts of fluids. Of great interest are metamorphic rim analyses at ca. 38-39 Ma, together with a series of data scattering between this and the ca. 31.5 Ma age. The Eocene data can best be explained with a first Alpine metamorphism (eclogite-facies) in the Furgg zone. They support the assumption that the Furgg mlange was formed and metamorphosed during subduction of the Valais ocean at 38-39 Ma. This is later than subduction and HP-metamorphism of the Piemont-Ligurian domain (44-45 Ma) and earlier than subduction of the European continental margin (ca. 35 Ma), as well as Lepontine overprinting under amphibolite facies conditions 31-32 Ma ago. Dal Piaz, G.V. Schweiz. Mineral. Petrogr. Mitt. 81: 275-303 (2001). Liati,A. et al., Schweiz. Mineral. Petrogr. Mitt. 81: 379-393 (2001) Froitzheim, N. Bull. Geol. Soc. Amer., 113: 604-614 (2001)

  10. Evaporite-hosted native sulfur in Trans-Pecos Texas: Relation to late-phase basin and range deformation

    International Nuclear Information System (INIS)

    Major deposits of biogenic native sulfur are associated with narrow, northeast-trending grabens and normal faults that disrupt the gently tilted, east-dipping Upper Permian evaporite succession of the western Delaware Basin in Trans-Pecos Texas. Orebodies are restricted to geologic traps in the fractured and dissolution-modified downfaulted blocks of the grabens. Other parallel, regionally distributed grabens and normal faults are commonly the sites of noncommercial sulfur deposits and genetically related secondary-replacement (diagenetic) limestone bodies. The sulfur-bearing structures probably formed during the later of two episodes of Basin and Range extension that have not previously been differentiated in Texas but are well defined elsewhere in the western United States. In Texas several lines of evidence collectively support the existence of late-phase, northwest-directed extension that was initiated in the middle Miocene

  11. Test the Ocean Acidification Hypothesis during the End-Permian Mass Extinction Using an Earth System Model

    Science.gov (United States)

    Cui, Y.; Kump, L.; Ridgwell, A. J.; Meyer, K. M.

    2012-12-01

    The end-Permian is associated with a 3-5 carbon isotope excursion in the ocean-atmosphere system within 20 kyr, which could be explained by a rapid and large amount of greenhouse gas emission. This leads to the hypothesis of ocean acidification as a primary driver for the end-Permian mass extinction event. In order to test this hypothesis, we conducted a series of experiments varying initial and boundary conditions using an Earth system model of intermediate complexity (GENIE: http://www.genie.ac.uk/). The late Permian ocean has been proposed as a "Neritan" ocean due to lack of pelagic carbonate production. We test the ocean buffering capacity to rapid CO2 emission by turning on the pelagic carbonate factory to result in a "Cretan" ocean similar to today. Due to the uncertainties on reconstructed paleo-pCO2 records, we test the model sensitivity by varying the initial pCO2, ranging from 1 PAL (preindustrial atmospheric level), 5 PAL, 10 PAL to 20 PAL. Ocean saturation state with respect to calcite (aragonite) in the Late Permian is also a key uncertainty, estimates have been varying from ?calcite =2.5 to supersaturated state (?calcite =10) (Ridgwell 2005; Montenegro et al. 2011). We test this key uncertainty in both the "Neritan" and "Cretan" ocean cases. GENIE was spun up for >200 kyr to allow sedimentary equilibrium to ensure the weathering input balance the sediment output. Temperature-dependent silicate weathering feedback is also turned on in the model as a driver of the long-term draw down of atmospheric pCO2. We then invert the model by forcing the atmosphere ?13C to track our prescribed carbon isotopes derived from Meishan section in South China and Gartnerkofel-1 core in Alps, Austria at each time step. The two carbon isotope records are statistically treated to remove the noise that could result in unrealistic fluctuations in the derivatives of ?13C. Due to the uncertainties in the age model applied on these two records and different magnitude of carbon isotope excursion and different initial ?13C, we allow the model ?13C values for the riverine input to be spun up at 3 as a global average (see review of Korte and Kozur 2010). The models are run for ~120 kyr from the initial sharp drop in ?13C (~70 kyr prior to the mass extinction event) to its initial recovery phase. Our modeling results indicate pH decline in response to a large amount of C addition within several thousand years. Reference Korte, C. and Kozur, H.W., 2010. Carbon-isotope stratigraphy across the Permian-Triassic boundary: A review. Journal of Asian Earth Sciences, 39(4): 215-235. Montenegro, A., Spence, P., Meissner, K., Eby, M., Melchin, M. and Johnston, S., 2011. Climate simulations of the Permian-Triassic boundary: Ocean acidification and the extinction event. Paleoceanography, 26(26): 3207. Ridgwell, A., 2005. A Mid Mesozoic Revolution in the regulation of ocean chemistry. Marine Geology, 217(3-4): 339-357.

  12. Geochemistry of rare earth elements in Permian coals from the Huaibei Coalfield, China

    Science.gov (United States)

    Zheng, Lingyun; Liu, Gaisheng; Chou, C.-L.; Qi, C.; Zhang, Y.

    2007-01-01

    The rare earth elements (REEs) in coals are important because of: (a) REE patterns can be an indicator of the nature of source rocks of the mineral matter as well as sedimentary environments; (b) REEs abundance in coal may have industrial-significance. In this study, a total of thirty-four samples of Permian coal, partings, roof, and floor were collected from the Huaibei Coalfield, Anhui Province, China. Abundances of rare earth elements (REEs) and other elements in the samples were determined by inductively coupled-plasma mass spectrometry (ICP-MS) and inductively coupled-plasma atomic emission spectrometry (ICP-AES). The results show that the REEs are enriched in coals in the Huaibei Coalfield as compared with Chinese and U.S. coals and the world coal average. Coals in the Lower Shihezi Formation (No. 7, 5, and 4 Coals) and Upper Shihezi Formation (No. 3) have higher REE abundances than the coals in Shanxi Formation (No. 10). Magmatic intrusion resulted in high enrichment of REEs concentrations in No. 5 and 7 Coals. The REE abundances are positively correlated with the ash content. The mineral matter in these coals is mainly made up of clay minerals and carbonates. The REEs are positively correlated with lithophile elements including Si, Al, Ti, Fe, and Na, which are mainly distributed in clay minerals, indicating that REEs are contained mainly in clay minerals. The REE abundances in coals normalized by the ash are higher than that in partings. REEs abundances of coals cannot be accounted for by the REE content in the mineral matter, and some REEs associated with organic matter in coals. ?? 2007 Elsevier Ltd. All rights reserved.

  13. Petrography, carbonate mineralogy and geochemistry of thermally altered coal in Permian coal measures, Hunter Valley, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Golab, Alexandra N. [School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Hutton, Adrian C. [School of Earth and Environmental Sciences, University of Wollongong, Wollongong NSW 2522 (Australia); French, David [CSIRO Energy Technology, Science and Technology Centre, Lucas Heights NSW 2234 (Australia)

    2007-04-02

    Carbonate minerals commonly occur in coals of many ages and from a utilisation viewpoint can be deleterious. Several studies have been undertaken of the carbonates in the Permian coals of the Hunter Valley, Australia, but few studies use a multi-technique approach. For this study, a combined petrographic, geochemical and mineralogical approach was used to determine the distribution and residence of carbonate minerals in coal that had been intruded by a dyke. The dominant carbonate assemblages comprise primary siderite in inertinite-rich microlithotypes and secondary calcite(-ankerite-dolomite)-dawsonite in vitrinite-rich microlithotypes. The secondary carbonates were found in both the aureole of heated coal and also in an unheated mine-face sample. It is believed that the secondary carbonate minerals precipitated from magma-derived fluids percolating through the coal following the emplacement of the intrusions. The textures and distribution of the secondary carbonate minerals suggest that the temperature and pressure of the fluids may be just as important in developing fractures near dykes (particularly those that have multiple phases of geometries), cleat mineralogy and coal textures as direct heating from the intrusion. The partitioning of primary siderite with inertinite and secondary carbonates with vitrinite indicates that it can be reasonably expected that there would be a partitioning of minerals in various density fractions derived from float-sink tests and consequently a partitioning of elements with inertinite-rich fractions containing elevated Fe levels and vitrinite-rich fractions containing elevated Ca, Mg and Al. This partitioning has implications for the behaviour of the coal during washing and combustion, and the composition of combustion products. (author)

  14. High influx of carbon in walls of agglutinated foraminifers during the Permian-Triassic transition in global oceans

    Science.gov (United States)

    Nestell, Galina P.; Nestell, Merlynd K.; Ellwood, Brooks B.; Wardlaw, Bruce R.; Basu, Asish R.; Ghosh, Nilotpal; Phuong Lan, Luu Thi; Rowe, Harry D.; Hunt, Andrew G.; Tomkin, Jonathan H.; Ratcliffe, Kenneth T.

    2015-01-01

    ThePermianTriassicmass extinction is postulated to be related to the rapid volcanism that produced the Siberian flood basalt (Traps). Unrelated volcanic eruptions producing several episodes of ash falls synchronous with the Siberian Traps are found in South China and Australia. Such regional eruptions could have caused wildfires, burning of coal deposits, and the dispersion of coal fly ash. These eruptions introduced a majorinfluxofcarboninto the atmosphere andoceansthat can be recognized in thewallstructure of foraminiferal tests present in survival populations in the boundary interval strata. Analysis of free specimens offoraminifersrecovered from residues of conodont samples taken at aPermianTriassicboundary section at Lung Cam in northern Vietnam has revealed the presence of a significant amount of elementalcarbon, along with oxygen and silica, in their testwallstructure, but an absence of calciumcarbonate. Theseforaminifers, identified asRectocornuspira kalhori,Cornuspira mahajeri, andEarlandiaspp. and whose tests previously were considered to be calcareous, are confirmed to beagglutinated, and are now referred to asAmmodiscus kalhoriandHyperammina deformis. Measurement of the207Pb/204Pb ratios in pyrite clusters attached to the foraminiferal tests confirmed that these tests inherited the Pb in their outer layer fromcarbon-contaminated seawater. We conclude that the source of thecarboncould have been eitherglobalcoal fly ash or forest fire-dispersedcarbon, or a combination of both, that was dispersed into the Palaeo-TethysOceanimmediately after the end-Permianextinction event.

  15. The Permian Dongfanghong island-arc gabbro of the Wandashan Orogen, NE China: Implications for Paleo-Pacific subduction

    Science.gov (United States)

    Sun, Ming-Dao; Xu, Yi-Gang; Wilde, Simon A.; Chen, Han-Lin; Yang, Shu-Feng

    2015-09-01

    The Dongfanghong hornblende gabbro is located in the western part of the Wandashan Orogen and to the east of the Jiamusi Block in NE China. It was emplaced into Early Paleozoic oceanic crust (i.e. Dongfanghong ophiolite) at ~ 275 Ma and both later collided with the eastern margin of the Jiamusi Block. The Dongfanghong gabbro is sub-alkaline with high Na2O contents and is characterized by enrichment in light rare earth elements (LREE), large ion lithosphile elements (LILE), Sr, Eu, and Ba, and depletion in high field strength elements (HFSE). The enriched isotopic signatures (87Sr/86Sri = ~ 0.7065, εNd(t) = ~- 0.5, 208Pb/204Pbi = ~ 38.05, 207Pb/204Pbi = ~ 15.56, 206Pb/204Pbi = ~ 18.20 and zircon εHf(t) = ~+ 5.8) indicate an enriched mantle (EM2) source, with some addition of continental material. It has arc geochemical affinities similar to Permian arc igneous rocks in the eastern margin of the Jiamusi Block, the Yakuno Ophiolite in SW Japan, arc rocks along the western margin of the North America Craton, and also the Gympie Group in eastern Australia. All these features, together with information from tectonic discrimination diagrams, suggest that the Dongfanghong gabbro formed in an immature island arc. The spatial configuration of ~ 290 Ma immature continental arc rocks in the eastern part of the Jiamusi Block and the ~ 275 Ma immature island arc Dongfanghong gabbro in the Wandashan Orogen to the east is best explained by eastward arc retreat and slab roll-back of the Paleo-Pacific Plate. This model is also supported by the Carboniferous-Permian stratigraphic transition in the Jiamusi Block from oceanic carbonate rocks to coal-bearing terrestrial clastic rocks and andesites. We thus suggest that both Paleo-Pacific subduction and roll-back occurred in the Early Permian along the eastern margin of Asia.

  16. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico, Class III; ANNUAL

    International Nuclear Information System (INIS)

    The overall objective of this project is to demonstrate that a development program based on advanced reservoir management methods can significantly improve oil recovery at the Nash Draw Pool (NDP). The plan includes developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced reservoir management methods. Specific goals are (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers in the Permian Basin and elsewhere throughout the U.S. oil and gas industry

  17. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico

    International Nuclear Information System (INIS)

    The overall objective of this project is to demonstrate that a development program based on advanced reservoir management methods can significantly improve oil recovery at the Nash Draw Pool (NDP). The plan includes developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced reservoir management methods. Specific goals are (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers in the Permian Basin and elsewhere throughout the U.S. oil and gas industry

  18. Massive volcanism at the Permian-Triassic boundary and its impact on the isotopic composition of the ocean and atmosphere

    DEFF Research Database (Denmark)

    Korte, Christoph; Pande, P.; Kalia, P.; Kozur, H.W.; Joachimski, M.M.; Oberhänsli, H.

    2010-01-01

    the latest Permian carbon isotope curve because of its prolonged (0.5 Ma) duration, gradual decrease and the existence of a >1‰ positive shift at the main extinction horizon. The P-T boundary d13C trend matches in time and magnitude the eruption of the Siberian Traps and other contemporaneous...... volcanism, suggesting that volcanogenic effects, such as outgassed CO2 from volcanism and, even more, thermal metamorphism of organic-rich sediments, as the likely cause of the negative trend....

  19. MORPHOLOGICAL VARIATION IN HEMIGORDIUS HARLTONI CUSHMAN & WATERS, 1928: REMARKS ON THE TAXONOMY OF CARBONIFEROUSAND PERMIAN HEMIGORDIOPSIDS

    Directory of Open Access Journals (Sweden)

    DEMIR ALTINER

    2003-07-01

    Full Text Available Nine morphotypes recognized within its population suggest that Hemigordius harltoni is a polytypic species. Narrowly discoidal to discoidal morphotypes are dominant in the population whereas lenticular ones are rare and sporadic. The degree of morphological variation in H. harltoni prompts us to question the validity of several previously named Carboniferous and Permian taxa. The definition of these taxa, generally based on few specimens, is far from being satisfactory to describe the intraspecific variability. Some named species are actually morphotypes belonging to highly variable species. 

