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Sample records for Permian Basin

  1. Exploratory shaft facility preliminary designs - Permian Basin

    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. On the origin of the Southern Permian Basin, Central Europe

    J.-D. van Wees; Stephenson, R.A.; Ziegler, P. A.; Ulf Bayer; McCann, T; R. Dadlez; Gaupp, R; M. Narkiewicz; F. Bitzer; Scheck, M.;  

    2000-01-01

    A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the Rotliegend-Zechstein development of this basin. The Late Permian-Early Jurassic tectonic subsidence curves are typical for a Permian to Early Triassic extensional stage that is followed by thermal subsidence. Howe...

  3. Permian Basin location recommendation report

    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

  4. Lower Permian Dry Mountain trough, eastern Nevada: preliminary basin analysis

    Schwarz, D.L.; Snyder, W.S.; Spinosa, C.

    1987-08-01

    The Lower Permian Dry Mountain trough (DMT) is one of several basins that developed during the Late Pennsylvanian to Permian along the western edge of the North American continent. A tectonic mechanism has been suggested for the subsidence of the DMT, possibly due to reactivation of the Antler orogenic belt during the waning stages of Ancestral Rocky Mountain deformation. The DMT records marked subsidence with the appearance during the Artinskian (latest Wolfcampian) of a deeper water facies that consists of thin-bedded silty micrites and micritic mudstones rich in radiolarians and sponge spicules, characterized by a relative abundance of ammonoids, and rarer conodonts and Nereites ichnofacies trace fossils. Taxa recovered from a distinctive concretionary horizon at various locations provide an Artinskian datum on which to palinspastically reconstruct the DMT paleogeography. These taxa include ammonoids: Uraloceras, Medlicottia, Marathonites, Crimites, Metalegoceras, properrinitids; and conodonts: Neogondolella bisselli, Sweetognathus whitei, S. behnkeni, and Diplognathodus stevensi. The western margin facies of the DMT consists of Permian Carbon Ridge/Garden Valley Formations. Here, lowermost black Artinskianage euxinic micrites, considered a potential source rock for petroleum generation, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by a thick, eastwardly prograding conglomerate wedge. Seismic profiles across Diamond Valley indicate a 3.0-4.6-km thick Tertiary sequence above the Paleozoic strata.

  5. Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

    Gen-Yao Wu

    2014-01-01

    One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust. The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples. The Dalandzadgad ocean subducted southwards during the Silurian-Devonian, created an intra-oceanic arc and a backarc basin in southern Mongolia. In addition, a continent marginal arc formed along the national boundary between China and Mongolia, the south of which was a backarc basin. The oceanic basin closed and arc-arc (continent) collision occurred dur-ing the early Early Permian, followed by two residual marine basins developing in the former backarc regions, named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia. The Solonker ocean subducted southwards and ifnally disappeared during the early Middle Permian. Afterwards, two residual marine basins occurred in northern China, the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region. The late Middle Permian was the most optimum period for the de-veloping residual marine basins, when they covered a vast area. The basin evolution differenti-ated during the early Late Permian, with a general trend of uplift in the east and of subsidence in the west. The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal ifelds. A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian. Correspondingly, the coal formation entered a lfourishing time, with thick coal beds and sedimentary interbeds. All of these basins, namely, both the marine and non-marine residual basins, reversed and closed by the end of Permian.

  6. Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

    Gen-Yao; Wu

    2014-01-01

    One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust.The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples.The Dalandzadgad ocean subducted southwards during the Silurian-Devonian,created an intra-oceanic arc and a backarc basin in southern Mongolia.In addition,a continent marginal arc formed along the national boundary between China and Mongolia,the south of which was a backarc basin.The oceanic basin closed and arc-arc(continent) collision occurred during the early Early Permian,followed by two residual marine basins developing in the former backarc regions,named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia.The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian.Afterwards,two residual marine basins occurred in northern China,the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region.The late Middle Permian was the most optimum period for the developing residual marine basins,when they covered a vast area.The basin evolution differentiated during the early Late Permian,with a general trend of uplift in the east and of subsidence in the west.The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields.A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian.Correspondingly,the coal formation entered a flourishing time,with thick coal beds and sedimentary interbeds.All of these basins,namely,both the marine and nonmarine residual basins,reversed and closed by the end of Permian.

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

    Olsen, D.K.; Johnson, W.I.

    1993-05-01

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

    Olsen, D.K.; Johnson, W.I.

    1993-05-01

    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.

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

    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

  10. Tectonic Evolution of the Junggar Foreland Basin in the Late Carboniferous-Permian

    2001-01-01

    A comprehensive study has been carried out to subdivide andcorrelate the Upper Carboniferous and Permian sedimentary successions in the Junggar basin based on outcrops and drilling and geophysical data. The study results, combined with geological analyses of the basin's periphery and the basement, as well as studies of the sedimentary rocks within the basin, the unconformities, tectonic geometry, kinematics and geodynamics, lead to the conclusion that the Junggar basin was characterized by the development of foreland basin systems during the Late Carboniferous and Per mian, During that period, three foreland basin systems were developed: (1) the northwest foreland basin system, which trended nearly north-south from Mahu to the Chepaizi Palaeo-mountain during its early stage of development and thus it was also referred to as the west foreland basin system; (2) the Karamaili foreland basin system in the east and (3) the Northern Tianshan foreland basin system in the south. These systems are different in size, development stage and time of formation. The first two are developed earlier than the third, but they are smaller in size. All the structures in the Junggar basin have resulted from the integration and superposition of structural elements in the above three systems. In general, the development of the Junggar basin can be divided into four stages. Stage I was marked by the creation and evolution of the marginal western foreland and the peripheral Karamaili foreland basin systems during the Late Carboniferous-early Early Permian (C3-Pja). Stage Ⅱ was characterized by the development of complicated foreland basin systems during the mid dle-late Early Permian (Pjb-Pf) when the three foreland basin systems took their shapes. Stage Ⅲ was the integration stage of peripheral foreland basin systems during the Middle Permian (P2) in which steady and slow tectonic subsidence prevailed. Stage Ⅳ coincided with the shrinking of foreland basin development during the Late

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

    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.

  12. Palaeotopography-governed sediment distribution—a new predictive model for the Permian Upper Rotliegend in the Dutch sector of the Southern Permian Basin

    Mijnlieff, H.F.; Geluk, M.

    2011-01-01

    The Southern Permian Basin (SPB) formed a large, elongated saucer-shaped inland depression extending from the UK to Poland and from Belgium to Denmark. During the Middle to early Late Permian the SPB was filled progressively by playa sediments from its centre in northwestern Germany before it was fl

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

    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.

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

    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.

  15. The flora of Early Permian coal measures from the Parana Basin in Brazil: A review

    Iannuzzi, Roberto [Centro de Investigacoes do Gondwana, Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, Porto Alegre, RS, 91.509-900 (Brazil)

    2010-08-01

    This paper presents an updated overview integrating both previous and newly published data on the most important floras found associated with Early Permian coal seams in the Parana Basin, Brazil. These floras occur within the Rio Bonito Formation and correspond to the Gondwana ''Glossopteris Flora.'' For this review, five floras are selected, in ascending stratigraphic order: the ''Sao Joao do Triunfo,'' ''Figueira,'' ''Quiteria,'' ''Morro do Papaleo'' and ''Irapua Bed'' floras. They are the best-known floras of the basin in terms of taxonomic composition, paleoecology and environments of deposition. An early-mid Sakmarian to earliest Artinskian age is indicated for the Rio Bonito Formation based on absolute radiometric and relative biostratigraphic ages. Integration of available information about the selected floras allows evaluation of taphonomic and paleoecological factors to provide a more comprehensive understanding of the Early Permian floral record in the Parana Basin. The variation observed in both the taxonomic composition of individual floras and in the frequency of occurrence of different plant groups is due to the broad range of environmental/edaphic conditions that prevailed in the many different depositional settings represented in the Rio Bonito Formation. A more precise age determination obtained for the plant-bearing deposits permits the establishment of a more confident correlation between the Early Permian floral succession in the Parana Basin and other Early Permian floral successions in other basins. The Sakmarian global warming favored the appearance of pecopterid and sphenopterid ferns amongst the spore-producing plants, and the glossopterids amongst the pollen-producing plants. (author)

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

    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.

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

    Ivan Mlakar

    2003-01-01

    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...

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

    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.

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

    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

  20. Schematic designs for penetration seals for a repository in the Permian Basin. [Deaf Smith County, Texas

    Kelsall, P.C.; Case, J.B.; Coons, W.E.; Franzone, J.G.; Meyer, D.

    1985-12-01

    The isolation of radioactive wastes in geologic repositories requires that human-made penetrations such as shafts, tunnels, or boreholes are adequately sealed. This report describes schematic seal designs for a repository in bedded salt referenced to the stratigraphy of the Permian Basin. The designs are presented for extensive peer review and will be updated as conceptual designs if the Permian Basin is selected as a candidate repository site. The principal material used in the seal system in the repository-level rooms and tunnels is crushed salt obtained from excavating the repository. It is anticipated that crushed salt will consolidate in response to closure of the repository rooms, to the degree that mechanical and hydrologic properties will eventually match those of undisturbed, intact salt. For Permian Basin Unit 4 salt, analyses indicate that this process will require approximately 700 years for a seal located at the base of one of the repository shafts (where there is little increase in temperature due to waste emplacement) and approximately 200 years for a seal located in a main passageway within the repository. These analyses are based on uncertain laboratory data regarding intact salt creep rates and crushed salt consolidation characteristics, and must be regarded as preliminary. Bulkheads composed of concrete, as well as bentonite-rich earth fill, are also included in the seal system as components which will have low permeability during the period required for salt consolidation.

  1. Permian continental basins in the Southern Alps (Italy) and peri-mediterranean correlations

    Cassinis, Giuseppe; Perotti, Cesare R.; Ronchi, Ausonio

    2012-01-01

    The Late Carboniferous to Permian continental successions of the Southern Alps can be subdivided into two main tectono-sedimentary Cycles, separated by a marked unconformity sealing a Middle Permian time gap, generally estimated at over 10 Ma. The lower cycle (1), between the Variscan crystalline basement and the Early Permian, is mainly characterised by fluvio-lacustrine and volcanic deposits of calc-alkaline acidic-to-intermediate composition, which range up to a maximum thickness of more than 2,000 m. The upper cycle (2), which is devoid of volcanics, is mostly dominated through the Mid?-Late Permian by alluvial sedimentation which covered the previous basins and the surrounding highs, giving rise to the subaerial Verrucano Lombardo-Val Gardena (Gröden) red-beds, up to about 800 m thick. The palaeontological record from the terrigenous deposits of both the above cycles consists mainly of macro- and microfloras and tetrapod footprints. The age of the continental deposits is widely discussed because of the poor chronological significance of a large number of fossils which do not allow reliable datings; however, some sections are also controlled by radiometric calibrations. The comparison with some selected continental successions in southern Europe allows to determine their evolution and set up correlations. A marked stratigraphic gap shows everywhere between the above-mentioned Cycles 1 and 2. As in the Southern Alps, the gap reaches the greatest extent during the Mid-Permian, near the Illawarra Reversal geomagnetic event (265 Ma). In western Europe, however, such as in Provence and Sardinia, the discussed gap persists upwardly to Late Permian and Early Triassic or slightly younger times, i.e. to the onset of the "Alpine sedimentary Cycle", even though in northeastern Spain (Iberian Ranges, Balearic Islands) this gap results clearly interrupted by late Guadalupian-Lopingian deposits. The above two major tectonosedimentary cycles reflect, in our view, two main

  2. Geology, geochemistry and petrophysics of the Woodford Shale, Permian Basin, west Texas

    Harris, N.B.; Hemmesch, N.T.; Mnich, C.A. [Colorado School of Mines, Golden, CO (United States). Dept. of Geology and Geological Engineering; Aoudia, K.; Miskimins, J. [Colorado School of Mines, Golden, CO (United States). Dept. of Petroleum Engineering

    2009-07-01

    Sequence stratigraphic analysis can be done on black shales, however it requires an integrated multidisciplinary approach. Sea-level cycles are expressed even in the middle of a shale basin and are expressed in lithofacies, mineralogy, geochemistry and well logs. The cycles are important for shale gas, impacting gas generation, storage and fracture development. Geology, geochemistry and petrophysics of the Woodford Shale, located in the Permian Basin of west Texas were discussed in this presentation. Specifically, the presentation discussed the stratigraphy in a black shale, motivation for rock properties research, and factor analysis results. It was concluded that cycles affect gas generation capacity and rock properties. tabs., figs.

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

    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

  4. Socioeconomic data base report for the Permian Basin

    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

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

    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.

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

    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

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

    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.

  8. Assessment of undiscovered copper resources associated with the Permian Kupferschiefer, Southern Permian Basin, Europe: Chapter U in Global mineral resource assessment

    Zientek, Michael L.; Oszczepalski, Sławomir; Parks, Heather L.; Bliss, James D.; Borg, Gregor; Box, Stephen E.; Denning, Paul D.; Hayes, Timothy S.; Spieth, Volker; Taylor, Cliff D.

    2015-01-01

    This study synthesizes available information and estimates the location and quantity of undiscovered copper associated with a late Permian bituminous shale, the Kupferschiefer, of the Southern Permian Basin in Europe. The purpose of this study is to (1) delineate permissive areas (tracts) where undiscovered reduced-facies sediment-hosted stratabound copper deposits could occur within 2.5 kilometers of the surface, (2) provide a database of known reduced-facies-type sediment-hosted stratabound copper deposits and significant prospects, and (3) provide probabilistic estimates of amounts of undiscovered copper that could be present within each tract. This assessment is a contribution to a global assessment conducted by the U.S. Geological Survey (USGS).

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

    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

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

    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

  11. Upper Permian magnetic stratigraphy of the lower Beaufort Group, Karoo Basin

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

    2013-08-01

    We carried out a magnetostratigraphic and geochronological study of late Permian sediments in the Karoo Basin of the Western Cape Province, South Africa. A continuous, ~700 m thick section of deltaic sediments of the upper Waterford Formation (uppermost Ecca Group) and the fluvial sediments of the Abrahamskraal Formation (lowermost Beaufort Group) were sampled at the meter scale. U-Pb dating of zircons from interbedded volcanic ash beds by ion microprobe (SHRIMP) provided absolute age constraints on the age of the sedimentary rocks. Paleomagnetic analysis reveals a partial overprint of the Natural Remanent Magnetization (NRM) that is tentatively ascribed to the emplacement of the Karoo Large Igneous Province in the Western Cape region during the middle Jurassic. A stable component of the NRM was found at temperatures higher than 450 °C and was interpreted as a Characteristic Remanent Magnetization (ChRM) acquired during deposition, supported by a positive reversals test for this dual polarity ChRM. The virtual geomagnetic pole position for the Waterford and Abrahamskraal Formations computed from the average ChRM direction is in general agreement with the late Permian directions for stable Gondwana. A significantly different average inclination, and thus paleomagnetic pole position, is obtained by correcting the inclination shallowing error by the Elongation-Inclination method (Tauxe and Kent, 2004). The presence of both normal and reversed polarity zones indicate deposition after the end of the Kiaman Superchron, moreover the polarity sequence is in good agreement with the Illawarra sequence of Steiner (2006). Our results indicate a Capitanian (late Guadalupian) age for the Abrahamskraal Fm., in agreement with the Late Permian age, based on presence of Glossopteris flora and Dicynodont fauna, traditionally assigned to the fluvial-lacustrine sediments of the Beaufort Group. However, the U-Pb zircon ages of ca. 264-268 Ma suggest an age of 269 Ma for the top of the

  12. Palynomorphs of Permian Gondwana coal from borehole GDH-38, Barapukuria Coal Basin, Bangladesh

    Akhtar, A.; Kosanke, R.M. [Geological Survey of Bangladesh, Dhaka (Bangladesh)

    2000-07-01

    Thirty-two core samples of Permian Gondwana coal from three coal beds of borehole GDH-38, Barapukuria Coal Basin, Dinajpur, Bangladesh, were collected for palynological analysis. The lower coal bed (331.5-372.5 m) can easily be differentiated from the upper two coal beds by the presence of Alisporites, Cordaitina, Corisaccites, Hamiapollenites, Leuckisporites, Nuskoisporites, Tumoripollenites, Vestgisporites and Vittatina. It is difficult to palynologically differentiate the middle (198.1-208 m) and upper (162.3-172.9 m) coal beds as they contain a very limited number of specimens by which they can be identified. The middle bed is distinguished by the presence of Microbaculispora and Weylandites and the upper bed by the presence of a single taxon Acanthotriletes. Some of the vesiculate or saccate taxa extracted from these coal beds are typical of those occurring in Permian strata of Gondwana in India, South Africa, South America, Russia, Australia and Antarctica. They are thought to be derived from Glossopteris flora, which is characterised by an abundance of Pteridospermic plants of the gymnosperm group.

  13. Palynomorphs of Permian Gondwana coal from borehole GDH-38, Barapukuria Coal Basin, Bangladesh

    Akhtar, A.; Kosanke, R. M.

    2000-07-01

    Thirty-two core samples of Permian Gondwana coal from three coal beds of borehole GDH-38, Barapukuria Coal Basin, Dinajpur, the north-northwestern part of Bangladesh, have been collected for palynological analysis. All samples except one yielded palynomorphs and some samples contain well-preserved and abundant palynomorphs of the gymnospermal and cryptogamic groups that are considered to be useful for future correlation studies. The lower coal bed (331.6-372.5 m) can easily be differentiated from the upper two coal beds by the presence of Alisporites, Cordaitina, Corisaccites, Hamiapollenites, Leuckisporites, Nuskoisporites, Tumoripollenites, Vestgisporites and Vittatina. It is difficult to palynologically differentiate the middle (198.1-208 m) and upper (162.3-172.9 m) coal beds as they contain a very limited number of specimens by which they can be identified. The middle bed is distinguished by the presence of Microbaculispora and Weylandites and the upper bed by the presence of a single taxon Acanthotriletes. Some of the vesiculate or saccate taxa extracted from these coal beds are typical of those occurring in Permian strata of Gondwana in India, South Africa, South America, Russia, Australia and Antarctica. They are thought to be derived from Glossopteris flora, which is characterised by an abundance of Pteridospermic plants of the gymnosperm group.

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

    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.

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

    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

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

    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.

  17. Identification of the Early Permian (Autunian) in the subsurface of the Ebro Basin, NE Spain, and its paleogeographic consequences

    Arche, A.; Díez, J.B.; López-Gómez, José

    2007-01-01

    [EN] The Early Permian (Autunian) has not been identifi ed up to now in the subsurface of the Tertiary Ebro Basin because of the scarcity of oil well boreholes reaching the Variscan basement and the systematic attribution of a Carboniferous age, without any paleontological data, to the unmetamorfosed siliciclastic sediments found at the base of some of them, clearly above the Early Paleozoic basement. Grey and black shale samples recovered from cores preserved in the REPSOL-YPF archi...

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

    2005-01-01

    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 Protohaploxy...

  19. Identification of the Early Permian (Autunian) in the subsurface of the Ebro Basin, NE Spain, and its paleogeographic consequences

    Arche, Alfredo; Diez Ferrer, José B.; López Gómez, José

    2007-01-01

    The Early Permian (Autunian) has not been identifi ed up to now in the subsurface of the Tertiary Ebro Basin because of the scarcity of oil well boreholes reaching the Variscan basement and the systematic attribution of a Carboniferous age, without any paleontological data, to the unmetamorfosed siliciclastic sediments found at the base of some of them, clearly above the Early Paleozoic basement. Grey and black shale samples recovered from cores preserved in the REPSOL-YPF archives o...

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

    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

  1. Palaeomagnetic data for Permian and Triassic rocks from drill holes in the Southern Sydney Basin, New South Wales

    Facer, R. A.

    1981-04-01

    A section 300 m thick across the Permian—Triassic boundary has been sampled in the Southern Coalfield of the Sydney Basin, New South Wales. 55 samples, mainly grey to drab sandstones, were collected from 9 diamond drill holes which penetrated the entire Narrabeen Group and the upper part of the conformably underlying Illawarra Coal Measures, as well as a sill emplaced into the coal measures. The samples included fully oriented cores. Additional reconnaissance samples from two further drill holes were also studied. Partial alternating field demagnetization and petrography indicate the magnetic remanence to be a stable DRM. Partial thermal demagnetization above 300°C or 400°C caused large increases in magnetic susceptibility. Partial chemical demagnetization did not cause significant changes in remanence directions. For the Coal Cliff Sandstone (basal Narrabeen Group, Triassic) the palaeomagnetic pole position (Normal) was calculated to be at 59°N 322°E (dp = 27°, dm = 29°), which agrees with previously published data. For the uppermost coal measures (Permian) the pole position was calculated as 58°N 340°E (dp = 09°, dm = 10°). Data for samples from the lower to middle coal measures yield a pole position which is between the new Permian—Triassic pole position and that for the underlying Middle Permian igneous rocks. The top of the Reversed "Kiaman Magnetic Interval" (Permian) may be near the Tongarra coal and Appin Formation boundary — (early) Late Permian.

