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Sample records for carboniferous lisburne group

  1. Depositional setting and geochemistry of phosphorites and metalliferous black shales in the Carboniferous-Permian Lisburne Group, Northern Alaska

    Science.gov (United States)

    Dumoulin, Julie A.; Slack, John F.; Whalen, Michael T.; Harris, Anita G.

    2011-01-01

    Phosphatic rocks are distributed widely in the Lisburne Group, a mainly Carboniferous carbonate succession that occurs throughout northern Alaska. New sedimentologic, paleontologic, and geochemical data presented here constrain the geographic and stratigraphic extent of these strata and their depositional and paleogeographic settings. Our findings support models that propose very high oxygen contents of the Permo-Carboniferous atmosphere and oceans, and those that suggest enhanced phosphogenesis in iron-limited sediments; our data also have implications for Carboniferous paleogeography of the Arctic. Lisburne Group phosphorites range from granular to nodular, are interbedded with black shale and lime mudstone rich in radiolarians and sponge spicules, and accumulated primarily in suboxic outer- to middle-ramp environments. Age constraints from conodonts, foraminifers, and goniatite cephalopods indicate that most are middle Late Mississippian (early Chesterian; early late Visean). Phosphorites form 2- to 40-cm-thick beds of sand- to pebble-sized phosphatic peloids, coated grains, and (or) bioclasts cemented by carbonate, silica, or phosphate that occur through an interval =12 m thick. High gamma-ray response through this interval suggests strongly condensed facies related to sediment starvation and development of phosphatic hardgrounds. Phosphorite textures, such as unconformity-bounded coated grains, record multiple episodes of phosphogenesis and sedimentary reworking. Sharp bed bases and local grading indicate considerable redeposition of phosphatic material into deeper water by storms and (or) gravity flows. Lisburne Group phosphorites contain up to 37 weight percent P2O5, 7.6 weight percent F, 1,030 ppm Y, 517 ppm La, and 166 ppm U. Shale-normalized rare earth element (REE) plots show uniformly large negative Ce anomalies Ce/Ce*=0.11 + or - 0.03) that are interpreted to reflect phosphate deposition in seawater that was greatly depleted in Ce due to increased

  2. Results and synthesis of integrated geologic studies of the carboniferous Lisburne Group of Northeastern Alaska. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.

    1995-05-01

    The primary objective of this project was to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the Pennsylvanian Wahoo 1imestone. The Wahoo Limestone is the upper part of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A leading goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo. Aspects of rock units adjacent to the Wahoo, the underlying Endicott Group and Alapah Limestone and overlying Echooka Formation are also discussed. This report includes an overview of the regional geological framework; a discussion of biostratigraphic results; a summary of diagenetic studies; and preliminary results of comparative studies of a cored well in the Lisburne oil field. A computerized database system (the Wahoo database) was developed and is explained in a users manual. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  3. Regional stratigraphic framework of the Lisburne Group of ANWR

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.; Carlson, R.C. [Univ. of Alaska, Fairbanks, AK (United States); Harris, A.G. [Geological Survey, Reston, VA (United States)] [and others

    1995-05-01

    The Carboniferous Lisburne Group, a major carbonate platform succession, is widely exposed in the Brooks Range and forms an extensive hydrocarbon target in the subsurface of the North Slope of Alaska. Gradationally beneath carbonates of the Lisburne Group, terrigenous sediments of the Mississippian Endicott Group (conglomerate and sandstone of the Kekiktuk Formation overlain by the Kayak Shale) were derived from local and northern (Ellesmerian) source areas. Locally, at the Endicott-Lisburne transition, sandy limestones of the Itkilyariak Formation record another phase of siliciclastic influx that lies above and/or is a lateral equivalent of the Kayak Shale and Lisburne Group in areas adjacent to paleotopographic highs. This siliciclastic to carbonate transition represents a major transgressive succession that onlaps northward over the sub-Mississippian unconformity, a regional angular unconformity and sequence boundary in northern Alaska. The age and nature of onlap depend upon the paleotopography of the underlying sub-Mississippian rocks and regional passive margin subsidence. The Lisburne Group is a thick succession of carbonate rocks subdivided into the Alapah Limestone and overlying Wahoo Limestone, both having informal members.

  4. Lithofacies and stratigraphy of the Lisburne and Etivluk groups in the Lisburne 1 well and adjacent outcrops

    Science.gov (United States)

    Dumoulin, Julie A.; Bird, Kenneth J.

    2002-01-01

    The Lisburne 1 well in the thrust belt of the central Brooks Range penetrated 17,000 ft of imbricated, chiefly Ellesmerian sequence strata in the Endicott Mountains allochthon. Five thrust repeats of the Lisburne Group (Carboniferous) and overlying Etivluk Group (Permian-Jurassic) were drilled. Lithofacies analyses of >350 thin sections of cores and cuttings, and biostratigraphy based on foraminifers and conodonts, allow detailed correlation with coeval units in adjacent outcrops and provide data on the depositional setting and reservoir and source rock potential of these strata. The late Early- Late Mississippian (Osagean-Chesterian) Lisburne Group consists mainly of skeletal wackestone to grainstone, locally completely dolomitized. An interval of abundant glauconite and detrital quartz in the lower Lisburne may mark a sequence-bounding unconformity. Dolostone in the upper part of the unit has maximum porosities of 10-13% and common residual hydrocarbons. The uppermost Lisburne is thinly interbedded mudstone, chert, and shale that are locally dolomitic, phosphatic, spiculitic, and organic-rich; conodonts from this interval in outcrop represent an outer shelf to slope biofacies. The Etivluk Group here encompasses the Siksikpuk and Otuk Formations. The Siksikpuk is mainly varicolored shale and radiolarian chert, with a basal interval of glauconitic, pyritic sandstone. Phosphatic and organic-rich shale, radiolarian chert, and pelecypod coquinas make up the Otuk. Outcrop and subsurface data indicate that the Lisburne Group in this area accumulated near the seaward margin of a shallow-water carbonate platform that drowned during the Late Mississippian; outer shelf or deeper conditions predominated throughout deposition of the upper Lisburne and the Etivluk Group.

  5. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  6. Conodont biostratigraphy and biofacies of the Lisburne Group

    Energy Technology Data Exchange (ETDEWEB)

    Harris, A.G.; Krumhardt, A.P.; Watts, K.F.

    1995-05-01

    Conodont data from the Lisburne Group are presented in three parts. Part 1 summarizes the thesis work of Andrea P. Krumhardt on the conodont biostratigraphy and biofacies of the Wahoo Limestone in the eastern Sadlerochit Mountains. This is virtually the same report as Krumhardt and others. A more detailed report on the Wahoo Limestone is in the final stages of preparation as a US Geological Survey Professional Paper. The major results of this study include the precise determination of the Mississippian-Pennsylvanian boundary within the lower member of the Wahoo Limestone and establishment of a conodont biostratigraphy for the Pennsylvanian part of the Wahoo that is applicable to northern Alaska. Conodont biofacies are related to depositional environments and compared with carbonate microfacies analyses; both indicate high-energy, chiefly normal-marine conditions in the northern part ANWR. Part 2 describes the conodont zonation used for the middle Carboniferous in northern Alaska and the criteria used for assigning ages. A series of chronostratigraphic diagrams illustrates age variations and correlation of the Lisburne Group in ANWR, at two localities in the central Brooks Range, and in wells in the National Petroleum Reserve in Alaska. Part 3 includes a map showing conodont color alteration indices. Variations in the thermal history of different parts of ANWR are related to the tectonics of the northeastern Brooks Range.

  7. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  8. Diagenesis of the Lisburne Group, northeastern Brooks Range, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R.C.; Goldstein, R.H.; Enos, P. [and others

    1995-05-01

    Petrographic cathodoluminescence studies of the cement stratigraphy of the Lisburne Group yield insights on its diagenetic history. Crosscutting relationships between features of subaerial exposure and calcite cements show that early generations of nonferroan, nonluminescent and multibanded-luminescent calcites are synchronous with or postdated by subaerial exposure surfaces within the Lisburne. Surfaces of subaerial exposure occur at 18 horizons within the Lisburne and are distinguished by features as laminated crusts, rhizoliths, autoclastic breccia, fissure fills, mud cracks, and erosional surfaces. Crosscutting relationships also occur between calcite cements and clasts in karst breccias and conglomerates that formed along the sub-Permian unconformity at the top of the Lisburne. The sub-Permian unconformity postdates later generations of calcite cement. These cements formed in the following sequence: nonferroan to low-ferroan, dully luminescent calcite; ferroan, very-dully luminescent calcite; and second generation of nonferroan, multibanded calcite. The crosscutting relationships not only constrain the timing of cement precipitation, but also suggest that the cements probably were precipitated from meteoric groundwaters introduced during subaerial exposure of the Lisburne platform. Late cements in the Lisburne postdate the Permian Echooka Formation. These cements are low-ferroan, moderately-bright to dully luminescent calcite, followed by a second generation of ferroan, very-dully luminescent calcite. Features of compaction and pressure solution are coincident with the precipitation of the late ferroan calcite and further constrain its timing to deep burial of the Lisburne. The youngest phase of calcite cement precipitated in the Lisburne Group is nonferroan, very-dully luminescent calcite. It commonly fills tectonically-induced shear fractures, indicating precipitation after the onset of Cretaceous (and/or Cenozoic) tectonism in the northeastern Brooks Range.

  9. Lisburne Group (Mississippian and Pennsylvanian), potential major hydrocarbon objective of Arctic Slope, Alaska

    Science.gov (United States)

    Bird, Kenneth J.; Jordan, Clifton F.

    1977-01-01

    The Lisburne Group, a thick carbonate-rock unit of Mississippian and Pennsylvanian age, is one of the most widespread potential reservoir-rock units in northern Alaska. A comprehensive review of the Lisburne in the subsurface of the eastern Arctic Slope indicates attractive reservoir characteristics in a favorable source and migration setting where numerous trapping mechanisms appear to be available. Evaluation of this group as a potential exploration objective is particularly timely because of impending offshore sales in the Beaufort Sea and current exploration programs under way in the Prudhoe Bay area and the Naval Petroleum Reserve. Dolomite and sandstone have been identified as reservoir rocks. Oolitic grainstone is a common rock type, but observations indicate little reservoir potential owing to complete void filling by calcite cement. The most important reservoir rock as judged by thickness, areal extent, and predictability is microsucrosic (10 to 30µ) dolomite of intertidal to supratidal origin. It is present throughout the Lisburne and is most abundant near the middle of the sequence. Northward it decreases in thickness from 1,000 ft (300 m) to less than 100 ft (30 m). Porosity of the dolomite as determined in selected wells averages between 10 and 15% and attains a maximum of slightly more than 25%. Net thickness of reservoir rocks (i.e., rocks with greater than 5% porosity) ranges in these wells from 40 to 390 ft (40 to 120 m). Oil shows are common, and drill-stem tests have yielded as much as 1,600 bbl/day of oil and 22 MMcf/day of gas in the Lisburne pool of the Prudhoe Bay field and as much as 2,057 bbl/day of salt water outside the field area. The occurrence of dolomite over such a large area makes its presence in the offshore Beaufort Sea and adjacent Naval Petroleum Reserve 4 fairly certain. The presence of sandstone as thick as 140 ft (40 m) in the middle and upper part of the Lisburne in two coastal wells suggests that larger areas of sandstone

  10. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and

  11. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Michael T. Whalen; Jerry Jensen; Paul K. Atkinson; Joseph S. Brinton

    2000-05-01

    The Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding and lithostratigraphy on fracture patterns. (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. (4) The influence of lithostratigraphy and deformation on fluid flow. The results of field work during the summer of 1999 offer some preliminary insights: The Lisburne Limestone displays a range of symmetrical detachment fold geometries throughout the northeastern Brooks Range. The variation in fold geometry suggests a generalized progression in fold geometry with increasing shortening: Straight-limbed, narrow-crested folds at low shortening, box folds at intermediate shortening, and folds with a large height-to-width ratio and thickened hinges at high shortening. This sequence is interpreted to represent a progressive change in the dominant shortening mechanism from flexural-slip at low shortening to bulk strain at higher shortening. Structural variations in bed thickness occur throughout this progression. Parasitic folding accommodates structural thickening at low shortening and is gradually succeeded by penetrative strain as shortening increases. The amount of structural thickening at low to intermediate shortening may be inversely related to the local amount of structural thickening of the Kayak Shale, the incompetent unit that underlies the Lisburne. The Lisburne Limestone displays a different structural style in the south, across the boundary between the northeastern Brooks Range and the main axis of the Brooks Range fold

  12. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L.; Whalen, M.T.; Jensen, J.; Atkinson, P.K.; Brinton, J.S.

    2001-01-09

    The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

  13. New Paleomagnetic Results and Inclination Correction for the Carboniferous Conemaugh Group rocks, Southwestern Pennsylvania

    Science.gov (United States)

    Kodama, K. P.

    2004-05-01

    In order to check the inclination correction of the Carboniferous Mauch Chunk Formation red beds made by Tan and Kodama [2002], the Carboniferous Buffalo Siltstone and Brush Creek Limestone (Conemaugh Group) from southwestern Pennsylvania were sampled so that an inclination correction could be applied to these magnetite-bearing rocks. Paleopoles from the Buffalo Siltstone (BS) and Brush Creek Limestone (BCL) were previously reported by Payne et al. [1981]. Twenty-eight oriented hand samples were collected from 5 of Payne et al.'s 6 sites, predominately from clastic lithologies. A combination of low temperature thermal demagnetization (up to 200° C) followed by alternating field demagnetization (up to 50 mT) allowed characteristic remanences to be isolated in a majority of the samples. A mean direction for 21 samples from 5 sites of D=170.9° , I=23.4° , K=14.0 yielded an uncorrected paleopole at 36.6° N, 111.1° E, closer to the BCL paleopole (36.1° N, 124.3° E) than the BS paleopole (27.4° N, 123.0° E) of Payne et al. In order to make the inclination correction using the anisotropy of anhysteretic remanence (AAR) of the samples, we estimated the individual particle anisotropy (a), by fitting corrected directions to theoretical correction curves as a function of individual particle anisotropy. The best fit suggests an individual particle anisotropy (a value) of about 1.5 should be used; however, the corrected directions have a strongly elliptical distribution. Assuming that a circular distribution of directions would be closer to that caused by random errors in measurement and orientation, a correction using a=2 was made because it gives both an acceptable fit to the theoretical correction curves and a circular directional distribution. The mean corrected direction of D=173.5° , I=42.0° yields a corrected paleopole at 25° N, 106.5° E which agrees remarkably well with a corrected Mauch Chunk Formation paleopole at 26.3° N, 111.2° E. This corrected Mauch

  14. Geochemistry and provenance of the Carboniferous Baixo Alentejo Flysch Group, South Portuguese Zone

    Science.gov (United States)

    Jorge, R. C. G. S.; Fernandes, P.; Rodrigues, B.; Pereira, Z.; Oliveira, J. T.

    2013-02-01

    This work is focused on the turbiditic sediments from the Carboniferous Baixo Alentejo Flysch Group (BAFG) in the South Portuguese Zone, an external zone of the Iberian Variscides. The aim of this work is to constrain the provenance and tectonic setting of these sediments in a context of a complex evolution of SW Iberian Variscides. For this purpose, we performed a systematic study of petrographical and geochemical signatures of greywackes and shales from the three BAFG formations: Mértola, Mira and Brejeira. Major and trace element composition and ratios suggest heterogeneous source area composition for BAFG shales and greywackes. For the oldest Mértola Formation greywackes, source area is dominated by granitoid rocks with minor mafic input. The latter becomes residual in the Mira Formation. The youngest Brejeira Formation greywackes show clear felsic affiliation associated with an increase in recycled components. The shales of all three BAFG formations denote a granodioritic affiliation. Chemical Index of Alteration (CIA) and Plagioclase Index of Alteration (PIA) values suggest moderate weathering in the source areas of Mértola and Mira formations. These indices, together with A-CN-K relations, point out to steady-state weathering conditions in the source areas of both formations. In contrast, both CIA and PIA values for the Brejeira Formation indicate variable conditions of palaeoweathering, from moderate to intense, as a consequence of non-steady-state conditions probably triggered by tectonic instability in the provenance area. Compared to the greywackes, the shales of all three BAFG formations exhibit higher CIA and PIA values, as well as low K2O/Al2O3 (~ 0.2) and index of compositional variability (Morena Zone (Gondwanan affinity), with possible contribution from an external (Avalonian) source.

  15. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  16. Results of the 1986 seabird monitoring program at Cape Lisburne, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the results of the 1986 seabird monitoring program at Cape Lisburne, Alaska. Objectives of this reports includes determining reproductive...

  17. Upper Carboniferous herbaceous lycopsids

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B.A. [University of Wales, Cardigan (United Kingdom). Dept. of Geography

    1997-01-01

    Herbaceous lycopsids are often overlooked in palaeobotanical studies because of problems of morphological interpretation and identification. The literature on Euramerican Upper Carboniferous herbaceous lycopsids is reviewed on those species referred to the genera Selaginellites, Lycopodites, Paurodendron, Carinostrobus, Miadesmia, Spencerites and the identification of some specimens is challenged. The stratigraphical range of these lycopsids and those of dispersed spores referable to them are also reviewed and suggestions are given for the relatively late appearance of many of these lycopsids in the Euramerican Coal Measures swamps. It is suggested that anisophyllous Selaginella-like lycopsids made their first appearance in the Bolsovian (ex Westphalian C) of the Saar-Lorraine intramontane basin. Evidence from studies of coal balls and dispersed spore assemblages confirm that herbaceous lycopsids were most abundantly present in open-moor communities. Certain species of these herbaceous lycopsids, the Selaginella-like ones, are included within the extant genus Selaginella Linnaeus. For this reason a number of new combinations are proposed.

  18. Carboniferous geology of Northern England

    OpenAIRE

    Waters, Colin N.

    2009-01-01

    The British Geological Survey (BGS) has produced a wholesale rationalisation of Carboniferous lithostratigraphical nomenclature. This presentation describes the Carboniferous stratigraphy of northern England, illustrated with research carried out as part of recent BGS mapping projects. During the Tournaisian and Visean a phase of north–south rifting resulted in the development of grabens and half-grabens, separated by platforms and tilt-block highs. Visean marine transgressions re...

  19. The Carboniferous reefs in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The Carboniferous period was a unique period for reef developments during the Late Paleozoic;however,in past years,studies dealing with the Carboniferous reefs in China were very rare.In recent years,the Carboniferous reefs were studied in detail and diverse types of reefs have been discovered in different areas of China.In these areas,the Mississippian reefs were primarily built of bryozoans and rugose corals,which were associated with various kinds of calcareous algae.During the Pennsylvanian,in South China,the reef builders were composed of the rugose coral Fomichevella and phylloid algae,whereas in North China,the reef builders were composed of Chaetetes,bryozoans and corals.There are two main reef-building communities within Carboniferous reefs in China;an algal reef-building community and a reef-building community dominated by colonial coral.No evolutionary relationships between these two types of communities can be detected,thus indicating that two different linerages of reef-building communities evolved during the Carboniferous;the former community consists of cyanobacteria,bacteria and calcareous algae,while the latter one consists of various skeletal metazoan organisms.Through careful study of the developments of Chinese Carboniferous reefs,the evidence indicates that various communities of organisms played important reef-building functions during this period.The occurrence of these metazoan framework reefs also indicates that,during the Carboniferous,most areas in China would have been dominated by the environments with a tropical or subtropical climate.

  20. Carboniferous paleogeographic and paleoclimatic reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Scotese, C.R. (Univ. of Texas, Arlington, TX (United States). Dept. of Geology); Raymond, A. (Texas A and M Univ., College Station, TX (United States). Dept. Geology)

    1992-01-01

    The Carboniferous was an important transitional period in earth history. The Paleozoic oceans separating the continents of Gondwana, Laurentia, Baltica, Kazakhstan, and Siberia had closed by the late Carboniferous forming the late Paleozoic supercontinent of Pangea. Plate motions which appear to have been rapid during the Early Carboniferous (6--10 cm/yr), slowed to a temperature gradient increased as the Earth's climate changed from hot-house to ice-house conditions. Sea level, which stood high during the Early Carboniferous, fell as a result of continental collision and mountain-building, and then began to rise and fall rhythmically as the South Polar ice-cap waxed and waned. These environmental changes intersected important evolutionary events, namely, the explosive colonization of the emergent land areas by plants and the rise of terrestrial vertebrates. In this paper the authors present paleogeographic reconstructions for 6 intervals during the Carboniferous. These maps illustrate the latitudinal position of the continents deduced from paleomagnetic data and the distribution of climatically restricted lithofacies (coal, bauxite, evaporite, calcrete, and tillite), the inferred location of active plate boundaries, and the changing configuration of mountains, land, shallow seas, and deep ocean basins. For each of these paleogeographic maps a climatic simulation was run using the Parametric Climate Model. These simulations predict the distribution of high and low pressure cells, prevailing wind directions, pole-to-equator temperature gradient, relative wetness/dryness, as well as zones of coastal upwelling.

  1. Depositional settings, correlation, and age carboniferous rocks in the western Brooks Range, Alaska

    Science.gov (United States)

    Dumoulin, J.A.; Harris, A.G.; Blome, C.D.; Young, L.E.

    2004-01-01

    The Kuna Formation (Lisburne Group) in northwest Alaska hosts the Red Dog and other Zn-Pb-Ag massive sulfide deposits in the Red Dog district. New studies of the sedimentology and paleontology of the Lisburne Group constrain the setting, age, and thermal history of these deposits. In the western and west-central Brooks Range, the Lisburne Group includes both deep- and shallow-water sedimentary facies and local volcanic rocks that are exposed in a series of thrust sheets or allochthons. Deep-water facies in the Red Dog area (i.e., the Kuna Formation and related rocks) are found chiefly in the Endicott Mountains and structurally higher Picnic Creek allochthons. In the Red Dog plate of the Endicott Mountains allochthon, the Kuna consists of at least 122 m of thinly interbedded calcareous shale, calcareous spiculite, and bioclastic supportstone (Kivalina unit) overlain by 30 to 240 m of siliceous shale, mudstone, calcareous radiolarite, and calcareous lithic turbidite (Ikalukrok unit). The Ikalukrok unit in the Red Dog plate hosts all massive sulfide deposits in the area. It is notably carbonaceous, is generally finely laminated, and contains siliceous sponge spicules and radiolarians. The Kuna Formation in the Key Creek plate of the Endicott Mountains allochthon (60-110 m) resembles the Ikalukrok unit but is unmineralized and has thinner carbonate layers that are mainly organic-rich dolostone. Correlative strata in the Picnic Creek allochthon include less shale and mudstone and more carbonate (mostly calcareous spiculite). Conodonts and radiolarians indicate an age range of Osagean to early Chesterian (late Early to Late Mississippian) for the Kuna in the Red Dog area. Sedimentologic, faunal, and geochemical data imply that most of the Kuna formed in slope and basin settings characterized by anoxic or dysoxic bottom water and by local high productivity. Shallow-water facies of th e Lisburne Group in the Red Dog area are present locally in the Endicott Mountains

  2. Changes in tropical Late Carboniferous compression floras and their causes

    Energy Technology Data Exchange (ETDEWEB)

    Pfefferkorn, H.W. (Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Geology)

    1992-01-01

    In the Late Carboniferous ten biostratigraphic boundaries can be recognized based on compression floras. Some of these boundaries coincide with classical stage boundaries whereas others do not. These boundaries are observable throughout Eurameria. In most cases the same species are involved in North America and Europe. Four boundaries are characterized by extinction events that involve only a few or many taxa. Four boundaries are characterized by origination of single taxa or by changes in the dominance of taxonomic groups. Two boundaries near the base of the Late Carboniferous seem to coincide with different stages in the onset of the ice age on Gondwanaland. However, it has not been clearly demonstrated what the local climatic signals in the tropics were. Three boundaries in the late Late Carboniferous are connected with well established trends toward dryer climate. It appears that many of these floral changes were climatically controlled. The actual triggering condition seems to have been produced by a variable combination of short term (allocyclic) and long term (orogeny, continental movement) effects. In one case the reason for the extinction is not obvious and could be biotic in nature.

  3. Plant biodiversity changes in Carboniferous tropical wetlands

    DEFF Research Database (Denmark)

    Cleal, C.J.; Uhl, D.; Cascales-Miñana, B.;

    2012-01-01

    Using a combination of species richness, polycohort and constrained cluster analyses, the plant biodiversity of Pennsylvanian (late Carboniferous) tropical wetlands (“coal swamps”) has been investigated in five areas in Western Europe and eastern North America: South Wales, Pennines, Ruhr, Saarland...

  4. High-temperature carbidization of carboniferous rocks

    Science.gov (United States)

    Goldin, B. A.; Grass, V. E.; Nadutkin, A. V.; Nazarova, L. Yu.

    2009-08-01

    Processes of thermal metamorphism of carboniferous rocks have been studied experimentally. The conditions of high-temperature interaction of shungite carbon with components of the contained rocks, leading to formation of carbide compounds, have been determined. The results of this investigation contribute to the works on searching for new raw material for prospective material production.

  5. Permo-Carboniferous Sequence Stratigraphy and Sea Level Changes in North China Platform

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Through a sequence stratigraphic research on the Permo-Carboniferous in North China, it is suggested that the boundary of the Carboniferous and the Permian may be better moved down to the bottom of the main workable coalbed which is overlain by the limestones containing Pseudoschwagerina zone. This study mainly deals with the Upper Carboniferous, the Lower Permian and the lower part of the Middle Permian coal-bearing strata, which are 150-180 m thick totally and can be divided into 2 mesosequences, including 6 sequence sets and 19 sequences. The lithostratigraphic units are diachronous in North China. The upper two limestones of the Taiyuan Formation in the central part of the study area may be correlated with the bottom two limestones of the lower Taiyuan Formation in the southern part. The Shanxi Formation in the central and northern parts may be correlated with most of the Taiyuan Formation in the southern part. The Xiashihezi Formation in the northern part may be correlated with the upper part of Shanxi Formation in the central and southern parts. The Shangshihezi Formation in the northern part may be correlated with the Xiashihezi Formation in the southern part. The paleogeographical maps are compiled in a chrono-stratigraphic framework. From the Late Carboniferous to the Early Permian, 3 cycles of sea level change and transgression-regression occurred, and the major transgression took place in the Asselian. In the Late Carboniferous, the direction of transgression was from the east to the west, and in the Early Permian it was from the southeast and the southwest to the north. Three workable coalbed groups were formed in Asselian, early Sakmarian and late Sakmarian respectively. The TST coals developed under the bottom of the Asselian limestones are the best coals for coalbed meathane extracting. The Sakmarian coal beds were formed in HST. The coal beds of Lower Permian distribute southward along with the relative sea level falls and sediment progradation.

  6. Uplift and late orogenic deformation of the Central European Variscan belt as revealed by sediment provenance and structural record in the Carboniferous foreland basin of western Poland

    Science.gov (United States)

    Mazur, S.; Aleksandrowski, P.; Turniak, K.; Krzemiński, L.; Mastalerz, K.; Górecka-Nowak, A.; Kurowski, L.; Krzywiec, P.; Żelaźniewicz, A.; Fanning, M. C.

    2010-01-01

    The Carboniferous foreland basin of western Poland contains a coherent succession of late Viséan through Westphalian turbidites derived from a uniform group of sources located within a continental magmatic arc. Detrital zircon geochronology indicates that two main crustal components were present in the source area of Namurian A sediments. They represent Late Devonian and Early Carboniferous ages, respectively. The detritus from Westphalian D beds is much more diversified and contains admixture of Late Carboniferous zircons suggesting rapid unroofing of Variscan igneous intrusions in the hinterland between Namurian A and Westphalian D times. Tectonic repetitions of tens of metres thick fault-bounded stratigraphic intervals, recorded in several wells, provide evidence for compressional regime that occurred in the SW part of the Carboniferous basin not earlier than during the Westphalian C and produced NW-SE trending folds, concordant with the structural grain of the adjacent, NE part of the Bohemian Massif.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-15

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

  8. Carboniferous coprolites from Qinhuangdao of North China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Here we reported the coprolites that are preserved in the dark grey silty shale of the Carboniferous Benxi Formation from Shimenzhai,Qinhuangdao,North China.The coprolites occur in a sinusoidal and ribbon-like aggregate.A coprolite granule is sesame-shaped,roundish at the terminals,equidimensional and equimorphic.It is 2.2 mm long and 0.6 mm wide.Its ventral surface appears flat,and its dorsal surface is slightly convex and has an axial furrow consisting of a string of bead-shaped pits.The coprolite granule has a directional arrangement and general equality in distribution within the aggregate.Its long axis is commonly perpendicular to the margins of the aggregate.The undigested food remains of animals and plants and the organomineral calcites with heteromorphology can be seen within the coprolite granule under photomicroscope and SEM.We deduced that a tracemaker of coprolites may be a tiny polyphagia animal similar to a modern loach or a tiny fish and that the tracemaker defecated and moved in synchronization below the interface between water and sediment.The coprolites may have a high viscidity and intensity while they were defecated.Diagenesis of feces may take place earlier and quicker than the host strata because of microbes.The lagersttte of coprolites described herein may result from the combination of many factors,such as the high content of oxygen in the Carboniferous atmosphere,the brackish lagoon in humid and tropic climate background,the low water energy,and the anoxic taphonomic environment that was lack of other animals.Further we suggested that the deoxidized color (dark grey) of host strata of coprolites may be formed in the sedimentary environment rich in oxygen and the early anoxic diagenetic environment.

  9. Contributions of palynology to Carboniferous biostratigraphy and coal geology of the Atlantic provinces of Canada

    Energy Technology Data Exchange (ETDEWEB)

    Hacquebard, P.A. [Geological Survey of Canada, Dartmouth, NS (Canada). Atlantic Geoscience Centre

    1997-01-01

    W.A. Bell`s palaeobotanical and geological studies carried out between 1927 and 1948 resulted in the recognition of six stratigraphic units in the Carboniferous system of the Atlantic Provinces of Canada. Subsequent palynological research provided additional information on: (1) The recognition of nineteen miospore zones in the six groups of the Carboniferous succession. (2) Regional correlation of the stratigraphic units in areas where, due to lack of plant megafossils, no age relationship had been established. This resulted in recognizing the existence of the Gulf of St. Lawrence coalfield, the largest in eastern Canada. (3) Detailed coal seam correlations from miospore histograms, as an aid to structural and stratigraphic interpretations, resulted in delineating hitherto unknown coal reserves, notably in the Mabou and Pictou coalfields of Nova Scotia and in the Central Pennsylvanian Basin of New Brunswick. (4) The miospore assemblages provided information on the negotiation of the ancient peat mires that are valuable to coal-facies interpretations.

  10. Junggar basin is a lower Carboniferous hydrocarbon source rock group drop springs scientific utilization evaluation%准噶尔盆地下石炭统滴水泉组烃源岩科学利用评价

    Institute of Scientific and Technical Information of China (English)

    陈飞; 曹远远

    2016-01-01

    滴水泉组是准噶尔盆地重要的烃源岩层系之一,其烃源岩特征研究对石炭系油气资源勘探有重要意义。本文利用露头样品和钻井岩心的勘查及化验资料,系统分析评价了滴水泉组烃源岩的分布状况、有机质丰度、类型和成熟度。认为滴水泉组烃源岩发育于滴水泉组中上部,平面上分布在滴水泉凹陷至五彩湾凹陷一带,沉积中心厚度超过400米。滴水泉组烃源岩有机质丰度高,类型以Ⅱ2-Ⅲ为主,处于成熟至高成熟演化阶段,具有良好的生烃潜力。%In this paper,the distribution of source rocks, organic matter abundance,type and maturity of the hydrocarbon source rocks of the water fountain formation are evaluated by systematic analysis and evaluation of the exploration and laboratory data of outcrop and drilling cores.The hydrocarbon source rocks of the water fountain group are developed in the upper part of the water drop spring group,and the plane is distributed in the area of the water dripping spring to the area of the colorful Bay,and the thickness of the deposition center is more than 400 meters. Organic matter abundance of source rocks in the water source rocks is high,and the type of the source rocks is mainly 2- III, which is in the mature stage and has good hydrocarbon generating potential.

  11. Revision of the Xenacanthida (Chondrichthyes : Elasmobranchii) from the Carboniferous of the British Isles

    Energy Technology Data Exchange (ETDEWEB)

    Hampe, O. [Humboldt University, Berlin (Germany)

    2003-07-01

    Xenacanthids were a very successful group of elasmobranchs that ranged from the Lower Carboniferous to the Upper Triassic. The history of discovery of the xenacanthids, which is closely connected with the history of coal prospecting in England, began with the finding of the type specimen of Xenacanthus laevissimus in the Westphalian B of the West Midlands. In this first review of British Carboniferous xenacanthids, the number of taxa, mainly erected during Victorian times, is reduced to 14 species distributed among six genera. Determinable remains are recorded from at least 96 localities in the British Isles. Unique characteristics of the Dinantian Diplodoselache suggest that the lineage to which this taxon belongs marks a dead end in xenacanthid evolution. This investigation also shows that the Pendleian Dicentrodus, formerly described as Cladodus, belongs to the xenacanthids. The occurrence of Orthacanthus cf. kounoviensis in the Pennines, also known from the German Saar-Nahe basin, the Saale depression and from Bohemia, indicates a faunal exchange between these intramontainous basins during the Carboniferous. The genus Triodus is identified from British deposits for the first time. A cladistic analysis of the xenacanthids suggests that they evolved from phoebodontid elasmobranchs. This analysis also confirms separation of the Middle Devonian Antarctilamna from a relationship with xenacanthid sharks.

  12. Carboniferous paleogeographic, phytogeographic, and paleoclimatic reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, D.B.; Raymond, A.; Parrish, J.T.; Lottes, A.L.; Scotese, C.R.; Ziegler, A.M.

    1985-06-01

    Two revised paleographic reconstructions of the Visean and Westphalian C-D stages are presented based on recent paleomagnetic, phytogeographic, stratigraphic, and tectonic data. These data change the positions of some continental blocks, and allow the definition of several new ones. The most important modifications that have been incorporated in these reconstructions are: (1) a proposed isthmus linking North America and Siberia across the Bering Strait; and (2) the separation of China and Southeast Asia in six major blocks, including South China, North China, Shan Thai-Malaya, Indo-China, Qangtang, and Tarim blocks. Evidence is presented that suggests that at least the South China, Shan Thai-Malaya, and Qangtang blocks were derived from the northern margin of Gondwana. Multivariate statistical analysis of phytogeographic data from the middle and late Paleozoic allow definition of a number of different phytogeographic units for four time intervals: (1) the Early Devonian, (2) Tournaisian-early Visean, (3) Visean, and (4) late Visean-early Namurian A. In addition, we have constructed paleoclimatic maps for the two Carboniferous time intervals. 125 references.

  13. Lower Carboniferous marine bivalves from the Cantabrian Mountains (Spain)

    NARCIS (Netherlands)

    Amler, M.R.W.; Winkler Prins, C.F.

    1999-01-01

    The Lower Carboniferous bivalves of the Vegamián and Genicera formations are described, followed by a brief discussion on palaeoenvironmental and palaeogeographical aspects. The black shales of the Vegamián Fm. (Tournaisian) yield a peculiar association of euchondriid taxa (Euchondria wagneri sp. no

  14. Devonian and Lower Carboniferous conodont biostratigraphy, Spanish Central Pyrenees

    NARCIS (Netherlands)

    Boersma, Kerst Th.

    1973-01-01

    Conodont faunas were collected from the Devonian and Lower Carboniferous in an area ranging from the Rio Fsera (prov. of Huesca) in the west to the Rio Llobregat (prov. of Barcelona) in the east. Most conodont zones and -Faunas recognized in Germany and Spain could be distinguished. The ages of the

  15. Early Carboniferous ammonoid faunas and stratigraphy of the Montagne Noire (France

    Directory of Open Access Journals (Sweden)

    D. Korn

    2007-08-01

    Full Text Available The early Carboniferous (Mississippian sedimentary succession of the Montagne Noire is subdivided into three major lithostratigraphic units, in ascending order the Montagne Noire Griotte Group (Devonian to Early Tournaisian, the Tournaisian to Viséan Saint-Nazaire Group (with the Lydiennes, Faugères, Colonnes, and Puech Capel Formations, the latter new, and the Laurens Flysch Group (late Viséan. The ammonoid assemblages in these rock units are reviewed. A total of 29 Early Carboniferous ammonoid taxa at species level are determined. The new genus Nigrocyclus n. gen., and the new species Gattendorfia nazairensis n. sp., Globimitoceras albaillei n. sp., and Neogoniatites canovasi n. sp. are described. Die unterkarbonische Abfolge von Sedimentgesteinen in der Montagne Noire wird in drei lithostratigraphische Einheiten untergliedert, von unten nach oben die Montagne Noire Griotte Gruppe (Oberdevon bis Untertournai, die Saint-Nazaire Gruppe des Tournaisium und Viséum (mit den Lydiennes Faugères, Colonnes und Puech Capel Formationen, von denen die letzte neu ist, und der Laurens Flysch Gruppe (Oberviséum. Die Ammonoideen-Vergesellschaftungen in diesen Gesteinen werden revidiert. Insgesamt werden 29 unterkarbonische Ammonoideen-Taxa auf Artebene aufgeführt; neu beschrieben werden die Gattung Nigrocyclus n. gen. sowie die Arten Gattendorfia nazairensis n. sp., Globimitoceras albaillei n. sp. und Neogoniatites canovasi n. sp. doi:10.1002/mmng.200700002

  16. Summary and interpretive synthesis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This chapter summarizes the major advances made through our integrated geological studies of the Lisburne Group in northern Alaska. The depositional history of the Lisburne Group is discussed in a framework of depositional sequence stratigraphy. Although individual parasequences (small-scale carbonate cycles) of the Wahoo Limestone cannot be correlated with certainty, parasequence sets can be interpreted as different systems tracts within the large-scale depositional sequences, providing insights on the paleoenvironments, paleogeography and platform geometry. Conodont biostratigraphy precisely established the position of the Mississippian-Pennsylvanian boundary within an important reference section, where established foraminiferal biostratigraphy is inconsistent with respect to conodont-based time-rock boundaries. However, existing Carboniferous conodont zonations are not readily applicable because most zonal indicators are absent, so a local zonation scheme was developed. Diagenetic studies of the Lisburne Group recognized nineteen subaerial exposure surfaces and developed a cement stratigraphy that includes: early cements associated with subaerial exposure surfaces in the Lisburne Group; cements associated with the sub-Permian unconformity; and later burial cements. Subaerial exposure surfaces in the Alapah Limestone are easily explained, being associated with peritidal environments at the boundaries of Sequence A. The Lisburne exposed in ANWR is generally tightly cemented and supermature, but could still be a good reservoir target in the adjacent subsurface of ANWR given the appropriate diagenetic, deformational and thermal history. Our ongoing research on the Lisburne Group will hopefully provide additional insights in future publications.

  17. LATE DEVONIAN-CARBONIFEROUS CONODONTS FROM EASTERN IRAN

    Directory of Open Access Journals (Sweden)

    MEHDI YAZDI

    1999-07-01

    Full Text Available Conodont data from acid-leaching 110 samples from two Late Devonian-Carboniferous areas in the Shotori Range (Tabas region of eastern Iran are presented. At Howz-e-Dorah, a section (88 samples commencing high in the Bahram Formation (Givetian-early Frasnian extended through the Shishtu Formation (Frasnian, Early hassi Zone or older, to latest Tournaisian, anchoralis-latus Zone and the Sardar Formation (earliest Visean, texanus Zone, to late Namurian, sinuatus-corrugatus-sulcatus Zone and into the Jamal Formation (Permian. Four less exhaustively sampled sections (22 samples show the Kale Sardar area to be tectonically more complicated than the Howz-e-Dorah area. Useful marker horizons in the Howz-e-Dorah section, well constrained by conodont data, are: the early Frasnian (no older than Early hassi Zone biostromal beds of the Shishtu Formation, an early Famennian (Late triangularis to Early crepida interval of oolitic limestone, a cyclothem sequence straddling the Early Carboniferous-Late Carboniferous boundary, and an Early Permian interval of siliceous sand ("the white quartzite" of previous authors. Additionally, several iron-rich horizons, readily traceable from locality to locality, are well constrained by conodont ages. Eighty-five conodont species/subspecies are documented representing 24 genera.. Two new species, Polygnathus capollocki and Polygnathus ratebi and one new subspecies, Icriodus alternatus mawsonae are described. 

  18. Carboniferous-Permian rugose coral Cyathaxonia faunas in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

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

  19. The role of Spain in the development of the reef Brachiopod faunas during the Carboniferous

    NARCIS (Netherlands)

    Winkler Prins, C.P.

    2007-01-01

    After a short introduction on the reef development during the Late Palaeozoic, the tectono-stratigraphic history of the Cantabrian Mountains (northern Spain) during the Carboniferous is discussed, with an emphasis on the tectonically active Pennsylvanian (i.e., Late Carboniferous). The reef-bearing

  20. New data on the formation of Carboniferous coal balls

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A.C.; Mattey, D.P.; Howard, R. [University of London, Egham (United Kingdom). Royal Holloway and Bedford New College, Dept. of Geology

    1996-10-01

    Coal balls are formed from the precipitation of carbonate minerals, predominantly calcite, from water during or immediately post-peat formation. Previous petrological studies suggest permineralization occurred at various stages during the peatificiation process by precipitation from a mixture of marine and meteoric freshwater. The geochemical studies reported here aimed to test previous theories of coal ball formation. The coal balls studied are from Upper Carboniferous and Carboniferous/Permian coal seams in Britain, United States of America, Belgium and China. Stable carbon isotopic values of calcites range from {delta}{sup 13}C of -5 to -35 parts per thousand indicating highly variable contribution of decayed organic matter to the carbonate cement. Oxygen isotopic values of delta({sup 18}) range from -3 to -15 parts per thousand suggest both marine and meteoric freshwater sources. The range, in the British coal balls in particular, with {delta}{sup 13}C ranging from -7 to -25 parts per thousand indicates the complexity of carbonate generation. Isotopic data support at least four theories of carbonate coal ball formation. This makes their absence from post-Permian coals the more puzzling and it is suggested that the overall structure of the peat may play a role.

  1. Permo-Carboniferous gold epoch of northeast Queensland

    International Nuclear Information System (INIS)

    The 40Ar/39Ar and U-Pb methods of isotopic dating have been used to determine the age of alteration minerals and host rocks from a number of Permo-Carboniferous Au deposits in the Tasman Fold Belt system of northeast Queensland. There was a continuum in porphyry-style Au mineralisation from ca 330 to 290 Ma, which post-dates epithermal Au in the Eastern Basin sequence of the Drummond Basin. Porphyry-style Au at Kidston. and the Buck Reef. Ravenswood, formed at ca 330 Ma. The Red Dome and Mungana skarns were deposited at ca 320-310 Ma and ca 310 Ma. respectively The Au mineralisation at Mt Wright. and in the quartz-sulfide veins. Ravenswood. was emplaced at ca 310-305 Ma. The youngest porphyry-style Au deposit is Mt Leyshon, which probably formed at ca 290 Ma Where high-level intrusions are associated with Au, magmatism and mineralisation are. in general. essentially coeval. The age of the host rocks to the Permo-Carboniferous Au deposits is variable, and may be more than 150 million years older than the mineralisation. The plutonic-style Au deposit at Charters Towers is significantly older than the porphyry systems, and formed at ca 414 Ma. Copyright (1998) Blackwell Science Asia

  2. Devonian and carboniferous arcs of the oyu tolgoi porphyry Cu-Au district, South Gobi region, Mongolia

    Science.gov (United States)

    Wainwright, A.J.; Tosdal, R.M.; Forster, C.N.; Kirwin, D.J.; Lewis, P.D.; Wooden, J.L.

    2011-01-01

    The Central Asian orogenic belt consists of microcontinental blocks and mobile belts positioned between the Siberian craton and the Tarim and North China cratons. Extending across Asia for 5000 km, the belt consists of terranes that decrease in age southward away from the Siberian craton. A time-stratigraphic-structural sequence for the rocks is critical to defining the tectonic evolution of the belt. In the Oyu Tolgoi area of the South Gobi Desert (Mongolia), Devonian and Carboniferous rocks record the construction of multiple arcs, formation of a giant porphyry Cu-Au system, exhumation, and polyphase deformation. The oldest rocks are basaltic volcanic and subvolcanic rocks of the Devonian Alagbayan Group intruded by Late Devonian quartz monzodiorite stocks and dikes, which host giant porphyry Cu-Au deposits. The rocks were exhumed, overlain by pyroclastic rocks, and then tectonically buried by marine mafic supracrustal rocks prior to the youngest Devonian granodiorite intrusions. The postmineral Carboniferous Gurvankharaat Group unconformably overlying the deformed terrane consists of effusive, pyroclastic, subvolcanic and volcaniclastic rocks, as well as sedimentary units. The supracrustal rocks underwent polyphase shortening after 330 Ma and prior to 290 Ma. Variations in stratigraphic sequences suggest that the region is underlain by a submarine arc that became emergent during the Upper Devonian and remained subaerial to shallow subaqueous through much of the Carboniferous. Xenocrystic zircons in igneous rocks suggest that the offshore arcs were sufficiently close to ancient crust to have interacted with detritus shed into marine basins, most likely from the Siberian craton and fringing early Paleozoic terranes. ?? 2011 Geological Society of America.

  3. Early Carboniferous Radiolarian Fauna from Heiyingshan South of the Tianshan Mountains and Its Geotectonic Significance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Abundant and well-preserved fossil radiolarians found from the Artencasher Formation, Heiyingshan of Baicheng County, Xinjiang Uygur Autonomous Region, are identified, including 15 species and 2 unnamed species in 9 genera. The fauna is dominated by the Family Entactiniidae of Spumellaria. According to the faunal characteristics, the radiolarians may be divided into five assemblages, namely, the Triaenosphaera sicarius, Entatinosphaera palimbola, Entactinia vulgaris, Belowea cf. variabilis and Archocyrtium sp assemblages. The fauna may be correlated with that from the Early Carboniferous of Frankenwald and Rein in Germany. Thus, ophiolite was formed in the Carboniferous, while the age of collision between the Ili plate and the Tarim plate is Early Carboniferous.

  4. Response of Late Carboniferous and Early Permian Plant Communities to Climate Change

    Science.gov (United States)

    Dimichele, William A.; Pfefferkorn, Hermann W.; Gastaldo, Robert A.

    Late Carboniferous and Early Permian strata record the transition from a cold interval in Earth history, characterized by the repeated periods of glaciation and deglaciation of the southern pole, to a warm-climate interval. Consequently, this time period is the best available analogue to the Recent in which to study patterns of vegetational response, both to glacial-interglacial oscillation and to the appearance of warm climate. Carboniferous wetland ecosystems were dominated by spore-producing plants and early gymnospermous seed plants. Global climate changes, largely drying, forced vegetational changes, resulting in a change to a seed plant-dominated world, beginning first at high latitudes during the Carboniferous, reaching the tropics near the Permo-Carboniferous boundary. For most of this time plant assemblages were very conservative in their composition. Change in the dominant vegetation was generally a rapid process, which suggests that environmental thresholds were crossed, and involved little mixing of elements from the wet and dry floras.

  5. Response of Late Carboniferous and Early Permian plant communities to climate change

    Energy Technology Data Exchange (ETDEWEB)

    DiMichele, W.A.; Pfefferkorn, H.W.; Gastaldo, R.A. [Smithsonian Institute, Washington, DC (USA). National Museum of National History

    2001-07-01

    Late Carboniferous and Early Permian strata record the transition from a cold interval in Earth history, characterized by the repeated periods of glaciation and deglaciation of the southern pole, to a warm-climate interval. Consequently, this time period is the best available analogue to the Recent in which to study patterns of vegetational response, both to glacial-interglacial oscillation and to the appearance of warm climate. Carboniferous wetland ecosystems were dominated by spore-producing plants and early gymnospermous seed plants. Global climate changes, largely drying, forced vegetational changes, resulting in a change to a seed plant-dominated world, beginning first at high latitudes during the Carboniferous, reaching the tropics near the Permo-Carboniferous boundary. For most of this time plant assemblages were very conservative in their composition. Change in the dominant vegetation was generally a rapid process, which suggests that environmental thresholds were crossed, and involved little mixing of elements from the wet and dry floras.

  6. Synthetic analysis of the Neuropterids - their interest for the decipherment of Carboniferous palaeogeography

    Energy Technology Data Exchange (ETDEWEB)

    Laveine, J.P. [Universitaire de Science et Technologie de Lille, Villeneuve d`Ascq (France). Lab. Paleobotanique

    1997-01-01

    `Neuropterids` are of the dominant groups of Carboniferous fossil-plants. The original definition of Nevropteris, initially given as a section of the genus Filicites, was based only on the shape, the mode of attachment to the rachis, and the venation of the pinnules. Subsequent information has shown that the originally defined taxon, in fact, comprises many genera belonging to several distinct families of Pteridosperms, which are distinguished on various features of frond architecture, male and female reproductive organs and apparatuses, anatom, and morphology and venation of the pinnules. Unfortunately, these characteristics are not equally known within each group, even at a general level, and are not always available through usual palaeobotanical collecting. However, it is essential to reach the most precise, `natural` level of taxonomy for the decipherment of the many interrelated problems raised by palaeobotanical studies, i.e. evolution, biostratigraphy, palaeobiogeography, palaeoecology and, as a feedback consequence, systematics. Despite restricting the analysis mainly to the external morphological characters, the `Neuropterids` provide a fine example of such interrelated fundamental questions.

  7. The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongfeng; ZHANG Lifei; GU Libing; GUO Xuan; ZHOU Jing

    2005-01-01

    The genesis of the Carboniferous volcanic rocks in the Dahalajunshan group, mainly consisting of trachytes and trachy-andesites and distributing widely in western Tianshan Mountains, remains to be controversial. It has been proposed to be relevant to "rift" or "plume". Detailed petrology and geochemical data presented in this paper show that these volcanic rocks represent typical continental arc magmatism. The volcanic rocks are mainly trachy-andesitic, and the magma source is enriched in LILE, Th and Pb, and depleted in HFSE and Ce. Trace element geochemical study suggests that the basalts could be modeled by 7%-11% partial melt of garnet lherzolite. The volcanic rocks in the Dahalajunshan group are neither the products of "rift" nor so-called "plume" but represent the continental island arc of the Paleo-Southern Tianshan Ocean. The mantle wedge had been modified by the melt generating in subduction zone during a long evolution history of this island arc. The continental crust materials (i.e. mainly sediment on ocean floor) had been added into island arc through melt in subduction zone. Volcanic rocks occurring in different regions might represent magma eruption in different time. The zircon SHRIMP dating indicates that the ages of the basalt varies between 334.0 Ma and 394.9 Ma. The 13 analyses give an average age of 353.7 (4.5 Ma (MSWD = 1.7). The apparent ages of zircons in trachy-andesite vary between 293.0 Ma and 465.4 Ma. All analyses fall on the U-Pb concordant line and are divided into two groups. 8 analyses produce an average age of 312.8(4.2 Ma (MSWD = 1.7), which represents the crystallizing age of zircon rims in trachy-andesite. The acquired two ages (i.e. 354 and 313 Ma) belong to the Early Carboniferous and Late Carboniferous epochs, respectively. Thus, the Dahalajunshan group would be separated into several groups with the accumulation of high-quality age dating and data of trace element and isotopic geochemistry, in our opinion.

  8. Enigmatic Fossils from the Lower Carboniferous Shrimp Bed, Granton, Scotland.

    Directory of Open Access Journals (Sweden)

    Mikołaj K Zapalski

    Full Text Available The Lower Carboniferous (Visean Granton Lagerstätte (Edinburgh, Scotland is principally known for the discovery of the conodont animal, but has also yielded numerous crustaceans and other faunas. Here we report on small branching colonies, reaching 10 mm in length. They are small, erect, arborescent, and irregularly branched with predominant monopodial and dichotomous growth. They bud in a single plane. In one specimen the wall microstructure is well preserved and it is composed of evenly spaced, linear fibers, running parallel to the axis of the stems, and connected by transverse bars. We discuss possible biological affinities of these organisms; we consider algal, poriferan, hydrozoan and bryozoan affinities. The general pattern of branching, presence of fan-like structures (interpreted here as possible gonophores and microstructure suggests affinity to Hydrozoa, affinity to non-calcifying algae is less likely. Assuming hydrozoan nature; the microstructure might suggest affinities with the extant family Solanderiidae Marshall, 1892 that possess an internal chitinous skeleton. The EDS analysis shows that fossils discussed here are preserved as phosphates. The skeletons were probably not mineralized, the presence of phosphorus suggests that the colonies were originally composed of chitin. We describe these organisms as Caledonicratis caridum gen. et sp. nov. (Solanderiidae?, Capitata?. Colonies of C. caridum gen et. sp. nov. sometimes encrust the exuviae of crustaceans, which very probably lived in fresh to brackish water thus indicating a likely habitat of Caledonicratis.

  9. Petrography and detrital zircon study of late Carboniferous sequences in the southwestern North China Craton: Implications for the regional tectonic evolution and bauxite genesis

    Science.gov (United States)

    Cai, Shuhui; Wang, Qingfei; Liu, Xuefei; Feng, Yuewen; Zhang, Ying

    2015-02-01

    The North China Craton (NCC) has been flanked by the North Qilian and North Qinling arc-accretionary belts to the south and southwest since ∼400 Ma. The part of the NCC to the east of the Alax terrane (E-NCC) experienced a long sedimentary hiatus and tectonic quiescence between the Middle Ordovician and the late Carboniferous. The northern margin of the E-NCC was reactivated and uplifted with contemporaneous volcanism during the late Carboniferous, an event that partly induced the transformation of the E-NCC from an erosional platform to a continental sedimentary basin. However, the factors controlling this transformation are still not fully understood. A series of sedimentary rocks overlying Ordovician carbonates in the southwestern E-NCC contains a lower iron-oxide layer and an upper phyllosilicate layer. Detrital zircons from different parts of the profile, from the base to the top of the two layers, have similar U-Pb ages. These zircons have a minimum age of ca. 300 Ma and a prominent peak at ca. 450 Ma, with subordinate peaks at ca. 1000 and 2500 Ma. The near-identical minimum age for the two layers suggests they were semi-simultaneously deposited in the late Carboniferous after the long hiatus in sedimentation. Detrital zircons with ages of ∼450 Ma have initial Hf isotopic compositions that vary from large negative to elevated positive. These data, together with the trace element compositions of these zircons, indicate that these minerals formed in a continental arc environment. Samples from the upper sedimentary layer contain mica group minerals that are weakly buckled and fractured, and have weathered to form clay minerals, including chlorite and illite. This suggests that the protolith of this sedimentary layer was dominated by mica schist or mica-bearing granitoid that most likely located near the adjoined part between the North Qilian and North Qinling arc-accretionary belts. Detrital zircons with the youngest ages (ca. 300 Ma) were considered to

  10. Earliest Carboniferous tetrapod and arthropod faunas from Scotland populate Romer's Gap

    Science.gov (United States)

    Smithson, Timothy R.; Wood, Stanley P.; Marshall, John E. A.; Clack, Jennifer A.

    2012-03-01

    Devonian tetrapods (limbed vertebrates), known from an increasingly large number of localities, have been shown to be mainly aquatic with many primitive features. In contrast, the post-Devonian record is marked by an Early Mississippian temporal gap ranging from the earliest Carboniferous (Tournaisian and early Viséan) to the mid-Viséan. By the mid-Viséan, tetrapods had become effectively terrestrial as attested by the presence of stem amniotes, developed an essentially modern aspect, and given rise to the crown group. Up to now, only two localities have yielded tetrapod specimens from the Tournaisian stage: one in Scotland with a single articulated skeleton and one in Nova Scotia with isolated bones, many of uncertain identity. We announce a series of discoveries of Tournaisian-age localities in Scotland that have yielded a wealth of new tetrapod and arthropod fossils. These include both terrestrial and aquatic forms and new taxa. We conclude that the gap in the fossil record has been an artifact of collection failure.

  11. A FOSSIL WHIP-SCORPION (ARACHNIDA: THELYPHONIDA FROM THE UPPER CARBONIFEROUS OF THE CARNIC ALPS (FRIULI, NE ITALY

    Directory of Open Access Journals (Sweden)

    PAUL A. SELDEN

    2016-03-01

    Full Text Available A new and well-preserved fossil whip scorpion (Arachnida: Uropygi: Thelyphonida is described from the Late Carboniferous of the Carnic Alps, Friuli, Italy. It is referred to Parageralinura marsiglioi n. sp. The new specimen is the first Carboniferous arachnid to be described from mainland Italy and is possibly the youngest Palaeozoic thelyphonid.

  12. A Late Carboniferous fossil scorpion from the Piesberg, near Osnabrück, Germany

    Directory of Open Access Journals (Sweden)

    J. A. Dunlop

    2008-02-01

    Full Text Available A new fossil scorpion – only the second from the Late Carboniferous (Pennsylvanian of western Germany – is described from the Westphalian D of the Piesberg near Osnabrück, Germany. This slender and rather gracile specimen is very closely related to the stratigraphically contemporary Eoscorpius carbonarius Meek & Worthern, 1868 from Mazon Creek, Illinois, USA and is here assigned to E. cf. carbonarius. A precise placement is hindered by the need for revision of the late Carboniferous scorpion fauna. doi:10.1002/mmng.200700010

  13. High-alumina basalts from the Bogda Mountains suggest an arc setting for Chinese Northern Tianshan during the Late Carboniferous

    Science.gov (United States)

    Xie, Wei; Xu, Yi-Gang; Chen, Yi-Bing; Luo, Zhen-Yu; Hong, Lu-Bing; Ma, Liang; Liu, Hai-Quan

    2016-07-01

    Considerable debate persists as to the tectonic setting of the Tianshan Orogen during the Late Paleozoic, with active subduction system and intraplate large igneous provinces as two dominant schools. With aims of providing constraints on this issue, geochronological and geochemical analyses have been carried out on the Late Carboniferous high-Al basaltic lava (HAB) from the Bogda Mountains. These lavas, in conformable contact with the felsic rocks, belong to the Upper Carboniferous Liushugou Group. Zircon SHRIMP U-Pb dating of two felsic ignimbrites further suggest that they were mainly erupted during 315-319 Ma. The Bogda basaltic lava is classified as HAB given their high Al contents > 16% and their chemical resemblance to those from modern arcs such as Aleutian and Kamchatka. They are characterized by strong enrichment in large ion lithophile elements (LILE), strong negative Nb-Ta and Ti anomalies, and distinct positive Pb anomalies. Hence, they are significantly different from the mantle plume-related basalts, as exemplified by those from Siberian, Emeishan, and Tarim large igneous provinces. Instead, their MORB-like Nd-Hf-Pb isotopes and arc-like trace elements indicate that the Bogda HABs may have been generated from a mantle wedge metasomatized by sediment-derived melts. The sector and oscillatory zoning in clinopyroxene phenocrysts in the Bogda HABs is attributable to rapid dynamic crystallization during magma ascent. High Al content is due to delayed plagioclase nucleation likely by the high crystallization pressure rather than water content. Collectively, our data lend support to an island arc environment during the Late Paleozoic, probably related to southward subduction of the Paleo-Tianshan Ocean.

