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Sample records for Permian Basin

  1. Exploratory shaft facility preliminary designs - Permian Basin

    International Nuclear Information System (INIS)

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

  2. Permian Basin location recommendation report

    International Nuclear Information System (INIS)

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

  3. Exploratory shaft conceptual design report: Permian Basin

    International Nuclear Information System (INIS)

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Permian Basin locatd in the western part of Texas. Conceptualized designs for other possible locations (Paradox Basin in Utah and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

  4. The Central European Permian Basins; Rheological and structural controls on basin history and on inter-basin connectivity

    Science.gov (United States)

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

    2014-05-01

    We analyse the relative importance of the major crustal-scale fault zones and crustal architecture in controlling basin formation, deformation and the structural connections between basins. The North and South Permian Basins of Central Europe are usually defined by the extend of Rotliegend sedimentary and volcanic units and not by a common tectonic origin or development. Instead, the sub-basins that together form the Permian Basins are each controlled by different structural and/or rheological controls that are inherited from Early Paleozoïc and older geodynamic processes, they are even located in different crustal/lithospheric domains. The North Permian basin is located on Baltic crust that was thinned during Late Proterozoïc - Early Paleozoïc times. South of the Thor suture, the South Permian basin and its sub-basins are located on Avalonian crust (Southern North Sea and North German Basins) and on the transition of East European cratonic and Avalonian crust (Polish Through). The size of crustal domains and of the faults that govern basin formation requires a regional-scale to assess their impact on basins and sub-basins. In the case of the Permian Basins this encompasses East Avalonia and surroundings, roughly speaking the area north of the Variscan Rheïc suture, east of the Atlantic and southwest of the Teisseyre-Tornquist line. This approach sheds light on the effects of long lived differences in crustal fabric which are responsible for spatial heterogeneity in stress and strain magnitudes and zonations of fracturing, burial history and temperature history. The focus on understanding the geomechanical control of large crustal-scale fault structures will provide the constraints and geometrical and compositional input for local models of stress and strain. Considering their fundamentally different structural and rheological controls, the Permian (sub)basins have a remarkably common history of subsidence and inversion, suggesting a more or less continuous link between them. Post-Variscan, Late Carboniferous-Early Permian wrench tectonics is the oldest and main identified cause for regional basin formation in Central Europe. This relatively short-lived tectonic regime cannot explain the observed common history of subsidence of the Permian Basins during the 200 My that followed. Our analysis demonstrates that transfer faults that both follow and cross rheological transitions and inherited fault zones continued to be active after the early Permian. We therefore suggests that crustal-scale transfer faults may be the missing link that explains the common subsidence history of basins with a fundamentally different crustal architecture and structural history.

  5. Development of the Permian Basin beam pump failure database

    Science.gov (United States)

    Rahman, Mohammed Mahbubur

    Artificial Lift Energy Optimization Consortium (ALEOC) was formed by eleven oil companies operating in the Permian Basin with the primary goal of improving oil field operations through sharing experiences. Beam pumping system received special attention because it is the most widely used artificial lift method in the Permian Basin as well as in the world. The combined effort to optimize beam pumping system calls for the creation of a central database, which will hold beam pump related data from diverse sources and will offer ways to analyze the data to obtain valuable insight about the nature, magnitude and trend of beam pump failure. The database mentioned above has been created as part of this work. The database combines beam pump failure data from about 25,000 wells owned by different companies into a single, uniform and consistent format. Moreover, two front-end computer applications have been developed to interact with the database, to run queries, and to make plots form the query results. One application is designed for desktop, while the other one is designed for the Internet. Both applications calculate failure frequencies of pump, rod, and tubing, and summarize the results in various ways. Thus the database and the front-end applications together provide a powerful means for analyzing beam pump failure data. Much useful information can be gathered from the database, such as the most vulnerable component in the system, the best and the worst performers, and the most troublesome operating area. Such information can be used for benchmarking performance, identifying best design/operational practices, design modification, and long term production planning. Results from data analysis show that the pump has the highest probability to fail in a beam pumping system, followed by the rod string and the tubing string. The overall failure in the Permian Basin shows a general decline with time.

  6. Geology Resources: The University of Texas of the Permian Basin

    Science.gov (United States)

    The University of Texas of the Permian Basin (UTPB) has a well-regarded geology program, and they have created this engaging site to profile the geology of their unique corner of West Texas. Their geology resources page contains the following sections: "Geological Overview", "West Texas Geology", "Interesting Links", "Road Logs", "Cores & Samples & Topo Maps", and "Presentations". The "Geological Overview" area offers a brief rundown of the geological milieu surrounding the UTPB campus. Moving on, the site really comes alive in "West Texas Geology", with insightful descriptions of the Basin and Range Province, faults, folds, igneous intrusions, and a relief map of Texas. Those with a penchant for travel will be delighted with the "Road Logs" area. Essentially, they are geological tour guides for persons driving from Midland to Van Horn, the Guadalupe Mountains, and other locations. Overall, it's a well-done site, and one that visitors will want to share with friends.

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

    International Nuclear Information System (INIS)

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

  8. Permian and Triassic microfloral assemblages from the Blue Nile Basin, central Ethiopia

    Science.gov (United States)

    Dawit, Enkurie L.

    2014-11-01

    Palynological investigation was carried out on surface samples from up to 400 m thick continental siliciclastic sediments, here referred to as “Fincha Sandstone”, in the Blue Nile Basin, central Ethiopia. One hundred sixty species were identified from 15 productive samples collected along a continuous road-cut exposure. Six informal palynological assemblage zones have been identified. These assemblage zones, in ascending order, are: “Central Ethiopian Permian Assemblage Zone - CEPAZ I”, earliest Permian (Asselian-Sakmarian); “CEPAZ II”, late Early Permian (Artinskian-Kungurian); CEPAZ III - Late Permian (Kazanian-Tatarian); “CETAZ IV”, Lower Triassic (Olenekian Induan); “CETAZ V”, Middle Triassic (Anisian Ladinian); “CETAZ VI”, Late Triassic (Carnian Norian). Tentative age ranges proposed herein are compared with faunally calibrated palynological zones in Gondwana. The overall composition and vertical distribution of miospores throughout the studied section reveals a wide variation both qualitatively and quantitatively. The high frequency of monosaccate pollen in CEPAZ I may reflect a Glossopterid-dominated upland flora in the earliest Permian. The succeeding zone is dominated by straite/taeniate disaccate pollen and polyplicates, suggesting a notable increase in diversity of glossopterids. The decline in the diversity of taeniate disaccate pollen and the concomitant rise in abundance of non-taeniate disaccates in CEPAZ III may suggest the decline in Glossopteris diversity, though no additional evidence is available to equate this change with End-Permian extinction. More diverse and dominant non-taeniate, disaccate, seed fern pollen assignable to FalcisporitesAlisporites in CETAZ IV may represent an earliest Triassic recovery flora. The introduction of new disaccate forms with thick, rigid sacci, such as Staurosaccites and Cuneatisporites, in CETAZ V and VI may indicate the emergence of new gymnospermous plants that might have favourably adapted to coastal plain wetland environments with the return of humid conditions in the Middle to early Late Triassic. The present data constitute the first paleontologically substantiated record for the existence of Permian strata in the Blue Nile Basin. The new results allow for the first time a reliable biostratigraphic subdivision of the central Ethiopia Karoo and its correlation with coeval strata of adjacent regions in Gondwana. From a phytogeographic point of view, the overall microfloral evidence is in support of the position of central Ethiopia occupying the northern part of the southern Gondwana palynofloral province. In view of palaeoecological and paleoclimatic conditions, the microfloral change from the base to the top of the studied section may indicate a response to shifting climatic belts from warm- and cool-temparate climate in the earliest Permian to progressively drier seasonal conditions at successively higher palaeolatitudes during the Late Permian to Middle Triassic.

  9. Selection of nuclear waste repository sites in the Permian Basin

    International Nuclear Information System (INIS)

    Since late 1977, the US Department of Energy (DOE) has been conducting environmental and geologic studies in order to identify potential sites for the disposal of high-level nuclear waste from commercial reactors. The DOE proposes to bury the waste deep underground in conventionally-mined repositories located in stable geologic deposits such as salt formations. Geologic, environmental, and socioeconomic studies led to the identification of two potentially suitable repository sites in the Permian bedded salt formation of west Texas. Detailed multi-disciplinary studies will be required to confirm the ability of these sites to isolate the high-level nuclear waste from the human environment for a period of 10,000 years in an environmentally sound manner. This report provides a description and discussion of the multi-step site selection process that identified the two 9 square mile (23 square kilometer) sites from the 80,000 square mile (26,000 square kilometer) Permian salt formation

  10. Uranium mineralization in Broumov Permian System of Lower Silesia basin

    International Nuclear Information System (INIS)

    The geological characteristics are given of the Broumov Permian. Anomalous uranium accumulations are mainly bound to volcanogenous rocks and volcanoclastic sediments. It was determined mineralogically that uranium mineralization in melaphyre tuffaceous agglomerates consisted of secondary uranium minerals, mainly of tyuyamunite and sengierite, which was confirmed using an electron microanalyzer. The occurrence of other elements (V, Si, Al, Ca, P, Ti, Fe, Cu) on the uranium mineralization site is described from X-ray planar distribution. (E.S.) 1 fig., 1 tab

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

    International Nuclear Information System (INIS)

    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 oloral 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)

  12. 77 FR 49863 - Iowa Pacific Holdings, LLC and Permian Basin Railways-Continuance in Control Exemption-Santa Cruz...

    Science.gov (United States)

    2012-08-17

    ...and Monterey Bay Railway Company Iowa Pacific...and Permian Basin Railways (IPH/PBR), noncarriers...to continue in control of Santa Cruz and Monterey Bay Railway Company (SCMB...Acquis. & Operation...

  13. Assessment of potential unconventional Carboniferous-Permian gas resources of the Liaohe Basin eastern uplift, Liaoning Province, China, 2011

    Science.gov (United States)

    Pollastro, Richard M.; Potter, Christopher J.; Schenk, Christopher J.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.; Kirschbaum, Mark A.

    2012-01-01

    The U.S. Geological Survey estimated a mean of 448 billion cubic feet of potential technically recoverable unconventional natural gas in Carboniferous and Permian coal-bearing strata in the eastern uplift of the Liaohe Basin, Liaoning Province, China.

  14. Permian continental paleoenvironments in Southeastern Asia: New insights from the Luang Prabang Basin (Laos)

    Science.gov (United States)

    Bercovici, Antoine; Bourquin, Sylvie; Broutin, Jean; Steyer, Jean-Sébastien; Battail, Bernard; Véran, Monette; Vacant, Renaud; Khenthavong, Bounxou; Vongphamany, Sotsy

    2012-10-01

    In Laos (Southeastern Asia), Late Paleozoic sediments were identified by early French explorations across Indochina during the late 19th century (Pavie missions), but little work was undertaken to characterize the sedimentological and stratigraphical context until now. From detailed sedimentological and paleontological studies, we propose an interpretation of the depositional environment and of the stratigraphic context of series located on the right bank of the Mekong River in the Luang Prabang Basin where three main formations were described. The silicoclastic Red Claystone Formation, attributed to alluvial plain environment, contains large fragments of unidentified dicynodonts. The Limestones and Sandstones Formation preserves a new macrofloral assemblage displaying affinities with Middle to Late Permian Cathaysian floras of South China. This assemblage occurs as an intercalation within marine calcareous sandstones that have yielded a marine fauna, including the ammonoid Pseudotirolites sp. which indicates a Late Permian (Changhsingian) age. The well-developed Purple Claystones Formation yielded an abundant and well preserved Late Permian fauna composed of a carnivorous amphibian and numerous Dicynodon cranial and postcranial elements. This formation shows a vertical evolution from braided river to alluvial plain with sheet-flood sand bed and bed-load rivers, with a constant supply of volcanic clasts. Results from the analysis of the paleontological associations in the Luang Prabang Basin suggest that a continental communication between Laurussia and the Indochina Block existed during the Permian, allowing for migration of the terrestrial Dicynodon fauna.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    Energy Technology Data Exchange (ETDEWEB)

    Rychel, Dwight

    2013-09-30

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

  17. Charcoal remains from a tonstein layer in the Faxinal Coalfield, Lower Permian, southern Paraná Basin, Brazil

    OpenAIRE

    André Jasper; Dieter Uhl; Margot Guerra-Sommer; Abu Hamad, Abdalla M. B.; Machado, Neli T. G.

    2011-01-01

    Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumpti...

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

    Directory of Open Access Journals (Sweden)

    Ivan Mlakar

    2003-06-01

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

  19. Late Permian-early Middle Triassic back-arc basin development in West Qinling, China

    Science.gov (United States)

    Li, Lin; Meng, Qingren; Pullen, Alex; Garzione, Carmala N.; Wu, Guoli; Wang, Yanling; Ma, Shouxian; Duan, Liang

    2014-06-01

    The Late Permian-early Middle Triassic strata of the northern West Qinling area, northeastern Tibetan Plateau, are composed of sediment gravity flow deposits. Detailed sedimentary facies analysis indicates these strata were deposited in three successive deep-marine environments. The Late Permian-early Early Triassic strata of the Maomaolong Formation and the lowest part of the Longwuhe Formation define a NW-SE trending proximal slope environment. Facies of the Early Triassic strata composing the middle and upper Longwuhe Formation are consistent with deposition in a base-of-slope apron environment, whereas facies of the Middle Triassic Anisian age Gulangdi Formation are more closely associated with a base-of-slope fan depositional environment. The lithofacies and the spatial-temporal changes in paleocurrent data from these strata suggest the opening of a continental margin back-arc basin system during Late Permian to early Middle Triassic time in the northern West Qinling. U-Pb zircon ages for geochemically varied igneous rocks with diabasic through granitic compositions intruded into these deep-marine strata range from 250 to 234 Ma. These observations are consistent with extensional back-arc basin development and rifting between the Permian-Triassic Eastern Kunlun arc and North China block during the continent-continent collision and underthrusting of the South China block northward beneath the Qinling terrane of the North China block. Deep-marine sedimentation ended in the northern West Qinling by the Middle Triassic Ladinian age, but started in the southern West Qinling and Songpan-Ganzi to the south. We attribute these observations to southward directed rollback of Paleo-Tethys oceanic lithosphere, continued attenuation of the West Qinling on the upper plate, local post-rift isostatic compensation in the northern West Qinling area, and continued opening of a back-arc basin in the southern West Qinling and Songpan-Ganzi. Rollback and back-arc basin development during Late Permian to early Middle Triassic time in the West Qinling area explains: the truncated map pattern of the Eastern Kunlun arc, the age difference of deep-marine sediment gravity flow deposits between the Late Permian-early Middle Triassic northern West Qinling and the late Middle Triassic-Late Triassic southern West Qinling and Songpan-Ganzi, and the discontinuous trace of ophiolitic rocks associated with the Anyemaqen-Kunlun suture.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Strontium and sulfur isotope study of well-preserved Permian anhydrite, Palo Duro basin, Texas

    International Nuclear Information System (INIS)

    The ?34S, 87Sr/86Sr ratio, and strontium concentrations for 50 well-preserved samples of Permian marine anhydrite have been determined. The samples were collected from two continuous cores drilled through cyclic Permian evaporites, The Department of Energy drilled the samples in its search for a permanent storage facility for high-level nuclear waste. Primary depositional fabrics (selenite pseudomorphs) and high strontium concentrations (average 1,850 ppm), in association with published bromide and fluid inclusion data from associated halite, suggest primary seawater 87Sr/86Sr ratios may be recorded in many of the samples. The general shape of the 87Sr/86Sr ratio curve through the Permian is in accord with previously published observations. However, the increased stratigraphic detail from this unique set of cores constrains the abrupt charge in 87Sr/86Sr during the Permian at a precision previously available only in Deep Sea Drilling Project material. Interpretation of the more complex portions of the curve is limited by poor biostratigraphic control, the specter of provincial early diagenetic effects, and interpretation of the time significance of hiatal surfaces in cyclic strata. Age relationships are constrained by a K-Ar date on an interbedded volcanic ash in the Ochoan strata, and fusulinid age determinations of a well-documented regional transgression during the eented regional transgression during the earliest Guadalupe. Sulfur isotopes yield typical Permian values of 12 per-thousand during the marine portion of the basin fill phase, and abruptly shift to 10 per-thousand in those cycles with a significant component of siliciclastic sediment

  2. Socioeconomic data base report for the Permian Basin

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  4. Cyclic sedimentation in the shallow marine Upper Permian Kennedy Group, Carnarvon Basin, Western Australia

    Science.gov (United States)

    Lever, Helen

    2004-11-01

    The Upper Permian Kennedy Group of the Carnarvon Basin, Western Australia, was deposited while the Merlinleigh Sub-basin was undergoing thermal subsidence, and the global climate was warming from the Carboniferous-Permian glaciation to the Mesozoic Greenhouse conditions. The Kennedy Group comprises siliciclastic sedimentary rocks, dominated by sandstones in the lower part, with coarsening-up cycles from mudstones to very coarse sandstones and granule conglomerates in the upper part. Cycles were observed and logged in the field, and although many types of cycles were found, three main motifs describe most of the cycles. Cycle motifs are defined based on the dominance of the various facies: Mooka motif cycles are dominated by fine-grained and bioturbated facies (interpreted as deposition during relative sea-level highstand) with only thin laminated or cross-bedded sandstones (interpreted as deposited during relative sea-level fall); Binthalya motif cycles are dominated by laminated and cross-bedded sandstones; and Coolkilya motif cycles consist of alternating laminated and bioturbated beds. A hierarchy of cycles was observed in the field, and this correlated well with spectral analysis of logged parameters. Spectral analysis of section log data and data sets corrected for the effects of compaction and sedimentation rates detected regular cyclicity. Geochronology of the Kennedy Group is not well enough constrained to allow the cycle periods in time to be calculated, but ratios of the different scale cycle thicknesses correlate well with ratios of the Milankovitch orbital cycles that have been calculated for the Permian. The presence of regular cyclicity and even bed thicknesses across large distances are not consistent with tectonic or autocyclic models of cycle formation. The cycles are more likely to have been caused by fluctuating eustatic sea levels, perhaps enhanced by changing amounts or seasonality of precipitation. Both sea levels and climatic fluctuations would ultimately be controlled by the Milankovitch orbital cycles.

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

    Science.gov (United States)

    Zientek, Michael L.; Oszczepalski, S?awomir; 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).

  6. 77 FR 57188 - Iowa Pacific Holdings, LLC and Permian Basin Railways-Continuance in Control Exemption-Rusk...

    Science.gov (United States)

    2012-09-17

    ...Permian Basin Railways (PBR), have filed...to continue in control of Rusk, Palestine...American Heritage Railways of Texas, LLC...Pacific R.R.--Operation Exemption--Tex...Saratoga & North Creek Railway, located in New...authority to continue in control of a new...

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

    Czech Academy of Sciences Publication Activity Database

    Opluštil, S.; Šim?nek, Z.; Zajíc, Jaroslav; Mencl, V.

    2013-01-01

    Ro?. 119, ?. 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

  8. Assessment of remaining recoverable oil in selected major oil fields of the Permian Basin, Texas and New Mexico

    Science.gov (United States)

    Tennyson, Marilyn E.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Klett, Timothy R.; Verma, Mahendra K.; Ryder, Robert T.; Attanasi, Emil D.; Freeman, Philip A.; Le, Phoung A.

    2012-01-01

    The U.S. Geological Survey (USGS) recently completed an estimate of technically recoverable, conventional oil in selected oil fields in the Permian Basin in west Texas and southeastern New Mexico. The mean total volume of potential additional oil resources that might be added using improved oil-recovery technologies was estimated to be about 2.7 billion barrels of oil.

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

    Science.gov (United States)

    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 Kiaman superchron.

  10. The origin and formation model of Permian dolostones on the northwestern margin of Junggar Basin, China

    Science.gov (United States)

    Lu, Xinchuan; Shi, Ji'an; Zhang, Shuncun; Zou, Niuniu; Sun, Guoqiang; Zhang, Shengyin

    2015-06-01

    This study investigates the mechanism of dolostone formation and establishes a dolomitization model in the Permian strata on the northwestern margin of Junggar Basin, China. Dolomitic rock samples are collected from the Permian Fengcheng Formation in Urho area and then characterized by petrological, mineralogical, carbon and oxygen isotope, and trace element geochemical analyses. Results show that the major types of dolomitic rocks include dolomitic mudstone, dolomitic siltstone, dolomitized tuffaceous siltstone, and dolomitized tuffaceous mudstone. The dolomitized rocks are dominated by euhedral or subhedral powder- and fine-crystal dolomites formed by replacement lacustrine argilla-calcareous and siliceous (tuffaceous) components and commonly filled with residual and late calcite cements. The parameters of dolomitic rocks show great variations, including the V/Ni ratio (1.02-4.88), Sr content (95.9-783.6 ?g/g), Mg/Ca ratio (0.68-5.13), degree of ordering (0.39-1.00), ?18OPDB (-14.8‰ to 3.2‰), and ?13CPDB (-1‰ to 5.2‰). The dolomitic rocks have multi-stage origins and were formed in a semi-closed continental brackish-saltwater bay with weak hydrodynamic processes, deep water bodies, and relatively quiet conditions. In the Permian depositional stage, a combination of complex tectonic activities, fault development, hot subtropical climate, and frequent volcanic activities provided not only Mg2+ source for dolomitization but also channels for rapid flow and seepage of Mg-rich fluids. The origins of dolostones in the study area include penecontemporaneous dolomitization, burial dolomitization, and hydrothermal dolomitization. This study lays a foundation for further studies on dolomite formation and dolomite reservoir, and provides effective methods for researching complex dolostone (tuffaceous, shale and silty dolomite) formation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-03

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-09-23

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

  13. A mid-Permian chert event: widespread deposition of biogenic siliceous sediments in coastal, island arc and oceanic basins

    Science.gov (United States)

    Murchey, B.L.; Jones, D.L.

    1992-01-01

    Radiolarian and conodont of Permian siliceous rocks from twenty-three areas in teh the circum-Pacific and Mediterranean regions reveal a widespread Permian Chert Event during the middle Leonardian to Wordian. Radiolarian- and (or) sponge spicule-rich siliceous sediments accumulated beneath high productivity zones in coastal, island arc and oceanic basins. Most of these deposits now crop out in fault-bounded accreted terranes. Biogenic siliceous sediments did not accumulate in terranes lying beneath infertile waters including the marine sequences in terranes of northern and central Alaska. The Permian Chert Event is coeval with major phosphorite deposition along the western margin of Pangea (Phosphoria Formation and related deposits). A well-known analogue for this event is middle Miocene deposition of biogenic siliceous sediments beneath high productivity zones in many parts of the Pacific and concurrent deposition of phosphatic as well as siliceous sediments in basins along the coast of California. Interrelated factors associated with both the Miocene and Permian depositional events include plate reorientations, small sea-level rises and cool polar waters. ?? 1992.

  14. Geochemistry of End-Permian Crater Lake Sediments in the Tunguska Basin, Siberia, and the Implications for Extinction Mechanisms

    Science.gov (United States)

    Fristad, K. E.; Svensen, H.; Planke, S.; Polozov, A. G.

    2008-12-01

    The end of the Permian period is marked by global warming and the largest known mass extinction on Earth. The crisis is commonly attributed to the formation of the Siberian Traps Large Igneous Province although the causal mechanisms remain disputed. One of the proposed mechanisms is the generation of carbon gases and halocarbons in contact aureoles in the Tunguska Basin and subsequent gas venting to the atmosphere. We are testing this hypothesis by performing detailed geochemistry and biostratigraphy on crater lake deposits overlying an end-Permian phreatomagmatic pipe in the southern parts of the Tunguska Basin. During an expedition to the Bratsk region in 2006 we sampled a 1300 meter long core drilled through the center of a crater lake and the underlying brecciated pipe. The core consists of 550 meters of fine to coarse grained clastic lake deposits and 750 meters of sedimentary and volcanic breccias. Preliminary biostratigraphy results show that the sediments contain abundant and exceptionally well preserved end- Permian and early-Triassic palynomorphs, supporting a causal link between the formation of the breccia pipe and the crater lake and the end-Permian extinction. Ongoing isotope stratigraphy aims at documenting the exact timing between the crater lake formation and the initial Triassic carbon isotope excursion.

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

    Science.gov (United States)

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

    2008-01-01

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

  16. Late Permian cycle-stratigraphy in the continental deposits of the Karoo basin (South Africa) (Invited)

    Science.gov (United States)

    Lanci, L.; Tohver, E.; Wilson, A.; Ratcliffe, K. T.; Flint, S.

    2013-12-01

    Magnetostratigraphic and geochronological studies of late Permian Waterford and Abrahamskraal Formations (uppermost Ecca Group and lowermost Beaufort Group, respectively) in the Karoo Basin of South Africa yielded age-constrained magnetostratigraphy that can be correlated with the most recent reference geomagnetic polarity time scale. This precise chronological framework provides the basis for a chemostratigraphic analysis of cyclicity based on the measured major and trace element composition of these fluvial mudstones and sandstones. Our multi-taper spectral power analysis was computed using the concentration of major oxides, showing clear peaks at frequencies that are compatible with the expected orbital periodicities according to the magnetostratigraphic chronology. Given the length of the studied section (~500 m) and the relatively high sedimentation rate (~100m/Myr), we consider that the short hiatuses that are to be expected in river deposits are not likely to obliterate long-period cyclicity such as orbital eccentricity. We interpret long period cyclicity as reflecting orbital eccentricity (ca. 400 kyr), with even shorter period orbital frequencies observed in the record. Statistical analysis suggests that the chemical composition does not correlate with the sediments grain size but is related to the lithology through their relative abundance of clays and SiO2-rich clastic material. Although chemical changes might partly reflect stochastic fluctuation due to fluvial hydrodynamics, their orbital periodicity suggests that they are mainly paced by environmental changes that in turn may control the sediment weathering and/or fluvial dynamics. Recognition of the orbitally controlled sedimentation allows very precise dating of the time involved in the deposition of these sedimentary rocks. Astronomical tuning provides an improved calibration of this portion of the polarity time scale and give hints on the variability of the environmental conditions during the Late Permian.

  17. Charcoal remains from a tonstein layer in the Faxinal Coalfield, Lower Permian, southern Paraná Basin, Brazil

    Directory of Open Access Journals (Sweden)

    André Jasper

    2011-06-01

    Full Text Available Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Paraná Basin.Charcoal fóssil foi encontrado na Mina do Faxinal, Permiano Inferior, Formação Rio Bonito, na porção sul da Bacia do Paraná, Brasil. Foram descritos três tipos de lenhos gimnospérmicos picnoxílicos originários de um único nível de tonstein, o que confirma a ocorrência de paleoincêndios vegetacionais nesta área. Uma redução da concentração de charcoal da base para o topo no nível de tonstein indica que a quantidade de combustível diminuiu durante a deposição, provavelmente devido ao consumo da vegetação existente pelo fogo. A presença de inertinita na camada de carvão, em níveis sobrepostos e sotopostos ao tonstein , indica que incêndios não estavam restritos ao intervalo de deposição da cinza vulcânica. A integração dos novos dados aqui apresentados com outros publicados anteriormente acerca da Mina do Faxinal, demonstra que eventos vulcânicos ocorridos nas áreas circunvizinhas podem ser identificados como potenciais fatores de ignição para os incêndios. A presença de chacoal em sedimentos associados a níveis de carvão em diferentes localidades no Permiano, demonstra que incêndios vegetacionais foram relativamente comuns nos ambientes formadores dos depósitos de carvão da Bacia do Paraná.

  18. Charcoal remains from a tonstein layer in the Faxinal Coalfield, Lower Permian, southern Paraná Basin, Brazil

    Scientific Electronic Library Online (English)

    André, Jasper; Dieter, Uhl; Margot, Guerra-Sommer; Abdalla M. B, Abu Hamad; Neli T. G, Machado.

    2011-06-01

    Full Text Available Charcoal fóssil foi encontrado na Mina do Faxinal, Permiano Inferior, Formação Rio Bonito, na porção sul da Bacia do Paraná, Brasil. Foram descritos três tipos de lenhos gimnospérmicos picnoxílicos originários de um único nível de tonstein, o que confirma a ocorrência de paleoincêndios vegetacionais [...] nesta área. Uma redução da concentração de charcoal da base para o topo no nível de tonstein indica que a quantidade de combustível diminuiu durante a deposição, provavelmente devido ao consumo da vegetação existente pelo fogo. A presença de inertinita na camada de carvão, em níveis sobrepostos e sotopostos ao tonstein , indica que incêndios não estavam restritos ao intervalo de deposição da cinza vulcânica. A integração dos novos dados aqui apresentados com outros publicados anteriormente acerca da Mina do Faxinal, demonstra que eventos vulcânicos ocorridos nas áreas circunvizinhas podem ser identificados como potenciais fatores de ignição para os incêndios. A presença de chacoal em sedimentos associados a níveis de carvão em diferentes localidades no Permiano, demonstra que incêndios vegetacionais foram relativamente comuns nos ambientes formadores dos depósitos de carvão da Bacia do Paraná. Abstract in english Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in t [...] his area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Paraná Basin.

  19. Why stratigraphy and sedimentology in shales are important : an example from the Woodford Shale, Permian Basin, west Texas

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

    This presentation explained why stratigraphy and sedimentology in shales are important. The presentation provided an example from the Woodford Shale, Permian Basin, located in western Texas. Several illustrations were presented to demonstrate a stratigraphic sequence in black shale. Other topics that were discussed included geologic settings; paleogeography; silled basins; motivation for rock properties research; and factor analysis results. It was concluded that sequence stratigraphic analyses in black shales requires an integrated, multidisciplinary approach. The presentation showed that third and fourth order stratigraphic cycles are indicated by the repetition of exotic beds whose composition vary regionally. tabs., figs.

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

    International Nuclear Information System (INIS)

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

  1. U-Pb zircon ages from the southwestern Karoo Basin, South Africa - Implications for the Permian-Triassic boundary

    Science.gov (United States)

    Fildani, A.; Weislogel, A.; Drinkwater, N.J.; McHargue, T.; Tankard, A.; Wooden, J.; Hodgson, D.; Flint, S.

    2009-01-01

    U-Pb ages determined using sensitive high-resolution ion microprobe-reverse geometry on 205 single-grain zircons from 16 ash beds within submarine fan deposits of the Ecca Group provide the first evidence of a marine Permian-Triassic (P-T) boundary in the Karoo Basin of South Africa. These U-Pb ages provide an objective basis for correlating the deep-marine sediments of the southwest Karoo Basin with fluvial-deltaic deposits in the central and eastern parts of the basin where the P-T boundary is recorded in a diverse macrofauna. Furthermore, these new zircon ages and their correlation imply asymmetric subsidence and variable sedimentation rates across the basin. ?? 2009 Geological Society of America.

  2. Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa

    Scientific Electronic Library Online (English)

    Nicholas, Fordyce; Roger, Smith; Anusuya, Chinsamy.

    Full Text Available Dicynodonts are an extinct group of herbivorous non-mammalian therapsids ('mammal-like' reptiles) that are widely known from terrestrial Permo-Triassic strata throughout Pangaea. Dicynodont fossil remains are common within the Late Permian Beaufort Group of the Karoo Basin in South Africa. A large, [...] partially articulated dicynodont skeleton recovered from the Tropidostoma Assemblage Zone is taphonomically important in having an unusual disarticulation pattern, bone surface punctures and a broken tooth of an unidentified carnivore associated with it. Here we report on the nature of the bone damage, and the identity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass. The morphological characteristics of the serrations on the unidentified tooth were compared with those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanning electron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive 0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature, cross-sectional shape and morphology of the serrations revealed that the unidentified canine most closely matched Aelurognathus, a gorgonopsian known from the same assemblage zone.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-04-01

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

  5. Regional summary and recommended study areas for the Texas panhandle portion of the Permian Basin. Technical report

    International Nuclear Information System (INIS)

    This report summarizes the regional geologic and environmental characterizations that have been completed for the Permian region of study, and describes the procedure used to identify study areas for the next phase of investigation. The factors evaluated in the Permian region fall into three broad areas: health and safety, environmental and socioeconomic, and engineering and economic considerations. Health and safety considerations included salt depth and thickness, faults, seismic activity, groundwater, salt dissolution, energy and mineral resources, presence of boreholes, and interactive land uses. Salt depth and thickness was the key health and safety factor, and when mapped, proved 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Valenta, Jan; Rapprich, V.; Stárková, M.; Skácelová, Z.; Fojtíková, Lucia; Stan?k, František; Balek, Jan

    2014-01-01

    Ro?. 59, ?. 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: 0.744, year: 2013 http://www.jgeosci.org/detail/jgeosci.170

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

    Energy Technology Data Exchange (ETDEWEB)

    John Jackson; Katherine Jackson

    2008-09-30

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

  13. A new aeduellid actinopterygian from the Lower Permian of the Krkonoše Piedmont Basin (Bohemian Massif) and its relationship to other Aeduellidae

    OpenAIRE

    Štamberg S

    2010-01-01

    A new aeduellid actinopterygian, Neslovicella elongata sp. nov., is described from the Lower Permian of the Krkonoše Piedmont Basin (Bohemian Massif). The new taxon is based upon a collection of specimens that facilitated the revision of several characters of the Aeduellidae. N. elongata is described in detail and compared to other aeduellids. A second occurrence of this species in the Weissig Basin of Germany is also discussed.

  14. Provenance study of Permian non-marine sandstones and conglomerates of the Krkonoše Piedmont Basin (Czech Republic): exotic marine limestone pebbles, heavy minerals and garnet composition

    OpenAIRE

    Martínek K; Štolfová K

    2009-01-01

    This study focuses on identifying major source areas in several stratigraphic intervals in the Permian sediments of the Krkonoše Piedmont Basin and integrates it with existing sedimentological data. Pebbles in Cisuralian-Guadalupian conglomerates of alluvial fans, nearshore lacustrine and lacustrine fan-delta deposits that were deposited close to the northwestern and southeastern basin margin, respectively, correspond almost exclusively to local material from adjacent crystalline complexes. T...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-13

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

  16. Irradiation of quartz grains - a new method of sedimentological analysis applied to Permian - Carboniferous arenites in the Maranhao Basin - Brazil

    International Nuclear Information System (INIS)

    The quartz grains of sediments and sedimentary rocks change their colour in variable intensity to smoky-quartz by X-ray irradiation, Co60 or in reactors, dependent on their temperature of cristallization. The quantity of quartz grains which were stained and which were not stained after being irradiated are related to rock types from the source areas. This method was applied for selected sandstones of different stratigraphical levels of the Permian-Carboniferous in the Maranhao Basin of Brazil. Studeis on heavy minerals of these sandstones have been done before. The heavy mineral associations of the Permian Pedra de Fogo Formation corroborate the results of the analysis of quartz grains which indicate a predominance of the metamorphic rocks in the source area. However, the heavy mineral parageneses of the Carboniferous Piaui Formation are different. This may be because the frequency of those heavy minerals depend directly on the stage of the weathering of the sandstones. It should be mentioned that heavy minerals occur in paleozoic sediments only in a small quantity, sometimes below 1% of the rock constitution. The irradiation analysis, which is applied for the predominant mineral in sandstones, appears to be most reliable. It is used here as the basis for the interpretations presented. (Author)

  17. Pipe formation and degassing from the Tunguska Basin in East Siberia and the consequences for the end-Permian environment

    Science.gov (United States)

    Svensen, Henrik; Planke, Sverre; Fristad, Kirsten; Polozov, Alexander; Schmidbauer, Norbert

    2010-05-01

    The end of the Permian period is marked by a perturbation of the global carbon cycle and the largest known mass extinction on Earth. The crisis is commonly attributed to the formation of the Siberian Traps Large Igneous Province although the causal mechanisms remain disputed. We have recently suggested that heating of Tunguska Basin sediments by the ascending magma played a key role in triggering the crisis. Our conclusions are based on extensive field work in Siberia in 2004 and 2006. Here we present new data on contact metamorphism and gas release. Heating of organic-rich shale and petroleum bearing evaporites led to greenhouse gas and halocarbon generation in sufficient volumes to cause global warming and atmospheric ozone depletion. This is supported by experiments on heated rock samples from Siberia. The gases were released to the end-Permian atmosphere partly through spectacular phreatomagmatic pipe structures with kilometre-sized craters, formed during sill emplacement 252.0 ± 0.4 million years ago. We demonstrate that the composition of the heated sedimentary rocks below the flood basalts is the most important factor in controlling whether a Large Igneous Provinces causes an environmental crisis or not.

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

    Directory of Open Access Journals (Sweden)

    Paulo A. Souza

    2005-06-01

    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.Com base na distribuição de grãos de pólen, duas unidades palinobioestratigráficas são formalisadas para o Permiano da Bacia do Paraná no Rio Grande do Sul. As unidades correspondem, da base para o topo, às zonas de intervalo Vittatina costabilis e Lueckisporites virkkiae, sendo a primeira subdividida em duas subzonas: Protohaploxypinus goraiensis e Hamiapollenites karrooensis. A primeira zona é considerada eopermiana (Eo a Mesocisuraliano, tendo sido detectada junto à seqüência glacial e pós-glacial referente ao Grupo Itararé e Formação Rio Bonito, abrangendo ainda porções inferiores da Formação Palermo. A Zona Lueckisporites virkkiae, considerada neo-eopermiana a mesopermiana (neocisuraliana a eoguadalupiana, ocorre nas formações Palermo e Irati, podendo ainda ser estendida a estratos mais superiores da bacia (formações Serra Alta e Teresina. Suas principais características e seções de referência são apresentadas, bem como outros critérios requeridos pelo Código Estratigráfico Internacional na proposição de unidades bioestratigráficas.

  19. Thermochronological Constraints on Detrital Sediments of the Late Permian Karoo Basin: Insights Into Uplift History of the Cape Fold Belt

    Science.gov (United States)

    Tohver, E.; Arosio, R.; Schmieder, M.; Jourdan, F.; Wilson, A.; Flint, S.

    2012-12-01

    The Karoo Basin and its equivalents cover most of southern Africa, with correlative basins found also in South America. The vast geographic expanse of these basins indicates a common history of deposition along the active Panthalassan margin of southern Gondwana. The early Paleozoic history of the Karoo Basin is marked by early glacio-marine to later shallow marine-deltaic sedimentation with a final shift to a continental setting by the late Permian. In South Africa, this transition to a fluvial environment is defined by the deposition of the Beaufort Group, a ca. 5 km thick sequence of meandering river channel sandstones and muddy overbank deposits. We have identified an 800 m thick sequence of the lowermost Beaufort Group where magnetostratigraphy and U-Pb dating of zircon in volcanic tuffs establish a depositional age of 264-268 Ma. Detrital zircon from sandstone samples were dated by U-Pb SHRIMP, revealing age populations typical of the cratonic/metamorphic provinces of the Kalahari craton (Kaapval and Namaqua-Natal provinces) as well as late Paleozoic magmatic zircons probably from southern South America. Populations of detrital muscovite dated using the 40Ar/39Ar step-heating technique are dominated by a tight cluster of ca. 272 Ma cooling ages, indicating rapid exhumation of the tectonically active Cape Fold belt and short lag times (4-8 Ma) for detritus deposited into the Karoo foreland basin, similar to rates observed for modern sediments of Himalayan-draining rivers. Ongoing work will reveal whether the Cape Belt is the source for the sediments of the Karoo foreland basin.

  20. Radioactivity distribution in some Permian sediments from the Irati and Corumbatai Formations of the Parana Basin, Southeastern Brazil

    International Nuclear Information System (INIS)

    In the city of Limeira, southeastern Brazil, an important exposure of Permian sediments of the Parana basin was revealed by an open pit mine that exploits limestone for production of soil correction compounds and raw materials for the ceramic industry. The radioactivity of these sediments was investigated in some detail and the results provided a general view of the vertical distributions of uranium, thorium and potassium concentrations and of the element ratios U/K, U/Th and Th/K. In general, the concentrations of the main natural radioactive elements are low, with uranium being enriched in some limestone and shale levels. In addition the results showed that the 238U series is in radioactive disequilibrium in many of the analyzed samples. Although the origin of the observed disequilibrium has not been investigated, the results suggest that it is due to weathering processes and water interaction with the rock matrix

  1. The Permian Whitehill Formation (Karoo Basin, South Africa): deciphering the complexity and potential of an unconventional gas resource

    Science.gov (United States)

    Götz, Annette E.

    2014-05-01

    A key energy policy objective of the South African government is to diversify its energy mix from coal which constitutes 85% of the current mix. Gas will play a key role in the future South African economy with demand coming from electricity generation and gas-to-liquids projects. A study on world shale reserves conducted by the Energy Information Agency (EIA) in 2011 concluded that there could be as much as 485 Tcf recoverable reserves of shale gas in the South African Karoo Basin. However, the true extent and commercial viability is still unknown, due to the lack of exploration drilling and modern 3D seismic. The present study compiles existing data from literature review and new data from outcrop analogue studies on the Permian Whitehill Formation, the main target formation for future shale gas production, including thickness, depth, maturity, TOC, lithologies, sedimentary and organic facies, and dolerite occurrence to provide a first reference dataset for further investigations and resource estimates.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. A brief lithostratigraphic review of the Abrahamskraal and Koonap formations of the Beaufort Group, South Africa: Towards a basin-wide stratigraphic scheme for the Middle Permian Karoo

    Science.gov (United States)

    Day, Michael Oliver; Rubidge, Bruce Sidney

    2014-12-01

    The basal strata of the Beaufort Group of the South African Karoo Basin, comprising the western Abrahamskraal and eastern Koonap formations, contain the most time extensive record of Middle Permian fossil tetrapods and hold the key to understanding Middle Permian biodiversity change in the continental realm. To determine faunal stratigraphic ranges a reliable lithostratigraphic framework for Middle Permian Beaufort deposits is essential. Until now this has proved difficult to achieve, largely due to the homogeneity of the fluvial succession coupled with structural complexity as a result of Cape Fold Belt orogenesis. Accordingly, the Abrahamskraal Formation has been only locally subdivided on the basis of sandstone packages but regional stratigraphic subdivision has not yet achieved satisfactorily. Collation of stratigraphic sections from around the Karoo Basin for this study demonstrates the presence of four sandstone packages are present within the Abrahamskraal Formation in the south-western corner of the basin. These sandstone packages are given member status, based upon the nomenclature of Le Roux (1985) with the addition of the newly recognised Grootfontein Member. The Combrinkskraal and Grootfontein Members occur in the lower half of the Abrahamskraal Formation and are laterally persistent along the southern margin of the basin. The Koornplaats Member is more restricted to the south west corner of the basin, where it quite thick, suggesting the narrowing of the highly channelized area. The overlying Moordenaars Member, more extensive towards the north than underlying packages, indicates subsequent northwesterly expansion of the locus of active channelization with time. Although thin sandstone packages in the more easterly positioned and stratigraphically equivalent Koonap Formation, this does not facilitate lithostratigraphic subdivision of this part of the stratigraphic succession and may indicate a different form of fluvial architecture. Our study provides a regional lithostratigraphic scheme for the Abrahamskraal Formation that will facilitate its biostratigraphic subdivision and the investigation of Middle Permian Gondwanan basin evolution.

  4. Paleomagnetism of the Carboniferous-Permian Patquia Formation, Paganzo basin, Argentina: implications for the apparent polar wander path for South America and Gondwana during the Late Palaeozoic

    OpenAIRE

    Geuna, S.E.

    2010-01-01

    The magnetic properties of the Carboniferous-Permian red beds of the Patquía Formation at Punta del Viento, Sierra de Umango and some previously reported localities, all in the Paganzo Basin (Argentina), have been studied. Whereas all sites are characterized by hematite as the main magnetic carrier and a reversed-polarity magnetic remanence, we found a pattern of variation in magnetic properties along the integrated column for Patquía Formation. The Lower Member (Late Carboniferous) showed ...

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-07-22

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Mikuláš R; Martínek K

    2006-01-01

    In the area of the Boskovice Basin, simple ichnoassemblages and ichnofabric patterns characterize a suite of lacustrine and fluvial deposits. The succession of ichnofabrics enables us to correlate several sections in the northern part of the basin, supporting the correlation of the previously recognized Ba?ov, Míchov and Obora horizons. The mostly finegrained lacustrine deposits below bituminous limestones contain Planolites beverleyensis, Planolites montanus

  9. Sedimentology of the Madumabisa Mudstone Formation (Late Permian), Lower Karoo Group, mid-Zambezi Valley Basin, southern Zambia

    Science.gov (United States)

    Nyambe, Imasiku A.; Dixon, Owen

    2000-04-01

    Sediments of the Upper Carboniferous to Lower Jurassic Karoo Supergroup (˜ 4.5 km thick) were deposited in the mid-Zambezi Valley Basin, southern Zambia. The Upper Palæozoic Lower Karoo Group in this area ends with a Late Permian sedimentary unit called the Madumabisa Mudstone Formation. The formation is 700 m thick and comprises four lithofacies grouped into two facies assemblages, collectively interpreted as lacustrine deposits. Sediments of a massive mudrock facies assemblage were deposited from suspension, probably from sediment-laden rivers entering a lake. Concretionary calcilutite beds probably mark the positions of palæosediment-water interfaces where calcite was precipitated. A laminated mudrock facies assemblage is attributed to lacustrine deposition from inflowing rivers at the lake margins and shallow parts of the lake. Repeated thickening-upward cycles are evidence of upward shallowing, interrupted by events of more abrupt deepening. Sandstone interbeds are interpreted as fluvial deposits laid down during low lake stands, with cross-lamination and asymmetrical ripples indicating current rather than wave deposition. A fossil assemblage of ostracods, bivalves, gastropods, fish scales, the alga Botryococcus sp. and fossil burrows is consistent with a lacustrine origin for the formation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-05-01

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

  11. Sequence stratigraphy of a lagoonal estuarine system—an example from the lower Permian Rio Bonito Formation, Paraná Basin, Brazil

    Science.gov (United States)

    Holz, Michael

    2003-12-01

    Detailed stratigraphic analysis of the Early Permian (Artinskian/Kungurian) succession of the intracratonic Paraná Basin in southernmost Brazil has revealed that the study region, previously interpreted as formed by a barrier island system in a shallow, wave-dominated sea, actually originated mainly in a mixed (tide and wave) influenced estuary setting. Four main depositional systems have been recognized: alluvial fan, fluvial-dominated delta, lagoonal estuary and barrier/shoreface. The regional correlation of the lithofacies within the different depositional systems has led to a high-resolution-stratigraphic framework, with three third-order depositional sequences. Sequence boundary SB1 marks the base of the Permian succession above the crystalline basement, sequence boundary SB2 is characterized by fluvial sediments overlying marine shales and sandstones. Sequence boundary 3 (SB3) has a different signature reflecting differential subsidence: some areas clearly experienced temporary regression and basinward shift of facies, while in others the transgression rapidly reworked the regressive sediments and left only a thin veneer of pebbly sandstone, the typical signature of a transgressive surface coinciding with a sequence boundary. Within depositional sequence 2, the main target of the study because it has economically important coal seams, seven parasequences are recognized, two forming the lowstand systems tract of the sequence, four forming the transgressive systems tract and one parasequence forming the highstand systems tract. Two parasequence limits are erosional transgressive surfaces, as indicated by the occurrence of a substrate-controlled ichnofacies ( Glossifungites) and a veneer of intraclasts composed of nodules (chert?), shell fragments and muddy rip-up clasts. The base-level variations had a strong tectonic component, as indicated by (1) the shift in shoreline configuration from east-west to a north-south direction after unconformity SB3 formation, (2) the transgressive reworking of regressive sediments in the southern part of the study area indicating differential subsidence and consequent differential accommodation available for the sediments and (3) the angularity displayed by the strata adjacent to the sequence boundary SB3.

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Mikuláš R

    2006-03-01

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

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    Marcello Guimarães Simões

    2012-04-01

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

  16. Record of the genus Lycopodites in the Lower Permian of Paraná Basin, Brazil

    Scientific Electronic Library Online (English)

    Juliana, Salvi; André, Jasper; Fresia, Ricardi-Branco; Mary Elizabeth C., Bernardes-de-Oliveira; Margot, Guerra-Sommer.

    2008-09-01

    Full Text Available O gênero Lycopodites, que engloba formas herbáceas de licópsidas, apresenta ampla distribuição temporal e espacial durante o Paleozóico no Hemisfério Norte, iniciando seu registro no Devoniano da Europa. Já no Paleozóico do Gondwana, até o presente momento, somente Lycopodites amazonica Dolianiti ha [...] via sido reportada para o Devoniano Médio da Amazônia (Grupo Curuá). Assim, os exemplares reportados no presente trabalho como Lycopodites sp., provenientes de rochas sedimentares do Subgrupo Itararé, SP, e Lycopodites riograndensis sp. nov., coletados na Formação Rio Bonito, RS, representam as formas férteis mais antigas registradas para o Gondwana e as primeiras a serem descritas para a Bacia do Paraná. A sua presença em camadas depositadas após o término da glaciação neopaleozóica, evidencia o ingresso de novos taxa em latitudes altas, bem como a diversidade das licópsidas presentes na Bacia, já esboçada através dos abundantes esporos associados à Classe Lycopsida presentes nas assembléias de palinomorfos. Abstract in english The genus Lycopodites, which encompasses the herbaceous forms of the lycopsids, presents broad time and spacial distribution during the Paleozoic in the Northern Hemisphere, with its initial records dating from the European Devonian. As to Gondwanan Paleozoic, to this moment, only Lycopodites amazon [...] ica Dolianiti had been reported for the Amazonian Middle Devonian (Curuá Group). Thus, the specimens reported in this study such as Lycopodites sp., coming from sedimentary rocks of the Itararé Subgroup, São Paulo State, and Lycopodites riograndensis sp. nov., collected in Rio Bonito Formation, Rio Grande do Sul, represent the oldest fertile forms recorded for Gondwana and the first ones to be described for the Paraná Basin. Its presence in layers, deposited after the end of the Neopaleozoic Glaciation, shows the appearance of new taxa in high latitudes, as well as the diversity of the lycopsids present in the Basin, previously indicated through the abundance of spores associated to the Class Lycopsida present in the palinomorphous assemblages.

  17. The Carboniferous-Permian boundary in the central western Argentinean basins: paleontological evidences / El límite Carbonífero-Pérmico en las cuencas del centro oeste de Argentina: evidencias paleontológicas

    Scientific Electronic Library Online (English)

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

    2011-07-01

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

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

    International Nuclear Information System (INIS)

    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%, 130-2500C) 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

  19. Relative sea level control of deposition in the Late Permian Newcastle Coal Measures of the Sydney Basin, Australia

    Science.gov (United States)

    Herbert, Chris

    1997-01-01

    Accumulation of the 400 m-thick Late Permian Newcastle Coal Measures of the Sydney Basin was controlled by changes in relative sea level. Three 3rd-order sequences, which constitute the coal measures, consist of 4th-order depositional sequences of fluvial conglomerate, coal, and small paralic/lacustrine deltas/crevasse splays, deposited on a coastal plain landward of a marine shoreline. Each 4th-order sequence was deposited during a single 4th-order relative sea level cycle. Following falls in relative sea level alluvial conglomerates derived from the New England Orogen filled incised valleys above sequence boundaries forming lowstand systems tracts. Sigmoidal conglomerates with 'giant crossbeds' were deposited as alluvial fill in compactional moats formed at the toes of abandoned paralic deltas. Alluvial sediments passed through the coastal plain directly to the marine shoreline causing the shoreface to prograde. Rising relative sea level, caused siliciclastic sedimentation to wane. During these hiatuses, in the transgressive systems tract, a rising water table stimulated peat mire growth blanketing the entire non-marine area. When the vertical accumulation of peat was outpaced by increasing rates of rising relative sea level, transgressing lagoons, interdistributary bays and lakes inundated the mires above maximum flooding surfaces. Continuing relative sea level rise in the highstand systems tracts caused paralic/lacustrine crevasse splays, crevasse subdeltas, and small deltas to prograde westwards into the Newcastle half-graben from a volcanic source on the Offshore Uplift. At this time of rising base-levels sediments were trapped on the coastal plain while the marine shoreface was starved. Falling relative sea level terminated paralic/lacustrine delta progradation and initiated exposure and erosion to repeat the cycle and initiate another 4th-order sequence. Two source areas supplied sediment into the Newcastle half-graben. An easterly source on the Offshore Uplift shed volcanic detritus into the Newcastle Coalfield via paralic/lacustrine deltas, and the New England Orogen shed volcano-lithic detritus via braided streams. The supply from the New England Orogen was switched on or increased by a fall in relative sea level while supply from the Offshore Uplift was switched off, reduced, or diverted, and vice versa during a rise in relative sea level. Increasing rates of 2nd-order falling relative sea level resulted in an upward change from predominantly marine shoreface and coastal plain sedimentation to predominantly fluvial sedimentation in the upper Newcastle Coal Measures.

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

    Scientific Electronic Library Online (English)

    Juliane M., Souza; Roberto, Iannuzzi.

    2012-03-01

    Full Text Available 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 in [...] terpretações 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 Bacia do Paraná, no Rio Grande do Sul. Baseado em sementes previamente classificadas e utilizando seus dados biológicos e tafonômicos, a síndrome de dispersão foi interpretada, e a classificação das sementes nos grupos successionais (pioneira, secundária inicial ou secundária tardia) foi sugerida. Sete morfoespécies foram analisadas: Samaropsis gigas, representando uma espécie de secundária-tardia, vivendo próximo a corpos d'água, com síndrome de dispesão hidrocórica; Samaropsis kurtzii, típica espécie de sucessão secundária inicial, apresentando a anemocoria como síndrome de dispersão e habitando áreas distantes em relação a corpos d'água; Samaropsis aff. S. millaniana, Cordaicarpus aff. C. brasilianus, Cordaicarpus cerronegrensis e Cordaicarpus truncata com características típicas de plantas pioneiras, sendo a barocoria sua principal síndrome de dispersão com outras síndromes associadas. Abstract in english 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 Pa [...] leozoic 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.

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

    Directory of Open Access Journals (Sweden)

    Juliane M. Souza

    2012-03-01

    Full Text Available The morphological analysis of seeds has been an important subject in modern ecological studies, once it provides evidence about the biology and adaptations of the parent plant. However, this kind of study has been restricted to the ecology of modern plants and is rarely used in interpretations of Paleozoic data. From the understanding of dispersal syndromes analysis as an important tool to paleoecological reconstruction, this study provides a first approach using this tool with seeds from the Lower Permian strata of southern 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 Bacia do Paraná, no Rio Grande do Sul. Baseado em sementes previamente classificadas e utilizando seus dados biológicos e tafonômicos, a síndrome de dispersão foi interpretada, e a classificação das sementes nos grupos successionais (pioneira, secundária inicial ou secundária tardia foi sugerida. Sete morfoespécies foram analisadas: Samaropsis gigas, representando uma espécie de secundária-tardia, vivendo próximo a corpos d'água, com síndrome de dispesão hidrocórica; Samaropsis kurtzii, típica espécie de sucessão secundária inicial, apresentando a anemocoria como síndrome de dispersão e habitando áreas distantes em relação a corpos d'água; Samaropsis aff. S. millaniana, Cordaicarpus aff. C. brasilianus, Cordaicarpus cerronegrensis e Cordaicarpus truncata com características típicas de plantas pioneiras, sendo a barocoria sua principal síndrome de dispersão com outras síndromes associadas.

  2. Geochemical characteristics of the Permian basins and their provenances across the Solonker Suture Zone: Assessment of net crustal growth during the closure of the Palaeo-Asian Ocean

    Science.gov (United States)

    Eizenhöfer, Paul R.; Zhao, Guochun; Zhang, Jian; Han, Yigui; Hou, Wenzhu; Liu, Dongxing; Wang, Bo

    2015-05-01

    The Solonker Suture Zone is commonly recognised as the location of the Late Permian to Early Triassic closure of the Palaeo-Asian Ocean in the southeastern segment of the Central Asian Orogenic Belt. However, the absence of typical suture-related features, as a consequence of uncommon collisional geometries, gave it a cryptic nature. Thus, the tectonic setting, which led to suturing, still remains enigmatic. A geochemical characterisation of Permian sedimentary and volcanic rocks across the suture was carried out. Supplemented with Hf and Nd isotopic analyses, this approach enables not only a better definition of such regional suture, but also estimates on the long-controversial issue of net crustal growth in accretionary tectonic environments. The results indicate short sedimentary transport distances between the arc basins and their provenances, of which the studied volcanic rocks were a major contributor. Similar enrichment and depletion patterns with respect to N-MORB and average continental crust further corroborate a close source-sediment relationship. Immobile element provenance analyses indicate that the active continental northern margin of the North China Craton was a major source for arc basins to the south of the Solonker Suture Zone. To its north, arc basins are interpreted to be sourced by a more complex mixture of provenances, e.g., the Baolidao volcanic arc suite and the heterogenous Precambrian basement of southern Mongolia. An overall collisional tectonic setting across the suture is recognised. The geochemical signature of sedimentary rocks to the south of the suture points at an active continental arc setting, whereas the bimodal geochemical distribution of the samples to the north shows a contemporaneous active oceanic island arc as well as a passive margin environment. These features favour a double-sided subduction of the Palaeo-Asian Ocean beneath the North China Craton and the Mongolian Arcs throughout the Palaeozoic, including back-arc basin opening north of the suture in the Permian. Analysis of Hf and Nd isotopic compositions revealed that magmas to the south were produced involving significant crustal contamination, thus having less radiogenic compositions. North of the suture, however, isotopic compositions tend to be more radiogenic, implying a more juvenile contribution. However, the bulk isotopic compositions are close to present-day CHUR, suggesting that crustal reworking appears to be equally balanced by juvenile addition during the Palaeozoic closure of the Palaeo-Asian Ocean across the Solonker Suture Zone.

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

    Science.gov (United States)

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

    2014-12-01

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

  4. Diagenesis of clay minerals and K-bentonites in Late Permian/Early Triassic sediments of the Sichuan Basin (Chaotian section, Central China)

    Science.gov (United States)

    Deconinck, J. F.; Crasquin, S.; Bruneau, L.; Pellenard, P.; Baudin, F.; Feng, Q.

    2014-02-01

    Detailed clay mineralogical analyses were carried out on Late Permian/Early Triassic carbonate sediments exposed on the Chaotian section (Sichuan Basin, Central China). The clay assemblages are dominantly composed of illite in platform carbonates and clay seams, and illite-smectite mixed-layers (I/S) in tuff layers (K-bentonites) intercalated in the carbonate succession. Detrital and authigenic volcanogenic clay minerals have been partially replaced through illitisation processes during burial, raising questions about diagenetic effects. The precise determination of I/S occurring in K-bentonites shows that the sediments reached a temperature of about 180 °C, which is consistent with (1) previous estimates based on fluid-inclusion homogenisation temperature analysis, (2) the burial depth of the sedimentary series deduced from the post-Palaeozoic geological history of the Sichuan Basin and (3) the new data (Tmax) obtained on organic matter indicating the transition between oil and gas windows. The Wangpo Bed, located close to the Guadalupian-Lopingian Boundary, is interpreted either as a volcanic acidic tuff or as a clastic horizon. This controversial origin probably results from mixed volcanogenic and detrital influences. The Wangpo Bed is therefore interpreted as a reworked bentonite as revealed by the occurrence of I/S similar to those found in tuff layers, together with preserved detrital kaolinite.

  5. Occurrence of Early Permian palynofossils in the subsurface sediments of Dhansiri Valley, Assam-Arakan Basin, India

    Energy Technology Data Exchange (ETDEWEB)

    Basavaraju, M.H.; Pundeer, B.S. [ONGC Ltd, Sivasagar (India). Regional Geological Labs.

