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Sample records for carboniferous period

  1. 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.

  2. Division of carboniferous lycospores

    Czech Academy of Sciences Publication Activity Database

    Bek, Jiří

    Prague : National Museum, 2006. s. 12-12. ISBN 80-7036-198-0. [European Palaeobotany- Palynology Conference /7./. 06.09.2006-11.09.2006, Prague] R&D Projects: GA AV ČR IAA3013902 Institutional research plan: CEZ:AV0Z30130516 Keywords : lycospores * palynology * Carboniferous Subject RIV: EF - Botanics

  3. Melo carboniferous basin

    International Nuclear Information System (INIS)

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

  4. 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.

  5. 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...

  6. 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.

  7. Carboniferous and Permian magmatism in Scotland

    OpenAIRE

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

    2004-01-01

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

  8. 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...... species in the lower to middle Westphalian Stage, falling to about 40–50 species in the upper Westphalian Stage. Regional-scale diversity (within an area > 105 km2) is difficult to estimate but was at least 120 species. Species turn-over was typically very low, at about 4 species per million years, but...

  9. Periodization

    OpenAIRE

    Lorenz, Daniel S.; Reiman, Michael P.; Walker, John C.

    2010-01-01

    Background: Clinicians are constantly faced with the challenge of designing training programs for injured and noninjured athletes that maximize healing and optimize performance. Periodization is a concept of systematic progression—that is, resistance training programs that follow predictable patterns of change in training variables. The strength training literature is abundant with studies comparing periodization schemes on uninjured, trained, and untrained athletes. The rehabilitation litera...

  10. 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

  11. 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

    in the Dianqiangui basin and its adjacent areas in terms of two types of facies-changing surfaces as well as two kinds of diachronism in stratigraphic records. The sequence-stratigraphic subdivisions from the Carboniferous to the Permian Chuanshanian epoch in the study area show that the duration of third-order sequences, formed in the convergent period of Pangea, is more than 10 Ma. This could reflect the elementary feature that the period of sea-level change cycles formed in a relatively quiet period of tectonic action is more than 10 Ma. And this succession shows a marked cyclicity which is supposed to be the low-latitude response to the Gondwanan glaciation in the southern hemisphere.

  12. 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

  13. Taxonomy and stratigraphic importance of the Carboniferous miospore genus Vestispora

    Czech Academy of Sciences Publication Activity Database

    Bek, Jiří; Dimitrova, T.

    2014-01-01

    Roč. 202, March (2014), s. 15-28. ISSN 0034-6667 R&D Projects: GA AV ČR IAA301110701 Institutional support: RVO:67985831 Keywords : Vestispora * stratigraphy * Carboniferous * dispersed in situ spores Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.940, year: 2014

  14. Late Carboniferous to Late Permian carbon isotope stratigraphy

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  15. 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

  16. Molybdenum isotopic composition of modern and Carboniferous carbonates

    OpenAIRE

    Voegelin, Andrea R.; Nägler, Thomas F.; Samankassou, Elias; Villa, Igor M.

    2009-01-01

    We investigate the redox-sensitive isotope system of molybdenum (Mo) in marine carbonates to evaluate their potential as archive of the Mo isotopic composition of coeval seawater. We present Mo isotope data (δ98/95Mo) of modern skeletal and non-skeletal carbonates as well as a variety of precipitates from the mid and late Carboniferous. The external reproducibility is determined by repeated analyses of two commercially available carbonate standards. The resulting uncertainty of the low concen...

  17. Isotope tools to support conceptual model building of the Carboniferous limestone aquifer of Northern France and Belgium

    Science.gov (United States)

    Gourcy, L.; Castres de Paulet, F.; Rorive, A.; Bastien, J.

    2012-04-01

    Since the beginning of the 20th century, the Carboniferous aquifer was known as a high potential limestone aquifer. Groundwater has been exploited for decades to provide drinkable water and supply heavy factories in north of France and Belgium. Over-pumped during the last century, the Carboniferous aquifer has seen its water level dramatically decreased between Lille (Fr), Mouscron and Tournai (Be). Since the end of industrial period and some agreements to reduce pumpings, groundwater consumption has declined and water table is now stabilized and slowly coming back to a more "natural" level in some areas. In order to sustainably manage this aquifer, French and Belgian environmental agencies and local authorities underlined the need of a better hydrogeological knowledge. Within the framework of the "Scaldwin" project (launched in 2008), a hydrogeological model will be built. To reach these objectives, existing data were compiled, updated and treated. Moreover, new data were collected since 2009: 11 boreholes were drilled, 2 piezometrical maps were drawn and 2 field sampling campaigns were carried out in March and November 2011 to collect groundwater for further analyses. As a first step, the conceptual hydrogeological map was reviewed considering new knowledge of the geometry and water levels of this aquifer. Then, the hydrogeochemical study was undertaken in order to dispel doubts on some specific aspects such as: relationships between the deep (carbonated Carboniferous) and the surface (chalky Cretaceous) aquifers, delineation of the southern Carboniferous aquifer limit, mechanisms of sulphate enrichment… Major and trace elements, dissolved gases (CFC-11, CFC-12, CFC-113, SF6) and various isotopes (δ2H, δ18O, δ11B, δ34S, δ18O-SO4, δ13C, 14C) were analysed in water sampled from 36 wells exploiting the Carboniferous limestones (16 in the French part and 20 in Belgium) and 4 waters from the chalk aquifer. Cation exchange process is playing an important role

  18. 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. 

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Origin of natural waters and gases within the Upper Carboniferous coal-bearing and autochthonous Miocene strata in South-Western part of the Upper Silesian Coal Basin, Poland

    International Nuclear Information System (INIS)

    The molecular and stable isotope compositions of coalbed gases from the Upper Carboniferous strata and natural gases accumulated within the autochthonous Upper Miocene Skawina Formation of the Debowiec-Simoradz gas deposit were determined, as well as the chemical and stable isotope compositions of waters from the Skawina Formation and waters at the top of the Upper Carboniferous strata of the Kaczyce Ridge (the abandoned 'Morcinek' coal mine) in the South-Western part of the Upper Silesian Coal Basin. Two genetic types of natural gases within the Upper Carboniferous coal-bearing strata were identified: thermogenic (CH4, small amounts of higher gaseous hydrocarbons, and CO2) and microbial (CH4, very small amounts of ethane, and CO2). Thermogenic gases were generated during the bituminous stage of coalification and completed at the end of the Variscan orogeny. Degassing (desorption) of thermogenic gases began at the end of late Carboniferous until the late Miocene time-period and extended to the present-day. This process took place in the Upper Carboniferous strata up to a depth of about 550 m under the sealing Upper Miocene cover. A primary accumulation zone of indigenous, thermogenic gases is present below the degassing zone. Up to 200 m depth from the top of the Upper Carboniferous strata, within the weathered complex, an accumulation zone of secondary, microbial gas occurs. Waters within these strata are mainly of meteoric origin of the infiltration period just before the last sea transgression in the late Miocene and partly of marine origin having migrated from the Upper Miocene strata. Then, both methanogenic archaebacteria and their nutrients were transported by meteoric water into the near-surface Carboniferous strata where the generated microbial CH4 saturated coal seams. Waters within the Miocene strata of the Debowiec-Simoradz and Zablocie are of marine origin, and natural gases accumulated within autochthonous Miocene strata of the Debowiec-Simoradz gas

  4. 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.

  5. Abrupt ocean anoxia and mass extinction at the Hangenberg crisis, Devonian-Carboniferous boundary

    Science.gov (United States)

    Schmitz, M. D.; Davydov, V. I.

    2012-12-01

    The late Devonian period hosts a set of profound biotic crises accompanying episodes of tropical ocean anoxia, positive carbon isotope excursions, relative sea level rise and fall, and apparent global climatic cooling. The Hangenberg event, at the close of the Devonian, is the last of these crises which ushered in a new and long-lived icehouse climate regime spanning the Carboniferous and early Permian. New high-precision U-Pb zircon ages for bracketing volcanic tuffs constrain the timing and tempo of the Hangenberg biotic crisis. When combined with quantitative biostratigraphic analysis, these data constrain the duration of tropical ocean anoxia, mass extinction and carbon cycle perturbation to less than 100 thousand years. This rapidity and duration is consistent with a model of orbitally-forced cooling resulting in enhancement of oceanic circulation, in turn promoting catastrophic overturn, upwelling of anoxic bottom waters onto the tropical continental shelves, and consequent biotic reorganization. Enhanced organic carbon burial evidenced by a positive carbon isotope spike is also revealed as rapid and short-lived, but sufficient to draw down atmospheric CO2 and initiate a glacial pulse restricted to a single short period eccentricity cycle at the end-Devonian.

  6. Ostracods and sedimentology of the Devonian-Carboniferous stratotype section (La Serre, Montagne Noire, France)

    OpenAIRE

    Casier, J.-G.; Lethiers, F; Préat, A.

    2002-01-01

    Despite their low abundance, ostracods are very diversified in the La Serre Devonian-Carboniferous (= D-C) Global Stratotype Section and Point (= GSSP). Seventy-one species are identified, 58 in the Devonian and 29 in the Carboniferous. The ostracod fauna is composed of ostracods belonging to the Eifelian ecotype alone or to a mixed assemblage of the Eifelian and Thuringian ecotypes. The relative abundance of these two ecotypes, the abnormal number of instars in some beds, the presence of ost...

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

    OpenAIRE

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

    2012-01-01

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

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

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    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.

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

    OpenAIRE

    Selden, Paul A; Dunlop, Jason A.; LUCA SIMONETTO

    2016-01-01

    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.

  11. 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

  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. A structural reinterpretation of the enigmatic Carboniferous miospore Pteroretis Felix & Burbridge 1961 emend. Nov

    Czech Academy of Sciences Publication Activity Database

    McLean, D.; Owens, B.; Bek, Jiří; Oliwkiewicz-Miklasinska, M.

    2006-01-01

    Roč. 30, č. 1 (2006), s. 17-32. ISSN 0191-6122 R&D Projects: GA AV ČR IAA3013306 Institutional research plan: CEZ:AV0Z30130516 Keywords : biostratigraphy * Carboniferous * costate miospores * cuppa structures * Operculate * taxonomy Subject RIV: EF - Botanics

  14. 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

  15. An Early Cambrian archaeocyath–trilobite fauna in limestone erratics from the Upper Carboniferous Fitzroy Tillite Formation, Falkland Islands

    OpenAIRE

    Stone, P; Thomson, M.R.A; Rushton, A.W.A.

    2012-01-01

    Rare clasts of limestone contained in the uppermost Carboniferous Fitzroy Tillite Formation of the Falkland Islands contain a rich Cambrian fauna of archaeocyaths together with a radiocyath and a few trilobites. Neither Cambrian strata nor limestone are present in the indigenous rock succession and the clasts are regarded as exotic erratics, introduced during the Permo-Carboniferous glaciation of southern Gondwana, prior to its Mesozoic break-up. Nineteen archaeocyath taxa have been identifie...

  16. 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.

  17. 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.

  18. Molecular characterization of flash pyrolysates of two Carboniferous coals and their constituting maceral fractions

    OpenAIRE

    J. S. Sinninghe Damsté; Hartgers, W.A.; Ling, Y.; Leeuw, J. W.; Dyrckacz, G.

    1994-01-01

    Two high-volatile bituminous Upper Carboniferous coals from the Argonne Premium Coal Set and their constituting liptinite, vitrinite, and inertinite fractions, obtained by density gradient centrifugation (DGC), were characterized by Curie point pyrolysis-gas chromatography-mass spectrometry. A detailed analysis of the pyrolysis products was performed to relate individual macerals to their (plant-derived) precursors. Liptinite fractions were found to be mainly composed of sporinite, the diagen...

  19. Mass extinctions, climatic and oceanographic changes at the Devonian/Carboniferous boundary

    OpenAIRE

    Kaiser, Sandra Isabella

    2005-01-01

    A positive carbon isotope excursion is reported for the global Hangenberg Event at the Devonian/Carboniferous boundary, revealed by a correlation of Austrian, Italian, French and German sections using high-resolution conodont biostratigraphy. The δ13Ccarb,org excursions indicate global change in the isotopic composition of marine dissolved HCO3- and atmospheric CO2, which resulted from the increased burial of organic matter by globally widespread black shale deposition during high...

  20. Ostracods and lithofacies of the Devonian-Carboniferous boundary beds in the Avesnois, North of France

    OpenAIRE

    Casier, J.-G.; Préat, A.

    2003-01-01

    Seven major carbonate microfacies are defined in the Devonian-Carboniferous (D-C) transitional strata (90 m) of the Bocahut quarry (Avesnes "basin"), and ten levels ranging through the Epinette, Etroeungt, Avesnelles and Hastiere formations are recognized. The "bathymetric" sequences range from open marine spiculite, below the storm wave base to semi-restricted lagoon. A standard sequence records a shallowing-upward trend, from environments below the storm wave base to strongly eroded suprati...

  1. Magnetic fabric of the upper carboniferous molasse sediments (upper Silesian coal basin, Poland)

    International Nuclear Information System (INIS)

    Complete text of publication follows. The Upper Silesian Coal Basin (USCB), considered as a foredeep of the Variscan Moravo-Silesian Fold Zone, is situated in the borderland of Poland and Czech Republic. Upper Carboniferous coal-bearing molasse developed in the NE part of the Moravo-Silesian Basin on the Lower Carboniferous flysch sediments. Depositional process took place in the compressional regime, during the latest stages of the basin's closure. Numerous structural analyses and models revealed several stages of structural development in the USCB. The current tectonic style of the rock sequences is thought to be formed mainly during the 'after Namurian A' stage with maximum compression axis changing from NE-SW to N-S direction. Conventional anisotropy of magnetic susceptibility measurements were performed to analyze relations between magnetic fabric and structural development of the basin. Over 200 oriented samples from Namurian and Westphalian molasse association (mudstones, sandstones) were selected from six brickyards and mines. Variability of AMS trend was analyzed in all of the sites respectively. In addition, anisotropy of remanence was measured, as well as detailed rock magnetic studies were performed, to test the reliability of the obtained AMS data. Measured magnetic fabric is of sedimentary origin or typical for the earliest deformational stages. Bedding-parallel foliation with maximum anisotropy axes trending NNE-SSW to NE-SW suggest NW-SE structural shortening direction. AMS pattern is comparable with the data from some slightly deformed Lower Carboniferous flysch deposits, located SE from USCB, in the Czech Republic. It corresponds also with Moravo-Silesian folds and thrusts direction. Obtained results are contrary to the main deformational stage, however they are consistent with models, where the principal stress axis is oriented approximately NW-SE. Therefore, AMS data from the Upper Carboniferous molasse sediments reflect probably tectonic regime

  2. Baseline Scotland : groundwater chemistry of the Carboniferous sedimentary aquifers of the Midland Valley

    OpenAIRE

    O Dochartaigh, B.E.; Smedley, P. L.; MacDonald, A.M.; Darling, W. G.; Homoncik, S.

    2011-01-01

    This report describes the baseline groundwater chemistry of the sedimentary aquifers of Carboniferous age in the Midland Valley of Scotland. Groundwater is an important resource in the Midland Valley, largely for agriculture, but also for industry – including food and drink processing and mineral water bottling, and for domestic use. A large but unquantified volume of groundwater is also still pumped from former mine workings, largely coal mines, in order to maintain water levels and for qual...

  3. 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.

  4. Lead distribution in Permo-Carboniferous coal from the North China Plate, China.

    Science.gov (United States)

    Kunli, Luo; Jidong, Lu; Lianwu, Chen

    2005-02-01

    The content and distribution of the lead in coal, gangue and the sulfur ball and the pyritic gangue of the Permo-Carboniferous in the North China Plate have been systematically studied (nearly 300 samples) in this paper. The Permo-Carboniferous coals in the North China Plate account for nearly 44.45% of total Chinese coal resources, and most of the steam coals in China come from the Permo-Carboniferous coals in the North China Plate. The result shows that lead content in the coal varied from 1.45 to 63.60 mg kg(-1), averaging 23.95 mg kg(-1); the lead content of the sulfur ball and the pyritic gangue in the coal seam ranges from 70.26-1060 mg kg(-1), with an average of 271.28 mg kg(-1); the lead content of the gangue is from 29.5 to 77.81 mg kg(-1), averaging at 40.77 mg kg(-1). The lead in the coal seam is mainly concentrated in the pyrite, such as sulfur ball, pyritic gangue or pyrite, and is the least concentrated in the organic of coal. The content of the lead has a direct ratio with the ash and the pyretic sulfur. Coal washing can reduce the content of the pyretic sulfur and the lead. PMID:15688128

  5. Sedimentology, conodonts and ostracods of the Devonian - Carboniferous strata of the Anseremme railway bridge section, Dinant Basin, Belgium

    Science.gov (United States)

    Casier, J.-G.; Mamet, B.; Preat, A.; Sandberg, C.A.

