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)

1983-07-01

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

Uranium potential in outcropping Permian basins in France and their extensions beneath mesozoic and tertiary cover

International Nuclear Information System (INIS)

Hery, B.

1990-01-01

About a third of metropolitan France's uranium production is from Permian deposits located in the Lodeve and, to a lesser extent, Bourbon-l'Archambault basins. Of the Autun, west Vanoise, St-Affrique, Rodez, Brive and Var basins investigated in this study, only those of Rodez and Var have been shown to contain significant deposits. Some of the basins contain potentially interesting targets, often removed from the areas of known mineral occurrences, that have never been investigated. Geophysical exploration and drilling have shown that the Permian extends over a vast area beneath the cover of the large Mesozoic and Tertiary basins. However zones within reach of mineral exploration, ie. those less than 500 m deep, are only found in a few areas. To reach the distant targets down-dip in the outcropping basins or beneath the Mesozoic and Tertiary cover, a detailed study of the basin must be undertaken beforehand. To define and locate targets that are obviously more costly to investigate, direct methods of investigation need to be used such as drilling and geochemistry, and indirect methods such as remote sensing, geophysics and well-logging [fr

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

DEFF Research Database (Denmark)

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

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...

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.

Permian salt dissolution, alkaline lake basins, and nuclear-waste storage, Southern High Plains, Texas and New Mexico

International Nuclear Information System (INIS)

Reeves, C.C. Jr.; Temple, J.M.

1986-01-01

Areas of Permian salt dissolution associated with 15 large alkaline lake basins on and adjacent to the Southern High Plains of west Texas and eastern New Mexico suggest formation of the basins by collapse of strata over the dissolution cavities. However, data from 6 other alkaline basins reveal no evidence of underlying salt dissolution. Thus, whether the basins were initiated by subsidence over the salt dissolution areas or whether the salt dissolution was caused by infiltration of overlying lake water is conjectural. However, the fact that the lacustrine fill in Mound Lake greatly exceeds the amount of salt dissolution and subsidence of overlying beds indicates that at least Mound Lake basin was antecedent to the salt dissolution. The association of topography, structure, and dissolution in areas well removed from zones of shallow burial emphasizes the susceptibility of Permian salt-bed dissolution throughout the west Texas-eastern New Mexico area. Such evidence, combined with previous studies documenting salt-bed dissolution in areas surrounding a proposed high-level nuclear-waste repository site in Deaf Smith County, Texas, leads to serious questions about the rationale of using salt beds for nuclear-waste storage

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

International Nuclear Information System (INIS)

Bein, A.; Dutton, A.R.

1993-01-01

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

Tectono-sedimentary evolution of the Permian-Triassic extension event in the Zagros basin (Iran): results from analogue modelling

Science.gov (United States)

Madani-kivi, M.; Zulauf, G.

2015-12-01

Since the 1970s, the largest oil and gas reservoirs have been discovered in the Permian-Early Triassic formationsin Saudi Arabia. Thus, this time period is important for the discovery of new oil reserves in Iran. The Arabian passivecontinental margin has undergone lithospheric extension during the Permian-Triassic, which led to the formation of theNeo-Tethys. The aim of this paper is to describe the development of the continental rift basin in the Zagros region basedon the tectono-sedimentological evolution. We have studied well-log data to specify the distribution of synrift depositsin the Zagros and have related this information to the modelling. Environmental changes indicated by various sedimentarysequences, from a siliciclastic basin to a carbonate platform setting, are described. The Cambrian Hormuz salt, whichoverlies the metamorphosed Precambrian basement, becomes effective as a basal detachment layer influencing the styleof overburden deformation during the Permian-Triassic extension event. We have investigated the formation of variousstructures linked to the presence or absence of the Hormuz layer by analogue modelling and relating these structures to theLate Palaeozoic sedimentation. Based on results of the analogue modelling, we argue that the basal detachment layer (Hormuzseries) has contributed to the various structural styles of the extensional basin development in the Fars domain and theLorestan domain.

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

Energy Technology Data Exchange (ETDEWEB)

Rychel, Dwight [Petroleum Tech Transfer Council, Oak Hill, VA (United States)

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.

Exploratory shaft conceptual design report: Permian Basin

International Nuclear Information System (INIS)

1983-07-01

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

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

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

International Nuclear Information System (INIS)

1983-12-01

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

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

Science.gov (United States)

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

2016-07-01

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

The Tunas Formation (Permian) in the Sierras Australes foldbelt, east central Argentina: evidence for syntectonic sedimentation in a foreland basin

Science.gov (United States)

Lopez-Gamundi, O. R.; Conaghan, P. J.; Rossello, E. A.; Cobbold, P. R.

1995-04-01

The Tunas Formation, extensively exposed in the Sierras Australes foldbelt of eastern central Argentina, completes the sedimentation of the Gondwanan (Late Carboniferous-Permian) sequence, locally known as the Pillahuincó Group. The underlying units of the Group show an integrated depositional history which can be explained in terms of glaciomarine sedimentation (Sauce Grande Formation) and postglacial transgression (Piedra Azul and Bonete Formations). This succession also has a rather uniform quartz-rich, sand-sized composition indicative of a cratonic provenance from the Tandilia Massif to the northeast. Early to Late Permian deformation folded and thrusted the southwestern basin margin (Sierras Australes) and triggered the deposition of a 1,500 m — thick, synorogenic prograding wedge, the Tunas Formation, in the adjacent foreland basin (Sauce Grande or Claromecó Basin). Sandstone detrital modes for the Tunas deposits show moderate to low contents of quartz and abundant lithics, mostly of volcanic and metasedimentary origin. Paleocurrents are consistently from the SW. Tuffs interbedded with sandstones in the upper half of Tunas Formation (Early — early Late? Permian) are interpreted as being derived from volcanic glass-rich tuffs settled in a body of water. Extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region during that period. The age constraints and similarities in composition between these volcanics and the tuffaceous horizons present in the Sauce Grande, Parana and Karoo Basins suggest a genetic linkage between these two episodes. The intimate relationship between volcanic activity inboard of the paleo-Pacific margin, deformation in the adjacent orogenic belt and subsidence and sedimentation in the contiguous foreland basin constitutes a common motif in the Sauce Grande and Karoo Basins of southwestern Gondwana.

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

International Nuclear Information System (INIS)

1987-09-01

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

An appraisal of the Permian palaeobiodiversity and geology of the Ib-River Basin, eastern coastal area, India

Science.gov (United States)

Goswami, Shreerup; Saxena, Anju; Singh, Kamal Jeet; Chandra, Shaila; Cleal, Christopher J.

2018-05-01

The Ib-River Basin situated in the east coastal area of India, in Odisha State is a south-eastern part of the Mahanadi Master Basin. A large number of plant macrofossils belonging to the Glossopteris flora were described and documented between 2006 and 2010 from various localities of the Barakar and Lower Kamthi formations of this basin. The floral components representing leaves, roots and fructifications in these assemblages belong to the Lycopodiales, Equisetales, Sphenophyllales, Filicales, Cordaitales, Cycadales, Ginkgoales, Coniferales and Glossopteridales. In the present study, all the available data pertaining to the biological remains, petrological analyses as well as the geology of this basin are reviewed and analyzed to deduce and reconstruct the biostratigraphy, palaeoclimate, palaeoenvironment and the landscape of this basin during Permian time in general and during the deposition of Barakar (Artinskian - Kungurian) and Lower Kamthi (Lopingian) formations in particular. The floral composition suggests the prevalence of a temperate climate with a slight change from warm moist to warm dry conditions during the deposition of the Barakar Formation and warm and humid during the deposition of Lower Kamthi sediments. Distribution of various plant groups in the Barakar and Lower Kamthi formations have been shown to depict the biodiversity trends. Vegetational reconstructions during the deposition of the Barakar and Lower Kamthi formations around the Ib-River Basin have also been attempted based on all the fossil records from this area. The status of unclassified Barakar and Kamthi formations has been redefined. Apart from megafloristics, the palynology of the basin is also discussed. Possible marine incursions and marine marginal environment in the Ib-Basin during Permian are overtly summarized on the basis of records of acritarchs, typical marine ichnofossils and evidences of wave activity in Lower Gondwana sediments of this Basin.

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.

Late Permian (Zechstein) carbonate-facies maps, the Netherlands

NARCIS (Netherlands)

Geluk, M.C.

2000-01-01

The Late Permian Zechstein carbonates in the Southern Permian Basin were deposited under marine conditions. The carbonates form part of a largely progradational infill, with a gradual northward facies shift. The paleogeography of the Zechstein carbonate deposits has been reviewed recently on the

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

Czech Academy of Sciences Publication Activity Database

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

2013-01-01

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

Speculative petroleum systems of the Punta del Este Basin (offshore Uruguay

Directory of Open Access Journals (Sweden)

Ethel Morales

Full Text Available ABSTRACT: The Uruguayan continental margin was generated as the result of the breakup of Gondwana and, later, the opening of the South Atlantic Ocean, which began in the Jurassic. Three major areas of Meso-Cenozoic sedimentation are located in the Uruguayan offshore: the Punta del Este Basin, the southernmost sector of the Pelotas Basin and the Oriental del Plata Basin. These basins share the classical stages of tectono-sedimentary evolution of the other Atlantic basins, including the prerift (Paleozoic, rift (Jurassic-Early Cretaceous, transition (Barremian-Aptian and postrift (Aptian-present phases. Based on the analysis of basin evolution through seismic sections and well data as well as on the establishment of analogies with productive Atlantic basins, four speculative petroleum systems are proposed for the Punta del Este Basin: 1 Marine petroleum system of the prerift stage: Devonian/Permian-Devonian/Permian(?, 2 Lacustrine petroleum system of the synrift stage: Neocomian-Neocomian(?, 3 Marine petroleum system of the Cretaceous postrift: Aptian-Late Cretaceous(?, 4 Marine petroleum system of the Cenozoic postrift: Paleocene-Paleogene/Neogene(?.

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

Stratigraphy and paleogeographic significance of a Late Pennsylvanian to Early Permian channeled slope sequence in the Darwin Basin, southern Darwin Hills, east-central California

Science.gov (United States)

Stevens, Calvin H.; Stone, Paul; Magginetti, Robert T.; Ritter, Scott M.

2015-01-01

The complex stratigraphy of late Paleozoic rocks in the southern Darwin Hills consists of regionally extensive Mississippian and Early to Middle Pennsylvanian rocks overlain by latest Pennsylvanian to Early Permian rocks, herein called the Darwin Hills sequence. Deposition of this latter sequence marked the beginning of the Darwin Basin. In Mississippian time, a carbonate platform prograded westward over slightly older slope deposits. In the Late Mississippian this platform was exposed to erosion and siliciclastic sediments were deposited. In Early to Middle Pennsylvanian time the area subsided, forming a west-facing ramp that was subjected to deformation and erosion in Middle or early Late Pennsylvanian time. Later this area was tilted westward and deep-water sediments were deposited on this slope. In latest Pennsylvanian to earliest Permian time, a major channel was cut through the older Pennsylvanian rocks and into the Upper Mississippian strata. This channel was gradually filled with increasingly finer grained, deep-water sediment as the area evolved into a basin floor by Early Permian (Sakmarian) time. Expansion of the Darwin Basin in Artinskian time led to a second phase of deposition represented by strata of the regionally extensive Darwin Canyon Formation. The geology in this small area thus documents tectonic events occurring during the early development of the Darwin Basin.

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

International Nuclear Information System (INIS)

1979-10-01

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

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

Directory of Open Access Journals (Sweden)

Souza Paulo A.

2005-01-01

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

Prolonged Permian Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages.

Science.gov (United States)

Clapham, Matthew E; Bottjer, David J

2007-08-07

The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous-Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian-Triassic switch in diversity.

Geochemistry of formation waters from the Wolfcamp and “Cline” shales: Insights into brine origin, reservoir connectivity, and fluid flow in the Permian Basin, USA

Science.gov (United States)

Engle, Mark A.; Reyes, Francisco R.; Varonka, Matthew S.; Orem, William H.; Lin, Ma; Ianno, Adam J.; Westphal, Tiffani M.; Xu, Pei; Carroll, Kenneth C.

2016-01-01

Despite being one of the most important oil producing provinces in the United States, information on basinal hydrogeology and fluid flow in the Permian Basin of Texas and New Mexico is lacking. The source and geochemistry of brines from the basin were investigated (Ordovician- to Guadalupian-age reservoirs) by combining previously published data from conventional reservoirs with geochemical results for 39 new produced water samples, with a focus on those from shales. Salinity of the Ca–Cl-type brines in the basin generally increases with depth reaching a maximum in Devonian (median = 154 g/L) reservoirs, followed by decreases in salinity in the Silurian (median = 77 g/L) and Ordovician (median = 70 g/L) reservoirs. Isotopic data for B, O, H, and Sr and ion chemistry indicate three major types of water. Lower salinity fluids (100 g/L), isotopically heavy (O and H) water in Leonardian [Permian] to Pennsylvanian reservoirs (2–3.2 km depth) is evaporated, Late Permian seawater. Water from the Permian Wolfcamp and Pennsylvanian “Cline” shales, which are isotopically similar but lower in salinity and enriched in alkalis, appear to have developed their composition due to post-illitization diffusion into the shales. Samples from the “Cline” shale are further enriched with NH4, Br, I and isotopically light B, sourced from the breakdown of marine kerogen in the unit. Lower salinity waters (3 km depth), which plot near the modern local meteoric water line, are distinct from the water in overlying reservoirs. We propose that these deep meteoric waters are part of a newly identified hydrogeologic unit: the Deep Basin Meteoric Aquifer System. Chemical, isotopic, and pressure data suggest that despite over-pressuring in the Wolfcamp shale, there is little potential for vertical fluid migration to the surface environment via natural conduits.

Late Permian Palynology and depositional environment of Chintalapudi sub basin, Pranhita-Godavari basin, Andhra Pradesh, India

Science.gov (United States)

Jha, Neerja; Pauline Sabina, K.; Aggarwal, Neha; Mahesh, S.

2014-01-01

The present study deals with the palynological dating, correlation and depositional setting of the sediments from bore cores MGP-11 and MGP-4 from Gauridevipet area of Chintalapudi sub-basin of Godavari master basin, south India. On the basis of palynological studies, three palynoassemblages have been identified, one in bore core MGP-11 a Faunipollenites (=Protohaploxypinus) and Striasulcites assemblage and two in bore core MGP-4; one is characterized by the dominance of striate bisaccates and Densipollenites and the other by Striatopodocarpites and Cresentipollenites palynoassemblages. The other stratigraphically significant taxa include Guttulapollenites hannonicus, Lunatisporites noviaulensis, Lunatisporites pellucidus, Densoisporites contactus, Chordasporites australiensis, Goubinispora spp., Lundbladispora microconata, Lundbladispora raniganjensis and Klausipollenites schaubergeri. The recovered taxa suggest a Late Permian, Lopingian age for these rocks. This interpretation is based on the correlation of the assemblages with similar assemblages from previous Gondwana studies chiefly Densipollenites magnicorpus Zone of Damodar Basin, India and Late Permian palynoassemblages from Africa, Antarctica, Australia and South America. On the basis of palaeobotanical affinity of the identified microflora it has been inferred that the peat forming plant community was composed mainly of gymnosperm pollen attributable to glossopterids, that includes striate and non-striate bisaccates and paucity of cordaites which includes monosaccates. Spores are subordinate and are derived from lycopsids (Lundbladispora, Densoisporites), sphenopsids (Latosporites) and filicopsids (Horriditriletes, Lophotriletes, Verrucosisporites, Osmundacidites, Leiotriletes, Callumispora, Brevitriletes and Microbaculispora) occurring in variable proportions. The dominance of subarborescent/arborescent vegetation suggests a development in a forest swamp probably in a small distant marginal part of the

Structural changes of marine communities over the Permian-Triassic transition: Ecologically assessing the end-Permian mass extinction and its aftermath

Science.gov (United States)

Chen, Zhong-Qiang; Tong, Jinnan; Liao, Zhuo-Ting; Chen, Jing

2010-08-01

The Permian/Triassic (P/Tr) transition is ecologically assessed based on examining 23 shelly communities from five shallow platform, ramp and shelf basin facies Permian-Triassic boundary (PTB) sections in South China. The shelly communities have undergone two major collapses coinciding with the two episodes of the end-Permian mass extinction. The first P/Tr extinction event devastated shelly communities in all types of settings to some extent. The basin communities have been more severely impacted than both platform and ramp communities. The survival faunas have rebounded more rapidly in shallow niches than in relatively deep habitats. The second P/Tr crisis destroyed the survival communities in shallow setting and had little impact on the basin communities in terms of community structures. The early Griesbachian communities are overall low-diversity and high-dominance. The governorship switch from brachiopods to bivalves in marine communities has been facilitated by two pulses of the end-Permian mass extinction and the whole takeover process took about 200 ka across the P/Tr boundary. Bivalve ecologic takeover initially occurred immediately after the first P/Tr extinction in shallow water habitats and was eventually completed in all niches after the second P/Tr event. Some post-extinction communities have the irregular rarefaction curves due to the unusual community structures rather than sampling intensities.

Geochemical characteristics of the Permian sedimentary rocks from Qiangtang Basin: Constraints for paleoenvironment and paleoclimate

Directory of Open Access Journals (Sweden)

Junjie Hu

2017-01-01

Full Text Available Qiangtang Basin is expected to become important strategic petroleum exploitation area in China. However, little research has been done on the Permian strata in this area. This paper presents Lower Permian Zhanjin Formation geochemical data from the Jiaomuri area, reconstructing the paleo-depositional environment and providing information for further petroleum exploration. The geochemical characteristics of 19 samples were investigated. These geochemical samples show a developed mud flat characteristic with light rich clay content. The geological data were used to constrain the paleoredox environment, which proved that these sediments were deposited mainly beneath a slightly oxic water column with relatively low paleoproductivity as evidenced by the P/Ti (mean of 0.07 and Ba/Al (mean of 20.5. Palaeoclimate indexes such as the C-value (0.24-1.75 and Sr/Cu (1.28-11.58 reveal a humid climatic condition during Zhanjin Formation sediment deposition. The ω(LaN/ω(YbN ratio values indicate a fast sedimentary rate during the deposition period.

High-Resolution Zircon U-Pb CA-TIMS Dating of the Carboniferous—Permian Successions, Paraná Basin, Brazil

Science.gov (United States)

Griffis, N. P.; Mundil, R.; Montanez, I. P.; Isbell, J.; Fedorchuk, N.; Lopes, R.; Vesely, F.; Iannuzzi, R.

2015-12-01

The late Paleozoic Ice Age (LPIA) is Earth's only record of a CO2-forced climatic transition from an icehouse to greenhouse state in a vegetated world. Despite a refined framework of Gondwanan ice distribution, questions remain about the timing, volume, and synchronicity of high-latitude continental ice and the subsequent deglaciation. These questions ultimately preclude our understanding of linkages between ice volume, sea level, and high- and low-latitude climate. Poor constraints on the timing and synchronicity of glacial and interglacial transitions reflect a lack of high-resolution radioisotopic dates from high-latitude, ice-proximal Carboniferous-Permian successions. The Rio Bonito Fm in Rio Grande do Sul State of southern Brazil hosts the oldest non-glaciogenic Carboniferous- Permian deposits of the Paraná Basin, thus recording the icehouse-to-greenhouse transition. Despite a widespread effort over the last two decades to constrain these deposits in time by means of U-Pb zircon geochronology, published data sets of the Candiota and Faxinal coals of the Rio Bonito Fm host discrepancies that may reflect post- eruptive open system behavior of zircon and analytical artifacts. These discrepancies have hindered the correlation of the Candiota and Faxinal sediments within the larger Gondwanan framework. Here we present the first U-Pb ages on closed system single zircons using CA-TIMS techniques on Permo-Carboniferous ash deposits of the Paraná Basin. Preliminary results indicate two major and distinct coal-forming periods that are separated by ca 10 Ma. Our results and conclusions are not in agreement with multi- crystal U-Pb TIMS and SIMS ages that suggest coeval deposition of the Candiota and Faxinal coals. CA-TIMS analyses applied to zircons from additional ash deposits are aimed at constructing a robust chronostratigraphic framework for the Carboniferous- Permian succession of the Paraná Basin, which will facilitate a better understanding of the timing and

The earliest Permian shark fossils from Texas and their implications for later marine faunas

Science.gov (United States)

Shell, R.; Ciampaglio, C. N.

2017-12-01

Complex marine vertebrate faunas from lower Permian rocks are incredibly rare. Recent research suggests that the composition of what few communities can be found varied wildly, especially in regard to the presence or absence of Hybodontiform sharks. Early Permian marine faunas in Texas are generally richer in Hybodont sharks than similarly aged communities in Russia and Bolivia, but the cause of this variation is unknown. A fossil hybodont spine fragment from just above the Pennsylvanian/Permian boundary in Texas, however, suggests that that regional climatic events allowed Hybodont sharks to migrate into the Permian Basin at the outset of the Permian itself. As the Basin evolved tectonically and sedimentologically, these sharks likely evolved to fill new niches as they opened up- which may have resulted in the increased number of Hybodont species in the Permian of Texas: a major factor to consider in the faunal evolution of the Western Interior Seaway during the Mesozoic and beyond.

Isotope shifts in the late Permian of the Delaware Basin, Texas, precisely timed by varved sediments

International Nuclear Information System (INIS)

Magaritz, M.; Oregon Univ., Eugene; Anderson, R.Y.; Holser, W.T.; Saltzmann, E.S.; Garber, J.

1983-01-01

Closely spaced samples (285 in number) of varved sediments from the Upper Permian in Delaware Basin, Texas, have been analyzed for delta 13 Csub(carb), delta 13 Csub(org), delta 18 Osub(carb), Csub(org), Csub(carb) and calcite/dolomite. delta 13 C records a dramatic rise from -2.8 to + 5.7per mille in only 4400 years, detected in three sections across the basin, extrapolating smoothly through a 600-year interruption by a local (west side of the basin) fresh-water inflow evidenced by low delta 18 O. This continuity and low Csub(org) within the basin, both indicate that the excess net deposition of Csub(org), necessary to generate the rise in delta 13 C, took place in the ocean external to the Delaware Basin, Correlation with similar records from the Zechstein Basin suggest that the event was world-wide, although this poses obvious difficulties for the carbon cycle. The rate of rise of delta 13 C, and its sustained high level, must imply conversions of oxidized carbon to reduced carbon that are very large depending on which reservoirs were involved. (orig.)

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

Prelude of benthic community collapse during the end-Permian mass extinction in siliciclastic offshore sub-basin: Brachiopod evidence from South China

Science.gov (United States)

Wu, Huiting; He, Weihong; Weldon, Elizabeth A.

2018-04-01

Analysis of the Permian-Triassic palaeocommunities from basinal facies in South China provides an insight into the environmental deterioration occurring in the prelude to the mass extinction event. Quantitative and multivariate analyses on three brachiopod palaeocommunities from the Changhsingian to the earliest Triassic in basinal facies in South China have been undertaken in this study. Although the end-Permian extinction has been proved to be a one-stepped event, ecological warning signals appeared in the palaeocommunities long before the main pulse of the event. A brachiopod palaeocommunity turnover occurred in the upper part of the Clarkina changxingensis Zone, associated with a significant decrease of palaeocommunity diversity and brachiopod body size. During this turnover the dominant genera changed from Fusichonetes and Crurithyris (or/and Paracrurithyris) to the more competitive genus Crurithyris (or/and Paracrurithyris). The brachiopod palaeocommunity turnover was supposed to be triggered by the decreased marine primary productivity and increased volcanic activity. Moreover, such early warning signals are found not only in the deep-water siliceous facies, but also in the shallow-water clastic facies and carbonate rock facies in South China.

U.S. Geological Survey input-data forms for the assessment of the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017

Science.gov (United States)

Marra, Kristen R.

2017-10-24

In 2017, the U.S. Geological Survey (USGS) completed an updated assessment of undiscovered, technically recoverable oil and gas resources in the Spraberry Formation of the Midland Basin (Permian Basin Province) in southwestern Texas (Marra and others, 2017). The Spraberry Formation was assessed using both the standard continuous (unconventional) and conventional methodologies established by the USGS for three assessment units (AUs): (1) Lower Spraberry Continuous Oil Trend AU, (2) Middle Spraberry Continuous Oil Trend AU, and (3) Northern Spraberry Conventional Oil AU. The revised assessment resulted in total estimated mean resources of 4,245 million barrels of oil, 3,112 billion cubic feet of gas, and 311 million barrels of natural gas liquids. The purpose of this report is to provide supplemental documentation of the input parameters used in the USGS 2017 Spraberry Formation assessment.

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

International Nuclear Information System (INIS)

Dunagan, J.F. Jr.; Kadish, K.A.

1977-11-01

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

Thermomechanical analyses of conceptual repository designs for the Paradox and Permian Basins

International Nuclear Information System (INIS)

Loken, M.C.; Callahan, G.D.; Svalstad, D.K.; Wagner, R.A.

1987-11-01

The potential repositories are designed to accommodate all waste forms emplaced at various thermal loadings; specifically, commercial high-level waste (30 W/m 2 ), spent fuel (15 W/m 2 ), defense high-level waste (20 W/m 2 ), and remote-handled and contact-handled transuranic nonheat-generating waste. The study evaluates the design parameters, primarily thermal loading, based on a comparison of calculable thermomechanical parameters with prescribed performance constraints. This evaluation was accomplished by numerical simulation using finite element techniques of the canister, disposal room, and repository regions of each potential site. Important thermal and thermomechanical results were compared with their prescribed constraint or limit value. All of the performance constraints were satisfied at the Davis Canyon site in the Paradox Basin for commercial high-level waste, spent fuel, and defense high-level waste at areal thermal loadings of 20 W/m 2 , 15 W/m 2 , and 20 W/m 2 , respectively. Similarly, for the Deaf Smith County site in the Permian Basin, commercial high-level waste, spent fuel, and defense high-level waste thermal loadings of 13.5 W/m 2 , 8.5 W/m 2 , and 6.0 W/m 2 , respectively, satisfied all of the performance constraints. 89 refs., 64 figs., 22 tabs

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

Czech Academy of Sciences Publication Activity Database

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

2014-01-01

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

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

OpenAIRE

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

2007-01-01

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

A 25 million year macrofloral record (Carboniferous-Permian) in the Czech part of the Intra-Sudetic Basin, biostratigraphy, plant diversity and vegetation patterns

Czech Academy of Sciences Publication Activity Database

Opluštil, S.; Šimůnek, Z.; Pšenička, J.; Bek, Jiří; Libertín, M.

2017-01-01

Roč. 244, SEP 2017 (2017), s. 241-307 ISSN 0034-6667 R&D Projects: GA ČR GAP210/12/2053 Institutional support: RVO:67985831 Keywords : Early Permian * floral zonation * Intra-Sudetic Basin * Pennsylvanian * plant diversity * plant taphonomy * vegetation patterns Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Paleontology Impact factor: 1.817, year: 2016

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

International Nuclear Information System (INIS)

1986-12-01

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

Organic richness and gas generation potential of Permian Barren ...

Indian Academy of Sciences (India)

this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin ... number of factors like (i) quality and quantity of organic matter ...... Gujarat Energy Research and Management Insti-.

Evidence of lacustrine sedimentation in the Upper Permian Bijori

Indian Academy of Sciences (India)

The Upper Permian Bijori Formation of the Satpura Gondwana basin comprising fine- to coarsegrained sandstone, carbonaceous shale/mudstone and thin coal bands was previously interpreted as the deposits of meandering rivers. The present study documents abundance of wave ripples, hummocky and swaley ...

Paleomagnetic and magnetostratigraphic investigations of the whitehorse group/quartermaster (Dewey Lake) formation (upper permian-lowermost triassic) in the Palo Duro basin, northwest Texas, USA

Science.gov (United States)

Collins, Dylan R.

In northwest Texas, upper Permian to lowermost Triassic hematite-cemented detrital sedimentary rocks, which include a small number of regionally extensive ash beds, were deposited during the time interval of the greatest mass extinction event sequences in Earth history. The magnetic polarity stratigraphy, as well as key rock magnetic properties, of the upper Whitehorse Group (WH) and Quartermaster formations (QM) at selected sections in the Palo Duro Basin, have been determined using thermal, and chemical demagnetization approaches and anisotropy of magnetic susceptibility, acquisition of isothermal remanent magnetization (IRM) and backfield demagnetization, and thermal demagnetization of three component IRM methods. Demagnetization results show that the WH/QM contains a primary/near-primary characteristic remanent magnetization at each level sampled and thus the magnetic polarity stratigraphy for each section can be compared with existing polarity time scales across the Permian-Triassic boundary. Estimated site mean directions yield a paleomagnetic pole for the latest Permian for North America of 57.8°N, 130.6°E from 38 sampled sites.

Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup, Paraná Basin, Brazil: implications for the exploration model

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António Mateus

Full Text Available 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/hydrocarbon 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.

Formation of phreatomagmatic pipes in the Tunguska Basin (Siberia, Russia) during the end-Permian

Science.gov (United States)

Polozov, Alexander; Svensen, Henrik; Planke, Sverre

2010-05-01

We recently proposed that numerous pipes piercing sedimentary rocks of Tunguska Basin triggered the Permian-Triassic mass extinction (Svensen et al., 2009). Large amounts of greenhouse and poisonous gases were released through the pipes and into P-Tr atmosphere, partly formed by heating of petroleum-bearing evaporites. The sub-volcanic part of the Siberian Traps was emplaced in the Tunguska Basin sedimentary sequences, which includes Pre-Cambrian source rocks, Early Cambrian evaporites, and Paleozoic terrigenous and coal-bearing rocks. Spectacular breccia pipes are numerous in the evaporate-parts of the basin, and are filled with volcaniclastic rocks and commercial magnetite mineralization. Although these pipes have been intensively studied in order to understand the iron ore formation, the origin and formation of the pipes is poorly understood. Many researchers emphasize that magma-sediments interaction as a key reason of pipe formation, whereas phreatomagmatic hypothesis are also proposed. In order to improve the understanding of pipe formation and ore-deposition, we have studied a basalt-rich breccia pipe piercing Cambrian evaporates at the Nepa locality in East Siberia. Textural features of the volcanic fragments in the breccias include lapilli, Pele's hear, glassy basalt and dolerite clasts, blocks of tuffs in addition to sedimentary rocks. Calcite and halite are the most common types of cement. We have studied minerals from the breccia cement and from reaction rims around clasts in order to understand the hydrothermal system that developed after the pipe formed. Calcite and dolomite are the dominating carbonates, and two types of anhydrite is present. Biotite, Cl-Fe-bearing amphibole (hastingsite), and Cl-F-apatite are amongst early hydrothermal minerals covering magmatic clast and lapillies. Our new data confirm (i) the phreatomagmatic nature of breccia filling in the Tunguska Basin pipes and (ii) the key role of sedimentary brine and petroleum involved in

A new mid-Permian burnetiamorph therapsid from the Main Karoo Basin of South Africa and a phylogenetic review of Burnetiamorpha

Directory of Open Access Journals (Sweden)

Michael O. Day

2016-12-01

Full Text Available Discoveries of burnetiamorph therapsids in the last decade and a half have increased their known diversity but they remain a minor constituent of middle–late Permian tetrapod faunas. In the Main Karoo Basin of South Africa, from where the clade is traditionally best known, specimens have been reported from all of the Permian biozones except the Eodicynodon and Pristerognathus assemblage zones. Although the addition of new taxa has provided more evidence for burnetiamorph synapomorphies, phylogenetic hypotheses for the clade remain incongruent with their appearances in the stratigraphic column. Here we describe a new burnetiamorph specimen (BP/1/7098 from the Pristerognathus Assemblage Zone and review the phylogeny of the Burnetiamorpha through a comprehensive comparison of known material. Phylogenetic analysis suggests that BP/1/7098 is closely related to the Russian species Niuksenitia sukhonensis. Remarkably, the supposed mid-Permian burnetiids Bullacephalus and Pachydectes are not recovered as burnetiids and in most cases are not burnetiamorphs at all, instead representing an earlier-diverging clade of biarmosuchians that are characterised by their large size, dentigerous transverse process of the pterygoid and exclusion of the jugal from the lateral temporal fenestra. The evolution of pachyostosis therefore appears to have occurred independently in these genera. The resulting biarmosuchian tree is significantly more congruent with the stratigraphic appearance of its constituent taxa than in previous phylogenetic hypotheses and, consequently, does not necessarily constrain the diversification of the Burnetiamorpha to before the Capitanian.

Late Permian rivers draining the uplifted Cape Fold Belt: magnetostratigraphy and detrital thermochronology of Karoo Basin sediments

Science.gov (United States)

Tohver, E.; Schmieder, M.; Arosio, R.; Lanci, L.; Jourdan, F.; Wilson, A.; Ratcliffe, K.; Payenberg, T.; Flint, S.

2017-12-01

The Cape Fold Belt and Karoo Basin of southern Africa formed during the Permian orogeny that affected the 13,000 km southern margin of the Gondwanan continent. In this report, we synthesize new and recent magnetostratigraphic and geochronologic data to establish a chronostratigraphic framework for Karoo Basin sedimentation for comparison with the thermal/exhumation history of the Cape Fold Belt. The source-sink model is evaluated using new data from detrital muscovite and zircon from 2 km composite section of fluvial sandstone and mudstones deposited at ca.275 - 260 Ma. Coherent age populations of detrital zircon grains indicate rapid incorporation of contemporary volcanic ashbeds into the sedimentary record. In contrast, cooling age distributions of detrital muscovite are typically ca. 5 - 10 Ma older than the age of deposition; similar lag times are observed from modern sediments in active mountain belts. Trace element geochemical signatures demonstrate a clear shift towards crustal recycling via headland erosion in the Beaufort Group relative to the underlying Ecca Group. These observations pinpoint the age of uplift for the Cape Fold Belt, which began to function as the major sediment source for the foreland Karoo Basin with the deposition of the uppermost Ecca Group and basal Beaufort Group.

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

Science.gov (United States)

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

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

Early Permian transgressive-regressive cycles: Sequence stratigraphic reappraisal of the coal-bearing Barakar Formation, Raniganj Basin, India

Science.gov (United States)

Bhattacharya, Biplab; Bhattacharjee, Joyeeta; Bandyopadhyay, Sandip; Banerjee, Sudipto; Adhikari, Kalyan

2018-03-01

The present research is an attempt to assess the Barakar Formation of the Raniganj Gondwana Basin, India, in the frame of fluvio-marine (estuarine) depositional systems using sequence stratigraphic elements. Analysis of predominant facies associations signify deposition in three sub-environments: (i) a river-dominated bay-head delta zone in the inner estuary, with transition from braided fluvial channels (FA-B1) to tide-affected meandering fluvial channels and flood plains (FA-B2) in the basal part of the succession; (ii) a mixed energy central basin zone, which consists of transitional fluvio-tidal channels (FA-B2), tidal flats, associated with tidal channels and bars (FA-B3) in the middle-upper part of the succession; and (iii) a wave-dominated outer estuary (coastal) zone (FA-B4 with FA-B3) in the upper part of the succession. Stacked progradational (P1, P2)-retrogradational (R1, R2) successions attest to one major base level fluctuation, leading to distinct transgressive-regressive (T-R) cycles with development of initial falling stage systems tract (FSST), followed by lowstand systems tract (LST) and successive transgressive systems tracts (TST-1 and TST-2). Shift in the depositional regime from regressive to transgressive estuarine system in the early Permian Barakar Formation is attributed to change in accommodation space caused by mutual interactions of (i) base level fluctuations in response to climatic amelioration and (ii) basinal tectonisms (exhumation/sagging) related to post-glacial isostatic adjustments in the riftogenic Gondwana basins.

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

Directory of Open Access Journals (Sweden)

Amiruddin Amiruddin

2014-06-01

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

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

Directory of Open Access Journals (Sweden)

Nicholas Fordyce

2012-10-01

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 TropidostomaAssemblage 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.

A sedimentological analysis of sediments corresponding to the San Gregorio Formation )Lower Permian), located in the eastern border of the North Uruguayan Basin, Sierra Guazunambi

International Nuclear Information System (INIS)

Goso Aguilar, C.; Gama, E.

1998-01-01

A sedimentological analysis of sediments corresponding to the San Gregorio Formation (Lower Permian), located in the eastern border of the Norte Uruguayan Basin, Sierra Guazunambi, Cerro Largo Departament was made. Facies analysis of about 100 otucrops fand more than 1.300 meters, in an area of 45 square kilometers showed diamictites rhytmites and massive sandstones, formed by gravitational sedimentary flows. Also present are prodelta mudrocks and deltaic front sandstones.(author)

Paleogeographic changes across the Pennsylvanian-Permian boundary within the Mid-Continent (USA) inferred from detrital zircon geochronology of continental deposits

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Soreghan, M. J.; Soreghan, G. S.

2017-12-01

The Permo-Pennsylvanian was characterized by intense orogenesis associated with Pangaean assembly, and profound climate shifts as earth transitioned from full icehouse conditions in the Pennsylvanian-early Permian to collapse into greenhouse conditions by latest Permian time. The modern U.S. Midcontinent was part of equatorial western Pangaea (North America) sandwiched between a continental-scale orogenic zone to the east and south (Appalachian-Ouachita-Marathon orogenic belt) and a series of basement-cored, intra-plate uplifts along western Pangaea (Ancestral Rocky Mountains). Here, we present a compilation of detrital zircon geochronology data from the Permo-Pennsylvanian of the Midcontinent as well as coeval strata of the east and west to explore sediment dispersal and potential tectonic and climatic influences on these provenance signatures. Zircon provenance data come from mostly eolian and fluvial silt- and sandstones of Early Pennsylvanian through Mid Permian age, although some data include marine sandstones. Our new data were acquired by LA-ICPMS at the University of Arizona Laserchron, and predominant age groups include >2500 Ma (Archean), 1600-1800 Ma (Yavapai-Matzatzal), 1300-900 Ma (Grenville), 790-570 Ma (Neoproterozoic), and 480-360 (E-M Paleozoic). However, the relative distributions of these populations exhibit distinctive temporal differences, especially across the Pennsylvanian-Permian boundary, but also spatially in comparison to published data from the Appalachian-Ouachita-Marathon basin, Ancestral Rocky Mountain basins, and the western Pangaean margin. Although the Central Pangaean Mountains, and in particular the Grenville-age basement rocks, were a dominant source of sediment to the Midcontinent, the data suggest an abrupt introduction of Neoproterozoic zircons in the early Permian. This signature also appears within the Ancestral Rocky Mountains region, but is rare along the western margin and the Appalachian basin in the early Permian. This

Refining the chronostratigraphy of the Karoo Basin, South Africa: magnetostratigraphic constraints support an early Permian age for the Ecca Group

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Belica, Mercedes E.; Tohver, Eric; Poyatos-Moré, Miquel; Flint, Stephen; Parra-Avila, Luis A.; Lanci, Luca; Denyszyn, Steven; Pisarevsky, Sergei A.

2017-12-01

The Beaufort Group of the Karoo Basin, South Africa provides an important chrono- and biostratigraphic record of vertebrate turnovers that have been attributed to the end-Permian mass extinction events at ca. 252 and 260 Ma. However, an unresolved controversy exists over the age of the Beaufort Group due to a large data set of published U-Pb SHRIMP (Sensitive High Resolution Ion Microprobe) zircon results that indicate a ca. 274-250 Ma age range for deposition of the underlying Ecca Group. This age range requires the application of a highly diachronous sedimentation model to the Karoo Basin stratigraphy and is not supported by published palaeontologic and palynologic data. This study tested the strength of these U-Pb isotopic data sets using a magnetostratigraphic approach. Here, we present a composite ∼1500 m section through a large part of the Ecca Group from the Tanqua depocentre, located in the southwestern segment of the Karoo Basin. After the removal of two normal polarity overprints, a likely primary magnetic signal was isolated at temperatures above 450 °C. This section is restricted to a reverse polarity, indicating that it formed during the Kiaman Reverse Superchron (ca. 318-265 Ma), a distinctive magnetostratigraphic marker for early-middle Permian rocks. The Ecca Group has a corresponding palaeomagnetic pole at 40.8°S, 77.4°E (A95 = 5.5°). U-Pb SHRIMP ages on zircons are presented here for comparison with prior isotopic studies of the Ecca Group. A weighted mean U-Pb age of 269.5 ± 1.2 Ma was determined from a volcanic ash bed located in the uppermost Tierberg Formation sampled from the O + R1 research core. The age is interpreted here as a minimum constraint due to a proposed Pb-loss event that has likely influenced a number of published results. A comparison with the Geomagnetic Polarity Time Scale as well as published U-Pb TIMS ages from the overlying Beaufort Group supports a ca. 290-265 Ma age for deposition of the Ecca Group.

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

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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.

A high resolution magnetostratigraphic profile across the Permian-Triassic boundary in the Southern Sydney Basin, eastern Australia

Science.gov (United States)

Belica, M. E.; Tohver, E.; Nicoll, R.; Denyszyn, S. W.; Pisarevsky, S.; George, A. D.

2016-12-01

The Permian-Triassic boundary (PTB) is associated with the largest mass extinction in Phanerozoic geologic history. Despite several decades of intense study, there is ongoing debate regarding the exact timing of extinction and the global correlation of marine and terrestrial P-T sections. The terrestrial record is hampered by a lack of index fossils; however, magnetostratigraphy offers an opportunity for correlation because it relies on the global synchronicity of magnetic reversals. A magnetostratigraphic profile across the Permian-Triassic boundary has been obtained from a stratigraphically continuous terrestrial section in the Southern Sydney Basin of eastern Australia. The 60 m section is located within the Narrabeen Group, which consists of fluvial to lacustrine sandstones and mudstones. Paleomagnetic samples were collected at one meter intervals to determine a detailed reversal record. Samples were stepwise thermally demagnetized to isolate a primary remanence, and magnetic susceptibility was measured in the field at 30 cm intervals with values ranging from -0.047-2.50 (10-3 SI units). Three normal and three reverse magnetozones were detected after removal of a low temperature overprint, and the results show good agreement with the Global Magnetic Polarity Timescale as well as marine Permian-Triassic sections where the PTB is well constrained. Furthermore, a reverse polarity subchron has been identified within the normal magnetozone spanning the PTB similar to results published from the Netherlands and China. The magnetic stratigraphy suggests that the Narrabeen Group was deposited during the late Changhsingian to early Induan, and provides a revised placement of the PTB in the lower Wombarra Claystone. Integration of the magnetostratigraphy with existing isotopic datasets suggests that the terrestrial extinction in eastern Australia occurred 7.5 m below the PTB in the Changhsingian Coalcliff Sandstone. A tuff within a coal seam underlying the Coalcliff

Stratigraphy and tectonics of Permo-Triassic basins in the Netherlands and surrounding areas

NARCIS (Netherlands)

Geluk, M.C.

2005-01-01

This thesis addresses different aspects of the geological development during the Permian and Triassic (300 to 200 Ma) of the Netherlands and surrounding areas. The study area encompasses the Southern Permian Basin (SPB), a large intracratonic basin stretched out from the United Kingdom in the west

The age of the Tunas formation in the Sauce Grande basin-Ventana foldbelt (Argentina): Implications for the Permian evolution of the southwestern margin of Gondwana

Science.gov (United States)

López-Gamundí, Oscar; Fildani, Andrea; Weislogel, Amy; Rossello, Eduardo

2013-08-01

New SHRIMP radiogenic isotope dating on zircons in tuffs (280.8 ± 1.9 Ma) confirms the Early Permian (Artinskian) age of the uppermost section of the Tunas Formation. Tuff-rich levels in the Tunas Formation are exposed in the Ventana foldbelt of central Argentina; they are part of a deltaic to fluvial section corresponding to the late overfilled stage of the Late Paleozoic Sauce Grande foreland basin. Recent SHRIMP dating of zircons from the basal Choiyoi volcanics exposed in western Argentina yielded an age of 281.4 ± 2.5 Ma (Rocha-Campos et al., 2011). The new data for the Tunas tuffs suggest that the volcanism present in the Sauce Grande basin can be considered as the distal equivalent of the earliest episodes of the Choiyoi volcanism of western Argentina. From the palaeoclimatic viewpoint the new Tunas SHRIMP age confirms that by early Artinskian glacial conditions ceased in the Sauce Grande basin and, probably, in adajacent basins in western Gondwana.

Descartes highlands: Possible analogs around the Orientale Basin, part D

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Carroll, A. H.

1972-01-01

Two possible analogs, although not entirely satisfactory, offer reasonable alternatives to the volcanic interpretation of the Descartes highlands. Reconsideration of this complex terrain, prompted by the preliminary results of the Apollo 16 mission, will lead to the revision of some theories on lunar volcanism and also to a better understanding of the landforms caused by the formation of multi-ring basins.

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

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

2012-08-01

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

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)

Carmo Faria Junior, L.E. do

1980-01-01

The quartz grains of sediments and sedimentary rocks change their colour in variable intensity to smoky-quartz by X-ray irradiation, Co 60 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) [pt

Prolonged Permian–Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages

Science.gov (United States)

Clapham, Matthew E.; Bottjer, David J.

2007-01-01

The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous–Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian–Triassic switch in diversity. PMID:17664426

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

International Nuclear Information System (INIS)

1983-07-01

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

Dalhart's only Permian field gets best oil well

International Nuclear Information System (INIS)

Land, R.

1992-01-01

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

Petroleum geology of the Palo Duro Basin, Texas Panhandle

International Nuclear Information System (INIS)

Rose, P.R.

1986-03-01

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

The evolution of a Late Cretaceous-Cenozoic intraplate basin (Duaringa Basin), eastern Australia: evidence for the negative inversion of a pre-existing fold-thrust belt

Science.gov (United States)

Babaahmadi, Abbas; Sliwa, Renate; Esterle, Joan; Rosenbaum, Gideon

2017-12-01

The Duaringa Basin in eastern Australia is a Late Cretaceous?-early Cenozoic sedimentary basin that developed simultaneously with the opening of the Tasman and Coral Seas. The basin occurs on the top of an earlier (Permian-Triassic) fold-thrust belt, but the negative inversion of this fold-thrust belt, and its contribution to the development of the Duaringa Basin, are not well understood. Here, we present geophysical datasets, including recently surveyed 2D seismic reflection lines, aeromagnetic and Bouguer gravity data. These data provide new insights into the structural style in the Duaringa Basin, showing that the NNW-striking, NE-dipping, deep-seated Duaringa Fault is the main boundary fault that controlled sedimentation in the Duaringa Basin. The major activity of the Duaringa Fault is observed in the southern part of the basin, where it has undergone the highest amount of displacement, resulting in the deepest and oldest depocentre. The results reveal that the Duaringa Basin developed in response to the partial negative inversion of the pre-existing Permian-Triassic fold-thrust belt, which has similar orientation to the extensional faults. The Duaringa Fault is the negative inverted part of a single Triassic thrust, known as the Banana Thrust. Furthermore, small syn-depositional normal faults at the base of the basin likely developed due to the reactivation of pre-existing foliations, accommodation faults, and joints associated with Permian-Triassic folds. In contrast to equivalent offshore basins, the Duaringa Basin lacks a complex structural style and thick syn-rift sediments, possibly because of the weakening of extensional stresses away from the developing Tasman Sea.

Major factors controlling fracture development in the Middle Permian Lucaogou Formation tight oil reservoir, Junggar Basin, NW China

Science.gov (United States)

Zhang, Chen; Zhu, Deyu; Luo, Qun; Liu, Luofu; Liu, Dongdong; Yan, Lin; Zhang, Yunzhao

2017-09-01

Natural fractures in seven wells from the Middle Permian Lucaogou Formation in the Junggar Basin were evaluated in light of regional structural evolution, tight reservoir geochemistry (including TOC and mineral composition), carbon and oxygen isotopes of calcite-filled fractures, and acoustic emission (AE). Factors controlling the development of natural fractures were analyzed using qualitative and/or semi-quantitative techniques, with results showing that tectonic factors are the primary control on fracture development in the Middle Permian Lucaogou Formation of the Junggar Basin. Analyses of calcite, dolomite, and TOC show positive correlations with the number of fractures, while deltaic lithofacies appear to be the most favorable for fracture development. Mineral content was found to be a major control on tectonic fracture development, while TOC content and sedimentary facies mainly control bedding fractures. Carbon and oxygen isotopes vary greatly in calcite-filled fractures (δ13C ranges from 0.87‰ to 7.98‰, while δ18O ranges from -12.63‰ to -5.65‰), indicating that fracture development increases with intensified tectonic activity or enhanced diagenetic alteration. By analyzing the cross-cutting relationships of fractures in core, as well as four Kaiser Effect points in the acoustic emission curve, we observed four stages of tectonic fracture development. First-stage fractures are extensional, and were generated in the late Triassic, with calcite fracture fills formed between 36.51 °C and 56.89 °C. Second-stage fractures are shear fractures caused by extrusion stress from the southwest to the northeast, generated by the rapid uplift of the Tianshan in the Middle and Late Jurassic; calcite fracture fills formed between 62.91 °C and 69.88 °C. Third-stage fractures are NNW-trending shear fractures that resulted from north-south extrusion and thrusting in a foreland depression along the front of the Early Cretaceous Bogda Mountains. Calcite fracture

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.

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

Science.gov (United States)

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

1987-01-01

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

Paleomagnetism and Magnetostratigraphy of Upper Permian to Lower Triassic (?) Beaufort Group Strata at Bethulie, Karoo Basin, Free State Province, South Africa

Science.gov (United States)

Geissman, J. W.; Gastaldo, R. A.; Neveling, J.; Makubalo, S.

2017-12-01

A multifaceted approach to understand the timing of interpreted environmental changes during the Late Permian to possibly Early Triassic (?) time in the Beaufort Group strata of the Karoo Basin includes work to establish robust magnetic polarity records for sections previously interpreted to encompass end-Permian extinction events. Demonstrating the preservation of an early-acquired remanence (RM) in Karoo strata is required for a robust magnetostratigraphy. Yet, this is challenging due to thermochemical effects related to the Early Jurassic (ca. 183 Ma) Karoo Large Igneous Province (LIP), and the NE to SW increase in burial diagenesis attending Cape Fold Belt tectonism. Documentation of a primary RM in these strata, which appears to be preserved in some areas, requires careful laboratory- and field-based assessment. We report data from 53 sites collected at the well-studied Bethulie section, Free State Province, in which several samples per individual horizon to assess ChRM uniformity. Strata well-removed from dikes yield both normal and reverse polarity ChRM. It is always the case that the first-removed RM is a NNW seeking, moderate to steep negative-inclination ChRM (normal polarity); NRM intensities are typically 1 to 5 mA/m. Sites BT15 and BT21, which are located in strata lying some 4 m below the often-cited "event bed" interval inferred to be the terrestrial expression of the Permian/Triassic boundary, is dominated by a well-defined reverse RM with a normal overprint RM unblocked below 400oC, implying elevated temperatures (i.e., 100 to 250oC+) for ca. 1 Ma (+/-). Contact tests are positive but complicated. Host strata collected in distances equal to or less than 1-2 dike widths from the intrusions have been thermally remagnetized and demonstrate high NRM intensities (> 50 mA/m). Collectively, we interpret these data to indicate that any ChRM, with the exception of those from host strata in baked contacts, that persists above Tlub of 425oC is pre-Karoo LIP

Sedimentary architecture and palaeogeography of lower Slochteren Aeolian cycles from the Rotliegend desert-lake margin (Permian), the Markham area, Southern North Sea

NARCIS (Netherlands)

Belt, F.J.G. van den; Hulten, F.F.N. van

2011-01-01

The Rotliegend gas play in the Southern Permian Basin has yielded over 200 gas fields in the Netherlands; they are found in an E-W fairway along the southern flank of the basin. Sandstones generally pinch out basinward, but localized, isolated sands are present north of the main fairway. The

Physicochemical analysis of Permian coprolites from Brazil

Science.gov (United States)

Rodrigues, M. I. C.; da Silva, J. H.; Santos, F. Eroni P.; Dentzien-Dias, P.; Cisneros, J. C.; de Menezes, A. S.; Freire, P. T. C.; Viana, B. C.