    2003-11-01

    The occurrence of Lower Gondwana palynoassemblage has been recorded from the subsurface sediments of an exploratory well Dergaon-A in Dhansiri Valley of Assam-Arakan Basin. The recorded palynoassemblage includes rich radial monosaccate genera Potoneisporites sp, Parasaccites sp, Plicatipollenites sp, Virkkipollenites sp, associated with the trilete spores viz. Microfoveolatispora sp, Microbaculispora sp, along with acritarch Leiosphaeridia sp. These palynofossils are correlatable with those recorded from the Talchir Formation of South Rewa Basin, Jayantia coal field, Cauvery Basin and Krishna Godavari Basin. Occurrence of Leiosphaeridia indicate that the sediments appears to be deposited under marine conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Erdlac, Richard J., Jr.

    2006-10-12

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

  7. Permian-triassic life crisis on land.

    Science.gov (United States)

    Retallack, G J

    1995-01-01

    Recent advances in radiometric dating and isotopic stratigraphy have resulted in a different placement of the Permian-Triassic boundary within the sedimentary sequence of the Sydney Basin of southeastern Australia. This boundary at 251 million years ago was a time of abrupt decline in both diversity and provincialism of floras in southeastern Australia and extinction of the Glossopteris flora. Early Triassic vegetation was low in diversity and dominated by lycopods and voltzialean conifers. The seed fern Dicroidium appeared in the wake of Permian-Triassic boundary floral reorganization, but floras dominated by Dicroidium did not attain Permian levels of diversity and provinciality until the Middle Triassic (244 million years ago). PMID:17840061

  8. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico - petrophysical characterization of the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, F.J.

    1997-06-01

    Reservoir performance of the South Cowden Grayburg field suggests that only 21 percent of the original oil in place has been recovered. The purpose of this study is to construct a realistic reservoir model to be used to predict the location of the remaining mobile oil. Construction of reservoir models for fluid-flow simulation of carbonate reservoirs is difficult because they typically have complicated and unpredictable permeability patterns. Much of the difficulty results from the degree to which diagenetic overprinting masks depositional textures and patterns. For example, the task of constructing a reservoir model of a limestone reservoir that has undergone only cementation and compaction is easier than constructing a model of a karsted reservoir that has undergone cavern formation and collapse as well as cementation and compaction. The Permian-age carbonate-ramp reservoirs in the Permian Basin, West Texas and New Mexico, are typically anhydritic dolomitized limestone. Because the dolomitization occurred soon after deposition, depositional fabrics and patterns are often retained, and a reservoir model can be constructed using depositional concepts. Recent studies of the San Andres outcrop in the Guadalupe Mountains and the Seminole San Andres reservoir in the Permian Basin illustrate how depositional fabrics and patterns can be used to construct a reservoir model when depositional features are retained.

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

    Ro?. 46, ?. 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

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  12. Depositional environments and sequence stratigraphy of the Late Carboniferous-Early Permian coal-bearing successions (Shandong Province, China): Sequence development in an epicontinental basin

    Science.gov (United States)

    Lv, Dawei; Chen, Jitao

    2014-01-01

    This study focuses on the Late Carboniferous-Early Permian coal-bearing successions in Shandong Province, North China in order to understand the depositional processes and sequence-stratigraphic framework in an epicontinental basin. Based on detailed analysis of eleven facies, five facies assemblages (FAs) were recognized in the studied succession. FA1-3 are present mainly in the Benxi and Taiyuan formations, and consist of mixed siliciclastic and carbonate lithofacies, representing eluvial-lagoon, barrier-lagoon, and tidal-flat environments. FA4 occurs in the Shanxi formation and consists mainly of interbedded medium to fine sandstone, siltstone, mudstone, and coal lithofacies, representing river-dominated deltaic environments. FA5 is characterized by interbeds of trough cross-stratified coarse sandstone, and silty mudstone, mainly in the Lower Shihezi Formation, which was deposited in meandering river channel and floodplain. Three third-order sequences were established based on the vertical arrangement of facies assemblages and identification of physical surfaces (i.e., subaerial unconformity, transgressive surface, and regressive surface). Each sequence comprises a transgressive systems tract (TST) and a highstand systems tract (HST). TST of sequence 1 is composed of eluvial lagoonal deposits (FA1), whereas HST formed in lagoon-barrier and tidal-flat settings (FA2 and FA3). TST of sequence 2 formed in a barrier-lagoon system (FA2), whereas HST is characterized by repetitive accumulation of interbedded limestone, sandstone, mudstone, and coal, deposited under lagoonal and tidal-flat settings (FA2 and FA3). TST of sequence 3 comprises FA2, and HST mainly FA4, deposited in a river-dominated shallow-water delta system. Sequence 3 is overlain by a fluvial sequence (FA5). The three third-order sequences in the Shandong region are generally correlated with those in the Taebaeksan Basin (South Korea), the eastern part of the North China Block. The relative sea-level curves established in the two regions show a generally similar long-term rising trend.

  13. TSR versus non-TSR processes and their impact on gas geochemistry and carbon stable isotopes in Carboniferous, Permian and Lower Triassic marine carbonate gas reservoirs in the Eastern Sichuan Basin, China

    Science.gov (United States)

    Liu, Q. Y.; Worden, R. H.; Jin, Z. J.; Liu, W. H.; Li, J.; Gao, B.; Zhang, D. W.; Hu, A. P.; Yang, C.

    2013-01-01

    The Palaeozoic and lowermost Mesozoic marine carbonate reservoirs of the Sichuan Basin in China contain variably sour and very dry gas. The source of the gas in the Carboniferous, Permian and Lower Triassic reservoirs is not known for certain and it has proved difficult to discriminate and differentiate the effects of thermal cracking- and TSR-related processes for these gases. Sixty-three gas samples were collected and analysed for their composition and carbon stable isotope values. The gases are all typically very dry (alkane gases being >97.5% methane), with low (sour while the Lower Triassic gas tends to be most sour. The elevated H2S (up to 62%) is due to thermochemical sulphate reduction with the most sour Triassic and Permian reservoirs being deeper than 4800 m. The non-TSR affected Carboniferous gas is a secondary gas that was derived from the cracking of sapropelic kerogen-derived oil and primary gas and is highly mature. Carboniferous (and non-sour Triassic and Permian) gas has unusual carbon isotopes with methane and propane being isotopically heavier than ethane (a reversal of typical low- to moderate-maturity patterns). The gas in the non-sour Triassic and Permian reservoirs has the same geochemical and isotopic characteristics (and therefore the same source) as the Carboniferous gas. TSR in the deepest Triassic reservoirs altered the gas composition reaching 100% dryness in the deepest, most sour reservoirs showing that ethane and propane react faster than methane during TSR. Ethane evolves to heavier carbon isotope values than methane during TSR leading to removal of the reversed alkane gas isotope trend found in the Carboniferous and non-sour Triassic and Permian reservoirs. However, methane was directly involved in TSR as shown by the progressive increase in its carbon isotope ratio as gas souring proceeded. CO2 increased in concentration as gas souring proceeded, but typical CO2 carbon isotope ratios in sour gases remained about -4‰ V-PDB showing that it was not solely derived from the oxidation of alkanes. Instead CO2 may partly result from reaction of sour gas with carbonate reservoir minerals, such as Fe-rich dolomite or calcite, resulting in pyrite growth as well as CO2-generation.

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

    International Nuclear Information System (INIS)

    Petrographic features, C, O and Sr isotopes, rare earth and trace elements were determined, and fluid inclusions were analyzed on various stages of interparticle cements and vug-fillings from the Upper Permian and Lower Triassic sour reservoirs in northeastern Sichuan basin. The aim was to assess the origin and evolution of palaeo-waters in the carbonates. The original water was contemporary seawater, from which marine cements precipitated with slightly high Sr contents (mean 1911 ppm), 87Sr/86Sr ratios from 0.7067 to 0.7082 and nonluminescent CL. The palaeo-seawater was diluted by meteoric water, as indicated by bright cathodoluminescence (CL) and Sr-depletion (0–516 ppm) in low-temperature calcite. When buried to temperatures of about 60–90 °C during Middle to Late Triassic, the palaeo-water was enriched in Sr released from the transformation of precursor aragonite and calcite to dolomite, resulting in precipitation of substantial pre-bitumen Sr-rich minerals (SrSO4 and SrCO3). For un-dolomitized limestone sections, aragonite neomorphism may have contributed Sr to the precipitation of small amounts of Sr-bearing minerals and calcite crystals with elevated homogenization temperatures (HTs, mainly from 90 to 130 °C) and wide Sr contents (from 34 to 3825 ppm), as recorded in stage III calcite. Since the Middle Jurassic, almost all of the early stage celestite and significant amounts of solid CaSO4 have been cf 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 ?13C values (down to ?18.9‰), 87Sr/86Sr ratios from 0.7072 to 0.7076, high HTs (mainly 110–198 °C), positive Eu anomalies and high Sr and Ba contents. Subsequently, the water was uplifted and cooled down to about 115 °C, celestite and strontianite were precipitated with the occurrence of natural elemental S immiscible inclusions. TSR may have produced significant amounts of freshwater, which brought down Sr concentrations and salinities of the palaeo-waters to not more than about 6.0 wt.% NaCl equivalent.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Francisco Hervé

    2010-07-01

    Full Text Available Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC, obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (523±7 Ma, 522±6 Ma and 538±6 Ma, interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770°C event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobífera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.Cinco nuevas edades radiométricas logradas mediante análisis U-Pb en circón utilizando el SHRIMP, fueron determinadas en gneises y rocas plutónicas foliadas obtenidas desde el fondo de pozos de sondajes en la Cuenca de Magallanes y pertenecientes al denominado Complejo ígneo y Metamór-fico de Tierra del Fuego. En tres de las muestras fueron calculadas edades del Cámbrico Temprano (523±7 Ma, 522±6 Ma y 538±6 Ma, interpretadas como edades de cristalización ígnea de las rocas estudiadas. Un gneis migmatítico presenta 'peaks' de circones heredados de ca. 950-1.100 Ma y de 560-650 Ma además de dos granos de edades de 525 Ma, indicando la participación de material Grenviliano y Brasiliano en el protolito de la migmatita cámbrica. Un gneiss de cordierita-sillimanita-granate presenta una población de circones ígneos de edad cámbrica y otro grupo de circones metamórficos, ricos en U, de edad pérmica, indicando que en el Pérmico un evento metamórfico del alto grado acompañado de anatexis (P=2-3 kbar, T=730-770°C afectó a rocas ígneas cámbricas y/o a rocas sedimentarias derivadas de ellas. Rocas plutónicas cámbricas/ediacaranas han sido descritas en el NW de Argentina, en los basamentos de la Sierra de la Ventana y del Cinturón Plegado del Cabo (en el sur de África, y en el Orógeno de Ross en Antartica. El evento metamórfico Pérmico es contemporáneo con la deformación y metamorfismo de bajo grado, registrado en las sucesiones sedimentarias que sobreyacen el basamento en muchas de estas areas. Siguiendo al episodio Pérmico de metamorfismo de alto grado, en Tierra del Fuego fueron removidos al menos 8 a 12 km de rocas de cobertura antes de la depositación de las rocas volcánicas de la Formación Tobífera en el Jurásico Medio y Superior. Las rocas erosionadas representan una fuente importante de material para las sucesiones conglomerádicas pérmicas y triásicas? ubicadas en las regiones vecinas de América del Sur, África y Antartica.

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

    Scientific Electronic Library Online (English)

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

    2010-07-01

    Full Text Available Cinco nuevas edades radiométricas logradas mediante análisis U-Pb en circón utilizando el SHRIMP, fueron determinadas en gneises y rocas plutónicas foliadas obtenidas desde el fondo de pozos de sondajes en la Cuenca de Magallanes y pertenecientes al denominado Complejo ígneo y Metamór-fico de Tierra [...] del Fuego. En tres de las muestras fueron calculadas edades del Cámbrico Temprano (523±7 Ma, 522±6 Ma y 538±6 Ma), interpretadas como edades de cristalización ígnea de las rocas estudiadas. Un gneis migmatítico presenta 'peaks' de circones heredados de ca. 950-1.100 Ma y de 560-650 Ma además de dos granos de edades de 525 Ma, indicando la participación de material Grenviliano y Brasiliano en el protolito de la migmatita cámbrica. Un gneiss de cordierita-sillimanita-granate presenta una población de circones ígneos de edad cámbrica y otro grupo de circones metamórficos, ricos en U, de edad pérmica, indicando que en el Pérmico un evento metamórfico del alto grado acompañado de anatexis (P=2-3 kbar, T=730-770°C) afectó a rocas ígneas cámbricas y/o a rocas sedimentarias derivadas de ellas. Rocas plutónicas cámbricas/ediacaranas han sido descritas en el NW de Argentina, en los basamentos de la Sierra de la Ventana y del Cinturón Plegado del Cabo (en el sur de África), y en el Orógeno de Ross en Antartica. El evento metamórfico Pérmico es contemporáneo con la deformación y metamorfismo de bajo grado, registrado en las sucesiones sedimentarias que sobreyacen el basamento en muchas de estas areas. Siguiendo al episodio Pérmico de metamorfismo de alto grado, en Tierra del Fuego fueron removidos al menos 8 a 12 km de rocas de cobertura antes de la depositación de las rocas volcánicas de la Formación Tobífera en el Jurásico Medio y Superior. Las rocas erosionadas representan una fuente importante de material para las sucesiones conglomerádicas pérmicas y triásicas? ubicadas en las regiones vecinas de América del Sur, África y Antartica. Abstract in english Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ag [...] es (523±7 Ma, 522±6 Ma and 538±6 Ma), interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770°C) event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobífera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-04-01

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

  20. Spectral gamma-ray signature of fluvial deposits: a case study from the Late Permian Rio do Rasto Formation, Parana Basin, Brazil

    International Nuclear Information System (INIS)

    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)

  1. Contribution of research borehole data to modelling fine-grained turbidite reservoir analogues, Permian Tanqua-Karoo basin-floor fans (South Africa)

    Energy Technology Data Exchange (ETDEWEB)

    Luthi, Stefan M. [Delft Univ. of Technology, Dept. of Geotechnology, Delft (Netherlands); Hodgson, David M.; Flint, Stephen S. [Liverpool Univ., Dept. of Earth and Ocean Sciences, Liverpool (United Kingdom); Drinkwater, Nicholas J. [Schlumberger Cambridge Research, Cambridge (United Kingdom); Johannessen, Erik P. [Statoil, Stavanger (Norway); Geel, Cees R.; Goedbloed, Jan Willem

    2006-07-01

    Outcrop analogue studies can be augmented and constrained by drilling research wells through the same stratigraphic interval. Close-to-outcrop wells help to validate outcrop observations with well log and core data and thus improve the use of such data in actual field developments. Research wells located further away from the outcrops increase the spatial data coverage and can give important insight into regional facies distributions and net:gross changes. In the Tanqua-Karoo Basin (South Africa), seven wells were drilled into fine-grained sand-rich basin-floor fans and interfan mudstones to supplement outcrop data. Three close-to-outcrop wells proved useful in establishing characteristic log responses of the main architectural elements identified from the nearby outcrops. Lithofacies were correctly identified in more than 80% of cases using an artificial neural network. Borehole images provided detailed information on sedimentary structures, including a wealth of palaeocurrent data from climbing ripples that significantly enhanced the interpretations based only on outcrops. Wells sited away from the outcrops supplied information on lateral thickness and facies trends and intrafan stacking patterns, which helped to define the stratigraphic evolution of the fans. The combined data indicate that deposition was controlled in part by subtle basin-floor topography, and that intrafan lobe switching took place, leading to internal subdivisions that potentially caused effective compartmentalization of the basin-floor fan. (Author)

  2. The Permian aquifer of Dumfries : groundwater chemistry and age

    OpenAIRE

    Macdonald, A. M.; Ball, D.F.; Darling, W. G.

    2000-01-01

    The Dumfries aquifer has been studied for over 20 years. However, investigations have been piecemeal and little attempt has been made to bring all the different approaches together. This study, although entirely hydrochemical, aims to help understanding of the groundwater flow within the basin in order to validate (or otherwise) existing hydrogeological conceptual models. The age and hydrochemistry of groundwater in the Permian sediments of the Dumfries Basin was assessed from ...

  3. An accurate record of volcanic ash fall deposition as characterized by dispersed organic matter in a Lower Permian tonstein bed (Faxinal Coalfield, Paraná Basin, Brazil)

    OpenAIRE

    Simas, M. W.

    2013-01-01

    For the first time, the dispersed organic matter in the tonstein layer interbedded with a coal seam in the Faxinal Coalfield (Sakmarian, Southern Paraná Basin, Brazil) is characterized. The deposition of clusters of pollen grains was highly influenced by the intense ash fall process that probably occurred during seasonal dehiscence of reproductive structures. The well-preserved phytoclasts with their upper and lower leaf cuticles stuck together indicate that the rapid fall of ash on this mat...

  4. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico--waterflood performance analysis for the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, J.W. Jr.

    1997-05-01

    A reservoir engineering study was conducted of waterflood performance in the South Cowden field, an Upper Permian Grayburg reservoir on the Central Basin Platform in West Texas. The study was undertaken to understand the historically poor waterflood performance, evaluate three techniques for incorporating petrophysical measurements and geological interpretation into heterogeneous reservoir models, and identify issues in heterogeneity modeling and fluid-flow scaleup that require further research. The approach included analysis of relative permeability data, analysis of injection and production data, heterogeneity modeling, and waterflood simulation. The poor South Cowden waterflood recovery is due, in part, to completion of wells in only the top half of the formation. Recompletion of wells through the entire formation is estimated to improve recovery in ten years by 6 percent of the original oil in place in some areas of the field. A direct three-dimensional stochastic approach to heterogeneity modeling produced the best fit to waterflood performance and injectivity, but a more conventional model based on smooth mapping of layer-averaged properties was almost as good. The results reaffirm the importance of large-scale heterogeneities in waterflood modeling but demonstrate only a slight advantage for stochastic modeling at this scale. All the flow simulations required a reduction to the measured whole-core k{sub v}/k{sub h} to explain waterflood behavior, suggesting the presence of barriers to vertical flow not explicitly accounted for in any of the heterogeneity models. They also required modifications to the measured steady-state relative permeabilities, suggesting the importance of small-scale heterogeneities and scaleup. Vertical flow barriers, small-scale heterogeneity modeling, and relative permeability scaleup require additional research for waterflood performance prediction in reservoirs like South Cowden.

  5. A Formação Serra Alta, Permiano, no centro-leste do Estado de São Paulo, Bacia do Paraná, Brasil / The Serra Alta Formation, Permian, in the central-eastern portion of São Paulo State, Paraná Basin, Brazil

    Scientific Electronic Library Online (English)

    Lucas Veríssimo, Warren; Mario Luis, Assine; Marcello Guimarães, Simões; Claudio, Riccomini; Luís Eduardo, Anelli.

    2015-03-01

    Full Text Available A individualização e o mapeamento da Formação Serra Alta no Estado de São Paulo sempre foi motivo de controvérsia na comunidade geológica. Apesar de apresentar extensão comparável à Formação Irati em subsuperfície, a unidade ainda carece de estudos mais acurados acerca de seu posicionamento estratig [...] ráfico, conteúdo fossilífero, sistema deposicional e idade. Na região centro-leste do Estado de São Paulo, a Formação Serra Alta sucede estratigraficamente a Formação Irati, sendo constituída por depósitos pelíticos cinza escuros. A unidade é mapeada desde o limite sul do estado até o Domo de Gibóia, no Município de Rio das Pedras. Neste local, as formações Serra Alta e Teresina são substituídas pelos depósitos pelíticos da Formação Corumbataí, que se estende para norte, além do limite do Estado de São Paulo, e pode ser considerada unidade correlata a estas. Neste estudo, são apresentadas seções colunares e caracterizados os contatos da Formação Serra Alta com as formações permianas verticalmente contíguas. É apresentada também detalhada análise de fácies, com a finalidade de caracterizar o sistema deposicional. A análise de perfis de sondagem possibilitou também melhor compreensão dos padrões arquiteturais da Formação Serra Alta, auxiliando na determinação de sua real distribuição e posição estratigráfica na porção centro-sul do estado. A integração das informações obtidas permitiu identificar tendências de empilhamento transgressivo particulares, contribuindo para o detalhamento da sucessão predominantemente regressiva em que se depositaram as unidades permianas da Bacia do Paraná. Abstract in english The delimitation and mapping of the Serra Alta Formation in the São Paulo State, Brazil, has always been a focus of controversy in the Brazilian geological community. Despite its large extension in subsurface, which may be comparable to the Irati Formation, the Serra Alta Formation still needs more [...] detailed studies on its stratigraphic position, fossil content, depositional systems and age. In the east-central portion of the São Paulo State, the Serra Alta Formation overlies the Irati Formation and is predominantly composed of dark grey pelitic facies. The unit is mapped from the southern boundary of the São Paulo State to the Gibóia Dome, located in the county of Rio das Pedras. In this place, the Serra Alta and Teresina formations are replaced by the red colored pelites of the Corumbataí Formation, unit that extends to north beyond the state boundaries and may be considered correlated to these units. In this work, we present columnar sections and describe the contacts of the Serra Alta Formation with vertically adjacent Permian units. We also present the detailed facies analysis, in order to characterize the depositional system. The investigation of subsurface profiles also enabled a better understanding of the architectural patterns of the succession, helping to determine its real distribution and stratigraphic position in the central-south of São Paulo State. The integration of the data allowed identifying a particular transgressive stacking pattern, contributing to detail the late Permian regressive cycle in the Paraná Basin.

  6. Permian potentiometric analysis

    International Nuclear Information System (INIS)

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

  7. Residual basins

    International Nuclear Information System (INIS)

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

  8. Siberian gas venting and the end-Permian environmental crisis

    Science.gov (United States)

    Svensen, Henrik; Planke, Sverre; Polozov, Alexander G.; Schmidbauer, Norbert; Corfu, Fernando; Podladchikov, Yuri Y.; Jamtveit, Bjørn

    2009-01-01

    The end of the Permian period is marked by global warming and the biggest known mass extinction on Earth. The crisis is commonly attributed to the formation of the Siberian Traps Large Igneous Province although the causal mechanisms remain disputed. We show that heating of Tunguska Basin sediments by the ascending magma played a key role in triggering the crisis. Our conclusions are based on extensive field work in Siberia in 2004 and 2006. Heating of organic-rich shale and petroleum bearing evaporites around sill intrusions led to greenhouse gas and halocarbon generation in sufficient volumes to cause global warming and atmospheric ozone depletion. Basin scale gas production potential estimates show that metamorphism of organic matter and petroleum could have generated > 100,000 Gt CO 2. The gases were released to the end-Permian atmosphere partly through spectacular pipe structures with kilometre-sized craters. Dating of a sill intrusion by the U-Pb method shows that the gas release occurred at 252.0 ± 0.4 million years ago, overlapping in time with the end-Permian global warming and mass extinction. Heating experiments to 275 °C on petroleum-bearing rock salt from Siberia suggests that methyl chloride and methyl bromide were significant components of the erupted gases. The results indicate that global warming and ozone depletion were the two main drivers for the end-Permian environmental crisis. We demonstrate that the composition of the heated sedimentary rocks below the flood basalts is the most important factor in controlling whether a Large Igneous Provinces causes an environmental crisis or not. We propose that a similar mechanism could have been responsible for the Triassic-Jurassic (~ 200 Ma) global warming and mass extinction, based on the presence of thick sill intrusions in the evaporite deposits of the Amazon Basin in Brazil.

  9. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

  10. Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup), Paraná Basin, Brazil: implications for the exploration model / Maturação permotriássica e os vários estágios de migração de hidrocarbonetos na Formação Assistência (Subgrupo Irati), Bacia do Paraná: implicações para os modelos exploratórios

    Scientific Electronic Library Online (English)

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

    2014-09-01

    Full Text Available Novas linhas de evidências geológicas sugerem fortemente que o principal período de maturação de hidrocarbonetos na Formação Assistência teria ocorrido no Permotriássico, estimulado por um gradiente geotérmico elevado que também sustentou várias manifestações de atividade hidrotermal. Três fases pri [...] ncipais de migração de fluidos e hidrocarbonetos também podem ser inferidas a partir de observações em multiescala: fluxo confinado no final do Permiano ao Triássico, dependente do acúmulo local de pressões de fluidos; fluxo heterogêneo no Cretáceo Inferior, desencadeado por um gradiente de temperatura rejuvenescido, assistido pelas condições de permeabilidade antes desenvolvidas; e um fluxo tardio, possivelmente impulsionado por gradientes de pressão locais, posteriormente ao esfriamento dos diques e soleiras de diabásio. A maturação precoce e a existência de vários estágios de migração de hidrocarbonetos apresentam implicações significativas na concepção de modelos exploratórios a serem aplicados na Bacia do Paraná. Abstract in english New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarb [...] on migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paraná Basin.

  11. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    DEFF Research Database (Denmark)

    Clausen, O.R.; Andresen, Katrine Juul

    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 in the Northern Permian Basin which in the eastern North Sea is separated from the Southern Permian Basin by the Ringkøbing-Fyn High. The Permian basins were initiated during thermal subsidence following a late Carboniferous- early Permian rifting phase associated with extensive igneous activity 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 known presence of hydrocarbons within the Paleozoic sediments, the Northern Permian Basin has gained much less interest outside the hydrocarbon producing Mesozoic graben systems. This is mainly due to an apparent lack of potential source rocks. A major E-W striking northward dipping fault system characterizes the study area and causes rotation of older probably Paleozoic sediments and creates syn-tectonic sediment wedges. The syn-tectonic wedges most probably contain volcaniclastic sediments of the Karl Formation or sandstones of the Auk Formation, but it cannot be excluded that the earliest late 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 of the E-W striking fault system are generally planar and strike parallel to the fault with a southward dip geometrically similar to antithetic faults. In contrast, the intrusions in the footwall segment show a much more complex pattern striking at a high angle to the E-W basement fault and outlining a sill complex, which in certain areas resembles a poorly outlined composite cone. The intrusions are not observed in the syn-tectonic sedimentary wedges and this combined with the general age of the intrusions suggests that the syn-tectonic wedges are of latest early Permian or earliest late Permian age. The study demonstrates Paleozoic intrusions with a systematic orientation and geometry that most likely was directly controlled by the basement faulting. Syn-tectonic hanging-wall deformation represented by antithetic fractures is suggested to be the most important controlling factor for the intrusions at the hanging-wall. At the footwall a more composite geometry of the intrusions is observed, resulting in a much more complex compartmentalization of the Paleozoic sediments due to intrusions compared to the hanging-wall segment. The intrusions and especially the compartmentalization must be taken into account during evaluation of the hydrocarbon potential of the Paleozoic.

  13. The Paleomagnetic record of Uppermost Permian, Lower Triassic rocks from the South China Block

    Science.gov (United States)

    Enkin, R. J.; Courtillot, V.; Leloup, Ph.; Yang, Z.; Xing, L.; Zhang, J.; Zhuang, Z.

    1992-11-01

    Paleomagnetic samples were collected from Uppermost Permian to Middle Triassic limestones from two localities in the Sichuan Basin in order to better constrain the paleography of the blocks now comprising China. Corresponding remanences found in other studies of the Permo-Triassic rocks from the Sichuan Basin are reviewed, and it is shown that the component is probably characteristic of the Lower Triassic. The difference between the Emeishan Basalts and the Sichuan Basin poles is interpreted to be the result of motion of the whole South China Block around the time of the Permo-Triassic boundary rather than that of strain within the block.

  14. Structure and depositional environments of Permian-Triassic terrigeneous complex of the Barents Sea shelf

    Science.gov (United States)

    Norina, Daria; Stoupakova, Antonina

    2014-05-01

    Permian-Triassic complex of the Barents Sea shelf composed of up to 8-12 km of clastic sediments has a great interest for geology as it contains hydrocarbon-bearing reservoirs and source rocks. It is drilled on shelf margins and structural highs; it outcrops in adjoining archipelagos. However within depositional centers like the South-Barents basin where Permian-Triassic reaches maximum thickness and burial, its structure can only be understood from seismic data. We present an evaluation of structure, depositional environments and cyclicity of Permian-Triassic terrigeneous complex based on interpretation of 18 000 km of regional seismic profiles with record length of 10-12 s acquired by MAGE in 2007-09 in the south-east shelf. Transgressive-regressive sequences were identified and correlated using well log analysis for 17 wells, descriptions of well sections and outcrops in Franz Josef Land, Svalbard and Novaya Zemlya archipelagos. Cooling of the climate throughout Sakmarian-Artinskian (Lower Permian), marine transgression, and Ural orogeny in the south-east had interrupted carbonate deposition and initiated the deposition of terrigeneous (East Barents) and spiculite, siliceous-carbonate, and siliciclastic (West Barents) sediments (Geological history, 2009). Triassic is represented by clastic lithologies all over the basin. On seismic data lower boundary of Permian-Triassic complex is a high-amplitude reflector (Ia) and downlap surface corresponding to the top of Lower Permian carbonates. Upper boundary is related to Rhaetian erosional unconformity best pronounced in the pre-Novaya Zemlya foredeep, Kola monocline and Pechora Sea. Permian is represented by 5 transgressive-regressive sequences with upward regressive trend and total thickness of 100-800 m. Low-angle clinoforms prograding from south-east (Ural provenance) and east were interpreted on seismic. Increasing thickness of Permian towards Novaya Zemlya is consistent with up to 4 km of sediments in the archipelago's outcrops and indicates Kara provenance. In the south-eastern basin margin Permian-Triassic boundary is well-traced due to its erosional origin and downlapping of overlaying Induan clinoforms. Triassic sediments were formed in deltaic, shallow-marine to deep shelf environments in the large epicontinental basin with vast transgressions and significant lateral shift of the shoreline during sea level changes. Interpreted Triassic horizons correspond to Induan/Olenekian (top Havert), Lower/Upper Olenekian, Olenekian/Anisian (top Klappmyss) and Ladinian/Carnian boundaries. These relatively continuous reflectors were formed as transgressive shaly packages overlaid sequence boundaries. During Induan clinoforms (height ~100 s) had prograded to the north-west and west compensating the steady subsidence of the South- and North Barents depressions and pre-Novaya Zemlya foredeep. We traced migration of the clinoform break (platform margin) of several Induan prograding sequences across the South-Barents basin towards Norwegian Barents Sea, where the area of non-compensated deposition in deep shelf environments was delineated (Glorstad-Clark, 2010). During Olenekian and Middle Triassic the clinoform break persisted in the western shelf, thus no clinoforms are observed in the south-east of the Barents Sea where deltaic environments had prevailed. Late Triassic was characterized by shallowing of the basin, spreading of deltas and filling of previously non-compensated area in the north-west. Maximum thickness of Triassic is related to Lower Triassic within South Barents basin and Lower-Middle Triassic within the pre-Novaya Zemlya foredeep.

  15. Permian of Southeast Asia: an overview

    Science.gov (United States)

    Fontaine, Henri

    2002-08-01

    Permian rocks are widely distributed throughout Southeast Asia. Because of the tropical-equatorial climate the rocks are commonly deeply weathered and covered by dense vegetation over much of the region. Elsewhere, Permian rocks are well exposed and easy to access, particularly where limestone outcrops have weathered to form spectacular, castellated, tower karst. Many limestone outcrops, containing abundant fusulinaceans, were early recognized to be of Permian age, but many outcrops without fusulinaceans, erroneously assigned to the Permian, were found subsequently to be of Triassic age, and more careful studies have established the Permian age of rocks of other lithologies. It is now recognized that different depositional environments are represented by the Permian deposits in various parts of the region. Massive limestones, widespread throughout the region, represent extensive carbonate platforms; local occurrences of thick bedded cherts indicate deposition in deep marine environments, coal, bauxite and clastic sediments with vertebrate remains in North Vietnam and Laos indicate deposition in a continental environment, and pebbly mudstones in Myanmar, Peninsular Thailand, northwest Malaysia and Sumatra, are considered to have been formed in a glacial environment. Volcanic rocks are absent in northwest Peninsular Malaysia and Peninsular Thailand, but are extensively developed in North Vietnam, Sumatra, the eastern Malay Peninsula and Timor. Fossils, representing many fossil groups, are often prolific in Permian sediments, with fusulinaceans, for example, occurring in astronomical numbers in many limestone outcrops. Age-diagnostic fossils demonstrate that the whole of the Permian is represented in different areas of Southeast Asia. Fossil faunal and floral assemblages have been used to establish climatic conditions and environments of deposition, to define distinct crustal blocks and to provide the basis for reconstructing the palaeogeography during Permian times.

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

    Science.gov (United States)

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

    2015-04-01

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

  17. Palinologia das formações Rio Bonito e Palermo (Permiano Inferior, Bacia do Paraná) em Candiota, Rio Grande do Sul, Brasil: novos dados e implicações bioestratigráficas / Palynology of the Rio Bonito and Palermo formations (Lower Permian, Paraná Basin) in Candiota, Rio Grande do Sul, Brazil: new data and biostratigraphic implications

    Scientific Electronic Library Online (English)

    Ana L.O., Mori; Paulo A., Souza.

    2010-03-30

    Full Text Available Novos conjuntos palinológicos foram recuperados de um afloramento localizado às margens da BR 293, situado entre os municípios de Bagé e Candiota, sul do Estado do Rio Grande do Sul, correspondentes às formações Rio Bonito e Palermo, Permiano Inferior da Bacia do Paraná. Um total de oito amostras fo [...] i estudado, revelando palinofloras ricas e diversificadas, com a identificação de 76 espécies, dentre as quais 42 são relativas a esporos, 24 a grãos de pólen, e 10 relacionadas a algas e fungos. Em termos bioestratigráficos, palinomorfos documentados na seqüência sedimentar analisada permitiram identificar duas unidades bioestratigráficas na seção, as zonas Vittatina costabilis e Lueckisporites virrkiae. Algumas espécies de distribuição estratigráfica limitada a determinados níveis do Subgrupo Itararé e da Formação Rio Bonito foram registrados em posição estratigráfica mais superior, podendo sugerir, à primeira vista, aumento na amplitude estratigráfica destes táxons. Entretanto, outras implicações estratigráficas são também admitidas, e constituem parte da discussão da presente contribuição. Abstract in english New palynologic associations were recovered from an outcrop located at BR 293 Highway, between Bagé and Candiota municipalities, Rio Grande do Sul state, Brazil, related to the Rio Bonito and Palermo formations, Lower Permian of Paraná Basin. Eight samples were colected and studied, showing rich and [...] diversified palynofloras. A total of 76 species were recognized, 42 corresponding to spores, 24 to pollen grains and 10 related to algae and fungi. Palynomorphs registered in the section here analysed indicate the recognition of the Vittatina costabilis and Lueckisporites virrkiae zones. Species with stratigraphic ranges limitated to Itararé Subgroup and Rio Bonito Formation were identified in a higher stratigrapical levels, meaning for instance, increasing on the stratigraphic range of these taxa. On the other hand, other stratigraphic interpretations are possible, constituting the scope of the present contribution.

  18. Dalhart's only Permian field gets best oil well

    International Nuclear Information System (INIS)

    This paper reports that activity is picking up in Proctor Ranch oil field in the northwestern Texas panhandle, the only Permian producing field in the lightly drilled Dalhart basin. During the last 2 1/2 months, the field has a new operator and a new producing well, the best of five drilled since discovery in 1990. Corlena Oil Co., Amarillo, acquired the field from McKinney Oil Co. in May and tested its first well in early July. The 1-64 Proctor, 18 miles west of Channing, pumped at rates as high as 178 bd of oil and 6 b/d of water from Permian Wolfcamp dolomite perforations at 4,016-29 ft. Corlena plans to drill another well south of the field soon. The lease requires that the next well be spudded by early November. The field appears to be combination structural-stratigraphic trap in which the dolomite pinches out against the Bravo Domes-Oldham nose to the west

  19. Paleophysiology and End-Permian Mass Extinction

    OpenAIRE

    Knoll, Andrew; Fischer, Woodward W.; Pruss, Sara; Payne, Jonathan L.; Bambach, Richard K.

    2007-01-01

    Physiological research aimed at understanding current global change provides a basis for evaluating selective survivoyship associated with Permo-Triassic mass extinction. Comparative physiology links paleontological and palcoenvironmental observations, supporting the hypothesis that an end-Permian trigger, most likely Siberian Trap volcanism, touched off a set of physically-l inked perturbations that acted synergistically to disrupt the metabolisms of latest Permian organisms. Global wan-ning...

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

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ademar de Oliveira

    2008-02-15

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

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

    International Nuclear Information System (INIS)

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

  2. High-resolution stable carbon isotope record of the Permian to earliest Triassic from East Greenland

    Science.gov (United States)

    Sanson Barrera, Anna; Hochuli, Peter A.; Bucher, Hugo; Meier, Maximiliano; Schneebeli Hermann, Elke; Weissert, Helmut; Bernasconi, Stefano M.

    2013-04-01

    The Late Permian and Early Triassic organic carbon isotope records show global major excursions probably triggered by episodic volcanic degasing of the Siberian Large Igneous Province. Important and rapid fluctuations of the global carbon cycle are also reflected in the biosphere. The geological record seems to comprise several major floral and marine faunal turnovers indicating short-lived biotic recoveries. In northwest Pangea, the active Early Triassic Greenland - Norway rifting system led to the accommodation of thick sedimentary sequences. This basin has a great potential for detailed studies of regional and global biotic and climatic changes with high temporal resolution during this critical interval in Earth's history. The western part of this basin is exposed in north-eastern Greenland and is represented by a succession of deltaic sediments organized in a general regressive trend ranging throughout the Griesbachian and the onset of the Dienerian. On the eastern side of the basin the succession has been drilled off the Norwegian coast. On Hold with Hope (East Greenland, 74°N) up to ca. 800m thick sections of the ammonoid-bearing Early Triassic Wordie Creek Formation have been logged and sampled. Here we present a high-resolution organic carbon isotope record and preliminary palynofacies data of a 500m thick composite section ranging from the Permian into the earliest Triassic. The organic carbon isotope record is closely comparable to the coeval section from the Trøndelag platform in Mid-Norway. The two records show a first major negative shift (ca. -6‰) representing the unconformity between the Ravnefjeld and the Wordie Creek formations, regionally known as the lithological Permian-Triassic boundary. Higher up, a second negative shift of ca. -4‰ correlates with the carbon shift associated with the GSSP Permian-Triassic boundary as defined at Meishan (China), represented by carbon isotope values around -30‰. This negative shift is followed by a steady positive trend, which is interrupted by two striking events, (a) a positive shift reaching values of ca. -22‰, comparable to the values of the Permian Ravnefjeld Formation, and (b) another negative shift of ca. -7‰ bringing the carbon record back to values around -31‰. Our data from north-eastern Greenland indicate multiple and major events recorded by the carbon cycle within less than a million years at the onset of the Triassic.

  3. A new model of the geological structure and evolution of the North Kara Sedimentary Basin

    Science.gov (United States)

    Malyshev, N. A.; Nikishin, V. A.; Nikishin, A. M.; Obmetko, V. V.; Martirosyan, V. N.; Kleshchina, L. N.; Reydik, Yu. V.

    2012-07-01

    Based on the new seismic data, the geological structure and evolution of the North Kara Basin are presented. The North Kara Basin formed as an Early Ordovician rift system. Approximately at the Devonian-Carboniferous boundary, the North Kara Basin suffered intraplate compressional deformations, which caused formation of inversion swells, and then it was covered by a thin Carboniferous-Permian or Permian cover. The Urvantsev Trough probably comprising Late Ordovician evaporites was distinguished in the north-eastern part of the basin. Paleozoic folded deformations took place within the limits of the Vize-Ushakov and Central Kara rises.

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

    International Nuclear Information System (INIS)

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

  5. Preliminary numerical modelling of groundwater flow in the Dumfries basin

    OpenAIRE

    C. R. Jackson; A. G. Hughes; O Dochartaigh, B.E.

    2004-01-01

    The Dumfries Basin occupies the lower part of the River Nith catchment in south-west Scotland. The basin is a deep, partly fault bounded, outlier of Permian sandstone and breccia, with a partial superficial cover comprising a variety of lithologies which range from gravel to sandy clay. There is a complex interaction between the River Nith and the aquifer as the river and its various tributaries cross the basin. Piecemeal investigation of the aquifer had taken place since the f...

  6. Deep crustal structure of the Northeast German basin: New DEKORP-BASIN '96 deep-profiling results

    OpenAIRE

      DEKORP-BASINResearch Group

    1999-01-01

    An integrated reflection and refraction seismic survey across the Permian-Cenozoic Northeast German basin yields new insights on the evolution of intracontinental basins. No precursor rift basin was observed, but there is evidence of lower-crustal thinning and an initial magmatic stage. Minor Triassic rifting and Late Cretaceous compressional tectonics indicate that intraplate deformation was strongly influenced by older structures. Intraplate thinning and contraction were strongly decoupled ...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  9. Recrystallized microbial trace fossils from metamorphosed Permian basalt, southwestern Japan

    Science.gov (United States)

    Sugawara, H.; Sakakibara, M.; Ikehara, M.

    2014-05-01

    Microbial trace fossils on terrestrial basalts can be used as an analogue in the search for traces of life on other terrestrial planets. This study reports on microbial trace fossils within Permian greenstones in the Maizuru Terrane, southwest Japan, which is recognized as back-arc basin oceanic crust that consists mainly of metabasalt and metagabbro. The trace fossils have been studied by means of morphology, mineralogy, elemental mapping, and carbon isotope analysis. Although minute original textures of trace fossils are recrystallized in these rocks, Granulohyalichnus vulgaris isp., Tubulohyalichnus spiralis isp., and Tubulohyalichnus annularis isp. were identified. Significant concentration of C within the trace fossils implies these are organic remnants from microbes. The ?13CPDB values support that microbial trace fossils within low-grade metamorphic basalt can be reliably identified based on their morphology and chemical composition, as reveled by elemental mapping. In this context, glassy Martian basalt may be the best rock type to investigate in terms of searching for signs of microbial activity on Earth and other planets.

  10. Geochemistry and alteration of a Siberian crater lake coeval with the end-Permian mass extinction

    Science.gov (United States)

    Fristad, Kirsten; Svensen, Henrik; Planke, Sverre; Polozov, Alexander

    2010-05-01

    Hundreds of phreatomagmatic breccia pipes formed contemporaneously with the Siberian Traps are located in the Tunguska Basin, Siberia. These pipes are believed to be formed by sill intrusions into organic rich sediments, which caused the violent release of gigatonnes of greenhouse gases to the atmosphere with serious implications for the end-Permian environment (Svensen et al., EPSL, 2009). Crater lake deposits overlying the pipes are preserved in some cases and contain a record of the local biology and sedimentation during formation of the Siberian Traps. We are studying the upper 550m of a core drilled through the center of a former crater lake and underlying brecciated pipe in the southern reaches of the Tunguska Basin. The core consists of fine to coarse-grained volcanoclastic sediments cemented by calcite and interspersed with tuff. We report on the bulk geochemistry and the nature of alteration throughout the sequence of crater lake sediments. We propose a model for lake formation, subsequent diagenesis, and the influence of degassing from the underlying breccia pipe. The development of the crater lake is explored in the context of the Siberian Trap flood basalts, phreatomagmatic deposits and the end-Permian environmental crisis.

  11. The stratigraphic significance of the Solenoid Complex in the Permian of Gondwana

    Directory of Open Access Journals (Sweden)

    Margot Guerra-Sommer

    2014-06-01

    Full Text Available The Solenoid Complex comprises a fossil wood assemblage with stratigraphic distribution restricted to the middle-late Kungurian, present in Western (Irati Formation, Paraná Basin, Brazil and Eastern (Upper Barakar Interval of the Indian basins Gondwana. Its occurrence seems to be related to the adaptation of certain plant groups to paleoenvironmental stress in lowland niches of coastal areas subject to salinity variation. The disappearance of these forms in the latest Kungurian is probably linked to the cessation of these conditions, which is confirmed by the sedimentary record. The here designated “Solenoid Complex Zone” correlates with the acme in diversification of striate and taeniate patterns especially in bisacatte pollen grains, but also in monosacatte ones, reflecting important tectonically and climatically driven changes in the vegetational pattern. The waning icehouse stage during the Permian was an important factor to the development of similar vegetation patterns in Western and Eastern Gondwana in the latitudinal belt of 40° – 55°.

  12. Seismic and sub-seismic deformation on different scales in the NW German Basin

    OpenAIRE

    Tina Lohr

    2007-01-01

    The main objective of this study is the quantification and qualification of strain over a broad scale range, including its distribution, magnitude, and accumulation history during basin evolution. These objectives are important contributions to the questions of stress transfer and deformation processes in the Southern Permian Basin.

  13. Ocean anoxia did not cause the Latest Permian Extinction

    Science.gov (United States)

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

    2014-05-01

    The Latest Permian Extinction (LPE, ~252 million years ago) was a turning point in the history of life on Earth with a loss of ~96% of all marine species and ~70% of all terrestrial species. While, the event undoubtedly shaped the evolution of life its cause remains enigmatic. A leading hypothesis is that the global oceans became depleted in oxygen (anoxia). In order to test this hypothesis we investigated a proxy for marine oxygen levels (molybdenum isotopic composition) in shale across the LPE horizon located on the subtropical northwest margin of Pangea at that time. We studied two sedimentary records in the Sverdrup basin, Canadian High Arctic: Buchanan Lake (eastern Axel Heiberg Island; 79° 26.1'N, 87° 12.6'W), representing a distal deep-water slope environment, and West Blind Fiord (southwest Ellesmere Island; 78° 23.9'N, 85° 57.2'W), representing a deep outer shelf environment (below storm wave base). The molybdenum isotopic composition (?98/95Mo) 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 ?98/95Mo values. Results from the Buchanan Lake section show a large shift in ?98/95Mo values from 2.02o to +2.23o at the extinction horizon, consistent with onset of euxinic conditions. In contrast, West Blind Fiord shales, representing the sub-storm wave base shelf environment, show little change in the molybdenum isotopic composition (1.34o to +0.05), indicating ongoing oxic conditions across the LPE (Proemse et al., 2013). Our results suggest that areas of the Pangea continental shelf (North West Pangea) experienced oxic conditions throughout the LPE event, while anoxic conditions developed in the deep ocean. Hence, anoxic marine waters did not extend globally onto shelf environments and as such ocean anoxia cannot have been the main driver of the extinction event. While global systems were stressed by anoxia, the anoxic conditions may better represent a symptom of Siberian Trap eruptions that had catastrophic impact on the environment, potentially through nutrient loading and deposition of toxic substances into marine and terrestrial systems. Proemse et al., 2013: Molybdenum isotopic evidence for oxic marine conditions during the latest Permian extinction. Geology 41, 967-970.

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

    Science.gov (United States)

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

    2010-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-05-01

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

  16. Gas hydrate contribution to Late Permian global warming.

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

    Ro?. 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: 4.724, year: 2013

  17. Microfloristic and petrographic study of coal from Faxinal mine, Rio Bonito formation from the Permian period, RS

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Sommer, M.; Marques-Toigo, M.; Paim, P.S.G.

    1984-01-01

    This paper is the result of the petrological and microfloristic analysis of coal seams from the Faxinal Mine (Rio Bonito Formation, Lower Permian, Parana Basin, southern Brazil). Petrological data showed a great predominance of the Vitrinite maceral group (mainly Vitrite) and a low amount of the Exinite and Inertinite groups. Dispersed wood and cuticular fragments were predominant in the palynological samples, while pollens and spores were less abundant and in general poorly preserved. Microfloristic analysis has revealed an association with a predominance of spores related to a pteridophytic plant community. The available petrological and palynological data suggest that the coal seams originated mainly in a telmatic environment. 8 references.

  18. Biostratigraphic correlation in the Karoo: The case of the Middle Permian parareptile Eunotosaurus

    Scientific Electronic Library Online (English)

    Mike, Day; Bruce, Rubidge; John, Almond; Sifelani, Jirah.

    Full Text Available The richness of fossil tetrapods from the Beaufort Group of South Africa has enabled biostratigraphic subdivision of this Permo-Triassic succession, with global applicability. Despite being the thickest of the seven biozones recognised, attempts at further subdivision of the Middle Permian Tapinocep [...] halus Assemblage Zone (Abrahamskraal Formation) have not been successful, largely because the exact stratigraphic ranges of fossil taxa are unknown. This gap in knowledge has limited stratigraphic correlation of the Abrahamskraal Formation and hindered understanding of Middle Permian Karoo basin development. Currently, the lowermost Beaufort Group is split between an eastern and a western stratigraphic scheme and, because of poor outcrop and the relative paucity of fossils in the east, stratigraphic correlation between the two areas has been uncertain. Recent fossil discoveries of the parareptile Eunotosaurus africanus in the Eastern Cape and Free State provinces have extended its known geographic range in the east. An additional specimen from the lower Middleton Formation in the Eastern Cape has, for the first time, enabled the biostratigraphic correlation of this unit with the Poortjie Member of the Teekloof Formation in the west. These finds confirm the diachroneity of the boundary between the marine Ecca Group and the terrestrial Beaufort Group.

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

    Science.gov (United States)

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

    2014-12-01

    Nitrogen isotopic compositions of upper Permian to lowermost Triassic rocks were analyzed at Chaotian, Sichuan, China, to clarify changes in the oceanic N cycle around the Permian-Triassic boundary (P-TB) including the entire Changhsingian (Late Late Permian) prior to the extinction. The analyzed ca. 40 m thick interval across the P-TB at Chaotian consists of three stratigraphic units: the upper Wujiaping Formation, the Dalong Formation, and the lowermost Feixianguan Formation, in ascending order. The upper Wujiaping Formation is composed of dark gray limestone with diverse shallow-marine fossils, such as calcareous algae, deposited on the shallow shelf. In contrast, the overlying Dalong Formation, ca. 25 m thick, is mainly composed of thinly bedded black mudstone and siliceous mudstone containing abundant radiolarians, deposited on the relatively deep slope/basin. Absence of bioturbation, substantially high TOC contents, and abundant occurrence of pyrite framboids in the Dalong Formation indicate deposition under anoxic conditions. The lowermost Feixianguan Formation is composed of thinly bedded gray marl and micritic limestone with minor fossils, deposited on the relatively shallow slope. ?15N values are in positive values around +1 to +2‰ in the upper Wujiaping Formation implying denitrification and/or anammox in the ocean. ?15N values gradually decrease to -1‰ in the lower Dalong Formation and are consistently low (around 0‰) in the middle Dalong to lowermost Feixianguan Formation. No clear ?15N shift is recognized across the extinction horizon. The consistently low ?15N values suggest the enhanced N fixation in the ocean during the Changhsingian at Chaotian. Composite profiles based on previous and the present studies demonstrate the substantial ?15N variation on a global scale in the late Permian to earliest Triassic; a systematic ?15N difference by low and high latitudes is particularly clarified. Although the enhanced N fixation throughout the Changhsingian at Chaotian was likely a regional event in northwestern South China, the composite ?15N profiles imply that the sea area in which fixed N is depleted has gradually developed worldwide in the Changhsingian, possibly acting as a prolonged stress to the shallow-marine biota.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-15

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

  1. Coal clasts in the carboniferous sediments of the Upper Silesian basin.

    Czech Academy of Sciences Publication Activity Database

    Kožušníková, Alena; Martinec, Petr; Pešek, J.; Valterová, P.

    Calgary : Canadian Society of Petroleum Geologists, 2002 - (Hills, L.), s. 895-901 - (Memoir. 19). [Carboniferous and permian of the world/14./. Calgary (CA), 17.08.1999-21.08.1999] R&D Projects: GA ?R GA205/97/0307 Institutional research plan: CEZ:AV0Z3086906 Keywords : carboniferous sediments * Upper Silesian basin Subject RIV: DB - Geology ; Mineralogy

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

    Science.gov (United States)

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

    2000-01-01

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

  3. Permian plants from the Chutani Formation (Titicaca Group, Northern Altiplano of Bolivia: II. The morphogenus Glossopteris

    Directory of Open Access Journals (Sweden)

    Roberto Iannuzzi

    2004-03-01

    Full Text Available Fossil plants belonging to the morphogenera Glossopteris, Pecopteris and Asterotheca were collected from the upper part of the Chutani Formation (Titicaca Group, near the town of San Pablo de Tiquina, on the southeastern shore of Lake Titicaca (northern Altiplano, Bolivia. This paper presents the first description of specimens of the morphogenus Glossopteris from Bolivia. The Bolivian specimens of Glossopteris consist of poorly-preserved impressions, although they present the diagnostic features of this morphogenus. They are fragments of leaves with secondary veins of taeniopterid-type, typical of glossopterids from Late Permian deposits of Gondwana. The only species of Pecopteris confirmed in the first part of this study, i.e. P. dolianitii Rösler and Rohn (see Vieira et al. 2004, was previously reported from the Late Permian beds of the Rio do Rasto and Estrada Nova formations in the Paraná Basin (southern Brazil. Therefore, a Late Permian age is proposed for the fossil plant-bearing beds of the Chutani Formation based on the analyzed assemblage. The phytogeographic implications of this new find are briefly analyzed.Plantas fósseis, pertencentes aos morfo-gêneros Glossopteris, Pecopteris e Asterotheca, foram coletadas na porção superior da seção aflorante da Formação Chutani, próxima ao povoado de San Pablo de Tiquina, sudeste do lago Titicaca (Altiplano norte, Bolívia. Este trabalho apresenta a primeira descrição de espécimes do morfo-gênero Glossopteris provenientes da Bolívia. Os espécimes estudados de Glossopteris consistem em impressões foliares pobremente preservadas nas quais feições diagnósticas estão presentes. Os fragmentos foliares apresentam venação secundária do tipo teniopteróide, uma característica típica de glossopterídeas encontradas em depósitos do Permiano Superior do Gondwana. Por sua vez, a única espécie de Pecopteris confirmada para estes níveis da Formação Chutani, i.e. P. dolianitii Rohn and Rösler (ver Vieira et al. 2004, foi previamente assinalada para estratos do Permiano Superior da Bacia do Paraná (formações Estrada Nova e Rio do Rasto. Portanto, uma idade neopermiana é tentativamente proposta para os níveis da Formação Chutani que contém a associação estudada. As implicações fitogeográficas deste novo achado são brevemente analisadas.

  4. Permian plants from the Chutani Formation (Titicaca Group, Northern Altiplano of Bolivia): II. The morphogenus Glossopteris

    Scientific Electronic Library Online (English)

    Roberto, Iannuzzi; Carlos E. L., Vieira; Margot, Guerra-Sommer; Enrique, Díaz-Martínez; George W., Grader.

    2004-03-01

    Full Text Available Plantas fósseis, pertencentes aos morfo-gêneros Glossopteris, Pecopteris e Asterotheca, foram coletadas na porção superior da seção aflorante da Formação Chutani, próxima ao povoado de San Pablo de Tiquina, sudeste do lago Titicaca (Altiplano norte, Bolívia). Este trabalho apresenta a primeira descr [...] ição de espécimes do morfo-gênero Glossopteris provenientes da Bolívia. Os espécimes estudados de Glossopteris consistem em impressões foliares pobremente preservadas nas quais feições diagnósticas estão presentes. Os fragmentos foliares apresentam venação secundária do tipo teniopteróide, uma característica típica de glossopterídeas encontradas em depósitos do Permiano Superior do Gondwana. Por sua vez, a única espécie de Pecopteris confirmada para estes níveis da Formação Chutani, i.e. P. dolianitii Rohn and Rösler (ver Vieira et al. 2004), foi previamente assinalada para estratos do Permiano Superior da Bacia do Paraná (formações Estrada Nova e Rio do Rasto). Portanto, uma idade neopermiana é tentativamente proposta para os níveis da Formação Chutani que contém a associação estudada. As implicações fitogeográficas deste novo achado são brevemente analisadas. Abstract in english Fossil plants belonging to the morphogenera Glossopteris, Pecopteris and Asterotheca were collected from the upper part of the Chutani Formation (Titicaca Group), near the town of San Pablo de Tiquina, on the southeastern shore of Lake Titicaca (northern Altiplano, Bolivia). This paper presents the [...] first description of specimens of the morphogenus Glossopteris from Bolivia. The Bolivian specimens of Glossopteris consist of poorly-preserved impressions, although they present the diagnostic features of this morphogenus. They are fragments of leaves with secondary veins of taeniopterid-type, typical of glossopterids from Late Permian deposits of Gondwana. The only species of Pecopteris confirmed in the first part of this study, i.e. P. dolianitii Rösler and Rohn (see Vieira et al. 2004), was previously reported from the Late Permian beds of the Rio do Rasto and Estrada Nova formations in the Paraná Basin (southern Brazil). Therefore, a Late Permian age is proposed for the fossil plant-bearing beds of the Chutani Formation based on the analyzed assemblage. The phytogeographic implications of this new find are briefly analyzed.

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

    Science.gov (United States)

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

    2006-12-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

  7. Did an Impact Trigger the Permian-Triassic Extinction?

    Science.gov (United States)

    Morrison, David

    This resource, authored by David Morrison, contains the National Aeronautics and Space Administration's Astrobiology Institute news story on new evidence of a 251-million year-old impact crater off the western coast of Australia that may have caused the "Great Dying", the Permian-Triassic extinction event.

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

    Science.gov (United States)

    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 ?13C excursions. This gradient subsequently collapses to less than 1‰ in the Middle Triassic, coincident with accelerated biotic recovery and cessation of ?13C excursions. Based on the relationship between ?18O and ?13C, 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 ?13C 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.

  9. High precision time calibration of the Permian-Triassic boundary mass extinction event in a deep marine context

    Science.gov (United States)

    Baresel, Björn; Bucher, Hugo; Brosse, Morgane; Bagherpour, Borhan; Schaltegger, Urs

    2015-04-01

    To construct a revised and high resolution calibrated time scale for the Permian-Triassic boundary (PTB) we use (1) high-precision U-Pb zircon age determinations of a unique succession of volcanic ash layers interbedded with deep water fossiliferous sediments in the Nanpanjiang Basin (South China) combined with (2) accurate quantitative biochronology based on ammonoids, conodonts, radiolarians, and foraminifera and (3) tracers of marine bioproductivity (carbon isotopes) across the PTB. The unprecedented precision of the single grain chemical abrasion isotope-dilution thermal ionization mass spectrometry (CA-ID-TIMS) dating technique at sub-per mil level (radio-isotopic calibration of the PTB at the biological timescales at resolution adequate for both groups of processes. Using these alignments allows (1) positioning the PTB in different depositional setting and (2) solving the age contradictions generated by the misleading use of the first occurrence (FO) of the conodont Hindeodus parvus, whose diachronous first occurrences are arbitrarily used for placing the base of the Triassic. This new age framework provides the basis for a combined calibration of chemostratigraphic records with high-resolution biochronozones of the Late Permian and Early Triassic. Here, we present new single grain U-Pb zircon data of volcanic ash layers from two deep marine sections (Dongpan and Penglaitan) revealing stratigraphic consistent dates over several volcanic ash layers bracketing the PTB. These analyses define weighted mean 206Pb/238U ages of 251.956±0.033 Ma (Dongpan) and 252.062±0.043 Ma (Penglaitan) for the last Permian ash bed. By calibration with detailed litho- and biostratigraphy new U-Pb ages of 251.953±0.038 Ma (Dongpan) and 251.907±0.033 Ma (Penglaitan) are established for the onset of the Triassic.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    K, Pauline Sabina; Jha, Neerja

    2014-10-01

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

  12. Volatile Release from The Siberian Traps and the End-Permian Environment

    Science.gov (United States)

    Black, B. A.; Elkins-Tanton, L. T.; Rowe, M. C.; Ukstins Peate, I.