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

    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.

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

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

    2010-01-01

    compositions of pyrites from the East Greenland Basin. The size distributions of framboidal pyrites in sediments from a continuous section across the Permian–Triassic boundary reveal that sulfidic conditions in water columns were established about 0.7 m above the extinction event in the East Greenland Basin...... 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...

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

    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

  5. Diagenesis and Fluid Flow History in Sandstones of the Upper Permian Black Jack Formation, Gunnedah Basin, Eastern Australia

    BAI Guoping; John B. KEENE

    2007-01-01

    The fluid flow history during diagenesis of sandstones in the Upper Permian Black Jack Formation of the Gunnedah Basin has been investigated through integrated petrographic observations, fluid inclusion investigations and stable isotope analyses. The early precipitation of mixed-layer illite/smectite, siderite, calcite, ankerite and kaolin proceeded at the presence of Late Permian connate meteoric waters at temperatures of up to 60℃. These evolved connate pore waters were also parental to quartz, which formed at temperatures of up to 87℃. The phase of maximum burial was characterized by development of filamentous illite and late calcite at temperatures of up to ~90℃. Subsequent uplifting and cooling led to deep meteoric influx from surface, which in turn resulted in dissolution of labile grains and carbonate cements, and formation of second generation of kaolin. Dawsonite was the last diagenetic mineral precipitated and its formation is genetically related to deep-seated mamagtic sourced CO2.

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

    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

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

    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

  8. Mixed volcanogenic-lithogenic sources for Permian bauxite deposits in southwestern Youjiang Basin, South China, and their metallogenic significance

    Yu, Wenchao; Algeo, Thomas J.; Du, Yuansheng; Zhang, Qilian; Liang, Yuping

    2016-07-01

    Bauxite deposits at the base of the Upper Permian Heshan Formation in the Youjiang Basin, South China, contain zircons with dominant age peaks at 263-262 Ma. During the Middle to Late Permian, the Youjiang Basin consisted of a number of isolated and attached carbonate platforms separated by inter-platform troughs. The bauxite deposits are limited to the isolated carbonate platform facies and are not present on attached carbonate platforms and inter-platform troughs. Discriminant plots based on the trace element composition of the zircons indicate a combination of within-plate/anorogenic and arc-related/orogenic sources. Geochemical and isotopic data suggest that the metallogenic materials of the bauxite deposit came from felsic volcanic rocks of the Emeishan Large Igneous Provence (ELIP) in South China and from the Truong Son volcanic arc located between the South China and Indochina cratons. The northwestern and southeastern parts of the Youjiang Basin received larger amounts of ELIP detritus and volcanic arc detritus, respectively. Coarser siliciclastic material in proximal attached carbonate platform and inter-platform trough settings was delivered by rivers, but finer siliciclastics that accumulated on distally located carbonate platforms in isolated deep-water areas was probably transported by wind.

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

    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

  10. A comparison of the Iberian and Ebro Basins during the Permian and Triassic, eastern Spain: A quantitative subsidence modelling approach

    Vargas, Henar; Gaspar-Escribano, Jorge M.; López-Gómez, José; Van Wees, Jan-Diederik; Cloetingh, Sierd; de La Horra, Raúl; Arche, Alfredo

    2009-09-01

    The Permian-Triassic sediments of the Iberian Plate are a well studied case of classical Buntsandstein-Muschelkalk-Keuper facies, with good sedimentological interpretations and precise datings based on pollen and spore assemblages, ammonoids and foraminifera. Synrift-postrift cycles are recorded in these facies, but there are only a few studies of quantitative subsidence analysis (backstripping method) and only a previous one using forward modelling for the quantification of synrift-postrift phases of this period. Here we present the results obtained by the quantitative analysis of fourteen field sections and oil-well electric log records in the Iberian and Ebro Basins, Spain. Backstripping analysis showed five synrift phases of 1 to 3 million years duration followed by postrift periods for the Permian-Triassic interval. The duration, however, shows lateral variations and some of them are absent in the Ebro Basin. The forward modelling analysis, assuming local isostatic compensation, has been applied to each observation point using one-layer and two-layer lithospheric configurations. The second one shows a better fit between observation and model prediction in a systematic way, so a two layer configuration is assumed for the sedimentary basin filling analysis. Lithospheric stretching factors β and δ obtained in the forward modelling analysis are never higher than 1.2, but sometimes β 1 in the same section. If surficial extension is compensated by deep compression either at the roots of the rift basins or in far-away zones is not yet clear, but this anomaly can be explained using a simple shear extensional model for the Iberian and Ebro basins.

  11. The Post-Permian evolution of the Northern Part of the North German Basin

    Hansen, M. B.; Huebscher, C.; Lykke-Andersen, H.; Gajewski, D.; Dehghani, A.; Reicherter, K.

    2004-12-01

    In the frame of the Priority Program 1135 of the German Research Foundation (DFG) "Dynamics of sedimentary systems under varying stress conditions by example of the Central European Basin System", the scientific goal of the NeoBaltic project is to describe the post-Permian to recent geological evolution of the entire western Baltic Sea region, with a special emphasis on neotectonic activity and it relation to salt dynamics. The western Baltic Sea comprises the northern part of the North German Basin (NGB), a part of the Central European Basin System (CEBS), and the transitional zone between the NGB and the Baltic Shield. In order to investigate these scientific goals the Universities of Aarhus (Denmark) and Hamburg (Germany) has since 1998 completed seven marine campaigns in the western Baltic Sea, collecting 2D high resolution seismic (HRS), gravity and magnetic data in the entire region during different projects. Since 2003 all these data has been available for the NeoBaltic project. All together the data pool have more than 7000 km HRS, 5000 km gravity and 4000 km magnetic data. Until now the project work has been focused on the completion of the data processing and the digital interpretation of important Mesozoic and Cenozoic markers on the seismic sections from the Bays of Kiel and Mecklenburg. Furthermore, several maps have been completed from the potential field data (gravity and magnetic). As a result of the digital interpretation of the HRS data, the overall geological evolution of the northern part of the NGB can be subdivided into four distinct periods. During the Triassic and the Early Jurassic, E-W extension and the deposition of clastic sediments initiated the movement of the underlying Zechstein evaporites. This is seen by the presence of several salt pillows in the region. The deposition ceased during the Middle Jurassic, when the entire area was uplifted, due to the Mid North Sea Doming. The uplift resulted in a pronounced erosion of Upper Triassic

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

    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

  13. Earthquake-controlled event deposits and its tectonic significance from the Middle Permian Wandrawandian Siltstone in the Sydney Basin, Australia

    DU; Yuansheng; G.; R.; Shi; GONG; Yiming

    2005-01-01

    The Sydney-Bowen basin in eastern Australia is an elongate back arc-converted foreland basin system situated between the Lachlan Fold Belt in the west and the New England Fold Belt in the east. The Middle Permian Wandrawandian Siltstone at Warden Head near Ulladulla in the southern Sydney Basin is dominated by fossiliferous siltstone and mudstone, with a large amount of dropstones and minor pebbly sandstone beds. Two general types of deposits are recognized from the siltstone unit in view of the timing and mechanism of formation. One is represented by the primary deposits from offshore to subtidal environments with abundant dropstones of glacial marine origin. The second type is distinguished by secondary, soft-sediment deformational deposits and structures, and comprises three layers of mudstone dykes of seismic origin. In the latter type, metre scale, laterally extensive syn-depositional slump deformation structures occur in the middle part of the Wandrawandian Siltstone. The deformation structures vary in morphology and pattern, including large-scale complex-type folds, flexural stratification, concave-up structures, faulting of small displacements accompanied by folding and brecciation. The slumps and associated syn-sedimentary structures are attributed to penecontemporaneous deformations of soft sediments (mostly silty mud) formed as a result of mass movement of unconsolidated and/or semi-consolidated substrate following an earthquake event. The occurrence of the earthquake event deposits supports the current view that the Sydney Basin was located in a back-arc setting near the New England magmatic arc on an active continental margin during the Middle Permian.

  14. 3D seismic interpretation of subsurface eruptive centers in a Permian large igneous province, Tazhong Uplift, central Tarim Basin, NW China

    Yang, Jiangfeng; Zhu, Wenbin; Guan, Da; Zhu, Beibei; Yuan, Liansheng; Xiang, Xuemei; Su, Jinbao; He, Jingwen; Wu, Xinhui

    2015-12-01

    A 1445-km2 high-resolution 3D seismic reflection dataset is used to analyze the Permian large igneous province in the subsurface of the Tazhong area in the central Tarim Basin in northwestern China. Constrained by the synthetic seismograms of four wells, the top and base of the igneous rocks were identified in the seismic data. Seven large volcanic craters, each >10 km2 in area, have been discovered via the application of coherency and amplitude attributes. The thickness and volume of the igneous rocks were obtained by time-depth transformation. In the study area, all of the igneous rocks, with thicknesses from 120 to 1133 m, were formed by eruptions in the Early Permian. These events produced huge erupted volumes (178 km3) and multiple closely spaced volcanic edifices (eruptive center of the Permian igneous rocks in the Tarim Basin.

  15. 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.

    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

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

    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

  17. 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

    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.

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

    Luiz Saturnino de Andrade

    2014-12-01

    Full Text Available Stratigraphic and facies analysis in the Filadélfia region, TO, BR, at the western of the Parnaíba 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.

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

    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.

  20. 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

    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

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

    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

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

    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.

  3. Lower Permian facies of the Palo Duro Basin, Texas: depositional systems, shelf-margin evolution, paleogeography, and petroleum potential

    Handford, C.R.

    1980-01-01

    A Palo geological study suggests that potential hydrocarbon reservoirs occur in shelf-margin carbonates, delta-front sandstones, and fan-delta arkoses. Zones of porous (greater than 10 percent) dolomite are concentrated near shelf margins and have configurations similar to productive Lower Permian shelf-margin trends in New Mexico. Delta-front sandstones (log-computed porosity of 18 to 25 percent) are similar to producing deltaic sandstones of Morris Buie-Blaco Fields in North-Central Texas. Porous (18 percent) fan-delta sandstones along the south flank of the Amarillo Uplift may form reservoirs similiar to that of the Mobeetie Field on the north side of the Amarillo Uplife in Wheeler County, Texas. Potential hydrocarbon source beds occur in slope and basinal environments. Total organic carbon generally ranges from 1 to 2.3 percent by weight and averages 0.589 percent by weight.

  4. On a moderately diverse continental ichnofauna from the Permian Ikakern Formation (Argana Basin, Western High Atlas, Morocco)

    Hminna, Abdelkbir; Voigt, Sebastian; Saber, Hafid; Schneider, Jörg W.; Hmich, Driss

    2012-06-01

    The Permian Ikakern Formation of the Argana Basin yielded important tetrapod skeletal remains but is still poorly known for any other kind of fossils. Here we present a moderately diverse assemblage of invertebrate and vertebrate traces from red beds in the upper part of the formation (Tourbihine Member, T2) near Timezgadiouine. Recorded ichnotaxa include Spongeliomorpha carlsbergi (Bromley and Asgaard, 1979), Striatichnium natalisWalter, 1982, AmphisauropusHaubold, 1970, HyloidichnusGilmore, 1927, ErpetopusMoodie, 1929, and DromopusMarsh, 1894. The traces occur in laminated muddy siltstone and fine-grained sandstone that we interpret as slack-water deposits in an episodically high energy fluvial setting. Including arthropod burrows, arthropod grazing traces and tetrapod footprints, the ichnofossil assemblage corresponds to the Scoyenia ichnofacies. The described trace fossils provide evidence for various invertebrates and vertebrates hitherto unknown from the body fossil record of the study area. By extending the stratigraphic and geographic range of some of the recorded ichnotaxa, our finds strongly emphasise the importance of the Argana Basin for the reconstruction and understanding of Late Palaeozoic terrestrial ecosystems.

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

    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.

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

    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

  7. A synthesis of palynological data from the Lower Permian Cerro Pelado Formation (Parana Basin, Uruguay): A record of warmer climate stages during Gondwana glaciations

    Beri, A.; Martínez-Blanco, X.; Mourelle, D.

    2010-01-01

    This paper presents a synthesis of the palynological record in the Cerro Pelado Formation deposits (Lower Permian, Paraná basin, Cerro Largo Department, north-eastern Uruguay) based on pre-existing data and new findings. The successions studied in this formation consist mainly of non-marine to glacial-marine mudstones and sandy mudstones. The palynological assemblages yielded by 32 samples collected from two outcrops and thirty borehole samples demonstrate that not significant floral changes ...

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

    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.

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

    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

  10. Sequence-Stratigraphic Framework from the Carboniferous to the Permian Chuanshanian Epoch in Dianqiangui Basin and Its Adjacent Areas, Southwest China

    Mei Mingxiang; Ma Yongsheng; Deng Jun; Meng Qingfen; Li Donghai

    2005-01-01

    The Carboniferous can be divided into four series in the Dianqiangui basin and its adjacent areas, Southwest China: the Yanguanian series, the Datangian series, the Weiningian series and the Mapingian series. The Maping Formation, traditionally used as the lithostratigraphic unit of the Upper Carboniferous, became an inter-system unit from the Carboniferous to the Permian. Thus, the top part of the Carboniferous and the bottom part of the Permian (Chuanshanian series) constitute a third-order sequence in the Dianqiangui basin and its adjacent areas. In the study area, the Carboniferous system and the Chuanshanian series of the Permian constitute a second-order sequence that can be subdivided into 6 third-order sequences. The bottom boundary of this second-order sequence is an unconformity formed in the principal episode of the Ziyun movement (the second episode), and the top boundary is also an unconformity formed in the principal episode of the Qiangui movement (the second episode). In different paleogeographical backgrounds, the strata from the Carboniferous to the Permian Chuanshanian epoch are marked by different sedimentary features. For example, coal measures and more dolomitic strata are developed in the attached platform; carbonate rocks mainly constitute the isolated platform strata; the inter-platform ditch strata are mainly composed of dark and fine sediments. Therefore, third-order sequences with different architectures of sedimentary-facies succession are formed in different paleogeographical backgrounds. Although the third-order sequences are different in the architecture of sedimentary-succession in space, the processes of their depositional environmental changes due to the third-order relative sea-level changes are simultaneous. Biostratigraphically, the surfaces of the third-order sequences can be correlated and traced in space; the framework of sequence stratigraphy from the Carboniferous to the Chuanshanian epoch of the Permian can be established

  11. Temporal variation in groundwater quality in the Permian Basin of Texas, a region of increasing unconventional oil and gas development.

    Hildenbrand, Zacariah L; Carlton, Doug D; Fontenot, Brian E; Meik, Jesse M; Walton, Jayme L; Thacker, Jonathan B; Korlie, Stephanie; Shelor, C Phillip; Kadjo, Akinde F; Clark, Adelaide; Usenko, Sascha; Hamilton, Jason S; Mach, Phillip M; Verbeck, Guido F; Hudak, Paul; Schug, Kevin A

    2016-08-15

    The recent expansion of natural gas and oil extraction using unconventional oil and gas development (UD) practices such as horizontal drilling and hydraulic fracturing has raised questions about the potential for environmental impacts. Prior research has focused on evaluations of air and water quality in particular regions without explicitly considering temporal variation; thus, little is known about the potential effects of UD activity on the environment over longer periods of time. Here, we present an assessment of private well water quality in an area of increasing UD activity over a period of 13months. We analyzed samples from 42 private water wells located in three contiguous counties on the Eastern Shelf of the Permian Basin in Texas. This area has experienced a rise in UD activity in the last few years, and we analyzed samples in four separate time points to assess variation in groundwater quality over time as UD activities increased. We monitored general water quality parameters as well as several compounds used in UD activities. We found that some constituents remained stable over time, but others experienced significant variation over the period of study. Notable findings include significant changes in total organic carbon and pH along with ephemeral detections of ethanol, bromide, and dichloromethane after the initial sampling phase. These data provide insight into the potentially transient nature of compounds associated with groundwater contamination in areas experiencing UD activity. PMID:27125684

  12. Latest Permian to Middle Triassic cyclo-magnetostratigraphy from the Central European Basin, Germany: Implications for the geomagnetic polarity timescale

    Szurlies, Michael

    2007-09-01

    In Central Germany, the about 1 km thick mainly clastic Germanic Lower Triassic (Buntsandstein) consists of about 60 sedimentary cycles, which are considered to reflect variability in precipitation within the epicontinental Central European Basin, most probably due to solar-induced short eccentricity cycles. They provide a high-resolution cyclostratigraphic framework that constitutes the base for creating a composite geomagnetic polarity record, in which this paper presents a Middle Buntsandstein to lowermost Muschelkalk magnetostratigraphy obtained from 6 outcrops and 2 wells where a total of 471 samples was collected. Combined with recently established records, a well-documented magnetostratigraphy for the upper Zechstein to lowermost Muschelkalk (latest Permian to Middle Triassic) of Central Germany has been constructed, encompassing an overall stratigraphic thickness of about 1.3 km and 22 magnetozones derived from about 2050 paleomagnetic samples. Along with available biostratigraphy, this multi-disciplinary study facilitates detailed links to the marine realm, in order to directly refer biostratigraphically calibrated Triassic stage boundaries as well as radioisotopic ages to the Buntsandstein cyclostratigraphy and, conversely, to contribute to calibrating the geologic timescale.

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

    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 east–northeast to west–southwest 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

  14. 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

    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

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

    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

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

    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

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

    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.

  18. Late Permian to Middle Triassic correlations and palaeogeographical reconstructions in south-western European basins: New sedimentological data from Minorca (Balearic Islands, Spain)

    Linol, Bastien; Bercovici, Antoine; Bourquin, Sylvie; Diez, José Bienvenido; López-Gómez, José; Broutin, Jean; Durand, Marc; Villanueva-Amadoz, Uxue

    2009-09-01

    Description of sedimentary sections and interpretations of sequence stratigraphic evolution of Permian-Triassic red beds of Minorca, allow a new proposal of palaeoenvironment reconstructions. The Permian sediments mainly correspond to floodplain and pond deposits with sheetflood sand-bed rivers (environment DE 1), within a warm and semi-arid climate, and the preserved succession forms one complete stratigraphic cycle. The retrogradational phase of this cycle is represented by alluvial/colluvial deposits grading upwards to environment DE 1 and to extensive floodplain and pond deposits. The progradational phase is characterized by increasing fluvial influence (with palaeocurrent mainly oriented to the SW), palaeosol horizons, and preservation of a Late Permian palynoflora. The uppermost part of this succession is truncated by a major erosional surface. The sediments above this unconformity are characterized by braided river deposits (environment DE 2) with palaeocurrent oriented to the SSW within the more basal conglomeratic facies and to the WNW in overlying units. The absence of extensive floodplain deposits, a paucity of evidence for biogenic activity and palaeosols, together with the presence of ventifacts indicate an arid climatic setting for the succession. This environment evolved from braided rivers (palaeocurrents mainly oriented to the SE, environment DE 3) with in situ palaeosols and reworked breccias to fluvial-coastal and shallow marine deposits (environment DE 4) dated as upper Anisian to Ladinian. This succession characterizes a retrogradational trend. Although the transition between DE 2 and DE 3 was not observed, a switch in palaeocurrent directions may indicate a change in source area. A comparison at a regional scale with other Peri-Tethyan basins allows the succession to be placed within a broader palaeoenvironmental and stratigraphic context during Late Permian to Middle Triassic. During the Late Permian, sedimentation occurred in alluvial, playa

  19. Age and significance of the Platypus Tuff Bed, a regional reference horizon in the Upper Permian Moranbah Coal Measures, north Bowen Basin

    Michaelsen, P.; Henderson, R.A.; Crosdale, P.J.; Fanning, C.M. [James Cook University of North Queensland, Townsville, Qld. (Australia). School of Earth Science

    2001-07-01

    The Platypus Tuff Bed in the Permian Moranbah Coal Measures provides a basin-wide marker horizon traceable for over 300 km along strike. The bed is a tephra event unit, the product of a large-scale volcanic eruptive episode involving a pyroclastic volume {gt} 10 km{sup 3}. The relatively even thickness of the tuff across the entire northern Bowen Basin implies a distant source. The tuff is ash-rich and its original geochemistry has been compromised by diagenetic alteration. Crystal content (10-15%) is dominated by quartz, suggesting a rhyolitic association. SHRIMP U-Pb analysis of zircons indicates an age of 258.9 +/- 2.7 Ma for the Platypus Tuff Bed, confirming the Late Permian age that has generally been assigned to the Blackwater Group. The age framework now apparent for the coal-bearing Blackwater Group suggests an average depositional rate ranging from about to 133 m/10{sup 6} years for its eastern depocentre in the northern Bowen Basin to similar to 70 m/10{sup 6} years in more marginal settings to the west.