  14. Maturity of carboniferous source rocks in Central Onshore Netherlands. the impact of the Permian thermal anomaly

    NARCIS (Netherlands)

    Abdul Fattah, R.; Verweij, J.M.

    2014-01-01

    Pre-Westphalian layers are considered as potential source rocks in the Netherlands. However, there is little amount of information available on their maturity. 3D basin modelling is carried out on Central Onshore Netherlands to investigate the maturity of the deep Carboniferous source rocks. A detai

  15. Tonganoxichnus, a new insect trace from the Upper Carboniferous of eastern Kansas

    Science.gov (United States)

    Mangano, M.G.; Buatois, L.A.; Maples, C.G.; Lanier, Wendy E.

    1997-01-01

    Upper Carboniferous tidal rhythmites of the Tonganoxie Sandstone Member (Stranger Formation) at Buildex Quarry, eastern Kansas, USA, host a relatively diverse arthropod-dominated ichnofauna. Bilaterally symmetrical traces displaying unique anterior and posterior sets of morphological features are well represented within the assemblage. A new ichnogenus, Tonganoxichnus, is proposed for these traces. T. buildexensis, the type ichnospecies, has an anterior region characterized by the presence of a frontal pair of maxillary palp impressions, followed by a head impression and three pairs of conspicuous thoracic appendage imprints symmetrically opposite along a median axis. The posterior region commonly exhibits numerous delicate chevron-like markings, recording the abdominal appendages, and a thin, straight, terminal extension. T. buildexensis is interpreted as a resting trace. A second ichnospecies, T. ottawensis, is characterized by a fan-like arrangement of mostly bifid scratch marks at the anterior area that records the head- and thoracic-appendage backstrokes against the substrate. The posterior area shows chevron-like markings or small subcircular impressions that record the abdominal appendages of the animal, also ending in a thin, straight, terminal extension. Specimens display lateral repetition, and are commonly grouped into twos or threes with a fix point at the posteriormost tail-like structure. T. ottawensis is interpreted as a jumping structure, probably in connection with feeding purposes. The two ichnospecies occur in close association, and share sufficient morphologic features to support the same type of arthropod producer. T. buildexensis closely mimics the ventral anatomy of the tracemaker, whereas T. ottawensis records the jumping abilities of the animal providing significant ethologic and paleoecologic information. The presence of well-differentiated cephalic, thoracic, and abdominal features, particularly in T. buildexensis, resembles the

  16. A micropalaeontological and palynological insight into Early Carboniferous floodplain environments

    Science.gov (United States)

    Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John; Reeves, Emma

    2016-04-01

    Romer's Gap, the interval following the end Devonian mass extinction, is traditionally considered to be depauperate in tetrapod and fish fossils. A major research project (TW:eed -Tetrapod World: early evolution and diversification) focusing on the Tournaisian Ballagan Formation of Scotland is investigating how early Carboniferous ecosystems rebuilt following the extinction. A multi-proxy approach, combining sedimentology, micropalaeontology and palynology, is used to investigate the different floodplain environments in which tetrapods, fish, arthropods and molluscs lived. The formation is characterised by an overbank facies association of siltstone, sandstone and palaeosols, interbedded with dolostone and evaporite units, and cut by fluvial sandstone facies associations of fining-upwards conglomerate lags, cross-bedded sandstone and rippled siltstone. Macrofossils are identified from 326 horizons within a 520 metre thick Ballagan Formation field section at Burnmouth, near Berwick-upon-Tweed, Scottish Borders. Common fauna are ostracods, bivalves, arthropods, sarcopterygians, dipnoans, acanthodians, tetrapods and chondrichthyans. Quantitative microfossil picking of the three sedimentary rock types in which tetrapods occur was undertaken to gain further insight into the palaeoecology. The sediments are; 1) laminated grey siltstones, deposited in floodplain lakes; 2) sandy siltstones, grey siltstones with millimetre size clasts. 71% of these beds overlie palaeosols or desiccated surfaces and are formed in small-scale flooding events; 3) conglomerates, mostly lags at the base of thick sandstones, with centimetre sized siltstone, sandstone and dolostone clasts. Grey siltstones contain a microfauna of common plant fragments, megaspores and sparse actinopterygian and rhizodont fragments. Sandy siltstones have the highest fossil diversity and contain microfossil fragments of plants, megaspores, charcoal, ostracods, actinopterygians, rhizodonts, eurypterids and rarer non

  17. Carboniferous granites on the northern margin of Gondwana, Anatolide-Tauride Block, Turkey - Evidence for southward subduction of Paleotethys

    Science.gov (United States)

    Candan, O.; Akal, C.; Koralay, O. E.; Okay, A. I.; Oberhänsli, R.; Prelević, D.; Mertz-Kraus, R.

    2016-06-01

    Carboniferous metagranites with U-Pb zircon crystallization ages of 331-315 Ma crop out in the Afyon zone in the northern margin of the Anatolide-Tauride Block, which is commonly regarded as part of Gondwana during the Late Palaeozoic. They are peraluminous, calc-alkaline and are characterized by increase in Rb and Ba, decrease in Nb-Ta, and enrichment in Sr and high LILE/HFSE ratios compatible with a continental arc setting. The metagranites intrude a metasedimentary sequence of phyllite, metaquartzite and marble; both the Carboniferous metagranites and metasedimentary rocks are overlain unconformably by Lower Triassic metaconglomerates, metavolcanics and Upper Triassic to Cretaceous recrystallized limestones. The low-grade metamorphism and deformation occurred at the Cretaceous-Tertiary boundary. There is no evidence for Carboniferous deformation and metamorphism in the region. Carboniferous arc-type granites and previously described Carboniferous subduction-accretion complexes on the northern margin of the Anatolide-Tauride Block suggest southward subduction of Paleotethys under Gondwana during the Carboniferous. Considering the Variscan-related arc granites in Pelagonian and Sakarya zones on the active southern margin of Laurasia, a dual subduction of Paleotethys can be envisaged between Early Carboniferous and Late Permian. However, the southward subduction was short-lived and by the Late Permian the Gondwana margin became passive.

  18. Sedimentological and sequence stratigraphic analysis of Carboniferous deposits in western Libya: Recording the sedimentary response of the northern Gondwana margin to climate and sea-level changes

    Science.gov (United States)

    Fröhlich, Sebastian; Petitpierre, Laurent; Redfern, Jonathan; Grech, Paul; Bodin, Stéphane; Lang, Simon

    2010-06-01

    Detailed sedimentological and sequence stratigraphic analysis of Carboniferous (Tournaisian to Moscovian) strata exposed in the north-western Murzuq Basin and southern Ghadames Basin, western Libya, provides new insights into the sedimentary response of the northern Gondwana margin to climate and sea-level change. The Lower Carboniferous Marar and Assedjefar Formations can be divided into five depositional sequences of 3rd order. In total 27 facies types are defined, grouped into four facies associations: offshore shales, shallow marine clastics, fluvial sandstones and marine carbonates. The bulk of the Lower Carboniferous interval is dominated by an alternation of offshore shales and shallow marine clastics, which were deposited during the transgressive and highstand systems tracts. The clastic deposits mostly consist of laterally persistent coarsening and thickening upward cycles with a common succession from basal hummocky cross-stratified sandstones to ripple-laminated sandstones, capped by multidirectional cross-stratified sandstones. Within the lowstand systems tracts, lenticular sandbodies have been identified, which vary in thickness from 1.5 m (ca. 40 m wide) to 50 m (ca. 1.5 km wide). These are interpreted to be fluvial channel complexes based on their geometry, erosive base, and presence of thick stacked sandstones with unidirectional planar and trough cross-bedding, the absence of bioturbation and occurrence of land plant fragments. These channel complexes mostly cut down into offshore shales, and are interpreted to be bound at the base by sequence boundaries. Palaeogeographic maps generated for each lowstand system show the location and palaeoflow direction of these fluvial channel complexes. They are interpreted to represent large incised valleys filled with thick fluvial sandstones. Their identification and distribution indicates repeated exposure of large areas of western Libya, most-likely controlled by major eustatic sea-level changes. The

  19. Conodont-bearing formations of Devonian and Lower Carboniferous age in northern León and Palencia (Spain)

    NARCIS (Netherlands)

    Adrichem Boogaert, van H.A.

    1965-01-01

    Conodonts have been extracted from calcareous units of the Devonian and Lower Carboniferous sequence from 3 areas in the S. part of the Cantabrian Mountains. There can be distinguished Emsian, Givetian, Frasnian, Famennian and Viséan faunas.

  20. Devonian-Carboniferous unconformity in Argentina and its relation to the Eo-Hercynian orogeny in southern South America

    Science.gov (United States)

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

    1993-04-01

    The Devonian-Carboniferous contact in southern South America, characterized by a sharp unconformity, has been related to the Late Devonian-Early Carboniferous Eo-Hercynian orogeny. The Calingasta-Uspallata basin of western Argentina and the Sauce-Grande basin (Ventana Foldbelt) of eastern Argentina have been selected to characterize this unconformity. The Eo-Hercynian movements were accompanied in western Argentina by igneous activity related to a Late Devonian—Early Carboniferous magmatic arc mainly exposed today along the Andean Cordillera. This magmatic activity is partly reflected also in eastern Argentina (Ventana Foldbelt), where isotopic dates suggest a thermal event also related to the intrusions present to the west in the North Patagonian Massif and Sierras Pampeanas. The scarcity of Lower Carboniferous deposits in the stratigraphic record of southern South America suggests that the Early Carboniferous was a time interval dominated by uplift and erosion followed by widespread subsidence during the Middle and Late Carboniferous. The origin of the Eo-Hercynian orogeny can be linked with the convergence between the Arequipa Massif, and its southern extension, and the South American continent. Its effects are best represented along the ‘Palaeo-Pacific’ margin, although distant effects are discernible in the cratonic areas of eastern South America.

  1. Paleoecology of Late Carboniferous Phylloid Algae in Southern Guizhou,SW China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Phylloid algae are important reef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County,Guizhou Province. Phylloid algae growing closely packed are attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli are of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine organisms are relatively scarce.Obviously, phylloid algae are stronger competitors for living space than other co-occurring organisms.

  2. High-fidelity X-ray micro-tomography reconstruction of siderite-hosted Carboniferous arachnids

    OpenAIRE

    Garwood, Russell; Dunlop, Jason A.; Sutton, Mark D.

    2009-01-01

    A new approach to maximize data recovery from siderite-hosted fossils is presented. Late Carboniferous trigonotarbids (Arachnida: Trigonotarbida) from Coseley, UK, were chosen to assess the potential of high-resolution X-ray micro-tomography (XMT). Three-dimensional computer reconstruction visualizes the animals at 20 µm or better resolution, resolving subtle and previously unseen details. Novel data recovered includes (possibly plesiomorphic) retention of endites on leg coxae of Cryptomartus...

  3. Zircon age and heavy mineral constraints on provenance of North Sea Carboniferous sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Morton, A.C. [HM Research Associates, Woodhouse Eaves (United Kingdom); University of Aberdeen (United Kingdom). Dept. of Geology and Petroleum Geology; Hallsworth, C.R. [HM Research Associates, Woodhouse Eaves (United Kingdom); Claoue-Long, J.C. [Australian Geological Survey Organisation, Canberra (Australia)

    2001-03-01

    The understanding of sediment provenance and sediment transport routes is a key element in establishing reservoir presence in clastic petroleum systems. Determination of sediment provenance is particularly difficult in structurally complex areas and in sequences that have undergone extensive burial diagenesis. This paper describes a method that overcomes these problems, by combining quantitative heavy mineral analysis with detrital zircon age dating. Quantitative heavy mineral analysis identifies differences in sediment provenance within the sample set, and zircon age data provide diagnostic criteria for the identification of the various source terrains. The high degree of resolution shown by this approach is demonstrated using the North Sea Carboniferous as an example. The Carboniferous of the North Sea has suffered extensive diagenetic modification during its complex burial history, is difficult to image with seismic data, and in some areas, notably the central and northern North Sea, preservation is patchy. The understanding of Carboniferous sand provenance is therefore rudimentary. The Tayport and Firth Coal formations (latest Devonian to Early Carboniferous) of the Outer Moray Firth (central North Sea) were derived from a source area to the north of the British Isles, with sediment transported along the proto-Viking Graben. Some local input is recognised in the Firth Coal Formation. The Westoe Coal Formation (Westphalian B) in the southern North Sea was derived from the southeast, probably from the Saxo-Thuringian Zone of the central European Variscides. The Lower Ketch Member (Westphalian C) in the southern North Sea has a northern provenance, with abundant chrome spinel suggesting derivation from ophiolitic material on the Rinkoebing-Fyn High. (author)

  4. Sedimentary geology of the middle Carboniferous of the Donbas region (Dniepr-Donets Basin, Ukraine).

    Science.gov (United States)

    van Hinsbergen, Douwe J J; Abels, Hemmo A; Bosch, Wolter; Boekhout, Flora; Kitchka, Alexander; Hamers, Maartje; van der Meer, Douwe G; Geluk, Mark; Stephenson, Randell A

    2015-03-20

    The Paleozoic Dniepr-Donets Basin in Belarus, Ukraine, and Russia forms a major hydrocarbon province. Although well- and seismic data have established a 20 km thick stratigraphy, field-studies of its sediments are scarce. The inverted Donbas segment (Ukraine) exposes the middle Carboniferous part of the basin's stratigraphy. Here, we provide detailed sedimentological data from 13 sections that cover 1.5 of the total of 5 km of the Bashkirian and Moscovian stages and assess the paleoenvironment and paleo-current directions. Middle Carboniferous deposition occurred in a shelf environment, with coal deposition, subordinate fluvial facies, and abundant lower and middle shoreface facies, comprising an intercalated package of potential source and reservoir rocks. Sedimentary facies indicate a paleodepth range from below storm wave base to near-coastal swamp environments. Sedimentation and subsidence were hence in pace, with subtle facies changes likely representing relative sea-level changes. Paleocurrent directions are remarkably consistently southeastward in time and space in the different sedimentary facies across the Donbas Fold Belt, illustrating a dominant sedimentary infill along the basin axis, with little basin margin influence. This suggests that the middle Carboniferous stratigraphy of the Dniepr-Donets basin to the northwest probably contains significant amounts of fluvial sandstones, important for assessing hydrocarbon reservoir potential.

  5. Glacioeustasy, meteoric diagenesis, and the carbon cycle during the Middle Carboniferous

    Science.gov (United States)

    Dyer, Blake; Maloof, Adam C.; Higgins, John A.

    2015-10-01

    Middle Carboniferous carbonates in the western U.S. have undergone Pleistocene Bahamas-style meteoric diagenesis that may be associated with expanding late Paleozoic ice sheets. Fourteen stratigraphic sections from carbonate platforms illustrate the regional distribution and variable intensity of physical and chemical diagenesis just below the Middle Carboniferous unconformity. These sections contain top-negative carbon isotope excursions that terminate in regional exposure surfaces that are associated with some combination of karst towers, desiccation cracks, fabric destructive recrystallization, or extensive root systems. The timing of the diagenesis is synchronous with similarly scaled top-negative carbon isotope excursions observed by others in England, Kazakhstan, and China. The mass flux of negative carbon required to generate similar isotopic profiles across the areal extent of Middle Carboniferous platform carbonates is a significant component of the global carbon cycle. We present a simple carbon box model to illustrate that the δ13C of dissolved inorganic carbon in the ocean could be elevated by ˜1.4‰ as isotopically light carbon from the weathering of terrestrial organic matter reacts with exposed platforms before reaching the ocean and atmosphere. These results represent an improvement on global biogeochemical models that have struggled to provide a congruent solution to the high δ13C of the late Paleozoic icehouse.

  6. A new paleozoic Symmoriiformes (Chondrichthyes from the late Carboniferous of Kansas (USA and cladistic analysis of early chondrichthyans.

    Directory of Open Access Journals (Sweden)

    Alan Pradel

    Full Text Available BACKGROUND: The relationships of cartilaginous fishes are discussed in the light of well preserved three-dimensional Paleozoic specimens. There is no consensus to date on the interrelationship of Paleozoic chondrichthyans, although three main phylogenetic hypotheses exist in the current literature: 1. the Paleozoic shark-like chondrichthyans, such as the Symmoriiformes, are grouped along with the modern sharks (neoselachians into a clade which is sister group of holocephalans; 2. the Symmoriiformes are related to holocephalans, whereas the other Paleozoic shark-like chondrichthyans are related to neoselachians; 3. many Paleozoic shark-like chondrichthyans, such as the Symmoriiformes, are stem chondrichthyans, whereas stem and crown holocephalans are sister group to the stem and crown neoselachians in a crown-chondrichthyan clade. This third hypothesis was proposed recently, based mainly on dental characters. METHODOLOGY/PRINCIPAL FINDINGS: On the basis of two well preserved chondrichthyan neurocrania from the Late Carboniferous of Kansas, USA, we describe here a new species of Symmoriiformes, Kawichthys moodiei gen. et sp. nov., which was investigated by means of computerized X-ray synchrotron microtomography. We present a new phylogenetic analysis based on neurocranial characters, which supports the third hypothesis and corroborates the hypothesis that crown-group chondrichthyans (Holocephali+Neoselachii form a tightly-knit group within the chondrichthyan total group, by providing additional, non dental characters. CONCLUSIONS/SIGNIFICANCE: Our results highlight the importance of new well preserved Paleozoic fossils and new techniques of observation, and suggest that a new look at the synapomorphies of the crown-group chondrichthyans would be worthwhile in terms of understanding the adaptive significance of phylogenetically important characters.

  7. Activation of northern margin of the North China Craton in Late Paleozoic: Evidence from U-Pb dating and Hf isotopes of detrital zircons from the Upper Carboniferous Taiyuan Formation in the Ningwu-Jingle basin

    Institute of Scientific and Technical Information of China (English)

    LI HongYan; XU YiGang; HUANG XiaoLong; HE Bin; LUO ZhenYu; YAN Bin

    2009-01-01

    LA-MC-ICPMS U-Pb dating has been performed on detrital zircons from the Upper Carboniferous Tai-yuan Formation (N-8) in the Ningwu-Jingle Basin, west of the North China Craton (NCC). The ages of 72 detrital zircon grains are divided into three groups: 303-320 Ma (6 grains), 1631-2194 Ma (37 grains, peaked at 1850 Ma), 2318-2646 Ma (29 grains, peaked at 2500 Ma). Detrital zircons of Group 2 and Group 3 were likely derived from the basement of the NCC. Group 1 zircons exhibit 176Hf/177Hf ratios ranging from 0.281725 to 0.282239, with corresponding negative εHf(t) values of -12.4-30.3 and old Hf model ages of 1.4-2.2 Ga. These characteristics show a strong resemblance to those of Carboniferous igneous zircons from the Inner Mongolia Paleo-uplift (IMPU) on the northern margin of the NCC, but differ significantly from those of the Xing-Meng Orogenic Belt, suggesting that the source of the Tai-yuan Formation partly came from the IMPU. All detrital zircons of Group 1 have relatively high Th/U ratios (0.67), indicating a magmatic origin. The mean age (304±6 Ma) of the two youngest grains is close to the depositional age of the Taiyuan Formation, suggesting a strong tectonic uplift and mag-matism in the IMPU during the Late Carboniferous. This paper provides important geological evidence for the activation of the northern margin of the NCC in the Late Paleozoic.

  8. Rugose corals across the Devonian-Carboniferous boundary in NW Turkey

    Directory of Open Access Journals (Sweden)

    Julien Denayer

    2016-02-01

    Full Text Available An uppermost Famennian (Strunian coral assemblage has been recovered in the middle part of the Yılanlı Formation of the Istanbul Zone (Zonguldak and Bartın areas, NW Turkey. In the Bartın area, the studied fossiliferous interval corresponds to a c. 30 m-thick unit of bioclastic to peloidal wackestone to packstone grading to grainstone and including two stromatoporoid biostromes. In the Zonguldak area, 60 km westward, the bioclastic facies is dominant. The rugose corals are mainly solitary taxa belonging to the genera Campophyllum, Bounophyllum, Amplexocarinia, and ?Metriophyllum, and only one colonial genus occurs: Pseudoendophyllum. This fauna is similar to that documented in Europe. The campophyllids and dibunophyllids are the main component of the uppermost Famennian assemblages in S Belgium, N France, W Germany, NW and S Poland. The endophyllids occur in S Poland, Novaya Zemlya, and in the Ural Mountains. The Istanbul Zone is supposed to be situated in the central part of the Palaeotethys Ocean, along the southern margin of Laurussia during the uppermost Devonian and Carboniferous. The rugose corals indicate some relationship with the eastern part of Laurussia, or that both areas were under a common marine influence at this time. The global Hangenberg event was not recognized in the Turkish localities, except for the disappearance of the corals, occurring less than 19 m below the Devonian–Carboniferous boundary based on the foraminifers. There is no major facies change through the boundary and the first Carboniferous corals (small Uralinia and Caninophyllum appear 6 m above the D–C boundary. The new species Caninophyllum charli sp. nov. is described from the upper part of the lower Tournaisian.

  9. Permo-Carboniferous sedimentary basins related to the distribution of planetary cryptoblemes

    Science.gov (United States)

    Windolph, J.F.

    1997-01-01

    Massive/high velocity solar, galactic, and cosmic debris impacting the Earths surface may account for the enormous energy required for the formation of Permo-Carboniferous sedimentary basins and related mountain building orogenies. Analysis of satellite immagry, sea floor sonar, geophysical data, and geotectonic fabrics show a strong correlation throughout geologic time between sedimentary basin origin and planetary cryptoblemes. Cryptoblemes are subtile, multi-ringed, radial centric impact shock signatures covering the entire terrestrial surface and ocean floors, having a geometry and distribution strikingly similar to the surfaces of the lunar planetary bodies in the solar system. Investigations of Permo-Carboniferous basins show an intensely overprinted pattern of cryptoblemes coinciding with partial obliteration and elliptical compression of pre-existing basins and accompanying shock patterns. Large distorted cryptoblemes may incorporate thin skin deformation, localized sediment diagenesis, regional metamorphism, and juxtaposed exotic terrains. These data, related to basin morphogenic symmetry, suggest that large episodic impact events are the primary cause of tectonogenic features, geologic boundary formation and mass extinction episodes on the planet Earth. Plate tectonics may be only a slow moving, low energy secondary effect defined and set in motion by megacosmic accretion events. Permo-Carboniferous sediments of note are preserved or accumulated in relatively small rectangular to arcuate rift valleys and synclinal down warps, such as the Narraganset basin of Massachusetts, USA, and Paganzo basin in Argentina, S.A. These deposits and depocenters may originate from dynamic reinforcement/cancellation impact effects, as can be seen in the Basin Range of Nevada and Utah, USA. Large circular to oval sedimentary basins commonly include internal ring structures indicating post depositional subsidence and rebound adjustments with growth faulting, notable in the

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

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  11. Metallogenesis of Devonian—Carboniferous Strata—bound Carbonate—type Uranium Deposits in South China

    Institute of Scientific and Technical Information of China (English)

    庞玉蕙

    1990-01-01

    This paper deais with the geological conditions.mineralization characteristics,genetic types and space-time distribution of the Devonian-Carboniferous strata-bound carbonate-type uranium deposits in South China.These ore deposits are genetically classified as the leaching type and the leaching-hydrothermal superimposed type,These ore deposits are confined mainly to the strata (D2-3,C1)of platform-lagoon carbonate facies.Unique tectonic settings are a vital factor leading to the formation of these uranium deposits.A metallogenetic model for these uranium deposits has been proposed.

  12. Mrar formation of western Libya - evolution of an early Carboniferous delta system

    Energy Technology Data Exchange (ETDEWEB)

    Whitbread, T. (Univ. of Keele, England); Kelling, G.

    1982-08-01

    The Lower Carboniferous Mrar Formation is exposed extensively along the southern margin of the Ghadames basin in northwest Libya. The basal part of the Mrar forms the cap rock and possible hydrocarbon source for many of the producing reservoirs in the underlying Tahara sandstones. Furthermore, the Mrar itself is known to contain significant gas shows southwest of the outcrop, associated with some oil potential. The Mrar formation was deposited in a deltaic environment which developed on the northern part of the stable Saharan platform. The history of the Mrar formation's deposition is discussed. (JMT)

  13. ANALYZING THE CLASSIC METHODS OF ORGANIZING THE ADMINISTRATION ACCOUNTACY USED IN THE CARBONIFEROUS MINING INDUSTRY

    Directory of Open Access Journals (Sweden)

    PALIU-POPA Lucia

    2009-12-01

    Full Text Available Information regarding production costs occupy a central slot, determined by their implications regarding the present and future evolution of a company. The value of information regarding the cost of production justifies its use both in decisions regarding the current activity and in the company’s future strategy. The efficient organization of economic activity in the carboniferous mining industry imposes a constant improvement of management methods, which also implies a reconsideration of administration accountancy methods and cost control, which have to become capable of offering information that can be compatible to the requirements for an efficient management of the production process, in a market economy.

  14. A detrital zircon provenance study of the Lower Carboniferous sequences in the East Fife section of the Midland Valley of Scotland

    Science.gov (United States)

    Murchie, Sean; Robinson, Ruth, ,, Dr; Lancaster, Penelope, ,, Dr

    2014-05-01

    Detrital zircons from the Lower Carboniferous clastic rocks of the Midland Valley of Scotland have been dated using U-Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to determine which source areas contributed sediment to the basin during its development, and to investigate whether provenance changed during deposition of these units. Specific provenance detection using U/Pb dating of zircons has never been attempted in these rocks, and there are uncertainties remaining about the regional paleogeographic setting for the Midland Valley. Four samples from the Dinantian Strathclyde Group have been analysed, and the units are locally known as the Fife Ness, Anstruther, Pittenweem, Sandy Craig, and Pathhead formations. The formations are composed of shallow marine, deltaic, fluvial and floodplain deposits and these predominantly siliciclastic sedimentary rocks are interbedded with thin fossiliferous carbonate bands. The samples are quartz arenitic, sub-arkosic and lithic arkosic medium-grained sandstones, predominantly from a fluvial origin. The British Geological Survey developed a lithostratigraphy which is the most used framework for the Strathclyde Group (Browne et al., 1997), but a different biostratigraphical framework based on palynology has been proposed by Owens et al. (2005). In addition to identifying provenance, the zircon age populations for each formation are compared to test which stratigraphic framework is correct. More broadly, the provenance data provides a way to improve the regional palaeogeographic setting for the Midland Valley. Zircon ages in the Strathclyde Group are dominated by Late Mesoproterozoic to Late Palaeoproterozoic (0.9 - 2.0 Ga) and Early Palaeozoic (350 - 450 Ma) ages which reflect Caledonide (Laurentian-Baltica margin including Scotland, Scandinavia, Greenland, Newfoundland), Grampian and internal Midland Valley source areas. Notable peaks occur at 400 Ma, 1.0 --1.1 Ga, 1.3 Ga, 1.6 - 1.7 Ga, and 2.7 Ga, and

  15. Late Carboniferous macrofauna from Wadi Araba, Eastern Desert, Egypt, and their paleoecological implications

    Science.gov (United States)

    El-Shazly, Soheir H.

    2011-12-01

    The Upper Carboniferous rocks at Wadi Araba are highly rich in macrofaunal content. The systematic description of these macrofauna reveals the identification of 34 species, 17 species of which are recorded for the first time from the Carboniferous rocks of Egypt, among them the trilobite Cummingella ( C.) carringtonensis carringtonensis (Etheridge). Moreover, the paleoeclogic study on some crinoid and brachiopod specimens shows predation and commensal relations with some endo and epibionts fauna. The study presents also crinoidal infestation by Oxytoma ( Palmoxytoma) cygnipes (Young and Bird) species, a relation which is recorded for the first time. Evidences of crushing or biting damages on some brachiopod shells that have been attributed to nautiloids or conchostracan arthropods are also reported. The microfacies study of the carbonate rocks in this area reveals the identification of five microfacies types indicating that the rocks were deposited in an environment ranging from restricted inner to outer shelf lagoonal environments with open circulation. The microfacies study indicates also the presence of two types of microorganisms, the filamentous microorganisms and the fossilized microbial carbonate communities, which played an important role in iron oxide precipitation and rock diagenesis.

  16. Changes in dominance patterns in upper Carboniferous plant-fossil assemblages

    Science.gov (United States)

    Pfefferkorn, Hermann W.; Thomson, Margaret C.

    1982-12-01

    Upper Carboniferous (Pennsylvanian) terrestrial clastic rocks from North America and Europe contain compression-impression plant-fossil assemblages that represent the remains of plant communities that grew on floodplains, levees, and other clastic facies of fluvial and deltaic lowlands. Quantitative analysis of 66 plant-fossil assemblages spanning the entire late Carboniferous demonstrates that before the middle of the Westphalian D Stage the majority of plant-fossil assemblages are dominated by pteridosperms and sphenopsids. Lycopods and cordaites dominate only a few assemblages counted. Ferns do not dominate any assemblages. These findings contrast sharply with the dominance of lycopods reported by others from coal swamps of the same time interval. Above the middle of the Westphalian D, however, one-third of the compression-impression assemblages counted are dominated by ferns. The change in dominance pattern in compression-impression plant-fossil assemblages occurs half a stage earlier than the previously reported change from lycopod-dominated to fern-dominated assemblages at the Westphalian-Stephanian boundary in coal swamps. A trend toward dryer climate during Westphalian D apparently influenced plants growing on better-drained alluvial soils earlier than those growing on water-logged soils of contemporaneous coal swamps. *Present address: Room 108 Math.-Geology Building, University of Minnesota, Duluth, Minnesota 55812

  17. Aspects of late devonian and early carboniferous palynology of southern Ireland. III. Palynology of devonian—carboniferous transition sequences with special reference to the bantry bay area, co. cork

    NARCIS (Netherlands)

    Zwan, C.J. van der

    1980-01-01

    The present paper provides: (1) an analysis of the qualitative and quantitative compositional development of Late Devonian-Early Carboniferous palynological assemblages from the Bantry Bay and other sections of southern Ireland; (2) a scheme of successive phases, (inter) regionally recognizable in t

  18. Petroleum exploration of shallow marine deposit Carboniferous volcanic tuff reservoir in the western margin of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    Wang Jianyong; Wang Xuezhong; Ma Liqun

    2013-01-01

    In 2011,petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re-alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pai 61 well ,with 855.7 ~949.6 m section,in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa· s (50℃). The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.

  19. Three upper carboniferous limestone-rich, high-destructive, delta systems with submarine fan deposits, Cantabrian mountains, Spain

    NARCIS (Netherlands)

    Graaf, Willem Jacob Evert van de

    1971-01-01

    A synthesis of the development of the Variscan orogene, of which the present Cantabrian Mountains form only a part, was given by Matte (1968). Wagner (1970) presented a general outline of Carboniferous stratigraphy in this area. For purposes of a general background it is sufficient to state that fro

  20. Genesis of Pb-Zn-Cu-Ag Deposits within Permian Carboniferous-Carbonate Rocks in Madina Regency, North Sumatra

    Directory of Open Access Journals (Sweden)

    Bhakti Hamonangan Harahap

    2015-11-01

    Full Text Available Strong mineralized carbonate rock-bearing Pb-Zn-Cu-Ag-(Au ores are well exposed on the Latong River area, Madina Regency, North Sumatra Province. The ore deposit is hosted within the carbonate rocks of the Permian to Carboniferous Tapanuli Group. It is mainly accumulated in hollows replacing limestone in the forms of lensoidal, colloform, veins, veinlets, cavity filling, breccia, and dissemination. The ores dominantly consist of galena (126 000 ppm Pb and sphalerite (2347 ppm Zn. The other minerals are silver, azurite, covellite, pyrite, marcasite, and chalcopyrite. This deposit was formed by at least three phases of mineralization, i.e. pyrite and then galena replaced pyrite, sphalerite replaced galena, and pyrite. The last phase is the deposition of chalcopyrite that replaced sphalerite. The Latong sulfide ore deposits posses Pb isotope ratio of 206Pb/204Pb = 19.16 - 20.72, 207Pb/204Pb = 16.16 - 17.29, and 208Pb/204Pb = 42.92 - 40.78. The characteristic feature of the deposit indicates that it is formed by a sedimentary process rather than an igneous activity in origin. This leads to an interpretation that the Latong deposit belongs to the Sedimentary Hosted Massive Sulfide (SHMS of Mississippi Valley-Type (MVT. The presence of SHMS in the island arc such as Sumatra has become controversial. For a long time, ore deposits in the Indonesian Island Arc are always identical with the porphyry and hydrothermal processes related to arc magmatism. This paper is dealing with the geology of Latong and its base metal deposits. This work is also to interpret their genesis as well as general relationship to the regional geology and tectonic setting of Sumatra.

  1. Late Carboniferous remagnetisation of Palaeozoic rocks in the NE Rhenish Massif, Germany

    Science.gov (United States)

    Zwing, A.; Bachtadse, V.; Soffel, H. C.

    During stepwise thermal and alternating field demagnetisation experiments on Devonian and Lower Carboniferous carbonate and clastic rocks from the north-eastern part of the Rhenish Massif, Germany, three components of magnetisation (A, B, C) are identified. Component A is a recent viscous overprint that parallels the local present day geomagnetic field. Component B is mainly observed from 260 up to 550 °C during thermal demagnetisation and is carried by magnetite. In two localities, where red siltstones and red carbonate rocks were sampled, component B is stable up to 670 °C, indicating the presence of hematite. Three clusters of in situ B directions can be identified, which are controlled by the tectonic position of the sampling areas. These are from NW to SE: the Remscheid anticline (RA), the Lüdenscheid syncline (LS) and the Attendorn and Wittgenstein synclines (AS/WS). Standard and inclination-only fold tests, using parametric resampling, yield optimal statistical parameters at increasing amounts of untilting ranging from 0% in the South up to 57% in the North of the NE Rhenish Massif. Despite the variations in optimal untilting, the resulting site mean directions of component B do not differ significantly in inclination. These results are interpreted to reflect the acquisition of magnetisation during progressive northward migration of the deformation front in Late Carboniferous times. The resulting palaeolatitudes (RA: 1°S +2°-3°; LS: 2°S +3°-2°; AS/WS: 1°S +3°-4°) are in good agreement with the predicted position of the sampling area in the Late Carboniferous, as derived from a published Apparent Polar Wander Path for Baltica and Laurentia. The unblocking temperature spectra and the synfolding nature of B yield strong evidence that chemical processes, possibly driven by fluid migration during orogenesis, caused this remagnetisation. A third component C was observed in zones of tight folding with steeply dipping to overturned bedding planes and is

  2. Organic facies characteristics of the Carboniferous Pamucakyayla Formation, western Taurus, Antalya Nappes, Kemer (Antalya/Turkey)

    Science.gov (United States)

    Bertan Gulludag, Cevdet; Altunsoy, Mehmet; Ozcelik, Orhan

    2015-04-01

    The study area is located in the western part of the Taurus Belt (SW Turkey). This region exhibits a complex structure involving two autochthonous units surrounded and imbricated with three allochthonous complexes. Antalya Nappes is a complex tectonic imbricate structure including sedimantary and ultrabasic rocks. In this study, organic facies characteristics of Carboniferous coaly units in the Pamucakyayla region (Kemer, Antalya-Turkey) were examined. The Carboniferous Pamucakyayla Formation, which is characterized by sandstone, claystone, marl and coaly units. This units includes different levels of coal seams in different thicknesses. Organic matter is composed predominantly of woody and amorphous material, with a minor contribution of planty and coaly material. Kerogen in the deposits is type II/III, as indicated by organic petrographic observations and Rock-Eval data. Total organic carbon (TOC) values are generally between 0.01 and 1.44 %, but reach 5.81 % in the formation. Tmax values vary between 446 and 451 °C and indicate mature zone (Based on the value of 0.25 % TOC). Organic facies type BC, C and CD were identified in the investigated units. Organic facies BC is related sandstoneand marl lithofacies. This facis is deposited under an anoxic water column in a fine grained clastics, where rapid deposition creates anoxia in the sediments after deposition. This facies is characterized by average values of HI around 317 (equivalent to type II kerogene), TOC around 0.02 %, and an average of S2 of 0.04 mg HC/g of rock. Organic facies C is related to sandstone, marl and coal lithofacies. This facies is characterized by average values of HI around 176 (equivalent to type III kerogene), TOC around 0.19 %, and an average of S2 of 0.03 mg HC/g of rock. The organic matter is partly oxidized, and terrestrial. Organic facies C is the "gas-prone" facies. Organic facies CD is related to limestone, marl and coal lithofacies. This facies is characterized by average values

  3. STRATIGRAPHY AND FUSULINIDS OF THE MOSCOVIAN STAGE (MIDDLE CARBONIFEROUS IN THE SOUTHWESTERN DARVAZ (PAMIR

    Directory of Open Access Journals (Sweden)

    ERNST JA. LEVEN

    1998-03-01

    Full Text Available A refined subdivision, based on fusulinids, of the Moscovian stage in southwestern Darvaz is proposed. Seven local zones, three in the Lower Moscovian substage and four in the Upper Moscovian substage were established, based on investigations of three stratigraphic sections. The zones were correlated with those of the Eastern European and Middle Asian stratigraphic schemes. One hundred and forty-three species and subspecies, which belong to 29 genera and 13 families of fusulinids, were identified in the Middle Carboniferous of Darvaz. Among them, one genus (Undatafusulina and 16 species, i.e. Taitzehoella compacta, Ovatella panjensis, Aljutovella darvasica, Undatafusulina asiatica, Citronites panjensis, C. reticulatus, Beedeina darvasica, B. dutkevichi, Putrella admiranda, Hemifusulina orientalis, Fusulinella (Moellerites subundulata, F. (M. jucunda, F. (M. orientalis, F.(Fusulinella crassitectoria, F. (F. bogushi, and F. (F. pamirensis are new. 

  4. Shell microstructure of the late Carboniferous rostroconch mollusc Apotocardium lanterna (Branson, 1965)

    Science.gov (United States)

    Rogalla, N.S.; Carter, J.G.; Pojeta, J.

    2003-01-01

    The Late Carboniferous bransoniid conocardioidean Apotocardium lanterna (Branson, 1965) had an entirely aragonitic shell with a finely prismatic outer shell layer, a predominantly crossed lamellar to complex crossed lamellar middle shell layer, and an "inner" shell layer of finely textured porcelaneous and/or matted structure. This "inner" layer is probably homologous with the inner part of the middle shell layer and the inner layer sensu stricto of bivalved molluscs. Shell morphological and microstructural convergences between conocardioids and living heart cockles suggest that at least some conocardioids may have farmed algal endosymbionts in their posterior mantle margins. This symbiosis may have helped conocardioids compete with the biomechanically more efficient bivalves during the latter part of the Paleozoic.

  5. Carboniferous Bimodal Volcanic Rocks and Their Plate Tectonic Setting,Hainan Island

    Institute of Scientific and Technical Information of China (English)

    夏邦栋; 施光宇; 等

    1992-01-01

    The Carboniferous volcanic rocks in western Hainan Island consist of a series of oceanic tholeite and rhyoporphyrite,showing bimodal nature.Similar geochemical characters,in terms of abun-daces and relative rations of incompatible elements and REE and the REE patterns,between the basalt and continental rift-associated tholeiite indicate the occurrence of Late Paleozoic rifting in the area.The basaltic magma,with a low degree of evolution,was originated from deep mantle,show-ing contamination by low crustal material.The rhyolite is thought to be formed from partial melting of the continental crust by higher thermal flow in a rift environment rather than from fractional crystallization of a basaltic magma.

  6. EFFECTS OF SOIL TREATMENT BY COAL MINING CARBONIFEROUS WASTE SLUDGE IN MAIZE GROWING

    Directory of Open Access Journals (Sweden)

    Robin Mujačić

    2011-11-01

    Full Text Available The multifuncional role and importance of organic matter in soil is widely known. It is also known that the organic matter in soil is subjected to microbiological-biochemical processes of transformation, which includes synthesis of humus as well as it’s decomposition -mineralization. Mineralization means transformation-decomposition of organic matter by microbiological processes to mineral products; plant nutrients and water + CO2 as starting and ending component of photosyntesis. Nutrients are partly plant available with fertilizing effect, partly lost from the soil - leaching in ground water, causing it’s eutrophication, but CO2 in atmosphere participates in greenhouse effect. Practically, mineralization means decreasing of organic matter content in soil and soil degradation [1,4]. In natural ecosystems (phytocenoses natural forests and meadows, it is almost a balanced between inflow and consumption of organic matter, while the cultural and anthropogenic soils agrobiocenosis in general, this relationship is disturbed that there is a disproportion between the inflow and loss [1,4]. Therefore, various materials that contains organic material (waste, various flotation, sludge, etc. are often used with more or less success. One of such materials, as well as the potential fertilizer, is carboniferous lake sludge like waste of coal mining sedimented at the bottom of the lake in huge quantities, which is the subject of our reasearch. The research were conducted to determine its fertilizing efects and value for repairing of physical and chemical properties of soil. The research refered to: -- Laboratory analysis of physical and chemical characteristics of the carboniferous sludge samples, -- Analysis of soil of the experimental field -- Research on heavy metals concentration in soil of the experimental farm and in carboniferous sludge, and Research of fertilizing effects of sludge, comparative mineral fertilizer and farmyard manure treatment by

  7. Diversity dynamics of silurian-early carboniferous land plants in South china.

    Directory of Open Access Journals (Sweden)

    Conghui Xiong

    Full Text Available New megafossil and microfossil data indicate four episodes in the diversification of Silurian-Early Carboniferous land plants of South China, a relatively continuous regional record. Plant diversity increased throughout, but the rising curve was punctuated by three major falls. There were peaks of origination in the Ludlow-Pragian, Givetian, late Famennian and Visean and peaks of extinction in the Pragian-Emsian, Givetian and early Tournaisian. Speciation and extinction rates were highest in the Lochkovian-Pragian and became progressively lower in subsequent stages. High correlation coefficients indicate that these events are associated with the availability of land habitat contingent on eustatic variations and increasing numbers of cosmopolitan genera. Meanwhile, proportions of endemic genera declined gradually. Due to less endemism and more migrations, both speciation and species extinction rates reduced. The changes of diversity and the timing of the three extinctions of land plants in South China are similar to those known already from Laurussia. However, the largest events in the Lochkovian-Pragian and subsequent smaller ones have not been seen in the global pattern of plant evolution. These land plant events do not correspond well temporally with those affecting land vertebrates or marine invertebrates. In South China, the diversity curve of land plants is generally opposite to that of marine faunas, showing a strong effect of eustatic variations. The increasing diversity of both land vertebrates and plants was punctuated above the Devonian-Carboniferous boundary, known as Romer's Gap, implying common underlying constraints on macroevolution of land animals and plants.

  8. Carbon isotope evidence implying high O2/CO2 ratios in the Permo-Carboniferous atmosphere

    Science.gov (United States)

    Beerling, D. J.; Lake, J. A.; Berner, R. A.; Hickey, L. J.; Taylor, D. W.; Royer, D. L.

    2002-11-01

    Theoretical models predict a marked increase in atmospheric O2 to ∼35% during the Permo-Carboniferous (∼300 Ma) occurring against a low (∼0.03%) CO2 level. An upper O2 value of 35%, however, remains disputed because ignition data indicate that excessive global forest fires would have ensued. This uncertainty limits interpretation of the role played by atmospheric oxygen in Late Paleozoic biotic evolution. Here, we describe new results from laboratory experiments with vascular land plants that establish that a rise in O2 to 35% increases isotopic fractionation (Δ13C) during growth relative to control plants grown at 21% O2. Despite some effect of the background atmospheric CO2 level on the magnitude of the increase, we hypothesize that a substantial Permo-Carboniferous rise in O2 could have imprinted a detectable geochemical signature in the plant fossil record. Over 50 carbon isotope measurements on intact carbon from four fossil plant clades with differing physiological ecologies and ranging in age from Devonian to Cretaceous reveal a substantial Δ13C anomaly (5‰) occurring between 300 and 250 Ma. The timing and direction of the Δ13C excursion is consistent with the effects of a high O2 atmosphere on plants, as predicted from photosynthetic theory and observed in our experiments. Preliminary calibration of the fossil Δ13C record against experimental data yields a predicted O2/CO2 mixing ratio of the ancient atmosphere consistent with that calculated from long-term models of the global carbon and oxygen cycles. We conclude that further work on the effects of O2 in the combustion of plant materials and the spread of wildfire is necessary before existing data can be used to reliably set the upper limit for paleo-O2 levels.

  9. Magmatism of the Shuteen Complex and Carboniferous subduction of the Gurvansaikhan terrane, South Mongolia

    Science.gov (United States)

    Batkhishig, Bayaraa; Noriyoshi, Tsuchiya; Greg, Bignall

    2010-03-01

    The Carboniferous Shuteen Complex, a volcano-plutonic ring complex associated with Cu-Au porphyry mineralization, is located in the Gurvansaikhan island arc terrane of South Mongolia. This paper presents new data on the petrography, major and trace element chemistry, and Sr-Nd isotopic chemistry of the Shuteen Complex. We discuss the relationship between volcanic and plutonic rocks of the complex, and consider their similarity to high-Al 2O 3 trondhjemite-tonalite-granodiorite and adakites. We also consider the origin, magma source, and dynamic processes of the Shuteen Complex; propose a petrogenetic model; and investigate the composition of the subducting slab and the features of arc volcanism at the time. We assess some of the magmatic processes likely to have occurred within the Shuteen Complex, such as Carboniferous slab subduction and partial melting, and examine their influence on magma composition. The Shuteen Complex is geochemically similar to adakite-type rocks. The complex is silica-saturated (SiO 2 ⩾ 56%), rich in Al 2O 3 (⩾15%), MgO (400 ppm), and depleted in high field strength elements. It also has a high Sr/Y value, and ( 87Sr/ 86Sr) I arc setting, and partial melting was the dominant process during petrogenesis. The primary Shuteen magma had an adakitic composition and was probably derived from the partial melting of subducting oceanic crust, possibly with minor local interaction with mantle material. The results of quantitative modelling of mass balance and partial melt equilibrium for the magma source indicate that the subducting slab contained oceanic basalt and a minor component of oceanic sediment, which together with a restite eclogite phase formed the source of the Shuteen magma. The conclusive results of this study provide new insights into the magmatic evolution of the Shuteen Complex.

  10. Inactive dumps in Santa Catarina's carboniferous area: analysis of risks to the public health and the environment.

    Energy Technology Data Exchange (ETDEWEB)

    Possamai, Fernando Pagani [Universidade do Extremo Sul Catarinense, UNESC, Criciuma (Brazil)

    2007-07-01

    The existence of inactive dumps considerably increases the so-called 'environmental liability'; so much so that the final destination of urban solid residues takes a prominent place on the list of environmental issues of societies. In the state of Santa Catarina, it can be said that, currently, the real conditions of the 'final destination deposits', or simply the inactive dumps, is officially unknown. This is maybe most evident in the carboniferous area of the state that already suffers from the environmental impact of coal mining. This study attempts to make a survey of the inactive dumps in the carboniferous area of Santa Catarina, analysing the risks they represent to public health and to the environment. The results gathered show that, of the eleven municipal districts in the carboniferous area, nine have inactive dumps. In these nine districts, there are eleven inactive dumps that, according to the this evaluation, represent a large risk to public health and the environment when the parameters analysed are taken into account. 21 refs.

  11. Paleoenvironmental changes recorded on UPPer Carboniferous reef in Guangxi,China

    Institute of Scientific and Technical Information of China (English)

    GONG EnPu; CHEN Xiaohong; ZHANG Yongli; GUAN Changqing; CHANG Honglun; HONG Guang

    2014-01-01

    Based on detailed measurement in the field and a comPrehensive analysis of carbonate microfacies, the Pennsylvanian reefal microfacies characteristic and sedimentary environment from Longjiangdong,Guangxi, China are analyzed. The twelve carbonate microfacies have been recognized including micritic/microsParitic limestone,Peloidal/aggregate-grain grainstone,bioclastic wackestone/Packstone,laminated mudstone,bounds-tone,bioclastic wackestone/Packstone with single shell,coral framestone/bafflestone,bioclastic Packstones/grainstones with abundant benthic foraminifera or crinoids,wackestone/mudstone with calcisPheres,bioclastic Packstone/grainstone,unname reef-building organism framestone and brachioPod grainstone. In addition,four facies have been identified including oPen Platform facies,restricted Platform facies,coral reefal facies and shoal facies. According to analysis of microfacies combination and facies evolution,three stages and three reef units during the reef formation Process have been noted. The evolution of each stage indicates a rePeating fluctu-ation of the sea-level,but the water energy is still relatively low overall,which rePresents frequent changes of Paleoclimate in the early Late Carboniferous.

  12. Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye.

    Science.gov (United States)

    Gabbott, Sarah E; Donoghue, Philip C J; Sansom, Robert S; Vinther, Jakob; Dolocan, Andrei; Purnell, Mark A

    2016-08-17

    The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive 'eye spot' in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report-based on evidence of size, shape, preservation mode and localized occurrence-the presence of melanosomes (pigment-bearing organelles) in fossil cyclostome eyes. Time of flight secondary ion mass spectrometry analyses reveal secondary ions with a relative intensity characteristic of melanin as revealed through principal components analyses. Our data support the hypotheses that extant hagfish eyes are degenerate, not rudimentary, that cyclostomes are monophyletic, and that the ancestral vertebrate had a functional visual system. We also demonstrate integument pigmentation in fossil lampreys, opening up the exciting possibility of investigating colour patterning in Palaeozoic vertebrates. The examples we report add to the record of melanosome preservation in Carboniferous fossils and attest to surprising durability of melanosomes and biomolecular melanin. PMID:27488650

  13. High resolution stratigraphy of the Devonian-Carboniferous transitional beds in the Rhenish Mountains

    Directory of Open Access Journals (Sweden)

    D. Korn

    2003-01-01

    Full Text Available The Devonian-Carboniferous Boundary sections at Hasselbachtal, Oese, Apricke, and Ober-Rödinghausen, all located at the northern margin of the Rhenish Mountains, were measured in detail. A semi-quantitative evaluation of the carbonate content and resulting carbonate curves permitted a highly exact correlation of these sections. This result is supported by data on ammonoid records and volcanoclastic horizons. Carbonate fluctuations within the Hangenberg Limestone are regarded as showing a 100000 years cyclicity. A new ammonoid genus Hasselbachia n. gen. and the species Paprothites ruzhencevi n. sp. are described. Among the rugose corals, a new species Hillaxon hassel n. sp., is erected. Die Devon/Karbon-Grenzprofile Hasselbachtal, Oese, Apricke und Ober-Rödinghausen, alle auf der Nordflanke des Remscheid-Altenaer Sattels gelegen, wurden detailliert aufgenommen. Die halbquantitative Ermittlung des Karbonatgehaltes und daraus resultierenden Karbonatkurven eignen sich für eine sehr genaue Korrelation dieser Profile, die durch Funde von Ammonoideen sowie durch vulkanoklastische Horizonte unterstützt wird. Wechsel im Karbonatgehalt werden als 100000 Jahres-Zyklizität gedeutet. Die neue Ammonoideen-Gattung Hasselbachia n. gen. sowie die Art Paprothites ruzhencevi n. sp. werden beschrieben. Unter den rugosen Korallen wird die neue Art Hillaxon hassel n. sp. errrichtet. doi:10.1002/mmng.20030060105

  14. Persistence of Late Carboniferous tropical vegetation during glacially driven climatic and sea-level fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Di Michele, W.A.; Pfefferkorn, H.; Phillips, T.L. [Smithsonian Institution, Washington, DC (United States). Dept. of Paleobiology

    1996-10-01

    The Late Carboniferous glaciation reached its peak during the latter part of the Westphalian. In the tropical Illinois basin this was the time of deposition of the Carbondale and lower Modesto Formations, characterized by the cyclic repetition of major coal deposits, black shales, limestone, gray shales and sandstones. These lithological changes evidence repeated major fluctuations in climate and sealevel. Floras from coals, known from coal balls and palynology, characteristically were composed of three major plant communities: the wettest sites were dominated by monocarpic lycopsids, intermediate sites were dominated by polycarpic lycopsids, and areas subject to fires and intermittent flooding were dominated by medullosans and the small lycopsid Paralycopodites. Clastic-substrate environments were dominated by ferns and pteridosperms and conform to a single biozone, indicating their compositional unit and distinctness from earlier and later assemblages. The composition of lowland floras is poorly known from times between the deposition of coals and associated terrestrial rocks, intervals during which most of the lowlands were flooded and marine rocks were being deposited. Consequently, the temporally intermittent recurrence of lowland floras despite repeated, widespread environmental disruption may be explained either by vegetational persistence and migration of floras, or repeated disruption and reassembly. Several lines of evidence suggest persistence as a likely explanation.

  15. Reservoir heterogeneity in Carboniferous sandstone of the Black Warrior basin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-04-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  16. Reservoir heterogeneity in carboniferous sandstone of the Black Warrior basin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-06-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  17. Paleomagnetism of the Upper Carboniferous and Upper Permian sedimentary rocks from Novaya Zemlya Archipelago

    Science.gov (United States)

    Abashev, Victor V.; Mikhaltsov, Nikolay E.; Vernikovsky, Valery A.; Metelkin, Dmitry V.; Matushkin, Nikolay Yu.; Doubrovine, Pavel V.

    2016-04-01

    Here we present the first paleomagnetic directions and paleomagnetic poles for Upper Permian and Upper Carboniferous sedimentary rocks (sandstones and limestones) of the Novaya Zemlya Archipelago in the Russian High Arctic region. The paleomagnetic directions were obtained through detailed thermal and alternating field demagnetization experiments, using the principal component analysis of demagnetization data. A positive fold test and a positive reversal test indicate that the isolated paleomagnetic directions correspond to the primary magnetization components. Magnetic remanence carriers were characterized through rock-magnetic analyses, including measurements of temperature dependence of low-field magnetic susceptibility, magnetic hysteresis curves, and first-order reversal curves (FORC). We will describe the rock-magnetic properties of different lithological units and discuss their implications for the stability of natural remanent magnetization (NRM) and the veracity of paleomagnetic record. The tectonics implications of the new paleomagnetic data for the evolution of the Barents-Kara continental margin and the Novaya Zemlya Archipelago will be also discussed. The paleomagnetic poles differ slightly from the corresponding section of the APWP for Baltica, which is probably due to inclination shallowing effect or the tectonic features of the region. The study was supported by Russian Science Foundation grant 14-37-00030, the SIU project HNPla-2013/10049 (HEAT) and by Ministry of Education and Science of the Russian Federation grant 5.515.2014/K.

  18. Origin and accumulation mechanisms of petroleum in the Carboniferous volcanic rocks of the Kebai Fault zone, Western Junggar Basin, China

    Science.gov (United States)

    Chen, Zhonghong; Zha, Ming; Liu, Keyu; Zhang, Yueqian; Yang, Disheng; Tang, Yong; Wu, Kongyou; Chen, Yong

    2016-09-01

    The Kebai Fault zone of the West Junggar Basin in northwestern China is a unique region to gain insights on the formation of large-scale petroleum reservoirs in volcanic rocks of the western Central Asian Orogenic Belt. Carboniferous volcanic rocks are widespread in the Kebai Fault zone and consist of basalt, basaltic andesite, andesite, tuff, volcanic breccia, sandy conglomerate and metamorphic rocks. The volcanic oil reservoirs are characterized by multiple sources and multi-stage charge and filling history, characteristic of a complex petroleum system. Geochemical analysis of the reservoir oil, hydrocarbon inclusions and source rocks associated with these volcanic rocks was conducted to better constrain the oil source, the petroleum filling history, and the dominant mechanisms controlling the petroleum accumulation. Reservoir oil geochemistry indicates that the oil contained in the Carboniferous volcanic rocks of the Kebai Fault zone is a mixture. The oil is primarily derived from the source rock of the Permian Fengcheng Formation (P1f), and secondarily from the Permian Lower Wuerhe Formation (P2w). Compared with the P2w source rock, P1f exhibits lower values of C19 TT/C23 TT, C19+20TT/ΣTT, Ts/(Ts + Tm) and ααα-20R sterane C27/C28 ratios but higher values of TT C23/C21, HHI, gammacerane/αβ C30 hopane, hopane (20S) C34/C33, C29ββ/(ββ + αα), and C29 20S/(20S + 20R) ratios. Three major stages of oil charge occurred in the Carboniferous, in the Middle Triassic, Late Triassic to Early Jurassic, and in the Middle Jurassic to Late Jurassic periods, respectively. Most of the oil charged during the first stage was lost, while moderately and highly mature oils were generated and accumulated during the second and third stages. Oil migration and accumulation in the large-scale stratigraphic reservoir was primarily controlled by the top Carboniferous unconformity with better porosity and high oil enrichment developed near the unconformity. Secondary dissolution

  19. Blastoid Body Size - Changes from the Carboniferous to the End-Permian

    Science.gov (United States)

    Nguyen, L.; Tolosa, R.; Heim, N. A.; Payne, J.