    2010-12-01

    The Siberian Traps (ca. 252 Ma) is one of the most voluminous known eruptions of continental basaltic magma, and has been invoked as a trigger for the end-Permian mass extinction: the single largest loss of biological diversity in the Phanerozoic. Constraining the degassing of volatiles such as sulfur, chlorine, fluorine, and carbon dioxide is critical to understanding the environmental consequences of flood basalt emplacement. We measured concentrations of these volatiles in melt inclusions in olivine, plagioclase and clinopyroxene crystals from Siberian Traps lavas, sills, and tuffs. New ion probe analysis results provide insight into the volatile budget of the earliest pyroclastic and later flow-dominated periods of flood volcanism. In particular, melt inclusions from four flows and tuffs belonging to the stratigraphically lowest extrusive suites provide the first estimates of dissolved volatiles within early-erupted Siberian Traps magmas. Comparison with studies of melt inclusions from Iceland’s Laki eruption, the Deccan Traps and the Columbia River flood basalts suggests that Cl, F, and S concentrations in some Siberian Traps magmas were anomalously high. Measured concentrations reach 0.75 wt % Cl and 1.95 wt % F in one sample. In other samples, we also measure significant concentrations of S, Cl, F, and C. We hypothesize that assimilation of evaporites and other sedimentary rocks from the Tunguska basin might have contributed to the volatile budget of Siberian magmatism. Our melt inclusion data, in conjunction with the present-day volumes of the associated flows, sills, and tuffs, indicate that even individual Siberian Traps eruption events probably carried massive volatile loads. We observe tuff sequences tens to hundreds of meters thick near the base of the volcanic sequence in the Maymecha-Kotuy and Angara regions; these volcaniclastic deposits may reach 700 meters in thickness in the central Tunguska basin. Locally well-preserved accretionary lapilli provide evidence that many of these deposits are primary pyroclastic rocks. These explosive episodes may have enhanced the efficiency with which degassing volatiles were entrained into an ascending thermal plume. The high volatile contents we observe in many Siberian Traps rocks, if injected into the stratosphere, may have significantly contributed to ozone depletion and a drastic deterioration in global environmental conditions at the time of the Permian-Triassic boundary.

  13. Astronomical forcing of a Middle Permian chert sequence in Chaohu, South China

    Science.gov (United States)

    Yao, Xu; Zhou, Yaoqi; Hinnov, Linda A.

    2015-07-01

    Astronomical forcing has been shown to be a fundamental driver of climate change through geological time. Pelagic, bedded cherts deposited in Mesozoic ocean basins with chert-mudstone cycles have been shown to contain the imprint of Milankovitch astronomical climate forcing. In the Chaohu region, South China, we studied a Middle Permian radiolarian chert sequence (Gufeng Formation) with chert-mudstone couplets reminiscent of the Mesozoic cherts, but deposited on a continental shelf. Spectral analysis of lithologic bed thickness data from two sections of this chert sequence reveals that 13 cm to 20 cm chert-mudstone cycles in the stratigraphic domain match theoretical 32-kyr Middle Permian obliquity cycling, together with a hierarchy of other cycles with 12 cm, 9 cm, 7 cm, 6.6 cm and 5.4 cm wavelengths. Tuning the 13 cm to 20 cm stratigraphic cycles to Earth's obliquity cycle periodicity indicates that the cm-scale cycles are precession-scale variations with a strong ?400 kyr amplitude modulation. Tuning to theoretical precession terms provides further support for the astronomical forcing of the chert sequence. We propose that monsoon-controlled upwelling contributed to the development of the chert-mudstone cycles. A seasonal monsoon controlled by astronomical forcing (i.e., insolation) influenced the intensity of upwelling. Stronger upwelling increased radiolarian productivity in the surface ocean, increasing silica deposition. Glacio-eustatic oscillations from ice sheet dynamics in southern Gondwana modulated terrigenous mud flux to the basin. The two processes jointly contributed to the astronomical rhythms of these tropical chert-mudstone sequences, which are characterized by comparably strong obliquity and precession responses. Subsequent diagenesis distorted the chert and mudstone layering, but not enough to destroy the original stratigraphic patterns. The resulting astronomical time scale (ATS) assumes a Roadian/Wordian boundary age of 268.8 Ma for the onset of the first chert layer at the base of the sequence and ends at 264.1 Ma, for a total duration of 4.7 myr.

  14. Evolution of the West Siberian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Vyssotski, A.V. [Chevron, 1500 Louisiana Street, Houston (United States); Vyssotski, V.N. [TNK-BP, 1 Arbat St, Moscow 119019 (Russian Federation); Nezhdanov, A.A. [OOO TyumenNIIgiprogas, 2 Vorovskogo Str., Tyumen 625019 (Russian Federation)

    2006-01-01

    The West Siberian Basin is one of the largest intra-cratonic basins of the world and an important hydrocarbon province of Russia. Perhaps the most important geologic event in Siberia was the emplacement of basalts around {approx} 250Ma (i.e. Permo-Triassic boundary) covering an area of about 5x10{sup 6} km{sup 2}. This volcanism may be responsible for a mass extinction that occurred around Permian-Triassic time. The pre-basaltic rifting event was limited to the north-northeastern sector of the basin. Initial basin wide subsidence took place in the Jurassic as a result of which the western part of Siberia became the West Siberian Basin bounded by uplifts to the east and to the west. One of the surprising aspects of the West Siberian Basin is the abundance of sub-vertical faults believed to be result of strike-slip movement. While intra-plate inversions and fault reactivation structures have been observed in many cratons, sub-vertical faults observed in the West Siberian Basin are unique because of their geometries and abundance. The differentiation between the effects of tectonics and eustasy in cratonic basins is simple-the global eustatic signal is basin-wide with regional and local tectonics playing an overprinting role. Thus, the Middle Jurassic-Turonian 1st, 2nd, and 3rd order cycles in the West Siberian Basin were primarily driven by eustasy. The Middle Jurassic-Turonian series can be subdivided into two second-order and 16 third-order transgressive-regressive cycles (within dataset extent). Fourth-order cycles appear to be controlled by delta shifting. Although extensively studied, a number of fundamental questions regarding the origin and evolution of the West Siberian Basin remain unresolved or poorly documented in the literature. [Author].

  15. Permian plants from the Chutani Formation (Titicaca Group, Northern Altiplano of Bolivia: I. Genera Pecopteris and Asterotheca

    Directory of Open Access Journals (Sweden)

    Vieira Carlos E. L.

    2004-01-01

    Full Text Available Fossil plants belonging to the morphogenera Glossopteris, Pecopteris and Asterotheca were collected from the upper part of the Chutani Formation (Titicaca Group, near the town of San Pablo de Tiquina, on the southeastern shore of Lake Titicaca (northern Altiplano, Bolivia. Here we report the analysis of fern-type foliage found at this location. Three species of pecopterid fronds are identified: Pecopteris dolianitii Rohn and Rösler, P. cf. P. cadeadensis Rohn and Rösler, and P. cf. P. pedrasica Read. All these species are typically found in Permian deposits of the Paraná Basin in southern Brazil. Despite the poor preservation of the material, a fertile specimen could be studied and was determined as Asterotheca sp. The paleoenvironmental and paleoecological implications of this new find are briefly analyzed.

  16. Climate simulation of the latest Permian: Implications for mass extinction

    Science.gov (United States)

    Jeffrey Kiehl

    This report presents the results of climate modeling research which indicates that elevated levels of carbon dioxide in the atmosphere at the end of the Permian period led to climatic conditions inhospitable to both marine and terrestrial life. The Permian-Triassic boundary (about 251 million years ago) was the time of the largest known mass extinction in Earth's history, when greater than ninety percent of all marine species, and approximately seventy percent of all terrestrial species, died out. The model, which used paleogeography and paleotopography correct for the time period, indicated that warm high-latitude surface air temperatures and elevated carbon dioxide levels may have resulted in slowed circulation and stagnant, anoxic conditions in Earth's oceans. The report also suggests that the excess carbon dioxide (and sulfur dioxide) may have originated from volcanic activity associated with eruption of the Siberian Trap flood basalts, which took place at the same time.

  17. Petrified peat from a permian coal bed in Antarctica

    Science.gov (United States)

    Schopf, J.M.

    1970-01-01

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

  18. Palynostratigraphic correlation of the Sardhai Formation (Permian) of Pakistan

    OpenAIRE

    Jan, Irfan U.; Stephenson, Michael H.; Khan, Fazli R.

    2009-01-01

    Palynological assemblages from the Sardhai Formation shale (Permian), lying between the red-bed Warchha Formation and the Amb Formation limestones in the Salt and Khisor ranges of Pakistan contain abundant bisaccate pollen grains and few spores. In particular, well-preserved specimens of Florinites? balmei, a bilaterally symmetrical monosaccate pollen grain, are common. The presence of this pollen and the stratigraphic context suggest that the Sardhai Formation correlates with the Khuff trans...

  19. Megaspores from coals of the Triunfo Member, Rio Bonito Formation (Lower Permian, northeastern Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    FRESIA RICARDI-BRANCO

    2002-09-01

    Full Text Available This paper presents the results of a detailed study of megaspores occurring in coal seams of the Triunfo Member, Rio Bonito Formation at Figueira, Paraná State, Brazil. This coal-bearing sequence accumulated in a marine delta system during the Early Permian. Four species are described and illustrated: Lagenoisporites triunfensis, L. scutiformis, Sublagenicula cf. brasiliensis, and Setosisporites cf. furcatus. Of these, the two species of Lagenoisporites are predominant. Relationships to other megaspore species are discussed; and the temporal and spatial distributions of the four species in the Paraná Basin are documented.No presente trabalho são apresentados os resultados obtidos a partir do estudo sistemático detalhado dos megásporos provenientes das camadas de carvão do Membro Triunfo, Formação Rio Bonito, Estado do Paraná, Brasil. A seqüência portadora de carvão, foi o resultado do acúmulo de matéria orgânica num de sistema deltaico marinho durante o Eopermiano. Quatro espécies são aqui descritas e ilustradas: Lagenoisporites triunfensis, L. scutiformis, Sublagenicula cf. brasiliensis, e Setosisporites cf. furcatus. Destas, as duas espécies de Lagenoisporites são dominantes. São igualmente discutidas as relações existentes com outras espécies de megásporos, assim como documentada a distribuição temporal e espacial das quatro espécies na Bacia do Paraná.

  20. Megaspores from coals of the Triunfo Member, Rio Bonito Formation (Lower Permian), northeastern Paraná State, Brazil

    Scientific Electronic Library Online (English)

    FRESIA, RICARDI-BRANCO; MITSURU, ARAI; OSCAR, RÖSLER.

    2002-09-01

    Full Text Available No presente trabalho são apresentados os resultados obtidos a partir do estudo sistemático detalhado dos megásporos provenientes das camadas de carvão do Membro Triunfo, Formação Rio Bonito, Estado do Paraná, Brasil. A seqüência portadora de carvão, foi o resultado do acúmulo de matéria orgânica num [...] de sistema deltaico marinho durante o Eopermiano. Quatro espécies são aqui descritas e ilustradas: Lagenoisporites triunfensis, L. scutiformis, Sublagenicula cf. brasiliensis, e Setosisporites cf. furcatus. Destas, as duas espécies de Lagenoisporites são dominantes. São igualmente discutidas as relações existentes com outras espécies de megásporos, assim como documentada a distribuição temporal e espacial das quatro espécies na Bacia do Paraná. Abstract in english This paper presents the results of a detailed study of megaspores occurring in coal seams of the Triunfo Member, Rio Bonito Formation at Figueira, Paraná State, Brazil. This coal-bearing sequence accumulated in a marine delta system during the Early Permian. Four species are described and illustrate [...] d: Lagenoisporites triunfensis, L. scutiformis, Sublagenicula cf. brasiliensis, and Setosisporites cf. furcatus. Of these, the two species of Lagenoisporites are predominant. Relationships to other megaspore species are discussed; and the temporal and spatial distributions of the four species in the Paraná Basin are documented.

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

    Science.gov (United States)

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

    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.

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

    International Nuclear Information System (INIS)

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

  3. Fistulipora Microparallela (Yang and Lu, 1962 from Lower Permian Bryozoans of Lut Block, Central Iran

    Directory of Open Access Journals (Sweden)

    H. Yarahmadzahi

    2012-10-01

    Full Text Available The Fistulipora microparallela (Yang and Lu, 1962 species is described for the first time from the Sakmarian deposits of the Sarab section in Lut Block, Central Iran. This species has been reported only from the Permian (Cisuralian-Guadalupian of the Qilianshan and Kankerin formations, and the Baliqliq Group (Upper Carboniferous to Lower Permian of Western Xinjiang, China.

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

    Science.gov (United States)

    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 the ~290 Ma (U-Pb on zircon) mafic intrusion give conditions of ~6 kbar and > 900°C. Our results bring constrains on the thermal and mechanical relation between the pluton and the host rock in the middle crust and confirm the mid-crustal position of the Campo unit during the Permian. Furthermore, this study highlights the contrasted evolution of mid-crustal levels compared to lower-crustal systems such as the Ivrea zone. Eventually at a larger scale, these results provide insights on the tectonic and magmatic processes and thermal conditions of the continental crust during Variscan post-orogenic evolution.

  5. Deep-seated salt dissolution in the Delaware basin, Texas and New Mexico

    International Nuclear Information System (INIS)

    Patterns of salt dissolution in the Delaware Basin are related to the bedrock geometry and hydrology that developed following uplift, tilting, and erosion in the late Cenozoic, and the greatest volume of salt has been removed since that time. During the Permian, some salt was dissolved from the top of the Castile Formation before deposition of the Salado Formation and from the top of the Salado before deposition of the Rustler Formation. In addition, some salt dissolution occurred after the Permian and before the Cretaceous. Post-uplift surface dissolution has progressed across the Delaware Basin from south to north and west to east and generally down the regional dip. Deep-seated dissolution has occurred around the margin of the basin where the Capitan Limestone aquifer is in contact with the Permian evaporites and within the basin where selective dissolution in the lower Salado has undercut the overlying salt beds of the middle and upper Salado. Dissolution has not advanced down regional dip uniformly but has left outliers of salt and has progressed selectively into structurally predisposed areas. This selective advance has significance for the stability of the U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP) site

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

    Scientific Electronic Library Online (English)

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

    2015-04-01

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

  7. Emplacement of magma in sedimentary basins

    Science.gov (United States)

    Malthe-Sorenssen, A.; Planke, S.

    2002-12-01

    Sheet-like intrusive complexes are commonly present in sedimentary basins on rifted volcanic margins. Such sill complexes have important impact on petroleum maturation, migration and trapping. We are currently completing an integrated seismic, field and theoretical study on the petroleum implications of sill intrusions. One aspect of this study has been to get new understanding of the magma emplacement processes based on integrated numerical modeling and geophysical/geological mapping activities. Extensive sill complexes have been identified and mapped in the NE Atlantic and Karoo basins based on seismic, borehole, remote sensing and field data. Early Tertiary intrusive complexes are present in the Voring and More basins offshore mid-Norway. Similar sill complexes are exposed onshore in Cretaceous to Permian age sedimentary sequences on the conjugate central-east Greenland margin. A voluminous Jurassic age intrusive complex is well exposed in the Permian to Jurassic Karoo basin as the erosionally strong dolerites form an impressive mountainous landscape in large parts of South Africa. The sheet intrusions are found at paleodepths of 0-6 km. Deep intrusions are generally long and smooth, whereas shallow intrusions are rough, transgressive and commonly saucer-shaped. Saucer-shaped intrusions are present in unstructured basin segments. The diameter of the saucers increases with depth. Structured basin segments are characterized by a variety of sill complex geometries. The intrusions generally mimic the basin structure. In nature, magma is emplaced in internally pressurized, planar cracks. The emplacement process is controlled by the local stress field and complex interactions of buoyancy forces, host rock resistance to fracture, elastic deformation of country rock, magma hydrostatic pressure and fluctuating magma pressure, magma viscosity and weight of overburden. We have developed a discrete element model to study the emplacement process. Results from the modeling and geological/geophysical mapping show that sill emplacement is a dynamic process where both 1) stress field anisotropy generated by the emplacement process and 2) local structural heterogeneities have important influence on the final geometry of the sill complex. Saucer-shaped sill complexes are formed spontaneously by the numerical model in a simple, stratified basin. Asymmetric stress field is developed around the tip of the sill during the emplacement, causing the melt to transgress and forming the inclined sheets. The modeling and field data show that faults and weak intra-sedimentary horizons are preferentially used during the emplacement process. Inflation and deflation cycles are particularly common in the vicinity of major structural heterogeneities.

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

    DEFF Research Database (Denmark)

    Ruhl, Micha; Bjerrum, Christian J.

    2013-01-01

    Earth’s history is marked by multiple events of ocean anoxia developing along continental margins and po¬tentially into the open ocean realm. These events of¬ten coincide with the emplacement of large igneous provinces (LIPs) on continents, major perturbations of global geochemical cycles and marine (mass) ex¬tinction. The geographic and temporal extend and the intensity (ferruginous vs. euxinic) of anoxic con¬ditions is, however, strongly debated and not well constraint. This complicates understanding of close coupling between Earth’s physical, chemical and bi¬ological processes. We studied 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 outgassing from the Siberian Traps. We measured redox-sensitive trace element concentrations (e.g. Mo, Cu, U) and the speciation of iron [Fe-HR/Fe-T and Fe-PY/ Fe- HR] in marine sediments from Svalbard (Festningen). We compare these data to additional, new, high-lati-tude data from eastern Greenland and the equatorial Tethys realm in Iran. We show that the Permian-Tri¬assic boundary at Svalbard is marked by 2 phases of euxinic (sulfidic) ocean conditions. An initial short phase at the onset of atmospheric carbon release is separated from a subsequent longer phase by a re¬turn to ferruginous ocean conditions (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 Iran. It sug¬gests a strongly decreased global ocean molybdenum (and possibly also ocean sulfate) inventory by massive molybdenum drawdown (and possibly pyrite buri¬al) at the onset of end-Permian atmospheric carbon release and leading up to the Permian-Triassic mass extinction. We compare these 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

  9. The Permian volcanism of Sardinia revisited: new geochronological and geochemical data as a key for geodynamic evolution of the western Peri-Tethian sector

    Science.gov (United States)

    Gaggero, Laura; Gretter, Nicola; Lago, Marceliano; Langone, Antonio; Oggiano, Giacomo; Ronchi, Ausonio

    2014-05-01

    Recent studies have confirmed the important role played by magmatism affecting Sardinian basins during the latest Carboniferous and Permian age (Cortesogno et al. 1998; Buzzi et al., 2008; Casini et al., 2012). To-date, most of the geochronological analysis performed on the Permian volcanic events in the island are methodologically overcome and frequently not in tune with the stratigraphy. In the north-western and central-southeastern Sardinian basins (Nurra, Perdasdefogu, Seui-Seulo and Escalaplano), the late-post Variscan tectonic collapse favored the emplacement of a calc-alkaline products not only in the form of generally shallow intrusions but also volcanism within intramontane strike-slip basins. This magmatism is expressed both as pyroclastic rocks-lava flows filling small half-graben basins and hypabyssal intrusions (lava-domes and dykes). These volcano-sedimentary troughs generally include both external and internal igneous eruptions as well as the detrital products eroded from the surrounding structural highs. Rhyolites, andesites and dacites are the main rock types while trachydacites and trachyandesites are less represented. Our goal is to couple the petrographic and geochemical features of 17 selected samples stratigraphically constrained and new U-Pb ages data on zircons from the post-Variscan effusive rocks in Sardinia. The whole-rock and REE geochemical features confirm a progressive evolution in the post-Variscan extensional, trans-tensile regime in with and fits an origin in a stacking of nappes associated with thermal re-equilibration of lithospheric mantle and telescopic partial melting of the thickened crust. The process is dominated by AFC. As far as the geochronological analysis is concerned, a preliminary cathodoluminescence study has been performed on all mounted crystals in order to select the precise location of the shot points. Each crystal has been analyzed for U, Th and Pb in the epoxy mount by laser-ablation inductively coupled plasma mass spectrometry (LA ICP-MS) at the Institute of Geosciences and Earth Resources IGG-CNR of Pavia. The time lag of Permian ages recorded along the Sardinia cross section is significant in the modeling of the post- Variscan tectonic, sedimentary evolution and in the perspective of the geodynamic evolution of Southern Variscides. REFERENCES Casini L., Cuccuru S., Maino M., Oggiano G., Tiepolo M 2012. Emplacement of the Arzachena Pluton (Corsica-Sardinia Batholith) and the geodynamics of incoming Pangaea. Tectonophysics 544-545 (2012) 31-49. Buzzi L., Gaggero L., Oggiano G. 2008. The Santa Giusta ignimbrite (NW Sardinia): a clue for the magmatic, structural and sedimentary evolution of a Variscan segment between Early Permian and Triassic. Italian Journal of Geoscience 127(3), 683-695. Cortesogno L., Cassinis G., Dallagiovanna G., Gaggero L., Oggiano G., Ronchi A., Seno S., Vanossi M. 1998. The Variscan post-collisional volcanism in Late Carboniferous-Permian sequences of Ligurian Alps, Southern Alps and Sardinia (Italy): a synthesis. Lithos 45, 305-328.

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

    Science.gov (United States)

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

    2004-01-01

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

  11. Evolution of a complex behavior: the origin and initial diversification of foliar galling by Permian insects

    Science.gov (United States)

    Schachat, Sandra R.; Labandeira, Conrad C.

    2015-04-01

    A central notion of the early evolution of insect galling is that this unique behavior was uncommon to rare before the diversification of angiosperms 135 to 125 m.yr. ago. However, evidence accumulated during recent years shows that foliar galls were diverse and locally abundant as early as the Permian Period, 299 to 252 m.yr. ago. In particular, a diversity of leaf galling during the Early Permian has recently been documented by the plant-damage record of foliar galls and, now, our interpretation of the body-fossil record of culprit insect gallers. Small size is a prerequisite for gallers. Wing-length measurements of Permian insects indicate that several small-bodied hemipteroid lineages originated early during the Permian, some descendant lineages of which gall the leaves of seed plants to the present day. The earliest foliar gallers likely were Protopsyllidiidae (Hemiptera) and Lophioneuridae (Thripida). Much of the Early Permian was a xeric interval, and modern galls are most common in dry, extra-tropical habitats such as scrubland and deserts. Plant-damage, insect body fossils, and the paleoclimate record collectively support the ecological expansion of foliar galling during the Early Permian and its continued expansion through the Late Permian.

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

    Science.gov (United States)

    Gregori, Daniel; Benedini, Leonardo

    2013-03-01

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

  13. The Dynamic Response of Marine Life to Extreme Temperature and Low Oxygen Events Following the End-Permian Mass Extinction.

    Science.gov (United States)

    Pietsch, C.; Bottjer, D. J.

    2014-12-01

    The end-Permian mass extinction was the most devastating taxonomic and ecological crisis in the history of life on Earth. The recovery lasted 5 My making it the longest in geologic history, although the cause of the delay is still heavily debated. We find that additional environmental changes during the recovery interval reset the attempts that marine communities made toward ecological complexity, resulting in the overall appearance of a stagnant recovery. The extinction mechanisms during the end-Permian include extreme temperature change and low oxygen environments resulting from the volcanic emission of carbon dioxide and other toxic gasses to the atmosphere. The biotic response to ancient environmental change is a direct analog for the ecological impacts of modern anthropogenic climate change. We applied an ecological recovery rubric to benthic, sea floor dwelling, communities throughout the Early Triassic recovery in two major ocean basins. Newly collected bulk fossil data from the Moenkopi and Thaynes Formations from the Southwest US and the Werfen Formation in Italy were analyzed along with literature data. In Italy, directly following the extinction, low oxygen environments prevented an ecological rebound. Once low oxygen conditions receded, 600 kyr after the extinction, taxonomic diversity, fossil body size, and trace fossil complexity rebounded. A little more than 1 My into the Early Triassic, an extreme temperature event resulted in a reset of community complexity in both Italy and the Southwest US. The body size of gastropods and the repopulation of echinoderms were significantly inhibited as was trace fossil complexity. Low oxygen conditions that developed in the last ~2My of the Early Triassic limited diversity and body size in the Southwest United States. The stagnant recovery is re-interpreted as dynamic resets and rapid rebounds driven by environmental perturbations throughout the Early Triassic.

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    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 ta...

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2011-12-01

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

  18. New evidence for 250 Ma age of halotolerant bacterium from a Permian salt crystal

    Science.gov (United States)

    Satterfield, Cindy L.; Lowenstein, Tim K.; Vreeland, Russell H.; Rosenzweig, William D.; Powers, Dennis W.

    2005-04-01

    The purported oldest living organism, the spore-forming bacterium Virgibacillus sp. Permian strain 2 9-3, was recently cultured from a brine inclusion in halite of the 250 Ma Permian Salado Formation. However, the antiquity of Virgibacillus sp. 2 9-3 has been challenged; it has been argued that the halite crystal and the fluid inclusion from which the bacterial spores were extracted may be younger than the Permian Salado salts. Here we report that brine inclusions from the same layer of salt that housed Virgibacillus sp. 2 9-3 are composed of evaporated Late Permian seawater that was trapped in halite cement crystals precipitated syndepositionally from shallow groundwater brines at temperatures of 17 37 °C. These results support the 250 Ma age of the fluid inclusions, and by inference, the long-term survivability of microorganisms such as Virgibacillus sp. 2 9-3.

  19. Permian biogeography of the Indian subcontinent with special reference to the marine fauna

    Science.gov (United States)

    Singh, Trilochan

    Permian biogeography of the Indian subcontinent is discussed in the light of brachiopods and associated fossils from different localities. The discussion is based primarily on the Permian "biome" concept of Waterhouse and Bonham-Carter (1975), wherein three biomes are proposed: group A of subpolar, group B of temperate, and group C of tropical character. Data on the occurrence of Permian brachiopods and associated fossils are given for the Salt Range, Karakoram, and Himalayan regions of India, Nepal, Bhutan, Tibet, and Peninsular India with respect to the age of the fauna. Marine Permian localities of the Himalayan region include those of Ladakh, Zanskar, Lahaul and Spiti, Kashmir, Bhadarwah-Bhallesh-Chamba, Kinnaur, Garhwal, Kumaun, Darjeeling, Sikkim, and Arunachal Pradesh. Permian marine localities of Peninsular India, which forms a part of central Gondwanaland, include those of Bap, Badhaura, Umaria, Manendragarh, and Daltonganj, where marine transgression occurred in Early Permian time. The faunas of these localities are discussed with respect to their age, which falls into two groups, Early and Late Permian. It is suggested that widespread colder climatic conditions prevailed in the Indian subcontinent during the early Early Permian. Similar conditions continued in most of the localities until the late Early Permian, except at west Karakoram (Shaksgam valley), Zanskar, north Tibet (central and western part), and the Salt Range. However, during the Late Permian, climatic conditions were varied. Cold climatic conditions prevailed in north Tibet (central part), Kumaun Tethyan Himalaya, and south Tibet; temperate conditions occurred in west Karakoram (Shaksgam valley), Zanskar, Lahaul and Spiti, Bhadarwah-Bhallesh-Chamba, north Nepal, and north Sikkim; and tropical conditions occurred in the Salt Range, east Karakoram, Ladakh, Kashmir, and north Tibet (western and eastern parts). At a few localities there appear to be some anomalies that might be due to lack of stratigraphical details and/or lack of detailed faunal investigations. An analysis of the Permian fauna of the Indian subcontinent reveals that the fauna belongs to one single biogeographic province, the Gondwana province. The northern boundary of this biogeographic province passes through the Karakoram Pass, Bangong Lake, and the Nujiang River. The Gondwana biogeographic province, further, shows two subprovinces, the Himalayan and the Tibetan.

  20. Upper Permian (Changxingian) Radiolarian Cherts within the Clastic Successions of the "Karakaya Complex" in NW Anatolia

    OpenAIRE

    Go?ncu?og?lu, M. Cemal; Kuwahara, Kiyoko; Turhan, U. Kag?an Teki?n Necati?

    2004-01-01

    The arkosic sandstones with olistostromes within the "Karakaya Complex" in NW Anatolia to the south of Geyve include a thin layer of green chert with radiolaria. Based on the composition of Albaillellids, the radiolarian assemblage corresponds to the Neoalbaillella ornithoformis assemblage, and its age is assigned to the Changxingian (Late Permian). This is the first finding of synsedimentary radiolarian cherts within the Karakaya units and the indication of latest Permian rifting o...

  1. Autochthonous Upper Permian (Midian) Carbonates in the Western Sakarya Composite Terrane, Geyve Area, Turkey: Preliminary Data

    OpenAIRE

    Turhan, Necati?; Go?ncu?og?lu, Cengi?z Okuyucu M. Cemal

    2004-01-01

    Permian limestones occur widely within the clastic units of the "Karakaya Complex" and are interpreted as allochthonous bodies or olistoliths. In the Kadirler area to the south of Geyve, however, Upper Permian (Midian) quartz sandstones and carbonates with a rich foraminifer fauna disconformably overlie a crystalline basement complex. This basement complex comprises metaclastic rocks, recrystallised limestones, metacherts, and metadiabases, and is intruded by granodiorites. The over...

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

    Science.gov (United States)

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

    2015-05-01

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

  3. Late Triassic volcanic activity in South-East Asia: New stratigraphical, geochronological and paleontological evidence from the Luang Prabang Basin (Laos)

    Science.gov (United States)

    Blanchard, Sébastien; Rossignol, Camille; Bourquin, Sylvie; Dabard, Marie-Pierre; Hallot, Erwan; Nalpas, Thierry; Poujol, Marc; Battail, Bernard; Jalil, Nour-Eddine; Steyer, Jean-Sébastien; Vacant, Renaud; Véran, Monette; Bercovici, Antoine; Diez, José Bienvenido; Paquette, Jean-Louis; Khenthavong, Bounxou; Vongphamany, Sotsy

    2013-07-01

    In South-East Asia, sedimentary basins displaying continental Permian and Triassic deposits have been poorly studied. Among these, the Luang Prabang Basin (North Laos) represents a potential key target to constrain the stratigraphic and structural evolutions of South-East Asia. A combined approach involving sedimentology, palaeontology, geochronology and structural analysis, was thus implemented to study the basin. It resulted in a new geological map, in defining new formations, and in proposing a complete revision of the Late Permian to Triassic stratigraphic succession as well as of the structural organization of the basin. Radiometric ages are used to discuss the synchronism of volcanic activity and sedimentation. The Luang Prabang Basin consists of an asymmetric NE-SW syncline with NE-SW thrusts, located at the contact between Late Permian and Late Triassic deposits. The potential stratigraphic gap at the Permian-Triassic boundary is therefore masked by deformation in the basin. The Late Triassic volcaniclastic continental deposits are representative of alluvial plain and fluvial environments. The basin was fed by several sources, varying from volcanic, carbonated to silicic (non-volcanic). U-Pb dating of euhedral zircon grains provided maximum sedimentation ages. The stratigraphic vertical succession of these ages, from ca. 225, ca. 220 to ca. 216 Ma, indicates that a long lasting volcanism was active during sedimentation and illustrates significant variations in sediment preservation rates in continental environments (from ˜100 m/Ma to ˜3 m/Ma). Anhedral inherited zircon grains gave older ages. A large number of them, at ca. 1870 Ma, imply the reworking of a Proterozoic basement and/or of sediments containing fragments of such a basement. In addition, the Late Triassic (Carnian to Norian) sediments yielded to a new dicynodont skull, attributed to the Kannemeyeriiform group family, from layers dated in between ˜225 and ˜221 Ma (Carnian).

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

    International Nuclear Information System (INIS)

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

  5. Devonian stratigraphy and depositional environments in the southern Illizi Basin (Algerian Sahara)

    Science.gov (United States)

    Wendt, Jobst; Kaufmann, Bernd; Belka, Zdzislaw

    2009-06-01

    The Illizi Basin is the easternmost one of a series of cratonic basins of the Algerian Sahara which extend along the northern margins of the Precambrian Reguibat and Hoggar massifs. Devonian rocks crop out along the erosional southern border of the basin and can be roughly divided into three major lithostratigraphic units: (1) Lower Devonian sandstones (upper part of the Tassilis externes), (2) Middle Devonian carbonates (Illizi Formation, introduced in this article) and (3) Upper Devonian shales (Tin Meras Formation). In the present study emphasis was laid on the Middle Devonian carbonates which were dated by conodonts and correlated in 12 sections over a W-E distance of about 350 km. The sequence shows a lateral transition from condensed series in the west, deposited on a submarine high (Amguid Ridge), into a shallow basin (Illizi Basin) which was additionally differentiated into minor ridges and sub-basins. The eastern portion of the basin is characterized by an enhanced clastic input from the Tihemboka Ridge which separates the Illizi Basin from the Murzuq Basin in western Libya. The differential subsidence during the Devonian shows that the Illizi Basin is primarily a depositional structure which subsequently became more accentuated after the Variscan orogenesis at the Carboniferous/Permian transition.

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

    Science.gov (United States)

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

    2015-05-01

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

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

    CERN Document Server

    Standard, J C

    2003-01-01

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

  8. Occurrence and origin of minerals in a chamosite-bearing coal of Late Permian age, Zhaotong, Yunnan, China

    Science.gov (United States)

    Dai, S.; Chou, C.-L.

    2007-01-01

    The minerals found in the no.5 coal (Late Permian) from the Zhaotong Coalfield, Yunnan Province, southwestern China, have been examined and found to consist mainly of kaolinite, pyrite, chamosite, quartz, and calcite, with trace amounts of illite and mixed-layer illite-smectite. The proportion of chamosite in clay minerals ranges from 32 to 56 wt%, with an average of 46 wt%. Chamosite is distributed not only in collodetrinite, but also occurs as cell fillings in fusinite, semifusinite, and telinite. The high content and mode of occurrence of chamosite in this mine indicate its formation by interaction of kaolinite with Fe-Mg-rich fluids during early diagenesis. Except for a minor amount of terfigenous quartz, most quartz is of authigenic origin and formed from kaolinite desilication. The calcite content of the no. 5 coal is 1.4-6.3% (with an average of 3%) and is distributed in collodetrinite and as cell fillings of coal-forming plants. Calcite originated from seawater invasion during peat accumulation. Pyrite occurs in several ways: as massive, framboidal, isolated enhedral/ anhedral, and euhedral forms. In addition, the presence of a large amount of pyritized red algae provides strong evidence of seawater invasion during peat accumulation. The red algae may have played an important role in the enrichment of sulfur in the coal. The characteristic assemblage of minerals in this mine resulted from a unique basinal environment in which the mineral matter was derived from a basaltic source region, volcanic activity, and seawater transgression during coal formation.

  9. Permian plants from the Chutani Formation (Titicaca Group, Northern Altiplano of Bolivia): I. Genera Pecopteris and Asterotheca

    Scientific Electronic Library Online (English)

    Carlos E. L., Vieira; Roberto, Iannuzzi; Margot, Guerra-Sommer; Enrique, Díaz-Matrínez; George W., Grader.

    2004-03-01

    Full Text Available Plantas fósseis, pertencentes aos morfo-gêneros Glossopteris, Pecopteris e Asterotheca, foram coletadas na porção superior da seção aflorante da Formação Chutani, próxima ao povoado de San Pablo de Tiquina, sudeste do lago Titicaca (Altiplano norte, Bolívia). Este trabalho analisa folhagens do tipo [...] feto encontradas neste sítio. Entre os espécimes estéreis, três espécies de frondes pecopterídeas foram identificadas: Pecopteris dolianiti, P. cf. cadeadensis e P. cf. pedrasica. Todas essas espécies eram até agora restritas aos depósitos permianos da Bacia do Paraná. A despeito do estado de preservação ruim do material, um espécime fértil pôde ser determinado como pertencente ao gênero Asterotheca. Implicações paleoambientais e paleoecológicas deste novo achado são brevemente analisadas. Abstract in english Fossil plants belonging to the morphogenera Glossopteris, Pecopteris and Asterotheca were collected from the upper part of the Chutani Formation (Titicaca Group), near the town of San Pablo de Tiquina, on the southeastern shore of Lake Titicaca (northern Altiplano, Bolivia). Here we report the analy [...] sis of fern-type foliage found at this location. Three species of pecopterid fronds are identified: Pecopteris dolianitii Rohn and Rösler, P. cf. P. cadeadensis Rohn and Rösler, and P. cf. P. pedrasica Read. All these species are typically found in Permian deposits of the Paraná Basin in southern Brazil. Despite the poor preservation of the material, a fertile specimen could be studied and was determined as Asterotheca sp. The paleoenvironmental and paleoecological implications of this new find are briefly analyzed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-01

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

  11. Origin and deposition of organic matter in continental chert of the Middle Permian Gufeng Formation in the northeastern Yangtze platform

    Science.gov (United States)

    Takebe, Masamichi; Kametaka, Masao; Takayanagi, Yukio; Mimura, Koichi; Sugitani, Kenichiro; Yamamoto, Koshi

    2007-09-01

    The Middle Permian Gufeng Formation in the northeastern Yangtze platform, China, contains radiolarian chert that is characterized by black color, high content of Fe, Mo, Ni, Cu, and Zn. Based on the inorganic geochemical features, previous work concluded that the cherts were deposited under sulfate-reducing conditions. In this study, organic carbon (C org), N and S contents of the cherts and H/C and O/C ratios of kerogen were examined to explore the origin of the organic matter. The concentration of C org in the black chert is extremely high relative to other cherts in accretionary complexes and continental platforms. The average C/N ratio of organic matter is 35, indicating that the organic matter originates from land plants. The kerogen from the chert is classed as type IV based on the H/C and O/C ratios, suggesting that oxidized or reworked organic matter was supplied to the Gufeng basin. Therefore, the organic matter is considered to originate from terrestrial plants or reworked material from land. Due to the depositional setting on a continental platform, nutrient supplied with organic matter from land probably played an important role in abundant biogenic productivity and sedimentation of the radiolarian chert on the continental platform.

  12. Late Permian marine ecosystem collapse began in deeper waters: evidence from brachiopod diversity and body size changes.

    Science.gov (United States)

    He, W-H; Shi, G R; Twitchett, R J; Zhang, Y; Zhang, K-X; Song, H-J; Yue, M-L; Wu, S-B; Wu, H-T; Yang, T-L; Xiao, Y-F

    2015-03-01

    Analysis of Permian-Triassic brachiopod diversity and body size changes from different water depths spanning the continental shelf to basinal facies in South China provides insights into the process of environmental deterioration. Comparison of the temporal changes of brachiopod diversity between deepwater and shallow-water facies demonstrates that deepwater brachiopods disappeared earlier than shallow-water brachiopods. This indicates that high environmental stress commenced first in deepwater settings and later extended to shallow waters. This environmental stress is attributed to major volcanic eruptions, which first led to formation of a stratified ocean and a chemocline in the outer shelf and deeper water environments, causing the disappearance of deep marine benthos including brachiopods. The chemocline then rapidly migrated upward and extended to shallow waters, causing widespread mass extinction of shallow marine benthos. We predict that the spatial and temporal patterns of earlier onset of disappearance/extinction and ecological crisis in deeper water ecosystems will be recorded during other episodes of rapid global warming. PMID:25412754

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

    OpenAIRE

    Modie B N; Le Hérissé A

    2009-01-01

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

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

    Science.gov (United States)

    Yuan, Wei; Yang, Zhenyu

    2015-05-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

  16. 77 FR 47921 - Watco Holdings, Inc.-Continuance in Control Exemption-Pecos Valley Permian Railroad, L.L.C. d/b/a...

    Science.gov (United States)

    2012-08-10

    ...Exemption--Pecos Valley Permian Railroad, L.L.C. d/b/a Pecos...control of Pecos Valley Permian Railroad, L.L.C. d/b/a Pecos...outstanding stock of PVR, a Texas limited liability company...exemption in Pecos Valley Permian Railroad, L.L.C. d/b/a...

  17. Late Permian brachiopoda fauna in north-western Iran

    Scientific Electronic Library Online (English)

    Yousefirad, Mostafa; Khamooshi, Touran; Shaabanian, Rahim.

    2013-06-01

    Full Text Available La secuencia marina del Pérmico superior en el noroeste de Irán y el este de Azerbaiyán, sección estatigráfica de Zal, fue seleccionada para este estudio de braquiópodos. Las muestras fueron tomadas en las formaciones Ali Bashi y Jolfa. Se reconocieron 27 especies de 13 géneros de braquiópodos en es [...] te análisis. Las muestras recolectadas fueron comparadas con sus similares de otras regiones de Irán y de la región del Tetis, lo que sugirió el período de tardío de Dzhulfan como la proveniencia de estos depósitos. Los braquiópodos reconocidos en este trabajo pertenecen a las familias de Athyris, Rhynconellida, Productida y Strophomenida. Abstract in english The Late Permian marine sequence in the north- west of Iran, in eastern Azerbaijan province in the Zal stratigraphic section, was selected for studying brachiopods. Samples were collected from the Ali Bashi and Jolfa Formation.S. Twenty-seven species from 13 brachiopoda genera were recognised in thi [...] s study.The recognised fossil community was compared to brachiopod communities in some regions of Iran and the Tethyan region, suggesting the Late Dzhulfian period as the age for the deposits being studied. Recognized brachiopods belonge to the orders Athyris, Rhynconellida, Productida and Strophomenida.

  18. Simulated warm polar currents during the middle Permian

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

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

  19. Sedimentary facies and environmental ichnology of a ?Permian playa-lake complex in western Argentina

    Science.gov (United States)

    Zhang, G.; Buatois, L.A.; Mangano, M.G.; Acenolaza, F.G.

    1998-01-01

    A moderately diverse arthropod icnofauna occurs in ?Permian ephemeral lacustrine deposits of the Paganzo Basin that crop out at Bordo Atravesado, Cuesta de Miranda, western Argentina. Sedimentary successions are interpreted as having accumulated in a playa-lake complex. Deposits include three sedimentary facies: (A) laminated siltstone and mudstone: (B) current-rippled cross-laminated very fine grained sandstone: and (C) climbing and wave-rippled cross-laminated fine-grained sandstone deposited by sheet floods under wave influence in the playa-lake complex. Analysis of facies sequences suggests that repeated vertical facies associations result from transgressive regressive episodes of variable time spans. The Bordo Atravesado ichnofauna includes Cruziana problematica, Diplocraterion isp., cf. Diplopadichnus biformis, Kouphichnium? isp., Merostomichnites aicunai, Mirandaichnium famatinense, Monomorphichnus lineatus, Palaeophyeus tubularis, Umfolozia sinuosa and Umfolozia ef. U. longula. The assemblage is largely dominated by arthropod trackways and represents an example of the Scoyenia ichnofacies. Trace fossils are mostly preserved as hypichnial ridges on the soles of facies C beds, being comparatively rare in facies A and B. Ichnofossil preservation was linked to rapid influx of sand via sheet floods entering into the lake. Four taphonomic variants (types 1-4) are recognized, each determined by substrate consistency and time averaging. Type 1 is recorded by the presence of low density assemblages consisting of poorly defined trackways, which suggests that arthropods crawled in soft, probably slightly subaqueous substrates. Type 2 is represented by low to moderate density suites that include sharply defined trackways commonly associated with mud cracks, suggesting that the tracemakers inhabited a firm, desiccated lacustrine substrate. Type 3 displays features of types 1 and 2 and represents palimpsestic bedding surfaces, resulting from the overprint of terrestrial ichnocoenoses over previously formed softground suites. Type 4 differs from type 2 only in that assemblages display a high density of traces, recorded by numerous superimposed trackways, which suggests a major time gap of subaerial exposure before sheet flood entrance. Therefore, type 4 surfaces are mostly interpreted as track imprinted omission surfaces.

  20. Terrestrial paleoenvironment characterization across the Permian-Triassic boundary in South China

    Science.gov (United States)

    Bercovici, Antoine; Cui, Ying; Forel, Marie-Béatrice; Yu, Jianxin; Vajda, Vivi

    2015-02-01

    Well-preserved marine fossils in carbonate rocks permit detailed studies of the end-Permian extinction event in the marine realm. However, the rarity of fossils in terrestrial depositional environments makes it more challenging to attain a satisfactory degree of resolution to describe the biotic turnover on land. Here we present new sedimentological, paleontological and geochemical (X-ray fluorescence) analysis from the study of four terrestrial sections (Chahe, Zhejue, Mide and Jiucaichong) in Western Guizhou and Eastern Yunnan (Yangtze Platform, South China) to evaluate paleoenvironmental changes through the Permian-Triassic transition. Our results show major differences in the depositional environments between the Permian Xuanwei and the Triassic Kayitou formations with a change from fluvial-lacustrine to coastal marine settings. This change is associated with a drastic modification of the preservation mode of the fossil plants, from large compressions to small comminuted debris. Plant fossils spanning the Permian-Triassic boundary show the existence of two distinct assemblages: In the Xuanwei Formation, a Late Permian (Changhsingian) assemblage with characteristic Cathaysian wetland plants (mainly Gigantopteris dictyophylloides, Gigantonoclea guizhouensis, G. nicotianaefolia, G. plumosa, G. hallei, Lobatannularia heinanensis, L. cathaysiana, L. multifolia, Annularia pingloensis, A. shirakii, Paracalamites stenocostatus, Cordaites sp.) is identified. In the lowermost Kayitou Formation, an Early Triassic (Induan) Annalepis-Peltaspermum assemblage is shown, associated with very rare, relictual gigantopterids. Palynological samples are poor, and low yield samples show assemblages almost exclusively represented by spores. A ?1 m thick zone enriched in putative fungal spores was identified near the top of the Xuanwei Formation, including diverse multicellular forms, such as Reduviasporonites sp. This interval likely corresponds to the PTB "fungal spike" conventionally associated with land denudation and ecosystem collapse. While the floral turnover is evident, further studies based on plant diversity would be required in order to assess contribution linked to the end-Permian mass extinction versus local paleoenvironmental changes associated with the transition between the Xuanwei and Kayitou formations.

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

    Science.gov (United States)

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

    2011-03-01

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

  2. The first record of Upper Permian and Lower Triassic scorpions from Russia (Chelicerata: Scorpiones.

    Directory of Open Access Journals (Sweden)

    Fet, V.

    2011-08-01

    Full Text Available Several small fragments of fossil scorpions are reported from two localities in Vologda Province, Russia, representing the Upper Permian (Severodvinian, correlated to Wuchiapingian (Isady and Lower Triassic just above the Permian-Triassic boundary (Induan (Nedubrovo. Most observed structures are not diagnostic at genus or family level. The Isady leg fragment possesses ungues (claws, which are both denticulated and setaceous, and resembles a Carboniferous Eobuthus sp. (Eobuthidae. It is the latest record of this type of ungues, which are known in some Paleozoic scorpions (extinct suborder Mesoscorpiones; all extant scorpions have smooth claws without enticulation or setation.

  3. Vinna Basin.

    Czech Academy of Sciences Publication Activity Database

    Hon?k, J.; Franc?, J.; Mikuláš, Radek; Pešek, J.; Sýkorová, Ivana; Tomanová-Petrová, P.

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

  4. Water-rock-CO2 interactions in saline aquifers aimed for carbon dioxide storage: Experimental and numerical modeling studies of the Rio Bonito Formation (Permian), southern Brazil

    International Nuclear Information System (INIS)

    Mineral trapping is one of the safest ways to store CO2 underground as C will be immobilized in a solid phase. Carbon dioxide will be, therefore, sequestered for geological periods of time, helping to diminish greenhouse gas emissions and mitigate global warming. Although mineral trapping is considered a fairly long process, owing to the existence of kinetic barriers for mineral precipitation, it has been demonstrated both experimentally and by numerical modeling. Here the results of experimental and numerical modeling studies performed in sandstones of the saline aquifer of the Rio Bonito Formation, Parana Basin, are presented. The Rio Bonito Formation consists of paralic sandstones deposited in the intracratonic Parana Basin, southern Brazil, during the Permian (Artinskian-Kungurian). These rocks have the largest potential for CO2 storage because of their appropriated reservoir quality, depth and proximity to the most important stationary CO2 sources in Brazil. Here it is suggested that CO2 can be permanently stored as carbonates as CO2 reacts with rocks of the Rio Bonito Formation and forms CaCO3 at temperatures and pressures similar to those encountered for CO2 storage in geological formations. Results of this work will be useful for studies of partitioning mechanisms for C trapping in CO2 storage programs.

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

    Science.gov (United States)

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

    2014-05-01

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

  6. Stratigraphy and palynostratigraphy, Karoo Supergroup (Permian and Triassic), mid-Zambezi Valley, southern Zambia

    Science.gov (United States)

    Nyambe, Imasiku A.; Utting, John

    1997-05-01

    The Karoo Supergroup outcropst in the mid-Zambezi Valley, southern Zambia. It is underlain by the Sinakumbe Group of Ordovician to Devonian age. The Lower Karoo Group (Late Carboniferous to Permian age) consists of the basal Siankondobo Sandstone Formation, which comprises three facies, overlain by the Gwembe Coal Formation with its economically important coal deposits, in turn overlain by the Madumabisa Mudstone Formation which consists of lacustrine mudstone, calcilutite, sandstone, and concretionary calcareous beds. The Upper Karoo Group (Triassic to Early Jurassic) is sub-divided into the coarsely arenaceous Escarpment Grit, overlain by the fining upwards Interbedded Sandstone and Mudstone, Red Sandstone; and Batoka Basalt Formations. Palynomorph assemblages suggest that the Siankondobo Sandstone Formation is Late Carboniferous (Gzhelian) to Early Permian (Asselian to Early Sakmarian) in age, the Gwembe Coal Formation Early Permian (Artinskian to Kungurian), the Madumabisa Mudstone Late Permian (Tatarian), and the Interbedded Sandstone and Mudstone Early or Middle Triassic (Late Scythian or Anisian). The marked quantitative variations in the assemblages are due partly to age differences, but they also reflect vegetational differences resulting from different paleoclimates and different facies. The low thermal maturity of the formations (Thermal Alteration Index 2) suggests that the rocks are oil prone. However, the general scarcity of amorphous kerogen, such as the alga Botryococcus sp., and the low proportion of exinous material, indicates a low potential for liquid hydrocarbons. Gas may have been generated, particularly in the coal seams of the Gwembe Coal Formation, that are more deeply buried.

  7. Phosphatic Permian rocks of the Adobe Range, Nevada, and their environment of deposition

    Science.gov (United States)

    Ketner, Keith Brindley

    1979-01-01

    Permian sedimentary rocks in the Adobe range, northern Nevada, are phosphatic, and although the particles of phosphate are relatively more disseminated, they closely resemble the rocks of the Phosphoria Formation. In the northern Adobe Range, where the entire Permian sequence is approximately correlative with the Phosphoria Formation, it is 200 m thick and averages 1.7 percent P2O5 . In the southern Adobe Range, the Permian sequence is more than 1,700 m thick, and the upper half which is roughly correlative with the Phosphoria Formation averages more than 2 percent P2O5. Some thin beds in rocks of Permian age contain more than 20 percent P2O5. Phosphatic rocks of the Adobe Range were deposited in shallow water among islands in the western part of the epicontinental Phosphoria sea. The continental margin and the open ocean lay far to the west. At the same time, the Phosphoria Formation was being deposited in the eastern and central parts of the Phosphoria sea. Theories based on the work of Kasakov done in 1937 relating phosphate deposition directly to sites of upwelling oceanic waters are questioned. Nondeposition of diluent materials such as detritus and carbonate is probably of more importance in producing phosphate in economic concentrations than is geographic position with respect to upwelling waters.

  8. Exploratory shaft conceptual design report: Paradox Basin

    International Nuclear Information System (INIS)

    This conceptual design report summarizes the conceptualized design for an exploratory shaft facility at a representative site in the Paradox Basin located in the southeastern part of Utah. Conceptualized designs for other possible locations (Permian Basin in Texas and Gulf Interior Region salt domes in Louisiana and Mississippi) are summarized in separate reports. The purpose of the exploratory shaft facility is to provide access to the reference repository horizon to permit in situ testing of the salt. The in-situ testing is necessary to verify repository salt design parameters, evaluate isotropy and homogeneity of the salt, and provide a demonstration of the constructability and confirmation of the design to gain access to the repository. The fundamental purpose of this conceptual design report is to assure the feasibility of the exploratory shaft project and to develop a reliable cost estimate and realistic schedule. Because a site has not been selected and site-specific subsurface data are not available, it has been necessary to make certain assumptions in order to develop a conceptual design for an exploratory shaft facility in salt. As more definitive information becomes available to support the design process, adjustments in the projected schedule and estimated costs will be required

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

    Directory of Open Access Journals (Sweden)

    Marie-Beatrice FOREL

    2012-08-01

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

  10. Upper Permian vertebrates and their sedimentological context in the South Urals, Russia

    Science.gov (United States)

    Tverdokhlebov, Valentin P.; Tverdokhlebova, Galina I.; Minikh, Alla V.; Surkov, Mikhail V.; Benton, Michael J.

    2005-02-01

    Fossil fishes and tetrapods (amphibians and reptiles) have been discovered at 81 localities in the Upper Permian of the Southern Urals area of European Russia. The first sites were found in the 1940s, and subsequent surveys have revealed many more. Broad-scale stratigraphic schemes have been published, but full documentation of the rich tetrapod faunas has not been presented before. The area of richest deposits covers some 900,000 km 2 of territory between Samara on the River Volga in the NW, and Orenburg and Sakmara in the SW. A continental succession, some 3 km thick, of mudstones, siltstones, and sandstones, deposited on mudflats and in small rivers flowing off the Ural Mountain chain, span the last two stages of the Permian (Kazanian, Tatarian). The succession is divided into seven successive units of Kazanian (Kalinovskaya, Osinovskaya, and Belebey svitas, in succession) and Tatarian age, which is further subdivided into the early Tatatian Urzhumian Gorizont (Bolshekinelskaya and Amanakskaya svitas, in succession), and the late Tatarian Severodvinian (Vyazovskaya and Malokinelskaya svitas, of equivalent age) and Vyatkian gorizonts (Kulchumovskaya and Kutulukskaya svitas, of equivalent age). This succession documents major climatic changes, with increasing aridity through the Late Permian. The climate changes are manifested in changing sedimentation and the spread of dryland plants, and peak aridity was achieved right at the Permo-Triassic (PTr) boundary, coincident with global warming. Uplift of the Urals and extinction of land plants led to stripping of soils and massive run-off from the mountains; these phenomena have been identified at the PTr boundary elsewhere (South Africa, Australia) and this may be a key part of the end-Permian mass extinction. The succession of Late Permian fish and tetrapod faunas in Russia documents their richness and diversity before the mass extinction. The terminal Permian Kulchomovskaya and Kutulukskaya svitas have yielded respectively some 6 and 13 species of fishes (sharks, bony fishes, lungfishes) and 11 and 14 species of tetrapods (aquatic amphibians, herbivorous and carnivorous reptiles of all sizes up to the hippo-sized pareiasaurs and sabre-toothed gorgonopsians). Immediately following the end-Permian environmental catastrophe, earliest Triassic faunas consisted only of a few fish taxa and small, aquatic tetrapods, in low-diversity, low-abundance assemblages.

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

    International Nuclear Information System (INIS)

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

  12. Bituminous coal of the Upper Silesian basin, Czech Republic - relationship between mean vitrinite reflectance Ro, volatile matter Vdaf and content of carbon, hydrogen and nitrogen.

    Czech Academy of Sciences Publication Activity Database

    Martinec, Petr; Hon?k, J.; Stan?k, F.

    Calgary : Canadian Society of Petroleum Geologists, 2002 - (Hills, L.), s. 902-909 - (Memoir. 19). [Carboniferous and permian of the world/14./. Calgary (CA), 17.08.1999-21.08.1999] R&D Projects: GA AV ?R IAA3013903; GA ?R GA205/97/0307 Institutional research plan: CEZ:AV0Z3086906 Keywords : Upper Silesian basin * bituminous coal Subject RIV: DB - Geology ; Mineralogy

  13. Using conodont elements to distinguish Permian-Triassic boundary disconformity near Haftad Gholleh, central Iran

    Scientific Electronic Library Online (English)

    Mostafa, Yousefirad; Somayeh, Ghanbari; Mahnaz, Parvanehnejad Shirazi.

    2013-06-01

    Full Text Available El presente estudio se enfoca en la estatigrafía del Límite Pérmico-Triásico en el área de Haftad Gholleh, al este de Arak y al norte de Mahallat, centro de Irán. Este límite de discordancia erosiva, al igual que en otras secuencias iraníes relacionadas al período Pérmico, contiene calizas dolomías, [...] esquistos y areniscas discordantes localizadas debajo de la secuencia Triásica. En una medida estratigráfica detallada del área de estudio se encontraron conodontas del Límite Pérmico-Triásico (PTB, por sus siglas en inglés). Se reconocieron tres áreas de conodontas, lo que ubica esta sección del PTB como bioestatigráfica precisa. Una de las secuencias superiores del Pérmico pertenece al período Guadalupiense. La secuencia Triásica consiste en calizas con capas vermiculitas coloreadas de esquisto que pertenecen al período Triásico temprano. La discordancia del Límite Pérmico Triásico, entonces, representa un lapso cercano a los 10 millones de años. Abstract in english The present study focuses on the stratigraphy of the Permian-Triassic boundary in the Haftad Gholleh area in eastern Arak and north of Mahallat,located in central Iran. This boundary of erosional unconformity or disconformity and as in other Iranian sequences related to the Permian period, contains [...] dolomitic limestone and shale and sandstone disconformably located below the Triassic sequence. A detailed measured stratigraphic section has provided conodonts from the Permian-Triassic boundary (PTB) sequences in the area being studied. Three conodont areas have been recognied which place the PTB in this section by precise biostratigraphy. One of the most upper Permian sequences belongs to the Guadalupian period. The Triassic sequence consists of vermiculate limestone layers with coloured shale inter beds belonging to the Early Triassic period; unconformity at the Permian-Triassic boundary therefore represents a hiatus of about 10 million years.

  14. Paleomagnetism of Late Permian volcanic rocks from South Transbaikalia: preliminary results

    Science.gov (United States)

    Fedyukin, I.; Shatsillo, A.

    2013-12-01

    Tamir volcano-tectonic structure (VTS) is one of the largest Late Paleozoic rift related features within Selengin-Vitim volcano-plutonic belt. The belt was formed in the back area of Siberian continent active margin (Gordienko et al., 2010). Igneous-sedimentary rocks within Tamir VTS are presented by contrastive volcanites more than 5 km thick. The deposits are subdivided into three suits: Ungurkuy (mostly basaltic), Tamir (acidic volcanics and tuffs) and Chernoyar (presented mostly by basalts, andesites and tuffs, sandstones and conglomerates). The age of youngest suits (Tamir and Chernoyar) is Late Permian, Middle-late Triassic accordingly. The age of Ungurkuy suit is deemed to be between Late Carboniferous and Late Permian (Gordienko et al., 1998; Popeko et al., 2005). Volcanic deposits of the three suits were studied to create APWP for the Siberian craton. 200 oriented samples from 31 sites were collected from the Tamir, Shazaga, Kiret, Ungurkuy and Ara-Kiret river valleys within South Transbaikalia. A number of samples were characterized by interpretable paleomagnetic signal. Tamir and Chernoyar rocks were collected from monoclinal structure within Tamir river valley. 5 sites show direction of magnetization similar to directions revealed from Early Cretaceous volcanites from nearby area (Metelkin et al., 2004). The magnetization is metachronous. In the other 8 sites the directions of magnetization are bipolar. The magnetization direction is well-correlated with Triassic APWP of Europe (Torsvik, Cocks, 2005). The volcanites of Ungurkuy suite show mostly monopolar (normal polarity) magnetization direction (formed before crustal folding) between Early Permian and Permian-Triassic Siberian poles, which indicates its Late Permian age. The normal polarity of the deposits indicates its formation in the period between Kiama superchron, characterized by reversal polarity, and Illavara hyperchron with mixed polarity - 265 Ma. This work was supported by the Russian Foundation for Basic Research, project no. 13-05-12030.