  20. Authigenic carbonate precipitation at the end-Guadalupian (Middle Permian) in China: Implications for the carbon cycle in ancient anoxic oceans

    Science.gov (United States)

    Saitoh, Masafumi; Ueno, Yuichiro; Isozaki, Yukio; Shibuya, Takazo; Yao, Jianxin; Ji, Zhansheng; Shozugawa, Katsumi; Matsuo, Motoyuki; Yoshida, Naohiro

    2015-12-01

    Carbonate precipitation is a major process in the global carbon cycle. It was recently proposed that authigenic carbonate (carbonate precipitated in situ at the sediment-water interface and/or within the sediment) played a major role in the carbon cycle throughout Earth's history. The carbon isotopic composition of authigenic carbonates in ancient oceans have been assumed to be significantly lower than that of dissolved inorganic carbon (DIC) in seawater, as is observed in the modern oceans. However, the δ13Ccarb values of authigenic carbonates in the past has not been analyzed in detail. Here, we report authigenic carbonates in the uppermost Guadalupian (Middle Permian) rocks at Chaotian, Sichuan, South China. Monocrystalline calcite crystals black mudstone/chert sequence that was deposited on a relatively deep anoxic slope/basin along the continental margin. Textures of the crystals indicate in situ precipitation on the seafloor and/or within the sediments. The calcite precipitation corresponds stratigraphically with denitrification and sulfate reduction in the anoxic deep-water mass, as indicated by previously reported nitrogen and sulfur isotope records, respectively. Relatively high δ13Ccarb values of the authigenic carbonates (largely -1 ‰) compared with those of organic matter in the rocks (ca. -26 ‰) suggest that the main carbon source of the carbonates was DIC in the water column. The calcite crystals precipitated in an open system with respect to carbonate, possibly near the sediment-water interface rather than deep within the sediments. The δ13Ccarb values of the carbonates were close to the δ13CDIC value of seawater due to mixing of 13C-depleted remineralized organic carbon (that was released into the water column by the water-mass anaerobic respiration) with the large DIC pool in the oceans. Our results imply that δ13Ccarb values of authigenic carbonates in the anoxic oceans might have been systematically different from the values in the oxic oceans in Earth's history, controlled by the depth of the redoxcline in the water column and sediments. If our model is correct, authigenic carbonates with relatively high δ13Ccarb values in the ancient anoxic oceans may have had a less substantial influence on the bulk δ13Ccarb values in geologic records than has been previously suggested.

  1. Preservation of Permian allanite within an Alpine eclogite facies shear zone at Mt Mucrone, Italy: Mechanical and chemical behaviour of allanite during mylonitization

    DEFF Research Database (Denmark)

    Cenki-Tok, Benedicte; Oliot, E.; Berger, Alfons; Rubatto, D.; Engi, M.; Janots, E.; Thomsen, T.B.; Manzotti, P.; Regis, D.; Spandler, C.; Robyr, M.; Goncalves, P.

    within an eclogite facies mylonite yielded Permian ages (208Pb/232Th average age: 287±7 Ma). These mm-sized allanite grains are rimmed by an aggregate of coarse-grained garnet+phengite, thought to derive from former epidote. These aggregates were immersed in a weak matrix that experienced granular flow...... mosaic zoning. These results indicate that allanite crystals retained their chemical and isotopic characteristics, and thus their Permian age, as a result of strong strain partitioning between the epidote group porphyroclasts and the eclogite facies matrix in HP-mylonites. The observed partial...

  2. Progress in the Gondwanan CarboniferousPermian palynology and correlation of the Nilawahan Group of the Salt Range, Pakistan: A brief review

    Indian Academy of Sciences (India)

    Irfan U Jan

    2014-02-01

    This paper comprises of two sections. The first section describes challenges in the CarboniferousPermian Gondwanan stratigraphic palynology, and progress in techniques such as presence of the rare-marine intervals, and radiometric dating in some Gondwanan successions, e.g., South Africa, Australia and South America, as tools to confidently calibrate these palynozones. The second section describes developments in the palynological work on the CarboniferousPermian Nilawahan Group of the Salt Range, Pakistan, and summarises their correlation with the coeval succession of the Gondwana continents and with the Russian/International stages.

  3. Basalt stratigraphy - Pasco Basin

    International Nuclear Information System (INIS)

    The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

  4. Melo carboniferous basin

    International Nuclear Information System (INIS)

    This report is about of the Melo carboniferous basin which limits are: in the South the large and high Tupambae hill, in the west the Paraiso hill and the river mountains, in the North Yaguaron river basin to Candidata in Rio Grande del Sur in Brazil.

  5. Basin Hopping Graph

    DEFF Research Database (Denmark)

    Kucharik, Marcel; Hofacker, Ivo; Stadler, Peter; Qin, Jing

    2014-01-01

    folding free energy landscape, however, can provide the relevant information. Results We introduce the basin hopping graph (BHG) as a novel coarse-grained model of folding landscapes. Each vertex of the BHG is a local minimum, which represents the corresponding basin in the landscape. Its edges connect...

  6. High-resolution seismic imaging of the Sohagpur Gondwana basin, central India: Evidence for syn-sedimentary subsidence and faulting

    Indian Academy of Sciences (India)

    K Dhanam; P Senthil Kumar; D Mysaiah; P Prabhakara Prasad; T Seshunarayana

    2013-12-01

    Gondwana sedimentary basins in the Indian Shield preserve a rich record of tectonic, sedimentary and volcanic processes that affected Gondwanaland. The Gondwana rocks were deposited in the linear rift basins that were formed during PermianCretaceous time, similar to their neighbours in Australia, Africa and Antarctica. In this study, we illustrate how Gondwana tectonics affected the Sohagpur Gondwana basin that occurs at the junction of the Mahanadi and SonNarmada rift systems in the central India, through a high-resolution seismic reflection study along six profiles, covering the central part of the Sohagpur basin. The study reveals (1) ?1000 m thick, gently dipping Barakar Formation, (2) thick coal seams at a depth of 350550 m, and (3) NNWSSE to NWSE striking steeply dipping normal faults defining rift geometry. These results indicate that the Sohagpur basin contains a thick Lower Gondwana sedimentary succession with a high potential of coal resources and were affected by extensional tectonics. The rift structure in the study area is a syn- to post-sedimentary deformational structure that was formed arguably in response to tectonics that pervasively affected Gondwanaland.

  7. K Basin safety analysis

    International Nuclear Information System (INIS)

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall

  8. Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters

    Directory of Open Access Journals (Sweden)

    Helga Stan-Lotter

    2013-02-01

    Full Text Available Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl, whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing hypotheses on prokaryotic evolution, such as the molecular clock concept, or the net-like history of genome evolution. A comparison of available taxonomic characteristics from strains of Hcc. salifodinae and other Halococcus species, most of them originating from surface waters, is presented. The cell wall polymer of Hcc. salifodinae was examined and found to be a heteropolysaccharide, similar to that of Hcc. morrhuae. Polyhydroxyalkanoate granules were present in Hcc. salifodinae, suggesting a possible lateral gene transfer before Permian times.

  9. Relationships between ocean anoxia, the biological pump, and marine animal life during the Permian-Triassic mass extinction (Invited)

    Science.gov (United States)

    Meyer, K. M.; Schaal, E. K.; Payne, J.

    2013-12-01

    Ocean anoxia/euxinia and carbon cycle instability have long been linked to the end-Permian mass extinction and the Early Triassic interval of delayed or interrupted biotic recovery. Many hypotheses to explain this extinction event invoke the release of greenhouse gases during the emplacement of the Siberian Traps, which likely triggered abrupt changes in marine biogeochemical cycling, atmospheric chemistry, and biodiversity. However, the precise ways in which volcanism and these perturbations are linked and how they governed the tempo and mode of biotic recovery remain poorly understood. Here we highlight new C, Ca, and Sr isotopic data that serve to link volcanic CO2 inputs to changes in marine biogeochemistry and environmental change. We then examine the relationship between ocean biogeochemistry, the biological pump, and marine animal ecosystems during the end-Permian mass extinction and Early Triassic recovery. Finally, we use numerical simulations to probe whether these relationships also explain broad Phanerozoic trends in ocean nutrient status, anoxia, and productivity of marine ecosystems.

  10. OMANASTER IMBRICATUS (ECHINODERMATA, ASTEROIDEA, A NEW GENUS AND SPECIES FROM THE SAKMARIAN (LOWER PERMIAN SAIWAN FORMATION OF OMAN, ARABIAN PENINSULA

    Directory of Open Access Journals (Sweden)

    DANIEL B. BLAKE

    2014-11-01

    Full Text Available Omanasterimbricatusis a new genu s and species of Sakmarian (Early Permian asteroids collected from the basalPachycyrtellaBed of the Saiwan Formation of Oman, Arabian Peninsula; the family Omanasteridae is recognized. Late Paleozoic and especially Permian asteroids are rare andO. imbricatusdiffers significantly from those previously described, thereby providing an important addition to known late Paleozoic diversity. Unfortunately the single available specimen is incomplete with remaining ossicles both leached and partially fused, and available data are limited. Adambulacral form and arrangement ofO. imbricatusare both suggestive of corresponding expressions of certain earlier Paleozoic species and unlike those of the crown-group, suggesting an enduring Paleozoic lineage but one not phylogenetically a part of the Mesozoic diversification. ThePachycyrtellaBed has been interpreted as recording a succession of pioneer palaeocommunities colonizing a turbulent, shallow-water settingaffected by oscillatory flows. The apparently flattened appearance ofO. imbricatusis suggestive of appearances of certain Cretaceous and extant species recovered from similar environments thus suggesting both homoplasy and the versatility of asteroid evolution across extended spans of geologic time.

  11. Early Permian supra-subduction assemblage of the South Island terrane, Percy Isles, New England Fold Belt, Queensland

    International Nuclear Information System (INIS)

    Ultramafic-intermediate rocks exposed on the South Island of the Percy Isles have been previously grouped into the ophiolitic Marlborough terrane of the northern New England Fold Belt. However, petrological, geochemical and geochronological data all suggest a different origin for the South Island rocks and a new terrane, the South Island terrane, is proposed. The South Island terrane rocks differ from ultramafic-mafic rocks of the Marlborough terrane not only in lithological association, but also in geochemical features and age. These data demonstrate that the South Island terrane is genetically unrelated to the Marlborough terrane but developed in a supra-subduction zone environment probably associated with an Early Permian oceanic arc. There is, however, a correlation between the South Island terrane rocks and intrusive units of the Marlborough ophiolite. This indicates that the two terranes were in relative proximity to one another during Early Permian times. A K/Ar age of 277 ± 7 Ma on a cumulative amphibole-rich diorite from the South Island terrane suggests possible affinities with the Gympie and Berserker terranes of the northern New England Fold Belt. Copyright (1999) Geological Society of Australia

  12. Magnetostratigraphy susceptibility for the Guadalupian Series GSSPs (Middle Permian) in Guadalupe Mountains National Park and adjacent areas in West Texas

    Science.gov (United States)

    Wardlaw, Bruce R.; Ellwood, Brooks B.; Lambert, Lance L.; Tomkin, Jonathan H.; Bell, Gordon L.; Nestell, Galina P.

    2012-01-01

    Here we establish a magnetostratigraphy susceptibility zonation for the three Middle Permian Global boundary Stratotype Sections and Points (GSSPs) that have recently been defined, located in Guadalupe Mountains National Park, West Texas, USA. These GSSPs, all within the Middle Permian Guadalupian Series, define (1) the base of the Roadian Stage (base of the Guadalupian Series), (2) the base of the Wordian Stage and (3) the base of the Capitanian Stage. Data from two additional stratigraphic successions in the region, equivalent in age to the KungurianRoadian and WordianCapitanian boundary intervals, are also reported. Based on low-field, mass specific magnetic susceptibility (?) measurements of 706 closely spaced samples from these stratigraphic sections and time-series analysis of one of these sections, we (1) define the magnetostratigraphy susceptibility zonation for the three Guadalupian Series Global boundary Stratotype Sections and Points; (2) demonstrate that ? datasets provide a proxy for climate cyclicity; (3) give quantitative estimates of the time it took for some of these sediments to accumulate; (4) give the rates at which sediments were accumulated; (5) allow more precise correlation to equivalent sections in the region; (6) identify anomalous stratigraphic horizons; and (7) give estimates for timing and duration of geological events within sections.

  13. Thermal structure of the Paris Basin from tectonic-Heat Flow modelling

    Science.gov (United States)

    Bont, Damien; van Wees, Jan-Diederik; Guillou-Frottier, Laurent; Cloetingh, Sierd

    2015-04-01

    Located on the inner part of the Variscan Orogen, the Paris Basin has evolved from the Permo-Carboniferous as an intracratonic basin. The usual description of the sediments in the Paris Basin involves imbricated bowl shaped layers, starting from the Triassic. Due to their discontinuity, depth and complexity the Permian and Carboniferous layers have been commonly left aside. Fortunately, recent studies have been completed to looks specifically at these deeper sedimentary layers. With the development of geothermal energy and the widely use shallow medium enthalpy geothermal resources in the Paris Basin (Dogger) these pre-Mesozoic sediments are of a lot of interest. In this work, we use a tectonic-heat flow modelling methodology to model the present day thermal structure of the Paris Basin. The modelling takes into account the geometry of the layering and the petrophysical parameters (i.e., thermal conductivity, the radiogenic heat production of the sedimentary layers in relation with their facies). In addition, the upper part of the basement is closely considered to allow the description of magmatic intrusions that could have a major impact on the present day temperature (i.e., the variation of the radiogenic heat production). To assess the result of our thermal modelling, the obtained temperature is compared to BHT's (Bottom Hole Temperature) and DST's (Drill Stem Test) values when available. As a result of this modelling, we are able to present present-day temperature within the basin as well as in the shallower part of the basement. The aim of this work is identify the sources of the temperature perturbation. The impact of the sediment's thermal conductivity has already been assed on a previous work, in this work the deeper source of perturbation are of great interest (thermal conductivity and heat production of the pre-Mesozoic sedimentary layers, heat production of magmatic intrusion in the basement, and regional faults in the sediments and basement).