    2013-12-01

    Climate, known for affecting biodiversity within genera of animal species, is often addressed as a major variable of geological systems. The Mississippian subperiod of the Carboniferous was noted for its lush, tropical climate that sustained a variety of biological life. In contrast, the Permian era was marked primarily by an ice age that had started earlier during the Pennsylvanian. The blastoids, a class of the Echinodermata phylum, were in existence from the Silurian (443.4 Ma) to the end of the Permian (252.28 Ma). This study focused on whether climate affected blastoid theca size over the span of those one hundred million years between the Mississippian and the Permian or if was simply a negligible factor. We analyzed size data from the Treatise on Invertebrate Paleontology and correlated it to both Cope's Rule, which states that size increases with geologic time, and Bergmann's Rule, which states that latitude and temperature are catalysts for size change. CO2 levels from known records served as a proxy for global temperature. Our results indicated that the blastoids increased in size by 59% over geologic time. The size of the blastoids increased over geologic time, following Cope's Rule. According to our graphs in R, there was an inverse relationship between volume and climate. Size decreased as temperature increased, which follows Bergmann's Rule. However, we also wanted to observe spatial factors regarding Bergmann's Rule such as paleolatitude and paleolongitude. This info was taken from the Paleobiology Database and showed that a majority of the blastoids were found near the equator, which, according to the other part of Bergmann's Rule, suggests that they would therefore increase in size. Further tests implied strong correlations between temperature, volume, and paleolocation. We ultimately believe that although Cope's Rule is in effect, Bergmann's mechanisms for size may not apply to the blastoids due to the environments that the blastoids lived in or

  20. Late Carboniferous N-MORB-type basalts in central Inner Mongolia, China: Products of hydrous melting in an intraplate setting?

    Science.gov (United States)

    Pang, Chong-Jin; Wang, Xuan-Ce; Xu, Bei; Zhao, Jian-Xin; Feng, Yue-Xing; Wang, Yan-Yang; Luo, Zhi-Wen; Liao, Wen

    2016-09-01

    Petrogenesis of the ca. 310 Ma Benbatu basalts in central Inner Mongolia is crucial for constraining the evolution of the Xing'an Mongolia Orogenic Belt (XMOB), eastern segment of the Central Asian Orogenic Belt. The Benbatu basalts have low initial 87Sr/86Sr ratios (0.7042-0.7048), positive εNd(t) (+ 8.99 to + 9.24) and εHf(t) values (+ 15.38 to + 15.65), and are characterized by relatively flat rare earth element patterns and enrichment of Rb, U, Pb, Zr and Hf, but depletion of Nb, Ta, Sr and Ti, resembling those of the normal Mid-Ocean-Ridge Basalt (N-MORB). Variations of trace element ratios (e.g., Sm/Yb and La/Sm) suggest that the basalts were derived from spinel peridotites, with a melting depth of basalts from typical arc basalts and back arc basin basalts. The arc-like geochemical signatures (i.e., enrichment of large ion lithophile elements and depletion of Nb and Ta) are attributed to hydrated mantle source that may be caused by fluids released from stagnant oceanic slabs in the mantle transition zone. Integrating geological evidences with geochemical and isotopic features of the Benbatu basalts, we proposed that these basalts were produced under an intraplate extensional setting during the Late Carboniferous. The genesis of the Benbatu basalts therefore argues for the pre-Carboniferous accretion of the XMOB and highlights the importance of the deep-Earth recycling water in the generation of the Late Carboniferous magmatism in this region.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  2. Diagenesis and porosity evolution of tight sand reservoirs in Carboniferous Benxi Formation, Southeast Ordos Basin

    Science.gov (United States)

    Hu, Peng; Yu, Xinghe; Shan, Xin; Su, Dongxu; Wang, Jiao; Li, Yalong; Shi, Xin; Xu, Liqiang

    2016-04-01

    The Ordos Basin, situated in west-central China, is one of the oldest and most important fossil-fuel energy base, which contains large reserves of coal, oil and natural gas. The Upper Palaeozoic strata are widely distributed with rich gas-bearing and large natural gas resources, whose potential is tremendous. Recent years have witnessed a great tight gas exploration improvement of the Upper Paleozoic in Southeastern Ordos basin. The Carboniferous Benxi Formation, mainly buried more than 2,500m, is the key target strata for hydrocarbon exploration, which was deposited in a barrier island and tidal flat environment. The sandy bars and flats are the favorable sedimentary microfacies. With an integrated approach of thin-section petrophysics, constant velocity mercury injection test, scanning electron microscopy and X-ray diffractometry, diagenesis and porosity evolution of tight sand reservoirs of Benxi Formation were analyzed in detail. The result shows that the main lithology of sandstone in this area is dominated by moderately to well sorted quartz sandstone. The average porosity and permeability is 4.72% and 1.22mD. The reservoirs of Benxi Formation holds a variety of pore types and the pore throats, with obvious heterogeneity and poor connection. Based on the capillary pressure curve morphological characteristics and parameters, combined with thin section and phycical property data, the reservoir pore structure of Benxi Formation can be divided into 4 types, including mid pore mid throat type(I), mid pore fine throat type(II), small pore fine throat type(III) and micro pro micro throat type(Ⅳ). The reservoirs primarily fall in B-subsate of middle diagenesis and late diagenesis, which mainly undergo compaction, cmentation, dissolution and fracturing process. Employing the empirical formula of different sorting for unconsolideated sandstone porosity, the initial sandstone porosity is 38.32% on average. Quantitative evaluation of the increase and decrease of

  3. Structural diagenesis in Upper Carboniferous tight gas sandstones. Lessons learned from the Piesberg analog study

    Energy Technology Data Exchange (ETDEWEB)

    Steindorf, P.; Hoehne, M.; Becker, S.; Hilgers, C. [RWTH Aachen Univ. (Germany). Energy and Mineral Resources Group (EMR); Koehrer, B. [Wintershall Holding GmbH, Barnstorf (Germany)

    2013-08-01

    Upper Carboniferous tight gas sandstone reservoirs in NW-Germany consist of thick successions of cyclothems. Our focus is the Westphalian D of the Piesberg quarry near Osnabrueck, which exposes cemented, faulted and jointed third-order coarse- to fine-grained sandstone cycles separated by anthracite coal seams. We characterize the rocks and the lateral variation of rock properties such as porosity to better constrain input data for reservoir modelling. Three cycles are exposed, each approximately 50 m thick. Rock types can be clearly distinguished by spectral gamma ray in the quarry. Sandstones are intensely compacted and cemented with quartz and generally characterized by low porosities < 8 % (Hepycnometry on plugs and cuttings). Porosities are secondary and mainly related to detrital carbonate dissolution. Around faults dissolution is higher and the porosities can increase to up to 25%. The normal faults show different throws in the quarry and bands of shale and coal have smeared into the fault at juxtaposed beds, which may result in compartments. They dominantly strike W-E and NNW-SSE, but subordinate NE-SW striking fault patterns are also present. Joints were analyzed in a 50 x 50 m section of the quarry wall using Lidar (Light detection and ranging) laser scanning, which allows the characterization of the lithology and quantitative measurement of bedding and fracture orientation data in inaccessible areas. NNE-SSW and W-E joint sets are accompanied by northeasterly and northwesterly striking sets. Around faults, fault planes and fractures are cemented with quartz veins, showing localized mass transport. Due to the intense cementation, the sandstones can reach uniaxial strengths of more than 100 MPa normal to bedding, and approximately 50 MPa parallel to bedding. Sandstone beds within and close to faults are leached by fluids, and their uniaxial strength is reduced by a factor of more than two. Our high resolution field data enables a better understanding of

  4. Organic geochemistry of Upper Carboniferous bituminous coals and clastic sediments from the Lublin Coal Basin

    Science.gov (United States)

    Gola, Marek R.; Karger, Michał; Gazda, Lucjan; Grafka, Oliwia

    2013-09-01

    Bituminous coals and clastic rocks from the Lublin Formation (Pennsylvanian, Westphalian B) were subjected to detailed biomarker and Rock-Eval analyses. The investigation of aliphatic and aromatic fractions and Rock-Eval Tmax suggests that the Carboniferous deposits attained relatively low levels of thermal maturity, at the end of the microbial processes/initial phase of the oil window. Somewhat higher values of maturity in the clastic sediments were caused by postdiagenetic biodegradation of organic matter. The dominance of the odd carbon-numbered n-alkanes in the range n-C25 to n-C31 , high concentrations of moretanes and a predominance of C 28 and C29 steranes are indicative of a terrigenous origin of the organic matter in the study material. This is supported by the presence of eudesmane, bisabolane, dihydro-ar-curcumene and cadalene, found mainly in the coal samples. In addition, tri- and tetracyclic diterpanes, e. g. 16β(H)-kaurane, 16β(H)-phyllocladane, 16α(H)-kaurane and norisopimarane, were identified, suggesting an admixture of conifer ancestors among the deposited higher plants. Parameters Pr/n-C17 and Rdit in the coal samples show deposition of organic matter from peat swamp environments, with the water levels varying from high (water-logged swamp) to very low (ephemeral swamp). Clastic deposits were accumulated in a flood plain environment with local small ponds/lakes. In pond/lake sediments, apart from the dominant terrigenous organic matter, research also revealed a certain quantity of algal matter, indicated, i.a., by the presence of tricyclic triterpanes C28 and C29 and elevated concentrations of steranes. The Paq parameter can prove to be a useful tool in the identification of organic matter, but the processes of organic matter biodegradation observed in clastic rocks most likely influence the value of the parameter, at the same time lowering the interpretation potential of these compounds. The value of Pr/Ph varies from 0.93 to 5.24 and from 3

  5. Seismic interpretation of dinantian carbonate platforms in the Netherlands; implications for the palaeogeographical and structural development of the Northwest European Carboniferous Basin

    NARCIS (Netherlands)

    Kombrink, H.; Lochem, H. van; Zwan, K.J. van der

    2010-01-01

    The Northwest European Carboniferous Basin is characterized by a series of carbonate platforms and intervening shale-dominated troughs during the Dinantian Sub-period. These structures have been mainly found along the margins of the basin. Here we present the results of an investigation of high-qual

  6. Carboniferous sediment dispersal in the Appalachian-Ouachita juncture: Provenance of selected late Mississippian sandstones in the Black Warrior Basin, Mississippi, United States

    Science.gov (United States)

    Xie, Xiangyang; O'Connor, Patrick M.; Alsleben, Helge

    2016-08-01

    The Black Warrior Basin is one of several Carboniferous foreland basins along the Appalachian-Ouachita fold-thrust belt in the southeastern United States. Sediment dispersal within the Black Warrior Basin has been a long-debated topic because of a complex tectonic history and the potential interaction between the Appalachian and Ouachita orogenic belts, as well as far field sediment sources. Three dispersal patterns have been proposed, including dispersal routes from the craton, dispersal via the Appalachian foreland, and dispersal from the arc side of the Ouachita suture, but sediment dispersal in the Black Warrior Basin remains inconclusive. In this study, sandstone modal analysis and U-Pb detrital zircon geochronology are used to document the provenance and potential dispersal patterns for selected Mississippian sandstone units in the Black Warrior Basin, Missouri, USA. Results show that the majority of the Lewis, Evans, Sanders, and Carter sandstones are sublitharenite to mature quartzarenite and fall within the Cratonic Interior field on Q-F-L diagrams. U-Pb detrital zircon analyses of the Lewis, Sanders, and Carter sandstones show that there are four distinctive age clusters, including a prominent Paleozoic age cluster (~ 350-500 Ma), a broad Grenville age cluster (~ 900-1350 Ma), and two minor age clusters of the Granite-Rhyolite (~ 1360-1600 Ma) and the Yavapai-Mazatzal (~ 1600-1800 Ma) provinces. All Mississippian sandstones have similar age distributions except for the Lewis sandstone, which lacks zircon grains from the Superior province (>~2500 Ma). Based on the compositional maturity, similarity of age distributions, and changes of relative abundance among different age groups, we conclude that the Late Mississippian sandstone units analyzed during this study were derived from the Laurussian craton and the northern part of the Appalachian foreland through a major axial drainage that occupied the Mississippi Valley Graben.

  7. 2D Geochemical Characterisation of Late Carboniferous Concretions: Constraints for 3D Fossil Preservation

    Science.gov (United States)

    Howell, C. P.; Montenari, M.

    2012-04-01

    Because of their potential to perfectly preserve fossils in three dimensions, concretions and nodules from various stratigraphic positions and different geological settings have been the subject of intense investigations in the past. The results of these studies aided to elucidate the fine- and ultrastructure of fossilised materials, and gave detailed insights into the anatomy of many plants and animals of the geological past. Nodules have been described as concretionary bodies which are formed by the precipitation of authigenic minerals. They are sometimes monomineralic and homogenous, but polymineralic nodules are characterised by concentric zones of different mineralogical compositions (such as chert, barite, phosphates or manganiferous ores) around a mostly biogenic core. Several factors have been recognised which are thought to play an important role for the formation of nodules. These include [1] the availability of nucleating materials, [2] presence of metals in the water column and sediment, [3] favourable tectonic and physiographic features, [4] favourable sediment-water interface, [5] low rate of sedimentation, [6] presence of nutrient rich bottom water mass and [7] an oxidizing/reducing environment. Up to now, no consistent generic model has been proposed to address the complex geochemical interactions between these factors in the course of nodule formation. With the aim, to describe the different geochemical reactions that lead to nodule generation and hence fossil preservation, a ferromanganese nodule was extracted from the Upper Carboniferous sequences at Broadhaven, Pembrokshire, UK. The geology of this area consists of cyclothems, which contain cyclic sequences of limestones, sandstones and shales. Within this sequence, the nodules are located in the shale beds. The extracted ferromanganese nodule was cut in half using a diamond rock saw and is 7.1 cm in height and 9.8 cm in width. For the analysis of major and trace elements a Niton XL3t X

  8. Reconstructing the pre-Quaternary landscape in Agnew-Lawlers area, Western Australia with emphasis on the Permo-Carboniferous glaciation and post-glacial weathering

    Science.gov (United States)

    Salama, Walid; Anand, Ravi R.

    2016-04-01

    The pre-Quaternary stratigraphic section in Agnew-Lawlers area consists of Permo-Carboniferous glacial sediments, unconformably overlain by Tertiary clastics of palaeochannel sequence and Quaternary alluvial and colluvial sediments. The unique Permo-Carboniferous glacial sedimentary succession in the Yilgarn Craton has not been studied in detail in terms of vertical chemostratigraphic variations, basin and landscape evolution, diagenesis and post-Permian weathering overprints. In Agnew-Lawlers district, continental facies of glacial diamictites, glaciofluvial sandstones and glaciolacustrine rhythmites vary in thickness from 28 m to 181 m and is preserved beneath Cenozoic sediments as relict landforms in highly irregular, asymmetrical and poorly drained basins. The Permo-Carboniferous sediments were mechanically weathered and eroded by glaciers from the surrounding Archaean basement palaeohighs under a cold arid climate. Textural relationships of diamictites indicate that they were derived from proximal and distal source rocks. The denuded palaeotopography of the basement palaeohighs (source rocks) and Permo-Carboniferous sediments were subjected simultaneously to an intensive, post-Permian chemical weathering. The exposed basement rocks were deeply weathered into residual saprolite, whereas the Permo-Carboniferous sediments were differentiated into three chemostratigraphic units. The diamictite and rhythmite of the lower unit are unweathered and preserves the signature of the glacial/interglacial weathering. Mineralogical and geochemical changes dominated in this unit are related mainly to diagenesis at shallow depth (eogenesis) with no significant compaction. The formation of a paragenetic diagenetic sequence of chlorite, ferroan dolomite and pyrite indicates diagenesis has occurred under reducing and alkaline conditions below the permafrost and modern water table. Mineralogical and geochemical changes dominated in the middle unit are linked mainly to eogenetic

  9. Nearshore half-grabens as analogues for offshore, early Carboniferous rift basins along the SW Barents Sea Margin

    Science.gov (United States)

    Koehl, Jean-Baptiste; Bergh, Steffen G.; Indrevær, Kjetil; Lea, Halldis; Bergø, Espen; Henningsen, Tormod; Forthun, Tore; Faleide, Jan-Inge

    2016-04-01

    The present study focuses on the onshore-offshore correlation of brittle faults along the SW Barents Sea Margin, northern Norway. Several studies indicate that the SW Barents Sea Margin experienced a pulse of extensional deformation in the Late Devonian?-early Carboniferous, shortly after the Caledonian contractional deformation ended. The formation of major brittle faults and associated offshore basins that represent targets for hydrocarbon exploration, such as the NE-SW trending Nordkapp Basin, are thought to have initiated during this rifting event. Half-graben structures similar in shape and orientation to the southern segment of the Nordkapp Basin have been identified on the Finnmark Platform and in nearshore areas in coastal Finnmark, northern Norway. Although relatively smaller, these half-graben structures display the same asymmetric, sigma-shaped to triangular architecture in map view as the Nordkapp Basin and also initiated in the earliest Carboniferous, as confirmed by fossiliferous assemblages from shallow cores. The triangular shape of these half-graben structures is related to the presence of possible fault segments of the Trollfjord-Komagelv Fault Zone that trend WNW-ESE and partly truncate the NE-SW trending, sometimes arcuate, extensional brittle faults that bound the half-graben structures. High-resolution bathymetry data show that these half-graben structures internally display minor, NE-SW trending brittle faults and relatively high seafloor relief, thus possible fault displacement, at the intersection between these minor faults and the major, arcuate bounding faults. Microstructural analysis of fault-rocks in nearby onshore fault zones showed multiple generations of cataclasite, suggesting several episodes of faulting in the region. A major goal for future work will be to constrain the exact timing of the faulting event(s) with K/Ar radiometric dating of onshore fault-rocks. This may help estimating the timing of potential fluid migration

  10. Paleotemperatures of Upper Carboniferous sedimentary rocks in the NW part of the Upper Silesian coal basin, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Krystian Probierz; Malgorzata Lewandowska [Silesian University of Technology, Gliwice (Poland). Faculty of Mining and Geology, Institute of Applied Geology

    2004-07-01

    Paleothermal conditions of Upper Carboniferous sedimentary rocks in the strongly folded north-western part of the Upper Silesian Coal Basin (USCB) are characterized in this paper. NS-oriented narrow folds predominate, with amplitudes ranging from 100 to 800 m, often dislocated by axial faults. The paleothermal conditions, i.e. maximum paleotemperatures and paleothermal gradient were calculated according to Bostick's nomogram and Barker and Pawlewicz's method on the basis of studies of 115 samples of coal taken from depths between +17 and -368 m b.s.l. The paleotemperatures range from 135 to 220{degree}C and the paleothermal gradients from 2.4 to 5.9{degree}C/100 m. The coalification process probably has a synorogenic character. 11 refs., 5 figs., 2 tabs.

  11. Shenzhousia qilianshanensis gen. et sp. nov. (Protodonata, Meganeuridae), a giant dragonfly from the Upper Carboniferous of China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new dragonfly of family Meganeuridae Shenzhousia qilianshanensis gen. et sp. nov., discovered from Ningxia Hui Autonomous Region in North China, is described in the present paper. It has an estimated wingspan of about 450-500 mm and may be the largest fossil insect in Late Carboniferous Namurian Stage discovered by far. The new species is referred to Meganeuridae because of the presence of the characteristic oblique vein between anterior branch of radius (RA) and posterior branch of radius (RP) near the base of RP2. It differs from other genera within the family in the following characteristics: Precostal area short and not extending to the midwing;posterior branch of subcostal vein short, merging into costal vein near the level of originating point of IR2; RP forking earlier than anterior branch of media basally; RP1 + 2 and RP3 + 4 parallel and close to each other for a long distance, and then diverge gradually surpass midwing.

  12. A new brittle star from the early Carboniferous of Poland and its implications on Paleozoic modern-type ophiuroid systematics

    Directory of Open Access Journals (Sweden)

    Ben Thuy

    2015-12-01

    Full Text Available The fossil record of Paleozoic ophiuroids includes a number of forms which share striking similarities with modern relatives in terms of skeletal morphology. These so called modern-type Paleozoic ophiuroids yield an enormous potential for a better understanding of ophiuroid evolution, yet the scarcity of accurate and sufficiently detailed morphological descriptions available to date precludes any further-reaching assessments. Here, we describe an articulated ophiuroid specimen from the Late Tournaisian (early Carboniferous of Czatkowice quarry, southern Poland, as a new species Aganaster jagiellonicus sp. nov. The good preservation of the specimen allowed for a morphological analysis at a level comparable to recent ophiuroid descriptions. It shows remarkable morphological similarities with extant former ophiolepidids Ophiomusium and Ophiosphalma. The new find thus contributes to a solid basis for future investigations on the position of the modern-type Paleozoic ophiuroid in the phylogeny of the class.

  13. A Carboniferous Cabinet of Wonders: an example of how the collaboration of art and Earth Sciences can inspire conservation

    Science.gov (United States)

    Grey, Melissa; Rogers, Janine

    2016-04-01

    The Joggins Fossil Cliffs (Nova Scotia, Canada) is a UNESCO World Heritage Site representing the Late Carboniferous time period (ca. 310-325 mya). The site was formative for Charles Lyell in constructing his geological principles. It is still the best place in the world to view fossils from the Carboniferous 'Coal Age', a time when much of the coal that we use today was formed. The Joggins Fossil Institute is a not-for-profit, charitable organization that co-manages the site with the Province of Nova Scotia. Its mission is to conduct research and educate the public about Earth Sciences through interpretation (e.g., exhibits and tours of the site) and a fossil collection. Fossils are the only direct evidence of how biodiversity has changed over deep time; they are the texts and artifacts that we 'read' in order to understand the development of the earth and that can help humans decipher the deeper histories that produced us. At the Joggins Fossil Institute we primarily present the scientific history of the Carboniferous Period through the use of fossils, but we are also interested in the cultural history of coal production and usage, which is an essential part of the region's economic history. However, this industry has also contributed to climate change and the emergence of a new geological age called the Anthropocene. We encourage our visitors to connect palaeontology and coal energy consumption, and ask them to consider how different values (economic and scientific) are attributed to both coal and fossils; such questions lead directly to discussions about conservation issues. The Joggins Fossil Institute has partnered with the Faculty of Arts at nearby Mount Allison University to create an exhibit that will interrogate these questions. The medium of display that we have chosen is the "cabinet of wonders" or "cabinet of curiosity," which has a rich tradition in western cultures going back to the Renaissance. A venerable intersection of art and science, the cabinet

  14. Evolution of pores and fractures in an unconventional Upper Carboniferous reservoir analogue, Westphalian D, W-Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, M.; Schurk, K.; Hilgers, C. [RWTH Aachen Univ. (Germany). Reservoir-Petrology, Energy and Mineral Resources Group (EMR); Koehrer, B. [Wintershall Holding GmbH, Barnstorf (Germany); Bertier, P. [RWTH Aachen Univ. (Germany). Inst. of Clay and Interface Mineralogy

    2013-08-01

    Uncertainties in reservoir characterization of tight gas sandstones can be significantly reduced by using quantitative data from outcrops. The active Piesberg quarry near Osnabrueck exposes Upper Carboniferous strata and therefore provides a reservoir outcrop analog to the gas-bearing tight gas fields in NW-Germany. This study focused on variations of sedimentary facies, porosity, diagenesis and structural inventory in the quarry. The Westphalian D strata at Piesberg consist of siliciclastic, coarse- to fine-grained sandstones with a strong cementation, intercalated with coal seams, siltstones and mudstones. Petrography shows shale-, mudstone and clay rip-up fragments squeezed into primary porosity during eodiagenesis. Sandstone types commonly show low porosities (<10 %) and very low permeabilities (<0.01 mD) mainly due to intense quartz cementation. Scarce authigenic carbonates are euhedral ankerites formed during burial. Secondary porosity resulted mostly from detrital carbonate leaching and limited dissolution of feldspars. Within a zone of up to several meters around faults, porosity is much higher. Feldspars are almost completely altered to illite and locally to kaolinite. Partly dissolved detrital carbonates show Fe-oxide margins around intragranular pores, indicative of Fe-rich compositions formed during telo-diagenesis. Both joints and faults were mapped throughout the quarry and strike, slip and throw of the latter were documented. Cemented fractures prevail around faults and may thus be associated with the structural and diagenetic evolution of the Upper Carboniferous of the Piesberg area. This study is embedded into a larger outcrop analog study of RWTH Aachen in cooperation with Wintershall. Its aim is to unravel the impact of structural diagenesis on the alteration and evolution of pore space and thus reservoir quality. Results can be used to develop datadriven exploration strategies and improved development options for analogous subsurface tight gas

  15. Diagenetic and post-diagenetic alteration (thermicity, oxidation) of carboniferous coals from the French Massif Central (Saint-Etienne, Graissessac and other areas); Alteration diagenetique et post-diagenetique (thermicite, oxydation) des charbons carboniferes du Massif Central francais (Saint-Etienne, Graissessac et autres lieux)

    Energy Technology Data Exchange (ETDEWEB)

    Copard, Y.

    2002-02-01

    This work deals with some prominent properties of the organic matter (OM), such as its to record the thermal history of basins, (hydro)thermal events of more limited influence or oxidising processes. Two of these topics have been developed in the frame of the study of Carboniferous coals sampled in several basins in the Massif Central. As a consequence of the tectonic regime that prevailed at the end of Hercynian orogenesis, thermal domes and even faults acting as conduits for hydrothermal fluids, have generated a heterogeneous hyper-thermicity in the studied basins. Local coalification conditions such as Maximum Paleo-temperatures of Burial (MP TB), paleo-burial depths, durations of maturation, have been estimated. A compilation of OM characteristic parameters suggests that some mature coals have been affected by a restricted hyperthermal activity, while others lave solely recorded a simple oxidation. Astonishingly, this latter process that occurred at low temperature, is characterised by an increase in. Tmax (and a decrease in Hydrogen Index), which mimics a classical thermal degradation. This peculiar behaviour is reinforced both by the study of profiles of weathered mature coals and by oxidation experiments. The considered oxidation process consists in two successive reaction stages. The first is defined by a notable loss in hydrogen and a weak gain in oxygen, while the second, is characterised by a weak loss in hydrogen and a gain in oxygen. The increase in Tmax occurs at the beginning of the second stage, this later one being reached all the more -faster than the raw coal is poor in hydrogen (i.e. has reached a high level of maturity). This alteration process preferentially affects the periphery of the carbon skeleton (Base Structural Units) by provoking the degradation of 'thermo-labile / oxi-labile' functional groups. -fence, these features Justify and explain the strong similarity evidenced between the effects of thermal and oxidising processes

  16. Organic matter maturation vs clay mineralogy: A comparison for Carboniferous to Eocene sediments from the Alpine – Dinaride junction (Slovenia, Austria)

    OpenAIRE

    Thomas Rainer; Uroš Herlec; Gerd Rantitsch; Sachsenhofer, Reinhard F.

    2002-01-01

    Clay mineral diagenesis of Carboniferous to Paleogene rocks within the Alpine-Dinaric junction was studied and compared to vitrinite reflectance. Generally, there is a good fit between clay mineral diagenesis and VR. However, clay mineral alterations lag behindmaturation in some Ladinian and Carnian rocks (e.g. northern margin of the Dinaric Platform). Most probably, the lag in clay mineral diagenesis reflects an highly varying geochemical background in these stratigraphic horizons. Carbonife...

  17. Primary Carboniferous and Permian paleomagnetic results from the Yili Block (NW China) and their implications on the geodynamic evolution of Chinese Tianshan Belt

    OpenAIRE

    Wang, Bo; Chen, Yan; Zhan, Sheng; Shua, Liangshu; Faure, Michel; Cluzel, Dominique; Charvet, Jacques; Laurent-Charvet, Sébastien

    2007-01-01

    International audience In order to better understand the tectonic role of the Yili Block on the Paleozoic evolution of the Chinese Tianshan Belt, we performed a primary paleomagnetic study on Carboniferous and Permian rocks from different areas in the Yili Block, NW of China. More than 320 sedimentary and volcanic samples were collected from 39 sites. Except for the Ordovician samples showing a weak and unstable magnetic remanence, the majority of this collection presents characteristic re...

  18. Late Carboniferous N-MORB-type basalts in central Inner Mongolia, China: Products of hydrous melting in an intraplate setting?

    Science.gov (United States)

    Pang, Chong-Jin; Wang, Xuan-Ce; Xu, Bei; Zhao, Jian-Xin; Feng, Yue-Xing; Wang, Yan-Yang; Luo, Zhi-Wen; Liao, Wen

    2016-09-01

    Petrogenesis of the ca. 310 Ma Benbatu basalts in central Inner Mongolia is crucial for constraining the evolution of the Xing'an Mongolia Orogenic Belt (XMOB), eastern segment of the Central Asian Orogenic Belt. The Benbatu basalts have low initial 87Sr/86Sr ratios (0.7042-0.7048), positive εNd(t) (+ 8.99 to + 9.24) and εHf(t) values (+ 15.38 to + 15.65), and are characterized by relatively flat rare earth element patterns and enrichment of Rb, U, Pb, Zr and Hf, but depletion of Nb, Ta, Sr and Ti, resembling those of the normal Mid-Ocean-Ridge Basalt (N-MORB). Variations of trace element ratios (e.g., Sm/Yb and La/Sm) suggest that the basalts were derived from spinel peridotites, with a melting depth of importance of the deep-Earth recycling water in the generation of the Late Carboniferous magmatism in this region.

  19. Geochemistry and 40Ar/39Ar age of Early Carboniferous dolerite sills in the southern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Gediminas Motuza

    2015-08-01

    Full Text Available The Early Carboniferous magmatic event in the southern Baltic Sea is manifested by dolerite intrusions. The presumable area in which the dolerite intrusions occur ranges from 30 to 60 km in east–west direction, and is about 100 km in north–south direction. The dolerites were sampled in well D1-1 and investigated by applying chemical analysis and 40Ar/39Ar step-heating dating. Dolerites are classified as alkali and sodic, characterized by high TiO2 (3.92, 3.99 wt% and P2O5 (1.67, 1.77 wt% and low MgO (4.89, 4.91 wt% concentrations, enriched in light rare earth elements, originated from an enriched mantle magma source and emplaced in a continental rift tectonic setting. The 351 ± 11 Ma 40Ar/39Ar plateau age for groundmass plagioclase indicates a considerable age gap with the 310–250 Ma magmatism in southern Scandinavia and northern Germany. The magmatic rocks in the Baltic Sedimentary Basin are coeval with alkaline intrusions of NE Poland. Both magmatic provinces lie in the northwestward prolongation of the Pripyat–Dnieper–Donetsk Rift (370–359 Ma and may constitute a later phase of magmatic activity of this propagating rift system.

  20. Late Carboniferous porphyry copper mineralization at La Voluntad, Neuquén, Argentina: Constraints from Re-Os molybdenite dating

    Science.gov (United States)

    Garrido, Mirta; Barra, Fernando; Domínguez, Eduardo; Ruiz, Joaquin; Valencia, Victor A.

    2008-07-01

    The La Voluntad porphyry Cu-Mo deposit in Neuquén, Argentina, is one of several poorly known porphyry-type deposits of Paleozoic to Early Jurassic age in the central and southern Andes. Mineralization at La Voluntad is related to a tonalite porphyry from the Chachil Plutonic Complex that intruded metasedimentary units of the Piedra Santa Complex. Five new Re-Os molybdenite ages from four samples representing three different vein types (i.e., quartz-molybdenite, quartz-sericite-molybdenite and quartz-sericite-molybdenite ± chalcopyrite-pyrite) are identical within error and were formed between ~312 to ~316 Ma. Rhenium and Os concentrations range between 34 to 183 ppm and 112 to 599 ppb, respectively. The new Re-Os ages indicate that the main mineralization event at La Voluntad, associated to sericitic alteration, was emplaced during a time span of 1.7 ± 3.2 Ma and that the deposit is Carboniferous in age, not Permian as previously thought. La Voluntad is the oldest porphyry copper deposit so far recognized in the Andes and indicates the presence of an active magmatic arc, with associated porphyry style mineralization, at the proto-Pacific margin of Gondwana during the Early Pennsylvanian.

  1. A juvenile Early Carboniferous (Viséan coelacanth from Rösenbeck (Rhenish Mountains, Germany with derived postcranial characters

    Directory of Open Access Journals (Sweden)

    F. Witzmann

    2010-08-01

    Full Text Available A small coelacanth specimen of Viséan age from a newly described locality near Rösenbeck at the northern margin of the Rhenish Mountains (North Rhine-Westphalia, Germany is described. The head and pectoral girdle are not preserved, however, the specimen can be distinguished from all other known Carboniferous coelacanths by derived characters of the articulated postcranial skeleton. Derived characters include: (1 The slender first and second dorsal fins that carry only seven to eight and six fin rays, respectively. (2 Both the pelvic and anal fin have a broad base and are unusually weakly lobed. (3 The fin rays of the second dorsal fin are much more robust than those of the first dorsal fin. (4 The second dorsal and anal fins are longer than the first dorsal and pelvic fins. The Rösenbeck coelacanth is interpreted as a juvenile specimen, since the basal plates that support the fins are not ossified. doi:10.1002/mmng.201000004

  2. Carboniferous-Permian sedimentology and stratigraphy of the Nordfjorden High and Loppa Spur, Arctic Norway

    DEFF Research Database (Denmark)

    Ahlborn, Morten

    Abstract (shortened) Facies analysis of Late Paleozoic warm-water carbonates, were conducted in order to investigate the depositional evolution, cyclicity, internal architecture and sequence stratigraphy of the upper Gipsdalen Group carbonate platform on the Nordfjorden High in central Spitsbergen...... the evolution of the Northern Pangean margin. In this study, the emphasis has been to understand the warm-water carbonate deposition, cyclicity, sequence stratigraphy and subaerial exposure events in high resolution across a structural high, all problems not fully understood so far in the Barents Sea...

  3. Testing new methodologies and assessing their potential for reservoir characterisation: Geoelectrical studies in the Northwest Carboniferous Basin (Ireland).

    Science.gov (United States)

    Ogaya, Xènia; Campanyà, Joan; Rath, Volker; Jones, Alan G.; Reay, Derek; Raine, Rob; McConnell, Brian; Ledo, Juanjo

    2016-04-01

    The overarching objective of this study is to improve our methods of characterising saline aquifers by integrating newly acquired electromagnetic data with existing geophysical and geological data. The work presented here is part of an ongoing project to evaluate Ireland's potential for onshore carbon sequestration (IRECCSEM; funded by Science Foundation Ireland). The methodology presented in this characterisation work is not only relevant for studying the potential for onshore carbon sequestration, but is generally applicable for aquifer characterisation, particularly for the evaluation of geothermal resources in appropriate geological settings. We present first results of the three-dimensional (3D) modelling and inversion of the magnetotelluric (MT) data acquired in the Northwest Carboniferous Basin (Ireland) in summer 2015. The electrical resistivity distribution beneath the survey area is constrained using a joint inversion of three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). The preliminary 3D resistivity model obtained reveals the geoelectrical structure of the subsurface, which is translated into parameters relevant to fluid flow. The electromagnetic data were acquired along profiles linking four wells drilled in the area and the available well log data from those wells are used to evaluate some of the existing petrophysical relationships and calibrate them for the study area. This allows us to interpolate the rock physical properties from one well to another well, using the computed geoelectrical model as a reference. The obtained results are compared to available independent geological and geophysical data in order to analyse the validity of this technique, to characterise the uncertainties inherent to our approach, and to assess the potential of this methodology for reservoir characterisation.

  4. Paleomagnetic and geochronological study of Carboniferous forearc basin rocks in the Southern New England Orogen (Eastern Australia)

    Science.gov (United States)

    Pisarevsky, Sergei A.; Rosenbaum, Gideon; Shaanan, Uri; Hoy, Derek; Speranza, Fabio; Mochales, Tania

    2016-06-01

    We present results of a paleomagnetic study from Carboniferous forearc basin rocks that occur at both limbs of the Texas Orocline (New England Orogen, eastern Australia). Using thermal and alternating field demagnetizations, two remanence components have been isolated from rocks sampled from the Emu Creek terrane, in the eastern limb of the orocline. A middle-temperature Component M is post-folding and was likely acquired during low-temperature oxidation at 65-35 Ma. A high-temperature Component H is pre-folding, but its comparison with the paleomagnetic data from coeval rocks in the northern Tamworth terrane on the other limb of Texas Orocline does not indicate rotations around a vertical axis, as expected from geological data. A likely explanation for this apparent discrepancy is that Component H postdates the oroclinal bending, but predates folding in late stages of the 265-230 Ma Hunter Bowen Orogeny. The post-Kiaman age of Component H is supported by the presence of an alternating paleomagnetic polarity in the studied rocks. A paleomagnetic study of volcanic and volcaniclastic rocks in the Boomi Creek area (northern Tamworth terrane) revealed a stable high-temperature pre-folding characteristic remanence, which is dated to c. 318 Ma using U-Pb zircon geochronology. The new paleopole (37.8°S, 182.7°E, A95 = 16.2°) is consistent with previously published poles from coeval rocks from the northern Tamworth terrane. The combination of our new paleomagnetic and geochronological data with previously published results allows us to develop a revised kinematic model of the New England Orogen from 340 Ma to 270 Ma, which compared to the previous model, incorporates a different orientation of the northern Tamworth terrane at 340 Ma.

  5. Hidden surface microstructures on Carboniferous insect Brodioptera sinensis (Megasecoptera) enlighten functional morphology and sensorial perception.

    Science.gov (United States)

    Prokop, Jakub; Pecharová, Martina; Ren, Dong

    2016-01-01

    Megasecoptera are insects with haustellate mouthparts and petiolate wings closely related to Palaeodictyoptera and one of the few insect groups that didn't survive the Permian-Triassic mass extinction. Recent discovery of Brodioptera sinensis in early Pennsylvanian deposits at Xiaheyan in northern China has increased our knowledge of its external morphology using conventional optical stereomicroscopy. Environmental scanning electron microscopy (ESEM) of structures, such as antennae, mouthparts, wing surfaces, external copulatory organs and cerci have shed light on their micromorphology and supposed function. A comparative study has shown an unexpected dense pattern of setae on the wing membrane of B. sinensis. In addition, unlike the results obtained by stereomicroscopy it revealed that the male and female external genitalia clearly differ in their fine structure and setation. Therefore, the present study resulted in a closer examination of the microstructure and function of previously poorly studied parts of the body of Paleozoic insects and a comparison with homologous structures occurring in other Palaeodictyopteroida, Odonatoptera and Ephemerida. This indicates, that the role and presumptive function of these integumental protuberances is likely to have been a sensory one in the coordination of mouthparts and manipulation of stylets, escape from predators, enhancement of aerodynamic properties and copulatory behaviour. PMID:27321551

  6. 对西天山石炭纪地层及生物群的一些认识%Some Understandings about Carboniferous Strata and Biota of Western Tianshan,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    张建东

    2012-01-01

    据前人资料结合1∶25万区调新资料研究成果,对西天山石炭纪典型岩石地层单位及时代、基本特征形成一些新的认识.对新疆北部石炭系腕足“管孔石燕动物群”、“安加拉植物群”及腕足“拟穆武贝动物群”的分布范围、生物区系意义进行总结和讨论.利用多年来西天山陆续发现的菊石化石,建立了本区7个石炭纪菊石带,并结合“R带”为主的菊石化石资料对西天山上、下石炭统年代界线进行讨论.%Based on the regional geological data that completed so many years especially new materials of recent years,this article mainly deal with the carboniferous lithostratigraphic units,biota and ammonoids zone of western Tianshan.Three typical carboniferous biota of "northern type",early carboniferous "Syringothyris fauna",late carboniferous "Angara flora", late carboniferous"Paramuirwoodia fauna",and theirs distribution are discussed in this peper.Acoding to some important ammonoids have been discovered last decades,sevem ammonoids zone can be recognized,they are Dzhaprakocera (Akesahkeceras)Zone,Beyrichoceras-Goniatites Zone,Platygoniatites zone,Homoceras Zone,Reticuloceras Zone,Diaboloceras Zone and Paralegoceras Zone.The lower and upper carboniferous boundary should be drawn at the middle of Homoceras and Reticuloceras zone.

  7. Contrasting behavioral and feeding strategies recorded by tidal-flat bivalve trace fossils from the Upper Carboniferous of eastern Kansas

    Science.gov (United States)

    Mangano, M.G.; Buatois, L.A.; West, R.R.; Maples, C.G.

    1998-01-01

    Upper Carboniferous tidal-flat deposits near Waverly, eastern Kansas (Stull Shale Member, Kanwaka Shale Formation), host abundant and very well-preserved trace fossils attributed to the activity of burrowing bivalves. Thin shell lenses with an abundant bivalve fauna area associated with the ichnofossil-bearing beds and afford an unusual opportunity to relate trace fossils to their makers. Two distinctive life and feeding strategies can be reconstructed on the basis of trace fossil analysis and functional morphology. Lockeria siliquaria hyporeliefs commonly are connected with vertical to inclined, truncated endichnial shafts in the absence of horizontal locomotion traces. These structures record vertical and oblique displacement through the sediment, and suggest relatively stable domiciles rather than temporary resting traces as typically considered. Crowded bedding surfaces displaying cross-cutting relationships between specimens of L. siliquaria and differential preservation at the top (concave versus convex epireliefs) record a complex history of successive events of colonization, erosion, deposition, and recolonization (time-averaged assemblages). Irregujlar contours of some large hypichnia indicate the cast of the foot, while other outlines closely match the anterior area of Wilkingia, its suggested tracemaker. Relatively stable, vertical to inclined life positions and dominanit vertical mobility suggest a filter-feeding strategy. Moreover, the elongate shell and pallial sinus of Wilkingia providfe a strong independent line of evidence for an opisthosiphonate, moderately deep-tier inhabitant. Wilingia may represent a pioneer attempt at siphon-feeding in the late Paleozoic, preceding the outcome of the Mesozoic infaunal radiation. A second strategy is represented by Lockeia ornata and association locomotionm and locomotion/feding structures. Lockeia ornata is commonly connected with chevron locomotion traces that record the bifurcated foot of a protobranch

  8. Permo-Carboniferous coal measures in the Qinshui basin: Lithofacies paleogeography and its control on coal accumulation

    Institute of Scientific and Technical Information of China (English)

    SHAO Longyi; XIAO Zhenghui; LU Jing; HE Zhiping; WANG Hao; ZHANG Pengfei

    2007-01-01

    The Qinshui basin in southeastern Shanxi Province is an important base for coalbed methane explora-tion and production in China. The methane reservoirs in this basin are the Carboniferous and Permian coals. Their thick-ness is strongly controlled by the depositional environments and the paleogeography. In this paper, sedimentological research was undertaken on the outcrop and borehole sections of the Taiyuan and Shanxi formations in the Qinshui basin and the basin-wide lithofacies paleogeography maps for these two formations have been reconstructed. The Taiyuan Forma-tion is composed of limestones, alttrninous mudstones, silt-stones, silty mudstones, sandstones, and mineable coal seams,with a total thickness varying from 44.9 m to 193.48 m. The coal seams have a thickness ranging between 0.10 and 16.89 m, averaging 7.19 m. During the deposition of the Taiyuan Formation, the northern part of the basin was domi-nated by a lower deltaic depositional system, the central and southern parts were dominated by a lagoon environment, and the southeastern comer was occupied by a carbonate platform setting. Coal is relatively thick in the northern part and the southeastern corner. The Shanxi Formation consists of sand-stones, siltstones, mudstones, and coals, with the limestones being locally developed. The thickness of the Shanxi Forma-tion is from 18.6 m to 213.25 m, with the thickness of coal seams from 0.10 to 10 m and averaging 4.2 m. During the deposition of the Shanxi Formation, the northern part of the Qinshui basin was mainly dominated by a lower deltaic plain distributary channel environment, the central and southern parts were mainly an interdistributary bay environment, and the southeastern part was occupied by a delta front mouth bar environment. The thick coals are distributed in the central and southern parts where an interdistributary bay dominates. It is evident that the thick coal zones of the Taiyuan Formation are consistent with the sandstone-rich belts

  9. Ion Probe U-Pb dating of the Central Sakarya basement: a peri-Gondwana terrane cut by late Lower Carboniferous subduction/collision related granitic magmatism

    Science.gov (United States)

    Ayda Ustaömer, P.; Ustaömer, Timur; Robertson, Alastair. H. F.

    2010-05-01

    Our aim here is to better understand the age and tectonic history of crystalline basement units in the Sakarya Zone of N Turkey, north of the Neotethyan İzmir-Ankara-Erzincan Suture Zone, utilising field, petrographic and ion probe dating, the latter carried out at the University of Edinburgh. One of the largest basement units, Central Sakarya, is dominated by paragneisses and schists that are best exposed between Bilecik and Sarıcakaya, forming a belt ~15 km wide x 100 km long. Smaller outcrops of this basement are exposed further north, for instance in the Geyve area. High-grade metamorphic basement is unconformably overlain by Lower Jurassic-Upper Cretaceous cover sediments of the Sakarya Zone and is in tectonic contact with the Late Palaeozoic-Early Mesozoic Karakaya Complex to the south. Ion-probe U-Pb dating of 89 detrital zircons, separated from one garnet micaschist sample, range from 551 Ma (Ediacaran) to 2738 Ma (Neoarchean). 85% of the ages are > 90 % concordant. Zircon populations cluster at ~550-750 Ma (28 grains), ~950-1050 Ma (27 grains) and ~2000 Ma (5 grains), with smaller groupings at ~800 Ma and ~1850 Ma. The first, prominent population (Neoproterozoic) reflects derivation from a source area related to a Cadomian-Avalonian magmatic arc, likely to be associated with a Cadomian/NE African terrane rather than Baltica (Baltica is known to be magmatically inactive during this period), or Avalonia/Amazonia (in view of the absence of Mesoproterozoic ages in Avalonian-Amazonian terranes). The early Neoproterozoic ages (0.9-1 Ga) deviate significantly from the known age spectra of Cadomian terranes (i.e. Armorican Terrane Assemblage) and instead suggest derivation from an original part of NE Africa. The detrital zircon age spectrum of Cambrian-Ordovician sandstones deposited at the northern periphery of the Arabian-Nubian Shield (i.e. the Elat sandstone) is notably similar to that of the Sakarya basement. The Central Sakarya terrane may have rifted in

  10. Geological analysis and petrographic training Tarata in careers (Upper Paleozoic)-test paleoclimatic interpretation in the light of the glacial episode devono-carboniferous (Arlit region, northern Niger)

    International Nuclear Information System (INIS)

    I - Lower Carboniferous glacial Designed west of the Air (northern Niger), it consists mainly of coarse sandstone with few pebbles scattered or polygenic conglomerate matrix abundant silty-clay sandstone. The ice structures, such as eskers, kames and Pingo are very well represented, but are smaller. The glacial facies are characterized by rapid lateral variations and fall into a narrow submeridional. The small extension of these facies and the position of this region at about 50 degrees south latitude in the Carboniferous period Devono-lead to believe that these phenomena related to valley glaciers mountain, but not necessarily requiring very high altitude at this latitude. II - Formation of Tarat:1-Stratigraphy. The sedimentological and petrographic study of tarat in the quarries in the region SOMAIR Arlit shows that this training has three distinct lithostratigraphic units separated by erosive surfaces of discontinuities with a major tarat located between the middle and upper Tarat . Biostratigraphy made from pollen analysis and paleobotanical studies confirm that major lithologic discontinuity between the deposition of Lower Carboniferous and Upper Permian those with a gap in the Upper Carboniferous and Lower Permian, it will be specified by further studies.2-Paleoclimatology. The new observations in the same career and the existence of glacial phenomena mentioned above before submitting the formation of tarat, led to consider the latter assuming a palaeoenvironment periglacial hypothesis that, in light periglacial seems to reject. Indeed, many characters observed (solifluction, grooves and ridges possible, relatively fresh feldspar) can also be observed in temperate and cold at that time, the region was located approximately 40 degrees south latitude.3-Volcanism.The existence of volcanism contemporaneous with deposition of Tarat was highlighted on one hand with the study of elements vitroclastiques, other hand with the cluster analysis of zircon, the zirconium

  11. Evolutionary and biogeographical history of an ancient and global group of arachnids (Arachnida: Opiliones: Cyphophthalmi) with a new taxonomic arrangement

    DEFF Research Database (Denmark)

    Giribet, Gonzalo; Sharma, Prashant P.; Benavides, Ligia R.;

    2012-01-01

    We investigate the phylogeny, biogeography, time of origin and diversification, ancestral area reconstruction and large-scale distributional patterns of an ancient group of arachnids, the harvestman suborder Cyphophthalmi. Analysis of molecular and morphological data allow us to propose a new......; Boreophthalmi includes Stylocellidae and Sironidae, the latter family of questionable monophyly. The internal resolution of each family is discussed and traced back to its geological time origin, as well as to its original landmass, using methods for estimating divergence times and ancestral area reconstruction....... The origin of Cyphophthalmi can be traced back to the Carboniferous, whereas the diversification time of most families ranges between the Carboniferous and the Jurassic, with the exception of Troglosironidae, whose current diversity originates in the Cretaceous/Tertiary. Ancestral area reconstruction...

  12. Zircon U-Pb geochronology and Sr-Nd isotopes of volcanic rocks from the Dahalajunshan Formation: implications for Late Devonian-Middle Carboniferous tectonic evolution of the Chinese Western Tianshan

    Science.gov (United States)

    Yu, Xinqi; Wang, Zongxiu; Zhou, Xiang; Xiao, Weifeng; Yang, Xinpeng

    2016-07-01

    The widespread Late Devonian-Middle Carboniferous volcanic rocks in the Chinese Western Tianshan provide important constraints on the subduction history of the South Tianshan oceanic lithosphere. Here, we investigate the basalt, basaltic andesite, andesite, trachyandesite, and rhyolite from the Dahalajunshan Formation from Western Tianshan. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology constrains their age of formation to between 376 and 333 Ma (i.e., Late Devonian-Middle Carboniferous) with distinct variation in space (from west to east) and time (from early to late). Based on geochemical, zircon geochronological, and Sr-Nd isotopic data, we demonstrate that the Dahalajunshan volcanic was generated in a continental arc setting associated with the subduction of the south Tianshan Ocean during Late Devonian to Middle Carboniferous. The volcanic rocks belonging to Dahalajunshan Formation in the northwestern part of the Yili Block suggest that the northward subduction of the south Tianshan Ocean was initiated in the Early Devonian; those in the southern and eastern part of the Yili Block were probably produced by a northward subduction of South Tianshan Ocean during Late Devonian to Middle Carboniferous.

  13. Zircon U-Pb age, Hf isotope and geochemistry of Carboniferous intrusions from the Langshan area, Inner Mongolia: Petrogenesis and tectonic implications

    Science.gov (United States)

    Liu, Min; Zhang, Da; Xiong, Guangqiang; Zhao, Hongtao; Di, Yongjun; Wang, Zhong; Zhou, Zhiguang

    2016-04-01

    Late Paleozoic was a critical period for the tectonic evolution of the northern margin of the Alxa-North China craton, but the evolutionary history is not well constrained. The Carboniferous intrusions in the Langshan area in the western part of the northern margin of the Alxa-North China craton are mainly composed of tonalite, quartz diorite, olivine gabbro and pyroxene peridotite. Zircon LA-ICP-MS U-Pb dating indicates that the Langshan Carboniferous intrusions were emplaced at ca. 338-324 Ma. The quartz diorites are characterized by high amounts of compatible trace elements (Cr, Ni and V) and high Mg# values, which may suggest a significant mantle source. The positive Pb and negative Nb-Ta-Ti anomalies, the variable εHf(t) (-6.9 to 2.0) values and the old Hf model ages (1218-1783 Ma) imply some involvement of ancient continental materials in its petrogenesis. The tonalite has relatively high Sr/Y ratios, low Mg#, Yb and Y contents, features of adakite-like rocks, negative εHf(t) values (-9.8 to -0.1) and older Hf model ages (1344-1953 Ma), which suggest significant involvement of ancient crust materials and mantle-derived basaltic component in its petrogenesis. The high Mg# values, high Cr and Ni contents, and low Zr and Hf contents of the mafic-ultramafic rocks show evidence of a mantle source, and the relatively low zircon εHf(t) values (-5.9 to 3.2) might point to an enriched mantle. The trace element characteristics indicate the influence of subducted sediments and slab-derived fluids. In the tectonic discrimination diagrams, all the rocks plot in subduction-related environment, such as volcanic arc and continental arc. Considering the regional geology, we suggest that the Carboniferous intrusions in the Langshan area were likely emplaced during the late stage of the southward subduction of the Paleo-Asian Ocean plate, which formed a continental arc along the northern margin of the Alxa-North China craton.

  14. Evaluation of Carboniferous Source Rocks in Santanghu Basin%三塘湖盆地石炭系烃源岩评价

    Institute of Scientific and Technical Information of China (English)

    宋到福; 何登发; 王书荣; 李涤; 王志勇; 黄卫东

    2012-01-01

    三塘湖盆地石炭系烃源岩分布具有南厚北薄的特点,且以马朗凹陷和条湖凹陷的烃源岩厚度最大。烃源岩类型主要包括滨浅海相一海陆交互相的暗色泥岩、凝灰质泥岩和碳质泥岩。盆地内部石炭系烃源岩有机碳含量、生烃潜量及氯仿沥青A的含量均较丰富。干酪根稳定碳同位素值及岩石热解分析结果指示石炭系烃源岩有机质来源广泛,干酪根类型以Ⅱ型为主,也有少量Ⅰ型和Ⅲ型。大部分烃源岩样品实测镜质体反射率大于0.7%,对应的最大热解温度大于435℃,达到了有机质热演化的成熟至高成熟阶段。研究表明,三塘湖盆地石炭系烃源岩为一套好至极好的烃源岩,具有很高的生烃潜力。%The distribution of the Carboniferous source rocks in Santanghu basin is characterized by thick in south and thin in north, in which Malang and Tiaohu sags have the maximum thickness of them. The lithologic types of source rocks mainly include dark mudstone, tuffaceous mudstone and carbonaceous medstone deposited in littoral-neritic or marine-continental alternating environment. The total or- ganic carbon content, potential hydrocarbon generation amount and bitumen extraction abundance in them are all higher. RockEval pyroly- sis parameters suggest that the organic matter in Carboniferous source rocks is dominated by Type-Ⅱ kerogen, with minor Type-Ⅰ and -Ⅲ kerogen contribution. Vitrinite reflectance (Ro) values for most source rock samples are bigger than 0.7%, corresponding Tmax values is over 435℃, indicating a mature to high-mature stage for most source rocks. The study shows that all the Carboniferous source rocks in Santang- hu basin are high quality source rocks, with a good potential for hydrocarbon generation.

  15. Early Carboniferous adakitic rocks in the area of the Tuwu deposit, eastern Tianshan, NW China: Slab melting and implications for porphyry copper mineralization

    Science.gov (United States)

    Wang, Yin-Hong; Xue, Chun-Ji; Liu, Jia-Jun; Wang, Jian-Ping; Yang, Jun-Tao; Zhang, Fang-Fang; Zhao, Ze-Nan; Zhao, Yun-Jiang; Liu, Bin

    2015-05-01

    Existing geochronological and geochemical data for the Early Carboniferous magmatic rocks in the eastern Tianshan, Xinjiang, have been interpreted in a variety of theories regarding petrogenesis and geodynamic setting. The proposed settings include rift, back-arc basin, passive continental margin, island arc, ridge subduction, and post-collisional environment. To evaluate these possibilities, we present new SHRIMP zircon U-Pb geochronology and geochemical data, whole-rock geochemical, Hf isotope, and S isotope data for tonalitic rocks and ores associated with the Tuwu porphyry copper deposit located in the center of the late Paleozoic Dananhu-Tousuquan arc, eastern Tianshan. SHRIMP zircon U-Pb dating indicates that the magmatic activity and thus associated copper mineralization occurred ca.332 Ma. The tonalitic rocks are calc-alkaline granites with A/CNK values ranging from 1.16 to 1.58; are enriched in K, Rb, Sr, and Ba; and are markedly depleted in Nb, Ta, Ti, and Th. They show geochemical affinities similar to adakites, with high Sr, Al2O3, and Na2O contents and La/Yb ratios; low Y and Yb contents; and slight positive Eu anomalies. In situ Hf isotopic analyses of zircons yielded positive initial εHf(t) values ranging from 6.9 to 17.2. The δ34S values of the ore sulfides range from -3.0‰ to +1.7‰, reflecting a deep sulfur source. Our results indicate that the paleo-Tianshan oceanic slab was being simultaneously subducted northward beneath the Dananhu-Tousuquan arc, and southward beneath the Aqishan-Yamansu arc during the Early Carboniferous. The Tuwu adakitic tonalitic rocks were derived from the partial melting of the subducted paleo-Tianshan oceanic slab, which was subsequently hybridized by mantle wedge peridotites. The slab-derived magmas have considerably high copper contents and are highly oxidized, thus leading to porphyry copper mineralization. Such Early Carboniferous tonalitic rocks that are widespread in the eastern Tianshan define a province

  16. Bacteria-like bodies in coalified Carboniferous xylem-enigmatic microspheroids or possible evidence of microbial saprophytes in a vitrinite precursor?

    Science.gov (United States)

    Lyons, P.C.

    1991-01-01

    Possible fossil cocci, both solitary and diplococcus types, have been discovered in coalified tissue (xylem) from coal balls and bituminous coal of Carboniferous age. Most of the presumed bacteria are microspheroids 1-2.5 ??m in diameter and were found in partly degraded humic tissue (xylem) from a medullosan seed fern preserved in a coal ball (Herrin No. 6 coal bed, Westphalian D), an indication that they may have been saprotrophs (decay causing). The same kind of bodies were also found in coalified xylem from the Pittsburgh coal bed (early Stephanian). Whatever the origin of the bacteria-like bodies, they provide direct evidence of secondary organic components in tissue that gives rise to vitrinite and fusinite, major macerals of bituminous and anthracitic coals. ?? 1991.