  15. Sediment-hosted micro-disseminated gold mineralization constrained by basin paleo-topographic highs in the Youjiang basin, South China

    Science.gov (United States)

    Liu, Jianming; Ye, Jie; Ying, Hanlong; Liu, Jiajun; Zheng, Minghua; Gu, Xuexiang

    2002-06-01

    The Youjiang basin is a Devonian-Triassic rift basin on the southern margin of the Yangtze Craton in South China. Strong syndepositional faulting defined the basin-and-range style paleo-topography that further developed into isolated carbonate platforms surrounded by siliciclastic filled depressions. Finally, thick Triassic siliciclastic deposits covered the platforms completely. In the Youjiang basin, numerous sediment-hosted, micro-disseminated gold (SMG) deposits occur mainly in Permian-Triassic chert and siliciclastic rocks. SMG ores are often auriferous sedimentary rocks with relatively low sulfide contents and moderate to weak alteration. Similar to Carlin-type gold ores in North America, SMG ores in the Youjiang basin are characterized by low-temperature mineral assemblages of pyrite, arsenopyrite, realgar, stibnite, cinnabar, marcasite, chalcedony and carbonate. Most of the SMG deposits are remarkably distributed around the carbonate platforms. Accordingly, there are platform-proximal and platform-distal SMG deposits. Platform-proximal SMG deposits often occur in the facies transition zone between the underlying platform carbonate rocks and the overlying siliciclastic rocks with an unconformity (often a paleo-karst surface) in between. In the ores and hostrocks there are abundant synsedimentary-syndiagenetic fabrics such as lamination, convolute bedding, slump texture, soft-sediment deformation etc. indicating submarine hydrothermal deposition and syndepositional faulting. Numerous fluid-escape and liquefaction fabrics imply strong fluid migration during sediment basin evolution. Such large-scale geological and fabric evidence implies that SMG ores were formed during basin evolution, probably in connection with basinal fluids. It is well known that basinal fluids (especially sediment-sourced fluids) will migrate generally (1) upwards, (2) towards basin margins or basin topographic highs, (3) and from thicker towards thinner deposits during basin evolution. The isolated carbonate platform (as a basin paleo-high) and related syndepositional fault system, together with the unconformity-related facies succession, may have controlled the migration pathway of ore-forming basinal fluids and subsequently determined the location of SMG deposits in the Youjiang basin. Unlike Carlin-type gold deposits, SMG mineralization in the Youjiang basin may represent an integral aspect of the dynamic evolution of extensional basins along divergent continental margins.

  16. Integrated provenance analysis of Zakeen (Devonian) and Faraghan (early Permian) sandstones in the Zagros belt, SW Iran

    Science.gov (United States)

    Zoleikhaei, Yousef; Amini, Abdolhossein; Zamanzadeh, S. Mohammad

    2015-01-01

    Successions of a controversial period of time in the Zagros and Arabian Plate stratigraphic column, including Zakeen (Devonian) and Faraghan (early Permian) formations are investigated for their provenance characteristics. Nearly similar depositional environments of the formations, regardless of 70-80 My hiatus between them, is the main motivation for this study. Evidence from various methods are put together to reconstruct a comprehensive image of their provenance. Results from petrographic and detrital mode analysis indicate a continental block provenance for of the sandstones of both formations. In addition, evidence of recycling is evident from some rock fragments in the conglomeratic facies. Heavy mineral diversities are limited to the ultra-stable species which represent consistent morphological characteristics in both formations. However, the values of rutile: zircon index (RZi) showed intermittent changes from low RZi to high RZi intervals in both formations. Detrital zircon age data in previous studies represented the same source for these two formations, which also remained unchanged from Neo-Proterozoic to late Paleozoic successions. Zircon grains' morphology, however, showed remarkable difference between the Zakeen and Faraghan formations on the one hand and successions deposited in the basin prior to the tectonic movements of mid-Paleozoic time on the other. Outcomes of this study show that, although each single technique may shed light on a particular aspect of the greater provenance problem, by integration of all the data, important evidence of recycled nature of these successions could be confirmed. Changes in the thickness of the Paleozoic units, the nature of their stratal surfaces, along with the information from magmatic events in the area provide a tectono-stratigraphic framework for northern margin of Gondwana in which the recycled nature of these successions is justifiable. The recycled nature of the studied formations on the one hand, and their identical provenance on the other, raise a challenge for the timing proposed for two tectonic activities of middle Paleozoic and mid-Carboniferous.

  17. Evolution of overpressured and underpressured oil and gas reservoirs, Anadarko Basin of Oklahoma, Texas, and Kansas

    Science.gov (United States)

    Nelson, Phillip H.; Gianoutsos, Nicholas J.

    2011-01-01

    Departures of resistivity logs from a normal compaction gradient indicate that overpressure previously extended north of the present-day overpressured zone. These indicators of paleopressure, which are strongest in the deep basin, are mapped to the Kansas-Oklahoma border in shales of Desmoinesian age. The broad area of paleopressure has contracted to the deep basin, and today the overpressured deep basin, as determined from drillstem tests, is bounded on the north by strata with near normal pressures (hydrostatic), grading to the northwest to pressures that are less than hydrostatic (underpressured). Thus the pressure regime in the northwest portion of the Anadarko Basin has evolved from paleo-overpressure to present-day underpressure. Using pressure data from drillstem tests, we constructed cross sections and potentiometric maps that illustrate the extent and nature of present-day underpressuring. Downcutting and exposure of Lower Permian and Pennsylvanian strata along, and east of, the Nemaha fault zone in central Oklahoma form the discharge locus where pressure reaches near atmospheric. From east to west, hydraulic head increases by several hundred feet in each rock formation, whereas elevation increases by thousands of feet. The resulting underpressuring of the aquifer-supported oil and gas fields, which also increases from east to west, is a consequence of the vertical separation between surface elevation and hydraulic head. A 1,000-ft thick cap of Permian evaporites and shales isolates the underlying strata from the surface, preventing re-establishment of a normal hydrostatic gradient. Thus, the present-day pressure regime of oil and gas reservoirs, overpressured in the deep basin and underpressured on the northwest flank of the basin, is the result of two distinct geologic events-rapid burial and uplift/erosion-widely separated in time.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  19. Magnetic stratigraphy of the lower Beaufort group, Karoo basin (South Africa)

    Science.gov (United States)

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

    2012-04-01

    The fluvial-lacustrine sediments of the Beaufort Group of the Karoo Basin of South Africa have been traditionally assigned a Late Permian age based on presence of Glossopteris flora and Dicynodont fauna. However, recently published U-Pb zircon ages suggest that the Permo-Triassic boundary lies below the Beaufort Group. In order to test this proposition, we performed magnetostratigraphic analysis of the Abrahamskraal Formation at the base of the Beaufort Group, coupled with U-Pb dating by ion microprobe (SHRIMP) of zircon from interbedded volcanic ashbeds (tuffs). Paleomagnetic analysis has found a partial remagnetization of the natural remanent magnetization, which is tentatively ascribed to the emplacement of the Karoo Large Igneous Province in the Western Cape region in the Jurassic. A stable component of the natural remanent magnetization was found at temperatures higher than 450°C and was interpreted as the characteristic remanence. The virtual geomagnetic pole position for the Abrahamskraal Fm. is in general agreement with the Permian/Triassic boundary direction of the continental Karoo. However, a slightly different average inclination, and thus paleomagnetic pole position, is obtained by correcting the inclination shallowing error by the Elongation-Inclination method. The U-Pb zircon ages of ca. 260-265 Ma and the presence of both normal and reversed polarities indicate deposition after the end of the Kiaman Superchron, confirming a Capitanian (late Guadalupian, Permian) age for the Abrahamskraal Fm.

  20. Generation and hydrocarbon entrapment within Gondwanan sediments of the Mandapeta area, Krishna-Godavari Basin, India

    Energy Technology Data Exchange (ETDEWEB)

    Raza Khan, M.S.; Sharma, A.K.; Sahota, S.K.; Mathur, M. [RCL, ERBC, ONGC, Assam (India)

    2000-07-01

    The discovery of hydrocarbons (mainly gas) in commercial quantities from Gondwanan sediments in the Mandapeta field of Krishna-Godavari Basin, India, provided impetus for intensified exploration in Mandapeta and the adjoining Kommugudem, Draksharama and Endamuru fields. Both oil and gas have been found in the reservoirs of Mandapeta (Triassic) and Golapalli (Early Cretaceous) formations. Mature, localised, basal shales (1.0-1.1% Ro) in the Mandapeta formation have sourced the oils from the Mandapeta Sandstone reservoir (Triassic). The oils being produced from Golapalli Sandstone reservoir (Early Cretaceous) are relatively less mature and have been sourced by the underlying shales in the Mandapeta Formation at a maturity level of 0.80-0.85% Ro. The source and maturity data preclude liquid hydrocarbon sourcing from the Kommugudem (Permian) sequence. Permian coals and shales of the Kommugudem Formation are the major source rocks for gaseous hydrocarbons in this area. The hydrocarbon generation started in Early Cretaceous in the Kommugudem Formation, but the intermittent tectonic activity (with associated structural developments) has resulted in reorientation and redistribution of the then existing trap configurations. The present day maturity level of the Permian sediments in the Mandapeta field is 1.2% Ro or greater, capable of generating gas dominantly. The Raghavapuram shale in the Mandapeta area is adequately mature and has good hydrocarbon potential for oil generation. The probability of finding hydrocarbon reserves in the sands of Raghavapuram shales and other suitable traps is high. Modern seismic information together with geologic models can give new exploration leads. (Author)

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

    OpenAIRE

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

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

  3. Las sucesiones carbonáticas marinas del Pérmico Temprano en Antofagasta, norte de Chile / Early Permian marine carbonate sequences in Antofagasta, northern Chile

    Scientific Electronic Library Online (English)

    Gabriela A, Cisterna; Andrea F, Sterren; Hans R, Niemeyer.

    2014-09-01

    Full Text Available Se analizan las sucesiones carbonáticas de las formaciones Cerro El Árbol y Cerros de Cuevitas, en la depresión central de Antofagasta, norte de Chile. Ellas están caracterizadas por una asociación de invertebrados marinos compuesta, en general, por braquiópodos, bivalvos, gastrópodos, crinoideos y [...] briozoos, en el que el braquiópodo Kochiproductus Dunbar es el elemento dominante. La presencia de este género, de amplia distribución mundial en secuencias pérmicas, sería clave para encontrar la posible vinculación de esta región con las cuencas clásticas del centro oeste de Argentina. Si bien la fauna del norte de Chile presenta claras afinidades con aquellas de las cuencas de Bolivia y Perú, su composición no es exactamente equivalente y es, además, marcadamente menos diversa. El conocimiento taxonómico aquí alcanzado indica que esta fauna, particularmente braquiópodos y bivalvos, representaría una asociación de mezcla. En términos bioestratigráficos, esta podría ser considerada intermedia entre las faunas más antiguas del Carbonífero tardío-Pérmico temprano del centro oeste de Argentina y las más jóvenes del Pérmico de Bolivia y Perú. Abstract in english The carbonate successions of the Cerro El Árbol and Cerros de Cuevitas formations in the central region of Antofagasta are herein studied. These stratigraphic units are characterized by an invertebrate marine fossil assemblage integrated by brachiopods, bivalves, gastropods, crinoids and bryozoans, [...] in which the brachiopod Kochiproductus Dunbar is the dominant component. This genus, widely known in the Permian sequences of the world, can be considered a key to understand the possible connection between northern Chile and the central western Argentinean basins. Although the fauna studied shows clear affinities with those from Bolivia and Perú, it is notably less diverse and its composition appears to be not exactly equivalent. The taxonomic knowledge reached, indicates that this fauna, particularly brachiopods and bivalves, would represent a mixed-assemblage. From a biostratigraphic perspective, the fauna of northern Chile could be considered intermediate between the oldest Late Carboniferous-Early Permian faunas of central western Argentinian basins and the younger ones from Bolivia and Perú.

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

    Science.gov (United States)

    Peng, Yuanqiao; Shi, G. R.

    2009-02-01

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

  5. Episodic euxinia in the Changhsingian (late Permian) of South China: Evidence from framboidal pyrite and geochemical data

    Science.gov (United States)

    Wei, Hengye; Algeo, Thomas J.; Yu, Hao; Wang, Jiangguo; Guo, Chuan; Shi, Guo

    2015-04-01

    A multiproxy study of a new Upper Permian-Lower Triassic section (Xiaojiaba) in Sichuan Province, China, documents large changes in marine productivity, redox conditions and detrital input prior to the latest Permian mass extinction. Marine productivity, as proxied by total organic carbon content (TOC), biogenic SiO2, and excess barium, displays a long-term decline through most of the Changhsingian stage (late late Permian), culminating in very low values around the Permian-Triassic boundary. Concurrently, redox proxies including pyrite framboid, ?34Spy, Moauth and Uauth, and Corg/P document a shift from suboxic to dysoxic/oxic conditions that was interrupted by several episodes of benthic euxinia, and detrital siliciclastic proxies (Al, Hf, Nb, and REEs) suggest an increased flux of weathered material from land areas. The long-term changes in productivity, redox conditions, and terrigenous detrital fluxes were probably caused by a regional sea-level fall across the South China Craton. On the other hand, the brief euxinic episodes occurring during the late Permian had oceanographic causes, probably related to the transient upward expansion of the chemocline at the top of the oceanic oxygen-minimum zone. These euxinic episodes may have been harbingers of the more widespread anoxia that developed concurrently with the latest Permian mass extinction and that may have played a major role in triggering the largest biotic crisis of the Phanerozoic.

  6. Palynological assemblages of non-marine rocks at the Permian Triassic boundary, western Guizhou and eastern Yunnan, South China

    Science.gov (United States)

    Peng, Yuanqiao; Yu, Jianxin; Gao, Yongqun; Yang, Fengqing

    2006-12-01

    Marine and non-marine facies of the Permian-Triassic boundary stratigraphic set (PTBST) are well developed in South China. Palynological assemblages enable subdivision and correlation of the Permian-Triassic boundary (PTB) rocks. Three palynological assemblages are recognized across the PTBST in two terrestrial PTB sections in western Guizhou and eastern Yunnan, South China. Assemblage 1 (Xuanwei Formation) is a Late Permian palynological assemblage dominated by ferns and pteridosperms, with minor gymnosperms. Most taxa are typical long-ranging Paleozoic forms, but the appearance of Lueckisporites confirms a Late Permian age for this assemblage. Assemblage 2 (PTBST) is marked by an abrupt decrease in palynomorph abundance and diversity, and thriving fungal/algal(?) spores. Assemblage 2 is still dominated by ferns and pteridosperms, with a few gymnosperms, but is characterized by a mixed palynoflora containing both Late Permian and Early Triassic elements. Most taxa are typical Late Permian ones also found in Assemblage 1, however, some taxa of Early Triassic aspect, e.g. Lundbladispora and Taeniaesporites, appeared for the first time. In Assemblage 3 (top Xuanwei Formation and Kayitou Formation), the proportion of gymnosperm pollen increases rapidly, exceeding that of ferns and pteridosperms, but the abundance of palynomorphs is still low. Typical Early Triassic taxa (such as Lundbladispora, Aratrisporites and Taeniaesporites) are present in greater abundance and confirms an Early Triassic age for this assemblage.

  7. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    International Nuclear Information System (INIS)

    This report presents the results of a small-scale pilot study of the mineralogy and alteration characteristics of unusual sheet-like native copper occurring together with uraniferous and vanadiferous concretions in mudstones and siltstones of the Permian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The host mudstones and siltstones are smectitic and have been compacted through deep Mesozoic burial. The occurrence of native copper within these rocks represents a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of high-level radioactive waste by the SKB. The study was undertaken by the British Geological Survey (BGS) on behalf of SKB between November 1999 and June 2000. The study was based primarily on archived reference material collected by the BGS during regional geological and mineralogical surveys of the area in the 1970's and 1980's. However, a brief visit was made to Littleham Cove in January 2000 to try to examine the native copper in situ and to collect additional material. Unfortunately, recent landslips and mudflows obscured much of the outcrop, and only one new sample of native copper could be collected. The native copper occurs as thin plates, up to 160 mm in diameter, which occur parallel to bedding in the Permian Littleham Mudstone Formation at Littleham Cove (near Budleigh Salterton) in south Devon. Each plate is made up of composite stacks of individual thin copper sheets each 1-2 mm thick. The copper is very pure (>99.4% Cu) but is accompanied by minor amounts of native silver (also pure - >99%) which occurs as small inclusions within the native copper. Detailed mineralogical and petrological studies of the native copper sheets, using optical petrography, backscattered scanning electron microscopy, X-ray diffraction analysis and electron probe microanalytical techniques, reveal a complex history of mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30-80% of the original thickness) of the copper sheets has been preserved in the saturated compacted clay environment

  8. A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Styles, M.T.; Hards, V.L. [Natural Environment Research Council (United Kingdom). British Geological Survey

    2000-08-01

    This report presents the results of a small-scale pilot study of the mineralogy and alteration characteristics of unusual sheet-like native copper occurring together with uraniferous and vanadiferous concretions in mudstones and siltstones of the Permian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The host mudstones and siltstones are smectitic and have been compacted through deep Mesozoic burial. The occurrence of native copper within these rocks represents a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of high-level radioactive waste by the SKB. The study was undertaken by the British Geological Survey (BGS) on behalf of SKB between November 1999 and June 2000. The study was based primarily on archived reference material collected by the BGS during regional geological and mineralogical surveys of the area in the 1970's and 1980's. However, a brief visit was made to Littleham Cove in January 2000 to try to examine the native copper in situ and to collect additional material. Unfortunately, recent landslips and mudflows obscured much of the outcrop, and only one new sample of native copper could be collected. The native copper occurs as thin plates, up to 160 mm in diameter, which occur parallel to bedding in the Permian Littleham Mudstone Formation at Littleham Cove (near Budleigh Salterton) in south Devon. Each plate is made up of composite stacks of individual thin copper sheets each 1-2 mm thick. The copper is very pure (>99.4% Cu) but is accompanied by minor amounts of native silver (also pure - >99%) which occurs as small inclusions within the native copper. Detailed mineralogical and petrological studies of the native copper sheets, using optical petrography, backscattered scanning electron microscopy, X-ray diffraction analysis and electron probe microanalytical techniques, reveal a complex history of mineralisation and alteration that can be related to the burial and diagenetic history of the Permian strata. The native copper mineralisation exhibits close temporal association with the formation of uraniferous and vanadiferous concretions (known as 'fish-eyes') in the same rocks. Petrographical relationships indicate that both the copper and the 'fish-eye' concretions formed during burial diagenesis but before the maximum compaction of the host mudstone and siltstone. The regional burial history Wessex Basin, indicates that the maximum compaction of the Permian strata would have been achieved by at least the end of the Lower Jurassic (possibly even in the Triassic). Therefore, the native copper mineralisation is older than 176 Ma. The native copper sheets display a complex sequence of alteration and subsequent mineral growth of minerals on their surfaces. The earliest alteration was to copper oxides - principally cuprite with minor tenorite, indicating a change to more oxidising groundwater conditions. The dissolution of native silver and the growth of fringes of copper arsenides followed this. Nickel arsenides and chalcocite, associated with the precipitation of uranium silicates occurred in the later stages of alteration. This suggests a return to a more reducing pore water environment. Again, petrographical relationships indicate that this alteration and subsequent mineralisation is geologically old (i.e. Lower Jurassic or older). Secondary malachite, intimately intergrown copper sulphate and copper oxides, copper chloride, copper-uranium arsenate and uranium vanadates have formed as late-stage alteration products of the native copper and earlier diagenetic cuprite, chalcocite, copper-nickel arsenide and uranium silicate alteration and mineralisation. This latest stage alteration is most probably attributable to near-surface weathering processes. Although the native copper is affected by corrosion, the study has shown that a significant proportion (30-80% of the original thickness) of the copper sheets has been preserved in the s

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

    International Nuclear Information System (INIS)

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

  10. Geochemical changes at the Permian–Triassic transition in Southern Alps and adjacent area: a review

    Directory of Open Access Journals (Sweden)

    Aymon Baud

    2005-10-01

    Full Text Available Compilation of the recent literature from the Southern Alps and adjacent area confirms the geochemical variations of unusual amplitudes during the Permian-Triassic boundary interval (PTBI. A great attention has been given to the negative ?13C anomaly within the Tesero Member close to the Permian-Triassic boundary. Very detailed geochemical works have been done on the scientific Gartnerkofel core (Gk-1 and on the Slovenian sections. Major minor and rare earth elements (REE data are reported and show a marked enrichment in alkaline metals and REE of some levels of the boundary interval. But recent studies show that the low Iridium anomalies and the Osmium and Helium isotopes anomalies lack the characteristics of a large extraterrestrial impact.

  11. Imbricate structure of the Permian Yoshii Group in the Otakeyama area, Okayama Prefecture, southwest Japan

    Science.gov (United States)

    Ito, Tsuyoshi; Matsuoka, Atsushi

    2015-03-01

    The Yoshii Group of the Akiyoshi terrane is distributed over the Otakeyama area, Okayama Prefecture, southwest Japan. The Yoshii Group is composed of siliceous rocks and clastics, comprising chert-clastic sequences. The Yoshii Group is divided into four structural units (Units Ot 1, Ot 2, Ot 3, and Ot 4) in structurally ascending order. Lithological similarities and radiolarian age suggest that these units exhibit almost identical ocean plate stratigraphy. These units are structurally-repeated to form an imbricate structure. This structure was possibly formed by off-scrape accretion at a toe of an accretionary complex. Additionally, a review of previous studies indicates that an imbricate structure is common in the Akiyoshi terrane. The presence of an imbricate structure in the Akiyoshi terrane, Permian accretionary complex, indicates the possibility that a specific horizon of Permian pelagic sequences acted as a décollement zone.

  12. A high resolution palynozonation for the Al Khlata Formation (Pennsylvanian to Lower Permian), South Oman

    OpenAIRE

    Penney, Randall A.; Al Barram, Issam; Stephenson, Michael

    2008-01-01

    Palynology is the main method of correlating the subsurface glaciogenic Al Khlata Formation (Pennsylvanian to Lower Permian) of Oman due to the extreme lateral variability of facies and poor seismic resolution. The chief operating company in Oman, Petroleum Development Oman (PDO), has developed a robust in-house palynozonation during almost 40 years of exploration and production based on thousands of samples and hundreds of well sections. In this paper, the formal definitions of the biozones ...

  13. Sedimentology of a Permian playa lake: the Boda Claystone Formation, Hungary

    OpenAIRE

    Konrád, Gyula; Sebe, Krisztina; Halász, Amadé; Babinszki, Edit

    2010-01-01

    The Upper Permian Boda Claystone Formation (BCF) in SW Hungary has been previously been identified as a saline lake deposit. A country-wide screening found this 800–1000 m thick succession the most suitable for the disposal of high-level radioactive waste in Hungary, and research into this formation has consequently been intensified since. The investigations included a detailed study of the sedimentological characteristics. Data obtained by mapping of the 25 km2 outcrop area of the formatio...

  14. Stratigraphy and paleontology of Lower Permian rocks north of Cananea, northern Sonora, Mexico

    Science.gov (United States)

    Blodgett, Robert B.; Moore, Thomas E.; Gray, Floyd

    2002-09-01

    Lower Permian carbonate and overlying red bed clastic rocks are present in a 2 km 2 stratigraphic window in the vicinity of Rancho La Cueva, Santa Cruz sheet (scale 1:50,000), northern Sonora, Mexico. This exposure lies unconformably beneath predominantly intermediate Upper Cretaceous volcanics yielding 40Ar/ 39Ar ages of 73.4±0.18 and 71.1±0.35 Ma. The lower part of the Permian succession consists of light- to medium-gray colored limestones of the Colina Limestone, with a minimum thickness of 235 m. Sedimentary features suggest shallow water, slightly restricted depositional environments. Although lacking observable fossils for the most part, two intervals of richly fossiliferous, silicified shell beds are present near the base and top of the Colina Limestone. The lower fauna consist mostly of gastropods and bivalves. The presence of a new microdomatid gastropod species, Glyptospira sonorensis n. sp., close to Glytospira arelela Plas, suggests a late Wolfcampian age for this horizon. The upper fauna are predominantly molluscan dominated (gastropods and bivalves), but some brachiopods (productids and the rhynchonellid genus Pontisia) are also present. Gastropod genera include Bellerophon, Warthia, Euomphalus (represented by the species, Euomphalus kaibabensis Chronic), Baylea, Worthenia, Naticopsis, Goniasma, Kinishbia, Cibecuia, and Glyptospira. The gastropods suggest a Leonardian (late Early Permian) age for this horizon, and many of the species have previously been recorded from the Supai Group and Kaibab Formation of northern and central Arizona. The Colina Limestone is conformably overlain by 11.2 m of light-gray lime mudstone and dolostone, assigned here to the Epitaph Dolomite, which in turn is succeeded by 58.8 m of red-colored sandstone and gray lime mudstone, assigned here to the Scherrer Formation. This Lower Permian succession is significant because it further strengthens the stratigraphic ties of southeastern Arizona rocks with those of northern Sonora and confirms the presence of North American cratonal stratigraphy in the northern part of the state of Sonora, Mexico.

  15. Abrupt environmental and climatic change during the deposition of the Early Permian Haushi limestone, Oman

    OpenAIRE

    Stephenson, Michael; Angiolini, Lucia; Leng, Melanie; Brewer, T. S.; Berra, F.; Jadoul, F.; Gambacorta, G.; Verna, V.; Al Beloushi, B.

    2008-01-01

    During the late Sakmarian (Early Permian), the Haushi limestone was deposited in a shallow embayment of the Neotethys Ocean covering what is now north Oman and parts of southeast Saudi Arabia. The sea persisted through the late Sakmarian, but by the time of the deposition of the ?Artinskian Middle Gharif Member, limestone deposition had ceased and generally arid fluvial and minor lacustrine palaeonvironments in a low accommodation space setting had become established. Analysis of three subsur...

  16. Three New Species of Deltoblastus Fay from the Permian of Timor

    OpenAIRE

    Morgan, Ryan FitzGerald

    2015-01-01

    Deltoblastus is a genus of Permian blastoid comprised of 15 species, each differing based on subtle thecal morphology differences. Three new species are introduced here, based on characteristics present which distinguish individuals from established morphotypes. In order to guarantee a more complete understanding of the genus, a complex character matrix containing all 15 named and three new species was created, defining all species based on the presence or absence of 30 unique traits. Differe...

  17. Diagenetic and Detrial Origin of Moretane Anomalies through the Permian-Triassic Boundary

    OpenAIRE

    French, Katherine L.; Tosca, Nicholas J.; Cao, Changqun; Summons, Roger Everett

    2011-01-01

    Many biogeochemical anomalies coincide with the Late Permian Extinction (LPE; 252.28 Ma). Several mechanisms have been proposed to explain the moretane/hopane anomaly that has been identified in samples from Meishan GSSP section in southeastern China. Here, we report homohopane, 2?- and 3?-methylhomohopane and lithological data for a drill core from the Meishan section in southeastern China. Three intervals of elevated C30 moretane/hopane ratios are recorded in the Lungtan, Yinkeng and Helo...

  18. Permian non-marine bivalves of the Falkland Islands and their palaeoenvironmental significance

    OpenAIRE

    Simões, Marcello G.; Quaglio, Fernanda; Warren, Lucas V.; Anelli, Luiz E.; Stone, Philip; Riccomini, Claudio; Grohmann, Carlos H.; Chamani, Marlei A.C.

    2012-01-01

    We describe the occurrence of non-marine bivalves in exposures of the Middle Permian (Capitanian) Brenton Loch Formation on the southern shore of Choiseul Sound, East Falklands. The bivalves are associated with ichnofossils and were collected from a bed in the upper part of the formation, within a 25 cm thick interval of dark siltstones and mudstones with planar lamination, overlain by massive sandstones. The shells are articulated, with the valves either splayed open or closed. At the top of...

  19. The building limestones of the Upper Permian, Cadeby Formation (Magnesian Limestone) of Yorkshire

    OpenAIRE

    Lott, G.K.; Cooper, A.H.

    2005-01-01

    The late Permian dolomitic limestones (dolostones), which form an almost continuous outcrop from north Nottinghamshire to the Northumberland coast at Teeside, have been an important source of industrial minerals for many centuries. They have been quarried extensively for building stone, aggregate and lime for agricultural, industrial and chemical processes (see Buist & Ineson 1992) The limestones, because of their magnesium-rich carbonate mineralogy are perhaps still best known...

  20. The Late Permian herbivore Suminia and the early evolution of arboreality in terrestrial vertebrate ecosystems

    OpenAIRE

    Fro?bisch, Jo?rg; Reisz, Robert R.

    2009-01-01

    Vertebrates have repeatedly filled and partitioned the terrestrial ecosystem, and have been able to occupy new, previously unexplored habitats throughout their history on land. The arboreal ecospace is particularly important in vertebrate evolution because it provides new food resources and protection from large ground-dwelling predators. We investigated the skeletal anatomy of the Late Permian (approx. 260 Ma) herbivorous synapsid Suminia getmanovi and performed a morphometric analysis of th...

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

    OpenAIRE

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

    2012-01-01

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

  2. The petroleum system of the lower Palaeozoic strata in the central part of the Baltic basin

    Science.gov (United States)

    Lazauskiene, Jurga; Zdanaviciute, Onyte

    2013-04-01

    The Baltic Basin is an intra-cratonic sedimentary basin with conspicuous Early Palaeozoic sections. In terms of hydrocarbon prospectively, the it has been perceived as a classical oil basin with several tens of relatively small oil and gas fields occur there over a wide stratigraphic interval, ranging from the crystalline basement through the entire Lower Palaeozoic succession. Until now conventional oil has been predominantly produced in the basin, i.e. only few conventional gas accumulations have been found in the Polish Baltic Sea offshore. Petroleum potential within the basin also is associated with Silurian reefogenic and carbonate build-ups. New organic geochemistry data as well revealed the potential for shale gas/oil in the basin. The analysis of the composition of the organic matter and crude oils from Kaliningrad region (Russia) and Lithuanian revealed genesis and the general trends of the migration of hydrocarbons in the Baltic Basin. The organic matter of the source rocks is of similar composition and represents typical marine type II, showing considerable variations of the maturity thought the basin: ranging from immature in the eastern Lithuania and Kaliningrad region of Russia to oil window to the south-west. In some places the anomalously high maturity of organic matter, indicating the lower part of the wet gas/condensate window have been recorded, most probably being related to the locally increased paleo-temperatures. Oils of the Baltic Basin have low densities (derived from different kitchens. The hydrocarbon generation in the Baltic Basin started by the end of Silurian, while the basic phase is thought to occur in Devonian and Permian. Different source rocks contributed to the hydrocarbon expulsion. Slow deposition and tectonically stable regime ensured slow formation of the oil and gase-condensate fields with replenishing oil portions incoming with time: e.g. Cambrian oil traps could accumulate also Ordovician and Silurian oils.

  3. Evidence for an Alleghanian (Early Carboniferous to Late Permian) tectonothermal event in the New Jersey Coastal Plain basement from 40Ar/39Ar biotite data, geochemistry and gravity modeling

    Science.gov (United States)

    Maguire, T.J.; Volkert, R.A.; Swisher, C. C., III; Sheridan, R.E.

    2009-01-01

    40Ar/39Ar dating of biotite from felsic orthogneiss recovered from the -3890-foot level of the Island Beach State Park (IBSP) well beneath the outer New Jersey Coastal Plain was accomplished using CO2 laser incremental-heating techniques. Over 75% of the Ar released from the incremental-heating experiment form a well-behaved plateau with a calculated age of 243.98 ?? 0.10 Ma. The new 244 Ma biotite age reported here is a cooling age younger than the metamorphic event that crystallized or reheated the biotite. We consider reheating of older biotite to be unlikely because the concordant 40Ar/39Ar spectrum upon repeated incremental laser heating showed a well-developed plateau. Thus, biotites from the IBSP gneiss are interpreted as having crystallized during a single thermal event, followed by cooling to below 300 ??C. The IBSP well falls on a structural and geophysical anomaly trend that is along strike with rocks of the Bronson Hill anticlinorium to the north of the IBSP gneiss. Locally graphitic metasedimentary schists and gneisses recovered from New Jersey wells inboard of the IBSP well gneiss correlate to similar lithologies of the Connecticut Valley synclinorium west of the Hartford basin. Our reinterpretation of the IBSP gneiss as metamorphosed dacite or dacitic tuff is consistent with a correlation to some rocks of the Bronson Hill magmatic arc east of the Hartford basin. If correct, this would imply a Late Ordovician age for the protolith of the IBSP gneiss. Reported 40Ar/39Ar biotite ages of 235-253 Ma from southwestern Rhode Island, and of 238-247 Ma from southeastern Connecticut, are interpreted as cooling ages following a tectonothermal event associated with the Alleghanian orogeny (Early Carboniferous to Late Permian). Cooling ages of Alleghanian age (Early Carboniferous to Late Permian) are not recognized west of the Bronson Hill volcanic arc in either central Connecticut or in Massachusetts. Therefore, the 244 Ma cooling age presented here, and the geochemical affinity of the IBSP gneiss to some orthogneisses of the Bronson Hill arc, support an interpretation of the IBSP well as representing the southern continuation of the Bronson Hill arc into New Jersey. Moreover, it documents the presence of rocks beneath the outer New Jersey Coastal Plain that experienced a Permian Alleghanian metamorphism. ?? 2009 Elsevier Ltd. All rights reserved.

  4. Hydrocarbon potential of the Lamu basin of south-east Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Nyagah, K.; Cloeter, J.J.; Maende, A. (National Oil Corp. of Kenya, Nairobi (Kenya))

    1996-01-01

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

  5. Hydrocarbon potential of the Lamu basin of south-east Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Nyagah, K.; Cloeter, J.J.; Maende, A. [National Oil Corp. of Kenya, Nairobi (Kenya)

    1996-12-31

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

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

    Science.gov (United States)

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

    2015-05-01

    The Baoshan Terrane of southwestern China is considered to have been part of the Cimmerian block during the late Paleozoic; consequently, knowledge of its paleoposition and geological evolution can provide constraints on the Permian breakup of northern East Gondwana. Therefore, we conducted paleomagnetic and rockmagnetic studies on lower Permian basalts from four localities in the Baoshan Terrane. The basalts hold a stable characteristic remanent magnetization (ChRM) at high temperatures (300-680 °C) that is carried by magnetite, maghemite, and hematite with both pseudo-single and multiple domains. To test the reliability of data from these volcanic rocks, we analyzed the geomagnetic secular variation (GSV) and reliability of both the present data and previous paleomagnetic data. The results from 23 sites yield a single reversed polarity directed downwards to the southwest, giving a site-mean direction of Dg/Ig = 156.7°/56.6° (kg = 8.0, ?95 = 11.4°) before tilt correction, and Ds/Is = 218.3°/60.1° (ks = 14.1, ?95 = 8.4°) after tilt correction. The result passed the fold test, but the GSV was able to be averaged out in only two sections. All available data were examined section-by-section using the angular dispersion (SB) of virtual geomagnetic poles (VGPs) to ensure that the GSV was completely averaged out. Because the dispersion in declinations is likely to have been affectedby subsequent tectonic deformation, the paleosecular variation (PSV) could not be evaluated from all the data amassed from different sections, and the PSV was able to be removed from only four (combined) sections. A small-circle fit of these VGPs gives an averaged paleocolatitude of 51.9° ± 3.7° (N = 31 sites) centered on 24°N, 99°E. The result indicates that the sampled area of the Baoshan Terrane was located at a latitude of 38°S ± 3.7° during the late early Permian. A comparison of this result with early Permian data from Gondwanan blocks suggests that the Baoshan Terrane was situated near the junction of northern India and northwestern Australia, and that it broke away from western Australia after the early Permian.

  7. Nuevos gastrópodos del Pérmico inferior de la Formación Mojón de Hierro, provincia del Chubut, Argentina / New Lower Permian gastropods from the Mojón de Hierro Formation, Chubut Province, Argentina

    Scientific Electronic Library Online (English)

    Karina, Pinilla; Nora, Sabattini; Julio, Hlebszevitsch.

    2007-06-01

    Full Text Available Se describen nuevos gastrópodos del Pérmico inferior (Zona de Euphemites chubutensis-Palaeoneilo aff. concentrica) de la cuenca Tepuel-Genoa. El material corresponde a las localidades de Quebrada Honda y El Molle de la Formación Mojón de Hierro. El género Borestus Thomas (Pleurotomarioidea) es regis [...] trado por primera vez para Argentina con la nueva especie Borestus lunatus. También se propone un nuevo subgénero y nueva especie, Sinuitina (Spirilira) tenuis. El nuevo subgénero se caracteriza por la presencia de ornamentación espiral, perfil de las vueltas subcordado y debilitamiento de la ornamentación colabral de la mitad exterior del flanco hacia el dorso. Abstract in english New gastropods from the Lower Permian (Euphemites chubutensis-Palaeoneilo aff. concentrica Zone) of the Tepuel-Genoa Basin are described. The material was recovered from the Mojón de Hierro Formation, at the Quebrada Honda and El Molle localities. The genus Borestus Thomas (Pleuroto-marioidea) is re [...] ported for the first time in Argentina with the new species Borestus lunatus. In addition, Sinuitina (Spirilira) tenuis nov. subgen. nov. sp. ( Bellerophontoidea) is proposed. The new subgenus is characterized by spiral ornamentation, subcordate whorls in section, and a reduced collabral ornamentation on outer flanks and dorsum.

  8. Timing of Emeishan magmatic activity and implications for the end-Middle Permian biotic crisis

    Science.gov (United States)

    Mundil, R.; Denyszyn, S. W.; Shellnutt, J. G.; Jost, A. B.; Payne, J. L.; Renne, P. R.; He, B.; Zhong, Y.; Xu, Y.

    2012-04-01

    Evidence from high-resolution geochronology combined with fossil records and proxies for changes in the paleoenvironment suggest that there is a link between large-scale (but short-term) volcanic events and mass extinctions. Synchroneity has been shown between large-scale volcanic events and three of the five most severe mass extinctions: the end-Permian extinction (P-T) coincides with Siberian Traps LIP; the end-Triassic extinction (Tr-J) with Central Atlantic Magmatic Province; and the end-Cretaceous (K-P) with the Deccan Traps LIP. Recent studies also show that the magnitude of the extinction is not a simple function of the size (volume) of the igneous event; rather, the eruption rate and nature of the host rock that is intruded exert important controls on the rate and magnitude of the release of gases that affect climate and ocean chemistry. Consequently, high-resolution geochronological constraints on LIP volcanism, biotic extinctions, and climatic change are essential to understanding the role of magmatism in these evolutionary catastrophes. The end-Guadalupian (latest Middle Permian) extinction event shows a selectivity pattern similar to the better-studied end-Permian extinction. Single zircon U-Pb ages from intrusions related to the late Middle Permian ca 260 Ma Emeishan LIP (central and southwest China) have recently been shown to have intruded within a very narrow time interval between 260 and 257 Ma, broadly overlapping the timing of end-Guadalupian biotic change. New zircon U-Pb ages from felsic volcanic rocks overlying the youngest Emeishan related basalts show that effusive volcanism was terminated between 258 and 259 Ma, suggesting that the main stage of volcanism was very short. Unfortunately, 40Ar/39Ar analyses applied to minerals extracted from basalts have proven notoriously difficult because of thermal overprint in the studied area. Whereas the timing of Emeishan related magmatic activity is now better constrained by our new U-Pb zircon analyses, there are so far only few robust geochronologic data from biostratigraphically constrained sedimentary sequences across the Middle to Late Permian boundary. The volume of intrusive and effusive rocks related to the Emeishan LIP is difficult to reconstruct, but is thought to be significantly smaller than the three LIPs mentioned above. Consequently, the volume of gas release and its effects on the atmosphere and hydrosphere may have been not as devastating as during the following three major extinctions (P-T, Tr-J, K-P). Initial results from stable calcium isotope records in marine carbonates and conodont microfossils across the Middle to Late Permian boundary indicate the magnitude of changes in ocean carbonate and redox chemistry was much smaller than those associated with the subsequent end-Permian mass extinction. Ongoing research is aimed at corroborating this finding but compromised by the scarcity of marine sedimentary archives of this age. In addition, our current efforts concentrate on constructing a robust chronostratigraphic framework for this time interval.

  9. Crustal and basin evolution of the southwestern Barents Sea: from the Caledonian orogeny to continental breakup

    Science.gov (United States)

    Gernigon, Laurent; Brönner, Marco; Roberts, David; Olesen, Odleiv

    2013-04-01

    A new generation of aeromagnetic data documents the post-Caledonian tectonic evolution of the southwestern Barents Sea (SBS) up to the continent-ocean transition. Clear evidence of reactivation of Caledonian structures controlling both, Late Palaeozoic and Mesozoic basins can be observed at the edge of the Hammerfest and Nordkapp basins where reactivated low-angle detachments are observed on seismics. Our new aeromagnetic surveys confirm most of the previous structural elements, but new features appear and illustrate the complexity of the pre-Permian tectonic and the basement architecture in the SBS. We propose an updated tectonic scenario of the SBS where the Caledonian nappes and thrust sheets, well constrained onshore, swing anticlockwise from a NE-SW trend close to the Varanger Peninsula to NW-SE across the Nordkapp Basin and the Bjarmeland Platform. On the Bjarmeland Platform, the dominant magnetic grain is clearly NNW-SSE. We show that this pattern reflects a regional pre-Permian system involving several Caledonian thrust sheets that possibly collapsed and controlled the post-Caledonian late Palaeozoic rift development of the SBS. We also consider that this model can explain the later development of the SBS. One specific case is the Bjørnøya Basin, located between the Loppa and Stappen highs which are interpreted as a series of rigid and poorly thinned continental blocks (ribbons) flanked by the Hammerfest and Bjørnøya basins and the basins of the Vestbakken volcanic province. As part of this extensive complex system, the Bjørnøya Basin is interpreted as a extensively thinned and propagating system that aborted in Late Mesozoic time. This thick, Cretaceous sag basin is characterised by a deep high-density body, interpreted as a combination of exhumed lower crust and/or potential serpentinised mantle as suggested by potential field modelling. The abortion of this propagating basin may be partly explained by its trend, which is oblique to the inherited regional structural grain, as revealed by the new aeromagnetic compilation. This abortion coincides with a migration and complete reorganisation of the crustal extension towards the western volcanic sheared margin and proto-breakup axis.

  10. Oil migration examples in Irati Formation, Parana basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Espitalie, J.; Mizuta, K.; Carvalho, T.E.M.; Triguis, J.A.

    1983-03-01

    The Irati Formation (Late Permian), in the Parana basin, is a source rock with high oil generating potential. The TOC contents range from 0.5 to 13% according to the quality of the organic matter. Pyrolysis analysis indicates that the area where the Irati has the highest oil-generating source rock is in the north and south of the Parana basin. In these areas petroleum potential can reach 90 kg HC/t of rock. In the central part of the basin the Irati Formation might reach a depth of about 3200 m (10,498 ft). In many wells diabase intrusions have more or less completely cooked this formation, thus generating oil or gas, and leaving residual organic matter. The phenomenon of migration into the Irati Formation has been observed in many wells. In certain places, oil is accumulated in shales embedded between intrusion levels; in other places oil is accumulated into limestone beds, intercalated in the Irati Formation. It seems safe to assume that the oil accumulated in the deeper beds resulted from the effect of thermal intrusions and also from the effects of normal burial. Oil migration occurred after diabase intrusions (Late Cretaceous) during the increasing subsidence of the basin. In the Parana basin, the Irati Formation may be compared to a drain with a lateral oil migration. Vertical migration was hindered by the lack of enough porosity and permeability in the shales above the Irati source rock. Consequently, migration and accumulation of oil above and below the formation might have resulted from changes in facies of the Irati itself, by faulting, or by fractures due to diabase intrusions.

  11. Effects of late Paleozoic foreland deformation on underground coal mine ground instability, Illinois and Appalachian Basins

    Energy Technology Data Exchange (ETDEWEB)

    Phillipson, S.E. [Mine Safety and Health Administration, Roof Control Division, Pittsburgh Safety and Health Technology Center, P.O. Box 18233, Pittsburgh, PA 15236 (United States)

    2005-10-17

    Slickensides are commonly associated with potentially hazardous ground conditions in underground coal mines. Investigations by the Mine Safety and Health Administration's Roof Control Division indicate that slickensided drag folds in the immediate roof of Pennsylvanian-age coal seams represent instances of ground instability of various scales, from skin control hazards to roof falls that block travelways and belt entries. The occurrence of features in the roof of the Illinois Basin's Springfield coal seam that are identical to structures interpreted as drag folds in Pennsylvanian-age coal measure rocks of the Appalachian Basin suggests that tectonic stress associated with the late Pennsylvanian-Permian Alleghanian orogeny was transmitted into the mid-continent. This paper relates slickenside occurrences in the Pennsylvanian-age Springfield coal seam to local structural geologic features that are associated with the late Pennsylvanian-Permian Alleghanian orogeny. Because the slickensides discussed are interpreted to have formed in response to regional tectonic stress, small-scale controls on coal mine ground instability can be related to large-scale, regional tectonic processes. Field investigations indicate that mine-wide geologic mapping of structural geologic features can be used to project zones of subtle, yet problematic, structural weakness in advance of face positions. By incorporating this style of structural geologic hazard mapping in mine planning and operation, miners can be prepared to install appropriate supplemental support, or reduce the effects of structural weaknesses with local modifications to mine design. (author)

  12. Paris Basin Subsidence And Its Genesis : An Extensional Collapse Of The Variscan Belt Or "delamination" Of The Mantle Lithosphere ?

    Science.gov (United States)

    Le Solleuz, A.; Doin, M.-P.; Robin, C.; Guillocheau, F.

    The aim of this study is to characterize the Permian tectonic setting of the Paris basin using the basin meso-cenozoic subsidence history and a two-dimensional thermal evo- lution model of the lithosphere. This model integrates some thermal and mechani- cal time- and space- variable properties (porosity of sediments, density, thermal ca- pacity and conductivity of the litosphere, etc.) and mineralogical characteristics of the litosphere. Accommodation curves have been obtained from a stratigraphic study (palaeoenvironments and correlations) of about one hundred wells and outcrops on a North-South and a West-East transects across the Paris Basin. These curves are cor- rected from the effects of sediment compaction, of the elastic flexure of the basin under sediment and sea-water load and from global sea-level variations. Finally, we compute the 2-D thermal evolution of the lithosphere, taking into account temperature- and pressure- dependent thermal characteristics, phase transition in the mantle and meta- morphism, that yields the best fit (by optimisation of extensional rates and lithosphere thickness) with subsidence curves for each transect. The long-term subsidence of the Paris Basin results from a large late Variscan thermal anomaly. The latter may result from either (1) a Stephanian to Early Permian extensional collapse of a mountain belt or, an important thinning (or "delamination") of the mantle lithosphere. The sub- sidence enables to constrain, in case, the expected amount of crustal thickening during the Variscan orogen or, in case, of the expected amount of mantle litho- spheric thinning. The predicted magmatism chronology and topographic evolution in the Paris Basin area by the model, in both cases, are compared to the timing of mag- matism in surrounding Variscan terranes. The North-South transect, perpendicular to the trend of the Variscan belt, yields a better understanding of extensional rates inten- sities and a better calibration of the topography of external to internal domains of the chain.

  13. Characterization of bedded salt for storage caverns -- A case study from the Midland Basin, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hovorka, Susan D.; Nava, Robin

    2000-06-13

    The geometry of Permian bedding salt in the Midland Basin is a product of interaction between depositional facies and postdepositional modification by salt dissolution. Mapping high-frequency cycle patterns in cross section and map view using wireline logs documents the salt geometry. Geologically based interpretation of depositional and dissolution processes provides a powerful tool for mapping and geometry of salt to assess the suitability of sites for development of solution-mined storage caverns. In addition, this process-based description of salt geometry complements existing data about the evolution of one of the best-known sedimentary basins in the world, and can serve as a genetic model to assist in interpreting other salts.

  14. Regional well-log correlation in the New Mexico portion of the Delaware Basin

    International Nuclear Information System (INIS)

    Although well logs provide the most complete record of stratigraphy and structure in the northern Delaware Basin, regional interpretations of these logs generate problems of ambiguous lithologic signatures and on-hole anomalies. Interpretation must therefore be based on log-to-log correlation rather than on inferences from single logs. In this report, logs from 276 wells were used to make stratigraphic picks of Ochoan horizons (the Rustler, Salado, and Castile Formations) in the New Mexico portion of the Delaware Basin. Current log correlation suggests that: (1) the Castile is characterized by lateral thickening and thinning; (2) some Castile thinnings are of Permian age; (3) irregular topography in the Guadalupian Bell Canyon Formation may produce apparent structures in the overlying Ochoan units; and (4) extensive dissolution of the Salado is not apparent in the area of the Waste Isolation Pilot Project (WIPP) site. 13 refs., 37 figs

  15. Geology and uranium mineralization of the Collio basin (central Southern Alps, Italy)

    International Nuclear Information System (INIS)

    The continental, Lower Permian Collio basin is a complex post-Variscan structure which derives from the superimposition of a multi-stage volcanic cauldron and a narrow elongated clastics-filled graben. The Collio volcanic apparata erupted at least 150 km3 of mainly acidic magma (rhyolites and minor andesites) of crustal anatectic origin, during two major periods of activity separated by partial resurgent doming. The largest uranium mineralizations in the basin (two of which are economic) have been found both in the volcanics and in the younger late Collio sediments. They show broad similarities in mineralogy, elemental associations and wall-rock alteration. Furthermore, both economic deposits and the major showing so far discovered exhibit U-Zr and U-Nb positive correlations, rather shallow depth of emplacement and definite structural controls. (Auth.)

  16. Origin and correlation of tuffs in the Permian Newcastle and Wollombi Coal Measures, NSW, Australia, using chemical fingerprinting

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, W.; Weatherall, G.; Offler, R. [Discipline of Geology, School of Geosciences, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2001-08-01

    Felsic tuffs are common throughout the Late Permian Newcastle and Wollombi Coal Measures (NCM, WCM) of the northern Sydney Basin. Petrographic studies reveal that they are composed of fragmented crystals of plagioclase, quartz, and less common degraded biotite and K-feldspar, together with lithic fragments and relict, altered glass shards. Alteration during burial at T<100 C has resulted in the formation of illite/smectite (I/S; I{sub 62-78}), kaolinite, siderite/ankerite and, in extreme circumstances, tonsteins dominated by I/S. The latter is formed by the alteration of vitric tuffs. Zr/TiO{sub 2} and Nb/Y ratios, and rock-primordial and chondrite-normalised REE patterns (La/Yb=4.05 to 11.37) indicate that the tuffs have been derived from rhyodacitic to dacitic, continental arc, calc-alkaline magmas. The accuracy of a recent lithostratigraphic correlations between the NCM and the WCM has been tested by determining the chemical composition of four stratigraphically well defined tuffs in the NCM and comparing them with those obtained from tuffs of the WCM which are thought to be stratigraphically equivalent. The comparison was carried out using multivariate statistical analysis. The analysis revealed that two of the tuffs (Awaba, Nobbys) in the NCM could be distinguished; the others (Mt. Hutton, Warners Bay) showed considerable scatter. This contrasted with the tonsteins formed from the tuffs, which, apart from the Mt. Hutton Tuff, were able to be separated. In the WCM, three of the tuffs (Nalleen, unnamed tuff equivalent to the Mt. Hutton Tuff, Monkey Place Creek) could be separated; however, the fourth (unnamed tuff equivalent to the Warners Bay Tuff) exhibited some scatter. Treating tuffs in the WCM separately, as unknowns in the discriminant model to determine possible correlatives in the NCM, revealed that the Nalleen Tuff is equivalent to the Awaba Tuff in the NCM, confirming the lithostratigraphic correlation. The remainder of the tuffs in the WCM, however, show moderate to poor correlation with the proposed stratigraphically equivalents in the NCM. Thus, the analysis shows that correlation based on lithostratigraphic grounds may be incorrect.

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

    Science.gov (United States)

    Payne, Jonathan L.; Clapham, Matthew E.

    2012-05-01

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

  18. Remote Stratigraphic Analysis: Combined TM and AIS Results in the Wind River/bighorn Basin Area, Wyoming

    Science.gov (United States)

    Lang, H. R.; Paylor, E. D.; Adams, S.

    1985-01-01

    An in-progress study demonstrates the utility of airborne imaging spectrometer (AIS) data for unraveling the stratigraphic evolution of a North American, western interior foreland basin. AIS data are used to determine the stratigraphic distribution of mineralogical facies that are diagnostic of specific depositional environments. After wavelength and amplitude calibration using natural ground targets with known spectral characteristics, AIS data identify calcite, dolomite, gypsum and montmorillonite-bearing strata in the Permian-Cretaceous sequence. Combined AIS and TM results illustrate the feasibility of spectral stratigraphy, remote analysis of stratigraphic sequences.

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

    OpenAIRE

    Wang, Bo; Cluzel, Dominique; Shu, Liangshu S.; Faure, Michel; Charvet, Jacques; Chen, Yan; Meffre, Se?bastien; Jong, Koenraad

    2009-01-01

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

  20. 78 FR 16569 - Iowa Pacific Holdings, LLC, Permian Basin Railways, and San Luis & Rio Grande Railroad-Corporate...

    Science.gov (United States)

    2013-03-15

    ...San Luis & Rio Grande Railroad--Corporate Family Transaction Exemption...49 CFR 1180.2(d)(3) for a corporate family transaction pursuant to which...applicants would reorganize their corporate structure. According to the...

  1. 77 FR 65446 - Iowa Pacific Holdings, LLC and Permian Basin Railways-Control Exemption-Cape Rail, Inc. and...

    Science.gov (United States)

    2012-10-26

    ...States: Austin & Northwestern Railroad Company, Inc. (operating as the Texas-New Mexico Railroad), Chicago Terminal Railroad...Railroad, San Luis & Rio Grande Railroad, Saratoga & North Creek Railway, the West Texas & Lubbock Railway...

  2. Timing of recovery from the end-Permian extinction: Geochronologic and biostratigraphic constraints from south China

    Science.gov (United States)

    Lehrmann, Daniel J.; Ramezani, Jahandar; Bowring, Samuel A.; Martin, Mark W.; Montgomery, Paul; Enos, Paul; Payne, Jonathan L.; Orchard, Michael J.; Hongmei, Wang; Jiayong, Wei

    2006-12-01

    Four volcanic-ash beds bracket the Early-Middle Triassic boundary, as defined by conodont biostratigraphy, in a stratigraphic section in south China. High-precision U-Pb dates of single zircons allow us to place the Early to Middle Triassic (Olenekian-Anisian) boundary at 247.2 Ma. Magnetic-reversal stratigraphy allows global correlation. The new dates constrain the Early Triassic interval characterized by delayed biotic recovery and carbon-cycle instability to ˜5 m.y. This time constraint must be considered in any model for the end-Permian extinction and subsequent recovery.

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

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.P.; Flores, R.M. [China University of Mining and Technology, Beijing (China). Beijing Graduate School

    1996-02-01

    This paper compares the sedimentary facies types of the Pleistocene deposits of the Modern Pearl River Delta in Guangdong Province, China with the Permian Member D deposits in Huainan coalfield in Anhui Province. Both are exemplified by depositional facies of anastomosing fluvial systems. Sand/sandstone and mud/mudstone-dominated facies types formed in diverging and converging, coeval fluvial channels laterally juxtaposed with flood plains containing ponds, lakes, and topogeneous mires. The mires accumulated thin to thick peat/coal deposits that vary in vertical and lateral distribution between the two study areas. This difference is probably due to attendant sedimentary processes that affected the floodplain environments.

  4. Facies and sedimentary environment of the Permian carbonates (Khuff Formation) in the United Arab Emirates

    Science.gov (United States)

    Alsharhan, A. S.

    1993-04-01

    The Late Permian to Early Triassic Khuff Formation of the United Arab Emirates is a 625-970 m thick sequence of shallow water carbonates (dolomites, limestones and dolomitic limestones with subordinate anhydrite). It can be subdivided into ten facies units distinguished on the basis of their depositional textures, that represent an overall regressive carbonate—evaporite sequence. Based on the paleoecology, sedimentary structures and lithology, four distinct depositional settings can be recognized: supratidal (sabkha), lagoon, shoal and shallow shelf. The Khuff Formation has both primary (interparticle) and secondary (dissolution vugs and intercrystalline) porosities.

  5. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna / Sedimentological study of Carboniferous and Permian deposits on the western edge of the Puna

    Scientific Electronic Library Online (English)

    Claudia Inés, Galli; María Cristina, Moya; Marcelo, Arnosio.

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior) y a las calizas marinas de la Formación Arizaro [...] (Pérmico Inferior). La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución. Abstract in english The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of the Argentine Puna has been carried out. These deposits include the continental red beds of the Cerro Oscuro Formation (Upper Carboniferous) and the marine limestones of the Arizaro Fo [...] rmation (Lower to Middle Permian). The stratigraphic column analyzed consists of 480 m of clastic and carbonate rocks with interbedded volcaniclastic levels. The deposits integrate a synclinal structure of NNW-SSE trend, which pitches to the NW. The carboniferous-permian deposits were analized in both flanks of the syncline. Based on the stratigraphic and sedimentologic characteristics analyzed in the Cerro Oscuro and Arizaro Formations, new paleoenvironmental interpretations are given: i. The thinning and fining sequence that documents the Cerro Oscuro Formation includes, from base to top, debris flows accumulated in an alluvial fan system, and three cycles or minor positive sequences, corresponding to a sand-gravel braided fluvial system. ii. In the analyzed sections, the relationship between the Cerro Oscuro and Arizaro formations is a paraconformity. iii. The Arizaro Formation includes three cycles developed in a mixed carbonate-siliciclastic marine shelf paleoenvironment. Mineralogic and petrographic characteristics of the recognized facies are described and a provenance analysis wich suggests the existence of different source areas is included. The transgression that documents the Arizaro Formation is analyzed and it has been related with the global sea level rise event caused by deglaciation phenomena during the Artinskian-Kungurian time. The effect of tectonic and volcanic processes that would have affected the basin during their evolution is discussed.

  6. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna Sedimentological study of Carboniferous and Permian deposits on the western edge of the Puna

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of the Argentine Puna has been carried out. These deposits include the continental red beds of the Cerro Oscuro Formation (Upper Carboniferous and the marine limestones of the Arizaro Formation (Lower to Middle Permian. The stratigraphic column analyzed consists of 480 m of clastic and carbonate rocks with interbedded volcaniclastic levels. The deposits integrate a synclinal structure of NNW-SSE trend, which pitches to the NW. The carboniferous-permian deposits were analized in both flanks of the syncline. Based on the stratigraphic and sedimentologic characteristics analyzed in the Cerro Oscuro and Arizaro Formations, new paleoenvironmental interpretations are given: i. The thinning and fining sequence that documents the Cerro Oscuro Formation includes, from base to top, debris flows accumulated in an alluvial fan system, and three cycles or minor positive sequences, corresponding to a sand-gravel braided fluvial system. ii. In the analyzed sections, the relationship between the Cerro Oscuro and Arizaro formations is a paraconformity. iii. The Arizaro Formation includes three cycles developed in a mixed carbonate-siliciclastic marine shelf paleoenvironment. Mineralogic and petrographic characteristics of the recognized facies are described and a provenance analysis wich suggests the existence of different source areas is included. The transgression that documents the Arizaro Formation is analyzed and it has been related with the global sea level rise event caused by deglaciation phenomena during the Artinskian-Kungurian time. The effect of tectonic and volcanic processes that would have affected the basin during their evolution is discussed.