2018-01-01

In this paper we performed the study of two coprolites (fossilized feces) collected from the exposed levels of the Pedra de Fogo Formation, Parnaiba Sedimentary Basin, and Rio do Rasto Formation, Paraná Sedimentary Basin, both of the Palaeozoic era (Permian age). They were characterized using X-ray diffractometry, infrared, Raman and energy dispersive spectroscopy techniques in order to aid our understanding of the processes of fossilization and to discuss issues related to the feeding habits of the animals which generated those coprolites, probably cartilaginous fishes. The results obtained using a multitechnique approach showed that although these coprolites are from different geological formations, 3000 km away from each other, they show the same major crystalline phases and elemental composition. The main phases found were hydroxyapatite, silica, calcite and hematite, which lead to infer that those coprolites were formed under similar conditions and produced by a similar group of carnivore or omnivore fishes.

An Early Permian epithermal gold system in the Tulasu Basin in North Xinjiang, NW China: Constraints from in situ oxygen-sulfur isotopes and geochronology

Science.gov (United States)

Dong, Leilei; Wan, Bo; Deng, Chen; Cai, Keda; Xiao, Wenjiao

2018-03-01

The Axi and Jingxi-Yelmand gold deposits, being the largest gold deposits in the Chinese North Tianshan, NW China, are located ca. l0 km apart in the Tulasu Basin, and are hosted by the Late Devonian - Early Carboniferous Dahalajunshan Formation. In situ LA-ICP-MS titanium analyses on quartz from the Axi and Jingxi-Yelmand deposits are broadly identical. Accordingly, the calculated ore-forming temperatures by Ti-in-quartz thermometer give average temperatures of 279 °C and 294 °C, respectively. Results of in situ SIMS analyses of oxygen and sulfur isotopes on quartz and pyrite from these two deposits are similar. Temperature-corrected fluids of the Axi deposit have δ18O values of 2.6-8.1‰ and δ34S values of 0.8-2.4‰, whereas the fluids of the Jingxi-Yelmand deposit have δ18O of 6.4-8.9‰ and δ34S of -0.4 to 4.0‰. The oxygen and sulfur isotopes from the two deposits indicate a magmatic origin. LA-ICP-MS zircon U-Pb ages of Aqialehe Formation sandstone provided a lower limit for the mineralization timing of the Axi deposit (288 Ma). In situ SIMS U-Pb analyses on entrapped zircon (297 Ma) and newly recognized 284.5 Ma columnar rhyolite implies that the Jingxi-Yelmand deposit formed in the Early Permian. Based on the magmatic affinity of the ore fluids, similar age and ore-formation temperatures, we propose that the Axi and Jingxi-Yelmand deposits comprise an epithermal gold system, which was driven by the same Permian magma in the Tulasu Basin. The ore geological features together with our new results indicate that the Axi and Jingxi-Yelmand deposits are intermediate and high sulfidation type epithermal deposits, respectively.

Subsurface Permian reef complexes of southern Tunisia: Shelf carbonate setting and paleogeographic implications

Science.gov (United States)

Zaafouri, Adel; Haddad, Sofiene; Mannaî-Tayech, Beya

2017-05-01

2-D seismic reflection sections, borehole data as well as published and unpublished data have been investigated to reconstruct the paleogeography of southern Tunisia during Middle to Late Permian times. Paleogeographical reconstruction based on the integration of petroleum well data and 2-D seismic facies interpretation shows three main depositional areas with very contrasting sedimentary pile. These are 1) a subsiding basin; 2) an outer shelf carbonate, and 3) an inner shelf carbonate. Based on typical electric responses of reef buildups to seismic wave, we shall urge that during Middle Permian times, the outer carbonate shelf was subject of reef barrier development. Lithology evidences from core samples show that reef framework correspond mainly to fossiliferous limestone and dolomite. The WNW-ESE recognized reef barrier led between latitudes 33° 10‧ 00″N and 33° 20‧ 00″N. The Tebaga of Medenine outcrop constitutes the northern-edge of this barrier. Westward it may be extended to Bir Soltane area whereas its extension eastward is still to be determined. Biogenic buildups took place preferentially over faulted Carboniferous and lower Paleozoic paleohighs resulting likely from the Hercynian orogeny. The subsiding basin is located north of Tebaga of Medenine outcrop where Upper Permian sedimentary sequence is made entirely of 4000 m deep marine green silty shale facies. These are ascribed to unorganized and chaotic reflectors. Inner carbonate shelf facies succession corresponds to a typical interbedding of shallow marine carbonate deposits, shale, dolomite, and anhydrite inducing parallel-layered of strong amplitude and good continuity reflectors. Also within the inner carbonate shelf patch reef or reef pinnacles have been identified based on their seismic signature particularly their low vertical development as compared to reef complexes. Southward, towards Sidi Toui area, the Upper Permian depositional sequence thins out and bears witness of land

Geologic implications of gas hydrates in the offshore of India: Krishna-Godavari Basin, Mahanadi Basin, Andaman Sea, Kerala-Konkan Basin

Digital Repository Service at National Institute of Oceanography (India)

Kumar, P.; Collett, T.S.; Boswell, R.; Cochran, J.R.; Lall, M.; Mazumdar, A.; Ramana, M.V.; Ramprasad, T.; Riedel, M.; Sain, K.; Sathe, A.V.; Vishwanath, K.; Yadav, U.S.

history of the Mahanadi Basin is similar to that of the Krishna-Godavari Basin. The Late Jurassic rift structures along the eastern margin of India cut across older NW-SE-trending Permian-Triassic Gondwana grabens including the Mahanadi and Pranhita...-Godavari grabens (Sastri et al., 1981). The Mahanadi graben appears to have a continuation in Antarctica as the Lambert graben (Federov et al., 1982). These structures served to delineate the fluvial drainage system throughout the evolution of the margin...

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

International Nuclear Information System (INIS)

Anderson, R.Y.

1981-01-01

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

Permian of Southeast Asia: an overview

Energy Technology Data Exchange (ETDEWEB)

Fontaine, H.

2002-07-01

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 recognized early on 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. Different depositional environments are represented by the Permian deposits in various parts of the region. Massive limestones, 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 not found in northwest Peninsular Malaysia and Peninsular Thailand, but are extensively developed in North Vietnam, Sumatra, the eastern Malay Peninsula and Timor. Fossils are often prolific in Permian sediments, with fusulinaceans, for example, occurring in large 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.

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.

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

International Nuclear Information System (INIS)

Olmsted, R.W.; Hanson, R.E.; May, R.T.; Owens, R.T.

1976-01-01

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

Gondwana basins and their coal resources in Bangladesh

International Nuclear Information System (INIS)

Nehaluddin, M.; Sultan-ul-Islam, M.

1994-01-01

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

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

Directory of Open Access Journals (Sweden)

Gabriela A Cisterna

2011-07-01

Full Text Available 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.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 identificación 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.

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

International Nuclear Information System (INIS)

Durham, W.B.; Boro, C.O.; Beiriger, J.M.; Montan, D.N.

1983-10-01

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 m 2 /s at room temperature, and 1.5 +- 0.3 x 10 -6 m 2 /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

Architecture and quantitative assessment of channeled clastic deposits, Shihezi sandstone (Lower Permian, Ordos Basin, China

Directory of Open Access Journals (Sweden)

Chengye Jia

2017-02-01

Full Text Available Lower Permian Shihezi sandstone in Ordos Basin is the largest gas reservoir in China. Architecture elements of channel, overbank and floodplain facies of braided channel deposits were identified through an outcrops survey, and their proportion of channel facies have been quantitatively estimated from well logging. Characteristics of architecture elements, such as sand thickness, bounding surfaces and lithofacies were investigated through outcrops and core. Petrology of Shihezi sandstone has also been studied in detail. Analysis on sandstone components shows that monocrystalline quartz with approximately 76% bulk volume, and lithic up to 5%–45% bulk volume, are the two main components. Litharenite and lithic quartz sandstone are the main rock types. Compaction is concluded by former researchers as the control factor of low permeability. Examination through thin section reveals that secondary pores developed well in coarse sand. Inter-granular dissolution is included as the positive effect to increasing porosity, and is concluded as the control factor to the generation of net pay. Scale of coarse grained channel fills and channel bar sandstone bodies are quantitatively estimated. Strike-oriented, dip-oriented, and vertical distribution of channel fills and channel bar sandstone bodies have been investigated. The geometry of sand bodies can be depicted as an elongated lens. Subsurface mapping reveals that channel sandstone bodies distribute widely from both lateral and longitudinal cross section profiles, and are poorly connected.

A review of the petroleum geochemistry of the Precaspian Basin

Energy Technology Data Exchange (ETDEWEB)

Pairazian, V.V. [All-Russian Geological Oil Research and Prospecting Inst. (VNIGNI), Moscow (Russian Federation); ENI-AGIP, San Donato Milanese (Italy)

1999-11-01

On the territory of the former Soviet Union more than 30- oil and gas-bearing basins have been defined. Among them the Precaspian basin is one of the most prolific in terms of oil and gas exploration and production. The basin is situated in the southeastern part of the East European Platform and covers an areas of about 500 000 km{sup 2}. There are a number of source rocks of different ages, among which the principal ones are Lower Permian, Middle Carboniferous and Middle Devonian marine shales and carbonates. The post-salt Mesozoic sources are of less significance. Geological and geochemical data interpretation allows the main oil/gas accumulation zones and new exploration prospects to be defined. Two main petroleum systems are recognised in the Palaeozoic sequence of the basin, containing 90% of the recoverable hydrocarbon resources: Lower Permian-Middle Carboniferous and Lower Carboniferous-Upper Devonian. The new exploration targets are deep Middle Devonian clastic reservoirs on the passive continental margins and Middle Carboniferous (Bashkirian) carbonates in the Caspian offshore part of the basin. (Author)

Appalachian Piedmont landscapes from the Permian to the Holocene

Science.gov (United States)

Cleaves, E.T.

1989-01-01

past Baltimore. The Late Triassic landscape was influenced by rift basin development. Streams drained into a hydrologically closed basin: no through-flowing rivers seem to have been present. A limestone escarpment along the Blue Ridge may have existed as a consequence of a semi-arid climate. The Permian may have been a time of Himalayan-like mountains and mountain glaciers. Streams (and glaciers) generally flowed southwest and west. ?? 1989.

Anoxia, toxic metals and acidification: volcanically-driven causes of the Middle Permian (Capitanian) mass extinction in NW Pangaea?

Science.gov (United States)

Bond, David; Grasby, Stephen; Wignall, Paul

2017-04-01

The controversial Capitanian (Middle Permian, 262 Ma) mass extinction, mostly known from equatorial latitudes, has recently been identified in a Boreal setting in Spitsbergen. We now document this extinction in the record of brachiopods from the Sverdrup Basin in NW Pangaea (Ellesmere Island, Canada), confirming Middle Permian losses as a global crisis on par with the "Big Five". Redox proxies (pyrite framboids and trace metals) show that the high latitude crisis coincided with an intensification of oxygen-poor conditions - a potent killer that is not clearly developed in lower latitude sections. Mercury becomes briefly enriched in strata at the level of the Middle Permian extinction level in Spitsbergen and Ellesmere Island, indicating voluminous but short-lived volcanism that is likely to have been the emplacement of the Emeishan large igneous province (LIP) in SW China. A potent cocktail of poisons appears to have impacted across the Boreal Realm, whilst the near-total loss of carbonates near the extinction level is also consistent with reduced pH across the region. Multiple stresses, possibly with origins in low-latitude LIP volcanism, are therefore implicated in the Middle Permian extinction and there was no respite even in the far-distant Boreal Realm.

The main fish communities of the limnic Permian and Carboniferous basins of the Czech Republic

Czech Academy of Sciences Publication Activity Database

Zajíc, Jaroslav

33-34, - (2006), s. 99-101. ISBN 80-210-4097-1. ISSN 1211-281X. [Paleontological Conference /7./. Brno, 19.10.2006-20.10.2006] Institutional research plan: CEZ:AV0Z30130516 Keywords : ichthyofaunae * Upper Carboniferous * Lower Permian Subject RIV: EG - Zoology

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

International Nuclear Information System (INIS)

1984-07-01

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

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

International Nuclear Information System (INIS)

Stemmerik, L.; Magaritz, M.

1989-01-01

Isotope data from Late Palaeozoic limestones of the Wandel Sea Basin in eastern North Greenland show a variation of δ 13 C from 0.0 0/00 to 5.7 0/00 vs PDB. Carbonates depleted in 13 C occur in the basal part of lower Moscovian, upper Moscovian and middle Gzhelian transgressive sequences. 13 C enriched limestones occur later in the cycles. The most 13 C 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 13 C enriched carbonates correlate to periods of burial of organic carbon mostly as coal, while 13 C depleted carbonates formed as the result of erosion and oxidation of organic carbon during sea-level low stands. (author)

The Cannery Formation--Devonian to Early Permian arc-marginal deposits within the Alexander Terrane, Southeastern Alaska

Science.gov (United States)

Karl, Susan M.; Layer, Paul W.; Harris, Anita G.; Haeussler, Peter J.; Murchey, Benita L.

2011-01-01

cherts on both Admiralty and Kupreanof Islands contain radiolarians as young as Permian, the age of the Cannery Formation is herein extended to Late Devonian through early Permian, to include the early Permian rocks exposed in its type locality. The Cannery Formation is folded and faulted, and its stratigraphic thickness is unknown but inferred to be several hundred meters. The Cannery Formation represents an extended period of marine deposition in moderately deep water, with slow rates of deposition and limited clastic input during Devonian through Pennsylvanian time and increasing argillaceous, volcaniclastic, and bioclastic input during the Permian. The Cannery Formation comprises upper Paleozoic rocks in the Alexander terrane of southeastern Alaska. In the pre-Permian upper Paleozoic, the tectonic setting of the Alexander terrane consisted of two or more evolved oceanic arcs. The lower Permian section is represented by a distinctive suite of rocks in the Alexander terrane, which includes sedimentary and volcanic rocks containing early Permian fossils, metamorphosed rocks with early Permian cooling ages, and intrusive rocks with early Permian cooling ages, that form discrete northwest-trending belts. After restoration of 180 km of dextral displacement of the Chilkat-Chichagof block on the Chatham Strait Fault, these belts consist, from northeast to southwest, of (1) bedded chert, siliceous argillite, volcaniclastic turbidites, pillow basalt, and limestone of the Cannery Formation and the Porcupine Slate of Gilbert and others (1987); (2) greenschist-facies Paleozoic metasedimentary and metavolcanic rocks that have Permian cooling ages; (3) silty limestone and calcareous argillite interbedded with pillow basalt and volcaniclastic rocks of the Halleck Formation and the William Henry Bay area; and (4) intermediate-composition and syenitic plutons. These belts correspond to components of an accretionary complex, contemporary metamorphic rocks, forearc-basin deposits,

Geology of Santa Rita Coal Basin, Rio Grande do Sul, Brazil

Energy Technology Data Exchange (ETDEWEB)

Correa da Silva, Z.C.; Bortoluzzi, C.A.; Cazzulo-Klepzig, M.; Dias-Fabricio, M.E.; Guerra-Sommer, M.; Marques-Toigo, M.; Paim, P.S.G.; Piccoli, A.E.M.; Silva Filho, B.C.

1984-04-01

Data on the sedimentology, stratigraphy, palynology, coal petrography and geochemistry of the Santa Rita Coal Basin, Rio Grande do Sul, Brazil, are presented. The investigations were carried out on samples obtained from drill cores of the sedimentary rocks of Tubarao Supergroup, Lower Permian of Parana Basin. (25 refs.)

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

International Nuclear Information System (INIS)

Tien, P.; Nimick, F.B.; Muller, A.B.; Davis, P.A.; Guzowski, R.V.; Duda, L.E.; Hunter, R.L.

1983-11-01

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

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

Science.gov (United States)

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

2010-12-01

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

Residual basins

International Nuclear Information System (INIS)

D'Elboux, C.V.; Paiva, I.B.

1980-01-01

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) [pt

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

Czech Academy of Sciences Publication Activity Database

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

2014-01-01

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

Folded Basinal Compartments of the Southern Mongolian Borderland: A Structural Archive of the Final Consolidation of the Central Asian Orogenic Belt

Directory of Open Access Journals (Sweden)

Dickson Cunningham

2017-01-01

Full Text Available The Central Asian Orogenic Belt (CAOB records multiple Phanerozoic tectonic events involving consolidation of disparate terranes and cratonic blocks and subsequent reactivation of Eurasia’s continental interior. The final amalgamation of the CAOB terrane collage involved diachronous closure of the Permian-Triassic Solonker suture in northernmost China and the Jurassic Mongol-Okhotsk suture in northeast Mongolia and eastern Siberia. The distribution, style, and kinematics of deformation associated with these two terminal collision events is poorly documented in southern Mongolia and northernmost China because these regions were later tectonically overprinted by widespread Cretaceous basin and range-style crustal extension and Miocene-recent sinistral transpressional mountain building. These younger events structurally compartmentalized the crust into uplifted crystalline basement blocks and intermontane basins. Consequently, widespread Cretaceous and Late Cenozoic clastic sedimentary deposits overlie older Permian-Jurassic sedimentary rocks in most basinal areas and obscure the deformation record associated with Permian-Triassic Solonker and Jurassic Mongol-Okhotsk collisional suturing. In this report, satellite image mapping of basinal compartments that expose folded Permian-Jurassic sedimentary successions that are unconformably overlapped by Cretaceous-Quaternary clastic sediments is presented for remote and poorly studied regions of southern Mongolia and two areas of the Beishan. The largest folds are tens of kilometers in strike length, east-west trending, and reveal north-south Late Jurassic shortening (present coordinates. Late Jurassic fold vergence is dominantly northerly in the southern Gobi Altai within a regional-scale fold-and-thrust belt. Local refolding of older Permian north-south trending folds is also evident in some areas. The folds identified and mapped in this study provide new evidence for the regional distribution and

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

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

2015-04-01

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

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

International Nuclear Information System (INIS)

Belkin, H.E.; Libelo, E.L.

1987-01-01

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

The paleoclimate of the Kazanian (early Late Permian) world

Energy Technology Data Exchange (ETDEWEB)

Moore, G.T. (Chevron Oil Field Research Co., La Habra, CA (USA)); Peoples, C.J. (Texas A and M Univ., College Station (USA))

1990-05-01

The Kazanian (early Late Permian, 258-253 m.y.) marked the onset of a unique interval in the Phanerozoic, distinguished by a classic end-member case of continental assembly, the megacontinent Pangaea. Compilation of biostratigraphic and lithofacies data indicate a warm, extensively arid world, largely ice free, and characterized by the onset of atmospheric conditions that were exceedingly stressful to the biosphere, the worst of the eon. Using Chevron's version of the Community Climate model, the authors report here on two Kazanian paleoclimate seasonal simulations, one using 200 ppm CO{sub 2} and the other with 2,000 ppm CO{sub 2}. The authors consider the knowledge of plate assembly back to the Permian accurate enough to allow employment of a seasonal model. Simulation of a warmer Earth with an elevated greenhouse effect (modeled as CO{sub 2}) fits the observed geology and isotope signals. The increased CO{sub 2} experiment warmed the entire planet with the greatest increases north of 50{degree} latitude and least changes in the tropics. The warming caused the poleward retreat of sea ice in both hemispheres. Precipitation and evaporation increased, but runoff was confined to areas of very intense rainfall. Monsoons are limited to the southern hemisphere, associated with the western Tethys sea and the eastern equatorial Panthalassa ocean. Extreme southeastern Pangaea (northern Australia) was a focus of precipitation throughout the year. Precipitation occurred in the higher latitudes (50-55{degree}) on the western coast, of Pangaea where storm tracks make landfall. High evaporation rates characterized the restricted Permian (US), Zechstein, and Perm (Soviet Union) basins, a time of evaporite, deposition. Interior Pangaea at middle to high latitudes endured frigid winters ({minus}40{degree}C) and torrid summers (60{degree}C).

A paleoclimatic simulation of the Late Permian greenhouse world and its consequences

Energy Technology Data Exchange (ETDEWEB)

Moore, G.T.; Jacobson, S.R.; Hayashida, D.N. (Chevron Oil Field Research Co., La Habra, CA (United States))

1991-03-01

Sea-floor spreading assembled all the major cratonic blocks into a single supercontinent once in the Phanerozoic Eon. This unique Late Permian crustal tectonic event produced Pangaea and an enormous oceanic basin volume that dropped sea level to a global lowstand unrivaled in the Phanerozoic. Two paleoclimatic simulations using a numerical three-dimensional general circulation model tested changes in the greenhouse effect. The authors conclude that for a simulation to fit the Late Permian geologic record, the paleoatmosphere must contain an enhanced greenhouse gas effect. A third simulation tested changes of paleogeography in southern Pangaea (Gondwana) that did not appreciably alter the harsh continental paleoclimate. The simulated paleoclimatic changes provide extraordinarily warm ocean and atmosphere, and a significant reduction in continental rainfall and runoff. These conditions inevitably lead to more aridity and less vegetation on land, gradually reduce the delivery of vital nutrients from continental sources to marine margins, systematically liberate CO{sub 2} dissolved in ocean water, and incrementally increase stress on marine and terrestrial biotas. These consequences severely disrupted rates of oxygen and carbon cycling. Their quantitative paleoclimatic simulation is consistent with distributions of red beds, evaporites, coals, marine shelf areas, seawater isotope trends, and paleontologic originations and extinctions. Thus, the Pangaean plate assembly probably triggered an inexorable sequence of geophysical, geochemical, and biological events that forced an elevated greenhouse effect in the Late Permian, nearly annihilating the Phanerozoic biota.

Permian arc evolution associated with Panthalassa subduction along the eastern margin of the South China block, based on sandstone provenance and U-Pb detrital zircon ages of the Kurosegawa belt, Southwest Japan

Science.gov (United States)

Hara, Hidetoshi; Hirano, Miho; Kurihara, Toshiyuki; Takahashi, Toshiro; Ueda, Hayato

2018-01-01

We have studied the petrography, geochemistry, and detrital zircon U-Pb ages of sandstones from shallow-marine forearc sediments, accretionary complexes (ACs), and metamorphosed accretionary complexes (Meta-ACs) within the Kurosegawa belt of Southwest Japan. Those rocks formed in a forearc region of a Permian island arc associated with subduction of the Panthalassa oceanic crust along the eastern margin of the South China block (Yangtze block). The provenance of the shallow-marine sediments was dominated by basaltic to andesitic volcanic rocks and minor granitic rocks during the late Middle to Late Permian. The ACs were derived from felsic to andesitic volcanic rocks during the Late Permian. The provenance of Meta-ACs was dominated by andesitic volcanic rocks in the Middle Permian. The provenance, source rock compositions, and zircon age distribution for the forearc sediments, ACs and Meta-ACs have allowed us to reconstruct the geological history of the Permian arc system of the Kurosegawa belt. During the Middle Permian, the ACs were accreted along the eastern margin of the South China block. The Middle Permian arc was an immature oceanic island arc consisting of andesitic volcanic rocks. During the Late Permian, the ACs formed in a mature arc, producing voluminous felsic to andesitic volcanic rocks. A forearc basin developed during the late Middle to Late Permian. Subsequently, the Middle Permian ACs and part of the Late Permian AC underwent low-grade metamorphism in the Late to Early Jurassic, presenting the Meta-ACs.

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

International Nuclear Information System (INIS)

Durham, W.B.; Heard, H.C.; Boro, C.O.; Keller, K.T.; Ralph, W.E.; Trimmer, D.A.

1987-03-01

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 m 2 /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

Contrasting Permo - Carboniferous Evolution of Resita and Sirinia - Presacina Basins (South Carpathians, Romania); an overview.

Science.gov (United States)

Tatu, M.; Seghedi, I.; Nutu, L. M.; Nicolae, I.

2009-04-01

Two important Permo-Carboniferous molasses basins Resita and Sirinia - Presacina occur in Romanian Banat (south-western part of Carpathian chain), unconformable overlie the Getic and Danubian domains with different pre-Variscan and Variscan geodynamic history. They show differences in their lithology reflecting various geotectonic settings and evolutions. In the Resita domain the Upper Carboniferous deposits (Westphalian - Stephanian in age, according to the previous paleobotanic and palynological data) are important in volume and they contain terrigeneous siliciclastic rocks represented by sandy - conglomerate and argillaceous - sandy rocks variable in thickness with siltstone, carbonaceous shale and coal beds interlayering. There are not volcanic rocks present in Upper Carboniferous of Resita domain. In contrast with Resita in the Sirinia - Presacina basins the Upper Carboniferous deposits are volumetrically more restrictive. These deposits transgresively overlie pre-Sudetian formations and consist of continental - lacustrine terrigeneous formations, rarely associated with limnic carbonatic rocks. In this association the alternating conglomerate, siliceous sandstone, siltstone and clay with lens - like coal inter-layers prevails. In two small areas Dragosela - Tulinecea - Camenita (in the western part) and Baia Noua - Cucuiova (in the eastern part) the terrigeneous deposits are associated with basaltic andesite and andesite rocks with alkaline affinity. In both of these basins the Lower Permian deposits (according to the paleobotanic data) unconformably overlie the Upper Carboniferous formations and/or pre-Sudetian basements. The Lower Permian deposits in the Resita basin occur in two superposed formations (Nastaseanu, 1987): (1) Walchia Beds dominated by black argillaceous shales, slightly bituminous with rare sandy-conglomerate interlayers and (2) Red Beds composed by sandy-conglomerate deposits with some argillaceous intercalations, all red in color, with

The Gañuelas-Mazarrón Tertiary Basin (Murcia, Spain): Features, Analogies, implications for the Safety of a CO2-DGS and Methodology

International Nuclear Information System (INIS)

Rodrigo-Naharro, J.; Clemente-Jul, C.; Pérez del Villar, L.

2015-01-01

This work summarizes the main features of the Gañuelas-Mazarrón Tertiary basin, emphasising on the: i) geological, hydrogeological and hydrogeochemical characteristics; ii) current carbonate precipitation related to waters from several hydrogeological and geothermal wells in the basin; and iii) dissolved and free CO2 leakages and associated gases, mainly 222Rn. Furthermore, it has been summarised the main analogies established between the natural system studied and a CO2-Deep Geological Storage (CO2-DGS) conceptual model; as well as the implications of these analogies to qualitatively analyse the behaviour and evaluate the safety, in short, medium and long term, of a CO2-DGS. Finally, a useful methodology for any sedimentary basin, similar to the Gañuelas-Mazarrón basin, capable to host a CO2-DGS is also proposed. In conclusion, the full or partial study of a natural system analogous to a CO2-DGS must not be confused with the study to characterise a site for a CO2-DGS, since natural analogues should provide information about the behaviour, evolution and safety, in long-term, of the natural system, and that this information could be applied to a CO2-DGS system.

Assessing the role of detrital zircon sorting on provenance interpretations in an ancient fluvial system using paleohydraulics - Permian Cutler Group, Paradox Basin, Utah and Colorado

Science.gov (United States)

Findlay, C. P., III; Ewing, R. C.; Perez, N. D.

2017-12-01

Detrital zircon age signatures used in provenance studies are assumed to be representative of entire catchments from which the sediment was derived, but the extent to which hydraulic sorting can bias provenance interpretations is poorly constrained. Sediment and mineral sorting occurs with changes in hydraulic conditions driven by both allogenic and autogenic processes. Zircon is sorted from less dense minerals due to the difference in density, and any age dependence on zircon size could potentially bias provenance interpretations. In this study, a coupled paleohydraulic and geochemical provenance approach is used to identify changes in paleohydraulic conditions and relate them to spatial variations in provenance signatures from samples collected along an approximately time-correlative source-to-sink pathway in the Permian Cutler Group of the Paradox Basin. Samples proximal to the uplift have a paleoflow direction to the southwest. In the medial basin, paleocurrent direction indicates salt movement caused fluvial pathways divert to the north and northwest on the flanks of anticlines. Channel depth, flow velocity, and discharge calculations were derived from field measurements of grain size and dune and bar cross-stratification indicate that competency of the fluvial system decreased from proximal to the medial basin by up to a factor of 12. Based upon the paleohydraulic calculations, zircon size fractionation would occur along the transect such that the larger zircons are removed from the system prior to reaching the medial basin. Analysis of the size and age distribution of zircons from the proximal and distal fluvial system of the Cutler Group tests if this hydraulic sorting affects the expected Uncompahgre Uplift age distribution.

Analog modeling and kinematic restoration of inverted hangingwall synclinal basins developed above syn-kinematic salt: Application to the Lusitanian and Parentis basins

Science.gov (United States)

Roma, Maria; Vidal-Royo, Oskar; McClay, Ken; Ferrer, Oriol; Muñoz, Josep Anton

2017-04-01

The formation of hagingwall syncline basins is basically constrained by the geometry of the basement-involved fault, but also by salt distribution . The formation of such basins is common around the Iberian Peninsula (e.g. Lusitanian, Parentis, Basque-Cantabian, Cameros and Organyà basins) where Upper Triassic (Keuper) salt governed their polyphasic Mesozoic extension and their subsequent Alpine inversion. In this scenario, a precise interpretation of the sub-salt faults geometry and a reconstruction of the initial salt thickness are key to understand the kinematic evolution of such basins. Using an experimental approach (sandbox models) and these Mesozoic basins as natural analogues, the aim of this work is to: 1) investigate the main parameters that controlled the formation and evolution of hagingwall syncline basins analyzing the role of syn-kinematic salt during extension and subsequent inversion; and 2) quantify the deformation and salt mobilization based on restoration of analog model cross sections. The experimental results demonstrate that premature welds are developed by salt deflation with consequent upward propagation of the basal fault in salt-bearing rift systems with a large amount of extension,. In contrast, thicker salt inhibits the upward fault propagation, which results into a further salt migration and development of a hagingwall syncline basins flanked by salt walls. The inherited extensional architecture as well as salt continuity dramatically controlled subsequent inversion. Shortening initially produced the folding and the uplift of the synclinal basins. Minor reverse faults form as a consequence of overtightening of welded diapir stems. However, no trace of reverse faulting is found around diapirs stems, as ductile unit is still available for extrusion, squeezing and accommodation of shortening. Restoration of the sandbox models has demonstrated that this is a powerful tool to unravel the complex structures in the models and this may

Geochemistry and hydrodynamics of the Paradox Basin region, Utah, Colorado and New Mexico

Science.gov (United States)

Hanshaw, B.B.; Hill, G.A.

1969-01-01

The Paradox Basin region is approximately bounded by the south flank of the Uinta Basin to the north, the Uncompahgre uplift and San Juan Mountains to the east, the Four Corners structural platform to the southeast, the north rim of the Black Mesa Basin and the Grand Canyon to the south and southwest, and the Wasatch Plateau and Hurricane fault system to the west. Some of these geologic features are areas of ground-water recharge or discharge whereas others such as the Four Corners platform do not directly influence fluid movement. The aquifer systems studied were: (1) Mississippian rocks; (2) Pinkerton Trail Limestone of Wengerd and Strickland, 1954; (3) Paradox Member of the Hermosa Formation; (4) Honaker Trail Formation of Wengerd and Matheny, 1958; (5) Permian rocks. Recharge in the Paradox Basin occurs on the west flank of the San Juan Mountains and along the west side of the Uncompahgre uplift. The direction of ground-water movement in each analyzed unit is principally southwest-ward toward the topographically low outcrop areas along the Colorado River in Arizona. However, at any point in the basin, flow may be in some other direction owing to the influence of intrabasin recharge areas or local obstructions to flow, such as faults or dikes. A series of potentiometric surface maps was prepared for the five systems studied. Material used in construction of the maps included outcrop altitudes of springs and streams, drill-stem tests, water-well records, and an electric analog model of the entire basin. Many structurally and topographically high areas within the basin are above the regional potentiometric surface; recharge in these areas will drain rapidly off the high areas and adjust to the regional water level. With a few exceptions, most wells in formations above the Pennsylvanian contain fresh ( 35,000 mg/l T.D.S.) reported. Most water samples from strata below the Permian are brines of the sodium chloride type but with large amounts of calcium sulfate or

REGIONAL MAGNETOTELLURIC SURVEYS IN HYDROCARBON EXPLORATION, PARANA BASIN, BRAZIL.

Science.gov (United States)

Stanley, William D.; Saad, Antonio; Ohofugi, Walter

1985-01-01

The mangetotelluric geophysical method has been used effectively as a hydrocarbon exploration tool in the intracratonic Parana basin of South America. The 1-2 km thick surface basalts and buried diabase sills pose no problem for the magnetotelluric method because the natural electromagnetic fields used as the energy source pass easily through the basalt. Data for the regional study were taken on six profiles with sounding spaced 8 to 15 km apart. The magnetotelluric sounding data outline a linear uplift known as the Ponta Grossa arch. This major structural feature cuts across the northeast-trending intracratonic basin almost perpendicularly, and is injected with numerous diabase dikes. Significant electrical contrasts occur between the Permian sediments and older units, so that magnetotelluric measurements can give an indication of the regional thickness of the Permian and younger sediments to aid in interpreting hydrocarbon migration patterns and possible trap areas. Refs.

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

International Nuclear Information System (INIS)

Durham, W.B.; Heard, H.C.; Boro, C.O.; Keller, K.T.; Ralph, W.E.; Trimmer, D.A.

1987-01-01

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 m 2 /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 m 2 /s over the temperature range. In the nonsalts, conductivity and diffusivity decreased 10 to 20% over the temperature range explored, which was 308 -6 m 2 /s for the anhydrites and 1.4 x 10 -6 m 2 /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

Timing of global regression and microbial bloom linked with the Permian-Triassic boundary mass extinction: implications for driving mechanisms

Science.gov (United States)

Baresel, Bjoern; Bucher, Hugo; Bagherpour, Borhan; Brosse, Morgane; Guodun, Kuang; Schaltegger, Urs

2017-04-01

High-precision U-Pb dating of single-zircon crystals by chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) is applied to volcanic beds that are intercalated in sedimentary sequences across the Permian-Triassic boundary (PTB). By assuming that the zircon crystallization age closely approximate that of the volcanic eruption and subsequent deposition, U-Pb zircon geochronology is the preferred approach for dating abiotic and biotic events, such as the formational PTB and the Permian-Triassic boundary mass extinction (PTBME). We will present new U-Pb zircon dates for a series of volcanic ash beds in shallow-marine Permian-Triassic sections in the Nanpanjiang Basin, South China. These high-resolution U-Pb dates indicate a duration of 90 ± 38 kyr for the Permian sedimentary hiatus and a duration of 13 ± 57 kyr for the overlying Triassic microbial limestone in the shallow water settings of the Nanpanjiang pull apart Basin. The age and duration of the hiatus coincides with the formational PTB and the extinction interval in the Meishan Global Stratotype Section and Point, thus strongly supporting a glacio-eustatic regression, which best explains the genesis of the worldwide hiatus straddling the PTB in shallow water records. In adjacent deep marine troughs, rates of sediment accumulation display a six-fold decrease across the PTB compatible with a dryer and cooler climate during the Griesbachian as indicated by terrestrial plants. Our model of the PTBME hinges on the synchronicity of the hiatus with the onset of the Siberian Traps volcanism. This early eruptive phase likely released sulfur-rich volatiles into the stratosphere, thus simultaneously eliciting a short-lived ice age responsible for the global regression and a brief but intense acidification. Abrupt cooling, shrunk habitats on shelves and acidification may all have synergistically triggered the PTBME. Subsequently, the build-up of volcanic CO2 induced this transient cool

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

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

Insuring Water Sustainability for Resource Extraction in the New Mexico Permian Basin

Science.gov (United States)

Lowry, T. S.; Schuhen, M. D.; Lofton, O. W.; Walker, L. T. N.; Johnson, P. B.; Land, L. A.; Herrell, D.

2017-12-01

Advancements in directional drilling and well completion technologies have resulted in an exponential growth in the use of hydraulic fracturing for oil and gas extraction. Within the New Mexico portion of the Permian Basin (see figure), water demand to complete each hydraulically fractured well is estimated to average 7.3 acre-feet (2.4 million gallons), which has resulted in an increase in the regional water demand of over 5000 acre-feet per year. The rise in demand along with proposed rule changes that govern the regulation and management of hydraulic fracturing on Federal and Indian lands (40 CFS 3160) has created concern as to the regions ability to meet the demand in a manner that can sustainably meet the needs of the variety of water users and other stakeholders in the region while also protecting human health and the environment. Funded by the Bureau of Land Management who is charged with managing the regions water resources on Federal lands, this project is addressing those concerns using a multi-disciplinary approach that synthesizes data collection, field verification, and system dynamics (SD) modeling to better understand the dynamics of the regional water supply and demand under different management, policy, and growth scenarios. The scientific challenge has been in bringing together disparate data in a manner that exposes the temporal and spatial dynamics of the regional water supply in the context of increasing demands and changing policy and management scenarios. Field verification and testing activities are used to evaluate existing borehole data to insure that the data are accurate and up to date. The SD model simulates forecasted increases in drilling activity and water demand relative to each water source to identify areas that are most vulnerable and to estimate risk to water sustainability. Key to this is the models ability to seamlessly handle uncertainty such that it produces probabilistic outputs that allow decision makers to explore and

OIL RESERVOIR CHARACTERIZATION AND CO2 INJECTION MONITORING IN THE PERMIAN BASIN WITH CROSSWELL ELECTROMAGNETIC IMAGING

Energy Technology Data Exchange (ETDEWEB)

Michael Wilt

2004-02-01

Substantial petroleum reserves exist in US oil fields that cannot be produced economically, at current prices, unless improvements in technology are forthcoming. Recovery of these reserves is vital to US economic and security interests as it lessens our dependence on foreign sources and keeps our domestic petroleum industry vital. Several new technologies have emerged that may improve the situation. The first is a series of new flooding techniques to re-pressurize reservoirs and improve the recovery. Of these the most promising is miscible CO{sub 2} flooding, which has been used in several US petroleum basins. The second is the emergence of new monitoring technologies to track and help manage this injection. One of the major players in here is crosswell electromagnetics, which has a proven sensitivity to reservoir fluids. In this project, we are applying the crosswell EM technology to a CO{sub 2} flood in the Permian Basin oil fields of New Mexico. With our partner ChevronTexaco, we are testing the suitability of using EM for tracking the flow of injected CO{sub 2} through the San Andreas reservoir in the Vacuum field in New Mexico. The project consisted of three phases, the first of which was a preliminary field test at Vacuum, where a prototype system was tested in oil field conditions including widely spaced wells with steel casing. The results, although useful, demonstrated that the older technology was not suitable for practical deployment. In the second phase of the project, we developed a much more powerful and robust field system capable of collecting and interpreting field data through steel-cased wells. The final phase of the project involved applying this system in field tests in the US and overseas. Results for tests in steam and water floods showed remarkable capability to image between steel wells and provided images that helped understand the geology and ongoing flood and helped better manage the field. The future of this technology is indeed bright

Whirling in the late Permian: ancestral Gyrinidae show early radiation of beetles before Permian-Triassic mass extinction.

Science.gov (United States)

Yan, Evgeny V; Beutel, Rolf G; Lawrence, John F

2018-03-16

Gyrinidae are a charismatic group of highly specialized beetles, adapted for a unique lifestyle of swimming on the water surface. They prey on drowning insects and other small arthropods caught in the surface film. Studies based on morphological and molecular data suggest that gyrinids were the first branch splitting off in Adephaga, the second largest suborder of beetles. Despite its basal position within this lineage and a very peculiar morphology, earliest Gyrinidae were recorded not earlier than from the Upper Triassic. Tunguskagyrus. with the single species Tunguskagyrus planus is described from Late Permian deposits of the Anakit area in Middle Siberia. The genus is assigned to the stemgroup of Gyrinidae, thus shifting back the minimum age of this taxon considerably: Tunguskagyrus demonstrates 250 million years of evolutionary stability for a very specialized lifestyle, with a number of key apomorphies characteristic for these epineuston predators and scavengers, but also with some preserved ancestral features not found in extant members of the family. It also implies that major splitting events in this suborder and in crown group Coleoptera had already occurred in the Permian. Gyrinidae and especially aquatic groups of Dytiscoidea flourished in the Mesozoic (for example Coptoclavidae and Dytiscidae) and most survive until the present day, despite the dramatic "Great Dying" - Permian-Triassic mass extinction, which took place shortly (in geological terms) after the time when Tunguskagyrus lived. Tunguskagyrus confirms a Permian origin of Adephaga, which was recently suggested by phylogenetic "tip-dating" analysis including both fossil and Recent gyrinids. This also confirms that main splitting events leading to the "modern" lineages of beetles took place before the Permian-Triassic mass extinction. Tunguskagyrus shows that Gyrinidae became adapted to swimming on the water surface long before Mesozoic invasions of the aquatic environment took place

Permian Basin location recommendation report

International Nuclear Information System (INIS)

1983-09-01

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

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 δ13C excursions. This gradient subsequently collapses to less than 1‰ in the Middle Triassic, coincident with accelerated biotic recovery and cessation of δ13C excursions. Based on the relationship between δ18O and δ13C, trace metal analyses, and lithostratigraphic context, we conclude that the carbon isotope gradient is unlikely to reflect meteoric diagenesis, organic matter remineralization, or changes in the mixing ratio of sediment sources and minerals across the platform. Instead, we interpret the relatively depleted δ13C values toward the basin as reflecting DIC input from 13C-depleted deep waters during early diagenesis in a nutrient-rich, euxinic ocean. These observations suggest that a vigorous prokaryote-driven biological pump sustained Early Triassic ocean anoxia and inhibited recovery of animal ecosystems.

Comparative Earth history and Late Permian mass extinction

Science.gov (United States)

Knoll, A. H.; Bambach, R. K.; Canfield, D. E.; Grotzinger, J. P.

1996-01-01

The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction.

Seismic reflection surveys in central Palo Duro basin

International Nuclear Information System (INIS)

Acharya, H.; Buller, M.L.; Lewkowicz, J.; Murphy, P.

1983-01-01

Seismic reflection surveys have been conducted in the central Palo Duro basin to provide a basis for identifying localities suitable for the emplacement of an underground high level nuclear waste repository. The objectives of this effort were to determine the structure and stratigraphy in the central Palo Duro basin and evaluate the potential for hydrocarbon resources. Of primary interest is the Upper Permian salt section to a depth of about 3000 ft (914 m). Various tests were carried out along a 3 mi (5 km) segment to determine the most appropriate combination of vibrating source and recording parameters. Approximately 130 mi (209 km) of 24-fold CDP stacked data were acquired. The survey lines were tied to test wells in which velocity surveys were conducted. These data were supplemented by about 400 mi (644 km) of available proprietary CDP stacked data. Analysis of these data strongly suggests that central Palo Duro basin has been tectonically stable since Early Permian time. The maximum offset of the basement is about 600 ft (183 m). These basement faults do not appear to affect any strata above. The San Andres Formation and underlying formations can be traced continuously throughout the area surveyed. Available velocity data from various wells in the central Palo Duro basin show few anomalies, confirming the continuity of the reflecting horizons and the tectonic stability of the area. Hydrocarbon potential of the area is presently being evaluated. The preliminary results of this study are in agreement with the stratigraphic correlations among well logs in the Palo Duro basin

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

Science.gov (United States)

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

2014-01-01

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

The Paleozoic ichthyofauna of the Amazonas and Parnaíba basins, Brazil

Science.gov (United States)

Figueroa, Rodrigo Tinoco; Machado, Deusana Maria da Costa

2018-03-01

The Brazilian Paleozoic ichthyofauna from the Parnaíba and Amazonas basins regard a sparsely known diversity, including chondrichthyans and acanthodians, besides some osteichthyan remains. This work proposes a revision of the fossil material from these two sedimentary basins and synthesizes the morphological aspect of such material trying to understand the influences of those fossils to the paleontology of the region, comparing the Brazilian fossils with other gondwanan faunas. The Brazilian Paleozoic fish fauna shows great resemblance to those of Bolivia, especially during the Devonian. Many of the Acanthodian spines from the Manacapuru Formation (Amazonas Basin), and the Pimenteira Formation (Parnaíba Basin), are comparable to the taxa found in Bolivia. The lack of more Placoderm remains in the Brazilian outcrops is similar to the low diversity of this group in Bolivia, when compared to other South American and Euramerican localities. The most diverse Brazilian ichthyofauna is encountered in the Permian Pedra de Fogo Formation where numerous chondrichthyans and 'paleopterygians' remains are found, together with dipnoans and actinistians. Despite the apparent lack of more representative Paleozoic ichthyofaunas in Brazil, the available material that ranges from Lower Devonian to early Permian from Brazil bears important taxa that could address valuable taxonomic and biogeographic informations.

Fold superimposition in the Permian groups in the central Beishan orogenic collage (northwestern China): highlights for the late evolution of the Altaids

Science.gov (United States)

Zhonghua, Tian; Wenjiao, Xiao; Yehua, Shan

2013-04-01

The southernmost part of the Central Asian Orogenic Belt (CAOB) or Altaids (Sengör and Burtman, 1993; Xiao et al., 2009), a rare and magnificent example of mesoscopic fold superimposition, involving the Permian sandstone, slightly to mildly metamorphosed clastic rocks, is well exposed in the central Beishan Orogenic Collage (BOC). We provide a detailed description of the morphological features of this phenomenon, based on an enormous amount of structural data collected during recent twice field mapping in the study area. Two phases of folds are readily distinguishable both in satellite image (Fig.la) and our own field map (Fig.1b). Fold is tight to close, N-S-trending in the first phase (F1), and open and E-W-trending in the second phase (F2). The first phase upright folds were refolded into a smaller number of (F2), whose axial planes and axes are vertical or subvertical. They plunge gentle to moderately in the former and moderately to steeply in the latter. Their interference is in general categorized as Ramsay's (Ramsay, 1967) type 2 or Ghosh's third/fourth mode based on the value of initial tightness. However, from east to west there exists a slight variation of a zigzag to crescent to mushroom interference pattern. This subtle variation corresponds with the westward increases of the F2 interlimb angle and of the percentage of coarse-grain clastic rocks, suggesting its dependence upon the F2 deformation and the lithology. Axial slaty cleavages (S1) and associated dip-slip slickensides are more abundant in the first phase. Cleavages and strike-slip slickensides related to the seconding refolding are also occurred in the area. Finally, according to the petrological, geochemical and geochronological data, we conclude that the deformation history of the superposed folds were associated with the late evolution in the BOC. In the late Permian, the fold superimposition occurred in sedimentary rocks deposited in a Permian back-arc basin. The basin was intensely

Permian basalts and trachytes from Esterel (SE France): a transitional tholeiitic suite emplaced during lithosphere thinning; Basaltes et trachytes permiens de l`Esterel (SE France): une serie tholeiitique transitionnelle epanchee pendant l`amincissement lithospherique

Energy Technology Data Exchange (ETDEWEB)

Lapierre, H.; Basile, Ch. [Grenoble-1 Univ., 38 - Grenoble (France). Laboratoire de Geodynamique des Chaines Alpines, CNRS UPRES-A5025; Dupuis, V. [Institut de Geodynamique, UMR Geosciences Azur, 06 - Valbonne (France)

1999-11-01

Geochemical (major, trace and rare earth elements) and isotopic ({sup 143}Nd/{sup 144}Nd) compositions of lavas emplaced in the Esterel Massif (eastern Provence, France) at the end of the Permian allow to estimate the evolution of the continental lithosphere between the end of the Hercynian orogenesis and the beginning of the Tethyan rifting. Basalts from Agay basin and trachyte from Batterie des Lions belong to a transitional tholeiitic suite, characterized by negative Nb and Ta anomalies (relative to N-MORB) and homogeneous {epsilon}Nd{sub (T=250Ma)} ratios, close to the Bulk Earth. This suggests that the basalts from Agay basin and trachyte from Batterie des Lions derived from the partial melting of a mantle contaminated by lower continental crust. Maure Vieille trachytes differ from the differentiated rocks of the transitional suite by higher heavy rare earth abundances and {epsilon}Nd{sub (T=250Ma)} of +4/+5. These high {xi}Nd ratios suggest that the Maure Vieille trachytes could derive from the partial melting of a more depleted source, likely an asthenospheric mantle. The isotopic compositions of the Permian lavas from Esterel suggest the thinning (and perhaps the disappearance) of the lithospheric mantle which is associated at the surface with a NNW-SSE extension. The progressive change recorded in Agay basin from a stretching regime to a strike-slip regime may be related to the end of the lithospheric thinning and of the Permian magmatism. (authors) 37 refs.

Socioeconomic data base report for the Permian Basin

International Nuclear Information System (INIS)

1984-01-01

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

Correlation of structural lineaments with oil discoveries in Potwar sub-basin, Pakistan

International Nuclear Information System (INIS)

Iqbal, M.; Ali, S.M.

2001-01-01

The Potwar sub-basin is located in the foothills of western Himalayas. It is developed as a result of continent collision between the Indian and Eurasian plates. This sub-basin is one of the major oil and gas producing-region of the country. Clastics of Cambrian, Permian, Jurassic, Paleocene, and carbonates of Permian, Paleocene, and Eocene are producing reservoir. Fractured and eocene carbonate reservoirs (Sakesar and Chorgali) are the main producing horizons in the region. Shale of infra-Cambrian-Cambrian and Paleocene are the main source rocks in the area. Interpretation of satellite data for lineament analysis coupled with stress models indicate that 63% of oil and gas fields fall along and 37% within 2-5 km radius of extensional lineaments and their corresponding open fractured zones developed due to various stress regimes. It is therefore suggested that exploration for hydrocarbon may be targeted in the strike extension of the mentioned lineaments in areas where optimum conditions for hydrocarbon generation exist. (author)

Revised models for hydrocarbon generation, migration and accumulation in Jurassic coal measures of the Turpan basin, NW China

Energy Technology Data Exchange (ETDEWEB)

Li Maowen; Stasiuk, L.D. [Geological Survey of Canada, Calgary, Alberta (Canada); Bao Jianping [Jianghan Petroleum University, Hubei (China); Lin, R. [Petroleum University (Beijing), Changping (China); Yuan Mingsheng [PetroChina Tu-Ha Oilfield Company, Xingjiang (China)

2001-07-01

Whether or not the Lower-Middle Jurassic coal measures in the Turpan basin of NW China have generated commercial quantities of liquid petroleums is a problem of considerable importance that remains contentious as it has not yet been resolved unequivocally. This study provides evidence against the Jurassic humic coals as the only major source for the oils discovered in the Taibei depression of this basin and suggests additional significant contributions from the Upper Permian and Middle-Lower Jurassic lacustrine source rocks. The Carboniferous-Permian marine source rocks may have been important also in limited locations along the major basement faults. Molecular and petrographic data indicate that the majority of the Middle Jurassic strata are currently immature or marginally mature with respect to hydrocarbon generation. Within the major depocenters, the Middle-Lower Jurassic coal-bearing strata of the Baodaowan and Xishanyao formations has reached the conventional oil window (i.e. with vitrinite reflectance >0.7 per cent Ro). Pre-Jurassic (Upper Permian in particular) derived hydrocarbons appear to be widespread in extracts of fractured Jurassic coal and fine-grained rocks. Large differences have been observed in the absolute concentrations of biomarker compounds in rock extracts of various source intervals. Thus, 'coaly' biomarker signatures of the oils most likely resulted from mixing and migration contamination when hydrocarbons derived from mature source rocks migrated up through highly fractured coal seams along deep-seated faults. In addition to conventional exploration targets, revised petroleum generation and accumulation models predict that the focus in the Turpan basin should also include deep structures within the Carboniferous-Permian strata and subtle, low magnitude anticlines and stratigraphic traps within thr Triassic-Jurassic sections. (author)

Syndepositional tectonics recorded by soft-sediment deformation and liquefaction structures (continental Lower Permian sediments, Southern Alps, Northern Italy): Stratigraphic significance

Science.gov (United States)

Berra, F.; Felletti, F.

2011-04-01

The Lower Permian succession of the Central Southern Alps (Lombardy, Northern Italy) was deposited in fault-controlled continental basins, probably related to transtensional tectonics. We focussed our study on the stratigraphic record of the Lower Permian Orobic Basin, which consists of a 1000 m thick succession of prevailing continental clastics with intercalations of ignimbritic flows and tuffs (Pizzo del Diavolo Formation, PDV) resting on the underlying prevailing pyroclastic flows of the Cabianca Volcanite. The PDV consists of a lower part (composed of conglomerates passing laterally to sandstones and distally to silt and shales), a middle part (pelitic, with carbonates) and an upper part (alternating sandstone, silt and volcanic flows). Syndepositional tectonics during the deposition of the PDV is recorded by facies distribution, thickness changes and by the presence of deformation and liquefaction structures interpreted as seismites. Deformation is recorded by both ductile structures (ball-and-pillow, plastic intrusion, disturbed lamination, convolute stratification and slumps) and brittle structures (sand dykes and autoclastic breccias). Both the sedimentological features and the geodynamic setting of the depositional basin confidently support the interpretation of the described deformation features as related to seismic shocks. The most significant seismically-induced deformation is represented by a slumped horizon (about 4 m thick on average) which can be followed laterally for more than 5 km. The slumped bed consists of playa-lake deposits (alternating pelites and microbial carbonates, associated with mud cracks and vertebrate tracks). The lateral continuity and the evidence of deposition on a very low-angle surface along with the deformation/liquefaction of the sediments suggest that the slump was triggered by a high-magnitude earthquake. The stratigraphic distribution of the seismites allows us to identify time intervals of intense seismic activity

Timing of global regression and microbial bloom linked with the Permian-Triassic boundary mass extinction: implications for driving mechanisms.