    2004-01-01

    as Late praesulcata Zone, with the Early and Middle praesulcata Zones unrepresented because of an hiatus or unconformity. Sparse conodont faunas suggest that only the two next-to-oldest Carboniferous duplicata and sandbergi Zones are represented in the higher part of the Hastie??re Formation. The oldest Carboniferous sulcata Zone and possibly part ofthe duplicata Zone are unrepresented because of an hiatus or unconformity above bed 159. Ostracods are abundant and diversified at most levels in the Anseremme railway bridge section and sixty taxa, the majority in open nomenclature, have been identified and nearly all of them are figured. The ostracod fauna is indicative of shallow-marine environments between fair-weather and storm wave bases in the Etroeungt Formation, and to shallower water conditions periodically subjected to minor salinity variations in the base of the Hastie??re Formation. The upper part of the Hastie??re Formation is marked by a sea-level rise associated with a moderate decrease of the oxygenation of bottom waters. The intra-Devonian hiatus at the Etroeungt-Hastie??re boundary shows no abnormal extinctions and no appearance of new taxa. Thus, the Hangenberg Event is not recognizable in the studied section. Neither the sedimentological analysis nor the palaeontological study of the Bocahut quarry in the Avesnois and of the Anseremme railway bridge section confirm the hypothesis of a highstand for the Hastie??re Formation.

  6. Organic petrology and geochemistry of the Carboniferous coal seams from the Central Asturian Coal Basin (NW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, Noe; Martinez, Luis; Izart, Alain; Elie, Marcel [UMR G2R/7566, Geologie et Gestion des Ressources Minerales et Energetiques, Faculte des Sciences, Universite Henri Poincare, Nancy 1, BP-239, Boulevard des Aiguillettes, Vandoeuvre-les-Nancy Cedex 54506 (France); Suarez-Ruiz, Isabel [Instituto Nacional del Carbon (CSIC), C/ Francisco Pintado Fe, 26, Ap. Co., 73, Oviedo 33011 (Spain); Keravis, Didier [Institut des Sciences de la Terre (ISTO), CNRS-Universite d' Orleans, Batiment Geosciences, BP 6759, Orleans 45067 (France)

    2004-03-23

    This paper presents for the first time a petrological and geochemical study of coals from the Central Asturian Coal Basin (North Spain) of Carboniferous (Pennsylvanian), mainly of Moscovian, age. A paleoenvironmental approach was used, taking into account both petrographic and organic geochemical studies. Vitrinite reflectance (R{sub r}) ranges from 0.5% to 2.5%, which indicates a high volatile bituminous to semianthracite and anthracite coal rank. The coal samples selected for paleoenvironmental reconstruction are located inside the oil-gas-prone phase, corresponding to the interval between the onset of oil generation and first gas generation and efficient expulsion of oil. This phase is represented by coals that have retained their hydrocarbon potential and also preserved biomarker information. Paleodepositional reconstruction based on maceral and petrographic indices points to a swamp environment with vitrinite-rich coal facies and variable mineral matter content. The gelification index (GI) and groundwater influence index (GWI) indicate strong gelification and wet conditions. The biomarkers exhibit a high pristane/phytane ratio, suggesting an increase in this ratio from diagenetic processes, and a high diterpanes ratio. This, in turn, would seem to indicate a high swamp water table and a humid climate. The maximum point of coal accumulation occurred during the regressive part of the Late Moscovian sequence and in the most humid climate described for this period of time in the well-known coal basins of Europe and North America.

  7. 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

  8. 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.

  9. Sedimentological and diagenetic controls of gas in Lower and Early Upper Carboniferous sediments, NE Germany

    Science.gov (United States)

    Kerschke, Dorit I.; Schulz, Hans-Martin

    2015-07-01

    Fine-grained, organic-rich Paleozoic sediments are proven source rocks for conventional gas systems in NW Europe and large, unconventional gas reservoirs are assumed in Lower to Early Upper Carboniferous black shales. However, despite numerous boreholes exploring for hydrocarbons, the shale gas potential remains uncertain. This paper comprises detailed information on the sedimentary structure and lithofacies associations along with spatial distribution, thickness, thermal maturity, organic and inorganic petrology as well as geochemistry and mineralogy of Lower to Early Upper Carboniferous black shales in NE Germany to unravel the evolution of shale gas-relevant properties. Sediments of the "Kohlenkalk" Formation (Carboniferous Limestone) in the Rügen Island area were deposited on an extensive deep-water carbonate shelf. Transgressive-regressive cycles led to the formation of an up to 2000 m thick intercalation of mud- and limestones. High total organic carbon contents (2.4-7.0 wt.%) of a mainly Type II + III kerogen have been deposited under dysoxic to anoxic conditions and attained favorable present-day thermal maturities (0.8-1.8% VRr) indicating a shale oil potential in the upper part of the succession and a shale gas potential in the deeper parts. Sediments of the "Altmark-North-Brandenburg Culm" (Synorogenic Flysch Formation) were deposited as a turbidity current-derived intercalation of a sand/silt-mud interbedded and black mudrock lithofacies in a deep marine siliciclastic slope to basinal setting. The ~ 1900 m thick succession has TOC contents of 0.5-2 wt.% and present-day thermal maturities of 2.3-3.2% VRr indicating a possible hybrid gas accumulation in areas where the succession is buried < 5000 m.

  10. 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.

  11. 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.

  12. 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.

  13. CARBONIFEROUS CORALS AND CHAETETIDS FROM EXOTIC LIMESTONE BLOCK OF THE CRIMEA

    Directory of Open Access Journals (Sweden)

    VICTOR OGAR

    2015-11-01

    Full Text Available A chaetetid sponge and coral fauna from a Carboniferous exotic limestone block in the Lower Jurassic Esciorda olistostrome on the Bodrak River (Crimean Mountains are described for the first time. The Bodrak exotic block is composed of massive limestone. It contains the chaetetid Chaetetes (Boswellia sp., the tabulate coral Multithecopora sp., and poorly preserved rugose corals, including Dibunophyllum? sp., Cordibia? sp. and gen. et sp. indet. Only the fasciculate colonies of the rugose coral Lytvophyllum askynensis (Kossovaya, 2009 are confidently identified. The studied association of fossils is similar to that of the Donets Basin and the Urals and confirms the Lower Bashkirian age of the Bodrak limestone block. 

  14. First Report of a Trilobite in the Carboniferous of Eastern Pontides, NE Turkey

    OpenAIRE

    LEROSEY-AUBRIL, RAİF KANDEMİR & RUDY

    2011-01-01

    The pre-Mesozoic basement of the Eastern Pontides consists of a Permo-Carboniferous sedimentary sequence including the Çatalçeşme and Hardişi formations. The Çatalçeşme Formation has yielded rich assemblages of fusulinids, corals, gastropods, brachiopods, bryozoans, algae, conodonts and plants. Hitherto trilobites were unknown from this formation; here we report the discovery of a pygidium from a dark grey limestone bed near the top. Trilobites are a minor component of benthic marine communit...

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  16. Fluvio-lacustrine sedimentation and volcanism in a Late Carboniferous tensional intra-arc basin, northern Chile

    Science.gov (United States)

    Breitkreuz, Christoph

    1991-11-01

    Extensive outcrops of Late Carboniferous to Triassic volcanoplutonic magnetic-arc complexes occur in the Andes of northern Chile. In the Salar de Atacama area, terrestrial volcanosedimentary successions include a 200-600 m thick fluvio-lacustrine sequence ("Miembro Medio"). The terrestrial basin which accommodated this sequence formed during the latest Carboniferous on top of the deposits of the pre-existing Carboniferous composite volcanoes. The lower part of the Miembro Medio consists of green limnic and multicoloured alluvial fan deposits; the upper part is made up of red fluvial sedimentary rocks. Basic volcanic rocks occur locally throughout the sequence. The climate is inferred to have been warm and humid. The limnic (freshwater) environment had a minimum extension of 300 × 100 km. Limnic facies is inferred from the existence of fine-parallel-bedded sediments, ooliths and a limnic benthic fauna. Lake-shore deposits prevail in the outcrops. In some sections, the green limnic sequence is followed by red fine-grained floodplain or alluvial plain, and fluvial channel deposits. The framework composition of the Miembro Medio is dominated by volcanogenic detritus presumably eroded from the successions of the previous Late Carboniferous volcanic arc. Another volcanogenic clast type was provided by syndepositional basalto-andesitic phreatomagmatic activity, which also produced peperitic sills, dykes and lavas. The limnic-alluvial fan facies association, the predominance of volcanogenic detritus, and the accompanying intrabasinal basic calc-alkaline volcanism together with the considerable size of the basin point to a ?NW-SE trending half-graben setting controlled by (trans-)tensional arc tectonics. With regard to the Late Carboniferous-Triassic volcanosedimentary successions of northern Chile, this Latest Carboniferous tensional setting is the only feature in this area supporting those models, which inferred an extensional magmatic arc for the entire Central and

  17. Carboniferous non-marine source rocks from Spitsbergen and Bjoernoeya: comparison with the Western Arctic

    Energy Technology Data Exchange (ETDEWEB)

    van Koeverden, J.H.; Karlsen, D.A.; Backer-Owe, K. [University of Oslo, Oslo (Norway). Dept. of Geoscience

    2011-01-15

    In this paper, we demonstrate that Carboniferous coaly and lacustrine strata have significant liquid hydrocarbon potential in an area extending from the Norwegian Barents Sea in the east to the Canadian Arctic in the west. Organic geochemical analyses were conducted on seven coals and coaly shales from the islands of Spitsbergen (Svalbard archipelago) and Bjpernoeya (Norwegian Barents Sea). The results were interpreted in the context of published data from the two areas, and of time-equivalent non-marine successions on the Finnmark Platform (Norwegian Barents Sea), East Greenland, and the Sverdrup Basin (Canadian Arctic). In each of these areas, a warm and humid climate, together with the onset of rifting on the northern Pangea margin, facilitated the deposition and preservation of organic-rich non-marine sediments on a regional scale. All of the sediments have an elevated content of liptinitic macerals, dominated by alginite or sporinite. In the studied areas, the prolific younger source rocks which may be common in adjacent regions are often immature or absent. The identification of Carboniferous terrestrial strata with source rock potential may therefore enhance the petroleum potential of the studied regions.

  18. Description of synangia and spores of the holotype of the Carboniferous fern Lobatopteris miltoni, with taxonomic comments

    Czech Academy of Sciences Publication Activity Database

    Pšenička, J.; Bek, Jiří; Cleal, Ch. J.; Wittry, J.; Zodrow, E. L.

    2009-01-01

    Roč. 155, 3-4 (2009), s. 133-144. ISSN 0034-6667 R&D Projects: GA AV ČR IAA300130503 Institutional research plan: CEZ:AV0Z30130516 Keywords : Carboniferous * Marattiales * Lobatopteris * synangia * in situ spores Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.145, year: 2009

  19. 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.

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

    Czech Academy of Sciences Publication Activity Database

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

    2013-01-01

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

  1. 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

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

    Science.gov (United States)

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

    2009-04-01

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

  3. 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

  4. On the genesis of the uranium occurrence in the carboniferous sediments, wadi Intahahah area, southwest Libya

    International Nuclear Information System (INIS)

    In the course of covering the southwestern part of Libya by a systematic airborne radiometric survey, a significant group of anomalies was detected in the carboniferous sediments. Ground verification of these anomalies disclosed the confinement of these anomalies to the limestone and sandstone beds of the Assedjefar Formation assigned to visean-namurian age. Uranium content as much as 1000 PPm was detected. The strong lithologic control of these uranium mineralizations together with the lack of evidences of hydrothermal activity implies an intrinsic source for the uranium. The uranium, most likely, was transported and introduced into the sediments, by geochemically active groundwater, during their deposition. Uranium, from this solution, could have been adsorbed onto organic matter or clay minerals

  5. 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. 

  6. 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.

  7. Tribolbina Latham, 1932, an early Carboniferous through Permian palaeocopid ostracode genus

    Science.gov (United States)

    Sohn, I.G.

    1978-01-01

    The type-species of Tribolbina Latham, 1932, T. carnegiei, and T. gigantea (Jones, Kirkby, and Brady, 1884) are redefined and reillustrated, and lectotypes for both are designated. T. permiana (Kellett, 1933) and T. tumida (Scott and Borger, 1941) are also redefined and reillustrated. Beyrichiana Kellett, 1933, is considered a junior subjective synonym of Tribolbina Latham, 1932. On the basis of abundant silicified specimens from the Permian of Greece, T. doescheri n. sp. is described, and T. aff. T. doescheri and T. sp. 1 are illustrated. The stratigraphic range of Tribolbina as redefined is lower Carboniferous through Permian, and its known distribution is Europe and North America where representatives lived in shallow seas. Tribolbinidae and Tribolbinecea are established as new suprageneric categories in the Palaeocopida for Tribolbina and the Silurian Kolmodinia Martinsson, 1962.

  8. 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

  9. Late Carboniferous cyclothems in Atlantic Canada and event correlation in the Euramerican Coal Province

    Energy Technology Data Exchange (ETDEWEB)

    Gibling, M.R. (Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Earth Sciences)

    1992-01-01

    The Maritimes Basin of Atlantic Canada contains a thick Late Carboniferous succession and is interposed between US and European coal basins. In the Sydney coalfield of the Maritimes Basin, events of probable regional significance are recorded in ten mid Westphalian D to early Stephanian cyclothems, 20--70 m thick and about 2--300,000 years in mean duration. Coals up to 4.3 m thick are associated with coastal sandstones/shales and are overlain by thin black shales/limestones; agglutinated foraminifera indicate restricted marine conditions. Coal-bearing units alternate with alluvial-plain deposits that include red mudstones formed as mature paleosols in a strongly season climate. Stacked alluvial channel bodies above some coals are interpreted as paleovalley fills that reflect incision and subsequent aggradation, probably related to relative sea-level fluctuation associated with Gondwanan glaciation. Red strata predominate and coals become uneconomic higher in the Stephanian as Euramerican climates became more continental. Coeval coal-bearing strata (and, probably, cyclothems) also underlie large areas of the Gulf of St. Lawrence which, together with the Sydney region, is about 80,000 km[sup 2] in area. Biostratigraphic studies indicate that the Westphalian D to early Stephanian correlates with the Desmoinesian/Missourian of the interior US. The Maritimes Basin cyclothems are thus coeval with cylothemic intervals in the Midcontinental, Illinois and Appalachian Basins that include major economic seams (Herrin No. 6, springfield No. 5, Freeport, Kittanning). Although the level of biostratigraphic resolution currently precludes precise correlation, cyclothem-generating events probably influenced and may be traceable in coastal plain settings through much of the Euramerican Coal Province in the latest Carboniferous.

  10. 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.

  11. Sedimentary evolution and trace fossils of Carboniferous turbidite systems on the Variscan foreland, Czech Republic : guide to fild trip A8 (20-22 June 2015)

    Czech Academy of Sciences Publication Activity Database

    Bábek, O.; Mikuláš, Radek; Šimíček, D.

    Kraków: International Association of Sedimentologist, 2015 - (Haczewski, G.), s. 115-143 ISBN 978--83-942304-0-1 Institutional support: RVO:67985831 Keywords : Carboniferous * trace fossils * Variscan foreland Subject RIV: DB - Geology ; Mineralogy

  12. Biochemostratigraphy of the Devonian-Carboniferous boundary Global Stratotype Section and Point, Griotte Formation, La Serre, Montagne Noire, France

    OpenAIRE

    Brand, U.; Legrand-Blain, M.; Streel, Maurice

    2004-01-01

    The Griotte Formation and the base of Bed 89 exposed at La Serre, Montagne Noire, France represent the Global Stratotype Section and Point (GSSP) for the Devonian-Carboniferous (D-C) boundary. This study represents the geochemical work on brachiopods and matrix covering the Siphonodella praesulcata to Siphonodella sulcata Zones at the GSSP. Values of Sr-87/Sr-86 of unaltered brachiopods provide the most powerful biochemostratigraphic tool in recognizing and correlating the Devonian-Carbonifer...

  13. Sedimentology, conodonts and ostracods of the Devonian - Carboniferous strata of the Anseremme railway bridge section, Dinant Basin, Belgium

    OpenAIRE

    Casier, J.-G.; Mamet, B.; Préat, A.; Sandberg, C.A.

    2004-01-01

    Seven major carbonate microfacies are defined in the Devonian - Carboniferous (D/C) strata (50 m) of the Anseremme railway bridge section, south of Dinant. They permit recognition of several levels encompassing the Etroeungt and Hastière formations. "Bathymetric" sequences range from open marine, below the storm wave base, to semi-restricted lagoon. This sequence records a shallowing-upward trend of the relative sea level, from environments below the storm wave base to strongly eroded suprati...

  14. High-resolution isotope stratigraphy of the Devonian-Carboniferous boundary in the Namur-Dinant Basin, Belgium

    OpenAIRE

    Amy, K.; Poty, E.; Brand, U.

    2009-01-01

    The Devonian–Carboniferous (D–C) boundary sequence of the Namur–Dinant Basin in southern Belgium consists of marine platform carbonates. Global biostratigraphic correlation of the boundary has been a dilemma due to the absence of index conodont zones. Despite the scarcity of brachiopods, we managed to sample twenty-five calcitic shells from boundary beds at the Royseux-Gare section, to reconstruct biochemostratigraphic profiles of oxygen-, carbon- and strontium-isotopes for correlations with ...

  15. Conodont biostratigraphy and depositional history of the Middle Devonian to Lower Carboniferous in the Cantabrian zone (Cantabrian Mountains, Spain)

    OpenAIRE

    Raven, J.G.M.

    1983-01-01

    Within the Cantabrian zone during the Devonian and Early Carboniferous three large palaeogeographical units were of importance: the Asturian geanticline, the Palencian basin and the Asturo-Leonesian basin. These units have a different history of sedimentation, particularly the Palencian basin. Further, in the Asturo-Leonesian basin there were some important structural elements: the Intra-Asturo-Leonesian facies line, formed by an active, normal fault parallel to the border of the basin, and t...