  20. Age and significance of the Platypus Tuff Bed, a regional reference horizon in the upper Permian Moranbah coal measures, north Bowen Basin

    The Platypus Tuff Bed in the Permian Moranbah Coal Measures provides a basin-wide marker horizon traceable for over 300 km along strike. The bed is a tephra event unit, the product of a large-scale volcanic eruptive episode involving a pyroclastic volume > 10 km3. The relatively even thickness (∼1-1.5 m) of the tuff across the entire northern Bowen Basin (∼10 000 km2) implies a distant source. The tuff is ash-rich and its original geochemistry has been compromised by diagenetic alteration. Crystal content (10-15%) is dominated by quartz, suggesting a rhyolitic association. SHRIMP U-Pb analysis of zircons indicates an age of 258.9 ± 2.7 Ma for the Platypus Tuff Bed, confirming the Late Permian age that has generally been assigned to the Blackwater Group. The age framework now apparent for the coal-bearing Blackwater Group suggests an average depositional rate ranging from ∼133 m/106 years for its eastern depocentre in the northern Bowen Basin to ∼70 m/106 years in more marginal settings to the west. Copyright (2001) Geological Society of Australia

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

    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

  2. Liassic U-Pb age of the Rabejac pitchblende. Isotopic arguments for a Permian uraniferous preconcentration in the Lodeve basin (Herault)

    Lancelot, J.; Vella, V.

    Located in the basal part of the Saxonian formations of he Lodeve basin, the massive pitchblendes of the Rabejac ore deposit provide an age of 183 +- 4 Ma (Pb-Pb isochron), consistent with a Liassic mobilization of uranium in southern Massif central previously dated in the U ore deposits of Lodeve (Herault), Bertholene (Aveyron) and Pierres-Plantees (Lozere). This mobilization is related to the circulation of rather hot saline fluids (3-14%, 130-250/sup 0/C) induced by the tectonic phase of continental crust thinning (horsts, grabens, tilted blocks) which preceded the opening of the Ligurian-Piemontais ocean. Using Concordias diagrams we discuss the isotopic composition of the initial lead incorporated into the Rabejac pitchblendes during their cristallization which appears to have been radiogenic. This constitutes the first isotopic argument in favour of a primary U concentration during Permian times in the Lodeve basin.

  3. Sills, evaporites, and contact metamorphic gas generation in the Tunguska Basin, East Siberia: Implications for the end-Permian environmental crisis

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

    2016-04-01

    The emplacement of the Siberian Traps Large igneous province (LIP) through the Tunguska Basin is regarded as the main process triggering the end-Permian environmental crisis. Still, the lack of data from the Tunguska Basin represents one of the main challenges in understanding the link between the LIP formation and the crisis. Degassing from contact metamorphic aureoles in evaporites is suggested as a key factor to the continental mass extinction, but little is known about the actual distribution of sills and aureoles within these lithologies. Here, we present results from a borehole database with more than 700 wells in the Tunguska Basin, where 293 borehole sare studied in detail and presented. 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 studied boreholes contain sill intrusions. The sill thicknesses vary considerably from kilometer-scale intrusive complexes to individual thin sills of a few tens of meters. Thick sills are emplaced within the vast Cambrian salt formations, with average thicknesses in the 115-130 meter range. Petrographic investigations of metamorphic sediments, and thermal modelling of sediment heating, demonstrate high temperature devolatilization. Degassing to the atmosphere took place via explosive pipe degassing and gas 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.

  4. Depositional setting, petrology and chemistry of Permian coals from the Paraná Basin: 2. South Santa Catarina Coalfield, Brazil

    Kalkreuth, W.; Holz, M.; Mexias, A.; Balbinot, M.; Levandowski, J.; Willett, J.; Finkelman, R.; Burger, H.

    2010-01-01

    In Brazil economically important coal deposits occur in the southern part of the Paran?? Basin, where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina. The current paper presents results on sequence stratigraphic interpretation of the coal-bearing strata, and petrological and geochemical coal seam characterization from the South Santa Catarina Coalfield, Paran?? Basin.In terms of sequence stratigraphic interpretation the precursor mires of the Santa Catarina coal seams formed in an estuarine-barrier shoreface depositional environment, with major peat accumulation in a high stand systems tract (Pre-Bonito and Bonito seams), a lowstand systems tract (Ponta Alta seam, seam A, seam B) and a transgressive systems tract (Irapu??, Barro Branco and Treviso seams).Seam thicknesses range from 1.70 to 2.39. m, but high proportions of impure coal (coaly shale and shaley coal), carbonaceous shale and partings reduce the net coal thickness significantly. Coal lithoypes are variable, with banded coal predominant in the Barro Branco seam, and banded dull and dull coal predominantly in Bonito and Irapu?? seams, respectively. Results from petrographic analyses indicate a vitrinite reflectance range from 0.76 to 1.63 %Rrandom (HVB A to LVB coal). Maceral group distribution varies significantly, with the Barro Branco seam having the highest vitrinite content (mean 67.5 vol%), whereas the Irapu?? seam has the highest inertinite content (33.8. vol%). Liptinite mean values range from 7.8. vol% (Barro Branco seam) to 22.5. vol% (Irapu?? seam).Results from proximate analyses indicate for the three seams high ash yields (50.2 - 64.2wt.%). Considering the International Classification of in-Seam Coals, all samples are in fact classified as carbonaceous rocks (>50wt.% ash). Sulfur contents range from 3.4 to 7.7 wt.%, of which the major part occurs as pyritic sulfur. Results of X-ray diffraction indicate the

  5. Sequence-stratigraphic frameworks and their palaeogeographic patterns for the Permian Lopingian of the Dianqiangui Basin and its adjacent areas of Southwestern China

    2007-01-01

    The Permian Lopingian in the Dianqiangui Basin and its adjacent areas is marked by the coal measures of the Wuchiapingian and the carbonate strata of the Changhsingian stages. For the Lopingian of the Dianqiangui Basin and its adjacent areas,the diversity of sedimentary facies and the obviousness of facies change provide an advantaged condition on a study of sequence stratigraphy. Approximately,the Wuchiapingian stage constitutes a third-order sequence and the Changhsingian stage forms an-other. For the Wuchiapingian stage in the study area,coal-measures were developed on the attached platform and,in addition,a special coal-measure that is composed of both limestone beds and coal beds was also developed in the central part of some isolated platforms. Grain-bank grainstones and packstones were formed on the margin of the attached platform as well as in the windward part of iso-lated platforms. For the Changhsingian stage in the study area,open-platform limestones were formed on the attached platform,while sponge-reef limestones were developed both on the margin of the at-tached platform and on the isolated platforms. The Lopingian Series is a set of basin-facies muddy shales with interbeds of silicalites in the inter-platform basin,which appears a set of the large-thick coarse clastic strata of molasses covering direct the deep-water strata from the Devonian to the Per-mian Yangsingian in the Qinzhou-Fangcheng region in the southern part of the study area. All of these features indicate the complexity of temporal-spatial facies-changes. Sequence-stratigraphic frame-works could be established,which would illustrate two types of facies-changing surfaces and dia-chronisms in the stratigraphic records,based on the combination of both biostratigraphic and chronostratigraphic materials and the regularity reflected by temporal evolutionary succession of sediments as well as spatial distributional patterns of sedimentary facies. Ultimately,features of sedi

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

    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.

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

    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.

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

    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 Paraná 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 Análise morfológica das sementes tem sido um importante objeto em estudos ecológicos modernos, uma vez que fornece evidências sobre a biologia e as adaptações das plantas-mãe de sementes. Entretanto, este tipo de estudo tem sido restrito a ecologia de plantas modernas e é raramente utilizado em interpretações de dados paleozóicos. A partir do entendimento da análise das sindromes de dispersão como uma importante ferramenta para reconstruções paleoecológicas, este estudo oferece uma primeira abordagem utilizando essa ferramenta com sementes do Permiano Inferior do Sul da

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

    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.

  10. Permian paleogeography of west-central Pangea: Reconstruction using sabkha-type gypsum-bearing deposits of Parnaíba Basin, Northern Brazil

    Abrantes, Francisco R.; Nogueira, Afonso C. R.; Soares, Joelson L.

    2016-07-01

    Extreme aridity during Late Permian - Early Triassic period was the main factor for resetting the entire paleoclimate of the planet. Permian evaporite basins and lacustrine red beds were widely distributed along the supercontinent of Pangea. Sulphate deposits in Western Pangea, particularly in Northern Brazil, accumulated in an extensive playa lake system. Outcrop-based facies and stratigraphic analysis of up to 20 m thick evaporite-siliciclastic deposits reveal the predominance of laminated reddish mudstone with subordinate limestone, marl and lenses of gypsum. The succession was deposited in shallow lacustrine and inland sabkha environments associated with saline pans and mudflats. Gypsum deposits comprise six lithofacies: 1) bottom-growth gypsum, 2) nodular/micronodular gypsum, 3) mosaic gypsum, 4) fibrous/prismatic gypsum, 5) alabastrine gypsum, and 6) rosettes of gypsum. Gypsum types 1 and 2 are interpreted as primary deposition in saline pans. Bottom-growth gypsum forms grass-like crusts while nodular/micronodular gypsum indicates displacive precipitation of the crust in shallow water and the groundwater capillary zone. Types 3 and 4 are early diagenetic precipitates. Abundant inclusions of tiny lath-like anhydrite crystals suggest a primary origin of anhydrite. Alabastrine gypsum, fibrous gypsum (satinspar) and rosettes of gypsum probably derived from near-surface hydration of anhydrite. The gypsum-bearing deposits in the Parnaíba Basin contribute towards understanding paleogeographic changes in Western Pangea. A progressive uplift of East Pangea, culminated in the forced regression and retreat of epicontinental seas to the West. Restricted seas or large lakes were formed before the definitive onset of desert conditions in Pangea, leading to the development of extensive ergs.

  11. Paleoenvironmental reconstitution of Motuca and Sambaíba formations, Permian-Triassic of the Parnaíba Basin in southwest Maranhão state, Brazil

    Francisco Romério Abrantes Júnior

    2013-09-01

    Full Text Available The interval between the Late Paleozoic and Early Mesozoic was marked by paleogeographic and paleoclimatic global changes, partly attributed to catastrophic events. The intense continentalization of the supercontinent Pangaea of End-Permian propitiated the development of extensive deserts that succeeded the coastal and platform environments of Early Permian. The records of these events in northern Brazil are found in intracratonic basins, particularly in the Permo-triassic succession of the Parnaíba Basin. The facies and stratigraphic outcrops analysis of this succession allowed the individualization of 14 sedimentary facies grouped into four facies associations (FA: FA1 and FA2 related to deposits of Motuca Formation and, FA3 and FA4, representative of the base of Sambaíba Formation. The FA1 – Shallow lake/Mudflat consists of red laminated mudstone with lenses of gypsum, calcite and marl, besides lobes of sigmoidal sandstones. The FA2 – Saline pan consists of lenticular bodies of laminated gypsum, nodular gypsum and gypsarenite, overlapped by greenish mudstones with dolomite nodules and palygorskite. The FA3 – sand sheet and FA4 – dunes field are formed, respectively, for orange cream sandstones with even parallel stratification and medium- to large-scale cross-bedding. In the contact between Motuca and Sambaíba formations occurs a deformed interval, laterally continuous for hundreds of kilometers. Brecciated and contorted bedded siltstones and mudstone (Motuca Formation and sandstone with sinsedimentary faults/microfaults, convolute lamination and mud-filled injection dykes (Sambaíba Formation are interpreted as seismites triggered by high magnitude earthquakes (> 8 according Richter scale.

  12. États de contraintes et mécanismes d'ouverture et de fermeture des bassins permiens du Maroc hercynien. L'exemple des bassins des Jebilet et des RéhamnaStates of stresses and opening/closing mechanisms of the Permian basins in Hercynian Morocco. The example of the Jebilet and Réhamna Basins

    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.

  13. 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

    Benito, M. Isabel; De la Horra, Raúl; López-Gómez, José; Barrenechea, José F.; Luque, Javier; Arche, Alfredo

    2011-06-01

    This work is focused on carbonate paleosols developed in three stratigraphic sections (Landete, Talayuelas and Henarejos) of the Middle-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 closer to the basin boundary fault than the other two sections. The mineralogy and texture of the carbonate precursor of paleosols in the three studied sections are not preserved because original carbonate is replaced by coarse crystals of dolomite and/or magnesite. Dolomite crystals are typically euhedral, displaying rhombohedral shapes and reddish luminescence, although in the Henarejos section dolomite displays non-planar boundaries and frequently saddle habit. Micas are deformed and adapted to dolomite crystals, which, in turn, are affected by stylolites, suggesting that dolomite precipitated before mechanical and chemical compaction. Carbon and oxygen isotopic compositions of dolomite from the three sections show different values (δ 13C VPDB mean values = - 6.7‰, - 5.5‰ and - 7.5‰; δ 18O VPDB mean values = - 4.0‰; -5.6‰ and - 8.2‰, at Landete, Talayuelas and Henarejos sections, respectively). The 87Sr/ 86Sr ratios are similar in the three sections yielding values between 0.71391 and 0.72213. The petrographic and geochemical features of dolomite in the three studied sections suggest precipitation from similar fluids and during shallow burial diagenesis. Assuming that the minimum temperature for dolomite precipitation in the Henarejos section was 60 °C (as suggested by the presence of non-planar saddle habit), and that the dolomitizing fluid had similar δ 18O values at the three localities, then dolomite in the Talayuelas and Landete sections precipitated at temperatures

  14. A preliminary biogeochemistry-based quantification of primary productivity of end-Permian deep-water basin in Dongpan Section ,Guangxi ,South China

    ZHANG Yang; HE Weihong; FENG Qinglai

    2007-01-01

    In this Paper,the mean primary productivity of the Talung Formation in the deep-water basin(50-500 m depth)of Dongpan,Guangxi,South China,was calculated,of the content of the trace element Cu.Results showed that the primary productivity obtained was comparable with the previously-reported data for the black shale of the Phosphoria Formation,a Permian phosphate deposit in the northwest United States,and also similar to that of the modern deposit in the Cariaco basin,Venezuela.It was observed that the primary productivity increased with the enhanced abundance of algae and photosynthetic bacteria,and with the decrease in both the radiolarian individuals and the body size of brachiopods during the faunal mass extinction.This ecological coupling indicates that the changes of primary productivity are closely related to the propagation and the decline of producers(algae and bacteria),and that consumers(radiolarians and brachiopods)probably have little influence on the changes of primary productivity.

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

    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

  16. 300-Myr-old magmatic CO2 in natural gas reservoirs of the west Texas Permian basin.

    Ballentine, C J; Schoell, M; Coleman, D; Cain, B A

    2001-01-18

    Except in regions of recent crustal extension, the dominant origin of carbon dioxide in fluids in sedimentary basins has been assumed to be from crustal organic matter or mineral reactions. Here we show, by contrast, that Rayleigh fractionation caused by partial degassing of a magma body can explain the CO2/3He ratios and delta13C(CO2) values observed in CO2-rich natural gases in the west Texas Val Verde basin and also the mantle 3He/22Ne ratios observed in other basin systems. Regional changes in CO2/3He and CO2/CH4 ratios can be explained if the CO2 input pre-dates methane generation in the basin, which occurred about 280 Myr ago. Uplift to the north of the Val Verde basin between 310 and 280 Myr ago appears to be the only tectonic event with appropriate timing and location to be the source of the magmatic CO2. Our identification of magmatic CO2 in a foreland basin indicates that the origin of CO2 in other mid-continent basin systems should be re-evaluated. Also, the inferred closed-system preservation of natural gas in a trapping structure for approximately 300 Myr is far longer than the residence time predicted by diffusion models. PMID:11201738

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

    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

  18. 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

    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.

  19. Latest Permian to Middle Triassic cyclo-magnetostratigraphy from the Central European Basin, Germany: Implications for the geomagnetic polarity timescale

    Michael Szurlies

    2007-01-01

    In Central Germany, the about 1 km thick mainly clastic Germanic Lower Triassic (Buntsandstein) consists of about 60 sedimentary cycles, which are considered to reflect variability in precipitation within the epicontinental Central European Basin, most probably due to solar-induced short eccentricity cycles. They provide a high-resolution cyclostratigraphic framework that constitutes the base for creating a composite geomagnetic polarity record, in which this paper presents a Middle Buntsands...

  20. 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?

    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

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

    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

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

    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.

  3. Rock-physics-based carbonate pore type characterization and reservoir permeability heterogeneity evaluation, Upper San Andres reservoir, Permian Basin, west Texas

    Dou, Qifeng; Sun, Yuefeng; Sullivan, Charlotte

    2011-05-01

    In addition to mineral composition and pore fluid, pore type variations play an important role in affecting the complexity of velocity-porosity relationship and permeability heterogeneity of carbonate reservoirs. Without consideration of pore type diversity, most rock physics models applicable to clastic rocks for explaining the rock acoustic properties and reservoir parameters relationship may not work well for carbonate reservoirs. A frame flexibility factor ( γ) defined in a new carbonate rock physics model can quantify the effect of pore structure changes on seismic wave velocity and permeability heterogeneity in carbonate reservoirs. Our study of an Upper San Andres carbonate reservoir, Permian Basin, shows that for core samples of given porosity, the lower the frame flexibility factor ( γ), the higher the sonic wave velocity. For the studied reservoir, samples with frame flexibility factor ( γ) 3.85 indicate either dominant interparticle pore space in dolopackstone or microcrack pore space in dolowackstone or dolomudstone. Using the frame flexibility factor ( γ), different porosity-impedance and porosity-permeability trends can be classified with clear geologic interpretation such as pore type and rock texture variations to improve porosity and permeability prediction accuracy. New porosity-permeability relations with γ classification help delineate permeability heterogeneity in the Upper San Andres reservoir, and could be useful for other similar carbonate reservoir studies. In addition, results from analysis of amplitude variation with offset (AVO) and impedance modeling indicate that by combining rock physics model and pre-stack seismic inversion, simultaneous estimation of porosity and frame flexibility factor ( γ) is quite feasible because of the strong influence of carbonate pore types on AVO especially when offset is large.

  4. Late Permian paleomagnetic results from the Lodève, Le Luc, and Bas-Argens Basins (southern France): Magnetostratigraphy and geomagnetic field morphology

    Evans, M. E.; Pavlov, V.; Veselovsky, R.; Fetisova, A.

    2014-12-01

    Paleomagnetic results are presented from 271 stratigraphically-ordered horizons at four locations in southern France. Our focus is mainly on the Late Permian (258 horizons), but results from 13 horizons in the Triassic Buntsandstein are also reported. We argue that the Permian results extend magnetostratigraphic coverage up to the upper Capitanian Stage, some 6 million years after the end of the Permo-Carboniferous Reversed Superchron defined by the Illawarra Reversal in the Wordian Stage. When combined with published data, an overall mean paleopole at 49°N, 161°E (A95 = 4°, N = 9) is obtained. This is virtually identical to the upper Permian pole obtained by Bazhenov and Shatsillo (2010) using the intersecting great-circle method. Agreement between the two procedures, which are based on entirely independent data, supports the geocentric axial dipole (GAD) model.

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

    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

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

    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.

  7. 川西北二叠系栖霞组小有孔虫动物群%Non-fusulinid Foraminiferal Fauna from the Permian Chihsia Formation,Northwestern Sichuan Basin

    张舟; 张廷山; 蓝光志

    2011-01-01

    川西北广元旺苍王家沟剖面二叠系栖霞组小有孔虫动物群由14属27种组成(含比较种、亚种而不含未定种),其中Globivalvulina属及Palaeotextularidae科的物种分异度最高,合计约占总种数的50%.在系统分类的基础上,建立了Globivalvulina组合,作为识别该区二叠纪最大海进时期的标志性动物群.通过对该剖面栖霞组小有孔虫动物群的研究,不仅丰富了四川盆地二叠纪有孔虫的资料,而且为川西北王家沟剖面栖霞组与华南其他地区同期地层的对比提供了更多生物方面的依据.%The Permian non-fusulinid foraminifers of the Chihsia Formation are collected from Wangjiagou section in Wangcang County, Northwestern Sichuan Basin. The Chihsia Formation of Wangjiagou section is a suit of medium-bedded to thick-bedded limestones, with thickness of about 108 meters. Based on the systematic study to the Chihsia Formation, 27 species of 14 genera (including conformis species and subspecies) of the non-fusulinid foraminiferal fauna have been recognized in the Wangjiagou section. The Globivalvulina assemblage is suggested as indicative fauna for recognition of the Permian largest transgressive period. The result of this study not only enriches the fossil database of Sichuan Basin, but also provides more palaeontological evidences for stratigraphic correlation in South China.