  14. Discussion on the exploration & development prospect of shale gas in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Dazhong Dong

    2015-01-01

    Full Text Available The Sichuan Basin, a hotspot and one of the most successful areas for shale gas exploration and development, can largely reflect and have a big say in the future prospect of shale gas in China. Through an overall review on the progress in shale gas exploration and development in the Sichuan Basin, we obtained the following findings: (1 the Sichuan Basin has experienced the marine and terrestrial depositional evolution, resulting in the deposition of three types of organic-matter-rich shales (i.e. marine, transitional, and terrestrial, and the occurrence of six sets of favorable shale gas enrichment strata (i.e. the Sinian Doushantuo Fm, the Cambrian Qiongzhusi Fm, the Ordovician Wufeng–Silurian Longmaxi Fm, the Permian Longtan Fm, the Triassic Xujiahe Fm, and the Jurassic Zhiliujing Fm; (2 the five key elements for shale gas accumulation in the Wufeng-Longmaxi Fm are deep-water shelf facies, greater thickness of organic-rich shales, moderate thermal evolution, abundant structural fractures, reservoir overpressure; and (3 the exploration and development of shale gas in this basin still confronts two major challenges, namely, uncertain sweet spots and potential prospect of shale gas, and the immature technologies in the development of shale gas resources at a depth of more than 3500 m. In conclusion, shale gas has been discovered in the Jurassic, Triassic and Cambrian, and preliminary industrial-scale gas has been produced in the Ordovician-Silurian Fm in the Sichuan Basin, indicating a promising prospect there; commercial shale gas can be produced there with an estimated annual gas output of 30–60 billion m3; and shale gas exploration and production experiences in this basin will provide valuable theoretical and technical support for commercial shale gas development in China.

  15. Evaluating transition-metal catalysis in gas generation from the Permian Kupferschiefer by hydrous pyrolysis

    Science.gov (United States)

    Lewan, M.D.; Kotarba, M.J.; Wieclaw, D.; Piestrzynski, A.

    2008-01-01

    Transition metals in source rocks have been advocated as catalysts in determining extent, composition, and timing of natural gas generation (Mango, F. D. (1996) Transition metal catalysis in the generation of natural gas. Org. Geochem.24, 977–984). This controversial hypothesis may have important implications concerning gas generation in unconventional shale-gas accumulations. Although experiments have been conducted to test the metal-catalysis hypothesis, their approach and results remain equivocal in evaluating natural assemblages of transition metals and organic matter in shale. The Permian Kupferschiefer of Poland offers an excellent opportunity to test the hypothesis with immature to marginally mature shale rich in both transition metals and organic matter. Twelve subsurface samples containing similar Type-II kerogen with different amounts and types of transition metals were subjected to hydrous pyrolysis at 330° and 355 °C for 72 h. The gases generated in these experiments were quantitatively collected and analyzed for molecular composition and stable isotopes. Expelled immiscible oils, reacted waters, and spent rock were also quantitatively collected. The results show that transition metals have no effect on methane yields or enrichment. δ13C values of generated methane, ethane, propane and butanes show no systematic changes with increasing transition metals. The potential for transition metals to enhance gas generation and oil cracking was examined by looking at the ratio of the generated hydrocarbon gases to generated expelled immiscible oil (i.e., GOR), which showed no systematic change with increasing transition metals. Assuming maximum yields at 355 °C for 72 h and first-order reaction rates, pseudo-rate constants for methane generation at 330 °C were calculated. These rate constants showed no increase with increasing transition metals. The lack of a significant catalytic effect of transition metals on the extent, composition, and timing of natural gas generation in these experiments is attributed to the metals not occurring in the proper form or the poisoning of potential catalytic microcosms by polar-rich bitumen, which impregnates the rock matrix during the early stages of petroleum formation.

  16. Signature recognition for rift structures of different sediment strata in ordos basin

    International Nuclear Information System (INIS)

    The rift structure weak information of high Bouguer gravity anomaly data among different Sediment strata are extracted By the horizontal gradient Maximum modulus, the wavelet variation, stripped gravity anomaly of basement and interfaces above/under researched layer, image processing method. So the linear rift structures of different Sediment strata are recognized on data images, such as Cretaceous, Jurassic, Triassic, Permian and Carboniferous, Ordovician System. Development rifts of different Sediment strata occur in stereo structure with quasi-uniform spacing, the rift density of above Sediment stratum is more than lower in different Sediment strata, but the north rift density of the same Sediment stratum is less than south's. It is useful to study rift structure and co-explore for oil, gas, coal and uranium resources in Ordos Basin. (authors)

  17. Ferroan dolomite cement in Cambrian sandstones: burial history and hydrocarbon generation of the Baltic sedimentary basin

    DEFF Research Database (Denmark)

    Sliaupa, S.; Cyziene, J.; Molenaar, Nicolaas; Musteikyte, D.

    2008-01-01

    burial depth from 340 to 2150 m. The carbonate cement is dominantly ferroan dolomite that occurs as dispersed patches of poikilotopic crystals. Temperatures of dolomite precipitation, based on delta O-18 values, range from 27 degrees C in the shallow buried to 95 degrees C in the deep buried sandstones....... The burial history modelling points to development of most of the dolomite cement during rapid Silurian-Devonian subsidence and Carboniferous-early Permian uplift. A wide range of precipitation temperatures indicate that temperature was not a major factor in triggering the carbonate cementation....... Dolomite precipitation is related to early stages of organic matter maturation and thus to the oil generation history in the basin. delta C-13 values vary from +0.03% to -6.2%( PDB), suggesting limited addition of carbon from an organic source, with the major part derived from marine bicarbonate. The...

  18. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna Sedimentological study of Carboniferous and Permian deposits on the western edge of the Puna

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of the Argentine Puna has been carried out. These deposits include the continental red beds of the Cerro Oscuro Formation (Upper Carboniferous and the marine limestones of the Arizaro Formation (Lower to Middle Permian. The stratigraphic column analyzed consists of 480 m of clastic and carbonate rocks with interbedded volcaniclastic levels. The deposits integrate a synclinal structure of NNW-SSE trend, which pitches to the NW. The carboniferous-permian deposits were analized in both flanks of the syncline. Based on the stratigraphic and sedimentologic characteristics analyzed in the Cerro Oscuro and Arizaro Formations, new paleoenvironmental interpretations are given: i. The thinning and fining sequence that documents the Cerro Oscuro Formation includes, from base to top, debris flows accumulated in an alluvial fan system, and three cycles or minor positive sequences, corresponding to a sand-gravel braided fluvial system. ii. In the analyzed sections, the relationship between the Cerro Oscuro and Arizaro formations is a paraconformity. iii. The Arizaro Formation includes three cycles developed in a mixed carbonate-siliciclastic marine shelf paleoenvironment. Mineralogic and petrographic characteristics of the recognized facies are described and a provenance analysis wich suggests the existence of different source areas is included. The transgression that documents the Arizaro Formation is analyzed and it has been related with the global sea level rise event caused by deglaciation phenomena during the Artinskian-Kungurian time. The effect of tectonic and volcanic processes that would have affected the basin during their evolution is discussed.

  19. Reserves in western basins

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, R.H.; Cotton, B.W. [Scotia Group, Dallas, TX (United States)

    1995-04-01

    The objective of this project is to investigate the reserves potential of tight gas reservoirs in three Rocky Mountain basins: the Greater Green River (GGRB), Uinta and Piceance basins. The basins contain vast gas resources that have been estimated in the thousands of Tcf hosted in low permeability clastic reservoirs. This study documents the productive characteristics of these tight reservoirs, requantifies gas in place resources, and characterizes the reserves potential of each basin. The purpose of this work is to promote understanding of the resource and to encourage its exploitation by private industry. At this point in time, the GGRB work has been completed and a final report published. Work is well underway in the Uinta and Piceance basins which are being handled concurrently, with reports on these basins being scheduled for the middle of this year. Since the GGRB portion of the project has been completed, this presentation win focus upon that basin. A key conclusion of this study was the subdivision of the resource, based upon economic and technological considerations, into groupings that have distinct properties with regard to potential for future producibility, economics and risk profile.

  20. Ocean's response to a changing climate: Clues from variations in carbonate mineralogy across the Permian-Triassic boundary of the Shareza Section, Iran

    Science.gov (United States)

    Heydari, Ezat; Arzani, Nasser; Safaei, Mohammad; Hassanzadeh, Jamshid

    2013-06-01

    This investigation focuses on the original mineralogy of Wuchiapingian (Late Permian) to Induan (Early Triassic) strata of the Shahreza section of Iran to understand changes in marine carbonate system during this transition. Aragonitic carbonates precipitated during the early part of the Wuchiapingian, gradually changing to calcite during the middle part of the Wuchiapingian and continuing through the Changhsingian. Carbonate precipitation ceased during the latest Changhsingian at the end-Permian Event Horizon (EH). A sharp reversal back to aragonite precipitation occurred in the Early Triassic. These changes are interpreted as the ocean's response to a changing climate. This study proposes three types of seawater for the Late Permian to Early Triassic interval. Normal (Anahita-type) seawater during the Late Permian was hospitable to life and supported a highly active carbonate factory. Acidic (Jahi-type) seawater during the PTB transition was acidic and hostile to life, slowing or halting carbonate production. Alkaline (Amordad-type) seawater during the Early Triassic was life-nurturing and supported an active carbonate factory. It sustained life until a normal (Anahita-type) seawater could be re-established.

  1. Geology of the Williston basin, North Dakota, Montana, and South Dakota, with reference to subsurface disposal of radioactive wastes

    Science.gov (United States)

    Sandberg, C.A.

    1962-01-01

    The southern Williston basin, which underlies about 110,000 square miles #n North Dakota, South Dakota, and eastern Montana, is part of a large structural and sedimentary basin. Its surface is a flat to gently rolling plain, standing about 1,500 to 3,500 feet above sea level and locally studded by a few high buttes. The sedimentary sequence that fills the basin has a maximum thickness of about 16,700 feet and rests on Precambrian metamorphic rocks at depths of 500 to 13,900 feet below sea level. It contains rocks of every geologic system, from Cambrian to Quaternary. Rocks of Middle Cambrian through Middle Ordovician age are largely shale and sandstone, as much as 1,200 feet thick; rocks of Late Ordovician through Pennsylvanian age are largely limestone and dolomite, as much as 7,500 feet thick; and rocks of Permian through Tertiary age are predominantly shale and siltstone, as much as 8,000 feet thick. Pleistocene glacial drift mantles the northern and eastern parts of the area. Rocks of the Williston basin are gently folded and regional dips are 1? or less from the margins to the basin center. Dips on the flanks of the major anticlinal folds, the Nesson and cedar Creek anticlines and the Poplar and Bowdoin domes, generally are about 1? to 3? except on the steep west limb of the Cedar Creek anticline. The basin was shaped by Laramide orogeny during latest Cretaceous and early Tertiary time. Most of the present structural features, however, were initiated during the Precambrian and reactivated by several subsequent orogenies, of which the latest was the Laramide. The most important mineral resource of the area is oil, which is produced predominantly from the Paleozoic carbonate sequence and largely on three of the major anticlinal folds, and lignite, which is present near the surface in Paleocene rocks. The subsurface disposal of radioactive wastes at some places in the Williston basin appears to be geographically and geologically feasible. Many sites, at which large quantities of wastes might be injected with minimal danger of contamination of fresh-water aquifers and-oil-producing strata, are available.. The strata and types of reservoirs that deserve primary consideration for waste disposal are the Winnipeg Formation of Middle Ordovician age as a deep salaquifer, the Permian to Jurassic salt beds as moderately deep-units in which solution cavities might be created for storage, the thick Upper Cretaceous shale beds as shallow hydraulically fractured shale reservoirs, and the Newcastle Sandstone of Early Cretaceous age as a shallow shale-enclosed sandstone reservoir.

  2. Geochronology and geochemistry of middle Permian-Middle Triassic intrusive rocks from central-eastern Jilin Province, NE China: Constraints on the tectonic evolution of the eastern segment of the Paleo-Asian Ocean

    Science.gov (United States)

    Wang, Zi-Jin; Xu, Wen-Liang; Pei, Fu-Ping; Wang, Zhi-Wei; Li, Yu; Cao, Hua-Hua

    2015-12-01

    To constrain the Permian-Early Mesozoic tectonic evolution of the eastern segment of the Paleo-Asian Ocean, we conducted zircon U-Pb dating and whole-rock geochemical analyses on six middle Permian-Middle Triassic intrusive plutons in central-eastern Jilin Province, NE China. Zircons from the six plutons display distinct oscillatory zoning and striped absorption in cathodoluminescence (CL) images, and Th/U ratios of 0.11-1.41, indicating a magmatic origin. Zircon U-Pb dating indicates that the intrusive rocks formed in the middle Permian (ca. 260 Ma) to Middle Triassic (ca. 245 Ma). In central-eastern Jilin Province, the middle Permian and Middle Triassic plutons are composed mainly of strongly deformed monzogranites with affinities to adakitic rocks, which are formed from partial melting of thickened mafic lower crust. In contrast, the late Permian-the Early Triassic plutons in central-eastern Jilin Province consist of a bimodal association (including gabbros and granitoids) and deformed monzonites, which typically form in extensional settings. These observations, along with the results of previous studies on early-middle Permian granitoids in western Jilin Province, indicate that the eastern segment of the Paleo-Asian Ocean underwent the initial closure in central-western Jilin Province during the middle Permian and the final closure in eastern Jilin Province in the Middle Triassic.

  3. Tectonic and paleoenvironmental evolution of Mesozoic sedimentary basins along the Andean foothills of Argentina (32°-54°S)

    Science.gov (United States)

    Franzese, Juan; Spalletti, Luis; Pérez, Irene Gómez; Macdonald, David

    2003-05-01

    Chronoenvironmental and tectonic charts are presented for Mesozoic basins located along the Andean foothills of the South American plate. On the basis of the main tectonic events, pre-Andean basins, break-up-related basins, extensional back-arc basins, and Andean foreland basins are recognized. The pre-Andean basins were formed by continental extension and strike-slip movement before the development of the Mesozoic-Cenozoic Andean magmatic arc. Upper Permian to Middle Triassic extension along Palaeozoic terrane sutures resulted in rifting, bimodal magmatism (Choiyoi group), and continental deposition (Cuyo basin). From the Late Triassic to the Early Jurassic, continental extension related to the collapse of the Gondwana orogen initiated a series of long, narrow half-grabens that filled with continental volcaniclastic deposits. These depocenters were later integrated into the Neuquén basin. Coeval development of the shallow marine Pampa de Agnia basin (42-44°S) is related to short-lived extension, probably driven by dextral displacement along major strike-slip faults (e.g. the Gastre fault system). Widespread extension related to the Gondwana breakup (180-165 Ma) and the opening of the Weddell Sea reached the western margin of the South American plate. As a result, wide areas of Patagonia were affected by intraplate volcanism (Chon Aike province), and early rifting occurred in the Magallanes basin. The Andean magmatic arc was almost fully developed by Late Jurassic times. A transgressive stage with starvation and anoxia characterized the Neuquén basin. In western Patagonia, back-arc and intra-arc extension produced the opening of several grabens associated with explosive volcanism and lava flows (e.g. Rı´o Mayo, El Quemado). To the south, a deep marginal basin floored by oceanic crust (Rocas Verdes) developed along the back-arc axis. In mid-to late Cretaceous times, Andean compressional tectonics related to South Atlantic spreading caused the inversion of previous extensional structures and the beginning of a retro-arc foreland phase in the Neuquén and Austral basins.