  16. 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.

  17. Permo-Carboniferous granitoids with Jurassic high temperature metamorphism in Central Pontides, Northern Turkey

    Science.gov (United States)

    Gücer, Mehmet Ali; Arslan, Mehmet; Sherlock, Sarah; Heaman, Larry M.

    2016-04-01

    In the northern part of the Central Pontides (N Turkey) there are different metamorphic rocks exposed, notably the Devrekani metamorphic rocks. Here, upper amphibolite-lower granulite facies metamorphic rocks contain predominantly paragneiss, orthogneiss and metacarbonate, and to a lesser extent, amphibolite and quartzite, with cross-cutting aplite, pegmatite and granite veins. This is the first report of these rocks and includes new data on the petrochemistry, geochronology and metamorphic evolution of the Devrekani orthogneisses from the Central Pontides. The orthogneisses show five different mineral parageneses with the characteristic mineral assemblage quartz + K-feldspar + plagioclase + biotite ± hornblende ± opaque (± ilmenite and ± magnetite), and accessory minerals (zircon, sphene and apatite). These metamorphic rocks exhibit generally granoblastic, lepidogranoblastic and nematolepidogranoblastic with locally migmatitic and relic micrographic textures. They have well-developed centimeter-spaced gneissic banding and display gneissose structure with symmetric, asymmetric and irregular folds. The petrographic features, mineralogical assemblages and weak migmatization reflect high temperature conditions. Thermometric calculations in the orthogneisses indicate metamorphic temperatures reached 744 ± 33 °C. Field relations, petrography and petrochemistry suggest that the orthogneisses have predominantly granodioritic and some granitic protoliths, that show features of I-type, medium to high-potassic calc-alkaline volcanic arc granitoids. The orthogneisses have high contents of LILEs and low contents of HFSEs with negative Nb and Ti anomalies, which are typical of subduction-related magmas. The orthogneisses also show significant LREE enrichment relative to HREE with negative Eu anomalies (EuN/Eu* = 0.33-1.07) with LaN/LuN = 6.98-20.47 values. Based on U-Pb zircon dating data, the protoliths are related to Permo-Carboniferous (316-252 Ma) magmatism. It is

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. An Early Carboniferous seep community and hydrocarbon-derived carbonates from the Harz Mountains, Germany

    Science.gov (United States)

    Peckmann, Jörn; Gischler, Eberhard; Oschmann, Wolfgang; Reitner, Joachim

    2001-03-01

    Early Carboniferous (latest Visean) seep deposits occur on top of the drowned Middle Devonian Late Devonian Iberg atoll reef, Harz Mountains, Germany. These deposits include limestone with a low-diversity but high-abundance fauna of rhynchonellid brachiopods and rare solemyid bivalves, as well as microbial limestone. Rhynchonellids form dense, autochthonous shell accumulations and are generally articulated. They are closely associated with hydrocarbon-derived carbonates. The carbonates exhibit δ13C values as low as -32‰, relative to the Peedee belemnite standard, revealing that they are predominantly hydrocarbon derived. The fauna, carbonate fabrics, and isotope signatures provide unequivocal evidence for a seep origin of the Visean deposit. The occurrence of solemyid bivalves supports this interpretation as members of this family (1) are well known for their relationship with chemoautotrophic bacteria and (2) have been reported from ancient and modern seeps. Possible hydrocarbon sources are thermogenic methane derived from the volcanic base of the Iberg reef or methane from a petroleum reservoir.

  4. 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.

  5. 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

  6. 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.

  7. Carboniferous geology and uranium potential of the northeast flank of the Parana Basin and southwest flank of the Parnaiba Basin, Brazil

    International Nuclear Information System (INIS)

    The Carboniferous sequences of the northeast flank of the Parana Basin and those of the southwest flank of the Parnaiba Basin have been the subject of discussion and polemics for quite a long time, especially in terms of their stratigraphic relations and depositional environments. Thus, we reinforce our main objective, which is to furnish data for the definition of the uranium potential in these Carboniferous sediments, by adding recently acquired information that should aid in the clarification of the existing controversies. The Carboniferous along the northeast flank of the Parana Basin is represented by the Aquidauana Formation which has been informally divided into three members: lower, middle and upper members. The middle member, of marine origin, constitutes a prospective target for uranium and phosphate associations, in which sandstones interbedded with shales constitute the host rocks. On the other hand, the Carboniferous of the southwest margin of the Parnaiba Basin, which encompasses the Longa, Poti and Piaui Formations has shown very remote possibilities of uranium occurrences. The regional structural framework, as reflected by the Carboniferous rocks along both basin flanks, is characterized by homoclines cut by gravity faults. The faults along these weakness zones were occasionally intruded by basic rocks of Cretaceous age. Superimposed on the regional structure, open folds appear in the form of anticlines and domes. These folds are discontinuous structures resulting from uplift due to vertical stresses or result from differential subsidence along the limbs of the folds. (Author)

  8. Geochemical anomaly across the Devonian Carboniferous extinction boundary, Eastern Alps, Austria

    Science.gov (United States)

    Bojar, A. V.; Neubauer, F.

    2003-04-01

    The mass extinction recognized at the Devonian/Carboniferous (D/C) boundary represents the sixth largest extinction of the Phanerozoic, with practically the same extent as the Frasnian-Famennian mass extinction. This affected many organisms, such as conodonts, ammonoids, echinoderms, trilobites, ancient agnatian and placodermian fishes, continental plant communities and, secondary ostracodes, foraminifera and corals. The extinction was followed after a short time by a phase of radiation and biotic innovations. This phase was characterized by the diversity and blossom of certain groups of organisms as for example tetrapods. The D/C extinction has been associated with the world anoxic event represented by organic rich deposits known as the Hangenberg Shale. The development of the Hangenberg Shale is interpreted to have been related to an inversion within the ocean circulation. Worldwide, geochemical data have put in evidence weak iridium anomalies near the bottom and the top of the shales. The origin of these anomalies is still under debate. They may be related to an asteroid impact or to limestone-shale lithological transition. There are only a few D/C transitions within a homogenous lithological section. One of these is the Steinberg section of the Eastern Alps. Through the use of detailed geochemical investigations we show that the D/C boundary is the effect of several events. Our geochemical data, together with that described in the literature, suggest that an asteroid impact may occurred at the D/C boundary. However this event is clearly younger than the anoxic Hangenberg event, which had started already in the late Devonian.

  9. 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

  10. First Records of Conodonts from "the Permo-Carboniferous of Demirözü" (Bayburt), Eastern Pontides, NE Turkey

    OpenAIRE

    ÇAPKINOĞLU, ŞENOL

    2003-01-01

    Permo-Carboniferous sedimentary rocks, which belong to the pre-Jurassic basement of the Eastern Pontides, occur in the Cebre relative autochthon and the Hamurkesen thrust sheet in the Demirözü area, Bayburt, NE Turkey, and consist of the Çatalçeşme and Hardişi formations, respectively. Some limestone beds of the Çatalçeşme Formation in the village of Çatalçeşme produced the first conodont faunas encountered in Palaeozoic sediments of the Eastern Pontides. A rich conodont fauna with abundant N...

  11. Anoxia, sealevel changes and mass extinctions at the Devonian/Carboniferous boundary

    Science.gov (United States)

    Kaiser, S. I.; Steuber, T.; Becker, R. T.

    2003-04-01

    During the Latest Devonian, the transition from global greenhouse to icehouse conditions began with a first glaciation pulse in SW Gondwana. Decisive palaeoclimatic and palaeoceanographic changes are reflected in the multiphase Late Devonian Hangenberg Event. Mass extinctions, blackshale and sandstone deposits in different palaeogeographical settings were the result of eustatic sea level changes, and probably also of variations in the composition and temperature of seawater during the Late Devonian -- Early Carboniferous. The investigated boundary sections from different palaeogeographical settings include localities in Europe and North Africa. Detailed bed-by-bed sampling of limestones, and field observations on the sedimentology of intercalated siliciclastics were considered important in order to achieve a high-resolution biostratigraphical zonation, precise records of biofacies evolution, and correlation of changes in sedimentary environments. The carbon isotopic composition of micritic limestones and the oxygen isotopic composition of conodont apatite provide important information about palaeoceanographic changes and perturbations in the global carbon cycle during the event interval. Detailed investigations of the sedimentology in Moroccan sections indicate significant variations of facies patterns over short distances. The Famennian pelagic carbonate platform of North-Gondwana was not re-established in the latest Famennian or in the post-event early Tournaisian, which yielded new rich goniatites from blackshales and sandstones. These observations and microfacies analyses from other sections of different palaeolatitudes are important for the reconstruction and correlation of global transgression-regression cycles. The first results of biostratigraphical correlations will be presented together with carbon isotope data of micritic limestone collected from boundary sections in the Rheinische Schiefergebirge and in the Carnic Alps. A slight but continuous decrease

  12. 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

  13. 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

  14. 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

  15. Functional groups and elemental analyses of cuticular morphotypes of Cordaites principalis (Germar) Geinitz, Carboniferous Maritimes Basin, Canada

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria; Orem, W.H.; Simunek, Z.; Bashforth, A.R.

    2000-01-01

    Well-preserved cuticles were isolated from Cordaites principalis (Germar) Geinitz leaf compressions, i.e., foliage from extinct gymnosperm trees Coniferophyta: Order Cordaitales. The specimens were collected from the Sydney. Stellarton and Bay St. George subbasins of the once extensive Carboniferous Maritimes Basin of Atlantic Canada. Fourier transformation of infrared spectra (FTIR) and elemental analyses indicate that the ca. 300-306-million-year-old fossil cuticles share many of the functional groups observed in modern cuticles. The similarities of the functional groups in each of the three cuticular morphotypes studied support the inclusion into a single cordaite-leaf taxon, i.e., C. principalis (Germar), confirming previous morphological investigations. Vitrinite reflectance measurements on coal seams in close proximity to the fossil-bearing sediments reveal that the Bay St. George sample site has the lowest thermal maturity, whereas the sites in Sydney and Stellarton are more mature. IR absorption and elemental analyses of the cordaite compressions corroborate this trend, which suggests that the coalified mesophyll in the leaves follows a maturation path similar to that of vitrinite. Comparison of functional groups of the cordaite cuticles with those from certain pteridosperms previously studied from the Sydney Subbasin shows that in the cordaite cuticles highly conjugated C-O (1632 cm-1) bands dominate over carbonyl stretch that characterizes the pteridosperm cuticles. The differences demonstrate the potential of chemotaxonomy as a valuable tool to assist distinguishing between Carboniferous plant-fossil groups. Published by Elsevier Science B.V.

  16. Periodic functions with variable period

    OpenAIRE

    Pryjmak, M. V

    2010-01-01

    The examples of rhythmical signals with variable period are considered. The definition of periodic function with the variable period is given as a model of such signals. The examples of such functions are given and their variable periods are written in the explicit form. The system of trigonometric functions with the variable period is considered and its orthogonality is proved. The generalized system of trigonometric functions with the variable period is also suggested; some conditions of it...

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

    Czech Academy of Sciences Publication Activity Database

    Bábek, O.; Kumpan, T.; Kalvoda, J.; Matys Grygar, Tomáš

    2016-01-01

    Roč. 337, MAY (2016), s. 81-99. ISSN 0037-0738 Institutional support: RVO:61388980 Keywords : Element geochemistry * Hangenberg event * Glacioeustasy * Devonian/Carboniferous boundary * Sedimentation rate Subject RIV: DD - Geochemistry Impact factor: 2.665, year: 2014

  18. Trace fossils of the Moravice Formation from the southern Nízký Jeseník Mts. (Lower Carboniferous, Culm facies; Moravia, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Mikuláš, Radek; Lehotský, T.; Bábek, O.

    2004-01-01

    Roč. 79, č. 2 (2004), s. 81-98. ISSN 1214-1119 R&D Projects: GA ČR(CZ) GA205/00/0118 Keywords : ichnofossils * Lower Carboniferous * Culm facies Subject RIV: DB - Geology ; Mineralogy http://www.geology.cz/bulletin/contents/2004/vol79no2/bullgeosci200402081.pdf

  19. 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

  20. 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

  1. 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.

  2. 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 Earth recycling water in the generation of the Late Carboniferous magmatism in this region.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Evolution of Pennsylvanian (Late Carboniferous) peat swamps of the Ruhr Basin, Germany: Comparison of palynological, coal petrographical and organic geochemical data

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, K. [Institute of Geology and Geochemistry of Petroleum and Coal, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany); Institute of Geology and Palaeontology, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany); Hartkopf-Froeder, C. [Geological Survey North Rhine-Westphalia, de-Greiff-Strasse 195, 47803 Krefeld (Germany); Flajs, G. [Institute of Geology and Palaeontology, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany); Littke, R. [Institute of Geology and Geochemistry of Petroleum and Coal, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany)

    2010-09-01

    This study focuses on the reconstruction of the environment during peat swamp development. Eight coal and sedimentary organic rock bearing seam successions were examined all belonging to the Duckmantian (Pennsylvanian, Late Carboniferous). 410 samples were analysed with coal petrographical methods, 155 of these also by palynological methods. In addition, on 55 samples organic geochemical investigations were carried out with respect to n-alkanes and iso-alkanes. The established coal petrographical parameters gelification index (GI), tissue preservation index (TPI), groundwater index (GWI) and vegetation index (VI) were used to characterize different periods of peat swamp development. Furthermore, the new index WCI (= Water Cover Index) was introduced to reflect water level conditions by using the ratio between hydrophilous/hygrophilous and mesophilous plants. In this study the index is based on palynological data but can be equally applied when quantitative macrofloral counts are available. GI versus TPI values show two general trends of peat swamp evolution: low GI and TPI values as indicator for drier swamp conditions like ombrogenous mires and high GI and TPI values which show a trend to water covered environments like topogenous mires. In addition, ash yields and GWI versus VI data also emphasize a general trend from topogenous to ombrogenous mires. A decrease in water level towards the top of the seams and thus resulting in the development of domed mires is reflected by the newly introduced WCI. Hence, these parameters show recurrent peat swamp successions, characterized by mineral- and vitrinite-rich coals, typical for topogenous swamps and an evolution towards inertinite/liptinite-rich coals with low ash yield, typical for ombrogenous swamps. n-alkane ratios like the carbon preference index (CPI), pristane/n-C{sub 17}, phytane/n-C{sub 18}, pristane/phytane and the n-C{sub 17}/n-C{sub 27} relationship indicate a strong correlation of these parameters with

  9. 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...

  10. Tephrostratigraphy, petrography, geochemistry, age and fossil record of the Ganigobis Shale Member and associated glaciomarine deposits of the Dwyka Group, Late Carboniferous, southern Africa

    OpenAIRE

    Bangert, Berthold

    2002-01-01

    Thin, pyroclastic marker beds are preserved in argillaceous units of the Dwyka Group in southern Nambia and South Africa which are the earliest witnesses of volcanism in Karoo-equivalent strata of southern Africa. The aim of this study is to present the field appearance of these marker beds, to characterise their mineralogy, geochemistry and heavy mineral contents and to present new radiometric age data from their juvenile zircons. Carboniferous-Permian Karoo deposits in the Aranos Basin of s...

  11. FIRST EURYPTERID FROM ITALY: A NEW SPECIES OFADELOPHTHALMUS (CHELICERATA: EURYPTERIDA) FROM THE UPPER CARBONIFEROUS OF THE CARNIC ALPS (FRIULI, NE ITALY)

    OpenAIRE

    Lamsdell, James C; LUCA SIMONETTO; Selden, Paul A

    2013-01-01

    The first eurypterid known from Italy is described, as Adelophthalmus piussii n. sp. It comes from the Upper Carboniferous of the Carnic Alps (Friuli, NE Italy). Relationships with related species are discussed. Adelophthalmids are the commonest eurypterids of the late Palaeozoic, at which time the disparity of the order was waning. The new record enhances our knowledge of adelophthalmid distribution and diversity.

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

    Science.gov (United States)

    Manzotti, Paola; Poujol, Marc; Ballèvre, Michel

    2015-04-01

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

  13. 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...

  14. Borehole core recovered from the Late Carboniferous to early Permian Fitzroy tillite and Port Sussex formations, Falkland Islands : geological background and sample details

    OpenAIRE

    Stone, P

    2011-01-01

    Within the Palaeozoic sedimentary succession of the Falkland Islands the Fitzroy Tillite Formation is the local representative of glacigenic strata deposited widely across Gondwana during Late Carboniferous glaciation. In West Falkland, a terrestrial lithofacies contains a wide range of erratic pebbles, cobbles and boulders; in East Falkland a glaciomarine diamictite contains fewer and generally smaller clasts from a more restricted lithological range. At the top of the East Falkland successi...

  15. 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

  16. 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

  17. 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.

  18. Geochemistry of autochthonous and hypautochthonous siderite-dolomite coal-balls (Foord Seam, Bolsovian, Upper Carboniferous), Nova Scotia, Canada

    Science.gov (United States)

    Zodrow, E.L.; Lyons, P.C.; Millay, M.A.