  17. Different sources involved in generation of continental arc volcanism: The Carboniferous-Permian volcanic rocks in the northern margin of the North China block

    Science.gov (United States)

    Zhang, Shuan-Hong; Zhao, Yue; Liu, Jian-Min; Hu, Zhao-Chu

    2016-01-01

    New zircon U-Pb dating results on the Carboniferous-Permian volcanic rocks in the northern margin of the North China block (NCB) indicate their eruption during the Early Carboniferous to Late Permian from 347 ± 3 Ma to 258 ± 1 Ma and a slight decrease of the upper limits of the volcanic sequences from west to east. They have a main rock association of basalt, basaltic andesite, andesite, dacite, rhyolite, tuff, and tufaceous sandstone. Most of them have calc-alkaline compositions and exhibit variable SiO2 contents from 48.2 wt.% to 77.1 wt.%. There is no significant gap between the mafic and felsic volcanic rocks in major and trace element classification diagrams, indicating that they are not bimodal in composition. The Carboniferous-Permian volcanic rocks exhibit subduction-related geochemical features such as negative Nb and Ta anomalies of mafic to intermediate rocks on primitive mantle-normalized diagrams, indicating they were formed in an Andean-type continental arc during southward subduction of the Paleo-Asian oceanic plate beneath the northern NCB. However, their wide range of whole-rock Sr-Nd and zircon Hf isotopic compositions indicate that their source areas are very complex and different sources were involved in generation of these volcanic rocks. Geochemical and Sr-Nd-Hf isotopic results show that the basalt and some andesite were produced by fractional crystallization of mafic magma derived from partial melting of mantle wedge and subducted oceanic crust; however, most of the intermediate to felsic volcanic rocks were derived from partial melting of lower continental crust. There is an increasing input of crustal materials from the Carboniferous to Permian as indicated by increasing volumes of felsic volcanic rocks in the volcanic sequences. The results show that origin of the continental arc volcanism is very complex and both materials from the subducted oceanic crust and sediments, mantle wedge and arc continental crust could be involved in their

  18. Magnetic susceptibility variations of carbonates controlled by sea-level changes--Examples in Devonian to Carboniferous strata in southern Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper presents magnetic susceptibility results of 578 samples from three Devono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates are controlled by ancient sea-level changes. It is particularly so if the supply of detrital materials was low, when the magnetic susceptibility was mainly controlled by the content of authigenic minerals. If the supply of detrital materials was high, the average susceptibility value would be higher, but there is still a correlation between susceptibility and sea-level curves. A sea level rise would lead to a decrease in the content of the detrital materials, and therefore to a decrease in the susceptibility values. On the top of HST, the uplift and exposure events may lead to elevated magnetic susceptibility values. Carbonate susceptibilities can therefore be considered as one of the environmental proxy data for the research of sequence stratigraphy.

  19. Magnetic susceptibility variations of carbonates controlled by sea-level changes——Examples in Devonian to Carboniferous strata in southern Guizhou Province,China

    Institute of Scientific and Technical Information of China (English)

    张世红; 王训练; 朱鸿

    2000-01-01

    This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates are controlled by ancient sea-level changes. It is particularly so if the supply of detrital materials was low, when the magnetic susceptibility was mainly controlled by the content of authigenic minerals. If the supply of detrital materials was high, the average susceptibility value would be higher, but there is still a correlation between susceptibility and sea-level curves. A sea level rise would lead to a decrease in the content of the detrital materials, and therefore to a decrease in the susceptibility values. On the top of HST, the uplift and exposure events may lead to elevated magnetic susceptibility values. Carbonate susceptibilities can therefore be considered as one of the environmental proxy data for the research of sequence stratigraphy.

  20. Zircon age and geochemistry of the Tost bimodal volcanic rocks: Constraints on the Early Carboniferous tectonic evolution of the South Mongolia

    Science.gov (United States)

    Yang, Shunhu; Miao, Laicheng; Zhang, Fochin; Meng, Qingren; Zhu, Mingshuai; Baatar, Munkhtsengel; Anaad, Chimedtseren

    2016-04-01

    SIMS zircon U-Pb dating, geochemical and Sr-Nd isotopic data are presented for the Late Paleozoic volcanic rocks from Tost area in Mongolia, the southern portion of the Central Asian Orogenic Belt (CAOB). The Tost volcanic rocks show a bimodal feature characterized by a mafic member of basalt and a felsic component of rhyolite, which are temporally and spatially related each other, implying a genetic relationship. Zircon U-Pb isotopic data of the rhyolite constrain the Tost bimodal magmatism occurring from 355 Ma to 320 Ma. The Tost basalt is characterized by high abundances in Th, U and Pb, slightly enriched LREE patterns and low HFSE/LREE ratios. These features, together with their OIB-like isotopic signature ((87Sr/86Sr)i = 0.7039378-0.704397, εNd(t) = 3.55-5.02), suggest that they were likely derived from low-degree partial melting of a metasomatized asthenospheric mantle source with subordinate input of subduction components. The Tost rhyolite, which displays an intimate affinity to Tost basalt, with enrichment in Th, U and Pb, depleted in Nb, Ta and Ti, and gently right-tilted REE patterns, is inferred to be generated by partial melting of a juvenile lower crustal source heated by underplating mafic magmas which rise from asthenosphere during continued rifting. The Tost bimodal volcanic rocks are comparable both in age and composition with those in the East Tianshan, which together constitute an E-W-oriented belt of bimodal volcanic rocks, marking an Early Carboniferous rifting event. Considering regional geology, we propose that the rifting took place in a back-arc extensional setting, probably induced by the subduction of the Dzungaria Ocean between the East Tianshan and Junggar-Kazakhstan plate during the Early Carboniferous.

  1. Relationships between Basic and Silicic Magmatism in Continental Rift Settings: A Petrogeochemical Study of Carboniferous Post-collisional Rift Silicic Volcanics in Tianshan, NW China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Petrogeochemical data are reported for silicic volcanic rocks from the Tianshan Carboniferous rift, with the aim of discussing the petrogenesis of silicic magmas. Incompatible element vs. incompatible element diagrams display smooth positive trends for the Tianshan Carboniferous rift-related volcanic rocks; the isotope ratios of the silicic lavas [87Sr/86Sr(t)=0.69988-0.70532; εNd(t)=4.76-8.00; 206Pb/204Pb(t)=17.435-18.017; 207Pb/204Pb(t)=15.438-15.509; 208Pb/204Pb(t) = 37.075-37.723] encompass those of the basic lavas. These data suggest a genetic link between rhyolites and basalts, but are not definitive in establishing whether silicic rocks are related to basalts through fractional crystallization or partial melting. Geochemical modeling of incompatible vs. compatible elements excludes the possibility that silicic melts are generated by the melting of basaltic rocks, and indicates a derivation by fractional crystallization plus moderate assimilation of wall rocks (AFC) starting from intermediate rocks to silicic rocks. Continuous AFC from basalt to rhyolite,with small rates of crustal assimilation, best explains the geochemical data. The presence or absence of bimodal volcanism (the "Daly Gap") might be related to cooling rates of magma chambers. In central and eastern Tianshan, the crust was thinner and the cooling rates of the magma chamber within the crust were greater. These conditions resulted in a rapid fall in temperature within the magma reservoir and caused a narrow temperature interval over which intermediate melts formed, effectively reducing the volume of the intermediate melts.

  2. Carboniferous arc magmatism in the Qiangtang area, northern Tibet: Zircon U-Pb ages, geochemical and Lu-Hf isotopic characteristics, and tectonic implications

    Science.gov (United States)

    Jiang, Qing-yuan; Li, Cai; Su, Li; Hu, Pei-yuan; Xie, Chao-ming; Wu, Hao

    2015-03-01

    The Longmu Co-Shuanghu suture zone (LSSZ), which lies between the southern Qiangtang-Baoshan block and northern Qiangtang-Qamdo block on the Tibetan Plateau, represents remnants of the Paleo-Tethys Ocean. Previous investigations have focused on the ophiolite, high-pressure zone, and metamorphic belt in this zone, whereas few studies have considered the arc magmatism. The present study examines a suite of Carboniferous arc-magmatic rocks in the western region of the LSSZ that consist of acidic to basic volcanic rocks, including rhyolite, dacite, andesite, basaltic andesite, basalt, and pyroclastics. Zircon U-Pb dating of three samples (two andesites and one dacite) by laser ablation-inductively coupled plasma-mass spectrometry demonstrates that these rocks were emplaced at ca. 351-346 Ma. The basalts have low Cr and Ni abundances, indicating that they were generated by varying degrees of partial melting of an enriched lithospheric mantle that was metasomatized by subduction-derived components. Zircons in the felsic rocks have positive εHf(t) values of 0.8-14.8, indicating an origin by varying degrees of partial melting of juvenile basaltic lower crust, consisting mainly of underplated magmas with similar compositions to the basalts. Geochemical data show that the volcanic rocks are enriched in light rare earth elements and large ion lithophile elements (e.g., Th, U, and Pb) but are strongly depleted in high field strength elements (e.g., Nb, Ta, and Ti), have high Al2O3 and low Zr concentrations, and are calc-alkaline. These magmas are therefore subduction-related volcanic arc rocks, indicating that Paleo-Tethys subduction began in the early Carboniferous.

  3. Palaeomagnetism and magnetic anisotropy of Carboniferous red beds from the Maritime Provinces of Canada: evidence for shallow palaeomagnetic inclinations and implications for North American apparent polar wander

    Science.gov (United States)

    Bilardello, Dario; Kodama, Kenneth P.

    2010-03-01

    A palaeomagnetic and magnetic anisotropy study was conducted on the lower-middle Carboniferous Maringouin and Shepody red bed formations of the Maritime Provinces of Canada to detect and correct inclination shallowing. Because of the shallow inclinations commonly observed in red beds and the strong dependence of North America's Palaeo-Mesozoic apparent polar wander (APW) on red beds, inclination shallowing may substantially affect large portions of North America's APW path. Hematite is the primary magnetic mineral carrier in these red beds, accompanied by secondary magnetite, maghemite, goethite and pigmentary hematite. Thermal and chemical demagnetization of the Shepody Fm. successfully isolated characteristic remanence directions of D = 177°, I = 20.4°, α95 = 6.5°, N = 19 and D = 177.8° I = 17.7°, α95 = 6.9°, N = 16, respectively. Thermal demagnetization of the Maringouin Fm. isolated a characteristic remanence direction of D = 178.7°, I = 24.9°, α95 = 14.5°, N = 9. High field anisotropy of isothermal remanence followed by alternating field and thermal cleaning on leached samples was used to isolate the fabric of hematite. Individual particle anisotropy was measured directly from magnetic separates using a new technique. Hematite's magnetic fabric and particle anisotropy were used to apply an inclination correction. Our inclination corrections indicate up to 10° of inclination shallowing, corresponding to corrected palaeopole positions of 27.2°N, 118.3°E, A95 = 6.2° and 27.4°N, 117.2°E, A95 = 13.1° for the Shepody and Maringouin formations, respectively. This correction corresponds to a ~ 6° increase in colatitude for Carboniferous North America, which translates into approximately a 650 km change in North America's palaeogeographic position. The proposed position of North America supports a Pangea B-type reconstruction.

  4. The Capilla del Monte pluton, Sierras de Córdoba, Argentina: the easternmost Early Carboniferous magmatism in the pre-Andean SW Gondwana margin

    Science.gov (United States)

    Dahlquist, Juan A.; Pankhurst, Robert J.; Rapela, Carlos W.; Basei, Miguel A. S.; Alasino, Pablo H.; Saavedra, Julio; Baldo, Edgardo G.; Murra, Juan A.; da Costa Campos Neto, Mario

    2016-07-01

    New geochronological, geochemical, and isotopic data are reported for the Capilla del Monte two-mica granite pluton in the northeastern Sierras de Córdoba. An Early Carboniferous age is established by a U-Pb zircon concordia (336 ± 3 Ma) and a Rb-Sr whole-rock isochron (337 ± 2 Ma). Zircon saturation geothermometry indicates relatively high temperatures (735-800 °C). The granites have high average SiO2 (74.2 %), Na2O + K2O (7.8 %), and high field-strength elements, high K2O/Na2O (1.7) and FeO/MgO ratios (5.1), with low CaO content (0.71 %). REE patterns with marked negative Eu anomalies (Eu/Eu* 0.14-0.56) indicate crystal fractionation, dominantly of plagioclase and K-feldspar, from a peraluminous magma enriched in F. Isotope data (87Sr/86Srinitial = 0.7086, ɛ Nd336 = -5.5 to -4.4 with T DM = 1.5 Ga, zircon ɛ Hf336 +0.8 to -6.1; mean T DM = 1.5 Ga) suggest a Mesoproterozoic continental source, albeit with some younger or more juvenile material indicated by the Hf data. The pluton is the easternmost member of a Carboniferous A-type magmatic suite which shows an increase in juvenile input toward the west in this part of the pre-Andean margin. The petrological and geochemical data strongly suggest a similar intraplate geodynamic setting to that of the nearby but much larger, Late Devonian, Achala batholith, although Hf isotope signatures of zircon suggest a more uniformly crustal origin for the latter. Further studies are required to understand whether these bodies represent two independent magmatic episodes or more continuous activity.

  5. Quantification and economic valuation of the capture of CO2 for plantations of the Eucalyptus, genus, settled down by the PRECA in the carboniferous basins of Cesar, Cauca Valley, Cauca and Cundiboyacense Highland

    International Nuclear Information System (INIS)

    In this study, the first measure is to quantify the tons of CO2 captured by the increment in the biomass of forest plantations of the Eucalyptus genus, settled down by the PRECA of Ecocarbon in the carboniferous basins of the Cesar, Cauca Valley, Cauca and Cundiboyacense highland and in second measure to determine the economic value that the sale of this environmental service can represent for a developing country as Colombia. The results obtained for each one of the plantations settled down in each carboniferous basin are determined and statistical models that will allow to calculate the capture of CO2 carried out by plantations of three different species of Eucalyptus (E. Camaldulensis, E. grandis and E. globulus)

  6. Quantification and economic valuation of the capture of CO2 for Eucalyptus plantations, established by the Preca in the carboniferous Basins of Cesar, Cauca Valley, Cauca and Highland Cundiboyacense

    International Nuclear Information System (INIS)

    This study, as first measure it looks for to quantify the tons of CO2 captured by the increment in the biomass of forestall plantations of the Eucalyptus genus established by the PRECA of Ecocarbon in the carboniferous basins of the Cesar, Cauca Valley, Cauca and Highland Cundiboyacense and in second measure to determine the economic value that the sale of this environmental service can represent for a developing country as Colombia. The results obtained for each one of the plantations in each carboniferous basin are determined, and statistical models that will allow calculating the capture of CO2 carried out by plantations of three different species of Eucalyptus (E. camaldulensis, e. grandis and E. globulus), starting from the volume in foot of the timber only barked

  7. Pyrolysis experiment and hydrocarbon generation potential of Carboniferous source rocks in the east of Qaidam basin%柴达木盆地东部石炭系烃源岩热模拟实验及生烃潜力

    Institute of Scientific and Technical Information of China (English)

    邱军利; 妥进才; 张明峰; 雷天柱; 夏燕青

    2011-01-01

    By taking pyrolysis experiment and analyzing composition and carbon isotopes of pyrolysis products, the hydrocarbon generation potential and products of carboniferous source rocks in the east of Qaidam basin were studied. The results showed that gas hydrocarbon generation of carboniferous source rocks were 67.27~161.01 m3/t(TOC), the total gas generation of carboniferous source rocks was 220.51-453.39 m3/t(TOC), these values showed that Carboniferous source rocks in the east of Qaidam basin had a high ability to produce natural gas. The yield of liquid organic matter only was from 1.73 kg/t. (TOC) to 4.30 kg/t(TOC), indicating lower residual oil generation capacity. However, since carboniferous source rocks are close to the maturity of oil window of the lower limit (1.3%), so the liquid organic matter yields can not reflect the oil-generating potential of Carboniferous source rocks. The reservoir-forming potential of Carboniferous source rocks has been discussed in this paper, it is predicted that the hydrocarbon generation intensity can be 14.2×108~42.5×l08m3/km2 on Carboniferous in the east of Qaidam basin, capable of forming gas pools in certain scales.%通过热模拟实验及热模拟产物组分和稳定碳同位素分析,对柴达木盆地东部石炭系烃源岩的生烃能力及产物特征进行了研究。结果表明:石炭系烃源岩的气态烃产率为67.27~161.01m3/t(TOC),总气体产率为220.51~453.39 m3/t(TOC),显示柴达木盆地东部石炭系烃源岩具有较高的生气能力;液态有机质产率仅为1.73~4.30 kg/t(TOC),残余生油能力相对较低,但考虑到石炭系烃源岩的成熟度已经接近生油窗的下限值(1.3%),因此模拟实验的液态有机质产率不能真实反映石炭系烃源岩的生油潜力。根据模拟实验的气态烃产率可知,柴达木盆地东部石炭系泥质烃源岩的生气强度为14.2×108~42.5×108m3/km2,显示其具备形成规模气藏的生烃条件。

  8. Geochemical Characteristics of Carboniferous Source Rocks in the Jimunai Basin and the Tacheng Basin of Northwest Xinjiang%新疆北部吉木乃盆地与塔城盆地石炭系烃源岩特征

    Institute of Scientific and Technical Information of China (English)

    裴立新; 高岗; 王绪龙; 枊广弟; 张越千; 唐勇

    2012-01-01

    通过对新疆西北部吉参1井及塔参1井石炭系烃源岩样品有机地球化学特征进行分析,明确研究区石炭系烃源岩生气潜力。吉参1井石炭系烃源岩主要以炭质泥岩为主,塔参1井石炭系烃源岩主要为暗色泥岩。吉参1井及塔参1井泥质烃源岩有机质丰度较高,都达到好烃源岩的标准。有机质类型以Ⅲ型为主,热演化均达到高成熟阶段,具有良好的天然气生成能力。%Organic geochemistry measurements and analyses were conducted on Carboniferous source rock samples from well Jican-1 and well Tacan-1. The results indicated that Carboniferous source rock in well Jican-1 predominantly consists of carbonaceous mudstones and that in well Tacan-1 predominantly consists of darkcolored mudstones. Both of the Carboniferous carbonaceous mudstones in well Jican-1 and dark mudstones in well Tacan-1 contain high abundance of organic matter, and are evaluated as good source rocks. Organic matters are mainly type Ⅲ kerogens in the Carboniferous samples of well Jican-1 and well Tacan-l,and have been at the high-mature stage with large gas source potential.

  9. Correcting for inclination shallowing of early Carboniferous sedimentary rocks from Kyrgyzstan—indication of stable subtropical position of the North Tianshan Zone in the mid-late Palaeozoic

    Science.gov (United States)

    Kirscher, U.; Bilardello, D.; Mikolaichuk, A.; Bachtadse, V.

    2014-08-01

    High-quality palaeomagnetic data for the early Carboniferous of Central Asia are scarce and the palaeogeographic evolution of this area prior to final amalgamation of the region east of the Ural mountains is still rather obscure. Here, we present palaeomagnetic data for early Carboniferous deposits from two areas in the Kyrgyz North Tianshan (NTS). Detailed rock-magnetic analysis indicates the presence of magnetite and haematite as magnetic carriers in these red sediments. In the Kazakh basin section (KEL), we identify a high-temperature component (HTC) of magnetization during stepwise thermal demagnetization at temperatures of up to ˜680 °C yielding a site mean direction of D = 176.2°, I = -36.4°, k = 57.4 and α95 = 8.9° after tilt correction. Two HTCs of magnetization were identified in samples from the Sonkul Basin (DUN) with maximum blocking temperatures of ˜600 °C (magnetite) and ˜680 °C (haematite). The magnetite component was also identified with alternating field demagnetization. The resulting site mean directions for these two components identified in 16 and 14 sites, respectively, are D = 149.3°, I = -50.3°, k = 73.6 and α95 = 4.3° for the magnetite and D = 139.6°, I = -35.1°, k = 71.6 and α95 = 4.7° for the haematite component. All three mean directions show a significant increase of the precision parameter k after tilt correction indicating acquisition of the high-temperature magnetization prior to the main folding event in the Jurassic. We explain the difference of the two components of DUN by a process of inclination bias due to compaction to which the platy haematite particles are more susceptible. Applying the elongation-inclination (E/I) method to directional data from over 100 individual samples from location DUN results in a negligible correction for the magnetite component (Baltica or Siberia prior to the late Palaeozoic.

  10. Molecular and isotopic compositions and origin of natural gases from Cambrian and Carboniferous-Lower Permian reservoirs of the onshore Polish Baltic region

    Science.gov (United States)

    Kotarba, Maciej J.; Nagao, Keisuke

    2015-01-01

    Natural gases from Middle Cambrian and Carboniferous-Lower Permian reservoirs of the onshore Polish Baltic region were studied for their molecular and stable isotope compositions. The following gas species were analysed: 12,13C in CH4, C2H6, C3H8, n-C4H10, i-C4H10 and CO2, 1,2H in CH4, 14,15N in N2, and stable isotopes of all noble gases. Due to significantly different geological settings and genetic types of source rocks of Eastern and Western Pomerania, the molecular and isotopic compositions of natural gases of these two regions exhibit distinct differences. Hydrocarbon gases associated with oil accumulated in the Middle Cambrian reservoir of Eastern Pomerania were generated during low-temperature thermogenic processes from a single source rock containing Type-II kerogen at one phase of petroleum generation. Non-associated hydrocarbon gases accumulated in the Carboniferous (Mississippian and Pennsylvanian)-Lower Permian (Rotliegend) reservoirs of Western Pomerania originated during at least two phases of gas generation by thermogenic processes from mainly Type-III kerogen and a small component of mixed Type-III/II kerogen. Noble gases are in general heavily enriched in radiogenic and nucleogenic isotopes such as 4He, 40Ar and 21Ne accumulated in the reservoirs. Weak contributions of mantle-derived He and Ne are observed. Radiogenic 4He/40Ar ratios are higher than the average production rate ratio of about 5 for radiogenic 4He/40Ar in crustal materials, which might have been caused by a selective supply of 4He that is lighter than 40Ar from crustal rocks, or (U + Th)/K ratio might be higher than the average in crustal block. Carbon dioxide from gases of both the Western and Eastern Pomerania were mainly generated during thermogenic processes of transformation of organic matter, although gases of Western Pomerania can contain an endogenic component. Molecular nitrogen from the Eastern Pomeranian natural gases was mainly generated during low-temperature thermal

  11. Characterising the hydrothermal circulation patterns beneath thermal springs in the limestones of the Carboniferous Dublin Basin, Ireland: a geophysical and geochemical approach.

    Science.gov (United States)

    Blake, Sarah; Henry, Tiernan; Muller, Mark R.; Jones, Alan G.; Moore, John Paul; Murray, John; Campanyà, Joan; Vozár, Jan; Walsh, John; Rath, Volker

    2016-04-01

    A hydrogeological conceptual model of the sources, circulation pathways and temporal variations of two low-enthalpy thermal springs is derived from a multi-disciplinary approach. The springs are situated in the Carboniferous limestones of the Dublin Basin, in east-central Ireland. Kilbrook spring (Co. Kildare) has the highest recorded temperatures for any thermal spring in Ireland (maximum of 25.0 °C), and St. Gorman's Well (Co. Meath) has a complex and variable temperature profile (maximum of 21.8 °C). These temperatures are elevated with respect to average Irish groundwater temperatures (9.5 - 10.5 °C), and represent a geothermal energy potential, which is currently under evaluation. A multi-disciplinary investigation based upon audio-magnetotelluric (AMT) surveys, time-lapse temperature and chemistry measurements, and hydrochemical analysis, has been undertaken with the aims of investigating the provenance of the thermal groundwater and characterising the geological structures facilitating groundwater circulation in the bedrock. The hydrochemical analysis indicates that the thermal waters flow within the limestones of the Dublin Basin, and there is evidence that Kilbrook spring receives a contribution from deep-basinal fluids. The time-lapse temperature, electrical conductivity and water level records for St. Gorman's Well indicate a strongly non-linear response to recharge inputs to the system, suggestive of fluid flow in karst conduits. The 3-D electrical resistivity models of the subsurface revealed two types of geological structure beneath the springs; (1) Carboniferous normal faults, and (2) Cenozoic strike-slip faults. These structures are dissolutionally enhanced, particularly where they intersect. The karstification of these structures, which extend to depths of at least 500 m, has provided conduits that facilitate the operation of a relatively deep hydrothermal circulation pattern (likely estimated depths between 240 and 1,000 m) within the Dublin

  12. THE LATE CARBONIFEROUS RUGOSA IN TANGSHAN AND QINHUANGDAO REGION%唐山—秦皇岛地区晚石炭世的皱纹珊瑚

    Institute of Scientific and Technical Information of China (English)

    彭向东; 林英铴

    2001-01-01

    The researching region is located in the north ea stern part ofNorth China Plate. The Late Carboniferous depositional environment of this region was alternate phase of marine and continent. There are a lot of Coral, Fusulinacea, Brachopoda and Bivalvia fossils in the marine strata. 7 genera and 15 species including 11 new species and 1 undefined species have been described in this paper. Among the coral assemblage, the minor solid coral, mid dle to large solid coral and massive coral has all been fou nd. The diversification of the coral genera and species and the proportion of th e endemic species are high, which may hint that the coral assemblage belongs to tropical and subtropical provincialism. We may also conclude that the North China Plate, as one of the paleo-plates in Tethys, was located in tropi cal-subtropical zone (near equator) in the Late Carboniferous.%研究区位于华北板块的东北部,晚石炭世为海陆交互相沉积。海相灰岩层中产有大量珊瑚、(竹蜓)、腕足类及双壳类化石。共描述皱纹珊瑚7属15种,其中新种11个,1个未定种。珊瑚化石组合中,小型单体珊瑚、中大型单体珊瑚和群体珊瑚共同繁育,种属分异度高,且地方性种数量大,表现为热带-亚热带生物区系的特点,说明华北板块晚石炭世古地理位置应位于古赤道附近的热带-亚热带,为古特提斯洋中的古板块之一。

  13. Late Carboniferous high ɛNd(t)-ɛHf(t) granitoids, enclaves and dikes in western Junggar, NW China: Ridge-subduction-related magmatism and crustal growth

    Science.gov (United States)

    Tang, Gong-Jian; Wang, Qiang; Wyman, Derek A.; Li, Zheng-Xiang; Zhao, Zhen-Hua; Yang, Yue-Heng

    2012-05-01

    We report results of petrologic, geochronological and geochemical investigation of the Late Carboniferous diorites, granodiorites, amphibole (Am)-bearing granites, and associated dioritic and monzonitic enclaves and mafic and granitic dikes in the Keramay area, of the western Junggar region of Central Asian Orogenic Belt (CAOB). Zircon U-Pb dating suggests that they were generated in the Late Carboniferous (316-304 Ma). The diorite and granodiorite compositions extend over a wide range of SiO2 (53-70 wt.%), Sr (240-602 ppm), and Mg# (41-58) values, and are characterized by moderately fractionated rare earth element (REE) patterns, Nb-Ta depletion and relatively low Y and Yb contents. The mafic dikes consist of dolerites, diorite porphyries and minor granodiorite porphyries, and have variable SiO2 (51-59 wt.%) and high Mg#, Cr and Ni values. With the exception of two samples with relatively high heavy REE (HREE) contents, the mafic dikes exhibit trace element characteristics similar to diorites and granodiorites. The Am-bearing granites and a granite porphyry dike sample have high levels of SiO2 (73-77 wt.%), HREEs (e.g., Yb = 3.46-15.7 ppm) and low Mg#, Cr and Ni contents, along with clearly negative Eu, Ba and Sr anomalies, similar to typical A-type granites. All granitoids, enclaves and dikes in this region have high positive ɛNd(t) (+ 7.13 to + 9.74) and zircon ɛHf(t) (+ 10 to + 16) values and moderate initial 87Sr/87Sr ratios (0.7004-0.7049). Mineral composition data suggest that the parental magmas for mafic dikes are similar to Cenozoic sanukitoids in the Setouchi arc area (Japan) and were possibly generated under water-rich and high oxygen fugacity (NNO + 1.5 to NNO + 2.7) conditions. They most likely originated from partial melting of a mantle source variably modified by subducted oceanic crust-derived melts and minor fluids and subsequently underwent fractional crystallization. The diorites and granodiorites were possibly generated by magma mixing

  14. Evaluation of the carboniferous resources of the sectors El Jupal, El Carmen y Guayabal. Zone Chinavita, Umbita, Tibana, Department of Boyaca

    International Nuclear Information System (INIS)

    The area of the sub-project Chinavita-Umbita-Tibana, located in the Southwest part of the Department of Boyaca was object of a geologic exploration with the purpose of evaluating its carboniferous resources. It was defined an stratigraphic interval of 250 m denominated, middle member from the Guaduas Formation of Maestrichtian to Paleocene age; in which they were determined until 9 coal layers, that were recognized total or partially in 7 chosen sectors during the exploration stage. In them it was made the quantification of the resources and the determination of the physical-chemical characteristics of the coal. The results of 4 of these denominated, El Arenal, Quina, Chiguata and Sisa sectors, they were presented in previous reports. In this report the 3 remaining, denominated El Jupal, El Carmen and Guayabal sectors are studied. The certain coal is bituminous high volatile, capable for thermal use and their importance are in the use that can be given inside the plan of national electrification, of the future amplifications of the thermoelectric of Paipa or Zipaquira. Keeping in mind that resources of the order of 148 million tons were calculated with a power heating average of 6.000 kcal/kg. It is possible to planning a new thermoelectric in this area that could serve as energy source in the critical times of the hydroelectric of Chivor

  15. Coupled heat and fluid flow modeling of the Carboniferous Kuna Basin, Alaska: Implications for the genesis of the Red Dog Pb-Zn-Ag-Ba ore district

    Science.gov (United States)

    Garven, G.; Raffensperger, J.P.; Dumoulin, J.A.; Bradley, D.A.; Young, L.E.; Kelley, K.D.; Leach, D.L.

    2003-01-01

    The Red Dog deposit is a giant 175 Mton (16% Zn, 5% Pb), shale-hosted Pb-Zn-Ag-Ba ore district situated in the Carboniferous Kuna Basin, Western Brooks Range, Alaska. These SEDEX-type ores are thought to have formed in calcareous turbidites and black mudstone at elevated sub-seafloor temperatures (120-150??C) within a hydrogeologic framework of submarine convection that was structurally organized by large normal faults. The theory for modeling brine migration and heat transport in the Kuna Basin is discussed with application to evaluating flow patterns and heat transport in faulted rift basins and the effects of buoyancy-driven free convection on reactive flow and ore genesis. Finite element simulations show that hydrothermal fluid was discharged into the Red Dog subbasin during a period of basin-wide crustal heat flow of 150-160 mW/m2. Basinal brines circulated to depths as great as 1-3 km along multiple normal faults flowed laterally through thick clastic aquifers acquiring metals and heat, and then rapidly ascended a single discharge fault zone at rates ??? 5 m/year to mix with seafloor sulfur and precipitate massive sulfide ores. ?? 2003 Elsevier Science B.V. All rights reserved.

  16. New archaeorthopteran insects from the Late Carboniferous of the Nord and Pas-de-Calais basins in northern France (Insecta: Cnemidolestodea, Panorthoptera).

    Science.gov (United States)

    Coty, David; Háva, Jiří; Prokop, Jakub; Roques, Patrick; Nel, André

    2014-01-01

    New polyneopteran insects are described from Pennsylvanian (Bashkirian, Moscovian) compressed fossils from the North of France (Insecta: Archaeorthoptera). Discovery of wing apex with distinct venation, e.g., apical fusion of RA with RP, numerous parallel posterior branches of RP with transversal crossveins, can be assigned to cf. Tococladus sp. (Cnemidolestodea: Tococladidae). It represents the second record of Cnemidolestodea from the Avion locality apart from Aviocladus pectinatus Prokop et al., 2014. Bruaylogus magnificus gen. et sp. nov., based on forewing venation, is attributed to Panorthoptera nec Orthoptera having some distinct characters for the placement either close to Oedischiidae or a more basal position possibly with affinities to genus Heterologus. Aviologus duquesnei gen. et sp. nov., based on forewing venation, differs from Oedischiidae by the presence of basal fork of M far from point of separation between M and Cu and fusion of MA with first posterior branch of RP. Aviologus share a long stem of M and simple CuPaβ with Heterologus duyiwuer and H. langfordorum, but both differ in well separated median and radial veins. These new fossils demonstrate that the archaeorthopterid insect fauna from the North of France was rather diverse with links to late Carboniferous and early Permian assemblages in Euramerica such as the Mazon Creek, Carbondale Formation or Elmo, Wellington Formation (Illinois, Kansas, USA) entomofaunas.

  17. 新疆西天山伊犁地区石炭纪火山-沉积序列及盆地性质%Carboniferous Volcanic-Sedimentary Succession and Basin Properties in Ili Area,Western Tianshan,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    白建科; 李智佩; 徐学义; 孙吉明; 牛亚卓

    2015-01-01

    新疆西天山伊犁地区作为中天山微板块的一部分,呈“倒三角形”被缝合带或断裂带所围限。其上广泛出露的石炭纪火山—沉积岩系,是研究西天山石炭纪盆地性质和天山古生代造山作用演化过程最为直接的载体。本文通过对石炭纪火山—沉积剖面的岩石组合、地层序列、构造环境及盆地演化过程研究表明:伊犁地区石炭纪火山—沉积岩与下伏地层(前寒武纪结晶基底或前石炭纪褶皱基底)之间呈广泛的区域性角度不整合接触;火山—沉积岩系由下到上可以划分为2个序列,分别对应于盆地伸展—裂陷演化的两个旋回:序列Ⅰ:大哈拉军山组底部扇三角洲相、向上出现2次爆发相—喷溢相的火山喷发旋回,阿克沙克组底部扇三角洲相,向上过渡为滨浅海相—开阔台地相;序列Ⅱ:伊什基里克组由下到上由3次爆发相—喷溢相的火山喷发旋回构成,东图津河组为浅海陆棚相。西天山伊犁地区石炭纪火山—沉积序列反映了后碰撞伸展环境下的裂谷盆地充填演化过程。%The Ili area,as a part of the Central Tianshan micro-continent,is a inverse-triangular area bordered by sutures and zones in the Tianshan belt.Carboniferous volcanic—sedimentary rocks widely outcropping in Ili area is the most direct carrier in the study of Carboniferous basin properties of western Tianshan and Paleozoic orogenic evolution of Tianshan.According to the rock assemblage,stratigraphic sequence,tectonic setting and basin evolution of the Carboniferous volcanic—sedimentary section,we can draw the following conclusions:there is a wide regional angular unconformity between the Lower Carboniferous and its underlying strata (the Precambrian crystalline basemen or pre-Carboniferous folded basement ). From bottom to top, Carboniferous volcanic—sedimentary rocks can be divided into two sequences respectively corresponding to

  18. Testing alternative tectonic models of Palaeotethys in the E Mediterranean region: new U-Pb and Lu-Hf isotopic analyses of detrital zircons from Late Carboniferous and Late Triassic sandstones associated with the Anatolide and Tauride blocks (S Turkey)

    Science.gov (United States)

    Ustaömer, Timur; Ayda Ustaömer, Petek; Robertson, Alastair; Gerdes, Axel

    2016-04-01

    Alternative tectonic models of Palaeotethys during Late Palaeozoic-Early Mesozoic time infer: 1. southward subduction beneath the north margin of Gondwana; 2. northward subduction beneath the south margin of Eurasia, or 3. double subduction (northwards and southwards), at least during Late Carboniferous. U-Pb and Lu-Hf isotopic analysis of detrital zircons, extracted from sandstones, can provide strong indications of age and identity of source terranes. Here, we consider the provenance of both Late Carboniferous and Late Triassic sandstones from both relatively allochthonous and relatively autochthonous units that are all spatially associated with the Anatolide and Tauride continental blocks. The relatively allochthonous units are sandstones (3 samples) from the Late Carboniferous Aladaǧ Nappe (Tauride; in the east), the Konya Complex (Anatolide; central area) and the Karaburun Mélange (Tauride-related; in the west). The relatively autochthonous units are Late Triassic sandstones (4 samples) from the Üzümdere Formation, the Kasımlar Formation (both western Taurides) and the Güvercinlik Formation (Karaburun Peninsula-Tauride related; far west). The Late Carboniferous sandstones from the three relatively allochthonous units are dominated by Precambrian zircon populations, the age distribution of which suggests derivation from two contrasting source regions: First, a NE African-type source (i.e. Saharan craton) for the sandstones of the Konya Mélange and the Aladaǧ Nappe because these sediments have prominent zircon populations dated at 0.5-0.7, 0.8 and 0.9-1.1 Ga. Palaeozoic zircons are minimal in the sandstones of the Aladaǧ Nappe and the Konya Complex (3 and 5% of the whole data, respectively) and are confined to Cambrian to Ordovician. Secondly, a contrasting NW African-type source is inferred for sandstone from the Karaburun Mélange because of the marked absence of Tonian-Stenian zircons and the predominance of ~2 Ga zircons over ~2.5 Ga zircons. In

  19. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  20. 塔里木盆地巴楚地区石炭纪地层问题讨论%Discussions on Carboniferous stratigraphy of Bachu uplift, Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    黄太柱; 蔡习尧; 郭书元

    2013-01-01

    通过对大量钻井资料的综合分析,详细讨论了塔里木盆地巴楚地区石炭纪地层存在的主要问题。建立了该区两统4组新的地层层序,恢复了巴楚组与卡拉沙依组的原定义,新建玛扎塔格组。确认“巴楚运动”发生在早石炭世晚期,其在塔里木盆地表现为西强东弱。巴楚隆起东段砂泥岩段角度不整合于上泥岩段之上,西段为小海子组覆盖在中泥岩段或生屑灰岩段之上,至隆起西端---柯坪地区则为康克林组覆盖在四石厂组之上,巴楚组至玛扎塔格组剥蚀殆尽。巴楚隆起西部小海子组产Triticites带,发育逍遥阶,东部则缺失。建立了小海子组与南闸组的岩电划分标准,2组分别产S. suberectus-S. parvus-G. bella带、Triticites带与S. isolatus带、S. whitei-N. pequopensis带、Pseudoschwagerina带;2组间的间断由东向西逐渐缩小,至巴楚隆起西端为整合接触关系。%Based on the comprehensive analysis of drilling data, the Carboniferous stratigraphy of the Bachu uplift in the Tarim Basin was discussed. Four new stratigraphic sequences were found, the original definitions of the Ba-chu and Kalashayi Formations were restored, and the Mazatage Formation was established. It was confirmed that the Bachu Movement took place at the end of the Early Carboniferous, and the movement was severe in the west and weak in the east of the Tarim Basin. In the east of the Bachu uplift, sandstones and mudstones lay on the upper mudstones with an angle unconformity. In the west of the uplift, the Xiaohaizi Formation lay on the middle mud-stones or the bioclast limestones. From the west of the uplift to the Keping area, the Kangkelin Formation lay on the Sishichang Formation, and the Bachu and Mazatage Formations were eroded. Triticites belt and the strata of Xiao-yiaoan Stage developed in the Xiaohaizi Formation in the west of the Bachu uplift and disappeared in the east. A

  1. Diversity patterns and palaeobiogeographical relationships of latest Devonian-Lower Carboniferous foraminifers from South China: What is global, what is local?

    Institute of Scientific and Technical Information of China (English)

    Markus; Aretz; Elise; Nardin; Daniel; Vachard

    2014-01-01

    During latest Devonian and early Carboniferous times,calcareous foraminifers were abundant,widely distributed,and showed the most rapid rate of evolution in the shallow?sea deposits.These factors,especially their fast phylogenetic changes,make them an essen?tial element in biostratigraphic schemes of this time interval.However,the distribution patterns of calcareous foraminifers depend on a series of biological and non?biological factors,such as population sizes,dispersion,oceanic currents and temperatures,and substrate types,which are not always well?controlled when interpreting spatial and temporal distribution patterns.For this study,a dataset of calcareous foraminifers was compiled containing the tempo?ral distribution(biozone level)of 420 species belonging to 155 genera currently described from Strunian(latest Devonian)to basal Serpukhovian(Lower Carboniferous)key sections in southern China,and the presence of those species in eleven palaeobiogeographical units.The comparison of the regional Chinese diversity curve,which has a bell?shaped form with a dou?ble peak in the Ivorian,to a global curve shows the influence of local and regional factors.Mini?mum values in the Chinese Strunian,basal Tournaisian and early late Visean can be explained by the small number of studied outcrops,unfavourable facies and depositional gaps in these stratigraphic intervals in South China.This is especially obvious in the late Visean and Serpuk?hovian,which is a peak time of global diversity.The fall observed at that time interval in southern China is easily explained by the fact that this time peried is far less intensively studied and thus fewer data are present in the database.The opposite situation is seen around the TournaisianVisean boundary.Here,a peak is found in both regional and global curves,but that up to 87%of all known species are found in southern China seems to be unlikely,especially when the normal average value are 35%-40%.This anomalously high percentage is a

  2. Hot Groups.

    Science.gov (United States)

    Vail, Kathleen

    1996-01-01

    Collaborators sparked by creative ideas and obsessed by a common task may not realize they're part of a "hot group"--a term coined by business professors Harold J. Leavitt and Jean Lipman-Blumen. Spawned by group decision making and employee empowerment, hot groups can flourish in education settings. They're typically small, short lived, and goal…

  3. Abelian Groups

    Energy Technology Data Exchange (ETDEWEB)

    Mishina, A.P.

    1995-10-15

    This fifth survey of reviews on abelian groups comprises papers reviewed in 1985-1992. Just as in the preceding surveys, the issues concerning finite abelian groups, topological groups, ordered groups, group algebras, modules (with rare exceptions), and topics on logic are not considered. The issues on the lattice of subgroups of an abelian group are included in Section 11. In contrast to the fourth survey, this one does not contain Sections 6 (N-high subgroups), 9 (rings with a given additive group), and 10 (valuated groups); since only a few papers treated these topics, the material discussed earlier in Sections 9, and 10 is now included in Section 11 and the material of the former Section 6 will be found in Sections 1, 7, 8, and 11 of this survey. On the other hand, the fifth survey has three new sections devoted to separable groups (a new Sect. 5), Butler groups (a new Sect. 6), and the endormorphism rings and automorphism groups of abelian groups (a new Sect. 9).

  4. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  5. Paleoecological Characteristics of the Carboniferous Phylloid Algal Buildups in Southern Guizhou%贵州南部石炭纪叶状藻礁古生态学特征

    Institute of Scientific and Technical Information of China (English)

    巩恩普; 董旭明; 张永利; 关长庆; 孙宝亮

    2009-01-01

    The Carboniferous phylloid algal buildups are widespread and well exposed in southern Guizhou. A unique depositional sequence consists of phylloid algal buildups, bioclastic banks and mud facies affected by frequent changes of depositional environments. The phylloid algae that grow on the margin of carbonate platform prefer to live in clean water with medium turbulence. Therefore the phylloid algae must be a narrow spectrum of ecological environment. Adjacent two leaves of phylloid algae rarely are tightly together in the growth-form and the spaces between two leaves are often filled with sparry calcite. It indicates that phylloid algae thallus should be a certain tenacity and intensity. The worm may be taked part in the construction of buildup substrate, and they are the pioneer of phylloid algal buildup.%贵州紫云石炭纪叶状藻礁极为发育.叶状藻礁在沉积环境频繁变化作用下,与碎屑滩相、灰泥相共同形成独特的沉积序列.产于碳酸盐岩台地边缘的叶状藻生态适应范围较窄,不能忍受混浊的海水,喜欢清洁动荡中等水动力条件.野外很少见到相邻叶状藻片紧密生长在一起,其间空隙常充填亮晶方解石,表明叶状藻片具有一定的强度和韧性.蠕虫很可能参与了基底的建造,并成为叶状藻礁的先驱.

  6. Permutation groups

    CERN Document Server

    Passman, Donald S

    2012-01-01

    This volume by a prominent authority on permutation groups consists of lecture notes that provide a self-contained account of distinct classification theorems. A ready source of frequently quoted but usually inaccessible theorems, it is ideally suited for professional group theorists as well as students with a solid background in modern algebra.The three-part treatment begins with an introductory chapter and advances to an economical development of the tools of basic group theory, including group extensions, transfer theorems, and group representations and characters. The final chapter feature

  7. Galaxy Groups

    Science.gov (United States)

    Tully, R. Brent

    2015-02-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well-studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times {{10}12}{{M}⊙ } are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosity systems rather than variations in the number per unit mass of dwarfs. Finally, returning to the characteristic radii of groups, the ratio of first to second turnaround depends on the dark matter and dark energy content of the universe and a crude estimate can be made from the current observations of {{Ω}matter}˜ 0.15 in a flat topology, with a 68% probability of being less than 0.44.

  8. Galaxy groups

    Energy Technology Data Exchange (ETDEWEB)

    Brent Tully, R. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2015-02-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well-studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times 10{sup 12}M{sub ⊙} are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosity systems rather than variations in the number per unit mass of dwarfs. Finally, returning to the characteristic radii of groups, the ratio of first to second turnaround depends on the dark matter and dark energy content of the universe and a crude estimate can be made from the current observations of Ω{sub matter}∼0.15 in a flat topology, with a 68% probability of being less than 0.44.

  9. Galaxy Groups

    CERN Document Server

    Tully, R Brent

    2014-01-01

    Galaxy groups can be characterized by the radius of decoupling from cosmic expansion, the radius of the caustic of second turnaround, and the velocity dispersion of galaxies within this latter radius. These parameters can be a challenge to measure, especially for small groups with few members. In this study, results are gathered pertaining to particularly well studied groups over four decades in group mass. Scaling relations anticipated from theory are demonstrated and coefficients of the relationships are specified. There is an update of the relationship between light and mass for groups, confirming that groups with mass of a few times 10^12 Msun are the most lit up while groups with more and less mass are darker. It is demonstrated that there is an interesting one-to-one correlation between the number of dwarf satellites in a group and the group mass. There is the suggestion that small variations in the slope of the luminosity function in groups are caused by the degree of depletion of intermediate luminosi...

  10. Detrital zircon age distribution from Devonian and Carboniferous sandstone in the Southern Variscan Fold-and-Thrust belt (Montagne Noire, French Massif Central), and their bearings on the Variscan belt evolution

    Science.gov (United States)

    Lin, Wei; Faure, Michel; Li, Xian-hua; Chu, Yang; Ji, Wenbin; Xue, Zhenhua

    2016-05-01

    In the Southern French Massif Central, the Late Paleozoic sedimentary sequences of the Montagne Noire area provide clues to decipher the successive tectonic events that occurred during the evolution of the Variscan belt. Previous sedimentological studies already demonstrated that the siliciclastic deposits were supplied from the northern part of the Massif Central. In this study, detrital zircon provenance analysis has been investigated in Early Devonian (Lochkovian) conglomerate and sandstone, and in Carboniferous (Visean to Early Serpukhovian) sandstone from the recumbent folds and the foreland basin of the Variscan Southern Massif Central in Montagne Noire. The zircon grains from all of the samples yielded U-Pb age spectra ranging from Neoarchean to Late Paleozoic with several age population peaks at 2700 Ma, 2000 Ma, 980 Ma, 750 Ma, 620 Ma, 590 Ma, 560 Ma, 480 Ma, 450 Ma, and 350 Ma. The dominant age populations concentrate on the Neoproterozoic and Paleozoic. The dominant concordant detrital zircon age populations in the Lochkovian samples, the 480-445 Ma with a statistical peak around 450 Ma, are interpreted as reflecting the rifting event that separated several continental stripes, such as Armorica, Mid-German Crystalline Rise, and Avalonia from the northern part of Gondwana. However, Ediacaran and Cambrian secondary peaks are also observed. The detrital zircons with ages at 352 - 340 Ma, with a statistical peak around 350 Ma, came from the Early Carboniferous volcanic and plutonic rocks similar to those exposed in the NE part of the French Massif Central. Moreover, some Precambrian grains recorded a more complex itinerary and may have experienced a multi-recycling history: the Archean and Proterozoic grains have been firstly deposited in Cambrian or Ordovician terrigenous rocks, and secondly re-sedimented in Devonian and/or Carboniferous formations. Another possibility is that ancient grains would be inherited grains, scavenged from an underlying but not

  11. Relationship between the physico-mechanical properties of middle carboniferous rock of the Donetsk Basin coal-bearing basins and the depth of stratification. [Dependence on depth and degree of metamorphism

    Energy Technology Data Exchange (ETDEWEB)

    Sverzhevskii, V.L.; Karnaukhova, L.A.; Pikalova, V.P.

    1977-06-01

    A compilation was made of data indicating the relationship between the stratal depth and physico-mechanical properties of aleurite, argyllite and sandstone in various zones and graphs of coal metamorphism. Also indicated are the relative changes in the hardness limits during compression in relation to lithological-petrographic and textural factors, depth and catagenesis, and categenesis alone. The comparative data indicate that the physico-mechanical properties of middle Carboniferous limestone are practically independent of the depth of occurrence, and are significantly dependent upon categories. 4 references, 2 tables.

  12. 松辽盆地基底石炭-二叠系热演化史%Restoration of thermal history of the Permo-Carboniferous basement in the Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    任战利; 萧德铭; 迟元林; 任延广; 梁宇

    2011-01-01

    松辽盆地北部石炭-二叠系镜质体反射率值普遍较高,普遍大干3.0%,不同构造单元石炭-二叠系镜质体反射率值差异较大.松辽盆地深层石炭-二叠系基底镜质体反射率-深度关系曲线分为两种类型,表明松辽盆地深层石炭-二叠系基底有不同的热演化过程.一种是两段型,镜质体反射率-深度曲线在石炭-二叠系顶部不整合面上、下镜质体反射率值发生突变,不整合面之下石炭-二叠系镜质体反射率值及古地温明显高于上覆地层,表明石炭-二叠系最大古地温是在早白垩世登娄库组沉积之前达到的,白垩纪以来沉积地层厚度对石炭-二叠系古地温提高及热演化程度没有影响.另一种为似线型,石炭-二叠系顶部不整合面上、下镜质体反射率值及古地温连续变化,表明石炭-二叠系最大古地温是在晚白垩世—渐新世之前达到的,白垩纪以来沉积的地层厚度对石炭-二叠系古地温及热演化程度的提高有贡献.在综合分析有机质镜质体反射率、包裹体测温、裂变径迹年龄等多种参数的基础上,对松辽盆地基底石炭-二叠系热演化史进行了恢复,并分析了热演化史与油气生成的关系.%Vitrinite reflectance of the Permo-Carboniferous in the north of Songliao Basin is generally high, usually more than 3. 0%,and varies greatly in different tectonic units. The curve of vitrinite reflectance (RO) -depth (H) of the Permo-Carboniferous basement in Songliao Basin has two types, which means that they have different thermal history. One is a two-section type. Vitrinite reflectance values change abruptly across the unconformity on top of the Permo-Carboniferous. The Ro values and paleotemperature of the Permo-Carboniferous strata under the unconformity are obviously higher than that of the overlying strata, indicating that the maximum paleotemperature of Permo-Carboniferous strata had been reached before the deposition of the

  13. Provenance Direction and Sedimentary Characteristics of the Carboniferous in Bayanhot Basin%巴彦浩特盆地石炭系物源及沉积相研究

    Institute of Scientific and Technical Information of China (English)

    陈蓉; 侯明才; 王峰; 王涛; 王艳琴

    2013-01-01

    Provenance of the Carboniferous in the Bayanhot Basin has been studied by means of thin section analysis cathodoluminescence of quartz etc.. The results show that the dominant sediment source during the deposition of the Car-boniferous in Bayanhot Basin came from the Alxa ancient land in the northern, the Longxi ancient land in the southeast, the Longshou mountain in the western, and the Luozi mountain in the Eastern. The mother rock is mainly metamorphic rocks of Archean and Proterozoic, sedimentary rocks of Former Carboniferous and magmatic rocks of Caledonian. Paleo-provenance have favorable spatial combination with depositional system. By outcrop observation and the study of phase signs, the early Carboniferous of the study area developed barrier coast and the diamictic continental shelf,which is af-fected by the Alxa ancient land,and in the late,the study area developed barrier coast,no-barrier coast,fan delta, meander-ing river delta and the diamictic continental shelf,which is affected by the combined effect of multi-material source.%  通过岩石薄片分析和石英阴极发光特征,对巴彦浩特盆地石炭系进行物源分析。结果表明,该盆地石炭系存在北部阿拉善古陆、东南部陇西古陆、西部龙首山隆起及东部骡子山隆起4个物源方向,母岩分别为太古界及元古界变质岩、前石炭系沉积岩及加里东期岩浆岩。古物源与沉积体系具良好空间配置关系,通过野外剖面观察,结合物源和相标志,认为研究区石炭系早期主要受阿拉善古陆影响,发育障壁海岸和混积陆棚相,中晚期受多物源共同影响,发育障壁海岸、无障壁海岸、扇三角洲、曲流河三角洲和混积陆棚相。

  14. Late Devonian - Early Carboniferous polyphase metamorphic evolution of the Orlica-Śnieżnik Dome (NE Bohemian Massif, Poland): evidence from Th-U-total Pb monazite dating

    Science.gov (United States)

    Budzyń, Bartosz; Jastrzębski, Mirosław; Stawikowski, Wojciech

    2014-05-01

    younger age domains of 371-356 Ma and 336-331 Ma are defined by monazite from four K-feldspar free light quartzites (SF), and two K-feldspar bearing light quartzite (SF). Similar two age domains of 372-363 Ma and 342-332 Ma yields monazite from six mica schists (SF), with a faint record of ca. 406 Ma in one of these samples. The geochronological results suggest polyphase Devono-Carboniferous metamorphic evolution that embraced at least two tectonometamorphic episodes. Microstructures indicate that the record of 370-360 Ma ages presumably defines a progressive metamorphism, whereas pervasive record of 340-330 Ma ages presumably reflects the superimposed penetrative shearing connected with exhumation. There is no evidence of pre-Variscan regional or contact metamorphism of the Młynowiec-Stronie Group. Cambrian to Ordovician monazites developed only in K-feldspar bearing rocks, i.e. orthogneisses and light quartzites (SF), which suggests growth of the Early Palaeozoic monazites during formation of their, respectively, magmatic and partially volcanic protoliths. Acknowledgements. The project was funded by the National Science Center of Poland, grant number DEC 2011/03/B/ST10/05638.

  15. Hydra groups

    CERN Document Server

    Dison, Will

    2010-01-01

    We give examples of CAT(0), biautomatic, free-by-cyclic, one-relator groups which have finite-rank free subgroups of huge (Ackermannian) distortion. This leads to elementary examples of groups whose Dehn functions are similarly extravagant. This behaviour originates in manifestations of Hercules-versus-the-hydra battles in string-rewriting.

  16. Devonian/Carboniferous boundary glacioeustatic fluctuations in a platform-to-basin direction: A geochemical approach of sequence stratigraphy in pelagic settings

    Science.gov (United States)

    Bábek, Ondrej; Kumpan, Tomáš; Kalvoda, Jiří; Matys Grygar, Tomáš

    2016-05-01

    We investigated high-resolution stratigraphic distribution of selected major and trace elements and gamma-ray spectra of fourteen Devonian/Carboniferous (D/C) boundary sections of Europe located in the late Palaeozoic Laurussia and Gondwana. The aim was to trace the geochemical signature of a marked forced and normal regressive interval which was associated with rapid progradation of siliciclastics into the marine carbonate systems (Rhenish Massif) and a prominent hiatus in shallow-water ramp settings (Namur-Dinant Basin). This interval represents the late Devonian Hangenberg event (HBE) sensu lato (middle praesulcata conodont zone) as defined by previous authors. This regressive interval (FSST to LST) correlates with thin shale layers (HBE shale) sandwiched between monotonous nodular calcilutite/calcisiltite successions at five pelagic sections of Moravia, Carnic Alps, Montagne Noire, and Pyrenees. In all sections with continuous D/C sedimentation (i.e., except those of the Namur-Dinant Basin), the HBE s.l. interval is accompanied by elevated percentages of detrital proxies (Al, K, Rb, Zr) and changes in their ratios (Zr/Rb, K/Al, Rb/K) which are normally interpreted as indicators of increased siliciclastic input, provenance, and grain size. Zr/Rb and other proxies are traceable even without apparent lithological evidence and can, therefore, facilitate stratigraphic correlation. Paleoredox and productivity proxies (U/Th and Ni/Rb enrichment factors) only rarely show elevated values in the Hangenberg black shale interval, indicating that the associated water dysoxia/anoxia was a local rather than global phenomenon. Global correlations based on the HBE black shales should therefore be dropped in favor of the HBE s.l. interval. Moreover, analysis of sedimentation rates in the upper expansa to kockeli zone interval using the published radiometric ages suggests that the HBE s.l. was a time of significant increase in the rate of siliciclastic supply into the ocean, even

  17. Combined tectonic-sediment supply-driven cycles in a Lower Carboniferous deep-marine foreland basin, Moravice Formation, Czech Republic

    Science.gov (United States)

    Bábek, Ondřej; Mikuláš, Radek; Zapletal, Jan; Lehotský, Tomáš

    The Lower Carboniferous Moravian-Silesian Culm Basin (MSCB) represents the easternmost part of the Rhenohercynian system of collision-related, deep-water foreland basins (Culm facies). The Upper Viséan Moravice Formation (MF) of the MSCB shows a distinct cyclic stratigraphic arrangement. Two major asymmetric megacycles bounded by basal sequence boundary, each about 500 to 900 m thick, have been revealed. The megacycles start with 50- to 250-m-thick, basal segments of erosive channels: overbank successions and slope apron deposits interpreted as lowstand turbidite systems. Up-section they pass into hundred metre-thick, fine-grained, low-efficiency turbidite systems. Palaeocurrent data show two prominent directions, basin axis-parallel, SSW-NNE directions, which are abundant in the whole MF, and basin axis-perpendicular to oblique, W-E to NW-SE directions, which tend to be confined to the basal parts of the megacycles or channel-lobe transition systems in their upper parts. Based on the facies characteristics, palaeocurrent data, sandstone composition data and trace-fossil distribution data, we suggest a combined tectonics-sediment supply-driven model for the MF basin fill. Periods of increased tectonic activity resulted in slope oversteepening probably combined with increased rate of lateral W-E sediment supply into the basin, producing the basal sequence boundary and the subsequent lowstand turbidite systems. During subsequent periods of tectonic quiescence, the system was filled mainly from a distant southern point source, producing the thick, low efficiency turbidite systems. Consistently with the previous models, our own sediment composition data indicate a progressively increasing sediment input from high-grade metamorphic and magmatic sources up-section, most probably related to an uplift in the source area and progressive unroofing of its structurally deeper crustal parts. The first occurrence of the Cruziana-Nereites ichnofacies in sand-rich turbidite

  18. Group Grammar

    Science.gov (United States)

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  19. MUYANG GROUP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research&development.project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.