  4. Conodont color alteration index and upper Paleozoic thermal history of the Amazonas Basin, Brazil

    Science.gov (United States)

    Cardoso, Cassiane Negreiros; Sanz-López, Javier; Blanco-Ferrera, Silvia; Lemos, Valesca Brasil; Scomazzon, Ana Karina

    2015-12-01

    The conodont color alteration index (CAI) was determined in elements from core samples of the Frasnian Barreirinha Formation (one well) and of the Pennsylvanian-Permian Tapajós Group (twenty three wells and one limestone quarry) in the Amazonas Basin. The thermal history of the basin is analyzed using the CAI value distribution represented in maps and stratigraphic sections through correlation schemes, and in conjunction with previously published data. The pattern of palaeotemperatures for CAI values of 1.5-3 is coincident with organic matter maturation under a sedimentary overburden providing diagenetic conditions in the oil/gas window. Locally, conodonts show metamorphism (CAI value of 6-7) in relation to the intrusion of diabase bodies in beds including high geothermal gradient evaporites. Microtextural alteration on the surface conodonts commonly shows several types of overgrowth microtextures developed in diagenetic conditions. Locally, recrystallization in conodonts with a high CAI value is congruent with contact metamorphism in relation to Mesozoic intrusions. The CAI values of 1.5 or 2 observed close to the surface in several areas of the basin may be interpreted in relation to a high thermal palaeogradient derived from the magmatic episode or/and to the local denudation of the upper part of the Paleozoic succession prior to this thermal event.

  5. Early Mesozoic basin aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior This data set represents the extent of the Early Mesozoic basin aquifers in the states of Massachusettes, Connecticut, New York, New Jersey, Pennsylvania, Maryland,...

  6. California Air Basins

    Data.gov (United States)

    California Department of Resources Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  7. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  8. Revised conodont-based integrated high-resolution timescale for the Changhsingian Stage and end-Permian extinction interval at the Meishan sections, South China

    Science.gov (United States)

    Yuan, Dong-xun; Shen, Shu-zhong; Henderson, Charles M.; Chen, Jun; Zhang, Hua; Feng, Hong-zhen

    2014-09-01

    Meishan Section D with the Wuchiapingian/Changhsingian and Permian/Triassic GSSPs has become the most intensively studied section because it records the whole process of the largest biological extinction during the Phanerozoic. Numerous data including high-precision geochronology, multiple isotope chemostratigraphy, magnetostratigraphy, and high-resolution multiple fossil biostratigraphy have been determined during the last decade. Conodonts are very abundant in the Changhsingian Stage at the Meishan sections and their biostratigraphy together with geochronologic and multiple geochemical data provide a basic temporal framework to calibrate the end-Permian mass extinction and realize global correlation between sections at Meishan and those in other regions of the world. However, major discrepancies exist in various previous studies of conodonts from the Meishan sections. Many different authors have documented very different species ranges based on different concepts and approaches of taxonomy. We here employ a sample population approach to revise and refine the high-resolution conodont biostratigraphic framework for the Changhsingian Stage and end-Permian mass extinction interval across the Permian-Triassic boundary (PTB) at the Meishan sections. Eight zones are recognized from the latest Wuchiapingian to the basal Triassic. They are, in ascending order, the Clarkina longicuspidata Zone in the uppermost Wuchiapingian; the Clarkina wangi Zone, Clarkina subcarinata Zone, Clarkina changxingensis Zone, Clarkina yini Zone, Clarkina meishanensis Zone, Clarkina zhejiangensis-Hindeodus changxingensis Zone in the Changhsingian Stage, and the Hindeodus parvus Zone in the basal Triassic. Conodont evolutionary lineages for the whole Changhsingian are also tentatively established. All species are described in detail and growth series of different specimens for valid species are figured as completely as possible. The temporal relationship of each conodont zone with geochemical excursions, geochronologic calibration and magnetostratigraphical polarity zones are provided, which is critical to understand the tempo of the end-Permian mass extinction.

  9. Origin of Permian exotic limestone blocks in the Yarlung Zangbo Suture Zone, Southern Tibet, China: With biostratigraphic, sedimentary and regional geological constraints

    Science.gov (United States)

    Jin, Xiaochi; Huang, Hao; Shi, Yukun; Zhan, Lipei

    2015-05-01

    The Yarlung Zangbo Suture Zone in Southern Tibet represents the collision zone between the Indian and Eurasian continents. It is, to a lesser extent, also the boundary between the Himalayan region and the Lhasa Block. A fascinating aspect of it is the appearance of Permian limestone blocks in Late Triassic (and sometimes Late Jurassic-Cretaceous) siliciclastic sediments south of the ophiolite belt. They are meter- to kilometer-scale, randomly scattered blocks in a clastic matrix. Large blocks often form ridges of mountains or occur as projecting rocks; small blocks are often seen half buried or floating within matrix. They are therefore often noted as exotic blocks. Fossils from the limestone blocks have ages mainly in the range of Guadalupian-Lopingian. The faunas have mixed Gondwanan and Cathaysian features. Petrographic study of the limestone blocks shows that their deposition processes were often influenced by terrigenous clasts and suggests that they were deposited in a generally proximal environment. The age range, lithofacies and fossil content of these limestone blocks in the Yarlung Zangbo Suture Zone are highly compatible with those of the Permian successions north and south of the zone in the framework of northern Greater India. They were originally deposited in peri-Gondwana environment, like the Permian limestone successions of the Lhasa Block and the Himalayan region. The exotic Permian limestone blocks are dismembered units of Permian carbonate successions broken during the rifting process in the Late Triassic. Their entering in the Late Triassic clastic sediments is resulted from either block faulting or olistostrome. Final emplacement of different components, including the limestone blocks, in the suture zone were achieved in the Paleogene accompanied by strong deformation.

  10. Two episodes of 13C-depletion in organic carbon in the latest Permian: Evidence from the terrestrial sequences in northern Xinjiang, China

    Science.gov (United States)

    Cao, Changqun; Wang, Wei; Liu, Lujun; Shen, Shuzhong; Summons, Roger E.

    2008-06-01

    New analyses reveal two intervals of distinctly lower δ13C values in the terrestrial organic matter of Permian-Triassic sequences in northern Xinjiang, China. The younger negative δ13C org spike can be correlated to the conspicuous and sharp δ13C drops both in carbonate carbon and organic carbon near the Permian-Triassic event boundary (PTEB) in the marine section at Meishan. The geochemical correlation criteria are accompanied by a magnetic susceptibility pulse and higher abundances of distinctive, chain-like organic fossil remains of Reduviasporonites. The older negative δ13C org spike originates within a latest Permian regression. Significant changes in organic geochemical proxies are recorded in the equivalent interval of the marine section at Meishan. These include relatively higher concentrations of total organic carbon, isorenieratane, C 14-C 30 aryl isoprenoids and lower ratios of pristane/phytane that, together, indicate the onset of anoxic, euxinic and restricted environments within the photic zone. The massive and widespread oxidation of buried organic matter that induced these euxinic conditions in the ocean would also result in increased concentrations of 13C-depleted atmospheric CO 2. The latest Permian environmental stress marked by the older negative δ13C org episode can be correlated with the distinct changeover of ostracod assemblages and the occurrences of morphological abnormalities of pollen grains. These observations imply that biogeochemical disturbance was manifested on the land at the end of the Permian and that terrestrial organisms responded to it before the main extinction of the marine fauna.

  11. Shallow water redox conditions from Permian-Triassic boundary microbialites: The rare earth element and iodine geochemistry of carbonates from Turkey and South China

    Science.gov (United States)

    Loope, G.; Kump, L.

    2012-12-01

    Rare earths and yittrium (REY), iodine, and major elements are determined in two carbonate sections spanning the Permian-Triassic transition in Demirtas, Turkey and Cili, South China. We use major oxides to measure contamination associated with siliciclastics, Fe-oxides, and phosphates. Additionally, we employ Y/Ho ratio, La anomaly, and light rare earth element depletion to identify which samples preserve a seawater-like REY distribution. Despite siliciclastic input, we find the Permian-Triassic boundary microbialites in both sections contain a negative Ce anomaly (average Pr/Pr*=1.07) indicative of deposition in an oxic environment. These boundary microbialites have their base at the extinction horizon and are widespread within the Tethyan region. In the Cili section, the underlying Permian limestone also preserves a seawater-like REY signature with a negative Ce anomaly indicating that the water column was oxygenated both before and after the extinction event. The Permian limestone in the Demirtas section does not preserve a seawater-like REY distribution, so the absence of a Ce anomaly cannot be used to distinguish prevailing redox conditions during deposition. However, in these samples, we find the presence of a diverse Permian benthic community sufficient to identify deposition in an oxic environment. The geochemical evidence for a continuously oxic environment during the deposition of the boundary microbialite presented in this study strongly supports work done using ostracods as redox indicators within the boundary microbialite in South China. These microbialites have been proposed as a disaster facies caused by the exclusion of grazers. Although anoxia is one of the suggested mechanisms for the exclusion of grazers, we find that it is not supported by geochemical evidence.

  12. Ca, Sr, Mo and U isotopes evidence ocean acidification and deoxygenation during the Late Permian mass extinction

    Science.gov (United States)

    Silva-Tamayo, Juan Carlos; Payne, Jon; Wignall, Paul; Newton, Rob; Eisenhauer, Anton; Weyer, Stenfan; Neubert, Nadja; Lau, Kim; Maher, Kate; Paytan, Adina; Lehrmann, Dan; Altiner, Demir; Yu, Meiyi

    2014-05-01

    The most catastrophic extinction event in the history of animal life occurred at the end of the Permian Period, ca. 252 Mya. Ocean acidification and global oceanic euxinia have each been proposed as causes of this biotic crisis, but the magnitude and timing of change in global ocean chemistry remains poorly constrained. Here we use multiple isotope systems - Ca, Sr, Mo and U - measured from well dated Upper Permian- Lower Triassic sedimentary sections to better constrain the magnitude and timing of change in ocean chemistry and the effects of ocean acidification and de-oxygenation through this interval. All the investigated carbonate successions (Turkey, Italy and China) exhibit decreasing δ44/40Ca compositions, from ~-1.4‰ to -2.0‰ in the interval preceding the main extinction. These values remain low during most of the Griesbachian, to finally return to -1.4‰ in the middle Dienerian. The limestone succession from southern Turkey also displays a major decrease in the δ88/86Sr values from 0.45‰ to 0.3‰ before the extinction. These values remain low during the Griesbachian and finally increase to 0.55‰ by the middle Dienerian. The paired negative anomalies on the carbonate δ44/40Ca and δ88/86Sr suggest a decrease in the carbonate precipitation and thus an episode of ocean acidification coincident with the major biotic crisis. The Mo and U isotope records also exhibit significant rapid negative anomalies at the onset of the main extinction interval, suggesting rapid expansion of anoxic and euxinic marine bottom waters during the extinction interval. The rapidity of the isotope excursions in Mo and U suggests substantially reduced residence times of these elements in seawater relative to the modern, consistent with expectations for a time of widespread anoxia. The large C-isotope variability within Lower Triassic rocks, which is similar to that of the Lower-Middle Cambrian, may reflect biologically controlled perturbations of the oceanic carbon cycle. These findings strengthen the evidence for a global ocean acidification event coupled with rapid expansion of anoxic zones as drivers of end-Permian extinction in the oceans.

  13. The magnetic anomaly on the Permian Alcaparrosa porphyry (Argentina). A case of pyrrhotite-remanence-dominated anomaly

    International Nuclear Information System (INIS)

    Complete text of publication follows. The Permian Alcaparrosa porphyry is a small (600 meters in diameter) rhyodacite stock outcropping in the Precordillera geological province, San Juan, Argentina. It developed a 3-kilometers-long, NW-SE-trending alteration halo ('Faja Amarilla', yellow belt) in the host rocks, which is a sequence of Ordovician marine mudstones with interbedded basaltic flows included in the Alcaparrosa Fm. The porphyry-related alteration overprinted a previous low-grade-metamorphic alteration assemblage characteristic of an oceanic floor environment. The aeromagnetic survey revealed a bipolar anomaly in the total magnetic intensity (TMI) coinciding with the outcropping alteration halo. The surrounding Alcaparrosa Fm is non-magnetic and therefore the anomaly is clearly defined in a quiet magnetic zone, showing a minimum to the north, centred on the porphyry, and a semi lunar maximum to the south. The shape of the anomaly is opposed to the expected shape of induced magnetic anomalies in mid latitudes of the southern hemisphere. Available data show that both the Permian porphyry and its alteration halo carry a magnetic remanence with positive inclination (i.e. reversed polarity), probably acquired during the Permo-Carboniferous Reversed Superchron. The Koenigsberger ratio (Q) for the porphyry resulted lower than 1, which means that remanence is not intense enough to control the shape of the magnetic anomaly. On the other side, outcropping rocks of the alteration halo show intense supergene alteration and are non-magnetic. However, relics of phyllic alteration where found relatively preserved of supergene alteration, and they showed monoclinic pyrrhotite as magnetic carrier, and a Q ratio higher than 1. We used those data to model a body carrying a reversed magnetic remanence. The shape and extension of the modelled body seems a good approximation to the possible shape of the sulphide-bearing alteration halo around the rhyodacite porphyry. The presence of monoclinic pyrrhotite carrying reversed-polarity, high-Q remanence in the Permian porphyry systems of Precordillera should be assessed, as its related inverted anomalies could be used as an exploration guide in aeromagnetic surveys.

  14. K Basins Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    WEBB, R.H.

    1999-12-29

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062, Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  15. K Basins Hazard Analysis

    International Nuclear Information System (INIS)

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062/Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  16. K Basin Hazard Analysis

    International Nuclear Information System (INIS)

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  17. K Basin Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    PECH, S.H.

    2000-08-23

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  18. Transboundary river basin management

    OpenAIRE

    Hassenforder, E.

    2014-01-01

    Managing transboundary river basins is a complex endeavor that requires specific approaches and methods of management and governance. Part 1 of this chapter introduces transboundary river basins and their management: why they are now widely used as a unit of management, potential linkages with the management of other natural resources and with national and regional development planning efforts. It highlights the difference between operational management, strategic management and governanc...