Science.gov (United States)

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

2017-03-06

New high-resolution U-Pb dates indicate a duration of 89 ± 38 kyr for the Permian hiatus and of 14 ± 57 kyr for the overlying Triassic microbial limestone in shallow water settings of the Nanpanjiang Basin, South China. The age and duration of the hiatus coincides with the Permian-Triassic boundary (PTB) and the extinction interval in the Meishan Global Stratotype Section and Point, and strongly supports a glacio-eustatic regression, which best explains the genesis of the worldwide hiatus straddling the PTB in shallow water records. In adjacent deep marine troughs, rates of sediment accumulation display a six-fold decrease across the PTB compatible with a dryer and cooler climate as indicated by terrestrial plants. Our model of the Permian-Triassic boundary mass extinction (PTBME) hinges on the synchronicity of the hiatus with the onset of the Siberian Traps volcanism. This early eruptive phase released sulfur-rich volatiles into the stratosphere, thus simultaneously eliciting a short-lived ice age responsible for the global regression and a brief but intense acidification. Abrupt cooling, shrunk habitats on shelves and acidification may all have synergistically triggered the PTBME. Subsequently, the build-up of volcanic CO 2 induced a transient cool climate whose early phase saw the deposition of the microbial limestone.

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

International Nuclear Information System (INIS)

1984-05-01

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

Possible Involvement of Permian Phosphoria Formation Oil as a Source of REE and Other Metals Associated with Complex U-V Mineralization in the Northern Bighorn Basin?

Directory of Open Access Journals (Sweden)

Anita L. Moore-Nall

2017-11-01

Full Text Available The origin of V, U, REE and other metals in the Permian Phosphoria Formation have been speculated and studied by numerous scientists. The exceptionally high concentrations of metals have been interpreted to reflect fundamental transitions from anoxic to oxic marine conditions. Much of the oil in the Bighorn Basin, is sourced by the Phosphoria Formation. Two of the top 10 producing oil fields in Wyoming are located approximately 50 km west of two abandoned U-V mining districts in the northern portion of the basin. These fields produce from basin margin anticlinal structures from Mississippian age reservoir rock. Samples collected from abandoned U-V mines and prospects hosted in Mississippian aged paleokarst in Montana and Wyoming have hydrocarbon residue present and contain anomalous high concentrations of many metals that are found in similar concentrations in the Phosphoria Formation. As, Hg, Mo, Pb, Tl, U, V and Zn, often metals of environmental concern occur in high concentrations in Phosphoria Formation samples and had values ranging from 30–1295 ppm As, 0.179–12.8 ppm Hg, 2–791 ppm Mo, <2–146 ppm Pb, 10–490 ppm Tl, 907–86,800 ppm U, 1240–18,900 ppm V, and 7–2230 ppm Zn, in mineralized samples from this study. The REE plus Y composition of Madison Limestone- and limestone breccia hosted-bitumen reflect similar patterns to both mineralized samples from this study and to U.S. Geological Survey rock samples from studies of the Phosphoria Formation. Geochemical, mineralogical and field data were used to investigate past theories for mineralization of these deposits to determine if U present in home wells and Hg content of fish from rivers on the proximal Crow Indian Reservation may have been derived from these deposits or related to their mode of mineralization.

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

Science.gov (United States)

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

2002-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-02-15

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

Geochemical Identification of Windblown Dust Deposits in the Upper Permian Brushy Canyon Formation, Southern New Mexico

Science.gov (United States)

Tice, M. M.; Motanated, K.; Weiss, R.

2009-12-01

Windblown dust is a potentially important but difficult-to-quantify source of siliciclastics for sedimentary basins worldwide. Positively identifying windblown deposits requires distinguishing them from other low density suspension transport deposits. For instance, laminated very fine grained sandstones and siltstones of the Upper Permian Brushy Canyon Formation have been variously interpreted as 1) the deposits of slow-moving, low-density turbidity currents, 2) distal overbank deposits of turbidity currents, 3) the deposits of turbulent suspensions transported across a pycnocline (interflows), and 4) windblown dust. This facies forms the bulk of Brushy Canyon Formation slope deposits, so understanding its origin is critical to understanding the evolution of the basin as a whole. We use a geochemical mapping technique (x-ray fluorescence microscopy) to show that these rocks are up to two times enriched in very fine sand sized zircon and rutile grains relative to Bouma A divisions of interbedded turbidites, suggesting substantial turbulence during transport. However, in contrast with the A divisions, the laminated sandstones and siltstones never show evidence of scour or amalgamation, implying that flow turbulence did not interact with underlying beds. Moreover, proximal loess deposits are often characterized by elevated Zr/Al2O3. These observations are most consistent with windblown interpretations for Brushy Canyon Formation slope sediments, and suggest that evolution of this early deepwater slope system was controlled largely by short-distance aeolian transport of very fine sand and silt from the coast. Heavy mineral incorporation into Brushy Canyon Formation slope deposits as reflected in laminae-scale bulk Zr and Ti abundances may preserve a long-term record of local wind intensity during the Upper Permian.

Extinguishing a Permian World

NARCIS (Netherlands)

Schneebeli-Hermann, E.

2012-01-01

At the end of the Permian, ca. 252 Ma ago, marine and terrestrial fauna were facing the most extensive mass extinction in Earth history (Raup and Sepkoski, 1982). 80%–95% of all species on Earth, on land and in the oceans, became extinct (Benton et al., 2004) within an estimated time interval of

Density characteristics in the upper part of the platform of the Pripyatskiy Basin

Energy Technology Data Exchange (ETDEWEB)

Bulyga, V.K.; Anpilogov, A.P.; Ksenofontov, V.A.; Ur' yev, I.I.

1981-01-01

Density characteristics are examined for the Devonian (upper saline and suprasaline), Carboniferous, Permian, Mesozoic and Cenozoic deposits of the Pripyatskiy Basin. Maps are compiled for isodensities, variability is established in the average values of density both in a regional sense and on local elevations which are characterized for the most part by density minimums.

An early geikiid dicynodont from the Tropidostoma Assemblage Zone (late Permian of South Africa

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Christian F. Kammerer

2017-01-01

Full Text Available Based on specimens previously identified as Tropidostoma, a new taxon of dicynodont (Bulbasaurus phylloxyron gen. et sp. nov. from the Karoo Basin of South Africa is described. Bulbasaurus is a medium-sized dicynodont (maximum dorsal skull length 16.0 cm restricted to the Tropidostoma Assemblage Zone (early Lopingian of the Beaufort Group. Bulbasaurus can be distinguished from Tropidostoma by an array of characters including the presence of a tall, sharp premaxillary ridge, large, rugose, nearly-confluent nasal bosses, a nasofrontal ridge, massive tusks, robust pterygoids, prominently twisted subtemporal bar, and absence of a distinct postfrontal. Inclusion of Bulbasaurus in a phylogenetic analysis of anomodont therapsids recovers it as a member of Geikiidae, a clade of otherwise later Permian dicynodonts such as Aulacephalodon and Pelanomodon. Bulbasaurus exhibits many of the characters typical of adult Aulacephalodon, but at substantially smaller skull size (these characters are absent in comparably-sized Aulacephalodon juveniles, suggesting that the evolution of typical geikiid morphology preceded gigantism in the clade. Bulbasaurus is the earliest known geikiid and the only member of the group known from the Tropidostoma Assemblage Zone; discovery of this taxon shortens a perplexing ghost lineage and indicates that abundant clades from the later Permian of South Africa (e.g., Geikiidae, Dicynodontoidea may have originated as rare components of earlier Karoo assemblage zones.

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.; Ruppert, Leslie F.; Ryder, Robert T.

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.

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

International Nuclear Information System (INIS)

1982-09-01

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

40Ar/ 39Ar dating of Late Permian evaporites, southeastern New Mexico, USA

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Renne, Paul R.; Sharp, Warren D.; Montañez, Isabel P.; Becker, Tim A.; Zierenberg, Robert A.

2001-12-01

40Ar/ 39Ar dating of the potassium-magnesium sulfate mineral langbeinite from Permian evaporites of the Salado formation near Carlsbad, New Mexico, provides quantitative evidence that some salts in these deposits have not recrystallized for 251 Myr since deposition. Survival of Permian salts supports the possibility that Bacillus bacteria recovered from nearby halite was isolated in a closed system and represents a sample of uncontaminated Permian life. Local recrystallization of langbeinite and other nearby minerals is also indicated by the dating, suggesting both the need and the opportunity to document closed system behavior more rigorously. The shoaling and desiccation event recorded by the Salado formation began at least 1 Myr before the Permian-Triassic boundary. Temporal correlation of the Salado with the Zechstein evaporites of north-central Europe supports previously inferred regression models for the origin of these deposits. Significant paleoenvironmental change at the Permian-Triassic boundary thus occurred on a time scale more protracted than that implied by geologically instantaneous events such as bolide impacts.

The Permian mega floras of Uruguay.A synthesis

International Nuclear Information System (INIS)

Crisafulli, A.; Herbst, R.

2007-01-01

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

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

International Nuclear Information System (INIS)

McCleary, J.; Rogers, T.; Ely, R.

1983-08-01

Geophysical well log analysis, literature review, and field work were conducted to develop isopach, structure contour, outcrop, and facies maps and cross sections for the Devonian through Permian strata of a 14,586-km 2 (5632-square-mile) area in southeastern Utah. The study area includes part of the Paradox Basin, the salt deposits of which are of interest in siting studies for a nuclear waste repository. For this reason hydrologic models of this area are needed. This study, part of which included the development of a three-dimensional stratigraphic computer model utilizing Geographic Information System software, can serve as a base for hydrologic or other models for this area. Within and adjacent to the study area, 730 wells were screened to select the 191 wells analyzed for the study. It was found that the Elbert through Molas formations did not exhibit noticeable facies changes within the study area. The Pinkerton Trail Formation exhibits moderate changes: anhydrite and shale become somewhat more abundant toward the northeast. Facies changes in the Paradox Formation are more dramatic. Thick saline facies deposits are present in the northeast, grading to thinner anhydrite and then to carbonate facies in the south and west. The lithology of the Honaker Trail Formation appears to be fairly uniform throughout the area. Facies changes in the Cutler Group are numerous and sometimes dramatic, and generally correspond to the named formations of the group. Other factors that could affect groundwater flow, such as stratigraphic cover of fine-grained rocks, area of formation outcrops, and fracturing and faulting are discussed and delineated on maps

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 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.

Lithofacies palaeogeography of the Late Permian Wujiaping Age in the Middle and Upper Yangtze Region, China

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Jin-Xiong Luo

2014-10-01

Full Text Available The lithofacies palaeogeography of the Late Permian Wujiaping Age in Middle and Upper Yangtze Region was studied based on petrography and the “single factor analysis and multifactor comprehensive mapping” method. The Upper Permian Wujiaping Stage in the Middle and Upper Yangtze Region is mainly composed of carbonate rocks and clastic rocks, with lesser amounts of siliceous rocks, pyroclastic rocks, volcanic rocks and coal. The rocks can be divided into three types, including clastic rock, clastic rock–limestone and limestone–siliceous rock, and four fundamental ecological types and four fossil assemblages are recognized in the Wujiaping Stage. Based on a petrological and palaeoecological study, six single factors were selected, namely, thickness (m, content (% of marine rocks, content (% of shallow water carbonate rocks, content (% of biograins with limemud, content (% of thin-bedded siliceous rocks and content (% of deep water sedimentary rocks. Six single factors maps of the Wujiaping Stage and one lithofacies palaeogeography map of the Wujiaping Age were composed. Palaeogeographic units from west to east include an eroded area, an alluvial plain, a clastic rock platform, a carbonate rock platform where biocrowds developed, a slope and a basin. In addition, a clastic rock platform exists in the southeast of the study area. Hydrocarbon source rock and reservoir conditions were preliminarily analyzed based on lithofacies palaeogeography. Sedimentary environments have obvious controls over the development of the resource rocks. With regard to the abundance of organic matter, the hydrocarbon potential of the coastal swamp environment is the best, followed by the basin environment and the carbonate rock platform. The gas reservoir types of the Wujiaping Stage can be classified as conventional and unconventional gas reservoirs, like coal bed gas and shale gas; all of them have well exploration prospects.

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume II. Palo Duro basin

International Nuclear Information System (INIS)

1982-09-01

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 high variable precipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

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

Science.gov (United States)

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

2013-01-01

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

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

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Rui Castanhinha

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

Circum-Pacific accretion of oceanic terranes to continental blocks: accretion of the Early Permian Dun Mountain ophiolite to the E Gondwana continental margin, South Island, New Zealand

Science.gov (United States)

Robertson, Alastair

2016-04-01

Accretionary orogens, in part, grow as a result of the accretion of oceanic terranes to pre-existing continental blocks, as in the circum-Pacific and central Asian regions. However, the accretionary processes involved remain poorly understood. Here, we consider settings in which oceanic crust formed in a supra-subduction zone setting and later accreted to continental terranes (some, themselves of accretionary origin). Good examples include some Late Cretaceous ophiolites in SE Turkey, the Jurassic Coast Range ophiolite, W USA and the Early Permian Dun Mountain ophiolite of South Island, New Zealand. In the last two cases, the ophiolites are depositionally overlain by coarse clastic sedimentary rocks (e.g. Permian Upukerora Formation of South Island, NZ) that then pass upwards into very thick continental margin fore-arc basin sequences (Great Valley sequence, California; Matai sequence, South Island, NZ). Field observations, together with petrographical and geochemical studies in South Island, NZ, summarised here, provide evidence of terrane accretion processes. In a proposed tectonic model, the Early Permian Dun Mountain ophiolite was created by supra-subduction zone spreading above a W-dipping subduction zone (comparable to the present-day Izu-Bonin arc and fore arc, W Pacific). The SSZ oceanic crust in the New Zealand example is inferred to have included an intra-oceanic magmatic arc, which is no longer exposed (other than within a melange unit in Southland), but which is documented by petrographic and geochemical evidence. An additional subduction zone is likely to have dipped westwards beneath the E Gondwana margin during the Permian. As a result, relatively buoyant Early Permian supra-subduction zone oceanic crust was able to dock with the E Gondwana continental margin, terminating intra-oceanic subduction (although the exact timing is debatable). The amalgamation ('soft collision') was accompanied by crustal extension of the newly accreted oceanic slab, and

Geology and undiscovered resource assessment of the potash-bearing Pripyat and Dnieper-Donets Basins, Belarus and Ukraine

Science.gov (United States)

Cocker, Mark D.; Orris, Greta J.; Dunlap, Pamela; Lipin, Bruce R.; Ludington, Steve; Ryan, Robert J.; Słowakiewicz, Mirosław; Spanski, Gregory T.; Wynn, Jeff; Yang, Chao

2017-08-03

Undiscovered potash resources in the Pripyat Basin, Belarus, and Dnieper-Donets Basin, Ukraine, were assessed as part of a global mineral resource assessment led by the U.S. Geological Survey (USGS). The Pripyat Basin (in Belarus) and the Dnieper-Donets Basin (in Ukraine and southern Belarus) host stratabound and halokinetic Upper Devonian (Frasnian and Famennian) and Permian (Cisuralian) potash-bearing salt. The evaporite basins formed in the Donbass-Pripyat Rift, a Neoproterozoic continental rift structure that was reactivated during the Late Devonian and was flooded by seawater. Though the rift was divided, in part by volcanic deposits, into the separate Pripyat and Dnieper-Donets Basins, both basins contain similar potash‑bearing evaporite sequences. An Early Permian (Cisuralian) sag basin formed over the rift structure and was also inundated by seawater resulting in another sequence of evaporite deposition. Halokinetic activity initiated by basement faulting during the Devonian continued at least into the Permian and influenced potash salt deposition and structural evolution of potash-bearing salt in both basins.Within these basins, four areas (permissive tracts) that permit the presence of undiscovered potash deposits were defined by using geological criteria. Three tracts are permissive for stratabound potash-bearing deposits and include Famennian (Upper Devonian) salt in the Pripyat Basin, and Famennian and Cisuralian (lower Permian) salt in the Dnieper-Donets Basin. In addition, a tract was delineated for halokinetic potash-bearing Famennian salt in the Dnieper-Donets Basin.The Pripyat Basin is the third largest source of potash in the world, producing 6.4 million metric tons of potassium chloride (KCl) (the equivalent of about 4.0 million metric tons of potassium oxide or K2O) in 2012. Potash production began in 1963 in the Starobin #1 mine, near the town of Starobin, Belarus, in the northwestern corner of the basin. Potash is currently produced from

Geothermal constraints on Emeishan mantle plume magmatism: paleotemperature reconstruction of the Sichuan Basin, SW China

Science.gov (United States)

Zhu, Chuanqing; Hu, Shengbiao; Qiu, Nansheng; Jiang, Qiang; Rao, Song; Liu, Shuai

2018-01-01

The Middle-Late Permian Emeishan Large Igneous Province (ELIP) in southwestern China represents a classic example of a mantle plume origin. To constrain the thermal regime of the ELIP and contemporaneous magmatic activity in the northeastern Sichuan Basin, maximum paleotemperature profiles of deep boreholes were reconstructed using vitrinite reflectance (Ro) and apatite fission track data. Two heating patterns were identified: (1) heating of the overlying lithosphere by magma storage regions and/or magmatic activity related to the mantle plume, which resulted in a relatively strong geothermal field and (2) direct heating of country rock by stock or basalt. Borehole Ro data and reconstructed maximum paleotemperature profiles near the ELIP exhibit abrupt tectonothermal unconformities between the Middle and Late Permian. The profiles in the lower subsections (i.e., pre-Middle Permian) exhibited significantly higher gradients than those in the upper subsections. Distal to the basalt province, high paleo-geotemperatures (hereafter, paleotemperatures) were inferred, despite deformation of the paleogeothermal curve due to deep faults and igneous rocks within the boreholes. In contrast, Ro profiles from boreholes without igneous rocks (i.e., Late Permian) contained no break at the unconformity. Paleotemperature gradients of the upper and the lower subsections and erosion at the Middle/Late Permian unconformity revealed variations in the thermal regime. The inferred spatial distribution of the paleothermal regime and the erosion magnitudes record the magmatic and tectonic-thermal response to the Emeishan mantle plume.

Lithofacies paleogeography and favorable gas exploration zones of Qixia and Maokou Fms in the Sichuan Basin

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Jingao Zhou

2016-05-01

Full Text Available In the Sichuan Basin, the Middle Permian marine carbonate rocks are important natural gas pay zones with immense exploration potential, but the facies belts and distribution situations of layered dolomite reservoirs are not clear, which hinders the progress in natural gas exploration. In view of the sedimentary background of the Sichuan Basin, field outcrop section, drilling data and seismic data were comprehensively analyzed with the favorable reservoir intervals in the framework of sequence stratigraphy as the key research units. Research results about its lithofacies paleogeography were obtained as follows. First, a gentle slope SW high and NE low was presented during the sedimentation of the Qixia Fm in the Middle Permian. In the Maokou Fm of the Middle Permian, however, a series of the N–W trending intra-platform rifts were developed in this setting, and eventually a paleogeographic pattern of NE-dipping alternative uplift and depression was evolved. Second, in the Qixia Fm, the transgressive tract was in an open platform environment and the highstand system tract evolved into a rimmed platform. And the platform margin beach in the area of Jiange–Ya'an is the favorable reservoir facies belt. And third, in the Maokou Fm, the transgressive tract was in the carbonate shelf environment and the highstand system tract evolved into a rimmed platform. And the platform margin reef flat in the area of Jiange–Ya'an and the syneclise margin beach in the area of Yanting–Guang'an are favorable reservoir facies belts. It is concluded that the two grain beach facies belts in the areas of Jiange–Ya'an and Yanting–Guang'an were the favorable zones for the large-scale development of Middle Permian layered dolomite reservoirs and they are the main target of subsequent natural gas exploration.

The Gañuelas-Mazarrón Tertiary Basin (Murcia, Spain): Features, Analogies, implications for the Safety of a CO2-DGS and Methodology; La Cuenca de Gañuelas-Mazarrón (Murcia, España): Caracteristicas, Analogías, Implicaciones para la Seguridad de un AGP-CO y 2 Metodología de Estudio

Energy Technology Data Exchange (ETDEWEB)

Rodrigo-Naharro, J.; Clemente-Jul, C.; Pérez del Villar, L.

2015-07-01

This work summarizes the main features of the Gañuelas-Mazarrón Tertiary basin, emphasising on the: i) geological, hydrogeological and hydrogeochemical characteristics; ii) current carbonate precipitation related to waters from several hydrogeological and geothermal wells in the basin; and iii) dissolved and free CO2 leakages and associated gases, mainly 222Rn. Furthermore, it has been summarised the main analogies established between the natural system studied and a CO2-Deep Geological Storage (CO2-DGS) conceptual model; as well as the implications of these analogies to qualitatively analyse the behaviour and evaluate the safety, in short, medium and long term, of a CO2-DGS. Finally, a useful methodology for any sedimentary basin, similar to the Gañuelas-Mazarrón basin, capable to host a CO2-DGS is also proposed. In conclusion, the full or partial study of a natural system analogous to a CO2-DGS must not be confused with the study to characterise a site for a CO2-DGS, since natural analogues should provide information about the behaviour, evolution and safety, in long-term, of the natural system, and that this information could be applied to a CO2-DGS system.

Inferred Early Permian Arc Rifting in Bogda Mountain, Southernmost of the Central Asia Orogenic Belt: Evidence from a Peperite Bearing Volcano-Sedimentary Succession

Science.gov (United States)

Memtimin, M.; Guo, Z.

2017-12-01

Late Paleozoic tectonic history, especially Carboniferous-Permian periods, of the Central Asia Orogenic Belt (CAOB) is considered to be the turning point for the termination of terrane amalgamation and closure of the Paleoasian Ocean. However, the debate about the paleoenvironment and tectonic setting of the region during the period is still not resolved. In this study, we report a set of volcano-sedimentary sequence in the Bogda Mountain of the southernmost of CAOB, which is associated with contemporaneous subaqueous emplacement of and interaction between mafic lava and carbonate sediments. The succession contains four distinct facies including closely packed pillow basalts, pillow basalts with interstitial materials, hyaloclastites and peperites. We discuss their formation and emplacement mechanism, interaction between hot magma-water/unconsolidated sediments and thermal metamorphism during the interaction. Textural features of the sequence, especially hyaloclastites and peperites, provide clear evidence for in situ autofragmentation of lava flows, synvolcanic sedimentation of carbonates, fuel coolant interaction when hot magma bulldozed into wet unconsolidated sediments, and represent autochthonous origin of the succession. Lateral transition of the lithofacies indicate a progressively deepening subaqueous environment, resembling a stepwise evolution from early stage of volcanic intrusion with lower lava flux in shallower water level to increasingly subsiding basin with more lava flux in greater depth. Previous studies determined that the mafic magma was intruded around the Carboniferous-Permian boundary ( 300Ma), and geochemical studies showed the magma was originated from dry depleted mantle with little crustal contamination. Nevertheless, the succession was thought to be fault related allochthones formation which was transferred in as part of a Carboniferous intraplate arc. Combining our findings with the previous study results, we propose a new model to

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

Science.gov (United States)

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

2016-05-01

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

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

International Nuclear Information System (INIS)

L'Homer, A; Manigault, B; Doyhernart, A; Rossi, P; Spoturno, J; De Santana, H; Vaz Chaves, N.

1982-01-01

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

Report on information collection and analysis for fundamental survey on coal resource development in fiscal 1998. Survey on coal supply potentiality in Bowen Basin in Australia; 1998 nendo sekitan shigen kaihatsu kiso chosa joho shushu kaiseki hokokusho. Goshu Bowen bonchi sekitan kyokyu potentiality chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

A survey was made on coal supply potentiality in Bowen Basin in Australia. The main coal beds exist in the order of four beds in the Permian period. The oldest bed is the Reids Dome bed in the Lower Permian period, deposited in the south-west part of the basin. The later wide-area transgression has caused the Back Creek bed groups to deposit, whereas three coal measures have deposited in a concave on the raised basic bed. Later, the ocean has invaded into the entire basin. After having turned into the Upper Permian period, regression had occurred from north to south, where major coal measures such as the Moranbah and German Creek beds had deposited over the entire basin. Further regression has taken place to south, causing three uppermost coal measures to have deposited over the entire basin. In major part of the areas identified currently with existence of coal measures, and even in areas without mines, the mining right or the exploration right has been established, limiting the areas having development potentiality. Five abandoned mining areas exist in the Rangal coal measure, two in the Moranbah coal measure, two in the Reids Dome coal measure, and one in the Baralaba coal measure. There is a possibility of discovering areas developable for a scale of several ten million tons. (NEDO)

The Saint Martin de Belleville syncline and its uraniferous permian sandstone

International Nuclear Information System (INIS)

Schade, Johannes

1983-01-01

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

Permian potentiometric analysis

International Nuclear Information System (INIS)

Devary, J.L.

1983-09-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Wu, Ya; Wang, Yanxin, E-mail: yx.wang@cug.edu.cn; Xie, Xianjun

2014-02-01

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 < 1 mg/kg for the igneous and metamorphic rocks, typically 2–5 mg/kg for the Carboniferous and Permian sedimentary rocks and around 3 mg/kg for 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 < 0.02–288 μg/L (average 24 μg/L), with 24% of the investigated boreholes above the WHO provisional guideline of 30 μg/L for U in drinking water. Average U concentration for surface water was 5.8 μg/L. In oxidizing waters, uranyl (UO{sub 2}{sup 2+}) species is dominant and strongly adsorbed onto iron (hydro)xides, while it would be preferentially complexed with carbonate in the alkaline groundwater, forming highly soluble uranyl-carbonate complexes at Datong. Under reducing conditions, uranous (U(IV)) species is ready to precipitate or bind to organic matter, therefore having a low mobility. At the study area, high U groundwater (> 30 μg/L) occurs at the alluvial plains due to intermediate redox and enhanced alkaline conditions. The abnormally high levels of U in groundwater (> 100 μg/L) are locally found at the west alluvial plains. By contrast, U co-precipitation with secondary carbonate minerals like Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3} in the dominant Ca–Mg–Na–HCO{sub 3} 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

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

International Nuclear Information System (INIS)

DeConto, R.T.; Murphy, P.J.

1987-09-01

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

The Upper Permian in the Netherlands

NARCIS (Netherlands)

Visser, W.A.

1955-01-01

The Upper Permian in the Netherlands, as known from borehole data, is deposited in a mainly evaporitic facies north of the Brabant and Rhenish Massifs. In the extreme south (Belgian Campine, de Peel) a near-shore facies of reef dolomites and elastics occurs. In the western and central Netherlands

Trouble Upstairs: Reconstructing Permian-Triassic Climate during Siberian Traps Magmatism

Science.gov (United States)

Black, B. A.; Neely, R. R., III; Lamarque, J. F.; Elkins-Tanton, L. T.; Mills, M. J.

2014-12-01

The eruption of large igneous provinces can transfer significant masses of volatiles from Earth's interior to the atmosphere. What are the consequences of this degassing for habitability and extinction? In this presentation, we consider this question in the context of Siberian Traps magmatism, which has been shown to overlap within geochronologic uncertainty with catastrophic deterioration of Permian-Triassic marine and terrestrial ecosystems. To investigate the impacts of endogenic gases on climate, atmospheric chemistry, and ocean circulation, we conducted a series of numerical experiments with a comprehensive global model for the Permian-Triassic. Our simulations predict the intensity and distribution of acid rain and ozone depletion, with implications for terrestrial biota. We further explore feedbacks between sulfur emissions, transient cooling, and shifts in ocean circulation. We suggest that Siberian Traps magmatism may have triggered several distinct kill mechanisms in the oceans and on land, contributing to a complex combined pattern of environmental stress and latest Permian ecological failure.

Carboniferous and Permian evolutionary records for the Paleo-Tethys Ocean constrained by newly discovered Xiangtaohu ophiolites from central Qiangtang, central Tibet

Science.gov (United States)

Zhang, Xiu-Zheng; Dong, Yong-Sheng; Wang, Qiang; Dan, Wei; Zhang, Chunfu; Deng, Ming-Rong; Xu, Wang; Xia, Xiao-Ping; Zeng, Ji-Peng; Liang, He

2016-07-01

Reconstructing the evolutionary history of the Paleo-Tethys Ocean remains at the center of debates over the linkage between Gondwana dispersion and Asian accretion. Identifying the remnants of oceanic lithosphere (ophiolites) has very important implications for identifying suture zones, unveiling the evolutionary history of fossil oceans, and reconstructing the amalgamation history between different blocks. Here we report newly documented ophiolite suites from the Longmu Co-Shuanghu Suture zone (LSSZ) in the Xiangtaohu area, central Qiangtang block, Tibet. Detailed geological investigations and zircon U-Pb dating reveal that the Xiangtaohu ophiolites are composed of a suite of Permian (281-275 Ma) ophiolites with a nearly complete Penrose sequence and a suite of Early Carboniferous (circa 350 Ma) ophiolite remnants containing only part of the lower oceanic crust. Geochemical and Sr-Nd-O isotopic data show that the Permian and Carboniferous ophiolites in this study were derived from an N-mid-ocean ridge basalts-like mantle source with varied suprasubduction-zone (SSZ) signatures and were characterized by crystallization sequences from wet magmas, suggesting typical SSZ-affinity ophiolites. Permian and Carboniferous SSZ ophiolites in the central Qiangtang provide robust evidence for the existence and evolution of an ancient ocean basin. Combining with previous studies on high-pressure metamorphic rocks and pelagic radiolarian cherts, and with tectonostratigraphic and paleontological data, we support the LSSZ as representing the main suture of the Paleo-Tethys Ocean which probably existed and evolved from Devonian to Triassic. The opening and demise of the Paleo-Tethys Ocean dominated the formation of the major framework for the East and/or Southeast Asia.

Lower Permian stems as fluvial paleocurrent indicators of the Parnaíba Basin, northern Brazil

Science.gov (United States)

Capretz, Robson Louiz; Rohn, Rosemarie

2013-08-01

A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit "Tocantins Fossil Trees Natural Monument". In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry

Permian tetrapods from the Sahara show climate-controlled endemism in Pangaea.

Science.gov (United States)

Sidor, Christian A; O'Keefe, F Robin; Damiani, Ross; Steyer, J Sébastien; Smith, Roger M H; Larsson, Hans C E; Sereno, Paul C; Ide, Oumarou; Maga, Abdoulaye

2005-04-14

New fossils from the Upper Permian Moradi Formation of northern Niger provide an insight into the faunas that inhabited low-latitude, xeric environments near the end of the Palaeozoic era (approximately 251 million years ago). We describe here two new temnospondyl amphibians, the cochleosaurid Nigerpeton ricqlesi gen. et sp. nov. and the stem edopoid Saharastega moradiensis gen. et sp. nov., as relicts of Carboniferous lineages that diverged 40-90 million years earlier. Coupled with a scarcity of therapsids, the new finds suggest that faunas from the poorly sampled xeric belt that straddled the Equator during the Permian period differed markedly from well-sampled faunas that dominated tropical-to-temperate zones to the north and south. Our results show that long-standing theories of Late Permian faunal homogeneity are probably oversimplified as the result of uneven latitudinal sampling.

Lithofacies palaeogeography of the Carboniferous and Permian in the Qinshui Basin, Shanxi Province, China

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Long-Yi Shao

2015-10-01

The Xiashihezi, Shangshihezi, and Shiqianfeng Formations consist mainly of red mudstones with thick-interbedded sandstones. During the deposition of these formations, most areas of the basin were occupied by a fluvial channel, resulting in palaeogeographic units that include fluvial channel zones and flood basins. The fluvial channel deposits consist mainly of relatively-thick sandstones, which could have potential for exploration of tight sandstone gas.

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

Science.gov (United States)

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

2010-02-01

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

Migrated hydrocarbons in outcrop samples: revised petroleum exploration directions in the Tarim Basin

Energy Technology Data Exchange (ETDEWEB)

Li, Maowen; Snowdon, Lloyd [Geological Survey of Canada, Calgary, AB (Canada); Xiao, Zhongyao [CNPC Tarim Petroleum Exploration Bureau, Kuerle, Xinjiang (China); Lin, Renzi [Petroleum Univ., Changping, Beijing (China); Wang, Peirong; Hou, Dujie [Jianghan Petroleum Univ., Hubei (China); Zhang, Linye [SINOPEC Shengli Petroleum Bureau, Dongying, Shandong (China); Zhang, Shuichang; Liang, Digang [Research Inst. of Petroleum Exploration and Development, Beijing (China)

2000-07-01

The application of age-specific biomarker distributions established from mature exploration areas of the Tarim Basin, northwestern China, indicates that most Carboniferous-Permian outcrop samples in the eastern segment of the Southwest Depression, previously believed to have significant petroleum source potential, in fact contain migrated hydrocarbons derived from Cambrian-Lower Ordovician strata. New geochemical results have led to a major revision of petroleum exploration directions in this area. (Author)

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

DAGMARITA SHHREZAENSIS N. SP. GLOBIVALVULINID FORAMINIFER, (WUCHIAPINGIAN, LATE PERMIAN, CENTRAL IRAN

Directory of Open Access Journals (Sweden)

PARVIN MOHTAT-AGHAI

2003-03-01

Full Text Available In the course of an investigation on the major mass extintion event near the P/T boundary, in the vicinity of Shahreza (South Isfahan in Iran, a stratigraphically significant new species of foraminifera (Dagmarita shahreaensis n. sp. has been discovered in the Wuchiapingian/Dzhulfian (Late Permian of central Iran (Hambast Formation. This new species is described and emplaced in the phylogeny of the globivalvulinid foraminifera, which evolved rapidly during the Middle/Late Permian. 

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

Science.gov (United States)

Jha, Neerja; Chary, M. Basava; Aggarwal, Neha

2012-10-01

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

Organic-rich shales from internal Betic basins (SE Spain): potential source rocks analogs for the pre-Messinian Salt play in the western Mediterranean

Energy Technology Data Exchange (ETDEWEB)

Permanyer, A.; Jorge, R.; Baudino, R.; Gilbert, L.

2016-07-01

Southeastern Spain has a large number of Late Neogene basins with substantial evaporitic deposits that developed under an overall NNW-SSE compressional regime related to the African-European tectonic plates collision. Located in the Betic Cordillera, they can be considered as marginal Mediterranean basins that became gradually isolated during the Tortonian and Early Messinian due to tectonic uplift. Different evaporitic units accumulated in these basins during isolation and, in several cases, evaporitic conditions were associated to episodes of important organic matter accumulation. Results obtained from Late Tortonian to Early Messinian shales collected from boreholes, mines and outcrops in the internal Betic basins of Las Minas de Hellín, Cenajo and Socovos are presented. The organic matter was studied under fluorescence and scanning electron microscopy (SEM), and the main geochemical characteristics defined. They show a relation between organic-rich intervals with high potential of hydrocarbon generation, native sulfur, bio-induced dolomite and evaporitic deposits. These organicrich shales can be found before, during and after the evaporitic episodes. Results from the present study are compared with those previously obtained in the pre-evaporitic deposits of the Lorca Basin that showed high oil generation potential, a restricted-marine origin of the organic matter and a low degree of maturity. The occurrence of such potential source rocks in several basins points to a broad regional distribution. At a larger scale, in the Mediterranean Basin, organic-rich sediments were deposited before and during the Messinian Salinity Crisis. The studied examples could represent analogs for potential source rocks of the pre-Messinian salt play in the Western Mediterranean. (Author)

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

Progress in the Gondwanan Carboniferous–Permian palynology ...

Indian Academy of Sciences (India)

The first section describes challenges in the Carboniferous–Permian Gondwanan stratigraphic palynology, and progress in techniques such as presence of the 'rare-marine intervals', and 'radiometric dating' in some Gondwanan successions, e.g., South Africa, Australia and South America, as tools to confidently calibrate ...

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)

Cullers, R.; Chaudhuri, S.; Kilbane, N.; Koch, R.

1979-01-01

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

Permian macro- and miofloral diversity, palynodating and ...

Indian Academy of Sciences (India)

The order Glossopteridales is highly diversi- fied with 23 taxa and the genus Glossopteris, with 22 species, dominates the flora. The mioflora of this colliery is represented by two distinct palynoassemblages. The palynoassemblage-III is correlatable with the palynoflora of Early Permian (Artinskian) Lower Barakar Formation.

Microbialites and global environmental change across the Permian-Triassic boundary: a synthesis.

Science.gov (United States)

Kershaw, S; Crasquin, S; Li, Y; Collin, P-Y; Forel, M-B; Mu, X; Baud, A; Wang, Y; Xie, S; Maurer, F; Guo, L

2012-01-01

Permian-Triassic boundary microbialites (PTBMs) are thin (0.05-15 m) carbonates formed after the end-Permian mass extinction. They comprise Renalcis-group calcimicrobes, microbially mediated micrite, presumed inorganic micrite, calcite cement (some may be microbially influenced) and shelly faunas. PTBMs are abundant in low-latitude shallow-marine carbonate shelves in central Tethyan continents but are rare in higher latitudes, likely inhibited by clastic supply on Pangaea margins. PTBMs occupied broadly similar environments to Late Permian reefs in Tethys, but extended into deeper waters. Late Permian reefs are also rich in microbes (and cements), so post-extinction seawater carbonate saturation was likely similar to the Late Permian. However, PTBMs lack widespread abundant inorganic carbonate cement fans, so a previous interpretation that anoxic bicarbonate-rich water upwelled to rapidly increase carbonate saturation of shallow seawater, post-extinction, is problematic. Preliminary pyrite framboid evidence shows anoxia in PTBM facies, but interbedded shelly faunas indicate oxygenated water, perhaps there was short-term pulsing of normally saturated anoxic water from the oxygen-minimum zone to surface waters. In Tethys, PTBMs show geographic variations: (i) in south China, PTBMs are mostly thrombolites in open shelf settings, largely recrystallised, with remnant structure of Renalcis-group calcimicrobes; (ii) in south Turkey, in shallow waters, stromatolites and thrombolites, lacking calcimicrobes, are interbedded, likely depth-controlled; and (iii) in the Middle East, especially Iran, stromatolites and thrombolites (calcimicrobes uncommon) occur in different sites on open shelves, where controls are unclear. Thus, PTBMs were under more complex control than previously portrayed, with local facies control playing a significant role in their structure and composition. © 2011 Blackwell Publishing Ltd.

Global taxonomic diversity of anomodonts (tetrapoda, therapsida and the terrestrial rock record across the Permian-Triassic boundary.

Directory of Open Access Journals (Sweden)

Jörg Fröbisch

Full Text Available The end-Permian biotic crisis (~252.5 Ma represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids ('mammal-like reptiles', through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates.

Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

Science.gov (United States)

Schöpfer, Kateřina; Hinsch, Ralph

2017-04-01

are present in the Faroe-Shetland Basin, but are not recognisable in the Vøring Basin. (iv) Based on seismic data only, a Permian/Triassic rift phase can be suggested for the Vøring Basin, but the evidence for an equivalent rift phase in the Faroe-Shetland Basin is inconclusive. The present study demonstrates that basins developing above a complex mosaic of basement terrains accreted during orogenic phases can exhibit significant differences in their architecture. The origin of these differences may be considered to be a result of inherited pre-existing large-scale structures (e.g. pre-existing fault blocks) and/or a non-uniform crustal thickness prior to rifting.

Gas hydrate contribution to Late Permian global warming

Czech Academy of Sciences Publication Activity Database

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

2014-01-01

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

Permian-Triassic palynofacies and chemostratigraphy in a core recovered from central Spitsbergen.

Science.gov (United States)

van Soelen, Els; Hasic, Edi; Planke, Sverre; Svensen, Henrik; Sleveland, Arve; Midtkandal, Ivar; Twitchett, Richard; Kürschner, Wolfram

2017-04-01

The Late Permian biotic crisis is one of the most severe extinction events in the history of the Earth, affecting both terrestrial and marine environments. A large igneous province (LIP) in Siberia is thought to be linked with this global event; however, correlation between the volcanic event and the biotic crisis is difficult and requires well dated and high resolution Permian-Triassic boundary successions from the Arctic region. The Svalbard end-Permian drilling project is aimed at improved correlation of the Permian-Triassic sections in Svalbard with the Siberian Traps. The core was collected from Deltadalen, in central Spitsbergen, with additional samples collected from an outcrop close to the drilling site. As part of this collaborative project, carbon isotope geochemistry, palynofacies and palynomorphs were studied in order to learn more about the biostratigraphy and to understand changes in the source(s) of organic matter. Objectives were to reconstruct the paleo-environment; to correlate the core with other sites on Svalbard, and with global records; and to identify and characterize the Late Permian extinction event in the core. A carbon isotope shift is an important global stratigraphic marker in the latest Permian and occurs near the base of the Vikinghøgda Formation in the Deltadalen core, where bulk rock values change from -24.5 to -32.7‰. Palynomorph preservation was generally poor in both core and outcrop samples which prevented detailed examination of species and limited their usefulness for biostratigraphy. Still, palynofacies were useful for correlative purposes. AOM (amorphous organic matter) in the core increases at the lithological change from sandstones to siltstones, and is indicative of anoxic conditions. Similar high levels of AOM in the outcrop samples can be correlated with the core. Palynological analyses show that the spore/pollen ratio starts to increase before the negative shift in the isotope curve. Such an increase in spore

Palynostratigraphy of Permian succession in the Mand–Raigarh ...

Indian Academy of Sciences (India)

Palynofloras have been recorded from the Barakar Formation in the Borehole MBKW-3, Barpali–. Karmitikra Block, Mand–Raigarh Coalfield, Chhattisgarh. Three distinct palynoassemblages have been identified and referred to the following palynoassemblage zones – Gondisporites raniganjensis (Latest. Permian); ...

Palynostratigraphy of Permian succession in the Mand–Raigarh ...

Indian Academy of Sciences (India)

Palynofloras have been recorded from the Barakar Formation in the Borehole MBKW-3, Barpali–Karmitikra Block, Mand–Raigarh Coalfield, Chhattisgarh. Three distinct palynoassemblages have been identified and referred to the following palynoassemblage zones – Gondisporites raniganjensis (Latest Permian); ...

Oxygen and Carbon Isotopic Composition of Carbonate Rocks of the Permian Qixia Formation, Sichuan Basin: Thermal Effects of Emeishan Basalt

Directory of Open Access Journals (Sweden)

Keke Huang

2016-01-01

Full Text Available The late Permian thermal events related to Emeishan Basalt has made a great impact on the underlying carbonate rock properties in the western margin of the Yangtze Platform. In this paper, we investigate the carbon and oxygen isotopic composition of the Qixia Formation carbonates from two sections: the Qiaoting Section in the northeastern part of the Sichuan Basin and the Changjianggou Section at the northwestern edge of the Basin. The data reveal that: (i Samples from Qiaoting section show a relatively narrow range of δ13C and δ18O, varying from 2.7‰ to 5.2‰ with an average of 4.2‰, and -3.8‰ to -7.8‰ with an average of -5.4‰, respectively. In contrast, Samples from Changjianggou section exhibit larger magnitude of variation in δ13C and δ18O, ranging from -1‰ to 3.8‰ with an average of 1.5‰, and -2.1 to -9.2‰, with an average of -6.0‰ respectively; (ii δ13C and δ18O records in carbonates from Qiaoting section are similar to those of Middle Permian seawater whereas carbonates from the Changjianggou section are depleted in 13C and 18O compared to contemporary seawater; (iii On the basis of combined petrographic and paleo-heat flow evidence, the lower carbon and oxygen isotopic composition of the carbonates from the Changjianggou section are interpreted to be the results of thermal effects of Emeishan Basalt because of its proximity to the eruption center of the basalt. The high temperature reduced the δ18O values of the carbonates and forced the organic matter to mature at an early stage, thus producing 13C-enriched carbon dioxide to participate in the formation of carbonates.     Composición Isotópica de Oxígeno y Carbón en Rocas de Carbonato de la Formación de Edad Pérmica Qixia, en la Cuenca de Sichuan: Efectos Térmicos del Basalto Emeishan   Resumen Los eventos térmicos del Pérmico tardío relacionados con el Basalto Emeishan han tenido un gran impacto en las propiedades de las rocas de carbonato

Paleogeothermal record of the Emeishan mantle plume: evidences from borehole Ro data in the Sichuan basin, SW China

Science.gov (United States)

Hu, S.

2013-12-01

The Emeishan basalt province located in the southwest of China is widely accepted to be a result of the eruption of a mantle plume at the time of middle-late Permian. If it was a mantle plume, the ambient sedimentary rocks must be heated up during the development of the mantle plume and this thermal effect must be recorded by some geothermometers in the country rocks. The vitrinite reflectance (Ro) data as a maximum paleotemperature recorder from boreholes in Sichuan basin was employed to expose the thermal regime related to the proposed Emeishan mantle plume. The Ro profiles from boreholes which drilled close to the Emeishan basalts shows a ';dog-leg' (break) style at the unconformity between the middle and the upper Permian, and the Ro profiles in the lower subsection (pre-middle Permian) shows a significantly higher slopes (gradients) than those in the upper subsection. In contrast, those Ro profiles from boreholes far away from the center of the basalt province have no break at the uncomformity. Based on the chemical kinetic model of Ro, the paleo-temperature gradients for the upper and the lower subsections in different boreholes, as well as the erosion at the unconformity between the middle and the upper Permian, were reconstructed to reveal the variations of the temperature gradients and erosion thickness with geological time and space. Both the thermal regime and the erosion thickness together with their spatial variation (structure) provide strong geothermal evidence for the existence of the Emeishan mantle plume in the middle-late Permian.

Archaeolithoporella and Tubiphytes : Affinties and Paleoecology in Permian Reefs of South China

Institute of Scientific and Technical Information of China (English)

王生海; 范嘉松; J.Keith Rigby

1994-01-01

Archaeolithoporella is one of the most important Permian reef-building organisms, but itsaffinity has long been controversial. It was first reported in Japan and was considered as a coralline red alga. Since then it has been recognized in Permian reefs in other parts of the world. Many researchers have studied the materials they had found and the Japanese holotype specimen. Most have concluded that it is a problematic alga. or just a problematica because of weak criteria for definition. Some have even considered it inorganic. However, relict cellular structures and microtubular laminae found in well-preserved specimens from Permian reefs in South China strongly support a coralline red algal affinity for the genus.In situ preserved Archaeolithoporella is restricted within the typical framework facies and it occurs most abundantly in syndepositionally cemented framestones. This suggests that Archaeolithoporella required a firm substrate and clear but agitated sea water. Archaeolithoporella is often found

New absolute paleointensity determinations for the Permian-Triassic boundary from the Kuznetsk Trap Basalts.

Science.gov (United States)

Kulakov, E.; Metelkin, D. V.; Kazansky, A.

2015-12-01

We report the results of a pilot absolute paleointensity study of the ~250 Ma basalts of Kuznetsk traps (Kuznetsk Basin, Altai-Sayan folded area). Studied samples are characterized by a reversed polarity of natural remanent magnetization that corresponds to the lower part of Siberian Trap basalts sequence. Geochemical similarity of Kuznets basalts with those from Norilsk region supports this interpretation. Primary origin of thermal remanence in our sample is confirmed by a positive backed contact test. Rock magnetic analyses indicate that the ChRM is carried by single-domain titanomagnetite. The Coe-version of the Thellier-Therllier double-heating method was utilized for the paleointensity determinations. In contrast to the previous studies of the Permian-Triassic Siberian trap basalts, our data indicate that by the P-T boundary the paleofield intensity was relatively high and comparable with geomagnetic field strength for the last 10 millions of years. New results question the duration of the "Mesozoic dipole-low".

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

Science.gov (United States)

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

2016-03-01

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

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

Directory of Open Access Journals (Sweden)

TEA KOLAR-JURKOVSEK

2011-03-01

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

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

Evaluation of the Tindouf Basin Region in Southern Morocco as an Analog Site for Soil Geochemistry on Noachian Mars.

Science.gov (United States)

Oberlin, Elizabeth A; Claire, Mark W; Kounaves, Samuel P

2018-02-09

Locations on Earth that provide insights into processes that may be occurring or may have occurred throughout martian history are often broadly deemed "Mars analog environments." As no single locale can precisely represent a past or present martian environment, it is important to focus on characterization of terrestrial processes that produce analogous features to those observed in specific regions of Mars or, if possible, specific time periods during martian history. Here, we report on the preservation of ionic species in soil samples collected from the Tindouf region of Morocco and compare them with the McMurdo Dry Valleys of Antarctica, the Atacama Desert in Chile, the martian meteorite EETA79001, and the in situ Mars analyses from the Phoenix Wet Chemistry Laboratory (WCL). The Moroccan samples show the greatest similarity with those from Victoria Valley, Beacon Valley, and the Atacama, while being consistently depleted compared to University Valley and enriched compared to Taylor Valley. The NO 3 /Cl ratios are most similar to Victoria Valley and Atacama, while the SO 4 /Cl ratios are similar to those from Beacon Valley, Victoria Valley, and the Atacama. While perchlorate concentrations in the Moroccan samples are typically lower than those found in samples of other analog sites, conditions in the region are sufficiently arid to retain oxychlorines at detectable levels. Our results suggest that the Tindouf Basin in Morocco can serve as a suitable analogue for the soil geochemistry and subsequent aridification of the Noachian epoch on Mars. Key Words: Mars analogues-Antarctica-Morocco-Oxyanions-Perchlorate-Nitrate. Astrobiology 18, xxx-xxx.

The Collyhurst Sandstone as a secondary storage unit for CCS in the East Irish Sea Basin (UK)

Science.gov (United States)

Gamboa, D.; Williams, J. D. O.; Kirk, K.; Gent, C. M. A.; Bentham, M.; Schofield, D. I.

2016-12-01

Carbon Capture and Storage (CCS) is key technology for low-carbon energy and industry. The UK hosts a large CO2 storage potential offshore with an estimated capacity of 78 Gt. The East Irish Sea Basin (EISB) is the key area for CCS in the western UK, with a CO2 storage potential of 1.7 Gt in hydrocarbon fields and in saline aquifers within the Triassic Sherwood Sandstone Formation. However, this theoretical storage capacity does not consider the secondary storage potential in the lower Permian Collyhurst Sandstone Formation. 3D seismic data were used to characterise the Collyhurst Sandstone Formation in the EISB. On the southern basin domain, numerous fault-bound blocks limit the lateral continuity of the sandstone strata, while on the northern domain the sandstones are intersected by less faults. The caprock for the Collyhurst sandstones is variable. The Manchester Marls predominate in the south, transitioning to the St. Bees evaporites towards the north. The evaporites in the EISB cause overburden faults to terminate or detach along Upper Permian strata, limiting the deformation of the underlying reservoir units. Five main storage closures have been identified in the Permian strata. In the southern and central area these are predominantly fault bounded, occurring at depths over 1000m. Despite the higher Collyhurst sandstone thickness in the southern IESB, the dolomitic nature of the caprock constitutes a storage risk in this area. Closures in the northern area are deeper (around 2000-2500m) and wider, reaching areas of 34Km2, and are overlain by evaporitic caprocks. The larger Collyhurst closures to the north underlie large Triassic fields with high storage potential. The spatial overlap favours storage plans including secondary storage units in the EISB. The results of this work also expand the understanding of prospective areas for CO2 sequestration in the East Irish Sea Basin in locations where the primary Sherwood Sandstone Formation is either too shallow

Environmental mutagenesis during the end-Permian ecological crisis.