  8. The terminal Permian in European Russia: Vyaznikovian Horizon, Nedubrovo Member, and Permian-Triassic boundary

    Lozovsky, V. R.; Balabanov, Yu. P.; Karasev, E. V.; Novikov, I. V.; Ponomarenko, A. G.; Yaroshenko, O. P.

    2016-07-01

    The comprehensive analysis of the data obtained on terrestrial vertebrata, ostracods, entomologic fauna, megaflora, and microflora in deposits of the Vyaznikovian Horizon and Nedubrovo Member, as well as the paleomagnetic data measured in enclosing rocks, confirms heterogeneity of these deposits. Accordingly, it is necessary to distinguish these two stratons in the terminal Permian of the East European Platform. The combined sequence of Triassic-Permian boundary deposits in the Moscow Syneclise, which is considered to be the most complete sequence in the East European Platform, is as follows (from bottom upward): Vyatkian deposits; Vyaznikovian Horizon, including Sokovka and Zhukovo members; Nedubrovo Member (Upper Permian); Astashikha and Ryabi members of the Vokhmian Horizon (Lower Triassic). None of the sequences of Permian-Triassic boundary deposits known in the area of study characterizes this sequence in full volume. In the north, the Triassic deposits are underlain by the Nedubrovo Member; in the south (the Klyazma River basin), the sections are underlain by the Vyaznikovian Horizon. The Permian-Triassic boundary adopted in the General Stratigraphic Scale of Russia for continental deposits of the East European platform (the lower boundary of the Astashikha Member) is more ancient than the one adopted in the International Stratigraphic Chart. The same geological situation is observed in the German Basin and other localities where Triassic continental deposits are developed. The ways of solving this problem are discussed in this article.

  9. Salt movements in the Northeast German Basin and its relation to major post-Permian tectonic phases—results from 3D structural modelling, backstripping and reflection seismic data

    Scheck, Magdalena; Bayer, Ulf; Lewerenz, Björn

    2003-01-01

    The NW-SE-striking Northeast German Basin (NEGB) forms part of the Southern Permian Basin and contains up to 8 km of Permian to Cenozoic deposits. During its polyphase evolution, mobilization of the Zechstein salt layer resulted in a complex structural configuration with thin-skinned deformation in the basin and thick-skinned deformation at the basin margins. We investigated the role of salt as a decoupling horizon between its substratum and its cover during the Mesozoic deformation by integration of 3D structural modelling, backstripping and seismic interpretation. Our results suggest that periods of Mesozoic salt movement correlate temporally with changes of the regional stress field structures. Post-depositional salt mobilisation was weakest in the area of highest initial salt thickness and thickest overburden. This also indicates that regional tectonics is responsible for the initiation of salt movements rather than stratigraphic density inversion. Salt movement mainly took place in post-Muschelkalk times. The onset of salt diapirism with the formation of N-S-oriented rim synclines in Late Triassic was synchronous with the development of the NNE-SSW-striking Rheinsberg Trough due to regional E-W extension. In the Middle and Late Jurassic, uplift affected the northern part of the basin and may have induced south-directed gravity gliding in the salt layer. In the southern part, deposition continued in the Early Cretaceous. However, rotation of salt rim synclines axes to NW-SE as well as accelerated rim syncline subsidence near the NW-SE-striking Gardelegen Fault at the southern basin margin indicates a change from E-W extension to a tectonic regime favoring the activation of NW-SE-oriented structural elements. During the Late Cretaceous-Earliest Cenozoic, diapirism was associated with regional N-S compression and progressed further north and west. The Mesozoic interval was folded with the formation of WNW-trending salt-cored anticlines parallel to inversion

  10. 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

    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

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

    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

  12. 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

    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

  13. 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

    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.

  14. The Permian system in Kansas

    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...

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

    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 %.

  16. Formation of the Permian basalts and implications of geochemical tracing for paleo-tectonic setting and regional tectonic background in the Turpan-Hami and Santanghu basins, Xinjiang

    ZHOU Dingwu; LIU Yiqun; XING Xiujuan; HAO Jianrong; DONG Yunpeng; OUYANG Zhengjian

    2006-01-01

    The Turpan-Hami and Santanghu basins are the late Paleozoic-Mesozoic-Cenozoic reworked intracontinental basins that superposed on the folded basement of the Paleozoic orogenic belt. 40Ar/39Ar geochronological study of the basalts developed in the basins reveals that the formation period is Permain (293-266 Ma). From geochemical comparison of the basalts, the Santanghu basalts exhibit a strong depletion in Nb and Ta, and a selective enrichment in HFSE, reflecting that the source region is influenced by the subducted components related to subduction of the ancient oceanic crust and characterized with "lagged arc volcanic rocks". In contrast, the Turpan-Hami basalts show a slight depletion in Nb and Ta, high Th/Ta ratio, similar to the basalts formed in an intracontinental extensional zone or in an initial rift. Combined with the formation period of the ophiolite and ophiolite mélange zones and regional magmatic activities occurring on the post-orogenic extensional background in northern Xinjiang, it can be inferred from these geochemical characteristics that the tectonic background for forming the Turpan-Hami and Santanghu basins is closely related to the regional extension after the continent-continent collisional orogeny. The basalts of the two basins came from different sources on the post-orogenic extensional background of the similar basin-forming dynamics. Although the settings are all intracontinental rift, the source for the Santanghu basalts is obviously subjected to the metasomatism of the subducted components, implying the existence of the previous subduction.

  17. Study of the Genesis of Permian Volcanic Reservoir in Yuenan Region Tarim Basin%塔里木盆地跃南地区二叠系火山岩储层成因机理研究

    潘文庆; 张巍; 于红枫; 于红娇; 张正红; 关平; 简星

    2013-01-01

    Petrology,mineralogy and geochemistry method such as thin section,cast thin section,scanning electron microscope observation,cathodoluminescence,energy spectrum and major element experiment were used to analyze the genesis of Permian volcanic reservoir in Yuenan Region,Tarim Basin.It is found that Permian volcanic reservoir,dominated by secondary pore space can be regarded as favorable reservoir because the porosity of the primary pore space can reach 14% and 13.1 × 10-3 μm2 respectively.Genesis of the secondary pore and cracks is the weathering,whose intensity increases with the depth decreasing.The porosity and the permeability is positively correlated to weathering.The thickness of weathering effect can reach at least 220 m.The weathering dissolution and leaching process take priority of weak plane,such as large number of primary pores,cooling contracted crack,cryptoexplosion fracture which generate in the cooling of volcanic and cleavage crack,twin stitch of primary mineral.Weathering sequence of feldspar phenocryst and matrix is found in rhyolite,weathering products are mainly illite,with small amounts of montmorillonite,and the entire sequence of clay minerals growth process is preserved.Weathering can modify substantially pore structure on the basis of primary porosity,and improve the porosity and permeability greatly,which is the main controlling factor of Permian volcanic reservoir of Yuenan Region,Tarim Basin.%通过普通薄片及铸体薄片观察、扫描电子显微镜、阴极发光、能谱分析及主量元素分析等岩石学、矿物学、地球化学手段,对塔里木盆地跃南地区二叠系火山岩储层成因机理进行系统研究.研究发现,二叠系火山岩储层中以次生储集空间为主,孔隙度可高达14%,渗透率最高可达13.1×10-3 μm2,可以作为有利的储层.风化作用是次生孔隙和裂缝的主要成因,风化作用强度由深到浅逐渐增大,储层物理性能与之呈正相

  18. Palynostratigraphy of Permian succession in the Mand–Raigarh Coalfield, Chhattisgarh, India and phytogeographical provincialism

    Srikanta Murthy; Ram-Awatar; Saurabh Gautam

    2014-12-01

    Palynofloras have been recorded from the Barakar Formation in the Borehole MBKW-3, Barpali–Karmitikra Block, Mand–Raigarh 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.

  19. Extinguishing a Permian World

    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 les

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

    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.

  1. Permian division and correlation and distribution of volcanic rocks of Tarim basin%塔里木盆地二叠系划分对比与火山岩分布

    蒲仁海; 党晓红; 许璟; 郭倩; 伊红佳

    2011-01-01

    Based on the basin-wide analysis of well, outcrops and tracing of seismic data, the underground Permian petrologic stratigraphy is re-divided and correlated throughout the Tarim Basin. Permian System upward consists of one aggradation interval and three retrogradation intervals of natural gamma ray logs. The aggradation interval belongs to Nanzha Formation, and the other three intervals belong to respectively Kupkuciman Formation, Kaipeleicike Formation and Shajingzi Formation. Nanzha Formation is dominated by rocks of brown gray shales interbedded with thin limestones that represent littoral to neritic deposits during the last transgression in Tarim basin. Kupkuciman and Kaipeleicike Formations are two cycles from basic to acidic volcanic rocks or from basic volcanic to terrestrial clastic rocks. Shajingzi Formation is an allocycle from alluvial fan to branded channel to meandering fluvial deposition resulted from a tectonic movement The Permian volcanic rocks are thicker over the areas from Hetian River to Tazhong to Shuntuoguole. The volcanic rocks are atypically 0 ~ 60m in Kupkuciman Formation, and 0 ~ 200m or locally over 400m in Kaipeleicike Formation. The volcanic rocks of Kaipeleicike Formation are accumulated further northeast compared to that of Kupkuciman Formation. Over the middle to west region of Tarim basin, part of Kupkuciman volcanic rocks might have formed underwater. Volcanic passage and craters seen on seismic sections are distributed extensively on the anticlines or fault nose structures in uplifted region and rarely seen in depression area. Volcanic rocks can serve as cap or shelter rocks of a pool, or be reworked to be one kind of reservoir rocks, but mostly the volcanic activity might have affected or to some extent destroyed the earlier formed oil-gas pools.%根据全盆地钻井与露头剖面对比和地震剖面追踪解释,探讨了塔里木盆地覆盖区二叠系岩石地层的划分对比.二叠系自下而上由一个自然伽

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

    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...

  3. Permian karst topography in the Wichita uplift, southwestern Oklahoma

    Donovan, R.N. Busbey, A.B. (Texas Christian Univ., Ft. Worth, TX (United States). Geology Dept.)

    1993-02-01

    The Wichita uplift in southwestern Oklahoma is one part of a record of Pennsylvania and early Permian deformation that affected the Southern Oklahoma aulacogen. As a result of a partial inversion, the Lower Paleozoic section of this aulacogen was sequentially stripped off an uplift between the Wichita uplift and the Anadarko basin, resulting in the exposure of ultrabasic rocks deep in the Cambrian igneous fill of the aulacogen. Following the late Paleozoic tectonism, the topography of the uplift was entombed beneath Permian sediments and remained essentially undisturbed until exhumation during the present erosional cycle. Modern erosion is gradually exposing this topography, permitting morphometric analysis of the Permian hill forms. Because of the variation of lithology in the uplift, it is possible to isolate the effects of weathering processes such as intense hydrolysis of the igneous rocks (producing, among other features, or topography) and limestone dissolution, in the form of a surface and subsurface karst imprint. The latter process resulted in a network of small caves that are essentially fissures eroded along tectonic fractures. These small caves can be found in all the exposed areas of limestone. They are particularly noteworthy for three reasons: in at least five examples they contain a complex fauna of Permian vertebrates (mostly fragmentary), speleothems in some examples contain hydrocarbon inclusions, derived from the underlying Anadarko basin, some of the caves yield evidence of post burial evolution in the form of clay infiltration from the surface and brine flushing from the underlying Anadarko basin.

  4. Middle-Late Permian mass extinction on land

    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.

  5. Permian potentiometric analysis

    Devary, J.L.

    1983-09-01

    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.

  6. Permian potentiometric analysis

    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

  7. Late Permian-Early Triassic Sedimentary Evolution in Sichuan Basin and Its Significance on Gas Accumulation%四川盆地晚二叠世-早三叠世沉积演化及其对天然气富集的意义

    冯冲; 邹华耀; 郭彤楼

    2015-01-01

    四川盆地上二叠统—下三叠统碳酸盐岩地层中富集天然气,天然气藏的分布受优质烃源岩和礁滩相储层的控制。为了揭示四川盆地沉积演化背景下天然气的富集规律及预测成藏有利区,对晚二叠世—早三叠世扬子古板块地质构造背景进行分析,讨论地质构造背景控制下四川盆地晚二叠世—早三叠世沉积演化特征;根据不同时期构造和沉积演化特征确定优质烃源岩和储层的发育机理和分布范围;结合天然气成藏模式的认识,确定天然气成藏有利区。结果表明:四川盆地晚二叠世—早三叠世海湾及其后陆棚的发育演化控制了该区龙潭组主力烃源岩与长兴组—飞仙关组礁滩相储层的发育分布,形成了下生上储的有利配置关系;川东北地区长兴组—飞仙关组台地边缘礁滩相储层邻近龙潭组海湾相优质烃源岩的区域为天然气成藏最有利区。总之,四川盆地晚二叠世—早三叠世沉积演化特征控制了海相优质烃源岩和储层的发育分布,决定了天然气的富集与分布。%Upper Permian-Low Triassic carbonate formations in Sichuan Basin enrich gas,and the distribution of gas accumulation is controlled by high quality source rocks and reef-shoal facies reservoir.In order to reveal the gas enrichment rule and forecast the favorable areas under the sedimentary evolution settings in Sichuan Basin, the geological structure settings of Late Permian-Early Triassic Yangtze palaeoslab were analyzed, and the characteristics of Late Permian-Early Triassic sedimentary evolution under the geological structure settings were discussed;the development mechanism and distribution of high quality source rocks and reservoirs were explained according to the characteristics of tectonic evolution in different periods;combined with the gas accumulation model,the favorable areas of gas accumulation were divided.The results show that the

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

    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...

  9. Permian magmatism, Permian detachment faulting, and Alpine thrusting in the Orobic Anticline, southern Alps, Italy

    Pohl, Florian; Froitzheim, Niko; Geisler-Wierwille, Thorsten; Schlöder, Oliver

    2014-05-01

    Lombardo. It is therefore an Alpine structure. (4) Several south-directed Alpine thrusts duplicate the lithostratigraphy, including the detachment, and are related to the Orobic thrust further north. They also offset the Biandino Fault. U-Pb zircon ages measured with LA-ICP-MS (work in progress) will further clarify the temporal relations between the intrusions, volcanics, and the shear zones. Froitzheim, N., Derks, J.F., Walter, J.M. & Sciunnach, D. 2008. Evolution of an Early Permian extensional detachment fault from synintrusive, mylonitic flow to brittle faulting (Grassi Detachment Fault, Orobic Anticline, southern Alps, Italy) Geological Society, London, Special Publications, 298; 69-82. doi:10.1144/SP298.4 Thöni, M., Mottana, A., Delitala, M. C., De Capitani, L. & Liborio, G. 1992. The Val Biandino composite pluton: A late Hercynian intrusion into the South-Alpine metamorphic basement of the Alps (Italy). Neues Jahrbuch für Mineralogie-Monatshefte, 12, 545-554. Sciunnach, D. 2001. Early Permian palaeofaults at the western boundary of the Collio Basin (Valsassina, Lombardy). Natura Bresciana. Annuario del Museo Civico di Scienze Naturali, Brescia, Monografia, 25, 37-43.

  10. Origin of lacustrine dolostones of the Middle Permian Lucaogou Formation in Santanghu Basin of Xinjiang%新疆三塘湖盆地中二叠统芦草沟组湖相白云岩成因

    李红; 柳益群; 梁浩; 周小虎; 焦鑫; 刘洪福; 杨锐; 雷川

    2012-01-01

    新疆三塘湖盆地中二叠统芦草沟组发育湖泊背景下的白云岩、灰岩、黑色泥岩、页岩及碎屑岩的互层沉积.白云岩主要有两类:一类为粉—泥晶白云岩,主要由含量约70%的泥晶白云石和含量约30%的粉晶白云石构成,白云石有序度为0.48,扫描电镜下主要有菱形、他形、球状和管状4种微形态,自形程度较好的菱形晶体多为含铁白云石;另一类为方沸钾长白云岩,主要由晶粒为0.08~0.35 mm的细粒方沸石、泥晶钾长石(透长石)、泥晶白云石和铁白云石构成,个别为粗晶白云石,白云石有序度0.58.与粉—泥晶白云岩中的白云石相比,方沸钾长白云岩中的白云石以高的铁、锰含量为特征,扫描电镜下多为半自形的菱形晶体.两类白云岩中白云石的有序度均较低,且均为富Sr白云石,内部均缺乏次生交代证据.通过对两类白云岩成分、微量元素及稳定同位素的差异性分析,认为尽管两类白云岩都形成于浅—半深湖相强还原沉积环境,但是它们的形成机制有所不同,粉—泥晶白云岩具有原生沉淀白云石的特征,其中球状及管状的白云石可能与微生物吸附作用有关,而他形及菱形的白云石为直接沉淀的原生白云石;另一类方沸钾长白云岩中的白云石及铁白云石可能与湖底热泉的啧流沉积作用有关.%The Santanghu Basin is a small intermountain basin located in northeastern Xinjiang, NW China. The Middle Permian comprises the Wulapo, Jingjingzigou, Lucaogou and Hongyanchi Formations from bottom to top. The Lucaogou Formation was formed of interbeded sedimentary rocks such as dolostone, limestone, black mudstone, shale and detrital rock in lacustrine environment. Two kinds of dolostones were found in this basin. One was named silt-micrite dolostone which contains 70 percent of clay-sized dolomite, 30 percent of silt-sized dolomite. The dolomite exhibit weak ordering with degree of 0

  11. Permian-Triassic mafites of Sette-Daban

    The paper describe the ores which form the Permian-Triassic dike zones of the Southern part of the Sette-Daban fold-blowing structure adjacent to the Siberian platform. The data are presented on K-Ar age of gabbro-diabase dike in the basin of Ariavkan River: the age of plagioclase is 276 ± 1 million years and that of kali feldspar - 222 ± 30 million years. It agrees with potassium - argon dating of mafites with similar compositions in the Northern part of the region. It is shown that the Permian-Triassic dikes can be of interest for the prospecting of the deposits of lead, zinc, phosphates and other minerals. 10 refs., 1 fig., 1 tab,

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

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

    Permian Kupfershiefer which is a potential source rock, has local depositional maxima associated to the basement faults. Salt structures which have been periodically active during the post Paleozoic dominate the northern part of the study area. The Paleozoic intrusions observed in the hanging-wall segment......This study presents the geometry of Paleozoic intrusions in the Skagerrak area located at the northern flank of the Ringkøbing-Fyn High and suggests factors controlling the formation of the intrusions. The intrusions have here been mapped in detail using 3D seismic data. The study area is located...... recorded across the entire North Sea Basin. The easternmost intrusions and extrusions have been associated to the “Skagerrak-Centered Large Igneous Province” that has an early Permian age of c. 297 Ma. Compared to the Southern Permian Basin which historically has been intensely investigated because of the...

  13. Strontium isotope evolution of Late Permian and Triassic seawater

    Korte, Christoph; Kozur, Heinz W.; Bruckschen, Peter; Veizer, Ján

    2003-01-01

    The 87Sr/ 86Sr values based on brachiopods and conodonts define a nearly continuous record for the Late Permian and Triassic intervals. Minor gaps in measurements exist only for the uppermost Brahmanian, lower part of the Upper Olenekian, and Middle Norian, and only sparse data are available for the Late Permian. These 219 measurements include 67 brachiopods and 114 conodont samples from the Tethyan realm as well as 37 brachiopods and one conodont sample from the mid-European Middle Triassic Muschelkalk Sea. The Late Permian/Lower Triassic interval is characterized by a steep 1.3 × 10 -3 rise, from 0.7070 at the base of the Dzhulfian to 0.7082 in the late Olenekian, a rate of change comparable to that in the Cenozoic. In the mid-Triassic (Anisian and Ladinian), the isotope values fall to 0.7075, followed again by a rise to 0.7081 in the Middle/Late Norian. The 87Sr/ 86Sr values decline again in the Late Norian (Sevatian) and Rhaetian to 0.7076. The sharp rise in the 87Sr/ 86Sr values during the Late Permian/Early Triassic was coincident with widespread clastic sedimentation. Because of the paucity of tectonic uplifts, the enhanced erosion may have been due to intermittent humid phases, during mainly an arid interval, coupled with the absence of a dense protective land plant cover following the mass extinction during the latest Permian. The apex of the 87Sr/ 86Sr curve at the Olenekian/Anisian boundary coincides with cessation of the large-scale clastic sedimentation and also marks the final recovery of land vegetation, as indicated by the renewed onset of coal formation in the Middle Triassic. The rising 87Sr/ 86Sr values from the Middle Carnian to the Late Norian coincide with the uplift and erosion of the Cimmeride-Indosinian orogens marking the closure of the Palaeotethys. The subsequent Rhaetian decline that continues into Jurassic (Pliensbachian/Toarcian boundary), on the other hand, coincides with the opening of the Vardar Ocean and its eastern continuation

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

    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).