  19. The Ebro river basin

    OpenAIRE

    Darbra Roman, Rosa Maria

    2011-01-01

    River basins worldwide are under pressure from economic activities. In Europe, the two main factors hindering the achievement of good chemical and ecological status of European river basins are pollution, mainly coming from agriculture, and hydromorphology (e.g. for navigation, hydroelectricity and flood control). The economic activities affect the chemical and ecological status of rivers, lakes and groundwater and deplete available soil, sediments and water resources. The w...

  20. Unraveling the hydrocarbon charge potential of the Nordkapp Basin, Barents Sea: An integrated approach to reduce exploration risk in complex salt basins

    Science.gov (United States)

    Schenk, Oliver; Shtukert, Olga; Bishop, Andrew; Kornpihl, Kristijan; Milne, Graham

    2014-05-01

    The Nordkapp Basin, Barents Sea, is an intra-continental syn-rift basin containing many complex salt structures. The salt is late-Carboniferous to Early Permian in age, with regional extension in the Triassic initiating the salt movement resulting in formation of sub- and mini-basins with significant subsidence (especially in the northeastern part of the basin). Subsequent tectonic phases allowed growth and distortion of salt diapirs that were later affected by uplift and erosion during Tertiary resulting in the formation of salt-related traps in Triassic and Lower Jurassic strata. During Plio-Pleistocene, glacial erosion removed additional Mesozoic and Cenozoic strata. This basin is regarded as a frontier salt province. A small hydrocarbon discovery (Pandora well) in the southwestern part of the basin points to the presence several functioning petroleum systems. The primary play type is related to salt traps below overhangs. Such structures are however, very difficult to image with conventional seismic techniques due to i) generation of multiples from sea floor and top of shallow salt bodies and ii) seismic shadow zones within the salt (possibly resulting from shale and carbonate stringers) which cause severe diffractions so that prospective areas adjacent to the salt remain elusive. Arctic exploration is expensive and the ability to focus on the highest potential targets is essential. A unique solution to this challenging subsurface Arctic environment was developed by integrating petroleum system modeling with full azimuth broadband seismic acquisition and processing. This integrated approach allows intelligent location of seismic surveys over structures which have the maximum chance of success of hydrocarbon charge. Petroleum system modeling was conducted for four seismic sections. Salt was reconstructed according to the diapiric evolution presented in Nilsen et al. (1995) and Koyi et al. (1995). Episodes of major erosion were assigned to Tertiary (tectonic) and Pleistocene (glacial). The models have been thermally calibrated. Consideration of Pleistocene glacial/interglacial cycles was required for thermal calibration as well as to better understand and predict the hydrocarbon phase behavior. References: Koyi, H., Talbot, C.J., Trudbakken, B.O., 1993, Salt diapirs of the southwest Nordkapp Basin: analogue modelling, Tectonophysics, Volume 228, Issues 3-4, Pages 167-187. Nilsen, K.T., Vendeville, B.C., Johansen, J.-T., 1995, Influence of regional tectonics on halokinesis in the Nordkapp Basin, Barents Sea. In: Jackson, M.P.A., Roberts, D.G., Snelson, S. (eds), Salt tectonics, a global perspective, AAPG Memoir 65, 413-436.

  1. Chemical signature of two Permian volcanic ash deposits within a bentonite bed from Melo, Uruguay

    Directory of Open Access Journals (Sweden)

    Liane M. Calarge

    2006-09-01

    Full Text Available A Permian bentonite deposit at Melo, Uruguay is composed of a calcite-cemented sandstone containing clay pseudomorphs of glass shards (0-0.50 m overlying a pink massive clay deposit (0.50-2.10m. The massive bed is composed of two layers containing quartz and smectite or pure smectite respectively. The smectite is remarkably homogeneous throughout the profile: it is a complex mixed layer composed of three layer types whose expandability with ethylene glycol (2EG 1EG or 0EG sheets in the interlayer zone which correspond to low-, medium- and high-charge layers respectively varies with the cation saturating the interlayer zone. The smectite homogeneity through the profile is the signature of an early alteration process in a lagoonal water which was over saturated with respect to calcite. Compaction during burial has made the bentonite bed a K-depleted closed system in which diagenetic illitization was inhibited. Variations in major, REE and minor element abundances throughout the massive clay deposit suggest that it originated from two successive ash falls. The incompatible element abundances are consistent with that of a volcanic glass fractionated from a rhyolite magma formed in a subduction/collision geological context.Um depósito Permiano de bentonita em Melo, Uruguai,é composto por um arenito com cimento calcítico contendo pseudomorfos de argila sobre detritos vítreos(0-0.50 m superpostos a um deposito maciço de argila rosado (0.50-2.10 m. A camada maciça é composta por dois níveis contendo quartzo e esmectita ou esmectita pura, respectivamente. A homogeneidade de esmectita ao longo do perfil é notável: trata-se de um interestratificado composto de três tipos de camadas, cuja expansibilidade com etileno-glicol (folhas 2EG, 1EG ou 0EG na zona interfoliar correspondentes a camadas com baixa, média e alta carga, respectivamente variam com o tipo de cátion que satura a zona interfoliar. A homogeneidade da esmectita ao longo do perfil é a assinatura de um processo de alteração precoce em uma água lagunar supersaturada em calcita. A compactação durante o soterramento tornou a camada de bentonita um sistema fechado empobrecido em K no qual a ilitização diagenética foi inibida. Variações nas abundâncias de elementos maiores, menores e ETR no depósito maciço de argila sugere que este foi originado a partir de duas quedas sucessivas de cinza. A abundância de elementos incompatíveis é consistente com a de um vidro vulcânico fracionado a partir de um magma riolitico formado em um ambiente geológico de subducção/colisão.

  2. Deep suture zone in the North Barents Basin

    Science.gov (United States)

    Butsenko, Viktor; Kireev, Artem; Piskarev, Alexey; Savin, Vasily; Smirnov, Oleg

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low magnetization. Calculated basement magnetization is 1.9 A/m to the West from an anomaly zone that is a characteristic for many igneous and metamorphic rocks of the diorite composition. Magnetization of the basement formations sharply increases to 3.6 A/m to the East. Similar values of magnetization are characterized basalts and dolerites, and also many metamorphic rocks of the basic and ultrabasic composition. Thus, the simulated magnetic field anomaly not only corresponds to limits of the heterochronous sedimentary basins, but also shows the border between two heterogeneous basement blocks. "Bright spot" anomalies are marked out on seismic sections. Bright spots are mainly located near the zone of negative magnetic anomaly along the East part of the North Barents Basin. The AVO analysis of the anomalies of the seismic recording has allowed to allocate possible hydrocarbon reservoirs and to subdivide them into the gas-saturated and oil-gas-saturated.

  3. Palynology of an Early Permian coal seam from the Karoo Supergroup of Botswana

    Science.gov (United States)

    Barbolini, N.; Bamford, M. K.

    2014-12-01

    Two borehole cores from the south-east area of the Mmamantswe coalfield (Mmamabula area), Botswana, provided 124 samples for palynological analysis. The assemblage is dominated by trilete and alete spores, indicating a parent flora of mostly lower order lycopods, sphenophytes and ferns. Distinctive taxa at Mmamantswe include Brevitriletes levis, Cannanoropollis densus, Gondisporites raniganjensis, Platysaccus radialis, Scheuringipollenites ovatus, and Verrucosisporites naumovae. Saccate pollen is less common, suggesting the assemblage reflects the local vegetation of the coal swamp. The Mmamantswe microflora has been sub-divided into two assemblage zones, with the lower Assemblage Zone 1 correlating with Assemblage Zone 1 of Anderson (northern Karoo Basin, South Africa), Biozone B of the Waterberg (South Africa) and the Milorgfjella assemblage (Dronning Maud Land, Antarctica). The upper Assemblage Zone 2 of Mmamantswe is correlated with Assemblage Zone 2 of Anderson (northern Karoo Basin, South Africa), Biozone C of the Waterberg (South Africa), and the No. 2 Seam assemblage (Witbank coalfield, South Africa). On the basis of these correlations the Mmamantswe microfloral assemblage is assigned to the Asselian, Sakmarian and Early Artinskian periods.

  4. A new captorhinid reptile from the Lower Permian of Oklahoma showing remarkable dental and mandibular convergence with microsaurian tetrapods

    Science.gov (United States)

    Reisz, R. R.; LeBlanc, Aaron R. H.; Sidor, Christian A.; Scott, Diane; May, William

    2015-10-01

    The Lower Permian fossiliferous infills of the Dolese Brothers Limestone Quarry, near Richards Spur, Oklahoma, have preserved the most diverse assemblage of Paleozoic terrestrial vertebrates, including small-bodied reptiles and lepospondyl anamniotes. Many of these taxa were previously known only from fragmentary remains, predominantly dentigerous jaw elements and numerous isolated skeletal elements. The recent discovery of articulated skulls and skeletons of small reptiles permits the recognition that dentigerous elements, previously assigned at this locality to the anamniote lepospondyl Euryodus primus, belong to a new captorhinid eureptile, Opisthodontosaurus carrolli gen. et sp. nov. This mistaken identity points to a dramatic level of convergence in mandibular and dental anatomy in two distantly related and disparate clades of terrestrial tetrapods and sheds light on the earliest instance of durophagy in eureptiles.

  5. Provenance study from petrography of the late Permian - Early Triassic sandstones of the Balfour Formation Karoo Supergroup, South Africa

    Science.gov (United States)

    Oghenekome, M. E.; Chatterjee, T. K.; Hammond, N. Q.; van Bever Donker, J. M.

    2016-02-01

    Non marine clastic sediments from the Late Permian - Early Triassic Balfour Formation of the Karoo Supergroup were studied to infer the composition, provenance and influence of weathering conditions. Petrographic studies based on quantitative analysis of the detrital minerals reveal that these sediments (mainly sandstones) are mostly composed of quartz, feldspar and sedimentary and metamorphic rock fragments. There is no significant petrographic variation across the sandstone succession of the study. The sandstones are dominantly feldspathic litharenite and ultralithofeldspathic in composition indicating a metamorphic source area. Modal analysis data plot in the dissected and transitional arc block provenance fields of QmFLt (quartz-feldspar-lithic fragments) diagram suggesting an active margin and magmatic arc signature preserving a recycled provenance.

  6. Permian fusulinid biostratigraphy of the Baoshan Block in western Yunnan, China with constraints on paleogeography and paleoclimate

    Science.gov (United States)

    Huang, Hao; Shi, Yukun; Jin, Xiaochi

    2015-05-01

    Newly obtained fossil materials together with published data enable a review on the Permian fusulinids of the Gondwana-derived Baoshan Block in western Yunnan, China. The Baoshan Block yields rather impoverish Sakmarian-Yakhtashian fusulinids with just Eoparafusulina and Pseudofusulina in its northern and southern parts. These fusulinids biogeographically demonstrate the feature of peri-Gondwana province and signify a temperate-water condition. Further comparison suggests the Baoshan Block was located distant from the tropical region and even with higher latitude than Central Iran and Central Pamir during the Sakmarian-Yakhtashian. In contrast, Murgabian-Midian fusulinids are more diversified. In the southern Baoshan Block, the Schwagerina assemblage, the Eopolydiexodina assemblage, the Sumatrina assemblage and the Verbeekina assemblage could be recognized in the Xiaoxinzhai area, and the Yangchienia-Nankinella assemblage and the Chusenella-Rugosofusulina assemblage in the Bawei area, in ascending order. Contemporaneously, the Neofusulinella assemblage occurs in the northern and the Eopolydiexodina assemblage in the southwestern Baoshan Block respectively. These Murgabian-Midian fusulinids show affinity of western Tethyan province and suggest a warm-water environment. Interestingly, the Midian Verbeekina assemblage is characterized by relatively low diversity and rather abundance of just one genus. Such compositional feature most likely signifies warm but still not optimal sea-surface water for the diversification of fusulinids. Also taking into account of the presence of Verbeekinids and Neoschwagerinids and the moderate total diversity, the Middle Permian fusulinids indicate that the Baoshan Block, during the Murgabian-Midian, was probably located between equatorial region with warm water to the north and the majority of Sibumasu areas lacking Verbeekinids and Neoschwagerinids with temperate water to the south.

  7. The structure and stratigraphy of the sedimentary succession in the Swedish sector of the Baltic Basin: New insights from vintage 2D marine seismic data

    Science.gov (United States)

    Sopher, Daniel; Erlström, Mikael; Bell, Nicholas; Juhlin, Christopher

    2016-04-01

    We present five interpreted regional seismic profiles, describing the full sedimentary sequence across the Swedish sector of the Baltic Sea. The data for the study are part of an extensive and largely unpublished 2D seismic dataset acquired between 1970 and 1990 by the Swedish Oil Prospecting Company (OPAB). The Baltic Basin is an intracratonic basin located in northern Europe. Most of the Swedish sector of the basin constitutes the NW flank of a broad synclinal depression, the Baltic Basin. In the SW of the Swedish sector lies the Hanö Bay Basin, formed by subsidence associated with inversion of the Tornquist Zone during the Late Cretaceous. The geological history presented here is broadly consistent with previously published works. We observe an area between the Hanö Bay and the Baltic Basin where the Palaeozoic strata has been affected by transpression and subsequent inversion, associated with the Tornquist Zone during the late Carboniferous-Early Permian and Late Cretaceous, respectively. We propose that the Christiansø High was a structural low during the Late Jurassic, which was later inverted in the Late Cretaceous. We suggest that a fan shaped feature in the seismic data, adjacent to the Christiansø Fault within the Hanö Bay Basin, represents rapidly deposited, coarse-grained sediments eroded from the inverted Christiansø High during the Late Cretaceous. We identify a number of faults within the deeper part of the Baltic Basin, which we also interpret to be transpressional in nature, formed during the Caledonian Orogeny in the Late Silurian-Early Devonian. East of Gotland a number of sedimentary structures consisting of Silurian carbonate reefs and Ordovician carbonate mounds, as well as a large Quaternary glacial feature are observed. Finally, we use the seismic interpretation to infer the structural and stratigraphic history of the Baltic and Hanö Bay basins within the Swedish sector.