    1996-01-01

    The 11-13 m thick Foord Seam in the fault-bounded Stellarton Basin, Nova Scotia, is the thickest seam from the Euramerican floral province known to contain coal-balls. In addition to the first discovery of autochthonous coal-balls in the Foord Seam, Nova Scotia, its shale parting also contains hypautochthonous coal-balls with histologically preserved plant structures. The coal-ball discovery helps fill a stratigraphic gap in coal-ball occurrences in the upper Carboniferous (Bolsovian) of Euramerica. The autochthonous and hypautochthonous coal-balls have a similar mineralogical composition and are composed of siderite (81-100%), dolomite-ankerite (0-19%), minor quartz and illite, and trace amounts of 'calcite'. Similar is also their permineralizing mineralogy, which consists of dolomite-ankerite and siderite. Their low pyrite content and carbonate mineralogy, and nonmarine origin, differentiates the Foord Seam coal-balls from other Euramerican coal-ball occurrences. A preliminary geochemical model, which is based on oxygen and carbon isotopic data, indicates that siderite in both the autochthonous and hypautochthonous coal-balls is of very early diagenetic (nonmarine) origin from 13C-enriched bicarbonate derived from bacterial methanogenesis of organic matter.

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

    Science.gov (United States)

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

    2006-03-01

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

  20. High-resolution isotope stratigraphy of the Devonian-Carboniferous boundary in the Namur-Dinant Basin, Belgium

    Science.gov (United States)

    Azmy, Karem; Poty, Edouard; Brand, Uwe

    2009-04-01

    The Devonian-Carboniferous (D-C) boundary sequence of the Namur-Dinant Basin in southern Belgium consists of marine platform carbonates. Global biostratigraphic correlation of the boundary has been a dilemma due to the absence of index conodont zones. Despite the scarcity of brachiopods, we managed to sample twenty-five calcitic shells from boundary beds at the Royseux-Gare section, to reconstruct biochemostratigraphic profiles of oxygen-, carbon- and strontium-isotopes for correlations with established global counterparts. The δ18O and δ13C values of the well-preserved shells range from - 7.8 to - 6.3‰ VPDB (- 7.2 ± 0.4, n = 25) and from + 1.1 to + 2.4‰ VPDB (1.8 ± 0.3, n = 25), respectively. The shells also yielded 87Sr/ 86Sr ratios between 0.708185 and 0.708297. The Royseux isotope signatures are within the ranges documented for the global D-C boundary but their isotope profiles, however, show no significant shifts or excursions. Evaluation of the Royseux isotope profiles and correlation with their global counterparts may suggest a stratigraphic hiatus approximately from the middle Siphonodella praesulcata to the lower Siphonodella sulcata zones on the global D-C boundary conodont biostratigraphic scheme, while corresponding to the Hangenberg Event in Belgium.

  1. Paleomagnetic Euler Poles and the Apparent Polar Wander and Absolute Motion of North America Since the Carboniferous

    Science.gov (United States)

    Gordon, Richard G.; Cox, Allan; O'Hare, Scott

    1984-10-01

    spot Euler pole for 200-90 Ma lies only 15° outside the 95% confidence ellipsoid of the paleomagnetic Euler pole. The good but not perfect agreement reflects displacement between the hot spot and paleomagnetic reference frames at an average rate that is smaller by an order of magnitude than the rate at which the faster plates are moving. The angular velocity of North America about the Jurassic-Cretaceous paleomagnetic Euler pole was determined by plotting the angular positions of paleomagnetic poles along the track as a function of age. For the Cretaceous the angular velocity was too small to measure. During the Jurassic the angular velocity was high, corresponding to a root-mean-square velocity of 70 km/m.y. for the North American plate. A short time interval of even more rapid movement during the Middle and Late Jurassic, possibly corresponding to the beginning of rapid displacement between North America and Africa, is suggested by the data. The direction of absolute motion of North America during the Jurassic was toward the northwest. A Carboniferous-Permian-Triassic paleomagnetic Euler pole was determined from 26 paleomagnetic poles. The progression of poles along this track is consistent with known ages and stratigraphy, except for some systematic differences between poles from Triassic rocks on the Colorado Plateau and poles from Triassic rocks off the Colorado Plateau. These differences could be due to a small clockwise rotation of the Colorado Plateau with respect to cratonal North America, or to miscorrelations between Triassic rocks on the Colorado Plateau and off the Colorado Plateau, or to large lag times between the deposition and magnetization of some rock units, or to some combination of these possibilities. Despite these ambiguities in interpreting paleomagnetic data from Triassic rocks, the general pattern of apparent polar wander and plate motion during the Carboniferous through Triassic is clear: The root-mean-square velocity of North America was

  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. 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.

  4. 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.

  5. 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.

  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. 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.

  8. Petrogenesis of a Late Carboniferous mafic dike-granitoid association in the western Tianshan: Response to the geodynamics of oceanic subduction

    Science.gov (United States)

    Tang, Gong-Jian; Chung, Sun-Lin; Wang, Qiang; Wyman, Derek A.; Dan, Wei; Chen, Hong-Yi; Zhao, Zhen-Hua

    2014-08-01

    Mafic dike-granitoid associations are common in extensional tectonic settings and provide important opportunities for understanding mantle and crust melting during the tectonic evolution of host orogenic belts. We report results of petrologic, whole rock geochemical, Sr-Nd isotopic data and in situ zircon U-Pb and Hf isotopes for a mafic dike-granitoid association from the Zhongyangchang pluton in the western Tianshan, in order to constrain their petrogenesis and tectonic significance. The intrusive rocks are mainly composed of granodiorite, monzogranite, and minor granitic dikes, with mafic dikes intruded into the pluton. Zircon LA-ICP-MS U-Pb ages indicate that the Zhongyangchang intrusive rocks were all emplaced during a short interval in the Late Carboniferous (317-310 Ma), establishing that the mafic and felsic magmas were coeval. The mafic rocks have low SiO2 and high MgO concentrations, with low 87Sr/86Sr ratios from 0.7048 to 0.7053 and positive εNd(t) and zircon εHf(t) values from + 2.9 to + 3.8 and + 12.2 to + 13.6, respectively. They are enriched in large ion lithophile elements (LILEs) and depleted in high field strength elements (HFSEs), which can be explained by an origin from melting of a depleted lithospheric mantle source and source fluxing by fluids derived from the down-going slab. Granitoids from the pluton have high SiO2 contents and low MgO concentrations, suggesting that they were mainly derived from crustal sources. They also have positive whole rock εNd(t) and zircon εHf(t) values ranging from + 0.2 to + 2.8 and + 6.6 to + 15.3, respectively, similar to those of the mafic dikes. They were generated by partial melting of juvenile basaltic lower crust as a result of magma underplating. The Late Carboniferous mafic dike-granitoid association was not related to a post-collisional setting, but rather formed in an arc environment related to oceanic subduction. The most likely tectonic model accounting for the genesis of these rocks involves

  9. Ostracods and rock facies associated with the Devonian-Carboniferous boundary series in the Puech de la Suque section, Montagne Noire, France

    OpenAIRE

    Casier, J.-G.; Lethiers, F; Préat, A.

    2001-01-01

    4,750 ostracods valves and carapaces have been extracted from across the Devonian-Carboniferous boundary sequence in the Puech de la Suque section, Montagne Noire, southern France, and 72 species have been identified half of which belong to the Thuringian ecotype. The study revealed that a maximum of 31.5 percent of the species disappeared in this section as a result of the Hangenberg Event — a low rate of extinction compared to that generally associated worldwide with the Frasnian-Famennian ...

  10. Ostracods and lithofacies close to the Devonian-Carboniferous boundary in the Chanxhe and Rivage sections, northeastern part of the Dinant Basin, Belgium

    OpenAIRE

    Casier, J.-G.; Lebon, A.; Mamet, B.; Préat, A.

    2005-01-01

    The Chanxhe and Rivage sections along the Ourthe River are two important reference sections for the Devonian/Carboniferous (D/C) boundary in the northeastern part of the Dinant Basin. Seven major microfacies types are defined in the D/C strata (50 m) of these two sections. They permit recognition of several levels encompassing the Comblain-au-Pont and Hastière formations. These levels record shallow open-marine sedimentation oscillating between the storm and the fair-weather wave bases in the...

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

    Science.gov (United States)

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

    1994-11-01

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

  12. Provenance of Late Carboniferous to Jurassic sandstones for southern Taimyr, Arctic Russia: A comparison of heavy mineral analysis by optical and QEMSCAN methods

    Science.gov (United States)

    Zhang, Xiaojing; Pease, Victoria; Omma, Jenny; Benedictus, Aukje

    2015-11-01

    Sandstone framework-grain petrography, optical and QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) heavy mineral analysis carried out on 40 samples collected from east and west southern Taimyr are used to constrain the provenance and tectonic history of Late Carboniferous to Late Jurassic siliciclastic sequences. The tectonic settings of provenance evolved gradually from a mix of volcanic arc and recycled orogen to craton interior. Much of the detritus in the Late Paleozoic to Mesozoic siliciclastic succession came from proximal sources with contributions from multi-type source rocks including acid igneous rocks, basalts, sedimentary rocks and low to medium-grade metamorphic rocks. Carboniferous to Permian sandstones contain low-diversity suites of heavy minerals, including apatite, tourmaline, zircon, rutile, Cr-spinel, monazite and titanite. Cr-spinel indicates probable influx from exposed ophiolitic basement. Abundant euhedral zircon and apatite suggest a volcanic arc source related with Uralian collision. The appearance of garnet in the early Triassic signals the unroofing of a metamorphic source. The abrupt increase of clinopyroxene in Middle to Late Triassic sandstones indicates the influx of detritus from basic rocks related with Siberian Trap magmatism. The decrease of Cr-spinel and an abundance of staurolite in Jurassic samples indicate that unroofing of an ophiolitic source ceased and that stripping of a different thrust sheet containing plenty of staurolite-bearing metamorphic rocks commenced.

  13. 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。

  14. 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.

  15. The Carboniferous to Jurassic evolution of the pre-Alpine basement of Crete: Constraints from U-Pb and U-(Th)-Pb dating of orthogneiss, fission-track dating of zircon, structural and petrological data

    Czech Academy of Sciences Publication Activity Database

    Romano, S. S.; Brix, M. R.; Dörr, K.; Fiala, Jiří; Krenn, E.; Zulauf, G.

    2006-01-01

    Roč. 260, - (2006), s. 69-90. ISSN 0375-6440 Institutional research plan: CEZ:AV0Z30130516 Keywords : tectonic-evolution * Carboniferous * Jurassic * uranium-lead-dating * orthogneiss * fission-track-dating * zircon * structural-geology * petrology * metamorphism * high-temperature Subject RIV: DB - Geology ; Mineralogy

  16. 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

  17. 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

  18. 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

  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)

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Permo-Carboniferous and early Miocene geological evolution of the internal zones of the Maghrebides - New insights on the western Mediterranean evolution

    Science.gov (United States)

    Fernandez, Laure; Bosch, Delphine; Bruguier, Olivier; Hammor, Dalila; Caby, Renaud; Monié, Patrick; Arnaud, Nicolas; Toubal, Abder; Galland, Béatrice; Douchet, Chantal

    2016-05-01

    Geochemical and geochronological analyses were performed on metamorphic rocks from the footwall of an oceanic unit thrusted onto the North African margin. The footwall is mainly constituted by metamorphosed sediments and interlayered mafic rocks with scarce ultramafic lenses. Major and trace elements geochemistry of the sediments is consistent with a passive margin setting (16.9 rocks displays subduction related features (LILE and LREE enrichments, HFSE depletion). Pb, Sr, Nd and Hf isotopes further indicate a depleted mantle reservoir modified by a continental crust-derived component brought into the mantle during an ancient subduction event. The range of isotopic compositions and geochemical signatures displayed by the Carboniferous mafic rocks suggest they inherited their geochemical characteristics during melting of a heterogeneous lithospheric mantle containing variable metasomatic additions. Geochronological results indicate that the HT metamorphic evolution of this upper Paleozoic sequence resulted from two distinct events, each followed by fast cooling. The first one, dated at 20.85 ± 0.34 Ma (2σ), followed HP metamorphism and thrusting of the Kef Lakhal oceanic complex onto the Northern margin of Africa. The second event occurred at 17.65 ± 0.46 Ma (2σ) and is coeval with exhumation and anatexis of the lower crustal units of the neighbouring Edough dome. Fast cooling of the footwall rocks, through the closure temperatures of muscovite and biotite, occurred synchronously at 16.94 ± 0.10 Ma (2σ) and 17.02 ± 0.19 Ma (2σ) respectively. This study documents a further example of the complex history recorded by rocks of the Peri-Mediterranean area that contains an imbrication of geological units, witnesses of a protracted history related to Permo-Carboniferous and Miocene events.

  4. 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.

  5. 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.

  6. 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)

  7. 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

  8. Prograde P-T path of garnet-orthamphibole-gneiss from the Rhuys peninsula (Southern Brittany, France): evidence for a pre-carboniferous collisional stage in the Variscan orogeny

    International Nuclear Information System (INIS)

    A large lens of a magnesian garnet-orthamphibole gneiss with garnets up to 10 cm in diameter has been discovered within the Carboniferous Sarzeau leucogranite (Kerlin quarry, Rhuys peninsula). The garnets of a metamorphosed former magnesio-potassic lamprophyre have core-rim zonations with increasing Mg at constant Ca, and inclusions displaying a staurolite-breakdown reaction structure. Pressure and temperature estimates from garnet-biotite geo-thermometers and garnet-rutile-ilmenite-plagioclase-quartz geo-barometers indicate crystallization during increasing temperature and moderately increasing pressure along a prograde clockwise P-T path from 500 deg. C / 4 kbar to > 750 deg. C / 9 kbar. This prograde path identifies a major tectonic-metamorphic event during a pre-Carboniferous collisional stage in the Variscan orogeny. (authors). 14 refs., 3 figs., 1 tab

  9. 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。

  10. 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

  11. 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

  12. Latest Carboniferous closure of the Junggar Ocean constrained by geochemical and zircon U-Pb-Hf isotopic data of granitic gneisses from the Central Tianshan block, NW China

    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

    2015-12-01

    Once situated between the Central Tianshan and Junggar terranes during Paleozoic time, the Junggar Ocean was a major southern branch of the Paleo-Asian Ocean. Thus, when and how it was closed are essential in understanding the final assembly of the Central Asian Orogenic Belt. However, the exact closure time of the Junggar Ocean remains unresolved due to the lack of reliable timing of collision-related regional metamorphism. This paper reports whole-rock geochemical and zircon U-Pb and Lu-Hf isotopic data for granitic gneisses from the northern margin of the Central Tianshan block, which can provide crucial constraints on the final closure of the Junggar Ocean. Mineral assemblages and geochemical suggest that the protoliths of the Central Tianshan gneisses are weakly peraluminous high-K calc-alkaline I-type granites, possessing typical subduction-related features such as strong enrichment in LREE and LILE and depletion in HFSE. Negative Eu anomalies (δEu = 0.46-0.81) and highly variable zircon Hf isotope compositions indicate various amounts of residual plagioclase in the source and crustal contamination during magma formation. LA-ICPMS U-Pb dating on magmatic-type zircons (72%), characterized by euhedral to subhedral shapes, concentric oscillatory zoning, high Th/U ratios (0.30-2.05) and large ranges of εHf(t) values (- 3.4 to + 8.7; up to 6 epsilon units in each sample), yields consistent weighted mean 206Pb/238U ages of ca. 325-320 Ma, interpreted as the crystallization ages of the granitic protoliths. Geochemical signatures and dominantly positive zircon εHf(t) values reveal that the protoliths were emplaced in a continental arc setting, pinpointing the development of a late Early to early Late Carboniferous continental arc system on the northern margin of the Central Tianshan block, probably related to the southward subduction of the Junggar oceanic plate. Meanwhile, younger ages at ca. 303-301 Ma were obtained on recrystallized zircon-rims and unzoned

  13. Dysmenorrhea: Painful Periods

    Science.gov (United States)

    ... Management Education & Events Advocacy For Patients About ACOG Dysmenorrhea: Painful Periods Home For Patients Search FAQs Dysmenorrhea: ... Dysmenorrhea: Painful Periods FAQ046, January 2015 PDF Format Dysmenorrhea: Painful Periods Gynecologic Problems What is dysmenorrhea? How ...

  14. Familial Periodic Paralyses

    Science.gov (United States)

    ... two most common types of periodic paralyses are: Hypokalemic periodic paralysis is characterized by a fall in potassium levels ... chronic muscle weakness later in life. Hyperkalemic periodic paralysis is ... than the hypokalemic form. Muscle spasms are common. Is there any ...

  15. Algebraically periodic translation surfaces

    OpenAIRE

    Calta, Kariane; Smillie, John

    2007-01-01

    Algebraically periodic directions on translation surfaces were introduced by Calta in her study of genus two translation surfaces. We say that a translation surface with three or more algebraically periodic directions is an algebraically periodic surface. We show that for an algebraically periodic surface the slopes of the algebraically periodic directions are given by a number field which we call the periodic direction field. We show that translation surfaces with pseudo-Anosov automorphisms...