  20. Abelian groups

    CERN Document Server

    Fuchs, László

    2015-01-01

    Written by one of the subject’s foremost experts, this book focuses on the central developments and modern methods of the advanced theory of abelian groups, while remaining accessible, as an introduction and reference, to the non-specialist. It provides a coherent source for results scattered throughout the research literature with lots of new proofs. The presentation highlights major trends that have radically changed the modern character of the subject, in particular, the use of homological methods in the structure theory of various classes of abelian groups, and the use of advanced set-theoretical methods in the study of undecidability problems. The treatment of the latter trend includes Shelah’s seminal work on the undecidability in ZFC of Whitehead’s Problem; while the treatment of the former trend includes an extensive (but non-exhaustive) study of p-groups, torsion-free groups, mixed groups, and important classes of groups arising from ring theory. To prepare the reader to tackle these topics, th...

  1. Detrital zircon U-Pb ages and Hf isotopes of Permo-Carboniferous sandstones in central Inner Mongolia, China: Implications for provenance and tectonic evolution of the southeastern Central Asian Orogenic Belt

    Science.gov (United States)

    Chen, Yan; Zhang, Zhicheng; Li, Ke; Yu, Haifei; Wu, Tairan

    2016-03-01

    The tectonic setting of the southeastern Central Asian Orogenic Belt (CAOB) during the Late Paleozoic has been debated for many years. Provenance analysis of Permo-Carboniferous sedimentary rocks can effectively address this issue. In this study, eight sandstone samples were collected for zircon U-Pb and Lu-Hf isotopic analyses combined with petrographic analysis. Framework petrography and zircon morphology suggest that the samples were from recycled orogen of an igneous origin. Carboniferous rocks, with a significant age peak at 432 Ma and εHf (t) values of - 9.0 to 13.6, were mainly derived from Early to Mid-Paleozoic magmatic rocks and deposited in a piedmont zone, namely, the margin of an inland sea. Permian rocks, mostly with age peaks at 445 Ma and/or 280 Ma and εHf (t) values of - 25.2 to 11.4, dominantly originated from a pre-existing Early to Mid-Paleozoic magmatic arc and Late Paleozoic igneous rocks. These rocks formed in restricted basins of the piedmont and intermountain zones. Based on zircon spectral discrimination, sedimentary environmental analysis, and previous studies, this study supports the interpretation that the southeastern CAOB entered stages of extension and rifting during the Late Paleozoic. In the end, this study proposes a tectonic-paleogeographic reconstruction to explain the tectonic evolution of the southeastern CAOB and the exhumation-transportation-deposition processes between the basins and ranges developed in this orogen.

  2. Group dynamics.

    Science.gov (United States)

    Scandiffio, A L

    1990-12-01

    Group dynamics play a significant role within any organization, culture, or unit. The important thing to remember with any of these structures is that they are made up of people--people with different ideas, motivations, background, and sometimes different agendas. Most groups, formal or informal, look for a leader in an effort to maintain cohesiveness of the unit. At times, that cultural bond must be developed; once developed, it must be nurtured. There are also times that one of the group no longer finds the culture comfortable and begins to act out behaviorally. It is these times that become trying for the leader as she or he attempts to remain objective when that which was once in the building phase of group cohesiveness starts to fall apart. At all times, the manager must continue to view the employee creating the disturbance as an integral part of the group. It is at this time that it is beneficial to perceive the employee exhibiting problem behaviors as a special employee, as one who needs the benefit of your experience and skills, as one who is still part of the group. It is also during this time that the manager should focus upon her or his own views in the area of power, communication, and the corporate culture of the unit that one has established before attempting to understand another's point of view. Once we understand our own motivation and accept ourselves, it is then that we may move on to offer assistance to another. Once we understand our insecurities recognizing staff dysfunction as a symptom of system dysfunction will not be so threatening to the concept of the manager that we perceive ourselves to be. It takes a secure person to admit that she or he favors staff before deciding to do something to change things. The important thing to know is that it can be done. The favored staff can find a new way of relating to others, the special employee can find new modes of behavior (and even find self-esteem in the process), the group can find new ways

  3. Group dynamics.

    Science.gov (United States)

    Scandiffio, A L

    1990-12-01

    Group dynamics play a significant role within any organization, culture, or unit. The important thing to remember with any of these structures is that they are made up of people--people with different ideas, motivations, background, and sometimes different agendas. Most groups, formal or informal, look for a leader in an effort to maintain cohesiveness of the unit. At times, that cultural bond must be developed; once developed, it must be nurtured. There are also times that one of the group no longer finds the culture comfortable and begins to act out behaviorally. It is these times that become trying for the leader as she or he attempts to remain objective when that which was once in the building phase of group cohesiveness starts to fall apart. At all times, the manager must continue to view the employee creating the disturbance as an integral part of the group. It is at this time that it is beneficial to perceive the employee exhibiting problem behaviors as a special employee, as one who needs the benefit of your experience and skills, as one who is still part of the group. It is also during this time that the manager should focus upon her or his own views in the area of power, communication, and the corporate culture of the unit that one has established before attempting to understand another's point of view. Once we understand our own motivation and accept ourselves, it is then that we may move on to offer assistance to another. Once we understand our insecurities recognizing staff dysfunction as a symptom of system dysfunction will not be so threatening to the concept of the manager that we perceive ourselves to be. It takes a secure person to admit that she or he favors staff before deciding to do something to change things. The important thing to know is that it can be done. The favored staff can find a new way of relating to others, the special employee can find new modes of behavior (and even find self-esteem in the process), the group can find new ways

  4. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  5. Lego Group

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben; Slepniov, Dmitrij

    2010-01-01

    The last years’ rather adventurous journey from 2004 to 2009 had taught the fifth-largest toy-maker in the world - the LEGO Group - the importance of managing the global supply chain effectively. In order to survive the largest internal financial crisis in its roughly 70 years of existence......, the management had, among many initiatives, decided to offshore and outsource a major chunk of its production to Flextronics. In this pursuit of rapid cost-cutting sourcing advantages, the LEGO Group planned to license out as much as 80 per cent of its production besides closing down major parts...

  6. Group Learning.

    Science.gov (United States)

    Black, Susan

    1992-01-01

    Research suggests that cooperative learning works best when students are first taught group-processing skills, such as leadership, decision making, communication, trust building, and conflict management. Inadequate teacher training and boring assignments can torpedo cooperative learning efforts. Administrators should reassure teachers with…

  7. Tectaria group

    NARCIS (Netherlands)

    Holttum, R.E.

    1991-01-01

    Polypodiaceae subfam. Dryopteridoideae section A, auct.: C. Chr. in Verdoorn, Man. Pteridol. (1938) 543, p.p. Aspidiaceae tribe Aspidieae auct.: Ching, Sunyatsenia 5 (1940) 250, excl. Lomariopsis and related genera. — Aspidiaceae, group of Ctenitis Copel., Gen. Fil. (1947) 153. Aspidiaceae auct.: Pi

  8. 青海南部治多-杂多地区早石炭世珊瑚组合和生物地理特征%Early Carboniferous Coral Assemblages and Their Palaeobiogeography in the Zhidoi-Zadoi Area, Southern Qinghai

    Institute of Scientific and Technical Information of China (English)

    牛志军; 吴俊; 王建雄; 赵小明

    2011-01-01

    Abstract: Abundant coral fossils were collected from the Zadoi Group (Lower Carboniferous) in southern Qing-hai. In the study area, the Zadoi Group is composed of three formations, which are the Lower Carbonate Formation (C1Z1), the Clastic Formation (C1 z2), and the Upper Carbonate Formation (C1z3 ) in ascending order. Based on the characteristics of the coral fauna, two assemblages may be established, which are the Siphonodendron scitulus - Lithostrotionella zadoensis assembalge ( Visean ) occurred in the Lower Carbonate Formation and Clastic Formation, and the Lithostrotion decipkns - Kueichouphyllum sinense - Siphonodendron irregulare asiatic-um assembalge (Visean-Serpukhovian) occurred in the Upper Carbonate Formation. The Siphonodendron scitulus - Lithostrotionella zadoensis assembalge is characterized by endemic genera, and dominated by genera Siphonodendron and Lithostrotionella compound in form. In the Lithostrotion decipiens - Kueichouphyllum sinense - Siphonodendron irregulare asiaticum assembalge, genus Kueichouphyllum solitary in form, which is one of warm-water genera of South China, first occurred. As an important element of the North-type of Eurasia Province, genus Gangamophyllum also occurred, but in a small amount. And the diversity of this assemblage is significantly higher than that of the underlying assemblage. This coral fauna correlated well with those faunas from East Tibet, South China, and adjacent areas of the same period. The Otsuka similarity coefficient and Q-cluster analysis of these coral faunas shows that the Early Carboniferous coral fauna from southern Qinghai is warm-water Tethys-type, and belongs to the Bayankala-Sanjiang subprovince, Tethys Realm. And this fauna differs significantly from those faunas in south of Longmu Co-Shuanghu-Lancang River Suture Zone.%青海南部下石炭统杂多群珊瑚化石丰富,下部为维宪阶Siphonodendron scitulus - Lithostrotionella zadoensis组合,产于下碳酸盐岩组和碎屑岩组,

  9. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  10. Group therapy

    International Nuclear Information System (INIS)

    Full text: In his review 'Genesis of Unified Gauge Theories' at the symposium in Honour of Abdus Salam (June, page 23), Tom Kibble of Imperial College, London, looked back to the physics events around Salam from 1959-67. He described how, in the early 1960s, people were pushing to enlarge the symmetry of strong interactions beyond the SU(2) of isospin and incorporate the additional strangeness quantum number. Kibble wrote - 'Salam had students working on every conceivable symmetry group. One of these was Yuval Ne'eman, who had the good fortune and/or prescience to work on SU(3). From that work, and of course from the independent work of Murray Gell- Mann, stemmed the Eightfold Way, with its triumphant vindication in the discovery of the omega-minus in 1964.' Yuval Ne'eman writes - 'I was the Defence Attaché at the Israeli Embassy in London and was admitted by Salam as a part-time graduate student when I arrived in 1958. I started research after resigning from the Embassy in May 1960. Salam suggested a problem: provide vector mesons with mass - the problem which was eventually solved by Higgs, Guralnik, Kibble,.... (as described by Kibble in his article). I explained to Salam that I had become interested in symmetry. Nobody at Imperial College at the time, other than Salam himself, was doing anything in groups, and attention further afield was focused on the rotation - SO(N) - groups. Reacting to my own half-baked schemes, Salam told me to forget about the rotation groups he taught us, and study group theory in depth, directing me to Eugene Dynkin's classification of Lie subalgebras, about which he had heard from Morton Hamermesh. I found Dynkin incomprehensible without first learning about Lie algebras from Henri Cartan's thesis, which luckily had been reproduced by Dynkin in his 1946 thesis, using his diagram method. From a copy of a translation of Dynkin's thesis which I found in the British Museum Library, I

  11. Local Group

    Science.gov (United States)

    Mateo, M.; Murdin, P.

    2000-11-01

    Not long after EDWIN HUBBLE established that galaxies are `island universes' similar to our home galaxy, the MILKY WAY, he realized that a few of these external galaxies are considerably closer to us than any others. In 1936 he first coined the term `Local Group' in his famous book The Realm of the Nebulae to identify our nearest galactic neighbors. More than 60 yr later, the galaxies of the Loca...

  12. Carboniferous magmatism in the Evora Massif (southwest Portugal, Ossa-Morena Zone): from typical arc calc-alkaline to adakitic-like magmatism

    Science.gov (United States)

    Lima, Selma M.; Neiva, Ana M. R.; Ramos, Joao M. F.

    2014-05-01

    The Evora Massif is one of the subdivisions of western Ossa-Morena Zone. It is a dome-like structure mainly composed of Ediacaran, Cambrian and Ordovician country rocks, affected by medium- and high-grade metamorphism coeval with the emplacement of several mafic to felsic intrusive bodies. The last magmatic event recorded in this area (Carboniferous) consists of calc-alkaline volcanism and voluminous plutonism (mainly composed by tonalites, gabbros, diorites and late-orogenic granodiorites and granites) [1]. Detailed chemical and isotopic studies from Evora Massif plutons were performed in the last few years. Whole-rock chemical and isotopic data suggest that the Hospitais tonalite (HT), Alto de Sao Bento area (ASB) and Reguengos de Monsaraz pluton (RM) resulted from fractional crystallization of mantle-derived magmas followed by mixing with variable proportions of crustal melts [2-4]. U-Pb ID-TIMS data indicate an age of 337-335 for the RM [4]. The Pavia pluton is a multiphase granitic body constructed incrementally by the episodic emplacement of several batches of magma (at 328 Ma, ca. 324 Ma and 319-317 Ma) [5]. The main granitic phases range from tonalite to two-mica granite that contain rare surmicaceous and fine-grained enclaves, and granitic and amphibolitic xenoliths. On the other hand, they are cut by abundant rhyodacite porphyries, microgranites (s.l.) and pegmatite dikes, predominantly oriented NE-SW and NW-SE. Although each phase seems to represent a distinct batch of magma, whole-rock Sr-Nd isotopic data suggest a similar and fairly homogenous source for all the constituent phases. Initial 87Sr/86Sr varies between 0.70428 and 0.7058 and ɛ Ndt ranges from -3.4 to +0.4, pointing towards a mantle or juvenile crust origin. A higher variation is observed in whole-rock δ18O (5.6-9.6 o), consistent with assimilation of crust. The PP was interpreted as the result of assimilation-fractional crystallization of a basaltic magma. Substantial differences between

  13. Continental crust subducted deeply into lithospheric mantle: the driving force of Early Carboniferous magmatism in the Variscan collisional orogen (Bohemian Massif)

    Science.gov (United States)

    Janoušek, Vojtěch; Schulmann, Karel; Lexa, Ondrej; Holub, František; Franěk, Jan; Vrána, Stanislav

    2014-05-01

    The vigorous Late Devonian-Early Carboniferous plutonic activity in the core of the Bohemian Massif was marked by a transition from normal-K calc-alkaline, arc-related (~375-355 Ma), through high-K calc-alkaline (~346 Ma) to (ultra-)potassic (343-335 Ma) suites, the latter associated with mainly felsic HP granulites enclosing Grt/Spl mantle peridotite bodies. The changing chemistry, especially an increase in K2O/Na2O and 87Sr/86Sri with decrease in 143Nd/144Ndi in the basic end-members, cannot be reconciled by contamination during ascent. Instead it has to reflect the character of the mantle sources, changing over time. The tectonic model invokes an oceanic subduction passing to subduction of the attenuated Saxothuringian crust under the rifted Gondwana margin (Teplá-Barrandian and Moldanubian domains). The deep burial of this mostly refractory felsic metaigneous material is evidenced by the presence of coesite/diamond (Massonne 2001; Kotková et al. 2011) in the detached UHP slices exhumed through the subduction channel and thrusted over the Saxothuringian basement, and by the abundance of felsic HP granulites (> 2.3 GPa), some bearing evidence for small-scale HP melt separation, in the orogen's core (Vrána et al. 2013). The subduction channel was most likely formed by 'dirty' serpentinites contaminated by the melts/fluids derived from the underlying continental-crust slab (Zheng 2012). Upon the passage through the orogenic mantle, the continental crust-slab derived material not only contaminated the adjacent mantle forming small bodies/veins of pyroxenites (Becker 1996), glimmerites (Becker et al. 1999) or even phlogopite- and apatite-bearing peridotites (Naemura et al. 2009) but the felsic HP-HT granulites also sampled the individual peridotite types at various levels. Eventually the subducted felsic material would form an (U)HP continental wedge under the forearc/arc region, to be later redistributed under the Moldanubian crust by channel flow and crustal

  14. Early carboniferous wrenching, exhumation of high-grade metamorphic rocks and basin instability in SW Iberia: Constraints derived from structural geology and U-Pb and 40Ar-39Ar geochronology

    Science.gov (United States)

    Pereira, M. Francisco; Chichorro, Martim; Silva, J. Brandão; Ordóñez-Casado, Berta; Lee, James K. W.; Williams, Ian S.

    2012-08-01

    New U-Pb and 40Ar-39Ar geochronology and structural data from high- to medium grade metamorphic shear zones of the Ossa-Morena Zone, and structural data from Early Carboniferous basins (Ossa-Morena Zone and South-Portuguese Zone), place additional constraints on the Variscan tectonics in SW Iberia. A zircon U-Pb age of 465 ± 14 Ma (Middle Ordovician) measured on migmatite from the Coimbra-Cordoba shear zone is interpreted as the age of protolith crystallization. This age determination revises the information contained in the geological map of Portugal, in which these rocks were considered to be Proterozoic in age. This paper describes the evolution of Variscan wrench tectonics related to the development of shear zones, exhumation of deep crustal rocks and emplacement of magma in the Ossa-Morena Zone basement. In the Coimbra-Cordoba shear zone (transpressional), migmatites were rapidly exhumed from a depth of 42.5 km to 16.6 km over a period of ca. 10 Ma in the Viséan (ca. 340-330 Ma), indicating oblique slip exhumation rates of 8.5 to 10.6 mm/yr (Campo Maior migmatites) and 3.2 mm/yr (Ouguela gneisses) respectively. In the Évora Massif, the gneisses of the Boa Fé shear zone (transtensional) were exhumed from 18.5 to 7.4 km depth in the period ca. 344-334 Ma (Viséan), with exhumation oblique slip rates of 2.8 to 4.2 mm/yr. At the same time, the Early Carboniferous basins of SW Iberia were filled by turbidites and olistoliths, composed mostly of Devonian rocks. The presence of olistoliths indicates significant tectonic instability during sedimentation with large-scale mass movement, probably in the form of gravity slides. Deformation and metamorphism dated at 356 ± 12 Ma, 321 ± 13 Ma and 322 ± 29 Ma respectively suggests that Variscan wrench movements were active in SW Iberia during the Early Carboniferous for a period of at least 35 Ma.

  15. 塔城盆地石炭系烃源岩特征及其生烃潜力%Characteristics and hydrocarbon-generating potential of Carboniferous source rock in Tacheng Basin

    Institute of Scientific and Technical Information of China (English)

    蒋宜勤; 高岗; 柳广弟; 王绪龙; 裴立新; 向宝力; 唐勇

    2012-01-01

    在塔城盆地野外露头和塔参1井钻井烃源岩发育特征与有机地化特征分析的基础上,探讨了石炭系烃源岩的生烃潜力.通过烃源岩岩性与有机质丰度分析认为,较好的烃源岩主要为泥质岩,其次为碳质泥岩和煤,上石炭统泥岩总体要好于下石炭统.烃源岩母质类型主要为腐殖型,具有倾气型特征.烃源岩演化程度普遍达到了高—过成熟阶段,但仍有一定的残余生烃潜力.应加强烃源岩主要分布区及其生烃史与盆地构造演化的匹配关系和成藏历史的研究.%Based on the analyses of generation and organic geochemical characteristics of outcrops in the Tacheng Basin and source rocks from well Tacan 1, the hydrocarbon-generating potential of the Carboniferous source rocks was discussed. According to the lithology and organic abundance of source rocks, raudstones were good source rocks while carbonaceous mudstones and coals were also favorable. The mudstones in the Upper Carboniferous were generally more favorable than those in the Lower Carboniferous. The organic material types of source rocks were mainly humus ones with gas-generating feature. Source rock evolution had entered the high-mature and over-mature stages, but there still existed residual hydrocarbon-generating capacity. Studies should be focused on the main distribution areas of source rocks, the relationship between hydrocarbon generation and basin evolutions histories, and the history of accumulation.

  16. The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Haijun; WANG; Xunlian; DING; Lin; XIA; Guoying; WANG; Lei

    2006-01-01

    The study on the interrelation between sea-level changes and biodiversity with its evolution has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen'an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the species numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou,Zhen'an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, detailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, andthe number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive systems

  17. 准噶尔盆地春晖油田石炭系火山岩储层控制因素分析%Controlling factors of the Carboniferous volcanic reservoirs in the Chunhui Oil Field, Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    董臣强

    2014-01-01

    春晖油田石炭系火山岩地层中,油气富集程度与储层发育程度呈正相关关系。研究认为,储层的发育与分布主要受岩相、岩性和构造运动的控制。岩相控制岩性,岩性控制储集空间组合类型,溢流相和火山沉积相围绕爆发相具有环带状分布特点,从火山角砾岩→玄武岩、安山岩→凝灰岩,储集性能逐渐变差;构造运动则控制裂缝的发育及溶蚀作用,断层周边微裂缝发育,沿着微裂缝则溶蚀作用增强,次生孔隙发育。%The Chunhui Oil Field in the Junggar Basin lies in the western part of the Halaalate Mountain tectonic zone, in which the Carboniferous volcanic strata consist dominantly of the volcanic rocks such as tuff, andesite, basalt and volcanic breccias. There is a positive correlation between the hydrocarbon enrichment and reservoir development in the Carboniferous volcanic reservoir rocks from the Chunhui Oil Field. The distribution and development of the volcanic reservoir rocks are primarily controlled by lithofacies, lithology and tectonism. On the whole, the lithofacies may exercise a major control on lithology of the volcanic reservoir rocks, which, in turn, may control the reservoir spaces types. The volcanic rocks in the Chunhui Oil Field exhibit a trend of the girdle pattern of lithofacies changes from the explosive facies through the effusive facies to the volcano-sedimentary facies. The reservoir capacity is gradually getting poor and poor from volcanic breccias to basalt and andesite and finally to tuff. The tectonism is also believed to be a major control on the fissure development and dissolution. The structural stress may give rise to the formation of the cracks or fissures in the brittle rocks, which may greatly improve the reservoir spaces of the Carboniferous volcanic reservoir rocks in the study area.

  18. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  19. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  20. Cardiovascular group

    Science.gov (United States)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  1. Assessment of Appalachian basin oil and gas resources: Carboniferous Coal-bed Gas Total Petroleum System: Chapter G.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Milici, Robert C.

    2014-01-01

    The Carboniferous Coal-bed Gas Total Petroleum System, which lies within the central and southern Appalachian basin, consists of the following five assessment units (AUs): (1) the Pocahontas Basin AU in southern West Virginia, eastern Kentucky, and southwestern Virginia; (2) the Central Appalachian Shelf AU in Tennessee, eastern Kentucky, and southern West Virginia; (3) the East Dunkard (Folded) AU in western Pennsylvania and northern West Virginia; (4) the West Dunkard (Unfolded) AU in Ohio and adjacent parts of Pennsylvania and West Virginia; and (5) the Appalachian Anthracite and Semi-Anthracite AU in Pennsylvania and Virginia. Only two of these assessment units were assessed quantitatively by the U.S. Geological Survey (USGS) in the National Oil and Gas Assessment in 2002. The USGS estimated the Pocahontas Basin AU and the East Dunkard (Folded) AU to contain a mean of about 3.6 and 4.8 trillion cubic feet (TCF) of undiscovered, technically recoverable gas, respectively.

  2. 哈拉阿拉特山石炭系裂缝发育特征及成藏意义%Characteristics of the Carboniferous Volcanic Fractures and Its Hydrocarbon Accumulation Significance in Hala′alate Mountains

    Institute of Scientific and Technical Information of China (English)

    张关龙; 张奎华; 王圣柱; 许文国

    2014-01-01

    哈拉阿拉特山地区位于准噶尔盆地西北缘前陆褶皱冲断带,紧邻玛湖生烃凹陷,是油气运移和聚集的有利区域。针对该区石炭系油气藏主要赋存于火山岩构造裂缝中且富集规律不清楚的问题,开展了构造裂缝的发育特征、控制因素及其与油气成藏的关系研究。利用钻井岩芯、成像测井、岩石力学实验及流体包裹体分析等手段,研究了石炭系火山岩构造裂缝的产状、密度、发育次序、主控因素及其与油气成藏关系。结果表明,石炭系火山岩裂缝主要为高角度裂缝,裂缝发育的优势倾向为北西-南东向,影响裂缝发育的主控因素为岩石力学性质及所处的构造位置。同时,由于高角度缝充填程度低、形成时间晚、发育程度高,且与油气主要的运移成藏期匹配较好,因而成为研究区石炭系油气主要勘探目标。该研究结果对于哈拉阿拉特山地区石炭系火山岩油气藏的勘探与开发具有重要的指导意义。%Hala′alate Mountains Area,situated in the foreland fold thrust belts of the northwestern margin of Junggar Basin, adjacent to hydrocarbon generation depression of Mahu,is a favorable area of hydrocarbon migration and accumulation. Car-boniferous hydrocarbon reservoir in this area was mainly hosted in the volcanic tectonic fractures and its enrichment regulation was unknown. Aiming at this problem,we study the development characteristics,controlling factors of tectonic fractures and its relationship with hydrocarbon accumulation. By using drilling core,imaging logging,rock mechanics tests and fluid in-clusion analysis technics,the paper studied the attitude,density,developing order,main controlling factors of Carboniferous volcanic tectonic fractures and their relationship with hydrocarbon accumulation. The results show that the cracks in carbonif-erous volcanic rocks are mainly high angle cracks,and the advantage fracture

  3. A DISCUSSING ON THE REASONABLE WELL-PATIERN SPACING OF CARBONIFEROUS RESERVOIRS IN EAST SICHUAN%川东石炭系气藏合理井网密度的探讨

    Institute of Scientific and Technical Information of China (English)

    唐玉林; 唐光平

    2000-01-01

    The Carboniferous is the major productive for mation, being of strong heterogeneity, and its drilling cost is high because of a large burial depth. According to measurement and calculation, the single-well economically-limiting cumulating production can' t be less than 8 000 × 104m3, economically-limiting minimum controlled reserves (1~1.6) × 108m3 and economically-limiting well spacing 0.5 ~ 1.4 km for the Carboniferous in East Sichuan;and the economically-limiting conditions of forming productive formation in the Carboniferous in East Sichuan are that the permeability must be larger than 0.5 × 10- 3μm2 or the pressure transmitting coefficient 0.01 m2/s. Through researching it is found that the permeability has a log-log linear relation to the single-well drainage radius in the Carboniferous reservoirs in East Sichuan. Based on this conclusion it is proposed that the initial well-pattern of the gas reservoir is formed by taking the sum of the drainage radii of two nearby wells as the well spacing,then through increasing the infill wells in high-permeability area a final well-pattern may be set up, which may fully utilize the gas reserves in the reservoir and maximally enhance gas recovery but also can obtain optimum economic benefit.%石炭系是川东主产层,非均质性明显,井深,钻井成本高。经测算川东石炭系单井经济极限累采气量不能低于8 000×104m3,经济极限最低控制储量(1~1.6)×108m3,经济极限井距0.5~1.4 km;石炭系产层经济极限条件是渗透率大于0.5×10-3μm2或导压系数大于0.01m2/s。研究发现川东石炭系储层渗透率与单井排泄半径具双对数线性关系,在此基础上提出以相邻两井的排泄半径之和为井距形成气藏的初始井网,在初始井网基础上对高渗区加密形成最终开发井网,既可充分动用气藏储量和最大限度地提高采收率,同时还能获取最佳经济效益。

  4. Functional groups in a single pteridosperm species: Variability and circumscription (Pennsylvanian, Nova Scotia, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Mastalerz, Maria [Indiana Geological Survey, Indiana University, 611 North Walnut Grove, Bloomington, IN 47405-2208 (United States); Zodrow, Erwin L.

    2007-05-01

    Multiple foliar specimens of the Late Pennsylvanian fossil pteridosperm [gymnosperm] Alethopteris zeilleri (Ragot) Wagner were collected from one restricted stratigraphical horizon in the Canadian Sydney Coalfield. Variability of functional-group distribution using FTIR technique was studied in compressions, adaxial versus abaxial cuticles, and in unseparated cuticles as a function of maceration time from 48 to 168 h. The results obtained document spectral variability that could be expected within specimens of one species. For example, CH{sub 2}/CH{sub 3} and Al/ox ratios can differ by as much as 20% of the values. Moreover, the experiments performed confirm that by using a previously established maceration protocol, long maceration periods do not bias FTIR spectra in terms of oxygenation overprinting. The inference that this cuticle is robust, under the given diagenetic level, probably reflects a reassuring degree of chemical fidelity of the Pennsylvanian plant to support Carboniferous chemotaxonomic observations. (author)

  5. Functional groups in a single pteridosperm species: Variability and circumscription (Pennsylvanian, Nova Scotia, Canada)

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2007-01-01

    Multiple foliar specimens of the Late Pennsylvanian fossil pteridosperm [gymnosperm] Alethopteris zeilleri (Ragot) Wagner were collected from one restricted stratigraphical horizon in the Canadian Sydney Coalfield. Variability of functional-group distribution using FTIR technique was studied in compressions, adaxial versus abaxial cuticles, and in unseparated cuticles as a function of maceration time from 48 to 168??h. The results obtained document spectral variability that could be expected within specimens of one species. For example, CH2/CH3 and Al/ox ratios can differ by as much as 20% of the values. Moreover, the experiments performed confirm that by using a previously established maceration protocol, long maceration periods do not bias FTIR spectra in terms of oxygenation overprinting. The inference that this cuticle is robust, under the given diagenetic level, probably reflects a reassuring degree of chemical fidelity of the Pennsylvanian plant to support Carboniferous chemotaxonomic observations. ?? 2006 Elsevier B.V. All rights reserved.

  6. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The recently established CMS Communications Group, led by Lucas Taylor, has been busy in all three of its main are areas of responsibility: Communications Infrastructure, Information Systems, and Outreach and Education Communications Infrastructure The damage caused by the flooding of the CMS Centre@CERN on 21st December has been completely repaired and all systems are back in operation. Major repairs were made to the roofs, ceilings and one third of the floor had to be completely replaced. Throughout these works, the CMS Centre was kept operating and even hosted a major press event for first 7 TeV collisions, as described below. Incremental work behind the scenes is steadily improving the quality of the CMS communications infrastructure, particularly Webcasting, video conferencing, and meeting rooms at CERN. CERN/IT is also deploying a pilot service of a new videoconference tool called Vidyo, to assess whether it might provide an enhanced service at a lower cost, compared to the EVO tool currently in w...

  7. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin is particularly busy at the moment, hosting about 50 physicists taking part in the heavy-ion data-taking and analysis. Three new CMS meeting room will be equipped for videoconferencing in early 2012: 40/5B-08, 42/R-031, and 28/S-029. The CMS-TV service showing LHC Page 1, CMS Page 1, etc. (http://cmsdoc.cern.ch/cmscc/projector/index.jsp) is now also available for mobile devices: http://cern.ch/mcmstv. Figure 12: Screenshots of CMS-TV for mobile devices Information Systems CMS has a new web site: (http://cern.ch/cms) using a modern web Content Management System to ensure content and links are managed and updated easily and coherently. It covers all CMS sub-projects and groups, replacing the iCMS internal pages. It also incorporates the existing CMS public web site (http:/...

  8. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2012-01-01

      Outreach and Education We are fortunate that our research has captured the public imagination, even though this inevitably puts us under the global media spotlight, as we saw with the Higgs seminar at CERN in December, which had 110,000 distinct webcast viewers. The media interest was huge with 71 media organisations registering to come to CERN to cover the Higgs seminar, which was followed by a press briefing with the DG and Spokespersons. This event resulted in about 2,000 generally positive stories in the global media. For this seminar, the CMS Communications Group prepared up-to-date news and public material, including links to the CMS results, animations and event displays [http://cern.ch/go/Ch8thttp://cern.ch/go/Ch8t]. There were 44,000 page-views on the CMS public website, with the Higgs news article being by far the most popular item. CMS event displays from iSpy are fast becoming the iconic media images, featuring on numerous major news outlets (BBC, CNN, MSN...) as well as in the sci...

  9. Reinterpretation of depositional processes in a classic flysch sequence (Pennsylvania Jackfork Group), Ouachita Mountains, Arkansas and Oklahoma: Reply

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G.; Moiola, R.J. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

    1997-03-01

    Progress in science is often made when we make new observations, question old paradigms that do not work, and introduce new concepts. We attempted to do all this in our paper on the Jackfork Group (Shanmugam and Moiola, 1995). To allow Bulletin readers to appreciate the sequence of events leading to our controversial paper that provoked the preceding critiques, we need to place our contributions in a historical perspective. Our involvement with the Ouachitas began in the late 1960s when Moiola initiated a study of the Upper Carboniferous deep-water succession. Throughout the 1970s and 1980s, we perpetuated the {open_quotes}turbidite{close_quotes} paradigm by continuing to interpret the Jackfork Group and associated strata according to conventional wisdom. However, we were always troubled by the virtual absence of normal grading in these classic turbidite deposits.

  10. Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance

    Science.gov (United States)

    Slack, John F.; Dumoulin, Julie A.; Schmidt, J.M.; Young, L.E.; Rombach, Cameron

    2004-01-01

    Geochemical analyses of Paleozoic sedimentary rocks in the western Brooks Range reveal a complex evolutionary history for strata surrounding the large Zn-Pb-Ag deposits of the Red Dog district. Data for major elements, trace elements, and rare earth elements (REE) were obtained on 220 samples of unaltered and unmineralized siliciclastic rocks from the Upper Devonian-Lower Mississippian Endicott Group (Hunt Fork Shale, Noatak Sandstone, Kanayut Conglomerate, Kayak Shale), the overlying Carboniferous Lisburne Group (Kuna Formation, unnamed drowned shelf facies), and the Pennsylvanian-Permian Siksikpuk Formation. Major base metal sulfide deposits of the region are present only in the Kuna Formation, which in the Red Dog district comprises siliceous black shale and black chert, minor limestone (calcareous radiolarite), and sparse lithic turbidite and bedded siliceous rock. Gray and rare black shales of the Kayak Shale and common black shales of the Kuna Formation are anomalously low in iron (avg Fe/Ti = 6.25 and 6.34, respectively) relative to other Paleozoic shales in the region (9.58-10.6) and to average shales worldwide (10.1-10.5). In contrast, the bedded siliceous rocks contain appreciable hematite (avg Fe/Ti = 35.0) and high U/Ti and REE/Ti ratios that are interpreted to reflect low amounts of detrital material and a major Fe-rich eolian component.

  11. Post-sedimentary tectonic evolution, cap rock condition and hydrocarbon information of Carboniferous-Permian in Ejin Banner and its vicinities, western Inner Mongolia: a study of Carboniferous-Permian petroleum geological conditions (part 3)%内蒙古西部额济纳旗及邻区石炭系-二叠系沉积后的构造演化、盖层条件与油气信息——石炭系-二叠系油气地质条件研究之三

    Institute of Scientific and Technical Information of China (English)

    卢进才; 陈高潮; 魏仙样; 李玉宏; 魏建设

    2011-01-01

    Based on an analysis of Mesozoic-Cenozoic sedimentary evolvement and a study of structural reformation after Carboniferous-Permian and Mesozoic magmatism, the authors hold that Cretaceous was a flourishing period of Yingen-Ejin Benner basin evolution: there existed the combination of lacustrine facies-swamp facies sandstone and mudstone characterized by large thickness and stable horizontal spread, and Cretaceous mudstone consitituted a good regional cap of the Carboniferous-Permian petroleum system.Although multistage tectonic reworking took place after Carboniferous-Permian, tectonic stress was dominated by extruding and uplifting.In general, the extrusion and uplift didn't affect the Carboniferous-Permian petroleum system except for local areas where structural dynamometamorphism occurred.There happened four stages of magmatism, in which the Early Cretaceous magmatism was strong.Affected by this magmatism, Carboniferous-Permian strata locally experienced thermal metamorphism, and hydrocarbon source rocks reached the mature stage, but the effect range was limited.There were four sedimentary cycles during Carboniferous-Permian;as a result, there existed mud shale of large thickness and stable horizontal spread especially in Amushan and Maihanhada Formations,and the mud shale was not only a good source rock but also a good cap rock.There was a long-term uplift-erosion from Late Variscan to Indo-Chinese epoch in Carboniferous-Permian, but there existed stable spread of Carboniferous-Permian strata in Ejin Banner-Wutaohai area based on geophysical data interpretation, with the residual thickness being generally from 1000 to 2000m and the thickness of local areas being over 3000m.Information of a series of Carboniferous-Permian hydrocarbon source rocks related hydrocarbon shows indicate that there existed processes of hydrocarbon generation, migration and accumulation in Carboniferous-Permian period, which suggests good hydrocarbon prospects.%通过对中-新生代

  12. 广西田林龙江垌上石炭统黄龙组珊瑚礁古生态%Longjiangdong Coral Reef Palaeoecology of the Upper Carboniferous Huanglong Formation in Tianlin County, Guangxi Province

    Institute of Scientific and Technical Information of China (English)

    杨大勇; 巩恩普; 孙宝亮; 陈晓红; 关长庆; 张永利

    2013-01-01

    广西田林县龙江垌见晚石炭世的珊瑚格架礁,分三层旋回式生长于海百合碎屑滩上.造礁生物为丛状群体珊瑚Diphyphyllum sp.,附礁生物主要是海百合、腕足动物、藻类和有孔虫.造礁生物种群间仅是共同栖息生存,缺乏长期、稳定、复杂的生态关系,礁体生物群落成熟度低,除Diphyphyllum sp.搭建格架外,缺少其他造礁方式,在当时多变的水动力条件下,只形成了未成熟的层礁.对于龙江垌珊瑚礁生态特征形成原因归纳为以下几点:石炭纪中期全球地质构造变化影响、微生物群团和藻类造礁作用不明显、海百合的强大竞争作用使底栖生物群落受到抑制、Diphyphyllum sp.生态特点使其造礁能力差.%A Late Carboniferous coral frame reef developes in Longjiangdong village,Tianlin County,Guangxi Province.The reef basing on the crinoid fragments beach has three separate cycles.The reef-builder is the fasciculate Diphyphyllum sp.and the reef-adherers mainly are crinoids,brachiopods,some kinds of algaes and foraminifers.Reef-building communities which just commonly grow together are lack of long-term,stable,complex ecological relationships.The maturity of reef biomes is poor and other reef-building ways are absence except Diphyphyllum sp.building the frame.It is formatted only immature stratigraphic reef under polytropic hydrodynamic conditions.The reasons why the Longjiangdong coral reef express such a distinctive characteristic are summarized as the following:the impacts of global geological structure changes in the Middle Carboniferous,the effects of microfloras and algaes in reef-building are not obvious,the benthic community is suppressed by crinoids,the reef-building capacity of Diphyphyllum sp.is poor for its ecological characteristics.

  13. Geochronology- and Geochemistry of Late Carboniferous-Middle Permian I- and A-Type Granites and Gabro-Diorites in the Eastern Jimausi Massif, NE, China: Implications for a Tectonic Transition

    Science.gov (United States)

    Bi, Junhui; Ge, Wenchun

    2016-04-01

    The late Paleozoic magmatism in the Jiamusi Massif of northeast China, located in the eastern segment of the Central Asian Orogenic Belt (CAOB), was dominated by an active continental margin environment due to subduction of the paleo-oceanic plate. Nevertheless, what deep geodynamic processes controlled the late Paleozoic evolution of the Jiamusi Massif are still poorly constrained. In this contribution, we present zircon U-Pb ages and geochemical data of late Carboniferous-middle Permian magmatism in the Jiamusi Massif, aiming to provide constraints on the question. Precise LA-ICP-MS U-Pb zircon ages indicate that the granitoids and gabbro-diorites were emplaced in the late Carboniferous-middle Permian (302-267 Ma). The granites belong to a high-potassium calc-alkaline series, are weakly peraluminous I- and A-type granites, and show high SiO2 and K2O contents; they are depleted in high field strength elements (HFSEs), enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), show weakly to mildly fractionated REE patterns, and on spidergrams show arc-type affinities with strong depletions in Nb, Ta, and Ti. The combination of heterogeneous values of ɛHf(t) for magmatic zircons in all granitoids (ranging from +7.9 to -5.6) and two-stage Hf model ages (TDM2) of 0.8-1.7 Ga suggests that the granites originated from partial melting of a predominantly "old" Meso-Neoproterozoic crustal source. The gabbro-diorites of the Longtouqiao pluton are depleted in Nb, Ta, P, and Ti, and show flat distributions of most LILEs and HFSEs, except for marked large positive anomalies in Ba, K, and Pb. These features reflect limited degrees of crustal contamination associated with subduction-related magma processes. These data, together with previously reported data and the occurrence of arc magmatic rocks along the eastern part of the Jiamusi Massif, suggest that the intrusive rocks formed during westward subduction of the Paleo-Pacific Ocean lithosphere

  14. Tectonic transition from Late Carboniferous subduction to Early Permian post-collisional extension in the Eastern Tianshan, NW China: Insights from geochronology and geochemistry of mafic-intermediate intrusions

    Science.gov (United States)

    Zhang, Xiaoran; Zhao, Guochun; Eizenhöfer, Paul R.; Sun, Min; Han, Yigui; Hou, Wenzhu; Liu, Dongxing; Wang, Bo; Liu, Qian; Xu, Bing; Zhu, Chloe Yanlin

    2016-07-01

    The closure of the Junggar Ocean between the Central Tianshan and Junggar terranes is essential in understanding the final assembly of the southern Central Asian Orogenic Belt. This study presents new whole-rock geochemical, Sr-Nd and zircon U-Pb-Hf isotopic data for mafic-intermediate intrusions from the Central Tianshan block to provide robust constraints on the final closure of the ocean. LA-ICP-MS U-Pb dating on magmatic-type zircons yields weighted mean 206Pb/238U ages of ca. 310 Ma and ca. 290 Ma, which are interpreted as the crystallization ages of the intrusions. Petrographic and geochemical analyses of the Late Carboniferous mafic-intermediate rocks, characterized by typical subduction-related signatures, low Sm/Yb (probably as a result of the southward subduction of the Junggar oceanic plate. In contrast, the Early Permian mafic magmatism exhibits typical within-plate basalt affinities, such as high TiO2 (2.7-3.2 wt.%) contents, elevated Ti/V (86.0-115.1) and Zr/Y (4.9-9.3) ratios, OIB-like trace element patterns and high εNd(t) (+ 1.1 to + 4.5) and zircon εHf(t) (+ 3.0 to + 9.8) values. In association with previous investigations, we suggest that their protoliths were most probably derived from the partial melting of an asthenospheric mantle source in the garnet stability field, plausibly induced by asthenosphere upwelling during the slab break-off of the Junggar oceanic plate, which agrees well with the linear distributions of Permian mafic-ultramafic rocks in the Eastern Tianshan. Collectively, our data pinpoint a tectonic transition from oceanic subduction to post-collisional extension during Late Carboniferous to Early Permian time, probably triggered by the closure of the Junggar Ocean and subsequent arc-continent collision between the Central Tianshan and Junggar terranes that gave rise to the final assembly of the Eastern Tianshan.

  15. A discussion on discordant whole rock Rb/Sr and fine fraction K-Ar dates from Trinity Peninsula group at Botany Bay, West Antarctica

    International Nuclear Information System (INIS)

    The term Trinity Peninsula Series (Adie, 1957) has been applied to a variety of deformed sedimentary rocks throughout the Antarctic Peninsula area. Different authors have carried out several studies (Croft, 1947, Bibby, 1965, Hyden and Tanner, 1981 and others). It has been considered as a flysch-like turbidite and greywacke sequence accumulated in a subduction-related accretionary prism. Hyden and Tanner (1981) re-examined the Trinity Peninsula Group (TPG) in the type area and divided it into the Hope Bay, View Point and Legoupil Formations. The TPG was assigned from the Carboniferous to the Triassic on the basis of geochronological and geological studies (Herve 1992; Loske and Miller, 1991; Trouw et al., 1995). Miller and Loske (1992), consider that the depositional age of the TPG is not older than late Carboniferous and Trouw et al. (1995) have obtained Triassic Rb-Sr ages for the north-west of Antarctic Peninsula in associated sequences. The aim of this work is to discuss the discordant dates obtained from two different geochronological methods, with a comparison between K-Ar dating on fine fractions (used successfully by other authors as Clauer, 1981; Bonhomme, 1982 and Kralik, 1983 to determine the age of the low grade metamorphic events) and Rb/Sr whole rock dating, which also has been used with the same purpose (author)

  16. Integrated Groups and Smooth Distribution Groups

    Institute of Scientific and Technical Information of China (English)

    Pedro J. MIANA

    2007-01-01

    In this paper, we prove directly that α-times integrated groups define algebra homo-morphisms. We also give a theorem of equivalence between smooth distribution groups and α-times integrated groups.

  17. 贵州省石炭纪早期古土壤的发现及其意义%The Discovery and Its Significance of Early CarboniferousPaleosols in Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    汤顺林; 冯新斌

    2001-01-01

    古土壤蕴涵着古老时期的大气氧、二氧化碳以及生态植被的演化信息,利用有效的手段提取这些信息并据此推测古气候环境。在贵州省的遵义苟江、道真县、正安县等地发现了保存完好的石炭纪早期的古土壤剖面,为恢复该地质时期云贵高原的大气氧演化、二氧化碳浓度与生态植被提供了天然的现场条件。%Paleosols (fossil soil) contained lots of the evolution information over geologic time scales, such as past oxygen, carbon dioxide, ecological plant. Paleo-environmental information could be speculated by using effective methods. The paleosols sections found in Goujiang of Zunyi county, Zhenan county and Daozheng county in Guizhou province provided condition to recover the past air oxygen, carbon dioxide, ecological plant in Early Carboniferous.

  18. Reservoir characteristics and diagenetic evolution of the carbonatite of Carboniferous System in the west part of Sunan area%苏南西部石炭系碳酸盐岩成岩演化与储集特征

    Institute of Scientific and Technical Information of China (English)

    戴祉平

    2012-01-01

    In the west part of Sunan area, there was a well developed stratum of carbonatite of Carboniferous System, which was the deposition of the supralittoral and subtidal zones in the muhi - beach (island) Epicontinental Sea ( plat- form) ,and the formations were complete. On the basis of the sedimentary characteristic of the rock,the lithofacies were classified into 10 kinds. The diagenesis was utilized to analyze the evolution of pore. And based on the research of the res- ervoir characteristic, the potential reservoir of carbonatite was forecasted.%苏南西部地区石炭系广泛发育有一套多滩(岛)浅陆表海(台地)潮上带至潮下带沉积的碳酸盐岩,层位齐全。根据岩石的沉积特征,划分为十种岩相。结合岩石成岩作用探讨了孔隙演化,并在现今储集特征分析的基础上,进行了潜在储层预测。

  19. U/Pb age of a large dacitic block locked in an Early Carboniferous synorogenic mélange in the Parautochthon of NW Iberia: New insights on the structure/sedimentation Variscan interplay

    Science.gov (United States)

    González Clavijo, Emilio; Dias da Silva, Ícaro Fróis; Gutiérrez-Alonso, Gabriel; Díez Montes, Alejandro

    2016-06-01

    At the NW of the Iberian Variscan Massif the Parautochthon is envisaged as an intervening structural unit located between the far-traveled allochthonous stacked units and the autochthon. It has been recently divided in two structural slices; the Upper constitutes a repetition of the upper Cambrian to Silurian sequence of the Central Iberian Zone autochthon, while the Lower has been proposed as a thick Variscan synorogenic deposit. A large volcanic block embedded in the uppermost Devonian-lower Carboniferous Lower Parautochthon yields an U/Pb age of 497 ± 2 Ma (upper Cambrian). This age, joined to the petrographic features and the chemical composition, supports the provenance area for the large glided block in the Upper Parautochthon, where a magmatic event of similar age and characteristics has been identified. This source area for the slid block reinforces the idea of a mélange developed in the synorogenic trough at the front of a main thrust structure, which over thrusts the Upper Parautochthon on top of the Lower Parautochthon.

  20. Which finite simple groups are unit groups?

    DEFF Research Database (Denmark)

    Davis, Christopher James; Occhipinti, Tommy

    2014-01-01

    We prove that if G is a finite simple group which is the unit group of a ring, then G is isomorphic to either (a) a cyclic group of order 2; (b) a cyclic group of prime order 2^k −1 for some k; or (c) a projective special linear group PSLn(F2) for some n ≥ 3. Moreover, these groups do all occur as...... unit groups. We deduce this classification from a more general result, which holds for groups G with no non-trivial normal 2-subgroup....

  1. Group Composition, Group Interaction and Achievement in Cooperative Small Groups.

    Science.gov (United States)

    Webb, Noreen M.

    This study investigated interaction and achievement in cooperative small groups in four junior high school mathematics classrooms. Ninety-six students learned a one-week unit on consumer mathematics in mixed-ability or uniform-ability groups. Students in mixed-ability groups scored higher on a problem-solving test than students in uniform-ability…

  2. Group Work Publication-1991.

    Science.gov (United States)

    Zimpfer, David G.

    1992-01-01

    Lists 21 new publications in group work, of which 9 are reviewed. Those discussed include publications on group counseling and psychotherapy, structured groups, support groups, psychodrama, and social group work. (Author/NB)

  3. Group dynamic processes in email groups

    OpenAIRE

    Alpay, Esat

    2005-01-01

    Abstract Discussion is given on the relevance of group dynamic processes in promoting decision-making in email discussion groups. General theories on social facilitation and social loafing are considered in the context of email groups, as well as the applicability of psychodynamic and interaction-based models. It is argued that such theories may indeed provide insight into email group interactions, but that...

  4. Group Cohesion in Experiential Growth Groups

    Science.gov (United States)

    Steen, Sam; Vasserman-Stokes, Elaina; Vannatta, Rachel

    2014-01-01

    This article explores the effect of web-based journaling on changes in group cohesion within experiential growth groups. Master's students were divided into 2 groups. Both used a web-based platform to journal after each session; however, only 1 of the groups was able to read each other's journals. Quantitative data collected before and…

  5. Probability groups as orbits of groups

    International Nuclear Information System (INIS)

    The set of double cosets of a group with respect to a subgroup and the set of orbits of a group with respect to a group of automorphisms have structures which can be studied as multigroups, hypergroups or Pasch geometries. When the subgroup or the group of automorphisms are finite, the multivalued products can be provided with some weightages forming so-called Probability Groups. It is shown in this paper that some abstract probability groups can be realized as orbit spaces of groups. (author)

  6. Group theories: relevance to group safety studies.

    Science.gov (United States)

    Benevento, A L

    1998-01-01

    Promoting safety in the workplace has been attempted in a variety of ways. Increasingly, industries are using groups such as safety teams and quality circles to promote worker safety. Group influences on individual behavior and attitudes have long been studied in the social psychology literature, but the theories have not been commonly found outside the psychology arena. This paper describes the group theories of group polarization, risky shift, social loafing, groupthink and team think and attempts to apply these theories to existing studies that examine work group influences on safety. Interesting parallels were found but only one study examined group influences as their primary focus of research. Since groups are increasingly used for safety promotion, future research on safety that studies group influences with respect to current group theories is recommended. PMID:24441299

  7. 黔南晚石炭世生物礁群落中的生态关系研究%Ecological Interactions among the Late Carboniferous Reef Communities in Southern Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    常洪伦; 巩恩普; 陈晓红; 杨大勇; 关长庆; 张永利; 韩炜忠

    2011-01-01

    黔南紫云地区发育了全球罕见的晚石炭世后生动物格架礁.主要的造礁生物--Formitchevella,Ivanovia cf.manchurica、叶状藻和"未名造礁生物"与附礁生物一起各自构成了不同的造礁生物群落,群落内部的生物存在着空间竞争和共栖,而群落之间还有替代的关系.种内竞争使Formitchevella个体不断生长,且有时为避免与相邻个体的空间竞争而发生弯曲.在种间竞争方面,"未名造礁生物"以缠绕和接触的方式与Ivanovia cf.manchurica之间存在着直接主动的空间竞争;Formitchevella与Ivanovia cf.manchurica则保持着均势的相持平衡型竞争;叶状藻还可以以个体数量的优势在空间竞争上压倒了珊瑚.叶状藻与腕足类之间为一类特殊的共栖关系,二者互惠互利,在生存空间上存在一定的竞争.在扁平村珊瑚礁的形成过程中,Formitchevella群落与其下部群落的更替为建造晚石炭世大型珊瑚礁奠定了条件.%The Late Carboniferous metazoan framework reefs are unusually well developed in Ziyun region, southern Guizhou Province, China, even in a global perspective. The main reef-building organisms include Formitchevella, Ivanovia cf. manchurica, phylloid algae, and "unnamed reef-building organisms", and along with other inhabitants they constitute different reef communities. Within a given community, the organisms compete for space while maintaining symbiosis. In addition, ecological replacement also occurs among the different communities. Intraspecies competition drives Formitchevella skeleton to grow continuously, and sometimes the skeleton may be curled to avoid the spatial competition with the neighbors. As for interspecies competition, the "unnamed reef-building organisms" and Ivanovia cf. manchurica maintain an active and direct spatial competition through enwinding and contacting each other. Formitchevella and Ivanovia cf. manchurica keep a balanced competition and reach a competitive

  8. Interagency mechanical operations group numerical systems group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This report consists of the minutes of the May 20-21, 1971 meeting of the Interagency Mechanical Operations Group (IMOG) Numerical Systems Group. This group looks at issues related to numerical control in the machining industry. Items discussed related to the use of CAD and CAM, EIA standards, data links, and numerical control.

  9. Group Dynamic Processes in Email Groups

    Science.gov (United States)

    Alpay, Esat

    2005-01-01

    Discussion is given on the relevance of group dynamic processes in promoting decision-making in email discussion groups. General theories on social facilitation and social loafing are considered in the context of email groups, as well as the applicability of psychodynamic and interaction-based models. It is argued that such theories may indeed…

  10. AREVA group overview; Presentation du groupe AREVA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-08

    This document presents the Group Areva, a world nuclear industry leader, from a financial holding company to an industrial group, operating in two businesses: the nuclear energy and the components. The structure and the market of the group are discussed, as the financial assets. (A.L.B.)

  11. 黔南晚石炭世旋回珊瑚礁群落演化研究%Research on community evolution of cycling coral reef of Late-Carboniferous in Southern Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    常洪伦; 宋晓东; 王艳敏

    2012-01-01

    Bianping-Yanbanzhai Carboniferous cycling reef in Southern Guizhou Province is composed of 3 cycles,in which the amount and the diversity of the organisms are both high.According to the abundance and features of the organisms,phylloid algae-"the undefined tube" community,Ivanovia cf.manchurica community,Tubiphytes community and Fomitchevella community are recognized.The reef-building process could be divided into 6 stages based on the community status.Analysis shows that a high-energy condition occurs in the reef-building process and the environment change sharply during the period of the second and third cycle.%发育于黔南地区的扁坪—岩板寨晚石炭世旋回珊瑚礁由3个旋回组成,每个旋回都具有较高的生物含量和生物多样性。根据生物的丰度和功能可识别出叶状藻-"不明管状物"群落、Ivanovia cf.manchurica群落、Tubiphytes群落和Fomitchevella群落。旋回珊瑚礁的演化过程可划分为6个阶段。分析表明,礁体形成过程中曾一度出现了高能的环境,第二、三旋回经历了迅速的环境变化。

  12. Introduction to Sporadic Groups

    Directory of Open Access Journals (Sweden)

    Luis J. Boya

    2011-01-01

    Full Text Available This is an introduction to finite simple groups, in particular sporadic groups, intended for physicists. After a short review of group theory, we enumerate the 1+1+16=18 families of finite simple groups, as an introduction to the sporadic groups. These are described next, in three levels of increasing complexity, plus the six isolated ''pariah'' groups. The (old five Mathieu groups make up the first, smallest order level. The seven groups related to the Leech lattice, including the three Conway groups, constitute the second level. The third and highest level contains the Monster group M, plus seven other related groups. Next a brief mention is made of the remaining six pariah groups, thus completing the 5+7+8+6=26 sporadic groups. The review ends up with a brief discussion of a few of physical applications of finite groups in physics, including a couple of recent examples which use sporadic groups.

  13. Introduction to Sporadic Groups

    CERN Document Server

    Boya, Luis J

    2011-01-01

    This is an introduction to finite simple groups, in particular sporadic groups, intended for physicists. After a short review of group theory, we enumerate the $1+1+16=18$ families of finite simple groups, as an introduction to the sporadic groups. These are described next, in three levels of increasing complexity, plus the six isolated "pariah" groups. The (old) five Mathieu groups make up the first, smallest order level. The seven groups related to the Leech lattice, including the three Conway groups, constitute the second level. The third and highest level contains the Monster group $\\mathbb M$, plus seven other related groups. Next a brief mention is made of the remaining six pariah groups, thus completing the $5+7+8+6=26$ sporadic groups. The review ends up with a brief discussion of a few of physical applications of finite groups in physics, including a couple of recent examples which use sporadic groups.

  14. Hydrocarbons prospecting using an integrated approach of petrography, geochemistry and modeling of organic matter transformation. Analysis and reconstitution of the thermal history of the central carboniferous basins of Asturias (Spain) and of the Sabinas - Piedras Negras basin (Coahuila, Mexico); Prospection des hydrocarbures par une approche integree de petrographie, geochimie et modelisation de la transformation de la matiere organique. Analyse et reconstitution de l'histoire thermique des Bassins Carbonifere Central des Asturies (Espagne) et Sabinas - Piedras Negras (Coahuila, Mexique)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, N.