  8. The thermal evolution and timing of hydrocarbon generation in the Maritimes Basin of eastern Canada: evidence from apatite fission track data

    International Nuclear Information System (INIS)

    Sandstone drill core and/or cuttings from six wells in the Gulf of St. Lawrence and cabot Strait have been analyzed using the apatite fission track (AFT) method. Measured AFT ages for the late Paleozoic sandstones range from 26 ±7 to 184 ±28 Ma (2-σ errors). The AFT data indicate that most Maritimes Basin strata were heated to temperatures in excess of 100-150oC very soon after their deposition. The strata also attained significant vitrinite reflectance (R0) levels (i.e., reaching the oil window) early in the burial history. These findings imply the generation of hydrocarbons and coalbed methane in the early basin history (pre-250 Ma). In the Maritimes Basin AFT and R0 data provide complementary information about the integrated thermal history, including maximum burial temperatures (from R0 data), and information on the subsequent cooling history from AFT analysis. The present study also supports the proposal made previously by others that substantial erosion of the Eastern Canadian margin (up to 4 km) has occurred since the Permian and extends the AFT evidence for this erosional event to include the southern Gulf of St. Lawrence area. Thermal models of the AFT data demonstrate that they are consistent with a history of exhumation of basin strata since late Permian time. The model-predicted AFT age and track length histograms closely correspond to the measured AFT parameters. AFT analysis also indicates present-day geothermal gradients of less than 40oC/km. (author). 42 refs.,3 tabs., 7 figs

  9. The distribution pattern of trace elements in Pedra do Fogo formation, permian of Maranhao Basin and it application as an environment indicator of sedimentation

    International Nuclear Information System (INIS)

    The present investigation consisted of a geochemical study of the medium and upper layers of the Pedra do Fogo Formation aiming at correlating its elemental distribution pattern with the sedimentary environment where that formation was deposited. Pelitic material with carbonate content below 30% was sampled in the three different outcrops of the Pedra do Fogo Formation for mineralogical and chemical analyses. Illite and dolomite, with subordinate amounts of smectite, calcite, quartz and K-feldspar were determined by X-ray diffraction techniques as the constituents of the mineral assemblages. Trace element (B, Ba, Co, Cr, Cu, Ga, Li, Mn, Ni, P, V, Pb, Sr, Rb and Zn), CO sub(2) and K concentrations were determined by emission spectrography, atomic absorption spectrometry and colorimetry. The interpretation of the chemical data based on B-V, Ga-B, B-K sub(2) O and B-Ga-Rb diagrams and on B content indicates a wite range of variation for the medium salinity during the deposition of the Pedra do Fogo rocks. Accordingly, the observed sequence is composed of intercalations of marine and fresh water sediments, the latter being dominant. The marine intercalations are more frequent in the bottom of the sampled stratigraphic section and become progressively rarer towards the top layers which were deposited in a typically fresh water environment. (author)

  10. Radioactive waste isolation in salt: peer review of the D'Appolonia report on Schematic Designs for Penetration Seals for a Repository in the Permian Basin, Texas

    International Nuclear Information System (INIS)

    Argonne made the following recommedations for improving the reviewed reports. The authors of the report should: state the major assumptions of the study in Sec. 1.1 rather than later in the report; consider using salt for the shaft seals in salt horizons; reconsider whether keys are needed for the bulkheads; provide for interface grouting because use of expansive cement will not guarantee that interfaces will be impermeable; discuss the sealing schedule and, where appropriate, consider what needs to be done to ensure that emplaced radioactive waste could be retrieved if necessary; describe in more detail the sealing of the Dockum and Ogallala aquifers; consider an as low as reasonably achievable approach to performance requirements for the initial design phase; address the concerns in the 1983 US Nuclear Regulatory Commission document entitled Draft Technical Position: Borehole and Shaft Sealing of High-Level Nuclear Waste Repositories; cite the requirements for release of radioactivity by referring to specific clauses in the regulations of the US Environmental Protection Agency; and provide further explanation in the outline of future activities about materials development and verification testing. More emphasis on development of accelerated testing programs is also required

  11. Canada Basin revealed

    Science.gov (United States)

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Chian, D; Lebedeva-Ivanova, Nina; Jackson, Ruth

    2012-01-01

    More than 15,000 line-km of new regional seismic reflection and refraction data in the western Arctic Ocean provide insights into the tectonic and sedimentologic history of Canada Basin, permitting development of new geologic understanding in one of Earth's last frontiers. These new data support a rotational opening model for southern Canada Basin. There is a central basement ridge possibly representing an extinct spreading center with oceanic crustal velocities and blocky basement morphology characteristic of spreading centre crust surrounding this ridge. Basement elevation is lower in the south, mostly due to sediment loading subsidence. The sedimentary succession is thickest in the southern Beaufort Sea region, reaching more than 15 km, and generally thins to the north and west. In the north, grabens and half-grabens are indicative of extension. Alpha-Mendeleev Ridge is a large igneous province in northern Amerasia Basin, presumably emplaced synchronously with basin formation. It overprints most of northern Canada Basin structure. The seafloor and sedimentary succession of Canada Basin is remarkably flat-lying in its central region, with little bathymetric change over most of its extent. Reflections that correlate over 100s of kms comprise most of the succession and on-lap bathymetric and basement highs. They are interpreted as representing deposits from unconfined turbidity current flows. Sediment distribution patterns reflect changing source directions during the basins history. Initially, probably late Cretaceous to Paleocene synrift sediments sourced from the Alaska and Mackenzie-Beaufort margins. This unit shows a progressive series of onlap unconformities with a younging trend towards Alpha and Northwind ridges, likely a response to contemporaneous subsidence. Sediment source direction appeared to shift to the Canadian Arctic Archipelago margin for the Eocene and Oligocene, likely due to uplift of Arctic islands during the Eurekan Orogeny. The final stage of sedimentation appears to be from the Mackenzie-Beaufort region for the Miocene and Pliocene when drainage patterns shifted in the Yukon and Alaska to the Mackenzie valley. Upturned reflections at onlap positions may indicate syn-depositional subsidence. There is little evidence, at least at a regional seismic data scale, of contemporaneous or post-depositional sediment reworking, suggesting little large-scale geostrophic or thermohaline-driven bottom current activity.

  12. Polynomial basins of infinity

    OpenAIRE

    Demarco, Laura; Pilgrim, Kevin

    2009-01-01

    We study the projection $\\pi: M_d \\to B_d$ which sends an affine conjugacy class of polynomial $f: \\mathbb{C}\\to\\mathbb{C}$ to the holomorphic conjugacy class of the restriction of $f$ to its basin of infinity. When $B_d$ is equipped with a dynamically natural Gromov-Hausdorff topology, the map $\\pi$ becomes continuous and a homeomorphism on the shift locus. Our main result is that all fibers of $\\pi$ are connected. Consequently, quasiconformal and topological basin-of-infinity conjugacy clas...

  13. Modifed Great Basin Extent (Buffered)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Two different great basin perimeter files were intersected and dissolved using ArcGIS 10.2.2 to create the outer perimeter of the great basin for use modeling...

  14. Stephanian-Early Permian basaltic trachyandesites from the Sławków and Nieporaz-Brodła Grabens near Kraków, Southern Poland

    Directory of Open Access Journals (Sweden)

    Anna LEWANDOWSKA

    2010-01-01

    Full Text Available In the Kraków-Lubliniec section of the major Hamburg-Kraków-Dobrogea Fault Zone (HKDFZ, the Stephanian-Early Permian magmatic activity was simultaneous with subsidence/uplift of formed blocks. In the proximity of the uplifted areas the sedimentation started with fanglomerates, distally passing into playa siltstone and was accompanied by volcanism. In the Nieporaz-Brodła graben, basaltic trachyandesite a-a lava flows with autoclastic breccias reach ca. 150 m in thickness. The weathering recorded as adhesive rims around breccia clasts reflects palaeosoil formation during quiescence periods between the eruptions. The eruptions were effusive although scoriaceous lava indicates high volatile content of the magma. The water content before eruption had to be over 2 wt. percent. Only then the crystallisation model predicts accurately the type, composition and order of the crystallising phases. Thus, the basaltic trachyandesite magma originated from a source containing hydrous phase (i.e., amphibole or phlogopite. All the studied basaltic trachyandesites had fayalitic olivine on their liquidus reflecting the crystallisation stage in a magma chamber at crustal depths. During final decompression on the magma ascent due to water exsolution, the olivine was followed by plagioclase, spinel, augite, ilmenite, apatite, K-feldspar and residual high-K rhyolitic glass. The high potassium content of these volcanics was thus a primary feature reflecting the source geochemistry and differentiation trend, and its consequence was potassium metaso- matism. Due to water exsolution the glass was altered, however, homogenous interstitial glass survived in some rocks. The glass is strongly enriched in incompatible trace elements, showing that it is a highly fractionated residual melt fraction of the basaltic trachyandesite magma. Thus, the glass geochemistry reflects the trend of fractional crystallisation indicating that co-occurring K-rich felsic rocks were not derived from the same magma. All the basaltic trachyandesites studied have calc-alkaline to alkaline affinity. They contain fayalitic olivine and are low in MgO 0.5-0.80 and small Eu/Eu* > 0.9-1.0 anomalies suggesting fractionation of plagioclase. The Eu/Eu* anomaly is probably compensated by amphibole retaining in the source. Negative Nb, Ti anomalies suggest Fe-Ti oxide fractionation characteristic for calc-alkaline evolution trend. A significant enrichment in LREE relatively to HREE (La/Yb > 10 indicates subduction-related metasomatism. However, the described tectonic context is inconsistent with subduction related characteristics. Concluding, the observed geochemical characteristics indicate remarkable role of water in magma evolution. The volcanism was related to strike-slip dextral movement along the Kraków-Lubliniec section of HKDFZ, transformed into crustal extension and subsidence, the features typical for the formation of pull-apart basins, in the late stages of the Variscan orogen evolution.

  15. Palaeomagnetism of Permian and Triassic red beds of NW Spain and implications for the tectonic evolution of the Asturian -- Cantabrian Arc

    Science.gov (United States)

    Parés, J. M.; Voo, R.; Stamatakos, J.

    1996-09-01

    A palaeomagnetic study of Permo-Triassic cover rocks in the Asturian -- Cantabrian Arc has revealed characteristic magnetizations in 136 samples from 14 sites, yielding a mean palaeopole for each of the three regions studied (Cabo de Peñas, Villaviciosa, and Tudanca). Previous work on remagnetized Palaeozoic formations in the area revealed Permian (or younger) tightening of the Arc on the basis of palaeomagnetic declinations that show relative rotations of more than 100°. According to the new palaeopoles obtained in this study, these rotations are not present to any comparable extent in the Permo-Triassic deposits, allowing us to conclude that the bulk of the rotations in the Arc is Permian in age.

  16. Climatic - biotic continuum - a few examples from the Pennsylvanian - Early Permian

    Science.gov (United States)

    Kossovaya, O.

    2012-04-01

    The subdivision of the Pennsylvanian Epoch based on the great difference in the biota composition and evolution. Extensive grows of the continental ice sheets near the Mississippian-Pennsylvanian (mid-Carboniferous) boundary expanded a large area comparative with Pleistocene (106 km2) (Crowley and Baum, 1991). One of the possible models is the restructuring of the oceanic circulation patterns (Saltzman, 2003). The Mid-Carboniferous boundary in the Urals demonstrates regional inconformity trigged by strong fall of the basin depth. Possibly following circulation was the reason of the positive carbon and isotope shift documented in the one of the Askyn key section of the South Urals. Renovated biota appeared far above the unconformity (Brand, Bruckschen, 2002, Kossovaya, 2009, 2010). The next level of biota replacement was found near by Mid-Pennsylvanian boundary. The isotope and microfacies fluctuations are traced in the Late Myachkovian -Kasimovian transitional in the "Kasimov quarry. The top of the Domodedovo Fm. is marked by double paleosoil profile emphasized by Microcodium crust (Leontiev, Kossovaya, 2011) and is characterized by ? 13C negative shift from +2,2 (sample Ks-23) up to - 4,4 (sample Ks -24) and possibly is reinforce by the presence of Microcodium. The extinction of the most of colonial rugosa (Petalaxidae) at this level in the Moscow Basin together with strong restriction of diversity of the other warm -water organisms is considered as biotic event which abiotic affinities are still not clear. The basin level fall is documented by a few erosion surfaces both in the Domodedovo and Peski Fms (Uppermost Myachkovian). Diachronic extinction embraced Perski interval. Data on stable isotope allows to propose the El-Nino scenario fro the first phase of the fauna replacement. Following diminishing of the carbon is indirectly relevant by change of carbonate to clay sedimentation at the beginning of the Voskresensk Fm. It is confirmed by low value of ?13C 0,5-1,0 in the overlay limestone. The taxonomic diversity is very low. The recovery of bentic biota is characteristic for the Asselian -Lower Artinskian and ended by abrupt extinction at the Late Artinskian or Kungurian. The paleoclimatic affinities of this event are rather controversial. In the Southern hemisphere the restriction of the glacial cover is supported by the appearance first temperate biota - forams, small solitary rugosa, bryozoan, rare bivalves and brachiopods, that are characteristic for the temperate water. This level coincides with colonial corals flourishing in the subtropical area. The average value within Asselian - Lower Artinskian in the Most section (Central Urals) is ? 13C 4- 5. The end of Early Artinskian coincides with the minimum value both ?13C and 18O probably mirroring Late Sakmarian deglaciation (Kossovaya et al., 2011). The obtained data in spite of the difference in the absolute value show the similar trend with published data (Korte et al., 2005). Following "small biotic event" fixed in the Northern Hemisphere is characterized by disappearance of Kleopatrinidae and Durhamihidae (Rugosa), other reef-building organisms, diversification of ostracods and replacement of the brachiopod genera composition. Possible trigger could be collision processes in the Eastern part of Pangea challenged the circulation change.

  17. Palynofacies analysis of the Permian-Triassic transition in the Amb section (Salt Range, Pakistan): implications for the anoxia on the South Tethyan Margin

    OpenAIRE

    Schneebeli-Hermann, E.; Kürschner, W.M.; P. A. Hochuli; Bucher, H.; Ware, D.; Goudemand, N.; Roohi, G

    2012-01-01

    The uppermost Chhidru Formation and the lower part of the Mianwali Formation were sampled in the Amb Valley, Salt Range, Pakistan for the study of the particulate organic matter (POM) content in order to evaluate the depositional environment during the Permian–Triassic transition. The POM content was assigned to four distinct palynofacies (palynofacies A–D). Palynofacies A recovered from siltstone within the white sandstone unit of the Upper Permian Chhidru Formation indicates a s...