Science.gov (United States)

Visscher, Henk; Looy, Cindy V; Collinson, Margaret E; Brinkhuis, Henk; van Konijnenburg-van Cittert, Johanna H A; Kürschner, Wolfram M; Sephton, Mark A

2004-08-31

During the end-Permian ecological crisis, terrestrial ecosystems experienced preferential dieback of woody vegetation. Across the world, surviving herbaceous lycopsids played a pioneering role in repopulating deforested terrain. We document that the microspores of these lycopsids were regularly released in unseparated tetrads indicative of failure to complete the normal process of spore development. Although involvement of mutation has long been hinted at or proposed in theory, this finding provides concrete evidence for chronic environmental mutagenesis at the time of global ecological crisis. Prolonged exposure to enhanced UV radiation could account satisfactorily for a worldwide increase in land plant mutation. At the end of the Permian, a period of raised UV stress may have been the consequence of severe disruption of the stratospheric ozone balance by excessive emission of hydrothermal organohalogens in the vast area of Siberian Traps volcanism. Copyright 2004 The National Academy of Sciencs of the USA

Review of monolete-producing Carboniferous-Permian sphenophylls

Czech Academy of Sciences Publication Activity Database

Libertín, M.; Bek, Jiří

2008-01-01

Roč. 2008, č. 2 (2008), s. 168-168 ISSN 0946-8978. [International Palynological Congress /12./ ; International Organisation of Palaeobotany Conference /8./. 30.08.2008-05.09.2008, Bonn] R&D Projects: GA AV ČR IAA300130503 Institutional research plan: CEZ:AV0Z30130516 Keywords : Carboniferous * Permian * sphenophylls Subject RIV: DB - Geology ; Mineralogy

Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

Science.gov (United States)

van Soelen, Elsbeth E.; Twitchett, Richard J.; Kürschner, Wolfram M.

2018-04-01

The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be

Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea.

Science.gov (United States)

Cisneros, Juan Carlos; Abdala, Fernando; Atayman-Güven, Saniye; Rubidge, Bruce S; Şengörc, A M Celâl; Schultz, Cesar L

2012-01-31

The medial Permian (~270-260 Ma: Guadalupian) was a time of important tetrapod faunal changes, in particular reflecting a turnover from pelycosaurian- to therapsid-grade synapsids. Until now, most knowledge on tetrapod distribution during the medial Permian has come from fossils found in the South African Karoo and the Russian Platform, whereas other areas of Pangaea are still poorly known. We present evidence for the presence of a terrestrial carnivorous vertebrate from the Middle Permian of South America based on a complete skull. Pampaphoneus biccai gen. et sp. nov. was a dinocephalian "mammal-like reptile" member of the Anteosauridae, an early therapsid predator clade known only from the Middle Permian of Russia, Kazakhstan, China, and South Africa. The genus is characterized, among other features, by postorbital bosses, short, bulbous postcanines, and strongly recurved canines. Phylogenetic analysis indicates that the Brazilian dinocephalian occupies a middle position within the Anteosauridae, reinforcing the model of a global distribution for therapsids as early as the Guadalupian. The close phylogenetic relationship of the Brazilian species to dinocephalians from South Africa and the Russian Platform suggests a closer faunistic relationship between South America and eastern Europe than previously thought, lending support to a Pangaea B-type continental reconstruction.

Geochemistry of the Late Paleozoic cherts in the Youjiang Basin: Implications for the basin evolution

Directory of Open Access Journals (Sweden)

Huang Hu

2013-10-01

Full Text Available We analyzed the major and rare earth element compositions of siliceous deposits from the Upper Devonian Liujiang Formation, Lower Carboniferous Luzhai Formation, Lower–Middle Permian Sidazhai Formation and Tapi Formation, which are widely distributed as bedded cherts in the interplatform basinal successions of the Youjiang Basin. The Liujiang Formation and Luzhai Formation cherts generally have high Al/(Al+Fe+Mn values (0.38–0.94 and are non-hydrothermal cherts. These cherts are generally characterized by moderately negative Ce anomalies and high Y/Ho values relatived to PAAS, indicating that the Youjiang Basin might have evolved into an open rift basin during the Late Devonian–Early Carboniferous. The Sidazhai Formation cherts from Ziyun generally have high Al/(Al+Fe+Mn values (0.60–0.78, suggesting negligible contribution from a hydrothermal component. The Sidazhai Formation cherts from Hechi and the Tapi Formation cherts from Malipo generally have low Al/(Al+Fe+Mn values (0.09–0.41, indicating an intense hydrothermal input. Relatived to the Sidazhai Formation cherts, the Tapi Formation cherts have higher Ce/Ce* values (0.68±0.19 and lower Y/Ho values (41.83±13.27, which may be affected by the terrigenous input from the Vietnam Block. The Sidazhai Formation cherts from Ziyun and Hechi exhibit negative Ce anomalies (0.43±0.12, 0.33±0.17, respectively with high Y/Ho values (57.44±16.20, 46.02±4.27, respectively, resembling the geochemical characteristics of open-ocean basin cherts. These cherts were deposited on a passive continental margin adjacent to the Babu branch ocean, which may have contributed to upwelling. Detailed spatial studies on geochemical characteristics of the Late Paleozoic cherts can unravel the evolution of the Youjiang Basin.

Terrestrial acidification during the end-Permian biosphere crisis?

NARCIS (Netherlands)

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

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

Coal petrology of coal seams from the Leao-Butia Coalfield, Lower Permian of the Parana Basin, Brazil - Implications for coal facies interpretations

Energy Technology Data Exchange (ETDEWEB)

Silva, M.B. [Laboratorio de Oceanografia Geologica, Departamento de Geociencias, Fundacao Universidade Federal do Rio Grande, FURG, Av. Italia km 08, Campus Carreiros, 96201-900, Rio Grande, RS (Brazil); Kalkreuth, W.; Holz, M. [Instituto de Geociencias, UFRGS, Av. Bento Goncalves, 9500 91501-970 Porto Alegre, RS (Brazil)

2008-02-01

In the Leao-Butia Coalfield, Rio Grande do Sul the coal seams occur in the Rio Bonito Formation, Guata Group, Tubarao Supergroup of the Parana Basin, Brazil and are of Permian (Artinskian-Kungurian) age. This study is the first detailed investigation on the coal petrographic characterization of the coal-bearing sequence in relation to the depositional settings of the precursor mires, both in terms of whole seam characterization and in-seam variations. The study is based on the analyses of nine coal seams (I2, CI, L4, L3, L2, L1, S3, S2, S1), which were selected from core of borehole D-193, Leao-Butia and represent the entire coal-bearing sequence. The interpretation of coal facies and depositional environment is based on lithotype, maceral and microlithotype analyses using different facies-critical petrographic indices, which were displayed in coal facies diagrams. The seams are characterized by the predominance of dull lithotypes (dull, banded dull). The dullness of the coal is attributed to relatively high mineral matter, inertinite and liptinite contents. The petrographic composition is dominated by vitrinite (28-70 vol.% mmf) and inertinite (> 30 vol.% mmf) groups. Liptinite contents range from 7 to 30 vol.% (mmf) and mineral matter from 4-30 vol.%. Microlithotypes associations are dominated by vitrite, duroclarite, carbominerite and inertite. It is suggested that the observed vertical variations in petrographic characteristics (lithotypes, microlithotypes, macerals, vitrinite reflectance) were controlled by groundwater level fluctuations in the ancient mires due to different accommodation/peat accumulation rates. Correlation of the borehole strata with the general sequence-stratigraphical setting suggests that the alluvial fan system and the coal-bearing mudstone succession are linked to a late transgressive systems tract of sequence 2. Based on average compositional values obtained from coal facies diagrams, a deposition in a limno-telmatic to limnic coal

Juvenile-adult habitat shift in permian fossil reptiles and amphibians.

Science.gov (United States)

Bakker, R T

1982-07-02

Among extant large reptiles, juveniles often occupy different habitats from those of adults or subadults and thus avoid competition with and predation from the older animals; small juveniles often choose cryptic habitats because they are vulnerable to a wide variety of predators. Evidence from fossil humeri and femora of Early Permian reptiles collected from sediments of several distinct habitats indicate that similar shifts in habitat occurred. Juvenile Dimetrodon seem to have favored cryptic habitats around swamp and swampy lake margins; adults favored open habitats on the floodplains. Similar patterns of habitat shift seem to be present in the reptile Ophiacodon and the amphibian Eryops and may have been common in fossil tetrapods of the Permian-Triassic.

Upper Permian ostracode assemblage from the Jadar Block (Vardar zone, NW Serbia

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Crasquin Sylvie

2010-01-01

Full Text Available Ostracodes from the Changhsingian (latest Permian age in the uppermost part of the “Bituminous Limestone” Formation of the Komirić Section in NW Serbia (Jadar Block, Vardar Zone are described and illustrated. Three new species of ostracodes are introduced: Basslerella jadarensis n. sp., Acratia serbianella n. sp., and Knoxiella vardarensis n. sp. The ostracode assemblage, together with conodonts and foraminifers, is the first record of the youngest Late Permian age microfaunas from Serbia and from the central part of the Balkan Peninsula.

Integrated multi-stratigraphic study of the Coll de Terrers late Permian-Early Triassic continental succession from the Catalan Pyrenees (NE Iberian Peninsula): A geologic reference record for equatorial Pangaea

Science.gov (United States)

Mujal, Eudald; Fortuny, Josep; Pérez-Cano, Jordi; Dinarès-Turell, Jaume; Ibáñez-Insa, Jordi; Oms, Oriol; Vila, Isabel; Bolet, Arnau; Anadón, Pere

2017-12-01

The most severe biotic crisis on Earth history occurred during the Permian-Triassic (PT) transition around 252 Ma. Whereas in the marine realm such extinction event is well-constrained, in terrestrial settings it is still poorly known, mainly due to the lack of suitable complete sections. This is utterly the case along the Western Tethys region, located at Pangaea's equator, where terrestrial successions are typically build-up of red beds often characterised by a significant erosive gap at the base of the Triassic strata. Henceforth, documenting potentially complete terrestrial successions along the PT transition becomes fundamental. Here, we document the exceptional Coll de Terrers area from the Catalan Pyrenees (NE Iberian Peninsula), for which a multidisciplinary research is conducted along the PT transition. The red-bed succession, located in a long E-W extended narrow rift system known as Pyrenean Basin, resulted from a continuous sedimentary deposition evolving from meandering (lower Upper Red Unit) to playa-lake/ephemeral lacustrine (upper Upper Red Unit) and again to meandering settings (Buntsandstein facies). Sedimentary continuity is suggested by preliminary cyclostratigraphic analysis that warrants further analysis. Our combined sedimentological, mineralogical and geochemical data infer a humid-semiarid-humid climatic trend across the studied succession. The uppermost Permian strata, deposited under an orbitally controlled monsoonal regime, yields a relatively diverse ichnoassemblage mainly composed of tetrapod footprints and arthropod trace fossils. Such fossils indicate appropriate life conditions and water presence in levels that also display desiccation structures. These levels alternate with barren intervals formed under dry conditions, being thus indicative of strong seasonality. All these features are correlated with those reported elsewhere in Gondwana and Laurasia, and suggest that the Permian-Triassic boundary might be recorded somewhere around

A new paleogeographic configuration of the Eurasian landmass resolves a paleomagnetic paradox of the Tarim Basin (China)

OpenAIRE

Gilder , Stuart ,; Gomez , Julia; Chen , Yan; Cogné , Jean-Pascal

2008-01-01

International audience; New paleomagnetic data from Permian red beds and Middle Jurassic limestones from the Tarim Basin pose a paradox. Their declinations are similar to Upper Carboniferous to Neogene rocks collected from the same sections, and their inclinations parallel present values. When assuming that lower than expected inclinations in continental sedimentary rocks arise from inclination shallowing effects, then the paleolatitudes of all Upper Carboniferous to Present rocks from Tarim ...

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.

Reassessment of petrogenesis of Carboniferous–Early Permian rift-related volcanic rocks in the Chinese Tianshan and its neighboring areas

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Linqi Xia

2012-07-01

Full Text Available The Carboniferous−Early Permian rift-related volcanic successions, covering large areas in the Chinese Tianshan and its adjacent areas, make up a newly recognized important Phanerozoic large igneous province in the world, which can be further divided into two sub-provinces: Tianshan and Tarim. The regional unconformity of Lower Carboniferous upon basement or pre-Carboniferous rocks, the ages (360–351 Ma of the youngest ophiolite and the peak of subduction metamorphism of high pressure–low temperature metamorphic belt and the occurrence of Ni-Cu-bearing mafic-ultramafic intrusion with age of ∼352 Ma and A-type granite with age of ∼358 Ma reveal that the final closure of the Paleo-Asian Ocean might take place in the Early Mississippian. Our summation shows that at least four criteria, being normally used to identify ancient asthenosphere upwelling (or mantle plumes, are met for this large igneous province: (1 surface uplift prior to magmatism; (2 being associated with continental rifting and breakup events; (3 chemical characteristics of asthenosphere (or plume derived basalts; (4 close links to large-scale mineralization and the uncontaminated basalts, being analogous to those of many “ore-bearing” large igneous provinces, display Sr-Nd isotopic variations between plume and EM1 geochemical signatures. These suggest that a Carboniferous asthenosphere upwelling and an Early Permian plume played the central role in the generation of the Tianshan–Tarim (central Asia large igneous province.

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

Energy Technology Data Exchange (ETDEWEB)

Kalkreuth, W.; Mexias, A.; Balbinot, M.; Levandowski, J. [Instituto de Geociencias, UFRGS, Porto Alegre (Brazil); Holz, M. [Inst. de Geociencias, UFBA, Salvador, Bahia (Brazil); Willett, J.; Finkelman, R. [U.S. Geological Survey, Reston, VA (United States); Burger, H. [Freie Universitaet Berlin, Geoinformatik, (Germany)

2010-12-01

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

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.

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

Directory of Open Access Journals (Sweden)

CRISTIANO LARGHI

2005-11-01

Full Text Available The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian bivalve fauna from the Saiwan Formation in the Huqf area, informally named "Dickinsartella Fauna", is described in the present paper. The specimens examined were collected from the "Pachycyrtella Bed" (Auctorum, the basal bed of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella, which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species. The bivalve fauna from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus  mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ?Oriocrassatella sp., and indeterminable aviculopectinids. This fauna shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament.  The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors.The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia,  indicates a wider distribution of the

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

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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.

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)

Grist, A.M.; Zentilli, M.

1995-01-01

Sandstone drill core and/or cuttings from six wells in the Gulf of St. Lawrence and cabot Strait have been analyzed using the apatite fission track (AFT) method. Measured AFT ages for the late Paleozoic sandstones range from 26 ±7 to 184 ±28 Ma (2-σ errors). The AFT data indicate that most Maritimes Basin strata were heated to temperatures in excess of 100-150 o C very soon after their deposition. The strata also attained significant vitrinite reflectance (R 0 ) 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 R 0 data provide complementary information about the integrated thermal history, including maximum burial temperatures (from R 0 data), and information on the subsequent cooling history from AFT analysis. The present study also supports the proposal made previously by others that substantial erosion of the Eastern Canadian margin (up to 4 km) has occurred since the Permian and extends the AFT evidence for this erosional event to include the southern Gulf of St. Lawrence area. Thermal models of the AFT data demonstrate that they are consistent with a history of exhumation of basin strata since late Permian time. The model-predicted AFT age and track length histograms closely correspond to the measured AFT parameters. AFT analysis also indicates present-day geothermal gradients of less than 40 o C/km. (author). 42 refs.,3 tabs., 7 figs

Repeated Carbon-Cycle Disturbances at the Permian-Triassic Boundary Separate two Mass Extinctions

Science.gov (United States)

Nicol, J. A.; Watson, L.; Claire, M.; Buick, R.; Catling, D. C.

2004-12-01

Non-marine organic matter in Permian-Triassic sediments from the Blue Mountains, eastern Australia shows seven negative δ13C excursions of up to 7%, terminating with a positive excursion of 4%. Fluctuations start at the late Permian Glossopteris floral extinction and continue until just above the palynological Permian-Triassic boundary, correlated with the peak of marine mass extinction. The isotopic fluctuations are not linked to changes in depositional setting, kerogen composition or plant community, so they evidently resulted from global perturbations in atmospheric δ13C and/or CO2. The pattern was not produced by a single catastrophe such as a meteorite impact, and carbon-cycle calculations indicate that gas release during flood-basalt volcanism was insufficient. Methane-hydrate melting can generate a single -7% shift, but cannot produce rapid multiple excursions without repeated reservoir regeneration and release. However, the data are consistent with repeated overturning of a stratified ocean, expelling toxic gases that promoted sequential mass extinctions in the terrestrial and marine realms.

Oil and gas potential of the Korotaikha Depression in the Timan-Pechora basin

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A.V. Stoupakova

2017-05-01

Full Text Available Prospects for the growth of hydrocarbon (HC reserves in the Timan-Pechora basin are associated with poorly explored areas, which include the Korotaikha Depression, which is a very difficult region for oil and gas exploration. Analysis and reinterpretation of both old and new seismic data made it possible to identify a number of anticlinal structures within the region, as well as to identify possible lithological HC traps, such as reefing bodies of late Devonian-Early Carboniferous age and delta sand formations of the Permian-Triassic age. The wide stratigraphic range of the sedimentary cover makes it possible to select several hydrocarbon systems in the basin of the Korotaikha Depression. Basin modeling has shown that there are all conditions for НС generation and accumulation in the Korotaikha Basin. Based on the results of the simulation, Korotaikha Basin should be considered as a potentially promising oil and gas area, where the main oil and gas accumulations are located in the side parts of the basin, and also within the inversion highs and saddles. The total booked geological resources of hydrocarbons may amount to about 1.7 billion tons standard fuel. Korotaikha Depression and its aquatorial continuation can be referred to the category of major oil-gas search regions.

Late Carboniferous to Late Permian carbon isotope stratigraphy

DEFF Research Database (Denmark)

Buggisch, Werner; Krainer, Karl; Schaffhauser, Maria

2015-01-01

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

MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

Energy Technology Data Exchange (ETDEWEB)

Stephen C. Ruppel

2005-02-01

Despite declining production rates, existing reservoirs in the US contain large quantities of remaining oil and gas that constitute a huge target for improved diagnosis and imaging of reservoir properties. The resource target is especially large in carbonate reservoirs, where conventional data and methodologies are normally insufficient to resolve critical scales of reservoir heterogeneity. The objectives of the research described in this report were to develop and test such methodologies for improved imaging, measurement, modeling, and prediction of reservoir properties in carbonate hydrocarbon reservoirs. The focus of the study is the Permian-age Fullerton Clear Fork reservoir of the Permian Basin of West Texas. This reservoir is an especially appropriate choice considering (a) the Permian Basin is the largest oil-bearing basin in the US, and (b) as a play, Clear Fork reservoirs have exhibited the lowest recovery efficiencies of all carbonate reservoirs in the Permian Basin.

On the Geological Age of the Sundyr Faunal Assemblage of Permian Tetrapods from the East European Platform

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Golubev V.K.

2015-03-01

Full Text Available A new Sundyr faunal assemblage of Permian tetrapods was discovered in Eastern Europe. It includes dinocephalians Titanosuchia fam. indet., tapinocephalians aff. Ulemosauridae, anomodontians aff. Suminia, therocephalians, gorgonopians Burnetioidea fam. indet., diapsids ? Eosuchia, chroniosuchians Suchonica vladimiri Golubev, enosuchids aff. Enosuchus, seymouriamorphs Microphon exiguus Ivachnenko and Leptoropha aff. talonophora, batrachomorphs Dvinosaurus sp. The Sundyr assemblage is a transitional one from the Isheevo to Sokolki assemblages. It is described as the last stage of evolution undergone by the dinocephalian community of tetrapods in Eastern Europe. Based on the bio- and magnetostratigraphic data, the beds with Sundyr tetrapod fauna pertain to the lower part of the Upper Severodvinian (= Putyatinian regional stage. These strata were distinguished into a new Suchonica vladimiri tetrapod assemblage zone. In the Sukhona River basin, the beds with Sundyr tetrapod fossils were distinguished into a new Ustpoldarsa Member of the Poldarsa Formation.

The fungal and acritarch events as time markers for the latest Permian mass extinction: An update

Directory of Open Access Journals (Sweden)

Michael R. Rampino

2018-01-01

Full Text Available The latest Permian extinction (252 Myr ago was the most severe in the geologic record. On land, widespread Late Permian gymnosperm/seed-fern dominated forests appear to have suffered rapid and almost complete destruction, as evidenced by increased soil erosion and changes in fluvial style in deforested areas, signs of wildfires, replacement of trees by lower plants, and almost complete loss of peat-forming and fire-susceptible vegetation. Permian–Triassic boundary strata at many sites show two widespread palynological events in the wake of the forest destruction: The fungal event, evidenced by a thin zone with >95% fungal cells (Reduviasporonites and woody debris, found in terrestrial and marine sediments, and the acritarch event, marked by the sudden flood of unusual phytoplankton in the marine realm. These two events represent the global temporary explosive spread of stress-tolerant and opportunistic organisms on land and in the sea just after the latest Permian disaster. They represent unique events, and thus they can provide a time marker in correlating latest Permian marine and terrestrial sequences.

Contrasting microbial community changes during mass extinctions at the Middle/Late Permian and Permian/Triassic boundaries

Science.gov (United States)

Xie, Shucheng; Algeo, Thomas J.; Zhou, Wenfeng; Ruan, Xiaoyan; Luo, Genming; Huang, Junhua; Yan, Jiaxin

2017-02-01

Microbial communities are known to expand as a result of environmental deterioration during mass extinctions, but differences in microbial community changes between extinction events and their underlying causes have received little study to date. Here, we present a systematic investigation of microbial lipid biomarkers spanning ∼20 Myr (Middle Permian to Early Triassic) at Shangsi, South China, to contrast microbial changes associated with the Guadalupian-Lopingian boundary (GLB) and Permian-Triassic boundary (PTB) mass extinctions. High-resolution analysis of the PTB crisis interval reveals a distinct succession of microbial communities based on secular variation in moretanes, 2-methylhopanes, aryl isoprenoids, steranes, n-alkyl cyclohexanes, and other biomarkers. The first episode of the PTB mass extinction (ME1) was associated with increases in red algae and nitrogen-fixing bacteria along with evidence for enhanced wildfires and elevated soil erosion, whereas the second episode was associated with expansions of green sulfur bacteria, nitrogen-fixing bacteria, and acritarchs coinciding with climatic hyperwarming, ocean stratification, and seawater acidification. This pattern of microbial community change suggests that marine environmental deterioration was greater during the second extinction episode (ME2). The GLB shows more limited changes in microbial community composition and more limited environmental deterioration than the PTB, consistent with differences in species-level extinction rates (∼71% vs. 90%, respectively). Microbial biomarker records have the potential to refine our understanding of the nature of these crises and to provide insights concerning possible outcomes of present-day anthropogenic stresses on Earth's ecosystems.

Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

Energy Technology Data Exchange (ETDEWEB)

Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

1997-11-01

The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

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.

Far-travelled permian chert of the North Fork terrane, Klamath mountains, California

Science.gov (United States)

Mankinen, E.A.; Irwin, W.P.; Blome, C.D.

1996-01-01

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

Sedimentary tectonic evolution and reservoir-forming conditions of the Dazhou–Kaijiang paleo-uplift, Sichuan Basin

Directory of Open Access Journals (Sweden)

Yueming Yang

2016-12-01

Full Text Available Great breakthrough recently achieved in the Sinian–Lower Paleozoic gas exploration in the Leshan–Longnüsi paleo-uplift, Sichuan Basin, has also made a common view reached, i.e., large-scale paleo-uplifts will be the most potential gas exploration target in the deep strata of this basin. Apart from the above-mentioned one, the other huge paleo-uplifts are all considered to be the ones formed in the post-Caledonian period, the impact of which, however, has rarely ever been discussed on the Sinian–Lower Paleozoic oil and gas reservoir formation. In view of this, based on outcrops, drilling and geophysical data, we analyzed the Sinian–Lower Paleozoic tectonic setting and sedimentary background in the East Sichuan Basin, studied the distribution rules of reservoirs and source rocks under the control of paleo-uplifts, and finally discussed, on the basis of structural evolution analysis, the conditions for the formation of Sinian–Lower Paleozoic gas reservoirs in this study area. The following findings were achieved. (1 The Dazhou–Kaijiang inherited uplift in NE Sichuan Basin which was developed before the Middle Cambrian controlled a large area of Sinian and Cambrian beach-facies development. (2 Beach-facies reservoirs were developed in the upper part of the paleo-uplift, while in the peripheral depression belts thick source rocks were developed like the Upper Sinian Doushantuo Fm and Lower Cambrian Qiongzhusi Fm, so there is a good source–reservoir assemblage. (3 Since the Permian epoch, the Dazhou–Kaijiang paleo-uplift had gradually become elevated from the slope zone, where the Permian oil generation peak occurred in the slope or lower and gentle uplift belts, while the Triassic gas generation peak occurred in the higher uplift belts, both with a favorable condition for hydrocarbon accumulation. (4 The lower structural layers, including the Lower Cambrian and its underlying strata, in the East Sichuan Basin, are now equipped with a

Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction.

Science.gov (United States)

Rampino, Michael R; Rodriguez, Sedelia; Baransky, Eva; Cai, Yue

2017-09-29

Anomalous peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon. We propose that the source of the nickel anomalies at the P-T boundary were Ni-rich volatiles released by the Siberian volcanism, and by coeval Ni-rich magma intrusions. The peaks in nickel abundance correlate with negative δ 13 C and δ 18 O anomalies, suggesting that explosive reactions between magma and coal during the Siberian flood-basalt eruptions released large amounts of CO 2 and CH 4 into the atmosphere, causing severe global warming and subsequent mass extinction. The nickel anomalies may provide a timeline in P-T boundary sections, and the timing of the peaks supports the Siberian Traps as a contributor to the latest Permian mass extinction.

Organic richness and gas generation potential of Permian Barren

Indian Academy of Sciences (India)

The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of ...

Geochronological and sedimentological evidences of Panyangshan foreland basin for tectonic control on the Late Paleozoic plate marginal orogenic belt along the northern margin of the North China Craton

Science.gov (United States)

Li, Jialiang; Zhou, Zhiguang; He, Yingfu; Wang, Guosheng; Wu, Chen; Liu, Changfeng; Yao, Guang; Xu, Wentao; Zhao, Xiaoqi; Dai, Pengfei

2017-08-01

There is a wide support that the Inner Mongolia Palaeo-uplift on the northern margin of the North China Craton has undergone an uplifting history. However, when and how did the uplift occurred keeps controversial. Extensive field-based structural, metamorphic, geochemical, geochronological and geophysical investigations on the Inner Mongolia Palaeo-uplift, which suggested that the Inner Mongolia Palaeo-uplift was an uplifted region since the Early Precambrian or range from Late Carboniferous-Early Jurassic. The geochemical characteristics of the Late Paleozoic to Early Mesozoic intrusive rocks indicated that the Inner Mongolia Palaeo-uplift was an Andean-type continental margin that is the extensional tectonic setting. To address the spatial and temporal development of the Inner Mongolia Palaeo-uplift, we have carried out provenance analysis of Permian sedimentary rocks which collected from the Panyangshan basin along the northern margin of the North China Craton. The QFL diagram revealed a dissected arc-recycled orogenic tectonic setting. Moreover, the framework grains are abundant with feldspar (36-50%), indicating the short transport distance and unstable tectonic setting. Detrital zircon U-Pb analysis ascertained possible provenance information: the Precambrian basement ( 2490 and 1840 Ma) and continental arc magmatic action ( 279 and 295 Ma) along the northern margin of the North China Craton. The projection in rose diagrams of the mean palaeocurrent direction, revealing the SSW and SSE palaeoflow direction, also shows the provenance of the Panyangshan basin sources mainly from the Inner Mongolia Palaeo-uplift. The andesite overlying the Naobaogou Formation has yielded U-Pb age of 277.3 ± 1.4 Ma. The additional dioritic porphyry dike intruded the Naobaogou and Laowopu Formations, which has an emplacement age of 236 ± 1 Ma. The above data identify that the basin formed ranges from Early Permian to Middle Triassic (277-236 Ma). Accordingly, the Inner Mongolia

Gondwana sedimentation in the Chintalapudi sub-basin, Godavari Valley, Andhra Pradesh

Energy Technology Data Exchange (ETDEWEB)

Lakshminarayana, G. [Geological Survey of India, Calcutta (India). Division of Monitoring

1995-10-01

A 3000 m thick Gondwana lithic fill consisting of multifacies associations were preserved in a NW-SE oriented intracratonic Chintalapudi sub-basin set across the Eastern Chat Complex (EGC). Sedimentation commenced with the deposition of diamictite-rhythmite sequence of the Talchir Formation in glacio-lacustrine environment. The succeeding sandstone-coal cyclothems of the Barakar Formation were formed in fluvial-coal swamps complex. The fluvial streams flowed across the EGC, originating somewhere in the southeast beyond the East Coast of India. Phase wise upliftment of the EGC during Mesozoic imparted changes to the Permian intercontinental drainage system which started supplying increased amount of detritus to the basin. Basin marginal faults were first formed at the beginning of Triassic. Alluvial fans originated in the east and southeast and northwesterly flowing braided streams deposited the conglomerate sandstone sequence of the Kamthi Formation. The Early Jurassic uplift of the Mailaram high in the north imparted westerly shift to the braided rivers during the Kota sedimentation. Due to prominence of Kamavarapukota ridge in the south by Early Cretaceous, the drainage pattern became centripetal and short-lived high sinuous rivers debouched into the basin. The silting up of the Chintalapudi sub-basin with the sandstone-claystone sequence of the Gangapur Formation marks the culmination of the Gondwana sedimentation, perhaps, coinciding with the breakup of India from the Gondwanaland.

Naturally fractured reservoirs: Optimized E and P strategies using a reaction-transport-mechanical simulator in an integrated approach. Annual report, 1996--1997

Energy Technology Data Exchange (ETDEWEB)

Hoak, T.; Jenkins, R. [Science Applications International Corp., McLean, VA (United States); Ortoleva, P.; Ozkan, G.; Shebl, M.; Sibo, W.; Tuncay, K. [Laboratory for Computational Geodynamics (United States); Sundberg, K. [Phillips Petroleum Company (United States)

1998-07-01

The methodology and results of this project are being tested using the Andector-Goldsmith Field in the Permian Basin, West Texas. The study area includes the Central Basin Platform and the Midland Basin. The Andector-Goldsmith Field lies at the juncture of these two zones in the greater West Texas Permian Basin. Although the modeling is being conducted in this area, the results have widespread applicability to other fractured carbonate and other reservoirs throughout the world.

Contrasting styles of aeolian, fluvial and marine interaction in the Cutler Group of the Paradox Basin, SE Utah, USA

OpenAIRE

Wakefield, Oliver; Mountney, Nigel

2017-01-01

The Permian-Pennsylvanian Cutler Group of the Paradox foreland basin of southeast Utah is characterised by a variety of styles of interaction between coeval aeolian, fluvial and marine environments that have resulted in the generation and preservation of a complex suite of stratal architectures. Detailed 3D architectural element analysis has enabled the nature of these interactions to be interpreted in order to constrain both the spatial and temporal scale over which competing ...

Analysis of cyclical sedimentation in the lower Permian Mchuchuma coalfield (South-West-Tanzania)

Energy Technology Data Exchange (ETDEWEB)

Casshyap, S M; Kreuser, T; Wopfner, H

1987-01-01

A statistical approach by a modified Markov process model was used to prove that the lower Permian coal measures of the Tanzanian Mchuchuma basin developed distinct cyclicities during deposition. From results the transition path of lithologic states typical for this coal sequence is as follows: (A) coarse sandstone, (B) medium sandstone, (C) fine-very fine sandstone, (D) shale, (E) mudstone, (F) coal or (E+F) and again (A) coarse sandstone. The majority of cycles is asymmetric (ABCDEF-ABC..) but symmetrical cycles are present as well (ABCDEFED). The statistical results concur with observed sedimentological evidence of depositional environment. Fining upward cycles correspond to the development of basal channel bars, changing into levees, then into back swamps which are topped by coal swamps. Frequent interbedding of coal and mudstone in the upper part of the coal measures calls for periodic flooding and flushing of fine clastics into coal-forming swamps causing interruption of peat formation. Cyclical deposition is explained by wandering channels in response to varying discharge and rate of deposition, their lateral frequent shifting caused the formation of asymmetrical cycles in this fluviodeltaic depositional model. 33 refs., 7 figs., 1 tab.

Permian-Triassic Tethyan realm reorganization: Implications for the outward Pangea margin

Science.gov (United States)

Riel, Nicolas; Jaillard, Etienne; Martelat, Jean-Emmanuel; Guillot, Stéphane; Braun, Jean

2018-01-01

We present a new conceptual model to explain the first order Permian-Triassic evolution of the whole > 30 000 km long Pangea margin facing the Panthalassa ocean. Compilation of available geological, geochemical, geochronogical and paleomagnetic data all along this system allowed us to distinguish three part of the margin: western Laurentia, western Gondwana and eastern Gondwana. These segments record distinct tectonic and magmatic events, which all occur synchronously along the whole margin and correlate well with the main geodynamic events of this period, i.e. subduction of the Paleotethys mid-ocean ridge at 310-280 Ma, opening of the Neotethys at 280-260 Ma, counterclockwise rotation of Pangea at 260-230 Ma and closure of the Paleotethys at 230-220 Ma. Between 260 and 230 Ma, the reorganization of the Tethyan realm triggered the up to 35° rotation of Pangea around an Euler pole located in northernmost South America. This implied both an increase and a decrease of the convergence rate between the margin and the Panthalassa ocean, north and south of the Euler pole, respectively. Thus, the Permian-Triassic Pangean margin was marked: in western Laurentia by marginal sea closure, in western Gondwana by widespread bimodal magmatic and volcanic activity, in eastern Gondwana by transpressive orogenic phase. Therefore, we propose that the Permian-Triassic evolution of the outward margin of Pangea was controlled by the Tethyan realm reorganization.

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. © 2014 John Wiley & Sons Ltd.

The salt that wasn't there: Mudflat facies equivalents to halite of the Permian Rustler Formation, southeastern New Mexico

International Nuclear Information System (INIS)

Powers, D.W.; Holt, R.M.

2000-01-01

Four halite beds of the Permian Restler Formation in southeastern New Mexico thin dramatically over horst lateral distances to correlative classic (mudstone) beds. The mudstones have long been considered residues after post-burial dissolution (subrosion) of halite, assumed to have been deposited continuously across the area. Hydraulic properties of the Culebra Dolomite Member have often been related to Rustler subrosion. In cores and three shafts at the Waste Isolation Pilot Plant (WIPP), however, these mudstones display flat bedding, graded bedding, cross-bedding, erosional contacts, and channels filled with intraformational conglomerates. Cutans indicate early stages of soil development during subaerial exposure. Smeared intraclasts developed locally as halite was removed syndepositionally during subaerial exposure. The authors interpret these beds as facies formed in salt-pan or hypersaline-lagoon, transitional, and mudflat environments. Halite is distributed approximately as it was deposited. Breccia in limited areas along one halite margin indicates post-burial dissolution, and these breccials are key to identifying areas of subrosion. A depositional model accounts for observed sedimentary features of Restler mudstones. Marked facies and thickness changes are consistent with influence by subsidence boundaries, as found in some modern continental evaporites. A subrosion model accounts for limited brecciated zones along (depositional)halite margins, but bedding observed in the mudstones would not survive 90% reduction in rock volume. Depositional margins for these halite beds will be useful in reconstructing detailed subsidence history of the Late Permian in the northern Delaware Basin, It also no longer is tenable to attribute large variations in Culebra transmissivity to Rustler subrosion

Organic geochemistry of oils and condensates in the Kekeya field, southwest depression of the Tarim Basin (China)

Energy Technology Data Exchange (ETDEWEB)

Maowen Li; Snowdon, L.R. [Geological Survey of Canada, Calgary (Canada); Renzi Lin; Peirong Wang [Jianghan Petroleum Institute, Hubei (China); Yongsheng Liao; Peilong Li [Shengli Petroleum Administrative Bureau, Shandong (China)

1999-07-01

This study shows that the oils and condensates in the Kekeya Field in the Tarim Basin, NW China, belong to a single family, most likely derived from marine shale source rocks deposited under oxic-suboxic conditions with mixed terrigenous and algal-bacterial organic inputs. The maturity data clearly indicate that the paraffinic condensates were not formed by thermal cracking of oil during late catagenesis (R{sub o} > 1.2%). Both the oils and condensates were generated within the normal oil window, whereas addition of gaseous hydrocarbons from a separate source resulted in migration fractionation and hence spuriously high heptane indices. Age specific biomarkers show that the oils and condensates were not generated from the Mesozoic-Cenozoic strata, but from the Carboniferous-Permian sections. 1D basin modelling results are consistent with this interpretation, suggesting that the Mesozoic-Eocene strata are currently immature with respect to hydrocarbon generation and expulsion. Deep-seated faults may have provided routes for upward fluid migration at the time of active deformation during several pulses of the Himalayan orogeny. The favoured targets for further petroleum exploration in front of the Kunlun Mountains include the deep structures within the Carboniferous-Permian strata for indigenous petroleum accumulations and anticlines and stratigraphic traps within the Mesozoic-Cenozoic sections that are cut by deep-seated thrust faults where secondary petroleum accumulations most likely occurred. (author)

Ocean anoxia did not cause the Latest Permian Extinction

Science.gov (United States)

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

2014-05-01

The Latest Permian Extinction (LPE, ~252 million years ago) was a turning point in the history of life on Earth with a loss of ~96% of all marine species and ~70% of all terrestrial species. While, the event undoubtedly shaped the evolution of life its cause remains enigmatic. A leading hypothesis is that the global oceans became depleted in oxygen (anoxia). In order to test this hypothesis we investigated a proxy for marine oxygen levels (molybdenum isotopic composition) in shale across the LPE horizon located on the subtropical northwest margin of Pangea at that time. We studied two sedimentary records in the Sverdrup basin, Canadian High Arctic: Buchanan Lake (eastern Axel Heiberg Island; 79° 26.1'N, 87° 12.6'W), representing a distal deep-water slope environment, and West Blind Fiord (southwest Ellesmere Island; 78° 23.9'N, 85° 57.2'W), representing a deep outer shelf environment (below storm wave base). The molybdenum isotopic composition (δ98/95Mo) of sediments has recently become a powerful tool as a paleo-oceanographic proxy of marine oxygen levels. Sample preparation was carried out in a metal-free clean room facility in the isotope laboratory of the Department of Physics and Astronomy, University of Calgary, Canada, that is supplied by HEPA-filtered air. Molybdenum isotope ratios were determined on a Thermo Scientific multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) with an uncertainty better than ±0.10o for δ98/95Mo values. Results from the Buchanan Lake section show a large shift in δ98/95Mo values from 2.02o to +2.23o at the extinction horizon, consistent with onset of euxinic conditions. In contrast, West Blind Fiord shales, representing the sub-storm wave base shelf environment, show little change in the molybdenum isotopic composition (1.34o to +0.05), indicating ongoing oxic conditions across the LPE (Proemse et al., 2013). Our results suggest that areas of the Pangea continental shelf (North West Pangea) experienced

New results of microfaunal and geochemical investigations in the Permian-Triassic boundary interval from the Jadar Block (NW Serbia)

Science.gov (United States)

Sudar, Milan N.; Kolar-Jurkovšek, Tea; Nestell, Galina P.; Jovanović, Divna; Jurkovšek, Bogdan; Williams, Jeremy; Brookfield, Michael; Stebbins, Alan

2018-04-01

Detail results of microfaunal, sedimentological and geochemical investigations are documented from a newly discovered section of the Permian-Triassic boundary (PTB) interval in the area of the town of Valjevo (northwestern Serbia). The presence of various and abundant microfossils (conodonts, foraminifers, and ostracodes) found in the Upper Permian "Bituminous limestone" Formation enabled a determination of the Changhsingian Hindeodus praeparvus conodont Zone. This paper is the first report of latest Permian strata from the region, as well as from all of Serbia, where the PTB interval sediments have been part of a complex/integrated study by means of biostratigraphy and geochemistry.

Paleomagnetic results from Late Pennsylvanian marls and Early Permian red paleosols of the Dunkard group, Ohio and West Virginia, U.S.A.

Science.gov (United States)

Abrajevitch, A.; Oliva, B.; Peters, S.; Beehr, A.; van der Voo, R.

2006-12-01

Sediments of the Dunkard Gr. were deposited in the Appalachian foreland basin during the Pennsylvanian and Early Permian, an interval encompassing the long reverse polarity Kiaman chron. Lithofacies in the Dunkard Gr. in eastern Ohio and western West Virginia include lenticular and sheet-form cross-bedded micaceous sandstones, coal, mottled red and purple mudstones, gray laminated mudstones and argillaceous lime mudstones. They are indicative of deposition on a low-gradient, tropical wet-dry fluvial plain. Few lithofacies are laterally persistent over sufficiently long distances, so that correlation schemes are based largely on coal horizons, partly for historical economic reasons and partly because coal beds appear to be more laterally persistent than most other lithofacies. Magnetostratigraphy would therefore provide a powerful additional correlation tool in the Dunkard Gr, A short normal polarity interval has been reported in the Dunkard Gr. (Helsley, 1965), but to date such a change in magnetic field polarity has not been confirmed by later studies. To confirm the presence of the normal polarity subchron and to explore the possibility of using it as a correlation tool in the Dunkard Gr., we sampled 5 sections thought to straddle the Late Pennyslvanian-Early Permian boundary. Sampled lithofacies include red and mottled red-purple paleosols, grey mudstones containing siderite concretions, micaceous sandstones, and dark gray argillaceous limestones. Samples were demagnetized thermally and by AF. The remanent magnetic directions agree with those expected for the Early Permian. A change in polarity was detected in three of the studied sections. Magnetization is carried by several different magnetic minerals, mostly hematite in paleosols and iron sulfides in combination with magnetite in sandstones, marls and limestones. Although we have found good evidence for the normal polarity interval within Kiaman age rocks of the Dunkard Gr., additional magnetostratigraphic

Molecular Evidence for Radical Changes in Ocean Chemistry Across the Permian Triassic Boundary at Meishan in South China

Science.gov (United States)

Love, G. D.; Cao, C.; Jin, Y.; Summons, R. E.

2004-12-01

Samples from outcrop and from a new core drilled through the Permian Triassic Boundary at the type section at Meishan have been examined for biomarker and isotopic evidence of biotic and associated environmental change. Late Permian sediments from Meishan Beds 22-27 are characterized by indicators of anoxia including low Pr/Ph ratios and abundant aryl isoprenoids and isoreneieratane derived from the precursor carotenoid isorenieratene. The latter compounds are biomarkers for green sulfur bacteria (Chlorobiaceae) and are considered reliable indicators of euxinic water columns where sulfide extends to the photic zone. The peak of Chlorobiaceae biomarker abundance coincides with a rapid and synchronous drop in the ƒO13C and ƒO15N values of kerogen. On passing up into the Early Triassic, the biomarker signal for Chlorobiaceae wanes and is almost absent by Bed 30 where it is replaced by one for cyanobacteria including abundant hopanes and 2-methylhopanes and accompanying methyl and dimethyl alkanes. A very high value for the hopane/sterane ratio from Beds 30-38 indicates continuing dominant cyanobacterial productivity and only minor inputs from an algal plankton. The prevalence of aryl isoprenoids in P-Tr sediments at the Meishan section of South China is also recorded in a recently cored borehole, Hovea-3, of the Perth Basin, Western Australia. This suggests similar paleoenvironmental conditions prevailed across the Tethys Ocean during and immediately after the P-Tr Boundary. In particular, the presence of biomarkers for Chlorobiaceae at two separate locations indicates that water column euxinia was pervasive during the extinction event and suggests that sulfide may have been a key toxic agent.

New discovery of Permian belemnoids in Hunan

Energy Technology Data Exchange (ETDEWEB)

Liu, Z.; Su, L. [Xiangtan Mining Institute, Hunan (China). Dept. of Geology

1999-06-01

The fossil belemnoids described here were discovered from the Upper Permian Dalong Formation in Hunan province. There are nearly one hundred specimens, including one genus and one species. The diagnosis of the species is as follows: Genus: palaeobelemnopsis Chen, 1982; Species: Palaeobelemnosis sp. The guard is small and slender, about six times the maximum transverse diameter in length, with outline slightly hastate or fusiform. The maximum transverse diameter locates the border between the apical region and the stem region, and is nearly cycloid or slightly compressed in the anterior of the alveolus. The apical angle is about 70{degree}. The median ventral groove is wide and shallow, and is sometimes absent. Two dorso-lateral grooves are apparent and extending from the alveolus to the apex. The Phragmocone is slender. The outer shape of the guard is very similar to that of P. sinensis and P. minor. Nevertheless, this species differs from the two latters in having many transverse lines covering on the whole surface of the guard. Because all of these specimens are fossils of external mold and no inner structures have been preserved except a piece of siphuncle remains, the species is not given a new species name. Permian belemnoids are rarely found and the Palaeobelemnopsis is a primitive genus of belemnoids, therefore these specimens have important significance for research on the origin of COLEOIDEA. 4 refs., 3 figs.

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

International Nuclear Information System (INIS)

Lhomer, A.; Manigault, B.; Doyhenart, A.; Rossi, P.; Spoturno, J.; De Santana, H.; Vaz, N.

1982-01-01

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.

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)

Li, Kaikai; Cai, Chunfang; Jiang, Lei; Cai, Liulu; Jia, Lianqi; Zhang, Bing; Xiang, Lei; Yuan, Yuyang

2012-01-01

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), 87 Sr/ 86 Sr 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 (SrSO 4 and SrCO 3 ). 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 CaSO 4 have been consumed by reactions with hydrocarbons (i.e., TSR), resulting in water enriched in isotopically light CO 2 and HCO 3 - ,Sr 2+ ,Ba 2+ and Eu 2+ , as recorded in calcite with low δ 13 C values (down to −18.9‰), 87 Sr/ 86 Sr 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

Palaeomagnetism of the Early Permian Mount Leyshon Intrusive Complex and Tuckers Igneous Complex, North Queensland, Australia

Science.gov (United States)

Clark, D. A.; Lackie, M. A.

2003-06-01

This study provides reliable, precisely defined and well-dated Early Permian (286 +/- 6 Ma) palaeomagnetic poles for Australia from the Mount Leyshon Intrusive Complex (MLIC) and the Tuckers Igneous Complex (TIC). Both complexes are associated with prominent negative magnetic anomalies, indicating the presence of rocks carrying stable remanence of reverse polarity, with a Koenigsberger ratio greater than unity. The characteristic remanence carried by the intrusive phases and by locally remagnetized, contact-metamorphosed host rocks is always of reverse polarity, consistent with acquisition during the Permo-Carboniferous (Kiaman) Reverse Superchron. The corresponding palaeopoles confirm that Australia occupied high latitudes in the Early Permian. The pole positions are: MLIC: lat. = 43.2 °S, long. = 137.3 °E dp = 6.0°, dm = 6.4° Q= 6; TIC: lat. = 47.5 °S, long. = 143.0 °E, dp = 6.0°, dm = 6.6° Q= 6. Permian palaeomagnetic overprinting is detectable at considerable distances from the MLIC (2-3 km), well beyond the zone of visible alteration. The primary nature of the Early Permian palaeomagnetic signature is established by full baked contact/aureole tests at both localities. Other new data from Australia are consistent with the poles reported here. Comparison of the Australian, African and South American Apparent Polar Wander Paths (APWP) suggests that mean Permian and Triassic poles from West Gondwana, particularly from South America, are biased by remagnetization in the Jurassic-Cretaceous and that the Late Palaeozoic-Mesozoic APWP for Gondwana is best defined by Australian data. The Australian APWP exhibits substantial movement through the Mesozoic. Provided only that the time-averaged palaeofield was zonal, the Early Triassic palaeomagnetic data from Australia provide an important palaeogeographic constraint that the south geographic pole was within, or very close to, SE Australia around 240 Ma. The new Early Permian poles are apparently more consistent

Evaporite-hosted native sulfur in Trans-Pecos Texas: Relation to late-phase basin and range deformation

International Nuclear Information System (INIS)

Hentz, T.F.; Henry, C.D.

1989-01-01

Major deposits of biogenic native sulfur are associated with narrow, northeast-trending grabens and normal faults that disrupt the gently tilted, east-dipping Upper Permian evaporite succession of the western Delaware Basin in Trans-Pecos Texas. Orebodies are restricted to geologic traps in the fractured and dissolution-modified downfaulted blocks of the grabens. Other parallel, regionally distributed grabens and normal faults are commonly the sites of noncommercial sulfur deposits and genetically related secondary-replacement (diagenetic) limestone bodies. The sulfur-bearing structures probably formed during the later of two episodes of Basin and Range extension that have not previously been differentiated in Texas but are well defined elsewhere in the western United States. In Texas several lines of evidence collectively support the existence of late-phase, northwest-directed extension that was initiated in the middle Miocene

The end-Permian regression in the western Tethys: sedimentological and geochemical evidence from offshore the Persian Gulf, Iran

Science.gov (United States)

Tavakoli, Vahid; Naderi-Khujin, Mehrangiz; Seyedmehdi, Zahra

2018-04-01

Detailed sedimentological and geochemical records across the Permian-Triassic boundary (PTB) in five offshore wells of the central Persian Gulf served to interpret the end-Permian sea-level change in this region. A decrease in sea level at the PTB was established by petrographical and geochemical study of the boundary. Thin sections showed that Upper Permian strata are composed of dolomite with minor anhydrite, changing into limestone in Lower Triassic sediments. Brine dilution toward the boundary supports sea-level fall in the Permian-Triassic transition, reflected by a decrease in anhydrite content and a shallowing-upward trend from lagoonal to peritidal facies. Isotopic changes at the boundary are in favor of sea-level fall. Changes in both carbon (from about 4 to -1‰) and oxygen (from 2 to -5‰) stable isotopes show negative excursions. The shift in carbon isotope values is a global phenomenon and is interpreted as resulting from carbonate sediment interaction with 12C-rich waters at the end-Permian sea-level fall. However, the oxygen isotope shift is attributed to the effect of meteoric waters with negative oxygen isotope values. The increase in strontium isotope ratios is also consistent with the high rate of terrestrial input at the boundary. The effect of meteoric conditions during diagenesis is evident from vuggy and moldic porosities below the PTB. The following transgression at the base of the Triassic is evident from the presence of reworked fossils and intraclasts resulting from deposition from agitated water.

Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu basin, Central Kazakhstan

Science.gov (United States)

Box, Stephen E.; Seltmann, Reimar; Zientek, Michael L.; Syusyura, Boris; Creaser, Robert A.; Dolgopolova, Alla

2012-01-01

Sandstone-hosted copper (sandstone Cu) deposits occur within a 200-km reach of the northern Chu-Sarysu basin of central Kazakhstan (Dzhezkazgan and Zhaman-Aibat deposits, and the Zhilandy group of deposits). The deposits consist of Cu sulfide minerals as intergranular cement and grain replacement in 10 ore-bearing members of sandstone and conglomerate within a 600- to 1,000-m thick Pennsylvanian fluvial red-bed sequence. Copper metal content of the deposits ranges from 22 million metric tons (Mt, Dzehzkazgan) to 0.13Mt (Karashoshak in the Zhilandy group), with average grades of 0.85 to 1.7% Cu and significant values for silver (Ag) and rhenium (Re). Broader zones of iron reduction (bleaching) of sandstones and conglomerates of the red-bed sequence extend over 10 km beyond each of the deposits along E-NE-trending anticlines, which began to form in the Pennsylvanian. The bleached zones and organic residues within them are remnants of ormer petroleum fluid accumulations trapped by these anticlines. Deposit sites along these F1anticlines are localized at and adjacent to the intersections of nearly orthogonal N-NW-trending F2synclines. These structural lows served to guide the flow of dense ore brines across the petroleum-bearing anticlines, resulting in ore sulfide precipitation where the two fluids mixed. The ore brine was sourced either from the overlying Early Permian lacustrine evaporitic basin, whose depocenter occurs between the major deposits, or from underlying Upper Devonian marine evaporites. Sulfur isotopes indicate biologic reduction of sulfate but do not resolve whether the sulfate was contributed from the brine or from the petroleum fluids. New Re-Os age dates of Cu sulfides from the Dzhezkazgan deposit indicate that mineralization took place between 299 to 309 Ma near the Pennsylvanian-Permian age boundary. At the Dzhezkazgan and some Zhilandy deposits, F2fold deformation continued after ore deposition. Copper orebodies in Lower Permian

New Paleomagnetic Data from Upper Permian and Lower Triassic Volcanic Sequences from Hua Binh, Quynh Nhai, and Thuan Chau Localities, Northwest Veitnam and Their Bearing on the Accretion History of Southeast Asia

Science.gov (United States)

Geissman, J. W.; Chi, C. T.