  15. Subaqueous systems fed by glacially derived hyperpycnal flows: a depositional model for Carboniferous-Permian sandstones of the Itarare Group, Parana Basin; Sistemas subaquosos alimentados por fluxos hiperpicnais glaciogenicos: modelo deposicional para arenitos do Grupo Itarare, Permocarbonifero da Bacia do Parana

    Vesely, Fernando Farias [PETROBRAS, Rio de Janeiro, RJ (Brazil). E e P. Gerencia de Estratigrafia]. E-mail: vesely@petrobras.br

    2006-11-15

    The glacial Itarare Group constitutes the lower interval of the Carboniferous-Permian mega sequence in the Parana Basin. Thick glacially related sandstone reservoirs present in this unit contain gas and condensate sourced by Devonian marine shales. Based on outcrop data from the eastern basin margin, the sedimentary facies and stacking patterns were analyzed in order to propose a depositional model for these sandstone successions. It is suggested that the sandstones were deposited subaqueously as pro glacial fans due to melt water-derived highly concentrated hyperpycnal flows. Regional Itarare Group's stratigraphy can be expressed as several unconformity-bounded sequences deposited in a marine glaciated basin during repeated deglaciation episodes. The lower half of each sequence is constituted of thick sand-rich successions typically showing fining-upward and a retrogradational stacking pattern. Eleven facies were recognized, ranging from conglomerates to fine-grained sandstones, massive, graded or stratified. Conglomerates and cross-bedded coarse sandstones represent proximal Subaqueous deposits and were formed as ice-contact out wash fans/aprons due to melt water-derived hyper concentrated and concentrated flows and traction dominated bottom currents. These flows served as feeder systems to stratified, massive or graded turbiditic sandstone lobes deposited more distally. Parallel bedding and climbing ripples present in these beds were formed due to continuous aggradation from waxing and/or waning long-lived turbidity currents. These characteristics typify hyperpycnites and suggest that melt water derived hyperpycnal flows were the main trigger mechanisms to turbidity currents in the Itarare Group. (author)

  16. Stratigraphy sequence analysis application for multi scalar characterization of paralic reservoirs - an example in the Guata group (E O-Permian) of the Parana Basin, in the state of Rio Grande do Sul, Brazil; Aplicacao da estratigrafia de sequencias para caracterizacao multiescalar de reservatorios paralicos - um exemplo no Grupo Guata (EO-Permiano) da Bacia do Parana, no Rio Grande do Sul, Brasil

    Kuechle, Juliano [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Geociencias. Curso de Pos-graduacao em Geociencias]. E-mail: juk666@zipmail.com.br; Holz, Michael [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Geociencias]. E-mail: michael.holz@ufrgs.br

    2003-07-01

    Detailed stratigraphic analysis of the Early Permian Rio Bonito and Palermo Formations of the Parana Basin in the region of Sao Gabriel County has been used for a study on reservoir characterization of paralic sandstones. Two main depositional systems were recognized, a fluvial-dominated delta system and a wave-dominated barrier island system. The succession is divided in two third-order depositional sequences, enclosing thirteen fourth-order para sequences. This high-resolution stratigraphic framework was the base for a multi scale approach on reservoir characterization of the sandstone bodies. Reservoir heterogeneities are discussed, staring from the scale of depositional sequence (heterogeneity level 1), passing down to heterogeneity at the scale of systems tracts (heterogeneity level 2) and finalizing with an approach at para sequence scale (heterogeneity level 3). Main control on heterogeneity at the first level is base-level variation as generating mechanism for un conformities at the sediment type and rate. At the second level, the reservoir heterogeneity is controlled by the lateral and vertical variations in thickness of particular systems within the different systems tracts, and at the third level, the heterogeneity occurs controlling reservoir continuity and connectivities between reservoirs. The study supplies a model which is useful as a predictive tool for similar geologic settings in producing oil fields. (author)

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

    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.

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

    Vozárová, Anna; Presnyakov, Sergey; Šarinová, Katarína; Šmelko, Miloš

    2015-10-01

    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.

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

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

    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...

  20. Depositional model of Early Permian reef-island ocean inEastern Kunlun

    2001-01-01

    Many fusulinid fossils have been found in thin- to middle-bedded limestones which aredistributed between the Early Permian limestone hills and formerly considered as Early Triassic.The fusulinid fossils, identified as Neoshwagerina sp., Verbeekina sp. and Schwagerina sp., canalso be found in massive limestone hills. At the same time, Early Permian radiolarian chert of deepbasin facies was discovered in Animaqing. All the above show that the massive limestone hills,thin- to middle-bedded limestones and radiolarian chert belong to syndeposits in Early Permianocean. The sediments in the study area can roughly be divided into three types: shallow facies,basin facies and transitional facies. The carbonate buildup can be subdivided into massive bioclas-tic limestone and reef framestone. Basin facies contains thin- or middle-bedded limestone, abyssalred mudstone or ooze, blue-green mudstone and radiolarian chert. Transitional facies includes reeftalus and platformal skirt facies. The Early Permian ocean in Eastern Kunlun is recognized as akind of reef-island ocean environment according to distribution and composition of different facies.The reef-island ocean in Eastern Kunlun is characterized by reef islands (or carbonate buildups)alternating with basins, complicated sea-floor topography, sharp facial change and well-developedreefs

  1. Late Permian to Early Triassic magnetostratigraphy

    Haag, Maja; Heller, Friedrich

    1991-10-01

    A Late Permian to Early Triassic magnetostratigraphic reference section is presented. The Lower Triassic part is based on results from marine limestone sections in South China published earlier [1,2]. Reliable new Permian data are added here which have been collected in the Nammal gorge (Salt Range, Northwest Pakistan) where marine sediments have been deposited quasi-continuously with occasional minor hiatuses during the late Palaeozoic to early Mesozoic. About 50% of the Permian samples from the Nammal section contain, hidden beneath a strong recent or Tertiary overprint, a characteristic remanent magnetization (ChRM) which is very likely of Permian age. This component, which was imprinted on the southern hemisphere, has normal as well as reversed polarity with a normal mean direction (Decl. = 289.3°, Incl. = -50.3°, α 95 = 4.3° , N = 113) which is in close agreement with the palaeofield direction expected for a site belonging to the Indian plate as part of Gondwanaland during the Permian. In the lower Upper Permian several normal polarity zones are recognized. This contradicts the current assumption that rocks of this age belong to the long, reversely polarized Kiaman hyperzone. The Kiaman interval must end and the Illawarra hyperzone of mixed polarity must begin in or prior to the lowermost Upper Permian. The Permian/Triassic boundary at Nammal as well as in the Chinese sections is situated very close to a transition from a reversed to a normal polarity zone. The Upper Permian at Nammal together with the Lower Triassic South China sections is estimated to cover about 20 Ma. Nearly 30 polarity changes are observed which result in an average reversal frequency very similar to that observed during the early Tertiary. The reversal rate after the end of the long-lasting reversed Kiaman hyperchron apparently increases in a manner similar to that after the end of the Cretaceous Long Normal Superchron. Only a few polarity zones are found in the lower Upper Permian

  2. Sedimentary evolution of Rio do Rastro formation (permian-triassic of the Parana Basin) at central south portion of Santa Catarina State, Brazil; Evolucao sedimentar da Formacao Rio do Rastro (Permo-Triassico da Bacia do Parana) na porcao centro sul do estado de Santa Catarina, Brasil

    Warren, Lucas Verissimo; Roldan, Luis Fernando; Steiner, Samar dos Santos; Chamani, Marlei Antonio Carrari [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Programa de Pos Graduacao em Geoquimica e Geotectonica]. E-mail: lvwarren@yahoo.com; Almeida, Renato Paes de; Hachiro, Jorge; Machado, Romulo [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Dept. de Geologia Sedimentar e Ambiental

    2008-06-15

    Between the Late Carboniferous and the Early Triassic, the south portion of the Gondwana Supercontinent witnessed the development of intracratonic basins related with the coeval Sanrafaelic Orogeny. The continuous subsidence and consequent generation accommodation space resulted in the formation of a large confined water body and the accumulation of a transgressive regressive sequence between the Late Permian and the Early Triassic. The progradational nature of the upper portion of this sequence, represented by de Rio do Rasto e Piramboia formations, culminated with the complete filling of the water body. In the south-eastern portion of Santa Catarina State (Southern Brazil), the Rio do Rasto Formation overlies the Teresina formation and is overlain by the Piramboia formation, both contacts being characterized by lithological transition. The lower portion of the Rio do Rasto Formation is characterized by architectural elements deposited in offshore environments subject to storm action. A marked change of the color of the pelitic facies, from gray to red and purple occurs at the top of the unit. At this stratigraphic level, there is also a predominance of deltaic and eolian architectural elements. The intercalation of near shore and offshore architectural elements can be explained by the strong auto cyclic character expected in deltaic depositional systems and by the variation of relative rates of base-level rise. The occurrence of eolian architectural elements interbedded with subaquatically deposited sediments on the second third of the unit can be considered an evidence of continentalization to the top, materialized as the transition to the Piramboia desert system. (author)

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

    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

  4. 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

    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

  5. 南祁连盆地下日哈坳陷二叠系泥岩地球化学特征及地质意义%Geochemistry and Geological Significance of the Permian Mudstone in the South Qilian Basin,China

    谢其锋; 周立发; 蔡元峰; 刘羽; 刘志武

    2015-01-01

    为探讨南祁连盆地下日哈坳陷二叠系泥岩的地球化学特征及其沉积环境、构造属性和物源属性,本文对野外系统采集的泥岩样品进行了有机、无机地球化学测试,分析了泥岩有机碳含量、生烃潜力、最高峰温度、主量、微量和稀土元素等。结果表明,二叠系泥岩有机质成熟度较高,以水生生物型为主兼有水生-陆源混合型,处于半封闭水体状态下,缺氧、还原程度一般、盐度中等的沉积环境。草地沟组属Ⅱ2-Ⅲ型干酪根,母质主要来源于海相浮游生物和微生物,为主力烃源岩层系;切尔玛组成熟度相对低,属Ⅲ型干酪根,母质来源于陆源生物,为潜在烃源岩层系。二叠系泥岩构造、物源属性指示二者具有较大的亲缘性,属于活动大陆边缘构造环境,物源主要来自中祁连低缓隆起区的上地壳长英质岩,并有安山质岩石的混入。%This study focused on the Permian mudstones geochemistry in the Xiariha depression,south Qilian basin,their implications to sedimentary environment,tectonic setting,and provenance attribute.On the basis of the organic and inor-ganic geochemistry,we discussed the total organic carbon content,hydrocarbon potential,maximum temperature,major and rare earth elements,and other features.The results showed that:The Permian mudstone organic has higher maturity, produced mainly by aquatic and aquatic-terrestrial mixed organisms,which live in the depositional environment of semi-enclosed,hypoxia,moderate reduction and salinity water bodies.The P 2 c kerogen of Ⅱ 2-Ⅲ type,whose parent material came from marine plankton and microorganisms,is the main source rock in the study area,while the P 3 q,which is the terrestrial materials derived lower maturity type Ⅲ kerogen,is the potentially source rock.The mudstone tectonic setting o-riginates from active continental margin tectonic setting,and the mudstone shows a great

  6. Paleoenvironment of the Permian rocks: a comparison between central and eastern Alborz, Iran

    Lankarani, M.; Amini, A.; Mosadegh, H.

    2009-04-01

    The succession of Permian rocks in Alborz region is composed of siliciclastic and carbonate facies. All of the sediments were deposited in the Paleotethyan passive continental margin but they show different facies architecture and paleoenvironmental condition in various parts of the region. This study, as part of a wider project, has investigated sedimentary facies and paleoenvironment of the Permian rocks in central and eastern Alborz. The Permian rocks in central Alborz are dominated by siliciclastic facies (Doroud Formation) in the lower, and carbonate facies (Ruteh Formation) in the upper half. Field studies and laboratory measurements resulted in recognition of 4 terrigenous and 13 carbonate facies in the succession. A siliciclastic shallow marine system was determined as depositional environment of the terrigenous facies. A homoclinal carbonate ramp, with scattered patch reefs, was determined as depositional environment of the carbonate facies. Dasycladacean green algae, ancestral red algae, hermatypic corals and bryozoans were the major bioconstructors of the ramp. The abundance of skeletal shoals respect to ooidal shoals in the ramp margin was high. The Permian rocks in eastern Alborz are dominated by mixed siliciclastic-carbonate facies (Ruteh Formation) in the lower, and siliciclastic facies (Nesen Formation) in the upper half. The studies resulted in recognition of 5 terrigenous and 6 carbonate facies in the succession. A mixed siliciclastic-carbonate shelf with high sediment influx was determined as depositional environment of the mixed siliciclastic-carbonate facies. Occurrence of the small patch reefs with high coral diversity in this mixed shelf indicates normal marine (hyposaline) condition. Upper terrigenous facies were deposited in fluvial-flood plain system. Difference in paleoclimate and tectonic activity of two sub-basins seems to be the major cause of the differences between the Permian facies in central and eastern Alborz.

  7. Pangean Reconstruction of the Yucatan Block and its Permian, Triassic, and Jurassic Geologic and Tectonic History

    Steiner, M.

    2004-12-01

    Paleomagnetic studies of Paleozoic sedimentary and plutonic rocks demonstrate that the Yucatan Block lay inverted off the NW coast of South America (SA) in Pangea, and rotated in a series of clockwise motions as SA and NA separated. Mid-Permian Yucatan was a fragment of the western margin of Pangea, just south of the equator. By 230 Ma, Yucatan rotated ˜20° clockwise and moved to the equator. Clockwise rotation continued through the Jurassic: ˜54° between 230 Ma and about Oxfordian, and another ˜32° between ˜Oxfordian and Tithonian, when the approximate present orientation was achieved. Passage of the Yucatan Block into the gap created by the separation of North and South America requires left-lateral motion relative to North America, perhaps by translation along the Mojave Sonora megashear. One remanence, carried by magnetite in red bed strata from the margins of the marine Santa Rosa basin (Maya Mtns), decays exceedingly linearly to the origin of orthogonal-axes plots. Biostratigraphy indicates a Late Pennsylvanian to Middle Permian age, and the presence of dual polarities in a 110 m, four polarity, magnetostratigraphic sequence demonstrates a post-Late Paleozoic Reversed Superchron (i.e., Middle Permian) age. Plutonic rocks exhibit a second, also dual-polarity, remanence, which corresponds to a paleopole 60° clockwise of the mid-Permian pole. The spatial relationship between the Permian and pluton paleopoles is very similar to that of the North American Permian and Late Triassic poles. Moreover, exceedingly uniform K/Ar ages of 231±7 Ma characterize all Maya Mtns plutons and the southern volcanic complex, indicating a 230 Ma resetting of the K/Ar radiometric systems of plutons dated by U/Pb as Late Silurian (Steiner and Walker, 1996). Metamorphic aureoles developed in the Pennsylvanian-Permian Santa Rosa strata bordering the Silurian plutonic complexes suggest the occurrence of a post-intrusion hydrothermal event. The 230 Ma reset K/Ar systems

  8. Sandrewia, n. gen., a problematical plant from the Lower Permian of Texas and Kansas

    Mamay, S.H.

    1975-01-01

    Sandrewia, n. gen., monotypified by S. texana, n. sp., is a plant from Lower Permian beds of north-central Texas and east-central Kansas. It is characterized by stout axes with spirally disposed, laxly inserted, petiolate leaves; the laminae are broadly flabelliform with coarse, open venation. The leaves are reminiscent of the vojnovskyalean Nephropsis, of the Permian Petchora Basin, U.S.S.R., but biologic relationships are only speculative because of limited material. However, leaf characteristics render Sandrewia easily identifiable. Its presently limited stratigraphic range, along with floristic associations, indicates it may be a useful guide fossil and supports the author's beliefs regarding important times and places in Paleozoic plant evolution. ?? 1975.

  9. Mechanism on bipolar distribution of Permian brachiopods

    Chengwen WANG; Songmei ZHANG

    2008-01-01

    By reasearch on geographic distribution, nine genera in bipolar distribution are selected from Permian brachiopods. These taxa originated from middle-high latitude areas in the boreal realm, of which five genera were derived from Late Carboniferous, and other four genera originated from Permian. They were all in bipolar distribution during some different stages in Permian. Specific diversity for each genus was high in the boreal realm, whereas in the Gondwana realm was very low. Perdurability was long in the boreal realm, and short in the Gondwana realm. It was the time when these nine genera came to their maximum diversity that these genera appeared in the Gondwana and formed bipolar distribution; while they also migrated to the low latitude from high latitude. This shows very close relationship between several main cooling events in Permian and the migration of genera from the boreal realm to the Gondwana realm through the Tethys. Therefore, the cooling events might be the main drive which caused these cold-water-type brachiopods migrated to the Gondwana realm and being bipolar distribution. In this process, the planula tolerance to warm water would be another important factor.

  10. Inorganic chemistry, petrography and palaeobotany of Permian coals in the Prince Charles Mountains, East Antarctica

    Holdgate, G.R.; McLoughlin, S.; Drinnan, A.N.; Finkelman, R.B.; Willett, J.C.; Chiehowsky, L.A.

    2005-01-01

    Sampled outcrops of Permian coal seams of the Bainmedart Coal Measures in the Lambert Graben, eastern Antarctica, have been analysed for their proximates, ultimates, ash constituents and trace elements. A similar series of samples has been analysed for their principle maceral and microlithotype components and vitrinite reflectance. The coals are sub-bituminous to high volatile bituminous in rank; maturity increases markedly in southern exposures around Radok Lake where the oldest part of the succession is exposed and some strata have been intruded by mafic dykes and ultramafic sills. The coal ash is mostly silica and aluminium oxides, indicating that the mineral ash component is mostly quartz and various clay minerals. The ratio of silica to aluminium oxides appears to increase in an upward stratigraphic direction. The coal macerals include a relatively high liptinite content (mainly sporinite) that is significantly higher than for typical Gondwana coals. Greater degrees of weathering within the floodbasin/peat mire environments associated with climatic drying towards the end of the Permian might account for both preferential sporopollenin preservation and increased silica:aluminium oxide ratios up-section. Correlation of the coal maceral components to adjacent peninsula India coals indicates the closest comparative coals of similar age and rank occur within the Godavari Basin, rather then the Mahanadi Basin, which is traditionally interpreted to have been contiguous with the Lambert Graben before Gondwanan breakup. The petrological characteristics suggest that either previous interpretations of Palaeozoic basin alignments between Antarctica and India are incorrect, or that environmental settings and post-Permian burial histories of these basins were strongly independent of their tectonic juxtaposition. A permineralized peat bed within the succession reveals that the coals predominantly comprise wood- and leaf-rich debris derived from low-diversity forest

  11. Grain-rimming kaolinite in Permian Rotliegend reservoir rocks

    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

  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

    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

  13. Global continental weathering trends across the Early Permian glacial to postglacial transition : correlating high- and low-paleolatitude sedimentary records

    Yang, Jianghai; Cawood, Peter A.; Du, Yuansheng; Feng, Bin; Yan, Jiaxin

    2014-01-01

    Time-equivalent Early Permian sedimentary successions from high-latitude Gondwana basins and from equatorial accumulations in North China, covering the glacial to postglacial transition, display correlatable trends in continental weathering intensity based on chemical index of alteration (CIA) values. The successions display a pattern of CIA values that varies with latitude, similar to modern estuarine suspended sediments. Based on the modern-day CIA-temperature correlation, the glacial Early...

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

    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

  15. Severest crisis overlooked-Worst disruption of terrestrial environments postdates the Permian-Triassic mass extinction.