  18. First report of a Middle-Upper Permian magmatism in the SE Iberian Ranges: characterisation and comparison with coeval magmatisms in the western Tethys

    OpenAIRE

    Lago San José, Marceliano; Horra del Barco, Raúl de la; Ubide Garralda, Teresa; Galé, Carlos; Galán Abellán, Ana Belén; Fernández Barrenechea, José María, ed. lit; López Gómez, José; Benito Moreno, María Isabel; Arche, Alfredo; Alonso Azcárate, Jacinto; Luque del Villar, Francisco Javier, ed. lit; Martin J. Timmerman

    2012-01-01

    A multiple basic to intermediate sill is reported for the first time in the south-eastern Iberian Ranges. It is composed of several tabular to irregular levels intercalated within the fluvial sediments of the Alcotas Formation (Middle-Upper Permian). The sill could represent the youngest Paleozoic subvolcanic intrusion in the Iberian Ranges. The igneous rocks are classified as basaltic andesites. They show a subophitic microstructure constituted by plagioclase (An62 – An6), augite (En48Wo44Fs...

  19. SMALLER FORAMINIFERS, CHARACTERISTIC ALGAE AND PSEUDO-ALGAE OF THE LATEST CARBONIFEROUS-EARLY PERMIAN RATTENDORF GROUP,CARNIC ALPS (AUSTRIA/ITALY)

    OpenAIRE

    DANIEL VACHARD; KARL KRAINER

    2001-01-01

    Limestones of the latest Carboniferous-early Permian Rattendorf Group (Lower Pseudoschwagerina Limestone, Grenzland Formation and Upper Pseudoschwagerina Limestone) of the Carnic Alps (Austria/Italy) contain a rich and interesting assemblage of smaller foraminifers, algae and pseudo-algae. The foraminiferal assemblage of the Lower Pseudoschwagerina Limestone is identical to that of the Auernig Formation. The Grenzland Formation is characterized by the appearance of the genus Geinitzinaand Pse...

  20. The Permian-Triassic rocks of the eastern Iberian Ranges: A general approach in the context of the first stages of the break-up of Pangea.

    OpenAIRE

    Horra, Raúl de la; López-Gómez, José; Arche, A.; Escudero-Mozo, M. J.; Galán, A. B.; Barrenechea, J.F.; Martín-Chivelet, J; Borruel, V.

    2013-01-01

    This field guide has been prepared for the 2013 10th International Field Workshop of the Pan-European Correlation of the Triassic. The Field Workshop has been organized as a four-day geological excursion and the guide covers sedimentary aspects of the continental and marine Permian-Middle Triassic rocks of the Iberian Ranges, Spain, but also on related topics such as tectonics, mineralogy, paleoclimate, paleontological content, paleosols, and biotic crises.

  1. Australian provenance for Upper Permian to Cretaceous rocks forming accretionary complexes on the New Zealand sector of the Gondwana land margin

    International Nuclear Information System (INIS)

    U-Pb (SHRIMP) detrital zircon age patterns are reported for 12 samples of Permian to Cretaceous turbiditic quartzo-feldspathic sandstone from the Torlesse and Waipapa suspect terranes of New Zealand. Their major Permian to Triassic, and minor Early Palaeozoic and Mesoproterozoic, age components indicate that most sediment was probably derived from the Carboniferous to Triassic New England Orogen in northeastern Australia. Rapid deposition of voluminous Torlesse/Waipapa turbidite fans during the Late Permian to Late Triassic appears to have been directly linked to uplift and exhumation of the magmatically active orogen during the 265-230 Ma Hunter-Bowen event. This period of cordilleran-type orogeny allowed transport of large volumes of quartzo-feldspathic sediment across the convergent Gondwana land margin. Post-Triassic depocentres also received (recycled?) sediment from the relict orogen as well as from Jurassic and Cretaceous volcanic provinces now offshore from southern Queensland and northern New South Wales. The detailed provenance-age fingerprints provided by the detrital zircon data are also consistent with progressive southward derivation of sediment: from northeastern Queensland during the Permian, southeastern Queensland during the Triassic, and northeastern New South Wales - Lord Howe Rise - Norfolk Ridge during the Jurassic to Cretaceous. Although the dextral sense of displacement is consistent with the tectonic regime during this period, detailed characterisation of source terranes at this scale is hindered by the scarcity of published zircon age data for igneous and sedimentary rocks in Queensland and northern New South Wales. Mesoproterozoic and Neoproterozoic age components cannot be adequately matched with likely source terranes in the Australian-Antarctic Precambrian craton, and it is possible they originated in the Proterozoic cores of the Cathaysia and Yangtze Blocks of southeast China. Copyright (1999) Geological Society of Australia

  2. Conjugacy between polynomial basins

    OpenAIRE

    Wang, Xiaoguang

    2013-01-01

    In this article, we study the properties of conjugacies between polynomial basins. For any conjugacy, there is a quasiconformal conjugacy in the same homotopy class minimizing the dilatation. We compute the precise value of the minimal dilatation. The quasiconformal conjugacy minimizing the dilatation is not unique in general. We give a necessary and sufficient condition when the extremal map is unique.

  3. Pasco Basin hydrometeorological study

    International Nuclear Information System (INIS)

    This report provides detailed precipitation and evapotranspiration distributions for the Pasco Basin for use in groundwater recharge calculations. The results are shown on precipitation and evapotranspiration distribution maps. The parameters, calculation methods, sensitivity determinations, and fitting methods used in the development of these maps are also discussed

  4. South Bohemian basins

    Czech Academy of Sciences Publication Activity Database

    Spudil, J.; Brož, B.; Dašková, Jiřina; Holcová, K.; Kvaček, Z.; Pešek, J.; Svobodová, Marcela; Sýkorová, Ivana; Teodoridis, V.

    Prague : Czech Geological Survey, 2014, s. 190-206 ISBN 978-80-7075-862-5 R&D Projects: GA ČR GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  5. Groundwater flow in an `underfit' carbonate aquifer in a semiarid climate: application of environmental tracers to the Salt Basin, New Mexico (USA)

    Science.gov (United States)

    Sigstedt, Sophia C.; Phillips, Fred M.; Ritchie, Andre B. O.

    2016-04-01

    The Salt Basin is a semiarid hydrologically closed drainage basin in southern New Mexico, USA. The aquifers in the basin consist largely of Permian limestone and dolomite. Groundwater flows from the high elevations (˜2,500 m) of the Sacramento Mountains south into the Salt Lakes, which are saline playas. The aquifer is `underfit' in the sense that depths to groundwater are great (˜300 m), implying that the aquifer could transmit much more water than it does. In this study, it is speculated that this characteristic is a result of a geologically recent reduction in recharge due to warming and drying at the end of the last glacial period. Water use is currently limited, but the basin has been proposed for large-scale groundwater extraction and export projects. Wells in the basin are of limited utility for hydraulic testing; therefore, the study focused on environmental tracers (major-ion geochemistry, stable isotopes of O, H, and C, and 14C dating) for basin analysis. The groundwater evolves from a Ca-HCO3 type water into a Ca-Mg (Na) - HCO3-Mg (Cl) water as it flows toward the center of the basin due to dedolomitization driven by gypsum dissolution. Carbon-14 ages corrected for dedolomitization ranged from less than 1,000 years in the recharge area to 19,000 years near the basin center. Stable isotopes are consistent with the presence of glacial-period recharge that is much less evaporated than modern. This supports the hypothesis that the underfit nature of the aquifer is a result of a geologically recent reduction in recharge.

  6. Provenance of Permian-Triassic volcaniclastic sedimentary terranes in New Zealand : evidence from their radiogenic isotope characteristics and detrital mineral age patterns

    International Nuclear Information System (INIS)

    Detrital mineral age patterns, Rb-Sr age, and initial strontium isotope ratio variations are reported for metasediments of the Brook Street, Dun Mountain-Maitai, and Murihiku Terranes (informally grouped as 'central arc terranes') of New Zealand. U-Pb SHRIMP detrital zircon age populations in Late Permian Tramway Formation, sandstones of the Dun Mountain-Maitai Terrane in Nelson and Southland, New Zealand, show restricted Late Permian (253-268 Ma) and broader Devonian-Carboniferous (330-373 Ma) age components in about equal proportions, with a minor (87Sr/86Sr ratios (i) at the time of metamorphism), reveal cooling age patterns consequent upon low-grade metamorphism in latest Triassic and earliest Jurassic times. The (t)-(i) data define a central arc terranes group consistently less radiogenic than Permian and Triassic time correlatives in the Torlesse Supergroup of the Rakaia Terrane. This feature suggests a provenance that includes sediment detritus dominantly from less radiogenic I-type igneous sources in both Lachlan and New England Fold Belts in similar proportions, and with little contribution from their Precambrian and early Paleozoic hinterlands. (author). 89 refs., 6 figs., 2 tabs

  7. High Biomass Polar Forests During the Permian: Evidence from the Buckley Formation, Beardmore Glacier Area, Antarctica Supports Climate Models

    Science.gov (United States)

    Miller, M.

    2006-12-01

    Newly discovered fossil forests in the Central Transantarctic Mountains (CTM) are composed of 74 in situ stumps. They are surrounded by impressions of leaves of the gymnosperm Glossopteris and record monospecific stands of glossopterids. The stumps allow reconstruction of the height, density, and basal area of trees growing at 75 degrees S and provide a unique glimpse of a high latitude forest flourishing less than a million years before the end-Permian extinction event. The forests occur in two closely spaced beds (LP1, LP2) of the upper Buckley Formation at Lamping Peak (LP); the wood has been replaced by magnetite. Roots extending outward from the stumps and leaf mats recorded by densely packed impressions of Glossopteris leaves indicate that the stumps are in growth position. Stumps exposed in cross section have radiating roots than penetrate shallowly beneath the stump-bearing horizons. Both LP1 and LP2 contain stumps of diverse sizes, ranging from a few to 75 cm in diameter, reflecting young to old trees. Mean diameters at ground line (dgl) are 20.9cm (LP1) and 39.2cm (LP2). These mean diameters correspond to maximum tree heights of 15.4m (LP1) and 24.6m and are comparable to or greater than other high latitude fossil forests. Tree densities (trees/hectare; t/ha) are 2505 t/ha (LP1 and 1185 (LP2), which are within the range of densities of stands of old growth in deepwater swamps of the southeastern US and of old growth in the Smokies and greater than densities of trees in forests in Costa Rica. Basal areas (m2/ha), a measure of tree abundance that is independent of forest maturity, are 65 m2/ha (LP1) and 85 m2/ha (LP2), which are within the range of some modern forests and greater than others. Although fossil forest biomasses are not known, trend of basal area vs biomass of modern forests suggest high biomass given the basal areas of the fossil forests. The forests support with geologic evidence climate models indicating high temperatures and high CO2 levels in the late Permian and demonstrate that humid-temperate forests could thrive under polar light regimes.

  8. Occurrence, behavior and distribution of high levels of uranium in shallow groundwater at Datong basin, northern China

    International Nuclear Information System (INIS)

    Geochemical investigations of uranium (U) occurrence in the environments were conducted at Datong basin of northern China. The results suggest that U contents were generally 22+) species is dominant and strongly adsorbed onto iron (hydro)xides, while it would be preferentially complexed with carbonate in the alkaline groundwater, forming highly soluble uranyl-carbonate complexes at Datong. Under reducing conditions, uranous (U(IV)) species is ready to precipitate or bind to organic matter, therefore having a low mobility. At the study area, high U groundwater (> 30 μg/L) occurs at the alluvial plains due to intermediate redox and enhanced alkaline conditions. The abnormally high levels of U in groundwater (> 100 μg/L) are locally found at the west alluvial plains. By contrast, U co-precipitation with secondary carbonate minerals like Ca2UO2(CO3)3 in the dominant Ca–Mg–Na–HCO3 type groundwater may prevail at the east alluvial plains. Besides, bedrocks such as Carboniferous and Permian sedimentary rocks, especially the coal-bearing strata which have higher U contents at the west mountain areas may also account for the abnormally high levels of U in groundwater. - Highlights: • High U groundwater occurs at the alluvial plains of Datong basin. • Redox state, complexation and adsorption are responsible for U enrichment. • Carboniferous and Permian sedimentary rocks have higher U contents at Datong. • Uranyl is preferentially complexed with carbonate in groundwater. • U in the aquifer sediments may be primarily associated with carnotite

  9. Assessment of undiscovered conventionally recoverable petroleum resources of the Arabian-Iranian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Masters, C.D.; Klemme, H.D.; Coury, A.B.

    1982-01-01

    The estimates of undiscovered conventionally recoverable petroleum resources in the Arabian-Iranian basin at probability levels of 95 percent, 5 percent, and statistical mean are for oil (in billions of barrels); 72,337, and 174; and for gas (in trillions of cubic feet): 299, 1792, and 849. The occurrence of petroleum can be accounted for in five definitive geological settings or plays. The five plays listed by geologic age are: (I) Upper Cretaceous and Tertiary, (II) Lower and Middle Cretaceous sandstone, (III) Lower and Middle Cretaceous limestone, (IV) Jurassic, and (V) Permian. The Permian play, located in the south-central Arabian Gulf region and extending northeast-southwest from southern Iran to the Ar Rub'al Khali in Saudi Arabia, accounts for over four-fifths of the mean estimate of undiscovered gas. The remainder of the gas is divided about equally among the other four plays. The Jurassic play, located on the south side of the Arabian Gulf, accounts for slightly less than one-third of the estimated undiscovered oil, which is split equally between Saudi Arabia and Iraq. The Lower and Middle Cretaceous limestone play is located in the southern Gulf region and accounts for about one-fifth of the undiscovered oil, most of which is located in Saudi Arabia and the remainder in the United Arab Emirates. The Lower and Middle Cretaceous sandstone play is centralized in Kuwait at the head of the Arabian Gulf with significant potential extending to the northwest in Iraq; the play accounts for about one-third of the undiscovered oil, the great majority of which is estimated to be in Iraq with the remainder divided between Saudi Arabia and Kuwait. The upper Cretaceous-Tertiary play is located in the Zagros fold belt of Iran and Iraq and accounts for about one-fifth of the undiscovered oil. 5 references, 16 figures, 3 tables.

  10. Assessment of undiscovered conventionally recoverable petroleum resources of Arabian-Iranian basin

    Energy Technology Data Exchange (ETDEWEB)

    Masters, C.D.; Klemme, H.D.; Coury, A.B.; Peterson, J.A.