2015-12-01

-Early Triassic SCB apparent polar wander path, the data show that volcanic crustal elements of northwest Vietnam, east of the Song Ma suture zone, have been close to, but not unequivocally a coherent part of the SCB, since the Late Permian. Development of the parallel NW-SE striking Song Ma and Song Chay orogenic belts did not involve the closure of wide (> 500 km) ocean basins.

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

International Nuclear Information System (INIS)

Borns, D.J.; Shaffer, S.E.

1985-09-01

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

Stratigraphic, regional unconformity analysis and potential petroleum plays of East Siberian Sea Basin

Science.gov (United States)

Karpov, Yury; Stoupakova, Antonina; Suslova, Anna; Agasheva, Mariia

2017-04-01

The East Siberian Sea basin (ESSB) one of the most unexplored part of the Russian Arctic shelf, extending for over 1000 km from New Siberian Islands archipelago to Wrangel Island. This region is considered as a region with probable high petroleum potential. Within the ESSB several phases of orogeny are recognized [1]: Elsmerian orogeny in Early Devonian, Early Brooks orogeny in Early Cretaceous, Late Brooks orogeny in Late Cretaceous. Two generations of the basins could be outlined. Both of these generations are controlled by the basement domains [1]: Paleozoic (post-Devonian) to Mesozoic basins preserved north of the Late Mesozoic frontal thrusts; Aptian-Albian to Quaternary basins, postdating the Verkhoyansk-Brookian orogeny, and evolving mainly over the New-Siberian-Chukchi Fold Belt. Basin is filled with siliclastic sediments and in the deepest depocentres sediments thickness exceeds 8-10 km in average. Seismic data was interpreted using methods of seismic stratigraphy. Finally, main seismic horizons were indicated and each horizon follows regional stratigraphic unconformities: mBU - in base of Cenozoic, BU - in base of Upper Cretaceous, LCU - in base of Cretaceous, JU - in middle of Jurassic, F - in top of Basement. In ESSB, we can identify Permian, Triassic, Jurassic, Cretaceous, Paleogene and Neogene seismic stratigraphy complexes. Perspective structures, investigated in ESSB were founded out by comparing seismogeological cross-sections with explored analogs in other onshore and offshore basins [2, 3, 4]. The majority of structures could be connected with stratigraphic and fault traps. The most perspective prospects are probably connected with grabens and depressions, where thickness of sediments exceed 10 km. Reservoirs in ESSB are proposed by regional geological explorations on New Siberian Islands Archipelago and Wrangel Island. Potential seals are predominantly assigned to Jurassic and Cretaceous periods. Thick clinoform units of various geometry and

Gravity signals from the lithosphere in the Central European Basin System

Science.gov (United States)

Yegorova, T.; Bayer, U.; Thybo, H.; Maystrenko, Y.; Scheck-Wenderoth, M.; Lyngsie, S. B.

2007-01-01

We study the gravity signals from different depth levels in the lithosphere of the Central European Basin System (CEBS). The major elements of the CEBS are the Northern and Southern Permian Basins which include the Norwegian-Danish Basin (NDB), the North-German Basin (NGB) and the Polish Trough (PT). An up to 10 km thick sedimentary cover of Mesozoic-Cenozoic sediments, hides the gravity signal from below the basin and masks the heterogeneous structure of the consolidated crust, which is assumed to be composed of domains that were accreted during the Paleozoic amalgamation of Europe. We performed a three-dimensional (3D) gravity backstripping to investigate the structure of the lithosphere below the CEBS. Residual anomalies are derived by removing the effect of sediments down to the base of Permian from the observed field. In order to correct for the influence of large salt structures, lateral density variations are incorporated. These sediment-free anomalies are interpreted to reflect Moho relief and density heterogeneities in the crystalline crust and uppermost mantle. The gravity effect of the Moho relief compensates to a large extent the effect of the sediments in the CEBS and in the North Sea. Removal of the effects of large-scale crustal inhomogeneities shows a clear expression of the Variscan arc system at the southern part of the study area and the old crust of Baltica further north-east. The remaining residual anomalies (after stripping off the effects of sediments, Moho topography and large-scale crustal heterogeneities) reveal long wavelength anomalies, which are caused mainly by density variations in the upper mantle, though gravity influence from the lower crust cannot be ruled out. They indicate that the three main subbasins of the CEBS originated on different lithospheric domains. The PT originated on a thick, strong and dense lithosphere of the Baltica type. The NDB was formed on a weakened Baltica low-density lithosphere formed during the Sveco

Record of palaeoenvironmental changes in a Lower Permian organic-rich lacustrine succession: Integrated sedimentological and geochemical study of the Rudník member, Krkonoše Piedmont Basin, Czech Republic

Czech Academy of Sciences Publication Activity Database

Martínek, K.; Blecha, M.; Daněk, V.; Franců, J.; Hladíková, J.; Johnová, R.; Uličný, David

2006-01-01

Roč. 230, 1/2 (2006), s. 85-128 ISSN 0031-0182 R&D Projects: GA ČR GA205/94/0692 Institutional research plan: CEZ:AV0Z30120515 Keywords : Lower Permian * Bohemian Massif * lacustrine facies Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.822, year: 2006

A Record of Rotaloid Foraminifera from the Upper Permian-Lower ...

African Journals Online (AJOL)

PRABHAS PANDE

INTRODUCTION. In the history of organic evolution, the end of Palaeozoic Era was marked by the conspicuous event of mass extinctions. Amongst foraminifera, as many as fourteen families became extinct. (Loeblich and Tappan, 1964) during the Permian Period and many new families evolved in the. Mesozoic. There is a ...

Palynology of Sub-Saharan Karoo Basins: Key to Early Mesozoic palaeoclimate reconstruction

Science.gov (United States)

Götz, Annette E.

2014-05-01

Palynological data of Permian-Triassic formations of the Sub-Saharan Karoo basins play a crucial role in the study and for the understanding of Gondwana's climate history and biodiversity in this time of major global changes in terrestrial and marine ecosystems. The palynological record reflects changes in land plant communities and vegetational patterns related to climate change and thus provides significant data for high-resolution palaeoclimate reconstructions in deep time. Recent palynological investigations of Triassic successions of South Africa, Mozambique and Tanzania document major changes in palaeoclimate. The spore/pollen ratios are used as a proxy for humidity changes. Stratal variations in the composition of the pollen group indicate warming and cooling phases. Variations in the amount and in the type, size and shape of phytoclasts reflect short-term changes in transport and weathering. The detected palaeoclimate signals are used for high-resolution correlation on basin-wide, intercontinental and intra-Gondwanic scales.

Organic maturation levels, thermal history and hydrocarbon source rock potential of the Namurian rocks of the Clare Basin, Ireland

Energy Technology Data Exchange (ETDEWEB)

Goodhue, Robbie; Clayton, Geoffrey [Trinity Coll., Dept. of Geology, Dublin (Ireland)

1999-11-01

Vitrinite reflectance data from two inland cored boreholes confirm high maturation levels throughout the onshore part of the Irish Clare Basin and suggest erosion of 2 to 4 km of late Carboniferous cover and elevated palaeogeothermal gradients in the Carboniferous section. The observed maturation gradients are fully consistent with the published hypothesis of a late Carboniferous/Permian 'superplume' beneath Pangaea but local vertical reversals in gradients also suggest a complex thermal regime probably involving advective heating. The uppermost Visean--lower Namurian Clare Shale is laterally extensive and up to 300 m thick. Although this unit is post-mature, TOC values of up to 15% suggest that it could have considerable hydrocarbon source rock potential in any less mature offshore parts of the basin. (Author)

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

Inclination Shallowing in the Permian/Triassic Boundary Sedimentary Sections of the East European Platform: the New Paleomagnetic Pole and its Significance for GAD Hypothesis

Science.gov (United States)

Veselovskiy, R. V.; Fetisova, A. M.; Balabanov, Y.

2017-12-01

One of the key challenges which are traditionally encountered in studying the paleomagnetism of terrigenous sedimentary strata is the necessity to allow for the effect of shallowing of paleomagnetic inclinations which takes place under the compaction of the sediment at the early stages of diagenesis and most clearly manifests itself in the case of midlatitude sedimentation. Traditionally, estimating the coefficient of inclination flattening (f) implies routine re-deposition experiments and studying their magnetic anisotropy (Kodama, 2012), which is not possible in every standard paleomagnetic laboratory. The Elongation-Inclination (E/I) statistical method for estimating the coefficient of inclination shallowing, which was recently suggested in (Tauxe and Kent, 2004), does not require the investigation of the rock material in a specially equipped laboratory but toughens the requirements on the paleomagnetic data and, primarily, regarding the volume of the data, which significantly restricts the possibilities of the post factum estimation and correction for inclination shallowing. We present the results of the paleomagnetic reinvestigation of the some key sections of the Upper Permian and Lower Triassic rocks located on the East European Platform. The obtained paleomagnetic data allowed us to estimate the coefficient of inclination shallowing by the E/I method and calculate a new P-Tr paleomagnetic pole for Europe. The absence of a statistically significant difference between the mean Siberian, European and North American Permian-Triassic paleomagnetic poles allow us to conclude that 252 Ma the configuration of the Earth's magnetic field was predominantly dipole. We believe that the assumption of the non-dipolarity of the geomagnetic field at the Permian-Triassic boundary, which has been repeatedly discussed in recent decades (Van der Voo and Torsvik, 2001; Bazhenov and Shatsillo, 2010; Veselovskiy and Pavlov, 2006), arose due to the failure to take into account the

Estimates of ground-water recharge rates for two small basins in central Nevada

International Nuclear Information System (INIS)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins, two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation, stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most reliable results are those derived from a reduced form of the chloride-ion model because they reflect integrated, basinwide processes in terms of only three measured variables: precipitation amount, precipitation chemistry, and streamflow chemistry

Paratingia wudensis sp. nov., a whole noeggerathialean plant preserved in an earliest Permian air fall tuff in Inner Mongolia, China

Czech Academy of Sciences Publication Activity Database

Wang, J.; Pfefferkorn, H. W.; Bek, Jiří

2009-01-01

Roč. 96, č. 9 (2009), s. 1676-1689 ISSN 0002-9122 R&D Projects: GA AV ČR IAA301110701 Institutional research plan: CEZ:AV0Z30130516 Keywords : noeggerathiales * whole plant reconstruction * in situ spores * Permian * Permian (China) Subject RIV: EF - Botanics Impact factor: 2.684, year: 2009

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

Directory of Open Access Journals (Sweden)

DIETER UHL

2012-07-01

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

Late Carboniferous and Early Permian algal microflora (Liuzhou, South China)

Energy Technology Data Exchange (ETDEWEB)

Li Chun (Nanjing Inst. of Geology and Paleontology, Nanjing (China)); Mamet, B. (Montreal Univ., PQ (Canada))

1993-03-01

Paleozoic algae are important contributors to the formation of carbonate sediments. A study was conducted to compare an Upper Carboniferous-Lower Permian carbonate succession of South China with what is generally observed in the Tethys Sea and North America. The sequence studied was in the Maping Limestone at the Loutishan section in Liuzhou, with some additional information derived from the Maping Limestone at Shangxinping and from the Chuanshan Limestone at Yuhuangshan and in the Nanjing Hills. In the Late Carboniferous, the beresellid algae are important builders and the Tubiphytes-Archaeolithophyllum community is locally replaced by a Tubiphytes-Ungdarella association. Early Permian oncolites were formed by complex Osagia, then by Esmerella. The Asselian Sphaeroschwagerina fauna is underlined by the outburst of epimastoporid dasycladales and phylloid Anchicodiaceae. Microcodium is observed at the contact of the Sphaeroschwagerina moelleri/sphaerica Zones. The overlying and paraconformable Chihsia Limestone is characterized by a Gymnocodium-Gyroporella-Mizzia flora. In most cases, the base of the fusulinid zones, therefore, coincides with an important local floristic change. 72 refs., 4 figs.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-08-01

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

Early Triassic development of a foreland basin in the Canadian high Arctic: Implications for a Pangean Rim of Fire

Science.gov (United States)

Hadlari, Thomas; Dewing, Keith; Matthews, William A.; Alonso-Torres, Daniel; Midwinter, Derrick

2018-06-01

Following the amalgamation of Laurasia and Gondwana to form Pangea, some Triassic tectonic models show an encircling arc system called the "Pangean Rim of Fire". Here we show that the stratigraphy and Early Triassic detrital zircon provenance of the Sverdrup Basin in the Canadian Arctic is most consistent with deposition in a retro-arc foreland basin. Late Permian and Early Triassic volcanism was accompanied by relatively high rates of subsidence leading to a starved basin with volcanic input from a magmatic arc to the northwest. The mostly starved basin persisted through the Middle and Late Triassic with nearly continuous input of volcanic ash recorded as bentonites on the northwestern edge of the basin. In the latest Triassic it is interpreted that decreasing subsidence and a significant influx of sand-grade sediment when the arc was exhumed led to filling of the basin at the end of an orogenic cycle. Combined with other hints of Early Triassic arc activity along the western margin of Laurentia we propose that the Pangean Rim of Fire configuration spanned the entire Triassic. This proposed configuration represents the ring of external subduction zones that some models suggest are necessary for the breakup of supercontinents such as Pangea.

Composition and palaeogeographic position of the Early Permian Jambi flora from Sumatra

NARCIS (Netherlands)

Waveren, van I.M.; Iskandar, E.A.P.; Booi, M.; Konijnenburg-van Cittert, van J.H.A.

2007-01-01

A preliminary taxonomic revision of the Early Permian Jambi flora results in a lower number of taxa, a number of new determinations and several new combinations (Dicranophyllum molle (Jongmans & Gothan) comb. nov., Oligocarpia posthumii (Jongmans & Gothan) nov. comb., Callipteridium strictinervis

Dedolomitization Potential of Fluids from Gypsum-to-Anhydrite Conversion: Mass Balance Constraints from the Late Permian Zechstein-2-Carbonates in NW Germany

Directory of Open Access Journals (Sweden)

M. Hallenberger

2018-01-01

Full Text Available The Zechstein-2-Carbonates represent one of the most prolific hydrocarbon systems of Central Europe. Carbonate reservoir quality is primarily controlled by mineralogy, with dolomite representing moderate-to-good porosities and calcite commonly representing low porosities. Current models suggest that this calcite is the result of a basin-wide phase of dedolomitization. The calcium (Ca source for the dedolomites is thought to be derived from the fluids liberated during gypsum-to-anhydrite conversion. We present an easy-to-use and generally applicable template to estimate the dedolomitization potential of these fluids. Depending on reaction stoichiometry, salinity, and temperature, we estimate that between 2.8⁎10−3 m3 and 6.2⁎10−3 m3 of calcite may replace dolomite for each m3 of anhydrite created. Within the constraints dictated by the environment of the late Permian Zechstein basin, we estimate that about 5⁎10−3 m3 of dedolomite is created for each m3 of anhydrite. Mass balance constraints indicate that fluids derived from gypsum-to-anhydrite conversion account for less than 1% of the observed dedolomite in most of the studied industry wells from northern Germany.

Facies-architecture of fossil arid siliciclastic depositional systems as outcrop analogue for Rotliegend reservoirs. Literature study; Faziesarchitektur fossiler arid-klastischer Ablagerungsraeume als Rotliegend-Reservoiranalog. Literaturstudie

Energy Technology Data Exchange (ETDEWEB)

Irmen, A.

1999-08-01

In this project a literature-based study was carried out in order to document the facies-architecture of siliciclastic sediments from arid environments and to investigate their suitability as outcrop-analogues for the strata of the Southern Permian Basin. The report resulting from this investigation presents possible analogues and case-studies. Three Formations (Flechtingen Sandstone, Corrie Sandstone and Cedar Mesa Sandstone of the Cutler Group) are especially well suited to serve as outcrop analogue for the 'Rotliegend' Sediments of the Southern Permian Basin. Possible analogues are documented at various scales, ranging from bed-scale to formation scale. Also, special attention was paid to general trends and what factors control them. To make a comparison of Formations from different settings possible, criteria were elaborated to qualify the relevant controlling factors. The catalog itself is preceded by a comprehensive preface, that introduces to the subject and points out the connection between the primary sediment fabric and its petrophysical properties. (orig.) [German] Im Rahmen dieses DGMK Forschungsvorhabens wurde eine Literaturstudie durchgefuehrt, welche die Faziesarchitektur fossiler arid-klastischer Sedimente darstellt und auf ihre Eignung als Rotliegend-Reservoiranalog untersucht. Die vorliegende Dokumentation stellt verschiedene moegliche Analoge und Fallbeispiele dar, wobei drei Abfolgen als besonders geeignet erscheinen. Es wurden Kriterien erarbeitet, die relevante Kontrollfaktoren qualifizieren, um einen Vergleich verschiedener arid-klastischer Sedimentationsraeume zu ermoeglichen. Die Bandbreite der Darstellung moeglicher Analoge umfasst das gesamte Spektrum vom Gefuegemassstab bis hin zu genetischen Einheiten und beleuchtet die jeweiligen Steuerungsfaktoren der Ablagerung. Der eigentlichen Dokumentation wurde eine umfassende Einleitung vorangestellt, welche in die Thematik einfuehrt und Zusammenhaenge zwischen primaerem

Facies-architecture of fossil arid siliciclastic depositional systems as outcrop analogue for Rotliegend reservoirs. Literature study; Faziesarchitektur fossiler arid-klastischer Ablagerungsraeume als Rotliegend-Reservoiranalog. Literaturstudie

Energy Technology Data Exchange (ETDEWEB)

Irmen, A

1999-08-01

In this project a literature-based study was carried out in order to document the facies-architecture of siliciclastic sediments from arid environments and to investigate their suitability as outcrop-analogues for the strata of the Southern Permian Basin. The report resulting from this investigation presents possible analogues and case-studies. Three Formations (Flechtingen Sandstone, Corrie Sandstone and Cedar Mesa Sandstone of the Cutler Group) are especially well suited to serve as outcrop analogue for the 'Rotliegend' Sediments of the Southern Permian Basin. Possible analogues are documented at various scales, ranging from bed-scale to formation scale. Also, special attention was paid to general trends and what factors control them. To make a comparison of Formations from different settings possible, criteria were elaborated to qualify the relevant controlling factors. The catalog itself is preceded by a comprehensive preface, that introduces to the subject and points out the connection between the primary sediment fabric and its petrophysical properties. (orig.) [German] Im Rahmen dieses DGMK Forschungsvorhabens wurde eine Literaturstudie durchgefuehrt, welche die Faziesarchitektur fossiler arid-klastischer Sedimente darstellt und auf ihre Eignung als Rotliegend-Reservoiranalog untersucht. Die vorliegende Dokumentation stellt verschiedene moegliche Analoge und Fallbeispiele dar, wobei drei Abfolgen als besonders geeignet erscheinen. Es wurden Kriterien erarbeitet, die relevante Kontrollfaktoren qualifizieren, um einen Vergleich verschiedener arid-klastischer Sedimentationsraeume zu ermoeglichen. Die Bandbreite der Darstellung moeglicher Analoge umfasst das gesamte Spektrum vom Gefuegemassstab bis hin zu genetischen Einheiten und beleuchtet die jeweiligen Steuerungsfaktoren der Ablagerung. Der eigentlichen Dokumentation wurde eine umfassende Einleitung vorangestellt, welche in die Thematik einfuehrt und Zusammenhaenge zwischen primaerem Sedimentgefuege und

Exploratory shaft conceptual design report: Paradox Basin

International Nuclear Information System (INIS)

1983-07-01

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

Late Early Permian continental ichnofauna from Lake Kemp, north-central Texas, USA

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Lucas, S.G.; Voigt, S.; Lerner, A.J.; Nelson, W.J.

2011-01-01

Continental trace fossils of Early Permian age are well known in the western United States from Wolfcampian (~. Asselian to Artinskian) strata, but few examples are known from Leonardian (~. Kungurian) deposits. A substantial ichnofauna from strata of the lower part of the Clear Fork Formation at Lake Kemp, Baylor County, Texas, augments the meager North American record of Leonardian continental trace fossil assemblages. Ichnofossils at Lake Kemp occur in the informally-named Craddock dolomite member of the Clear Fork Formation, which is 12-15. m above the local base of the Clear Fork. The trace-bearing stratum is an up-to-0.3. m thick, laminated to flaser-bedded, dolomitic siltstone that also contains mud cracks, raindrop impressions, microbially induced mat structures, and some land-plant impressions. We interpret the Craddock dolomite member as the feather-edge of a marine transgressive carbonate deposit of an irregular coastline marked by shallow bays or estuaries on the eastern shelf of the Midland basin, and the trace-fossil-bearing stratum at Lake Kemp is an unchannelized flow deposit on a muddy coastal plain. The fossil site at Lake Kemp yields a low to moderately diverse fauna of invertebrate and vertebrate traces. A sparse invertebrate ichnofauna consists of arthropod feeding and locomotion traces assigned to Walpia cf. W. hermitensis White, 1929 and Diplichnites gouldi Gevers in Gevers et al., 1971. Tetrapod footprints are most common and assigned to Batrachichnus salamandroides (Geinitz, 1861), cf. Amphisauropus kablikae (Geinitz and Deichm??ller, 1882), and Dromopus lacertoides (Geinitz, 1861), which represent small temnospondyl, seymouriamorph, and basal sauropsid trackmakers. Both the traces and sedimentary features of the fossil horizon indicate a freshwater setting at the time of track formation, and the trace assemblage represents the Scoyenia ichnofacies and the Batrachichnus ichnofacies in an overbank environment with sheet flooding and shallow

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

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Blodgett, R.B.; Moore, T.E.; Gray, F.

2002-01-01

Lower Permian carbonate and overlying red bed clastic rocks are present in a 2 km2 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

Aridification across the Carboniferous-Permian transition in central equatorial Pangea: The Catalan Pyrenean succession (NE Iberian Peninsula)

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Mujal, Eudald; Fortuny, Josep; Marmi, Josep; Dinarès-Turell, Jaume; Bolet, Arnau; Oms, Oriol

2018-01-01

The Carboniferous-Permian terrestrial successions record a global climatic shift from icehouse to hothouse conditions. Our multidisciplinary study documents an aridification trend throughout the 1000 m thick composite terrestrial succession of the western Catalan Pyrenees (NE Iberian Peninsula), representing this time period. The detailed stratigraphic framework integrates sedimentology, paleopedology, biochronology (plant fossils and tetrapod footprints) and geochronology (paleomagnetism). Additional absolute age correlation is also carried out. The new and reviewed data show that the late Carboniferous wet environments (with short drought periods) progressively changed to a strong seasonal semi-arid and arid climate (with short humid periods) through the early Permian. This paleoclimatic trend supports the previously suggested aridification of the Pangean pan-tropical belt, and supports the hypothesis of the influence of the recurrent climatic fluctuations in Central Pangea, being tentatively correlated to the Southern Gondwanan glaciation-deglaciation periods. Therefore, the Carboniferous-Permian terrestrial succession from the Catalan Pyrenees emerges as a continuous record that can help to constrain late Paleozoic paleoenvironmental events.

Late Permian to Triassic intraplate orogeny of the southern Tianshan and adjacent regions, NW China

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Wei Ju

2014-01-01

Based on previous studies and recent geochronogical data, we suggest that the final collision between the Tarim Craton and the North Asian continent occurred during the late Carboniferous. Therefore, the Permian was a period of intracontinental environment in the southern Tianshan and adjacent regions. We propose that an earlier, small-scale intraplate orogenic stage occurred in late Permian to Triassic time, which was the first intraplate process in the South Tianshan Orogen and adjacent regions. The later large-scale and well-known Neogene to Quaternary intraplate orogeny was induced by the collision between the India subcontinent and the Eurasian plate. The paper presents a new evolutionary model for the South Tianshan Orogen and adjacent regions, which includes seven stages: (I late Ordovician–early Silurian opening of the South Tianshan Ocean; (II middle Silurian–middle Devonian subduction of the South Tianshan Ocean beneath an active margin of the North Asian continent; (III late Devonian–late Carboniferous closure of the South Tianshan Ocean and collision between the Kazakhstan-Yili and Tarim continental blocks; (IV early Permian post-collisional magmatism and rifting; (V late Permian–Triassic the first intraplate orogeny; (VI Jurassic–Palaeogene tectonic stagnation and (VII Neocene–Quaternary intraplate orogeny.

Geochronologic evidence of a large magmatic province in northern Patagonia encompassing the Permian-Triassic boundary

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Luppo, Tomás; López de Luchi, Mónica G.; Rapalini, Augusto E.; Martínez Dopico, Carmen I.; Fanning, Christopher M.

2018-03-01

The Los Menucos Complex (northern Patagonia) consists of ∼6 km thick succession of acidic and intermediate volcanic and pyroclastic products, which has been traditionally assigned to the Middle/Late Triassic. New U/Pb (SHRIMP) zircon crystallization ages of 257 ± 2 Ma at the base, 252 ± 2 Ma at an intermediate level and 248 ± 2 Ma near the top of the sequence, indicate that this volcanic event took place in about 10 Ma around the Permian-Triassic boundary. This volcanism can now be considered as the effusive terms of the neighboring and coeval La Esperanza Plutono-Volcanic Complex. This indicates that the climax of activity of a large magmatic province in northern Patagonia was coetaneous with the end-Permian mass extinctions. Likely correlation of La Esperanza- Los Menucos magmatic province with similar volcanic and plutonic rocks across other areas of northern Patagonia suggest a much larger extension than previously envisaged for this event. Its age, large volume and explosive nature suggest that the previously ignored potential role that this volcanism might have played in climatic deterioration around the Permian-Triassic boundary should be investigated.

U-Th-Geochemistry of Permian and Triassic sediments of the Drauzug, Carinthia, Austria

International Nuclear Information System (INIS)

Kurat, G.; Korkisch, J.; Niedermayr, G.; Seemann, R.

1976-05-01

Chemical analysis of samples of Triassic and Permian rocks from the Drauzug, Carinthia and Austria was carried out. U concentration was measured by flurimetry, Th and Cu by spectrophotometry using Thoronol method or Arsenazo III method for Th, Fe by titrimetry and V, Ba, Sr by atomic absorption spectrophotometry. The average U concentration ranged from 0.8 to 4.6 ppm and the Th concentration from 3.2 to 15.6 ppm depending upon the mineral material. The quartzporphyries contained the highest concentration of both. It was concluded that the Permian-Triassic series are very similar to the equivalent deposits in Northern Italy. Assuming a lateral displacement, the former represent the Northern marginal part of the latter and therefore are inferior in thickness and thus not favourable for larger U mineralization

A tale of two extinctions : converging end-Permian and end-Triassic scenarios

NARCIS (Netherlands)

van de Schootbrugge, Bas; Wignall, Paul B.

The end-Permian (c. 252 Ma) and end-Triassic (c. 201 Ma) mass-extinction events are commonly linked to the emplacement of the large igneous provinces of the Siberia Traps and Central Atlantic Magmatic Province, respectively. Accordingly, scenarios for both extinctions are increasingly convergent and

Natural analog study of engineered protective barriers at the Hanford Site

International Nuclear Information System (INIS)

Bjornstad, B.N.; Teel, S.S.

1993-09-01

The purpose of this study is to evaluate surficial sedimentary deposits formed in the Pasco Basin over the geologic past as analogs for engineered protective barriers. Evidence for likely changes to be expected in an engineered barrier are preserved in geologically recent deposits. Although the design life of the engineered bonier is only 1,000 years, soils and sediments of this age are uncommon in the Pasco Basin. The evidence of and probability for the following natural processes that could adversely affect the long-term stability of an engineered protective barrier reviewed in this report are deflation by wind, soil compaction, soil eluviation/illuviation, bioturbation, and cryoturbation

A new stem group echinoid from the Triassic of China leads to a revised macroevolutionary history of echinoids during the end-Permian mass extinction

Science.gov (United States)

Thompson, Jeffrey R.; Hu, Shi-xue; Zhang, Qi-Yue; Petsios, Elizabeth; Cotton, Laura J.; Huang, Jin-Yuan; Zhou, Chang-yong; Wen, Wen; Bottjer, David J.

2018-01-01

The Permian-Triassic bottleneck has long been thought to have drastically altered the course of echinoid evolution, with the extinction of the entire echinoid stem group having taken place during the end-Permian mass extinction. The Early Triassic fossil record of echinoids is, however, sparse, and new fossils are paving the way for a revised interpretation of the evolutionary history of echinoids during the Permian-Triassic crisis and Early Mesozoic. A new species of echinoid, Yunnanechinus luopingensis n. sp. recovered from the Middle Triassic (Anisian) Luoping Biota fossil Lagerstätte of South China, displays morphologies that are not characteristic of the echinoid crown group. We have used phylogenetic analyses to further demonstrate that Yunnanechinus is not a member of the echinoid crown group. Thus a clade of stem group echinoids survived into the Middle Triassic, enduring the global crisis that characterized the end-Permian and Early Triassic. Therefore, stem group echinoids did not go extinct during the Palaeozoic, as previously thought, and appear to have coexisted with the echinoid crown group for at least 23 million years. Stem group echinoids thus exhibited the Lazarus effect during the latest Permian and Early Triassic, while crown group echinoids did not.

An integrated perspective on the Permian-Triassic "Great Dying"

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Algeo, T. J.

2017-12-01

The 252-Ma end-Permian mass extinction (EPME), marked by the loss of 90% of marine invertebrate species, was the largest biocrisis in Earth history. Intensive study of this "Great Dying" has led to major insights and a broad consensus regarding many aspects of this event. The ultimate trigger is regarded as eruption of the Siberian Traps Large Igneous Province (STLIP), which released large quantities of greenhouse gases (CO2 and CH4) and sulfate aerosols, triggering a catastrophic global warming of 10°C and acidification of both land surfaces and the surface ocean. On land, a massive die-off of vegetation led to a transient episode of rapid soil erosion and a longer-term increase in weathering rates linked to elevated temperatures. In the ocean, widespread anoxia developed concurrently with the EPME, triggered by ocean-surface warming that reduced dissolved oxygen solubility in seawater and that intensified vertical stratification. Expanded anoxia led to massive burial of organic matter and reduced sulfur, although the evidence for this is indirect (C, U and S isotopes); few organic-rich deposits of Early Triassic age have been found, suggesting that organic sedimentation occurred mainly on continental slopes or in the deep ocean. Other aspects of the end-Permian crisis remain under debate. For example, there is no consensus regarding changes in marine productivity levels in the aftermath of the EPME, which would have been stimulated by enhanced subaerial weathering but depressed by reduced overturning circulation-the evidence to date may favor localized positive and negative changes in productivity. Also under scrutiny is evidence for volcanic eruptions and environmental perturbations during the 100 kyr prior to the EPME, which are likely to have occurred but remain poorly dated and quantified. The greatest uncertainty, however, may surround the nature of the proximate kill mechanism(s) during the EPME. Many hypotheses have been advanced including mechanisms

Geology and assessment of undiscovered oil and gas resources of the Timan-Pechora Basin Province, Russia, 2008

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Schenk, Christopher J.; Moore, Thomas E.; Gautier, D.L.

2017-11-15

The Timan-Pechora Basin Province is a triangular area that represents the northeasternmost cratonic block of east European Russia. A 75-year history of petroleum exploration and production in the area there has led to the discovery of more than 16 billion barrels of oil (BBO) and 40 trillion cubic feet of gas (TCFG). Three geologic assessment units (AUs) were defined for assessing the potential for undiscovered oil and gas resources in the province: (1) the Northwest Izhma Depression AU, which includes all potential structures and reservoirs that formed in the northwestern part of the Izhma-Pechora Depression, although this part of the basin contains only sparse source and reservoir rocks and so was not assessed quantitatively; (2) the Main Basin Platform AU, which includes all potential structures and reservoirs that formed in the central part of the basin, where the tectonic and petroleum system evolution was complex; and (3) the Foredeep Basins AU, which includes all potential structures and reservoirs that formed within the thick sedimentary section of the foredeep basins west of the Uralian fold and thrust belt during the Permian and Triassic Uralian orogeny.For the Timan-Pechora Basin Province, the estimated means of undiscovered resources are 3.3 BBO, 17 TCFG, and 0.3 billion barrels of natural-gas liquids (BBNGL). For the AU areas north of the Arctic Circle in the province, the estimated means of undiscovered resources are 1.7 BBO, 9.0 TCFG, and 0.2 BBNGL. These assessment results indicate that exploration in the Timan-Pechora Basin Province is at a mature level.

Conodont succession and reassessment of major events around the Permian-Triassic boundary at the Selong Xishan section, southern Tibet, China

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Yuan, Dong-Xun; Zhang, Yi-Chun; Shen, Shu-Zhong

2018-02-01

A major discrepancy for the age of the Selong Group from middle Cisuralian (Early Permian) to Changhsingian resulted from previous reports of Sakmarian, Kungurian and Guadalupian (Middle Permian) conodonts and Lopingian (Late Permian) brachiopods. Recently, Cisuralian and Guadalupian conodonts were reported again from the Selong Group and the basal part of the Kangshare Formation at the Selong section, but the age discrepancy remains. We present our conodont materials based on large samples collected from the Selong Group and our interpretation based on identifications using a sample population approach. Three conodont zones are recognized in our re-investigation of the upper part of the Selong Group. They include the Vjalovognathus sp., the Mesogondolella hendersoni, and the M. sheni zones, in ascending order. These zones are overlain by the basal Triassic Hindeodus parvus Zone and the Otoceras woodwardi Zone. Our reassessment of conodonts reported by previous studies from Selong and nearby sections suggest that all specimens consistently point to a Lopingian age; the upper part of the Selong Group is latest Changhsingian in age based on the presence of Clarkina orchardi and Mesogondolella sheni. Previously reported early Cisuralian and Guadalupian conodonts are misidentified using a form species concept. A hiatus may be present at the erosional surface between the Selong Group and the Waagenites Bed of the basal part of the Kangshare Formation. However, the hiatus is minimal because conodont and brachiopod assemblages above and below this surface are very similar, and it results from a latest Changhsingian transgression just before the extinction that follows a global latest Changhsingian regression. There is a distinct rapid end-Permian mass extinction at Selong within the Waagenites Bed, as indicated by the disappearances of all benthic brachiopods, rugose corals and Permian bryozoans. The burst of Clarkina species in the Waagenites Bed and throughout the

Lithofacies palaeogeography of the Upper Permian Changxing Stage in the Middle and Upper Yangtze Region, China

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He Youbin

2013-04-01

Full Text Available Based on the petrological study, according to single factor analysis and multifactor comprehensive mapping method, the quantitative lithofacies palaeogeography of the Upper Permian Changxing Stage of the Middle and Upper Yangtze Region was studied. The Changxing Stage in the Middle and Upper Yangtze Region is mainly composed of carbonate rocks; in addition, clastic and siliceous rocks occur with rare coals and pyroclastic rocks. Lithofacies can be divided into five types, including clastic rock assemblage, clastic rock–limestone assemblage, limestone assemblage, limestone–siliceous rock assemblage, and siliceous rock–clastic rock assemblage. Four fundamental ecological types and five fossil assemblages were recognized in the Changxing Stage. On the basis of the petrological and palaeoecological study, eight single factors were chosen including thickness, content of marine rocks, content of shallow water carbonate rocks, content of bioclasts with limemud matrix, content of bioclasts with sparry cement, distribution of reefs, content of thin bedded siliceous rocks and content of deep water sedimentary rocks. And eight single factor maps and one lithofacies paleogeographic map of the Changxing Stage were compiled. Paleoenvironments from west to east include an erosional area, fluvial plain, clastic platform, carbonate platform and reefs that developed there, slope and basin, low energy organic banks, and high energy organic banks. Sedimentary environments have an obvious control on the development of the source rocks, and the excellent source rocks are developed in the Dalong Formation. Changxing Stage reservoirs should be dominated by the reef and platform surrounding the Guangyuan–Liangping Basin rim area, and is the most favorable exploration area of the reef petroleum reservoirs of the Changxing Formation.

DURATION OF GRANITOID MAGMATISM IN PERIPHERAL PARTS OF LARGE IGNEOUS PROVINCES (BASED ON 40AR/39AR ISOTOPIC STUDIES OF ALTAI PERMIAN-TRIASSIC GRANITOIDS

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O. A. Gavryushkina

2017-01-01

Full Text Available In large igneous provinces (LIP of fold areas, granitoid rocks are dominant, while mantle-derivated rocks play a subordinate role in rock formation. If magma emissions are impulsive, it may take 25–30 million years for a LIP to form and take shape. In this paper, we present the results of 40Ar/39Ar isotopic studies of Permian-Triassic grani­toids in the Altai region, Russia, and clarify the evolution of this region located at the periphery of the Siberian LIP. These granitoids are very diverse and differ not only in their rock set, but also in the composition features. In the study region, the granodiorite-granite and granite-leucogranite association with the characteristics of I- and S-types as well rare metal ore-bearing leucogranites are observed along with gabbro- and syenite-granite series, including mafic and intermediate rocks with the A2-type geochemical features. The 40Ar/39Ar data obtained in our study suggest that most of the studied granitoids intruded within a short period of time, 254–247 Ma. This timeline is closely related to the formation of granitoids in theKuznetsk basin and dolerite dikes in the Terekta complex (251–248 and 255±5 Ma, respectively, as well as intrusions of lamproite and lamprophyre dikes of the Chuya complex (245–242 and 237–235 Ma. Thus, we conclude that the Altai Permian-Triassic granitoids are varied mainly due to the evolution of mafic magmatism.

Pre-Alpine (Variscan) Inheritance: A Key for the Location of the Future Valaisan Basin (Western Alps)

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Ballèvre, M.; Manzotti, P.; Dal Piaz, G. V.

2018-03-01

The boundary between the Helvetic and the Penninic (=Briançonnais) Zones has long been recognized as a major fault ("Penninic Front") in the Western Alps. A narrow oceanic domain has been postulated at least along part of this boundary (the Valaisan Basin). However, the information provided by the pre-Triassic basement has not been fully exploited and will be discussed here in detail. The igneous and metamorphic history of the pre-Triassic basement shows significant differences between the External Massifs from the Helvetic Zone, with abundant Late Carboniferous granites, and the basement of the Briançonnais Zone, including the Internal Massifs (Dora-Maira, Gran Paradiso, and Monte Rosa), devoid of Carboniferous granites. A major coal-bearing basin, the "Zone Houillère," opened along this boundary. This limnic intramontane basin has never been properly investigated. The Zone Houillère is not comparable with the external, paralic, flexural, basins on both sides of the Variscan belt but shows similarities with the Saar-Saale Basin. Like the latter, we interpret the Zone Houillère as a transtensional basin opened along a major, crustal-scale, fault zone, namely, the East Variscan Shear Zone. The Permian magmatism and sedimentation displays contrasting distributions, being absent or very localized in the Helvetic Zone, and widespread in the Penninic Zone. The above data indicate that the structural inheritance from the Variscan belt plays a major role in defining the future location of the Valaisan Basin, that is, the boundary between the European paleomargin and the Briançonnais microcontinent.

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

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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.

Integrated Sedimentological Approach to Assess Reservoir Quality and Architecture of Khuff Carbonates: Outcrop Analog, Central Saudi Arabia

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Osman, Mutsim; Abdullatif, Osman

2017-04-01

The Permian to Triassic Khuff carbonate reservoirs (and equivalents) in the Middle East are estimated to contain about 38.4% of the world's natural gas reserves. Excellent exposed outcrops in central Saudi Arabia provide good outcrop equivalents to subsurface Khuff reservoirs. This study conduct high resolution outcrop scale investigations on an analog reservoir for upper Khartam of Khuff Formation. The main objective is to reconstruct litho- and chemo- stratigraphic outcrop analog model that may serve to characterize reservoir high resolution (interwell) heterogeneity, continuity and architecture. Given the fact of the limitation of subsurface data and toolsin capturing interwell reservoir heterogeneity, which in turn increases the value of this study.The methods applied integrate sedimentological, stratigraphic petrographic, petrophysical data and chemical analyses for major, trace and rare earth elements. In addition, laser scanning survey (LIDAR) was also utilized in this study. The results of the stratigraphic investigations revealed that the lithofacies range from mudstone, wackestone, packestone and grainstone. These lithofacies represent environments ranging from supratidal, intertidal, subtidal and shoal complex. Several meter-scale and less high resolution sequences and composite sequences within 4th and 5th order cycles were also recognized in the outcrop analog. The lithofacies and architectural analysis revealed several vertically and laterally stacked sequences at the outcrop as revealed from the stratigraphic sections and the lidar scan. Chemostratigraphy is effective in identifying lithofacies and sequences within the outcrop analog. Moreover, different chemical signatures were also recognized and allowed establishing and correlating high resolution lithofacies, reservoir zones, layers and surfaces bounding reservoirs and non-reservoir zones at scale of meters or less. The results of this high resolution outcrop analog study might help to understand

Enhanced recycling of organic matter and Os-isotopic evidence for multiple magmatic or meteoritic inputs to the Late Permian Panthalassic Ocean, Opal Creek, Canada

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Georgiev, Svetoslav V.; Stein, Holly J.; Hannah, Judith L.; Henderson, Charles M.; Algeo, Thomas J.

2015-02-01

The geochemical record for the Permian-Triassic boundary in northern latitudes is essential to evaluation of global changes associated with the most profound extinction of life on Earth. We present inorganic and organic geochemical data, and Re-Os isotope systematics in a critical stratigraphic interval of pre- and post-extinction Upper Permian-Lower Triassic sediments from Opal Creek, western Canada (paleolatitude of ∼30°N). We document significant and long-lived changes in Panthalassa seawater chemistry that were initiated during the first of four magmatic or meteoritic inputs to Late Permian seawater, evidenced by notable decreases of Os isotopic ratios upsection. Geochemical signals indicate establishment of anoxic bottom waters shortly after regional transgression reinitiated sedimentation in the Late Permian. Euxinic signals are most prominent in the Upper Permian sediments with low organic carbon and high sulfur contents, and gradually wane in the Lower Triassic. The observed features may have been generated in a strongly euxinic ocean in which high bacterioplankton productivity sustained prolific microbial sulfate reduction in the sediment and/or water column, providing hydrogen sulfide to form pyrite. This scenario requires nearly complete anaerobic decomposition of predominantly labile marine organic matter (OM) without the necessity for a complete collapse of primary marine productivity. Similar geochemical variations could have been achieved by widespread oxidation of methane by sulfate reducers after a methanogenic burst in the Late Permian. Both scenarios could have provided similar kill mechanisms for the latest Permian mass extinction. Despite the moderate thermal maturity of the section, OM in all studied samples is dominantly terrestrial and/or continentally derived, recycled and refractory ancient OM. We argue that, as such, the quantity of the OM in the section mainly reflects changes in terrestrial vegetation and/or weathering, and not in

Sr-Nd-Pb isotope systematics of the Permian volcanic rocks in the northern margin of the Alxa Block (the Shalazhashan Belt) and comparisons with the nearby regions: Implications for a Permian rift setting?

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Shi, Guanzhong; Wang, Hua; Liu, Entao; Huang, Chuanyan; Zhao, Jianxin; Song, Guangzeng; Liang, Chao

2018-04-01

The petrogenesis of the Permian magmatic rocks in the Shalazhashan Belt is helpful for us to understand the tectonic evolution of the Central Asian Orogenic Belt (CAOB) in the northern margin of the Alxa Block. The Permian volcanic rocks in the Shalazhashan Belt include basalts, trachyandesites and trachydacites. Our study shows that two basalt samples have negative εNd(t) values (-5.4 to -1.5) and higher radiogenic Pb values, which are relevant to the ancient subcontinental lithospheric mantle. One basalt sample has positive εNd(t) value (+10) representing mafic juvenile crust and is derived from depleted asthenosphere. The trachyandesites are dated at 284 ± 3 Ma with εNd(t) = +2.7 to +8.0; ISr = 0.7052 to 0.7057, and they are generated by different degrees of mixing between mafic magmas and crustal melts. The trachydacites have high εNd(t) values and slightly higher ISr contents, suggesting the derivation from juvenile sources with crustal contamination. The isotopic comparisons of the Permian magmatic rocks of the Shalazhashan Belt, the Nuru-Langshan Belt (representing the northern margin of the Alxa Block), the Solonker Belt (Mandula area) and the northern margin of the North China Craton (Bayan Obo area) indicate that the radiogenic isotopic compositions have an increasingly evolved trend from the south (the northern margins of the Alxa Block and the North China Craton) to the north (the Shalazhashan Belt and the Solonker Belt). Three end-member components are involved to generate the Permian magmatic rocks: the ancient subcontinental lithospheric mantle, the mafic juvenile crust or newly underplated mafic rocks that were originated from depleted asthenosphere, and the ancient crust. The rocks correlative with the mafic juvenile crust or newly underplated mafic rocks are predominantly distributed along the Shalazhashan Belt and the Solonker Belt, and the rocks derived from ancient, enriched subcontinental lithospheric mantle are mainly distributed along

Photogeology: Part D: Descartes highlands: possible analogs around the Orientale Basin

Science.gov (United States)

Hodges, Carroll Ann

1972-01-01

The Descartes highlands are adjacent to the terra plain on which the Apollo 16 lunar module landed (fig. 29-13). A variety of volcanic origins was proposed for the highlands before the mission (refs. 29-4, 29-21, and 29-35 to 29-37), but the returned samples of the area consist almost exclusively of nonvolcanic breccias. The breccias obtained from Stone Mountain have not been identified conclusively as sample materials of the Descartes Mountains (ref. 29-35). A volcanic origin is thus not yet precluded (sec. 6 of this report), but a review of possible impact-related origins seems to be appropriate. The orbital photography acquired during the Apollo 16 mission provides excellent imagery on which geomorphic interpretations may be based. No obvious local crater is a plausible source of the material, but there may be a relation to either the Nectaris or Imbrium Basin. The less degraded Orientale Basin (fig. 29-24) provides a model by which these comparisons can be made (part F of this section).

Rifting in heterogeneous lithosphere inferences from numerical modeling of the northern North Sea and the Oslo Graben.

NARCIS (Netherlands)

Pascal Candas, C.; Cloetingh, S.A.P.L.

2002-01-01

Permian rifting and magmatism are widely documented across NW Europe. The different Permian basins often display contrasting structural styles and evolved in lithospheric domains with contrasting past evolution and contrasting thermotectonic ages. In particular, the Oslo Graben and the northern

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

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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

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

International Nuclear Information System (INIS)

Marshallsea, S.J.

1987-01-01

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

Integrating petroleum and sulfur data to map the Guadalupian-Ochoan (Middle to Upper Permian) Boundary of the Delaware Basis, Trans-Pecos, Texas

Science.gov (United States)

Dishron, Joseph B.

2011-12-01

The Delaware Basin of the Permian Basin is a classic intra-cratonic basin of West Texas and Southeast New Mexico. Hydrocarbon exploration and production have occurred in the region since the early 1920s, and, as a result, the formations related to these oil and gas reserves have been studied in great detail. Some formations in the Delaware Basin, however, have not been studied in such detail, and this thesis examines one, lesser-known unit that could have economic potential. The Lamar Limestone (Lamar Lime) of the Bell Canyon Formation has commonly been dismissed as a production interval; rather, it has been described as a source and seal rock for the Ramsey Sand of the lower Bell Canyon Formation. However, recent studies found that the Lamar Lime was contributing to production, and it has been described by Trentham (2006) as a potentia "mini Barnett" reservoir. The depths of these deposits are in a range that is ideal for oil accumulation. This study made use of data from wells and test holes drilled in the western Delaware Basin, Culberson County, Texas. Many oil and gas wells have been drilled in the western Delaware Basin, but they are concentrated in the north and east portions of Culberson County. In addition, sulfur wells were drilled in the area in the late 1960s and early 1970s. Analyses of the well logs of these wells and of core and outcrop studies were completed to gain a better understanding of the distribution and economic potential of the Lamar. Both datasets were combined to provide information not readily available in the oil and gas dataset. The Lamar Lime is an excellent marker bed because it underlies thick evaporites. The evaporite sequences are Ochoan in age, and, therefore, the contact of the Lamar Lime (Bell Canyon Formation) and the Castile Formation is the approximate boundary for the Guadalupian-Ochoan Series. The Castile Formation, the Salado Formation, and the Rustler Formation (from oldest to youngest) are the evaporite units that

Permian Tethyan Fusulinina from the Kenai Peninsula, Alaska

Science.gov (United States)

Stevens, C.H.; Davydov, V.I.; Bradley, D.

1997-01-01

Two samples from a large, allochthonous limestone block in the McHugh Complex of the Chugach terrane on the Kenai Peninsula, Alaska, contain species of 12 genera of Permian Fusulinina including Abadehella, Kahlerina, Pseudokahlerina?, Nankinella, Codonofusiella, Dunbarula, Parafusulina?, Chusenella, Verbeekina, Pseudodoliolina, Metadoliolina?, Sumatrina?, and Yabeina, as well as several other foraminiferans and one alga. The assemblage of fusulinids is characteristically Tethyan, belonging to the Yabeina archaica zone of early Midian (late Wordian) age. Similar faunas are known from the Pamirs, Transcaucasia, and Japan, as well as from allochthonous terranes in British Columbia, northwestern Washington, and Koryakia in eastern Siberia.

Analog model study of the ground-water basin of the Upper Coachella Valley, California

Science.gov (United States)

Tyley, Stephen J.

1974-01-01

An analog model of the ground-water basin of the upper Coachella Valley was constructed to determine the effects of imported water on ground-water levels. The model was considered verified when the ground-water levels generated by the model approximated the historical change in water levels of the ground-water basin caused by man's activities for the period 1986-67. The ground-water basin was almost unaffected by man's activities until about 1945 when ground-water development caused the water levels to begin to decline. The Palm Springs area has had the largest water-level decline, 75 feet since 1986, because of large pumpage, reduced natural inflow from the San Gorgonio Pass area, and diversions of natural inflows at Snow and Falls Creeks and Chino Canyon starting in 1945. The San Gorgonio Pass inflow had been reduced from about 18,000 acre-feet in 1986 to about 9,000 acre-feet by 1967 because of increased ground-water pumpage in the San Gorgonio Pass area, dewatering of the San Gorgonio Pass area that took place when the tunnel for the Metropolitan Water District of Southern California was drilled, and diversions of surface inflow at Snow and Falls Creeks. In addition, 1944-64 was a period of below-normal precipitation which, in part, contributed to the declines in water levels in the Coachella Valley. The Desert Hot Springs, Garnet Hill, and Mission Creek subbasins have had relatively little development; consequently, the water-level declines have been small, ranging from 5 to 15 feet since 1986. In the Point Happy area a decline of about 2 feet per year continued until 1949 when delivery of Colorado River water to the lower valley through the Coachella Canal was initiated. Since 1949 the water levels in the Point Happy area have been rising and by 1967 were above their 1986 levels. The Whitewater River subbasin includes the largest aquifer in the basin, having sustained ground-water pumpage of about 740,000 acre-feet from 1986 to 1967, and will probably

Biogenic silica microfossils in sediments of the Permian - Carboniferous Unayzah Formation, Saudi Arabia

NARCIS (Netherlands)

Garming, J.F.L.; Franks, S.G.; Cremer, H.; Abbink, O.A.

2010-01-01

Biogenic silica particles (BSPs) have been discovered in sediments of the Permian - Carboniferous Unayzah Formation of Saudi Arabia. The BSPs are extracted from sediments that are generally barren of macro- or microfossils. BSPs have been found in the Basal Khuff Clastics (BKC), and the Unayzah A,

Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

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E. E. van Soelen

2018-04-01

Full Text Available The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian–Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction

Conodont color alteration index and upper Paleozoic thermal history of the Amazonas Basin, Brazil

Science.gov (United States)

Cardoso, Cassiane Negreiros; Sanz-López, Javier; Blanco-Ferrera, Silvia; Lemos, Valesca Brasil; Scomazzon, Ana Karina

2015-12-01

The conodont color alteration index (CAI) was determined in elements from core samples of the Frasnian Barreirinha Formation (one well) and of the Pennsylvanian-Permian Tapajós Group (twenty three wells and one limestone quarry) in the Amazonas Basin. The thermal history of the basin is analyzed using the CAI value distribution represented in maps and stratigraphic sections through correlation schemes, and in conjunction with previously published data. The pattern of palaeotemperatures for CAI values of 1.5-3 is coincident with organic matter maturation under a sedimentary overburden providing diagenetic conditions in the oil/gas window. Locally, conodonts show metamorphism (CAI value of 6-7) in relation to the intrusion of diabase bodies in beds including high geothermal gradient evaporites. Microtextural alteration on the surface conodonts commonly shows several types of overgrowth microtextures developed in diagenetic conditions. Locally, recrystallization in conodonts with a high CAI value is congruent with contact metamorphism in relation to Mesozoic intrusions. The CAI values of 1.5 or 2 observed close to the surface in several areas of the basin may be interpreted in relation to a high thermal palaeogradient derived from the magmatic episode or/and to the local denudation of the upper part of the Paleozoic succession prior to this thermal event.