    Hochuli, Peter A; Sanson-Barrera, Anna; Schneebeli-Hermann, Elke; Bucher, Hugo

    2016-01-01

    Generally Early Triassic floras are believed to be depauperate, suffering from protracted recovery following the Permian-Triassic extinction event. Here we present palynological data of an expanded East Greenland section documenting recovered floras in the basal Triassic (Griesbachian) and a subsequent fundamental floral turnover, postdating the Permian-Triassic boundary extinction by about 500 kyrs. This event is marked by a swap in dominating floral elements, changing from gymnosperm pollen-dominated associations in the Griesbachian to lycopsid spore-dominated assemblages in the Dienerian. This turnover coincides with an extreme δ(13)Corg negative shift revealing a severe environmental crisis, probably induced by volcanic outbursts of the Siberian Traps, accompanied by a climatic turnover, changing from cool and dry in the Griesbachian to hot and humid in the Dienerian. Estimates of sedimentation rates suggest that this environmental alteration took place within some 1000 years. Similar, coeval changes documented on the North Indian Margin (Pakistan) and the Bowen Basin (Australia) indicate the global extent of this crisis. Our results evidence the first profound disruption of the recovery of terrestrial environments about 500kyrs after the Permian-Triassic extinction event. It was followed by another crisis, about 1myrs later thus, the Early Triassic can be characterised as a time of successive environmental crises. PMID:27340926

  16. Palynology of the Permian succession of Spitsbergen, Svalbard

    Mangerud, G.; Konieczny, R. M.

    1993-01-01

    Palynological investigations of 16 sections from Spitsbergen, Svalbard, covering the uppermost Carboniferous, Permian and lowermost Triassic succession have been carried out. Because of general poor preservation and barrenness of the majority of the samples, it was not possible to establish a formal zonation for the Permian succession. The study resulted, however, in the recognition of three Permian palynological assemblages, restricted downwards by a Carboniferous assemblage and upwards by a...

  17. 乌尔禾—风城地区二叠系白云质岩类岩石学特征及成因分析%Petrological Characteristics and Origin of Permian Fengcheng Formation Dolomitic Rocks in Wuerhe-Fengcheng Area, Junggar Basin

    张杰; 何周; 徐怀宝; 季换成; 袁青; 史基安; 鲁新川

    2012-01-01

    In order to analyze the dolomite origin of Permian ( Fengcheng Formation) in the northwest edge of Junggar basin. This article take the rock-mineral analysis, thin-section analysis and geochemical analysis, and systematically analyzed this set of dolomite geochemistry characteristics and their origin. The research indicated that the dolomite mainly could divide into muddy dolostone, dolomitic tuff and dolomitic mudstones. The crystal size of dolomite greatly varies, mainly consisting of powder crystal, fine or micrite dolomites, which crystals are euhedral or subhedral. Dolo- mite fills in bedding or cracks or distribute in rocks with patterns of strip belts, laminated structure or gobbets. Dolo- mitization is not incompletely, residual calcite still be found in rocks. Dolostone commonly show ribbon, crumb, sau- sage or lens shapes in rocks, partly laminate and satellite. Sr content varies greatly between 95.9 - 783.6 txg/g with an average of 447 p~g/g because of replenishment of freshwater and intense evaporation. Conclusion can be reached that sedimentary environment is mainly salt water with little amount of freshwater supplement and related to evaporative lake. V/Ni ratio varies greatly, and largely distribute in an range of 1.2 -2.9. It refers to dolomitic rocks form in brackish lacustrine environment with complex setting and various salinity. Mn content is relatively low, varies between 133 - 985 μg/g with an average of 579 μg/g. From Mn data, we can conclude that aragonite forms in relatively deep water. In studying area, 813C is low and distributes in an range of-1.6%-5.2%(PDB) with an average of 2.9%v (PDB). 8180 data still be low, and varies between 14.8%v - 3.2 with average of 3.01 . The characteristics of petromineralogy and the data of geochemical analyzation in Fengcheng Formation show that the dolomite in this area mainly formed in a peaceful, deep and high salinity semi-closed bay environment. Permian periods climate is hot, speedy evaporation and

  18. 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

    Amiruddin Amiruddin

    2014-01-01

    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 Sou...

  19. Permian polar forests: deciduousness and environmental variation.

    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

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

    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

  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

    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. Permian Mengkarang coal facies and environment, based on organic petrology study

    Nana Suwarna

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol1no1.20061aThe Permian Mengkarang Coal Measures is situated in the middle part of Sumatera Island. Some fresh outcrop samples of the Permian Mengkarang coals have been analyzed both macroscopically and microscopically, to asses their depositional environment. On the basis of organic-petrological analysis, the coal seams show variation in the predominance of some macerals, indicating successions of environmental changes. The dominant maceral group is vitrinite, present in very low to very high values; whilst the minor one is inertinite showing low amount. Environmental information derived from the organic facies study shows that the coals were deposited in wet zone of mire, ranges from wet limnic-telmatic zone to telmatic wet forest swamp under rapid burial condition, due to rapid basin subsidence. The organic facies concept is thus applicable in basin studies context and has potential to become an additional tool for interpretation of depositional environment.    

  3. The carbon and sulfur cycles and atmospheric oxygen from middle Permian to middle Triassic

    Berner, Robert A.

    2005-07-01

    The results of a theoretical isotope mass balance model are presented for the time dependence of burial and weathering-plus-degassing fluxes within the combined long-term carbon and sulfur cycles. Averaged data for oceanic δ 13C and δ 34S were entered for every million years from 270 to 240 Ma (middle Permian to middle Triassic) to study general trends across the Permian-Triassic boundary. Results show a drop in the rate of global organic matter burial during the late Permian and a predominance of low values during the early-to-middle Triassic. This overall decrease with time is ascribed mainly to epochs of conversion of high biomass forests to low biomass herbaceous vegetation resulting in a decrease in the production of terrestrially derived organic debris. Additional contributions to lessened terrestrial carbon burial were increased aridity and a drop in sea level during the late Permian which led to smaller areas of low-lying coastal wetlands suitable for coal and peat deposition. Mirroring the drop in organic matter deposition was an increase in the burial of sedimentary pyrite, and a dramatic increase in the calculated global mean ratio of pyrite-S to organic-C. High S/C values resulted from an increase of deposition in marine euxinic basins combined with a decrease in the burial of low-pyrite associated terrestrial organic matter. The prediction of increased oceanic anoxia during the late Permian and early Triassic agrees with independent studies of the composition of sedimentary rocks. Weathering plus burial fluxes for organic carbon and pyrite sulfur were used to calculate changes in atmospheric oxygen. The striking result is a continuous drop in O 2 concentration from ˜30% to ˜13% over a twenty million year period. This drop was brought about mainly by a decrease in the burial of terrestrially derived organic matter. but with a possible contribution from the weathering of older organic matter on land. It must have exerted a considerable influence on

  4. The contorted New England Orogen (eastern Australia): New evidence from U-Pb geochronology of early Permian granitoids

    Rosenbaum, Gideon; Li, Pengfei; Rubatto, Daniela

    2012-02-01

    A series of sharp bends (oroclines) are recognized in the Paleozoic to early Mesozoic New England Orogen of eastern Australia. The exact geometry and origin of these bends is obscured by voluminous magmatism and is still debated. Here we present zircon U-Pb ages that confirm the lateral continuation of early Permian (296-288 Ma) granitoids and shed new light on the oroclinal structure. Orogenic curvature is defined by the alignment of early Permian granitoids parallel to the structural grain of the orogen, as well as the curved geometry of sub-vertical deformation fabrics, forearc basin terranes, and serpentinite outcrops. Alternative geometrical interpretations may involve two bends (Texas and Coffs Harbour Oroclines), three bends (+Manning Orocline), or even four bends (+Nambucca Orocline). We argue that the model involving four bends is most consistent with available data, although further kinematic constraints are required to confirm the existence of the Manning and Nambucca Oroclines. A subsequent phase of younger magmatism (Bowen orogeny.

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

    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

  6. Successor Characteristics of the Mesozoic and Cenozoic Songliao Basins

    LI Zhongquan; Timothy KUSKY; YING Danlin; GUO Xiaoyu; LI Hongkui

    2008-01-01

    The Songliao basin is a complex successor basin that was initiated in the Mesozoic and experienced multiple periods of reactivation. Based on seismic and drilling data, as well as regional geologic research, we suggest that the Songliao basin contains several different successor basins resting on top of Carboniferous-Permian folded strata forming the basement to the Songliao basin. These basins include the Triassic-Mid Jurassic Paleo-foreland basin, the Late Jurassic-Early Cretaceous downfaulted basin, and an early Cretaceous depressed basin (since the Denglouku Group). This paper presents a systematic study of the basin-mountain interactions, and reveals that there are different types of prototype basin at different geologic times. These prototype basins sequentially superimposed and formed the large Songliao basin. Discovery of the Triassic-early Middle Jurassic paleo-foreland basin fills a Triassic-early Middle Jurassic gap in the geologic history of the Songliao basin. The paleoforeland basin, downfaulted basin, and depressed thermal subsidence basin all together represent the whole Mesozoic-Cenozoic geologic history and deformation of the Songliao basin. Discovery of the Triassic-early Middle Jurassic paleo-foreland basin plays an important role both for deep natural gas exploration and the study of basin-mountain coupling in north China and eastern China in general. This example gives dramatic evidence that we should give much more attention to the polyphase tectonic evolution of related basins for the next phase of exploration and study.

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

    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.

  8. Carboniferous-Permian rugose coral Cyathaxonia faunas in China

    2010-01-01

    The Cyathaxonia faunas are widely distributed in the Carboniferous and Permian strata in China.The fauna in China contains 12 families and 40 genera,and can be recognized as three episodes from Early Carboniferous to the end-Permian in terms of their occurrence and composition:1) Mississippian;2) Pennsylvanian-Early Permian;3) Middle Permian-Late Permian.They were relatively abundant in episodes 1 and 2.A decrease of family Antiphyllidae and an increase of family Hapsiphyllidae can be observed from Early Carboniferous to the end-Permian.Two case studies are given to illustrate the bio-facies of the Cyathaxonia faunas,which are from the Mississippian of Baoshan,West Yunnan and the Mississippian of Chaohu,South Anhui.In both areas,Cyathaxonia faunas occur just below the large dissepimented solitary and compound coral assemblages in a continuous sequence in a single section,which implies that the occurrence of these small,non-dissepimented solitary corals is not strictly related with Gondwanan or Peri-gondwanan cold water environment,but might be controlled by such benthic conditions as deeper,mud-rich,quieter,and darker sedimentary environments.

  9. Structure and Hydrocarbons in Junggar Basin

    张庆春; 田在艺

    2002-01-01

    Having undergone four basin-forming tectonic cycles--Hercynian, Indosinian, Yanshanian, and Himalayan, the Junggar basin becomes a multi-cyclic superposed basin of old and hard mediun block pattern. Its multi-cyclic tectonic and sedimentary evolution results in five series of hydrocarbon source rock formations--Carboniferous, Permian, Upper Triassic, Middle-lower Jurassic, and Lower Tertiary, correspondingly forming five petroleum generation systems, of which the Permian and Middle-lower Jurassic petroleum generation systems are the most important with the highest exploration degree. Hydrocarbons are controlled by basin structure as follows: 1) Hydrocarbon accumulations are controlled by the structural styles of paleo-uplifts, paleo-overthrust belts and contorted anticline belts formed in multi-cyclic tectonic movements; 2) Important pathways for long distance lateral and vertical migration are provided respectively by unconformities and faults; 3) The pool-forming characteristics of the Permian petroleum system are controlled by paleo-structure; 4) The pool-forming characteristics of Jurassic and Tertiary petroleum system are controlled by recent structures.

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

    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

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

    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.

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

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

  14. Ocean anoxia did not cause the Latest Permian Extinction

    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

  15. Sedimentary environments of organic matter from Middle Permian source rocks in northern Xinjiang,China

    MIAO Jianyu; KOU Hansheng; ZHOU Lifa; HAN Zhongyuan

    2006-01-01

    A systematic analysis of the inorganic and organic geochemistry of Middle Permian source rocks comprising carbonate rocks and mudstones was carried out, with samples collected from the outcrop and bore of the Junggar, Turpan and Ili basins in northern Xinjiang. This study confirmed that sedimentary parameters for an ancient water body, such as inorganic geochemistry and paleosalinity, have a close relation to the organic matter of source rocks. It is also disclosed that phytane predominance in the source rocks is mainly due to a reducing environment. Biomarkers, such as gammacerane and β-carotene, in the samples reflect a specific salinity in the sedimentary environments. Sedimentary zones with a strong reducing environment are more likely to produce deposits of primary organic matter, which will be buried and preserved contemporarily. Consequently, the source rocks are generally high in organic content and better in organic type than ordinary ones, and vice versa.

  16. Interpretation of "fungal spikes" in Permian-Triassic boundary sections

    Hochuli, Peter A.

    2016-09-01

    Abundant occurrences of the palynomorph Reduviasporonites have been described as "fungal spike" from several Permian/Triassic boundary sections and related to the supposed destruction of woody vegetation by fungal pathogens during the Permian/Triassic extinction event. The biological affinity of this taxa considered by some authors of fungal origin is still controversially discussed since there is geochemical evidence that it is most probably related to algae. The abundance peak of this species is used by some authors as a stratigraphic marker, notably in terrestrial Permian/Triassic boundary sections from South China. Illustrations of the reported fungal remains however show potentially erroneous taxonomic identification of Reduviasporonites, and, based on differences in thermal maturation, they may represent recent contamination. Here Reduviasporonites chalastus of Early Triassic age is illustrated together with recent fungal remains originating from a strongly weathered and otherwise barren sample from a Middle Triassic section.

  17. 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

    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)

  18. Source potential and sequence stratigraphic characterization of microbial evaporitic mudrocks: Upper Permian Zechstein Group, Northern Germany

    Hammes, Ursula; Mutti, Maria

    2013-04-01

    Microbial evaporitic carbonate mudrocks are important source rocks throughout much of the earth history. Some of the largest hydrocarbon provinces are potentially sourced by evaporite source rocks such as the Cretaceous and Jurassic in the Middle East, the Tertiary in Spain, the Permian in northern Germany, the Devonian in Canada, and the Pennsylvanian in the USA. Carbonate mudrocks deposited under mesosaline conditions are often over-looked and dismissed as potential source rocks. However, preservation and accumulation of organic matter in salinity-layered intraplatform epeiric depressions and restricted basin centers are significant. These mudrocks may not only constitute the source but also exhibit reservoir qualities. Slope and basin laminated mudrocks were investigated for their source and reservoir potential using sequence stratigraphic and geochemical techniques to investigate the exploration potential of the northern German Upper Permian Zechstein Formation. The lower Zechstein cycles Z1 and Z2 are characterized by calcareous to argillaceous, laminated, organic-rich mudstones with TOC (total organic carbon) contents ranging mostly 6% in the Z1 cycle. Maturities range from 0.9 to >3% Ro depending on depth of burial for these two cycles. While the Z1 mudrocks deposited above the Rotliegend clastic section are more argillaceous and clay-rich grading upward from calcareous mudstones to intraclast, coated grain, thrombolitic wacke- and packstones into coated-grain grainstones, the Z2 mudrocks are dominated by calcareous to dolomitic laminated mudstones. Both cycles are characterized by microbially bound carbonates ranging from thrombolytic to crenulated laminated structures that are overlain by anhydrite and salt. Stacking patterns of the Z1 3rd-order cycle reveal three 5th-order parasequences stacking into two 4th-order sequences; Z2 3rd-order cycle is composed of three 4th-order parasequences that first deepen and then shallow upwards. Sediments associated

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

    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

  20. Group classification of mixed oils in central Junggar Basin, Northwest China and their migration

    WANG Xulong; SHI Xinpu; CAO Jian; LAN Wenfang; TAO Guoliang; HU Wenxuan; YAO Suping

    2010-01-01

    The produced oils in central Junggar Basin are commonly mixed in origin. In this paper, in order to reveal this complexity and thereby provide valuable clues to the study of oil source and formation mechanism, genetic groups of the mixed oils were classified and their migration/accumulation was investigated. Based on the artificial oil mixing experiments, some representative biomarkers of the mixed oils showed varying tendencies according to mixing ratios of the oils. Hence, these biomarkers are useful for determining the origin of the mixed oils. According to the criteria, oils in the area were divided into four basic groups, i.e., the Lower Permian Fengcheng oil, the Middle Permian Lower Wuerhe oil, the Jurassic source derived oil, and the mixed oil (including the Lower and Middle Permian mixed oil and the Permian and Jurassic mixed oil). Oil migration and accumulation were discussed in combination with the geological background.

  1. Carboniferous and Permian magmatism in Scotland

    Upton, B.G.J.; Stephenson, David; Smedley, Pauline; Wallis, S. M.; Fitton, J.G.

    2004-01-01

    Extensional tectonics to the north of the Variscan Front during the Early Carboniferous generated fault-controlled basins across the British Isles, with accompanying basaltic magmatism. In Scotland Dinantian magmatism was dominantly mildly alkaline-transitional in composition. Tournaisian activity was followed by widespread Visean eruptions largely concentrated within the Scottish Midland Valley where the lava successions, dominantly of basaltic-hawaiitic composition, attained thicknesses of ...

  2. Gondwana basins and their coal resources in Bangladesh

    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)

  3. Gas hydrate contribution to Late Permian global warming

    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

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

    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

  5. Late Carboniferous to Late Permian carbon isotope stratigraphy

    Buggisch, Werner; Krainer, Karl; Schaffhauser, Maria;

    2015-01-01

    An integrated study of the litho-, bio-, and isotope stratigraphy of carbonates in the Southern Alps was undertaken in order to better constrain δ13C variations during the Late Carboniferous to Late Permian. The presented high resolution isotope curves are based on 1299 δ13Ccarb and 396 δ13Corg...

  6. Terrestrial Permian - Triassic boundary sections in South China

    Bercovici, Antoine; Vajda, Vivi

    2016-08-01

    The Permian-Triassic boundary interval in China comprises a significant record of faunal and floral changes during this important extinction event. Here we discuss the details of palynomorph preservation at the classical Western Guizhou and Eastern Yunnan sections in an effort to expand the stratigraphy and paleontology from these earlier studies.

  7. Terrestrial acidification during the end-Permian biosphere crisis?

    Sephton, Mark A.; Jiao, Dan; Engel, Michael H.; Looy, Cindy V.; Visscher, Henk

    2015-01-01

    Excessive acid rainfall associated with emplacement of the Siberian Traps magmatic province is increasingly accepted as a major contributing factor to the end-Permian biosphere crisis. However, direct proxy evidence of terrestrial acidification is so far not available. In this paper, we seek to dete

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

    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

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

  10. The Jurassic of Denmark and Greenland: Late Triassic – Jurassic development of the Danish Basin and the Fennoscandian Border Zone, southern Scandinavia

    Nielsen, Lars Henrik

    2003-01-01

    The continental to marine Upper Triassic – Jurassic succession of the Danish Basin and the Fennoscandian Border Zone is interpreted within a sequence stratigraphic framework, and the evolution of the depositional basin is discussed. The intracratonic Permian–Cenozoic Danish Basin was formed by Late Carboniferous – Early Permian crustal extension followed by subsidence governed primarily by thermal cooling and local faulting. The basin is separated from thestable Precambrian Baltic Shield by t...

  11. Bringing Dicynodonts Back to Life: Paleobiology and Anatomy of a New Emydopoid Genus from the Upper Permian of Mozambique

    Júnior, Luís C.; Angielczyk, Kenneth D.; Martins, Gabriel G.; Martins, Rui M. S.; Chaouiya, Claudine; Beckmann, Felix; Wilde, Fabian

    2013-01-01

    Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia) from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT), combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, “reptilian-grade” morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known. PMID:24324653

  12. Bringing dicynodonts back to life: paleobiology and anatomy of a new emydopoid genus from the Upper Permian of Mozambique.

    Rui Castanhinha

    Full Text Available Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT, combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, "reptilian-grade" morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known.