  16. Detrital modes of the Pyeongan Supergroup (Late Carboniferous Early Triassic) sandstones in the Samcheog coalfield, Korea: implications for provenance and tectonic setting

    Science.gov (United States)

    Lee, Yong Il; Sheen, Dong-Hee

    1998-08-01

    Medium to coarse sandstones of the Carboniferous to Early Triassic Pyeongan Supergroup in the Samcheog coalfield, Korea, were studied to infer the provenance and tectonic settings of the source areas. Sandstone detrital modes change upwards stratigraphically. Sandstone types from the Manhang to Dosagog formations low to middle in the sequence are quartzarenite, and sublitharenite to litharenite, whereas sandstones of the Gohan and Donggo formations high in the sequence are feldspathic litharenite and arkose, respectively. Using various ternary diagrams, the provenance of the Manhang to Gohan formations is suggested to be a recycled orogen setting. Some Gohan Formation sandstones plot within the arc-related setting field, and the Donggo Formation sandstones plot within both continental block and recycled orogen fields. Results of quartz grain petrography are consistent with those of detrital modes. Quartz in sandstones of all units except the Donggo Formation indicates derivation from low-rank metamorphic sources. Quartz in Donggo sandstones was derived from medium- to high-rank metamorphic and plutonic source rocks. Considering the sandstone composition and palaeocurrent data, the Pyeongan Supergroup probably was deposited in a molasse foreland basin and was derived from a synbasinal orogenic belt, probably the Akiyoshi orogen located in southwest Japan.

  17. 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

  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. 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

  20. Periodic trajectories in TDHF

    International Nuclear Information System (INIS)

    A condition for the existence of a periodic TDHF trajectory of period T is derived. It takes a from very similar to the static H.F. equation and shows that associated to a periodic trajectory there is a static single particle hamiltonian which is a complicated functional of the time dependent density matrix. An explicit expansion for this functional is derived. It is shown that many properties of the static H.F. rest point are shared by periodic solutions. (Author)

  1. 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

  2. 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

  3. Painful menstrual periods

    Science.gov (United States)

    ... you sexually active? Do you use birth control? What type? When was your last menstrual period? Was the flow of your last menstrual period a normal amount for you? Do your periods tend ... with menstruation? What have you done to try to relieve the ...

  4. The Periodic Pyramid

    Science.gov (United States)

    Hennigan, Jennifer N.; Grubbs, W. Tandy

    2013-01-01

    The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

  5. 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.

  6. 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.

  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. 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

  9. 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

  10. 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。

  11. Periodicity of chaotic solutions

    CERN Document Server

    Berezowski, Marek

    2016-01-01

    The scope of the paper is the analysis of the impact of flow reversal on the dynamics of cascades of reactors. Periodic and chaotic oscillations occur in the analyzed system. There is a dependence between the oscillation period of the state variable of the system without flow reversal and the recurrence period of windows of chaos in the steady-state diagram of the system with flow reversal.

  12. Crystallography without periodicity

    International Nuclear Information System (INIS)

    A condition of physics stability, applied to materials with sharp Bragg peaks, leads to rules for a unified approach to their classification that make no use of periodicity, applying equally well to either periodic or quasiperiodic materials. Three-dimensional geometric intuition is the primary analytical tool for extracting the classification from the rules. Recognizing that periodicity is not required to formulate crystallography removes the need for an algebraic formalization of that intuition in a higher dimensional superspace, where the material can be embedded in a periodic supercrystal. Selected examples illustrate the simplicity of the resulting description of ordinary crystals, quasicrystals, modulated crystals, intergrowth crystals, or modulated quasicrystals. (Author) 9 refs

  13. 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

  14. Historically defined autobiographical periods

    DEFF Research Database (Denmark)

    Brown, Norman R.; Hansen, Tia G. B.; Lee, Peter J.;

    2012-01-01

    The chapter reviews a research programme that has demonstrated the existence of historically defined autobiographical periods and identified the conditions that bring them about. Data from four samples of World War II-generation adults show that historically defined autobiographical periods endure...

  15. The Living Periodic Table

    Science.gov (United States)

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  16. Second Period Access Report

    DEFF Research Database (Denmark)

    Maisondieu, Christophe; Giebhardt, Jochen; Tetu, Amelie; Johnstone, Cameron; Healy, Mark

    The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive....

  17. On some periodicity effects

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2015-01-01

    . In each case, special attention is paid to eigenfrequencies and eigenmodes of a single periodicity cell with appropriate boundary conditions. The influence of the amount of periodicity cells in a finite compound structure on its eigenfrequency spectrum is analyzed. Several features common for the......The talk is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim of...... the talk is to illustrate these issues in simple examples and to discuss possible applications and generalisations. First, the eigenfrequency spectra of finite periodic structures are compared with the location of stop-bands for their infinite counterparts for a hierarchy of four mathematical models...

  18. 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

  19. 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.

  20. Painful periods (dysmenorrhea) (image)

    Science.gov (United States)

    Primary dysmenorrhea is a normal cramping of the lower abdomen caused by hormone-induced uterine contractions before the period. Secondary dysmenorrhea may be caused by abnormal conditions such as ...

  1. Setting the Periodic Table.

    Science.gov (United States)

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  2. The Periodic Table CD.

    Science.gov (United States)

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  3. Establishing contract periods

    International Nuclear Information System (INIS)

    The lead time for executing the Adjustable Fixed-Commitment (AFC) contract and exceptions which may be considered are discussed. The initial delivery period is also discussed. Delays, deferrals, and schedule adjustment charges are finally considered

  4. Periodic solutions of periodically harvested lotka-volterra systems

    OpenAIRE

    Hausrath, Alan R.; Manasevich, Raul F.

    2012-01-01

    We study a Lotka-Volterra system with periodic harvesting, find sufficient conditions for the existence of periodic solutions with the same period, and, under certain conditions, count the number of such periodic solutions.

  5. 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,

  6. 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

  7. Periodic safety analyses

    International Nuclear Information System (INIS)

    The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989

  8. Periodic table of elements

    International Nuclear Information System (INIS)

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF)

  9. Periodically kicked turbulence

    Science.gov (United States)

    Lohse

    2000-10-01

    Periodically kicked turbulence is theoretically analyzed within a mean-field theory. For large enough kicking strength A and kicking frequency f the Reynolds number grows exponentially and then runs into some saturation. The saturation level Re(sat) can be calculated analytically; different regimes can be observed. For large enough Re we find Re(sat) approximately Af, but intermittency can modify this scaling law. We suggest an experimental realization of periodically kicked turbulence to study the different regimes we theoretically predict and thus to better understand the effect of forcing on fully developed turbulence. PMID:11089041

  10. Periodic Chandrasekhar recursions

    OpenAIRE

    Aknouche, Abdelhakim; Hamdi, Fayçal

    2007-01-01

    This paper extends the Chandrasekhar-type recursions due to Morf, Sidhu, and Kailath "Some new algorithms for recursive estimation in constant, linear, discrete-time systems, IEEE Trans. Autom. Control 19 (1974) 315-323" to the case of periodic time-varying state-space models. We show that the S-lagged increments of the one-step prediction error covariance satisfy certain recursions from which we derive some algorithms for linear least squares estimation for periodic state-space models. The p...

  11. Sea-level and environmental changes around the Devonian-Carboniferous boundary in the Namur-Dinant Basin (S Belgium, NE France): A multi-proxy stratigraphic analysis of carbonate ramp archives and its use in regional and interregional correlations

    Science.gov (United States)

    Kumpan, Tomáš; Bábek, Ondřej; Kalvoda, Jiří; Matys Grygar, Tomáš; Frýda, Jiří

    2014-08-01

    The paper focuses on high-resolution multidisciplinary research on three Devonian-Carboniferous boundary sections in shallow-water carbonate rocks in the Namur-Dinant Basin (Belgium, France). The aim of the study is to provide palaeo-environmental reconstructions and correlations supported by several independent quantitative proxies. We describe several correlative horizons and provide their sequence-stratigraphic interpretation based on facies analysis, spectral gamma-ray data, element concentrations (XRF) and δ13Ccarb, with foraminifer-biostratigraphy age control. The most prominent surface is a basal surface of forced regression, which is indicated by a sharp basinwards facies shift and a drop in clay-gamma-ray values and Al concentrations at the base of the Hastière and Avesnelles formations in more distal settings. In proximal settings, this surface merges with a hiatus at the Devonian-Carboniferous boundary inferred from foraminifer biostratigraphy. This hiatus can be correlated with the global Hangenberg sandstone event, which indicates a glacioeustatic sea-level fall. Increasing values of Zr/Al, K/Al, Sr/Al and Mn/Al coincide with the proximal facies of the falling stage system tract and lowstand system tract in the Hastière and Avesnelles formations as a consequence of the enhanced input of siliciclastics and nutrients during low sea levels. The top of the middle Hastière member is interpreted as the maximum regression surface, which is overlain by transgressive system tract of the upper Hastière member. The patterns of gamma-ray, δ13Ccarb, Th/K, Al and Zr/Al curves are well correlated between the studied sections. The δ13Ccarb excursions are correlated with the unnamed excursion in the Upper expansa conodont zone (Carnic Alps) and with the global Hangenberg event s.l. excursion in the kockeli conodont zone. This sequence-stratigraphic framework is used for correlations with deltaic successions from the Tafilalt Basin, Morocco. The basal surface of

  12. 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

  13. 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.

  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 (parental magmas were most likely generated by the partial melting of a metasomatized lithospheric mantle wedge in the spinel stability field and emplaced in a continental arc setting. This consideration is consistent with the occurrence of Carboniferous ophiolitic and arc-related granitoids in the region, 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

  15. 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

  16. 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

  17. Higher charge periodic monopoles

    OpenAIRE

    Maldonado, Rafael

    2013-01-01

    We consider singly periodic solutions to the SU(2) Bogomolny equations and use the Nahm transform to generate a class of monopoles of charge k>2, thereby extending known results for lower charge chains. Some simple scattering processes are presented and a comparison made with geodesic motion of monopoles in $\\mathbb{R}^3$.

  18. Ayurveda during Abbasid's period.

    Science.gov (United States)

    Husain, S A; Subhaktha, P K

    2000-01-01

    This is a historical paper which deals with a brief account of Abbasid's period. In this article the existence of Ayurveda in Arab countries, arrival of Ayurvedic physicians to Baghdad, their eminence, authenticity and literary additions in medical field has been studied and presented. PMID:12578013

  19. Periodic paralysis complicating malaria.

    OpenAIRE

    Senanayake, N; Wimalawansa, S J

    1981-01-01

    Episodic muscular weakness, commonly associated with alterations of serum potassium, is the cardinal feature of periodic paralysis. The combination of transient hyperkalaemia and rigors occurring during febrile episodes of malaria is suggested as the underlying cause which precipitated the muscular paralysis. Three patients with malaria who developed a similar paralysis during the paroxysms of fever are described to illustrate this.

  20. Treatment for periodic paralysis

    NARCIS (Netherlands)

    Sansone, [No Value; Meola, G.; Links, T. P.; Panzeri, M.; Rose, M. R.

    2008-01-01

    Background Primary periodic paralyses are rare inherited muscle diseases characterised by episodes of flaccid weakness affecting one or more limbs, lasting several hours to several days, caused by mutations in skeletal muscle channel genes. Objectives The objective of this review was to systematical

  1. A Modern Periodic Table.

    Science.gov (United States)

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  2. Periodic Table of Students.

    Science.gov (United States)

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  3. Almost periodic Schroedinger operators

    International Nuclear Information System (INIS)

    These lectures are devoted to recent developments in the theory of almost-periodic Schroedinger Operators. We specially describe the algebraic point of view, with applications to gap-labelling theorems. Particular models are also presented which exhibit various spectral properties. (orig.)

  4. Scheduling: Seven Period Day

    Science.gov (United States)

    Williamson, Ronald

    2010-01-01

    Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

  5. 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.

  6. 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。

  7. Cells anticipate periodic events

    Science.gov (United States)

    Nakagaki, Toshiyuki

    2009-03-01

    We show that an amoeboid organism can anticipate the timing of periodic events. The plasmodium of the true slime mold Physarum polycephalum moves rapidly under favourable conditions, but stops moving when transferred to less-favourable conditions. Plasmodia exposed to unfavourable conditions, presented in three consecutive pulses at constant intervals, reduced their locomotive speed in response to each episode. When subsequently subjected to favourable conditions, the plasmodia spontaneously reduced their locomotive speed at the time point when the next unfavourable episode would have occurred. This implied anticipation of impending environmental change. After this behaviour had been evoked several times, the locomotion of the plasmodia returned to normal; however, the anticipatory response could subsequently be induced by a single unfavourable pulse, implying recall of the memorized periodicity. We explored the mechanisms underlying these behaviours from a dynamical systems perspective. Our results hint at the cellular origins of primitive intelligence and imply that simple dynamics might be sufficient to explain its emergence.

  8. Notes on Periodic Solitons

    CERN Document Server

    Bakas, Ioannis

    2002-01-01

    We consider static solutions of the sine-Gordon theory defined on a cylinder, which can be either periodic or quasi-periodic in space. They are described by the different modes of a simple pendulum moving in an inverted effective potential and correspond to its libration or rotation. We review the decomposition of the solutions into an oscillatory sum of alternating kinks and anti-kinks or into a monotonic train of kinks, respectively, using properties of elliptic functions. The two sectors are naturally related to each other by a modular transformation, whereas the underlying spectral curve of the model can be used to express the energy of the static configurations in terms of contour integrals \\`a la Seiberg-Witten in either case. The stability properties are also examined by means of supersymmetric quantum mechanics, where we find that the unstable configurations are associated to singular superpotentials, thus allowing for negative modes in the spectrum of small fluctuations.

  9. Thyrotoxic periodic paralysis

    International Nuclear Information System (INIS)

    A case of thyrotoxic periodic paralysis is reported in a Hispanic man with an unusual recurrence six weeks after radioactive iodine treatment. Thyrotoxic periodic paralysis has now been well characterized in the literature: it occurs primarily in Orientals with an overwhelming male preponderance and a higher association of specific HLA antigens. Clinical manifestations include onset after high carbohydrate ingestion or heavy exertion, with progressive symmetric weakness leading to flaccid paralysis of the extremities and other muscle groups, lasting several hours. If hypokalemia is present, potassium administration may help abort the attack. Although propranolol can be efficacious in preventing further episodes, the only definitive treatment is establishing a euthyroid state. The pathophysiology is still controversial, but reflects altered potassium and calcium dynamics as well as certain morphologic characteristics within the muscle unit itself

  10. Hypokalemic periodic paralysis

    OpenAIRE

    Abbas, Haider; Kothari, Nikhil; Bogra, Jaishri

    2012-01-01

    Hypokalemic periodic paralysis is a rare genetic disorder characterized by recurrent attacks of skeletal muscle weakness with associated hypokalemia which is precipitated by stress, cold, carbohydrate load, infection, glucose infusion, hypothermia, metabolic alkalosis, anesthesia, and steroids. We encountered one such incidence of prolonged recovery after general anesthesia, which on further evaluation revealed a case of hypokalemic paralysis. The key to successful management of such a patien...

  11. Scattering of periodic solitons

    Energy Technology Data Exchange (ETDEWEB)

    Cova, R.J. [Carleton University, School of Mathematics and Statistics, 1125 Colonel by Drive, Ottawa, Ontario K1S 5B6 (Canada); Zakrzewski, W.J. [University of Durham, Dept. of Mathematical Sciences, Durham DH1 3LE (United Kingdom)]. e-mail: rcova@math.carleton.ca

    2004-07-01

    Through numerical simulations we study N-soliton scattering (N = 3, 4) in the (2 + 1)-dimensional CP{sup 1} model with periodic boundary conditions. Solitons colliding from symmetrical configurations scatter at {pi}/ N, as observed in the usual model with standard boundary conditions. When the initial configurations are not symmetric the angles differ from {pi}/ N. We describe our observed patterns based on a properly formulated geodesic approximation. (Author) 11 refs., 10 figs.

  12. Zircon ages and Hf isotopic compositions of Ordovician and Carboniferous granitoids from central Inner Mongolia and their significance for early and late Paleozoic evolution of the Central Asian Orogenic Belt

    Science.gov (United States)

    Shi, Yuruo; Jian, Ping; Kröner, Alfred; Li, Linlin; Liu, Cui; Zhang, Wei

    2016-03-01

    We present zircon ages and Hf-in-zircon isotopic data for plutonic rocks and review the evolution of central Inner Mongolia, China, in the early and late Paleozoic. Zircons of a granodiorite yielded a 206Pb/238U age of 472 ± 3 Ma that reflects the time of early Paleozoic magmatism. Zircon ages were also obtained for a tonalite (329 ± 3 Ma), quartz-diorite (320 ± 3 Ma), and granite vein (297 ± 2 Ma). Our results, in combination with published zircon ages and geochemical data, document distinct magmatic episodes in central Inner Mongolia. The dated samples are mostly granodiorite, tonalite and quartz-diorite in composition with intermediate to high-silica, high Na2O (3.08-4.26 wt.%), low K2O (0.89-2.86 wt.%), and high Na2O/K2O and Sr/Y ratios. Their chondrite-normalized REE patterns are characterized by LREE enrichment. In mantle-normalized multi-element variation diagrams they show typical negative Nb and Ta anomalies, and all samples display positive εHf(t) and εNd(t) values, and low ISr. The Ordovician rocks, however, show higher Sr/Y and La/Yb ratios than the Carboniferous samples, implying that the older granitoids represent adakitic granitoids, and the Carboniferous granitoids are typical subduction-related arc granitoids but also with adakite-like compositions. The results are compatible with the view that the Central Asian Orogenic Belt (CAOB) in Inner Mongolia evolved through operation of several subduction systems with different polarities: an early-middle Paleozoic subduction and accretion system along the northern margin of the North China Craton and the southern margin of the Mongolian terrane, and late Paleozoic northward subduction along the northern orogen and exhumation of a high-pressure metamorphic terrane on the northern margin of the North China Craton.