Laboratory testing of rock and salt samples for determination of specific gravity and total porosity of the Zeeck No. 1 well (PD-7), Palo Duro Basin, Texas: unanalyzed data

International Nuclear Information System (INIS)

1984-07-01

This report contains the specific gravity and total porosity determinations for rock and salt samples from Zeeck No. 1 Well of the Permian Basin. The laboratory test samples were measured for water content, apparent specific gravity, specific gravity of solids, total porosity and effective porosity. Specimen descriptions including specimen number, formation/group, and lithologic description as well as typical data sheets are included in the appendices. These data are preliminary. They have been neither analyzed nor evaluated

Nanometre-sized pores in coal: Variations between coal basins and coal origin

Science.gov (United States)

Sakurovs, Richard; Koval, Lukas; Grigore, Mihaela; Sokolava, Anna; Ruppert, Leslie F.; Melnichenko, Yuri B.

2018-01-01

We have used small angle neutron scattering (SANS) to investigate the differences in methane and hexane penetration in pores in bituminous coal samples from the U.S., Canada, South Africa, and China, and maceral concentrates from Australian coals. This work is an extension of previous work that showed consistent differences between the extent of penetration by methane into 10–20 nm size pores in inertinite in bituminous coals from Australia, North America and Poland.In this study we have confirmed that there are differences in the response of inertinite to methane and hexane penetration in coals sourced from different coal basins. Inertinite in Permian Australian coals generally has relatively high numbers of pores in the 2.5–250 nm size range and the pores are highly penetrable by methane and hexane; coals sourced from Western Canada had similar penetrability to these Australian coals. However, the penetrability of methane and hexane into inertinite from the Australian Illawarra Coal Measures (also Permian) is substantially less than that of the other Australian coals; there are about 80% fewer 12 nm pores in Illawarra inertinite compared to the other Australian coals examined. The inertinite in coals sourced from South Africa and China had accessibility intermediate between the Illawarra coals and the other Australian coals.The extent of hexane penetration was 10–20% less than CD4 penetration into the same coal and this difference was most pronounced in the 5–50 nm pore size range. Hexane and methane penetrability into the coals showed similar trends with inertinite content.The observed variations in inertinite porosity between coals from different coal regions and coal basins may explain why previous studies differ in their observations of the relationships between gas sorption behavior, permeability, porosity, and maceral composition. These variations are not simply a demarcation between Northern and Southern Hemisphere coals.

Nonmarine time-stratigraphy in a rift setting: An example from the Mid-Permian lower Quanzijie low-order cycle Bogda Mountains, NW China

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Jonathan Obrist-Farner

2015-01-01

Full Text Available Sedimentological and stratigraphic studies of seven stratigraphic sections of Permian Hongyanchi (HYC and Quanzijie (QZJ low-order cycles (LCs in the Tarlong-Taodonggou half graben and Dalongkou area in Bogda Mountains, NW China, demonstrate effective approaches and methodology in cyclo- and time-stratigraphic analyses of complex fluvial-lacustrine deposits in an intracontinental rift setting. A new synchronous stratigraphic unit, the lower QZJ LC is defined. The lower and upper boundaries of this cycle include a regionally correlative disconformity, erosional unconformity, and conformity, across which significant and abrupt changes in palaeoenvironments and tectonic and climatic conditions occurred. The lower boundary is an erosional unconformity and disconformity with a high-relief topography that juxtaposes lacustrine deposits of the underlying HYC LC with the overlying meandering stream deposits of the lower QZJ LC, and was caused by a regional tectonic uplift. The upper boundary is a disconformity and local erosional unconformity and conformity, juxtaposing stacked paleosols developed on fluvial sediments with overlying fluvial and loessial deposits of the upper QZJ LC. The paleosols indicate landscape stability and a prolonged period of subaerial exposure and minimal deposition and suggest that climatic conditions were semi-arid with strong precipitation seasonality in the Tarlong-Taodonggou half graben and subhumid in the Dalongkou area. The fluvial-loessial deposits indicate a renewed tectonic uplift and a change in the atmospheric circulation pattern. The newly-defined lower QZJ LC facilitates accurate palaeogeographic reconstruction in the study area during a period of major tectonic and climatic changes. The interpreted tectonic and climatic conditions provide a critical data point in the mid-latitude east coast of NE Pangea during the Mid-Permian icehouse-hothouse transition. The results demonstrate that a process-response approach

Discussion on the exploration & development prospect of shale gas in the Sichuan Basin

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Dazhong Dong

2015-01-01

Full Text Available The Sichuan Basin, a hotspot and one of the most successful areas for shale gas exploration and development, can largely reflect and have a big say in the future prospect of shale gas in China. Through an overall review on the progress in shale gas exploration and development in the Sichuan Basin, we obtained the following findings: (1 the Sichuan Basin has experienced the marine and terrestrial depositional evolution, resulting in the deposition of three types of organic-matter-rich shales (i.e. marine, transitional, and terrestrial, and the occurrence of six sets of favorable shale gas enrichment strata (i.e. the Sinian Doushantuo Fm, the Cambrian Qiongzhusi Fm, the Ordovician Wufeng–Silurian Longmaxi Fm, the Permian Longtan Fm, the Triassic Xujiahe Fm, and the Jurassic Zhiliujing Fm; (2 the five key elements for shale gas accumulation in the Wufeng-Longmaxi Fm are deep-water shelf facies, greater thickness of organic-rich shales, moderate thermal evolution, abundant structural fractures, reservoir overpressure; and (3 the exploration and development of shale gas in this basin still confronts two major challenges, namely, uncertain sweet spots and potential prospect of shale gas, and the immature technologies in the development of shale gas resources at a depth of more than 3500 m. In conclusion, shale gas has been discovered in the Jurassic, Triassic and Cambrian, and preliminary industrial-scale gas has been produced in the Ordovician-Silurian Fm in the Sichuan Basin, indicating a promising prospect there; commercial shale gas can be produced there with an estimated annual gas output of 30–60 billion m3; and shale gas exploration and production experiences in this basin will provide valuable theoretical and technical support for commercial shale gas development in China.

Detecting analogical resemblance without retrieving the source analogy.

Science.gov (United States)

Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

2010-06-01

We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

Extension of the Parana Basin to offshore Brazil: Implications for coalbed methane evaluation

Energy Technology Data Exchange (ETDEWEB)

Holz, M.; Kalkreuth, W.; Rolim, S.B.A. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

2010-05-15

Coalbed methane (CBM) is a worldwide exploration target of the petroleum industry. In Brazil, the most important coal-bearing succession is associated with the Permian Rio Bonito Formation of the Parana Basin. The gas-prone areas are located at the southeastern margin of the Parana Basin and possibly in the offshore region of the northern part of the Pelotas Basin. Coalfields end abruptly at the present day shoreline, a result of rifting of Gondwana and the evolution of the South Atlantic Ocean. All geologic indicators suggest that in pre-rift times the coal seams extended further eastwards, probably now lying deeply buried below the sedimentary succession of the Pelotas Basin. The present paper discusses structural, stratigraphic, seismic and aeromagenetic data that support the preservation of continental crust beneath ocean sediment. If the coal beds had similar lateral extent to known onshore coals, and coal beds extended across the projected extension of the Parana basin, and there was a conservative 5 m of cumulative coal thickness, then a potential methane volume can be estimated for this newly inferred resource. Average onshore coal gas content is 32 scf/ton (1.00 m(3)/ton). If this is similar in the offshore coal deposits, then the hypothetical methane volume in the offshore area could be in excess of 1.9 x 10(12) scf (56 x 10(9) m(3)). Metamorphism from dikes associated with rifting are potential complicating factors in these deposits, and since no borehole reaching the deep-lying strata in the offshore area are available, this is a hypothetical gas resource with a certain level of uncertainty which should be tested in the future by drilling a deep borehole.

Signature recognition for rift structures of different sediment strata in ordos basin

International Nuclear Information System (INIS)

Zhao Xigang

2006-10-01

The rift structure weak information of high Bouguer gravity anomaly data among different Sediment strata are extracted By the horizontal gradient Maximum modulus, the wavelet variation, stripped gravity anomaly of basement and interfaces above/under researched layer, image processing method. So the linear rift structures of different Sediment strata are recognized on data images, such as Cretaceous, Jurassic, Triassic, Permian and Carboniferous, Ordovician System. Development rifts of different Sediment strata occur in stereo structure with quasi-uniform spacing, the rift density of above Sediment stratum is more than lower in different Sediment strata, but the north rift density of the same Sediment stratum is less than south's. It is useful to study rift structure and co-explore for oil, gas, coal and uranium resources in Ordos Basin. (authors)

Estimates of ground-water recharge rates for two small basins in central Nevada

Science.gov (United States)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins. two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. The first model uses a traditional approach to quantify watershed hydrology through a precipitation-runoff modeling system that accounts for the spatial variability of hydrologic inputs, processes, and responses (outputs) using a dailycomputational time step. The second model is based on the conservative nature of the dissolved chloride ion in selected hydrologic environments, and its use as a natural tracer allows the computation of acoupled, water and chloride-ion, mass-balance system of equations to estimate available water (sum ofsurface runoff and groundwater recharge). Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-12-15

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

Tectonic model for the Late Paleozoic of southeastern New England

Energy Technology Data Exchange (ETDEWEB)

Wintsch, R.P.; Sutter, J.F.

1986-07-01

Hornblende and biotite /sup 40/Ar//sup 39/Ar age spectra from rocks in south-central Connecticut help define a Permian-Triassic cooling curve for the area. Together with petrologic and structural information, a time-temperature-pressure-strain path is established. Similar data for the Narragansett basin in Rhode Island and Massachusetts allow correlation of the late Paleozoic histories of the two areas. Together, these data suggest that in the late Paleozoic, south-central New England was part of a fold-thrust belt, and the Narragansett basin was a retroarc foreland basin. NW-SE compression during the final assembly of Pangaea resulted in SE directed thrusting, causing the development of clastic wedges in adjacent Rhode Island and Massachusetts in the Late Carboniferous-Early Permian. A clockwise rotation of this deformation from NW to NNE led to northward underthrusting and concomitant uplift of both eastern Connecticut and Rhode Island in the Permian and Triassic.

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 Mesozoic rift basins of eastern North America: Potential reservoir or Explorationist's folly

Energy Technology Data Exchange (ETDEWEB)

Pyron, A.

1991-08-01

Mesozoic rift basins are found on the East Coast of North America from Georgia to Nova Scotia. The basins formed as a result of extensional activity associated with the breakup of Pangaea. The internal geometry of the basins includes a depositional sequence ranging from coarse fanglomerates to fine-grained siltstones and argillites. Since these Mesozoic rift basins were first studied, they have not been considered to be likely spots for hydrocarbon accumulations. Recently, geologists have reconsidered these Mesozoic basins and have developed a more synergistic approach that suggests that many of these rift basins might be suitable targets for exploration. By analogy, these Mesozoic basins are correlative to similar basins in northwestern Africa, where significant reserved of oil and natural gas have been developed. The similarity between the productive basins in northwestern Africa and the Mesozoic basins of North America and their proximity to major markets provides sufficient rationale to further investigate these basins.

Biostratigraphy and event stratigraphy in Iran around the Permian Triassic Boundary (PTB): Implications for the causes of the PTB biotic crisis

Science.gov (United States)

Kozur, H. W.

2007-01-01

The conodont succession and stratigraphic events around the Permian-Triassic boundary (PTB) have been investigated in detail in the open sea deposits of Iran (Abadeh and Shahreza in central Iran, and Jolfa and Zal in northwestern Iran). This investigation produced a very detailed conodont zonation from the Clarkina nodosa Zone up to the Isarcicella isarcica Zone. All significant events have been accurately located and dated within this zonation, and the duration of most of these conodont zones has been calculated by cross-correlation with continental lake deposits that display obvious Milankovitch cyclicity. The unusually short duration of all conodont zones in the interval from the C. nodosa up to the Hindeodus parvus Zone indicates that there was persistent high ecological stress during this time interval. Most of the conodont zones can be accurately correlated with South China. In the interval from the C. hauschkei Zone to the H. parvus Zone, even correlation with the Arctic is possible. Within three thin stratigraphic intervals, the Changhsingian (Dorashamian) warm water conodont fauna of the C. subcarinata lineage is replaced by a cool water fauna with small H. typicalis, rare Merrillina sp., and cool water Clarkina that have very widely spaced denticles. The uppermost cool water fauna horizon comprises the lower C. zhangi Zone and can be accurately correlated with continental beds by recognition of a short reversed magnetozone below the long uppermost Permian-lowermost Triassic normal magnetozone. In Iran and Transcaucasia, this short reversed zone comprises the upper C. changxingensis- C. deflecta Zone and most of the C. zhangi Zone. Its top lies 50 cm below the top of the Paratirolites Limestone (s.s.) in the Dorasham 2 section, which is at the beginning of the upper quarter of the C. zhangi Zone. In the Germanic Basin, this short palaeomagnetic interval comprises the lower and the basal part of the upper Fulda Formation. On the Russian Platform, the

Permian-Triassic thermal anomaly of the active margin of South America as a result of plate kinematics reorganization

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Riel, Nicolas; Jaillard, Etienne; Guillot, Stéphane; Martelat, Jean-Emmanuel; Braun, Jean

2013-04-01

From Permian to Triassic times, tectonic plate reorganization provoked Pangaea breakup, counterclockwise rotation of Gondwana, closing of the Paleo-Tethys Ocean and opening of the Neo-Tethys oceanic realm. Meanwhile, the switch from arc volcanism to widespread S-type magmatism along the western South American active margin around 275-265 Ma is symptomatic of the onset of a large-scale Permian-Triassic thermal anomaly (PTTA)affecting the whole margin. Here we report metamorphic and U-Pb geochronological results from the El Oro metamorphic complex in the forearc zone of southwestern Ecuador, which recorded the last step, at 230-225 Ma, of the PTTA. The change in the drift direction of Gondwana from north to east at ca. 270 Ma was related to plate reorganization and provoked the verticalization of the subducted Panthalassa slab. As the slab verticalized, strong heat advection produced a high heat flow beneath the active margin inducing the development of a huge thermal anomaly responsible for the PTTA, which lasted 30 Ma. This voluminous magmatic activity culminated at the Permian-Triassic boundary, and may have contributed to the degradation of life conditions on the Earth surface.

Late Permian wood-borings reveal an intricate network of ecological relationships.

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Feng, Zhuo; Wang, Jun; Rößler, Ronny; Ślipiński, Adam; Labandeira, Conrad

2017-09-15

Beetles are the most diverse group of macroscopic organisms since the mid-Mesozoic. Much of beetle speciosity is attributable to myriad life habits, particularly diverse-feeding strategies involving interactions with plant substrates, such as wood. However, the life habits and early evolution of wood-boring beetles remain shrouded in mystery from a limited fossil record. Here we report new material from the upper Permian (Changhsingian Stage, ca. 254-252 million-years ago) of China documenting a microcosm of ecological associations involving a polyphagan wood-borer consuming cambial and wood tissues of the conifer Ningxiaites specialis. This earliest evidence for a component community of several trophically interacting taxa is frozen in time by exceptional preservation. The combination of an entry tunnel through bark, a cambium mother gallery, and up to 11 eggs placed in lateral niches-from which emerge multi-instar larval tunnels that consume cambium, wood and bark-is ecologically convergent with Early Cretaceous bark-beetle borings 120 million-years later.Numerous gaps remain in our knowledge of how groups of organisms interacted in ancient ecosystems. Here, Feng and colleagues describe a late Permian fossil wood-boring beetle microcosm, with the oldest known example of complex tunnel geometry, host tissue response, and the presence of fungi within.

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

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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.

Multiple episodes of extensive marine anoxia linked to global warming and continental weathering following the latest Permian mass extinction.

Science.gov (United States)

Zhang, Feifei; Romaniello, Stephen J; Algeo, Thomas J; Lau, Kimberly V; Clapham, Matthew E; Richoz, Sylvain; Herrmann, Achim D; Smith, Harrison; Horacek, Micha; Anbar, Ariel D

2018-04-01

Explaining the ~5-million-year delay in marine biotic recovery following the latest Permian mass extinction, the largest biotic crisis of the Phanerozoic, is a fundamental challenge for both geological and biological sciences. Ocean redox perturbations may have played a critical role in this delayed recovery. However, the lack of quantitative constraints on the details of Early Triassic oceanic anoxia (for example, time, duration, and extent) leaves the links between oceanic conditions and the delayed biotic recovery ambiguous. We report high-resolution U-isotope (δ 238 U) data from carbonates of the uppermost Permian to lowermost Middle Triassic Zal section (Iran) to characterize the timing and global extent of ocean redox variation during the Early Triassic. Our δ 238 U record reveals multiple negative shifts during the Early Triassic. Isotope mass-balance modeling suggests that the global area of anoxic seafloor expanded substantially in the Early Triassic, peaking during the latest Permian to mid-Griesbachian, the late Griesbachian to mid-Dienerian, the Smithian-Spathian transition, and the Early/Middle Triassic transition. Comparisons of the U-, C-, and Sr-isotope records with a modeled seawater PO 4 3- concentration curve for the Early Triassic suggest that elevated marine productivity and enhanced oceanic stratification were likely the immediate causes of expanded oceanic anoxia. The patterns of redox variation documented by the U-isotope record show a good first-order correspondence to peaks in ammonoid extinctions during the Early Triassic. Our results indicate that multiple oscillations in oceanic anoxia modulated the recovery of marine ecosystems following the latest Permian mass extinction.

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

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

2010-01-07

During the late Permian (Kungurian to Kazanian) a Neotethyan rift basin evolved at the western boundary of the Arabian Plate, in what is called today the Dead Sea Valley of western Jordan. The break-up of Pangaea was accompanied by low-sinuosity sandy braided- to meandering-fluvial drainage systems which were fed by the uplift of the Arabian Shield and by poorly aerated swamps and ponds that concentrated plant debris of the Cathaysian floral province in the Um Irna Formation. These proximal wet fan sediments are overlain by a dry fan characterized by extensive reddish floodplain deposits, anastomosing channel systems and paleosols. The wet fan is underlain by Cambrian sandstones. These units serve as the top and bottom seals of the OM-bearing system of the Um Irna Formation. The sedimentary rocks of the OM-bearing Um Irna Formation underwent supergene, diagenetic and epigenetic hydrothermal alteration under an elevated geothermal gradient. The temperature increased from the time of deposition of the wet to the time of deposition of the dry fan and caused remobilization of manganese already pre-concentrated in the Cambrian footwall rocks of the rift basin. The anomalous heat regime may be accounted for as a predecessor stage of the Dead Sea Rift which is still active today. Oil seeps are found along faults and fractures near this deep-seated lineamentary fault zone. The deposition and alteration of the organic matter in this late Permian rift are of great consequence for oil generation in the region. Organic petrographic investigations revealed that organic-rich terrestrial carbonaceous and coal rich sediments of mainly of type III kerogen are dominant in the Um Irna Formation. In addition, aquatic liptinite rich sedimentary input (fresh water lake and/or lacustrine swamp) of type I kerogen is also noted. Coal derived organic matter occurs in the form of coaly particles with ranks from subbituminous A to high volatile bituminous C. Higher plant-derived macerals as

Flourishing ocean drives the end-Permian marine mass extinction.

Science.gov (United States)

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

2015-08-18

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

Report of the panel on evaluation of ground-water flow in fractures at the Palo Duro Basin, Texas: Unanalyzed data: Technical report

International Nuclear Information System (INIS)

1988-01-01

A peer review group of hydrologists assessed the importance and availability of data on fracture-controlled ground-water flow at the Palo Duro Basin sites in the Permian Basin in Texas. After hearing presentations by US Department of Energy staff and consultants, and reviewing existing literature, they formed a conceptual model of basin flow that is downward across the salt facies and downdip in permeable formation in the lower hydrostratigraphic unit. Flow volumes and rates are very low. The panel examined several possible fracture-flow scenarios and concluded that flow within the salt section is probably porous-media-dominated with some fracture-flow influence in brittle zones. Fracture flow in the salt itself is rejected as a possibility based on current evidence. However, the panel recommended that fracture flow in the system should be included as a low-probability variable in any hydrogeologic modeling. They also concluded that many more data on lineament features and subsurface structures are needed to accurately characterize the system and to refine the modeling effort. 9 refs., 2 figs

Magnetic microsperules in Permian and Triassic bedded chert from Southwest Japan

OpenAIRE

Iwahashi,Junko; Yoshida,Masaru; Miono,Shigeyoshi; Santosh,Geetha; Santosh,M.

1991-01-01

Magnetic microspherules collected from the Permian and Triassic bedded cherts in Southwest Japan were studied. The size range, as estimated from 801 microspherules, vary from 3 to 100μm, with a peak size distribution between 10-20μm. Three broad shapes are recognized : spherical-, drop- and rocket-shaped, all categories including hollow particles. The surface textures as studied from scanning electron microscope show five dominant varieties : random mosaic, dendritic mosaic, feather crystal, ...

Carboniferous - Early Permian magmatic evolution of the Bogda Range (Xinjiang, NW China): Implications for the Late Paleozoic accretionary tectonics of the SW Central Asian Orogenic Belt

Science.gov (United States)

Wali, Guzalnur; Wang, Bo; Cluzel, Dominique; Zhong, Linglin

2018-03-01

The Late Paleozoic magmatic evolution of the Bogda Range (Chinese North Tianshan) is important for understanding the accretionary history of the Central Asian Orogenic Belt. We investigated the Carboniferous and Lower Permian volcanic and sedimentary sequences of the Daheyan section, southern Bogda Range, and present new zircon U-Pb ages and whole-rock geochemical data for the volcanic rocks. One Carboniferous rhyolite is dated at 298 ± 8 Ma; a Permian basalt yielded many Proterozoic zircon xenocrysts, and its maximum age (∼297 Ma) is constrained by the detrital zircon ages of the sandstone that stratigraphically underlies it. These volcanic rocks belong to calc-alkaline series. We further synthesize previous geochronological, geochemical and isotopic data of magmatic and sedimentary rocks in the Bogda Range. The available data indicate that the magmatism occurred continuously from 350 Ma to 280 Ma. A comprehensive analysis allows us to propose that: (1) the Carboniferous to Early Permian magmatic rocks of the Bogda Range generally show consistent arc-type features; (2) increasing mantle input through time suggests intra-arc extension in a supra-subduction zone; (3) the localized occurrence of Early Permian alkaline pillow basalts and deep water sediments close to the major shear zone advocate a transtensional crustal thinning during the transition from Carboniferous convergence to Early Permian transcurrent tectonics; (4) occurrence of a large number of Proterozoic zircon xenocrysts in the Late Paleozoic magmatic rocks, and Proterozoic detrital zircons in the coeval clastic sediments suggest a continental or transitional basement of the Bogda Arc; (5) subduction in the Bogda area terminated prior to the deposition of Middle Permian terrestrial sediments.

Late Paleozoic fusulinids from Sonora, Mexcio: importance for interpretation of depositional settings, biogeography, and paleotectonics

Science.gov (United States)

Stevens, Calvin H.; Poole, Forrest G.; Amaya-Martínez, Ricardo

2014-01-01

Three sets of fusulinid faunas in Sonora, Mexico, discussed herein, record different depositional and paleotectonic settings along the southwestern margin of Laurentia (North America) during Pennsylvanian and Permian time. The settings include: offshelf continental rise and ocean basin (Rancho Nuevo Formation in the Sonora allochthon), shallow continental shelf (La Cueva Limestone), and foredeep basin on the continental shelf (Mina México Formation). Our data represent 41 fusulinid collections from 23 localities with each locality providing one to eight collections.Reworked fusulinids in the Middle and Upper Pennsylvanian part of the Rancho Nuevo Formation range in age from Desmoinesian into Virgilian (Moscovian-Gzhelian). Indigenous Permian fusulinids in the La Cueva Limestone range in age from middle or late Wolfcampian to middle Leonardian (late Sakmarian-late Artinskian), and reworked Permian fusulinids in the Mina México Formation range in age from early to middle Leonardian (middle-late Artinskian). Conodonts of Guadalupian age occur in some turbidites in the Mina México Formation, indicating the youngest foredeep deposit is at least Middle Permian in age. Our fusulinid collections indicate a hiatus of at least 10 m.y. between the youngest Pennsylvanian (Virgilian) rocks in the Sonora allochthon and the oldest Permian (middle Wolfcampian) rocks in the region.Most fusulinid faunas in Sonora show affinities to those of West Texas, New Mexico, and Arizona; however, some genera and species are similar to those in southeastern California. As most species are similar to those east of the southwest-trending Transcontinental arch in New Mexico and Arizona, this arch may have formed a barrier preventing large-scale migration and mixing of faunas between the southern shelf of Laurentia in northwestern Mexico and the western shelf in the southwestern United States.The Sonora allochthon, consisting of pre-Permian (Lower Ordovician to Upper Pennsylvanian) deep

Body size reductions in nonmammalian eutheriodont therapsids (Synapsida) during the end-Permian mass extinction.

Science.gov (United States)

Huttenlocker, Adam K

2014-01-01

The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the 'Lilliput effect,' a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts) using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion) models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma) consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1) active, directional evolution in size traits is rare over macroevolutionary time scales and 2) geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns.

Structural geology of the Rub' Al-Khali Basin, Saudi Arabia

Science.gov (United States)

Stewart, S. A.

2016-10-01

The Rub' Al-Khali basin lies below a Quaternary sand sea, and the structural evolution from the Late Precambrian to Neogene is known only from reflection seismic, gravity, and magnetic data, and wells. Gravity and magnetic data show north-south and northwest-southeast trends, matching mapped Precambrian faults. The deepest structures imaged on reflection seismic data are undrilled Precambrian rifts filled with layered strata at depths up to 13 km. The distribution of Ediacaran-Cambrian Ara/Hormuz mobile salt is restricted to an embayment in the eastern Rub' Al-Khali. The Precambrian rifts show local inversion and were peneplained at base Phanerozoic. A broad crustal-scale fold (Qatar Arch) developed in the Carboniferous and amplified in the Late Triassic, separating subbasins in the west and east Rub' Al-Khali. A phase of kilometer-scale folding occurred in the Late Cretaceous, coeval with thrusting and ophiolite obduction in eastern Oman. These folds trend predominantly north-south, oblique to the northwesterly shortening direction, and occasionally have steep fault zones close to their axial surfaces. The trend and location of these folds closely matches the Precambrian lineaments identified in this study, demonstrating preferential reactivation of basement structures. Compression along the Zagros suture reactivated these folds in the Neogene, this time the result of highly oblique, north-northeast to south-southwest shortening. Cretaceous-Tertiary fold style is interpreted as transpression with minor strain partitioning. Permian, Jurassic, and Eocene evaporite horizons played no role in the structural evolution of the basin, but the Eocene evaporites caused widespread kilometer-scale dissolution collapse structures in the basin center.

The continental Permian-Triassic boundary in the Netherlands: Implications for the geomagnetic polarity time scale

NARCIS (Netherlands)

Szurlies, M.; Geluk, M.C.; Krijgsman, W.; Kürschner, W.M.

2012-01-01

In Central and NW Europe, the transition from the Permian to the Triassic (i.e., the Zechstein–Buntsandstein boundary interval) is developed mainly in red bed facies. This continental sedimentary succession is marked by relatively high sedimentation rates providing a high temporal resolution

A latest Permian non-reef calcisponge fauna from Laibin, Guangxi, southern China and its significance

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Ya-Sheng Wu

2017-01-01

Full Text Available A calcisponge fauna occurs in uppermost Permian Conodont Clarkina meishanensis yini zone of the sequence exposed in the vicinity of Laibin, Guangxi Zhuang Autonomous Region, southern China. The fauna is dominated by one thalamid species, Amblysiphonella vesiculosa de Koninck, 1863, and one new sclerosponge genus and species, Radiofibrosclera laibinensis gen. et sp. nov. They are associated with a few other accessory species, including the thalamid sponges Amblysiphonella laibinensis Deng, 1981, Colospongia sp., Polycystocoelia sp., and the inozoan sponge Acoelia discontinua sp. nov. Though the individuals are abundant, the species diversity is very low. Without common calcisponge components of Changhsingian reefal faunas, the assemblage is interpreted as not a reefal fauna. The water depth at which they dwelled was less than 105 m, and more probably less than 40 m. Its occurrence indicates a significant sea-level drop at the end of Late Permian Changhsingian Age.

Report on a structural and sedimentological analysis in the uranium province of the Orobic Alps, Italy

International Nuclear Information System (INIS)

Cassinis, G.; Dal Piaz, G.V.; Massari, P.F.

1986-01-01

Detailed structural and sedimentological studies have been conducted in two areas near the Val Vedello uranium mine in northern Italy. These studies indicate that both the Variscan basement (locally called the Orobic basement) and the Permian cover rocks were thrust southward during the Alpine orogeny. Variscan mylonitic zones were rejuvenated during the Alpine orogeny and became fault boundaries for the Permo-Triassic basins. Alpine faults also are related to contemporaneous east-west folds and these faults have displaced Permo-Triassic uranium deposits. Uranium mineralisation is attributed to a Late Permian to Triassic geothermal event which leached uranium from Permian ignimbrites and transported it along Permo-Triassic faults. Detailed mapping indicates that the host sediments formed in an arid, closed basin characterised by alluvial fans and perennial saline lakes. (orig.)

Geothermal regime and Jurassic source rock maturity of the Junggar basin, northwest China

Science.gov (United States)

Nansheng, Qiu; Zhihuan, Zhang; Ershe, Xu

2008-01-01

We analyze the thermal gradient distribution of the Junggar basin based on oil-test and well-logging temperature data. The basin-wide average thermal gradient in the depth interval of 0-4000 m is 22.6 °C/km, which is lower than other sedimentary basins in China. We report 21 measured terrestrial heat flow values based on detailed thermal conductivity data and systematical steady-state temperature data. These values vary from 27.0 to 54.1 mW/m 2 with a mean of 41.8 ± 7.8 mW/m 2. The Junggar basin appears to be a cool basin in terms of its thermal regime. The heat flow distribution within the basin shows the following characteristics. (1) The heat flow decreases from the Luliang Uplift to the Southern Depression; (2) relatively high heat flow values over 50 mW/m 2 are confined to the northern part of the Eastern Uplift and the adjacent parts of the Eastern Luliang Uplift and Central Depression; (3) The lowest heat flow of smaller than 35 mW/m 2 occurs in the southern parts of the basin. This low thermal regime of the Junggar basin is consistent with the geodynamic setting, the extrusion of plates around the basin, the considerably thick crust, the dense lithospheric mantle, the relatively stable continental basement of the basin, low heat generation and underground water flow of the basin. The heat flow of this basin is of great significance to oil exploration and hydrocarbon resource assessment, because it bears directly on issues of petroleum source-rock maturation. Almost all oil fields are limited to the areas of higher heat flows. The relatively low heat flow values in the Junggar basin will deepen the maturity threshold, making the deep-seated widespread Permian and Jurassic source rocks in the Junggar basin favorable for oil and gas generation. In addition, the maturity evolution of the Lower Jurassic Badaowan Group (J 1b) and Middle Jurassic Xishanyao Group (J 2x) were calculated based on the thermal data and burial depth. The maturity of the Jurassic

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

Science.gov (United States)

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

2012-03-27

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

Analogical scaffolding: Making meaning in physics through representation and analogy

Science.gov (United States)

Podolefsky, Noah Solomon

This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

Geomechanical Analysis and Design Considerations for Thin-Bedded Salt Caverns. Final Report

International Nuclear Information System (INIS)

Michael S. Bruno

2005-01-01

The bedded salt formations located throughout the United States are layered and interspersed with non-salt materials such as anhydrite, shale, dolomite and limestone. The salt layers often contain significant impurities. GRI and DOE have initialized this research proposal in order to increase the gas storage capabilities by providing operators with improved geotechnical design and operating guidelines for thin bedded salt caverns. Terralog has summarized the geologic conditions, pressure conditions, and critical design factors that may lead to: (1) Fracture in heterogeneous materials; (2) Differential deformation and bedding plane slip; (3) Propagation of damage around single and multiple cavern; and (4) Improved design recommendations for single and multiple cavern configurations in various bedded salt environments. The existing caverns within both the Permian Basin Complex and the Michigan and Appalachian Basins are normally found between 300 m to 1,000 m (1,000 ft to 3,300 ft) depth depending on local geology and salt dissolution depth. Currently, active cavern operations are found in the Midland and Anadarko Basins within the Permian Basin Complex and in the Appalachian and Michigan Basins. The Palo Duro and Delaware Basins within the Permian Basin Complex also offer salt cavern development potential. Terralog developed a number of numerical models for caverns located in thin bedded salt. A modified creep viscoplastic model has been developed and implemented in Flac3D to simulate the response of salt at the Permian, Michigan and Appalachian Basins. The formulation of the viscoplastic salt model, which is based on an empirical creep law developed for Waste Isolation Pilot Plant (WIPP) Program, is combined with the Drucker-Prager model to include the formation of damage and failure. The Permian salt lab test data provided by Pfeifle et al. 1983, are used to validate the assumptions made in the material model development. For the actual cavern simulations two

A REMAINING OPEN PALEOGEOGRAPHY OF PALEO-ASIAN OCEAN BY EARLY PERMIAN: PALEOMAGNETIC CONSTRAINTS FROM THE PERMIAN VOLCANIC ROCKS IN MIDDLE-EAST INNER MONGOLIA, NE CHINA

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Donghai Zhang

2017-01-01

Full Text Available We report a paleomagnetic investigation on Permian volcanic rocks in the middle-east Inner Mongolia, NE China, aiming to puzzle out the timing and position of the final closure of the eastern Paleo-Asian ocean (PAO and further to better understand tectonic evolution of the Central Asian Orogenic Belt (CAOB. Two pre-folding characteristic components are isolated from the Sanmianjing and Elitu formations (~283–266 Ma in the northern margin of the North China block (NMNCB and the Dashizhai Formation (~280 Ma in the Songliao-Xilinhot block (SXB, respectively.

A geochemical view into continental palaeotemperatures of the end-Permian using oxygen and hydrogen isotope composition of secondary silica in chert rubble breccia: Kaibab Formation, Grand Canyon (USA).

Science.gov (United States)

Kenny, Ray

2018-01-16

The upper carbonate member of the Kaibab Formation in northern Arizona (USA) was subaerially exposed during the end Permian and contains fractured and zoned chert rubble lag deposits typical of karst topography. The karst chert rubble has secondary (authigenic) silica precipitates suitable for estimating continental weathering temperatures during the end Permian karst event. New oxygen and hydrogen isotope ratios of secondary silica precipitates in the residual rubble breccia: (1) yield continental palaeotemperature estimates between 17 and 22 °C; and, (2) indicate that meteoric water played a role in the crystallization history of the secondary silica. The continental palaeotemperatures presented herein are broadly consistent with a global mean temperature estimate of 18.2 °C for the latest Permian derived from published climate system models. Few data sets are presently available that allow even approximate quantitative estimates of regional continental palaeotemperatures. These data provide a basis for better understanding the end Permian palaeoclimate at a seasonally-tropical latitude along the western shoreline of Pangaea.

Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico

International Nuclear Information System (INIS)

Murphy, Mark B.

1999-01-01

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

Detecting analogies unconsciously

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Thomas Peter Reber

2014-01-01

Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

Stratigraphic architecture of back-filled incised-valley systems: Pennsylvanian-Permian lower Cutler beds, Utah, USA

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Wakefield, Oliver J. W.; Mountney, Nigel P.

2013-12-01

The Pennsylvanian to Permian lower Cutler beds collectively form the lowermost stratigraphic unit of the Cutler Group in the Paradox Basin, southeast Utah. The lower Cutler beds represent a tripartite succession comprising lithofacies assemblages of aeolian, fluvial and shallow-marine origin, in near equal proportion. The succession results from a series of transgressive-regressive cycles, driven by repeated episodes of climatic variation and linked changes in relative sea-level. Relative sea-level changes created a number of incised-valleys, each forming through fluvial incision during lowered base-level. Aeolian dominance during periods of relative sea-level lowstand aids incised-valley identification as the erosive bounding surface juxtaposes incised-valley infill against stacked aeolian faces. Relative sea-level rises resulted in back-flooding of the incised-valleys and their infill via shallow-marine and estuarine processes. Back-flooded valleys generated marine embayments within which additional local accommodation was exploited. Back-filling is characterised by a distinctive suite of lithofacies arranged into a lowermost, basal fill of fluvial channel and floodplain architectural elements, passing upwards into barform elements with indicators of tidal influence, including inclined heterolithic strata and reactivation surfaces. The incised-valley fills are capped by laterally extensive and continuous marine limestone elements that record the drowning of the valleys and, ultimately, flooding and accumulation across surrounding interfluves (transgressive surface). Limestone elements are characterised by an open-marine fauna and represent the preserved expression of maximum transgression.

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

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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 (Oils of the Baltic Basin are not biodegraded, despite their early emplacement (e.g. by the Lower Palaeozoic age) and the relatively low present reservoir temperatures. Results of biomarker and stable carbon isotope analyses allow three genetic oil groups to be distinguished in the Kaliningrad region. These oils appear to be confined to tectonically distinct areas suggesting that the hydrocarbons were derived from different kitchens. The hydrocarbon generation in the Baltic Basin started by

The new Permian-Triassic paleomagnetic pole for the East European Platform corrected for inclination shallowing

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Fetisova, A. M.; Veselovskiy, R. V.; Scholze, F.; Balabanov, Yu. P.

2018-01-01

The results of detailed paleomagnetic studies in seven Upper Permian and Lower Triassic reference sections of East Europe (Middle Volga and Orenburg region) and Central Germany are presented. For each section, the coefficient of inclination shallowing f (King, 1955) is estimated by the Elongation-Inclination (E-I) method (Tauxe and Kent, 2004) and is found to vary from 0.4 to 0.9. The paleomagnetic directions, corrected for the inclination shallowing, are used to calculate the new Late Permian-Early Triassic paleomagnetic pole for the East European Platform (N = 7, PLat = 52.1°, PLong = 155.8°, A95 = 6.6°). Based on this pole, the geocentric axial dipole hypothesis close to the Paleozoic/Mesozoic boundary is tested by the single plate method. The absence of the statistically significant distinction between the obtained pole and the average Permian-Triassic (P-Tr) paleomagnetic pole of the Siberian Platform and the coeval pole of the North American Platform corrected for the opening of the Atlantic (Shatsillo et al., 2006) is interpreted by us as evidence that 250 Ma the configuration of the magnetic field of the Earth was predominantly dipolar; i.e., the contribution of nondipole components was at most 10% of the main magnetic field. In our opinion, the hypothesis of the nondipolity of the geomagnetic field at the P-Tr boundary, which has been repeatedly discussed in recent decades (Van der Voo and Torsvik, 2001; Bazhenov and Shatsillo, 2010; Veselovskiy and Pavlov, 2006), resulted from disregarding the effect of inclination shallowing in the paleomagnetic determinations from sedimentary rocks of "stable" Europe (the East European platform and West European plate).

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

International Nuclear Information System (INIS)

Spalletti, L.; Limarino, C.; Colombo, F.

2010-01-01

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

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

International Nuclear Information System (INIS)

Sepulveda, Fernando A; Palma-Heldt, Sylvia; Herve, Francisco; Fanning, Mark

2010-01-01

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

The youngest trigonotarbid Permotarbus schuberti n. gen., n. sp. from the Permian Petrified Forest of Chemnitz in Germany

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J. A. Dunlop

2013-08-01

Full Text Available A new trigonotarbid (Arachnida: Trigonotarbida is described as Permotarbus schuberti n. gen., n. sp. from the Early Permian Petrified Forest (Rotliegend of Chemnitz in Saxony (Germany. At ca. 290 Ma it represents the youngest record of this extinct arachnid order discovered to date. Its familial affinities are uncertain, but may lie close to the Aphantomartidae. The distribution of the trigonotarbid genera through time is summarised, together with a list of their seventy-seven fossil-yielding localities. Together they offer a broad overview of the group's fossil record, which is heavily biased towards the Moscovian Stage (ca. 307–312 Ma of the Late Carboniferous in Europe and North America. This is due in no small part to numerous localities associated with coal mining districts, and trigonotarbids are found less frequently after this stage. While it is tempting to associate this with biological events – such as a putative "Carboniferous Rainforest Collapse" dating to ca. 305 Ma – it is difficult to differentiate the effects of genuine extinction patterns from artefacts caused by fewer appropriate localities in the economically less relevant latest Carboniferous and Early Permian strata. Nevertheless, trigonotarbids became extinct at some point after the Early Permian and loss of the Coal Measures forests remains one of the most likely possible causes. doi:10.1002/mmng.201300012

Body size reductions in nonmammalian eutheriodont therapsids (Synapsida during the end-Permian mass extinction.

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Adam K Huttenlocker

Full Text Available The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the 'Lilliput effect,' a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1 active, directional evolution in size traits is rare over macroevolutionary time scales and 2 geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns.

Body Size Reductions in Nonmammalian Eutheriodont Therapsids (Synapsida) during the End-Permian Mass Extinction

Science.gov (United States)

Huttenlocker, Adam K.

2014-01-01

The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the ‘Lilliput effect,’ a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts) using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion) models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma) consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1) active, directional evolution in size traits is rare over macroevolutionary time scales and 2) geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns. PMID:24498335

Automatic activation of categorical and abstract analogical relations in analogical reasoning.

Science.gov (United States)

Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

2006-10-01

We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.

Structure of an inverted basin from subsurface and field data: the Late Jurassic-Early Cretaceous Maestrat Basin (Iberian Chain)

Energy Technology Data Exchange (ETDEWEB)

Nebot, M.; Guimera, J.

2016-07-01

The Maestrat Basin experienced two main rifting events: Late Permian-Late Triassic and Late Jurassic-Early Cretaceous, and was inverted during the Cenozoic Alpine orogeny. During the inversion, an E-W-trending, N-verging fold-and-thrust belt developed along its northern margin, detached in the Triassic evaporites, while southwards it also involved the Variscan basement. A structural study of the transition between these two areas is presented, using 2D seismic profiles, exploration wells and field data, to characterize its evolution during the Mesozoic extension and the Cenozoic contraction. The S-dipping Maestrat basement thrust traverses the Maestrat Basin from E to W; it is the result of the Cenozoic inversion of the lower segment–within the acoustic basement–of the Mesozoic extensional fault system that generated the Salzedella sub-basin. The syn-rift Lower Cretaceous rocks filling the Salzedella sub-basin thicken progressively northwards, from 350m to 1100m. During the inversion, a wide uplifted area –40km wide in the N-S direction– developed in the hanging wall of the Maestrat basement thrust. This uplifted area is limited to the North by the E-W-trending Calders monocline, whose limb is about 13km wide in its central part, dips about 5ºN, and generates a vertical tectonic step of 800-1200m. We interpreted the Calders monocline as a fault-bend fold; therefore, a flat-ramp-flat geometry is assumed in depth for the Maestrat basement thrust. The northern synformal hinge of the Calders monocline coincides with the transition from thick-skinned to thin-skinned areas. The vast uplifted area and the low-dip of the monocline suggest a very low-dip for the basement ramp, rooted in the upper crust. The Calders monocline narrows and disappears laterally, in coincidence with the outcrop of the Maestrat basement thrust. The evaporitic Middle Muschelkalk detachment conditioned the structural style. Salt structures are also related to it; they developed during the

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

International Nuclear Information System (INIS)

Fukui, L.M.

1983-09-01

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

CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Prieditis, J.; Wehner, S.

1998-01-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

Analog computing

CERN Document Server

Ulmann, Bernd

2013-01-01

This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

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)

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)

Ghavidel-Syooki, M.

1998-01-01

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 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

Neutron activation analysis of Permian-Triassic boundary layer samples at the Selong Site in China

International Nuclear Information System (INIS)

Miyamoto, Y.; Sakamoto, K.; Mingqing, W.

1997-01-01

Thirty samples from a limestone stratum across the Permian-Triassic (P-Tr) boundary layer in China were analyzed for 30 elements by instrumental neutron activation analysis, wavelength dispersive X-ray fluorescence and ICP-MS, and also for mineral compositions with a powder X-ray diffractometer. The depth profile was found to indicate a sudden change of elemental and mineral compositions across the P-Tr boundary. Also the profile showed several peaks in elemental concentrations in the lower Permian layered samples as well as in the overlying Triassic strata, which are associated with the change of mineral compositions. Elemental profiles were found to be classified into 4 groups and to give some insights in the geochemical records. Ir is far less abundant (0.1 ppt) compared with that of the K-T boundaries (10 ppb), and the Ir/Co ratio is outside the K-T and Cl chondrite trends. This change of elementary profile is suggestive of the internal causes rather than the external ones such as an asteroid impact for the mass extinction at the P-Tr boundary. (author)

Coal forming conditions for coal seams and coal measures of the Heshan Group Upper Permian Series in Guangxi Province (part 1)

Energy Technology Data Exchange (ETDEWEB)

Li, Y.

1980-10-01

Coal forming conditions for the coal measures of the Heshan Group are discussed based on the analysis of the historical background and paleogeographical environment of the Permian in Guangxi Province. The roof, floor, and partings of the seams are composed of algal micritic limestone, therefore affirming that the central part of Guangxi Province in the late Permian was a typical epi-continental sea. The compensative deposit of algea on the carbonate platform in very shallow water created the conditions for the occurrence of the peat swamp and established the supra-tidal swampy facies. The environment for the accumulation of the major coal seams are analyzed. (In Chinese)

The fluoride in the groundwater of Guarani Aquifer System: the origin associated with black shales of Paraná Basin

Science.gov (United States)

Kern, M. L.; Vieiro, A. P.; Machado, G.

2008-09-01

This work presents petrological and geochemical results of the black shales interval from Permian and Devonian strata of the Paraná Basin, Brazil and its relationships with fluoride of groundwater from Guarani Aquifer System. The Guarani Aquifer, located in South Brazil, Uruguay, Paraguay and Argentine, presents contents of fluoride higher than the Brazilian accepted potability limits. Several hypotheses have been presented for the origin of the fluoride in the groundwater of the Guarani Aquifer. Microcrystalline fluorite was registered in black shales of Ponta Grossa and Irati formations from Paraná Basin. The results shown in this work suggest that fluoride present in groundwater of Guarani Aquifer can be originated in deeper groundwater that circulates in Ponta Grossa and Irati formations. The interaction of the groundwater coming from deeper black shales with the groundwater-bearing Aquifer Guarani System occurs through regional fragile structures (faults and fractures) that constitute excellent hydraulic connectors between the two sedimentary packages. The microcrystalline fluorite registered in Ponta Grossa and Irati Formations can be dissolved promoting fluoride enrichment in groundwater of these black shales and Guarani Aquifer System.

THE SEDIMENTOLOGY OF THE LOWER PERMIAN DANDOT FORMATION: A COMPONENT OF THE GONDWANA DEGLACIATION SEQUENCE OF THE SALT RANGE, PAKISTAN

Directory of Open Access Journals (Sweden)

IRFAN U. JAN

2016-03-01

Full Text Available The Dandot Formation is a part of the Lower Permian, dominantly continental, Gondwanan Nilawahan Group in the Salt Range, Pakistan. The formation conformably overlies the glacio-fluvial Tobra Formation and has a sharp conformable contact with the overlying fluvio-continental Warchha Sandstone. Sedimentary analyses show that the Dandot Formation consists of: 1. bioturbated sandstone lithofacies (L1, 2. dark green mudstone/shale lithofacies (L2, 3. flaser bedded sandstone lithofacies (L3, 4. rippled sandstone lithofacies (L4, 5. cross-bedded sandstone lithofacies (L5, and 6. planar sandstone lithofacies (L6. These can be grouped into shoreface, inner shelf, and tidal flat and estuarine facies associations, deposited in shallow marine to intertidal environments. The upper part of the Tobra Formation at the Choa-Khewra road section, where it conformably underlies the Dandot Formation, contains palynomorphs assignable to the earliest Permian 2141B Biozone. In south Oman, the 2141B Biozone is closely associated with the Rahab Shale Member, a widespread shale unit which is considered to represent part of a Permian deglaciation sequence which culminates in the marine beds of the Lower Gharif Member, interpreted as due to post glacial marine transgression. Thus, the Tobra Formation and the overlying marine Dandot Formation may form part of a similar deglaciation sequence.

Science Teachers' Analogical Reasoning

Science.gov (United States)

Mozzer, Nilmara Braga; Justi, Rosária

2013-08-01

Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

The Agost Basin (Betic Cordillera, Alicante province, Spain): a pull-apart basin involving salt tectonics

Science.gov (United States)

Martín-Martín, Manuel; Estévez, Antonio; Martín-Rojas, Ivan; Guerrera, Francesco; Alcalá, Francisco J.; Serrano, Francisco; Tramontana, Mario

2018-03-01

, the Agost Basin can be considered a key case of the interference between salt tectonics and the evolution of strike-slip fault zones. The reconstructed model has been compared with several scaled sandbox analogical models and with some natural pull-apart basins.

Analog synthetic biology.

Science.gov (United States)

Sarpeshkar, R

2014-03-28

We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

Probable existence of a Gondwana transcontinental rift system in western India: Implications in hydrocarbon exploration in Kutch and Saurashtra offshore: A GIS-based approach

Science.gov (United States)

Mazumder, S.; Tep, Blecy; Pangtey, K. K. S.; Das, K. K.; Mitra, D. S.

2017-08-01

The Gondwanaland assembly rifted dominantly during Late Carboniferous-Early Permian forming several intracratonic rift basins. These rifts were subsequently filled with a thick sequence of continental clastic sediments with minor marine intercalations in early phase. In western part of India, these sediments are recorded in enclaves of Bikaner-Nagaur and Jaisalmer basins in Rajasthan. Facies correlatives of these sediments are observed in a number of basins that were earlier thought to be associated with the western part of India. The present work is a GIS based approach to reconnect those basins to their position during rifting and reconstruct the tectono-sedimentary environment at that time range. The study indicates a rift system spanning from Arabian plate in the north and extending to southern part of Africa that passes through Indus basin, western part of India and Madagascar, and existed from Late Carboniferous to Early Jurassic. Extensions related to the opening of Neo-Tethys led to the formation of a number of cross trends in the rift systems that acted as barriers to marine transgressions from the north as well as disrupted the earlier continuous longitudinal drainage systems. The axis of this rift system is envisaged to pass through present day offshore Kutch and Saurashtra and implies a thick deposit of Late Carboniferous to Early Jurassic sediments in these areas. Based on analogy with other basins associated with this rift system, these sediments may be targeted for hydrocarbon exploration.

Evidence for Late Permian-Upper Triassic ocean acidification from calcium isotopes in carbonate of the Kamura section in Japan

Science.gov (United States)

Ye, F.; Zhao, L., Sr.; Chen, Z. Q.; Wang, X.

2017-12-01

Calcium and carbon cycles are tightly related in the ocean, for example, through continental weathering and deposition of carbonate, thus, very important for exploring evolutions of marine environment during the earth history. The end-Permian mass extinction is the biggest biological disaster in the Phanerozoic and there are several studies talking about variations of calcium isotopes across the Permian-Triassic boundary (PTB). However, these studies are all from the Tethys regions (Payne et al., 2010; Hinojosa et al., 2012), while the Panthalassic Ocean is still unknown to people. Moreover, evolutions of the calcium isotopes during the Early to Late Triassic is also poorly studied (Blattler et al., 2012). Here, we studied an Uppermost Permian to Upper Triassic shallow water successions (Kamura section, Southwest Japan) in the Central Panthalassic Ocean. The Kamura section is far away from the continent without any clastic pollution, therefore, could preserved reliable δ44/40Cacarb signals. Conodont zonation and carbonate carbon isotope also provide precious time framework which is necessary for the explaining of the δ44/40Cacarb profile. In Kamura, δ44/40Cacarb and δ13Ccarb both exhibit negative excursions across the PTB, the δ44/40Cacarb value in the end-Permian is 1.0398‰ then abrupt decrease to the minimum value of 0.1524‰. CO2-driven global ocean acidification best explains the coincidence of the δ44/40Cacarb excursion with negative excursions in the δ13Ccarb of carbonates until the Early Smithian(N1a, N1b, N1c, P1, N2, P2). In the Middle and the Late Triassic, the δ44/40 Cacarb average approximately 1.1‰. During the Middle and Late Triassic, strong relationships between δ44/40Cacarb and δ13Ccarb are collapsed, indicating a normal pH values of the seawater in those time. The Siberian Trap volcanism probably played a significant role on the δ44/40Cacarb until the late Early Triassic. After that, δ44/40Cacarb was mostly controlled by carbonate

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

Science.gov (United States)

Chen, Z.