  7. Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, NE China: evidence from basin provenance and geochronology

    Science.gov (United States)

    Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei

    2010-05-01

    The main part of Jiamusi Block, named as Huanan-Uplift, is located in the northeastern Heilongjiang, China. The Huanan-Uplift is surrounded by many relatively small Mesozoic-Cenozoic basins, e.g. Sanjiang Basin, Hulin Basin, Boli Basin, Jixi Basin, Shuangyashan Basin and Shuanghua Basin. However previous research works were mainly focused on stratigraphy and palaeontology of the basins, therefore, the coupling relation between the uplift and the surrounding basins have not been clear. Based on the field investigations, conglomerate provenance studies of the Houshigou Formation in Boli Basin, geochronology of the Huanan-Uplift basement, we have been studied the relationships between Huanan-Uplift and the surrounding basins. The regional stratigraphic correlations indicates that the isolated basins in the area experienced the same evolution during the period of the Chengzihe and the Muling Formations (the Early Cretaceous). The paleogeography reconstructions suggest that the area had been a large-scale basin as a whole during the Early Cretaceous. The Huanan-Uplift did not exist. The paleocurrent directions, sandstone and conglomerate provenance analyses show that the Huanan-Uplift started to be the source area of the surrounding basins during the period of Houshigou Formation (early Late Cretaceous), therefore, it suggests that the Jiamusi Block commenced uplift in the early Late Cretaceous. The granitic gneisses in Huanan-Uplift give 494-415 Ma monazite U-Th-total Pb ages, 262-259 Ma biotite and 246-241 Ma K-feldspar 40Ar/39Ar ages. The cooling rates of 1-2 ?/Ma from 500-260 Ma and 10-11 ?/Ma from 260-240 Ma have been calculated based on the ages. This suggests that the Jiamusi Block had a rapid exhumation during late Permian, which should be related to the closure of the Paleo-Asian Ocean between the Siberian and North China continents. It is concluded that during the late Paleozoic the Jiamusi Block was stable with a very slow uplifting. With the closure of the Paleo-Asian Ocean the Jiamusi Block underwent a very rapid exhumation in the late Permian. In the early Mesozoic the area went into a basin developing stage and formed a large basin as a whole during the Early Cretaceous. In the Late Cretaceous the Jiamusi Block started uplifting and the basin was broken into isolate small basins. References: Bureau of Geology and Mineral Resources of Heilongjiang Province. Regional geology of Heilongjiang Province. Beijing: Geological Publishing House, 1993.578-581. Cao Chengrun, Zheng Qingdao. Structural evolution feature and its significance of hydrocarbon exploration in relict basin formation, Eastern Heilongjiang province. Journal of Jilin university (Earth Science Edition), 2003, 33(2):167-172. Lang Xiansheng. Biologic Assemblage features of Coal-bearing Strata in Shuangyashan-Jixian coal-field. Coal geology of China, 2002, 14(2):7-12. Piao Taiyuan , Cai Huawei , Jiang Baoyu. On the Cretaceous coal-bearing Strata in Eastern Heilongjiang. Journal Of Stratigraphy, 2005, 29:489-496. Wang Jie , He Zhonghua , Liu Zhaojun , Du Jiangfeng , Wang Weitao. Geochemical characteristics of Cretaceous detrital rocks and their constraint on provenance in Jixi Basin. Global Geology?2006, 25(4):341-348. DickinsonW R and Christopher A. Suczek. Plate Tectonics and Sandstone Composition. AAPG B. 1979,63(12 ):2164-2182. DickinsonW R, Beard L S, Brakenridge G R, et al. Provenance of North American Phanerozoic sandstones in relation to tectonic setting. Bull Geo-Soc Amer, 1983, 94: 222-235. Maruyama S, Seno T. Orogeny and relative plate motions: Example of the Japanese Islands. Tectonophysics, 1986?127(3-4):305-329. Maruyama S, Isozaki Y, Kimura Gand Terabayashi M C.Paleogeographic maps of the Japanese Islands: plate tectonic systhesis from 750 Ma to the present. Island Arc, 1997,6:121-142.

  8. Conodont biostratigraphy across the Permian-Triassic boundary at the Dawen section, Great Bank of Guizhou, Guizhou Province, South China: Implications for the Late Permian extinction and correlation with Meishan

    Science.gov (United States)

    Chen, Jun; Beatty, Tyler W.; Henderson, Charles M.; Rowe, Harry

    2009-11-01

    Several continuous Permian-Triassic boundary (PTB) sections are well exposed in the interior of the Great Bank of Guizhou (GBG) on the east limb of the Bianyang syncline, Luodian County, Guizhou Province, South China. Fourteen conodont taxa are identified, including Clarkina kazi, Clarkina lehrmanni n. sp., Clarkina taylorae, Clarkina zhejiangensis, Hindeodus eurypyge, Hindeodus inflatus, Hindeodus sxlatidentatus, Hindeodus parvus erectus, Hindeodus parvus parvus, Hindeodus postparvus, Hindeodus praeparvus, Hindeodus typicalis, Isarcicella staeschei, and Merrillina ultima based on a detailed study of the Permian-Triassic interval at the Dawen section. The first occurrence (FO) of H. parvus parvus in the lower Daye Formation, at about 7.45 m above the contact surface between the Upper Permian skeletal packstone and a calcimicrobial framestone unit, is correlated with the Permian-Triassic boundary; the occurrence of H. eurypyge, H. praeparvus and M. ultima immediately below and H. postparvus above the interval supports this interpretation. A morphometric analysis of 31 Hindeodus specimens helped distinguish H. parvus erectus from H. parvus parvus and H. postparvus. Correlation with the Meishan section (PTB GSSP) using both conodont biostratigraphy and carbon isotopes, indicates that the major extinction at the two localities is simultaneous and coincides with the top of the skeletal packstone at Dawen. The contact between the skeletal packstone and the calcimicrobialite is very irregular and has previously been interpreted as a dissolution surface and correlated with a surface in the lower part of bed 27 at Meishan. Our results confirm this interpretation and reveal that the dissolution event postdated the extinction.

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

    Directory of Open Access Journals (Sweden)

    R.N. Tomezzoli

    2006-09-01

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

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

    Scientific Electronic Library Online (English)

    R.N., Tomezzoli; M.S., Japas.

    2006-09-01

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

  11. Palaeotethys seawater temperature rise and an intensified hydrological cycle following the end-Permian mass extinction

    DEFF Research Database (Denmark)

    Schobben, Martin; Joachimski, Michael M.

    2014-01-01

    The end-Permian mass extinction has been associated with severe global warming. Main stage volcanism of the Siberian Traps occurred at or near the extinction interval and has been proposed as a likely greenhouse catalyst. In this study, a high-resolution ?18O record is established using diagenetically resistant apatite of conodonts and low-Mg calcite of brachiopods from stratigraphically well-constrained Permian–Triassic (P–Tr) boundary successions in northwestern Iran. A new evaluation is made for previously published conodont ?18O values from South China and revised palaeotemperatures are presented together with new data from Wuchiapingian to Griesbachian sections in Iran. ?18O data from P–Tr sections in Iran document tropical sea surface temperatures (SST) of 27–33 °C during the Changhsingian with a negative shift in ?18O starting at the extinction horizon, translating into a warming of SSTs to over 35 °C. The results are consistent with re-calculated SSTs of the South Chinese sections. Warming was associated with an enhanced hydrological cycle involving increased tropical precipitation and monsoonal activity in the Tethys Sea. Global warming, intensification of the hydrological cycle and associated processes, vertical water column stratification, eutrophication and subsequent local anoxia may all have facilitated an extinction event.

  12. Research on genesis of pyrite near the Permian-Triassic boundary in meishan, Zhejiang, China

    Science.gov (United States)

    Jiang, Y.-F.; Tang, Y.-G.; Chou, C.-L.

    2006-01-01

    The content and crystal forms of pyrite and sulfur isotope composition of pyrite sulfur as well as its vertical distribution near the Permian-Triassic (P/T) boundary in the Meishan section, Changxing county, Zhejiang province, China were studied using geological, petrological, mineralogical and geochemical methods (techniques). The result showed that the genesis of abundant pyrites in bed 24e2 at the uppermost part of the Changxing Formation in the Meishan section may be related to volcanic activity. In bed 24e2 of the Meishan section, pyrite has its highest content of 1.84% and the sulfur isotope composition has the highest ??34S value at + 2.2??? which is very similar to that of the average value of volcanic gas. There are some volcanic products such as ??-quartz, siliceous cylinders and siliceous spherules which coexisted with pyrites in beds 24e2 and 24f. It can be concluded that a large quantity of volcanic ash fell into the South China Sea and was incorporated into marine sediments during the formation of limestone at the uppermost part of the Changxing Formation. The volcanic eruption with massive amounts of H2S and S02 gas at the end of the Permian period resulted in the enrichment of H2S in the South China Sea areas. The reaction of H2S with reactive iron minerals formed the mass of abundant pyrites.

  13. Palaeobiogeography of Kazanian-Midian (Late Permian) western Pacific Brachiopod faunas

    Science.gov (United States)

    Shi, G. R.; Archbold, N. W.

    A data matrix of the presence/absence occurrence data of 129 genera from 16 faunal stations (selected from 19 initially compiled faunal stations on the basis of sampling and study adequacies) is analysed by cluster analysis, nonmetric multidimensional scaling, principal coordinate analysis and minimum spanning tree. Three core faunal groups are revealed and interpreted as representing three biotic provinces. They are the Verkolyma Province embracing the Kolyma Massif, Verchoyan Mountains, east Zabaikal and northern Mongolia; the Cathaysian Province of Japan, northern and southern China and the Indo-China block; and the Austrazean Province of eastern Australia and New Zealand. The overall evolving pattern of Permian marine provincialism of the western Pacific is summarized from our previous, as well as current studies, on the basis of three discrete time slices: Asselian-Tastubian, Baigendzhinian-Early Kungurian and Kazanian-Midian. An attempt is also made to explain the marked change of marine provinciality during the Permian in the western Pacific in the context of plate tectonics, transgression/regression and climatic amelioration.

  14. Siberian glaciation as a constraint on Permian Carboniferous CO2 levels

    Science.gov (United States)

    Hyde, William T.; Grossman, Ethan L.; Crowley, Thomas J.; Pollard, David; Scotese, Christopher R.

    2006-06-01

    Reconstructions of Phanerozoic CO2 levels have generally relied on geochemical modeling or proxy data. Because the uncertainty inherent in such reconstructions is large enough to be climatically significant, inverse climate modeling may help to constrain paleo-CO2 estimates. In particular, we test the plausibility of this technique by focusing on the climate from 360 to 260 Ma, a time in which the Siberian landmass was in middle to high latitudes, yet had little or no permanent land ice. Our climate model simulations predict a lower limit for CO2—the value beneath which Siberia acquires “excess” ice. Simulations provide little new information for the period in which Siberia was at a relatively low paleoaltitude (360 340 Ma), but model results imply that paleo-CO2 levels had to be greater than 2 4× modern values to be consistent with an apparently ice-free Siberia in the late Permian. These results for the later period in general agree with soil CO2 proxies and the timing of Gondwanan deglaciation, thus providing support for a significant CO2 increase before the end-Permian boundary event. Our technique may be applicable to other time intervals of unipolar glaciation.

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

    Directory of Open Access Journals (Sweden)

    Victoria B. Ershova

    2015-05-01

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

  16. Restudy of conodont biostratigraphy of the Permian-Triassic boundary section in Zhongzhai, southwestern Guizhou Province, South China

    Science.gov (United States)

    Zhang, Yang; Zhang, Ke-Xin; Shi, G. R.; He, Wei-Hong; Yuan, Dong-Xun; Yue, Ming-Liang; Yang, Ting-Lu

    2014-02-01

    New conodont samples have been systematically collected at high stratigraphic resolution from the upper part of the Longtan Formation through to the lower part of the Yelang Formation at the Zhongzhai section, southwestern Guizhou Province, South China, in an effort to verify the first local occurrence of Hindeodus parvus in relation to the Permian-Triassic boundary at this section. The resampled conodont fauna from the Permian-Triassic boundary interval comprises five identified species and two undetermined species in Hindeodus and Clarkina. Most importantly, the first local occurrence of Hindeodus parvus is found for the first time from the bottom of Bed 28a, 18 cm lower than the previously reported first local occurrence of this species at this section. Considering the previously accepted PTB at the Zhongzhai section, well calibrated by conodont biostratigraphy, geochronology and carbon isotope chemostratigraphy, this lower (earlier) occurrence of H. parvus suggests that this critical species could occur below the Permian-Triassic boundary. As such, this paper provides evidence that (1) the first local occurrences of H. parvus are diachronous in different sections with respect to the PTB defined by the First Appearance Datum (FAD) of this species at its GSSP section in Meishan, China and that (2) the lower stratigraphic range of H. parvus should now be extended to latest Permian.

  17. Occurrence, behavior and distribution of high levels of uranium in shallow groundwater at Datong basin, northern China

    International Nuclear Information System (INIS)

    Geochemical investigations of uranium (U) occurrence in the environments were conducted at Datong basin of northern China. The results suggest that U contents were generally 22+) species is dominant and strongly adsorbed onto iron (hydro)xides, while it would be preferentially complexed with carbonate in the alkaline groundwater, forming highly soluble uranyl-carbonate complexes at Datong. Under reducing conditions, uranous (U(IV)) species is ready to precipitate or bind to organic matter, therefore having a low mobility. At the study area, high U groundwater (> 30 ?g/L) occurs at the alluvial plains due to intermediate redox and enhanced alkaline conditions. The abnormally high levels of U in groundwater (> 100 ?g/L) are locally found at the west alluvial plains. By contrast, U co-precipitation with secondary carbonate minerals like Ca2UO2(CO3)3 in the dominant Ca–Mg–Na–HCO3 type groundwater may prevail at the east alluvial plains. Besides, bedrocks such as Carboniferous and Permian sedimentary rocks, especially the coal-bearing strata which have higher U contents at the west mountain areas may also account for the abnormally high levels of U in groundwater. - Highlights: • High U groundwater occurs at the alluvial plains of Datong basin. • Redox state, complexation and adsorption are responsible for U enrichment. • Carboniferous and Permian sedimentary rocks have higher U contents at Datong. • Uranyl is preferentially complexed with carbonate in groundwater. • U in the aquifer sediments may be primarily associated with carnotite

  18. Occurrence, behavior and distribution of high levels of uranium in shallow groundwater at Datong basin, northern China.

    Science.gov (United States)

    Wu, Ya; Wang, Yanxin; Xie, Xianjun

    2014-02-15

    Geochemical investigations of uranium (U) occurrence in the environments were conducted at Datong basin of northern China. The results suggest that U contents were generally sediments and topsoil, respectively. U in the Quaternary aquifer sediments may be primarily associated with carnotite from the Carboniferous and Permian coal-bearing clastic rocks around the basin. Shallow groundwater had U concentrations of study area, high U groundwater (>30 ?g/L) occurs at the alluvial plains due to intermediate redox and enhanced alkaline conditions. The abnormally high levels of U in groundwater (>100 ?g/L) are locally found at the west alluvial plains. By contrast, U co-precipitation with secondary carbonate minerals like Ca2UO2(CO3)3 in the dominant Ca-Mg-Na-HCO3 type groundwater may prevail at the east alluvial plains. Besides, bedrocks such as Carboniferous and Permian sedimentary rocks, especially the coal-bearing strata which have higher U contents at the west mountain areas may also account for the abnormally high levels of U in groundwater. PMID:24342086

  19. Waterford Formation in the south-eastern Karoo: Implications for basin development

    Directory of Open Access Journals (Sweden)

    Richard Mason

    2012-03-01

    Full Text Available Extensive research on the rocks of the Karoo Supergroup has shown that this sequence, which contains an unsurpassed record of Permian–Jurassic tetrapods, records a largely unbroken stratigraphic succession from 300 Ma to 180 Ma. This Gondwanan succession was deposited in a changing environmental setting reflecting glacial marine through deltaic to fluvial and aeolian desert conditions. The contact between the Ecca and Beaufort Groups (at the top of the Waterford Formation of the Ecca Group in the southern and western Karoo represents a change in depositional environment from a subaqueous to a subaerial delta plain. By contrast, the Waterford Formation has not yet been recognised in the south-eastern Karoo Basin, which might imply that a major unconformity is present between the Fort Brown Formation of the Ecca Group, deposited in a prodelta environment, and the overlying fluvially deposited Koonap Formation of the Beaufort Group. From careful documentation of lithofacies and sedimentological data, it can be demonstrated that the Waterford Formation is indeed present in the south-eastern part of the basin and that no major unconformity is present – a fact that has implications for the mapping of Karoo rocks in the Eastern Cape Province of South Africa, for understanding the depositional environment of ’reptilian‘ fossils from the lowermost Beaufort in this part of the Karoo basin, and for basin development models.

  20. Waterford Formation in the south-eastern Karoo: Implications for basin development

    Scientific Electronic Library Online (English)

    Bruce S, Rubidge; P. John, Hancox; Richard, Mason.

    Full Text Available Extensive research on the rocks of the Karoo Supergroup has shown that this sequence, which contains an unsurpassed record of Permian-Jurassic tetrapods, records a largely unbroken stratigraphic succession from 300 Ma to 180 Ma. This Gondwanan succession was deposited in a changing environmental set [...] ting reflecting glacial marine through deltaic to fluvial and aeolian desert conditions. The contact between the Ecca and Beaufort Groups (at the top of the Waterford Formation of the Ecca Group) in the southern and western Karoo represents a change in depositional environment from a subaqueous to a subaerial delta plain. By contrast, the Waterford Formation has not yet been recognised in the south-eastern Karoo Basin, which might imply that a major unconformity is present between the Fort Brown Formation of the Ecca Group, deposited in a prodelta environment, and the overlying fluvially deposited Koonap Formation of the Beaufort Group. From careful documentation of lithofacies and sedimentological data, it can be demonstrated that the Waterford Formation is indeed present in the south-eastern part of the basin and that no major unconformity is present - a fact that has implications for the mapping of Karoo rocks in the Eastern Cape Province of South Africa, for understanding the depositional environment of 'reptilian' fossils from the lowermost Beaufort in this part of the Karoo basin, and for basin development models.

  1. On the REE across the permian-triassic boundary in south China

    International Nuclear Information System (INIS)

    The author discusses the INAA results of REE in clays at and near some Permian/Triassic boundaries of South China,. It shows that the REE patterns of boundary clays differ from those of non-boundary clays. One difference is that the boundary clays are more enriched in LREE, with steeper slope of REE and a smaller Eu negative anomaly than the non-boundary clays. Another difference is that the boundary clays show a small Ce negative anomaly, but no Ce anomaly occurs in the non-boundary clays. From these REE patterns and some other experimental facts, it is proposed that the P/T boundary clay may be a mixed product consisting of the acidic-intermediate ash and the upper crust substance representing sputtering component, and the calculated fraction of the former and latter is 7/3

  2. Geochronological studies on clay minerals in carboniferous and permian strata of Cangcan well No.1

    International Nuclear Information System (INIS)

    The author deals with studies on clay minerals in Carboniferous (C) and Permian (P) strata of Cangcan Well No.1 and geochronological determination on those clay minerals in different depths by K-Ar, 40Ar-39Ar and Rb-Sr methods. The results show that illite were formed in at least three different stages: Clastic illite was formed at about 400 Ma and disturbed by heat at the ages between 214-234 Ma. High temperature illite has ages between 214-233 Ma, corresponding to Late Hercynian-Early Indosinian Periods, and was disturbed by heat at the age of 145 Ma. Widely distributed illite was formed in Early Jurassic Period, 180 Ma. All of these results are undoubtedly helpful to further study on regional heat evolution history and oil-gas bearing and producing abilities of the relevant strata

  3. Conodont survival and low iridium abundances across the Permian-Triassic boundary in south China

    Science.gov (United States)

    Clark, D. L.; Wang, C.-Y.; Orth, C. J.; Gilmore, J. S.

    1986-01-01

    The Permian-Triassic sedimentary sequence of China includes one of the most complete and fossiliferous Paleozoic-Mesozoic boundaries known. Closely spaced sampling across the boundary, which is an important extinction event for most organisms, has produced good conodont faunas that show little diversity change. A drop in conodont abundance is the only apparent response to the extinction event. A low concentration of iridium in the boundary clay (0.002 part per billion + or - 20 percent), as well as in samples immediately below and above, that range from 0.004 to 0.034 part per billion do not support the proposal of an extraterrestrial impact event at this boundary in China.

  4. Section of Permian deposits and fusulinids in the Halvan Mountains, Yazd province, Central Iran

    Science.gov (United States)

    Leven, E. Ya.; Gorgij, M. N.

    2009-04-01

    The Permian section situated northwest of Tabas in the Halvan Mountains is studied and fusulinids occurring in the section are described. The Chili, Sartakht, and Hermez formations distinguished in the section are separated by horizons of bauxitic laterite and belong to the Khan Group formerly ranked as a synonymous formation. Fusulinids occur at two levels in the section. The lower one confined to the Chili Formation yields the so-called Kalaktash fusulinid assemblage of the late Sakmarian age. The second late Asselian assemblage has been discovered in pebbles from conglomerate-breccia in the basal laterite of the Sartakht Formation. A brief characterization of fusulinids is presented and three new species are described. The new Benshiella genus is discriminated from the Rugosofusulinidae family. As Skinner and Wilde (1965, 1966) changed the original diagnosis of the Pseudofusulina genus, we suggest, regarding all species, which have been attributed to this genus but do not satisfy the new diagnosis, as representing the new Nonpseudofusulina genus.

  5. The Pattern and Timing of Biotic Recovery from the End-Permian Extinction on the Great Bank of Guizhou, Guizhou Province, China

    OpenAIRE

    Knoll, Andrew; Wei, Jiayong; Lehrmann, Daniel J.; Payne, Jonathan L.

    2006-01-01

    Microfacies analysis and point Counts of thin sections from 608 hand samples were used to track changes in the abundance and diversity of fossil grains through the extended recovery interval following end-Permian mass extinction on the Great Bank of Guizhou (GBG)-an isolated Late Permian to Late Triassic carbonate platform in south China. Exposure of a two-dimensional cross-section of the platform permits the comparison of faunal patterns along an environmental gradient front shallow to deep ...

  6. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico, Class III; ANNUAL

    International Nuclear Information System (INIS)

    The overall objective of this project is to demonstrate that a development program based on advanced reservoir management methods can significantly improve oil recovery at the Nash Draw Pool (NDP). The plan includes developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced reservoir management methods. Specific goals are (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers in the Permian Basin and elsewhere throughout the U.S. oil and gas industry

  7. Cadmium-isotopic evidence for increasing primary productivity during the Late Permian anoxic event

    Science.gov (United States)

    Georgiev, Svetoslav V.; Horner, Tristan J.; Stein, Holly J.; Hannah, Judith L.; Bingen, Bernard; Rehkämper, Mark

    2015-01-01

    Earth's most extreme extinction event near the end of the Late Permian decimated more than 90% of all extant marine species. Widespread and intensive oceanic anoxia almost certainly contributed to the catastrophe, though the driving mechanisms that sustained such conditions are still debated. Of particular interest is whether water column anoxia was a consequence of a 'stagnant ocean', or if it was controlled by increases in nutrient supply, primary productivity, and subsequent heterotrophic respiration. Testing these competing hypotheses requires deconvolving sedimentary/bottom water redox conditions from changes in surface water productivity in marine sediments. We address this issue by studying marine shales from East Greenland and the mid-Norwegian shelf and combining sedimentary redox proxies with cadmium-isotopic analyses. Sedimentary nitrogen-isotopic data, pyrite framboid analyses, and organic and inorganic shale geochemistry reveal sulfidic conditions with vigorous upwelling, and increasingly anoxic conditions with a strengthening upwelling in the Greenland and Norwegian sections, respectively. Detailed analysis of sedimentary metal budgets illustrates that Cd is primarily associated with organic carbon and records primary geochemical signatures, thus enabling reconstruction of surface water nutrient utilization. Cadmium-isotopic analyses of the authigenic shale fraction released by inverse aqua regia digestion yield an average ?114Cd110 of + 0.15 ± 0.01 ‰ (2 SE, n = 12; rel. NIST SRM 3108), indicative of incomplete surface water nutrient utilization up-section. The constant degree of nutrient utilization combined with strong upwelling requires increasing primary productivity - and not oceanic stagnation - to balance the larger nutrient fluxes to both study sites during the development of the Late Permian water column anoxia. Overall, our data illustrate that if bottom water redox and upwelling can be adequately constrained, Cd-isotopic analyses of organic-rich sediments can be used to provide valuable information on nutrient utilization and therefore past productivity.

  8. An Earth-system perspective on ocean deoxygenation during the end-Permian mass extinction

    Science.gov (United States)

    Cui, Y.

    2014-12-01

    Global ocean anoxia has been proposed to be the cause of the end-Permian (252 Ma) marine extinction event. Evidence for global-scale anoxia mainly comes from the study of organic geochemistry, framboidal pyrite, and redox-sensitive elements, although disagreement exists with respect to the interpretation of the observed patterns. Climate models with biogeochemical components often fail to generate global-scale anoxia induced by warming alone, unless increased phosphate level is invoked. Here, I use the carbon isotope inversion approach in an Earth system model of intermediate complexity (GENIE) with modern phosphate levels to investigate ocean deoxygenation due to global warming through continuous CO­2 emission. I evaluate the temporal and spatial extent of ocean deoxygenation for a best-fit scenario that represents contact metamorphism of organic-rich sediments (?13C = -25‰) during Siberian Traps volcanism eruption. This scenario is characterized by total peak amount of ~30,000 Gt of carbon and global sea surface temperature increase of 5 oC (Cui et al., 2014). The global surface ocean oxygen concentration shows only a modest decrease (from 230 to 215 µmol kg-1) during peak C emission, whereas the global deep ocean oxygen concentration shows a 70% decrease (from 160 to 50 µmol kg-1). During peak C emission, the oxygen minimum zone (~800 m depth) expands vertically and horizontally, and vast regions in the deep northern Panthalassa becomes hypoxic (press). Spatial and temporal patterns of ocean acidification during the end-Permian mass extinction - An Earth system model evaluation. Volcanism and Global Environmental Change. L. T. elkins-Tanton, Fristad, K. Cambridge, Cambridge University Press.

  9. Eopolydiexodina (Middle Permian giant fusulinids) from Afghanistan: Biometry, morphometry, paleobiogeography, and end-Guadalupian events

    Science.gov (United States)

    Colpaert, Clémentine; Monnet, Claude; Vachard, Daniel

    2015-04-01

    The most spectacular macroevolutionary trend presented by the genera of schwagerinoid fusulinids, during the Pennsylvanian -Permian, is an enormous increase in size, which culminated in the Middle Permian with Eopolydiexodina. However, this potential major biogeographic marker, during the Kubergandian-early Midian time interval, is as yet hampered by its poor taxonomic characterization. Hence, Eopolydiexodina is revised here using biometric and morphometric methods applied to large collections from Afghanistan and selected taxa in the literature. These multivariate analyses consist of classical linear test parameters, as well as new area parameters acquired by computer image analysis. The Afghan species are re-defined, and some other species, occasionally described as Cimmerian, are re-discussed. These methods, combined with classical morphological analyses, also permit to conclude that the largest Eopolydiexodina of Afghanistan are microspheric specimens (probably agamonts) of E. afghanensis and E. bithynica. Two megalospheric groups of individuals (probably gamonts and schizonts) are represented in both species, as well as in E. persica and E. darvasica. Due to this presence of gamonts, agamonts and schizonts in several species, Eopolydiexodina is probably the oldest identified trimorphic genus among the large benthic foraminifers. Biostratigraphically, Eopolydiexodina appears restricted to the late Kubergandian to early Midian. The associated Afghan fusulinids (Dunbarula, Kahlerina, Afghanella, Yangchienia, Sumatrina, and Codonofusiella) allow proposing an accurate biostratigraphy of the Eopolydiexodina species in the Murgabian-Midian boundary interval. Paleobiogeographically, Eopolydiexodina was essentially located in the Laurentian and Perigondwanan borders of the Tethys. The possible presence of Eopolydiexodina in the Cimmerian Continent and in some regions of China has never been irrefutably demonstrated. This paleobiological revision of Eopolydiexodina and the biostratigraphic revision of other large Capitanian fusulinids, permit to suggest that the end-Guadalupian event is most probably a protracted succession of last appearance data of giant genera rather than an instantaneous Lilliput effect at the Capitanian/Wuchiapingian boundary.

  10. Changhsingian conodont succession and the end-Permian mass extinction event at the Daijiagou section in Chongqing, Southwest China

    Science.gov (United States)

    Yuan, Dong-xun; Chen, Jun; Zhang, Yi-chun; Zheng, Quan-feng; Shen, Shu-zhong

    2015-06-01

    Previous studies suggested rapid evolution of conodonts across the Permian-Triassic boundary (PTB), and the end-Permian mass extinction pattern varies in different sections in South China. Here we document a high-resolution conodont succession from a carbonate facies of the Changhsingian Stage and across the PTB at the Daijiagou section, about 35 km north to Chongqing City, Southwest China. Two genera and twelve species are identified. Seven conodont zones are recognized from the uppermost part of the Lungtan Formation to the lowest Feixianguan Formation. They are the Clarkina liangshanensis, C. wangi, C. subcarinata, C. changxingensis, C. yini, C. meishanensis, and Hindeodus parvus zones in ascending order. Based on the high-resolution biostratigraphical framework at Daijiagou, the end-Permian mass extinction was rapid and it began in the base of the Clarkina meishanensis Zone. Associated with the extinction, a negative excursion of ?13Ccarb started in the middle part of Clarkina yini Zone with a progressive shift of 1.6‰ to the middle part of the Clarkina meishanensis, followed by a sharp shift of 3.51‰ from the Clarkina meishanensis Zone to the Hindeodus parvus Zone. Our study also suggests that the Triassic index species Hindeodus parvus co-occurred with Hindeodus changxingensis and Clarkina zhejiangensis and directly overlies the Clarkina meishanensis Zone at the Daijiagou section. All these data from the Daijiagou section and some previous studies of other sections in Sichuan, Guizhou provinces and Chongqing City suggest that the first occurrences of Hindeodus parvus are slightly earlier than the sharp negative excursion of ?13Ccarb and the FAD at the Meishan GSSP section. We consider that the slight difference of the end-Permian mass extinction, chemostratigraphy and conodont biostratigraphy at Daijiagou and its adjacent areas is most likely subject to different lithofacies, fossil preservation, and the constraint on the stratigraphic resolution rather than a different tempo of the end-Permian mass extinction in a global sense. The whole Changhsingian conodont succession at Daijiagou provides a high-resolution correlation with other equivalent sections in the Palaeotethys. The controversial results of biostratigraphy and chemostratigraphy between the sections investigated in this paper and the Meishan GSSP section also provide some important implications that accurate chronocorrelation requires the evaluation of multiple, varied stratigraphcal signals rather than relying solely on the FAD of the Triassic index species Hindeodus parvus for recognizing the Permian-Triassic boundary (PTB). Growth series of abundant specimens for each species are figured. The taxonomy of some Hindeodus species in the PTB interval is updated.

  11. Melo carboniferous basin

    International Nuclear Information System (INIS)

    This report is about of the Melo carboniferous basin which limits are: in the South the large and high Tupambae hill, in the west the Paraiso hill and the river mountains, in the North Yaguaron river basin to Candidata in Rio Grande del Sur in Brazil.

  12. Geysers: Lower Geyser Basin

    Science.gov (United States)

    Yellowstone National Park

    This Yellowstone National Park web site is dedicated to Lower Geyser Basin. It includes images and descriptions of Queen's Laundry and Sentinel Meadows, Sentinel Cone, Ojo Caliente, Pocket Basin Mud Pots, Imperial Geyser, Spray Geyser, Octopus Spring, Great Fountain Geyser, White Dome Geyser, Pink Cone Geyser, Bead Geyser, Narcissus Geyser, Steady Geyser, Silex Spring, Fountain Paint Pot, Fountain Geyser, Clepsydra Geyser, and Jelly Geyser.

  13. K Basin safety analysis

    International Nuclear Information System (INIS)

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall

  14. Thermal structure of the Paris Basin from tectonic-Heat Flow modelling

    Science.gov (United States)

    Bonté, Damien; van Wees, Jan-Diederik; Guillou-Frottier, Laurent; Cloetingh, Sierd

    2015-04-01

    Located on the inner part of the Variscan Orogen, the Paris Basin has evolved from the Permo-Carboniferous as an intracratonic basin. The usual description of the sediments in the Paris Basin involves imbricated bowl shaped layers, starting from the Triassic. Due to their discontinuity, depth and complexity the Permian and Carboniferous layers have been commonly left aside. Fortunately, recent studies have been completed to looks specifically at these deeper sedimentary layers. With the development of geothermal energy and the widely use shallow medium enthalpy geothermal resources in the Paris Basin (Dogger) these pre-Mesozoic sediments are of a lot of interest. In this work, we use a tectonic-heat flow modelling methodology to model the present day thermal structure of the Paris Basin. The modelling takes into account the geometry of the layering and the petrophysical parameters (i.e., thermal conductivity, the radiogenic heat production of the sedimentary layers in relation with their facies). In addition, the upper part of the basement is closely considered to allow the description of magmatic intrusions that could have a major impact on the present day temperature (i.e., the variation of the radiogenic heat production). To assess the result of our thermal modelling, the obtained temperature is compared to BHT's (Bottom Hole Temperature) and DST's (Drill Stem Test) values when available. As a result of this modelling, we are able to present present-day temperature within the basin as well as in the shallower part of the basement. The aim of this work is identify the sources of the temperature perturbation. The impact of the sediment's thermal conductivity has already been assed on a previous work, in this work the deeper source of perturbation are of great interest (thermal conductivity and heat production of the pre-Mesozoic sedimentary layers, heat production of magmatic intrusion in the basement, and regional faults in the sediments and basement).

  15. Stratigraphic sections and chemical analyses of phosphatic rocks of Permian and Mississippian age in Weber County, Utah

    Science.gov (United States)

    Schell, Elmer M.; Moore, K.P.

    1970-01-01

    Stratigraphic sections and chemical analyses of phosphatic rocks from five trench localities in Weber County, Utah, are presented. Four of the trenches are in Mississippian rocks, and one is in Permian rocks. Of the Mississippian rocks, the highest grade phosphatic interval is at the Wheat Grass Creek locality. Here the phosphatic rocks are 14.9 feet thick, and a 5.8-foot-thick zone has an average of 22.1 percent P2O5. Three localities of Mississippian rocks have 1.1 or less feet of phosphate rock that contains 24+ percent P2O5. The Permian Park City Formation and related strata, Where measured in Hardy Hollow, are 675 feet thick and consist of a 10.9-foot-thick phosphatic interval in the Grandeur Member of the Park City; the Meade Peak Phosphatic Shale Tongue of the Phosphoria Formation is 171 feet thick, but it is cut by numerous faults.

  16. Permian depositional age of metaturbidites of the Duque de York Complex, southern Chile: U-Pb SHRIMP data and palynology

    International Nuclear Information System (INIS)

    The Duque de York Complex (DYC) is part of the low grade metamorphic accretionary complexes of the pre-Andean Patagonian 'basement'. It is a sedimentary succession exposed along the western margin of southernmost South America. New U-Pb zircon ages and palynological data restrict the maximum depositional age of the DYC to the limit between the early Permian (Kungurian) and the middle Permian (Roadian). The palynological association recorded in the DYC, characterized mainly by Gymnospermopsida pollen, indicates a humid environment of forest with an under-growth of ferns. Regional paleogeographic correlations point out that an interpretation of DYC as an autochthonous terrane cannot be discarded, contrasting with previous hypotheses which suggest an allochthonous character for this complex

  17. An Exceptionally Preserved Transitional Lungfish from the Lower Permian of Nebraska, USA, and the Origin of Modern Lungfishes

    OpenAIRE

    Pardo, Jason D.; Huttenlocker, Adam K.; Small, Bryan J.

    2014-01-01

    Complete, exceptionally-preserved skulls of the Permian lungfish Persephonichthys chthonica gen. et sp. nov. are described. Persephonichthys chthonica is unique among post-Devonian lungfishes in preserving portions of the neurocranium, permitting description of the braincase of a stem-ceratodontiform for the first time. The completeness of P. chthonica permits robust phylogenetic analysis of the relationships of the extant lungfish lineage within the Devonian lungfish diversification for the ...

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

    OpenAIRE

    Marie-Beatrice FOREL

    2012-01-01

    26 samples were processed for a taxonomic study of ostracods from the Upper Permian (Changhsingian) - Lower Triassic (Griesbachian) interval of the Dajiang section, Guizhou Province, South China. 112 species belonging to 27 genera are recognized. Five new species are described: Acratia candyae sp. nov, Bairdia adelineae sp. nov., Bairdia? huberti sp. nov., Bairdia jeromei sp. nov., Orthobairdia jeanlouisi sp. nov. The unexpected survival faunas associated with microbial formations in the aft...

  19. Reserves in western basins

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, R.H.; Cotton, B.W. [Scotia Group, Dallas, TX (United States)

    1995-04-01

    The objective of this project is to investigate the reserves potential of tight gas reservoirs in three Rocky Mountain basins: the Greater Green River (GGRB), Uinta and Piceance basins. The basins contain vast gas resources that have been estimated in the thousands of Tcf hosted in low permeability clastic reservoirs. This study documents the productive characteristics of these tight reservoirs, requantifies gas in place resources, and characterizes the reserves potential of each basin. The purpose of this work is to promote understanding of the resource and to encourage its exploitation by private industry. At this point in time, the GGRB work has been completed and a final report published. Work is well underway in the Uinta and Piceance basins which are being handled concurrently, with reports on these basins being scheduled for the middle of this year. Since the GGRB portion of the project has been completed, this presentation win focus upon that basin. A key conclusion of this study was the subdivision of the resource, based upon economic and technological considerations, into groupings that have distinct properties with regard to potential for future producibility, economics and risk profile.

  20. Massive volcanism at the Permian-Triassic boundary and its impact on the isotopic composition of the ocean and atmosphere

    DEFF Research Database (Denmark)

    Korte, Christoph; Pande, P.

    2010-01-01

    Bulk carbonate and conodonts from three Permian-Triassic (P-T) boundary sections at Guryul Ravine (Kashmir), Abadeh (central Iran) and Pufels/Bula/Bulla (Italy) were investigated for d13C and d18O. Carbon isotope data highlight environmental changes across the P-T boundary and show the following features: (1) a gradual decrease of 4‰ to more than 7‰ starting in the Late Permian (Changhsingian) C. bachmanni Zone, with two superimposed transient positive excursions in the C. meishanensis-H. praeparvus and the M. ultima-S. ? mostleri Zones; (2) two d13C minima, the first at the P-T boundary and a higher, occasionally double-minimum in the lower I. isarcica Zone. It is unlikely that the short-lived phenomena, such as a breakdown in biological productivity due to catastrophic mass extinction, a sudden release of oceanic methane hydrates or meteorite impact(s), could have been the main control on the latest Permian carbon isotope curve because of its prolonged (0.5 Ma) duration, gradual decrease and the existenceof a >1‰ positive shift at the main extinction horizon. The P-T boundary d13C trend matches in time and magnitude the eruption of the Siberian Traps and other contemporaneous volcanism, suggesting that volcanogenic effects, such as outgassed CO2 from volcanism and, even more, thermal metamorphism of organic-rich sediments, as the likely cause of the negative trend.

  1. Mineralogical and Geochemical Characteristics of Late Permian Coals from the Mahe Mine, Zhaotong Coalfield, Northeastern Yunnan, China

    Directory of Open Access Journals (Sweden)

    Xibo Wang

    2015-07-01

    Full Text Available This paper reports the mineralogical and geochemical compositions of the Late Permian C2, C5a, C5b, C6a, and C6b semianthracite coals from the Mahe mine, northeastern Yunnan, China. Minerals in the coals are mainly made up of quartz, chamosite, kaolinite, mixed-layer illite/smectite (I/S, pyrite, and calcite; followed by anatase, dolomite, siderite, illite and marcasite. Similar to the Late Permian coals from eastern Yunnan, the authigenic quartz and chamosite were precipitated from the weathering solution of Emeishan basalt, while kaolinite and mixed-layer I/S occurring as lenses or thin beds were related to the weathering residual detrital of Emeishan basalt. However, the euhedral quartz and apatite particles in the Mahe coals were attributed to silicic-rock detrital input. It further indicates that there has been silicic igneous eruption in the northeastern Yunnan. Due to the silicic rock detrital input, the Eu/Eu* value of the Mahe coals is lower than that of the Late Permian coals from eastern Yunnan, where the detrital particles were mainly derived from the basalt. The high contents of Sc, V, Cr, Co, Ni, Cu, Ga, and Sn in the Mahe coals were mainly derived from the Kangdian Upland.

  2. Australian-derived detrital zircons in the Permian-Triassic Gympie terrane (eastern Australia): Evidence for an autochthonous origin

    Science.gov (United States)

    Li, Pengfei; Rosenbaum, Gideon; Yang, Jin-Hui; Hoy, Derek

    2015-05-01

    The Tasmanides in eastern Australia record accretionary processes along the eastern Gondwana margin during the Phanerozoic. The Gympie terrane is the easternmost segment of the Tasmanides, but whether its origin was autochthonous or allochthonous is a matter of debate. We present U-Pb ages of detrital zircons from Permian and Triassic sedimentary rocks of the Gympie terrane with the aim of tracing the source of the sediments and constraining their tectonic relationships with the Tasmanides. Our results show that the Permian stratigraphic units from the Gympie terrane mainly contain Carboniferous and Permian detrital zircons with dominant age peaks at ~263 Ma, ~300 Ma, ~310 Ma, and ~330 Ma. The provenance ages of the Triassic sedimentary units are similar (~256 Ma, ~295 Ma, and ~328 Ma) with an additional younger age peak of ~240 Ma. This pattern of provenance ages from the Gympie terrane is correlative to episodes of magmatism in the adjacent component of the Tasmanides (New England Orogen), indicating that the detrital zircons were dominantly derived from the Australian continent. Given the widespread input of detrital zircons from the Tasmanides, we think that the sedimentary sequence of the Gympie terrane was deposited along the margin of the eastern Australian continent, possibly in association with a Permo-Triassic continental arc system. Our results do not show evidence for an exotic origin of the Gympie terrane, indicating that similarly to the vast majority of the Tasmanides, the Gympie terrane was genetically linked to the Australian continent.

  3. An Introduction and Virtual Field Trip to the Permian Reef Complex, Guadalupe and Delaware Mountains, New Mexico-West Texas

    Science.gov (United States)

    Dr. Peter Scholle, a professor of geology at New Mexico Tech, oversees this site showcasing the geology of the Permian reefs of West Texas and southeastern New Mexico. The Salado Formation, part of this sequence, has been in the spotlight lately because it contains the newly discovered, 250 million-year-old, salt-dwelling bacteria (see this week's Scout Report's In the News). The classic sedimentary sections of the Guadalupe and Delaware mountains have been well studied because of their magnificent exposures of Permian aged carbonate platform and slope deposits. Each year, geology students flock to the region to learn about sequence stratigraphy, sedimentology, and tectonic history, among other things. At this information-rich, well-illustrated site, everyone gets a chance to see and learn about these rocks. Sections of the virtual guidebook feature text with links to the bibliography, and color diagrams and photographs. The site is divided into the following sections: General Settings, Previous Studies, Structural History, Stratigraphic Setting and Nomenclature, Depositional Patterns, Diagenetic Patterns, Recent Models, Oil and Gas Production, and Field Trip and Safety Notes. Especially useful to those planning a field trip are road logs and field stop descriptions of road cuts between El Paso and Carlsbad, McKittrick Canyon, Walnut Canyon, and Dark Canyon-Sitting Bull Falls-Rocky Arroyo. Take a moment to discover the beauty and amazing geology of these classic Permian Reefs.

  4. Geology of the Williston basin, North Dakota, Montana, and South Dakota, with reference to subsurface disposal of radioactive wastes

    Science.gov (United States)

    Sandberg, C.A.

    1962-01-01

    The southern Williston basin, which underlies about 110,000 square miles #n North Dakota, South Dakota, and eastern Montana, is part of a large structural and sedimentary basin. Its surface is a flat to gently rolling plain, standing about 1,500 to 3,500 feet above sea level and locally studded by a few high buttes. The sedimentary sequence that fills the basin has a maximum thickness of about 16,700 feet and rests on Precambrian metamorphic rocks at depths of 500 to 13,900 feet below sea level. It contains rocks of every geologic system, from Cambrian to Quaternary. Rocks of Middle Cambrian through Middle Ordovician age are largely shale and sandstone, as much as 1,200 feet thick; rocks of Late Ordovician through Pennsylvanian age are largely limestone and dolomite, as much as 7,500 feet thick; and rocks of Permian through Tertiary age are predominantly shale and siltstone, as much as 8,000 feet thick. Pleistocene glacial drift mantles the northern and eastern parts of the area. Rocks of the Williston basin are gently folded and regional dips are 1? or less from the margins to the basin center. Dips on the flanks of the major anticlinal folds, the Nesson and cedar Creek anticlines and the Poplar and Bowdoin domes, generally are about 1? to 3? except on the steep west limb of the Cedar Creek anticline. The basin was shaped by Laramide orogeny during latest Cretaceous and early Tertiary time. Most of the present structural features, however, were initiated during the Precambrian and reactivated by several subsequent orogenies, of which the latest was the Laramide. The most important mineral resource of the area is oil, which is produced predominantly from the Paleozoic carbonate sequence and largely on three of the major anticlinal folds, and lignite, which is present near the surface in Paleocene rocks. The subsurface disposal of radioactive wastes at some places in the Williston basin appears to be geographically and geologically feasible. Many sites, at which large quantities of wastes might be injected with minimal danger of contamination of fresh-water aquifers and-oil-producing strata, are available.. The strata and types of reservoirs that deserve primary consideration for waste disposal are the Winnipeg Formation of Middle Ordovician age as a deep salaquifer, the Permian to Jurassic salt beds as moderately deep-units in which solution cavities might be created for storage, the thick Upper Cretaceous shale beds as shallow hydraulically fractured shale reservoirs, and the Newcastle Sandstone of Early Cretaceous age as a shallow shale-enclosed sandstone reservoir.

  5. Evaluating the temporal link between Siberian Traps magmatism and the end-Permian mass extinction (Invited)

    Science.gov (United States)

    Burgess, S. D.; Bowring, S. A.

    2013-12-01

    Interest in Large Igneous Provinces as agents for massive climatic and biological change is steadily increasing, though the temporal constraints on both are seldom precise enough to allow detailed testing of a causal relationship. The end-Permian mass extinction is one of the most biologically important and intensely studied events in Earth history and has been linked to many possible trigger mechanisms, from voluminous volcanism to bolide impact. Proposed kill mechanisms range from acidic and/or anoxic oceans to a cocktail of toxic gases, although the link between trigger and kill mechanisms is unconstrained due to the lack of a high-precision timeline. Critical to assessing the plausibility of different trigger and kill mechanisms is an accurate age model for the biotic crisis and the perturbations to the global carbon cycle and ocean chemistry. Recent work using the EARTHTIME U/Pb tracer solution has refined the timing of the onset and duration of the marine mass extinction event and the earliest Triassic recovery at the GSSP for the Permian-Triassic boundary in Meishan, China. This work constrains the mass extinction duration to less than 100 kyr and provides an accurate and precise time point for the onset of extinction, against which the timing of potential trigger mechanisms may be compared. For more than two decades, eruption and emplacement of the Siberian traps has been implicated as a potential trigger of the end-Permian extinction. In this scenario, magmatism drives the biotic crisis through mobilization of volatiles from the sedimentary rock with which intruding and erupting magmas interact. Massive volatile release is believed to trigger major changes in atmospheric chemistry and temperature, both of which have been proposed as kill mechanisms. Current temporal constrains on the timing and duration of the Siberian magmatism are an order of magnitude less precise than those for the mass extinction event and associated environmental perturbations, limiting detailed testing of a causal relationship. We present new high-precision U/Pb geochronology on zircon crystals isolated from a suite of shallowly intruded dolerites in the Noril'sk region and two welded tuffs in the Maymecha river-valley. These two sections are the most extensively studied in the magmatic province and although there are thick exposures of lava and volcaniclastic rock elsewhere, the Noril'sk and Maymecha-Kotuy sections are thought to be representative of the entire extrusive stratigraphy. Our dates suggest that intrusive and extrusive magmatism began within analytical uncertainty of the onset of mass extinction, permitting a causal connection with age precision at the ~ × 0.06 Ma level. The new dates also allow projection of the extinction interval and associated chemostratigraphy onto the Siberian trap stratigraphy, which suggests that ~300m of volcanicalstic rocks and ~1800m of lavas in the Maymecha-Kotuy section were erupted just prior to the onset of mass extinction. Comparison of a detailed eruption history to biological and chemical records over the extinction and recovery intervals allows for better evaluation of plausible kill mechanisms.

  6. Origins of microspherules from the Permian-Triassic boundary event layers in South China

    Science.gov (United States)

    Zhang, Hua; Shen, Shu-zhong; Cao, Chang-qun; Zheng, Quan-feng

    2014-09-01

    Volcanism and impact scenarios are two of the most plausible ways of interpreting the causes of the largest biological mass extinction at the end-Permian. Microspherules have previously been widely reported from tens of different Permian-Triassic boundary (PTB) sections in South China and some other regions. These microspherules have been interpreted as either the product of volcanic eruptions or an impact event. In order to test these scenarios, we collected 60 samples from 12 intensively-studied PTB sections in South China. In addition, four soil samples close to these PTB layers were also collected for comparison. Our investigation indicates that abundant microspherules with mosaic or dot shape crystals on rounded surface are present in the surface samples in the PTB layers at Meishan, Meili, and Shatian sections and most soil background samples in South China. Those microspherules consist of four different types based on their main chemical composition, surface features, and internal structure including iron, magnetite-silicate, glassy, pyrite microspherules and framboids. In contrast, microspherules have not been found in a few sections in remote areas such as the Selong Xishan section in Tibet and the Dalongkou section in Xinjiang, Northwest China, in the deeply-excavated samples at the Shangsi section and the hard tuff layers around the PTB at the Xiaochehe Section in Guiyang. Microspherules decrease in abundance with depth in PTB clay beds. All these microspherules except the pyrite microspherules and framboids are found in both the PTB layers and the nearby soil background samples. The iron microspherules are pure iron oxides such as magnetite, hematite or maghemite and contain low concentrations of nickel and chromium, and lack an Ni-Fe core and general extraterrestrial mineral wüstite. All these external and chemical characteristics suggest that most of iron microspherules previously reported from PTB sections in South China are modern industrial fly ashes. A low ratio of Fe3 +/FeTotal in crystals of magnetite-silicate microspherules and high ZnO contents can identify them as industrial contaminants. The pyrite microspherules and framboidal pyrite found from bed 24e and bed 26 at the Meishan sections are of depositional or/and diagenetic origins, and only the rounded quartz and the fragments containing extremely high SiO2 and TiO2 are possibly of volcanic origin.

  7. Concentration and distribution of elements in Late Permian coals from western Guizhou Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Shifeng; Ren, Deyi; Tang, Yuegang; Yue, Mei; Hao, Liming [China University of Mining and Technology, D11, Xueyuan Road, Haidian District, Beijing 100083 (China)

    2005-01-18

    With the aim of better understanding geochemistry of coal, 71 Late Permian whole-seam coal channel samples from western Guizhou Province, Southwest China were studied and 57 elements in them were determined. The contents of Al, Ca, Co, Cr, Cu, Fe, Ga, Hf, K, Li, Mn, Mo, Nb, Ni, Sn, Ta, Ti, Th, U, V, Zr, and REEs in the Late Permian coals from western Guizhou Province are higher than the arithmetic means for the corresponding elements in the US coals, whereas As, Ba, Br, F, Hg, P, Se, and Tl are lower. Compared to common Chinese coals, the contents of Co, Cr, Cu, Ga, Hf, Li, Mn, Mo, Ni, Sc, Sn, Ti, U, V, Zn, and Zr in western Guizhou coals are higher, and As, F, Hg, Rb, Sb, Tl, and W are lower. Five groups of elements may be classified according to their mode of occurrence in coal: The first two, Group A, Tm-Yb-Lu-Y-Er-Ho-Dy-Tb-Ce-La-Nd-Pr-Gd-Sm, and Group B, As-Sr-K-Rb-Ba-F-Ash-Si-Sn-Ga-Hf-Al-Ta-Zr-Be-Th-Na, have high positive correlation coefficients with ash yield and they show mainly inorganic affinity. Some elements from Group B, such as Ba, Be, Ga, Hf, and Th, are also characterized by significant aluminosilicate affinity. In addition, arsenic also exhibits high sulfide affinity (r{sub S-Fe}>0.5). The elements, which have negative or lower positive correlation coefficients with ash yield (with exceptions of Bi, Cs, Nb, Mn, Se, and Ti), are grouped in other four associations: Group C, Cr-V-Mo-U-Cd-Tl; Group D, Hg-Li-Sc-Ti-Eu-Nb-Cs-W; Group E, Bi-Sb; and Group F, Co-Ni-Cu-Pb-Zn-Mg-Se-Ca-Mn-S-Fe. The correlation coefficients of some elements, including Co, Cr, Cu, Fe, Hg, Li, Mo, Ni, P, S, Sc, U, V, and Zn, with ash yield are below the statistically significant value. Only Cr and Cu are negatively correlated to ash yield (-0.07 and -0.01, respectively), showing intermediate (organic and inorganic) affinity. Manganese and Fe are characterized by carbonate affinity probably due to high content of epigenetic veined ankerite in some coals. Phosphorus has low correlation coefficients with any other elements and is not included in these six associations. There are five possible genetic types of enrichment of elements in coal from western Guizhou Province: source rock, volcanic ash, low-temperature hydrothermal fluid, groundwater, and magmatic hydrothermal inputs.

  8. Rare-earth elements in the Permian Phosphoria Formation: Paleo proxies of ocean geochemistry

    Science.gov (United States)

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

    2007-01-01

    The geochemistry of deposition of the Meade Peak Member of the Phosphoria Formation (MPM) in southeast Idaho, USA, a world-class sedimentary phosphate deposit of Permian age that extends over 300,000 km2, is ascertained from its rare earth element (REE) composition. Ratios of REE:Al2O3 suggest two sources-seawater and terrigenous debris. The seawater-derived marine fraction identifies bottom water in the Phosphoria Sea as O2-depleted, denitrifying (suboxic) most of the time, and seldom sulfate-reducing (anoxic). This interpretation is supported by earlier research that showed progressively greater ratios in the marine sediment fraction of Cr:Ni>V:Ni???Mo:Ni, relative to their ratios in seawater; for which marine Cr, V, and Mo can have a dominantly O2-depleted bottom-water source and Ni a photic-zone, largely algal, source. The water chemistry was maintained by a balance between bacterial oxidation of organic matter settling through the water column, determined largely by primary productivity in the photic zone, and the flux of oxidants into the bottom water via advection of seawater from the open ocean. Samples strongly enriched in carbonate fluorapatite, the dominant REE host mineral, have variable Er/Sm, Tm/Sm, and Yb/Sm ratios. Their distribution may represent greater advection of seawater between the Phosphoria Sea and open ocean during deposition of two ore zones than a center waste and greater upwelling of nutrient-enriched water into the photic zone. However, the mean rate of deposition of marine Ni, a trace nutrient of algae, and PO43-, a limiting nutrient, indicate that primary productivity was probably high throughout the depositional history. An alternative interpretation of the variable enrichments of Er, Tm, and Yb, relative to Sm, is that they may reflect temporally variable carbonate alkalinity of open-ocean seawater in Permian time. A more strongly negative Ce anomaly for all phosphatic units than the Ce anomaly of modern pelletal phosphate is further indicative of an elevated O2 concentration in the Permo-Carboniferous open ocean, as proposed by others, in contrast to the depletion of O2 in the bottom water of the Phosphoria Sea itself. The oceanographic conditions under which the deposit accumulated were likely similar to conditions under which many sedimentary phosphate deposits have accumulated and to conditions under which many black shales that are commonly phosphate poor have accumulated. A shortcoming of several earlier studies of these deposits has resulted from a failure to examine the marine fraction of elements separate from the terrigenous fraction. ?? 2007 Elsevier Ltd. All rights reserved.

  9. Tharsis Basin Aquifer System

    Science.gov (United States)

    University of Arizona

    This is a QuickTime movie animating an enormous ancient drainage basin and aquifer system in the Tharsis region of Mars. The movie shows the geological stages of the aquifer system, as reported in a University of Arizona study.

  10. Aquifer - Basin and range

    Science.gov (United States)

    Aquifer basics outlining the makeup of the basin and range aquifers. Description and maps of unconsolidated sand and gravel aquifers. This site consists of information for the Southwestern portion of the United States, consisted of Arizona, California, Nevada, and Utah.

  11. Unraveling the hydrocarbon charge potential of the Nordkapp Basin, Barents Sea: An integrated approach to reduce exploration risk in complex salt basins

    Science.gov (United States)

    Schenk, Oliver; Shtukert, Olga; Bishop, Andrew; Kornpihl, Kristijan; Milne, Graham

    2014-05-01

    The Nordkapp Basin, Barents Sea, is an intra-continental syn-rift basin containing many complex salt structures. The salt is late-Carboniferous to Early Permian in age, with regional extension in the Triassic initiating the salt movement resulting in formation of sub- and mini-basins with significant subsidence (especially in the northeastern part of the basin). Subsequent tectonic phases allowed growth and distortion of salt diapirs that were later affected by uplift and erosion during Tertiary resulting in the formation of salt-related traps in Triassic and Lower Jurassic strata. During Plio-Pleistocene, glacial erosion removed additional Mesozoic and Cenozoic strata. This basin is regarded as a frontier salt province. A small hydrocarbon discovery (Pandora well) in the southwestern part of the basin points to the presence several functioning petroleum systems. The primary play type is related to salt traps below overhangs. Such structures are however, very difficult to image with conventional seismic techniques due to i) generation of multiples from sea floor and top of shallow salt bodies and ii) seismic shadow zones within the salt (possibly resulting from shale and carbonate stringers) which cause severe diffractions so that prospective areas adjacent to the salt remain elusive. Arctic exploration is expensive and the ability to focus on the highest potential targets is essential. A unique solution to this challenging subsurface Arctic environment was developed by integrating petroleum system modeling with full azimuth broadband seismic acquisition and processing. This integrated approach allows intelligent location of seismic surveys over structures which have the maximum chance of success of hydrocarbon charge. Petroleum system modeling was conducted for four seismic sections. Salt was reconstructed according to the diapiric evolution presented in Nilsen et al. (1995) and Koyi et al. (1995). Episodes of major erosion were assigned to Tertiary (tectonic) and Pleistocene (glacial). The models have been thermally calibrated. Consideration of Pleistocene glacial/interglacial cycles was required for thermal calibration as well as to better understand and predict the hydrocarbon phase behavior. References: Koyi, H., Talbot, C.J., Tørudbakken, B.O., 1993, Salt diapirs of the southwest Nordkapp Basin: analogue modelling, Tectonophysics, Volume 228, Issues 3-4, Pages 167-187. Nilsen, K.T., Vendeville, B.C., Johansen, J.-T., 1995, Influence of regional tectonics on halokinesis in the Nordkapp Basin, Barents Sea. In: Jackson, M.P.A., Roberts, D.G., Snelson, S. (eds), Salt tectonics, a global perspective, AAPG Memoir 65, 413-436.