    1986-05-01

    Undiscovered, conventionally recoverable petroleum resources in the Arabian-Iranian basin are estimated at probability levels of 95%, 5%, and statistical mean. Estimates for oil are 72, 337, and 174 billion bbl; for gas, they are 299, 1, 792, and 849 tcf. Petroleum occurrences can be accounted for in five definitive geologic settings of plays. Undiscovered resource potential is assessed, assuming that new discoveries will expand the occurrence of petroleum in these basic plays. The five plays listed in sequence are: (1) Upper Cretaceous and Tertiary, (2) Lower and middle Cretaceous sandstone, (3) Lower and middle Cretaceous limestone, (4) Jurassic, and (5) Permian. The Permian play is located in the south-central Arabian Gulf region and extends northeast-southwest from southern Iran to the Ar Rub'al Khali in Saudi Arabia. It accounts for more than four-fifths of the mean estimate of undiscovered gas. The Jurassic play, located on the south side of the Arabian Gulf, accounts for slightly less than one-third of the estimated undiscovered oil, which is split equally between Saudi Arabia and Iraq. The Lower and middle Cretaceous limestone play is located in the southern gulf region and accounts for about one-fifth of the undiscovered oil. The Lower and middle Cretaceous sandstone play is centralized in Kuwait at the heat of the Arabian Gulf, with significant potential extending northwest into Iraq. This play accounts for about one-third of the undiscovered oil. The Upper Cretaceous-Tertiary play is located in the Zagros foldbelt of Iran and Iraq, and accounts for about one-fifth of the undiscovered oil.

  11. Serenitatis multi-ringed basin

    International Nuclear Information System (INIS)

    New topographic data allow a reassessment of the ring structure of the Serenitatis basin and correlation with the younger Orientale basin. The northern Serenitatis basin is smaller and less well preserved than the southern Serenitatis basin. Three major rings of the main (southern) Serenitatis basin are mapped: ring 1, Linne ring, outlined by mare ridges, average diameter 420 km; ring 2, Haemus ring, outlined by basin-facing scarps and massifs with crenulated borders, 610 km; ring 3, Vitruvius ring, outlined by basin-facing linear scarps and massifs, 880 km. Ring 1 corresponds to the inner Rook Mountain ring of Orientale, ring 2 with the outer Rook ring, and ring 3 with the Cordillera Mountain ring. The ring identifications and assignments indicate that the Serenitatis basin is essentially the same size as the Orientale basin, rather than much larger, as previously proposed. The Apollo 17 site lies near the second ring, which is interpreted as the rim of the transient cavity. Apollo 15 lies at the junction of the Serenitatis and Imbrium third rings; Serenitatis ejecta should be present in significant amounts at the Apollo 15 site. The new reconstruction indicates that portions of the Serenitatis basin are better preserved than previously thought, consistent with recent stratigraphic and sample studies that suggest an age for Serenitatis which is older than, but close to, the time of formation of the Imbrium basin. (Auth.)

  12. Late Variscan tectonothermal history of the Holy Cross Mts. (central Poland) as revealed by integrated palaeomagnetic and 1-D basin modelling study

    Science.gov (United States)

    Grabowski, J.; Narkiewicz, M.; Szaniawski, R.; Resak, M.; Littke, R.

    2009-04-01

    Classical outcrops of the Holy Cross Mountains (HCM) in Poland are among a few areas in Central Europe exposing a complete succession of Phanerozoic strata. The long-studied Palaeozoic sections are of a key importance to understand a complex Phanerozoic development in the region bordering the East European Craton from the south-west. The Palaeozoic core of HCM consists of two tectonostratigraphic units: southern (Kielce) and northern (Łysogóry), separated by a Holy Cross Fault. Different organic maturity data (conodont CAI, vitrinite reflectance - VR, biomarkers) consistently indicate an important difference in thermal alteration pattern between the pre-Permian Palaeozoic and the Permian-Mesozoic cover in the Kielce region. In its northern part, adjoining the Holy Cross Fault, the Devonian carbonates are characterized by VR≥0.7 % and CAI 1.5-3.5, while in the south they are less altered thermally, displaying VR≤0.65 % and CAI 1.0-1.5. On the other hand, Permian-Mesozoic cover reveals a uniformly low degree of thermal alteration (VR close to 0.6 % and CAI 1). Palaeomagnetic studies and thermal modelling were performed in outcrops and borehole sections of the Middle - Upper Devonian carbonates, situated in the areas of contrasting thermal histories. Rocks with a higher degree of thermal alteration revealed presence of secondary, most-probably post-folding magnetization residing in magnetite (component A). The age of this remagnetization might be estimated as Early Permian (ca. 290 - 260 Ma). The remagnetization is absent in the less thermally altered areas, where a pre- or early synfolding magnetization was preserved (component B). As presence of the component A correlates with thermal indexes, it might be concluded that its acquisition was controlled mostly by post-orogenic uplift and cooling. Radiogenic 87Sr/86Sr isotope ratios in carbonates do not coincide with occurrence of component A which means that chemical remagnetization due to influence of deeper basinal and/or juvenile fluids is rather unlikely. The results of burial-thermal modelling of borehole sections are in a good agreement with palaeomagnetic data. The results from Janczyce I borehole, situated in the northern part of Kielce region, indicate a significant role of elevated Variscan (Early to Late Carboniferous) heat flow, followed by cooling from ca. 130 to 70 degrees Celsius between 330 and 260 Ma. This is consistent with a concept attributing the Early Permian remagnetization to post-Variscan (i.e. Late Carboniferous) uplift and related cooling. The secondary magnetization could have been facilitated by oxidation of pyrite during a circulation of meteoric fluids. The absence of elevated heat flow and ensuing cooling in the southern part of the HCM corresponds to a lack of the Early Permian remagnetization. Our study seems to demonstrate that, under special circumstances, the palaeomagnetic data may represent a useful complementary tool in deciphering tectonothermal dynamics of a sedimentary basin.

  13. Geometrical model of the Baltic artesian basin

    Science.gov (United States)

    Sennikovs, J.; Virbulis, J.; Bethers, U.

    2012-04-01

    Baltic artesian basin (BAB) is a multi-layer sedimentary basin spanning around 480'000 km2. BAB is located in the territory of Latvia, Lithuania and Estonia, parts of Poland, Russia, Belarus and large area of the Baltic Sea, including island of Gotland. The thickness of sedimentary cover is about 5000 m in the south-western part. Crystalline bedding reaches the surface in the northern and north-western parts. The aim of the present work is development of the model of geometric structure and three dimensional finite element mesh for the hydrogeological model of the whole BAB. The information that is used to build the geometrical structure includes: (1) Stratigraphic information from boreholes in Latvia and Estonia (2) Maps of height isolines of geological layers for Latvia and Lithuania (3) Maps of sub-quaternary deposits in Latvia and Lithuania (4) Maps of fault lines on the crystalline basement surface in Latvia, Lithuania and Estonia (5) Buried valley data from Latvia and Estonia (6) Earth topography data (7) Baltic sea depth data (8) Data from published geological cross-sections, information from books and other sources. Unification of the heterogeneous information from different sources, which are employed for building of the geometrical structure of the model are performed. Special algorithms are developed for this purpose considering the priority, importance and plausibility of each of the data sources. Pre-processing of the borehole information to screen out the outlying borehole data has been performed. Model of geological structure contains 42 layers. It includes aquifers and aquitards from Cambrian up to the Quaternary deposits. Fault displacements are incorporated into the model taking into account data from the published structural maps. Four reconstructed regional erosion surfaces (upper Ordovician, Devonian, Permian and Quaternary) are included into the model Three dimensional mesh of the geological structure is constructed layer-wise. The triangular mesh in horizontal plane is constructed including characteristic lines such as rivers, borders of countries and areas of presence of geological layers. Mesh consists of triangular prisms, pyramids and tetrahedrons. The construction of the geometric mesh is implemented by specially developed script in Python. Such approach has several advantages: (1) flexibility in choosing ways to build the structure; (2) parallelization of workload in developing/updating of different structure elements; (3) documentation and maintenance of repeatable structure building path; (4) opportunity to rebuild the structure with slight or significant modifications at any time; (5) possibility to build, and maintain several structures of different complexity simultaneously. Acknowledgement The present work has been funded by the European Social Fund project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" (Project Nr. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060)

  14. Spectroscopic analysis and X-ray diffraction of trunk fossils from the Parnaba Basin, Northeast Brazil

    Science.gov (United States)

    Alencar, Wemerson J.; Santos, F. Eroni P.; Cisneros, Juan C.; da Silva, Joo H.; Freire, Paulo T. C.; Viana, Bartolomeu C.

    2015-01-01

    The Parnaiba Sedimentary Basin is of the Paleozoic age and is located in Northeast Brazil, covering the states of Piau, Maranho and Tocantins and a small part of Cear and Par. In this work we applied several chemical analytical techniques to characterize trunk fossils found in the Parnaba Sedimentary Basin, collected from four different sites, and discuss their fossilization process. We performed a study of the trunk fossils through X-ray diffraction, energy dispersive spectroscopy, infrared and Raman spectroscopy. The analysis allow us to identify the different compositions which are present in the trunk fossils: kaolinite (Al2Si2O5(OH)4), hematite (Fe2O3) and quartz (SiO2). Based in these results we were able to identify that the main fossilization mechanism of the trunk fossil was silicification. Furthermore, through Raman spectroscopy, we have observed the presence of carbonaceous materials in the Permian fossils, as evidenced by the D and G Raman bands. The relative intensities and bandwidths of the D and G bands indicated that the carbon has a low crystallinity. Thus, most of trunk fossils analyzed were permineralized and not petrified, because there is the presence of carbon that characterizes the partial decomposition of the organic matter in some trunks.

  15. The volcaniclastic series from the Luang Prabang Basin, Laos: A witness of a triassic magmatic arc?

    Science.gov (United States)

    Rossignol, Camille; Bourquin, Sylvie; Poujol, Marc; Hallot, Erwan; Dabard, Marie-Pierre; Nalpas, Thierry

    2016-04-01

    The paleogeographic evolution of South East Asia (SEA) during the early Mesozoic is still poorly understood and a number of models have recently been put forward to account for the geodynamic evolution of SEA. The Luang Prabang Basin (north Laos), located in the core of a "paleogeographic jigsaw" in SEA, recorded a long lasting volcanism that spanned for ∼ 35 my from the earliest Triassic up to Late Triassic as evidenced by combined stratigraphic and geochronological (U-Pb/zircon) analyses performed on both volcanic and volcaniclastic series. The volcanic rocks are arc tholeiites and calk-alkaline andesites to dacites. The volcaniclastic rocks contain, in part, volcaniclasts produced contemporaneously with sedimentation. Both the volcanic and volcaniclastic series display geochemical features characteristic of a subduction related volcanism. Therefore, the Luang Prabang Basin documents a magmatic arc in a good agreement with the recent recognition of neighboring ophiolitic rocks in the Luang Prabang area. Following a passive margin setting that prevailed from the late Carboniferous to the late Permian, an active margin then initiated along the western margin of the Indochina Block. This active magmatic arc developed as the result of an east-dipping subduction below the Indochina Block during most of the Triassic, at least from ca. 250 to 215 Ma. Subsequently, this oceanic subduction episode must have been followed by a continental collision of the Indochina Block with the eastern Simao Block, at a period that remains to be defined.

  16. Fault development and stress evolution of the post-Hercynian Asturian Basin (Asturias and Cantabria, northwestern Spain)

    Science.gov (United States)

    Lepvrier, C.; Martínez-García, E.

    1990-12-01

    The Asturian Basin, an emerged part of the North Iberian continental margin, has been investigated in terms of fault development and stress evolution. The Mesozoic history of this domain is mainly linked to the extensional faulting processes which preceded the opening of the Bay of Biscay. Preserved Jurassic faulted blocks and associated half-graben structures, bounded by WNW-ESE to NW-SE faults, are related to a Late Jurassic (Kimmeridgian?) rifting stage. This fault system seems to have played a major role during the Mesozoic structuring of the basin, suggesting an extension oriented approximately NE-SW. The Cenozoic evolution is related to the Iberia-Eurasia convergence and collision, leading to compressional and subsequent extensional structures. The direction of compression, documented in various sites, was NNW-SSE during an initial early-middle Eocene stage, reoriented probably in the Oligocene to NE-SW. This succession of stress regimes was applied to the same three major fault systems, NE-SW, NW-SE and E-W, which were inherited from the Variscan Orogeny, some of them having already been involved in the latest Stephanian — Early Permian rifting episode. During the Tertiary compressional phase, the NW-SE trend, which is believed to have controlled the late Jurassic tectonic development, was rejuvenated into dextral strike-slip faults, whereas the NE-SW system moved in a sinistral sense. The E-W system was reactivated as reverse faults, giving rise to a partial inversion of the basin.

  17. Genetic origin of Mesozoic natural gases in the Ordos Basin (China): Comparison of carbon and hydrogen isotopes and pyrolytic results

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.P.; Dai, J.X.; Zhao, C.Y.; Liu, J.Z. [Chinese Academy of Sciences, Guangzhou (China)

    2010-09-15

    Permian coal and Triassic mudstone from the Ordos Basin were pyrolyzed in a closed system using a gold tube technique. Carbon and hydrogen isotopes of the gases generated from pyrolysis were compared to Mesozoic gases in the basin to interpret the origin, maturity and any mixing of gases. Maturation trends for thermogenic methane from both coal and lacustrine kerogens in our experiment were found to be independent of heating rate, allowing their use for determination of gas provenance. Gases from a tectonically stable area like the Shanbei slope are derived mainly from Yanchang lacustrine kerogen, and gases in tectonically active areas consist of mixtures of coal-derived gases and oil-associated methane from deeply buried formations, as well as oil-associated gases and biogenic gases from shallow depth. The thermal maturity of the C{sub 2} and C{sub 3} gases is estimated to cover an equivalent vitrinite reflectance range from 0.7% to 1.2% R{sub o}, whereas C{sub 1} gas exhibits a wide maturity variation ranging from 05% to 1.5% R{sub o} and implying significant mixing of Mesozoic methane in the basin.

  18. Native copper in Permian Mudstones from South Devon: A natural analogue of copper canisters for high-level radioactive waste

    International Nuclear Information System (INIS)

    Native copper (>99.9% Cu) sheets associated with complex uraniferous and vanadiferous concretions in Upper Permian Mudstones from south Devon (United Kingdom) have been studied as a 'natural analogue' for copper canisters designed to be used in the isolation of spent fuel and high-level radioactive wastes (HLW) for deep geological disposal. Detailed analysis demonstrates that the copper formed before the mudstones were compacted. The copper displays complex corrosion and alteration. The earliest alteration was to copper oxides, followed sequentially by the formation of copper arsenides, nickel arsenide and copper sulphide, and finally nickel arsenide accompanied by nickel-copper arsenide, copper arsenide and uranium silicates. Petrographic observations demonstrate that these alteration products also formed prior to compaction. Consideration of the published history for the region indicates that maximum compaction of the rocks will have occurred by at least the Lower Jurassic (i.e. over 176 Ma ago). Since that time the copper sheets have remained isolated by the compacted mudstones and were unaffected by further corrosion until uplift and exposure to present-day surface weathering

  19. Impacts of a massive release of methane and hydrogen sulfide on oxygen and ozone during the late