2013-12-01

Life came closest to complete annihilation during the end-Permian mass extinction (EPME). Pattern and cause of this great dying have long been disputed. Similarly, there is also some debate on the recovery rate and pattern of marine organisms in the aftermath of the EPME. Some clades recovered rapidly, within the first 1-3 Myr of the Triassic. For instance, foraminiferal recovery began 1 Myr into the Triassic and was not much affected by Early Triassic crises. Further, some earliest Triassic body and trace fossil assemblages are also more diverse than predicted. Others, ie. Brachiopods, corals etc., however, did not rebound until the Middle Triassic. In addition, although ammonoids recovered fast, reaching a higher diversity by the Smithian than in the Late Permian, much of this Early Triassic radiation was within a single group, the Ceratitina, and their morphological disparity did not expand until the end-Spathian. Here, I like to broaden the modern ecologic network model to explore the complete trophic structure of fossilized ecosystems during the Permian-Triassic transition as a means of assessing the recovery. During the Late Permian and Early Triassic, primary producers, forming the lowest trophic level, were microbes. The middle part of the food web comprises primary and meso-consumer trophic levels, the former dominated by microorganisms such as foraminifers, the latter by opportunistic communities (i.e. disaster taxa), benthic shelly communities, and reef-builders. They were often consumed by invertebrate and vertebrate predators, the top trophic level. Fossil record from South China shows that the post-extinction ecosystems were degraded to a low level and typified by primary producers or opportunistic consumers, which are represented by widespread microbialites or high-abundance, low-diversity communities. Except for some opportunists, primary consumers, namely foraminifers, rebounded in Smithian. Trace-makers recovered in Spathian, which also saw

Regional tectonic framework of the Pranhita Godavari basin, India

Science.gov (United States)

Biswas, S. K.

2003-03-01

-rift sedimentation. The southeastern boundary fault developed as a strike-slip fault in response to plate rotation and the rift expansion was constrained by it.The basin fill sediments were deposited during two rifting events—Early Permian to (?) Early Jurassic Lower Gondwana rifting, and Early Cretaceous Upper Gondwana rifting. The Lower Gondwana sedimentation started with a pre-rift crustal sagging over the rift site and was filled by glaciogenic Talchir sediments. This was followed by syn-rift-fluvial sedimentation in repeating cycles during the early to late rift stages. Early Cretaceous Chikiala and Gangapur sediments were deposited during the Upper Gondwana rifting. The fluvial cycles were tectonically controlled during each rift stage. The absence of igneous intrusions indicates that the PGR is a passive rift in contrast to the rifts developed in the NSG zone.

Sedimentary and environmental history of the Late Permian Bonikowo Reef (Zechstein Limestone, Wuchiapingian, western Poland

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Paweł Raczyński

2017-07-01

Full Text Available The Bonikowo Reef occurs in the central part of the Zechstein Limestone Basin in western Poland and was growing on the topmost edges of tilted blocks and/or on the top of uplifted horsts of the Brandenburg–Wolsztyn–Pogorzela High. Its size is ca. 1.6 km2. The Bonikowo Reef shows the thickest reef section (90.5 m recorded in the High. The Zechstein Limestone unit is represented mostly by limestones, often thoroughly recrystallized, although the macrotextures and biota of the boundstone are identifiable in most cases. The drillcore section is a mixture of boundstones (microbial and bryozoan, wackestones, packstones and grainstones, which often co-occur. The δ13C and δ18O values for both calcite (avg. 3.8 ± 0.8‰ and −3.4 ± 1.7‰, respectively and dolomite (avg. 3.5 ± 0.7‰ and −5.2 ± 1.3‰, respectively are transitional between the values previously reported for condensed sequences of the basinal facies and larger reef complexes. The biofacies of the Bonikowo Reef are very similar to those recognized in other reefs of the Brandenburg–Wolsztyn–Pogorzela High, which owe their origin to the destruction of bryozoan boundstones. The biota composition is typical and characteristic of other Zechstein Limestone reefs. However, the Bonikowo Reef demonstrates the importance of microbialites, laminar and nodose encrustations, in the growth and cohesion of the Zechstein Limestone reefs. Such encrustations abound within the Zechstein Limestone although, in many cases, the real nature of the encrustations is difficult to ascertain. These laminated encrustations show great similarity to Archaeolithoporella that is one of the most important Permian reef-building organisms. The encrustations considered to represent Archaeolithoporella were also previously recorded in the Zechstein Limestone of western Poland and in its stratigraphic equivalent, the Middle Magnesian Limestone of Northeast England. The lower part of the sequence shows

Origins of the Salado, Seven Rivers, and San Andres salt margins in Texas and New Mexico: Revision 1: Topical report

International Nuclear Information System (INIS)

Boyd, S.D.; Murphy, P.J.

1987-02-01

The present boundaries of the San Andres, Seven Rivers, and Salado salts generally lie along the periphery of the Palo Duro and Tucumcari Basins. Various geologic mechanisms occurring singularly or in combination determined the positions of the salt margins. These mechanisms include nondeposition of salt and syndepositional and postdepositional dissolution. In New Mexico, San Andres units pinch out against the Pedernal and Sierra Grande Uplifts, indicating that nondeposition established the original salt margins there. Syndepositional dissolution of exposed Upper San Andres salts occurred in response to Guadalupian upwarp of the basin margins. Triassic erosion differentially removed Permian salt-bearing formations along the uplifts. Late Tertiary dissolution is indicated by fill of north-south trending collapse valleys. In Texas, Guadalupian upwarp along the Amarillo Uplift caused pinchout of Units 2 and 3 in the Lower San Andres and influenced the deposition of subsequent salt-bearing strata. The discontinuity of Upper San Andres evaporites across the Amarillo Uplift suggests syndepositional dissolution. Along the eastern and northeastern basin margin, dissolution may have accompanied Triassic erosion of locally uplifted Upper Permian strata. Tertiary dissolution is recognized beneath anomalously thick Ogallala Formation sections that overlie collasped Permian strata. 49 refs., 31 figs., 2 tabs

Late Carboniferous to early Permian sedimentary–tectonic evolution of the north of Alxa, Inner Mongolia, China: Evidence from the Amushan Formation

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Haiquan Yin

2016-09-01

Full Text Available The late Paleozoic evolution of the Wulijishanhen (WSH-Shangdan (SD area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biological associations, detrital materials, sandstone geochemistry and volcanic rocks indicates that the SD area was an epicontinental sea and rift during the late Paleozoic rather than a large-scale ocean undergoing spreading and closure. This study reveals that the actual evolution of the study area is from the late Carboniferous to the early Permian. The fusulinids Triticites sp. and Pseudoschwagerina sp. in the limestones demonstrate that the Amushan Formation develops during the late Carboniferous to the early Permian. The limestones at the base of the SD section indicate that it is a stable carbonate platform environment, the volcanic rocks in the middle of the sequence support a rift tectonic background, and the overlying conglomerates and sandstones are characteristic of an epicontinental sea or marine molasse setting. The rift volcanism made the differences in the fossil content of the SD and WSH sections and led to two sections expose different levels within the Amushan Formation and different process of tectonic evolution. Moreover, the geochemical characteristics and detrital materials of the sandstones show that the provenance and formation of the sandstones were related to the setting of active continental margin. The quartz-feldspar-lithic fragments distribution diagram indicates that the material source for the sandstones was a recycled orogenic belt. Thus, the source area of the sandstones may have been an active continental margin before the late Carboniferous–early Permian. The characteristics of the regional tectonic evolution of the area indicate that the region may form a small part of the Gobi–Tianshan rift of southern Mongolia.

Australian provenance for Upper Permian to Cretaceous rocks forming accretionary complexes on the New Zealand sector of the Gondwana land margin

International Nuclear Information System (INIS)

Pickard, A.L.; Barley, M.E.

2000-01-01

U-Pb (SHRIMP) detrital zircon age patterns are reported for 12 samples of Permian to Cretaceous turbiditic quartzo-feldspathic sandstone from the Torlesse and Waipapa suspect terranes of New Zealand. Their major Permian to Triassic, and minor Early Palaeozoic and Mesoproterozoic, age components indicate that most sediment was probably derived from the Carboniferous to Triassic New England Orogen in northeastern Australia. Rapid deposition of voluminous Torlesse/Waipapa turbidite fans during the Late Permian to Late Triassic appears to have been directly linked to uplift and exhumation of the magmatically active orogen during the 265-230 Ma Hunter-Bowen event. This period of cordilleran-type orogeny allowed transport of large volumes of quartzo-feldspathic sediment across the convergent Gondwana land margin. Post-Triassic depocentres also received (recycled?) sediment from the relict orogen as well as from Jurassic and Cretaceous volcanic provinces now offshore from southern Queensland and northern New South Wales. The detailed provenance-age fingerprints provided by the detrital zircon data are also consistent with progressive southward derivation of sediment: from northeastern Queensland during the Permian, southeastern Queensland during the Triassic, and northeastern New South Wales - Lord Howe Rise - Norfolk Ridge during the Jurassic to Cretaceous. Although the dextral sense of displacement is consistent with the tectonic regime during this period, detailed characterisation of source terranes at this scale is hindered by the scarcity of published zircon age data for igneous and sedimentary rocks in Queensland and northern New South Wales. Mesoproterozoic and Neoproterozoic age components cannot be adequately matched with likely source terranes in the Australian-Antarctic Precambrian craton, and it is possible they originated in the Proterozoic cores of the Cathaysia and Yangtze Blocks of southeast China. Copyright (1999) Geological Society of Australia

Oxygenation in carbonate microbialites and associated facies after the end-Permian mass extinction: Problems and potential solutions

Directory of Open Access Journals (Sweden)

Stephen Kershaw

2018-01-01

The oxygenation state of post-end-Permian extinction shallow marine facies continues to present a challenge of interpretation, and requires high-resolution sampling and careful attention to small-scale changes, as well as loss of rock through pressure solution, as the next step to resolve the issue.

Geology of Paleozoic Rocks in the Upper Colorado River Basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, Excluding the San Juan Basin

Science.gov (United States)

Geldon, Arthur L.

2003-01-01

The geology of the Paleozoic rocks in the Upper Colorado River Basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis Program to provide support for hydrogeological interpretations. The study area is segmented by numerous uplifts and basins caused by folding and faulting that have recurred repeatedly from Precambrian to Cenozoic time. Paleozoic rocks in the study area are 0-18,000 feet thick. They are underlain by Precambrian igneous, metamorphic, and sedimentary rocks and are overlain in most of the area by Triassic formations composed mostly of shale. The overlying Mesozoic and Tertiary rocks are 0-27,000 feet thick. All Paleozoic systems except the Silurian are represented in the region. The Paleozoic rocks are divisible into 11 hydrogeologic units. The basal hydrogeologic unit consisting of Paleozoic rocks, the Flathead aquifer, predominantly is composed of Lower to Upper Cambrian sandstone and quartzite. The aquifer is 0-800 feet thick and is overlain gradationally to unconformably by formations of Cambrian to Mississippian age. The Gros Ventre confining unit consists of Middle to Upper Cambrian shale with subordinate carbonate rocks and sandstone. The confining unit is 0-1,100 feet thick and is overlain gradationally to unconformably by formations of Cambrian to Mississippian age. The Bighom aquifer consists of Middle Cambrian to Upper Ordovician limestone and dolomite with subordinate shale and sandstone. The aquifer is 0-3,000 feet thick and is overlain unconformably by Devonian and Mississipplan rocks. The Elbert-Parting confining unit consists of Lower Devonian to Lower Mississippian limestone, dolomite, sandstone, quartzite, shale, and anhydrite. It is 0-700 feet thick and is overlain conformably to unconformably by Upper Devonian and Mississippian rocks. The Madison aquifer consists of two zones of distinctly different lithology. The lower (Redwall-Leadville) zone

Genesis of the North German basin - a metamorphosis model; Die Entstehung des Norddeutschen Beckens - ein Metamorphose-Modell

Energy Technology Data Exchange (ETDEWEB)

Brink, H.J. [ExxonMobil Production Deutschland GmbH, Hannover (Germany)

2003-07-01

In an integrative analysis, metamorphosis processes in the aggregated crust, potential field anomalies, the temperature field and the subsidence history are combined into a model of the genesis of the North German Basin. The model takes account of phenomena like high nitrogen concentrations in natural gases of permian sandstone and the structure of the crust and combines them with theoretical considerations. The new model for explaining geonsynclinals, in which geochemical and petrophysical processes in the lower crust have a decisive role, appears to be globally applicable. It can provide an intrinsic variant of the application of existing tectonic expansion models for explaining the subsidence of sediment basins. [German] In einer integrativen Analyse werden Metamorphoseprozesse in der aggregierten Kruste, Potentialfeldanomalien, Temperaturfeld sowie die Subsidenzgeschichte zu einem Modell fuer die Entstehung des Norddeutschen Beckens zusammengefasst, das beobachtete Phaenomene wie Stickstoffreichtum in Erdgasen permischer Sandsteine und die Struktur der Kruste mit theoretischen Ableitungen verknuepft. Das so entstandene neue Modell zur Erklaerung von Geosynklinalen, bei dem geochemisch/petrophysikalische Prozesse in der Unterkruste eine entscheidende Rolle spielen, scheint global anwendbar zu sein. Es kann die Anwendung existierender tektonischer Dehnungsmodelle zur Erklaerung der Subsidenz von Sedimentbecken um eine intrinsische Variante ergaenzen. (orig.)

The paleozoic of Amazonas basin south edge: Tapajos river, Para state; O paleozoico da borda sul da bacia do Amazonas: rio Tapajos, estado do Para

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Nilo Siguehiko [Petrobras E e P, Rio de Janeiro, RJ (Brazil). Exploracao. Estratigrafia e Sedimentologia Geologia Aplicada a Exploracao], E-mail: nilo@petrobras.com.br; Winter, Wilson Rubem [Petrobras, Campoas dos Goytacases, RJ (Brazil). Exploracao. Sedimentologia e Estratigrafia], E-mail: winter@petrobras.com.br; Wanderley Filho, Joaquim Ribeiro; Cacela, Alessandra Suzely Moda [Petrobras, Manaus, AM (Brazil). Exploracao. Unidade de Operacoes de Exploracao e Producao da Amazonia], Emails: jwand@petrobras.com.br, alessandra.suzely@petrobras.com.br

2009-11-15

The intracratonic Amazonas Basin covers an area close to 500.000km{sup 2} shared between the Amazonas and Para states. The phanerozoic stratigraphic framework is up to 6.000m thick and may be subdivided into two, first order depositional sequences: the Paleozoic sequence, intruded by diabase dikes and sills and the Mesozoic-Cenozoic sequence. Analyzing the stratigraphic framework, the great tectonic influence on the basin development can be appreciated. The mainly NW-SE structural directions of the basement, which mark the boundaries of the geochronological provinces of the Amazonas, are clearly identified along the Tapajos River. The Paleozoic sequence outcrops on the southern border of the Amazonas Basin embraces potential source rocks, reservoirs and seal rocks. They can be subdivided in three, second order sequences, limited by regional unconformities, as: the Ordovician/Devonian, which corresponds to the Pitinga lithostratigraphic formation; the Devonian-Tournaisian, which corresponds to the Maecuru, Erere, Barreirinha and Curiri formations and, the Pensylvanian-Permian that are represented by the Monte Alegre and Itaituba formations. This field trip guide presents these classic lithostratigraphic outcrop units, together with a brief sedimentological description and an analysis of their positioning related to sequence stratigraphical concepts. (author)

The structure and stratigraphy of the sedimentary succession in the Swedish sector of the Baltic Basin: New insights from vintage 2D marine seismic data

Science.gov (United States)

Sopher, Daniel; Erlström, Mikael; Bell, Nicholas; Juhlin, Christopher

2016-04-01

We present five interpreted regional seismic profiles, describing the full sedimentary sequence across the Swedish sector of the Baltic Sea. The data for the study are part of an extensive and largely unpublished 2D seismic dataset acquired between 1970 and 1990 by the Swedish Oil Prospecting Company (OPAB). The Baltic Basin is an intracratonic basin located in northern Europe. Most of the Swedish sector of the basin constitutes the NW flank of a broad synclinal depression, the Baltic Basin. In the SW of the Swedish sector lies the Hanö Bay Basin, formed by subsidence associated with inversion of the Tornquist Zone during the Late Cretaceous. The geological history presented here is broadly consistent with previously published works. We observe an area between the Hanö Bay and the Baltic Basin where the Palaeozoic strata has been affected by transpression and subsequent inversion, associated with the Tornquist Zone during the late Carboniferous-Early Permian and Late Cretaceous, respectively. We propose that the Christiansø High was a structural low during the Late Jurassic, which was later inverted in the Late Cretaceous. We suggest that a fan shaped feature in the seismic data, adjacent to the Christiansø Fault within the Hanö Bay Basin, represents rapidly deposited, coarse-grained sediments eroded from the inverted Christiansø High during the Late Cretaceous. We identify a number of faults within the deeper part of the Baltic Basin, which we also interpret to be transpressional in nature, formed during the Caledonian Orogeny in the Late Silurian-Early Devonian. East of Gotland a number of sedimentary structures consisting of Silurian carbonate reefs and Ordovician carbonate mounds, as well as a large Quaternary glacial feature are observed. Finally, we use the seismic interpretation to infer the structural and stratigraphic history of the Baltic and Hanö Bay basins within the Swedish sector.

Lunar and Planetary Science XXXV: Mars: Remote Sensing and Terrestrial Analogs

Science.gov (United States)

2004-01-01

The session "Mars: Remote Sensing and Terrestrial Analogs" included the following:Physical Meaning of the Hapke Parameter for Macroscopic Roughness: Experimental Determination for Planetary Regolith Surface Analogs and Numerical Approach; Near-Infrared Spectra of Martian Pyroxene Separates: First Results from Mars Spectroscopy Consortium; Anomalous Spectra of High-Ca Pyroxenes: Correlation Between Ir and M ssbauer Patterns; THEMIS-IR Emissivity Spectrum of a Large Dark Streak near Olympus Mons; Geomorphologic/Thermophysical Mapping of the Athabasca Region, Mars, Using THEMIS Infrared Imaging; Mars Thermal Inertia from THEMIS Data; Multispectral Analysis Methods for Mapping Aqueous Mineral Depostis in Proposed Paleolake Basins on Mars Using THEMIS Data; Joint Analysis of Mars Odyssey THEMIS Visible and Infrared Images: A Magic Airbrush for Qualitative and Quantitative Morphology; Analysis of Mars Thermal Emission Spectrometer Data Using Large Mineral Reference Libraries ; Negative Abundance : A Problem in Compositional Modeling of Hyperspectral Images; Mars-LAB: First Remote Sensing Data of Mineralogy Exposed at Small Mars-Analog Craters, Nevada Test Site; A Tool for the 2003 Rover Mini-TES: Downwelling Radiance Compensation Using Integrated Line-Sight Sky Measurements; Learning About Mars Geology Using Thermal Infrared Spectral Imaging: Orbiter and Rover Perspectives; Classifying Terrestrial Volcanic Alteration Processes and Defining Alteration Processes they Represent on Mars; Cemented Volcanic Soils, Martian Spectra and Implications for the Martian Climate; Palagonitic Mars: A Basalt Centric View of Surface Composition and Aqueous Alteration; Combining a Non Linear Unmixing Model and the Tetracorder Algorithm: Application to the ISM Dataset; Spectral Reflectance Properties of Some Basaltic Weathering Products; Morphometric LIDAR Analysis of Amboy Crater, California: Application to MOLA Analysis of Analog Features on Mars; Airborne Radar Study of Soil Moisture at

Permian storm current-produced offshore bars from an ancient shelf sequence : Northwestern Karoo basin, republic of South Africa

Science.gov (United States)

Smith, A. M.; Zawada, P. K.

The Ecca-Beaufort transition zone from the Karoo Basin comprises upward-coarsening sequences which are interpreted as prograding, storm-produced offshore bars. Eight facies are recognised: (A) dark-grey shale, (B) thinly interbedded siltstone and mudstone, (C) thinly interbedded siltstone and very fine-grained sandstone, (D) blue-grey coarse-grained siltstone, (E) low-angle truncated and flat-laminated sandstone, (F) wave-rippled sandstone, (G) planar cross-bedded sandstone, (H) intraformational clay-pellet conglomerate. Four sub-environments are recognised, these being: (1) the bar crest which comprises proximal tempestites, (2) the bar slope consisting of soft-sediment deformed siltstone, (3) the bar fringe/ margin which is composed of storm layers and offshore siltstones and (4) the interbar/offshore environment comprising siltstone and distal storm layers. These bars formed in response to wave and storm processes and migrated across a muddy shelf environment. The orientation of bars was probably coast-parallel to subparallel with respect to the inferred north-northwest-south-southeast coastline. These proposed, storm-produced bars acted as major depo-centres within the shelf setting of the study area. As shelf sediments are recorded from almost the entire northwestern Karoo Basin it is anticipated that bar formation was an important sedimentary factor in the deposition of the sediments now referred to as the Ecca-Beaufort transition zone.

Kerogen morphology and geochemistry at the Permian-Triassic transition in the Meishan section, South China: Implication for paleoenvironmental variation

Science.gov (United States)

Sawada, Ken; Kaiho, Kunio; Okano, Kazuki

2012-08-01

Detailed fluorescent microscopic observations and organic geochemical analyses for insoluble sedimentary organic matter (kerogens) are conducted on the end-Permian to earliest Triassic sediments in the Meishan section A of South China. The main objectives of the present study are to reconstruct variations of marine and terrestrial environments, and to evaluate bulk characteristics of terrestrial input in the palaeo-Tethys ocean for the Permian-Triassic boundary (PTB). Most of kerogens in the Meishan section are mainly composed of marine algae-derived amorphous organic matter, while terrestrial plant-derived amorphous organic matter is remarkably dominant in the mass extinction horizon reported previously. The relative abundances of marine organic matter may vary depending on marine production rather than terrestrial input in the palaeo-Tethys associated with changing terrestrial vegetation. We also identified aromatic furans as major compounds in kerogen pyrolysate of all layers. It is possible that sources of aromatic furans with alkyl group, fungi and lichen, proliferated as disaster biota in terrestrial ecosystem through the PTB. Higher abundances of herbaceous organic matter are observed in the layers above the mass extinction horizon. However, the conifer biomarker retene can be identified in kerogen pyrolysates of all layers. These results imply that the productions of herbaceous plants increased as dominant pioneer biota in early stage of recovery for terrestrial ecosystem after its collapse, but also that woody plant potentially continued to be produced in land area throughout the end-Permian and earliest-Triassic.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science. Prabir Dasgupta. Articles written in Journal of Earth System Science. Volume 114 Issue 3 June 2005 pp 287-302. Facies pattern of the middle Permian Barren Measures Formation, Jharia basin, India: The sedimentary response to basin tectonics · Prabir Dasgupta.

Rhetoric and analogies

OpenAIRE

Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

2013-01-01

The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

Two-phase southward subduction of the Mongol-Okhotsk oceanic plate constrained by Permian-Jurassic granitoids in the Erguna and Xing'an massifs (NE China)

Science.gov (United States)

Liu, Huichuan; Li, Yinglei; He, Hongyun; Huangfu, Pengpeng; Liu, Yongzheng

2018-04-01

Geodynamics of the Mongol-Okhotsk oceanic plate southward subduction are still pending problems. This paper presents new zircon LA-ICP-MS U-Pb age and whole-rock geochemical data for the middle Permian to Middle Jurassic granitoids in the western Erguna and central Xing'an massifs. 267-264 Ma, 241 Ma and 173 Ma I-type granites, and 216 Ma A-type granites were identified in the Erguna and Xing'an massifs (NE China). The I-type granites were produced by partial melting of the lower mafic crust. The 216 Ma A-type granites were derived from partial melting of crustal materials with tonalitic to granodioritic compositions. The 267-264 Ma and 241 Ma I-type granites were generated in an Andean-type arc setting, wheras the 216 Ma A-type and 173 Ma granites were formed in supra subduction extensional setting. We summarized previous age data of the middle Permian to Middle Jurassic magmtaic rocks in the Erguna and Xing'an Massifs and identified two isolated phases of magmatic activity including the ca. 267-225 Ma and ca. 215-165 Ma periods, with a significant magmatic gap at ca. 225-215 Ma. These middle Permian to Middle Jurassic magmatic rocks are closely related to the southward subduction of the Mongol-Okhotsk ocean. A two-stage tectonic evolutionary model was proposed to account for these geological observations in the Erguna and Xing'an massifs, involving Permian to Middle Triassic continuous southward subduction of the Mongol-Okhotsk oceanic plate and Late Triassic to Jurassic slab-rollback and supra subduction extension.

Intuitive analog circuit design

CERN Document Server

Thompson, Marc

2013-01-01

Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

Prolonged Permian–Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages

OpenAIRE

Clapham, Matthew E.; Bottjer, David J.

2007-01-01

The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effec...

Organic petrology and geochemistry of mudrocks from the lacustrine Lucaogou Formation, Santanghu Basin, northwest China: Application to lake basin evolution

Science.gov (United States)

Hackley, Paul C.; Fishman, Neil; Wu, Tao; Baugher, Gregory

2016-01-01

Exploration for tight oil in the frontier Santanghu Basin of northwest China has resulted in recent commercial discoveries sourced from the lacustrine Upper Permian Lucaogou Formation, already considered a “world class source rock” in the Junggar Basin to the west. Here we apply an integrated analytical program to carbonate-dominated mudrocks from the Lucaogou Formation in Santanghu Basin to document the nature of organic matter (OM) in the context of an evolving lake system. The organic-rich samples (TOC 2.8–11.4 wt%; n = 10) were widely spaced from an ~ 200 m cored section, interpreted from textural and mineralogical evidence to document transition from a lower under-filled to an overlying balanced-filled lake. Organic matter is dominated by moderate to strongly fluorescent amorphous material with Type I geochemical signature (HI values 510–755; n = 10) occurring in a continuum from lamellar stringers, 10–20 μm thick, some ≥ 1 mm in length (possible microbial mat; preserved only in lower under-filled section) to finely-disseminated amorphous groundmass intimately intermixed with mineral matrix. Biomarkers for methanotrophs and photosynthetic cyanobacteria indicate a complex microbial consortium. A unicellular prasinophyte green alga(?), similar to Tasmanites in marine rocks, is present as discrete flattened discs 50–100 μm in diameter. Type III OM including vitrinite (some fluorescent) and inertinite also is abundant. Solid bitumen, indicating local kerogen conversion, fills voids and occurs throughout the cored section. Vitrinite reflectance values are 0.47–0.58%, consistent with strong OM fluorescence but may be “suppressed”. Other proxies, e.g., biomarker parameters, indicate the Lucaogou Formation is in the early oil window at this location. On average, slightly more amorphous OM and telalginite are present in the lower section, consistent with a shallow, stratified, saline environment with low sediment dilution. More

A review of the stratigraphy and sedimentary environments of the Karoo-aged basins of Southern Africa

Science.gov (United States)

Smith, R. M. H.; Eriksson, P. G.; Botha, W. J.

1993-02-01

The Karoo Basin of South Africa was one of several contemporaneous intracratonic basins in southwestern Gondwana that became active in the Permo-Carboniferous (280 Ma) and continued to accumulate sediments until the earliest Jurassic, 100 million years later. At their maximum areal extent, during the early Permian, these basins covered some 4.5 million km 2. The present outcrop area of Karoo rocks in southern Africa is about 300 000 km 2 with a maximum thickness of some 8000 m. The economic importance of these sediments lies in the vast reserves of coal within the Ecca Group rocks of northern and eastern Transvaal and Natal, South Africa. Large reserves of sandstone-hosted uranium and molybdenum have been proven within the Beaufort Group rocks of the southern Karoo trough, although they are not mineable in the present market conditions. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo succession in South Africa demonstrates the changes in depositional style caused by regional and localized tectonism within the basin. These depocentres were influenced by a progressive aridification of climate which was primarily caused by the northward drift of southwestern Gondwana out of a polar climate and accentuated by the meteoric drying effect of the surrounding land masses. Changing palaeoenvironments clearly influenced the rate and direction of vertebrate evolution in southern Gondwana as evidenced by the numerous reptile fossils, including dinosaurs, which are found in the Karoo strata of South Africa, Lesotho, Namibia and Zimbabwe. During the Late Carboniferous 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 upland valleys and on the lowland shelf resulted in the Dwyka Formation at the base of the Karoo Sequence. After glaciation, an extensive shallow sea covered the gently subsiding shelf, fed by large volumes of meltwater

Sponge assemblage of some Upper Permian reef limestones from Phrae province (Northern Thailand

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Baba Senowbari-Daryan

1994-12-01

Full Text Available The sponge fauna of uppermost Permian reef or reefal limestones of the Phrae province in northern Thailand include representatives of hexactinellida, sclerospongea,"sphinctozoans", and "inozoans". The "sphinctozoans" and "inozoans"are described in detail. Following taxa are new:"Sphinctozoans": Phraethalamia tubulara n. gen., n. sp., Ambithalamia pérmican. gen., n. sp."Inozoans": Bisiphonella tubulara n. sp., Solutossaspongia crassimuralis n.gen., n. sp.The genus name Belyaevaspongia nom. nov. is proposed for PolysiphonellaBelyaeva, 1991 (in Boiko et al., 1991, non Polysiphonella Russo, 1981.

High-speed and high-resolution analog-to-digital and digital-to-analog converters

NARCIS (Netherlands)

van de Plassche, R.J.

1989-01-01

Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

UNIVERSAL REGULAR AUTONOMOUS ASYNCHRONOUS SYSTEMS: ω-LIMIT SETS, INVARIANCE AND BASINS OF ATTRACTION

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Serban Vlad

2011-07-01

Full Text Available The asynchronous systems are the non-deterministic real timebinarymodels of the asynchronous circuits from electrical engineering.Autonomy means that the circuits and their models have no input.Regularity means analogies with the dynamical systems, thus such systems may be considered to be real time dynamical systems with a’vector field’, Universality refers to the case when the state space of the system is the greatest possible in the sense of theinclusion. The purpose of this paper is that of defining, by analogy with the dynamical systems theory, the omega-limit sets, the invariance and the basins of attraction of the universal regular autonomous asynchronous systems.

Source and Extent of Volcanic Ashes at the Permian-Triassic Boundary in South China and Its implications

Science.gov (United States)

Wang, M.; Zhong, Y. T.; Hou, Y. L.; He, B.

2017-12-01

Highly correlated with the Permian-Triassic Boundary (PTB) Mass Extinction in stratigraphic section, volcanic ashes around the P-T Boundary in South China have been suggested to be a likely cause of the PTB Mass Extinction. So the nature, source and extent of these volcanic ashes have great significance in figuring out the cause of the PTB Mass Extinction. In this study, we attempt to constrain the source and extent of the PTB volcanic ashes in South China by studying pyroclastic sedimentary rocks and the spatial distribution of tuffs and ashes in South China. The detrital zircons of tuffaceous sandstones from Penglaitan section yield an age spectrum peaked at 252Ma, with ɛHf(t) values varying from -20 to -5 ,and have Nb/Hf, Th/Nb and Hf/Th ratios similar to those from arc/orogenic-related settings. Coarse tuffaceous sandstones imply that their source is in limited distance. Those pyroclastic sedimentary rocks in Penglaitan are well correlated with the PTB volcanic ashes in Meishan GSSP section in stratigraphy. In the spatial distribution, pyroclastic sedimentary rocks and tuffs distribute only in southwest of South China, while finer volcanic ashes are mainly in the northern part. This spatial distribution suggests the source of tuffs and ashes was to the south or southwest of South China. Former studies especially that of Permian-Triassic magmatism in Hainan Island have supported the existence of a continental arc related to the subduction and closure of Palaeo-Tethys on the southwestern margin of South China during Permian to early Triassic. It is suggested that the PTB ashes possibly derived from this Paleo-Tethys continental arc. The fact that volcanic ashes haven't been reported or found in PTB stratum in North China or Northwest China implies a limited extent of the volcanism, which thus is too small to cause the PTB mass extinction.

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

OpenAIRE

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

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...

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

OpenAIRE

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

2012-01-01

International audience; Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO 2 , 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 preserve...

Multiple isotopes (O, C, Li, Sr) as tracers of CO2 and brine leakage from CO2-enhanced oil recovery activities in Permian Basin, Texas, USA

Science.gov (United States)

Phan, T. T.; Sharma, S.; Gardiner, J. B.; Thomas, R. B.; Stuckman, M.; Spaulding, R.; Lopano, C. L.; Hakala, A.

2017-12-01

Potential CO2 and brine migration or leakage into shallow groundwater is a critical issue associated with CO2 injection at both enhanced oil recovery (EOR) and carbon sequestration sites. The effectiveness of multiple isotope systems (δ18OH2O, δ13C, δ7Li, 87Sr/86Sr) in monitoring CO2 and brine leakage at a CO2-EOR site located within the Permian basin (Seminole, Texas, USA) was studied. Water samples collected from an oil producing formation (San Andres), a deep groundwater formation (Santa Rosa), and a shallow groundwater aquifer (Ogallala) over a four-year period were analyzed for elemental and isotopic compositions. The absence of any change in δ18OH2O or δ13CDIC values of water in the overlying Ogallala aquifer after CO2 injection indicates that injected CO2 did not leak into this aquifer. The range of Ogallala water δ7Li (13-17‰) overlaps the San Andres water δ7Li (13-15‰) whereas 87Sr/86Sr of Ogallala (0.70792±0.00005) significantly differs from San Andres water (0.70865±0.00003). This observation demonstrates that Sr isotopes are much more sensitive than Li isotopes in tracking brine leakage into shallow groundwater at the studied site. In contrast, deep groundwater δ7Li (21-25‰) is isotopically distinct from San Andres produced water; thus, monitoring this intermitted formation water can provide an early indication of CO2 injection-induced brine migration from the underlying oil producing formation. During water alternating with gas (WAG) operations, a significant shift towards more positive δ13CDIC values was observed in the produced water from several of the San Andres formation wells. The carbon isotope trend suggests that the 13C enriched injected CO2 and formation carbonates became the primary sources of dissolved inorganic carbon in the area surrounding the injection wells. Moreover, one-way ANOVA statistical analysis shows that the differences in δ7Li (F(1,16) = 2.09, p = 0.17) and 87Sr/86Sr (F(1,18) = 4.47, p = 0.05) values of

Boron isotopes in brachiopods during the end-Permian mass extinction: constraints on pH evolution and seawater chemistry

Science.gov (United States)

Jurikova, Hana; Gutjahr, Marcus; Liebetrau, Volker; Brand, Uwe; Posenato, Renato; Garbelli, Claudio; Angiolini, Lucia; Eisenhauer, Anton

2017-04-01

The global biogeochemical cycling of carbon is fundamental for life on Earth with the ocean playing a key role as the largest and dynamically evolving CO2 reservoir. The boron isotope composition (commonly expressed in δ11B) of marine calcium carbonate is considered to be one of the most reliable paleo-pH proxies, potentially enabling us to reconstruct past ocean pH changes and understand carbon cycle perturbations along Earth's geological record (e.g. Foster et al., 2008; Clarkson et al., 2015). Brachiopods present an advantageous and largely underutilised archive for Phanerozoic carbon cycle reconstructions considering their high abundance in the geological record and its origin dating back to the early Cambrian. Moreover, their shell made of low-magnesium calcite makes these marine calcifiers more resistant to post-depositional diagenetic alteration of primary chemical signals. We have investigated the δ11B using MC-ICP-MS (Neptune Plus) and B/Ca and other elemental ratios (Mg/Ca, Sr/Ca, Al/Ca, Li/Ca, Ba/Ca, Na/Ca and Fe/Ca) using ICP-MS-Quadrupole (Agilent 7500cx) from the same specimens in pristine brachiopod shells from two sections from northern Italy during the Late Permian. These sections cover the δ13C excursion in excess of ˜4 ‰ (Brand et al., 2012) and are associated with major climate and environmental perturbations that lead to the mass extinction event at the Permian-Triassic boundary. Particular emphasis will be placed on the implications of our new paleo-pH estimates on the seawater chemistry during the Late Permian. Brand, U., Posenato, R., Came, R., Affek, H., Angiolini, L., Azmy, K. and Farabegoli, E.: The end-Permian mass extinction: A rapid volcanic CO2 and CH4-climatic catastrophe, Chemical Geology 323, 121-144, doi:10.1016/j.chemgeo.2012.06.015, 2012. Clarkson, M.O., Kasemann, S.A., Wood, R.A., Lenton, T.M., Daines, S.J., Richoz, S., Ohnemueller, F., Meixner, A., Poulton, S.W. and Tipper, E.T.: Ocean acidification and the Permo

CO2 Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Annual report, January 1, 1995--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

Wehner, S.C.; Boomer, R.J.; Cole, R.; Preiditus, J.; Vogt, J.

1996-09-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg/San Andres formation; a light oil, shallow shelf carbonate reservoir within the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico.

Late Jurassic – early Cretaceous inversion of rift structures, and linkage of petroleum system elements across post-rift unconformity, U.S. Chukchi Shelf, arctic Alaska

Science.gov (United States)

Houseknecht, David W.; Connors, Christopher D.

2015-01-01

Basin evolution of the U.S. Chukchi shelf involved multiple phases, including Late Devonian–Permian rifting, Permian–Early Jurassic sagging, Late Jurassic–Neocomian inversion, and Cretaceous–Cenozoic foreland-basin development. The focus of ongoing exploration is a petroleum system that includes sag-phase source rocks; inversion-phase reservoir rocks; structure spanning the rift, sag, and inversion phases; and hydrocarbon generation during the foreland-basin phase.

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)

May, R.T.; Strand, J.R.; Reid, B.E.; Phillips, W.R.

1977-12-01

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

Structured Analog CMOS Design

CERN Document Server

Stefanovic, Danica

2008-01-01

Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

Analog and hybrid computing

CERN Document Server

Hyndman, D E

2013-01-01

Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

Configuration of the magnetic field and reconstruction of Pangaea in the Permian period.

Science.gov (United States)

Westphal, M

1977-05-12

The virtual geomagnetic poles of Laurasia and Gondwanaland in the Carboniferous and Permian periods diverge significantly when these continents are reassembled according to the fit calculated by Bullard et al. Two interpretations have been offered: Briden et al. explain these divergences by a magnetic field configuration very different from that of a geocentric axial dipole; Irving (and private communication), Van der Voo and French(4) suggest a different reconstruction and it is shown here that these two interpretations are not incompatible and that the first may help the second.

Analog-to-digital conversion

CERN Document Server

Pelgrom, Marcel J M

2010-01-01

The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

Analog earthquakes

International Nuclear Information System (INIS)

Hofmann, R.B.

1995-01-01

Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

Asymmetrical cross-current turbidite facies tract in a structurally-confined mini-basin (Priabonian-Rupelian, Ranzano Sandstone, northern Apennines, Italy)

NARCIS (Netherlands)

Tinterri, R.; Laporta, M.; Ogata, K.

2017-01-01

This work discusses the stratigraphy and facies analysis of the Ranzano Sandstone, in the northern Apennines (Italy), a confined low-efficiency turbidite system deposited in a series of small piggy-back basins, which show strong analogies with intraslope minibasins commonly observed in divergent

Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China

Directory of Open Access Journals (Sweden)

Taotao Cao

2016-10-01

Full Text Available The Permian shale, a set of transitional shale reservoir, is considered to be an important shale gas exploration target in the Lower Yangtze region. Due to little research conducted on the pore system characteristic and its controlling factors of the shale gas reservoir, SEM, FE-SEM, low-pressure N2 adsorption, and mercury intrusion tests were carried out on the Permian shales from the outcrop and HC well in the southern Anhui. The results show that the Permian shales mainly consist of organic matter, quartz, illite, calcite, and pyrite, of which pyrite occurs as framboids coexisting with organic matter and the organic matter is distributed in shales in stripped, interstitial, thin film and shell shapes. The basic pore types are inorganic mineral pore (intercrystalline pore, intergranular edge pore, intergranular pore, and interlayer pore in clay minerals and the organic pore and microfracture, of which organic pore and microfracture are the dominating pore types. In shale, organic pores are not developed at all in some organic grains but are well developed in others, which may be related to the types of and maceral compositions of kerogen. Under tectonic stress, shale rocks could develop mylonitization phenomenon exhibiting organic grains well blend with clay minerals, and produce a mass of microfractures and nanopores between organic matter grains and clay minerals. Mercury intrusion tests show that the shale is mainly composed of micropore and transition pore with high porosity, good pore connectivity and high efficiency of mercury withdraw, while the shale that mainly dominated by mesopore and macropore has a low porosity, poor pore connectivity, and low efficiency of the mercury withdraw. The volume percentage of mesopore and marcopore is increasing with the increase of quartz, and that of micropore and transition pore has a decreased tendency along with the increase of soluble organic matter (S1. Organic matter is the main contributor to

Latest Permian carbonate carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation

Science.gov (United States)

Schobben, Martin; van de Velde, Sebastiaan; Gliwa, Jana; Leda, Lucyna; Korn, Dieter; Struck, Ulrich; Vinzenz Ullmann, Clemens; Hairapetian, Vachik; Ghaderi, Abbas; Korte, Christoph; Newton, Robert J.; Poulton, Simon W.; Wignall, Paul B.

2017-11-01

Bulk-carbonate carbon isotope ratios are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian-Triassic boundary in the marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data, we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub-)sea-floor microbial communities and their control on calcite nucleation and ambient porewater dissolved inorganic carbon δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization and linked carbon isotope alteration can be controlled by organic matter supply and subsequent microbial remineralization. A major biotic decline among Late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation. Combined with low marine sulfate, this resulted in varying degrees of carbon isotope overprinting. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to 1 out of 10 samples, is sufficient to induce the observed signal of carbon

A new tubeworm of possible serpulid affinity from the Permian of Sicily

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Rossana Sanfilippo

2016-08-01

Full Text Available A new tubeworm, Palaeotubus sosiensis gen. et sp. nov., is described from the Permian Pietra di Salomone limestone (Sosio Valley, W Sicily. The new species is characterized by a thick tube ornamented with slightly flared peristomes and numerous longitudinal keels. The internal structure of the tube was obliterated during diagenesis, which prevents the tube unequivocal systematic attribution. Nevertheless, all preserved morphological characters strongly suggest that the new tube belongs to serpulids. When confirmed by further findings, the positive attribution of this new species to serpulids will imply that it represents the ancestor of the Serpulidae, and the earliest evidence of calcareous tubeworm polychaetes from the Palaeozoic.

Delayed recovery of non-marine tetrapods after the end-Permian mass extinction tracks global carbon cycle

OpenAIRE

Irmis, Randall B.; Whiteside, Jessica H.

2011-01-01

During the end-Permian mass extinction, marine ecosystems suffered a major drop in diversity, which was maintained throughout the Early Triassic until delayed recovery during the Middle Triassic. This depressed diversity in the Early Triassic correlates with multiple major perturbations to the global carbon cycle, interpreted as either intrinsic ecosystem or external palaeoenvironmental effects. In contrast, the terrestrial record of extinction and recovery is less clear; the effects and magn...

Analog circuit design

CERN Document Server

Dobkin, Bob

2012-01-01

Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

Significance of detrital zircons in upper Devonian ocean-basin strata of the Sonora allochthon and Lower Permian synorogenic strata of the Mina Mexico foredeep, central Sonora, Mexico

Science.gov (United States)

Poole, F.G.; Gehrels, G.E.; Stewart, John H.

2008-01-01

U-Pb isotopic dating of detrital zircons from a conglomeratic barite sandstone in the Sonora allochthon and a calciclastic sandstone in the Mina Mexico foredeep of the Minas de Barita area reveals two main age groups in the Upper Devonian part of the Los Pozos Formation, 1.73-1.65 Ga and 1.44-1.42 Ga; and three main age groups in the Lower Permian part of the Mina Mexico Formation, 1.93-1.91 Ga, 1.45-1.42 Ga, and 1.1-1.0 Ga. Small numbers of zircons with ages of 2.72-2.65 Ga, 1.30-1.24 Ga, ca. 2.46 Ga, ca. 1.83 Ga, and ca. 0.53 Ga are also present in the Los Pozos sandstone. Detrital zircons ranging in age from 1.73 to 1.65 Ga are considered to have been derived from the Yavapai, Mojave, and Mazatzal Provinces and their transition zones of the southwestern United States and northwestern Mexico. The 1.45-1.30 Ga detrital zircons were probably derived from scattered granite bodies within the Mojave and Mazatzal basement rocks in the southwestern United States and northwestern Mexico, and possibly from the Southern and Eastern Granite-Rhyolite Provinces of the southern United States. The 1.24-1.0 Ga detrital zircons are believed to have been derived from the Grenville (Llano) Province to the east and northeast or from Grenvilleage intrusions or anatectites to the north. Several detrital zircon ages ranging from 2.72 to 1.91 Ga were probably derived originally from the Archean Wyoming Province and Early Paleoproterozoic rocks of the Lake Superior region. These older detrital zircons most likely have been recycled one or more times into the Paleozoic sandstones of central Sonora. The 0.53 Ga zircon is believed to have been derived from a Lower Cambrian granitoid or meta-morphic rock northeast of central Sonora, possibly in New Mexico and Colorado, or Oklahoma. Detrital zircon geochronology suggests that most of the detritus in both samples was derived from Laurentia to the north, whereas some detritus in the Permian synorogenic foredeep sequence was derived from the

Basinal analysis of the Ecca and Lowermost Beaufort Beds and associated coal, uranium and heavy mineral beach sand occurrences

International Nuclear Information System (INIS)

Ryan, P.J.; Whitfield, G.G.

1979-01-01

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. 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

Optical analogy. Synthesis report

International Nuclear Information System (INIS)

1965-01-01

The authors report the study of conditions under which light attenuation (reflection, diffusion, absorption) and the attenuation of some radiations (notably thermal neutrons) can be described with analogical calculations. The analogy between light physical properties and neutron properties is not searched for, but the analogy between their attenuation characteristics. After having discussed this possible analogy, they propose a mathematical formulation of neutron and optical phenomena which could theoretically justify the optical analogy. The second part reports a more practical study of optics problems such as the study of simple optics materials and illumination measurements, or more precisely the study of angular distributions of optical reflections, a determination of such angular distributions, and an experimental determination of the albedo

Formation of Si-Al-Mg-Ca-rich zoned magnetite in an end-Permian phreatomagmatic pipe in the Tunguska Basin, East Siberia

Science.gov (United States)

Neumann, Else-Ragnhild; Svensen, Henrik H.; Polozov, Alexander G.; Hammer, Øyvind

2017-12-01

Magma-sediment interactions in the evaporite-rich Tunguska Basin resulted in the formation of numerous phreatomagmatic pipes during emplacement of the Siberian Traps. The pipes contain magnetite-apatite deposits with copper and celestine mineralization. We have performed a detailed petrographic and geochemical study of magnetite from long cores drilled through three pipe breccia structures near Bratsk, East Siberia. The magnetite samples are zoned and rich in Si (≤5.3 wt% SiO2), Ca, Al, and Mg. They exhibit four textural types: (1) massive ore in veins, (2) coating on breccia clasts, (3) replacement ore, and (4) reworked ore at the crater base. The textural types have different chemical characteristics. "Breccia coating" magnetite has relatively low Mg content relative to Si, as compared to the other groups, and appears to have formed at lower oxygen fugacity. Time series analyses of MgO variations in microprobe transects across Si-bearing magnetite in massive ore indicate that oscillatory zoning in the massive ore was controlled by an internal self-organized process. We suggest that hydrothermal Fe-rich brines were supplied from basalt-sediment interaction zones in the evaporite-rich sedimentary basin, leading to magnetite ore deposition in the pipes. Hydrothermal fluid composition appears to be controlled by proximity to dolerite fragments, temperature, and oxygen fugacity. Magnetite from the pipes has attributes of iron oxide-apatite deposits (e.g., textures, oscillatory zoning, association with apatite, and high Si content) but has higher Mg and Ca content and different mineral assemblages. These features are similar to magnetite found in skarn deposits. We conclude that the Siberian Traps-related pipe magnetite deposit gives insight into the metamorphic and hydrothermal effects following magma emplacement in a sedimentary basin.

CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

Energy Technology Data Exchange (ETDEWEB)

Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

1999-02-24

The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

Petrophysical Properties of the Yeso, Abo and Cisco Formations in the Permian Basin in New Mexico, U.S.A

Science.gov (United States)

Mann, Griffin

The area that comprises the Northwest Shelf in Lea Co., New Mexico has been heavily drilled over the past half century. The main target being shallow reservoirs within the Permian section (San Andres and Grayburg Formations). With a focus shifting towards deeper horizons, there is a need for more petrophysical data pertaining to these formations, which is the focus of this study through a variety of techniques. This study involves the use of contact angle measurements, fluid imbibition tests, Mercury Injection Capillary Pressure (MICP) and log analysis to evaluate the nano-petrophysical properties of the Yeso, Abo and Cisco Formation within the Northwest Shelf area of southeast New Mexico. From contact angle measurements, all of the samples studied were found to be oil-wetting as n-decane spreads on to the rock surface much quicker than the other fluids (deionized water and API brine) tested. Imbibition tests resulted in a well-connected pore network being observed for all of the samples with the highest values of imbibition slopes being recorded for the Abo samples. MICP provided a variety of pore structure data which include porosity, pore-throat size distributions, permeability and tortuosity. The Abo samples saw the highest porosity percentages, which were above 15%, with all the other samples ranging from 4 - 7%. The majority of the pore-throat sizes for most of the samples fell within the 1 - 10 mum range. The only exceptions to this being the Paddock Member within the Yeso Formation, which saw a higher percentage of larger pores (10 - 1000mum) and one of the Cisco Formation samples, which had the majority of its pore sizes fall in the 0.1 - 1 mum range. The log analysis created log calculations and curves for cross-plot porosity and water saturation that were then used to derive a value for permeability. The porosity and permeability values were comparable with those measured from our MICP and literature values.

Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters

Directory of Open Access Journals (Sweden)

Helga Stan-Lotter

2013-02-01

Full Text Available Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl, whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing hypotheses on prokaryotic evolution, such as the molecular clock concept, or the net-like history of genome evolution. A comparison of available taxonomic characteristics from strains of Hcc. salifodinae and other Halococcus species, most of them originating from surface waters, is presented. The cell wall polymer of Hcc. salifodinae was examined and found to be a heteropolysaccharide, similar to that of Hcc. morrhuae. Polyhydroxyalkanoate granules were present in Hcc. salifodinae, suggesting a possible lateral gene transfer before Permian times.

Are all analogies created equal? Prefrontal cortical functioning may predict types of analogical reasoning.

Science.gov (United States)

Chrysikou, Evangelia G; Thompson-Schill, Sharon L

2010-06-01

Abstract The proposed theory can account for analogies based on learned relationships between elements in the source and target domains. However, its explanatory power regarding the discovery of new relationships during analogical reasoning is limited. We offer an alternative perspective for the role of PFC in analogical thought that may better address different types of analogical mappings.

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

International Nuclear Information System (INIS)

Beri, A; Daners, G.; Spoturno, J.

1998-01-01

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

Proterozoic structure, cambrian rifting, and younger faulting as revealed by a regional seismic reflection network in the Southern Illinois Basin

Science.gov (United States)

Potter, C.J.; Drahovzal, James A.; Sargent, M.L.; McBride, J.H.