  12. K Basins Hazard Analysis

    International Nuclear Information System (INIS)

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062/Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  13. K Basin Hazard Analysis

    International Nuclear Information System (INIS)

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report

  14. K Basins Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    WEBB, R.H.

    1999-12-29

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062, Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  15. The Cretaceous Gyeongsang Basin

    Energy Technology Data Exchange (ETDEWEB)

    Son, Jin-Dam; Kwak, Young-Hoon; Bong, Pil-Yoon [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    Since 1992 sedimentary basin analysis to assess petroleum potential of the Cretaceous and Tertiary strata in the Korean onshore and continental shelf have been carried out. The Cretaceous non-marine strata mainly occupy the Gyeongsang Basin in southeastern part of the Korean Peninsula and small basins such as Haenam and Gyeokpo depressions in western coastal areas. The Tertiary strata are mostly distributed in Domi, Cheju, Socotra subbasins, and Okinawa Trough in the South Continental Shelf, and Kunsan and Heuksan basins in the West. The basin evolution and petroleum potential for each basins are characterized as follow. The Cretaceous Gyeongsang sediments were deposited in three subbasins including Milyang, Euisung and Yongyang subbasins. Based on the volcaniclastic sediment distribution, the Gyeongsang Supergroup can be subdivided into Sindong, Hayang and Yucheon Groups. The Sindong Group was deposited in alluvial fan, flood plain and lacustrine margin environments: the Hayang Group was formed in flood plain, alluvial fan, braided stream and shallow lacustrine environments. The black shales in Nakdong and Jinju formations are interpreted to contain abundant organic matter during the deposition, thermal maturity reaching up to the zone of dry gas formation. Because porosity and permeability are too low, the sandstones can act as a tight gas reservoir rather than conventional oil and gas reservoir. (author). 6 tabs., 9 figs.

  16. Los bivalvos carboníferos y pérmicos de Patagonia (Chubut, Argentina): Parte IV: familias Aviculopectinidae, Deltopectinidae y Schizodidae / Carboniferous and Permian bivalves from Patagonia (Chubut, Argentina): Part VI: families Aviculopectinidae, Deltopectinidae and Schizodidae

    Scientific Electronic Library Online (English)

    María Alejandra, Pagani.

    2006-06-01

    Full Text Available En este trabajo se realizó un exhaustivo análisis sistemático de la fauna de bivalvos del Paleozoico Superior, provenientes de diferentes niveles fosilíferos de la cuenca Tepuel-Genoa (provincia del Chubut, Argentina). En esta cuarta parte se detallan los resultados obtenidos en relación a los repre [...] sentantes de las familias Aviculopectinidae, Deltopectinidae y Schizodidae. La abundancia de ejemplares y su buena preservación permitieron describir e ilustrar nueve especies. Entre ellas se reconocen tres especies nuevas: Limipecten herrerai nov. sp., Streblopteria lagunensis n. sp. y Streblopteria minuta n. sp.; y dos nuevos registros: Aviculopecten sp. y Aviculopecten? sp. Con relación a las especies ya conocidas para la cuenca, debido al hallazgo de nuevo material se han enmendado la diagnosis y ampliado la descripción y distribución geográfica de Orbiculopecten parma González y Schizodus paucus González. Estas formas han sido minuciosamente comparadas con formas de otras comarcas. Se discute, además, otro registro de Schizodus sp. Abstract in english A thorough systematic analysis is performed on the bivalve fauna of the Upper Paleozoic of the Tepuel-Genoa Basin (Chubut Province Argentina), as a contribution to the knowledge of early Permian faunas of Argentina. This fourth part comprises the families Aviculopectinidae, Deltopectinidae and Schiz [...] odidae, of which abundant well preserved specimens allowed the recognition of three new species, Limipecten herrerai nov. sp., Streblopteria lagunensis n. sp. and Streblopteria minuta n. sp. Two new records of Aviculopecten sp. and Aviculopecten? sp. are included too. On the basis of new material from the Tepuel-Genoa Basin, the diagnoses of Orbiculopecten parma González and Schizodus paucus González are emended. In addition, the descriptions of these and other previously known species are supplemented by new information and their geographical ranges are expanded. Detailed comparisons of all species with taxa from other regions are also provided. A new record of Schizodus sp. is discussed too.

  17. Two episodes of 13C-depletion in organic carbon in the latest Permian: Evidence from the terrestrial sequences in northern Xinjiang, China

    Science.gov (United States)

    Cao, Changqun; Wang, Wei; Liu, Lujun; Shen, Shuzhong; Summons, Roger E.

    2008-06-01

    New analyses reveal two intervals of distinctly lower ?13C values in the terrestrial organic matter of Permian-Triassic sequences in northern Xinjiang, China. The younger negative ?13C org spike can be correlated to the conspicuous and sharp ?13C drops both in carbonate carbon and organic carbon near the Permian-Triassic event boundary (PTEB) in the marine section at Meishan. The geochemical correlation criteria are accompanied by a magnetic susceptibility pulse and higher abundances of distinctive, chain-like organic fossil remains of Reduviasporonites. The older negative ?13C org spike originates within a latest Permian regression. Significant changes in organic geochemical proxies are recorded in the equivalent interval of the marine section at Meishan. These include relatively higher concentrations of total organic carbon, isorenieratane, C 14-C 30 aryl isoprenoids and lower ratios of pristane/phytane that, together, indicate the onset of anoxic, euxinic and restricted environments within the photic zone. The massive and widespread oxidation of buried organic matter that induced these euxinic conditions in the ocean would also result in increased concentrations of 13C-depleted atmospheric CO 2. The latest Permian environmental stress marked by the older negative ?13C org episode can be correlated with the distinct changeover of ostracod assemblages and the occurrences of morphological abnormalities of pollen grains. These observations imply that biogeochemical disturbance was manifested on the land at the end of the Permian and that terrestrial organisms responded to it before the main extinction of the marine fauna.

  18. Deep suture zone in the North Barents Basin

    Science.gov (United States)

    Butsenko, Viktor; Kireev, Artem; Piskarev, Alexey; Savin, Vasily; Smirnov, Oleg

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low magnetization. Calculated basement magnetization is 1.9 A/m to the West from an anomaly zone that is a characteristic for many igneous and metamorphic rocks of the diorite composition. Magnetization of the basement formations sharply increases to 3.6 A/m to the East. Similar values of magnetization are characterized basalts and dolerites, and also many metamorphic rocks of the basic and ultrabasic composition. Thus, the simulated magnetic field anomaly not only corresponds to limits of the heterochronous sedimentary basins, but also shows the border between two heterogeneous basement blocks. "Bright spot" anomalies are marked out on seismic sections. Bright spots are mainly located near the zone of negative magnetic anomaly along the East part of the North Barents Basin. The AVO analysis of the anomalies of the seismic recording has allowed to allocate possible hydrocarbon reservoirs and to subdivide them into the gas-saturated and oil-gas-saturated.

  19. The genesis and isotopic composition of carbonates associated with some Permian Australian coals

    International Nuclear Information System (INIS)

    Siderite and calcite are the two forms of carbonate commonly associated with Permian Australian coals. The former occurs as disseminated spherulites and is a product of the early post-depositional environment. Isotopic measurements show that the CO2 fixed as siderite did not result from the direct oxidation of photosynthetically derived materials, but rather from the anaerobic fermentation of these. The higher concentrations of calcite are generally found towards the roofs of coal seams and are characterized by isotopic enrichments to delta13C values of +25% PDB. Isotopic exchange between CO2 and CH4 within the coal seam is postulated as the mechanism which leads to the formation of isotopically heavy CO2. At sites along the seam margins where the CO2 escapes, interaction with circulating metal ions or preexisting calcite results in the deposition of ''heavy'' calcite. With increasing alteration of coal by thermal metamorphism, the 13C content of calcites and finally siderites decreases so that it more nearly approaches that of the associated coal. (Auth.)

  20. Revisiting platinum group elements of Late Permian coals from western Guizhou Province, SW China

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Liang [State Key Lab of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China); Gao, Jianfeng [Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China)

    2008-08-05

    Twenty five coal samples from the Late Permian coal-bearing strata in Weining, Nayong, and Zhijin, western Guizhou Province, SW, China, were analyzed for platinum group elements (PGEs). The coal ashes were digested by the Carius tube technique and accurately measured by isotope dilution-inductively coupled plasma mass spectrometry (ID-ICP-MS) for all PGEs. The results are much lower than the previous reported values. Our study suggested that the previously reported PGE values are incorrect and may due to the polyatomic interferences in ICP-MS measurements. In our study, samples from the Weining coalfield have the lowest PGE contents (from 0.019 Ir to 0.42 ng/g Pd), which represent the PGE background value in coal in western Guizhou province. Some of the coals have Pt and Pd contents about 20-times higher than the background value, indicating PGEs are concentrated. We also reported new and reliable PGE data and background value of coal in western Guizhou province, SW, China, and suggested to rework the PGE background values of Chinese coals. (author)

  1. Terrestrial events across the Permian Triassic boundary along the Yunnan Guizhou border, SW China

    Science.gov (United States)

    Jianxin, Yu; Yuanqiao, Peng; Suxin, Zhang; Fengqing, Yang; Quanming, Zhao; Qisheng, Huang

    2007-01-01

    The border area between western Guizhou and eastern Yunnan Provinces in SW China is an ideal place to undertake research considering the terrestrial-ecological system evolution across the Permian-Triassic boundary (PTB). The study of plant and palynomorph fossils, clay minerals, inorganic geochemistry and sedimentary facies in this area enable us to interpret the events occurring at that time. The extinction pattern of the flora interpreted from megafloral and palynomorph data is demonstrated by a sudden decline of species numbers at the PTB after a long-term of gradual changes, followed by a delayed extinction in the basal Triassic. The two boundary claybeds (Beds 66 and 68 in the Chahe Section, beds 47 and 49 in the Zhejue Section) are considered to be volcanogenic. The inorganic geochemical anomalies occurred between Beds 63 and 69, Chahe Section and Beds 45 and 50, Zhejue Section. Sedimentary facies changed from channels of braided rivers, into flood plains of braided rivers, then to shallow lakes, reflecting a gradual transgression by lakes across the area. Our conclusions are that the mass extinction across the PTB in western Guizhou and eastern Yunnan was probably caused by the Siberian basaltic eruption episode and the siliceous volcanism in South China. These lithospheric events represented by volcanisms heralded a series of climatic and environmental events, giving rise to a catastrophe for the biosphere.

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

    Directory of Open Access Journals (Sweden)

    Marie-Béatrice Forel

    2012-09-01

    Full Text Available Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO2, raising concern about marine diversity, food security and ecosystem services. Proxy evidence for acidification during past crises may help predict future change, but three issues limit confidence of comparisons between modern and ancient ocean acidification, illustrated from the end-Permian extinction, 252 million years ago: (1 problems with evidence for ocean acidification preserved in sedimentary rocks, where proposed marine dissolution surfaces may be subaerial. Sedimentary evidence that the extinction was partly due to ocean acidification is therefore inconclusive; (2 Fossils of marine animals potentially affected by ocean acidification are imperfect records of past conditions; selective extinction of hypercalcifying organisms is uncertain evidence for acidification; (3 The current high rates of acidification may not reflect past rates, which cannot be measured directly, and whose temporal resolution decreases in older rocks. Thus large increases in CO2 in the past may have occurred over a long enough time to have allowed assimilation into the oceans, and acidification may not have stressed ocean biota to the present extent. Although we acknowledge the very likely occurrence of past ocean acidification, obtaining support presents a continuing challenge for the Earth science community.

  3. The thermal history of the Bowen Basin: a comparison of apatite fission track analysis and vitrinite reflectance

    International Nuclear Information System (INIS)

    Vitrinite reflectance and apatite fission-track analysis (AFTA) are two techiques widely used to assess paleotemperatures of the order of 20-120 deg.C. in sedimentary basins. Whereas vitrinite reflectance is essentially a qualitative technique that gives an integrated measure of the entire thermal history, AFTA can reveal information on the variation of paleotemperatures through time because fission-tracks in apatite are continually produced throughout geological time. An apatite fission track study of the Upper Permian units of the Bowen Basin has offered the opportunity to compare the two paleotemperature indicators and place constraints on the timing of maximum paleotemperatures. The regional pattern of apatite fission-track ages closely coincides with the vitrinite reflectance indicating that maximum paleotemperatures have varied across the Basin with the central region of the Bowen Basin experiencing highest paleotemperatures. The reduction in apatite reflectance fission-track age with increasing reflectance represents the progressive annealing at temperatures around 60-120 deg. C. of those fission-tracks formed prior to the time of maximum temperatures. In those samples giving the youngest apatite fission-track ages all tacks were totally annealed at this time, and the fission-track age in these samples, in the range 90-120 Myr, indicate the time of cooling from the thermal maximum in the Early Cretaceous. 1 ref

  4. Transpression, transtension and reactivation during basin evolution: a case study from northern Scotland and Orkney

    Science.gov (United States)

    Dichiarante, Anna Maria; Holdsworth, Robert; McCaffrey, Ken; Dempsey, Edward; Selby, Dave; De Paola, Nicola; Conway, Andy; Wilson, Woody; Ogilvie, Steven

    2014-05-01

    The onshore Devonian sedimentary rocks of the Orcadian basin host significant amounts of fracturing, faulting and some localized folding. Most published accounts have assumed Devonian ages for the supposedly extensional faulting in the Orcadian Basin, with some limited inversion and reactivation proposed during the Carboniferous. More recently, however, regional studies, palaeomagnetic dating of fracture fills and structural studies in the adjacent basement rocks suggest that significant amounts of faulting may be related to the development of the contiguous offshore West Orkney Basin (WOB) during the Mesozoic. New field and microstructural analyses of the structures found within the Devonian cover sequences in Scotland and Orkney reveal 3 main groups of structures based on orientation, kinematics and infill. All are transtensional or transpressional on local to regional scales mainly due to reactivation of pre-existing structures: Group 1 faults trend ENE-WSW, N-S and NW-SE and display predominantly sinistral strike-slip to dip-slip extensional movements. They form the dominant structures in the eastern part of Caithness, and to a lesser extent Orkney. Gouges/breccias associated with these faults display little or no mineralization or veining. Group 2 structures are closely associated systems of metre- to kilometre-scale N-S trending folds and thrusts related to a highly heterogenous regional inversion event recognized locally throughout the field area, but especially on Orkney. Once again, fault rocks associated with these structures display little or no mineralization or veining. Group 3 structures are dextral oblique NE-SW trending faults and sinistral E-W trending faults with widespread syn-deformational carbonate mineralisation (± pyrite and bitumen) both along faults and in associated mineral veins. In a few localities (e.g. Dunnet Head, Scarfskerry, E. Scapa Fault) strike-slip inversion events have occurred at this time leading to localized transpression or transtensional folding during reactivation of pre-existing Devonian faults. Crucially, these later folds are synchronous with carbonate and associated mineralisation events. Preliminary Re-Os dating of syn-deformational pyrite in 2 faults in the Caithness Area gives model ages of 268.4 ± 4.9 & 266.4 ± 5.2 Ma (Permian). We propose that the deformation episodes are related to: i. Devonian sinistral transtension (ENE-WSW extension) related to the Great Glen Fault Zone (GGFZ) in part controlling the formation of the Orcadian basin and proto-WOB (= Group 1); ii. Late Carboniferous - Early Permian inversion (local E-W shortening) related to dextral reactivation of the GGF (= Group 2 structures); iii. Permo-Triassic rifting (NW-SE extension) which formed both new faults and locally reactivated earlier structures (= Group 3).

  5. Evolution and petrogenesis of Gondwanan volcanism from ashes within the Ecca and Beaufort Groups: Karoo Basin, South Africa

    Science.gov (United States)

    Mckay, M. P.; Weislogel, A. L.; Rawcliffe, H.; Brunt, R.; Hodgson, D. M.; Flint, S.

    2011-12-01

    Within the Permian-Jurassic Karoo basin of South Africa, the turbidite fan to shelf deposits of the Ecca Group and overlying fluvial complex of the Beaufort Group preserve numerous ash beds that were deposited along the southern margin of Gondwana. Currently the location and origin of the volcanic center that generated these ash beds remains uncertain, as is the relationship between the tectonic setting of the magmatic system and the subsidence mechanism of the Karoo basin itself. U-Pb geochronological studies using SHRIMP-RG at the Stanford-USGS Microanalysis Center have focused on zircon separated from 25 ash beds in order to provide chronostratigraphic markers to constrain the timing of deposition within the Karoo basin. For 13 of these samples, rare earth element (REE) concentrations of zircon spot analyses were also determined. Because trivalent REEs are fractionated as a function of magma genesis and magmatic evolutionary processes, REE element compositions of zircons within ashes can be used to assess the petrogenesis and chemistry of the magmatic source and to determine the tectonic setting. One current hypothesis posits that the Permian Karoo ash beds were sourced from arc-related magmatism along the southern margin of Gondwana, although little evidence of this arc remains. U/Yb vs. Hf and U/Yb vs. Y cross-plots indicate Karoo zircon lie primarily within the field associated with continental magmatic settings with some overlap into the oceanic magmatic field. This compares with results from analysis of 20 whole rock samples by XRF and XRD that suggest ash samples are bentonites with a composition that is generally dacitic. However, whole rock data compositional variability could either be due to element mobilization during transport and burial, or mixing of bentonitic ash with hemipelagic terrigenous detritus; detrital mixing is also indicated in some geochronology samples by a prevalence of reworked pre-Permian zircon. Together these results are consistent with ash generation by a magmatic system likely associated with mixing of mantle-derived magma with partial continental crustal melts, and could be associated with a mantle plume/rift from a within-plate magmatic setting or a continental magmatic arc associated with subducting oceanic crust. Modeling to test the compatibility of zircon geochemistry with magma genesis in these settings is underway.

  6. Putting the "Basin" Back in Southeastern Arizona's Basin and Range

    Science.gov (United States)

    Jungers, M. C.; Heimsath, A. M.

    2011-12-01

    The pace and pattern of southeastern Arizona's transition from a series of internally drained sedimentary basins to the modern, integrated Gila River system are poorly constrained. Steep normal faulting associated with the Basin and Range disturbance ~12-5 Ma created structural basins that filled with sediment throughout the Late Miocene and Early Pliocene. Early rates of basin deposition were rapid due to high upland erosion rates driven by continuous base level fall within the extensional basins. Subsequently, as tectonic forcing waned, sedimentation rates slowed until a combination of basin spillover events and headward capture integrated individual basins into a through-flowing drainage network. Newly integrated streams with suddenly lower base levels rapidly incised, perching the uppermost surfaces of basin fill and eroding large volumes of sediment throughout the Quaternary. Relatively thin (10-100 m), coarse-grained alluvial fan remnants on erosional surfaces of basin fill or bedrock pediments are commonly the highest elevation, undeformed deposits in basins of southeastern Arizona. Although they often overlie basin-bounding faults, it is rare that they are cut by these faults. This suggests quiescent tectonics both during and after the deposition of these alluvial fans. Early work on two complexes of these alluvial fan remnants (Menges and McFadden, 1981) used the degree of soil development of relict soils on the fan surfaces to estimate an age of at least 1 Ma for these basin high stands. Further, the degree of soil oxidation and the depth of weathering suggest a wetter climate when these relict soils were forming. This age estimate and inference of a different climate begin to inform a model for climatically driven deposition of these coarse-grained fan deposits at the Pliocene-Pleistocene shift, but absolute dates are lacking. Here we report spatial and temporal patterns of regional drainage integration focusing on the timing of abandonment for uppermost surfaces of basin fill (10Be derived surface exposure dates are pending) and we present basin surface reconstructions. Previous research has suggested that uppermost basin fill surfaces are roughly correlative. We use our data to 1) test the hypothesis of broadly synchronous timing for a regional shift from internal drainage to external drainage for southeastern Arizona's basins, and 2) infer incision rates through the Quaternary. We have identified basin high stand remnants throughout several basins of interest in southeastern Arizona, and use spline interpolations to reconstruct basin fill surfaces. By subtracting the modern day topography from reconstructed basin surfaces, we quantify first order estimates of incision rates through basin fill since drainage integration. Our surface exposure dates will allow accurate quantification of incision rates for each basin, and resolve regional patterns of drainage integration.

  7. The thermal evolution and timing of hydrocarbon generation in the Maritimes Basin of eastern Canada: evidence from apatite fission track data

    International Nuclear Information System (INIS)

    Sandstone drill core and/or cuttings from six wells in the Gulf of St. Lawrence and cabot Strait have been analyzed using the apatite fission track (AFT) method. Measured AFT ages for the late Paleozoic sandstones range from 26 ±7 to 184 ±28 Ma (2-? errors). The AFT data indicate that most Maritimes Basin strata were heated to temperatures in excess of 100-150oC very soon after their deposition. The strata also attained significant vitrinite reflectance (R0) levels (i.e., reaching the oil window) early in the burial history. These findings imply the generation of hydrocarbons and coalbed methane in the early basin history (pre-250 Ma). In the Maritimes Basin AFT and R0 data provide complementary information about the integrated thermal history, including maximum burial temperatures (from R0 data), and information on the subsequent cooling history from AFT analysis. The present study also supports the proposal made previously by others that substantial erosion of the Eastern Canadian margin (up to 4 km) has occurred since the Permian and extends the AFT evidence for this erosional event to include the southern Gulf of St. Lawrence area. Thermal models of the AFT data demonstrate that they are consistent with a history of exhumation of basin strata since late Permian time. The model-predicted AFT age and track length histograms closely correspond to the measured AFT parameters. AFT analysis also indicates present-day geothelysis also indicates present-day geothermal gradients of less than 40oC/km. (author). 42 refs.,3 tabs., 7 figs

  8. K Basin Hazard Analysis

    International Nuclear Information System (INIS)

    The K East (KE)/K West (KW) Basins in the 100 K Area of the Hanford Site have been used for storage of irradiated N Reactor and single-pass reactor fuel. Remaining spent fuel is continuing to be stored underwater in racks and canisters in the basins while fuel retrieval activities proceed to remove the fuel from the basins. The Spent Nuclear Fuel (SNF) Project is adding equipment to the facility in preparation for removing the fuel and sludge from the basins In preparing this hazard analysis, a variety of hazard analysis techniques were used by the K Basins hazard analysis team, including hazard and operability studies, preliminary hazard analyses, and ''what if'' analyses (WHC-SD-SNF-PHA-001, HNF-2032, HNF-2456, and HNF-SD-SNF-SAD-002). This document summarizes the hazard analyses performed as part of the safety evaluations for the various modification projects and combines them with the original hazard analyses to create a living hazard analysis document. As additional operational activities and modifications are developed, this document will be updated as needed to ensure it covers all the hazards at the K Basins in a summary form and to ensure the subsequent safety analysis is bounding. This hazard analysis also identifies the preliminary set of design features and controls that the facility could rely on to prevent or reduce the frequency or mitigate consequences of identified accident conditions based on their importance and significance to safety. The operation and significance to safety. The operational controls and institutional programs relied on for prevention or mitigation of an uncontrolled release are identified as potential technical safety requirements. All operational activities and energy sources at the K Basins are evaluated in this hazard analysis. Using a systematic approach, this document identifies hazards created by abnormal operating conditions and external events (e.g., earthquakes) that have the potential for causing undesirable consequences to the facility worker, the onsite individual, or the public. This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and complies with the requirements of 10 CFR 830

  9. Fluid and gas migration in the North German Basin: fluid inclusion and stable isotope constraints

    Science.gov (United States)

    Lüders, Volker; Reutel, Christian; Hoth, Peer; Banks, David A.; Mingram, Birgit; Pettke, Thomas

    2005-12-01

    Fluid inclusions have been studied in minerals infilling fissures (quartz, calcite, fluorite, anhydrite) hosted by Carboniferous and Permian strata from wells in the central and eastern part of the North German Basin in order to decipher the fluid and gas migration related to basin tectonics. The microthermometric data and the results of laser Raman spectroscopy reveal compelling evidence for multiple events of fluid migration. The fluid systems evolved from a H2O-NaCl±KCl type during early stage of basin subsidence to a H2O-NaCl-CaCl2 type during further burial. Locally, fluid inclusions are enriched in K, Cs, Li, B, Rb and other cations indicating intensive fluid-rock interaction of the saline brines with Lower Permian volcanic rocks or sediments. Fluid migration through Carboniferous sediments was often accompanied by the migration of gases. Aqueous fluid inclusions in quartz from fissures in Carboniferous sedimentary rocks are commonly associated with co-genetically trapped CH4-CO2 inclusions. P-T conditions estimated, via isochore construction, yield pressure conditions between 620 and 1,650 bar and temperatures between 170 and 300°C during fluid entrapment. The migration of CH4-rich gases within the Carboniferous rocks can be related to the main stage of basin subsidence and stages of basin uplift. A different situation is recorded in fluid inclusions in fissure minerals hosted by Permian sandstones and carbonates: aqueous fluid inclusions in calcite, quartz, fluorite and anhydrite are always H2O-NaCl-CaCl2-rich and show homogenization temperatures between 120 and 180°C. Co-genetically trapped gas inclusions are generally less frequent. When present, they show variable N2-CH4 compositions but contain no CO2. P-T reconstructions indicate low-pressure conditions during fluid entrapment, always below 500 bar. The entrapment of N2-CH4 inclusions seems to be related to phases of tectonic uplift during the Upper Cretaceous. A potential source for nitrogen in the inclusions and reservoirs is Corg-rich Carboniferous shales with high nitrogen content. Intensive interaction of brines with Carboniferous or even older shales is proposed from fluid inclusion data (enrichment in Li, Ba, Pb, Zn, Mg) and sulfur isotopic compositions of abundant anhydrite from fissures. The mainly light ?34S values of the fissure anhydrites suggest that sulfate is either derived through oxidation and re-deposition of biogenic sulfur or through mixing of SO{4/2-}-rich formation waters with variable amounts of dissolved biogenic sulfide. An igneous source for nitrogen seems to be unlikely since these rocks have low total nitrogen content and, furthermore, even extremely altered volcanic rocks from the study area do not show a decrease in total nitrogen content.

  10. WiBasin: basin management through an integrated platform

    OpenAIRE

    Llort Pavon, Xavier; Sánchez-Diezma Guijarro, Rafael; de Sancho, David; Rodríguez, Álvaro; Berenguer Ferrer, Marc; Sempere Torres, Daniel

    2014-01-01

    In this work we present WiBasin, a cloud platform for basin and dam management. It includes different sources of precipitation (both observed and forecasted), integration over the catchment domain (to provide an aggregated value of potential rainfall accumulated over the basin) , and a complete dissemination environment (web-viewer, capability of issuing hazard warnings with configurable thresholds, SMS, mails, etc.)

  11. The Chelyabinsk coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Ryleev, V.S.; Kornilkov, V.N. (Proizvodstvennoe Obedinenie Chelyabinskugol' (Russian Federation))

    1993-05-01

    Discusses coal mining in the Chelyabinsk coal basin in the Urals. The following aspects are evaluated: position of the Chelyabinsk basin, its coal reserves, properties of brown coal (calorific value of run-of-mine coal ranges from 4,000 to 4,500 kcal, carbon content from 72% to 74%), coal seam thickness, depth, coal seams prone to spontaneous combustion, underground coal mining (10 mines constructed from 1933 to 1969), schemes for coal deposit development and mining (schemes without leaving coal support pillars), coal losses, thin seam mining, problems associated with strata control, prevention of endogenous fires, equipment for underground coal mining. Selected aspects of surface coal mining in 3 surface mines of the Chelyabinsk basin are also discusssed: coal output, mining conditions, economic aspects of surface coal mining.

  12. Depositional setting and paleoenvironment of an alatoconchid-bearing Middle Permian carbonate ramp sequence in the Indochina Terrane

    Science.gov (United States)

    Udchachon, Mongkol; Burrett, Clive; Thassanapak, Hathaithip; Chonglakmani, Chongpan; Campbell, Hamish; Feng, Qinglai

    2014-06-01

    A Middle Permian carbonate sequence at Khao Somphot in the south of the Khao Khwang Platform has been measured and analyzed. This sequence is characterized by prolific fossil content and large, bizarre alatoconchid bivalves. Nine major microfacies types are differentiated and consist of: algal-foram facies, fusuline facies, alatoconchid facies, lime mudstone/wackestone facies, laminated bindstone facies, fine-grained cortoid grainstone facies, coral biostrome facies, crinoidal packstone facies and carbonate breccia/conglomerate facies. Laminated bindstone, lime mudstone with fenestral fabric and algal foram facies represent loferites deposited in a restricted intertidal zone of an inner ramp. Fusuline grainstone and cortoid grainstone facies indicate sand shoals of an inner ramp. The fusuline wackestone/packstone and alatoconchid facies were deposited in a subtidal, below fair-weather wave base environment in the mid-ramp. The crinoidal facies, which overlies collapse breccia, possibly accumulated during transgression in the deeper part of the mid-ramp. Storm deposits are prevalent throughout as thin accumulates and as alatoconchid floatstone/rudstone (coquinite) layers and are common in mid-ramp setting. The Khao Khwang Platform probably evolved from a rimmed platform in the Early Permian to a ramp in the Middle Permian. The general trend of ? 13C composition from both brachiopod shell and rock matrix from the lower part of the study section (Wordian) is significantly high. Moreover, the ? 13C signature from this interval is up to 8 VPDB‰, which suggests high productivity on the tropical Tethyan shelf of the Indochina Terrane. An abrupt negative shift in ? 13C in the late Wordian and late Capitanian indicating significant changes in paleoenvironment, productivity and the carbon cycle is probably contemporaneous with the Kamura event recorded from sediments of the mid-Panthalassa Ocean in Japan and elsewhere related to global cooling and a sea-level lowstand.

  13. Post-Middle Oligocene origin of paleomagnetic rotations in Upper Permian to Lower Jurassic rocks from northern and southern Peru

    Science.gov (United States)

    Gilder, Stuart; Rousse, Sonia; Farber, Daniel; McNulty, Brendan; Sempere, Thierry; Torres, Victor; Palacios, Oscar

    2003-05-01

    We report paleomagnetic data from 28 sites of Upper Permian to Lower Jurassic strata from northern and southern Peru. In northern Peru (6°S), a stable magnetic component from six Permo-Triassic sites passes fold and reversal tests. The overall mean pole agrees well with Late Permian to Triassic poles from cratonal South America, suggesting this part of Peru has experienced neither significant rotation nor latitudinal transport since the Permo-Triassic. In southern Peru (13 to 16°S), thermal demagnetization isolates stable magnetic components in 16 of 22 Upper Permian to Lower Jurassic sites collected along the transition between the Altiplano and the Eastern Cordillera. These 16 sites are rotated 14 to 147° counterclockwise and pass an inclinations-only fold test. Within the same structural zone, three other Permo-Triassic sites as well as 10 Paleocene sites also show important counterclockwise rotations [Roperch and Carlier, J. Geophys. Res. 97 (1992) 17233-17249; Butler et al., Geology 23 (1995) 799-802]. The large magnitude and exclusively counterclockwise sense of rotation suggest that the tectonic regime included an important sinistral shear component. No correlation exists between rotation amount and rock age, suggesting the rotations are post-Paleocene in age. Because the rotations occur along the fringe of the Eastern Cordillera, they were likely produced during its structural formation, hence from the Late Oligocene to Present. Sinistral shear acting in the northern part of the Bolivian Orocline appears much more pronounced than that north of the Abancay Deflection, which likely arises from differences in convergence obliquity.

  14. The fabrics and origins of peloids immediately after the end-Permian extinction, Guizhou Province, South China

    Science.gov (United States)

    Adachi, Natsuko; Ezaki, Yoichi; Liu, Jianbo

    2004-02-01

    Peloids are major contributors to modern and ancient limestones, although their origins are not yet comprehensively understood. Upper Permian to Lower Triassic carbonate successions are well preserved at the Bangeng area in Guizhou Province, South China, where microbialites (thrombolites), coccoidal microbes and peloids are preserved together. These peloids are classified into three types (Peloid-A, B, C) that typically occur together along with coccoidal microbes and restricted bioclasts in a variety of microenvironments. Peloid-A is most common and exhibits close relationship with coccoidal microbes. Peloid-A1 has spherical grain and a size range typical for coccoidal microbes (10-60 ?m in diameter), whereas Peloid-A2 is marked by larger spherical and subrounded grains with diffuse margins, ranging from 70 to 200 ?m in diameter. Peloid-A1 is in part produced by the complete micritic filling in coccoidal microbes by their metabolic activities, whereas Peloid-A2 is related to the calcification of a colony of coccoidal microbes by their metabolic activities, or simply to the aggregation of individual peloids and coccoidal microbes. Peloids of this type might also originate from other carbonate precipitation processes. Peloid-B is derived merely by micrite filling in ostracodes and gastropods skeletons, whereas Peloid-C is of micritized-bioclast origin. These peloidal origins do not explain those of all environments and ages. Peloids are polygenetic in origin, irrespective of the presence of coccoidal microbes. However, it is emphasized that the peloids formed after the end-Permian extinction are dominated by microbes related ones. Those kinds of peloids might have occurred repeatedly and predominantly, especially in severely deteriorated environments such as those after the end-Permian mass extinction.

  15. Characteristics of claystones across the terrestrial Permian-Triassic boundary: Evidence from the Chahe section, western Guizhou, South China

    Science.gov (United States)

    Zhang, Suxin; Peng, Yuanqiao; Yu, Jianxin; Lei, Xinrong; Gao, Yongqun

    2006-08-01

    X-ray diffraction (XRD), scanning electronic microscopy (SEM) and X-ray fluorescence spectroscopy (XFS) studies were undertaken for claystones and/or mudstones from the Chahe section—a terrestrial Permian-Triassic boundary (TPTB) section. Our results indicate that the compositions of claystones in the Permian-Triassic boundary (PTB) interval (Beds 66f-68) outlined by biostratigraphy are different from claystones and/or mudstones found either below or above the interval of the same section. The clay minerals in the claystones of the PTB interval are mainly composed of illite-montmorillonite interlayers, with a few montmorillonites and chlorites. The other claystones and/or mudstones underlying and overlying the PTB consist of chlorites and/or kaolinites. Some authigenic clastic minerals, such as hexagonal dipyramid quartz and zircons, are only found in claystones in the PTB interval from the Chahe section and some marine PTB sections in western Guizhou and eastern Yunnan, southwestern China. In addition, some elements are present in abnormal concentrations in the claystones of the PTB interval as well. Most important is that we found no spherules in all the claystones studied, indicating no evidence of an extraterrestrial impact during the Permian-Triassic transition. The particular characteristics of the TPTB claystones at the Chahe section indicate their volcanic origin and thus provide a reliable auxiliary event marker for high-resolution demarcation of the TPTB in South China. They are also indicative in the marine PTB claystones in South China. Thus, the PTB claystones can be used as auxiliary markers for high-resolution correlation of the PTB from marine facies to land in South China when direct fossil evidence in the PTB sequence is lacking.

  16. Evidence of fossil and recent diffusive element migration in reduction haloes from Permian red-beds of Northern Switzerland

    International Nuclear Information System (INIS)

    Reduction haloes are small, diffusion controlled redox systems involving the mobility of many elements and are common occurrences in Permian red beds in N. Switzerland. They can be regarded as sensitive indicators of recent water/rock interactions concentration profiles of 238U and 232Th are plotted as a function of distance from the centre of the halo and isotope ratios for 234U/238U and 230Th/234Th are given. Migration mechanisms and accumulation rates of uranium and thorium may yield important parameters for safety assessment modelling for radioactive waste disposal. (UK)

  17. Permian 40Ar/39Ar ages for post-Variscan minor intrusions in the Iberian Range and Spanish Central System

    OpenAIRE

    Perini, Giulia

    2008-01-01

    40Ar/39Ar dating of biotite from a calc-alkaline gabbro stock NW of Loscos in the Iberian Range yielded a slightly disturbed gas release spectrum. It has an early Permian, 288.5 ± 1.4 Ma total gas age, interpreted as the minimum emplacement age. The 40Ar/39Ar apparent age of the gabbro agrees with the Autunian stratigraphic age of related volcanic rocks. 40Ar/39Ar step-heating dating of amphibole phenocrysts from an alkaline camptonite dyke ca. 4 km SE of El Hoyo de Pinares in the Sierra Gua...

  18. Study of microspherules in the Permian-Triassic boundary of Wanmo section, Guizhou province, China, by PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Chengzhi [Osaka City University, Osaka (Japan). Fac. of Science, Dept. of Physical Sciences

    1998-03-01

    Many microspherules were extracted from the shale of the Permian-Triassic boundary of Wanmo section in the Guizhou province of China. Their number abruptly increased at one place leading to an interesting pattern similar to previous studies. The chemical patterns of these microspherules determined by PIXE analysis were compared with previous results from magnetic components of shale and meteorites. In contention with previous studies illustrating the intrusion of microspherules into the Solar System, it is postulated that the Solar System encountered the giant molecular clouds and the microspherules of the present study came from there.

  19. Study of microspherules in the Permian-Triassic boundary of Wanmo section, Guizhou province, China, by PIXE analysis

    International Nuclear Information System (INIS)

    Many microspherules were extracted from the shale of the Permian-Triassic boundary of Wanmo section in the Guizhou province of China. Their number abruptly increased at one place leading to an interesting pattern similar to previous studies. The chemical patterns of these microspherules determined by PIXE analysis were compared with previous results from magnetic components of shale and meteorites. In contention with previous studies illustrating the intrusion of microspherules into the Solar System, it is postulated that the Solar System encountered the giant molecular clouds and the microspherules of the present study came from there

  20. Fluid migration in sedimentary basins - a case study from the Central European Basin

    Science.gov (United States)

    Duschl, Florian; van den Kerkhof, Alfons; Leiss, Bernd; Sosa, Graciela; Wiegand, Bettina; Vollbrecht, Axel; Sauter, Martin

    2014-05-01

    Core samples from the cap rock of an Upper Permian dolomitic limestone from the Zechstein formation (Stassfurt carbonate sequence, Ca2) in the Central European Basin were studied for a better understanding of the tectonic control on fluid migration during the burial and uplift of CO2-rich gas reservoirs. Petrographical investigations were carried out by means of optical transmission and cathodoluminescence microscopy. A heating-freezing stage was applied for fluid inclusion analysis; gas compositions were measured by Laser-Raman spectroscopy. The study focuses on the quantification of paleo pressures, temperatures and compositions of diagenetic fluids trapped as inclusions in dolomite, anhydrite, calcite, and fluorite, as well as in postdiagenetic fluorite in mineralized fractures. Limestone matrix mainly consists of early diagenetic, euhedral dolomite with few hydrocarbon-bearing inclusions. Offset veins originating from fine-grained inclusion-free anhydrite nodules consist of coarse-grained recrystallized anhydrite containing primary aqueous CaCl2-rich inclusions. Late calcite cement fills remnant pores between the dolomite rhombs and contains H2O-NaCl-CaCl2 fluid inclusions. Subsequently, the dolomitic limestones were affected by pressure solution due to burial, followed by basin inversion (uplift) starting in Upper Cretaceous. Pressure solution generated carbonate rich fluids, which resulted in dolomite and calcite veinlets. Simultaneously, a first clearly zoned and brown coloured generation of fluorite (I) accumulated in nodules together with sulfides and organic matter. This fluorite (I) contains mostly H2O-NaCl-CaCl2 fluid inclusions with relatively high salinity (17.8 wt% NaCl, 8.9 wt% CaCl2). Colourless fluorite (II) is the latest observable (post-) diagenetic mineral phase filling veinlets in dolomitic limestone that crosscut pressure solution features. Fluorite (II) replaces fluorite (I) within the nodules as well. Carbonic inclusions together with CH4 and N2 are only found in fluorite (II). These results reveal almost no change in the composition of aqueous fluids during basin burial and uplift (H2O-NaCl-CaCl2, with only small variations in concentration). From the presence of hydrocarbons in the recrystallized dolomite and the recrystallization temperatures of anhydrite (Th ca. 125°C), mean temperatures during early diagenesis can be estimated. The calcite cement indicates a slightly higher temperature (Th ca. 147°C), followed by the early fluorite (I) phase (Th 152°C). The fact that CO2 was trapped only in type (II) fluorite (Th ca. 156°C/185°C) ascertains a late episode of gas trapping during the migration of gas rich fluids along fractures. Besides, co-existing fluid inclusions (H2O/CO2) in fluorite (II) veinlets reveal exact P-T conditions during trapping of CO2 and therefore provide an important data set for calibrating numerical basin models.

  1. New palaeomagnetic results from the Oslo Graben, a Permian Superchron lava province

    Science.gov (United States)

    Haldan, M. M.; Meijers, M. J. M.; Langereis, C. G.; Larsen, B. T.; Heyer, H.

    2014-12-01

    We have performed an extended palaeomagnetic study of the Oslo Graben volcanics, compared to the study of half a century ago by van Everdingen, using modern techniques and a four times larger amount of sites, plus additional rock magnetic experiments. We conclude that the average direction (D = 204.0, I = -37.9, k = 46.9, ?95 = 2.0) and associated palaeomagnetic pole (? = 48.3, ? = 155.5, K = 52.2, A95 = 1.9) of the Krokskogen and Vestfold volcanics together are statistically identical to those of the earlier study. This gives confidence in the fact that older palaeomagnetic studies can be reliable and robust, even though methods have improved. Our larger number of samples, and better age constraints, enable us to separate the data into two major intervals: the younger, on average, Krokskogen area and the older Vestfold area. The results show firstly that palaeolatitudes are slightly higher than predicted by the latest apparent polar wander path (APWP) for Eurasia by Torsvik et al. These data support an early Permian Pangaea A configuration and do not necessitate a Pangaea B configuration. The larger data set also allows us to assess the distribution of the characteristic remanent magnetization directions of the Oslo Graben in terms of geomagnetic field behaviour, which were acquired during a long period of dominantly single polarity the Permo-Carboniferous Reversed Superchron (PCRS). The distributions show a significantly lower virtual geomagnetic pole (VGP) scatter at the observed (low) latitudes than expected from a compilation from lavas of the last 5 Myr. The data do however show excellent agreement with the scatter observed both during the Cretaceous Normal Superchron and the PCRS. A comparison of the directional distributions in terms of elongation is less discriminating, since the large errors in all cases allow a fit to the predicted elongation/inclination behaviour of the TK03.GAD model.

  2. Bone-conduction hearing and seismic sensitivity of the Late Permian anomodont Kawingasaurus fossilis.

    Science.gov (United States)

    Laaß, Michael

    2015-02-01

    An investigation of the internal cranial anatomy of the anomodont Kawingasaurus from the Upper Permian Usili Formation in Tanzania by means of neutron tomography revealed an unusual inner and middle ear anatomy such as extraordinarily inflated vestibules, lateroventrally orientated stapes with large footplates, and a small angle between the planes of the anterior and lateral semicircular canals. The vestibule has a volume, which is about 25 times larger than the human vestibule, although Kawingasaurus has only a skull length of approximately 40 mm. Vestibule inflation and enlarged stapes footplates are thought to be functionally correlated with bone-conduction hearing; both morphologies have been observed in fossorial vertebrates using seismic signals for communication. The firmly fused triangular head with spatulate snout was probably used for digging and preadapted to seismic signal detection. The quadrate-quadratojugal complex was able to transmit sound from the articular to the stapes by small vibrations of the quadrate process, which formed a ball and socket joint with the squamosal. Mechanical considerations suggest that the ventrolaterally orientated stapes of Kawingasaurus was mechanically better suited to transmit seismic sound from the ground to the fenestra vestibuli than a horizontal orientated stapes. The low sound pressure level transformer ratio of 2-3 in Kawingasaurus points to a seismic sensitivity of the middle ear and a vestigial or reduced sensitivity to airborne sound. Three hypothetical pathways of bone conduction in Kawingasaurus are discussed: 1) sound transmission via the spatulate snout and skull roof to the otic capsules, 2) relative movements resulting from the inertia of the mandible if sound is percepted with the skull, and 3) bone conduction from the substrate via mandible, jaw articulation, and stapes to the inner ear. PMID:25284624

  3. Depositional facies and environments in the Permian Umm Irna formation, Dead Sea area, Jordan

    Science.gov (United States)

    Makhlouf, I. M.; Turner, B. R.; Abed, A. M.

    1991-09-01

    The Permian Umm Irna Formation in central Jordan consists of a 60 m thick sequence of clastic sediments which can be divided into two fluvial sedimentary facies. The lowermost facies (1) is characterized by the presence of five sandstone-dominated fining-upward sequences, each sequence comprising an erosively based coarse- to fine-grained, trough cross-bedded sandstone, overlain and laterally intertonguing with maroon siltstone and silty-shale, containing locally abundant carbonaceous plant material. The overlying facies (2) also consists of up to five fining-upward sequences, each comprising an erosively based coarse-grained pebbly sandstone grading up through fine-grained sandstone and siltstone into silty-shale. The sandstones are tabular, and laterally persistent, internally complex units structured by erosively bounded trough cosets. The thickness and grain size of the sandstones and the proportion of siltstone and silty-shale is much greater than in facies (1); it also contains abundant ferruginous concretions (glaebules). Deposition occurred on an unconfined braidplain sloping northwestwards away from an elevated provenance (Arabo-Nubian Shield) in the south and east. The lowermost facies (1) is regarded as a distal environmental equivalent of the overlying facies (2). Deposition was largely controlled by period c shifts of the active channel tract, influenced by a gradual increase in the elevation of the source area, thereby promoting basinwide progradation and vertical stacking of the two major facies components. The ferruginous concretions (glaebules) in facies (2) are thought to have resulted from diagenetic processes in the vadose zone of a humid, possibly tropical climate, characterized by alternating wet and dry seasons and strong leaching. The fluvial depositional system drained basinwards into a shallow-water marine depository along the southern margin of the Tethys Ocean. The ocean may have exerted a maritime influence on the climate of the alluvial plain.

  4. The lunar Procellarum basin

    Science.gov (United States)

    Whitaker, E. A.

    It is still widely assumed that the Imbrium basin is the largest such structure on the lunar nearside, even though it has been pointed out that geochemical and other data from the Apollo missions strongly indicate that the Imbrium impact occurred eccentrically within the confines of a pre-existing, much larger (the 'Gargantuan') basin. There does, in fact, also exist supporting topographical evidence for the reality of this basin, although the centroid of high radioactivity lies a little west of the topographical center. This topographical evidence consists of incomplete arcs of three closely concentric circles marked by mare shorelines, major systems of mare ridges, and some minor scarps. The rings have surface diameters of 1700, 2400 and 3200 km, and are centered at about 23 deg N, 15 deg W, near the crater Timocharis. Any discussions of the distribution of surface minerals, the compositions, ages, histories and petrology of lunar rocks, etc. should recognize and include any possible effects resulting from the formation of this basin.

  5. South Bohemian basins.

    Czech Academy of Sciences Publication Activity Database

    Spudil, J.; Brož, B.; Dašková, Ji?ina; Holcová, K.; Kva?ek, Z.; Pešek, J.; Svobodová, Marcela; Sýkorová, Ivana; Teodoridis, V.

    Prague : Czech Geological Survey, 2014, s. 190-206 ISBN 978-80-7075-862-5 R&D Projects: GA ?R GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  6. Enigmatic remagnetizations in the Silurian and Lower Devonian formations of the Tassili N-Ajjer (Illizi basin, Algeria)

    Science.gov (United States)

    Lamali, Atmane; Merabet, Nacer; Henry, Bernard; Maouche, Said; Hamoudi, Mohamed; Ayache, Mohamed

    2014-05-01

    With the aim to improve the relatively poorly defined African apparent polar wander path (APWP) curve for the Lower Paleozoic times, a paleomagnetic study has been performed on Silurian and Lower Devonian formations of the Illizi Basin in Algeria. Our paleomagnetic results evidenced two distinct magnetization components "B1" and "B2". Though positive paleomagnetic tests (reversal and fold tests for "B1" and fold test for "B2"), the comparison with the present African APWP however clearly shows that both components "B1" and "B2" are remagnetizations of Cenozoic and Permian ages, respectively. The acquisition of the B1 remagnetization seems to be related to level variations of ground-fluids. The present work also highlights a Cenozoic age for the deformation at the origin of the local dip variations within this mainly monoclinal series. It also confirms the necessary care for using reversal test as a criterion to determine the primary or secondary character of a magnetization.

  7. Vein mineralizations - record of paleo-fluid systems in the Thuringian basin (Germany)

    Science.gov (United States)

    Lepetit, Petra; Viereck, Lothar; Abratis, Michael; Fritsch, Stefanie

    2014-05-01

    Vein-related mineralizations within the Mesozoic sediments of the Thuringian basin (Germany) are investigated in analytical detail (petrography, XRD, XRF, EPMA, LA-ICP-MS, and isotope studies: O, C, S, Sr) in order to characterize paleo-fluid systems that intruded the basin and circulated within it millions of years ago. Samples from 55 outcrops, 34 quarries and 21 drill cores comprise mainly carbonates (calcite, dolomite, siderite, ankerite), additional sulfates (gypsum, celestine, barite,), and rarely sulfides. The mineralizations are almost exclusively restricted to WNW-ESE trending fault systems. First ?13C and ?18O isotope analyses of calcite mineralizations reveal differences between veins within Triassic sediments (Lower Muschelkalk: ?13C: 1.8 to 2.9 o, mean 2.3 o, ?18O: -7.3 to -10.4 o, mean -8.2 o) and Jurassic sediments (?13C: -0.7 to -2.1 o, mean -1.4 o, ?18O: -9.3 to -10.6 o, mean -9.9 o), indicating intra-formational and extra-formational paleo-fluid transport. Also first ?34S and ?18O isotope analyses of gypsum mineralizations display differences between veins within Triassic and Permian sediments, respectively. These initial data are comparable with isotope analyses of vein-related host rocks and hydrochemical signatures of recent well waters in the Thuringian basin indicating intra-formational in addition to extra-formational paleo-fluid transport. Further isotope studies are in progress including high resolution in situ-Sr- isotope analysis. The present study is part of INFLUINS, a BMBF-funded project bundle, which is dedicated to the comprehensive description and understanding of the fluid systems within the Thuringian basin in time and space.

  8. Serenitatis multi-ringed basin

    International Nuclear Information System (INIS)

    New topographic data allow a reassessment of the ring structure of the Serenitatis basin and correlation with the younger Orientale basin. The northern Serenitatis basin is smaller and less well preserved than the southern Serenitatis basin. Three major rings of the main (southern) Serenitatis basin are mapped: ring 1, Linne ring, outlined by mare ridges, average diameter 420 km; ring 2, Haemus ring, outlined by basin-facing scarps and massifs with crenulated borders, 610 km; ring 3, Vitruvius ring, outlined by basin-facing linear scarps and massifs, 880 km. Ring 1 corresponds to the inner Rook Mountain ring of Orientale, ring 2 with the outer Rook ring, and ring 3 with the Cordillera Mountain ring. The ring identifications and assignments indicate that the Serenitatis basin is essentially the same size as the Orientale basin, rather than much larger, as previously proposed. The Apollo 17 site lies near the second ring, which is interpreted as the rim of the transient cavity. Apollo 15 lies at the junction of the Serenitatis and Imbrium third rings; Serenitatis ejecta should be present in significant amounts at the Apollo 15 site. The new reconstruction indicates that portions of the Serenitatis basin are better preserved than previously thought, consistent with recent stratigraphic and sample studies that suggest an age for Serenitatis which is older than, but close to, the time of formation of the Imbrium basin. (Auth.)

  9. AUthigenic feldspar as an indicator of paleo-rock/water interactions in Permian carbonates of the Northern Calcareous Alps, Austria

    Science.gov (United States)

    Spotl, C.; Kralik, M.; Kunk, M.J.

    1996-01-01

    Dolostones interbedded with Upper Permian evaporites at the base of the Northern Calcareous Alps contain abundant authigenic K-feldspar. Two petrographically, structurally, and isotopically distinct generations of K-feldspar can be distinguished: crystals composed of an inclusion-rich core and a clear rim, and optically unzoned, transparent crystals. Both feldspar types have essentially identical K-feldspar end-member compositions with ??? 99.5 mole % Or component. Low oxygen isotope ratios (+16.1??? to +18.1??? SMOW) suggest precipitation from 18O-enriched, saline fluids at temperatures in excess of ??? 140??C. 40Ar/39Ar plateau-age spectra of five samples range from 145 ?? 1 to 144 ?? 1 Ma (Early Berriasian) and suggest that both types of feldspar were formed within an interval that did not exceed ??? 2 m.y. Rb/Sr model ages range from 152 to 140 Ma, assuming that the burial diagenetic regime was buffered with respect to strontium by the associated marine Permian evaporites. Authigenic K-feldspar records two distinct events of hot brine flow, most likely triggered by tectonic movements (detachment) and by an increase in the subsurface temperature in response to thrust loading.

  10. Authigenic feldspar as an indicator of paleo-rock/water interactions in Permian carbonates of the Northern Calcareous Alps, Austria

    Energy Technology Data Exchange (ETDEWEB)

    Spoetl, C. [Univ. Innsbruck (Austria). Inst. fuer Geologie und Palaeontologie; Kralik, M. [Bundesforschungs-und Pruefzentrum Arsenal, Vienna (Austria). Geotechnisches Inst.; Kunk, M.J. [Geological Survey, Reston, VA (United States)

    1996-01-01

    Dolostones interbedded with Upper Permian evaporites at the base of the Northern Calcareous alps contain abundant authigenic K-feldspar. Two petrographically, structurally, and isotopically distinct generations of K-feldspar can be distinguished: crystals composed of an inclusion-rich core and a clear rim, and optically unzoned, transparent crystals. Both feldspar types have essentially identical K-feldspar end-member compositions with {ge} 99.5 mole % Or component. Low oxygen isotope ratios (+16.1{per_thousand} to + 18.1{per_thousand} SMOW) suggest precipitation from {sup 18}O-enriched, saline fluids at temperatures in excess of {approximately} 140 C. {sup 40}Ar/{sup 39}Ar plateau-age spectra of five samples range from 145 {+-} 1 to 144 {+-} 1 Ma (Early Berriasian) and suggest that both types of feldspar were formed within an interval that did not exceed {approximately} 2 m.y. Rb/Sr model ages range from 152 to 140 Ma, assuming that the burial diagenetic regime was buffered with respect to strontium by the associated marine Permian evaporites. Authigenic K-feldspar records two distinct events of hot brine flow, most likely triggered by tectonic movements (detachment) and by an increase in the subsurface temperature in response to thrust loading.

  11. Relationships between ocean anoxia, the biological pump, and marine animal life during the Permian-Triassic mass extinction (Invited)

    Science.gov (United States)

    Meyer, K. M.; Schaal, E. K.; Payne, J.

    2013-12-01

    Ocean anoxia/euxinia and carbon cycle instability have long been linked to the end-Permian mass extinction and the Early Triassic interval of delayed or interrupted biotic recovery. Many hypotheses to explain this extinction event invoke the release of greenhouse gases during the emplacement of the Siberian Traps, which likely triggered abrupt changes in marine biogeochemical cycling, atmospheric chemistry, and biodiversity. However, the precise ways in which volcanism and these perturbations are linked and how they governed the tempo and mode of biotic recovery remain poorly understood. Here we highlight new C, Ca, and Sr isotopic data that serve to link volcanic CO2 inputs to changes in marine biogeochemistry and environmental change. We then examine the relationship between ocean biogeochemistry, the biological pump, and marine animal ecosystems during the end-Permian mass extinction and Early Triassic recovery. Finally, we use numerical simulations to probe whether these relationships also explain broad Phanerozoic trends in ocean nutrient status, anoxia, and productivity of marine ecosystems.

  12. An Exceptionally Preserved Transitional Lungfish from the Lower Permian of Nebraska, USA, and the Origin of Modern Lungfishes

    Science.gov (United States)

    Pardo, Jason D.; Huttenlocker, Adam K.; Small, Bryan J.

    2014-01-01

    Complete, exceptionally-preserved skulls of the Permian lungfish Persephonichthys chthonica gen. et sp. nov. are described. Persephonichthys chthonica is unique among post-Devonian lungfishes in preserving portions of the neurocranium, permitting description of the braincase of a stem-ceratodontiform for the first time. The completeness of P. chthonica permits robust phylogenetic analysis of the relationships of the extant lungfish lineage within the Devonian lungfish diversification for the first time. New analyses of the relationships of this new species within two published matrices using both maximum parsimony and Bayesian inference robustly place P. chthonica and modern lungfishes within dipterid-grade dipnoans rather than within a clade containing Late Devonian ‘phaneropleurids’ and common Late Paleozoic lungfishes such as Sagenodus. Monophyly of post-Devonian lungfishes is not supported and the Carboniferous-Permian taxon Sagenodus is found to be incidental to the origins of modern lungfishes, suggesting widespread convergence in Late Paleozoic lungfishes. Morphology of the skull, hyoid arch, and pectoral girdle suggests a deviation in feeding mechanics from that of Devonian lungfishes towards the more dynamic gape cycle and more effective buccal pumping seen in modern lungfishes. Similar anatomy observed previously in ‘Rhinodipterus’ kimberyensis likely represents an intermediate state between the strict durophagy observed in most Devonian lungfishes and the more dynamic buccal pump seen in Persephonichthys and modern lungfishes, rather than adaptation to air-breathing exclusively. PMID:25265394

  13. Enrichment of arsenic, antimony, mercury, and thallium in a Late Permian anthracite from Xingren, Guizhou, Southwest China

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Shifeng; Sun, Yuzhuang [Key Laboratory of Resource Exploration Research of Hebei Province, Handan 056038 (China); Zeng, Rongshu [Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

    2006-03-03

    Mineralogy and geochemistry of nine Late Permian coal-seam channel samples (anthracite) from Xingren, Guizhou, Southwest China were examined. Results showed that As, Sb, Hg, and Tl are significantly enriched in a Late Permian anthracite (sample XR-M1) in the study area, and their contents are as high as 2226 {mu}g/g, 3860 {mu}g/g, 12.1 {mu}g/g, and 7.5 {mu}g/g, respectively. However, the contents of the four elements in other coal-seam channel samples from Xingren, even the two channel samples (samples XR-M2 and XR-M3) that are from the same bed as sample XR-M1, are close to the ordinary coal average, indicating that these four elements varied greatly in different coal beds and different locations of the same bed, and such coals highly enriched in these hazardous elements are very local and restricted. The main carrier of As, Sb, Hg, and Tl in sample XR-M1 is an epigenetic getchellite rather than syngenetic pyrite and clay minerals. Getchellite occurs only in the veined kaolinite of hydrothermal origin. The high As, Sb, Hg, and Tl in coal are derived from an arsenic- and antimony-rich hydrothermal fluid. (author)

  14. Early Permian supra-subduction assemblage of the South Island terrane, Percy Isles, New England Fold Belt, Queensland

    International Nuclear Information System (INIS)

    Ultramafic-intermediate rocks exposed on the South Island of the Percy Isles have been previously grouped into the ophiolitic Marlborough terrane of the northern New England Fold Belt. However, petrological, geochemical and geochronological data all suggest a different origin for the South Island rocks and a new terrane, the South Island terrane, is proposed. The South Island terrane rocks differ from ultramafic-mafic rocks of the Marlborough terrane not only in lithological association, but also in geochemical features and age. These data demonstrate that the South Island terrane is genetically unrelated to the Marlborough terrane but developed in a supra-subduction zone environment probably associated with an Early Permian oceanic arc. There is, however, a correlation between the South Island terrane rocks and intrusive units of the Marlborough ophiolite. This indicates that the two terranes were in relative proximity to one another during Early Permian times. A K/Ar age of 277 ± 7 Ma on a cumulative amphibole-rich diorite from the South Island terrane suggests possible affinities with the Gympie and Berserker terranes of the northern New England Fold Belt. Copyright (1999) Geological Society of Australia

  15. Mass movement processes at the Motozintla Basin, Chiapas, Southern Mexico

    Scientific Electronic Library Online (English)

    Juan Manuel, Sánchez-Núñez; José Luis, Macias; José Juan, Zamorano-Orozco; Ricardo, Saucedo; José Ramón, Torres; David, Novelo.