  13. Astronomical tuning of the end-Permian extinction and the Early Triassic Epoch of South China and Germany

    Li, Mingsong; Ogg, James; Zhang, Yang; Huang, Chunju; Hinnov, Linda; Chen, Zhong-Qiang; Zou, Zhuoyan

    2016-05-01

    The timing of the end-Permian mass extinction and subsequent prolonged recovery during the Early Triassic Epoch can be established from astronomically controlled climate cycles recorded in continuous marine sedimentary sections. Astronomical-cycle tuning of spectral gamma-ray logs from biostratigraphically-constrained cyclic stratigraphy through marine sections at Meishan, Chaohu, Daxiakou and Guandao in South China yields an integrated time scale for the Early Triassic, which is consistent with scaling of magnetostratigraphy from climatic cycles in continental deposits of the Germanic Basin. The main marine mass extinction interval at Meishan is constrained to less than 40% of a 100-kyr (kilo-year) cycle (i.e., marine reptiles in the Mesozoic at Chaohu that are considered to represent a significant recovery of marine ecosystems did not appear until 4.7 myr (million years) after the end-Permian extinction. The durations of the Griesbachian, Dienerian, Smithian and Spathian substages, including the uncertainty in placement of widely used conodont biostratigraphic datums for their boundaries, are 1.4 ± 0.1, 0.6 ± 0.1, 1.7 ± 0.1 and 1.4 ± 0.1 myr, implying a total span for the Early Triassic of 5.1 ± 0.1 myr. Therefore, relative to an assigned 251.902 ± 0.024 Ma for the Permian-Triassic boundary from the Meishan GSSP, the ages for these substage boundaries are 250.5 ± 0.1 Ma for base Dienerian, 249.9 ± 0.1 Ma for base Smithian (base of Olenekian stage), 248.2 ± 0.1 Ma for base Spathian, and 246.8 ± 0.1 Ma for the base of the Anisian Stage. This astronomical-calibrated timescale provides rates for the recurrent carbon isotope excursions and for trends in sedimentation accumulation through the Early Triassic of studied sections in South China.

  14. Carbon isotope evidence for a vigorous biological pump in the wake of end-Permian mass extinction

    Meyer, K. M.; Yu, M.; Jost, A. B.; Payne, J.

    2009-12-01

    Ocean anoxia and euxinia have long been linked to the end-Permian mass extinction and the subsequent Early Triassic interval of delayed biotic recovery. This anoxic, sulfidic episode has been ascribed to both low- and high-productivity states in the marine water column, leaving the causes of euxinia and the mechanisms underlying delayed recovery poorly understood. To examine the nature of the end-Permian and Early Triassic biological production, we measured the carbon isotopic composition of carbonates from an exceptionally preserved carbonate platform in the Nanpanjiang Basin of south China. 13C of limestones from 5 stratigraphic sections displays a gradient of approximately 4‰ from shallow to deep water within the Lower Triassic. The limestones are systematically enriched in the platform interior relative to coeval slope and basin margin deposits by 2-4‰ at the peaks of correlative positive and negative δ13C excursions. This gradient subsequently collapses to less than 1‰ in the Middle Triassic, coincident with accelerated biotic recovery and cessation of δ13C excursions. Based on the relationship between δ18O and δ13C, trace metal analyses, and lithostratigraphic context, we conclude that the carbon isotope gradient is unlikely to reflect meteoric diagenesis, organic matter remineralization, or changes in the mixing ratio of sediment sources and minerals across the platform. Instead, we interpret the relatively depleted δ13C values toward the basin as reflecting DIC input from 13C-depleted deep waters during early diagenesis in a nutrient-rich, euxinic ocean. These observations suggest that a vigorous prokaryote-driven biological pump sustained Early Triassic ocean anoxia and inhibited recovery of animal ecosystems.

  15. Structural evolution of the early Permian Nambucca Block (New England Orogen, eastern Australia) and implications for oroclinal bending

    Shaanan, Uri; Rosenbaum, Gideon; Li, Pengfei; Vasconcelos, Paulo

    2014-07-01

    The Paleozoic to early Mesozoic southern New England Orogen of eastern Australia exhibits a remarkable ear-shaped curvature (orocline), but the geodynamic processes responsible for its formation are unclear. Oroclinal bending took place during the early Permian, simultaneously with the deposition of the rift-related Sydney, Gunnedah, and Bowen basins, which bound the oroclines to the west. The Nambucca Block is another early Permian rift basin, but it is situated in the core of the oroclinal structure. Here we present new stratigraphic, structural, and geochronological data from the Nambucca Block in an attempt to better understand its tectonic history and relationships to the formation of the oroclines. We recognized four phases of folding and associated structural fabrics (S1-4), with the second phase (S2) dated at 275-265 Ma by 40Ar/39Ar geochronology of muscovite. This age overlaps with independent constraints on the timing of oroclinal bending, suggesting that the earlier two phases of deformation in the Nambucca Block (F1 and F2) were associated with orocline formation. We propose that oroclinal bending involved three major stages. The first stage (basins in a hot extensional back-arc setting. This was followed by a second stage of oroclinal bending, possibly linked to dextral wrench faulting, which involved ~ N-S contraction (F1). Subsequent deformation at 275-265 Ma involved formation of nappe-style structures (F2). This phase of contractional deformation may have resulted from an increased plate coupling that was possibly linked to flat-slab subduction.

  16. Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico

    Hoak, T. [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K. [Phillips Petroleum Co., Bartlesville, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States)

    1998-12-31

    The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

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

    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.

  18. Characteristics of Late Permian Deep-Water Sedimentary Environments: A Case Study of Shaiwa Section, Ziyun County, Guizhou Province, Southwestern China

    Gao Yongqun; Yang Fengqing; Peng Yuanqiao

    2005-01-01

    Sediments of carbonate gravity flows and terrigenous debris turbidites, and normal bathyal deposits were found at the Shaiwa Section, Ziyun County, Guizhou Province, southwestern China. Through grain-size analysis of some typical sediments at this section, the changing patterns of the grain parameters and the grain-size cumulations were recovered. Results show that the study area was deposited under turbidite control during the Late Permian period, which we also recognized at the outcrop section upon sedimentary characteristics of the sediments. In addition, fossils are abundant in the Upper Permian of the Shaiwa Section, including radiolarians, sponge-spicules, bivalves, brachiopods, ammonoids and trace fossils. Radiolarians and siliceous sponge-spicules are typical deep water assemblages. Bivalves are dominated by genera of Hunanopecten and Claraia, both showing deep water living characteristics. Ammonoids are composed of planktonic types, showing characteristics of smooth and flat shells. Brachiopods are dominated by a small and thin shelled assemblage, which are commonly flat in shape and usually of slight ornamentations on shells. In addition, trace fossils found at the Shaiwa Section are also common types of deep water facies. Thus, the fossil evidence of the Shaiwa Section also suggests a deep water environment, possibly from the bathyal slope to the basin margin facies, of the studied area during the Late Permian period.

  19. The Permian-Triassic boundary & mass extinction in China

    Ian Metcalfe; Lance Black; Qu Xun; Mao Xiaodong; Robert S. Nicoll; Roland Mundil; Clinton Foster; Jonathan Glen; John Lyons; Wang Xiaofeng; Wang Cheng-yuan; Paul R. Renne

    2001-01-01

    @@ The first appearance of Hindeodus parvus (Kozur & Pjatakova) at the Permian-Triassic (P-T) GSSP level (base of Bed 27c) at Meishan is here confirmed. Hindeodus changxingensis Wang occurs from Beds 26 to 29 at Meishan and appears to be restricted to the narrow boundary interval immediately above the main mass extinction level in Bed 25. It is suggested that this species is therefore a valuable P-T boundary interval index taxon.

  20. Magnetostratigraphic correlations of Permian-Triassic marine-to-terrestrial sections from China

    Glen, J. M. G.; Nomade, S.; Lyons, J. J.; Metcalfe, I.; Mundil, R.; Renne, P. R.

    2009-11-01

    We have studied three Permian-Triassic (PT) localities from China as part of a combined magnetostratigraphic, 40Ar/ 39Ar and U-Pb radioisotopic, and biostratigraphic study aimed at resolving the temporal relations between terrestrial and marine records across the Permo-Triassic boundary, as well as the rate of the biotic recovery in the Early Triassic. The studied sections from Shangsi (Sichuan Province), Langdai (Guihzou Province), and the Junggar basin (Xinjiang Province), span marine, paralic, and terrestrial PT environments, respectively. Each of these sections was logged in detail in order to place geochronologic, paleomagnetic, geochemical, conodont and palynologic samples within a common stratigraphic context. Here we present rock-magnetic, paleomagnetic and magnetostratigraphic results from the three localities. At Shangsi, northern Sichuan Province, we sampled three sections spanning Permo-Triassic marine carbonates. Magnetostratigraphic results from the three sections indicate that the composite section contains at least eight polarity chrons and that the PT boundary occurs within a normal polarity chron a short distance above the mass extinction level and a reversed-to-normal (R-N) polarity reversal. Furthermore, the onset of the Illawarra mixed interval lies below the sampled section indicating that the uppermost Permian Changhsingian and at least part of the Wuchiapingian stages postdate the end of the Kiaman Permo-Carboniferous Reversed Superchron. At Langdai, Guizhou Province, we studied magnetostratigraphy of PT paralic mudstone and carbonate sediments in two sections. The composite section spans an R-N polarity sequence. Section-mean directions pass a fold test at the 95% confidence level, and the section-mean poles are close to the mean PT pole for the South China block. Based on biostratigraphic constraints, the R-N transition recorded at Langdai is consistent with that at Shangsi and demonstrates that the PT boundary occurred within a normal

  1. Spiral-shaped graphoglyptids from an Early Permian intertidal flat

    Minter, Nicholas J.; Buatois, Luis A.; Lucas, Spencer G.; Braddy, Simon J.; Smith, Joshua A.

    2006-12-01

    Spiral-shaped foraging trace fossils, assigned to the grapho glyptid cf. Spirorhaphe azteca, are reported from an Early Permian intertidal flat in the Robledo Mountains of southern New Mexico, USA. Remarkably similar spiral-shaped structures are produced in modern intertidal flats by the paraonid polychaete Paraonis fulgens, and function as traps to capture mobile microorganisms migrating in the sediment in response to tides. We envisage a similar function for the Early Permian trace fossils. Previous studies have suggested that the lack of P. fulgens type traces from ancient intertidal deposits indicates that such behavior only evolved geologically recently in such settings. However, this report demonstrates that such specialized foraging behavior was present in intertidal settings by at least the Early Permian. Graphoglyptids are typical of deep-marine settings, and characteristic of the Nereites ichnofacies. This represents their first undoubted occurrence in intertidal facies in the geological record. We postulate that the occurrence of graphoglyptids in deep-marine and intertidal settings is related to the predictability of resources. The scarcity of intertidal graphoglyptids in the geological record is most likely a preservational effect.

  2. Thecamoebians from Late Permian Gondwana sediments of peninsular India.

    Farooqui, Anjum; Aggarwal, Neha; Jha, Neerja

    2014-02-01

    The evolutionary history of thecamoebians (testate amoebae) extends back to the Neoproterozoic Era. However, until now, these have had a restricted, discontinuous and modest record across the world. The studied sediment of Raniganj Formation (Godavari Graben), Andhra Pradesh, India has been assigned as Late Permian on the basis of co-occurring age-diagnostic Late Permian palynomorphs. About sixteen thecamoebian species and one taxon incertae sedis have been recorded here in the palynological slides on the basis of shell morphology and morphometry. Out of these, five belong to the family Arcellidae, seven to Centropyxidae, two to Trigonopyxidae, one to Difflugiidae, one to Plagiopyxidae, and one is regarded incertae sedis. The morphometric characteristics of fossil forms resemble their corresponding extant species studied from ecologically diverse fresh water wetlands in India. In general, the ratio of shell diameter and aperture diameter of Late Permian fossil and extant specimens show significant correlation in all the studied species. Except that, the ratio of shell length and breadth is the distinguishing feature between Centropyxis aerophila and C. aerophila 'sylvatica', rather than the ratio of shell length and longest diameter of the shell aperture in both fossil and extant forms. The study elucidates the minimal morphological evolution in thecamoebians and their survival during mass extinction periods and stressful environmental conditions over the geological timescale. PMID:23876495

  3. Hooked: Habits of the Chinese Permian gigantopterid Gigantonoclea

    Seyfullah, Leyla J.; Glasspool, Ian J.; Hilton, Jason

    2014-04-01

    Based upon anatomical evidence, Permian aged gigantopterid fossils are in general reconstructed as climbing or scrambling plants. Gigantonoclea, a genus of adpressed gigantopterid foliage from the Permian of northern China, has been reported to co-occur with hook-like organs that were interpreted as indicating a scrambling/climbing habit. We reinvestigated these hook-like structures and re-evaluated the nature of the co-occurrences in context with the flora preserved in each plant-bearing fossil 'bed' in the North China sedimentary succession. New findings show that the species Gigantonoclea hallei probably climbed using specially adapted clusters of compound grappling hook-like shoots borne on the stems. This structural arrangement comprising shoots of hooks is new to the scrambling/climbing concept in gigantopterids. However, a key figured specimen previously reported as showing intermediate hook-tipped leaf morphology on a sole pinnule tip is discounted as such and is reinterpreted as a 'normal' pinnule partially hidden under sediment that results in an unusual appearance to this pinnule tip. Adaptations for climbing or scrambling based upon 'hooked leaves' observed in Gigantonoclea lagrelii are no longer supported and are reinterpreted as incompletely expanded leaves where the vernation process was interrupted. These data weaken prior interpretations of G. lagrelii as a climber/scrambler and raise doubts about the ubiquity of hooks amongst the gigantopterids as structures enabling them to climb or scramble their way through the Permian world.

  4. Source, evolution and emplacement of Permian Tarim Basalts: Evidence from U-Pb dating, Sr-Nd-Pb-Hf isotope systematics and whole rock geochemistry of basalts from the Keping area, Xinjiang Uygur Autonomous region, northwest China

    Zhang, Dayu; Zhou, Taofa; Yuan, Feng; Jowitt, Simon M.; Fan, Yu; Liu, Shuai

    2012-04-01

    Permian basalts distribute at least 250,000 km2, and underlie the southwest Tarim Basin in Xinjiang Uygur Autonomous region, northwest China. This vast accumulation of basalt is the main part of the Tarim Large Igneous Province (LIP). The basaltic units in the Lower Permian Kupukuziman and Kaipaizileike Formations in the Keping area, Tarim Basin; were the best exposure of the Permian basalt sequence in the basin. LA-ICP-MS U-Pb dating of zircon from the basal basaltic unit in the section gives an age of 291.9 ± 2.2 Ma (MSWD = 0.30, n = 17); this age, combined with previously published geochronological data, indicates that the basalts in the Tarim Basin were emplaced between 292 Ma and 272 Ma, with about 90% of the basalts being emplaced between 292 and 287 Ma. Basalts from the Keping area have high FeOT (10.8-18.6 wt.%), low Mg#s (0.26-0.60), and exhibit primitive mantle normalized patterns with positive Pb, P and Ti but negative Zr, Y and Ta anomalies. The basalts from both formations have similar 206Pb/204Pb (18.192-18.934), 207Pb/204Pb (15.555-15.598) and 208Pb/204Pb (38.643-38.793) ratios. The basalts also have high ɛSr(t) (45.7-62.1), low ɛNd(t) (-3.6 to -2.2) and low zircon ɛHf(t) (-4.84 to -0.65) values. These characteristics are typical of alkali basalts and suggest that the basalts within the Tarim Basin were derived from an OIB-type mantle source and interacted with enriched mantle (EMI-type) before emplacement. Rare earth element systematics indicate that the parental melts for the basalts were high-degree partial melts derived from garnet lherzolite mantle at the base of the lithosphere. Prior to emplacement, the Tarim Permian Basalts (TPB) underwent fractional crystallization and assimilated crustal material; the basalts were finally emplaced during crustal extension in an intra-plate setting. The wide distribution, deep source and high degree partial melting of the TPB was consistent with a mantle plume origin. The TPB and other coeval igneous

  5. Tectonic evolution of Tethyan tectonic field, formation of Northern Margin basin and explorative perspective of natural gas in Tarim Basin

    2002-01-01

    Analyzing the characteristics of the Tethyan tectonic field, the authors think that the Tethyan tectonic field underwent three evolutional stages: closing of Paleo-Tethys and rifting of Neo-Tethys from early Permian to late Triassic, subduction of Neo-Tethys and collision between the Indian plate and the Eurasia plate from Jurassic to early of low Tertiary, and collision between the Arab plate and the Eurasia plate and the A-type subduction of Indian plate from late of low Tertiary to the present. Combining the evolution of the Tethyan orogenic belt with the characteristics of the Northern Margin basin, it is suggested that the sedimentary and tectonic characteristics and types of the Northern Mar-gin basin are controlled by the formation and evolution of the Tethyan orogenic belt and the ingression of Tethys. The evolution of Northern Margin basin can be divided into three development stages: back-arc foreland basin from late Permian to Triassic, the back-arc fault subsidence and depression from Jurassic to the early of low Tertiary, and the reactive foreland basin from the late of low Tertiary to the present. The Northern Margin basin in the Tethyan tectonic field is an important region for natural gas accumulation, and the Tarim Basin is a part of this region.

  6. Permian U-Pb (CA-TIMS) zircon ages from Australia and China: Constraining the time scale of environmental and biotic change

    Denyszyn, S. W.; Mundil, R.; Metcalfe, I.; He, B.

    2010-12-01

    In eastern Australia, the interconnected Bowen and Sydney Basins are filled with terrestrial sediments of late Paleozoic to early Mesozoic age. These sedimentary units record significant evolutionary events of eastern Gondwana during the time interval between two major mass extinctions (end Middle Permian and Permian-Triassic), and also provide lithological evidence for the Carboniferous-Permian Late Paleozoic Ice Age of southern Pangea, considered to be divisible into up to seven discrete glaciation events in Australia [e.g., 1]. These glaciations are currently assigned ages that indicate that the last of the glaciations predate the end Middle Permian mass extinction at ca. 260 Ma. However, the estimates for the time and durations are largely based on biostratigraphy and lithostratigraphy that, in the absence of robust and precise radioisotopic ages, are unacceptably fragile for providing an accurate high-resolution framework. Interbedded with the sediments are numerous tuff layers that contain zircon, many of which are associated with extensive coal measures in the Sydney and Bowen Basins. Published SHRIMP U-Pb zircon ages [2, 3] have been shown to be less precise and inaccurate when compared to ages applying the CA-TIMS method to the same horizons. Also within the late Middle Permian, the eruption of the Emeishan flood basalts in SW China has been proposed to have caused the end Middle Permian mass extinction [e.g., 4], though a causal link between these events demands a rigorous test that can only be provided by high-resolution geochronology. We present new U-Pb (CA-TIMS) zircon ages on tuff layers from the Sydney and Bowen Basins, with the purpose of generating a timescale for the Upper Permian of Australia to allow correlation with different parts of the world. Initial results, with permil precision, date a tuff layer within the uppermost Bandanna Fm. to ca. 252 Ma, a tuff within the Moranbah Coal Measures to ca. 256 Ma, and a tuff within the Ingelara Fm. to

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

    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

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

    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

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

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

    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.

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

    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

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

    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

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

    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

  14. Permian and Triassic Sequence Stratigraphy and Sea Level Changes of Eastern Yangtze Platform

    1999-01-01

    The Permian and marine Triassic of eastern Yangtze platform, situated in eastern China, involve 19 orthosequences lasting about 2.7 Ma on average, which can be combined into five orthosequence sets ranging from 8 Ma to 12 Ma. Affected by the regional Dongwu and Indosinian movements, the sequence stratigraphic pattern and sea level changes in the Permian and Triassic of this region are distinctive and obviously different from most other regions in the world, but typical in the broad eastern Tethys and its neighboring areas. In this region not only did the continuous marine Permian and Triassic boundary sequences cause the orthosequence crossing the boundary belonging to type-Ⅱ sequence but also the mesosequence including these stratigraphic intervals had its basal boundary in the upper Longlinian (Artinskian) (ca. 278 Ma), that is, the traditional Carboniferous and Permian boundary, and its top boundary moved from the Permian and Triassic boundary upward into the Anisian of Middle Triassic.

  15. 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.