  13. Periodic Mesoporous Organosilica Nanorice

    Directory of Open Access Journals (Sweden)

    Mohanty Paritosh

    2008-01-01

    Full Text Available Abstract A periodic mesoporous organosilica (PMO with nanorice morphology was successfully synthesized by a template assisted sol–gel method using a chain-type precursor. The PMO is composed of D and T sites in the ratio 1:2. The obtained mesoporous nanorice has a surface area of 753 m2 g−1, one-dimensional channels, and a narrow pore size distribution centered at 4.3 nm. The nanorice particles have a length of ca. 600 nm and width of ca. 200 nm.

  14. Polysheroidal periodic functions

    International Nuclear Information System (INIS)

    Separation of variables in the Helmholtz N-dimensional (N≥4) equation in polyspheroidal coordinate systems leads to the necessity of solving equations going over into equations for polyspheroidal periodic functions used for solving the two-centre problem in quantum mechanics, the three-body problem with Coulomb interaction, etc. For these functions the expansions are derived in terms of the Jacobi polynomials and Bessel functions. Their basic properties, asymptotics are considered. The algorithm of their computer calculations is developed. The results of numerical calculations are given

  15. Scattering of periodic solitons

    CERN Document Server

    Cova, R J

    2003-01-01

    With the help of numerical simulations we study N-soliton scattering (N=3,4) in the (2+1)-dimensional CP^1 model with periodic boundary conditions. When the solitons are scattered from symmetrical configurations the scattering angles observed agree with the earlier \\pi/N predictions based on the model on R_2 with standard boundary conditions. When the boundary conditions are not symmetric the angles are different from \\pi/N. We present an explanation of our observed patterns based on a properly formulated geodesic approximation.

  16. Periods and Superstring Amplitudes

    CERN Document Server

    Stieberger, S

    2016-01-01

    Scattering amplitudes which describe the interaction of physical states play an important role in determining physical observables. In string theory the physical states are given by vibrations of open and closed strings and their interactions are described (at the leading order in perturbation theory) by a world-sheet given by the topology of a disk or sphere, respectively. Formally, for scattering of N strings this leads to N-3-dimensional iterated real integrals along the compactified real axis or N-3-dimensional complex sphere integrals, respectively. As a consequence the physical observables are described by periods on M_{0,N} - the moduli space of Riemann spheres of N ordered marked points. The mathematical structure of these string amplitudes share many recent advances in arithmetic algebraic geometry and number theory like multiple zeta values, single-valued multiple zeta values, Drinfeld, Deligne associators, Hopf algebra and Lie algebra structures related to Grothendiecks Galois theory. We review the...

  17. Transition from non-periodic to periodic explosions.

    Science.gov (United States)

    Cartes, Carlos; Descalzi, Orazio

    2015-12-13

    We show the existence of periodic exploding dissipative solitons. These non-chaotic explosions appear when higher-order nonlinear and dispersive effects are added to the complex cubic-quintic Ginzburg-Landau equation modelling soliton transmission lines. This counterintuitive phenomenon is the result of period-halving bifurcations leading to order (periodic explosions), followed by period-doubling bifurcations (or intermittency) leading to chaos (non-periodic explosions). PMID:26527807

  18. Periodic and limit-periodic discrete Schr\\"odinger operators

    OpenAIRE

    Krueger, Helge

    2011-01-01

    The theory of discrete periodic and limit-periodic Schr\\"odinger operators is developed. In particular, the Floquet--Bloch decomposition is discussed. Furthermore, it is shown that an arbitrarily small potential can add a gap for even periods. In dimension two, it is shown that for coprime periods small potential terms don't add gaps thus proving a Bethe--Sommerfeld type statement. Furthermore limit-periodic potentials whose spectrum is an interval are constructed.

  19. On solving periodic Riccati equations

    OpenAIRE

    Varga, Andreas

    2008-01-01

    Numerically reliable algorithms to compute the periodic non-negative definite stabilizing solutions of the periodic differential Riccati equation (PRDE) and discrete-time periodic Riccati equation (DPRE) are proposed. For the numerical solution of PRDEs, a new multiple shooting-type algorithm is developed to compute the periodic solutions in an arbitrary number of time moments within one period by employing suitable discretizations of the continuous-time problems. In contrast to single shooti...

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

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of

  1. 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

  2. Nuevos registros de moluscos carboníferos en la sierra del Tontal, Precordillera de San Juan A new Carboniferous mollusk record from the Tontal Range, Precordillera of San Juan

    Directory of Open Access Journals (Sweden)

    R.R. Lech

    2006-03-01

    Full Text Available Se da a conocer una asociación de moluscos fósiles, Peruvispira aff. 'P'. sueroi, Nuculopsis? sp. y Limipecten sp., hallada en la Formación Ciénaga Larga del Tontal. Esta formación aflora en el faldeo occidental de la sierra del Tontal, al este de la región de Rincón Blanco, Precordillera de San Juan. Las dos primeras especies se encuentran en la zona fosilífera 1, junto a Aseptella? sp. y Productella sp., en tanto que Limpecten sp. se presenta en la zona fosilífera 4 junto a gasterópodos y bivalvos indeterminados. Considerando la asociación de braquiópodos fósiles y el contenido de palinomorfos presentes en la Formación Ciénaga Larga del Tontal se estima que su edad estaría comprendida entre lo más tardío del Carbonífero Temprano y el Carbonífero Tardío.An association of fossils mollusks integrated by Peruvispira aff. 'P'. sueroi, Nuculopsis? sp. and Limipecten sp. found in the Ciénaga Larga del Tontal Formation is reported in this contribution. This Upper Paleozoic formation crops out along part of the western slope of the Tontal Range, quite close to the highest part of it, and right to the east of the area of Rincón Blanco where Triassic deposits crop out. The two first mentioned species belong to the Fossil Zone 1, along with Aseptella ? sp., and Productella sp., while Limpecten sp. was found in the Fossil Zone 4, along with undetermined gastropods and bivalves. Taking into account the complete fossil association, and also considering the palynomorphs determined in the same formation, we estimate the age of the Ciénaga Larga del Tontal Formation to span from the late Lower Carboniferous until the late Upper Carboniferous.

  3. The redoubtable ecological periodic table

    Science.gov (United States)

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  4. A new characterization of periodic oscillations in periodic difference equations

    Energy Technology Data Exchange (ETDEWEB)

    Al-Salman, Ahmad [Department of Mathematics and Statistics, Sultan Qaboos University, P.O. Box 36, PC 123, Al-Khod (Oman); AlSharawi, Ziyad, E-mail: alsha1zm@alsharawi.info [Department of Mathematics and Statistics, Sultan Qaboos University, P.O. Box 36, PC 123, Al-Khod (Oman)

    2011-11-15

    Highlights: > A characterization of periodic solutions of periodic difference equations is given. > The periods are classified as multiples and non-multiples of the phase-period. > Non-multiples of the phase-period depend on the intersections between the maps. > A refinement of Sharkovsky's theorem for periodic difference equations is given. - Abstract: In this paper, we characterize periodic solutions of p-periodic difference equations. We classify the periods into multiples of p and nonmultiples of p. We show that the elements of the set of multiples of p follow the well-known Sharkovsky's ordering multiplied by p. On the other hand, we show that the elements of the set {Gamma}{sub p} of nonmultiples of p are independent in their existence. Moreover, we show the existence of a p-periodic difference equation with infinite {Gamma}{sub p}-set in which the maps are defined on a compact domain and agree exactly on a countable set. Based on the proposed classification, we give a refinement of Sharkovsky's theorem for periodic difference equations.

  5. Periods and elementary real numbers

    OpenAIRE

    Yoshinaga, Masahiko

    2008-01-01

    The periods, introduced by Kontsevich and Zagier, form a class of complex numbers which contains all algebraic numbers and several transcendental quantities. Little has been known about qualitative properties of periods. In this paper, we compare the periods with hierarchy of real numbers induced from computational complexities. In particular we prove that periods can be effectively approximated by elementary rational Cauchy sequences. As an application, we exhibit a computable real number wh...

  6. 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.

  7. 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。

  8. 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.

  9. Characteristics of type III kerogen in coal-bearing strata from the Pennsylvanian (Upper Carboniferous) in the Ruhr Basin, Western Germany: Comparison of coals, dispersed organic matter, kerogen concentrates and coal-mineral mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, K. [Institute of Geology and Geochemistry of Petroleum and Coal, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany); Institute of Geology and Palaeontology, RWTH Aachen University, 52056 Aachen (Germany); Krooss, B.M.; Littke, R. [Institute of Geology and Geochemistry of Petroleum and Coal, Lochnerstr. 4-20, RWTH Aachen University, 52056 Aachen (Germany); Flajs, G. [Institute of Geology and Palaeontology, RWTH Aachen University, 52056 Aachen (Germany); Hartkopf-Froeder, C. [Geological Survey North Rhine-Westphalia, De-Greiff-Str. 195, 47803 Krefeld (Germany)

    2009-10-01

    Quality, quantity and maturity of coal and dispersed terrigenous organic matter were studied on six coal-bearing intervals in Duckmantian strata (Pennsylvanian/Upper Carboniferous) of the Ruhr Basin, Western Germany. Between 10 and 40 samples were collected from fresh drill cores of each interval typically consisting of a coal seam as well as clastic roof and floor strata (sandstone, siltstone, claystone). Coal seams constitute about 8 vol.% of the succession studied. The samples were analysed by organic petrological methods and Rock-Eval pyrolysis. Maturity expressed in terms of vitrinite reflectance is between 0.75 and 1.0 %. For the six successions studied, the total amount of dispersed organic matter in clastic rocks is about half of that stored in coal seams, both containing predominantly vitrinite. Significant differences between Rock-Eval parameters determined on whole rock samples and kerogen concentrates were observed, especially with respect to Hydrogen Index (HI) values. Thus, the HI of the coal is about twice as high as that of the dispersed organic matter, although the maceral composition is similar. The effects of minerals were further examined by Rock-Eval pyrolysis of artificial mixtures of coal (lignite) powder and different minerals. Reduced HI values are partly explained by the retention of generated hydrocarbons on mineral surfaces and partly by reactions of generated fluids with pyrite in kerogen concentrates. (author)

  10. Periodic waves in nonlinear metamaterials

    International Nuclear Information System (INIS)

    Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution. -- Highlights: ► Equations for the monochromatic waves in transverse magnetic polarization have been studied. ► Analytic periodic waves for the equations have been obtained. ► Periodic waves are theoretically presented and studied in the nonlinear metamaterials.

  11. Nonparametric Inference for Periodic Sequences

    KAUST Repository

    Sun, Ying

    2012-02-01

    This article proposes a nonparametric method for estimating the period and values of a periodic sequence when the data are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both theoretically and by simulation.We also propose a nonparametric test of the null hypothesis that the data have constantmean against the alternative that the sequence of means is periodic. Finally, our methodology is demonstrated on three well-known time series: the sunspots and lynx trapping data, and the El Niño series of sea surface temperatures. © 2012 American Statistical Association and the American Society for Quality.

  12. Positive periodic solutions of delayed periodic Lotka-Volterra systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Wei [Laboratory of Nonlinear Mathematics Science, Institute of Mathematics, Fudan University, Shanghai 200433 (China)]. E-mail: weilin@fudan.edu.cn; Chen Tianping [Laboratory of Nonlinear Mathematics Science, Institute of Mathematics, Fudan University, Shanghai 200433 (China)]. E-mail: tchen@fudan.edu.cn

    2005-01-17

    In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases.

  13. Positive periodic solutions of delayed periodic Lotka-Volterra systems

    Science.gov (United States)

    Lin, Wei; Chen, Tianping

    2005-01-01

    In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases.

  14. Fractional-period excitations in continuum periodic systems

    International Nuclear Information System (INIS)

    We investigate the generation of fractional-period states in continuum periodic systems. As an example, we consider a Bose-Einstein condensate confined in an optical-lattice potential. We show that when the potential is turned on nonadiabatically, the system explores a number of transient states whose periodicity is a fraction of that of the lattice. We illustrate the origin of fractional-period states analytically by treating them as resonant states of a parametrically forced Duffing oscillator and discuss their transient nature and potential observability

  15. Repelling periodic points of given periods of rational functions

    Institute of Scientific and Technical Information of China (English)

    CHANG; Jianming; FANG; Mingliang

    2006-01-01

    Let R(z) be a rational function of degree d ≥ 2. Then R(z) has at least one repelling periodic point of given period k ≥ 2, unless k = 4 and d=2, or k= 3 and d ≤ 3, or k=2 and d≤8. Examples show that all exceptional cases occur.

  16. Photolysis of Periodate and Periodic Acid in Aqueous Solution

    DEFF Research Database (Denmark)

    Sehested, Knud; Kläning, U. K.

    1978-01-01

    The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies of...

  17. From Periodic Properties to a Periodic Table Arrangement

    Science.gov (United States)

    Besalú, Emili

    2013-01-01

    A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

  18. Scaling limits of periodic monopoles

    Science.gov (United States)

    Maldonado, Rafael

    2015-01-01

    The purpose of this note is to explore the structure of singly periodic monopoles for different values of the size to period ratio. The transition between a chain of small monopoles and the approximately two dimensional chain of large monopoles takes us through a region with an unintuitive dependence on the periodic direction. The focus is mainly on the smooth SU(2) monopole of charge 2.

  19. Scaling limits of periodic monopoles

    OpenAIRE

    Maldonado, Rafael

    2014-01-01

    The purpose of this note is to explore the structure of singly periodic monopoles for different values of the size to period ratio. The transition between a chain of small monopoles and the approximately two dimensional chain of large monopoles takes us through a region with an unintuitive dependence on the periodic direction. The focus is mainly on the smooth SU(2) monopole of charge 2.

  20. Ap stars with variable periods

    OpenAIRE

    Mikulášek, Zdeněk; Krtička, Jiří; Janík, Jan; Zejda, Miloslav; Henry, Gegory W.; Paunzen, Ernst; Žižňovský, Jozef; Zverko, Juraj

    2013-01-01

    The majority of magnetic chemically peculiar (mCP) stars exhibit periodic light, magnetic, radio, and spectroscopic variations that can be adequately modelled as a rigidly-rotating main-sequence star with persistent surface structures. Nevertheless, there is a small sample of diverse mCP stars whose rotation periods vary on timescales of decades while the shapes of their phase curves remain unchanged. Alternating period increases and decreases have been suspected in the hot CP stars CU Vir an...

  1. Holonomic systems for period mappings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingyue, E-mail: jychen@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States); Huang, An, E-mail: anhuang@math.harvard.edu [Department of Mathematics, Harvard University, Cambridge, MA 02138 (United States); Lian, Bong H., E-mail: lian@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States)

    2015-09-15

    Period mappings were introduced in the sixties [4] to study variation of complex structures of families of algebraic varieties. The theory of tautological systems was introduced recently [7,8] to understand period integrals of algebraic manifolds. In this paper, we give an explicit construction of a tautological system for each component of a period mapping. We also show that the D-module associated with the tautological system gives rise to many interesting vanishing conditions for period integrals at certain special points of the parameter space.

  2. Quasi-periodicity in relative quasi-periodic tori

    Science.gov (United States)

    Fassò, Francesco; García-Naranjo, Luis C.; Giacobbe, Andrea

    2015-10-01

    At variance from the cases of relative equilibria and relative periodic orbits of dynamical systems with symmetry, the dynamics in relative quasi-periodic tori (namely, subsets of the phase space that project to an invariant torus of the reduced system on which the flow is quasi-periodic) is not yet completely understood. Even in the simplest situation of a free action of a compact and abelian connected group, the dynamics in a relative quasi-periodic torus is not necessarily quasi-periodic. It is known that quasi-periodicity of the unreduced dynamics is related to the reducibility of the reconstruction equation, and sufficient conditions for it are virtually known only in a perturbation context. We provide a different, though equivalent, approach to this subject, based on the hypothesis of the existence of commuting, group-invariant lifts of a set of generators of the reduced torus. Under this hypothesis, which is shown to be equivalent to the reducibility of the reconstruction equation, we give a complete description of the structure of the relative quasi-periodic torus, which is a principal torus bundle whose fibers are tori of a dimension which exceeds that of the reduced torus by at most the rank of the group. The construction can always be done in such a way that these tori have minimal dimension and carry ergodic flow.

  3. Beyond the periodic orbit theory

    OpenAIRE

    Cvitanovic, Predrag; Hansen, Kim; Rolf, Juri; Vattay, Gabor

    1997-01-01

    The global constraints on chaotic dynamics induced by the analyticity of smooth flows are used to dispense with individual periodic orbits and derive infinite families of exact sum rules for several simple dynamical systems. The associated Fredholm determinants are of particularly simple polynomial form. The theory developed suggests an alternative to the conventional periodic orbit theory approach to determining eigenspectra of transfer operators.