    2004-09-01

    Solid knowledge of the transformation and evolution of organic matter during hydrocarbon generation in sedimentary basins serves to improve natural gas exploration. With this geological problem in mind, the thermal influence on organic matter was analyzed in two basins containing different characteristics (age, composition of organic matter, litho-stratigraphy, depth, thickness of the layers of rock, the maturation of organic matter, etc.) in order to understand the natural processes in generating oil and natural gas. With a view to studying this geological phenomenon, this work outlines the study of the chemical and macerals composition, the coal rank and geochemical characteristics of organic matter in these two sedimentary basins for the first time: The Asturian Central Carboniferous Basin (Spain) and Sabinas - Piedras Negras Basin (Mexico). Moreover, an approach to shed light on the thermal history and evolution of organic matter through 1D modeling in the two basins is developed. The Central Carboniferous Basin in Asturias is an important coal mining area where coal types range from bituminous carbons with high content in volatile matter to anthracite. The petrographical and geochemical study in this region has shown that at the moment of oil and gas exploration, the coals correspond to an efficient expulsion of oil and have been formed in an environment of swamp with a facies rich in vitrinite, low in sulfur and ash and varying in mineral content. As regards the paleo-environmental reconstruction, the bio-markers suggest a swamp with a relatively high water table and a humid climate. The coal type, the vitrinite reflectance and the volatile matter content in the basin show a N-S trend which could be correlated to the paleo-temperatures calculated in this study. These data point to the influence of two thermal gradients in the region: A normal thermal gradient of long duration and an oblique thermal gradient of short duration due to a pluton. The evolution of

  15. The discovery of silicified wood in the Early Carboniferous strata on the northernmargin of Yili block, West Tianshan, and its significance.%西天山伊犁地块北缘早石炭世硅化木的发现及其意义

    Institute of Scientific and Technical Information of China (English)

    白建科; 李智佩; 徐学义; 茹艳娇; 李婷

    2011-01-01

    在西天山伊犁地块北缘琼阿希河谷中首次发现硅化木,对硅化木的基本特征进行了描述.根据地层中腕足、珊瑚化石的鉴定结果,将地层的时代定为早石炭世维宪期,因此该硅化木的产出层位为下石炭统阿克沙克组.硅化木产于阿克沙克组底部黑色薄层状泥岩、粉砂岩中,这套岩性组合形成于扇三角洲前缘水下分流间湾.伊犁地块北缘阿克沙克组底部扇三角洲沉积环境的确定和硅化木化石的发现说明:研究区早石炭世维宪期不是一套连续的海相沉积,而是陆相一海陆过渡相沉积,研究区所处的地理位置距离古陆地不远.这一发现对于重新认识伊犁地块早石炭世古地理和古构造格局具有重要意义.%Recently silicified wood was discovered for die first time in Qiong Axi valley on the northern margin of Yili block, West Tianshan, and its basic characteristics are described in this paper. The identification of brachiopods and corals reveals that the strata are of the Early Carboniferous Visean stage, and hence the strata that produced silicified wood should be the Lower Carboniferous Ake-shake Formation. Silicified wood was found in the black thin-bedded mudstone and siltstone formed in the subaqueous interdistribut ary estuary of the delta front The determination of fan delta fades and the discovery of silicified wood show that the study area was characterized by a continental or transitional facies sedimentation instead of a continuous marine facies sedimentation during the Early Carboniferous Visean stage. It is also proved that the ancient geographical position of the study area was not far from the old land. This new discovery is of great significance for re-understanding Early Carboniferous paleogeography and paleotectonic framework of Yili block.

  16. Free Boolean Topological Groups

    Directory of Open Access Journals (Sweden)

    Ol’ga Sipacheva

    2015-11-01

    Full Text Available Known and new results on free Boolean topological groups are collected. An account of the properties that these groups share with free or free Abelian topological groups and properties specific to free Boolean groups is given. Special emphasis is placed on the application of set-theoretic methods to the study of Boolean topological groups.

  17. Group Work: How to Use Groups Effectively

    Science.gov (United States)

    Burke, Alison

    2011-01-01

    Many students cringe and groan when told that they will need to work in a group. However, group work has been found to be good for students and good for teachers. Employers want college graduates to have developed teamwork skills. Additionally, students who participate in collaborative learning get better grades, are more satisfied with their…

  18. MSUD Family Support Group

    Science.gov (United States)

    ... Group The MSUD Family Support Group is a non-profit 501 (c)(3) organization for those with MSUD ... Family Support Group is a 501(c)(3) non-profit organization with no paid staff. Funds are needed ...

  19. Homomorphisms of quantum groups

    CERN Document Server

    Meyer, Ralf; Woronowicz, Stanisław Lech

    2010-01-01

    We introduce some equivalent notions of homomorphisms between quantum groups that behave well with respect to duality of quantum groups. Our equivalent definitions are based on bicharacters, coactions, and universal quantum groups, respectively.

  20. Redefining Cohesiveness in Groups.

    Science.gov (United States)

    Keyton, Joann; Springston, Jeff

    1990-01-01

    Attempted to replicate and extend research on work of Kelly and Duran in assessing relationship of group member perceptions of group interaction to group effectiveness. Concludes perceived similarity may not always align with perceptions of cohesiveness. (Author/ABL)

  1. 3D geological modeling technology and fracture prediction of Carboniferous gas reservoir in block W%W区块石炭系气藏三维地质建模技术及裂缝预测

    Institute of Scientific and Technical Information of China (English)

    李会娟; 肖宏跃; 张啸枫; 王博

    2014-01-01

    In the principle of multidisciplinary theory integration, by means of gas reservoir fine description, fully taking use of seis-mic, drilling, well logging, well testing and experimental analysis, and based on deposition, diagenetic studies and logging compre-hensive interpretation, 3D geological modeling was established on the gas reservoir of Carboniferous Huanglong formation in block W. Meanwhile, The 3D geological structure model, petrophysical phase model, phased properties model and 3D fracture prediction model were implemented to determine the best reservoir microfacies area of bioclastic banks, psammitic banks and grain banks, the optimal property parameter position and the development position of main fracture body. By the research, the gas reservoir was deeply understood, the potential was clarified and the exploration and development effectiveness was improved.%以多学科理论一体化为原则,以气藏精细描述为手段,充分利用地震、钻井、测井、试井及实验分析等资料,在沉积、成岩研究、测井综合解释等研究基础上,对W区块石炭系黄龙组气藏进行了三维地质建模,落实了该含气藏区块的三维地质结构模型、岩石物理相模型、相控属性模型、三维裂缝预测模型,从而确定了最有利的生屑滩、砂屑滩、粒屑滩等储集微相带位置、最佳属性参数位置和裂缝主体发育位置。通过研究深化了W区块气藏认识、弄清了气藏潜力、提高了该气藏勘探开发成效。

  2. Carboniferous Permian Stratigraphic Division of Kumubielegou Area in West Kunlun Xinjiang%新疆西昆仑库木别勒沟一带石炭-二叠系地层划分

    Institute of Scientific and Technical Information of China (English)

    高永利

    2014-01-01

    西昆仑库木别勒沟一带地层单位划分与厘定争议已久。通过1∶5万区域地质调查,在库木别勒沟一带发现一套深色浅变质含砾细碎屑岩夹碳酸盐岩及火山岩建造,沉积环境为浊流沉积。并在其下部灰岩内首次发现含珊瑚、腕足及海百合茎类化石;岩层内包含有下志留统中的大理岩砾石或块体,其形成时代要晚于下志留统。根据区域地层对比和化石,新划分为上石炭统-下二叠统喀拉塔什组(C2-P1k),另据岩石组合特征,该组自下而上划分为一段和二段两个段,这一地层单位的合理确立,为区域地质填图建立了正确的岩石地层单位,并为本区的地层划分和区域对比提供了新的依据。%The division and confirming of strata in Kumubielegou of West Kunlun is controversial for a long time. A suit of dark low-grade pebbly fine clastic rock with carbonate rock and volcano rock formation building was discovered in the Kumubielegou area using 1∶50 000 regional geologic and mineral surveying,and the sedimentary environment was turbidity deposition. Fossil with coral,brachiopods and crinoids was discovered for the first time in the lower limestone. And marble gravel or block was found in the rock of Lower Silurian,whose formation age is later than Lower Silurian. According to the regional stratigraphic correlation and fossil ,the strata in Kumubielegou was divided into the upper Carboniferous Lower Permian Aktashi form (C2-P1k). And according to the rock association characteristics,the form was divided into a segment and a two segment two segment. The reasonable establishment of the stratigraphic units,is helpful to establish the right lithostratigraphic unit for regional geological mapping,and affords a new basis for the stratigraphic division and regional correlation in this area.

  3. 广西田林县石炭纪礁内海百合生态功能分析%The Ecological Function of Crinoid in the Carboniferous Reefs in Tianlin, Guangxi

    Institute of Scientific and Technical Information of China (English)

    陈晓红; 巩恩普; 王铁晖; 关长庆; 张永利; 杨大勇; 王会敏

    2013-01-01

    本文以石炭纪的后生动物格架礁为例,从礁体生长过程和群落竞争关系的角度,对赋存于造礁生物群落中的海百合与造架珊瑚之间的关系,以及其在礁体发育过程中的作用进行详细探讨,揭示了礁生态系统内的生物因子之间的关系.研究发现:在礁体发育初期,以海百合为主的群落是造架珊瑚定殖的初始条件;在礁体的生长过程中,海百合与造架珊瑚之间存在一种受环境控制的竞争关系,两者在数量上呈现此消彼长的关系.当环境变化导致造架珊瑚死亡,礁体停止生长,海百合仍存活并不间断地为礁体提供沉积物,对已停止发育的珊瑚格架起到覆盖作用,从一定程度上保护了礁体.%In this paper,the metazoan-framing reef of Carboniferous is takeu as an example.The relationship between crinoids and frame-building corals in reef communities and the function of crinoids in reef building process are discussed according to reef growth and community ecological interactions.It demonstrated a relationship among the biological factors in reef ecosystem.It is found that the crinoids-dominating communities contribute the initialization of corals in primary stage of reef-development; while in reef-building process,an environmentcontroling competition is developed between crinoids and frame-building corals,which leads to an increase in one and a decrease in the other in biomass.Environmental changes resulted in the death of corals and the break of reef growth,leaving only crinoids,and competition disappeared.The crinoids provided bioclasts for the reef continually,which covered the coral reef framework and protected the reef to some degree.

  4. Early Carboniferous (Viséan) emplacement of the collisional Kłodzko-Złoty Stok granitoids (Sudetes, SW Poland): constraints from geochemical data and zircon U-Pb ages

    Science.gov (United States)

    Mikulski, Stanisław Z.; Williams, Ian S.; Bagiński, Bogusław

    2013-06-01

    Sensitive high-resolution ion microprobe zircon U-Pb dating and geochemical data of igneous rocks from the composite Kłodzko-Złoty Stok (KZS) Granite Pluton, Sudetic Block, indicate that the granitoids represent an Early Carboniferous Viséan phase of Variscan metaluminous, high-K, I-type, syn-collisional granite magmatism within the Saxothuringian Zone of the Central European Variscides. Igneous zircon records hypabyssal magmatism that produced various granitoids and lamprophyre (spessartite) emplaced from ca. 340 to 331 Ma. The KZS granitoids have compositions ranging from granodiorite to monzonite, low A/CNK ratios (origin with high-K material from partly melted continental crust was probably a more important factor than fractional crystallization, in controlling the evolution of the magmas. The mean Pb-U ages of the main population of igneous zircon from a quartz monzodiorite (Żelazno) and hornblende monzonite (Droszków) are 340.2 ± 2.5 Ma and 339.5 ± 3.1 Ma, respectively. A slightly younger biotite-hornblende granodiorite from Chwalisław, 336.7 ± 2.5 Ma, was cut by a spessartite dyke at 333.1 ± 3.1 Ma. This indicates that mafic magmas were immediately intruded into fractured, probably incompletely solidified, granodiorites. The lamprophyric dyke also contains igneous zircon of Neoproterozoic age, 566.3 ± 6.4 Ma, typical of the crust in the Saxothuringian Zone. Tonalite from Ptasznik Hill near Droszków is of similar age to the spessartite, 331.5 ± 2.6 Ma. High REE contents in the tonalite and its igneous zircon indicate advanced differentiation of granitic magma, producing a more leucocratic melt associated with post-magmatic activity including abundant late crosscutting pegmatites and quartz veins, and contact metasomatic mineralization. The KZS granitoids have rather similar petrographic and geochemical characteristics to granitoids from other parts of the Central European Variscides, where a thickened orogenic root caused a substantial rise in

  5. Ordered groups and infinite permutation groups

    CERN Document Server

    1996-01-01

    The subjects of ordered groups and of infinite permutation groups have long en­ joyed a symbiotic relationship. Although the two subjects come from very different sources, they have in certain ways come together, and each has derived considerable benefit from the other. My own personal contact with this interaction began in 1961. I had done Ph. D. work on sequence convergence in totally ordered groups under the direction of Paul Conrad. In the process, I had encountered "pseudo-convergent" sequences in an ordered group G, which are like Cauchy sequences, except that the differences be­ tween terms of large index approach not 0 but a convex subgroup G of G. If G is normal, then such sequences are conveniently described as Cauchy sequences in the quotient ordered group GIG. If G is not normal, of course GIG has no group structure, though it is still a totally ordered set. The best that can be said is that the elements of G permute GIG in an order-preserving fashion. In independent investigations around that t...

  6. Assertive Training in Groups

    Science.gov (United States)

    Sansbury, David L.

    1974-01-01

    This article describes a group approach to helping the nonassertive client. After describing the group composition and goals, he presents a session by session description for conducting the assertive training group. In addition, he presents suggestions based on experiences in leading the group. (Author)

  7. Formación Ciénaga Larga del Tontal: nomen novum para la Formación Casa de Piedra, Carbonífero, Precordillera de San Juan The Ciénaga Larga del Tontal Formation: nomen novum for the Casa de Piedra Formation, Carboniferous, Precordillera de San Juan

    Directory of Open Access Journals (Sweden)

    S. Barredo

    2003-06-01

    Full Text Available En el faldeo occidental de la sierra del Tontal y al este de la región de Rincón Blanco, Precordillera de San Juan, afloran sedimentitas de edad carbonífera originalmente denominadas Formación Casa de Piedra. Este nombre no es válido pues ha sido utilizado previamente en otra unidad de edad triásica. Se propone entonces para estas rocas el nombre de Formación Ciénaga Larga del Tontal, nomen novum. Estudios palinológicos, junto con el mapeo detallado y el análisis estructural de esta unidad han permitido corroborar parcialmente la edad y establecer con claridad la extensión areal de los afloramientos.A series of Carboniferous sedimentary rocks, initially named Casa de Piedra Formation crop out along the western slope of Sierra del Tontal, east of the Rincón Blanco area. That name is invalid because it was formerly used to identify a Triassic unit. We propose here to rename this Carboniferous rocks as Ciénaga Larga del Tontal Formation, nomem novum Palynological studies, together with a detailed mapping and structural analysis of the sedimentary succession permit confirmation, in part, the age of the sequence, and establish the areal extent of its development.

  8. Robust Group Linkage

    OpenAIRE

    Li, Pei; Dong, Xin Luna; Guo, Songtao; Maurino, Andrea; Srivastava, Divesh

    2015-01-01

    We study the problem of group linkage: linking records that refer to entities in the same group. Applications for group linkage include finding businesses in the same chain, finding conference attendees from the same affiliation, finding players from the same team, etc. Group linkage faces challenges not present for traditional record linkage. First, although different members in the same group can share some similar global values of an attribute, they represent different entities so can also...

  9. 东天山觉罗塔格地区石炭纪火山-沉积岩地层序列及地质时代%Stratigraphical Sequence of Carboniferous Marine Volcanic-Deposit Rock and Its Geological Age in Jueluotage Area, Eastern Tianshan

    Institute of Scientific and Technical Information of China (English)

    张雄华; 黄兴; 陈继平; 廖群安; 段先锋

    2012-01-01

    通过对东天山觉罗塔格地区路白山、夹白山及雅满苏一带石炭纪生物地层及年代地层研究,厘定了石炭系地层序列,划分出了(筵)带、四射珊瑚及腕足类化石组合,确定雅满苏组下段、中段地质时代为早石炭亚纪大塘世旧司期-上司期,上段时代为大塘世德坞期,与海相火山岩型铁矿有关的火山岩层位多为大塘世旧司期.根据古生物化石组合确定了底坎尔组地质时代为晚石炭亚纪威宁世罗苏期,土古土布拉克组时代为威宁世滑石板期,与火山岩型铁矿有关的火山岩层位为威宁世滑石板期.此外,通过区域岩石地层对比及地层时代研究,认为前人在雅满苏组之下所划分的小热泉子组在区域上可出现在雅满苏组的中下部,层位极不稳定,应予废弃.在上述年代地层序列的研究基础上,最后对觉罗塔格地区石炭纪大地构造背景演化进行了讨论.%By the study on the Carboniferous biostratigraphy and geological age in Lubaishan, Jiabaishan and Yamansu areas in Jueluotage, the Carboniferous sequence is revised, and the fusulinid zone, coral assemblages and brachiopod assemblages are divided. It is suggested that the geological age of Lower and Middle member of Yamansu Formation is Jiusian-Shangsian in the Early Carboniferous; while the Upper member is Dewuan, and the strata of volcanic deposit which is correlated with the marine volcanic type iron is Jiusiaa What's more, these fossil assemblages indicate that the age of Dikanr Formation is Luosuan in the Late Carboniferous, and the age of Tugutu Bulak Formation is Huashibanian, volcanics horizon here was forming in Huashiba-nian. Besides, this paper suggests that the Xiaorequanzi Formation should be abandoned since this formation can belong to the Middle-Lower part of Yamansu Formation in this area. The geotectonic background of Carboniferous is also discussed in this paper.

  10. Groups as Graphs

    CERN Document Server

    Kandasamy, W B Vasantha

    2009-01-01

    For the first time we represent every finite group in the form of a graph in this book. The authors choose to call these graphs as identity graph, since the main role in obtaining the graph is played by the identity element of the group. This study is innovative because through this description one can immediately look at the graph and say the number of elements in the group G which are self-inversed. Also study of different properties, like the subgroups of a group, normal subgroups of a group, p-sylow subgroups of a group and conjugate elements of a group are carried out using the identity graph of the group in this book. This book has four chapters. The first chapter is introductory. The second chapter represents groups as graphs. In the third chapter, we have defined similar types of graphs for algebraic structures like commutative semigroups, loops, commutative groupoids and commutative rings. The final chapter poses 52 problems.

  11. Higher arithmetic Chow groups

    CERN Document Server

    Gil, J I Burgos

    2009-01-01

    We give a new construction of higher arithmetic Chow groups for quasi-projective arithmetic varieties over a field. Our definition agrees with the higher arithmetic Chow groups defined by Goncharov for projective arithmetic varieties over a field. These groups are the analogue, in the Arakelov context, of the higher algebraic Chow groups defined by Bloch. The degree zero group agrees with the arithmetic Chow groups of Burgos. Our new construction is shown to be a contravariant functor and is endowed with a product structure, which is commutative and associative.

  12. Group B streptococcus - pregnancy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000511.htm Group B streptococcus - pregnancy To use the sharing features on this page, please enable JavaScript. Group B streptococcus (GBS) is a type of bacteria that ...

  13. Fast Overlapping Group Lasso

    CERN Document Server

    Liu, Jun

    2010-01-01

    The group Lasso is an extension of the Lasso for feature selection on (predefined) non-overlapping groups of features. The non-overlapping group structure limits its applicability in practice. There have been several recent attempts to study a more general formulation, where groups of features are given, potentially with overlaps between the groups. The resulting optimization is, however, much more challenging to solve due to the group overlaps. In this paper, we consider the efficient optimization of the overlapping group Lasso penalized problem. We reveal several key properties of the proximal operator associated with the overlapping group Lasso, and compute the proximal operator by solving the smooth and convex dual problem, which allows the use of the gradient descent type of algorithms for the optimization. We have performed empirical evaluations using the breast cancer gene expression data set, which consists of 8,141 genes organized into (overlapping) gene sets. Experimental results demonstrate the eff...

  14. Gestalt Interactional Groups

    Science.gov (United States)

    Harman, Robert L.; Franklin, Richard W.

    1975-01-01

    Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups interactionally. Interactions described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)

  15. Group Wage Curves

    OpenAIRE

    Bartik, Timothy J.

    2000-01-01

    Using panel data on U.S. MSAs, this paper estimates how a typical MSA's wages of different demographic groups, and prices, are affected by overall MSA unemployment, the distribution of unemployment among different groups, and national prices and wages. MSA unemployment has strong effects on MSA wages and prices, but the distribution of unemployment among different groups has weak effects on wages and prices. Using these estimates, simulations show that targeting high-unemployment groups for u...

  16. Introduction to quantum groups

    OpenAIRE

    Podles, P.; Muller, E.

    1997-01-01

    We give an elementary introduction to the theory of algebraic and topological quantum groups (in the spirit of S. L. Woronowicz). In particular, we recall the basic facts from Hopf (*-) algebra theory, theory of compact (matrix) quantum groups and the theory of their actions on compact quantum spaces. We also provide the most important examples, including the classification of quantum SL(2)-groups, their real forms and quantum spheres. We also consider quantum SL_q(N)-groups and quantum Loren...

  17. Multicultural group work

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2014-01-01

    Motivation for the activity I use this strategy for forming groups to ensure diverse/multicultural groups that combine a variety of different strengths and resources based on student's academic, disciplinary, linguistic, national, personal and work backgrounds.......Motivation for the activity I use this strategy for forming groups to ensure diverse/multicultural groups that combine a variety of different strengths and resources based on student's academic, disciplinary, linguistic, national, personal and work backgrounds....

  18. Higher arithmetic Chow groups

    DEFF Research Database (Denmark)

    Gil, J. I. Burgos; Feliu, Elisenda

    2012-01-01

    We give a new construction of higher arithmetic Chow groups for quasi-projective arithmetic varieties over a field. Our definition agrees with the higher arithmetic Chow groups defined by Goncharov for projective arithmetic varieties over a field. These groups are the analogue, in the Arakelov co...... and is endowed with a product structure, which is commutative and associative....

  19. CHAOTIC GROUP ACTIONS

    Institute of Scientific and Technical Information of China (English)

    ShiEnhui; ZhouLizhen; ZhouYoucheng

    2003-01-01

    It is proved that there is no chaotic group actions on any topological space with free arc.In this paper the chaotic actions of the group like G×F,where F is a finite group,are studied.In particular,under a suitable assumption ,if F is a cyclic group,then the topological space which admits a chaotic action of Z×F must admit a chatotic homeomorphism.A topological space which admits a chaotic group action but admits no chaotic horneomorphism is constructed.

  20. Group theory I essentials

    CERN Document Server

    Milewski, Emil G

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Group Theory I includes sets and mapping, groupoids and semi-groups, groups, isomorphisms and homomorphisms, cyclic groups, the Sylow theorems, and finite p-groups.

  1. Splittings of knot groups

    OpenAIRE

    Friedl, Stefan; Silver, Daniel S.; Williams, Susan G.

    2013-01-01

    Let K be a knot of genus g. If K is fibered, then it is well known that the knot group pi(K) splits only over a free group of rank 2g. We show that if K is not fibered, then pi(K) splits over non-free groups of arbitrarily large rank. Furthermore, if K is not fibered, then pi(K) splits over every free group of rank at least 2g. However, pi(K) cannot split over a group of rank less than 2g. The last statement is proved using the recent results of Agol, Przytycki-Wise and Wise.

  2. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  3. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, ML); Watkins, Ronnie Wade (Cypress, TX)

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  4. On -nilpotent abelian groups

    Indian Academy of Sciences (India)

    Mohammad Mehdi Nasrabadi; Ali Gholamian

    2014-11-01

    Let be a group and $A = \\text{Aut}(G)$ be the group of automorphisms of . Then, the element $[g, ] = g^{-1}(g)$ is an autocommutator of $g \\in G$ and $ \\in A$. Hence, for any natural number the -th autocommutator subgroup of is defined as $K_{m}(G)=\\langle [g,_{1},\\ldots,_{m}]|g\\in G,_{1},\\ldots,_{m}\\in A\\rangle$, where $[g, _{1}, _{2},\\ldots, _{m}] = [[g,_{1},\\ldots,_{m−1}], _{m}]$. In this paper, we introduce the new notion of -nilpotent groups and classify all abelian groups which are -nilpotent groups.

  5. Toleration, Groups, and Multiculturalism

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2014-01-01

    to the political and social relationship between the subject and the objects of toleration. Finally, toleration is often argued to be a normative requirement on the basis of the way it affects the object or receiver of toleration, e.g. on the basis of the good of or right to freedom from non-interference which....... The chapter relates the different possible meanings of groups toleration to widespread criticisms of multiculturalism for being excessively 'groupist' (e.g. to essentialise or reify groups), to promote group rights over individual rights, or to deny or ignore the internal heterogeneity of groups...... or the multiple identity affiliations of individuals. The chapter suggests that some of these standard criticisms of multiculturalism for being overly tolerant of minority groups, or being so in a way elevating groups over individuals, are less pressing on some understandings of the meaning of 'group...

  6. E-groups training

    CERN Multimedia

    HR Department

    2012-01-01

    There will be an e-groups training course on 16 March 2012 which will cover the main e-groups functionalities i.e.: creating and managing e-groups, difference between static and dynamic e-groups, configuring posting restrictions and archives, examples of where e-groups can be used in daily work. Even if you have already worked with e-groups, this may be a good opportunity to learn about the best practices and security related recommendations when using e-groups. You can find more details as well as enrolment form for the training (it’s free) here. The number of places is limited, so enrolling early is recommended.   Technical Training Tel. 72844

  7. Evolutional features and influencing factors of Carboniferous-Permian hydrocarbon source rocks in Ejin Banner and its vicinities, western Inner Mongolia%内蒙古西部额济纳旗及邻区石炭系-二叠系烃源岩演化特征及影响因素

    Institute of Scientific and Technical Information of China (English)

    魏建设; 卢进才; 魏仙样; 姜亭

    2011-01-01

    通过对额济纳旗及其邻区石炭系-二叠系烃源岩演化程度的平面展布和纵向分布特征的研究,结合对华力西中晚期-喜马拉雅期侵入岩露头分布和构造活动特征的分析,认为华力西晚期、燕山期侵入岩与构造活动对区内石炭系-二叠系烃源岩的演化程度影响较大,印支期侵入岩和构造活动仅对部分地区烃源岩成熟度有影响,喜马拉雅期构造活动对区内烃源岩演化程度无影响.区内石炭系-二叠系系阿木山组(干泉组)和下-中二叠统菊石滩组烃源岩过成熟主要受华力西晚期侵入岩和构造活动的影响,上二叠统哈尔苏海组烃源岩演化程度受燕山期侵入岩和构造活动的影响.明确了不同期次侵入岩和构造活动对石炭系-二叠系烃源岩演化程度影响的平面展布特征.综合研究认为,区内石炭系-二叠系烃源岩不存在区域变质,成熟度总体为成熟-高成熟,部分剖面(井)烃源岩演化程度较高(达到过成熟),是由侵入岩的热接触变质和构造活动的动力变质造成的.石炭系-二叠系沉积之后,岩浆活动和构造活动相对较弱的地区石炭系-二叠系烃源岩演化程度适中,为成熟-高成熟.%Based on the characteristics of planar and longitudinal distribution of the evolution degrees of Carboniferous-Permian hydrocarbon source rocks in Erin Banner and its vicinities, together with the study of the outcrop distribution of intrusive rocks of middle-late Hercynian to Himalayan period and their activity characteristics, the authors hold that the evolution degree of CarboniferousPermian hydrocarbon source rocks was mainly controlled by intrusive rocks and tectonic activity of late Hercynian and Yanshanian period. The intrusive rocks and tectonic activity of Indo-Chinese period only affected the evolution degree in several sections, and the intrusive rocks and tectonic activity of Himalayan period failed to affect the evolution degree

  8. Permo-Carboniferous Coal-bearing Property and Impacting Factor Analysis in Shuonan Mining Area,Shanxi%山西朔南矿区石炭—二叠系含煤性及影响因素分析

    Institute of Scientific and Technical Information of China (English)

    董明

    2012-01-01

    The Shuonan mining area is situated at the north end of the Ningwu coalfield. Main coal-bearing strata belong to Carboniferous Taiyuan Formation and Permian Shanxi Formation. Coal seams in the area has characteristics of large total thickness, steady hosted, and presents NE extending as a whole. Coal thickness is increasing both southward and northward. The coal-bearing property best part is in the northwest of the area, with total thickness over 30m largely, coal-bearing coefficient above 22%, maximum 34.5%; coal-bearing property in the middle is relatively poor, with total thickness 20~26m generally, coal-bearing coefficient 14%~18%. Based on thickness, coal-bearing characteristic, structural and sedimentary environmental studies of the Taiyuan and Shanxi formations, have considered that: in principle, the sedimentary system in the area has experienced an evolution of lagoon-delta - deltaic distributary channel, interdistributory bay-inland alluvial plain. Lateral and vertical variations of coal seam thicknesses are tally with sedimentary facies zone extending directions; coal-rich zone is situated on the fossil clinoform zone in northwest of the area. It has demonstrated that the coal-bearing property is controlled by paleostructure and paleogeography; the paleogeographic setting of coal thick zone should have long term stability.%朔南矿区位于宁武煤田北端,主要含煤地层为石炭系太原组和二叠系山西组,区内煤层总厚度大、赋存稳定,总体呈北东方向展布,厚度自中部向南北两侧加厚,含煤性最好的部位位于本区西北部,煤层总厚多在30m以上,含煤系数在22%以上,最高达34.5%,中部含煤性较差,煤层总厚度一般为20~26m,含煤系数14%~18%.根据太原组和山西组厚度、含煤性特征以及构造、沉积环境的研究,认为该区沉积体系大体经过了潟湖-三角洲-三角洲水上分流河道、分流间湾-内陆冲积平原的演变,煤层厚度在横向

  9. PRODUCTION TEST PERFORMANCE MONITOR ING OF THE CARBONIFEROUS GAS RESERVOIR IN LONGMEN FIELD IN EAST SICHUAN%川东龙门气田石炭系气藏试采动态监测及效果

    Institute of Scientific and Technical Information of China (English)

    冯万奎; 许清勇

    2000-01-01

    龙门气田石炭系气藏是一个储量较大的中型整装气藏,平面展布长24 km,宽仅1.0~2.5 km,含气面积45.1 km2,产层埋深4 600~4 800 m,带有边水,气水界面-4 420 m,含气高度仅460 m,储层非均质性较强,气藏地质和工程条件复杂。为尽快搞清其动态特征,为开发设计提供详实资料,试采中,根据气藏地质和工程特点,采用最先进的高精度电子压力计,在开井、关井条件下通过井口、井底单点或连续测试等方法,录取了大量可靠的监测资料,在不到一年的较短时间内,搞清了气藏井间动态关系以及产能、流体性质等,取得了很好的效果,这些监测方法对加快类似气田的试采工作有一定借鉴作用。%The Carboniferous gas reservoir in Longmen field is a medium-sized integral gs reservoir with a length of 24 km,widths of 1.0~2.5 km, a gas-bearing area of 45.1 km2 and payzone depths of 4 600~4 800 m. This gas reservoir is of edge water,its gas-water contact being at -4 420 m with a gas colunm height of 460 rn only. The heterageneity of the reservoir bed is serious and the gas reservoir geology and engineering con ditions are complicated. In order to detect the performance char acters of the reservoir as quickly as possible and to provid a set of detailed data for its development design, a great deal of reli able monitoring data were achieved in production test through adopting the most advanced high-accuracy electronic gauge and these methods of single-point or continuous testing at wellhead and bottomhole under open hole and shut-in well conditions in consideration of the gas reservoir geology and engineering prop erties. In a short time of less than a year, the interwell perfor mance relation,productivity and fluid properties of the reservoir were detected,a fair development effectiveness being achieved. These monitoring methods are of a certain referential signifi cance for

  10. Group Psychotherapy in Italy.

    Science.gov (United States)

    Giannone, Francesca; Giordano, Cecilia; Di Blasi, Maria

    2015-10-01

    This article describes the history and the prevailing orientations of group psychotherapy in Italy (psychoanalytically oriented, psychodrama, CBT groups) and particularly group analysis. Provided free of charge by the Italian health system, group psychotherapy is growing, but its expansion is patchy. The main pathways of Italian training in the different group psychotherapy orientations are also presented. Clinical-theoretical elaboration on self development, psychopathology related to group experiences, and the methodological attention paid to objectives and methods in different clinical groups are issues related to group therapy in Italy. Difficulties in the relationship between research and clinical practice are discussed, as well as the empirical research network that tries to bridge the gap between research and clinical work in group psychotherapy. The economic crisis in Italy has led to massive cuts in health care and to an increasing demand for some forms of psychological treatment. For these reasons, and because of its positive cost-benefit ratio, group psychotherapy is now considered an important tool in the national health care system to expand the clinical response to different forms of psychological distress. PMID:26401793

  11. Lixões inativos na região carbonífera de Santa Catarina: análise dos riscos à saúde pública e ao meio ambiente Inactive dumps in Santa Catarina´s carboniferous area: analysis of risks to the public health and the environment

    Directory of Open Access Journals (Sweden)

    Fernando Pagani Possamai

    2007-03-01

    Full Text Available A existência de lixões inativos aumenta consideravelmente o assim denominado "passivo ambiental"; tanto que a destinação final dos resíduos sólidos urbanos ocupa lugar primordial na pauta das questões ambientais das sociedades¹. No estado de Santa Catarina, pode-se afirmar que, atualmente, é formalmente desconhecido o estado real em que se encontram os "depósitos de destinação final" ou, mais simplesmente, os lixões inativos. Isto é talvez mais evidente na região carbonífera do estado, já tão sacrificada pelos impactos ambientais da mineração do carvão. Este trabalho buscou realizar um levantamento dos lixões inativos na região carbonífera de Santa Catarina, analisando os riscos que estes representam à saúde pública e ao meio ambiente. Os resultados obtidos mostram que, dos onze municípios pertencentes à região carbonífera, nove possuem lixões inativos. Nesses nove municípios, há onze lixões inativos que, segundo a presente avaliação, apresentam grande risco à saúde da população e ao meio ambiente quando considerados os parâmetros analisados.The existence of inactive dumps considerably increases the so-called "environmental liability"; so much so that the final destination of urban solid residues takes a prominent place on the list of environmental issues of societies¹. In the state of Santa Catarina, it can be said that, currently, the real conditions of the "final destination deposits", or simply the inactive dumps, is officially unknown. This is maybe most evident in the carboniferous area of the state that already suffers from the environmental impact of coal mining. This study attempts to make a survey of the inactive dumps in the carboniferous area of Santa Catarina, analysing the risks they represent to public health and to the environment. The results gathered show that, of the eleven municipal districts in the carboniferous area, nine have inactive dumps. In these nine districts, there are

  12. Blood groups systems

    Directory of Open Access Journals (Sweden)

    Ranadhir Mitra

    2014-01-01

    Full Text Available International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system.

  13. Blood groups systems.

    Science.gov (United States)

    Mitra, Ranadhir; Mishra, Nitasha; Rath, Girija Prasad

    2014-09-01

    International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system. PMID:25535412

  14. Stochastic Lie group integrators

    CERN Document Server

    Malham, Simon J A

    2007-01-01

    We present Lie group integrators for nonlinear stochastic differential equations with non-commutative vector fields whose solution evolves on a smooth finite dimensional manifold. Given a Lie group action that generates transport along the manifold, we pull back the stochastic flow on the manifold to the Lie group via the action, and subsequently pull back the flow to the corresponding Lie algebra via the exponential map. We construct an approximation to the stochastic flow in the Lie algebra via closed operations and then push back to the Lie group and then to the manifold, thus ensuring our approximation lies in the manifold. We call such schemes stochastic Munthe-Kaas methods after their deterministic counterparts. We also present stochastic Lie group integration schemes based on Castell--Gaines methods. These involve using an underlying ordinary differential integrator to approximate the flow generated by a truncated stochastic exponential Lie series. They become stochastic Lie group integrator schemes if...

  15. Blood groups systems

    OpenAIRE

    Ranadhir Mitra; Nitasha Mishra; Girija Prasad Rath

    2014-01-01

    International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importa...

  16. Group therapy for adolescents

    OpenAIRE

    Nada Hribar

    2001-01-01

    The group included adolescents from secondary school and some students. The group had weekly sessions or twice on mounth. The adolescents had varied simptoms: depressive, anxiety, psychosomatic disorders, learning difficulties, cunduct problems. All of adolescents were common on many problems in social interactions. The goal of therapeutic work were: to increase assertiveness skills and to reduce the anxious in social situations. The adolescents in group raised a self-esteem and developed som...

  17. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  18. Bayesian Group Factor Analysis

    OpenAIRE

    Virtanen, Seppo; Klami, Arto; Khan, Suleiman A; Kaski, Samuel

    2011-01-01

    We introduce a factor analysis model that summarizes the dependencies between observed variable groups, instead of dependencies between individual variables as standard factor analysis does. A group may correspond to one view of the same set of objects, one of many data sets tied by co-occurrence, or a set of alternative variables collected from statistics tables to measure one property of interest. We show that by assuming group-wise sparse factors, active in a subset of the sets, the variat...

  19. Semisimple Metacyclic Group Algebras

    Indian Academy of Sciences (India)

    Gurmeet K Bakshi; Shalini Gupta; Inder Bir S Passi

    2011-11-01

    Given a group of order $p_1p_2$, where $p_1,p_2$ are primes, and $\\mathbb{F}_q$, a finite field of order coprime to $p_1p_2$, the object of this paper is to compute a complete set of primitive central idempotents of the semisimple group algebra $\\mathbb{F}_q[G]$. As a consequence, we obtain the structure of $\\mathbb{F}_q[G]$ and its group of automorphisms.

  20. Incentives and group identity

    OpenAIRE

    MASELLA, Paolo; Meier, Stephan; Zahn, Philipp

    2012-01-01

    This paper investigates in a principal-agent environment whether and how group membership influences the effectiveness of incentives and when incentives can have “hidden costs”, i.e., a detrimental effect. We show experimentally that in all interactions control mechanisms can have hidden costs for reasons specific to group membership. In within-group interactions control has detrimental effects because the agent does not expect to be controlled and reacts negatively when being controlled. In ...

  1. Presentations of groups

    CERN Document Server

    Johnson, D L

    1997-01-01

    The aim of this book is to provide an introduction to combinatorial group theory. Any reader who has completed first courses in linear algebra, group theory and ring theory will find this book accessible. The emphasis is on computational techniques but rigorous proofs of all theorems are supplied. This new edition has been revised throughout, including new exercises and an additional chapter on proving that certain groups are infinite.

  2. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  3. CLASSIFICATION OF CRIMINAL GROUPS

    Directory of Open Access Journals (Sweden)

    Natalia Romanova

    2013-06-01

    Full Text Available New types of criminal groups are emerging in modern society.  These types have their special criminal subculture. The research objective is to develop new parameters of classification of modern criminal groups, create a new typology of criminal groups and identify some features of their subculture. Research methodology is based on the system approach that includes using the method of analysis of documentary sources (materials of a criminal case, method of conversations with themembers of the criminal group, method of testing the members of the criminal group and method of observation. As a result of the conducted research, we have created a new classification of criminal groups. The first type is a lawful group in its form and criminal according to its content (i.e., its target is criminal enrichment. The second type is a criminal organization which is run by so-called "white-collars" that "remain in the shadow". The third type is traditional criminal groups.  The fourth type is the criminal group, which openly demonstrates its criminal activity.

  4. Grouping for Inequity

    Science.gov (United States)

    Macqueen, Suzanne Elizabeth

    2013-01-01

    The inequity of streaming as a method of organising classes was established by research conducted in the 1960s and 1970s. While the practice produces small advantages for limited groups of students, it hinders the academic and social advancement of the majority. Although streaming has declined, new forms of achievement grouping have emerged, with…

  5. Kaleidoscopical configurations in groups

    Directory of Open Access Journals (Sweden)

    I. V. Protasov

    2011-11-01

    Full Text Available A subset A of a group G is called a kaleidoscopical configuration if there exists a surjective coloring χ:X→κ such that the restriction χ|gA is a bijection for each g∈G . We give two topological constructions of kaleidoscopical configurations and show that each infinite subset of an Abelian group contains an infinite kaleidoscopical configuration.

  6. Group Work. Research Brief

    Science.gov (United States)

    Walker, Karen

    2010-01-01

    According to Johnson and Johnson, group work helps increase student retention and satisfaction, develops strong oral communication and social skills, as well as higher self-esteem (University of Minnesota, n.d.). Group work, when planned and implemented deliberately and thoughtfully helps students develop cognitive and leadership skills as well as…

  7. Democratic Group Work

    Science.gov (United States)

    Laursen, Erik K.; Tate, Thomas F.

    2012-01-01

    For a century, democratic values have called for abandoning coercive approaches and teaching children and youth to be responsible citizens. The authors explore strategies for creating respectful environments and positive group cultures with challenging youth. They offer suggestions to adult group facilitators to support youth in developing…

  8. Fairness and Ability Grouping.

    Science.gov (United States)

    Strike, Kenneth A.

    1983-01-01

    A recent controversy regarding ability grouping is that it is often perceived as a means whereby racial or class bias can be subtly transformed into mechanisms of discrimination which exhibit the appearance of fairness and objectivity. This article addresses the question of fairness in ability grouping. (CJB)

  9. Small Group Inquiry.

    Science.gov (United States)

    Koller, Martin M.

    Learning in small groups is a practical way to bring about behavior change. The inquiry learning process is perceived to be the most natural and scientific way of learning. Skills developed include those of problem-solving task analysis, decision-making, value formation and adaptability. The art of small group interaction is developed. Factual…

  10. CHINA INTERNATIONAL PUBLISHING GROUP

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The China International Publishing Group (CIPG) specializes in international communications. Its operationsencompass reporting, editing, translation, publishing, printing, distribution, and the Internet. It incorporates sevenpublishing companies, five magazines and 19 periodicals, published in over 20 languages. The ChinaInternational Book Trading Corporation, another group facet, distributes all of these to over 180 countries and

  11. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  12. Group I intron ribozymes

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2012-01-01

    Group I intron ribozymes constitute one of the main classes of ribozymes and have been a particularly important model in the discovery of key concepts in RNA biology as well as in the development of new methods. Compared to other ribozyme classes, group I intron ribozymes display considerable...

  13. Natural analogue working group

    International Nuclear Information System (INIS)

    A Natural Analogue Working Group was established by the Commission of the European Communities in 1985. The purpose of this group is to bring together modellers with earth scientists and others, so that maximum benefit can be obtained from natural analogue studies with a view to safe geological disposal of radioactive waste. The first meeting of this group was held in Brussels from November 5 to 7, 1985. The discussions mainly concerned the identification of the modellers' needs and of the earth scientists' capacity to provide for them. Following the debates, a written statement was produced by the Group; this document forms the core of the present Report. Notes and outlines of many of the presentations made are grouped in four appendixes. The valuable contribution of all those involved in the meeting is gratefully acknowledged

  14. Perceiving persons and groups.

    Science.gov (United States)

    Hamilton, D L; Sherman, S J

    1996-04-01

    This article analyzes the similarities and differences in forming impressions of individuals and in developing conceptions of groups. In both cases, the perceiver develops a mental conception of the target (individual or group) on the basis of available information and uses that information to make judgments about that person or group. However, a review of existing evidence reveals differences in the outcomes of impressions formed of individual and group targets, even when those impressions are based on the very same behavioral information. A model is proposed to account for these differences. The model emphasizes the role of differing expectancies of unity and coherence in individual and group targets, which in turn engage different mechanisms for processing information and making judgments. Implications of the model are discussed.

  15. Automorphism groups of Quandles

    CERN Document Server

    Elhamdadi, M; Restrepo, R

    2010-01-01

    We prove that the automorphism group of the dihedral quandle with n elements is isomorphic to the affine group of the integers mod n, and also obtain the inner automorphism group of this quandle. In [9], automorphism groups of quandles (up to isomorphisms) of order less than or equal to 5 were given. With the help of the software Maple, we compute the inner and automorphism groups of all seventy three quandles of order six listed in the appendix of [4]. Since computations of automorphisms of quandles relates to the problem of classification of quandles, we also describe an algorithm implemented in C for computing all quandles (up to isomorphism) of order less than or equal to nine.

  16. Perceiving persons and groups.

    Science.gov (United States)

    Hamilton, D L; Sherman, S J

    1996-04-01

    This article analyzes the similarities and differences in forming impressions of individuals and in developing conceptions of groups. In both cases, the perceiver develops a mental conception of the target (individual or group) on the basis of available information and uses that information to make judgments about that person or group. However, a review of existing evidence reveals differences in the outcomes of impressions formed of individual and group targets, even when those impressions are based on the very same behavioral information. A model is proposed to account for these differences. The model emphasizes the role of differing expectancies of unity and coherence in individual and group targets, which in turn engage different mechanisms for processing information and making judgments. Implications of the model are discussed. PMID:8637962

  17. 内蒙古额尔古纳地区早石炭世红水泉组岩石学特征及物源分析①②%Analysis of Inner Mongolia Eergu'Na area in the Early Carboniferous Hongshuiquan formation lithology and source

    Institute of Scientific and Technical Information of China (English)

    张满利; 曲希玉; 刘立; 赵国祥

    2014-01-01

    Abstact:Through the nearby Red springs farm in Inner Mongolia area in the Early Carboniferous Hongshuiquan formation sandstone cathodoluminescence and sandstone skeleton analysis, studied the petrological characteristics and provenance. The results show, Inner Mongolia Eergu’Na area in the Early Carboniferous Hongshuiquan formation lithologic sandstone quartz sandstone and quartz sand with gravel; parent rock type is mainly in a high-grade metamorphic rocks, formed in the plutonic or volcano plutonic rocks; rock, a small part of quartz formed in lower (regional) metamorphic rocks; source may be derived from the stability of the through the deep strata uplift.%通过内蒙古地区红水泉农场附近早石炭世红水泉组砂岩阴极发光和砂岩骨架分析,对其岩石学特征及物源进行研究。结果显示,内蒙古额尔古纳地区早石炭世红水泉组砂岩岩性为石英砂岩和含砾石英砂岩;母岩类型主要为中-高级变质岩,少量深成岩;形成于深成岩或火山岩中,少部分石英形成于低级(区域)变质岩中;物源可能来源于稳定的克拉通内部深部地层的隆升。

  18. Cyclic Soft Groups and Their Applications on Groups

    Directory of Open Access Journals (Sweden)

    Hacı Aktaş

    2014-01-01

    Full Text Available In crisp environment the notions of order of group and cyclic group are well known due to many applications. In this paper, we introduce order of the soft groups, power of the soft sets, power of the soft groups, and cyclic soft group on a group. We also investigate the relationship between cyclic soft groups and classical groups.

  19. Critical groups - basic concepts

    International Nuclear Information System (INIS)

    The potential exposure pathways from the land application site to man are presented. It is emphasised that the critical group is not necessary the population group closest to the source. It could be the group impact by the most significant pathways(s). Only by assessing the importance of each of these pathways and then combining them can a proper choice of critical group be made. It would be wrong to select a critical group on the basis that it seems the most probable one, before the pathways have been properly assessed. A calculation in Carter (1983) suggested that for the operating mine site, the annual doses to an Aboriginal person, a service worker and a local housewife, were all about the same and were in the range 0.1 to 0.2 mSv per year. Thus it may be that for the land application area, the critical group turns out to be non-Aboriginal rather than the expected Aboriginal group. 6 refs., 3 figs

  20. Impedance group summary

    Science.gov (United States)

    Blaskiewicz, M.; Dooling, J.; Dyachkov, M.; Fedotov, A.; Gluckstern, R.; Hahn, H.; Huang, H.; Kurennoy, S.; Linnecar, T.; Shaposhnikova, E.; Stupakov, G.; Toyama, T.; Wang, J. G.; Weng, W. T.; Zhang, S. Y.; Zotter, B.

    1999-12-01

    The impedance working group was charged to reply to the following 8 questions relevant to the design of high-intensity proton machines such as the SNS or the FNAL driver. These questions were first discussed one by one in the whole group, then each ne of them assigned to one member to summarize. On the lst morning these contributions were publicly read, re-discussed and re-written where required—hence they are not the opinion of a particular person, but rather the averaged opinion of all members of the working group. (AIP)

  1. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  2. Group ring cryptography

    CERN Document Server

    Hurley, Barry

    2011-01-01

    Cryptographic systems are derived using units in group rings. Combinations of types of units in group rings give units not of any particular type. This includes cases of taking powers of units and products of such powers and adds the complexity of the {\\em discrete logarithm} problem to the system. The method enables encryption and (error-correcting) coding to be combined within one system. These group ring cryptographic systems may be combined in a neat way with existing cryptographic systems, such as RSA, and a combination has the combined strength of both systems. Examples are given.

  3. Group therapy for adolescents

    Directory of Open Access Journals (Sweden)

    Nada Hribar

    2001-03-01

    Full Text Available The group included adolescents from secondary school and some students. The group had weekly sessions or twice on mounth. The adolescents had varied simptoms: depressive, anxiety, psychosomatic disorders, learning difficulties, cunduct problems. All of adolescents were common on many problems in social interactions. The goal of therapeutic work were: to increase assertiveness skills and to reduce the anxious in social situations. The adolescents in group raised a self-esteem and developed some assertiveness skills: eye contact" and effective communication skills, persistence, refusing and requesting, giving and receiving critism, etc. The methods of work and techniques were based on principles of cognitive-behaviour therapy.

  4. Microfacies and Environment Analysis of the Carboniferous Carbonates in Jiangyou-Guangyuan Area, Sichuan Province%四川江油—广元地区上石炭统碳酸盐岩微相及其沉积环境分析

    Institute of Scientific and Technical Information of China (English)

    徐锦龙; 贾志海; 王伟; 罗雷; 李俊青

    2012-01-01

    The Jiangyou-Guangyuan area, which is located in the north margin of the Longmen Mountain Nappe Struc- tural Belts, is one of the classic areas for the upper Carboniferous researches in Sichuan Basin and even in the upper Yangtze Plate. The upper Carboniferous was deposited in semi-enclosed gulfs of the western Yangtze Block, which char- acterized by slight thickness, light color, many fossils and several fuchsia mudstone and containing gravels bioclastic limestone as a set of semi-restricted platform and open platform carbonate rocks in this area. The strata are revised ac- cording to sedimentary types, sedimentary structures, lithological characters, and paleontological combinations. The up- per Zongchanggou Formation, which was considered as one part of the lower Carboniferous, is amended to the upper Carboniferous Huanglong Formation in this paper. The upper Carboniferous is divided into four parts, as lower Huan- glong Formation, middle Huanglong Formation, upper Huanglong Formation and lower Chuanshan Formation. Fifteen microfacies can be divided according to field observation, laboratory micro-analysis and classification of car- bonate rocks by Dunham, as Unfossiliferous mudstones (MFI-1), Clastizoic mudstones (MF1-2), Calcareous green al- gae wackestones ( MF2-1 ), Bioclastic wackestones ( I~IF2-2), Birdseyes-Fenestral pelletoid packstones ( MF3 ), Bivalve wackestones (MF4-1), Bivalve packstones (MF4-2), Calcareous green algae packstones (MF5-1), Fusulinid pack- stones (MF5-2), Bioclastic wackestones with oncoids (MF5-3), Bioclastic wackestones (MF5-4), Fine- grained pe- loid grainstones (MF6), Bioclastic grainstones (MF7-1), Fusulinid grainstones (MF7-2), Worn foraminiferal grain- stones (MF7-3), Coated bioclastic grainstones (MF8), Bahamite peloids grainstones (MF9-1), Bioclastic-Bahamite peloids grainstones (MF9-2), Ooid grainstones with radial ooids( MF10-1 ), Ooid grainstones with micritizatal concen- tric ooids ( MF10-2), Lithoclasts grainstones with

  5. Homogeneous group, research, institution

    Directory of Open Access Journals (Sweden)

    Francesca Natascia Vasta

    2014-09-01

    Full Text Available The work outlines the complex connection among empiric research, therapeutic programs and host institution. It is considered the current research state in Italy. Italian research field is analyzed and critic data are outlined: lack of results regarding both the therapeutic processes and the effectiveness of eating disorders group analytic treatment. The work investigates on an eating disorders homogeneous group, led into an eating disorder outpatient service. First we present the methodological steps the research is based on including the strong connection among theory and clinical tools. Secondly clinical tools are described and the results commented. Finally, our results suggest the necessity of validating some more specifical hypothesis: verifying the relationship between clinical improvement (sense of exclusion and painful emotions reduction and specific group therapeutic processes; verifying the relationship between depressive feelings, relapses and transition trough a more differentiated groupal field.Keywords: Homogeneous group; Eating disorders; Institutional field; Therapeutic outcome

  6. Anxiety Disorders: Support Groups

    Science.gov (United States)

    ... Guidelines Scientific Council Special Interest Groups Child & Adolescent Anxiety SIG Peer Consultation OCD & Related Disorders SIG Peer ... Jobs and Fellowships Journal & Multimedia Announcements Depression and Anxiety Podcasts & Videos Resources Clinical Practice Reviews & Teaching Tools ...

  7. Homogenous finitary symmetric groups

    Directory of Open Access Journals (Sweden)

    Otto‎. ‎H‎. Kegel

    2015-03-01

    Full Text Available We characterize strictly diagonal type of embeddings of finitary symmetric groups in terms of cardinality and the characteristic. Namely, we prove the following. Let kappa be an infinite cardinal. If G=underseti=1stackrelinftybigcupG i , where G i =FSym(kappan i , (H=underseti=1stackrelinftybigcupH i , where H i =Alt(kappan i , is a group of strictly diagonal type and xi=(p 1 ,p 2 ,ldots is an infinite sequence of primes, then G is isomorphic to the homogenous finitary symmetric group FSym(kappa(xi (H is isomorphic to the homogenous alternating group Alt(kappa(xi , where n 0 =1,n i =p 1 p 2 ldotsp i .

  8. RAS Laboratory Groups

    Science.gov (United States)

    The RAS Initiative uses multiple technologies to attack RAS-driven cancers. The resources of the Frederick National Lab allocated to the RAS Hub are organized into seven laboratory groups, each contributing to the collaborative effort.

  9. Groups – Additive Notation

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  10. Radiation Protection Group

    CERN Multimedia

    2006-01-01

    The Radioactive Waste Section of the Radiation Protection Group wishes to inform you that the Radioactive Waste Treatment Centre will be closed on the afternoon of Tuesday 19 December 2006. Thank-you for your understanding.

  11. Interocular grouping without awareness.

    Science.gov (United States)

    Lin, San-Yuan; Yeh, Su-Ling

    2016-04-01

    Interocular grouping occurs when different parts of an image presented to each eye bound into a coherent whole. Previous studies anticipated that these parts are visible to both eyes simultaneously (i.e., the images altered back and forth). Although this view is consistent with the general consensus of binocular rivalry (BR) that suppressed stimuli receive no processing beyond rudimentary level (i.e., adaptation), it is actually inconsistent with studies that use continuous flash suppression (CFS). CFS is a form of interocular suppression that is more stable and causes stronger suppression of stimuli than BR. In the present study, we examined whether or not interocular grouping needs to occur at a conscious level as prior studies suggested. The modified double-rectangle paradigm used by Egly, Driver, and Rafal (1994) was adopted, and object-based attention was directed for successful grouping. To induce interocular grouping, we presented complementary parts of two rectangles dichoptically for possible interocular grouping and a dynamic Mondrian in front of one eye (i.e., CFS). Two concurrent targets were presented after one of the visible parts of the rectangles was cued. Participants were asked to judge which target appeared first. We found that the target showed on the cued rectangle after interocular grouping was reported to appear first more frequently than the target on the uncued rectangle. This result was based on the majority of trials where the suppressed parts of the objects remained invisible, which indicates that interocular grouping can occur without all the to-be-grouped parts being visible and without awareness. PMID:26851342

  12. Genomics Research Group Session

    OpenAIRE

    Baldwin, D.; Chittur, S.V.; Raghavachari, N.; N Jafari; Aquino, C.; Perera, A; Reyero, N.G.

    2014-01-01

    The Genomics Research Group (GRG) presentation is intended to describe the current activities of the group in applying the latest tools and technologies for transcriptome analysis to determine the advantages and disadvantages of each of the platforms. We will present three ongoing projects. In the first project, we specifically evaluated microarrays, QPCR and Next Generation Sequencing (NGS) platforms for examining the sensitivity and specificity of microRNA detection using synthetic miRNA st...

  13. Group Factor Analysis

    OpenAIRE

    Klami, Arto; Virtanen, Seppo; Leppäaho, Eemeli; Kaski, Samuel

    2014-01-01

    Factor analysis provides linear factors that describe relationships between individual variables of a data set. We extend this classical formulation into linear factors that describe relationships between groups of variables, where each group represents either a set of related variables or a data set. The model also naturally extends canonical correlation analysis to more than two sets, in a way that is more flexible than previous extensions. Our solution is formulated as variational inferenc...

  14. Fuzzy Soft Topological Groups

    Directory of Open Access Journals (Sweden)

    S. Nazmul

    2014-03-01

    Full Text Available Notions of Lowen type fuzzy soft topological space are introduced and some of their properties are established in the present paper. Besides this, a combined structure of a fuzzy soft topological space and a fuzzy soft group, which is termed here as fuzzy soft topological group is introduced. Homomorphic images and preimages are also examined. Finally, some definitions and results on fuzzy soft set are studied.

  15. Introduction to group theory

    Directory of Open Access Journals (Sweden)

    Canals B.

    2012-03-01

    Full Text Available This chapter is a concise mathematical introduction into the algebra of groups. It is build up in the way that definitions are followed by propositions and proofs. The concepts and the terminology introduced here will serve as a basis for the following chapters that deal with group theory in the stricter sense and its application to problems in physics. The mathematical prerequisites are at the bachelor level.1

  16. Group Capability Model

    Science.gov (United States)

    Olejarski, Michael; Appleton, Amy; Deltorchio, Stephen

    2009-01-01

    The Group Capability Model (GCM) is a software tool that allows an organization, from first line management to senior executive, to monitor and track the health (capability) of various groups in performing their contractual obligations. GCM calculates a Group Capability Index (GCI) by comparing actual head counts, certifications, and/or skills within a group. The model can also be used to simulate the effects of employee usage, training, and attrition on the GCI. A universal tool and common method was required due to the high risk of losing skills necessary to complete the Space Shuttle Program and meet the needs of the Constellation Program. During this transition from one space vehicle to another, the uncertainty among the critical skilled workforce is high and attrition has the potential to be unmanageable. GCM allows managers to establish requirements for their group in the form of head counts, certification requirements, or skills requirements. GCM then calculates a Group Capability Index (GCI), where a score of 1 indicates that the group is at the appropriate level; anything less than 1 indicates a potential for improvement. This shows the health of a group, both currently and over time. GCM accepts as input head count, certification needs, critical needs, competency needs, and competency critical needs. In addition, team members are categorized by years of experience, percentage of contribution, ex-members and their skills, availability, function, and in-work requirements. Outputs are several reports, including actual vs. required head count, actual vs. required certificates, CGI change over time (by month), and more. The program stores historical data for summary and historical reporting, which is done via an Excel spreadsheet that is color-coded to show health statistics at a glance. GCM has provided the Shuttle Ground Processing team with a quantifiable, repeatable approach to assessing and managing the skills in their organization. They now have a common

  17. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  18. Membership in citizen groups

    OpenAIRE

    Barbieri, Stefano; Mattozzi, Andrea

    2009-01-01

    We analyze the coordination problem of agents deciding to join a group that uses membership revenues to provide a discrete public good and excludable benefits. The public good and the benefits are jointly produced, so that benefits are valued only if the group succeeds in providing the public good. With asymmetric information about the cost of provision, the static membership game admits a unique equilibrium and we characterize the optimal membership fee. We show that heterogeneity in valuati...