    2012-06-01

    Full Text Available Uno de los principales desafíos que presentan las zonas montañosas es la identificación y predicción de áreas susceptibles a procesos de remoción en masa (PRM). Éste es el caso de la cuenca de Motozintla, localizada en el sureste de México, sobre la traza del sistema de fallas Polochic-Motagua en el [...] estado de Chiapas. En la zona predominan rocas del Pérmico y Terciario, severamente afectadas por fallas, fracturas y un intenso intemperismo y erosión. Motozintla ha sido gravemente afectado por dos fenómenos hidrometeorológicos en 1998 y 2005. Para determinar las zonas peligrosas, propensas a sufrir procesos gravitacionales de remoción de masas en la cuenca, se realizó un mapeo geológico-estructural (1:30,000) mediante fotointerpretación y técnicas de SIG. El inventario obtenido mostró 88 procesos cartografiables de remoción en masa, representados por avalanchas, caídas de roca, deslizamientos y flujos de escombros. Los procesos más peligrosos para la ciudad de Motozintla son los flujos de escombros, ya que éstos la han impactado negativamente y ponen en riesgo a 23,755 habitantes. La zona noroeste de la cuenca es considerada como la más vulnerable a sufrir procesos de remoción en masa, debido a que afloran rocas sumamente alteradas del Macizo de Chiapas y la Formación Todos Santos. Abstract in english Prediction of prone areas for mass movement processes (MMP) is one of the major challenges in mountainous areas. This is the case of the Motozintla basin that is located along the Motagua-Polochic fault system in the Chiapas State southeastern Mexico. The area is dominated by Permian to Tertiary roc [...] ks extremely affected by faults, weathering and intense erosion. Motozintla has been seriously disrupted by two hydrometeorological phenomena in 1998 and 2005. In this paper, geological and structural mapping (1:30 000), photointerpretation and GIS techniques were applied to determine the hazard areas that may go off by mass movement processes driven by gravity in the basin. The inventory shows 88 mapable mass movement processes ocurred during the past 25 ky represented by debris avalanches, rock falls, slides and debris flows. Debris flows are the most dangerous phenomena that may directly impact the city of Motozintla posing at risk 23,755 people. Future mass movement processes may happen mainly in the NW part of the basin where highly altered rocks of the Chiapas massif and Todos Santos Formation are exposed.

  16. Spectroscopic analysis and X-ray diffraction of trunk fossils from the Parnaíba Basin, Northeast Brazil

    Science.gov (United States)

    Alencar, Wemerson J.; Santos, F. Eroni P.; Cisneros, Juan C.; da Silva, João H.; Freire, Paulo T. C.; Viana, Bartolomeu C.

    2015-01-01

    The Parnaiba Sedimentary Basin is of the Paleozoic age and is located in Northeast Brazil, covering the states of Piauí, Maranhão and Tocantins and a small part of Ceará and Pará. In this work we applied several chemical analytical techniques to characterize trunk fossils found in the Parnaíba Sedimentary Basin, collected from four different sites, and discuss their fossilization process. We performed a study of the trunk fossils through X-ray diffraction, energy dispersive spectroscopy, infrared and Raman spectroscopy. The analysis allow us to identify the different compositions which are present in the trunk fossils: kaolinite (Al2Si2O5(OH)4), hematite (Fe2O3) and quartz (SiO2). Based in these results we were able to identify that the main fossilization mechanism of the trunk fossil was silicification. Furthermore, through Raman spectroscopy, we have observed the presence of carbonaceous materials in the Permian fossils, as evidenced by the D and G Raman bands. The relative intensities and bandwidths of the D and G bands indicated that the carbon has a low crystallinity. Thus, most of trunk fossils analyzed were permineralized and not petrified, because there is the presence of carbon that characterizes the partial decomposition of the organic matter in some trunks.

  17. Carbon isotopic shift and its cause at the Wuchiapingian-Changhsingian boundary in the Upper Permian at the Zhaojiaba section, South China: Evidences from multiple geochemical proxies

    Science.gov (United States)

    Wei, Hengye; Yu, Hao; Wang, Jianguo; Qiu, Zhen; Xiang, Lei; Shi, Guo

    2015-06-01

    The Late Permian environmental change, connecting the Guadalupian-Lopingian (G-L) (Middle-Upper Permian) boundary mass extinction and the Permain-Triassic (P-Tr) boundary mass extinction, has attracted more and more attentions. A significant negative shift for carbon isotope had been found at the Wuchiapingian-Changhsingian (W-C) boundary in the Upper Permian recently. However, the cause(s) of this negative excursion is still unknown. To resolve this problem, we analyzed the bulk organic carbon isotope, total organic carbon (TOC) content, pyritic sulfur (Spy) content, major element concentrations, and molecular organic biomarkers in the Wujiaping and Dalong formations in the Upper Permian from the Zhaojiaba section in western Hubei province, South China. Our results show that (1) there was a significant negative excursion in organic carbon isotopes at the W-C boundary and again a negative excursion at the top of Changhsingian stage; (2) the significant negative excursion at the W-C boundary was probably a global signal and mainly caused by the low primary productivity; and (3) the negative carbon isotope excursion at the top of Changhsingian was probably caused by the Siberian Traps eruptions. A decline in oceanic primary productivity at the W-C boundary probably represents a disturbance of the marine food web, leading to a vulnerable ecosystem prior to the P-Tr boundary mass extinction.

  18. Geometrical model of the Baltic artesian basin

    Science.gov (United States)

    Sennikovs, J.; Virbulis, J.; Bethers, U.

    2012-04-01

    Baltic artesian basin (BAB) is a multi-layer sedimentary basin spanning around 480'000 km2. BAB is located in the territory of Latvia, Lithuania and Estonia, parts of Poland, Russia, Belarus and large area of the Baltic Sea, including island of Gotland. The thickness of sedimentary cover is about 5000 m in the south-western part. Crystalline bedding reaches the surface in the northern and north-western parts. The aim of the present work is development of the model of geometric structure and three dimensional finite element mesh for the hydrogeological model of the whole BAB. The information that is used to build the geometrical structure includes: (1) Stratigraphic information from boreholes in Latvia and Estonia (2) Maps of height isolines of geological layers for Latvia and Lithuania (3) Maps of sub-quaternary deposits in Latvia and Lithuania (4) Maps of fault lines on the crystalline basement surface in Latvia, Lithuania and Estonia (5) Buried valley data from Latvia and Estonia (6) Earth topography data (7) Baltic sea depth data (8) Data from published geological cross-sections, information from books and other sources. Unification of the heterogeneous information from different sources, which are employed for building of the geometrical structure of the model are performed. Special algorithms are developed for this purpose considering the priority, importance and plausibility of each of the data sources. Pre-processing of the borehole information to screen out the outlying borehole data has been performed. Model of geological structure contains 42 layers. It includes aquifers and aquitards from Cambrian up to the Quaternary deposits. Fault displacements are incorporated into the model taking into account data from the published structural maps. Four reconstructed regional erosion surfaces (upper Ordovician, Devonian, Permian and Quaternary) are included into the model Three dimensional mesh of the geological structure is constructed layer-wise. The triangular mesh in horizontal plane is constructed including characteristic lines such as rivers, borders of countries and areas of presence of geological layers. Mesh consists of triangular prisms, pyramids and tetrahedrons. The construction of the geometric mesh is implemented by specially developed script in Python. Such approach has several advantages: (1) flexibility in choosing ways to build the structure; (2) parallelization of workload in developing/updating of different structure elements; (3) documentation and maintenance of repeatable structure building path; (4) opportunity to rebuild the structure with slight or significant modifications at any time; (5) possibility to build, and maintain several structures of different complexity simultaneously. Acknowledgement The present work has been funded by the European Social Fund project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" (Project Nr. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060)

  19. Late Variscan tectonothermal history of the Holy Cross Mts. (central Poland) as revealed by integrated palaeomagnetic and 1-D basin modelling study

    Science.gov (United States)

    Grabowski, J.; Narkiewicz, M.; Szaniawski, R.; Resak, M.; Littke, R.

    2009-04-01

    Classical outcrops of the Holy Cross Mountains (HCM) in Poland are among a few areas in Central Europe exposing a complete succession of Phanerozoic strata. The long-studied Palaeozoic sections are of a key importance to understand a complex Phanerozoic development in the region bordering the East European Craton from the south-west. The Palaeozoic core of HCM consists of two tectonostratigraphic units: southern (Kielce) and northern (?ysogóry), separated by a Holy Cross Fault. Different organic maturity data (conodont CAI, vitrinite reflectance - VR, biomarkers) consistently indicate an important difference in thermal alteration pattern between the pre-Permian Palaeozoic and the Permian-Mesozoic cover in the Kielce region. In its northern part, adjoining the Holy Cross Fault, the Devonian carbonates are characterized by VR?0.7 % and CAI 1.5-3.5, while in the south they are less altered thermally, displaying VR?0.65 % and CAI 1.0-1.5. On the other hand, Permian-Mesozoic cover reveals a uniformly low degree of thermal alteration (VR close to 0.6 % and CAI 1). Palaeomagnetic studies and thermal modelling were performed in outcrops and borehole sections of the Middle - Upper Devonian carbonates, situated in the areas of contrasting thermal histories. Rocks with a higher degree of thermal alteration revealed presence of secondary, most-probably post-folding magnetization residing in magnetite (component A). The age of this remagnetization might be estimated as Early Permian (ca. 290 - 260 Ma). The remagnetization is absent in the less thermally altered areas, where a pre- or early synfolding magnetization was preserved (component B). As presence of the component A correlates with thermal indexes, it might be concluded that its acquisition was controlled mostly by post-orogenic uplift and cooling. Radiogenic 87Sr/86Sr isotope ratios in carbonates do not coincide with occurrence of component A which means that chemical remagnetization due to influence of deeper basinal and/or juvenile fluids is rather unlikely. The results of burial-thermal modelling of borehole sections are in a good agreement with palaeomagnetic data. The results from Janczyce I borehole, situated in the northern part of Kielce region, indicate a significant role of elevated Variscan (Early to Late Carboniferous) heat flow, followed by cooling from ca. 130 to 70 degrees Celsius between 330 and 260 Ma. This is consistent with a concept attributing the Early Permian remagnetization to post-Variscan (i.e. Late Carboniferous) uplift and related cooling. The secondary magnetization could have been facilitated by oxidation of pyrite during a circulation of meteoric fluids. The absence of elevated heat flow and ensuing cooling in the southern part of the HCM corresponds to a lack of the Early Permian remagnetization. Our study seems to demonstrate that, under special circumstances, the palaeomagnetic data may represent a useful complementary tool in deciphering tectonothermal dynamics of a sedimentary basin.

  20. Chemical signature of two Permian volcanic ash deposits within a bentonite bed from Melo, Uruguay

    Directory of Open Access Journals (Sweden)

    Liane M. Calarge

    2006-09-01

    Full Text Available A Permian bentonite deposit at Melo, Uruguay is composed of a calcite-cemented sandstone containing clay pseudomorphs of glass shards (0-0.50 m overlying a pink massive clay deposit (0.50-2.10m. The massive bed is composed of two layers containing quartz and smectite or pure smectite respectively. The smectite is remarkably homogeneous throughout the profile: it is a complex mixed layer composed of three layer types whose expandability with ethylene glycol (2EG 1EG or 0EG sheets in the interlayer zone which correspond to low-, medium- and high-charge layers respectively varies with the cation saturating the interlayer zone. The smectite homogeneity through the profile is the signature of an early alteration process in a lagoonal water which was over saturated with respect to calcite. Compaction during burial has made the bentonite bed a K-depleted closed system in which diagenetic illitization was inhibited. Variations in major, REE and minor element abundances throughout the massive clay deposit suggest that it originated from two successive ash falls. The incompatible element abundances are consistent with that of a volcanic glass fractionated from a rhyolite magma formed in a subduction/collision geological context.Um depósito Permiano de bentonita em Melo, Uruguai,é composto por um arenito com cimento calcítico contendo pseudomorfos de argila sobre detritos vítreos(0-0.50 m superpostos a um deposito maciço de argila rosado (0.50-2.10 m. A camada maciça é composta por dois níveis contendo quartzo e esmectita ou esmectita pura, respectivamente. A homogeneidade de esmectita ao longo do perfil é notável: trata-se de um interestratificado composto de três tipos de camadas, cuja expansibilidade com etileno-glicol (folhas 2EG, 1EG ou 0EG na zona interfoliar correspondentes a camadas com baixa, média e alta carga, respectivamente variam com o tipo de cátion que satura a zona interfoliar. A homogeneidade da esmectita ao longo do perfil é a assinatura de um processo de alteração precoce em uma água lagunar supersaturada em calcita. A compactação durante o soterramento tornou a camada de bentonita um sistema fechado empobrecido em K no qual a ilitização diagenética foi inibida. Variações nas abundâncias de elementos maiores, menores e ETR no depósito maciço de argila sugere que este foi originado a partir de duas quedas sucessivas de cinza. A abundância de elementos incompatíveis é consistente com a de um vidro vulcânico fracionado a partir de um magma riolitico formado em um ambiente geológico de subducção/colisão.

  1. End-Permian mass extinction caused by high volatile halogenated gases from giant salt lakes?

    Science.gov (United States)

    Lisitsyna, Lidia; Weissflog, Ludwig

    2010-05-01

    Climatic and paleotoxicological processes, which caused mass extinction (ME) approx. 250 Ma ago may also play a decisive role in the present day sixth large-scale ME of species, caused by mankind. The speed with which the currently ME is taking effect is higher by a factor of 1000 than that of 100 years ago (8th UN Conference on Biological Diversity in 2006, Djoghlaf, 2006). The worldwide increasing temperature and dryness incorporated in climate change are already leading to progressive desertification and to an increase in number and surface areas of hyper saline salt lakes, salt lagoons, saline marshlands and sabkhas. Furthermore the predicted sea level rise by approx. 1 m (even up to 6 m according to more recent assumptions) leads to an expansion or new formation of salt ecosystems caused by flooding of coastal areas and hinterland. Particularly in regions with current and/or future semiarid and arid climatic features this will lead, amongst others, to increased emissions of naturally formed phytotoxic VHCs. Additionally, wind and storms will transport large quantities of salt (dust) from surfaces of these parched hyper saline salt ecosystems for uptake in so far unsalinated soils. An example of this is currently apparent in Central Asia, where several hundred thousand metric tons of salt dust are picked up every year from the former sea floor of the drying-up Aral Sea, the Kara-Bogaz-Gol and saline marshlands of Caspian Sea and transported several thousand kilometers [Orlovsky and Orlovsky, 2001]. In combination with increasing temperatures, intensive radiation and increasing input of man-made pollutants, desert areas of Central Asia are expanding ever faster. In this context it has to be borne in mind that today's observations only refer to a timeframe of a few years or decades. The developments at end-Permian, on the other hand, encompass approx. 100,000 years. In this respect, the current state of art does not permit any definite statements as to what extent present natural and man-made VHC emissions in combination with constantly increasing dry stress are able to provoke or favour a comparable ME process.

  2. Evaluating transition-metal catalysis in gas generation from the Permian Kupferschiefer by hydrous pyrolysis

    Science.gov (United States)

    Lewan, M.D.; Kotarba, M.J.; Wieclaw, D.; Piestrzynski, A.

    2008-01-01

    Transition metals in source rocks have been advocated as catalysts in determining extent, composition, and timing of natural gas generation (Mango, F. D. (1996) Transition metal catalysis in the generation of natural gas. Org. Geochem.24, 977–984). This controversial hypothesis may have important implications concerning gas generation in unconventional shale-gas accumulations. Although experiments have been conducted to test the metal-catalysis hypothesis, their approach and results remain equivocal in evaluating natural assemblages of transition metals and organic matter in shale. The Permian Kupferschiefer of Poland offers an excellent opportunity to test the hypothesis with immature to marginally mature shale rich in both transition metals and organic matter. Twelve subsurface samples containing similar Type-II kerogen with different amounts and types of transition metals were subjected to hydrous pyrolysis at 330° and 355 °C for 72 h. The gases generated in these experiments were quantitatively collected and analyzed for molecular composition and stable isotopes. Expelled immiscible oils, reacted waters, and spent rock were also quantitatively collected. The results show that transition metals have no effect on methane yields or enrichment. ?13C values of generated methane, ethane, propane and butanes show no systematic changes with increasing transition metals. The potential for transition metals to enhance gas generation and oil cracking was examined by looking at the ratio of the generated hydrocarbon gases to generated expelled immiscible oil (i.e., GOR), which showed no systematic change with increasing transition metals. Assuming maximum yields at 355 °C for 72 h and first-order reaction rates, pseudo-rate constants for methane generation at 330 °C were calculated. These rate constants showed no increase with increasing transition metals. The lack of a significant catalytic effect of transition metals on the extent, composition, and timing of natural gas generation in these experiments is attributed to the metals not occurring in the proper form or the poisoning of potential catalytic microcosms by polar-rich bitumen, which impregnates the rock matrix during the early stages of petroleum formation.

  3. Chemical composition of strata of the Meade Peak Phosphatic Shale Member of the Permian Phosphoria Formation

    Science.gov (United States)

    Herring, J.R.; Grauch, R.I.; Siems, D.F.; Tysdal, R.G.; Johnson, E.A.; Zielinski, R.A.; Desborough, G.A.; Knudsen, A.; Gunter, M.E.

    2001-01-01

    This study, one in a series, reports bulk chemical composition of rock samples collected from a core, referred to as Measured Section J, drilled at a site that subsequently was developed into the Enoch Valley phosphate mine in southeastern Idaho. The core is continuous and cuts through the entire thickness of the Meade Peak Phosphatic Shale Member of the Phosphoria Formation. The steeply dipping Meade Peak extends from 182 to 495 feet below the ground surface, which is the greatest below-ground depth of rock that has been sampled to date. The core was drilled before the start of mining, and the rocks consequently have not been exposed to the atmosphere or surficial weathering processes or fractured as a result of mining as are the rocks from other described sections. Hence, this section of the Meade Peak in the core is the least altered section of this member sampled in this series of studies. The channel-sampled rocks from Section J form a set of contiguous intervals across the entire thickness of the Meade Peak. These channel samples characterize?in ascending order?the lower phosphate ore, interlayered middle waste shale, upper phosphate ore, and upper waste shale units of the member. The Section J channel-sample suite includes 3 composite samples of the uppermost 7 feet of the Grandeur Tongue of the Permian Park City Formation, a dolomitic unit that directly underlies the Meade Peak. It also includes an analysis of a 0.1 foot section of chert directly overlying the Meade Peak. The concentrations of the chemical elements in the channel samples are compared with those of Measured Sections Aand B that were obtained from the same mine. In addition to the channel samples, 85 rock samples were selected from the core to address specific geochemical questions that resulted from examination of the core. For example, several of these samples correspond to cored rock that had unusual concentrations of various elements that were determined using a hand-held, x-ray fluorescence instrument. Other individual samples consist of several samples taken within a short interval of the core that leads to an abrupt change in lithology. Overall, the rocks from Measured Section J exhibit the least alteration from interaction with ground water compared with rocks from any of the measured sections that have been described in our previous studies.

  4. Trace element abundances in major minerals of Late Permian coals from southwestern Guizhou province, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Junying; Zheng, Chuguang; Liu, Jing [National Laboratory of Coal Combustion, Institute of Energy Science and Engineering, Huazhong University of Science and Technology, 430074 Wuhan (China); Ren, Deyi [China University of Mining and Technology, 100083 Beijing (China); Zeng, Rongshu [Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029 Beijing (China); Chou, Chen-Lin [Illinois State Geological Survey, 615 East Peabody Drive, 61820 Champaign, IL (United States)

    2002-12-01

    Fourteen samples of minerals were separated by handpicking from Late Permian coals in southwestern Guizhou province, China. These 14 minerals were nodular pyrite, massive recrystallized pyrite, pyrite deposited from low-temperature hydrothermal fluid and from ground water; clay minerals; and calcite deposited from low-temperature hydrothermal fluid and from ground water. The mineralogy, elemental composition, and distribution of 33 elements in these samples were studied by optical microscopy, scanning electron microscope equipped with energy-dispersive X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), cold-vapor atomic absorption spectrometry (CV-AAS), atomic fluorescence spectrometry (AFS), inductively coupled-plasma mass spectrometry (ICP-MS), and ion-selective electrode (ISE). The results show that various minerals in coal contain variable amounts of trace elements. Clay minerals have high concentrations of Ba, Be, Cs, F, Ga, Nb, Rb, Th, U, and Zr. Quartz has little contribution to the concentration of trace elements in bulk coal. Arsenic, Mn, and Sr are in high concentrations in calcite. Pyrite has high concentrations of As, Cd, Hg, Mo, Sb, Se, Tl, and Zn. Different genetic types of calcite in coal can accumulate different trace elements; for example Ba, Co, Cr, Hg, Ni, Rb, Sn, Sr, and Zn are in higher concentrations in calcite deposited from low-temperature hydrothermal fluid than in that deposited from ground water. Furthermore, the concentrations of some trace elements are quite variable in pyrite; different genetic types of pyrites (Py-A, B, C, D) have different concentrations of trace elements, and the concentrations of trace elements are also different in pyrite of low-temperature hydrothermal origin collected from different locations. The study shows that elemental concentration is rather uniform in a pyrite vein. There are many micron and submicron mosaic pyrites in a pyrite vein, which is enriched in some trace elements, such as As and Mo. The content of trace element in pyrite vein depends upon the content of mosaic pyrite and of trace elements in it. Many environmentally sensitive trace elements are mainly contained in the minerals in coal, and hence the physical coal cleaning techniques can remove minerals from coal and decrease the emissions of potentially hazardous trace elements.

  5. Trace element abundances in major minerals of Late Permian coals from southwestern Guizhou province, China

    Science.gov (United States)

    Zhang, J.; Ren, D.; Zheng, C.; Zeng, R.; Chou, C.-L.; Liu, J.

    2002-01-01

    Fourteen samples of minerals were separated by handpicking from Late Permian coals in southwestern Guizhou province, China. These 14 minerals were nodular pyrite, massive recrystallized pyrite, pyrite deposited from low-temperature hydrothermal fluid and from ground water; clay minerals; and calcite deposited from low-temperature hydrothermal fluid and from ground water. The mineralogy, elemental composition, and distribution of 33 elements in these samples were studied by optical microscopy, scanning electron microscope equipped with energy-dispersive X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), cold-vapor atomic absorption spectrometry (CV-AAS), atomic fluorescence spectrometry (AFS), inductively coupled-plasma mass spectrometry (ICP-MS), and ion-selective electrode (ISE). The results show that various minerals in coal contain variable amounts of trace elements. Clay minerals have high concentrations of Ba, Be, Cs, F, Ga, Nb, Rb, Th, U, and Zr. Quartz has little contribution to the concentration of trace elements in bulk coal. Arsenic, Mn, and Sr are in high concentrations in calcite. Pyrite has high concentrations of As, Cd, Hg, Mo, Sb, Se, Tl, and Zn. Different genetic types of calcite in coal can accumulate different trace elements; for example Ba, Co, Cr, Hg, Ni, Rb, Sn, Sr, and Zn are in higher concentrations in calcite deposited from low-temperature hydrothermal fluid than in that deposited from ground water. Furthermore, the concentrations of some trace elements are quite variable in pyrite; different genetic types of pyrites (Py-A, B, C, D) have different concentrations of trace elements, and the concentrations of trace elements are also different in pyrite of low-temperature hydrothermal origin collected from different locations. The study shows that elemental concentration is rather uniform in a pyrite vein. There are many micron and submicron mosaic pyrites in a pyrite vein, which is enriched in some trace elements, such as As and Mo. The content of trace element in pyrite vein depends upon the content of mosaic pyrite and of trace elements in it. Many environmentally sensitive trace elements are mainly contained in the minerals in coal, and hence the physical coal cleaning techniques can remove minerals from coal and decrease the emissions of potentially hazardous trace elements. ?? 2002 Elsevier Science B.V. All rights reserved.

  6. Origin of Permian exotic limestone blocks in the Yarlung Zangbo Suture Zone, Southern Tibet, China: With biostratigraphic, sedimentary and regional geological constraints

    Science.gov (United States)

    Jin, Xiaochi; Huang, Hao; Shi, Yukun; Zhan, Lipei

    2015-05-01

    The Yarlung Zangbo Suture Zone in Southern Tibet represents the collision zone between the Indian and Eurasian continents. It is, to a lesser extent, also the boundary between the Himalayan region and the Lhasa Block. A fascinating aspect of it is the appearance of Permian limestone blocks in Late Triassic (and sometimes Late Jurassic-Cretaceous) siliciclastic sediments south of the ophiolite belt. They are meter- to kilometer-scale, randomly scattered blocks in a clastic matrix. Large blocks often form ridges of mountains or occur as projecting rocks; small blocks are often seen half buried or floating within matrix. They are therefore often noted as exotic blocks. Fossils from the limestone blocks have ages mainly in the range of Guadalupian-Lopingian. The faunas have mixed Gondwanan and Cathaysian features. Petrographic study of the limestone blocks shows that their deposition processes were often influenced by terrigenous clasts and suggests that they were deposited in a generally proximal environment. The age range, lithofacies and fossil content of these limestone blocks in the Yarlung Zangbo Suture Zone are highly compatible with those of the Permian successions north and south of the zone in the framework of northern Greater India. They were originally deposited in peri-Gondwana environment, like the Permian limestone successions of the Lhasa Block and the Himalayan region. The exotic Permian limestone blocks are dismembered units of Permian carbonate successions broken during the rifting process in the Late Triassic. Their entering in the Late Triassic clastic sediments is resulted from either block faulting or olistostrome. Final emplacement of different components, including the limestone blocks, in the suture zone were achieved in the Paleogene accompanied by strong deformation.

  7. Seismic stratigraphy and subsidence history of the United Arab Emirates (UAE) rifted margin and overlying foreland basins

    Science.gov (United States)

    Ali, M. Y.; Watts, A. B.; Searle, M. P.

    2011-12-01

    Regional seismic reflection profiles and deep exploratory well data have been used to determine the structure and evolution of the United Arab Emirates (UAE) rifted margin and overlying foreland basins. We recognized three major tectonostratigraphic sequences in the seismic profiles. A lower rifted margin sequence which is characterised by an early syn-rift sequence of mainly Late Permian age that is overlain by a post-rift sequence of Triassic-Jurassic to Late Cretaceous age, and an upper foreland basin sequences of Aruma (Late Cretaceous) and Pabdeh (Palaeocene - Oligocene) Groups. Backstripping of the well data provides new constraints on the age of rifting, the amount of crustal and mantle extension, and the development of the UAE rifted margin and foreland basins. The tectonic subsidence and uplift history at the wells can be explained by a uniform extension model with at least two episodes of rifting punctuated by periods of relative tectonic quiescence and thermal subsidence. An initial age of rifting of 260 Ma and a stretching factor, ?, of 1.2 was followed by second period of stretching with an initial age of rifting of 180 Ma, and ?, of 1.1 (Fig. 1). This model accounts for the general exponential decrease observed in the backstripped tectonic subsidence. The model, fails, however, to completely explain the slow subsidence and uplift history of the margin during Late Triassic to Early Jurassic. We attribute this slow subsidence to combine effect of a sea-level fall and regional uplift which caused major unconformity particularly offshore western Abu Dhabi. The backstrip curves suggest that the transition from an extensional rifted margin to a compressional foreland basin occurred at ~90 Ma, which is within the range for the emplacement of the Semail Ophiolite (95-68 Ma). The history during this time is characterised by uplift followed by rapid subsidence. We attribute these differential vertical movements to orogenic loading and flexure of the Arabian rifted margin by the Semail Ophiolite and development of Aruma foreland basin

  8. PROSPECTIVIDAD DE HIDROCARBUROS EN LA CUENCA VAUPÉS-AMAZONAS, COLOMBIA / HYDROCARBON PROSPECTIVITY IN THE VAUPES-AMAZONAS BASIN, COLOMBIA

    Scientific Electronic Library Online (English)

    Mario, García-González; Luis Enrique, Cruz-Guevara; Ricardo, Mier-Umaña.

    2013-12-01

    Full Text Available La evaluación de la prospectividad de hidrocarburos en la Cuenca frontera Vaupés-Amazonas con un área de 155.000 km² indica que la región con mejor potencial de gas está situada en la región sur de la cuenca y está también relacionada con la Cuenca de Solimöes, la cual es productora de petróleo y ga [...] s en Brasil. Los potenciales yacimientos de hidrocarburos están relacionados a estructuras compresivas formadas durante la Orogenia Herciniana, las cuales se observan en las líneas sísmicas de la cuenca. Los modelos geoquímicos indican que los hidrocarburos fueron generados a finales del Pérmico y migraron durante el Mesozoico temprano. Los niveles altos de carbono orgánico total, así como los altos niveles de maduración termal de los shales del Devónico en la Cuenca de Solimöes indican que la Cuenca Vaupés-Amazonas también puede presentar un potencial de yacimientos no convencionales de gas tipo shale gas. Abstract in english The assessment of hydrocarbon prospectivity in the Vaupés-Amazon Basin frontier with an area of 155,000 km² indicates that the southern area presents the highest gas potential, and that is also related with the oil and gas potential in the Solimöes Basin in Brazil. The potential hydrocarbon reservoi [...] rs are related to compressive structures, which were identified in seismic lines of the Vaupes-Amazonas Basin, and formed during the Hercinian orogeny. The Geochemical models indicate that hydrocarbons were generated in the organic-rich Devonian shales in the late Permian and migrated later in the early Mesozoic. High TOC contents and high maturity maturation levels found in the Devonian organic-rich shales in the Solimöes Basin, indicate that the Vaupés-Amazon Basin may also have a potential for unconventional deposits of shale gas type.

  9. The magnetic anomaly on the Permian Alcaparrosa porphyry (Argentina). A case of pyrrhotite-remanence-dominated anomaly

    International Nuclear Information System (INIS)

    Complete text of publication follows. The Permian Alcaparrosa porphyry is a small (600 meters in diameter) rhyodacite stock outcropping in the Precordillera geological province, San Juan, Argentina. It developed a 3-kilometers-long, NW-SE-trending alteration halo ('Faja Amarilla', yellow belt) in the host rocks, which is a sequence of Ordovician marine mudstones with interbedded basaltic flows included in the Alcaparrosa Fm. The porphyry-related alteration overprinted a previous low-grade-metamorphic alteration assemblage characteristic of an oceanic floor environment. The aeromagnetic survey revealed a bipolar anomaly in the total magnetic intensity (TMI) coinciding with the outcropping alteration halo. The surrounding Alcaparrosa Fm is non-magnetic and therefore the anomaly is clearly defined in a quiet magnetic zone, showing a minimum to the north, centred on the porphyry, and a semi lunar maximum to the south. The shape of the anomaly is opposed to the expected shape of induced magnetic anomalies in mid latitudes of the southern hemisphere. Available data show that both the Permian porphyry and its alteration halo carry a magnetic remanence with positive inclination (i.e. reversed polarity), probably acquired during the Permo-Carboniferous Reversed Superchron. The Koenigsberger ratio (Q) for the porphyry resulted lower than 1, which means that remanence is not intense enough to control the shape of the magnetic anomaly. On the other side, outcropping rocks of the the other side, outcropping rocks of the alteration halo show intense supergene alteration and are non-magnetic. However, relics of phyllic alteration where found relatively preserved of supergene alteration, and they showed monoclinic pyrrhotite as magnetic carrier, and a Q ratio higher than 1. We used those data to model a body carrying a reversed magnetic remanence. The shape and extension of the modelled body seems a good approximation to the possible shape of the sulphide-bearing alteration halo around the rhyodacite porphyry. The presence of monoclinic pyrrhotite carrying reversed-polarity, high-Q remanence in the Permian porphyry systems of Precordillera should be assessed, as its related inverted anomalies could be used as an exploration guide in aeromagnetic surveys.

  10. The National Basin Delineation Project.

    Science.gov (United States)

    Arthur, Ami T.; Cox, Gina M.; Kuhnert, Nathan R.; Slayter, David L.; Howard, Kenneth W.

    2005-10-01

    The National Basin Delineation Project (NBDP) was undertaken by the National Severe Storms Laboratory to define flash-flood-scale basin boundaries for the country in support of the National Weather Service (NWS) Flash Flood Monitoring and Prediction (FFMP) system. FFMP-averaged basin rainfall calculations allow NWS forecasters to monitor precipitation in flash-flood-scale basins, improving their ability to make accurate and timely flash-flood-warning decisions. The NBDP was accomplished through a partnership with the U.S. Geological Survey Earth Resources Observation Systems (EROS) Data Center (EDC). The one-arc-second (approximately 30 m)-resolution digital terrain data in the EDC's National Elevation Dataset provided the basis for derivation of the following digital maps using a geographic information system: 1) a grid of hydrologically conditioned elevation values (all grid cells have a definned flow direction), 2) a grid of flow direction indicating which of eight directions water will travel based on slope, 3) a grid of flow accumulation containing a count of the number of upstream grid cells contributing flow to each grid cell, 4) synthetic streamlines derived from the flow accumulation grid, and 5) flash-flood-scale basin boundaries. Special techniques were applied in coastal areas and closed basins (basins with no outflow) to ensure the accuracy of derived basins and streams. Codifying each basin with a unique identifier and including hydrologic connectivity information produced a versatile, seamless dataset for use in FFMP and other national applications.

  11. The Paleozoic tectonothermal evolution of the Bachu Uplift of the Tarim Basin, NW China: Constraints from (U-Th)/He ages, apatite fission track and vitrinite reflectance data

    Science.gov (United States)

    Qiu, Nansheng; Jiang, Guang; Mei, Qinghua; Chang, Jian; Wang, Shengjun; Wang, Jiyang

    2011-06-01

    This study uses a new application of the apatite and zircon (U-Th)/He thermochronometry technique to investigate the thermal history and tectonic uplift of sedimentary basins. Based on measured apatite and zircon (U-Th)/He ages, apatite fission track data and equivalent vitrinite reflectance measurements of borehole core samples, the thermal history of the Bachu Uplift of the Tarim Basin was modeled. Our analysis indicates a complicated thermal history in the Bachu Uplift region during the Paleozoic. The thermal gradient initially increased from 28-30 °C/km in the Cambrian period to 30-33 °C/km in the Ordovician period and increased up to 33-34 °C/km in the Silurian period. The thermal gradient began to decrease during the Devonian period and was estimated to be approximately 30 °C/km during the Late Devonian and the Early Carboniferous periods. The low thermal gradient phase was followed by an additional high gradient phase from the Late Carboniferous to the Early Permian when the gradient was approximately 32 °C/km. Thermal gradients in the Paleozoic were substantially different than the present-day gradient (21 °C/km). Tectonothermal modeling results also revealed uplift events in the Bachu Uplift region that shifted from south to north (e.g., ˜150 Ma to ˜100 Ma) and from west to east (e.g., ˜250 Ma to ˜150 Ma). This thermal evolution of the Bachu Uplift is consistent with its tectonic progression. The thermal spike in the Late Carboniferous and Early Permian periods could be related to magmatic activities in the Early Permian period. The Paleozoic thermal history of the Bachu Uplift region of the Tarim Basin could not be reconstructed properly due to a lack of reliable thermal indicators in the Lower Paleozoic successions, and a poor understanding of the thermal evolution of Lower Paleozoic source rocks during the Paleozoic has hindered petroleum exploration in this area. This study provides a new Paleozoic thermal history and shows that the Paleozoic thermal history plays an important role in the maturation process of the Lower Paleozoic source rocks.

  12. Ichnology of transgressive-regressive surfaces in mixed carbonate-siliciclastic sequences, early Permian Chase Group, Oklahoma

    Science.gov (United States)

    Chaplin, J.R.

    1996-01-01

    Early Permian rocks of the Chase Group in north-central Oklahoma consist of repeated couplets of carbonates and clastics. The carbonates and clastics correlate to major transgressive and regressive events, respectively. The sole of the lowest (first) transgressive carbonate bed of each depositional couplet is covered with ubiquitous horizontal boxworks of the trace fossil Thalassinoides isp. Horizontal forms of the trace fossil Rhizocorallium isp. characterize the top bedding-plane surface of the highest (last) carbonate unit of each couplet, and mark the discontinuity surface at the culmination of a major transgression and the initial onset of a major regression. These trace-fossil associations are assigned to the substrate-controlled Glossifungites ichnofacies.

  13. Some Preliminary Results of Detailed Paleomagnetic Investigations of the Siberian Permian-Triassic Traps in the Kotuy River Valley

    Science.gov (United States)

    Latyshev, A.; Fetisova, A.; Veselovskiy, R.

    2009-04-01

    Now essential part of geological investigations is dedicated to revealing of reasons and time relation between the mass extinction on the Paleozoic-Mesozoic boundary and pulses of magmatic activity expressed in forming of the largest Permian-Triassic trap province on the Siberian platform. Thus revealing of the dynamic of the magmatic activity caused formation of the Siberian traps will allow to obtain an important information for establishing of its relation with Permian-Triassic extinction. Recent years several reliable paleomagnetic results from the Siberian traps were obtained, but there is a problem of correlation of Maimecha-Kotuy traps with other trap sequences. Especially this problem is actual in a case of traps of Norilsk and Maimecha-Kotuy regions (Gurevich et al., 2004), because an absence of clearly magnetostratigraphic scheme of the Maimecha-Kotuy region traps. This problem doesn't allow to estimate volume of traps explosion of the Northern part of the Siberian platform. In this work preliminary results of detailed paleomagnetic investigations of Maimecha-Kotuy traps are represented. The most complete and representative sequence of lava flows of Arydzhangsky suite (P2-T1) was exposed to the detailed paleomagnetic sampling. This sequence is situated on the left bank of the Kotuy river. Arydzhangsky suite overlays subhorizontally the eroded surface of the Permian sandstones (Fedorenko et al., 2000) and represents the sequence of lava flows of alkaline basaltic rocks, among which limburgites, augitites, melilite basalts, picrites and nephelinites are the most widely spread. Layers of tuffs are subordinated. Summary thickness of the Arydzhangsky suite in this outcrop is 240 m, and about 27 flows are distinguished there (section 1 in Fedorenko et al., 2000). 23 lava flows were sampled during our researches. 8-10 oriented samples were taken from each lava flow; all samples were obtained from the lower and middle parts in order to decrease the probability of remagnetization by overlayed flow. Orientation of samples was made with geological compass controlling absence of influence of the high-magnetic rocks. In the outcrop on the right bank of the Kotuy river were investigated 4 subhorizontal layers of alkaline mixed tuffs. These tuffs are underlayed by Permian sandstones and they are situated lower then lava flows in relief. Resemblance of these tuffs and alkaline-ultramafic tuffs of Khardakhsky suite (Egorov, 1995) allows to correlate them. Khardakhsky suite is correlated with the Pravoboyarsky suite (P2-T1) (Egorov, 1995). Paleomagnetic investigation revealed rather good paleomagnetic record in the studied samples. The quantity of steps of the thermal cleaning reached 20. Magnetization of tuff layers, correlated with Khardakhskaya suite, includes one or two (contemporary and characteristic) components, the second of them has only reversal polarity. Directions of distinguished characteristic components of magnetization tightly concentrated around their average meaning. Thermal demagnetization of the samples from all 23 sampled lava flows of Arydzhangsky suite showed that these rocks are magnetized in normal polarity. The quality of paleomagnetic record varies, but its interpretation is possible in almost flows: the average direction of magnetization and the corresponding paleomagnetic pole are calculated. Also measurements of the magnetic anisotropy were made. Obtained paleomagnetic pole of the Arydzhangsky suite lies in the area of other trap poles of the Siberian platform: this fact can be considered as evidence of absence of the essential tectonic movements. It indicates the perspective of this suite for detailed paleomagnetic investigations. An essential difference in paleomagnetic poles from the tuffs of the Khardakhsky suite and the lavas of Arydzhangsky suite is explained by absence of averaging of secular variations of the geomagnetic field. In the study (Gurevich et al., 2004) two variants of correlation of the Norilsk and Maimecha-Kotuy outcrops are offered. According to the first variant lower parts of

  14. Palynology of an Early Permian coal seam from the Karoo Supergroup of Botswana

    Science.gov (United States)

    Barbolini, N.; Bamford, M. K.

    2014-12-01

    Two borehole cores from the south-east area of the Mmamantswe coalfield (Mmamabula area), Botswana, provided 124 samples for palynological analysis. The assemblage is dominated by trilete and alete spores, indicating a parent flora of mostly lower order lycopods, sphenophytes and ferns. Distinctive taxa at Mmamantswe include Brevitriletes levis, Cannanoropollis densus, Gondisporites raniganjensis, Platysaccus radialis, Scheuringipollenites ovatus, and Verrucosisporites naumovae. Saccate pollen is less common, suggesting the assemblage reflects the local vegetation of the coal swamp. The Mmamantswe microflora has been sub-divided into two assemblage zones, with the lower Assemblage Zone 1 correlating with Assemblage Zone 1 of Anderson (northern Karoo Basin, South Africa), Biozone B of the Waterberg (South Africa) and the Milorgfjella assemblage (Dronning Maud Land, Antarctica). The upper Assemblage Zone 2 of Mmamantswe is correlated with Assemblage Zone 2 of Anderson (northern Karoo Basin, South Africa), Biozone C of the Waterberg (South Africa), and the No. 2 Seam assemblage (Witbank coalfield, South Africa). On the basis of these correlations the Mmamantswe microfloral assemblage is assigned to the Asselian, Sakmarian and Early Artinskian periods.

  15. Palaeomagnetism of Palaeozoic glacial sediments of Northern Ethiopia: a contribution towards African Permian palaeogeography

    Science.gov (United States)

    Kidane, Tesfaye; Bachtadse, Valerian; Alene, Mulugeta; Kirscher, Uwe

    2013-12-01

    One hundred fourteen oriented palaeomagnetic core samples were collected from 13 palaeomagnetic sites on subhorizontal to tilted glacial sediments at five localities of Northern Ethiopia. Combined alternating field (AF) and stepwise thermal demagnetization techniques were successfully applied to resolve the complete directional spectrum. A viscous remagnetization (VRM) and one stable component of magnetization were identified in most of the specimens. The VRM is removed between a temperature range of 120-350 °C and AF of up to 30 mT. Further heating until ˜650 °C results in smooth decay of the natural remanent magnetization (NRM) intensity to about 50 per cent and the rest of the NRM is efficiently removed by heating to 690 °C, while only 30-50 per cent of NRM is removed by the maximum AF available suggesting haematite as remanence carrier. Results of the magnetization decay curve plots and rock magnetic analyses using the variable field translation balance indicated the presence of magnetite with minor goethite, pyrrhotite as well. The high stability component defining a straightline segment, starting 350 °C and/or 30 mT is mostly directed towards the origin and interpreted as the characteristic remanent magnetizations (ChRMs). The direction of magnetization is determined both by best-fitting line using the least-square technique of Kirschvink and remagnetization circles of Halls for few unresolved overlapping components. The site mean directions of the sediments from two sites are normal polarity and are close to present-day field directions at the sample site. The site mean directions from 11 sites, on the other hand, are reversed in polarity with better grouping in the tilt-corrected coordinate and pass the McFadden fold test. This overall site mean direction is Dec = 143.4º, Inc = 58.8º (N = 11, ?95 = 9.7º) with a corresponding mean pole position of Lat = 26.0º, Lon = 249.5º (N = 11, A95 = 13.1º). This geomagnetic pole position is later rotated into West Africa coordinates to allow for extensional rifting in the Benue Trough about an Euler pole position, at 19.2ºN, 352.6ºE through an angle -6.3º (clockwise). The resulting pole position is located at ?s = 246.6ºE, ?s = 31.8ºS (N = 11, A95 = 13.1º), this pole with its 95 per cent confidence circle intersects the 270-310 Ma, segment of the APW path for West Africa consistent with ages of between late Carboniferous and early Permian. The result also implies that the Late Carboniferous Dwyka land ice sheet had probably extended more than 1000 km further north to Ethiopia than previously known.

  16. The First Paleomagnetic Data from Permian-Triassic Rocks of Belkovsky Island (New Siberian Islands)

    Science.gov (United States)

    Zhdanova, A.; Metelkin, D.

    2014-12-01

    Belkovsky Island is the part of New Siberian Island (NSI) terrane for which the paleomagnetic results for O-S periods were obtained previosly [1]. Its outcrops present the Paleozoic volcanic and sedimentary sequences intruded by mafic sills and dikes. The age of formation of igneous rocks is 252±2 Ma [2], which matches to the time of Siberian trap magmatism. The study was carried out on 45 samples from two dolerite sills at the Laboratory of Geodynamics and Paleomagnetism of IPGG SB RAS. The NRM in samples ranges from 30 mA/m to 400 mA/m. AF demagnetization allowed to remove the viscouse remanent magnetization at 5-10 nT field and then only one component is isolated. 90% NRM destroys in field up to 80-100 nT, MDF is about 30 nT that suppose the presence of low coercive minerals. The site mean directions were calculated for Sill 1 (Ds=35.7°, Is=-79.7°, K=64, ?95=4.2) and Sill 2 (Ds=214.2°, Is=81.4°, K=145.4, ?95=4.0). Considering high paleolatitudes (70.0°-72.4°) we suppose that NSI terrane should be in North hemisphere that's why Sill 1 formed in reversed polarity epoch and Sill 2 formed in the normal one. Taking into account this fact the VGPs were calculated for Sill 1: Plat=57.5°, Plong = 113.9°, dp/dm=8.0/7.7; for Sill 2: Plat=60.4°, Plong = 116.5°, dp/dm=7.7/7.5. To summarize we can conclude preliminarily that NSI terrane at Permian-Triassic time was located to the north from Siberia and the mafic rocks of Belkovsky Island can belong to the marginal part of P-T trap formation. The VGP position suppose significant rotation relatively to Siberia before accretion to it in J-K time and it's most likely that in the Late Paleozoic and Early Mesozoic NSI terrane migrate in Arctic latitudes together with other fragments of Arctida.The work was supported by grant RFBR 14-05-31399. Leterature: 1. V. A. Vernikovsky, D. V. Metelkin, T. Yu. Tolmacheva, N. A. Malyshev, O. V. Petrov, N. N. Sobolev, and N. Yu. Matushkin, 2013. Concerning the Issue of Paleotectonic Reconstructions in the Arctic and of the Tectonic Unity of the New Siberian Islands Terrane: New Paleomagnetic and Paleontological Data. Dokl. Earth Sci. 451, 423-429. 2. Kuzmichev, A.B., Pease, V.L., 2007. Siberian trap magmatism on the New Siberian Islands: constraints for Arctic Mesozoic plate tectonic reconstructions. Journal of the Geological Society, 164, 959-968.

  17. Permian fusulinid biostratigraphy of the Baoshan Block in western Yunnan, China with constraints on paleogeography and paleoclimate

    Science.gov (United States)

    Huang, Hao; Shi, Yukun; Jin, Xiaochi

    2015-05-01

    Newly obtained fossil materials together with published data enable a review on the Permian fusulinids of the Gondwana-derived Baoshan Block in western Yunnan, China. The Baoshan Block yields rather impoverish Sakmarian-Yakhtashian fusulinids with just Eoparafusulina and Pseudofusulina in its northern and southern parts. These fusulinids biogeographically demonstrate the feature of peri-Gondwana province and signify a temperate-water condition. Further comparison suggests the Baoshan Block was located distant from the tropical region and even with higher latitude than Central Iran and Central Pamir during the Sakmarian-Yakhtashian. In contrast, Murgabian-Midian fusulinids are more diversified. In the southern Baoshan Block, the Schwagerina assemblage, the Eopolydiexodina assemblage, the Sumatrina assemblage and the Verbeekina assemblage could be recognized in the Xiaoxinzhai area, and the Yangchienia-Nankinella assemblage and the Chusenella-Rugosofusulina assemblage in the Bawei area, in ascending order. Contemporaneously, the Neofusulinella assemblage occurs in the northern and the Eopolydiexodina assemblage in the southwestern Baoshan Block respectively. These Murgabian-Midian fusulinids show affinity of western Tethyan province and suggest a warm-water environment. Interestingly, the Midian Verbeekina assemblage is characterized by relatively low diversity and rather abundance of just one genus. Such compositional feature most likely signifies warm but still not optimal sea-surface water for the diversification of fusulinids. Also taking into account of the presence of Verbeekinids and Neoschwagerinids and the moderate total diversity, the Middle Permian fusulinids indicate that the Baoshan Block, during the Murgabian-Midian, was probably located between equatorial region with warm water to the north and the majority of Sibumasu areas lacking Verbeekinids and Neoschwagerinids with temperate water to the south.

  18. Ferroan dolomite cement in Cambrian sandstones: burial history and hydrocarbon generation of the Baltic sedimentary basin

    DEFF Research Database (Denmark)

    Sliaupa, S.; Cyziene, J.

    2008-01-01

    The conditions and timing of carbonate cementation in Cambrian sandstones of the Baltic sedimentary basin were determined by oxygen and carbon stable isotope and chemical data in combination with optical and cathodoluminescence petrographic studies. Studied samples represent a range in present burial depth from 340 to 2150 m. The carbonate cement is dominantly ferroan dolomite that occurs as dispersed patches of poikilotopic crystals. Temperatures of dolomite precipitation, based on delta O-18 values, range from 27 degrees C in the shallow buried to 95 degrees C in the deep buried sandstones. The burial history modelling points to development of most of the dolomite cement during rapid Silurian-Devonian subsidence and Carboniferous-early Permian uplift. A wide range of precipitation temperatures indicate that temperature was not a major factor in triggering the carbonate cementation. Dolomite precipitation is related to early stages of organic matter maturation and thus to the oil generation history in the basin. delta C-13 values vary from +0.03% to -6.2%( PDB), suggesting limited addition of carbon from an organic source, with the major part derived from marine bicarbonate. The sourcing of carbon from the organic-rich Cambrian shales is identified from the distribution of delta C-13 values in the dolomite cement within the Cambrian section. The chemical composition of the dolomite cement shows a depth-controlled trend that is coincident with the present-day hydrochemical zonation of the Cambrian aquifer. The increase in the Fe content of the dolomite towards the deeper buried part of the Baltic basin is related to increasing sourcing of ions ( Fe and Mg) from adjacent shales.

  19. Exploration for oil and gas in the sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M.N.V.

    1983-02-01

    Sedimentary basins, Pranhita-Godavari Graben, Krishna-Godavari Basin, Palar Basin, Cauvery Basin, and Kerala Basin in India are described as to dimensions, geological formation, and potential as hydrocarbon reserves. (BLM)

  20. Radioactive waste isolation in salt: peer review of the D'Appolonia report on Schematic Designs for Penetration Seals for a Repository in the Permian Basin, Texas

    International Nuclear Information System (INIS)

    Argonne made the following recommedations for improving the reviewed reports. The authors of the report should: state the major assumptions of the study in Sec. 1.1 rather than later in the report; consider using salt for the shaft seals in salt horizons; reconsider whether keys are needed for the bulkheads; provide for interface grouting because use of expansive cement will not guarantee that interfaces will be impermeable; discuss the sealing schedule and, where appropriate, consider what needs to be done to ensure that emplaced radioactive waste could be retrieved if necessary; describe in more detail the sealing of the Dockum and Ogallala aquifers; consider an as low as reasonably achievable approach to performance requirements for the initial design phase; address the concerns in the 1983 US Nuclear Regulatory Commission document entitled Draft Technical Position: Borehole and Shaft Sealing of High-Level Nuclear Waste Repositories; cite the requirements for release of radioactivity by referring to specific clauses in the regulations of the US Environmental Protection Agency; and provide further explanation in the outline of future activities about materials development and verification testing. More emphasis on development of accelerated testing programs is also required

  1. The distribution pattern of trace elements in Pedra do Fogo formation, permian of Maranhao Basin and it application as an environment indicator of sedimentation

    International Nuclear Information System (INIS)

    The present investigation consisted of a geochemical study of the medium and upper layers of the Pedra do Fogo Formation aiming at correlating its elemental distribution pattern with the sedimentary environment where that formation was deposited. Pelitic material with carbonate content below 30% was sampled in the three different outcrops of the Pedra do Fogo Formation for mineralogical and chemical analyses. Illite and dolomite, with subordinate amounts of smectite, calcite, quartz and K-feldspar were determined by X-ray diffraction techniques as the constituents of the mineral assemblages. Trace element (B, Ba, Co, Cr, Cu, Ga, Li, Mn, Ni, P, V, Pb, Sr, Rb and Zn), CO sub(2) and K concentrations were determined by emission spectrography, atomic absorption spectrometry and colorimetry. The interpretation of the chemical data based on B-V, Ga-B, B-K sub(2) O and B-Ga-Rb diagrams and on B content indicates a wite range of variation for the medium salinity during the deposition of the Pedra do Fogo rocks. Accordingly, the observed sequence is composed of intercalations of marine and fresh water sediments, the latter being dominant. The marine intercalations are more frequent in the bottom of the sampled stratigraphic section and become progressively rarer towards the top layers which were deposited in a typically fresh water environment. (author)

  2. Stephanian-Early Permian basaltic trachyandesites from the S?awków and Nieporaz-Brod?a Grabens near Kraków, Southern Poland

    Directory of Open Access Journals (Sweden)

    Anna LEWANDOWSKA

    2010-01-01

    Full Text Available In the Kraków-Lubliniec section of the major Hamburg-Kraków-Dobrogea Fault Zone (HKDFZ, the Stephanian-Early Permian magmatic activity was simultaneous with subsidence/uplift of formed blocks. In the proximity of the uplifted areas the sedimentation started with fanglomerates, distally passing into playa siltstone and was accompanied by volcanism. In the Nieporaz-Brod?a graben, basaltic trachyandesite a-a lava flows with autoclastic breccias reach ca. 150 m in thickness. The weathering recorded as adhesive rims around breccia clasts reflects palaeosoil formation during quiescence periods between the eruptions. The eruptions were effusive although scoriaceous lava indicates high volatile content of the magma. The water content before eruption had to be over 2 wt. percent. Only then the crystallisation model predicts accurately the type, composition and order of the crystallising phases. Thus, the basaltic trachyandesite magma originated from a source containing hydrous phase (i.e., amphibole or phlogopite. All the studied basaltic trachyandesites had fayalitic olivine on their liquidus reflecting the crystallisation stage in a magma chamber at crustal depths. During final decompression on the magma ascent due to water exsolution, the olivine was followed by plagioclase, spinel, augite, ilmenite, apatite, K-feldspar and residual high-K rhyolitic glass. The high potassium content of these volcanics was thus a primary feature reflecting the source geochemistry and differentiation trend, and its consequence was potassium metaso- matism. Due to water exsolution the glass was altered, however, homogenous interstitial glass survived in some rocks. The glass is strongly enriched in incompatible trace elements, showing that it is a highly fractionated residual melt fraction of the basaltic trachyandesite magma. Thus, the glass geochemistry reflects the trend of fractional crystallisation indicating that co-occurring K-rich felsic rocks were not derived from the same magma. All the basaltic trachyandesites studied have calc-alkaline to alkaline affinity. They contain fayalitic olivine and are low in MgO 0.5-0.80 and small Eu/Eu* > 0.9-1.0 anomalies suggesting fractionation of plagioclase. The Eu/Eu* anomaly is probably compensated by amphibole retaining in the source. Negative Nb, Ti anomalies suggest Fe-Ti oxide fractionation characteristic for calc-alkaline evolution trend. A significant enrichment in LREE relatively to HREE (La/Yb > 10 indicates subduction-related metasomatism. However, the described tectonic context is inconsistent with subduction related characteristics. Concluding, the observed geochemical characteristics indicate remarkable role of water in magma evolution. The volcanism was related to strike-slip dextral movement along the Kraków-Lubliniec section of HKDFZ, transformed into crustal extension and subsidence, the features typical for the formation of pull-apart basins, in the late stages of the Variscan orogen evolution.

  3. Paleo-environments, paleo-climates and sequences of Westphalian deposits of Lorraine coal basin (upper carboniferous, NE France); Paleoenvironnements, paleoclimats et sequences des depots westphaliens du Bassin houiller lorrain (carbonifere superieur, NE France)

    Energy Technology Data Exchange (ETDEWEB)

    Izart, A.; Fleck, St.; Michels, R. [Nancy Univ. Henri Poincare,UMR 7566, Geologie des Ressources Minerales et Energetiques, 54 -Vandoeuvre les Nancy (France); Palain, Ch.; Malartre, F. [Ecole Nationale Superieure de Geologie, UMR 7566, Geologie et Gestion des Ressources Minerales et Energetiques, 54 - Vandoeuvre les Nancy (France)

    2005-07-01

    Facies and sequences of the Westphalian C are identified in cores and well logs of three boreholes and three seismic lines supplied by Conoco-Phillips from the Lorraine coal Basin. The litho-facies associations suggest various paleo-environments and sequences during the Westphalian C. Decametric-thick sedimentary bodies display alluvial fan deposits in the northwestern border of the basin (Chaumont borehole). Decametric sedimentary bodies constituted either of conglomeratic and sandy facies with cylindrical shape in well logs represent braided river deposits, or alternations of fining and coarsening upward sequences with sandy, silty and clayey facies with bell and funnel shapes in well log correspond to meander river and lacustrine deltaic deposits in the Saulcy and Lorettes boreholes. Three fining upward third order sequences in the center of the basin in the Lorettes and Saulcy boreholes represent a period 1 with braided river deposits, a period 2 with flood plain, lake and meandering river deposits and a period 3 with anastomosed or meandering river deposits. Period 1 is correlated with a subsidence period in the basin and uplift of the borders, period 2 with the maximum fresh water flooding period with flood plain or lake deposits and period 3 with the filling period. The seismic profiles of Conoco-Phillips confirm the tectonic structures described by previous authors in Lorraine Basin. We agree that this basin was a strike-slip basin as demonstrated by previous authors with depocenters near the South Hunsruck and Metz faults from the Westphalian to the Permian. Bio-markers show that paleo-climate changes (wet/dry) of weak amplitude in the equatorial climate could also modify the sedimentation of this basin and act on sequences of second order. (authors)

  4. A review of stratigraphy and sedimentary environments of the Karoo Basin of South Africa

    Science.gov (United States)

    Smith, R. M. H.

    The Karoo Supergroup covers almost two thirds of the present land surface of southern Africa. Its strata record an almost continuous sequence of continental sedimentation that began in the Permo-Carboniferous (280 Ma) and terminated in the early Jurassic 100 million years later. The glacio-marine to terrestrial sequence accumulated in a variety of tectonically controlled depositories under progressively more arid climatic conditions. Numerous vertebrate fossils are preserved in these rocks, including fish, amphibians, primitive aquatic reptiles, primitive land reptiles, more advanced mammal-like reptiles, dinosaurs and even the earliest mammals. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo sequence demonstrates the effects of more localised tectonic basins in influencing depositional style. These are superimposed on a basinwide trend of progressive aridification attributed to the gradual northward migration of southwestern Gondwanaland out of polar climes and accentuated by the meteoric drying effect of the surrounding land masses. Combined with progressive climatic drying was a gradual shrinking of the basin brought about by the northward migration of the subducting palaeo-Pacific margin to the south. Following deposition of the Cape Supergroup in the pre-Karoo basin there was a period of uplift and erosion. At the same time the southern part of Gondwana migrated over the South Pole resulting in a major ice-sheet over the early Karoo basin and surrounding highlands. Glacial sedimentation in both upland valley and shelf depositories resulted in the basal Karoo Dwyka Formation. After glaciation, an extensive shallow sea remained over the gently subsiding shelf fed by large volumes of meltwater. Black clays and muds accumulated under relatively cool climatic conditions (Lower Ecca) with perhaps a warmer "interglacial" during which the distinctive Mesosaurus-bearing, carbonaceous shales of the Whitehill Formation were deposited. Deformation of the southern rim of the basin, caused by the subducting palaeo-Pacific plate, resulted in mountain ranges far to the south. Material derived from this source, as well as granitic uplands to the west and morth-east, was deposited on large deltas that built out into the Ecca sea (Upper Ecca). The relatively cool climate and lowland setting promoted thick accumulations of peat on the coastal and delta plains and which now constitute the major coal reserves of southern Africa. Later the prograding deltas coalesced to fill most of the basin after which fluvial sedimentation of the Beaufort Group dominated. The climate by this time (Late Permian) had warmed to become semi-arid with highly seasonal rainfall. The central parts of the basin were for the most part drained by fine-grained meanderbelts and semi-permanent lakes. Significant stratabound uranium reserves have been delimited in the channel sandstones of the Beaufort Group in the southwestern parts of the basin. Pulses of uplift in the southern source areas combined with a possible orogenic effect resulted in two coarser-grained alluvial fans prograding into the more central parts of the basin (Katberg Sandstone Member and Molteno Formation). In the upper Karoo sequence progressive aridification dominated depositional style with playa lake and wadi-type environments (Elliot Formation) that finally gave way to a dune sand dominated system (Clarens Formation). Basinwide volcanic activity of the early Jurassic Drakensberg Group brought deposition in the Karoo Basin to a close.