    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

  16. The Permian post-orogenic collapse in the Alps: insights from the Campo unit (Austroalpine nappes, N-Italy, SE-Switzerland)

    Petri, Benoît; Mohn, Geoffroy; Štípská, Pavla; Manatschal, Gianreto; Schulmann, Karel

    2014-05-01

    The final stage of the Variscan orogeny (310-270 Ma) is characterized by an intense tectonic, magmatic and metamorphic event. During the Permian, acid and mafic intrusions were emplaced at all crustal levels and are associated to high-temperature contact metamorphism. While most of the studies focus either on the formation of Permian basins or on the lower crustal magmatic and metamorphic evolution, the characterization of the middle crust is lacking. Therefore, this study aims to unravel the processes active at mid-crustal levels during the Permian. We investigate the contact aureole of the Sondalo gabbro emplaced in a mid-crustal position during the Permian, exposed in the Austroalpine Campo unit (N-Italy). This work is based on a multidisciplinary approach linking structural geology, metamorphic petrology and geochronology. The country rock of the gabbroic intrusion is composed of Grt-St micaschists and paragneisses indicating a prograde path in the amphibolite facies associated with the formation of a N-W steeply dipping S2 foliation. This foliation is pervasively reworked by a N-E trending sub-vertical S3 fabric made of Ms-Bt metasediments. This S3 fabric is also found in metapelitic septa in the core of the mafic intrusion, whereas in the narrow contact aureole a moderately dipping S4 fabric roughly parallel to the margins of the pluton is developed. From host-rock to the center of the intrusion, the metapelites show destabilization of muscovite, appearance of sillimanite, spinel, cordierite, crystallization of a large amount of garnet and finally disappearance of biotite and potassic feldspar. As a consequence, the kinzigitic restites of the contact aureole are replaced by Grt-Sil-Crd-Spl granulites in an intra-plutonic position. Qualitative P-T estimates indicate a barrovian prograde path during D2, similar to P-T evolutions found in other Austroalpine units (e.g. Ulten zone). Thermodynamic modelling of the high-grade granulites due to the thermal effect of

  17. Depositional Environment of Permian Tak Fa Formation, Nakhonsawan, Northern Thailand

    Ketwetsuriya, Chatchalerm; Nützel, Alexander; Kanjanapayont, Pitsanupong

    2016-04-01

    The carbonate rocks of the study area at Amphoe Tak Fa and Amphoe Takhli, Changwat Nakhon Sawan belong to the Tak Fa Formation, Saraburi Group. This formation crops out in the Khao Khwang Platform and consists of late Palaeozoic carbonate platform deposits. It reaches a thickness of 900 meters and crops out in a vast area. The exposures have been measured and samples were collected for petrographic study. The rock consists of limestones, argillaceous limestones, mudstones and dolomites with nodular and banded cherts, which comprise many invertebrate fossils such as fusulinids, ammonoid, pelecypod, gastropod, coral and bryozoa. Many of the fossils are silicified. The gastropod assemblage is currently under study and represents one of the most diverse faunas reported from SE Asia. The age of the rock is Yakhtashian or Artinskian (late Early Permian) to Midian or Capitanian (late Middle Permian). The study of carbonate facies and fauna indicates that the depositional environment was on shelf lagoon within the carbonate platform varying from shallow marine to barrier bar.

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

    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

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

    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

  20. The Cathaysia Flora and the Mixed Late Permian Cathaysian-Angaran Floras in East Asia

    2006-01-01

    The Cathaysia flora, one of the most prominent floras of the Carboniferous and Permian, was mainly distributed in East Asia and was characterized by numerous endemic elements. China is one of the most important localities of the Cathaysia flora and it is also the center of origin of this flora. This paper reviews and discusses the characteristics of the Cathaysia flora and the biogeographically mixed Permian Cathaysian-Angaran floras of East Asia. In addition, the formative mechanism of the mixed Permian floras is also discussed.

  1. Astronomical tuning of the end-Permian extinction and the Early Triassic Epoch of South China and Germany

    Li, Mingsong; Ogg, James; Zhang, Yang; Huang, Chunju; Hinnov, Linda; Chen, Zhong-Qiang; Zou, Zhuoyan

    2016-05-01

    The timing of the end-Permian mass extinction and subsequent prolonged recovery during the Early Triassic Epoch can be established from astronomically controlled climate cycles recorded in continuous marine sedimentary sections. Astronomical-cycle tuning of spectral gamma-ray logs from biostratigraphically-constrained cyclic stratigraphy through marine sections at Meishan, Chaohu, Daxiakou and Guandao in South China yields an integrated time scale for the Early Triassic, which is consistent with scaling of magnetostratigraphy from climatic cycles in continental deposits of the Germanic Basin. The main marine mass extinction interval at Meishan is constrained to less than 40% of a 100-kyr (kilo-year) cycle (i.e., extinction. The durations of the Griesbachian, Dienerian, Smithian and Spathian substages, including the uncertainty in placement of widely used conodont biostratigraphic datums for their boundaries, are 1.4 ± 0.1, 0.6 ± 0.1, 1.7 ± 0.1 and 1.4 ± 0.1 myr, implying a total span for the Early Triassic of 5.1 ± 0.1 myr. Therefore, relative to an assigned 251.902 ± 0.024 Ma for the Permian-Triassic boundary from the Meishan GSSP, the ages for these substage boundaries are 250.5 ± 0.1 Ma for base Dienerian, 249.9 ± 0.1 Ma for base Smithian (base of Olenekian stage), 248.2 ± 0.1 Ma for base Spathian, and 246.8 ± 0.1 Ma for the base of the Anisian Stage. This astronomical-calibrated timescale provides rates for the recurrent carbon isotope excursions and for trends in sedimentation accumulation through the Early Triassic of studied sections in South China.

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

    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. Calculating eustatic amplitude of Middle Permian from reefs

    WU; Yasheng; (吴亚生); FAN; Jiasong; (范嘉松)

    2002-01-01

    Methods for calculating ancient eustatic change amplitudes according to reef fabric- facies are proposed, with a new method for determining sediment-loading subsidence. Compared with methods based on non-reefal deposits, these methods are more accurate in restoration of original sediment thickness, determination of sediment-loading subsidence, as well as restoration of ancient water depth. According to the reef in Guangxi, China, the amplitude of sea-level rise during Middle Permian (Neoschwagerina-Yabeina zone) is 249.5 m. According to the coeval reef of the Guadalupe Mountains, New Mexico and Texas, the coeval sea-level rise is 247 m. With these effective methods available, it is feasible to establish more accurate eustatic curve of Phanerozoic.

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

    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...

  5. Mg Isotopes of the Late Permian Evaporites, New Mexico, USA

    Feng, C.; Gao, C. H.; Chang, S. C.

    2015-12-01

    Mg isotope holds promise to decipher the evaporative environment of evaporites. High-precision Mg isotope compositions of the late Permian langbeinites have been measured by using MC-ICPMS. The equilibrium Mg isotope fractionation factor between langbeinite and aqueous Mg2+ solutions has been determined using quantum chemistry calculations. All computations are employed at B3LYP/6-311++G(2d,2p) level and solvation effects are treated by solvent model ("water-droplet" approach), mineral structures are constructed using volume variable cluster models (VVCM). The Mg isotope compositions of the langbeinite samples, whose total formation thickness ranges up to 100 meters, are extremely isotopically lighter than that of modern seawater and relatively homogeneous (δ26MgDSM3 is from -4.12±0.03‰ to -3.81±0.07‰ v.s. -0.83‰ of modern seawater). The computed equilibrium Mg isotope fractionation factors between langbeinite and aqueous Mg2+ solutions are -2.73‰, -2.66‰ and -2.53‰ at 25, 30 and 40 ℃, respectively. These significant equilibrium fractionation factors indicate that a huge equilibrium Mg isotope fractionation between langbeinite and its parent brine can happen during langbeinite depositions, and langbeinites are enriched in isotopically light 24Mg comparing to the brine. Using the computed fractionation factors to simulate a Rayleigh fractionation process of langbeinite Mg precipitation, we find that a significant Mg isotope difference between langbeinite and its growing brine (seawater) is indeed present but the Mg isotope composition of langbeinite merely increase monotonically in a closed system. Because of that, the homogenous Mg isotope compositions of such a thick evaporite sequence suggest a disequlibrium effect rather than an equilibrium Mg isotope fractionation behavior during its formation. Combined with its prevailing Mg-bearing character, the homogenous Mg isotope compositions reveal that this the late Permian langbeinite sequence has

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

    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 = 94.2–97.04). 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°C 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. A Major Unconformity Between Permian and Triassic Strata at Cape Kekurnoi, Alaska Peninsula: Old and New Observations on Stratigraphy and Hydrocarbon Potential

    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.

  8. Application of Fluid Inclusions in the Study of Natural Gas Geology in Ordos Basin

    FAN Ai-ping; YANG Ren-chao; FENG Qiao; LIU Yi-qun; HAN Zuo-zhen

    2006-01-01

    The new recently demonstrated reserves of oil and gas in the Ordos basin are found at the top of petroliferous basins in China. Gas pools discovered in recent years in the Permian system have become the main natural gas resource in the basin. Therefore, synthetic research on fluid inclusions should be done in order to ascertain the pool-forming stage, the maturity of organic matters and the properties of Paleo-fluids. The main types of fluid inclusions in the Permian system in the basin include brine inclusions, carbon dioxide inclusions and organic inclusions. Homogenization temperatures (HT) of brine inclusions can be divided into four intervals: 66-83 ℃, 86-108 ℃, 112-138 ℃ and 142-153 ℃. The fluid inclusions in the interval of 112-138 ℃ are much more than that of other intervals, indicating that the second stage of hydrocarbon migration associated with the third temperature interval is the most important stage of gas pool formations. The fluid inclusion has extensive applications in the study of gas geology, not only in ascertaining the formation stage of gas pools, but also in estimating the maturity of organic matter and restoring Paleo-fluids. The result of testing the HT of brine inclusions shows that there are two stages of gas pool formations in the Permian system occurring ±150 Ma and ±100 Ma. The maturity of organic matter is moderate to high, a conclusion based on the color of fluid inclusions (radiated by fluorescence). The high salinity of Paleo-fluids of the NaCl-H2O and CaCl2-H2O systems shows good preservation conditions of the Paleo-fluids. Two stages of reservoir filling, high maturity of organic matter and good preservation conditions are factors favorable for the formation and preservation of large-scale gas pools in the Permian system in the Ordos basin.

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

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

    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.

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

    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

  12. Fractured Anhydrite as a Geothermal Source in a Low Enthalpy Context (Southern Permian Basin, Netherlands)

    Daniilidis, Alexandros; Herber, Marinus

    2015-01-01

    Increased heat flow associated with the presence of salt domes could be beneficial for geothermal energy applications in a low enthalpy nvironment. Anhydrite layers within such salt domes could be a potential geothermal target. These layers are known to undergo brittle deformation, which in turn can

  13. Effect of Relative Permeability on History Matching a Permian Basin Oil Well

    Silseth, Jørgen

    2015-01-01

    Production from shale oil and gas has increased significantly the last couple of decades. The industry is constantly developing horizontal well and stimulation technology to increase production from these wells. Data acquisition is fairly well established and reliable in conventional reservoirs. This, however, is not the case in unconventional shale reservoirs. In shales the data is usually limited to drilling logs, temperature and pressure measurements and fluid samples. Even the fluid sampl...

  14. Pore pressure evolution and induced seismicity within the Permian Basin, Southeast New Mexico USA

    Person, M. A.; Zhang, Y.; Mozley, P.; Broadhead, R.; Bilek, S.; Edel, S.

    2015-12-01

    We used three-dimensional hydrologic modeling to assess the potential linkages between crystalline basement seismicity (up to M3.2) beneath the Dagger Draw oil field in response to saline water reinjection. Production began in 2004 and preceded an increase in seismicity by about 5 years. Reinjection of produced brines occurred within the basal Ellenberger Group carbonate reservoir (yellow square). Published core permeability measurements for the Ellenberger vary between about 10-15 to 10-12 m2. Evidence for seismicity being triggered by injection include observations that the largest injection rates (> 106 barrels/month) occurred within wells closest to the induced seismicity (red circle about 15 km to the west of the injection well in A-C). Arguing against triggered seismicity is the apparent lack of temporal correlation between peak injection and felt seismicity as well as the extreme depth of the earthquakes (about 10-12 km below land surface). We conducted a numerical sensitivity study in which we varied the permeability of the basal reservoir as well as the crystalline basement rocks over several orders of magnitude. Assuming a crystalline basement permeability of 10-16 m2 and a basal reservoir permeability of 10-13 m2 produced about 50 m of excess heads in the seismogenic crust about 1900 days (D) after injection started. Prior studies suggest that excess heads of only a few meters could induce failure along critically stressed faults. The lag between injection and seismicity can be explained by the time required for the pressure envelope to propagate laterally 15 km and downward into the crystalline basement 11 km. Peak injection occurred 1900 days before recent increases in seismicity were observed. Future work will include assessing the potential role of relatively permeable Proterozoic faults in transmitting high fluid pressures into the crystalline basement.

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

    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

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

    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.

  17. A taphonomic model for the Mesosauride assemblage of the Irati Formation (Paraná Basin, Brazil)

    Soares, M B

    2003-01-01

    The Irati Formation (Permian, Paraná Basin, Brazil) is made up of a succession of black bituminous and nonbituminous shales and mudstones with interbedded carbonate layers, which record deposition in marine environments. Mesosaur remains are abundant at several sites in this formation, where they occur preserved in centimetre- thick beds and displaying various degrees of skeletal disarticulation. This paper seeks to establish a model to explain the processes that generated the mesosaurian tap...

  18. 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

    E.J. Llambías

    2007-06-01

    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

  19. From foreland rift to forearc basin: Tectono-thermal controls on subsidence and stratigraphic development in the Mesozoic-Recent Salar de Atacama basin, Chilean Andes

    Flint, S. (Univ. of Liverpool (United Kingdom)); Turner, P. (Univ. of Birmingham (United Kingdom)); Hartley, A. (Univ. of Wales, Cardiff (United Kingdom)); Jolley, E. (BP Exploration, Glasglow (United Kingdom))

    1991-03-01

    The Salar de Atacama and westerly adjacent Domeyko basins originated as Permian foreland rifts, containing some 2 km of Triassic synrift red beds. Continued extension and volcanic are establishment resulted in deposition of important Jurassic marine source rocks in the Domeyko basin. Rift basin subsidence was controlled by extension, followed by thermal sagging. Middle Cretaceous contraction (opening of the south Atlantic) inverted the Domeyko back-arc basin as a thrustbelt. To the east, the Salar basin subsequently accommodated 4 km of Late Cretaceous-Palaeocene continental detritus. Accommodation space reflected the interplay between limited flexural loading and thermal effects related to a 150 km eastward jump of the Andean volcanic arc to the margin of the arc-related, foreland-style basin. Late Eocene transpression (high rate of oblique convergence between the Farallon and South American plates) inverted the western basin margin, sourcing a 2 km thick Oligocene intra-arc basin-fill component. Accommodation space was controlled by thermal sagging associated with a further 100 km eastward arc jump. The Salar de Atacama basin thus provides a model for the evolution of complex, mixed origin basins associated with a migrating volcanic arc and varying crustal stress regime. The complex interplay between variable tectonic style and thermal processes in controlling subsidence and resultant stratigraphic development is not yet adequately constrained. However, simple, single stage tectono-sedimentary models commonly used in play definition may not be appropriate in complex, arc-related basin settings.

  20. Extremely acid Permian lakes and ground waters in North America

    Benison, K.C.; Goldstein, R.H.; Wopenka, B.; Burruss, R.C.; Pasteris, J.D.

    1998-01-01

    Evaporites hosted by red beds (red shales and sandstones), some 275-265 million years old, extend over a large area of the North American mid- continent. They were deposited in non-marine saline lakes, pans and mud- flats, settings that are typically assumed to have been alkaline. Here we use laser Raman microprobe analyses of fluid inclusions trapped in halites from these Permian deposits to argue for the existence of highly acidic (pH lakes and ground waters. These extremely acidic systems may have extended over an area of 200,000 km2. Modern analogues of such systems may be natural acid lake and groundwater systems (pH ~2-4) in southern Australia. Both the ancient and modern acid systems are characterized by closed drainage, arid climate, low acid-neutralizing capacity, and the oxidation of minerals such as pyrite to generate acidity. The discovery of widespread ancient acid lake and groundwater systems demands a re-evaluation of reconstructions of surface conditions of the past, and further investigations of the geochemistry and ecology of acid systems in general.

  1. Simulated warm polar currents during the middle Permian

    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.)

  2. Electrokinetic transport behavior of phenol in upper Permian soils

    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.)

  3. Application of Markov chain and entropy analysis to lithologic succession – an example from the early Permian Barakar Formation, Bellampalli coalfield, Andhra Pradesh, 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 → interbedded fine-grained sandstone/shale → shale → 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. Bioessential element-depleted ocean following the euxinic maximum of the end-Permian mass extinction

    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

  5. Two pulses of oceanic environmental disturbance during the Permian-Triassic boundary crisis

    Shen, Jun; Feng, Qinglai; Algeo, Thomas J.; Li, Chao; Planavsky, Noah J.; Zhou, Lian; Zhang, Mingliang

    2016-06-01

    Pyrite morphology, iron speciation, and pyrite sulfur isotope data from the Xiakou section (Hubei Province, South China) were integrated to explore oceanic environmental variations through the Permian-Triassic transition and their possible relations to the largest mass extinction in Earth history. High ratios of highly-reactive iron to total iron (FeHR/FeT > 0.6) and pyrite iron to highly-reactive iron (FePy/FeHR > 0.7) together with a high abundance of small (mean diameter 0.6) along with lower values of FePy/FeHR (punctuated by episodic euxinic events in the latest Permian to earliest Triassic (post-extinction interval). The largest fluctuations of these redox proxies are observed in the ∼1.0 m of strata directly overlying the first (latest Permian) extinction horizon, indicating unsettled marine environmental conditions marked by frequent perturbations during the ∼60-kyr interval immediately following the mass extinction. The two largest redox events at Xiakou coincided with deposition of volcanic ash layers that have been correlated with Beds 25 and 28 of the Meishan D section, each of which was associated with an extinction pulse (the first and second extinction horizons of latest Permian and earliest Triassic age, respectively). Thus, our observations document two pulses of oceanic environmental change during the Permian-Triassic transition, each associated with a faunal crisis and possibly triggered by contemporaneous volcanic activity.

  6. Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai,Northwest China

    2008-01-01

    sequence re-sulting from calm shallow water was deposited at the interior of the Qamdo Block from the Devonian to early Early Permian. At the beginning of the peak period of activity of pan-riftzation (Luodianian), al-ternate volcanic island and shallow marine environment within continent crust came into being. Uni-form and stable shallow-water carbonate platform was formed during the Xiangboan. This suggested that the activity of rift basin was evidently weakened. Subsequently the instability of the basin appre-ciably increased with the occurrence of basalt in late Kuhfengian. At last the whole Qamdo Block turned into the closure period of rift during the Late Permian.

  7. Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai, Northwest China

    NIU ZhiJun; XU AnWu; WANG JianXiong; DUAN QiFa; ZHAO XiaoMing; YAO HuaZhou

    2008-01-01

    resulting from calm shallow water was deposited at the interior of the Qamdo Block from the Devonian to early Early Permian. At the beginning of the peak period of activity of pan-riftzation (Luodianian), alternate volcanic island and shallow marine environment within continent crust came into being. Uniform and stable shallow-water carbonate platform was formed during the Xiangboan. This suggested that the activity of rift basin was evidently weakened. Subsequently the instability of the basin appreciably increased with the occurrence of basalt in late Kuhfengian. At last the whole Qamdo Block turned into the closure period of rift during the Late Permian.

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

    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...

  9. DETERMINATION OF TECTONIC EVOLUTION OF A SEDIMENTARY BASIN FROM SANDSTONE COMPONENTS

    Lei SHAO; Chuanlian LIU; Karl STATTEGGER

    2001-01-01

    Terrigenous sedimentary rocks are the dominant rock types in continental sedimentary basin, the components of these rocks are mainly controlled by source rocks. Through systematically analyzing the components of terrigenous sedimentary rocks, the tectonic evolution of a sedimentary basin can be reconstructed. The Turpan Basin was examined using sandstone petrological and geochemical methods.The consistency of the petrographical and geochemical results shows that the tectonic evolution of the basin can be subdivided into four stages: the first stage covers the Permian; the second stage the Triassic;the third stage from the Lower Jurassic to Upper Jurassic and the fourth stage from the Cretaceous to Tertiary. The components of sandstones among these stages are different, which reflect the influence of tectonics movements on the evolution of the basin and surrounding areas.

  10. Coexistence and inherence of diverse energy resources in the Ordos Basin, China

    CHANG Xiangchun; WANG Mingzhen; HAN Zuozhen

    2006-01-01

    The Ordos Basin is abundant in oil, natural gas, coal, coalbed gas and sandstone-type uranium deposits. Oil pools are hosted mainly in the Triassic and Jurassic systems in the southern part of the basin. Gas reservoirs which occur dominantly in the northern part of the basin are situated vertically beneath the oil pools. Coal measures are widely distributed in the Carboniferous, Permian, Jurassic and Triassic systems. Developed at the margin of the basin are the sandstone-type uranium deposits and coalbed gas. The investigations of sources and timing of various energy resources indicated that there are certain genetic connections among them. Especially the contributions of coal measures to natural gas, the supplement of coalbed gas to deep basin gas and the reduction of uranium deposits by natural gas are relatively remarkable.