  19. N-ary Groups

    CERN Document Server

    Gal'mak, Alexander M

    2011-01-01

    The book "N-ary Groups" (in Russian) consists of two Parts. It is intended on the one hand as an initial introduction to the theory of n-ary groups, and on the other hand it contains the published results by the author on this subject. At present, the theory of n-ary groups developing but slowly from group theory. Nonetheless, ternary and n-ary structures have recently been applied to modern models of elementary particle physics. One of the author's goals in this book is to draw the attention of mathematicians and theoretical physicists to the theory of n-ary groups, to some of its distinguishing features, and to details relevant to its further development and application. Part I: Theorems of Post and Gluskin-Hosszu. 1.1. Classical definitions of n-ary groups. Examples. 1.2. Analogies of identity and inverse elements. 1.3. Equivalent sequences. 1.4. Post's coset theorem. 1.5. Theorem of Gluskin-Hosszu. 1.6. Connection between the Post's coset theorem and theorem of Gluskin-Hosszu. Addition and comments. Part ...

  20. Coordinating Group report

    International Nuclear Information System (INIS)

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup

  1. Facilities removal working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This working group`s first objective is to identify major economic, technical, and regulatory constraints on operator practices and decisions relevant to offshore facilities removal. Then, the group will try to make recommendations as to regulatory and policy adjustments, additional research, or process improvements and/or technological advances, that may be needed to improve the efficiency and effectiveness of the removal process. The working group will focus primarily on issues dealing with Gulf of Mexico platform abandonments. In order to make the working group sessions as productive as possible, the Facilities Removal Working Group will focus on three topics that address a majority of the concerns and/or constraints relevant to facilities removal. The three areas are: (1) Explosive Severing and its Impact on Marine Life, (2) Pile and Conductor Severing, and (3) Deep Water Abandonments This paper will outline the current state of practice in the offshore industry, identifying current regulations and specific issues encountered when addressing each of the three main topics above. The intent of the paper is to highlight potential issues for panel discussion, not to provide a detailed review of all data relevant to the topic. Before each panel discussion, key speakers will review data and information to facilitate development and discussion of the main issues of each topic. Please refer to the attached agenda for the workshop format, key speakers, presentation topics, and panel participants. The goal of the panel discussions is to identify key issues for each of the three topics above. The working group will also make recommendations on how to proceed on these key issues.

  2. Sedimentary Characteristics and Evolution of the Upper Carboniferous Taiyuan Formation, Shenmu Gasfieid, Northeastern Ordos Basin%鄂尔多斯盆地神木气田太原组沉积特征与演化

    Institute of Scientific and Technical Information of China (English)

    兰朝利; 张君峰; 陶维祥; 张永忠; 杨明慧; 王金秀

    2011-01-01

    鄂尔多斯盆地东缘的神木气田太原组为特征性的碎屑岩与碳酸盐岩互层含煤岩系.近期天然气勘探证实其具有良好的开发潜力.为指导神木气田太原组开发和盆地太原组储层勘探,根据测井、录井、常规薄片、铸体薄片、物性和粒度资料,结合岩芯描述,研究了神木气田太原组地层组合、沉积特征、沉积环境演化、砂体宽度以及沉积相对储层控制作用.太原组地层发育了碎屑岩型、灰岩型和互层型3种组合.地层颜色、粒度、成分、结构、沉积构造、岩石相、测井相、含有物以及沉积序列特征反映其为潮控三角洲与低能碳酸盐台地沉积,主要发育三角洲平原分流河道、分流间洼地微相,三角洲前缘远砂坝、分流间湾微相,以及碳酸盐灰坪、灰泥坪微相.太原组下部(太二段)以三角洲平原沉积为主,分流河道砂体发育,但宽度较窄(7.1~131.9 m),上部太-段为三角洲前缘与碳酸盐潮坪沉积,反映其经历了一个沉积水体总体逐渐加深的海侵过程和/或碎屑供应逐渐减少的沉积过程,而太一段碎屑岩与灰岩的互层沉积则反映了太原组晚期沉积水体的振荡性加深→变浅和/或陆源碎屑供应的周期性缺乏.储层主要发育在太二段高能量的三角洲平原分流河道中、粗砂岩中.%The Upper Carboniferous Taiyuan Formation is a characteristic coal-bearing seam interbedded with terrigenous siliciclastic and carbonate rock in the Shenmu gasfield of northeastern Ordos basin, central China. Recent exploration shows its good potential for further gas development. To offer guidance for exploitation of Taiyuan Formation in this gas field as well as the Ordos basin, the strata assemblages,sedimentary characteristics, environment evolution, sandbody width and sedimentary facies control on reservoirs of Taiyuan Formation were investigated based on analysis of well-logging, mud-logging, routine thin

  3. Cement characteristics of the Upper Carboniferous phylloid algal reef limestone in Ziyun County, Guizhou Province%贵州紫云上石炭统叶状藻礁灰岩胶结物特征

    Institute of Scientific and Technical Information of China (English)

    孙宝亮; 巩恩普; 李金梅; 关长庆; 张永利

    2012-01-01

    贵州紫云县猴场镇扁平村的上石炭统叶状藻礁及其周边灰岩中广泛发育大量的各类胶结物.通过对胶结物的形态、结构和阴极发光特征以及胶结物间的接触关系的研究,可以确定成岩作用的先后并识别成岩环境.浅海海底同生成岩阶段大的孔隙中形成等厚环边针状胶结物、葡萄状胶结物,小的孔隙里形成微晶胶结物.早成岩阶段形成微亮晶和斑块状亮晶方解石胶结物和放射纤维扇状胶结物,表生成岩阶段的溶蚀作用和胶结作用强烈,胶结物类型有斑块状或等粒的方解石胶结物和等厚环壁柱状胶结物,等厚环壁柱状胶结物在所有胶结物中体积是较大的.早期胶结作用使叶状藻礁灰岩孔隙度大为降低.中、晚成岩阶段,孔隙被等厚环壁刃状胶结物和晶簇或斑块状亮晶方解石所充填,有些先成的胶结物被热液改造.后生作用阶段发生的主要是构造破裂作用,其中少数裂隙被红褐色含Fe2O3微晶层和晶体粉砂及渗流豆粒充填.叶状藻礁灰岩的孔隙在晚成岩阶段前或中被胶结而之后没有创造出大且连通的孔隙,是它没能成为油气储集层的原因之一.%Diagenesis and its corresponding cements are extensively developed in the upper Carboniferous phylloid algal reef and circumjacent limestone of Bianping Village, Houchang Town, Ziyun County. These cements are prominent and representative in Houchang Town. A study of crystal shape, fabric and cathodoluminescence images of cements as well as the contacts between cements can help determine paragenetic sequences, recognize dia-genetic environments, and understand the porosity evolution in the phylloid algal reef limestones. During the syndiagenetic stage, wackestone and packstone sediments generally had low porosity and permeability, pores were filled with sea-floor micrite cement, biological encrustation and sea-floor cementation sediments rich in the fragments of

  4. 贵州紫云上石炭统叶状藻礁灰岩的成岩作用%Diagenesis of the Upper Carboniferous Phylloid Algal Reef Limestone in Ziyun County,Guizhou

    Institute of Scientific and Technical Information of China (English)

    孙宝亮; 巩恩普; 李金梅; 关长庆; 张永利

    2012-01-01

    贵州紫云县猴场镇扁平村的上石炭统中的叶状藻礁及其周边灰岩中发育强烈的成岩作用和胶结物,这些胶结物在猴场研究区内是显著的和有代表性的。通过观察、分析野外露头、光片、薄片、薄片的阴极发光和染色,来研究礁体岩石的成岩作用,确定了成岩作用序列、成岩环境、成岩阶段。成岩作用类型主要有泥晶化、溶蚀、胶结、新生变形、机械压实、剪切或高温重结晶、构造破裂作用等。早成岩阶段的成岩作用有轻微压实、溶蚀作用和在礁灰岩成岩过程中发挥了至关重要的作用的胶结作用。胶结作用提供了大量的微亮晶、斑块状亮晶方解石、放射纤维扇状胶结物,构成了岩石骨架从而决定岩石的最终形态。表生成岩阶段,强烈的溶蚀作用形成大的晶洞孔隙或通道孔隙,后被潜流的等厚环壁柱状胶结物所充填。中、晚成岩阶段,接近封闭状态的孔隙被等厚环壁刃状胶结物和粗粒的等粒亮晶方解石胶结物充填,使礁灰岩孔隙度接近零;先成的胶结物被热液改造,使有机质含量和颜色发生变化而结构不变;小部分先成胶结物形成铸模后被充填。在后生作用阶段发生构造破裂作用。叶状藻礁灰岩的孔隙系统较早被充填,是其没能成为油气储集层的原因之一。在南盘江盆地内可能只有在后生作用阶段形成大且连通的孔隙的灰岩才能成为油气储集层。%The upper Carboniferous phylloid algal reef and circumjacent limestone has undergone intensive diagenesis in the Bianping Village of Houchang Town,Ziyun County,the cements,signs of the effect of the diagenesis,are prominent and representative in the region of Houchang Town.The diagenesis of phylloid algal reef limestone are studied in detail by means of rock outcrop and slab and thin section analysis and observation using polarising microscope,alizarin red and potassium ferricyanide

  5. Linear algebraic groups

    CERN Document Server

    Springer, T A

    1998-01-01

    "[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...

  6. Group Psychotherapy in Sweden.

    Science.gov (United States)

    Ahlin, Göran

    2015-10-01

    The paper presents an overview of the national developments of group psychotherapy (GPS) in Sweden during the period from World War II until the present time. Methods and concepts, imported primarily from England and the United States, inspired trainings and widespread psychodynamic and group analytic applications in schools, health treatment, and social care. Education in psychotherapy and GPS at universities opened new therapeutic and vocational areas during the period 1970-2005. Increasing criticism of psychodynamics, as in other Western societies, but more radical in Sweden, has in the last decades made group analytic GPS diminish in favor of cognitive behavioral therapy models. Prospects for GPS further development may presently look bleak but, in a longer perspective, are promising. PMID:26401795

  7. Financial Lie groups

    CERN Document Server

    carfí, David

    2011-01-01

    In this paper we see the evolution of a capitalized financial event e, with respect to a capitalization factor f, as the exponential map of a suitably defined Lie group G(f,e), supported by the half-space of capitalized financial events having the same capital sign of e. The Lie group G(f,e) depends upon the capitalization factor f and on the event e itself. After the extension of the definition of exponential map of a Lie group, we shall eliminate the dependence on the financial event e, recognizing the presence of essentially one unique financial Lie semigroup, supported by the entire space of capitalized financial events, determined by the capitalization factor f.

  8. Focus group discussions

    CERN Document Server

    Hennink, Monique M

    2014-01-01

    The Understanding Research series focuses on the process of writing up social research. The series is broken down into three categories: Understanding Statistics, Understanding Measurement, and Understanding Qualitative Research. The books provide researchers with guides to understanding, writing, and evaluating social research. Each volume demonstrates how research should be represented, including how to write up the methodology as well as the research findings. Each volume also reviews how to appropriately evaluate published research. Focus Group Discussions addresses the challenges associated with conducting and writing focus group research. It provides detailed guidance on the practical and theoretical considerations in conducting focus group discussions including: designing the discussion guide, recruiting participants, training a field team, moderating techniques and ethical considerations. Monique Hennink describes how a methodology section is read and evaluated by others, such as journal reviewers or ...

  9. Instructions to working groups

    Science.gov (United States)

    Foushee, H. Clayton

    1987-01-01

    The key to the success of this workshop is your active participation in the working group process. The goals of this workshop are to address four major questions regarding Cockpit Resource Management (CRM) Training. To some extent the working group topic areas parallel these issues, but in some cases they do not. However, it is important for all of the working groups to keep these general questions in mind during their deliberations: (1) What are the essential elements of an optimal CRM Training program; (2) What are the strengths and weaknesses of current approaches to CRM Training; (3) How can CRM Training best be implemented, and what barriers exist; and (4) Is CRM Training effective, do we know, and if not, how can we find out.

  10. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  11. Quantum threshold group signature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

  12. Colored Group Field Theory

    CERN Document Server

    Gurau, Razvan

    2009-01-01

    Group field theories are higher dimensional generalizations of matrix models. Their Feynman graphs are fat and in addition to vertices, edges and faces, they also contain higher dimensional cells, called bubbles. In this paper, we propose a new, fermionic Group Field Theory, posessing a color symmetry, and take the first steps in a systematic study of the topological properties of its graphs. Unlike its bosonic counterpart, the bubbles of the Feynman graphs of this theory are well defined and readily identified. We prove that this graphs are combinatorial cellular complexes. We define and study the cellular homology of this graphs. Furthermore we define a homotopy transformation appropriate to this graphs. Finally, the amplitude of the Feynman graphs is shown to be related to the fundamental group of the cellular complex.

  13. Group theory and chemistry

    CERN Document Server

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  14. GroupFinder

    DEFF Research Database (Denmark)

    Bøgh, Kenneth Sejdenfaden; Skovsgaard, Anders; Jensen, Christian S.

    2013-01-01

    The notion of point-of-interest (PoI) has existed since paper road maps began to include markings of useful places such as gas stations, hotels, and tourist attractions. With the introduction of geopositioned mobile devices such as smartphones and mapping services such as Google Maps, the retrieval....... Such groups are relevant to users who wish to conveniently explore several options before making a decision such as to purchase a specific product. Specifically, we demonstrate a practical proposal for finding top-k PoI groups in response to a query. We show how problem parameter settings can be mapped...

  15. Fourier Analysis on Groups

    CERN Document Server

    Rudin, Walter

    2011-01-01

    In the late 1950s, many of the more refined aspects of Fourier analysis were transferred from their original settings (the unit circle, the integers, the real line) to arbitrary locally compact abelian (LCA) groups. Rudin's book, published in 1962, was the first to give a systematic account of these developments and has come to be regarded as a classic in the field. The basic facts concerning Fourier analysis and the structure of LCA groups are proved in the opening chapters, in order to make the treatment relatively self-contained.

  16. Hierarchies in student groups

    OpenAIRE

    Güntert, Manuel

    2008-01-01

    This is a research about hierarchies in student groups. It shows how they are built und what sense they have. The position of a student in his student peer group is evaluated. The influence of the look, the style, the behaviour of the other sex, the gender, the origin, the prehistory, the appearance, achievement and their effect on hierarchies is analysed and the impact of charisma and organisation are compared. The meaning of this research is to indicate how a student must be to get the lead...

  17. Group B Streptococcus

    Directory of Open Access Journals (Sweden)

    Albert H. Adriaanse

    1995-01-01

    Full Text Available Objective: Group B streptococcus (GBS, Streptococcus agalactiae is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic performance are reported both for the newly developed rapid GBS antigen tests and Gram's stain.

  18. Teaching Badminton to Groups.

    Science.gov (United States)

    Nelson, Jonathan E.

    1980-01-01

    Numerous ideas for teaching badminton to large groups are presented. The focus is on drills and techniques for off the court instructional stations. Instead of having students waiting their turn to play, more students can participate actively as they rotate from one station to another. (JN)

  19. Abandoning wells working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  20. Supervision and group dynamics

    DEFF Research Database (Denmark)

    Hansen, Søren; Jensen, Lars Peter

    2004-01-01

    that many students are having difficulties with practical issues such as collaboration, communication, and project management. Most supervisors either ignore this demand, because they do not find it important or they find it frustrating, because they do not know, how to supervise group dynamics...

  1. With the Radiobiology Group

    CERN Multimedia

    1980-01-01

    The Radiobiology Group carries out experiments to study the effect of radiation on living cells. The photo shows the apparatus for growing broad beans which have been irradiated by 250 GeV protons. The roots are immersed in a tank of running water (CERN Weekly Bulletin 26 January 1981 and Annual Report 1980 p. 160). Karen Panman, Marilena Streit-Bianchi, Roger Paris.

  2. Cohomology of quantum groups

    CERN Document Server

    Frønsdal, Christian

    1995-01-01

    Lecture notes. Introduction to the cohomology of algebras, Lie algebras, Lie bialgebras and quantum groups. Contains a new derivation of the classification of classical r-matrices in terms of deformation cohomology, and a calculation of the esoteric forms of quantum gl(N) by deformation theory.

  3. Space Systems Academic Group

    OpenAIRE

    2006-01-01

    The Space Systems Academic Group (SSAG) along with eight academic departments is an integral part of the Graduate School of Engineering and Applied Sciences. As an interdisciplinary association of professors it provides direction and guidance for two curricula: Space Systems Engineering and Space Systems Operations.

  4. Group theory in physics

    CERN Document Server

    Cornwell, J F

    1989-01-01

    Recent devopments, particularly in high-energy physics, have projected group theory and symmetry consideration into a central position in theoretical physics. These developments have taken physicists increasingly deeper into the fascinating world of pure mathematics. This work presents important mathematical developments of the last fifteen years in a form that is easy to comprehend and appreciate.

  5. FAW Group Gorporation

    Institute of Scientific and Technical Information of China (English)

    Yan Feng

    2007-01-01

    @@ As the founder of China's automobile industry, FAW Group Corporation (FAW) has maintained a dominant position in the automotive industry since its founding in 1953 in terms of its total assets, Production capacity, domestic and international sales, market share, and brand recognition.

  6. Geodesic Renormalisation Group Flow

    OpenAIRE

    Dolan, Brian P

    1995-01-01

    It is shown that the renormalisation group flow in coupling constant space can be interpreted in terms of a dynamical equation for the couplings analogous to viscous fluid flow under the action of a potential. For free scalar field theory the flow is geodesic in two dimensions, while for $D \

  7. Functional Group Analysis.

    Science.gov (United States)

    Smith, Walter T., Jr.; Patterson, John M.

    1984-01-01

    Literature on analytical methods related to the functional groups of 17 chemical compounds is reviewed. These compounds include acids, acid azides, alcohols, aldehydes, ketones, amino acids, aromatic hydrocarbons, carbodiimides, carbohydrates, ethers, nitro compounds, nitrosamines, organometallic compounds, peroxides, phenols, silicon compounds,…

  8. Nonequilibrium Renormalization Group

    International Nuclear Information System (INIS)

    Thermal equilibrium properties of many-body or field theories are known to be efficiently classified in terms of renormalization group fixed points. A particularly powerful concept is the notion of infrared fixed points, which are characterized by universality. These correspond to critical phenomena in thermal equilibrium, where a characteristic large correlation length leads to independence of long-distance properties from details of the underlying microscopic theory. In contrast, a classification of properties of theories far from thermal equilibrium in terms of renormalization group fixed points is much less developed. The notion of universality or critical phenomena far from equilibrium is to a large extent unexplored, in particular, in relativistic quantum field theories. Here the strong interest is mainly driven by theoretical and experimental advances in our understanding of early universe cosmology as well as relativistic collision experiments of heavy nuclei in the laboratory. In these lectures I will introduce the functional renormalization group for the effective average action out of equilibrium. While in equilibrium typically a Euclidean formulation is adequate, nonequilibrium properties require real-time descriptions. For quantum systems a generating functional for nonequilibrium correlation functions with given density matrix at initial time can be written down using the Schwinger-Keldysh closed time path contour. In principle, this can be used to construct a nonequilibrium functional renormalization group along similar lines as for Euclidean field theories in thermal equilibrium. However, important differences include the absence of time-translation invariance for general out-of-equilibrium situations. The nonequilibrium renormalization group takes on a particularly simple form at a fixed point, since it becomes independent of the initial density matrix. I will discuss some simple examples for which I derive a hierarchy of fixed point solutions

  9. Anti- CC-Groups and Anti-PC-Groups

    Directory of Open Access Journals (Sweden)

    Francesco Russo

    2007-01-01

    subgroup H of G. An anti-PC group G is a group in which each nonfinitely generated subgroup K has the quotient group G/coreG(NG(K which is a polycyclic-by-finite group. Anti-CC groups and anti-PC groups are the subject of the present article.

  10. Working group 4: Terrestrial

    International Nuclear Information System (INIS)

    A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented

  11. Mindfulness for group facilitation

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Krohn, Simon

    2014-01-01

    In this paper, we argue that mindfulness techniques can be used for enhancing the outcome of group performance. The word mindfulness has different connotations in the academic literature. Broadly speaking there is ‘mindfulness without meditation’ or ‘Western’ mindfulness which involves active...... thinking and ‘Eastern’ mindfulness which refers to an open, accepting state of mind, as intended with Buddhist-inspired techniques such as meditation. In this paper, we are interested in the latter type of mindfulness and demonstrate how Eastern mindfulness techniques can be used as a tool for facilitation....... A brief introduction to the physiology and philosophy of Eastern mindfulness constitutes the basis for the arguments of the effect of mindfulness techniques. The use of mindfulness techniques for group facilitation is novel as it changes the focus from individuals’ mindfulness practice...

  12. Two Abelian group constructions

    International Nuclear Information System (INIS)

    Let A be an Abelian group and n an integer >1. Let D be a divisible hull of A. Define A0sup((D))=A,Asub(r)sup((D)) = set containing x is an element of D|nx=y, for some y is an element of Asub(r=1)sup((D)), r=1,2,3,..., and Asub([n])sup((D))=Usub(r=0)sup(infinity)Asub(r)sup((D)). Then each Asub(r)sup((D)) is a subgroup of D and Asub([n])sup((D)) is the smallest n-divisible subgroup of D which contains A. Define Asub((D))sup([n])=Asub([n])sup((D))/A. A number of theorems and propositions are proved for the groups Asub([n])sup((D)) and Asub((D))sup([n])

  13. ST Quality Working Group

    CERN Document Server

    Akhtar, S

    2000-01-01

    When CERN engages contractors or outside enterprises for supply and service contracts, a Quality certification is requested. CERN itself has no global certification. Nor are quality assurance systems well understood by the majority of CERN staff. This has not precluded successful activity but it is felt that a structured approach would have some benefits: elimination of occasional accelerator perturbations, improved documentation, efficient use of existing resources, enhanced sharing of experience and knowledge, avoidance of improper handover periods when staff leave CERN. In some cases talented staff spend too much time doing remedial jobs when they are capable of achieving much more. The ST quality working group was formed to address these problems. The goal of this quality working group is to help ST division maintain and continuously improve the quality of its services and operations, and give confidence to ST staff and clients that the requirements for quality are being fulfilled, maintained and improved...

  14. Group Formation in Economics

    Science.gov (United States)

    Demange, Gabrielle; Wooders, Myrna

    2005-01-01

    Broad and diverse ranges of activities are conducted within and by organized groups of individuals, including political, economic and social activities. These activities have recently become a subject of intense interest in economics and game theory. Some of the topics investigated in this collection are models of networks of power and privilege, trade networks, co-authorship networks, buyer-seller networks with differentiated products, and networks of medical innovation and the adaptation of new information. Other topics are social norms on punctuality, clubs and the provision of club goods and public goods, research and development and collusive alliances among corporations, and international alliances and trading agreements. While relatively recent, the literature on game theoretic studies of group formation in economics is already vast. This volume provides an introduction to this important literature on game-theoretic treatments of situations with networks, clubs, and coalitions, including some applications.

  15. The Ombudperson Initiative Group

    CERN Document Server

    Laura Stewart

    Following many discussions that took place at some of the ATLAS Women's Network lunch gatherings, a few ATLAS women joined forces with similarly concerned CERN staff women to form a small group last Fall to discuss the need for a CERN-wide Ombudsperson. This has since evolved into the Ombudsperson Initiative Group (OIG) currently composed of the following members: Barbro Asman, Stockholm University; Pierre Charrue, CERN AB; Anna Cook, CERN IT; Catherine Delamare, CERN and IT Ombudsperson; Paula Eerola, Lund University; Pauline Gagnon, Indiana University; Eugenia Hatziangeli, CERN AB; Doreen Klem, CERN IT; Bertrand Nicquevert, CERN TS and Laura Stewart, CERN AT. On June 12, members of the OIG met with representatives of Human Resources (HR) and the Equal Opportunity Advisory Panel (EOAP) to discuss the proposal drafted by the OIG. The meeting was very positive. Everybody agreed that the current procedures at CERN applicable in the event of conflict required a thorough review, and that a professionnally trai...

  16. The Areva Group

    International Nuclear Information System (INIS)

    This document provides information on the Areva Group, a world nuclear industry leader, offering solutions for nuclear power generation, electricity transmission and distribution and interconnect systems to the telecommunications, computer and automotive markets. It presents successively the front end division including the group business lines involved in producing nuclear fuel for electric power generation (uranium mining, concentration, conversion and enrichment and nuclear fuel fabrication); the reactors and services division which designs and builds PWR, BWR and research reactors; the back end division which encompasses the management of the fuel that has been used in nuclear power plants; the transmission and distribution division which provides products, systems and services to the medium and high voltage energy markets; the connectors division which designs and manufactures electrical, electronic and optical connectors, flexible micro circuitry and interconnection systems. Areva is implemented in Europe, north and south america, africa and asia-pacific. (A.L.B.)

  17. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    Please note that owing the preparations for the Open Days, the FM Group will not able to handle specific requests for waste collection from 2nd to 6th of April, nor removal or PC transport requests between the 31 March and 11 April. We kindly ask you to plan the collection of all types of waste and any urgent transport of office furniture or PCs before 31 March. Waste collection requests must be made by contacting FM Support on 77777 or at the e-mail address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form (select "Removals" or "PC transport" from the drop-down menu). For any question concerning the sorting of waste, please consult the following web site: http://dechets-waste.web.cern.ch/dechets-waste/ Thank you for your understanding and collaboration. TS/FM Group

  18. Ocenenie Volkswagen Group

    OpenAIRE

    Šusták, Tomáš

    2010-01-01

    Objective of the thesis is determination of Volkswagen Group's equity intrinsic value. Basic starting point of the analysis is seggregation of consolidated financial statements into financial and production division, which are valuated separately. The production division is valuated using both enterprise discounted cashflow and discounted economic profit analysis. Equity cashflow valuation is used to derive value of the financial division. Results of valuation implied by income approach are t...

  19. Combinatorial group theory

    CERN Document Server

    Lyndon, Roger C

    2001-01-01

    From the reviews: "This book (...) defines the boundaries of the subject now called combinatorial group theory. (...)it is a considerable achievement to have concentrated a survey of the subject into 339 pages. This includes a substantial and useful bibliography; (over 1100 ÄitemsÜ). ...the book is a valuable and welcome addition to the literature, containing many results not previously available in a book. It will undoubtedly become a standard reference." Mathematical Reviews, AMS, 1979.

  20. Equity valuation : Eurocash Group

    OpenAIRE

    Branco, Ana Isabel Antunes de Azevedo

    2015-01-01

    Equity valuation is an extremely complex and subjective process, it depends not only on the theoretical models but also on the analysis and assumptions used by the analyst. This thesis focuses on the valuation of Eurocash Group, a leading wholesale distributor of fast moving consumer goods (FMCG) in Poland. In order to present stronger conclusions we decided to use two different models: the discounted cash-flow (DCF) model and the multiples method as a complement. The combination of both l...

  1. KKG Group Paraffin Removal

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Ralph

    2001-12-01

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed a test of a paraffin removal system developed by the KKG Group utilizing the technology of two Russian scientists, Gennady Katzyn and Boris Koggi. The system consisting of chemical ''sticks'' that generate heat in-situ to melt the paraffin deposits in oilfield tubing. The melted paraffin is then brought to the surface utilizing the naturally flowing energy of the well.

  2. Multibunch working group

    International Nuclear Information System (INIS)

    The goal of this working group was to foment discussions about the use and limitations of multi-bunch, representatives from most operating or in-project synchrotron radiation sources (ALS, SPEAR, BESSY-2, SPRING-8, ANKA, DELTA, PEP-2, DIAMOND, ESRF...) have presented their experience. The discussions have been led around 3 topics: 1) resistive wall instabilities and ion instabilities, 2) higher harmonic cavities, and 3) multibunch feedback systems

  3. Heavy flavors study group

    International Nuclear Information System (INIS)

    The heavy flavor study group concentrated on three issues. First the investigation of an energy transverse trigger to be used to select out charm and beauty events. Second, in a dedicated high sensitivity two-body B experiment is it possible to ''tag'' the beauty particle. Third, the design of a photoproduction experiment that could accumulate 108 charm particles in a single Fermilab running period

  4. Finite groups with transitive semipermutability

    Institute of Scientific and Technical Information of China (English)

    Lifang WANG; Yanming WANG

    2008-01-01

    A group G is said to be a T-group (resp. PT-group, PST-group), if normality (resp. permutability, S-permutability) is a transitive relation. In this paper, we get the characterization of finite solvable PST-groups. We also give a new characterization of finite solvable PT-groups.

  5. Main Controlling Factors and Models of Carboniferous Volcanic Hydrocarbon Accumulation in the Malang Sag, Santang Basin%三塘湖盆地马朗凹陷石炭系火山岩系油气成藏主控因素及模式

    Institute of Scientific and Technical Information of China (English)

    黄志龙; 柳波; 罗权生; 吴红烛; 马剑; 陈旋; 陈建琪

    2012-01-01

    三塘湖盆地马朗凹陷石炭系主要发育两套烃源岩,分别为哈尔加乌组上段和哈尔加乌组下段,油气藏形成的源控作用十分明显.通过烃源岩和原油地球化学的分析以及油源对比,发现不同类型原油的形成与分布严格受控于对应源岩的分布范围.分析表明,马朗凹陷石炭系火山岩系油气成藏的主控因素是优质烃源岩、强充注油源断裂和有利火山岩相带的合理配置.根据烃源岩与储层的配置关系,石炭系油气藏的形成可以概括为两种模式:一种为风化壳型成藏模式,油气聚集在石炭系火山岩顶部受风化淋漓作用改造的优质储层中,其中的油气来自下部烃源岩,运移通道为与烃源岩相沟通的油源断裂;另一种模式为内幕型成藏模式,储层为流体溶蚀改造的储层,其中聚集的油气来自邻近火山喷发间歇期沉积的炭质泥岩.%There are two sets of source rocks in Carboniferous in the Malang sag, namely upper Haerjiawu Formation and lower Haerjiawu Formation. And source control effect is obvious on reservoir formation in this area. It is found that the formation and distribution of different types of crude oil are strictly controlled by the distribution of the corresponding source rocks using the geochemical comparative analysis of the source rock and crude oil as well as the oil-source correlation. Our analysis indicates that the main controlling factor of hydrocarbon accumulation is the reasonable configurations of high- quality source rock, strongly recharging of hydrocarbon into faults connecting source rock and reservoir, and favorable volcanic rock facies belt. There are two models of the carboniferous reservoir formation based on the configuration relations between the source rock and reservoir. One is weathering crust-type hydrocarbon accumulation model, in which oil and gas from the below source rock accumulate in the high-quality reservoirs of carboniferous volcanic top

  6. 甘肃北山地区下石炭统红柳园组四射珊瑚动物群及其地质意义%Early Carboniferous Rugose Coral Fauna Found in Hongliuyuan Formatioin in Beishan Area and Their Geological Significances

    Institute of Scientific and Technical Information of China (English)

    段先锋; 张雄华; 卜建军

    2011-01-01

    在北山地区下石炭统红柳园组中发现了丰富的的四射珊瑚,共计单体12属,17种;复体5属,7种,由下至上可划分为2个生物组合:Siphonodendron-Thysanophylloides组合和Yuanophyllum-Gangamophyllum组合,确定其时代为早石炭世大塘期.通过对北山地区珊瑚动物群与华南、欧洲以及北山地区内部不同小区的对比,认为黑鹰山小区(早古生代属哈萨克斯坦板块)和红柳园小区(属塔里木板块)珊瑚动物群面貌基本相似,总体具有特提斯大区生物群的特征,但部分地区仍具有北方大区和特提斯大区的混生特征,说明在早石炭世之前,哈萨克斯坦板块和塔里木板块之间生物未受明显的阻隔,也就是说两大板块已经拼合,北山地区海水与特提斯海域沟通,古亚洲洋在北山地区可能已经闭合.%Some Early Carboniferous rugose coral are found in Hongliuyuan section in Beishan area. They are 12 genera and 17 species of solitary coral, and 5 genera and 7 species of compound coral. They are can be divided into two biological assemblages,upwardely, Yuanophyllum-Gangamophyllum and Siphonoden-dron-Thysanophyllum. The geological time should be the Datangian. The correlation of the rugose coral fauna with that from Beishan area and South China and Europe, and with that from different districts inside the area suggests that coral fauna from Heiyingshan area,belonging to the Kazakhstan plate in Early Paleozoic, and that from Hongliuyuan area, belonging to Tarim plate, are similar,for they have the characteristic of the transitional type of the Tethyan faunal province and northern faunal province, mostly belonging to Tethyan faunal province. This implies that the biobarrier was not significant between Kazakhstan plate and Tarim plate before Early Carboniferous , which means that the two plates were put together in Early Carboniferous, Tethys Ocean communicated with the sea of Beishan area and Paleo-Asian Ocean might have been closed

  7. Group Milieu in systemic and psychodynamic group therapy

    DEFF Research Database (Denmark)

    Lau, Marianne Engelbrecht

    in a randomized study of systemic versus psychodynamic group therapy, that the short-term outcome for patients who received systemic group psychotherapy was significantly better than the outcome for patients who received psychodynamic group psychotherapy. The current study assessed the group milieu in both groups....... Methods: This randomized prospective study included 106 women: 52 assigned to psychodynamic group psychotherapy and 54 assigned to systemic group psychotherapy. The Group Environment Scale (GES) was filled in the mid phase of therapy and analysed in three dimensions and 10 subscales. Results: The systemic...... subscales: Cohesion (psystemic group turned out to be evaluated as the most structured therapy and also...

  8. Outer automorphism groups of certain 1-relator groups

    Institute of Scientific and Technical Information of China (English)

    KIM; Goansu

    2010-01-01

    Grossman first showed that outer automorphism groups of 1-relator groups given by orientable surface groups are residually finite,whence mapping class groups of orientable surfaces are residually finite.Allenby,Kim and Tang showed that outer automorphism groups of cyclically pinched 1-relator groups are residually finite,whence mapping class groups of orientable and non-orientable surfaces are residually finite.In this paper we show that outer automorphism groups of certain conjugacy separable 1-relator groups are residually finite.

  9. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  10. Unilever Group : equity valuation

    OpenAIRE

    Pires, Susana Sofia Castelo

    2014-01-01

    The following dissertation has the purpose to value the Unilever Group, but more specifically Unilever N.V. being publicly traded in the Amsterdam Exchange Index. Unilever is seen as a global player and one of most successful and competitive fast-moving consumer goods companies. In order to valuate Unilever’s equity, a Discounted Cash Flow (DCF) approach is first carried out, since it is believed to be the most reliable methodology. The value estimated was €36.39, advising one to buy its s...

  11. Applications of Quantum Groups

    Science.gov (United States)

    Chryssomalakos, Chryssomalis

    The main theme of this thesis is the search for applications of Quantum Group and Hopf algebraic concepts and techniques in Physics. We investigate in particular the possibilities that exist in deforming, in a self consistent way, the symmetry structure of physical theories with the hope that the resulting scheme will be of relevance in the description of physical reality. Our choice of topics reflects this motivation: we discuss deformations of rotations and Lorentz boosts, search for integrals on the quantum plane and attempt to Fourier transform functions of non -commuting coordinates. Along the way, more formal considerations prompt us to revisit integration on finite dimensional Hopf algebras, explore the interconnections between various descriptions of the quantum double and derive the algebraic structure of the quantum plane from that of the underlying deformed symmetry group. The material is structured as follows. Chapter 1 introduces the language, basic concepts and notation employed throughout this thesis. Chapter 2 focuses on Hopf algebras viewed as universal envelopes of deformed Lie algebras and their duals. Bicovariant generators enter the discussion as analogues of the classical Lie algebra generators and some of their properties are given. We comment on the geometrical interpretation of the algebraic formulation and introduce computational tools. In chapter 3 we take a close look at the quantum Lorentz Hopf algebra. The basics of complex quantum groups are presented and applied in the derivation of the algebra of the quantum Lorentz generators and its Hopf and involutive structures. We point also to isomorphisms with previous related constructions. The subject of quantum integration is explored in chapter 4. We derive a formula for the integral on a finite dimensional Hopf algebra and show its equivalence to the formulation in terms of the trace of the square of the antipode. Integration on the quantum plane is also examined and a Fourier transform

  12. Renormalization Group Functional Equations

    CERN Document Server

    Curtright, Thomas L

    2011-01-01

    Functional conjugation methods are used to analyze the global structure of various renormalization group trajectories. With minimal assumptions, the methods produce continuous flows from step-scaling {\\sigma} functions, and lead to exact functional relations for the local flow {\\beta} functions, whose solutions may have novel, exotic features, including multiple branches. As a result, fixed points of {\\sigma} are sometimes not true fixed points under continuous changes in scale, and zeroes of {\\beta} do not necessarily signal fixed points of the flow, but instead may only indicate turning points of the trajectories.

  13. Theory and modeling group

    Science.gov (United States)

    Holman, Gordon D.

    The primary purpose of the Theory and Modeling Group meeting was to identify scientists engaged or interested in theoretical work pertinent to the Max '91 program, and to encourage theorists to pursue modeling which is directly relevant to data which can be expected to result from the program. A list of participants and their institutions is presented. Two solar flare paradigms were discussed during the meeting -- the importance of magnetic reconnection in flares and the applicability of numerical simulation results to solar flare studies.

  14. Statistical Group Comparison

    CERN Document Server

    Liao, Tim Futing

    2011-01-01

    An incomparably useful examination of statistical methods for comparisonThe nature of doing science, be it natural or social, inevitably calls for comparison. Statistical methods are at the heart of such comparison, for they not only help us gain understanding of the world around us but often define how our research is to be carried out. The need to compare between groups is best exemplified by experiments, which have clearly defined statistical methods. However, true experiments are not always possible. What complicates the matter more is a great deal of diversity in factors that are not inde

  15. The technical review group

    International Nuclear Information System (INIS)

    This paper describes the formation of a technical review group (TRG) as an early application of the quality assurance program for high-level waste processing. The objectives and functions for a TRG are summarized. Organizational structure is presented. Interfaces for the TRG are described by a flow diagram following the review process from the originator's document submittal to the final approval. Interfacing organizations and their responsibilities during the review are shown. Experience to date with TRG activities are described and QA interaction is discussed

  16. Quantum Group $\\sigma$ Models

    CERN Document Server

    Frishman, Yitzhak; Zakrzewski, W J

    1993-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ are realised as $2N\\times 2N$ unitary matrices. Open problems are pointed out.

  17. Quantum Group $\\sigma$ Models

    OpenAIRE

    Frishman, Y.; Lukierski, J.; Zakrzewski, W. J.

    1992-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ ar...

  18. Quality of Group Member Agendas and Group Session Climate.

    Science.gov (United States)

    Kivlighan, Dennis M., Jr.; Jauquet, Carol A.

    1990-01-01

    Examined relationship between group members' (N=36) approach to group sessions and group session climate and relationship between length of time in group and agenda quality. Found average ratings of interpersonal and here-and-now dimensions of agendas were significantly related to average perception of group climate as more engaged and less…

  19. Group Life Insurance

    CERN Document Server

    2013-01-01

    The CERN Administration would like to remind you that staff members and fellows have the possibility to take out a life insurance contract on favourable terms through a Group Life Insurance.   This insurance is provided by the company Helvetia and is available to you on a voluntary basis. The premium, which varies depending on the age and gender of the person insured, is calculated on the basis of the amount of the death benefit chosen by the staff member/fellow and can be purchased in slices of 10,000 CHF.    The contract normally ends at the retirement age (65/67 years) or when the staff member/fellow leaves the Organization. The premium is deducted monthly from the payroll.   Upon retirement, the staff member can opt to maintain his membership under certain conditions.   More information about Group Life Insurance can be found at: Regulations (in French) Table of premiums The Pension Fund Benefit Service &...

  20. On the Brauer group

    International Nuclear Information System (INIS)

    For an arithmetic model X of a Fermat surface or a hyperkahler variety with Betti number b2(V otimes k-bar)>3 over a purely imaginary number field k, we prove the finiteness of the l-components of Br'(X) for all primes l>>0. This yields a variant of a conjecture of M. Artin. If V is a smooth projective irregular surface over a number field k and V(k)≠ nothing, then the l-primary component of Br(V)/Br(k) is an infinite group for every prime l. Let A1→M1 be the universal family of elliptic curves with a Jacobian structure of level N>=3 over a number field k supset of Q(e2πi/N). Assume that M1(k) ≠ nothing. If V is a smooth projective compactification of the surface A1, then the l-primary component of Br(V)/Br(M-bar1) is a finite group for each sufficiently large prime l

  1. Business working group

    International Nuclear Information System (INIS)

    The workshop of 26-27 june 2000, on nuclear power Plant LIfe Management (PLIM), also included working groups in which major issues facing PLIM activities for nuclear power plants were identified and discussed. The third group was on Business. The discussion concerned the following points: There are concerns about retaining experienced/trained personnel, and maintaining a good working relationship among them, as well as about the closure of research facilities, the reduction in staff numbers under increasing economic pressure and the lack of new nuclear power plant constructions. The marginal cost of producing electricity is lower for most existing nuclear power plants than for almost all other energy sources. Refurbishment costs are usually relatively small compared with new investments. The ongoing regulatory reform of the electricity market will bring increasing competition. Although PLIM has been carried out in many countries with favourable results, there are still uncertainties which affect business decisions regarding financial and market risks in PLIM activities. Recommendations were made. (author)

  2. Social group and mobbing

    Directory of Open Access Journals (Sweden)

    Baltezarević Vesna

    2009-01-01

    Full Text Available Our reality, having been subject to the numerous social crises during the last decades of the 20th century, is characterized by frequent incidences of powerlessness and alienation. The man is more frequently a subject to loneliness and overcomes the feeling of worthlessness, no matter whether he considers himself an individual or a part of a whole larger social. Such an environment leads to development of aggression in all fields of ones life. This paper has as an objective the pointing out of the mental harassment that is manifested in the working environment. There is a prevalence of mobbing cases, as a mode of pathological communication. The result of this is that a person, subjected to this kind of abuse, is soon faced with social isolation. This research also aspires to initiate the need for social groups self-organization of which victims are part of. The reaction modality of a social group directly conditions the outcome of the deliberate social drama, one is subjected to it as a result of mobbing.

  3. ATLAS Detector Interface Group

    CERN Document Server

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  4. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    In order to prepare the organization of the Open Days, please note that FM Group will not able to take into account either specific requests for waste collection from 2nd to 6th of April, either removal or PC transport requests between the 31st and the 11th of March. We kindly ask you to plan the collection of any type of waste and the urgent transport of office furniture or PC before the 31st of March. Waste collection requests shall be formulated contacting FM Support at 77777 or at the email address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form selecting the "Removals" or the "PC transport" category from the drop-down menu. For any question concerning the waste sorting, please consult the following web address: http://dechets-waste.web.cern.ch/dechets-waste/. Thank you for your understanding and collaboration. TS/FM Group

  5. Representation Theory of Algebraic Groups and Quantum Groups

    CERN Document Server

    Gyoja, A; Shinoda, K-I; Shoji, T; Tanisaki, Toshiyuki

    2010-01-01

    Invited articles by top notch expertsFocus is on topics in representation theory of algebraic groups and quantum groupsOf interest to graduate students and researchers in representation theory, group theory, algebraic geometry, quantum theory and math physics

  6. On Generalized PST-groups

    Institute of Scientific and Technical Information of China (English)

    WANG JUN-XIN; Du Xian-kun

    2011-01-01

    A finite group G is called a generalized PST-group if every subgroup contained in F(G) permutes all Sylow subgroups of G,where F(G) is the Fitting subgroup of G.The class of generalized PST-groups is not subgroup and quotient group closed,and it properly contains the class of PST-groups.In this paper,the structure of generalized PST-groups is first investigated.Then,with its help,groups whose every subgroup (or every quotient group) is a generalized PST-group are determined,and it is shown that such groups are precisely PST-groups.As applications,T-groups and PT-groups are characterized.

  7. Renormalization Group Therapy

    CERN Document Server

    Tomboulis, E T

    2007-01-01

    We point out a general problem with the procedures commonly used to obtain improved actions from MCRG decimated configurations. Straightforward measurement of the couplings from the decimated configurations, by one of the known methods, can result into actions that do not correctly reproduce the physics on the undecimated lattice. This is because the decimated configurations are generally not representative of the equilibrium configurations of the assumed form of the effective action at the measured couplings. Curing this involves fine-tuning of the chosen MCRG decimation procedure, which is also dependent on the form assumed for the effective action. We illustrate this in decimation studies of the SU(2) LGT using Swendsen and Double Smeared Blocking decimation procedures. A single-plaquette improved action involving five group representations and free of this pathology is given.

  8. Group life insurance

    CERN Document Server

    2013-01-01

    The CERN Administration wishes to inform staff members and fellows having taken out optional life insurance under the group contract signed by CERN that the following changes to the rules and regulations entered into force on 1 January 2013:   The maximum age for an active member has been extended from 65 to 67 years. The beneficiary clause now allows insured persons to designate one or more persons of their choice to be their beneficiary(-ies), either at the time of taking out the insurance or at a later date, in which case the membership/modification form must be updated accordingly. Beneficiaries must be clearly identified (name, first name, date of birth, address).   The membership/modification form is available on the FP website: http://fp.web.cern.ch/helvetia-life-insurance For further information, please contact: Valentina Clavel (Tel. 73904) Peggy Pithioud (Tel. 72736)

  9. Graphs, groups and surfaces

    CERN Document Server

    White, AT

    1985-01-01

    The field of topological graph theory has expanded greatly in the ten years since the first edition of this book appeared. The original nine chapters of this classic work have therefore been revised and updated. Six new chapters have been added, dealing with: voltage graphs, non-orientable imbeddings, block designs associated with graph imbeddings, hypergraph imbeddings, map automorphism groups and change ringing.Thirty-two new problems have been added to this new edition, so that there are now 181 in all; 22 of these have been designated as ``difficult'''' and 9 as ``unsolved''''. Three of the four unsolved problems from the first edition have been solved in the ten years between editions; they are now marked as ``difficult''''.

  10. Doing focus group research

    DEFF Research Database (Denmark)

    Lindegaard, Laura Bang

    2014-01-01

    interview data can be of some use if the distinction between natural and contrived data is given up and replaced with a distinction between interview data as topic or as resource. In greater detail, such scholars argue that interview data are perfectly adequate if the researcher wants to study the topic of......Scholars of ethnomethodologically informed discourse studies are often sceptical of the use of interview data such as focus group data. Some scholars quite simply reject interview data with reference to a general preference for so-called naturally occurring data. Other scholars acknowledge that...... interview interaction, but inadequate as data for studying phenomena that go beyond the phenomenon of interview interaction. Neither of these more and less sceptical positions are, on the face of it, surprising due to the ethnomethodological commitment to study social order as accomplished in situ, not as...

  11. Grouping Synonyms by Definitions

    CERN Document Server

    Falk, Ingrid; Jacquey, Evelyne; Venant, Fabienne

    2009-01-01

    We present a method for grouping the synonyms of a lemma according to its dictionary senses. The senses are defined by a large machine readable dictionary for French, the TLFi (Tr\\'esor de la langue fran\\c{c}aise informatis\\'e) and the synonyms are given by 5 synonym dictionaries (also for French). To evaluate the proposed method, we manually constructed a gold standard where for each (word, definition) pair and given the set of synonyms defined for that word by the 5 synonym dictionaries, 4 lexicographers specified the set of synonyms they judge adequate. While inter-annotator agreement ranges on that task from 67% to at best 88% depending on the annotator pair and on the synonym dictionary being considered, the automatic procedure we propose scores a precision of 67% and a recall of 71%. The proposed method is compared with related work namely, word sense disambiguation, synonym lexicon acquisition and WordNet construction.

  12. Working Group Report: Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Artuso, M.; et al.,

    2013-10-18

    Sensors play a key role in detecting both charged particles and photons for all three frontiers in Particle Physics. The signals from an individual sensor that can be used include ionization deposited, phonons created, or light emitted from excitations of the material. The individual sensors are then typically arrayed for detection of individual particles or groups of particles. Mounting of new, ever higher performance experiments, often depend on advances in sensors in a range of performance characteristics. These performance metrics can include position resolution for passing particles, time resolution on particles impacting the sensor, and overall rate capabilities. In addition the feasible detector area and cost frequently provides a limit to what can be built and therefore is often another area where improvements are important. Finally, radiation tolerance is becoming a requirement in a broad array of devices. We present a status report on a broad category of sensors, including challenges for the future and work in progress to solve those challenges.

  13. Gutzwiller renormalization group

    Science.gov (United States)

    Lanatà, Nicola; Yao, Yong-Xin; Deng, Xiaoyu; Wang, Cai-Zhuang; Ho, Kai-Ming; Kotliar, Gabriel

    2016-01-01

    We develop a variational scheme called the "Gutzwiller renormalization group" (GRG), which enables us to calculate the ground state of Anderson impurity models (AIM) with arbitrary numerical precision. Our method exploits the low-entanglement property of the ground state of local Hamiltonians in combination with the framework of the Gutzwiller wave function and indicates that the ground state of the AIM has a very simple structure, which can be represented very accurately in terms of a surprisingly small number of variational parameters. We perform benchmark calculations of the single-band AIM that validate our theory and suggest that the GRG might enable us to study complex systems beyond the reach of the other methods presently available and pave the way to interesting generalizations, e.g., to nonequilibrium transport in nanostructures.

  14. The analytic renormalization group

    Science.gov (United States)

    Ferrari, Frank

    2016-08-01

    Finite temperature Euclidean two-point functions in quantum mechanics or quantum field theory are characterized by a discrete set of Fourier coefficients Gk, k ∈ Z, associated with the Matsubara frequencies νk = 2 πk / β. We show that analyticity implies that the coefficients Gk must satisfy an infinite number of model-independent linear equations that we write down explicitly. In particular, we construct "Analytic Renormalization Group" linear maps Aμ which, for any choice of cut-off μ, allow to express the low energy Fourier coefficients for |νk | algorithm, we show that the exact universal linear constraints on Gk can be used to systematically improve any random approximate data set obtained, for example, from Monte-Carlo simulations. Our results are illustrated on several explicit examples.

  15. Braided C*-quantum groups

    OpenAIRE

    Roy, Sutanu

    2016-01-01

    We propose a general theory of braided quantum groups in the C*-algebraic framework. More precisely, we construct braided quantum groups using manageable braided multiplicative unitaries over a regular C*-quantum group. We show that braided C*-quantum groups are equivalent to C*-quantum groups with projection.

  16. Making Cooperative Learning Groups Work.

    Science.gov (United States)

    Hawley, James; De Jong, Cherie

    1995-01-01

    Discusses the use of cooperative-learning groups with middle school students. Describes cooperative-learning techniques, including group roles, peer evaluation, and observation and monitoring. Considers grouping options, including group size and configuration, dyads, the think-pair-share lecture, student teams achievement divisions, jigsaw groups,…

  17. Group and ring theoretic properties of polycyclic groups

    CERN Document Server

    Wehrfritz, BAF

    2009-01-01

    Polycyclic groups are built from cyclic groups in a specific way. They arise in many contexts within group theory itself but also more generally in algebra, for example in the theory of Noetherian rings. The first half of this book develops the standard group theoretic techniques for studying polycyclic groups and the basic properties of these groups. The second half then focuses specifically on the ring theoretic properties of polycyclic groups and their applications, often to purely group theoretic situations. The book is intended to be a study manual for graduate students and researchers co

  18. CORRELATION BETWEEN GROUP LOCAL DENSITY AND GROUP LUMINOSITY

    International Nuclear Information System (INIS)

    In this study, we investigate the correlation between group local number density and total luminosity of groups. In four volume-limited group catalogs, we can conclude that groups with high luminosity exist preferentially in high-density regions, while groups with low luminosity are located preferentially in low-density regions, and that in a volume-limited group sample with absolute magnitude limit Mr = –18, the correlation between group local number density and total luminosity of groups is the weakest. These results basically are consistent with the environmental dependence of galaxy luminosity.

  19. Modular Representations of Profinite Groups

    CERN Document Server

    MacQuarrie, John

    2010-01-01

    Our aim is to transfer several foundational results from the modular representation theory of finite groups to the wider context of profinite groups. We are thus interested in profinite modules over the completed group algebra k[[G

  20. Harmonic Analysis and Group Representation

    CERN Document Server

    Figa-Talamanca, Alessandro

    2011-01-01

    This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.

  1. Working Group Versus Team Work

    OpenAIRE

    Valentina-Vasilica Zaharia; Mirela-Mihaela Dogaru; Dan-Marin Boaja

    2014-01-01

    The cell organization is represented by the working group and not the individual, groups that are a major feature of life organization. Quality circles were designed as tools for building team spirit in Japanese companies as a tool to enhance group cohesion and the training of employees. The essential characteristic of human behavior and organizational performance is given by the working group and the influence on group members, so members of the group leader should use in order to achieve a ...

  2. Interagency Advanced Power Group -- Steering group meeting minutes

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-18

    This document contains the draft meeting minutes of the Steering Group of the Interagency Advanced Power Group. Included are the discussions resulting from the presentation of working group reports and the results of a discussion of IAPG policies and procedures. In the appendix are the reports of the following working groups: Electrical, Mechanical, Solar, and Systems.

  3. Group Leader Development: Effects of Personal Growth and Psychoeducational Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Robinson, E. H., III; Hagedorn, W. Bryce

    2013-01-01

    The purpose of this quasi-experimental study was to compare the effects of personal growth groups and psychoeducational groups on counselor education students' (n = 74) empathy and group leader self-efficacy. Additionally, we compared the degree to which participants in each group valued: (a) cohesion, (b) catharsis, and (c) insight. There were no…

  4. Post-Disaster Social Justice Group Work and Group Supervision

    Science.gov (United States)

    Bemak, Fred; Chung, Rita Chi-Ying

    2011-01-01

    This article discusses post-disaster group counseling and group supervision using a social justice orientation for working with post-disaster survivors from underserved populations. The Disaster Cross-Cultural Counseling model is a culturally responsive group counseling model that infuses social justice into post-disaster group counseling and…

  5. Group Development and Situational Leadership: A Model for Managing Groups.

    Science.gov (United States)

    Carew, Donald K.; And Others

    1986-01-01

    An integration of the concepts of situational leadership with what is known about group development and functioning of work groups is discussed as a tool in helping managers, trainers, and group members understand group development and determine the appropriate leader behaviors to use in various situations to build unified, cohesive, and…

  6. Oklo working group meeting

    International Nuclear Information System (INIS)

    Natural analogue studies have been carried out for several years in the framework of the European Community's R and D programme on radioactive waste; and within its recent fourth five-year programme on 'Management and storage of radioactive waste (1990-94)' the Community is participating in the Oklo study, natural analogue for transfer processes in a geological repository. The Oklo project is coordinated by CEA-IPSN (F) and involves laboratories from several CEA directorates (IPSN, DTA and DCC) which collaborate with other institutions from France: CREGU, Nancy; CNRS, Strasbourg and ENSMD, Fontainebleau. Moreover, institutes from non-EC member States are also taking part in the Oklo study. The second joint CEC-CEA progress meeting of the Oklo Working Group was held in April 1992 in Brussels and gave the possibility of reviewing and discussing progress made since its first meeting in February 1991 at CEA in Fontenay-aux-Roses. About 40 participants from 15 laboratories and organizations coming from France, Canada, Gabon, Japan, Sweden and the USA underline the great interest in the ongoing research activities. The meeting focused on the different tasks within the CEC-CEA Oklo project concerning (i) field survey and sampling, (ii) characterization of the source term, (iii) studies of the petrographical and geochemical system, and (iv) studies of the hydrogeological system and hydrodynamic modelling. (author) 17 papers are presented

  7. Reflexive Analysis of Groups

    Science.gov (United States)

    Lefebvre, Vladimir A.

    This chapter develops further a model I previously introduced, of an agent facing a choice between the positive and the negative poles. Here I will consider agents whose individual behavior depends on a ‘society’ compounded by all of them. Four ideas underlie the theory. The first idea is to consider relationships between the subgroups of agents, not just pairs of agents; this idea allows us to represent a decomposable graph corresponding to an agent or a group of agents as a tree of subgraphs. The second idea is to establish a correspondence between decomposable graphs and polynomials, allowing us to replace a tree of subgraphs with a tree of polynomials representing a computational process. The third idea consists of the interpretation of the tree of polynomials as an agent who has images of the self, which can have images of the self, etc. Finally, the fourth idea is putting an equation into correspondence to the agent, allowing us to find out the agent’s state. The theory is illustrated here with several examples from modern geopolitics, including scenarios of current interest.

  8. Les séries du carbonifère inférieur de la région d'Adarouch, NE du Maroc central: lithologie et biostratigraphieEarly carboniferous series of the Adarouch area, northeast central Morocco: lithology and biostratigraphy

    Science.gov (United States)

    Berkhli, M.; Vachard, D.; Paicheler, J.-C.

    2001-05-01

    The early Carboniferous series of the Adarouch area (northeast central Morocco) are subdivided into three sedimentological and biostratigraphical units. The first unit, which belongs to the Late Visean zones V3bβ and V3bγ, was deposited on shallow carbonate platforms. The second unit belongs to the Late Visean zone, V3c, and incudes terrigenous deposits, such as turbidites, shales and olistostromes. The third unit belongs to the Serpukhovian stage and consists of sandstones and limestones. A new biostratigraphical analysis, which is based on foraminiferal, algae and pseudoalgae, allows an accurate dating of the units. The deposits of the zones V3bβ and V3bγ contain characteristic calcareous microfossils, such as Stacheoides sp., Pseudoendothyra sp. and Ungdarella uralica. The V3c zone (300-400 m) is shown in two oolitic beds of the Mouarhaz and Akerchi Formations, respectively, with Janischewskina sp. and Asteroarchaediscus sp. The Serpukhovian stage is characterised by the disappearance of the algae Koninckopora and the appearance of the brachiopod Titanaria. The new data from the Adarouch area confirm the Moroccan biostratigraphical scale of the Moroccan meseta.