  5. Petrographic report on samples from units 4 and 5 salt, lower San Andres formation, J. Friemel No. 1 well, Deaf Smith County, Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    This report presents the results of mineralogic and petrographic analyses performed on samples of salt-bearing rock from a potential repository site in the Palo Duro Basin, Texas. The samples are from Permian Units 4 and 5 salt, Lower San Andres Formation, J. Friemel No. 1 well, Deaf Smith County, Texas. The mineralogic and petrographic data were obtained from polished thin sections cut parallel to the axis of the core for each sample. The polished thin sections were examined in order to determine the abundances of soluble (halite) and insoluble components (anhydrite, clay, carbonate, quartz, gypsum, etc.). The information reported here includes mineral associations (detrital, authigenic, cement, alteration, etc.), texture, grain size, and sedimentary fabrics. The report also includes representative photomicrographs with superimposed bar scales. Photomicrographs of polished thin sections have the up-core direction designated. X-ray diffraction was also used for identification of soluble and insoluble minerals. 7 refs., 2 tabs

  6. Preservation of Permian allanite within an Alpine eclogite facies shear zone at Mt Mucrone, Italy: Mechanical and chemical behaviour of allanite during mylonitization

    DEFF Research Database (Denmark)

    Cenki-Tok, Benedicte; Oliot, E.

    2011-01-01

    This study addresses the mechanical and cehmical behavior of allanite during shear zone formation under high-pressure metamorphism. Understanding physico-chemical processes related to the retention or resetting of Pb isotopes in allanite during geological processes is essential for robust petrochronology. Dating of allanite in meta-granodiorite showing variable amounts of strain (from an undeformed protolith to mylonite) at Monte Mucrone (Sesia Zone, NW Italy) gave surprising results. Based on structural and petrographic observations the shear zones at Mt Mucrone are Alpine, yet allanite located within an eclogite facies mylonite yielded Permian ages (208Pb/232Th average age: 287±7 Ma). These mm-sized allanite grains are rimmed by an aggregate of coarse-grained garnet+phengite, thought to derive from former epidote. These aggregates were immersed in a weak matrix that experienced granular flow, and they were thus chemically and mechanically shielded during Alpine mylonitization. In undeformed samples (8a and 8b), two populations of epidote group minerals were found. Allanite forms either coronas around Permianmonazite or individual grains with patchy zoning. Both types yield Permian ages (208Pb/232Th age: 291±5 Ma). On the other hand, grains of REE-rich clinozoisite of Cretaceous age are found in undeformed rocks. These grains appear as small fragments with embayed surface outlines and minute satellites or rims around Permian allanite. These (re)crystallized grains are Sr-rich and show mosaic zoning. These results indicate that allanite crystals retained their chemical and isotopic characteristics, and thus their Permian age, as a result of strong strain partitioning between the epidote group porphyroclasts and the eclogite facies matrix in HP-mylonites. The observed partial mobilization of Pb isotopes, which lead to the Cretaceous-aged rims or grains in undeformed samples was facilitated by (re)crystallization of allanite and not by mere Pb diffusion alone under the HP conditions.

  7. Stephanian-Early Permian basaltic trachyandesites from the S?awków and Nieporaz-Brod?a Grabens near Kraków, Southern Poland

    OpenAIRE

    Lewandowska, Anna; Mariusz J. ROSPONDEK; Nawrocki, Jerzy

    2010-01-01

    In the Kraków-Lubliniec section of the major Hamburg-Kraków-Dobrogea Fault Zone (HKDFZ), the Stephanian-Early Permian magmatic activity was simultaneous with subsidence/uplift of formed blocks. In the proximity of the uplifted areas the sedimentation started with fanglomerates, distally passing into playa siltstone and was accompanied by volcanism. In the Nieporaz-Brod?a graben, basaltic trachyandesite a-a lava flows with autoclastic breccias reach ca. 150 m in thickness. The weathering recor...

  8. Basinal analysis of the Ecca and Lowermost Beaufort Beds and associated coal, uranium and heavy mineral beach sand occurrences

    International Nuclear Information System (INIS)

    The regional sediment transport directions, major provenance areas and the controlling palaeotectonic and palaeogeographic frameworks of sedimentation have been reconstructed for the Great Karoo Basin during the Permian. Analyses of this magnitude can be useful in regional exploration programmes for coal, uranium and fossil heavy mineral beach sand deposits. The strong palaeogeographic control on coal deposition is demonstrated by the fact that some of the most important deposits accumulated in topographically low lying areas on the pre-Karoo surface. Such areas formed sheltered environments ideal for the growth and accumulation of organic material. Elsewhere relatively slow rates of subsidence of a broad, protected, low lying delta plain controlled the deposition of coal. North of the main Karoo Basin many of the coal deposits are confined to structurally controlled linear basins. Hundreds of sedimentary uranium occurrences of varying grade and size occur within a broad, discontinuous belt in the Lower Beaufort of the southwestern portion of the Karoo Basin. The uranium mineralization occurs in a variety of fluvial deposits usually rich in carbonaceous material. Minute tuffaceous fragments, reflecting contemporaneous vulcanism, form a minor but significant constituent in some of the uraniferous sandstones. The uranium occurrences are confined largely to the Southern and Western Facies of the Lower Beaufort, and occur mainly within the confines of the Karoo Trough. Coithin the confines of the Karoo Trough. Consolidated heavy mineral beach deposits have been found in the predominantly fluvio-deltaic Middle Ecca Group of the Northern Facies at a number of widely separated locations. These deposits were formed by shore line processes, such as the reworking of delta-front sands, during periods of temporary marine regression

  9. Preliminary study of favorability for uranium of the Sangre de Cristo Formation in the Las Vegas basin, northeastern New Mexico

    International Nuclear Information System (INIS)

    Uranium favorability of the Sangre de Cristo Formation (Pennsylvanian-Permian) in the Las Vegas basin has been evaluated. The Las Vegas basin project area, located in Colfax, Mora, and San Miguel Counties, New Mexico, comprises about 3,489 sq mi. The formation contains sedimentologic and stratigraphic characteristics that are considered favorable for uranium deposition. Field investigations consisted of section measuring, rock sampling, and ground radiometric reconnaissance. North-south and east-west cross sections of the basin were prepared from well logs and measured sections. Petrographic, chemical, and spectrographic analyses were conducted on selected samples. Stratigraphic and sedimentologic information were used to determine depositional environments. The most favorable potential host rocks include red to pink, coarse-grained, poorly sorted, feldspathic to arkosic lenticular sandstones with stacked sandstone thicknesses of more than 20 ft and sandstone-to-shale ratios between 1:1 and 2:1. The sandstone is interbedded with mudstone and contains carbonaceous debris and anomalous concentrations of uranium locally. Areas of maximum favorability are found in a braided-stream, alluvial-plain depositional environment in the north-central part of the Las Vegas basin. There, carbonaceous material is well preserved, probably due to rapid subsidence and burial. Furthermore, uranium favorability is highest in the lower half of the formation because carbonaceous wood and plant fragments, as well as known uranium deposits, are concentrated in this zone. Piedmont deposits in the north and east, and meander-belt, alluvial-plain deposits in the south, are not considered favorable because of the paucity of uranium deposits and a minimum of carbonaceous material

  10. K-Basins design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Roe, N.R.; Mills, W.C.

    1995-06-01

    The purpose of the design guidelines is to enable SNF and K Basin personnel to complete fuel and sludge removal, and basin water mitigation by providing engineering guidance for equipment design for the fuel basin, facility modifications (upgrades), remote tools, and new processes. It is not intended to be a purchase order reference for vendors. The document identifies materials, methods, and components that work at K Basins; it also Provides design input and a technical review process to facilitate project interfaces with operations in K Basins. This document is intended to compliment other engineering documentation used at K Basins and throughout the Spent Nuclear Fuel Project. Significant provisions, which are incorporated, include portions of the following: General Design Criteria (DOE 1989), Standard Engineering Practices (WHC-CM-6-1), Engineering Practices Guidelines (WHC 1994b), Hanford Plant Standards (DOE-RL 1989), Safety Analysis Manual (WHC-CM-4-46), and Radiological Design Guide (WHC 1994f). Documents (requirements) essential to the engineering design projects at K Basins are referenced in the guidelines.

  11. K-Basins design guidelines

    International Nuclear Information System (INIS)

    The purpose of the design guidelines is to enable SNF and K Basin personnel to complete fuel and sludge removal, and basin water mitigation by providing engineering guidance for equipment design for the fuel basin, facility modifications (upgrades), remote tools, and new processes. It is not intended to be a purchase order reference for vendors. The document identifies materials, methods, and components that work at K Basins; it also Provides design input and a technical review process to facilitate project interfaces with operations in K Basins. This document is intended to compliment other engineering documentation used at K Basins and throughout the Spent Nuclear Fuel Project. Significant provisions, which are incorporated, include portions of the following: General Design Criteria (DOE 1989), Standard Engineering Practices (WHC-CM-6-1), Engineering Practices Guidelines (WHC 1994b), Hanford Plant Standards (DOE-RL 1989), Safety Analysis Manual (WHC-CM-4-46), and Radiological Design Guide (WHC 1994f). Documents (requirements) essential to the engineering design projects at K Basins are referenced in the guidelines

  12. A global marine sedimentary response to the end-Permian mass extinction: Examples from southern Turkey and the western United States

    Science.gov (United States)

    Pruss, Sara B.; Bottjer, David J.; Corsetti, Frank A.; Baud, Aymon

    2006-10-01

    The end-Permian mass extinction greatly diminished marine diversity and brought about a whole-scale restructuring of marine ecosystems; these ecosystem changes also profoundly affected the sedimentary record. Data presented here, attained through facies analyses of strata deposited during the immediate aftermath of the end-Permian mass extinction (southern Turkey) and at the close of the Early Triassic (southwestern United States), in combination with a literature review, show that sedimentary systems were profoundly affected by: (1) a reduction in biotic diversity and abundance and (2) long-term environmental fluctuations that resulted from the end-Permian crisis. Lower Triassic strata display widespread microbialite and carbonate seafloor fan development and contain indicators of suppressed infaunal bioturbation such as flat-pebble conglomerates and wrinkle structures (facies considered unusual in post-Cambrian subtidal deposits). Our observations suggest that depositional systems, too, respond to biotic crises, and that certain facies may act as barometers of ecologic and environmental change independent of fossil assemblage analyses. Close investigation of facies changes during other critical times in Earth history may serve as an important tool in interpreting the ecology of metazoans and their environment.

  13. Provenance of Permian-Triassic volcaniclastic sedimentary terranes in New Zealand : evidence from their radiogenic isotope characteristics and detrital mineral age patterns

    International Nuclear Information System (INIS)

    Detrital mineral age patterns, Rb-Sr age, and initial strontium isotope ratio variations are reported for metasediments of the Brook Street, Dun Mountain-Maitai, and Murihiku Terranes (informally grouped as 'central arc terranes') of New Zealand. U-Pb SHRIMP detrital zircon age populations in Late Permian Tramway Formation, sandstones of the Dun Mountain-Maitai Terrane in Nelson and Southland, New Zealand, show restricted Late Permian (253-268 Ma) and broader Devonian-Carboniferous (330-373 Ma) age components in about equal proportions, with a minor (87Sr/86Sr ratios (i) at the time of metamorphism), reveal cooling age patterns consequent upon low-grade metamorphism in lonsequent upon low-grade metamorphism in latest Triassic and earliest Jurassic times. The (t)-(i) data define a central arc terranes group consistently less radiogenic than Permian and Triassic time correlatives in the Torlesse Supergroup of the Rakaia Terrane. This feature suggests a provenance that includes sediment detritus dominantly from less radiogenic I-type igneous sources in both Lachlan and New England Fold Belts in similar proportions, and with little contribution from their Precambrian and early Paleozoic hinterlands. (author). 89 refs., 6 figs., 2 tabs

  14. Concentraciones bioclásticas del Carbonífero - Pérmico Inferior en la Precordillera argentina: Variaciones temporales y relación con las tendencias propuestas para el Fanerozoico / Carboniferous and lower Permian shell beds in Precordillera Argentina: Temporal variations and relationships with the trends proposed for the Fanerozoic

    Scientific Electronic Library Online (English)

    Andrea F., Sterren.

    2008-06-01

    Full Text Available En este trabajo se presenta el estudio tafonómico de concentraciones fosilíferas del Carbonífero y Pérmico Temprano provenientes de ocho unidades de las cuencas de Río Blanco-Paganzo y Calingasta- Uspallata. Se analizaron dos parámetros de las acumulaciones bioclásticas: la composición taxonómica y [...] el espesor. El análisis de la composición taxonómica permitió reconocer un predominio de acumulaciones moluscodominadas en ambos períodos, siendo las concentraciones dominadas por rhynchonelliformes más abundantes en el Carbonífero que en el Pérmico Temprano. La distribución de espesores evidenció un aumento relativo de los mismos a través del intervalo, aunque nunca superan los 30 cm. Los depósitos bioclásticos estudiados, constituidos por elementos distintivos de la Fauna Moderna y por espesores relativamente delgados y típicamente arcaicos, podrían denominarse de estilo "mixto". Según la composición taxonómica, la transición de estilos en las acumulaciones bioclásticas tendría lugar hacia fines del Paleozoico, lo que respondería a una causa biótica relacionada con la diversificación relativamente temprana de bivalvos infaunales. El incremento de espesores observado en el intervalo estudiado sería resultado de la dinámica sedimentaria en los distintos sectores de las cuencas. La biodiversidad de moluscos y braquiópodos documentados es significativamente mayor en el Pérmico que en el Carbonífero, rasgo que se manifiesta también en la composición de las concentraciones fosilíferas analizadas. La presencia de esta superposición de estilos sugiere a estos períodos como intervalos clave donde focalizar este tipo de estudios, con el fin de testear la expresión local de los modelos globales. Abstract in english Taphonomic and biodiversity studies of Carboniferous and Permian shell beds recorded in several sections from the Río Blanco-Paganzo and Calingasta- Uspallata basins are carried out. Two parameters of bioclastic accumulations are analyzed: taxonomic composition and thickness. The analysis of the tax [...] onomic composition revealed that molluscan-dominated concentrations predominate in both periods, being rhynchonelliform-dominated ones more abundant during the Carboniferous than during the Early Permian. The distribution of thickness ranges exhibits a relative increase through the studied interval, reaching a maximum of 30 cm. Studied bioclastic deposits, are relatively thin and are composed of distinctive elements of the Modern Fauna; hence they could be included in a "mixed" style. On taxonomic grounds the transition between styles appeared to take place toward the ending of the Paleozoic, and might have been driven by a biotic factor related to the relatively early diversification of infaunal bivalves. The increase in thickness documented in the studied interval is the result of the sedimentary dynamics in different areas of the basins. Patterns of biodiversity among mollusks and brachiopods show significantly higher levels of richness in the Permian than in the Carboniferous, a feature that is also evident in the composition of fossiliferous concentrations. The superposition of styles herein documented suggests that the Neopaleozoic is a key interval to test the local expressions of global models.

  15. Burial History, Thermal Maturity, and Oil and Gas Generation History of Source Rocks in the Bighorn Basin, Wyoming and Montana

    Science.gov (United States)

    Roberts, Laura N.R.; Finn, Thomas M.; Lewan, Michael D.; Kirschbaum, Mark A.

    2008-01-01

    Burial history, thermal maturity, and timing of oil and gas generation were modeled for seven key source-rock units at eight well locations throughout the Bighorn Basin in Wyoming and Montana. Also modeled was the timing of cracking to gas of Phosphoria Formation-sourced oil in the Permian Park City Formation reservoirs at two well locations. Within the basin boundary, the Phosphoria is thin and only locally rich in organic carbon; it is thought that the Phosphoria oil produced from Park City and other reservoirs migrated from the Idaho-Wyoming thrust belt. Other petroleum source rocks include the Cretaceous Thermopolis Shale, Mowry Shale, Frontier Formation, Cody Shale, Mesaverde and Meeteetse Formations, and the Tertiary (Paleocene) Fort Union Formation. Locations (wells) selected for burial history reconstructions include three in the deepest parts of the Bighorn Basin (Emblem Bench, Red Point/Husky, and Sellers Draw), three at intermediate depths (Amoco BN 1, Santa Fe Tatman, and McCulloch Peak), and two at relatively shallow locations (Dobie Creek and Doctor Ditch). The thermal maturity of source rocks is greatest in the deep central part of the basin and decreases to the south, east, and north toward the basin margins. The Thermopolis and Mowry Shales are predominantly gas-prone source rocks, containing a mix of Type-III and Type-II kerogens. The Frontier, Cody, Mesaverde, Meeteetse, and Fort Union Formations are gas-prone source rocks containing Type-III kerogen. Modeling results indicate that in the deepest areas, (1) the onset of petroleum generation from Cretaceous rocks occurred from early Paleocene through early Eocene time, (2) peak petroleum generation from Cretaceous rocks occurred during Eocene time, and (3) onset of gas generation from the Fort Union Formation occurred during early Eocene time and peak generation occurred from late Eocene to early Miocene time. Only in the deepest part of the basin did the oil generated from the Thermopolis and Mowry Shales start generating gas from secondary cracking, which occurred in the late Eocene to Miocene. Also, based on modeling results, gas generation from the cracking of Phosphoria oil reservoired in the Park City Formation began in the late Eocene in the deep part of the basin but did not anywhere reach peak generation.

  16. Investigation on the upper Paleozoic Strata in Tang-e-Zakeen, and introducing Zakeen formation, Kuh-e Faraghan Zagros Basin, South Iran

    International Nuclear Information System (INIS)

    A thick clastic sequence is well-developed in Tang-e-Zakeen, Kuh-e-Faraghan, being situated approximately 80 Km north of Bandar Abbas. The sequence is 340 m. thick and mainly consists of sandstone, siltstone, shale and subordinate dolomitic beds. So far, this clastic sequence has been called Faraghan Formation. This rock unit lacks marine fauna and based on stratigraphic position, it was assigned to the Early Permian (Szabo and Kheradpir, 1978). Since then, a detailed palynological study has been carried out on the Faraghan Formation by the author. These studies resulted identification of numerous palynomorph taxa, including miospore and acritarch species. The known palynomorph taxa indicated that, a major part of Faraghan Formation belongs to the Devonian Period, while the rest is Early Permian. As a result, the National Iranian Stratigraphic Committee decided and agreed upon to divide the Faraghan Formation into two rock units, namely, the Zakeen Formation, embracing the Devonian strata, and Faraghan Formation for the Early Permian sequence in the Zagros Basin respectively. The Zakeen Formation derives from the Zakeen Village which is located in the southern flank of Kuh-e-Faraghan, about 80 km north of Bandar Abbas. The type section of Zakeen Formation attains a thickness of 285m. in Tang-e-Zakeen, Kuh-e-Faraghan, approximately 23 Km from the Zakeen village. It disconformably rests on the Sarchahan Formation, while it too, disconformably overlain by the Faraghan Fodisconformably overlain by the Faraghan Formation. A total of 100 samples from the Zakeen Formation were selected and treated in the palynological laboratory of the Exploration Division of National Iranian Oil Company. 63 palynomorph taxa were encountered from the Zakeen Formation. The known species were arranged in five local stratigraphic assemblage zones. Zones I and II occur in a thickness of 96 m. of the Zakeen Formation, in ascending order, suggesting the Early Devonian whereas Zones III and IV occur Within 156 m. interval of the Zakeen Formation, representing the Middle Devonian. Lastly, the zone V is represent by 35.5 m. of rock-interval indicating the Frasnian age. The Zakeen Formation is not similar to any Devonian rock unit in the Alborz Ranges, as well as the Central Iranian Basin, but it is similar and equivalent to the Devonian rock units (Tail, jauf and Jubah formations) of the Saudi Arabia and southern Persian Gulf regions

  17. Sustaining Exploration in Mature Basins

    International Nuclear Information System (INIS)

    Exploration is a business like any other business driven by opportunity, resources and expectation of profit. Therefore, exploration will thrive anywhere the opportunities are significant, the resources are available and the outlook for profit (or value creation) is good. To sustain exploration activities anywhere, irrespective of the environment, there must be good understanding of the drivers of these key investment criteria. This paper will examine these investment criteria as they relate to exploration business and address the peculiarity of exploration in mature basin. Mature basins are unique environment that lends themselves a mix of fears, paradigms and realities, particularly with respect to the perception of value. To sustain exploration activities in a mature basin, we need to understand these perceptions relative to the true drivers of profitability. Exploration in the mature basins can be as profitable as exploration in emerging basins if the dynamics of value definition-strategic and fiscal values are understood by operators, regulators and co ventures alike. Some suggestions are made in this presentation on what needs to be done in addressing these dynamic investment parameters and sustaining exploration activities in mature basins

  18. Provenance of the Lower Triassic Bunter Sandstone Formation: implications for distr ibution and architecture of aeolian versus alluvial-fluvial reservoir s in the Nor th German Basin

    DEFF Research Database (Denmark)

    Olivarius, Mette; Weibel, Rikke

    2015-01-01

    Zircon U–Pb geochronometry, heavy mineral analyses and conventional seismic reflection data were used to interpret the provenance of the Lower Triassic Bunter Sandstone Formation. The succession was sampled in five Danish wells in the northern part of the North German Basin. The zircon ages found in the Bunter Sandstone show that sediment supply was mainly derived from the Ringkøbing-Fyn High and the Variscan belt and not from the Fennoscandian Shield as previously believed. Seismic reflection data document that the Ringkøbing-Fyn High was a local barrier for sediment transport. Provenance analysis is an invaluable tool of correlation and subdivision of the Bunter Sandstone in this marginal basin setting. This is because the succession includes many hiatuses so the cyclo-, magneto-, and bio-stratigraphic frameworks established elsewhere in the basin cannot readily be applied here. Zircon ages in the Volpriehausen Member (lower Bunter Sandstone) indicate derivation from source areas located to the south of the North German Basin that are of late Neoproterozoic to Carboniferous age. The dominant age population with a peak age of 337 Ma corresponds to the culmination of Variscan high-grade metamorphism, whereas a secondary age population with a peak at 300 Ma matches the timing of volcanism and magmatism at the Carboniferous/Permian boundary in the northern Variscan belt. The Ringkøbing-Fyn High also supplied some sediment tothe Volpriehausen Member. The zircon ages obtained from the Solling Member (upper Bunter Sandstone) match basement ages from the Ringkøbing-Fyn High and show that sediment contributions came mainly from the north. The age distributions are dominated by Mesoproterozoic zircon grains with a Sveconorwegian metamorphic overprint. The heavy mineral assemblage of the Solling Member is uniform and has a high garnet content compared to the contemporaneous sediments in the southern part of the North German Basin. This finding confirms that a local source supplied most of the sediment in the northern part of the basin. The most promising reservoir in the basin area is the aeolian Volpriehausen Member since the sandstone constitutes a lateral continuous unit. This is because sediment from the Variscan belt was transported by wind activity across the North German Basin when it was dried out. The alluvial to ephemeral fluvial Solling Member may be a good reservoir in the platform areas and marginal basin areas, but the variable sand content makes it difficult to predict the reservoir quality.

  19. Cross-fault pressure depletion, Zechstein carbonate reservoir, Weser-Ems area, Northern German Gas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Corona, F.V.; Brauckmann, F.; Beckmann, H.; Gobi, A.; Grassmann, S.; Neble, J.; Roettgen, K. [ExxonMobil Production Deutschland GmbH (EMPG), Hannover (Germany)

    2013-08-01

    A cross-fault pressure depletion study in Upper Permian Zechstein Ca2 carbonate reservoir was undertaken in the Weser-Ems area of the Northern German Gas Basin. The primary objectives are to develop a practical workflow to define cross-fault pressures scenarios for Zechstein Ca2 reservoir drillwells, to determine the key factors of cross-fault pressure behavior in this platform carbonate reservoir, and to translate the observed cross-fault pressure depletion to fault transmissibility for reservoir simulation models. Analysis of Zechstein Ca2 cross-fault pressures indicates that most Zechstein-cutting faults appear to act as fluid-flow baffles with some local occurrences of fault seal. Moreover, there appears to be distinct cross-fault baffling or pressure depletion trends that may be related to the extent of the separating fault or fault system, degree of reservoir flow-path tortuosity, and quality of reservoir juxtaposition. Based on the above observations, a three-part workflow was developed consisting of (1) careful interpretation and mapping of faults and fault networks, (2) analysis of reservoir juxtaposition and reservoir juxtaposition quality, and (3) application of the observed cross-fault pressure depletion trends. This approach is field-analog based, is practical, and is being used currently to provide reliable and supportable pressure prediction scenarios for subsequent Zechstein fault-bounded drill-well opportunities.

  20. Biostratigraphy, sedimentology and paleoenvironments of the northern Danube Basin: Ratkovce 1 well case study

    Directory of Open Access Journals (Sweden)

    Rybár Samuel

    2015-02-01

    Full Text Available The Ratkovce 1 well, drilled in the Blatné depocenter of the northern Danube Basin penetrated the Miocene sedimentary record with a total thickness of 2000 m. Biostratigraphically, the NN4, NN5 and NN6 Zones of calcareous nannoplankton were documented; CPN7 and CPN8 foraminifer Zones (N9, 10, 11 of the global foraminiferal zonation; and MMi4a; MMi5 and MMi6 of the Mediterranean foraminiferal zonation were recognized. Sedimentology was based on description of well core material, and together with SP and RT logs, used to characterize paleoenvironmental conditions of the deposition. Five sedimentary facies were reconstructed: (1 fan-delta to onshore environment which developed during the Lower Badenian; (2 followed by the Lower Badenian proximal slope gravity currents sediments; (3 distal slope turbidites were deposited in the Lower and Upper Badenian; (4 at the very end of the Upper Badenian and during the Sarmatian a coastal plain of normal marine to brackish environment developed; (5 sedimentation finished with the Pannonian-Pliocene shallow lacustrine to alluvial plain deposits. The provenance analysis records that the sediment of the well-cores was derived from crystalline basement granitoides and gneisses and from the Permian to Lower Cretaceous sedimentary cover and nappe units of the Western Carpathians and the Eastern Alps. Moreover, the Lower Badenian volcanism was an important source of sediments in the lower part of the sequence.

  1. Los bivalvos carboníferos y pérmicos de Patagonia (Chubut, Argentina): Parte V: Familias Trigoniidae, Permophoridae, Cardiniidae, Crassatellidae, Pholadomyidae, Sanguinolitidae y Megadesmidae. Conclusiones / Carboniferous and Permian bivalves from Patagonia (Chubut, Argentina): Part V: Families Trigoniidae, Permophoridae, Cardiniidae, Crassatellidae, Pholadomyidae, Sanguinolitidae and Megadesmidae. Conclusions

    Scientific Electronic Library Online (English)

    María Alejandra, Pagani.

    2006-09-01

    Full Text Available En este trabajo se realizó un exhaustivo análisis sistemático de la fauna de bivalvos del Paleozoico superior, provenientes de diferentes niveles fosilíferos de la Cuenca Tepuel-Genoa (provincia del Chubut, Argentina). En esta última parte se detallan los resultados obtenidos en relación a los repre [...] sentantes de las familias Trigoniidae, Permophoridae, Cardiniidae, Crassatellidae, Pholadomyidae, Sanguinolitidae, Megadesmidae, y las conclusiones de todo el estudio realizado. La abundancia de ejemplares y su buena preservación permitieron describir e ilustrar quince especies. Entre ellas se reconoce una especie nueva Pleurophorella elongata n. sp. y siete nuevos registros: Permophorus sp., Lyroschizodus? sp., Oriocrassatella sp., Cosmomya (Palaeocosmomya) sp., Exochorhynchus sp. y Pyramus sp. Con relación a las especies ya conocidas para la cuenca, debido al hallazgo de nuevo material se ha revisado la diagnosis y ampliado la descripción y distribución geográfica de Cosmomya (Palaeocosmomya) chubutensis González, Pyramus tehuelchis González y Pyramus primigenius González. Se analiza también el registro de: Cypricardinia? elegantula Dickins, Sanguinolites freytesi González, Sanguinolites turneri González y Myofossa antiqua González. Abstract in english A thorough systematic analysis on the bivalve fauna of the Upper Paleozoic of the Tepuel-Genoa Basin (Chubut Province, Argentina) is performed, as a contribution to the knowledge of early Permian faunas of Argentina. This last part comprises the families Trigoniidae, Permophoridae, Cardiniidae, Cras [...] satellidae, Pholadomyidae, Sanguinolitidae, Megadesmidae, and conclusions of all study. The abundant well preserved specimens allowed the recognition of the new species Pleurophorella elongata n. sp. New records of Permophorus sp., Lyroschizodus? sp., Oriocrassatella sp., Cosmomya (Palaeocosmomya) sp., Exochorhynchus sp. and Pyramus sp. are also included. On the basis of new material from the Tepuel-Genoa Basin, the diagnoses of Cosmomya (Palaeocosmomya) chubutensis González, Pyramus tehuelchis González, and Pyramus primigenius González are revised. In addition, the descriptions of these and other previously known species (Cypricardinia? elegantula Dickins, Sanguinolites freytesi González, Sanguinolites turneri González and Myofossa antiqua González) are supplemented by new information and their geographical ranges are expanded.

  2. El registro más antiguo de Echinoidea enArgentina y el contacto Pérmico - Jurásico Inferior en la región del Río Geona,Chubut / The oldest record of Echinoidea in Argentinaand the Permian-Early Jurassic contact in the Río Genoa region, Chubut

    Scientific Electronic Library Online (English)

    Julio C., Hlebszevitsch; Jorge S., Cortiñas.

    2009-11-01

    Full Text Available Se describe por primera vez en Argentina la presenciade restos de equinoideos asignados al género Archaeocidaris M'Coy de edadpérmica temprana provenientes de la Fomación Río Genoa en la localidad Salar deFerrarotti y crinoideos de la familia Apiocrinitidae d'Orbigny, en el Miembrosuperior de la Fom [...] ación Mulanguiñeu del Pliensbachiano - Toarciano de LomasOccidentales, ambas en la provincia del Chubut. Observaciones en estas doslocalidades de la cuenca Tepuel - Genoa, permiten referir al pre-Pliensbachianolas sedimentitas continentales que precede a las capas marinas portadoras delos crinoideos descriptos en este trabajo y de abundantes restos de bivalvos,gastrópodos, braquiópodos y amonites. Esta unidad continental (Fomación Mulanguiñeu,miembro inferior) de nivel bajo del Jurásico Temprano es reconocida hasta ahorasólo en el ámbito austral de la cuenca Tepuel-Genoa. Abstract in english Echinoids of the genus Archaeocidaris M'Coy of LowerPermian age from Rio Genoa Formation, and Apiocrinitidae crinoids from thePliensbachian-Toarcian of upper member of the Mulanguiñeu Formation of LomasOccidentales, are described for the first time in Argentina; both localitiesare in the Chubut prov [...] ince. The observations made in these two localities ofthe Tepuel-Genoa Basin let us refer to Pre-Pliensbachian the continental sedimentationthat precedes de the marine beds with the crinoids described in this work, andabundant remains of bivalves, gastropods, braquiopods and ammonites. Thiscontinental low stand unit (Lower Member of the Mulanguiñeu Formation), fromEarly Jurassic, up to now was only known at the southern part of the TepuelGenoa Basin.

  3. El registro más antiguo de Echinoidea enArgentina y el contacto Pérmico - Jurásico Inferior en la región del Río Geona,Chubut The oldest record of Echinoidea in Argentinaand the Permian-Early Jurassic contact in the Río Genoa region, Chubut

    Directory of Open Access Journals (Sweden)

    Julio C. Hlebszevitsch

    2009-11-01

    Full Text Available Se describe por primera vez en Argentina la presenciade restos de equinoideos asignados al género Archaeocidaris M'Coy de edadpérmica temprana provenientes de la Fomación Río Genoa en la localidad Salar deFerrarotti y crinoideos de la familia Apiocrinitidae d'Orbigny, en el Miembrosuperior de la Fomación Mulanguiñeu del Pliensbachiano - Toarciano de LomasOccidentales, ambas en la provincia del Chubut. Observaciones en estas doslocalidades de la cuenca Tepuel - Genoa, permiten referir al pre-Pliensbachianolas sedimentitas continentales que precede a las capas marinas portadoras delos crinoideos descriptos en este trabajo y de abundantes restos de bivalvos,gastrópodos, braquiópodos y amonites. Esta unidad continental (Fomación Mulanguiñeu,miembro inferior de nivel bajo del Jurásico Temprano es reconocida hasta ahorasólo en el ámbito austral de la cuenca Tepuel-Genoa.Echinoids of the genus Archaeocidaris M'Coy of LowerPermian age from Rio Genoa Formation, and Apiocrinitidae crinoids from thePliensbachian-Toarcian of upper member of the Mulanguiñeu Formation of LomasOccidentales, are described for the first time in Argentina; both localitiesare in the Chubut province. The observations made in these two localities ofthe Tepuel-Genoa Basin let us refer to Pre-Pliensbachian the continental sedimentationthat precedes de the marine beds with the crinoids described in this work, andabundant remains of bivalves, gastropods, braquiopods and ammonites. Thiscontinental low stand unit (Lower Member of the Mulanguiñeu Formation, fromEarly Jurassic, up to now was only known at the southern part of the TepuelGenoa Basin.

  4. Characteristics of zircons from volcanic ash-derived tonsteins in Late Permian coal fields of eastern Yunnan, China

    Science.gov (United States)

    Zhou, Y.; Ren, Y.; Tang, D.; Bohor, B.

    1994-01-01

    Kaolinitic tonsteins of altered synsedimentary volcanic ash-fall origin are well developed in the Late Permian coal-bearing formations of eastern Yunnan Province. Because of their unique origin, wide lateral extent, relatively constant thickness and sharp contacts with enclosing strata, great importance has been attached to these isochronous petrographic markers. In order to compare tonsteins with co-existing, non-cineritic claystones and characterize the individuality of tonsteins from different horizons for coal bed correlation, a semi-quantitative method was developed that is based on statistical analyses of the concentration and morphology of zircons and their spatial distribution patterns. This zircon-based analytical method also serves as a means for reconstructing volcanic ash-fall dispersal patterns. The results demonstrate that zircons from claystones of two different origins (i.e., tonstein and non-cineritic claystone) differ greatly in their relative abundances, crystal morphologies and spatial distribution patterns. Tonsteins from the same area but from different horizons are characterized by their own unique statistical patterns in terms of zircon concentration values and morphologic parameters (crystal length, width and the ratio of these values), thus facilitating stratigraphic correlation. Zircons from the same tonstein horizon also show continuous variation in these statistical patterns as a function of areal distribution, making it possible to identify the main path and direction in which the volcanic source materials were transported by prevailing winds. ?? 1994.

  5. RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

    Energy Technology Data Exchange (ETDEWEB)

    Robert Caldwell

    1998-04-01

    Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies to understand and quantify the resource itself and to develop technologies that will permit commercial exploitation. This study is a contribution to that process.

  6. Fuel storage basin seismic analysis

    International Nuclear Information System (INIS)

    The 105-KE and 105-KW Fuel Storage Basins were constructed more than 35 years ago as repositories for irradiated fuel from the K East and K West Reactors. Currently, the basins contain irradiated fuel from the N Reactor. To continue to use the basins as desired, seismic adequacy in accordance with current US Department of Energy facility requirements must be demonstrated. The 105-KE and 105-KW Basins are reinforced concrete, belowground reservoirs with a 16-ft water depth. The entire water retention boundary, which currently includes a portion of the adjacent reactor buildings, must be qualified for the Hanford Site design basis earthquake. The reactor building interface joints are sealed against leakage with rubber water stops. Demonstration of the seismic adequacy of these interface joints was initially identified as a key issue in the seismic qualification effort. The issue of water leakage through seismicly induced cracks was also investigated. This issue, coupled with the relatively complex geometry of the basins, dictated a need for three-dimensional modeling. A three-dimensional soil/structure interaction model was developed with the SASSI computer code. The development of three-dimensional models of the interfacing structures using the ANSYS code was also found to be necessary. 8 refs., 7 figs., 1 tab

  7. Seismic constraints on a large mafic intrusion with implications for the subsidence mechanism of the Danish Basin

    DEFF Research Database (Denmark)

    Sandrin, Alessandro; Thybo, Hans

    2008-01-01

    Seismic refraction data from the ESTRID-1 profile are used for seismic velocity modeling along the strike of a large mafic intrusion in the Norwegian-Danish Basin, central Denmark. The P wave velocity structure identifies a ~8 km thick sedimentary succession with velocities between 1.8 and 5.7 km/s. The top basement is defined by a step to vp = 6.2 km/s. In the middle to lower crust a high-velocity body (vp > 6.7 km/s), with its top located at about 10-12 km depth, is interpreted as a high-velocity and high-density gabbroic intrusion of Permian age. This high-velocity body explains the large (~50 mGal) positive gravity anomaly known as Silkeborg Gravity High. The intrusion has a minimum volume of 40,000 km3, which implies that the magma influx and the consequent cooling of the lithosphere from high temperature could have had profound effects on the subsidence of the Danish Basin, in particular because the magma probably intruded during only a few events and other similar structures cover much of the basin. Ananomalously high velocity gradient (from 7.0 km/s in the middle crust to 7.7 km/s at 30-32 km depth) in the central part of the intrusion coincides with an interval without Moho reflections, indicative of a gradual transition zone between the crust and the mantle. This feature may show the location of the feeder dykes of the intrusion.

  8. Early Permian to Late Triassic batholiths of the Chilean Frontal Cordillera (28°-31°S): SHRIMP U-Pb zircon ages and Lu-Hf and O isotope systematics

    Science.gov (United States)

    Hervé, Francisco; Fanning, C. Mark; Calderón, Mauricio; Mpodozis, Constantino

    2014-01-01

    One of the major geological units of the Main Andean Range (Frontal Cordillera) of north-central Chile is a group of composite and heterochronous late Paleozoic-early Mesozoic batholiths that extends for 500 km roughly NS along from 26° to 31°S. Ten new SHRIMP zircon crystallization ages together with 11 recently published U-Pb zircon ages by other authors indicate an episodic intrusion history which can be divided in 4 groups: Mississippian (earliest Carboniferous; 330-326 Ma), Cisuralian (earliest Permian; 301-284 Ma), latest Permian to Middle Triassic (264-242 Ma) and Late Triassic (225-215 Ma). Volcanic rocks in the area span a similar time. Lu-Hf and O isotopic systematics in zircon grains from eight of the plutonic rocks indicate the magma source areas have contributed variable amounts of crustal and mantle components. Zircon ?18O values evolve from crustal values (+ 7‰) in the earliest Permian intrusives to mantle values in the latest Permian to Upper Triassic, including evidence for likely hydrothermal alteration of the source (+ 4‰). Zircon ?Hf values vary in a good linear correlation with the ?18O isotopes, from - 6 to 0 in rocks older than 270 Ma increasing to + 2 to + 7 from Lower to Upper Triassic (250 to 215 Ma). The petrogenetic constraints indicated by these values, suggest that the influence of magma sources varied with time from predominantly crustal to mantle like. In accord with the regional tectonic models, the earliest Permian rocks were generated in a subduction-related magmatic arc, which varied towards an extension-related environment in the latest Permian and Triassic.

  9. Martian double ring basins - New observations

    Science.gov (United States)

    Wood, C. A.

    1980-01-01

    A description is presented of 18 Martian basins which were newly discovered on Viking photographs. A study of the basins reveals that diameter dependent differences in the morphology of Martian basins are more complex than previously realized. Basins have been classified according to ring morphology, and a diameter dependent sequence apparently exists. The obtained morphology sequence does not conform to the progression observed on the moon, Mercury, and earth. The small Martian basins are 50 to 100 km smaller than any basin on Mercury and the moon, supporting the view that they are unique to Mars. On earth there are significant terrain influences on crater and basin morphology that encourage the speculation that localized unique characteristics of the Martian crust led to basin formation at diameters where craters would normally be formed.

  10. WATSTORE Stream Flow Basin Characteristics File

    U.S. Geological Survey, Department of the Interior — The Stream Flow Basin Characteristics file contains information about the drainage basins of selected USGS gaging stations. Data elements of this file were...

  11. Hydrologic Sub-basins of Greenland

    National Aeronautics and Space Administration — The Hydrologic Sub-basins of Greenland data set contains Geographic Information System (GIS) polygon shapefiles that include 293 hydrologic sub-basins of the...

  12. Capture basin approximation using interval analysis

    OpenAIRE

    Lhommeau, Mehdi; Jaulin, Luc; Hardouin, Laurent

    2011-01-01

    This paper proposes a new approach for computing the capture basin C of a target T. The capture basin corresponds to the set of initial state vectors such that the target could be reached in finite time via an appropriate control input, before possibly leaving the target. Whereas classical capture basin characterization does not provide any guarantee on the set of state vectors that belong to the capture basin, interval analysis and guaranteed numerical integration allow us to avoid any indet...

  13. 87Sr/86Sr, 18O, 2H and 3H as tracers for genesis and saturation history of intruding groundwater in evaporitic deposits of the German Zechstein basin

    International Nuclear Information System (INIS)

    Full text: Salt mines in evaporitic deposits of the Permian Zechstein basin might be subject to flooding if formation water seeps into the mine openings through fore instance tectonically induced fractures.We apply several isotopic tracers to localize the sources of intrusions and to reconstruct the genesis and evolution of such brines. The evolution from formation water to brine comprises several starting points for isotopic tracers. Once the water infiltrates the salt rock, it starts to solute and concentrate various constituents and extractives of the drained deposits, and later on precipitations could occur. This non-linear solution and partly undersaturation poses a problem to the regular tracing methods. The element content might provide only limited indications on the source, which can be an aquifer or a large brine occurrence within the deposits. An aggravating factor is that such inclusions must not be of Permian age. The draining fractures can be closed in direction of the aquifer while enclosing liquids in different sized caverns or jointed rocks. However, these confined volumes of fluids pose only a limited risk for flooding. A combination of isotopic tracers, which provide indications on meteoric water, mixed water, connate water and a mixture of all, has to be contemplated: The cosmogenic radionuclide tritium 3H (? = 12.35 yr) indicates -if present- a direct connection to the earths surface. The stable isotopes 18O and 2 isotopes 18O and 2H can give clues to the type of water when related to older data. We have applied 87Sr/86Sr isotopes as an additional tool to further define the source. Recent 87Sr/86Sr analyzes of one brine inflow in a potash mine in the upper Permian Zechstein series suggest that the Sr isotope composition is rather affected by salt clay detritus than by halite or anhydrite. Other data show variations according to several isotopic seawater curves of Permian age. A combination of different isotopic tools may help to further delimit the source regions of intruding formation water in salt mines. (author)

  14. Nanoquartz in Late Permian C1 coal and the high incidence of female lung cancer in the Pearl River Origin area: a retrospective cohort study

    OpenAIRE

    Zhou Yiping; Ho Suzanne C; Huang Yunchao; Wang Jianfang; Dai Shifeng; Tian Linwei; Lucas Donald; Koshland Catherine P

    2008-01-01

    Abstract Background The Pearl River Origin area, Qujing District of Yunnan Province, has one of the highest female lung cancer mortality rates in China. Smoking was excluded as a cause of the lung cancer excess because almost all women were non-smokers. Crystalline silica embedded in the soot emissions from coal combustion was found to be associated with the lung cancer risk in a geographical correlation study. Lung cancer rates tend to be higher in places where the Late Permian C1 coal is pr...

  15. A refined succession of Changhsingian and Griesbachian neogondolellid conodonts from the Meishan section, candidate of the global stratotype section and point of the Permian-Triassic boundary

    Science.gov (United States)

    Mei, S.; Zhang, K.; Wardlaw, B.R.

    1998-01-01

    A detailed study of new conodont collections from the Changxing Formation at the Meishan section has resulted in taxonomic refinement of several important neogondolellid species. Most of the previously erected species are much more strictly redefined, mainly based on the denticulation of the holotypes, and the stratigraphic ranges attributed to key conodont taxa are modified. Three new species and two new subspecies, all of which are form-species, are tentatively erected and described mainly for the purpose of taxonomic explanation. As a result of the taxonomic refinement, six neogondolellid conodont zones are recognized for the Changxing Formation and the Permian-Triassic boundary interval.

  16. Supplementary information on K-Basin sludges

    International Nuclear Information System (INIS)

    Three previous documents in this series have been published covering the analysis of: K East Basin Floor and Pit Sludge, K East Basin Canister Sludge, and K West Basin Canister Sludge. Since their publication, additional data have been acquired and analyses performed. It is the purpose of this volume to summarize the additional insights gained in the interim time period

  17. Krušné hory Piedmont basins. Sokolov Basin.

    Czech Academy of Sciences Publication Activity Database

    Rojík, P.; Dašková, Ji?ina; Kva?ek, Z.; Pešek, J.; Sýkorová, Ivana; Teodoridis, V.

    Prague : Czech Geological Survey, 2014, s. 90-142 ISBN 978-80-7075-862-5 R&D Projects: GA ?R GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  18. Metre-scale cyclicity in Permian ramp carbonates of equatorial Pangea (Venezuelan Andes): Implications for sedimentation under tropical Pangea conditions

    Science.gov (United States)

    Laya, Juan Carlos; Tucker, Maurice E.; Perez-Huerta, Alberto

    2013-06-01

    Palmarito strata in the mid-Permian of the Venezuelan Andes show three different types of metre-scale cycle: Type A cycles are mixed clastic-carbonate, shallowing-upward peritidal cycles. The upper boundaries of the cycles are exposure surfaces with calcrete. This kind of cycle shows a significant degree of randomness in its thickness pattern and this is attributed to an autocyclic origin through tidal-flat progradation, and variations in carbonate productivity and clastic input to the depositional area. Type B cycles consist entirely of shallow subtidal facies with a shallowing-upward arrangement and an alternation between heterozoan and photozoan assemblages. Type C cycles were deposited in a middle to outer ramp setting and are characterized by a heterozoan assemblage and shallowing-upward trends that includes spiculitic wackestone-packstone passing up into neomorphic bioclastic wackestone or bioclastic crinoidal-bryozoan wackestone-packstone. All cycles are interpreted as 4th-5th order (104 to 105 years duration) and some can be linked to Milankovitch orbital rhythms, notably short eccentricity (~ 100,000 years). Overall, the origin of the Palmarito cycles was a complex combination of autocyclic and allocyclic controls; however, the evidence suggests that cycles in the lower part of the succession were dominated more by autocyclic processes whereas those in the upper part were more the result of allocyclic controls. Climate-driven processes, such as migration of the intertropical convergence one and the waxing and waning of polar ice-caps, had significant effects on deposition of the Palmarito succession and the cycles therein, controlling the clastic sediment supply, nutrient availability and thus carbonate production, and sea-level change, and these factors determined the vertical stacking pattern of the cycles.

  19. Gasterópodos y bivalvos cisuralianos (Pérmico inferior) de Otlamalacatla, Hidalgo, México / Cisuralian gastropods and bivalves (Lower Permian) from Otlamalacatla, Hidalgo, Mexico

    Scientific Electronic Library Online (English)

    Sara A., Quiroz-Barroso; Francisco, Sour-Tovar; Elena, Centeno-García.

    2012-04-01

    Full Text Available En esta contribución se reporta la fauna de gasterópodos y bivalvos provenientes de la Formación Tuzancoa en las cercanías del poblado Otlamalacatla, en el noreste del estado de Hidalgo. Los ejemplares están preservados como moldes imperfectos con cierto grado de deformación, lo que dificulta su est [...] udio y limita la precisión de las determinaciones taxonómicas. A pesar de ello, se advierte la presencia de cinco especies de gasterópodos pertenecientes a las familias Bellerophontidae, Omphalotrochidae, Eotomariidae, Naticopsidae y Soleniscidae, y 20 especies de bivalvos de las familias Nuculidae, Mytilidae, Myalinidae, Pterineidae, Bakevellidae, Euchondriidae, Aviculopectinidae, Deltopectinidae, Chaenocardiidae, Streblochondriidae, Heteropectinidae, Acanthopectinidae, Limidae, Schizodidae, Trigoniidae, Astartidae, Sanguinolitidae y Solenomorphidae, que en su mayoría representan su primer registro para México. Las especies determinadas tienen afinidad con faunas del oeste de Texas, que formó parte de la provincia biogeográfica Grandian durante el Pérmico temprano (Cisuraliano). Abstract in english New fauna of gastropods and bivalves colleted in outcrops of Tuzancoa Formation, near Otlamalacatla town, northeast of Hidalgo state, are described. The specimens are preserved like imperfect moulds with some deformation that limit the precise taxonomic determination. However, it is possible to repo [...] rt the presence of five species of gastropods from the families Bellerophontidae, Omphalotrochidae, Eotomariidae, Naticopsidae and Soleniscidae, and 20 species of pelecypods from the families Nuculidae, Mytilidae, Myalinidae, Pterineidae, Bakevellidae, Euchondriidae, Aviculopectinidae, Deltopectinidae, Chaenocardiidae, Streblochondriidae, Heteropectinidae, Acanthopectinidae, Limidae, Schizodidae, Trigoniidae, Astartidae, Sanguinolitidae and Solenomorphidae; most of these species are reported for the first time in Mexico. The principal affinities of this fauna are found in West Texas and belong to earlier Permian (Cisuralian) of Grandian province.

  20. Concentrations and modes of occurrence of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.Y. [Xian University of Science & Technology, Xian (China)

    2006-12-15

    The concentration, mode of occurrence, and origin of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China, were examined using inductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence (XRF), cold-vapor atomic absorption spectrometry (CV-AAS), ion-selective electrode method (ISE), sequential chemical extraction procedure (SCEP), scanning electron microscopy equipped with energy-dispersive X-ray (SEM-EDX), and optical microscope. Results show that minerals in the No. 2 Coal from the Puan Coalfield were mainly made up of epigenetic pyrite of low-temperature hydrothermal fluid origin and kaolinite of detrital terrigenous origin. Elements including As (36.9 {mu} g/g), Cd (10.2 {mu} g/g), Cr (167.3 {mu} g/g), Cu (365.4 {mu} g/g), Hg (2.82 {mu} g/g), Mo (92.6 {mu} g/g), Ni (82.6 {mu} g/g), Pb (184.6 {mu} g/g), Se (6.23 {mu} g/g), Zn (242.3 {mu} g/g), and U (132.7 {mu} g/g) are significantly enriched in the No. 2 Coal from the Puan Coalfield. However, concentrations of trace elements in the other four coals, the No. 1, No. 8, No. 11, and No. 18 Coals, were close to the usual ranges found for Guizhou of China, China, and USA. Results of SEM-EDX and SCEP showed that As, Cd, Hg, Mo, Ni, Pb, and Zn occur mainly in veined pyrite, while Cr, Cu, and U distribute mainly in kaolinite, indicating that the low-temperature hydrothermal fluid and detrital materials of terrigenous origin are the main contributors to the enrichment of these trace elements in the No. 2 Coal.

  1. Modes of occurrence and origins of noble metals in the Late Permian coals from the Puan Coalfield, Guizhou, southwest China

    Energy Technology Data Exchange (ETDEWEB)

    Jianye Yang [Xi' an University of Science and Technology, Xi' an (China). Department of Materials

    2006-09-15

    The concentrations, modes of occurrence, and origins of noble metals in the Late Permian coals from the Puan Coalfield, southwest China were studied using high-resolution inductively coupled-plasma mass spectrometry (ICP-MS) and sequential chemical extraction procedures (SECP). The results show that the minerals in the No. 2 coal from the Puan Coalfield were dominated by pyrite of low-temperature hydrothermal origin and clay minerals of detrital terrigenous origin. As compared with the concentrations of noble metals in the ordinary Chinese and American coals, the No. 2 coal significantly enriched in elements Rh (38 ng/g), Pd (640 ng/g), Ir (9 ng/g), Pt (98 ng/g), Au (16 ng/g), and Ag (1620 ng/g). The concentrations of Pd, Ir, and Au in the No. 2 coal are 4.3, 9, and 5.3 times higher than those of the ordinary Chinese coals, respectively. The SECP results indicate that the noble metals enriched in the No. 2 coal were mainly distributed in the sulfide association. The concentrations of Rh, Pd, Ir, Pt, Au, and Ag in the sulfide association are as high as 720, 15,000, 310, 2380, 360, and 32,300 ng/g, respectively. However, these noble metals in organic and silicate associations were lower than or close to their background values of coal. The low-temperature hydrothermal fluids play a dominant role in the enrichment of noble metals in the coal. 46 refs., 4 figs., 5 tabs.

  2. Calc-alkaline mafic rocks of the Black Dyke Formation: Remnants of the final activity of a submerged Permian volcano

    Energy Technology Data Exchange (ETDEWEB)

    Blein, O.; Lapierre, H.; Pecher, A. (URA-CNRS, Grenoble (France)); Schweickert, R.A. (Univ. of Nevada, Reno, NV (United States). Dept. of Geological Science)

    1993-04-01

    The Permian Black Dyke Fm., which occurs as large tectonic slices within the Luning allochthon in the Excelsior Mountains, NV, forms an E-W trending anticline at Black Dyke Mountain. The 800-m thick stratigraphic succession consists of volcanic and pyroclastic rocks overlain conformably by volcaniclastic sediments. Along the northern limb of the anticline, the rocks consist of mafic porphyritic lavas, breccias, and graded and ungraded pyroclastic beds. The sedimentary unit consists of thick volcaniclastic turbidites overlain by conglomerates, sandstones, and mudstones. Along the southern limb of the anticline, the sequence is replaced by reworked breccia, tuffs, and sandstones. Mafic plutonic rocks occur as xenoliths in the lavas and breccias, and as coeval plugs intruding the section. Gabbros show cumulate or porphyritic textures and are composed of amph, cpx, and zoned plag. Their Ti/V (14.5--15) and Nb/Y (0.25--0.3) ratios fall in the range commonly found in calc-alkaline rocks. Diorite porphyry shows high Al[sub 2]O[sub 3], ZrO[sub 2], and REE abundances indicating that this rock is more fractionated. Basalts and andesites are plag-cpx-opx phyric. They often include glomeroporphyritic clots of cpx with amph coronas. Some rocks exhibit fluidal textures. Both volcanic and plutonic rocks show homogeneous geochemical features and similar crystallization sequences: Fe-Ti oxides---->plag---->opx + cpx----> brown zoned hbl, suggesting that they are cogenetic. Thus, the lower part of the Black Dyke Fm. likely represents the final products formed in a calc-alkaline magma chamber because pyroclastic rocks prevail over lava flows and abundant early crystal cumulates occur as plugs or as inclusions in the lavas and breccias.

  3. The Mackenzie Basin impacts study

    International Nuclear Information System (INIS)

    In 1989, a commitment was made to begin development of a framework for an integrated regional impact assessment of global warming scenarios in the Mackenzie Basin, the most populated region of Canada's north. The project, called Mackenzie Basin Impact Study (MBIS), is led by a multidisciplinary working group from government and non-governmental organizations with interests in the Basin. Objectives of MBIS include defining the direction and magnitude of regional-scale impacts of global warming scenarios on the physical, biological, and human systems of the Basin. MBIS will also identify regional sensitivities to climate, inter-system linkages, uncertainties, policy implications, and research needs. MBIS research activities as of March 1992 are outlined and policy concerns related to global warming are listed. Two new methodologies are being developed by MBIS to address particular economic and policy concerns: a socio-economic resource accounting framework and an integrated land assessment framework. Throughout MBIS, opportunities will be presented for western science and traditional native knowledge to be integrated

  4. Models of Fractal River Basins

    OpenAIRE

    Cieplak, Marek; Giacometti, Achille; Maritan, Amos; Rinaldo, Andrea; Rodriguez-iturbe, Ignacio; Banavar, Jayanth R.

    1998-01-01

    Two distinct models for self-similar and self-affine river basins are numerically investigated. They yield fractal aggregation patterns following non-trivial power laws in experimentally relevant distributions. Previous numerical estimates on the critical exponents, when existing, are confirmed and superseded. A physical motivation for both models in the present framework is also discussed.

  5. Great Basin paleoenvironmental studies project

    International Nuclear Information System (INIS)

    Project goals, project tasks, progress on tasks, and problems encountered are described and discussed for each of the studies that make up the Great Basin Paleoenvironmental Studies Project for Yucca Mountain. These studies are: Paleobotany, Paleofauna, Geomorphology, and Transportation. Budget summaries are also given for each of the studies and for the overall project

  6. 77 FR 57188 - Rusk, Palestine & Pacific Railroad, LLC-Operation Exemption-Texas State Railroad Authority

    Science.gov (United States)

    2012-09-17

    ...Railroad, LLC--Operation Exemption-- Texas...American Heritage Railways of Texas, LLC...and Permian Basin Railways-- Continuance in Control Exemption--Rusk...and Permian Basin Railways seek to continue in control of RP&P,...

  7. Distribution and Diversity of Carboniferous and Permian Colonial Rugose Coral Faunas in Western North America: Clues for Placement of Allochthonous Terranes

    Directory of Open Access Journals (Sweden)

    Calvin H. Stevens

    2012-05-01

    Full Text Available Colonial rugose corals are common in western cratonal North America and in some of the allochthonous terranes, now amalgamated against its western margin. Throughout the Late Paleozoic, the coral faunas in these two different settings were significantly different. Comparisons of these faunas suggest that during the Mississippian the Alexander terrane probably was southwest of Arctic Alaska and the Stikine terrane probably lay west of the southern part of the North American craton. The Cache Creek terrane lay far out in the Paleopacific Ocean. The Pennsylvanian faunas suggest that the Quesnellia and Eastern Klamath terranes were situated southwest of Arctic Alaska and the Alexander terrane was somewhat farther southwest and farther from cratonal North America. The Stikine terrane continued to be positioned west of the southern part of the North American craton. During the Early Permian, terranes with a cratonal faunal aspect may have lain 2000–3000 km west of cratonal North America and latitudinally generally southwest of their present positions. In the Middle Permian these terranes were carried southward relative to the North American craton. Simultaneously the Tethyan Realm expanded eastward.

  8. Enrichment of U-Se-Mo-Re-V in coals preserved within marine carbonate successions: geochemical and mineralogical data from the Late Permian Guiding Coalfield, Guizhou, China

    Science.gov (United States)

    Dai, Shifeng; Seredin, Vladimir V.; Ward, Colin R.; Hower, James C.; Xing, Yunwei; Zhang, Weiguo; Song, Weijiao; Wang, Peipei

    2015-02-01

    We present multi-element data on the super-high-organic-sulfur (SHOS; 5.19 % on average) coals of Late Permian age from Guiding, in Guizhou Province, China. The coals, formed on restricted carbonate platforms, are all highly enriched in S, U, Se, Mo, Re, V, and Cr, and, to a lesser extent, Ni and Cd. Although the Guiding coals were subjected to seawater influence, boron is very low and mainly occurs in tourmaline and mixed-layer illite/smectite. Uranium, Mo, and V in the coal are mainly associated with the organic matter. In addition, a small proportion of the U occurs in coffinite and brannerite. The major carrier of Se is p