1997-01-01

Four high-quality seismic reflection profiles through the southern Illinois Basin, totaling 245 km in length, provide an excellent regional subsurface stratigraphic and structural framework for evaluation of seismic risk, hydrocarbon occurrence, and other regional geologic studies. These data provide extensive subsurface information on the geometry of the intersection of the Cambrian Reelfoot and Rough Creek rifts, on extensive Proterozoic reflection sequences, and on structures (including the Fluorspar Area Fault Complex and Hicks Dome) that underlie a transitional area between the well-defined New Madrid seismic zone (to the southwest) and a more diffuse area of seismicity in the southern Illinois Basin. Our principal interpretations from these data are listed here in order of geologic age, from oldest to youngest: 1. Prominent Proterozoic layering, possibly equivalent to Proterozoic (???1 Ga) Middle Run Formation clastic strata and underlying (1.3-1.5 Ga) volcanic rocks of the East Continent rift basin, has been strongly deformed, probably as part of the Grenville foreland fold and thrust belt. 2. A well-defined angular unconformity is seen in many places between Proterozoic and Cambrian strata; a post-Grenville Proterozoic sequence is also apparent locally, directly beneath the base of the Cambrian. 3. We infer a major reversal in Cambrian rift polarity (accommodation zone) in the Rough Creek Graben in western Kentucky. 4. Seismic facies analysis suggests the presence of basin-floor fan complexes at and near the base of the Cambrian interval and within parts of a Proterozoic post-Grenville sequence in several parts of the Rough Creek Graben. 5. There is an abrupt pinchout of the Mount Simon Sandstone against crystalline basement beneath the Dale Dome (near the Texaco no. 1 Cuppy well, Hamilton County) in southeastern Illinois, and a more gradual Mount Simon pinchout to the southeast. 6. Where crossed by the seismic reflection line in southeast Illinois, some

Clockwise rotation of the Santa Marta massif and simultaneous Paleogene to Neogene deformation of the Plato-San Jorge and Cesar-Ranchería basins

Science.gov (United States)

Montes, Camilo; Guzman, Georgina; Bayona, German; Cardona, Agustin; Valencia, Victor; Jaramillo, Carlos

2010-10-01

A moderate amount of vertical-axis clockwise rotation of the Santa Marta massif (30°) explains as much as 115 km of extension (stretching of 1.75) along its trailing edge (Plato-San Jorge basin) and up to 56 km of simultaneous shortening with an angular shear of 0.57 along its leading edge (Perijá range). Extensional deformation is recorded in the 260 km-wide, fan-shaped Plato-San Jorge basin by a 2-8 km thick, shallowing-upward and almost entirely fine-grained, upper Eocene and younger sedimentary sequence. The simultaneous initiation of shortening in the Cesar-Ranchería basin is documented by Mesozoic strata placed on to lower Eocene syntectonic strata (Tabaco Formation and equivalents) along the northwest-verging, shallow dipping (9-12° to the southeast) and discrete Cerrejón thrust. First-order subsidence analysis in the Plato-San Jorge basin is consistent with crustal stretching values between 1.5 and 2, also predicted by the rigid-body rotation of the Santa Marta massif. The model predicts about 100 km of right-lateral displacement along the Oca fault and 45 km of left-lateral displacement along the Santa Marta-Bucaramanga fault. Clockwise rotation of a rigid Santa Marta massif, and simultaneous Paleogene opening of the Plato-San Jorge basin and emplacement of the Cerrejón thrust sheet would have resulted in the fragmentation of the Cordillera Central-Santa Marta massif province. New U/Pb ages (241 ± 3 Ma) on granitoid rocks from industry boreholes in the Plato-San Jorge basin confirm the presence of fragments of a now segmented, Late Permian to Early Triassic age, two-mica, granitic province that once spanned the Santa Marta massif to the northernmost Cordillera Central.

Troubleshooting analog circuits

CERN Document Server

Pease, Robert A

1991-01-01

Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

Record of Permian-Early Triassic continental arc magmatism in the western margin of the Jiamusi Block, NE China: petrogenesis and implications for Paleo-Pacific subduction

Science.gov (United States)

Yang, Hao; Ge, Wenchun; Dong, Yu; Bi, Junhui; Wang, Zhihui; Ji, Zheng; Yang, H.; Ge, W. C.; Dong, Y.; Bi, J. H.; Wang, Z. H.; Ji, Z.

2017-09-01

In this paper, we report zircon U-Pb ages, Hf isotopes and whole-rock geochemical data for the Permian to Early Triassic granitoids from the western margin of the Jiamusi Block (WJB), NE China. The intermediate to felsic (SiO2 = 59.67-74.04 wt%) granitoids belong to calc-alkaline series and are characterized by enrichments in light rare earth elements and large ion lithophile elements with pronounced negative Nb, Ta and Ti anomalies, revealing typical continental magmatic arc geochemical signatures. The zircon U-Pb determinations on the granodiorite, monzogranite, syenogranite and quartz diorite samples yielded ages between ca. 275-245 Ma, which, together with the published coeval intrusive rocks, indicates that Permian to Early Triassic continental arc magmatism occurred extensively in the WJB. The low and mainly negative zircon ɛ Hf( t) values between -7.6 and +1.6 and the zircon Hf model ages of 1.2-1.8 Ga, which are significantly older than their crystallization ages, suggest that they were mainly derived from reworking of ancient crustal materials with a limited input of juvenile components. The geochemical systematics and petrogenetic considerations indicate that the studied granitoids were generated from a zone of melting, assimilation, storage, and homogenization, i.e., a MASHed zone at the base of Paleo- to Mesoproterozoic continental crust, where large portions of igneous rocks and minor clay-poor sediments involved in the source region. In combination with regional geological data, we argue that the Jiamusi Block was unlikely the rifted segment of the Songliao Block and two possible geodynamical models were proposed to interpret the formation of the ca. 275-245 Ma granitoids in the WJB. In the context of Permian global plate reconstruction, we suggest that Paleo-Pacific plate subduction was initiated in the Permian to Early Triassic beneath the Jiamusi Block, and even whole eastern NE China.

Petroleum prospectivity of the Canada Basin, Arctic Ocean

Science.gov (United States)

Grantz, A.; Hart, P.E.

2011-01-01

Reconnaissance seismic reflection data indicate that Canada Basin is a remnant of the Amerasia Basin of the Arctic Ocean that lies south of the Alpha-Mendeleev Large Igneous Province, which was constructed on the northern part of the Amerasia Basin between about 127 and 89-75 Ma. Canada Basin is filled with Early Jurassic to Holocene detritus from the Mackenzie River system, which drains the northern third of interior North America, with sizable contributions from Alaska and Northwest Canada. Except for the absence of a salt- and shale-bearing mobile substrate Canada Basin is analogous to the Mississippi Delta and the western Gulf of Mexico. Canada Basin contains about 7 to >14 km of sediment beneath the Mackenzie Prodelta on the southeast, 6 to 7 km of sediment beneath the abyssal plain on the west, and roughly 5 or 6 million cubic km of sediment. About three fourths of the basin fill generates low amplitude seismic reflections, interpreted to represent hemiplegic deposits, and a fourth of the fill generates interbedded lenses to extensive layers of moderate to high amplitude reflections interpreted to represent unconfined turbidite and amalgamated channel deposits. Extrapolation from Arctic Alaska and Northwest Canada suggests that three fourths of the section in Canada Basin may contain intervals of hydrocarbon source rocks and the apparent age of the basin suggests that it contains three of the six stratigraphic intervals that together provided >90?? of the World's discovered reserves of oil and gas.. Worldwide heat flow averages suggest that about two thirds of Canada Basin lies in the oil or gas window. At least five types of structural or stratigraphic features of local to regional occurrence offer exploration targets in Canada Basin. These consist of 1) a belt of late Eocene to Miocene shale-cored detachment folds containing with at least two anticlines that are capped by beds with bright spots, 2) numerous moderate to high amplitude reflection packets

Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

Science.gov (United States)

Bahlburg, H.; Breitkreuz, C.

originated as an extensional structure at the continental margin of Gondwana. Independent lines of evidence imply that basin evolution was not connected to subduction. Thus, the basin could not have been in a fore-arc position as previously postulated. Above the folded Devonian-Early Carboniferous strata, a continental volcanic arc developed from the Late Carboniferous to the Middle Triassic. It represents the link between the Choiyoi Province in central Chile and Argentina, and the Mitu Group rift in southern Peru. The volcanic arc succession is characterized by the prevalence of silicic lavas and tuffs and volcaniclastic sedimentary rocks. During the latest Carboniferous, a thick ostracod-bearing lacustrine unit formed in an extended lake in the area of the Depresión Preandina. This lake basin originated in an intra-arc tensional setting. During the Early Permian, marine limestones were deposited on a marine platform west and east of the volcanic arc, connected to the depositional area of the Copacabana Formation in southern Peru.

Analogical Reasoning in Geometry Education

Science.gov (United States)

Magdas, Ioana

2015-01-01

The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

Late Guadalupian evolution of the Delaware Basin: insights from stable isotope and trace element geochemistry

Science.gov (United States)

Smith, B.; Kerans, C.

2017-12-01

Accurate characterization of mixed carbonate and evaporite deposits requires an understanding of basin-scale physical, chemical, and biological processes. In these settings, carbonate geochemistry often responds to changes in the prevailing conditions in the water column. It follows that the geochemical record presents a potential aid for interpretation of depositional systems provided that it is relatively free of diagenetic overprint. This is seldom the case in shallow-water settings as processes such as meteoric diagenesis and early dolomitization obscure or erase the original geochemical signal. Fine grained deep-water sediments are more likely to retain their original geochemical characteristics. If reliable shelf-to-basin correlations can be established, then basinal deposits provide critical data not only for the interpretation of deep water environments, but overall basin evolution as well. This study examines variations in trace element and stable isotope geochemistry from the Delaware Basin of West Texas and New Mexico. Interpretation of geochemical data within a pre-existing shelf-to-basin stratigraphic framework suggests a link between basin water chemistry and sea level changes during the entirety of the Guadalupian. This link is supported analogies to modern silled basins where changes in sea level and thus recharge across the sill can control nutrient input, circulation, and bottom water oxygenation. In light of these relationships, the filling of the Delaware Basin with basin-centered evaporites at the end of the Guadalupian likely represents the culmination of a more gradual, cyclic evolution towards basin restriction. Ongoing work will continue to focus on tying regional-scale changes in basin water chemistry to the combined geochemical and physical sedimentological records.

Generic aspects of salt repositories

International Nuclear Information System (INIS)

Laughon, R.B.

1979-01-01

The history of geological disposal of radioactive wastes in salt is presented from 1957 when a panel of the National Academy of Sciences-National Research Council recommended burial in bedded salt deposits. Early work began in the Kansas, portion of the Permian Basin where simulated wastes were placed in an abandoned salt mine at Lyons, Kansas, in the late 1960's. This project was terminated when the potential effect of nearby solution mining activities could not be resolved. Evaluation of bedded salts resumed a few years later in the Permian Basin in southeastern New Mexico, and search for suitable sites in the 1970's resulted in the formation of the National Waste Terminal Storage Program in 1976. Evaluation of salt deposits in many regions of the United States has been virtually completed and has shown that deposits having the greatest potential for radioactive waste disposal are those of the largest depositional basins and salt domes of the Gulf Coast region

Influences of Stocking Salmon Carcass Analogs on Salmonids in Yakima River Tributaries, 2001-2002 Technical Report.

Energy Technology Data Exchange (ETDEWEB)

Pearsons, Todd N.; Johnson, Christopher L. (Washington Department of Fish and Wildlife, Olympia, WA)

2003-04-01

The benefits that marine derived nutrients from adult salmon carcasses provide to juvenile salmonids are increasingly being recognized. Current estimates suggest that only 6-7% of marine-derived nitrogen and phosphorus that were historically available to salmonids in the Pacific Northwest are currently available. Food limitation may be a major constraint limiting the restoration of salmonids. A variety of methods have been proposed to offset this nutrient deficit including: allowing greater salmon spawning escapement, stocking hatchery salmon carcasses, and stocking inorganic nutrients. Unfortunately, each of these methods has some ecological or socio-economic shortcoming. We intend to overcome many of these shortcomings by making and evaluating a pathogen free product that simulates a salmon carcass (analog). Abundant sources of marine derived nutrients are available such as fish offal from commercial fishing and salmon carcasses from hatcheries. However, a method for recycling these nutrients into a pathogen free analog that degrades at a similar rate as a natural salmon carcass has never been developed. We endeavored to (1) develop a salmon carcass analog that will increase the food available to salmonids, (2) determine the pathways that salmonids use to acquire food from analogs, and (3) determine the benefits to salmonids and the potential for application to salmonid restoration. We used a before-after-control-impact-paired design in six tributaries of the upper Yakima basin to determine the utility of stocking carcass analogs. Our preliminary results suggest that the introduction of carcass analogs into food-limited streams can be used to restore food pathways previously provided by anadromous salmon. The analogs probably reproduced both of the major food pathways that salmon carcasses produce: direct consumption and food chain enhancement. Trout and salmon fed directly on the carcass analogs during the late summer and presumably benefited from the increased

Vegetation and plant food reconstruction of lowermost Bed II, Olduvai Gorge, using modern analogs.

Science.gov (United States)

Copeland, Sandi R

2007-08-01

Vegetation and plant foods for hominins of lowermost Bed II, Olduvai Gorge were modeled by examining vegetation in modern habitats in northern Tanzania (Lake Manyara, Ngorongoro, Serengeti) that are analogous to the paleolandscape in terms of climate, land forms, and soil types, as indicated by previous paleoenvironmental studies of Olduvai. Plant species in the modern habitats were identified in a series of sample plots, and those known to be eaten by modern humans, chimpanzees, or baboons were considered potentially edible for early hominins. Within the 50-80 kyr deposition of lowermost Bed II, periods of drier climate were characterized by low lake stands and a broad eastern lacustrine plain containing a mosaic of springs, marsh, woodland, and edaphic grassland. Based on results of this study, plant food diversity in each of those habitats was relatively low, but the mosaic nature of the area meant that hominins could reach several different habitat types within short distances, with access to potential plant foods including marsh plants, grass grains, roots, shrub fruits, edible parts from palms, leafy herbaceous plants, and Acacia pods, flowers, and gum. Based on Manyara analogs, a greater variety of plant foods, such as tree fruits (e.g., Ficus, Trichilia) and the roots and fruits of shrubs (e.g., Cordia, Salvadora) would be expected further east along the rivers in the lacustrine terrace and alluvial fans. Interfluves of the alluvial fans were probably less wooded and offered relatively fewer varieties of plant foods, but there is sparse paleoenvironmental evidence for the character of Olduvai's alluvial fans, making the choice of appropriate modern analogs difficult. In the western side of the basin, based on modern analogs in the Serengeti, riverine habitats provided the greatest variety of edible plant food species (e.g., Acacia, Grewia, Justicia). If the interfluves were grassland, then a large variety of potentially edible grasses and forbs were present

Tectonic Evolution of the Çayirhan Neogene Basin (Ankara), Central Turkey

Science.gov (United States)

Behzad, Bezhan; Koral, Hayrettin; İşb&idot; l, Duygu; Karaaǧa; ç, Serdal

2016-04-01

Çayırhan (Ankara) is located at crossroads of the Western Anatolian extensional region, analogous to the Basin and Range Province, and suture zone of the Neotethys-Ocean, which is locus of the North Anatolian Transform since the Late Miocene. To the north of Çayırhan (Ankara), a Neogene sedimentary basin comprises Lower-Middle Miocene and Upper Miocene age formations, characterized by swamp, fluvial and lacustrine settings respectively. This sequence is folded and transected by neotectonic faults. The Sekli thrust fault is older than the Lower-Middle Miocene age formations. The Davutoǧlan fault is younger than the Lower-Middle Miocene formations and is contemporaneous to the Upper Miocene formation. The Çatalkaya fault is younger than the Upper Miocene formation. The sedimentary and tectonic features provide information on mode, timing and evolution of this Neogene age sedimentary basin in Central Turkey. It is concluded that the region underwent a period of uplift and erosion under the influence of contractional tectonics prior to the Early-Middle Miocene, before becoming a semi-closed basin under influence of transtensional tectonics during the Early-Middle Miocene and under influence of predominantly extensional tectonics during the post-Late Miocene times. Keywords: Tectonics, Extension, Transtension, Stratigraphy, Neotectonic features.

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

International Nuclear Information System (INIS)

Ferreira, Ademar de Oliveira

2008-02-01

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 226 Ra, 238 U, 32 Th and 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 238 U were smaller for the limestones (17.80 ±0.09 Bq.Kg -1 ), larger for the bituminous shales (125.5 ± 2.6 Bq.Kg -1 with enrichment of uranium in the sample (200), 548 ± 16 Bq.Kg -1 , upper part of the column), and intermediate for the rhythmits (23.0 ± 1,3 Bq.Kg -1 . The ratio eTh/K obtained for the studied profiles has equivalent values, indicating similar mineralogical characteristics for the limestones, bituminous shales, rhythmits and studied rigolits. On the other hand, to the ratio eTh/eU showed that two of the three regolits samples belong to oxidizer atmospheres, favoring the leaching of uranium, what can be

Geochemistry of the Waste Isolation Pilot Plant (WIPP) site, southeastern New Mexico, U.S.A

International Nuclear Information System (INIS)

Lambert, S.J.

1992-01-01

An extensive geochemical data base, including analyses of major and minor solutes, mineralogical studies of core samples, and isotopic studies of waters, carbonates and sulfates, has been assembled for evaporites and related rocks in the northern Delaware Basin of southeastern New Mexico. These data were compiled for the geological and hydrological characterization of the Waste Isolation Pilot Plant (WIPP), which is excavated in the evaporites of the Salado Formation. These data were evaluated in order:(1) to determine the stability of the evaporite mineralogy over geological time; (2) to compare the aqueous geochemistry with host rock mineralogy; (3) to delineate the nature and timing of water-rock interactions, such as dissolution and recrystallization; and (4) to determine the geological and climatic conditions that have governed groundwater recharge. The resulting synthesis of data and current hypotheses concerning the origin, composition and history of waters in the evaporite rocks and related units of the Delaware Basin provides a tentative conceptual model for the behavior of the water-rock system since the deposition of the evaporites in the Permian. Essential components of this model include: (1) widespread Late Triassic/Early Jurassic evaporite recrystallization; (2) accumulation of deep-basin brines isolated from meteoric recharge; (3) evaporite dissolution by meteoric waters flowing in carbonates and sulfates interbedded in the uppermost Permian section and at the basin margin; (4) lateral rather than vertical infiltration of pre-Holocene meteoric waters in the uppermost Permian section; and (5) climatic conditions presently less conductive to recharge than in the Late Pleistocene. (author)

The Late Paleozoic relative gas fields of coal measure in China and their significances on the natural gas industry

Directory of Open Access Journals (Sweden)

Chenchen Fang

2016-12-01

Full Text Available The coal measure gas sources of coal-derived gas fields in the Late Paleozoic China are the Lower Carboniferous Dishuiquan Formation, the Upper Carboniferous Batamayineishan Formation and Benxi Formation, the Lower Permian Taiyuan Formation and Shanxi Formation, and the Upper Permian Longtan Formation. The coal-derived gas accumulates in Ordovician, Carboniferous, Permian, and Paleocene reservoirs and are distributed in Ordos Basin, Bohai Bay Basin, Junggar Basin, and Sichuan Basin. There are 16 gas fields and 12 of them are large gas fields such as the Sulige large gas field which is China's largest reserve with the highest annual output. According to component and alkane carbon isotope data of 99 gas samples, they are distinguished to be coal-derived gas from coal-derived gas with δ13C2 > −28.5‰ and δ13C1 -δ13C2 -δ13C3 identification chart. The Late Paleozoic relative gas fields of coal measure are significant for the Chinese natural gas industry: proven natural gas geological reserves and annual output of them account for 1/3 in China, and the gas source of three significant large gas fields is coal-derived, which of five significant large gas fields supporting China to be a great gas producing country. The average reserves of the gas fields and the large gas fields formed from the late Paleozoic coal measure are 5.3 and 1.7 times that of the gas fields and the large gas fields in China.

Analog and mixed-signal electronics

CERN Document Server

Stephan, Karl

2015-01-01

A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

Meat analog: a review.

Science.gov (United States)

Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

2015-01-01

The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers.

Digital and analog communication systems

Science.gov (United States)

Shanmugam, K. S.

1979-01-01

The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

Ca and Sr isotope records support ocean acidification during end-Permian mass extinction

Science.gov (United States)

Wang, J.; Jacobson, A. D.; Zhang, H.; Ramezani, J.; Sageman, B. B.; Hurtgen, M.; Bowring, S. A.; Shen, S.

2017-12-01

The end-Permian mass extinction represents the most devastating loss of biodiversity during the Phanerozoic. A negative carbon isotope (δ13C) excursion that accompanies the event suggests a significant perturbation to the global carbon cycle, likely induced by CO2 emissions during eruption of the Siberian Traps large igneous province. The carbon cycle is linked with the Ca and Sr cycles through chemical weathering and carbonate precipitation. Therefore, analyses of Ca (δ44/40Ca), radiogenic Sr (87Sr/86Sr), and stable Sr (δ88/86Sr) isotope abundance variations in marine carbonate rocks spanning the Permian-Triassic Boundary (PTB) can reveal key information about biogeochemical changes that occurred during this time. We report δ44/40Ca, 87Sr/86Sr, and δ88/86Sr records analyzed by TIMS for the Meishan and Dajiang sections in China. δ44/40Ca values exhibit similar patterns in both sections. The values remain unchanged across the extinction event layer (EXT) and then decrease by 0.20‰ before increasing by 0.20‰ to 0.40‰ around the PTB. In the Meishan section, 87Sr/86Sr ratios increase after the EXT and return to pre-excursion levels by the PTB. Simultaneously, δ88/86Sr values decrease by 0.12‰ across the EXT and increase by 0.08‰ by the PTB. The patterns of our data support the hypothesis that elevated atmospheric CO2 levels enhanced chemical weathering inputs and might have caused transient ocean acidification, with an "alkalinity overshoot" and increased carbonate deposition occurring after the extinction. Additional measurements and model calculations are underway to help refine and improve these preliminary interpretations.

Geochemical elements mobility during the history of a paleo-Proterozoic clastic sedimentary basin, the Athabasca Basin (Saskatchewan, Canada)

International Nuclear Information System (INIS)

Kister, P.

2003-10-01

In order to understand the mechanisms of migration and deposition of ore elements, it is essential to determine the timing, source, and destination of the geochemical element mass transfers and/or transportation on a scale encompassing the great sedimentary. The purpose of this study was to trace and to date the element migrations that occurred during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin, which hosts the world's largest and richest uranium deposits. As this geological environment was proved to be efficient to preserve high grade ore deposits for over more than one billion years, it provides an opportunity to study the mobility of some elements in a context that shows analogies with deep geological nuclear waste disposals. The natural analogies of interest include (i) uranium oxide and spent nuclear fuel; (ii) clay alteration halo and near field barrier, (iii) Athabasca sandstone cover and far-field barrier. Five research axis: (1) 3D modelling of the distribution of the main minerals and of some trace elements (U, Pb, Zr, Th, REE, Y, Rb, Sr) on a basin-wide scale and in the U mineralized zones, using the Gocad software. The models have been compared with detailed mineralogical studies performed on selected samples. (2) Pb-Pb and Rb-Sr systematics by TIMS (3) Mass balance calculation of the average Pb/U ratio at the scale of the deposit to evaluate whether the present day amount of radiogenic lead is sufficient to explain a U deposition in one or several episodes (geostatistical tools on Gocad) (4) Thermodynamic modelling of the mineralogical evolution of the Athabasca basin, considering the main mineral present in the sandstone (Phreeqc and Supcrt softwares) (5) U-Pb geochronology of uranium oxides using a 3 step approach: (i) optical and scanning electron microscopy; (ii) electron microprobe; (iii) ion microprobe (SIMS). The purpose was to study the long term stability of the uranium oxides and to characterise the

Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

Science.gov (United States)

Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

2006-01-01

We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

Microfacies, Depositional environment and Sequence Stratigraphy of Upper Carboniferous- Lower Permian rocks from Ozbak-Kuh region (Zaladou Section, East Central Iran

Directory of Open Access Journals (Sweden)

Ali Ahmadi

2016-01-01

Full Text Available Zaladou section is located in Ozbak-Kuh mountains in the nourthen part of Tabas block and consist of shale, limy sandstone, limestone and dolomite. Continous relationship of Upper Carboniferous and Lower Permian deposits, is quite evident in Zaladou section. The lower boundry of this section is located on the Absheni formation of Sardar Group with disconformity surface, and upper boundry’s is covered by disconformity surface and bauxite horizon of Bagh-e-Vang formation. According to the lithological Characters and microscopic studies, tidal flat, lagoon, bar, tidal inlet and open marine sub-environment are identified for Zaladou section. Results of this study show that Zaladou section was deposited in silisiclastic-carbonate mix homoclinal ramp in late Carboniferous and in carbonate homoclinal ramp in early Permian. Field study, microfacies and analysis through the sequence led to recognition of main sequence surface, such as: sequence boundry, maximum flooding surface, marine flooding surface, system tracts and two depositional sequences.

ESD analog circuits and design

CERN Document Server

Voldman, Steven H

2014-01-01

A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

Influences of Stocking Salmon Carcass Analogs on Salmonids in Klickitat River Tributaries, 2001-2005 Completion Report.

Energy Technology Data Exchange (ETDEWEB)

Zendt, Joe; Sharp, Bill (Yakama Nation Fisheries, Toppenish, WA)

2006-09-01

This report describes the work completed by the Yakama Nation Fisheries Program (YNFP) in the Klickitat subbasin in south-central Washington under BPA innovative project No.200105500--Influences of stocking salmon carcass analogs on salmonids in Columbia River Tributaries. Salmon carcasses historically provided a significant source of marine-derived nutrients to many stream systems in the Columbia basin, and decreased run sizes have led to a loss of this nutrient source in many streams. Partners in this project developed a pathogen-free carcass analog and stocked the analogs in streams with the following objectives: restoring food availability to streams with reduced anadromous salmon returns; mimicking the natural pathways and timing of food acquisition by salmonids; minimizing unintended negative ecological effects; and increasing the growth and survival of salmonids. In the Klickitat subbasin, carcass analogs were stocked in two streams in 2002 and 2003; a third stream was used as a control. Salmonid fish abundance, growth, and stomach contents were monitored in all three streams before and after carcass analog placement. Fish, invertebrate, and periphyton samples were also collected for stable isotope analysis (to determine if nutrients from carcass analogs were incorporated into the stream food web). Water quality samples were also collected to determine if nutrient overloading occurred in streams. Significant differences in growth were found between fish in treated and untreated stream reaches. Fish in treatment reaches exhibited higher instantaneous growth rates approximately one month after the first carcass analog stocking. Stomach contents sampling indicated that salmonid fish routinely consumed the carcass analog material directly, and that stomach fullness of fish in treatment reaches was higher than in untreated reaches in the first few weeks following carcass analog stockings. No significant differences were detected in fish abundance between

A new morphological type of operculate microspore, Discinispora sinensis gen. nov., from the Permian petrified Noeggerathialean strobilus Discinites sinensis Wang

Czech Academy of Sciences Publication Activity Database

Wang, J.; Zhang, G.; Bek, Jiří; Pfefferkorn, H. W.

2004-01-01

Roč. 128, č. 1 (2004), s. 1-17 ISSN 0034-6667 Grant - others:Chinese National Natural Science Foundation(CN) 40102002; NIGPAS(CN) 003102; NIGPAS(CN) 023117 Institutional research plan: CEZ:AV0Z3013912 Keywords : in situ spores * Noeggerathiales * Permian Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.886, year: 2004

Hydraulic Capacitor Analogy

Science.gov (United States)

Baser, Mustafa

2007-01-01

Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

Analog fourier transform channelizer and OFDM receiver

OpenAIRE

2007-01-01

An OFDM receiver having an analog multiplier based I-Q channelizing filter, samples and holds consecutive analog I-Q samples of an I-Q baseband, the I-Q basebands having OFDM sub-channels. A lattice of analog I-Q multipliers and analog I-Q summers concurrently receives the held analog I-Q samples, performs analog I-Q multiplications and analog I-Q additions to concurrently generate a plurality of analog I-Q output signals, representing an N-point discrete Fourier transform of the held analog ...

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

Science.gov (United States)

Chen, J.; Liu, Gaisheng; Jiang, M.; Chou, C.-L.; Li, H.; Wu, B.; Zheng, Lingyun; Jiang, D.

2011-01-01

To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals. ?? 2011 Elsevier B.V.

Preservation of Permian allanite within an Alpine eclogite facies shear zone at Mt Mucrone, Italy: Mechanical and chemical behaviour of allanite during mylonitization

DEFF Research Database (Denmark)

Cenki-Tok, Benedicte; Oliot, E.; Berger, Alfons

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......, 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...

Early Triassic alternative ecological states driven by anoxia, hyperthermals, and erosional pulses following the end-Permian mass extinction

Science.gov (United States)

Pietsch, C.; Petsios, E.; Bottjer, D. J.

2015-12-01

The end-Permian mass extinction, 252 million years ago, was the most devastating loss of biodiversity in Earth's history. Massive volcanic eruptions of the Siberian Traps and the concurrent burning of coal, carbonate, and evaporite deposits emplaced greenhouse and toxic gasses. Hyperthermal events of the surface ocean, up to 40°C, led to reduced gradient-driven ocean circulation which yielded extensive equatorial oxygen minimum zones. Today, anthropogenic greenhouse gas production is outpacing carbon input modeled for the end-Permian mass extinction, which suggests that modern ecosystems may yet experience a severe biotic crisis. The Early Triassic records the 5 million year aftermath of the end-Permian mass extinction and is often perceived as an interval of delayed recovery. We combined a new, high resolution carbon isotope record, sedimentological analysis, and paleoecological collections from the Italian Werfen Formation to fully integrate paleoenvironmental change with the benthic ecological response. We find that the marine ecosystem experienced additional community restructuring events due to subsequent hyperthermal events and pulses of erosion. The benthic microfauna and macrofauna both contributed to disaster communities that initially rebounded in the earliest Triassic. 'Disaster fauna' including microbialites, microconchids, foraminifera, and "flat clams" took advantage of anoxic conditions in the first ~500,000 years, dominating the benthic fauna. Later, in the re-oxygenated water column, opportunistic disaster groups were supplanted by a more diverse, mollusc-dominated benthic fauna and a complex ichnofauna. An extreme temperature run-up beginning in the Late Dienerian led to an additional hyperthermal event in the Late-Smithian which co-occurred with increased humidity and terrestrial run-off. Massive siliciclastic deposits replaced carbonate deposition which corresponds to the infaunalization of the benthic fauna. The disaster taxa dominated

Conditions for the formation and atmospheric dispersion of a toxic, heavy gas layer during thermal metamorphism of coal and evaporite deposits by sill intrusion

Science.gov (United States)

Storey, Michael; Hankin, Robin K. S.

2010-05-01

There is compelling evidence for massive discharge of volatiles, including toxic species, into the atmosphere at the end of the Permian. It has been argued that most of the gases were produced during thermal metamorphism of coal and evaporite deposits in the East Siberia Tunguska basin following sill intrusion (Retallack and Jahren, 2008; Svensen et al., 2009). The release of the volatiles has been proposed as a major cause of environmental and extinction events at the end of the Permian, with venting of carbon gases and halocarbons to the atmosphere leading to global warming and atmospheric ozone depletion (Svensen et al., 2009) Here we consider the conditions required for the formation and dispersion of toxic, heavier than air, gas plumes, made up of a mixture of CO2, CH4, H2S and SO2 and formed during the thermal metamorphism of C- and S- rich sediments. Dispersion models and density considerations within a range of CO2/CH4 ratios and volatile fluxes and temperatures, for gas discharge by both seepage and from vents, allow the possibility that following sill emplacement much of the vast East Siberia Tunguska basin was - at least intermittently - covered by a heavy, toxic gas layer that was unfavorable for life. Dispersion scenarios for a heavy gas layer beyond the Siberian region during end-Permian times will be presented. REFERENCES G. J. Retallack and A. H. Jahren, Methane release from igneous intrusion of coal during Late Permian extinction events, Journal of Geology, volume 116, 1-20, 2008 H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 2009

Lunar and Planetary Science XXXV: Astrobiology: Analogs and Applications to the Search for Life

Science.gov (United States)

2004-01-01

The session "Astrobiology: Analogs and Applications to the Search for Life" included the folowing reports:The Search for Life on Mars Using Macroscopically Visible Microbial Mats (Stromatolites) in 3.5/3.3 Ga Cherts from the Pilbara in Australia and Barberton in South Africa as Analogues; Life in a Mars Analog: Microbial Activity Associated with Carbonate Cemented Lava Breccias from NW Spitsbergen; Groundwater-fed Iron-rich Microbial Mats in a Freshwater Creek: Growth Cycles and Fossilization Potential of Microbial Features; Episodic Fossilization of Microorganisms on an Annual Timescale in an Anthropogenically Modified Natural Environment: Geochemical Controls and Implications for Astrobiology; Proterozoic Microfossils and Their Implications for Recognizing Life on Mars; Microbial Alteration of Volcanic Glass in Modern and Ancient Oceanic Crust as a Proxy for Studies of Extraterrestrial Material ; Olivine Alteration on Earth and Mars; Searching for an Acidic Aquifer in the R!o Tinto Basin. First Geobiology Results of MARTE Project; In-Field Testing of Life Detection Instruments and Protocols in a Mars Analogue Arctic Environment; Habitability of the Shallow Subsurface on Mars: Clues from the Meteorites; Mars Analog Rio Tinto Experiment (MARTE): 2003 Drilling Campaign to Search for a Subsurface Biosphere at Rio Tinto Spain; Characterization of the Organic Matter in an Archean Chert (Warrawoona, Australia); and The Solfatara Crater, Italy: Characterization of Hydrothermal Deposits, Biosignatures and Their Astrobiological Implication.

The thermal history of the Karoo Moatize-Minjova Basin, Tete Province, Mozambique: An integrated vitrinite reflectance and apatite fission track thermochronology study

Science.gov (United States)

Fernandes, Paulo; Cogné, Nathan; Chew, David M.; Rodrigues, Bruno; Jorge, Raul C. G. S.; Marques, João; Jamal, Daud; Vasconcelos, Lopo

2015-12-01

The Moatize-Minjova Basin is a Karoo-aged rift basin located in the Tete Province of central Mozambique along the present-day Zambezi River valley. In this basin the Permian Moatize and Matinde formations consist of interbedded carbonaceous mudstones and sandstones with coal seams. The thermal history has been determined using rock samples from two coal exploration boreholes (ca. 500 m depth) to constrain the burial and exhumation history of the basin. Organic maturation levels were determined using vitrinite reflectance and spore fluorescence/colour. Ages and rates of tectonic uplift and denudation have been assessed by apatite fission track analysis. The thermal history was modelled by inverse modelling of the fission track and vitrinite reflectance data. The Moatize Formation attained a coal rank of bituminous coals with low to medium volatiles (1.3-1.7%Rr). Organic maturation levels increase in a linear fashion downhole in the two boreholes, indicating that burial was the main process controlling peak temperature maturation. Calculated palaeogeothermal gradients range from 59 °C/km to 40 °C/km. According to the models, peak burial temperatures were attained shortly (3-10 Ma) after deposition. Apatite fission track ages [146 to 84 Ma (Cretaceous)] are younger than the stratigraphic age. Thermal modelling indicates two episodes of cooling and exhumation: a first period of rapid cooling between 240 and 230 Ma (Middle - Upper Triassic boundary) implying 2500-3000 m of denudation; and a second period, also of rapid cooling, from 6 Ma (late Miocene) onwards implying 1000-1500 m of denudation. The first episode is related to the main compressional deformation event within the Cape Fold Belt in South Africa, which transferred stress northwards on pre-existing transtensional fault systems within the Karoo rift basins, causing tectonic inversion and uplift. During the Mesozoic and most of the Cenozoic the basin is characterized by very slow cooling. The second period

Inductive, Analogical, and Communicative Generalization

Directory of Open Access Journals (Sweden)

Adri Smaling

2003-03-01

Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

Permian charnockites in the Pobeda area: Implications for Tarim mantle plume activity and HT metamorphism in the South Tien Shan range

Science.gov (United States)

Loury, Chloé; Rolland, Yann; Lanari, Pierre; Guillot, Stéphane; Bosch, Delphine; Ganino, Clément; Jourdon, Anthony; Petit, Carole; Gallet, Sylvain; Monié, Patrick; Riel, Nicolas

2018-04-01

The Permian history of the Central Asian Orogenic belt is marked by large-scale strike-slip faults that reactivate former Paleozoic structures, delineated by widespread alkaline magmatism. The genetic link between the syn-kinematic granitoids emplaced in the Tien Shan range and magmas emplaced within the Tarim Large Igneous Province, and the interaction between this plume and transcurrent tectonics, are still unsolved issues. We investigated the Pobeda massif, in the eastern Kyrgyz Tien Shan, located at the boundary between the Tien Shan range and the Tarim Craton, which exhibits a high-temperature unit. In this unit, Permian magmatism resulted in the emplacement of alkaline charnockites at mid-crustal levels. The primary mineralogical assemblage is nominally anhydrous and made of ortho- and clino-pyroxenes, fayalite, K-feldspar, plagioclase and quartz. These charnockites are associated with partially-molten paragneisses and marbles. Thermobarometry on these rocks indicates that the charnockites emplaced following the intrusion of a melt at a temperature > 1000 °C and pressure of around 6 kbar, corresponding to depth of 20 km. The resulting thermal anomaly triggered the partial melting of paragneisses. Bulk geochemistry including Sr, Nd, Pb and Hf isotopes suggests that charnockites fit into the Tarim Large Igneous Province magmatic series, with minor crustal assimilation. U-Pb ages on zircons of charnockites and surrounding paragneisses indicate that charnockites intruded and triggered partial melting of the gneisses at c. 287, 275 and 265 Ma. 40Ar/39Ar dating on amphibole gives a similar age as the U-Pb age at 276.2 ± 2.0 Ma. 40Ar/39Ar dating on biotite from the Charnockite unit marbles gives ages at ca. 256-265 Ma, which shows that exhumation onset directly follows the HT history, and is tentatively correlated to top-to-the-North thrusting of the Charnockite unit in a transpressive context. Additional 40Ar/39Ar dating on syn-kinematic white micas from an

National Uranium Resource Evaluation: Lawton Quadrangle, Oklahoma and Texas

International Nuclear Information System (INIS)

Al-Shaieb, Z.; Thomas, R.G.; Stewart, G.F.

1982-04-01

Uranium resources of the Lawton Quadrangle, Oklahoma and Texas, were evaluated to a depth of 1500 m using National Uranium Resource Evaluation criteria. Five areas of uranium favorability were delineated. Diagenetically altered, quartzose and sublithic, eolian and marginal-marine sandstones of the Permian Rush Springs Formation overlying the Cement Anticline are favorable for joint-controlled deposits in sandstone, non-channel-controlled peneconcordant deposits, and Texas roll-front deposits. Three areas contain lithologies favorable for channel-controlled peneconcordant deposits: arkosic sandstones and granule conglomerates of the Permian Post Oak Conglomerate south of the Wichita Mountains; subarkosic and sublithic Lower Permian fluvio-deltaic and coastal-plain sandstones of the eastern Red River Valley; and subsurface arkosic, subarkosic, and sublithic alluvial-fan and fan-delta sandstones of the Upper Pennsylvanian-Lower Permian sequence in the eastern Hollis Basin. The coarse-grained facies of the Cambrian Quanah Granite and genetically related aplite and pegmatite dikes in the Wichita Mountains are favorable for orthomagmatic and autometasomatic deposits, respectively

Electrokinetic transport behavior of phenol in upper Permian soils

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

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

Ocean redox change at the Permian-Triassic mass extinction

DEFF Research Database (Denmark)

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

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 mar...... 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...... 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...... (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...

Ca, Sr, Mo and U isotopes evidence ocean acidification and deoxygenation during the Late Permian mass extinction

Science.gov (United States)

Silva-Tamayo, Juan Carlos; Payne, Jon; Wignall, Paul; Newton, Rob; Eisenhauer, Anton; Weyer, Stenfan; Neubert, Nadja; Lau, Kim; Maher, Kate; Paytan, Adina; Lehrmann, Dan; Altiner, Demir; Yu, Meiyi

2014-05-01

The most catastrophic extinction event in the history of animal life occurred at the end of the Permian Period, ca. 252 Mya. Ocean acidification and global oceanic euxinia have each been proposed as causes of this biotic crisis, but the magnitude and timing of change in global ocean chemistry remains poorly constrained. Here we use multiple isotope systems - Ca, Sr, Mo and U - measured from well dated Upper Permian- Lower Triassic sedimentary sections to better constrain the magnitude and timing of change in ocean chemistry and the effects of ocean acidification and de-oxygenation through this interval. All the investigated carbonate successions (Turkey, Italy and China) exhibit decreasing δ44/40Ca compositions, from ~-1.4‰ to -2.0‰ in the interval preceding the main extinction. These values remain low during most of the Griesbachian, to finally return to -1.4‰ in the middle Dienerian. The limestone succession from southern Turkey also displays a major decrease in the δ88/86Sr values from 0.45‰ to 0.3‰ before the extinction. These values remain low during the Griesbachian and finally increase to 0.55‰ by the middle Dienerian. The paired negative anomalies on the carbonate δ44/40Ca and δ88/86Sr suggest a decrease in the carbonate precipitation and thus an episode of ocean acidification coincident with the major biotic crisis. The Mo and U isotope records also exhibit significant rapid negative anomalies at the onset of the main extinction interval, suggesting rapid expansion of anoxic and euxinic marine bottom waters during the extinction interval. The rapidity of the isotope excursions in Mo and U suggests substantially reduced residence times of these elements in seawater relative to the modern, consistent with expectations for a time of widespread anoxia. The large C-isotope variability within Lower Triassic rocks, which is similar to that of the Lower-Middle Cambrian, may reflect biologically controlled perturbations of the oceanic carbon cycle

Analogical Reasoning and Computer Programming.

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Clement, Catherine A.; And Others

1986-01-01

A study of correlations between analogical reasoning and Logo programming mastery among female high school students related the results of pretests of analogical reasoning to posttests of programming mastery. A significant correlation was found between analogical reasoning and the ability to write subprocedures for use in several different…

Origin and distribution of tonsteins in late permian coal seams of Southwestern China

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Zhou, Yinzhu; Ren, Y.-L.; Bohor, B.F.

1982-01-01

We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and petrographic data, we have concluded that these tonsteins originated as air-fall volcanic ashes. Following accumulation in the peat swamps, in situ alteration of the vitric and lithic components took place under acidic conditions, leading to the formation of kaolinite. Based on petrologic, mineralogic, and chemical analytical data, we have determined that the application of mineralogic and geochemical criteria for tonsteins may be useful in correlating coal beds, predicting coal qualities and reconstructing related sedimentary paleoenvironmental conditions. ?? 1982.

Isotope geochemistry of fluid inclusions in Permian halite with implications for the isotopic history of ocean water and the origin of saline formation waters

International Nuclear Information System (INIS)

Knauth, L.P.; Beeunas, M.A.

1986-01-01

deltaD and delta 18 O values have been determined for fluid inclusions in 45 samples of Permian halite. The inclusions are enriched in 18 O relative to the meteoric water line but are depleted in D relative to ocean water. Inclusions with the more positive delta-values coincide with the isotopic compositions expected for evaporating sea water which follows a hooked trajectory on a deltaD-delta 18 O diagram. Inclusions with more negative delta-values may represent more highly evaporated sea water but probably reflect synsedimentary or diagenetic mixing to those of a modern evaporite pan to indicate that Permian sea water was isotopically similar to modern sea water. Connate evaporite brines can have negative delta-values because of the probable hooked isotope trajectory of evaporating sea water and/or synsedimentary mixing of evaporite brines with meteoric waters. (author)

Abnormal high surface heat flow caused by the Emeishan mantle plume

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Jiang, Qiang; Qiu, Nansheng; Zhu, Chuanqing

2016-04-01

It is commonly believed that increase of heat flow caused by a mantle plume is small and transient. Seafloor heat flow data near the Hawaiian hotspot and the Iceland are comparable to that for oceanic lithosphere elsewhere. Numerical modeling of the thermal effect of the Parana large igneous province shows that the added heat flow at the surface caused by the magmatic underplating is less than 5mW/m2. However, the thermal effect of Emeishan mantle plume (EMP) may cause the surface hear-flow abnormally high. The Middle-Late Emeishan mantle plume is located in the western Yangtze Craton. The Sichuan basin, to the northeast of the EMP, is a superimposed basin composed of Paleozoic marine carbonate rocks and Mesozoic-Cenozoic terrestrial clastic rocks. The vitrinite reflectance (Ro) data as a paleogeothermal indicator records an apparent change of thermal regime of the Sichuan basin. The Ro profiles from boreholes and outcrops which are close to the center of the basalt province exhibit a 'dog-leg' style at the unconformity between the Middle and Upper Permian, and they show significantly higher gradients in the lower subsection (pre-Middle Permian) than the Upper subsection (Upper Permian to Mesozoic). Thermal history inversion based on these Ro data shows that the lower subsection experienced a heat flow peak much higher than that of the upper subsection. The abnormal heat flow in the Sichuan basin is consistent with the EMP in temporal and spatial distribution. The high-temperature magmas from deep mantle brought heat to the base of the lithosphere, and then large amount of heat was conducted upwards, resulting in the abnormal high surface heat flow.

Analogical reasoning in children with specific language impairment: Evidence from a scene analogy task.

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Krzemien, Magali; Jemel, Boutheina; Maillart, Christelle

2017-01-01

Analogical reasoning is a human ability that maps systems of relations. It develops along with relational knowledge, working memory and executive functions such as inhibition. It also maintains a mutual influence on language development. Some authors have taken a greater interest in the analogical reasoning ability of children with language disorders, specifically those with specific language impairment (SLI). These children apparently have weaker analogical reasoning abilities than their aged-matched peers without language disorders. Following cognitive theories of language acquisition, this deficit could be one of the causes of language disorders in SLI, especially those concerning productivity. To confirm this deficit and its link to language disorders, we use a scene analogy task to evaluate the analogical performance of SLI children and compare them to controls of the same age and linguistic abilities. Results show that children with SLI perform worse than age-matched peers, but similar to language-matched peers. They are more influenced by increased task difficulty. The association between language disorders and analogical reasoning in SLI can be confirmed. The hypothesis of limited processing capacity in SLI is also being considered.

Effects of Forecasted Climate Change on Stream Temperatures in the Nooksack River Basin

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Truitt, S. E.; Mitchell, R. J.; Yearsley, J. R.; Grah, O. J.

2017-12-01

The Nooksack River in northwest Washington State provides valuable habitat for endangered salmon species, as such it is critical to understand how stream temperatures will be affected by forecasted climate change. The Middle and North Forks basins of the Nooksack are high-relief and glaciated, whereas the South Fork is a lower relief rain and snow dominated basin. Due to a moderate Pacific maritime climate, snowpack in the basins is sensitive to temperature increases. Previous modeling studies in the upper Nooksack basins indicate a reduction in snowpack and spring runoff, and a recession of glaciers into the 21st century. How stream temperatures will respond to these changes is unknown. We use the Distributed Hydrology Soil Vegetation Model (DHSVM) coupled with a glacier dynamics model and the River Basin Model (RBM) to simulate hydrology and stream temperature from present to the year 2100. We calibrate the DHSVM and RBM to the three forks in the upper 1550 km2 of the Nooksack basin, which contain an estimated 3400 hectares of glacial ice. We employ observed stream-temperature data collected over the past decade and hydrologic data from the four USGS streamflow monitoring sites within the basin and observed gridded climate data developed by Linveh et al. (2013). Field work was conducted in the summer of 2016 to determine stream morphology, discharge, and stream temperatures at a number of stream segments for the RBM calibration. We simulate forecast climate change impacts, using gridded daily downscaled data from global climate models of the CMIP5 with RCP4.5 and RCP8.5 forcing scenarios developed using the multivariate adaptive constructed analogs method (MACA; Abatzoglou and Brown, 2011). Simulation results project a trending increase in stream temperature as a result of lower snowmelt and higher air temperatures into the 21st century, especially in the lower relief, unglaciated South Fork basin.

Fluid flow and sediment transport in evolving sedimentary basins

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Swenson, John Bradley

This thesis consists of three studies that focus on groundwater flow and sediment transport in evolving sedimentary basins. The first study considers the subsurface hydrodynamic response to basin-scale transgression and regression and its implications for stratiform ore genesis. I demonstrate that the transgressive sequence focuses marginward-directed, compaction-driven discharge within a basal aquifer during progradation and deposition of the overlying regressive sequence, isolates the basal aquifer from overlying flow systems, and serves as a chemical sink for metal-bearing brines. In the second study, I develop a new theory for the shoreline response to subsidence, sediment supply, and sea level. In this theory, sediment transport in a fluvio-deltaic basin is formally equivalent to heat transfer in a two-phase (liquid and isothermal solid) system: the fluvial system is analogous to a conduction-dominated liquid phase, the shoreline is the melting front, and the water depth at the delta toe is equivalent to the latent heat of fusion. A natural consequence of this theory is that sediment-starved basins do not possess an equilibrium state. In contrast to existing theories, I do not observe either strong phase shifting or attenuation of the shoreline response to low-frequency eustatic forcing; rather, shoreline tracks sea level over a spectrum of forcing frequencies, and its response to low-frequency forcing is amplified relative to the high-frequency response. For the third study, I use a set of dimensionless numbers from the previous study as a mathematical framework for providing a unified treatment of existing stratigraphic theories. In the limit of low-amplitude eustatic forcing, my study suggests that strong phase shifting between shoreline and sea level is a consequence of specifying the sedimentation rate at the shoreline; basins free of this constraint do not develop strong phase shifts.

Origin of the Squantum 'Tillite', Massachusetts, USA: Modern Analogs and Implications for Neoproterozoic Climate Models

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Carto, S. L.; Eyles, N.

2009-05-01

A central challenge to the 'Snowball Earth' hypothesis is whether the sedimentary rocks deposited during the Neoproterozoic (c. 750-570 Ma) are glacial tillites that accumulated under global ice sheets during this era. This uncertainty stems from the fact that diamictites are not uniquely glacial in origin, as the slumping and mixing of sediment downslope can also produce diamictites. A key deposit in this debate is the Squantum 'tillite' (ca. 595-570 Ma) preserved in the Boston Basin in Massachusetts, USA, which originated as an arc- related basin within the Avalon island arc terrane during the Neoproterozoic. Detailed field examinations of the Squantum by the author suggest that it owes its origin to the downslope transport of large volumes of unstable volcanic and sedimentary debris from steep basin margin slopes. No evidence of a glacial environment was identified. Thin-section analysis of this deposit has revealed a significant volcanic influence on sedimentation in the form of hitherto unrecognized volcanic lapilli tuff horizons and turbidites consisting of reworked ash in strata associated with Squantum diamictite. These results point to deposition related to tectonic activity and basin development rather than severe global glacial conditions. In light of these results, the Squantum diamictite was compared to the volcaniclastic mass flows deposits exposed along the active Lesser Antilles Arc in the Caribbean. Many of these flows are transported into the adjacent Grenada back-arc Basin by debris flows and turbidity currents resulting in the deposition of volcaniclastic conglomerates, diamictites and thin ash turbidites. Gross stratigraphic and sedimentological similarities of the mass flow facies in the Caribbean can be identified with the Squantum deposits, suggesting that appropriate depositional analogs for the Squantum can be found along the Lesser Antilles Arc. The significance of these results is that they emphasize the importance of detailed field

PEMETAAN ANALOGI PADA KONSEP ABSTRAK FISIKA

Directory of Open Access Journals (Sweden)

Nyoto Suseno

2014-11-01

Full Text Available The research of any where founded majority students have common difficulties in abstract physics concept. The result of observation, lecturers have problem  in teaching implementation of abstract concepts on physics learning. The objective of this research is to find out the ways how to overcome this problem. The research place of  physics education programs and senior high school. The data are colected by quetionere, observation and interview. The lecturer behavior to making out this case is use of analogy to make concrete a abstract concept. This action is true, because the analogies are dynamic tools that facilitate understanding, rather than representations of the correct and static explanations. Using analogies not only promoted profound understanding of abstract concept, but also helped students overcome their misconceptions. However used analogy in teaching not yet planed with seriousness, analogy used spontanously with the result that less optimal. By planing and selecting right analogy, the role of analogy can be achieved the optimal result. Therefore, it is important to maping analogies of abstract consepts on physics learning.

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

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Carlos E. L. Vieira

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. 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.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.