  9. Automorphism Groups of Finite p-Groups: Structure and Applications

    CERN Document Server

    Helleloid, Geir T

    2007-01-01

    This thesis has three goals related to the automorphism groups of finite $p$-groups. The primary goal is to provide a complete proof of a theorem showing that, in some asymptotic sense, the automorphism group of almost every finite $p$-group is itself a $p$-group. We originally proved this theorem in a paper with Martin; the presentation of the proof here contains omitted proof details and revised exposition. We also give a survey of the extant results on automorphism groups of finite $p$-groups, focusing on the order of the automorphism groups and on known examples. Finally, we explore a connection between automorphisms of finite $p$-groups and Markov chains. Specifically, we define a family of Markov chains on an elementary abelian $p$-group and bound the convergence rate of some of those chains.

  10. ON COLEMAN OUTER AUTOMORPHISM GROUPS OF FINITE GROUPS

    Institute of Scientific and Technical Information of China (English)

    海进科; 李正兴

    2014-01-01

    Let G be a finite group and OutCol(G) the Coleman outer automorphism group of G(for the definition, see below). The question whether OutCol(G) is a p′-group naturally arises from the study of the normalizer problem for integral group rings, where p is a prime. In this article, some sufficient conditions for OutCol(G) to be a p′-group are obtained. Our results generalize some well-known theorems.

  11. Instrumentation Working Group Summary

    Science.gov (United States)

    Zaller, Michelle; Miake-Lye, Richard

    1999-01-01

    The Instrumentation Working Group compiled a summary of measurement techniques applicable to gas turbine engine aerosol precursors and particulates. An assessment was made of the limits, accuracy, applicability, and technology readiness of the various techniques. Despite advances made in emissions characterization of aircraft engines, uncertainties still exist in the mechanisms by which aerosols and particulates are produced in the near-field engine exhaust. To adequately assess current understanding of the formation of sulfuric acid aerosols in the exhaust plumes of gas turbine engines, measurements are required to determine the degree and importance of sulfur oxidation in the turbine and at the engine exit. Ideally, concentrations of all sulfur species would be acquired, with emphasis on SO2 and SO3. Numerous options exist for extractive and non-extractive measurement of SO2 at the engine exit, most of which are well developed. SO2 measurements should be performed first to place an upper bound on the percentage of SO2 oxidation. If extractive and non-extractive techniques indicate that a large amount of the fuel sulfur is not detected as SO2, then efforts are needed to improve techniques for SO3 measurements. Additional work will be required to account for the fuel sulfur in the engine exhaust. Chemical Ionization Mass Spectrometry (CI-MS) measurements need to be pursued, although a careful assessment needs to be made of the sampling line impact on the extracted sample composition. Efforts should also be placed on implementing non-intrusive techniques and extending their capabilities by maximizing exhaust coverage for line-of-sight measurements, as well as development of 2-D techniques, where feasible. Recommendations were made to continue engine exit and combustor measurements of particulates. Particulate measurements should include particle size distribution, mass fraction, hydration properties, and volatile fraction. However, methods to ensure that unaltered

  12. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Beier, Eugene; /Pennsylvania U.; Butler, Joel; /Fermilab; Dawson, Sally; /Brookhaven; Edwards, Helen; /Fermilab; Himel, Thomas; /SLAC; Holmes, Stephen; /Fermilab; Kim, Young-Kee; /Fermilab /Chicago U.; Lankford, Andrew; /UC, Irvine; McGinnis, David; /Fermilab; Nagaitsev, Sergei; /Fermilab; Raubenheimer, Tor; /SLAC /Fermilab

    2007-01-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  13. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Steering Group, Fermilab; /Fermilab

    2007-12-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOvA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  14. Holographic renormalization group

    International Nuclear Information System (INIS)

    The holographic renormalization group (RG) is reviewed in a self-contained manner. The holographic RG is based on the idea that the radial coordinate of a space-time with asymptotically AdS geometry can be identified with the RG flow parameter of boundary field theory. After briefly discussing basic aspects of the AdS/CFT correspondence, we explain how the concept of the holographic GR emerges from this correspondence. We formulate the holographic RG on the basis of the Hamilton-Jacobi equations for bulk systems of gravity and scalar fields, as introduced by de Boer, Verlinde and Verlinde. We then show that the equations can be solved with a derivative expansion by carefully extracting local counterterms from the generating functional of the boundary field theory. The calculational methods used to obtain the Weyl anomaly and scaling dimensions are presented and applied to the RG flow from the N = 4 SYM to an N = 1 superconformal fixed point discovered by Leigh and Straussler. We further discuss the relation between the holographic RG and the noncritical string theory and show that the structure of the holographic RG should persist beyond the supergravity approximation as a consequence of the renormalizability of the nonlinear σ-model action of noncritical strings. As a check, we investigate the holographic RG structure of higher-derivative systems. We show that such systems can also be analyzed based on the Hamilton-Jacobi equations and that the behavior of bulk fields are determined solely by their boundary values. We also point out that higher-derivative gravity systems give rise to new multicritical points in the parameter space of boundary field theories. (author)

  15. ASYNCHRONOUS ELECTRONIC DISCUSSION GROUP:

    Directory of Open Access Journals (Sweden)

    Tina Lim Swee KIM

    2007-01-01

    Full Text Available This paper examines the practice of online discussion in a course specially tailored for in-service teachers who are pursuing their basic degree qualification at a teacher training institute. Analyses of postings to the asynchronous electronic discussion group were made according to the type of postings as proposed by Poole (2000. Four focus areas were looked into, that is, content, technical, procedural, or non-academic. Analyses were done for each quarter of the 12 weeks of interaction. At the end of the learners’ participation in the EDG and before their end-of-course examination, the participants were then given a paper-based questionnaire asking their perceptions on the use of EDG as part of their coursework on the whole. Six aspects of EDG were examined, these are;Ø technical aspects, Ø motivation to use the EDG, Ø quality of interaction, Ø tutor’s response, Ø perceived learning, and Ø attitude towards EDG. Analyses on postings for the EDG showed that the bulk of the postings were made in the last quarter of the online discussions. Further, 97.8% of the postings were on content and the types of content posting registered were predominantly questions (41.19% and those that sought clarification/elaboration (37.48%. Findings from this study suggest that overall the participants were satisfied with the six aspects of EDG examined. The aspect that recorded the highest mean was ‘motivation to read tutor’s responses’ whilst the lowest mean (and the only one with negative perception was for ‘worthiness of time spent on online discussions’.

  16. Depositional Characteristics and Their Geological Implications of the Permo-Carboniferous Carbonate Rocks from Yingen-Ejinaqi and Their Surrounding Areas, Inner Mongolia, China%银根-额济纳旗及邻区石炭-二叠纪碳酸盐岩的沉积特征及其地质意义

    Institute of Scientific and Technical Information of China (English)

    赵省民; 陈登超; 邓坚; 李锦平

    2011-01-01

    火山岩或火山碎屑岩、辫状三角洲或扇三角洲砂砾岩,以及碳酸盐岩建造中的火山岩、火山碎屑岩和砂砾岩夹层,成为本区域石炭一二叠纪的潜在油气储层.%A study of depositional characteristics on carbonate rocks of Permo-Carboniferous was carried out by analyzing of petrology and their formation characteristics of carbonate rocks. A lot of fieldworks of the Permo-Carboniferous system in the study area indicate that, the carbonate rocks of Permo-Carboniferouus are dominated by calcirudite, crinoidal limestone and micrite with massive structure and graded bedding, volcanic or pyroclastic rocks acting as pedestals and interteds of the carbonate formations prevail in the area, which show the neritic paleoenvironmental settings of frequent tension-faulting, strong volcanisn, steep topography and deeper water during the period of Permo-Carboniferous. The Permo-Carboniferous carbonate rock formations respeetively on the pedestals of volcanic or pyroclastic rocks, granulites from braided river or fan deltas, mudstones originated from littoral zone and shelf comprise volcano-elevated carbonate rock formation (VEF). delta-elevated carbonate rock formation (DEF), coast-subsiding carbonate rock formation (CSF) and shelf-sboaling carbonate rock formation (SSF). The formations, all of which were formed by working together of region tectonics andchange in sea level, show the distinct mechanism of construction. Among of them, the voleano-elevated formation, with volcanic or py-roclastic interbeds and prevailling in the area, originated from the relative sea level fall driven by volcano eruption r~ulting from tectonicextension, in the setting of long-term ri~ in sea level The delta-elevated formation inferior to the volcano-elevated in development,with granulite interbeds, arose from the relative swa level fall driven by braided river or fan deltas progradation r~ulting from tectonicuplifting, in the context of long-term ri~ in sea

  17. Marketing of Group Counseling Services.

    Science.gov (United States)

    Wilson, F. Robert; And Others

    1987-01-01

    Provides social marketing guidelines for attracting members of appropriate target groups and encouraging their participation in group activities. Includes examination of the personal and social framework of the group counselor, elements of social marketing theory, a case study illustrating difficulties encountered by novice group counselors in…

  18. 2010 Chemical Working Group Status

    Science.gov (United States)

    Reid, Concha M.

    2010-01-01

    The Steering Group for the Interagency Advanced Power Group (IAPG) held their business meeting on November 30-December 1st in McLean, Virginia. Status reports were presented from each of the IAPG's Working Groups. These charts contain a brief summary of the IAPG Chemical Working Group's activities during 2010 and its plans for 2011.

  19. Group B Streptococcus and Pregnancy

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ105 PREGNANCY Group B Strep and Pregnancy • What is group B streptococcus (GBS)? • What does it mean to be ... a planned cesarean birth? •Glossary What is group B streptococcus (GBS)? Group B streptococcus is one of ...

  20. About Hebei Jianxin Construction Group

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Hebei Jianxin Construction (Group) Ltd. was incorporated in August 1984. As the holding company, Hebei Jianxin Construction (Group)Ltd. along with five companies under its holding, such as Baoding New Generation Real Estate Development Co., Ltd. and Baoding New Generation Property Management Co., Ltd., formed Hebei Jianxin Architectural Group (hereafter, the Group).

  1. Graph-Constrained Group Testing

    OpenAIRE

    M. Cheraghchi; A. Karbasi; S. Mohajer; Saligrama, V.

    2012-01-01

    Non-adaptive group testing involves grouping arbitrary subsets of $n$ items into different pools. Each pool is then tested and defective items are identified. A fundamental question involves minimizing the number of pools required to identify at most $d$ defective items. Motivated by applications in network tomography, sensor networks and infection propagation, a variation of group testing problems on graphs is formulated. Unlike conventional group testing problems, each group here must confo...

  2. What Is a Group? Young Children's Perceptions of Different Types of Groups and Group Entitativity.

    Directory of Open Access Journals (Sweden)

    Maria Plötner

    Full Text Available To date, developmental research on groups has focused mainly on in-group biases and intergroup relations. However, little is known about children's general understanding of social groups and their perceptions of different forms of group. In this study, 5- to 6-year-old children were asked to evaluate prototypes of four key types of groups: an intimacy group (friends, a task group (people who are collaborating, a social category (people who look alike, and a loose association (people who coincidently meet at a tram stop. In line with previous work with adults, the vast majority of children perceived the intimacy group, task group, and social category, but not the loose association, to possess entitativity, that is, to be a 'real group.' In addition, children evaluated group member properties, social relations, and social obligations differently in each type of group, demonstrating that young children are able to distinguish between different types of in-group relations. The origins of the general group typology used by adults thus appear early in development. These findings contribute to our knowledge about children's intuitive understanding of groups and group members' behavior.

  3. Does group efficacy increase group identification? Resolving their paradoxical relationship

    NARCIS (Netherlands)

    van Zomeren, Martijn; Leach, Colin Wayne; Spears, Russell

    2010-01-01

    Although group identification and group efficacy are both important predictors of collective action against collective disadvantage, there is mixed evidence for their (causal) relationship. Meta-analytic and correlational evidence suggests an overall positive relationship that has been interpreted a

  4. Secure Group Communications for Large Dynamic Multicast Group

    Institute of Scientific and Technical Information of China (English)

    Liu Jing; Zhou Mingtian

    2003-01-01

    As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dynamic multicast group have been researched and a solution based on SubGroup Secure Controllers (SGSCs) is presented, which solves many problems in IOLUS system and WGL scheme.

  5. Infinitesimal group schemes as iterative differential Galois groups

    OpenAIRE

    Maurischat, Andreas

    2009-01-01

    This article is concerned with Galois theory for iterative differential fields (ID-fields) in positive characteristic. More precisely, we consider purely inseparable Picard-Vessiot extensions, because these are the ones having an infinitesimal group scheme as iterative differential Galois group. In this article we prove a necessary and sufficient condition to decide whether an infinitesimal group scheme occurs as Galois group scheme of a Picard-Vessiot extension over a given ID-field or not. ...

  6. Re-Examining Group Development in Adventure Therapy Groups.

    Science.gov (United States)

    DeGraaf, Don; Ashby, Jeff

    1998-01-01

    Small-group development is an important aspect of adventure therapy. Supplementing knowledge of sequential stages of group development with knowledge concerning within-stage nonsequential development yields a richer understanding of groups. Integrating elements of the individual counseling relationship (working alliance, transference, and real…

  7. Intensifying the Group Member's Experience Using the Group Log.

    Science.gov (United States)

    Valine, Warren J.

    1983-01-01

    Presents the use of a group log in which members analyze the content and process of each session using a suggested format. The log promotes dialogue between the leader and each group member and involves members more fully in the group process. Feedback indicates the log is valuable. (JAC)

  8. Structuring the Group Experience: A Format for Designing Psychoeducational Groups.

    Science.gov (United States)

    Furr, Susan R.

    2000-01-01

    Presents six-step model for moving from a general statement of purpose to a psychoeducational group design that includes didactic content, experiential activities, and processing. By following this model the group facilitator will be able to develop a psychoeducational group that provides a logical sequence of learning activities fostering…

  9. An Exploration of Group and Member Development in Experiential Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Prochenko, Yulia; Stulmaker, Hayley; Huffman, David; Fernando, Delini; Swan, Karrie

    2014-01-01

    In this phenomenological study, we explored 52 group members' development in experiential groups. Specifically, participants completed 10 weekly journal reflections about their experiences as members and also reflected on the group's overall development. Four overall themes--exploration, transition, working, closure--as well as multiple…

  10. How Much "Group" Is There in Online Group Work?

    Science.gov (United States)

    Lowes, Susan

    2014-01-01

    The ability to work in groups across time and space has become a frequent requirement for the workplace and is increasingly common in higher education, but there is a surprising lack of research on how online groups work. This research applies analytic approaches used in studies of face-to-face classroom "talk" to multiple groups in two…

  11. Ornstein-Uhlenbeck semi-groups on stratified groups

    CERN Document Server

    Lust-Piquard, Francoise

    2009-01-01

    We consider, in the setting of stratified groups G, two analogues of the Ornstein-Uhlenbeck semi-group, namely Markovian diffusion semi-groups acting on $L^q(pd g)$, whose invariant density $p$ is a heat kernel at time 1 on G.

  12. Group analysis of differential equations

    CERN Document Server

    Ovsiannikov, L V

    1982-01-01

    Group Analysis of Differential Equations provides a systematic exposition of the theory of Lie groups and Lie algebras and its application to creating algorithms for solving the problems of the group analysis of differential equations.This text is organized into eight chapters. Chapters I to III describe the one-parameter group with its tangential field of vectors. The nonstandard treatment of the Banach Lie groups is reviewed in Chapter IV, including a discussion of the complete theory of Lie group transformations. Chapters V and VI cover the construction of partial solution classes for the g

  13. Quantization on nilpotent Lie groups

    CERN Document Server

    Fischer, Veronique

    2016-01-01

    This book presents a consistent development of the Kohn-Nirenberg type global quantization theory in the setting of graded nilpotent Lie groups in terms of their representations. It contains a detailed exposition of related background topics on homogeneous Lie groups, nilpotent Lie groups, and the analysis of Rockland operators on graded Lie groups together with their associated Sobolev spaces. For the specific example of the Heisenberg group the theory is illustrated in detail. In addition, the book features a brief account of the corresponding quantization theory in the setting of compact Lie groups. The monograph is the winner of the 2014 Ferran Sunyer i Balaguer Prize.

  14. Saving Face and Group Identity

    DEFF Research Database (Denmark)

    Eriksson, Tor; Mao, Lei; Villeval, Marie-Claire

    2015-01-01

    their self- but also other group members' image. This behavior is frequent even in the absence of group identity. When group identity is more salient, individuals help regardless of whether the least performer is an in-group or an out-group. This suggests that saving others' face is a strong social norm.......Are people willing to sacrifice resources to save one's and others' face? In a laboratory experiment, we study whether individuals forego resources to avoid the public exposure of the least performer in their group. We show that a majority of individuals are willing to pay to preserve not only...

  15. Group Lasso with Overlaps: the Latent Group Lasso approach

    CERN Document Server

    Obozinski, Guillaume; Vert, Jean-Philippe

    2011-01-01

    We study a norm for structured sparsity which leads to sparse linear predictors whose supports are unions of prede ned overlapping groups of variables. We call the obtained formulation latent group Lasso, since it is based on applying the usual group Lasso penalty on a set of latent variables. A detailed analysis of the norm and its properties is presented and we characterize conditions under which the set of groups associated with latent variables are correctly identi ed. We motivate and discuss the delicate choice of weights associated to each group, and illustrate this approach on simulated data and on the problem of breast cancer prognosis from gene expression data.

  16. Nouvelles données palynologiques sur l'intervalle carbonifère viséen/moscovien - Bassin de Rhadamès (Libye. Comparaison avec les bassins sahariens. Appréciation des influences gondwaniennes et euraméricaines New Palynological Data on the Visean/Moscovian Carboniferous Interval in the Ghadames Basin (Libya. Comparison with Saharan Basins. Assesment of the Gondwanian and Euramerican Influences

    Directory of Open Access Journals (Sweden)

    Massa D.

    2006-11-01

    Full Text Available De nouvelles études palynologiques sur le Carbonifère du bassin de Rhadamès, entreprises dans l'Unité à Collenia et dans les formations Assedjefar et Dembaba, nous ont permis de préciser la palynozonation antérieurement établie (Massa et al. 1979. Une comparaison entre les divers bassins sahariens est proposée, tandis que les influences gondwaniennes et euraméricaines sont recherchées. New palynological data on the Carboniferous in the Ghadames Basin in the Collenia Unit and in the Assedjefar and Dembaba formations have been used to specify the previously established palynological zonation (Massa et al. , 1979. A comparison between the various Saharan basins is proposed, and an attempt is made to assess the Gondwanian and Euramerican influences.

  17. Riemannian means on special euclidean group and unipotent matrices group.

    Science.gov (United States)

    Duan, Xiaomin; Sun, Huafei; Peng, Linyu

    2013-01-01

    Among the noncompact matrix Lie groups, the special Euclidean group and the unipotent matrix group play important roles in both theoretic and applied studies. The Riemannian means of a finite set of the given points on the two matrix groups are investigated, respectively. Based on the left invariant metric on the matrix Lie groups, the geodesic between any two points is gotten. And the sum of the geodesic distances is taken as the cost function, whose minimizer is the Riemannian mean. Moreover, a Riemannian gradient algorithm for computing the Riemannian mean on the special Euclidean group and an iterative formula for that on the unipotent matrix group are proposed, respectively. Finally, several numerical simulations in the 3-dimensional case are given to illustrate our results.

  18. Two-transitive Lie groups

    OpenAIRE

    Kramer, Linus

    2001-01-01

    Using a characterization of parabolics in reductive Lie groups due to Furstenberg, elementary properties of buildings, and some algebraic topology, we give a new proof of Tits' classification of 2-transitive Lie groups.

  19. Cognitive Development and Group Stages.

    Science.gov (United States)

    Saidla, Debie D.

    1990-01-01

    Attempts to integrate Perry's (1970) scheme of the cognitive development of college students with a model of group development adapted by Waldo (1985) based on Tuckman's (1965) formulation of developmental group stages. (Author)

  20. Group process among novice students.

    Science.gov (United States)

    Blumkin, M K

    1996-03-01

    This paper explores the experiences of a group of registered nurses returning to graduate school. The organizing framework used is an integration of Tuckman and Jensen's group process theory and Benner's novice to expert model. PMID:8716180

  1. Alternating Quotients of Fuchsian Groups

    OpenAIRE

    Everitt, Brent

    1999-01-01

    It is shown that any finitely generated non-elementary Fuchsian group has among its homomorphic images all but finitely many of the alternating groups. This settles in the affirmative a conjecture of Graham Higman.

  2. On -supersolvability of finite groups

    Indian Academy of Sciences (India)

    Izabela Agata Malinowska

    2015-05-01

    A number of authors have studied the structure of a group under the assumption that some subgroups of are well located in . We will obtain some new criteria of -supersolvability and -nilpotency of groups.

  3. Costs of Control in Groups

    OpenAIRE

    Riener, Gerhard; Wiederhold, Simon

    2011-01-01

    This paper explores the role of social groups in explaining the reaction to control.We propose a simple model with a principal using control devices and a controlledagent, which incorporates the existence of social groups. Testing experimentally theconjectures derived from the model and related literature, we find that agents in socialgroups (i) perform more than other (no-group) agents; (ii) expect less control thanno-group agents; (iii) decrease their performance substantially when actual c...

  4. Group Norms and Consumer Behaviour

    OpenAIRE

    Pillai, Rajasekharan; Rajan, Jainey S.; Variyamveettil, Sunitha; Mathew, Dhanu E.; Nath, Subodh S.

    2011-01-01

    The impact of group norms on forming consumer behaviour is an important attribute of man’s social life. The market segmentation principles acknowledge the presence of this phenomenon. People belong to different age group, professional status, income levels, educational status etc. are seemed to display some specific consumer behaviour that can be attributed to a particular group. The present study attempts to find the influence of certain selected group norms on consumption pattern.

  5. Criminal groups and criminal subculture

    OpenAIRE

    Romanova N.M.

    2013-01-01

    The paper provides a classification of criminal groups, structured by the following parameters: a) operation mode (secret/open), b) law-enforcement and administrative support (presence/absence). We describe four types of criminal groups: a) legitimized criminal organization, b) secret criminal organization engaged in illegal business, c) secret general crime group, and d) general crime group operating openly. The four types differ in the content of criminal subculture. Modern criminal subcult...

  6. R-groups and parameters

    OpenAIRE

    Ban, Dubravka; Goldberg, David

    2011-01-01

    For classical groups we show the isomorphism of the Knapp-Stein $R$-group, which describes the structure of parabolically induced representations, and the Arthur $R$-group of the parameter associated to the inducing representation by the local Langlands conjecture. We do this in the case of inducing from discrete series representations. In the case of unitary groups we show this isomorphism under a mild assumption on the parameter, which we show holds in at least half the cases.

  7. Designing for informed group formation

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Juel Jacobsen, Alice; Riis, Marianne

    2012-01-01

    A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive...

  8. Vliv globalizace na Renault Group

    OpenAIRE

    Diviš, Petr

    2013-01-01

    This bachelor thesis describes the impact of globalization on Renault Group. The main target of the thesis is to confirm or disprove, whether Renault Group is impacted by globalization and shows it on particular examples. Firstly this bachelor thesis is occupied with general definition of globalization, afterwards with Renault Group. The final chapter interconnects knowledges from previous ones.

  9. The Variety of Group Learning

    Institute of Scientific and Technical Information of China (English)

    HaoYanyan; YuZhihao

    2004-01-01

    With the rapid enrollment expansion in the recent years,the author feels it urgent to reform the traditional group work,and therefore to form a new and more effective pattern of group learning. The new of group word is based on the principles of cooperation and that of the task with the more flexible marking system.

  10. Hierarchical classification of social groups

    OpenAIRE

    Витковская, Мария

    2001-01-01

    Classification problems are important for every science, and for sociology as well. Social phenomena, examined from the aspect of classification of social groups, can be examined deeper. At present one common classification of groups does not exist. This article offers the hierarchical classification of social group.

  11. Internal communication in corporate groups

    OpenAIRE

    Grzesik, Katarzyna

    2015-01-01

    This chapter is dedicated to internal communication in corporate groups. It discusses internal communication systems operating in the explored corporate groups and their significance for effective human resources management in those organisations. The chapter presents both the theoretical analysis based on the results of literature studies, and empirical research carried out in the explored groups. Narodowe Centrum Nauki Katarzyna Grzesik

  12. Torsion units in group rings

    OpenAIRE

    Bist, Vikas

    1992-01-01

    Let U(RG) be the unit group of the group ring RG. In this paper we study group rings RG whose support elements of every torsion unit are torsion, where R is either the ring of integers Z or a field K.

  13. K-Kolmogorov homology groups

    International Nuclear Information System (INIS)

    In the present work we use the idea of the K-groups to define the K-Kolmogorov homology groups, and their induced homomorphisms and boundary operators for the case of a pair of discrete coefficient groups, where K denotes a locally-finite simplicial complex. Moreover, we prove that our homology construction is exact. (author)

  14. Hyperbolic diagram groups are free

    OpenAIRE

    Genevois, Anthony

    2015-01-01

    In this paper, we study the so-called diagram groups. Our main result is that diagram groups are free if and only if they do not contain any subgroup isomorphic to $\\mathbb{Z}^2$. As an immediate corollary, we get that hyperbolic diagram groups are necessarily free, answering a question of Guba and Sapir.

  15. 准噶尔盆地陆东-五彩湾地区石炭系火山机构类型及其油气勘探%Volcano Types of Carboniferous and Implication of Hydrocarbon Exploration in Ludong-wucaiwan Region of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    王金秀; 杨明慧; 王东良; 兰朝利; 张君峰

    2009-01-01

    The hydrocarbon exploration of carboniferous volcanic rocks was succeeded in Ludong-Wucaiwan Region of Junggar Basin, it was indicated that it had the potential for oil and gas exploration in this area. To guide the hydrocarbon exploration effectively, the data of genesis, lithologies, facies, eruption succession assemblages and space distribution of the carboniferous volcanic rocks in Ludong-Wucaiwan Region were used based on core, mud logging, wireline logging, seismic data, gravity, magnetism and build-up depth data and their volcano types were (discussed. Study shows that the volcanic rock types are predominantly of andesites, volcanic breccias, tuffs and tuffites that resulted fromi explosion, effusion and volcanic sedimentation facies for the most parts. The volcanic rocks in Ludong-wucai-wan Region develop two typical types of eruption succession assemblages. One is characterized as intermediate-acidic lava and pyroclastic rock interbeds, they are products of stratovolcanoes development in the area of Dixi 21 to Dixi 11, the other behaves as wide distribution of intermediate-basic lavas, which may pile up from shield volcanoes at the Wucaiwan and Dishuiquan Sags. The two volcanic rock types provide an important guidance for oil and gas exploration in Ludong-Wucaiwan Region of Junggar Basin.%准噶尔盆地陆东-五彩湾地区石炭系火山岩油气勘探近年来取得了突破,表明该区具有进一步开展油气勘探的潜力.为有效指导该区石炭系火山岩油气勘探,应用岩心、录井、测井、地震、重力、磁力和建场测深资料,通过火山岩成因、岩性、岩相、喷发序列组合和空间分布研究;探讨了陆东-五彩湾地区石炭系火山机构类型.认识到陆东-五彩湾地区石炭系火山岩岩性复杂,以安山岩、火山角砾岩、凝灰岩和沉凝灰岩为主,岩相类型以爆发相、溢流相和火山沉积相最发育.该火山岩发育了两种典型喷发序列组合,一种以中酸性

  16. Estudio geocientífico aplicado a la evaluación de la aptitud para la urbanización en la cuenca carbonífera de Río Turbio, Santa Cruz Geoscientific study applied to the evaluation of urbanisation suitability at the carboniferous basin of Río Turbio, Santa Cruz

    Directory of Open Access Journals (Sweden)

    Fernando Pereyra

    2010-06-01

    Full Text Available Se realizó un estudio geocientífico para la evaluación de la aptitud para la urbanización en la cuenca carbonífera de Río Turbio. Este estudio incluyó la caracterización de los recursos naturales: suelos, agua y paisaje y la evaluación de áreas de riesgo natural y antrópico, la pérdida de espacios verdes y tierras agrícolas. La zona implicada se encuentra localizada en el extremo SO de la provincia de Santa Cruz. Conforma la llamada cuenca carbonífera del Río Turbio. Las localidades de Río Turbio y 28 de Noviembre exhiben el mayor número poblacional. Estas poblaciones se desarrollaron a partir de la actividad minera y ganadera. En función de las características geológicas, geomorfológicas, bióticas, geotécnicas, hidrológicas y edafológicas, se han diferenciado 7 unidades de paisaje. A partir de la información generada previamente y como insumo básico para la producción del plan de desarrollo urbano, se ha realizado un mapa de aptitud para la urbanización del área. Las unidades de paisaje con mejores posibilidades para la expansión urbana son dos: Morenas con estepa herbácea y planicies glacifluviales con estepa mixta. La unidad paisaje erosivo glaciar con bosque y la unidad terrazas fluviales son aceptables para la urbanización, mientras que las unidades: Cañadones y pendientes aluvio-coluviales, serranías poligenéticas terciarias y mallines y bajos, son inapropiadas para la urbanización, por diferentes motivos.A geoscientific study was accomplished to evaluate suitability for urban developments the in carboniferous basin of the Turbio River. This research included the characterization of natural resources: soil, water and landscape; the evaluation of natural and anthropic hazardous areas and the loss of farming and green lands. The implied area is located in the SW end of the Province of Santa Cruz. It is part of the carboniferous basin of the River Turbio. The towns of Rio Turbio and 28 de Noviembre hold

  17. Group Music Therapy for Prisoners

    DEFF Research Database (Denmark)

    Chen, Xi Jing; Hannibal, Niels; Xu, Kevin;

    2014-01-01

    study aims to investigate the effectiveness of group music therapy to reduce anxiety and depression, and raise self-esteem in prisoners. One hundred and ninety two inmates from a Chinese prison will be allocated to two groups through randomisation. The experimental group will participate in biweekly...... group music therapy for 10 weeks (20 sessions) while the control group will be placed on a waitlist. Anxiety, depression and self-esteem will be measured by self-report scales three times: before, at the middle, and at the end of the intervention. Logs by the participants and their daily routine...

  18. Invariant operators of inhomogeneous groups

    International Nuclear Information System (INIS)

    The problems concerning the invariant operators of the W(p, q) Weyl group of arbitrary dimension are considered. The Weyl group relative invariants, which do not contain the dilatation operators and which are the absolute invariants of the ISO (p, q) group, are searched for. The invariant operators of the Weyl group are represented in the form of the ratio of the Cazimir operators of the inhomogeneous pseudoorthogonal subgroup. It is shown that all the invariant operators of the W(p, q) Weyl group are rational and their number is [p+q-1/2

  19. Little Groups of Preon Branes

    CERN Document Server

    Mkrtchyan, H G

    2003-01-01

    Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,...,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group $T_{d-2}$ on a subgroup of (SO(d-2) $\\times$ R-invariance) group. E.g. at d=9 the subgroup is exceptional $G_2$ group. It is also argued, that 11d Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized space-times with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.

  20. Little Groups of Preon Branes

    Science.gov (United States)

    MKRTCHYAN, H.; MKRTCHYAN, R.

    Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,…,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group Td-2 on a subgroup of (SO(d-2) × R-invariance) group. E.g. at d=9 the subgroup is exceptional G2 group. It is also argued, that 11D Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized spacetimes with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.

  1. Isomorphic Commutative Group Algebras of p-Mixed Warfield Groups

    Institute of Scientific and Technical Information of China (English)

    Peter V.DANCHEV

    2005-01-01

    Let G be a p-mixed Warfield Abelian group and F a field of char F = p ≠ 0. It is proved that if for any group H the group algebras FH and FG are F-isomorphic, then H is isomorphic to G.This presentation enlarges a result of W. May argued when G is p-local Warfield Abelian and published in Proc. Amer. Math. Soc. (1988).

  2. Linear groups as right multiplication groups of quasifields

    OpenAIRE

    Nagy, Gábor P.

    2012-01-01

    For quasifields, the concept of parastrophy is slightly weaker than isotopy. Parastrophic quasifields yield isomorphic translation planes but not conversely. We investigate the right multiplication groups of finite quasifields. We classify all quasifields having an exceptional finite transitive linear group as right multiplication group. The classification is up to parastrophy, which turns out to be the same as up to the isomorphism of the corresponding translation planes.

  3. In-Group Versus Out-Group Source Memory.

    Science.gov (United States)

    Greenstein, Michael; Franklin, Nancy; Klug, Jessica

    2016-06-01

    A common finding in the source monitoring literature is that greater similarity impairs source discriminability. Experiments traditionally manipulate similarity overtly by describing or showing sources with explicitly differentiable features. However, people may also infer source characteristics themselves, which should also affect discriminability. Two studies examined inferred source characteristics by capitalizing on the out-group homogeneity effect, whereby in-group members are conceptualized as more diverse than out-group members. Participants learned about two sources who were described only as members of an in-group or an out-group and whose actions did not have higher a priori association with either group. Source memory was superior when participants believed the sources to be in-group members. This demonstrates that people spontaneously include inferred features with source representations and can capitalize on these features during source monitoring. Interestingly, information suggesting membership in one's in-group improved performance even for sources who had previously been considered out-group members (Experiment 2).

  4. Duality group actions on fermions

    CERN Document Server

    Pantev, T

    2016-01-01

    In this short paper we look at the action of T-duality and string duality groups on fermions, in maximally-supersymmetric theories and related theories. Briefly, we argue that typical duality groups such as SL(2,Z) have sign ambiguities in their actions on fermions, and propose that pertinent duality groups be extended by Z_2, to groups such as the metaplectic group. Specifically, we look at duality groups arising from mapping class groups of tori in M theory compactifications, T-duality, ten-dimensional type IIB S-duality, and (briefly) four-dimensional N=4 super Yang-Mills, and in each case, propose that the full duality group is a nontrivial Z_2 extension of the duality group acting on bosonic degrees of freedom, to more accurately describe possible actions on fermions. We also walk through U-duality groups for toroidal compactifications to nine, eight, and seven dimensions, which enables us to perform cross-consistency tests of these proposals.

  5. Group theory and its applications

    CERN Document Server

    Thapa, Ram Kumar

    2015-01-01

    Every molecule possesses symmetry and hence has symmetry operations and symmetry elements. From symmetry properties of a system we can deduce its significant physical results. Consequently it is essential to operations of a system forms a group. Group theory is an abstract mathematical tool that underlies the study of symmetry and invariance. By using the concepts of symmetry and group theory, it is possible to obtain the members of complete set of known basis functions of the various irreducible representations of the group. I practice this is achieved by applying the projection operators to linear combinations of atomic orbital (LCAO) when the valence electrons are tightly bound to the ions, to orthogonalized plane waves (OPW) when valence electrons are nearly free and to the other given functions that are judged to the particular system under consideration. In solid state physics the group theory is indispensable in the context of finding the energy bands of electrons in solids. Group theory can be applied...

  6. Group discussion improves lie detection.

    Science.gov (United States)

    Klein, Nadav; Epley, Nicholas

    2015-06-16

    Groups of individuals can sometimes make more accurate judgments than the average individual could make alone. We tested whether this group advantage extends to lie detection, an exceptionally challenging judgment with accuracy rates rarely exceeding chance. In four experiments, we find that groups are consistently more accurate than individuals in distinguishing truths from lies, an effect that comes primarily from an increased ability to correctly identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions (a "wisdom-of-crowds" effect) or of altering response biases (such as reducing the "truth bias"). Interventions to improve lie detection typically focus on improving individual judgment, a costly and generally ineffective endeavor. Our findings suggest a cheap and simple synergistic approach of enabling group discussion before rendering a judgment.

  7. Group discussion improves lie detection.

    Science.gov (United States)

    Klein, Nadav; Epley, Nicholas

    2015-06-16

    Groups of individuals can sometimes make more accurate judgments than the average individual could make alone. We tested whether this group advantage extends to lie detection, an exceptionally challenging judgment with accuracy rates rarely exceeding chance. In four experiments, we find that groups are consistently more accurate than individuals in distinguishing truths from lies, an effect that comes primarily from an increased ability to correctly identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions (a "wisdom-of-crowds" effect) or of altering response biases (such as reducing the "truth bias"). Interventions to improve lie detection typically focus on improving individual judgment, a costly and generally ineffective endeavor. Our findings suggest a cheap and simple synergistic approach of enabling group discussion before rendering a judgment. PMID:26015581

  8. Countably determined compact abelian groups

    CERN Document Server

    Dikranjan, Dikran

    2008-01-01

    For an abelian topological group G let G^* be the dual group of all continuous characters endowed with the compact open topology. A subgroup D of G determines G if the restriction homomorphism G^* --> D^* of the dual groups is a topological isomorphism. Given a scattered compact subset X of an infinite compact abelian group G such that |X|group, we show that the set of all characters which send X into U has the same size as G^*. (Here w(G) denotes the weight of G.) As an application, we prove that a compact abelian group determined by its countable subgroup must be metrizable. This gives a negative answer to questions of Comfort, Hernandez, Macario, Raczkowski and Trigos-Arrieta, as well as provides short proofs of main results established in three manuscripts by these authors.

  9. Group conflict and faculty engagement

    DEFF Research Database (Denmark)

    Selmer, Jan; Jonasson, Charlotte; Lauring, Jakob

    2013-01-01

    assessed the effect of group trust, group relational conflict and group task conflict on indicators of behavioural, cognitive and emotional engagement. Our findings show a strong positive association between group trust and all academic staff engagement variables as well as a strong negative association...... between group relational conflict and all staff engagement variables. Task conflict was negatively associated with indicators of staff cognitive engagement. However, surprisingly, group trust did not have any moderating effect. Implications for educational organisation managers and policy makers......In educational settings, substantial scholarly interest has focused on student engagement as an antecedent for educational development and positive school outcomes. Very limited research, however, has focused on the engagement of academic staff members. This may be a crucial oversight because...

  10. Statistics of sunspot group clusters

    Directory of Open Access Journals (Sweden)

    Getko Ryszarda

    2013-03-01

    Full Text Available The Zubrzycki method is utilized to find all sunspot groups which are close to each other during each Carrington rotation. The sunspot group areas and their positions for the years 1874–2008 are used. The descending, the ascending and the maximum phases of solar cycles for each solar hemisphere are considered separately. To establish the size of the region D where the clusters are searched, the correlation function dependent on the distance between two groups is applied. The method estimates the weighted area of each cluster. The weights dependent on the correlation function of distances between sunspot groups created each cluster. For each cluster the weighted position is also evaluated. The weights dependent on the areas of sunspot groups created a given cluster. The number distribution of the sunspot groups created each cluster and the cluster statistics within different phases of the 11-year cycle and within all considered solar cycles are also presented.

  11. Group Performance in Information Systems Project Groups: An Empirical Study

    Science.gov (United States)

    Bahli, Bouchaib; Buyukkurt, Meral Demirbag

    2005-01-01

    The importance of teamwork in Information Systems Development (ISD) practice and education has been acknowledged but not studied extensively to date. This paper tests a model of how groups participating in ISD projects perform and examines the relationships between some antecedents of this performance based on group research theory well…

  12. Picard Groups and Class Groups of Monoid Schemes

    OpenAIRE

    Flores, Jaret; Weibel, Charles

    2013-01-01

    We define and study the Picard group of a monoid scheme and the class group of a normal monoid scheme. To do so, we develop some ideal theory for (pointed abelian) noetherian monoids, including primary decomposition and discrete valuations. The normalization of a monoid turns out to be a monoid scheme, but not always a monoid.

  13. The Local Group and other neighboring galaxy groups

    CERN Document Server

    Karachentsev, I D

    2004-01-01

    Over the last few years, rapid progress has been made in distance measurements for nearby galaxies based on the magnitude of the tip of red giant branch stars. Current CCD surveys with HST and large ground- based telescopes bring $\\sim$10%-accurate distances for roughly a hundred galaxies within 5 Mpc. The new data on distances to galaxies situated in (and around) the nearest groups: the Local Group, M81 group, CenA/M83 group, IC342/Maffei group, Sculptor filament, and Canes Venatici cloud allowed us to determine their total mass from the radius of the zero- velocity surface, $R_0$, which separates a group as bound against the homogeneous cosmic expansion. The values of $R_0$ for the virialized groups turn out to be close each other, in the range of 0.9 -- 1.3 Mpc. As a result, the total masses of the groups are close to each other, too, yielding total mass-to-blue luminosity ratios of 10 -- 40 $M_{\\sun}/L_{\\sun}$. The new total mass estimates are 3 -- 5 times lower than old virial mass estimates of these gro...

  14. Platinum-group elements in the Eastern Deccan volcanic province and a comparison with platinum metals of the western Deccan

    Indian Academy of Sciences (India)

    James Crocket; Dalim Paul; Trisha Lala

    2013-08-01

    This study is the first detailed investigation of the platinum-group elements (PGE) at the eastern margin of the Deccan volcanic province of India. One of the PGE, osmium, is not included largely because of analytical problems. The study is focused on mafic volcanics and dykes from four areas including Amarkantak, Umaria, Shahdol and Chirimiri. The first two localities represent two lava piles of about 170 and 400 m thickness respectively. In Umaria, 16 flows have been demarcated based on petrography and field studies. The Shahdol samples are basal lava formations overlying Gondwana sediments (Carboniferous) and the Chirimiri samples are dykes. In this study, the western Deccan province is defined as the Western Ghats plus Kutch. On average, the PGE are ∼20% higher in Amarkantak than Umaria and the flows are ∼13% higher in PGE than the dykes. A Zr vs. Pd scattergram found a strong positive correlation for these two elements except for one Umaria sample which indicated severe Pd loss. A comparison of west and east parts of the Deccan volcanic province using primitive mantle normalization showed that higher values prevailed in the western province suite in the Ni-Ir-Ru-Pt region. In contrast, eastern province values dominated in the Pd-Au-Cu region at the ‘Cu’ end of the profiles. A strong dominance of Pd in the eastern Deccan was also of interest. A number of factors, for example, percentage partial melting of the source rock and the temperature and pressure of partial melting strongly influence the character of these profiles. The observed PGE profile characteristics probably result in part from a long distance of subsurface transport of Deccan magma from the western to eastern regions.

  15. Classifying Virtually Special Tubular Groups

    OpenAIRE

    Woodhouse, Daniel J.

    2016-01-01

    A group is tubular if it acts on a tree with $\\mathbb{Z}^2$ vertex stabilizers and $\\mathbb{Z}$ edge stabilizers. We prove that a tubular group is virtually special if and only if it acts freely on a locally finite CAT(0) cube complex. Furthermore, we prove that if a tubular group acts freely on a finite dimensional CAT(0) cube complex, then it virtually acts freely on a three dimensional CAT(0) cube complex.

  16. Complex cobordism and formal groups

    Science.gov (United States)

    Buchstaber, Viktor M.

    2012-10-01

    This paper surveys the current state of the theory of cobordism, focusing on geometric and universal properties of complex cobordism, the Landweber-Novikov algebra, and the formal group law of geometric cobordisms. The relationships with K-theory, algebraic cycles, formal group laws, compact Lie group actions on manifolds, toric topology, infinite-dimensional Lie algebras, and nilmanifolds are described. The survey contains key results and open problems. Bibliography: 124 titles.

  17. Arithmetic Aspects of Bianchi Groups

    CERN Document Server

    Sengun, Mehmet Haluk

    2012-01-01

    We discuss several arithmetic aspects of Bianchi groups, especially from a computational point of view. In particular, we consider computing the homology of Bianchi groups together with the Hecke action, connections with automorphic forms, abelian varieties, Galois representations and the torsion in the homology of Bianchi groups. Along the way, we list several open problems and conjectures, survey the related literature, presenting concrete examples and numerical data.

  18. Strategies of learning in groups

    OpenAIRE

    Göğüş, Aytaç; Gogus, Aytac; Arıkan, Huriye; Arikan, Huriye

    2009-01-01

    This paper presents the theoretical bases and applications of learning in groups and the impact of a student support program on supporting the quality of learning in higher education. A student support program, Academic Support Program (ASP) that captures the basis for various ‘active learning’ methods by implementing ‘learning in groups and learning from peers’ strategies, is represented in this paper. The peer study discussion groups of ASP allow university students to have permanent and me...

  19. Group discussion improves lie detection

    OpenAIRE

    Klein, Nadav; Epley, Nicholas

    2015-01-01

    Detecting lies is difficult. Accuracy rates in experiments are only slightly greater than chance, even among trained professionals. Costly programs aimed at training individual lie detectors have mostly been ineffective. Here we test a different strategy: asking individuals to detect lies as a group. We find a consistent group advantage for detecting small “white” lies as well as intentional high-stakes lies. This group advantage does not come through the statistical aggregation of individual...

  20. Taxonomy Working Group Final Report

    Science.gov (United States)

    Parsons, Vickie S.; Beil, Robert J.; Terrone, Mark; Barth, Timothy S.; Panontin, Tina L.; Wales, Roxana; Rackley, Michael W.; Milne, James S.; McPherson, John W.; Dutra, Jayne E.; Shaw, Larry C.

    2009-01-01

    The purpose of the Taxonomy Working Group was to develop a proposal for a common taxonomy to be used by all NASA projects in the classifying of nonconformances, anomalies, and problems. Specifically, the group developed a recommended list of data elements along with general suggestions for the development of a problem reporting system to better serve NASA's need for managing, reporting, and trending project aberrant events. The Group's recommendations are reported in this document.

  1. Automorphism groups of some algebras

    Institute of Scientific and Technical Information of China (English)

    PARK; Hong; Goo; LEE; Jeongsig; CHOI; Seul; Hee; NAM; Ki-Bong

    2009-01-01

    The automorphism groups of algebras are found in many papers. Using auto-invariance, we find the automorphism groups of the Laurent extension of the polynomial ring and the quantum n-plane (respectively, twisting polynomial ring) in this work. As an application of the results of this work, we can find the automorphism group of a twisting algebra. We define a generalized Weyl algebra and show that the generalized Weyl algebra is simple. We also find the automorphism group of a generalized Weyl algebra. We show that the generalized Weyl algebra Am,m+n is the universal enveloping algebra of the generalized Witt algebra W(m,m + n).

  2. Bosonization and Lie Group Structure

    CERN Document Server

    Ha, Yuan K

    2015-01-01

    We introduce a concise quantum operator formula for bosonization in which the Lie group structure appears in a natural way. The connection between fermions and bosons is found to be exactly the connection between Lie group elements and the group parameters. Bosonization is an extraordinary way of expressing the equation of motion of a complex fermion field in terms of a real scalar boson in two dimensions. All the properties of the fermion field theory are known to be preserved under this remarkable transformation with substantial simplification and elucidation of the original theory, much like Lie groups can be studied by their Lie algebras.

  3. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.;

    2014-01-01

    , to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual...... in non-ideal scenarios, we show that generally the estimation of models of this type is both feasible and ecologically informative. We illustrate the approach using real movement data from 11 reindeer (Rangifer tarandus). Results indicate a directional bias towards a group centroid for reindeer...

  4. Strategic Groups and Banks’ Performance

    Directory of Open Access Journals (Sweden)

    Gregorz Halaj

    2009-06-01

    Full Text Available The theory of strategic groups predicts the existence of stable groups of companies that adopt similar business strategies. The theory also predicts that groups will differ in performance and in their reaction to external shocks. We use cluster analysis to identify strategic groups in the Polish banking sector. We find stable groups in the Polish banking sector constituted after the year 2000 following the major privatisation and ownership changes connected with transition to the mostly-privately-owned banking sector in the late 90s. Using panel regression methods we show that the allocation of banks to groups is statistically significant in explaining the profitability of banks. Thus, breaking down the banks into strategic groups and allowing for the different reaction of the groups to external shocks helps in a more accurate explanation of profits of the banking sector as a whole.Therefore, a more precise ex ante assessment of the loss absorption capabilities of banks is possible, which is crucial for an analysis of banking sector stability. However, we did not find evidence of the usefulness of strategic groups in explaining the quality of bank portfolios as measured by irregular loans over total loans, which is a more direct way to assess risks to financial stability.

  5. The Nearest Group of Galaxies

    CERN Document Server

    Van den Bergh, S

    1999-01-01

    The small Antlia-Sextans clustering of galaxies is located at a distance of only 1.36 Mpc from the Sun, and 1.72 Mpc from the adopted barycenter of the Local Group. The latter value is significantly greater than the radius of the zero- velocity surface of the Local Group which, for an assumed age of 14 Gyr, has Ro = 1.18 " 0.15 Mpc. This, together with the observation that the members of the Ant-Sex group have a mean redshift of +114 " 12 km s-1 relative to the centroid of the Local Group, suggests that the Antlia-Sextans group is not bound to our Local Group, and that it is expanding with the Hubble flow. If this conclusion is correct, then Antlia-Sextans may be the nearest external clustering of galaxies. The total galaxian population of the Ant-Sex group is ~ 1/5 that of the Local Group. However, the integrated luminosity of Ant-Sex is two orders of magnitude lower than that of the Local Group. Subject headings: Galaxies - clusters: individual (Antlia-Sextans)

  6. Automorphism groups of some algebras

    Institute of Scientific and Technical Information of China (English)

    PARK Hong Goo; LEE Jeongsig; CHOI Seul Hee; CHEN XueQing; NAM Ki-Bong

    2009-01-01

    The automorphism groups of algebras are found in many papers. Using auto-invariance, we find the automorphism groups of the Laurent extension of the polynomial ring and the quantum n-plane (respectively, twisting polynomial ring) in this work. As an application of the results of this work, we can find the automorphism group of a twisting algebra. We define a generalized Weyl algebra and show that the generalized Weyl algebra is simple. We also find the automorphism group of a generalized Weyl algebra. We show that the generalized Weyl algebra Am,m+n is the universal enveloping algebra of the generalized Witt algebra W(m, m+n).

  7. The Nearest Group of Galaxies

    Science.gov (United States)

    van den Bergh, Sidney

    1999-06-01

    The small Antlia-Sextans clustering of galaxies is located at a distance of only 1.36 Mpc from the Sun and 1.72 Mpc from the adopted barycenter of the Local Group. The latter value is significantly greater than the radius of the zero-velocity surface of the Local Group that, for an assumed age of 14 Gyr, has R0=1.18+/-0.15 Mpc. This, together with the observation that the members of the Ant-Sex group have a mean redshift of 114+/-12 km s-1 relative to the centroid of the Local Group, suggests that the Antlia-Sextans group is not bound to our Local Group and that it is expanding with the Hubble flow. If this conclusion is correct, then Antlia-Sextans may be the nearest external clustering of galaxies. The total galactic population of the Ant-Sex group is ~1/5 that of the Local Group. However, the integrated luminosity of Ant-Sex is 2 orders of magnitude lower than that of the Local Group.

  8. Group Connectivity and Group Colorings of Graphs - A Survey

    Institute of Scientific and Technical Information of China (English)

    Hong-Jian LAI; Xiangwen LI; Yehong SHAO; Mingquan ZHAN

    2011-01-01

    In 1950s, Tutte introduced the theory of nowhere-zero flows as a tool to investigate the coloring problem of maps, together with his most fascinating conjectures on nowhere-zero flows. These have been extended by Jaeger et al. In 1992 to group connectivity, the nonhomogeneous form of nowhere-zero flows. Let G be a 2-edge-connected undirected graph, A be an (additive) abelian group and A* = A - {0}. The graph G is A-connected if G has an orientation D(G) such that for every each vertex v ∈ V(G), the total amount of f-values on the edges directed out from v minus the total amount of f-values on the edges directed into v is equal to b(v). The group coloring of a graph arises from the dual concept of group connectivity. There have been lots of investigations on these subjects.This survey provides a summary of researches on group connectivity and group colorings of graphs. It contains the following sections.1. Nowhere-zero Flows and Group Connectivity of Graphs 2. Complete Families and A-reductions 3. Reductions with Edge-deletions, Vertex-deletions and Vertex-splitting 4. Group Colorings as a Dual Concept of Group Connectivity 5. Brooks Theorem, Its Variations and Dual Forms 6. Planar Graphs 7. Group Connectivity of Graphs 7.1 Highly Connected Graphs and Collapsible Graphs 7.2 Degrees Conditions 7.3 Complementary Graphs 7.4 Products of Graphs 7.5 Graphs with Diameter at Most 2 7.6 Line Graphs and Claw-Free Graphs 7.7 Triangular Graphs 7.8 Claw-decompositions and All Tutte-orientations

  9. Group decision-making: Factors that affect group effectiveness

    Directory of Open Access Journals (Sweden)

    Juliana Osmani

    2016-03-01

    Full Text Available Organizations are operating in a dynamic and turbulent environment. In these conditions, they have to make decisions for new problems or situations. Most of decisions are therefore non-programmed and unstructured, accompanied by risk and uncertainty. Moreover, the problems and situations are complex. All organizations are oriented towards group decisionmaking processes, as useful tools to cope with uncertainty and complexity. Apart from the necessity, companies are turning towards participatory processes also to benefit from the important advantages that these processes offer. Organizations have realized the importance of group decision-making processes to contribute to the creation of sustainable competitive advantages. Main objective of this paper is to show that group decision-making processes do not offer guarantee for good decisions, because the effectiveness of group is affected by many factors. So, the first thing done in this paper is discussing about the benefits and limitations that accompany the use of groups with decision-making purpose. Afterwards, we stop on the different factors that influence the group’s ability to make good decisions. The aim is to emphasize that regardless of the many advantages of groups, some factors as group size, type of communication within the group, leadership style, the norms, the differentiation of roles and statuses, cohesion and compliance degree should be the main elements to keep into consideration because they affect the effectiveness of group. In this regard, is discussed how such factors influence the quality of decision and then we try to draw some conclusions that can improve and make better and easier group decision-making processes.

  10. Group Intervention in Pediatric Rehabilitation

    Science.gov (United States)

    LaForme Fiss, Alyssa

    2012-01-01

    Group intervention in pediatric physical and occupational therapy is an alternative to individual intervention allowing the therapist to meet the needs of multiple children at one time. Survey research indicates that approximately 40% to 60% of pediatric physical and occupational therapists use group intervention at least occasionally in practice,…

  11. Play and Positive Group Dynamics

    Science.gov (United States)

    Thompson, Pam; White, Samantha

    2010-01-01

    Play is an important part of a child's life and essential to learning and development (Vygotsky, 1978). It is vital that students participate in play and that play be conducted in a restorative manner. Play allows a variety of group dynamics to emerge. Irvin Yalom (1995) identifies 11 curative factors of the group experience. These factors include…

  12. My Career: Group Fitness Instructor

    Science.gov (United States)

    Green, Kathleen

    2013-01-01

    This article presents an interview with Tammy Kenney, who teaches a yoga-Pilates class in several different gyms. In this interview, Kenney talks about her career as a group fitness instructor and gives her best advice for someone who wants to teach group fitness.

  13. Exploring Interpersonal Compatibility in Groups.

    Science.gov (United States)

    Keyton, Joann

    This study investigated William Schutz's three-dimensional theory of interpersonal behavior and compatibility (FIRO) to determine its validity as a group measure of compatibility. Data were collected from 248 students enrolled in a multi-section course in small group communications at a large midwestern university. Subjects self-selected…

  14. Group Work with Transgender Clients

    Science.gov (United States)

    Dickey, Lore M.; Loewy, Michael I.

    2010-01-01

    Drawing on the existing literature, the authors' research and clinical experiences, and the first author's personal journey as a member and leader of the transgender community, this article offers a brief history of group work with transgender clients followed by suggestions for group work with transgender clients from a social justice…

  15. SOME IDEAS ON GROUP WORK

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Group work is a widely adopted activity in the oral English class, and certainly boasts a number of advantages. However, problems may occur in the organization of group discussions and the reports afterwards. This paper puts forward some suggestions for solving these problems.

  16. Group Work in Science Classrooms

    Science.gov (United States)

    McGregor, Debbie; Tolmie, Andrew

    2009-01-01

    This article considers how students might work together in small groups, from two to eight, in either a primary or secondary science classroom. The nature of group work can vary widely and could include, for example, a pair carrying out an illustrative experiment, a trio or quad debating climate change, or six or seven rehearsing how they will…

  17. Challenges Facing Group Work Online

    Science.gov (United States)

    Chang, Bo; Kang, Haijun

    2016-01-01

    Online group work can be complicated because of its asynchronous characteristics and lack of physical presence, and its requirements for skills in handling technology, human relationships, and content-related tasks. This study focuses on the administrative, logistical and relationship-related challenges in online group work. Challenges in areas…

  18. Group Invariance in Mathematical Morphology

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1995-01-01

    In this paper we discuss how invariance of operators arising in binary mathematical morphology can be achieved for the collection of groups commonly denoted as `the computer vision groups'. We present an overview, starting with set mappings such as dilations, erosions, openings and closings, which a

  19. Group Process and Sex Differences.

    Science.gov (United States)

    Kahn, Lynn Sandra

    1984-01-01

    Investigated theme development and role types in eight same-sex, self-analytic groups with male or female leadership, through the use of The General Inquirer, a computerized program of content analysis. All groups, male and female, showed a significant increase in the use of AFFILIATION words over time. (BH)

  20. The structure of approximate groups

    CERN Document Server

    Breuillard, Emmanuel; Tao, Terence

    2011-01-01

    Let K >= 1 be a parameter. A K-approximate group is a finite set A in a (local) group which contains the identity, is symmetric, and such that A^2 is covered by K left translates of A. The main result of this paper is a qualitative description of approximate groups as being essentially finite-by-nilpotent, answering a conjecture of H. Helfgott and E. Lindenstrauss. This may be viewed as a generalisation of the Freiman-Ruzsa theorem on sets of small doubling in the integers to arbitrary groups. We begin by establishing a correspondence principle between approximate groups and locally compact (local) groups that allows us to recover many results recently established in a fundamental paper of Hrushovski. In particular we establish that approximate groups can be approximately modeled by Lie groups. To prove our main theorem we apply some additional arguments essentially due to Gleason. These arose in the solution of Hilbert's fifth problem in the 1950s. Applications of our main theorem include a finitary refineme...