  4. Superconductivity and the periodic table

    International Nuclear Information System (INIS)

    Compiled data on superconducting transition temperature Tc for pure metals (including amorphous and high-pressure phases) from the first, second, and third long periods of the Periodic Table and for their analogous compounds show that a significant regularity exists in the relative values of Tc

  5. Periodicities in gamma ray bursts

    International Nuclear Information System (INIS)

    Gamma ray burst models based on magnetic neutron stars face a problem of account for the scarcity of observed periods. Both this scarcity and the typical period found when any is detected are explained if the neutron stars are accreting in binary systems

  6. 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

  7. Permian-Carboniferous arc magmatism in southern Mexico: U-Pb dating, trace element and Hf isotopic evidence on zircons of earliest subduction beneath the western margin of Gondwana

    Science.gov (United States)

    Ortega-Obregón, C.; Solari, L.; Gómez-Tuena, A.; Elías-Herrera, M.; Ortega-Gutiérrez, F.; Macías-Romo, C.

    2014-07-01

    Undeformed felsic to mafic igneous rocks, dated by U-Pb zircon geochronology between 311 and 255 Ma, intrude different units of the Oaxacan and Acatlán metamorphic complexes in southwestern Mexico. Rare earth element concentrations on zircons from most of these magmatic rocks have a typical igneous character, with fractionated heavy rare earths and negative Eu anomalies. Only inherited Precambrian zircons are depleted in heavy rare earth elements, which suggest contemporaneous crystallization in equilibrium with metamorphic garnet during granulite facies metamorphism. Hf isotopic signatures are, however, different among these magmatic units. For example, zircons from two of these magmatic units (Cuanana pluton and Honduras batholith) have positive ɛHf values (+3.8-+8.5) and depleted mantle model ages (using a mean crustal value of 176Lu/177Hf = 0.015) ( T DMC) ranging between 756 and 1,057 Ma, whereas zircons from the rest of the magmatic units (Etla granite, Zaniza batholith, Carbonera stock and Sosola rhyolite) have negative ɛHf values (-1 to -14) and model ages between 1,330 and 2,160 Ma. This suggests either recycling of different crustal sources or, more likely, different extents of crustal contamination of arc-related mafic magmas in which the Oaxacan Complex acted as the main contaminant. These plutons thus represent the magmatic expression of the initial stages of eastward subduction of the Pacific plate beneath the western margin of Gondwana, and confirm the existence of a Late Carboniferous-Permian magmatic arc that extended from southern North America to Central America.

  8. Transition Period and Immunosuppression: Critical Period of Dairy Cattle Reproduction

    OpenAIRE

    K. Simenew; M. Wondu

    2013-01-01

    This seminar study is prepared on the objectives of: revising important aspects of transition period of dairy cattle and highlighting some potential areas of research and challenges for the future. It has sufficiently been discussed that improved understanding of this frontier of the biology, immunology, nutrition and management of cows during the transition period will provide the largest gains in productivity and profitability of dairy farms. In the manuscript under each specific topic, tra...

  9. Optical Periodicity Analysis of 3C 446 using Period04

    Indian Academy of Sciences (India)

    Fei Guo; Hao Jing Zhang

    2014-09-01

    All the data of the blazar 3C446 at 8, 4.8, 14 and 22 GHz, presented in publications from 1977 to 2006, have been compiled to generate light curves. The light curves show violent activity of 3C446. Using Period04 analysis method, we have found that there is a period of 7.2 yr, which is consistent with the results that we found using wavelet analysis method. We get the instability region as = 123.83.

  10. Use of measurements of the concentration of radon in gases in carboniferous strata for prediction of instantaneous outbursts of gas and rocks

    International Nuclear Information System (INIS)

    An attempt is made to predict sudden outbursts of coal and gas (or rock and gas) by observing changes in radon concentration in gases occurring in coal seams and contingent strata. Instantaneous outbursts of gas and rocks are one of the most serious natural hazards in underground mines, the problem being especially serious in certain coal and salt mines, where there was heavy loss of life as a result of sudden outbursts. Thus, methods for prediction and preventive measures are very important and have been investigated by many scientists, although the ability to predict outbursts is still very poor. As a result, any new method which can aid in forecasting an outburst is welcome. Since changes in the radon concentration in water in wells and springs are known precursors of earthquakes, it was assumed that other geodynamic phenomena, such as rock and gas outbursts, could be preceded by variances in the radon concentration in gases. In order to prove this assumption, measurements of the radon concentration were carried out in gas samples collected from coal seams and sandstone prone to outbursts. The results cover a four year observation period conducted in the Lower Silesian Coal Basin, which is one of the most dangerous areas because of the very dynamic outbursts that occur in mines. During this period, wide variations in the radon concentration were observed in gases in coal seams as well as in sandstones. Outbursts were always preceded by very low radon concentrations, while after an outburst the concentration of radon was usually high. A different picture of the changes in radon concentration emerged from observations of sandstone. However, even in this case it seems possible to use the results as the basis for a warning, especially since for sandstone all other methods of warning have failed. In the paper, an attempt is also made to provide a physical explanation of the variation observed in radon concentrations under different conditions. In the paper, up

  11. Entanglement Entropy of Periodic Sublattices

    CERN Document Server

    He, Temple; Vandoren, Stefan

    2016-01-01

    We study the entanglement entropy (EE) of Gaussian systems on a lattice with periodic boundary conditions, both in the vacuum and at nonzero temperatures. By restricting the reduced subsystem to periodic sublattices, we can compute the entanglement spectrum and EE exactly. We illustrate this for a free (1+1)-dimensional massive scalar field at a fixed temperature. Consistent with previous literature, we demonstrate that for a sufficiently large periodic sublattice the EE grows extensively, even in the vacuum. Furthermore, the analytic expression for the EE allows us probe its behavior both in the massless limit and in the continuum limit at any temperature.

  12. The Periodic Table in Croatia

    Directory of Open Access Journals (Sweden)

    Raos, N.

    2011-12-01

    Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.

  13. 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

  14. Modular forms and period polynomials

    CERN Document Server

    Pasol, Vicentiu

    2012-01-01

    We study the space of period polynomials associated with modular forms for finite index subgroups of the modular group. For the full modular group, this space is endowed with a pairing, corresponding to the Petersson inner product on modular forms via a formula of Haberland, and with an action of Hecke operators, defined algebraically by Zagier. We extend Haberland's formula to arbitrary modular forms for finite index subgroups of the modular group, and we show that it conceals two stronger formulas. We extend the action of Hecke operators to \\Gamma_0(N) and \\Gamma_1(N), and we prove algebraically that the pairing on period polynomials appearing in Haberland's formula is Hecke equivariant. Two indefinite theta series identities follow from this proof. We give two ways of determining the extra relations satisfied by the even and odd parts of period polynomials associated with cusp forms, which are independent of the period relations.

  15. Periodicities in Aerosol Optical Depths

    CERN Document Server

    Ramachandran, S; Verma, Amit; Panigrahi, Prasanta K

    2011-01-01

    We investigate the temporal and spatial variability in aerosol optical depth (AOD) over different geographic locations in India due to their important role in the earth-atmosphere radiation budget. The use of continuous wavelet transform pinpoints the spatio-temporal non-stationarity of the periodic variations in the AOD depending on local factors. The optimal time-frequency localization ability of Morlet wavelet accurately isolates the periodic features in the different frequency domains, to study the variations in the dominant periods due to local effects. The origin of the effects on the periodic modulations is then related to physical phenomena of regional nature, which throws considerable light on the observed variations in aerosol optical depths. We also find the phase relationship between different locations and to identify the possible correlations between different geographic locations and related environmental variations.

  16. Periodicities in photospheric magnetic flux

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Magnetic field plays an important role in solar structure and activity. In principle, the determination of magnetic flux would provide the best general-purpose index of solar activity. Currently, the periodicity studies corresponding to photospheric magnetic flux (PMF) are very few possibly due to the absence of a uniform flux sequence. In this paper, by using 383 NSO/Kitt Peak magnetic synoptic charts we reconstruct a flux sequence from February 1975 to August 2003 and perform a relatively systemic periodicity analysis with two methods of the Scargle periodogram and the Morlet wavelet transform. As a result, four periods are found at around 1050, 500, 300 and 160 days. We analyze these periods' temporal variabilities in detail and discuss their respective origins briefly.

  17. The Periodic Table in Croatia

    OpenAIRE

    Raos, N.

    2011-01-01

    The Croatian (Yugoslav) Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882), whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev). Such enthusiasti...

  18. Prime numbers: periodicity, chaos, noise

    OpenAIRE

    Bershadskii, A.

    2011-01-01

    Logarithmic gaps have been used in order to find a periodic component of the sequence of prime numbers, hidden by a random noise (stochastic or chaotic). The recovered period for the sequence of the first 10000 prime numbers is equal to 8\\pm1 (subject to the prime number theorem). For small and moderate values of the prime numbers (first 2000 prime numbers) this result has been directly checked using the twin prime killing method.

  19. Cohort postponement and period measures

    OpenAIRE

    Joshua R. Goldstein; Thomas Cassidy

    2010-01-01

    We introduce a new class of models in which demographic behavior such as fertility is postponed by differing amounts depending only on cohort membership. We show how this model fits into a general framework of period and cohort postponement that includes the existing models in the literature, notably those of Bongaarts and Feeney and Kohler and Philipov. The cohort-based model shows the effects of cohort shifts on period fertility measures and provides an accompanying tempo-adjusted measure o...

  20. Rotational periodicities in Saturn's magnetosphere

    International Nuclear Information System (INIS)

    Complete text of publication follows. A central question for Saturn's magnetospheric dynamics is the origin of periodicities close to the presumed rotational period of Saturn (∼10.8 h). Periodic oscillations are observed in the magnetic field, particles, Saturn kilometric radiation (SKR) and more. We discuss the possibility that all periodicities are likely to have one common cause: periodic plasmoid release from the night side sector. The rapid magnetic field reconfigurations following the plasmoid release energize charged particles and create the large scale 'injections' that are clearly seen in energetic neutral atom (ENA) images observed by the INCA camera on board Cassini. We further show that the magnetic field oscillations and SKR can be explained by the currents driven by the injected and energized plasma pressure distribution drifting around Saturn. The evolution of these pressure-driven currents is consistent with the evolution of the SKR. To quantify the magnetic field oscillations we estimate the distribution and strength of the plasma pressure from Cassini/MIMI and CAPS observations of hot and cold plasma. An important constraint is the how the magnetospheric dynamics respond to variations in solar wind dynamic pressure (SWP). In order to quantify this constraint we use SWP measurements from when Cassini is in the solar wind as well as model propagated solar wind properties to investigate how periodicities vary as a function of SWP. We further speculate that the ultimate cause of the periodic plasmoid releases is an effect of the inherent stability of the cold plasma without the need of a longitudinal 'anomaly' tied to the planet's core or ionosphere.

  1. Drought periods during XXth century

    International Nuclear Information System (INIS)

    The drought problem always exists somewhere in the world so that the economy of some nation or nations is always being adversely influenced by this factor. Although drought is a natural component of the climate in arid and semi-arid areas, it can occur in areas, which normally receive adequate precipitation. Available hydro meteorological data indicate droughts have occurred through the last century in Bulgaria and they a part of the climatic cycle on the Balkan Peninsula. The precipitation distribution is one of the basic characteristics of the drought occurrence in a given region. However, the distributions of additional meteorological elements should be also taken into account in order to describe the degree of the climate dryness. For example, the distribution of air temperature is an especially important characteristic for drought classifications. The last years in Bulgaria were drier and warmer than the normals for the period of so-called 'current climate' (1961-1990). Precipitation was approximately 80-85 % less than the normals. Statistical methods were used in order to analyze the long-term variations of precipitation, air temperature. The long-term series of data were smoothed by averages and they were also approximated by means of a polynomial. These methods eliminate the random and short periodical fluctuations of the time series. The Spearman coefficient (r) and the Kendall coefficient (rl) were used in order to investigate the existence of eventual trends. Some quantitative criteria were also used for a comparison of the drought frequency and intensity between different regions and years. As a result of the conducted analysis, the investigated period can be divided to separate sub-periods with duration of 10-15 years. These years are characterized with different moisture conditions. Three periods can be determined during the 20 th century, which are characterized by longer and severe droughts, namely 1902-1913, 1942-1953 and 1982-1994. The drought

  2. Periodic sedimentation of three particles in periodic boundary conditions

    International Nuclear Information System (INIS)

    Solutions of the equations of Stokesian dynamics for point particles are found for periodic boundary conditions with three particles per unit cell of a simple cubic lattice. Two particles per cell move with equal velocity, but three particles per cell usually lead to irregular motion. Special situations are of interest, where initially the distance vector of one pair is parallel to one of the horizontal axes of the cubic lattice and the members of this pair are at equal distance to the third particle. By symmetry the configuration keeps this character during the motion, and numerically the motion is found to be periodic. In our numerical work we have studied mostly the case where the initial triangle is horizontal and equilateral. We have shown that the periodic motion is neutrally stable for sizes of the initial triangle less than the critical size. Such stable solutions of the equations of Stokesian dynamics are of relevance to the theory of sedimentation. In these solutions the particles move coherently in a complicated fashion with the same mean sedimentation velocity and a periodic internal motion of the three-particle cluster. If initially the particles are sufficiently widely separated, but the motion is still stable, the mean sedimentation velocity is less than that of a single particle. In this case the solution describes a situation of hindered settling. If the initial triangle is too large, with the side length larger than the critical size, the two base particles team up with partners in neighboring cells, and we get separate motion of a base pair and a single particle with different mean vertical velocities and with periodic motions superimposed. The columns of horizontal pairs pass the columns of apex particles. The corresponding solutions are unstable. (author)

  3. Ap stars with variable periods

    CERN Document Server

    Mikulášek, Zdeněk; Janík, Jan; Zejda, Miloslav; Henry, Gegory W; Paunzen, Ernst; Žižňovský, Jozef; Zverko, Juraj

    2013-01-01

    The majority of magnetic chemically peculiar (mCP) stars exhibit periodic light, magnetic, radio, and spectroscopic variations that can be adequately modelled as a rigidly-rotating main-sequence star with persistent surface structures. Nevertheless, there is a small sample of diverse mCP stars whose rotation periods vary on timescales of decades while the shapes of their phase curves remain unchanged. Alternating period increases and decreases have been suspected in the hot CP stars CU Vir and V901 Ori, while rotation in the moderately cool star BS Cir has been decelerating. These examples bring new insight into this theoretically unpredicted phenomenon. We discuss possible causes of such behaviour and propose that dynamic interactions between a thin, outer, magnetically-confined envelope braked by the stellar wind, and an inner faster-rotating stellar body are able to explain the observed rotational variability

  4. On composites with periodic structure

    Science.gov (United States)

    Nemat-Nasser, S.; Iwakuma, T.; Hejazi, M.

    1982-01-01

    The overall moduli of a composite with an isotropic elastic matrix containing periodically distributed (anisotropic) inclusions or voids, can be expressed in terms of several infinite series which only depend on the geometry of the inclusions or voids, and hence can be computed once and for all for given geometries. For solids with periodic structures these infinite series play exactly the same role as does Eshelby's tensor for a single inclusion or void in an unbounded elastic medium. For spherical and circular-cylindrical geometries, the required infinite series are calculated and the results are tabulated. These are then used to estimate the overall elastic moduli when either the overall strains or the overall stresses are prescribed, obtaining the same results. These results are compared with other estimates and with experimental data. It is found that the model of composites with periodic structure yields estimates in excellent agreement with the experimental observations.

  5. Periodicity, the Canon and Sport

    Directory of Open Access Journals (Sweden)

    Thomas F. Scanlon

    2015-10-01

    Full Text Available The topic according to this title is admittedly a broad one, embracing two very general concepts of time and of the cultural valuation of artistic products. Both phenomena are, in the present view, largely constructed by their contemporary cultures, and given authority to a great extent from the prestige of the past. The antiquity of tradition brings with it a certain cachet. Even though there may be peripheral debates in any given society which question the specifics of periodization or canonicity, individuals generally accept the consensus designation of a sequence of historical periods and they accept a list of highly valued artistic works as canonical or authoritative. We will first examine some of the processes of periodization and of canon-formation, after which we will discuss some specific examples of how these processes have worked in the sport of two ancient cultures, namely Greece and Mesoamerica.

  6. Profit optimization during crisis periods

    Directory of Open Access Journals (Sweden)

    Sorin BRICIU

    2013-06-01

    Full Text Available This article highlights the authors’ attempt to identify a simple and effective calculation method for profit optimization in crisis periods. This method was identified based on the analysis of a representative sample of professionals working in both state-owned and private bakery companies in Romania. The article also presents methodological case studies for three bakery products aimed to highlight the changes in results according to changes of variables in the current business environment. The results obtained are presented and analysed by the authors. The article ends with the authors’ conclusions on the benefits of the Direct-Costing Method and profit optimisation in crisis periods.

  7. Periodic Monopoles from Spectral Curves

    OpenAIRE

    Maldonado, R.

    2012-01-01

    We consider $\\text{SU}(2)$ Bogomolny equations on $\\mathbb{R}^2\\times\\hat{S}^1$ and use the spectral curve defined by the holonomy in the periodic direction to approximate the fields in the limit of large size to period ratio. Symmetries of the Nahm transform allow a study of the effective two dimensional dynamics, which is compared with known results on the full moduli space. The techniques are applied to systems of higher charge and higher rank gauge group, allowing a direct comparison to o...

  8. Availability of periodically tested systems

    International Nuclear Information System (INIS)

    There is at the present time a need in accurate models to asess the availability of periodically tested stand-by systems. This paper shows how to improve the well known 'saw-tooth curve' model in order to take into account various reliability parameters. A model is developed to assess the pointwise and the mean availabilities of periodically tested stand-by systems. Exact and approxination formulae are given. In addition, the model developed herein leads to optimize the test interval in order to minimize the mean unavailability. A safety diesel in a nuclear power plant is given as an example

  9. Periodic orbits in arithmetical chaos

    International Nuclear Information System (INIS)

    Length spectra of periodic orbits are investigated for some chaotic dynamical systems whose quantum energy spectra show unexpected statistical properties and for which the notion of arithmetical chaos has been introduced recently. These systems are defined as the unconstrained motions of particles on two dimensional surfaces of constant negative curvature whose fundamental groups are given by number theoretical statements (arithmetic Fuchsian groups). It is shown that the mean multiplicity of lengths l of periodic orbits grows asymptotically like c x el/2/l, l → ∞. Moreover, the constant c (depending on the arithmetic group) is determined. (orig.)

  10. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  11. 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。

  12. 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

  13. 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.

  14. Le Carbonifère de Lybie occidentale biostratigraphie et micropaléontologie position dans le domaine Téthysien d'Afrique du Nord The Carboniferous in Western Libya : Biostratigraphy and Micropaleontology

    Directory of Open Access Journals (Sweden)

    Massa D.

    2006-11-01

    Full Text Available Analyse des sondages et coupes de terrain effectués en Libye occidentale entre 1956 et 1966. Comparaison avec les formations d'lllizi en Algérie. Principaux résultats a Stratigraphiques : Treize biozones sont définies du Tournaisien supérieur au Moscovien inférieur. Tous les étages sont présents, en particulier le Bachkirien dont l'existence était mal établie. b Paléogéographiques : Identité des bassins de Rhadamès et d'lllizi, et sans doute de la plus grande partie du bassin de Djado-Mourzouk. Définition d'un golfe Libyque. Individualité de la baie de Serdelès, dont la limite nord peut être survie avec précision. c Paléoécologiques : Confinement biologique et pauvreté des microfaunes sauf en quelques niveaux. Importance des domaines supratidaux et intertidaux. Parti-cularités des formations stromatolithiques (à e Collenia » et oolithiques. Climat tropical sec, aride, dominant. d Systématiques : Données sur les Foraminifères, Algues, Aouigaliides et Calcifoliides. Deux créations, intéressantes du point de vue phylogénétique : Velebitella simplicissima VACHARD n. sp. (Algue Dasycladale , Conilolia africana VACHARD n. gen. n. sp. (Aouigaliide Ptychocladiidé. The Carboniferous from several boreholes and outcrops in western Libyan Basins is analyzed. Comparison is made with the Illizi Basin in Algeria. This study bas yielded new data on microfacies, microfossils, biostratig rophy and sedimentology, which con be used to attempt ta drow a rough outline of the paleogeographic development of these basins. The main results are: a Stratigrophy: From the uppermost Tournaisian into the Moscovien, thirteen biozones are defined. All stages are present, and the Bashkirian bas been identified with absolute certainty for the first time. b Paleogeography : Important paleogeographic facts become evident from the study of microfacies : - The Illizi and Rhadames Basins, and probably the major part of the Djado-Murzuk Basin, have the

  15. Long-period creep behaviour

    International Nuclear Information System (INIS)

    With a view to dimensioning and reliable determination of the service life of high-temperature components the following subjects are discussed: Creep data as criteria for materials selection; weld behaviour under creep stress; influence of the test atmosphere; influence of production process and initial structure; studies on creep behaviour extrapolation procedure; estimation of permissible operating periods. (orig./IHOE)

  16. 76 FR 52915 - Periodic Reporting

    Science.gov (United States)

    2011-08-24

    ... informal rulemaking on proposed changes in certain analytical methods used in periodic reporting. The... Service filed a petition pursuant to 39 CFR 3050.11 requesting that the Commission initiate an informal... distribution activities would make it easier to distinguish shape-related work from mixed-shape work at...

  17. Shanghai's Fashion During Republic Period

    Institute of Scientific and Technical Information of China (English)

    卞向阳

    2004-01-01

    The goal of this research is to describe and analyze Shanghai's fashion during Republic Period. Shanghai's fashion during Republic Period plays a special role in fashion history of China and Shanghai history. In the paper, three aspects including the fashion centre of China as well as Far East, men's fashion and women's fashion in Shanghai are discussed. The style, textiles, color, decoration and combination of clothing are described. Many costumes from the Clothing Museum at Donghua University and private collections as well as some historical writings, photographs and publications are elucidated and corroborated to give a more detailed description about Shanghai's fashion during that period.Here are some tentative conclusions. Firstly, Shanghai had always been the fashion center in China even Far East during Republic Period. Modeng was the main reflection of Shanghai fashion. Secondly, the traditional clothing exerted less influence and was less widely used, some kinds and combinations were out of fashion gradually. The fashion was described to be highly stylized, exquisite and concise. Thirdly, the influence of Western Style was further greater. The fashion in Shanghai was almost synchronous with fashion of Paris. Some western clothing was directly used in daily life and the elements of Western Style had an increasingly wide utilization. Fourthly, the New Chinese Style whose representatives were Qipao and Zhongshan Zhuang appeared and popularized in Shanghai. The fashion of Qipao changed frequently. Finally, the fashion in Shanghai called Shanghai Style could be summarized fashionable, exquisite, rapidly changeable, which is harmonious of both ancient and modern, Chinese and foreign.

  18. 76 FR 297 - Periodic Reporting

    Science.gov (United States)

    2011-01-04

    ... INFORMATION: Regulatory History, 75 FR 58449 (Sept. 24, 2010). On December 20, 2010, the Postal Service filed... ] estimated. The Postal Service proposes to rely primarily on data from the manual density table to estimate... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of...

  19. Genius of the periodic table

    International Nuclear Information System (INIS)

    'Isn't it the work of a genius!' exclaimed Academician V.I. Spitsyn, USSR, a member of the Scientific Advisory Committee when talking to an Agency audience in January. His listeners shared his enthusiasm. Academician Spitsyn was referring to the first formulation a hundred years ago by Professor Dmitry I. Mendeleyev of the Periodic Law of Elements. (author)

  20. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    XuChengqian; ZhaoXiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP)is proposed .A new class of block design-Difference Family Pair (DFP)is also proposed .The relationship between PCSP and DFP,the properties and exising conditions of PCSP and the recursive constructions for PCSP are given.

  1. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    Xu Chengqian; Zhao Xiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP) is proposed. A new class of block design-Difference Family Pair (DFP) is also proposed.The relationship between PCSP and DFP, the properties and existing conditions of PCSP and the recursive constructions for PCSP are given.

  2. Model selection in periodic autoregressions

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

    1994-01-01

    textabstractThis paper focuses on the issue of period autoagressive time series models (PAR) selection in practice. One aspect of model selection is the choice for the appropriate PAR order. This can be of interest for the valuation of economic models. Further, the appropriate PAR order is important

  3. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients in the...

  4. Portfolio Selection and Insurance Period

    OpenAIRE

    Aoba, Nobuko

    2001-01-01

    This paper examines market risks, portfolio selection and period of insurance in a life insurance market. Date from many countries indicate that over ninety percent of bankruptcies of life insurers are due of failures in financial risk management. Financial risk management is therefore central. ...

  5. 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.

  6. Transition Period and Immunosuppression: Critical Period of Dairy Cattle Reproduction

    Directory of Open Access Journals (Sweden)

    K. Simenew

    2013-04-01

    Full Text Available This seminar study is prepared on the objectives of: revising important aspects of transition period of dairy cattle and highlighting some potential areas of research and challenges for the future. It has sufficiently been discussed that improved understanding of this frontier of the biology, immunology, nutrition and management of cows during the transition period will provide the largest gains in productivity and profitability of dairy farms. In the manuscript under each specific topic, transition cow program and reproductive performance, immunosuppressant effect of transition period, early predictors of disorders and major abnormalities are discussed in an informative way. Future potential areas of research and possible challenges are also indicated briefly. Finally, it is concluded that despite decades of research in the area of transition cow health and management the high incidence of health disorders around calving continues to negatively affect milk production and reproductive performance; and as recommendation, implementing a transition nutrition program with the help of nutritionists can help dairy herd avoid most of the costly problems and molecular level research studies should get due attention to further understand the situation and devise proper intervention techniques.

  7. Geopulsation, Volcanism and Astronomical Periods

    Institute of Scientific and Technical Information of China (English)

    Yang Xuexiang; Chen Dianyou; Yang Xiaoying; Yang Shuchen

    2000-01-01

    Volcanism is mainly controlled by the intermittent release of energy in the earth. As far as the differential rotation of the earth's inner core is concerned, the Galactic Year may change the gravitational constant G, the solar radiative quantity and the moving speed of the solar system and affect the exchange of angular momentum between core and mantle as well as the energy exchange between crust and mantle. As a result, this leads to eruptions of superplumes and magma, and controls the energy flow from core - mantle boundary (CMB) to crust. When the earth' s speed decreases, it will release a huge amount of energy. They are the reason of the correspondence of the volcanic cycles one by one with the astronomical periods one by one. According to the astronomical periods, volcanic eruptions may possibly be predicted in the future.

  8. Periodizing Globalization: Histories of Globalization

    OpenAIRE

    Nederveen Pieterse Jan

    2012-01-01

    The article outlines the analytics and criteria that inform periodizing globalization. It criticizes presentist and Eurocentric views on globalization, the contemporary view, the modernity view (1800 plus) or the capitalism view (1500 plus). It discusses approaches to world history and how globalization fits in. Understandings of globalization, such as multicentric and centrist perspectives, and units of analysis affect how timelines of globalization are established. Taking into account globa...

  9. The Periodic Table in Flatland

    OpenAIRE

    Negadi, T.; Kibler, M.

    1995-01-01

    The $D$-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in $D$ dimensions. This rule together with an {\\it Aufbau Prinzip} is applied to produce a $D$-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the $q$-deformed algeb...

  10. Potassium-Related Periodic Paralysis

    OpenAIRE

    A Lesani; MH Moradi Nejad

    1995-01-01

    Potassium-related periodic paralysis may be associated with hypo, normo, or hyperkalemic disturbance of the Potassium level. Clinical features, laboratory findings and ECG as well as EMG changes are different in the 3 types of the disease. The treatment demands correction of the Potassium level of the blood serum. The disease is normally transferred as an autosomal dominant trait. In this article we present a 9-year old girl who suffered from hypokalemic paralysis since she was 4 years old.

  11. Social Research On Renaissance Period

    Institute of Scientific and Technical Information of China (English)

    张蕾蕾

    2009-01-01

    The historical period known as the Renaissance spans the fifteenth and siXteenth centuries. ‘Renaissance'means‘re-birth'in French and during this time Europe left behind the mindset of the Midge Ages and created the beginnings of the modern world.This thesis mainly rotates on the background,the main features and significance of Renaissance,especially focuses on the discovery of man and the humanism and the detailed unfolding of the society on several aspect in Renaissance.

  12. Nested long period grating interferometers

    OpenAIRE

    Murphy, Richard P.; James, Stephen W.; Tatam, Ralph P.

    2007-01-01

    The concept of nested fibre optic long period grating (LPG) based interferometers is introduced. A number of in-series, identical LPGs may be used to form a set of nested, multiplexed Mach-Zehnder interferometers that may demodulated and demultiplexed by virtue of a Fourier analysis of the optical spectrum. The concept is demonstrated by the use of three LPGs to form a nested set of interferometers.

  13. Carboniferous and Devonian Polysporia and its spores

    Czech Academy of Sciences Publication Activity Database

    Bek, Jiří; Dašková, Jiřina; Shyamala, Ch.; Drábková, J.

    Prague : Institute of Geology, Academy of Science, 2006 - (Bek, J.; Brocke, R.; Dašková, J.; Fatka, O.). s. 12-13 ISBN 80-903511-3-1. [Palaeozoic Palynology in Space and Time : CIMP General meeting 2006. 02.09.2006-06.09.2006, Prague] Institutional research plan: CEZ:AV0Z30130516 Keywords : Polysporia * spores * palaeobotany Subject RIV: DB - Geology ; Mineralogy

  14. A Periodic Lotka-Volterra System

    OpenAIRE

    Tsvetkov, D.

    1996-01-01

    In this paper periodic time-dependent Lotka-Volterra systems are considered. It is shown that such a system has positive periodic solutions. It is done without constructive conditions over the period and the parameters.

  15. 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

  16. Quasi Periodic Oscillations in Blazars

    Indian Academy of Sciences (India)

    Alok C. Gupta

    2014-09-01

    Here we report our recent discoveries of Quasi-Periodic Oscillations (QPOs) in blazars time series data in X-ray and optical electromagnetic bands. Any such detection can give important clues of the location and nature of the processes of emission mechanism. In the case of radio-quiet AGN, the detected QPOs are very likely to be associated with the accretion disk. But in the case of blazars, it may be associated with jets in the high and outburst states, and in the low-state, it is probably associated with the accretion disk. In this brief review, I summarize the recent QPO detections in blazars. There is one strong evidence of QPO detection in XMM–Newton time series data of narrow line Seyfert 1 galaxy RE J1034+396 about which we will also discuss briefly.

  17. The periodically oscillating plasma sphere

    International Nuclear Information System (INIS)

    A new method of operating an inertial electrostatic confinement (IEC) device is proposed, and its performance is evaluated. The scheme involved an oscillating thermal cloud of ions immersed in a bath of electrons that form a harmonic oscillator potential. The scheme is called the periodically oscillating plasma sphere, and it appears to solve many of the problems that may limit other IEC systems to low gain. A set of self-similar solutions to the ion fluid equations is presented, and plasma performance is evaluated. Results indicate that performance enhancement of gridded IEC systems such as the Los Alamos intense neutron source device is possible as well as high-performance operation for low-loss systems such as the Penning trap experiment. Finally, a conceptual idea for a massively modular Penning trap reactor is also presented

  18. The periodic table in Flatland

    International Nuclear Information System (INIS)

    The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aujbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of a Hamiltonian, invariant under the q-deformed algebra Uq(so(D)), that breaks down the SO(D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated in some detail. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. 55 refs

  19. The periodic table in Flatland

    International Nuclear Information System (INIS)

    The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aufbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the q-deformed algebra Uq (so(D)), that breaks down the SO (D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. (authors). 55 refs

  20. Periods of ZZ Ceti variables

    International Nuclear Information System (INIS)

    White dwarf pulsators (ZZ Ceti variables) osub solar acccur in the extension of the radial pulsation envelope ionization instability strip to the observed luminosities of 3 x 10-3L sub solar according to van Horn. Investigations were underway to see if the driving mechanisms of hydrogen and helium ionization can cause radial pulsations as they do for the Cepheids, the RR Lyrae variables, and the delta Scuti variables. Masses used in this study are 0.60 and 0.75 M sub solar for T/sub e/ between 10,000 K and 14,000 K, the observed range in T/sub e/. Helium rich surface compositions like Y = 0.78,, Z = 0.02 as well as Y = 0.28, Z = 0.02 were used in spite of observations showing only hydrogen lines in the spectrum. The deep layers are pure carbon, and several transition compositions are included. The models show radial pulsation instabilities for many overtone modes at periods between about 0.3 and 3 seconds. The driving mechanism is mostly helium ionization at 40,000 and 150,000 K. The blue edge at about 14,000 K is probably due to the driving region becoming too shallow, and the red edge at 10,000 K is due to so much convection in the pulsation deriving region that no radiative luminosity is available for modulation by the γ and kappa effects. It is speculated that the very long observed periods (100 to 1000 sec) of ZZ Ceti variables are not due to nonradial pulsations, but are possibly aliases due to data undersampling. 4 references

  1. 46 CFR 9.8 - Broken periods.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Broken periods. 9.8 Section 9.8 Shipping COAST GUARD... § 9.8 Broken periods. In computing extra compensation where the services rendered are in broken periods and less than 2 hours intervene between such broken periods the time served should be...

  2. Periodic and Almost Periodic Solutions of Functional Difference Equations with Finite Delay

    OpenAIRE

    Yihong Song

    2007-01-01

    For periodic and almost periodic functional difference equations with finite delay, the existence of periodic and almost periodic solutions is obtained by using stability properties of a bounded solution.

  3. Periodical plane puzzles with numbers

    CERN Document Server

    Rezende, Jorge

    2011-01-01

    Consider a periodical (in two independent directions) tiling of the plane with polygons (faces). In this article we shall only give examples using squares, regular hexagons, equilateral triangles and parallelograms ("unions" of two equilateral triangles). We shall call some "multiple" of the fundamental region "the board". We naturally identify pairs of corresponding edges of the the board. Figures 9 and 19-29, in this article, show different boards. The "border" of the board is represented by a yellow thick line, unless part of it or all of it is the edge of a face. The board is tiled by a finite number of polygons. Construct polygonal plates in the same number, shape and size as the polygons of the board. Adjacent to each side of each plate draw a number, or two numbers, like it is shown in Figures 1 and 18-29. Figure 1 shows the obvious possibility of having plates with simple drawings, coloured drawings, etc. Now the game is to put the plates over the board polygons in such a way that the numbers near eac...

  4. 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。

  5. Detection of superimposed periodic signals using wavelets

    OpenAIRE

    Otazu, X.; Ribo, M.; Peracaula, M.; Paredes, J. M.; Nunez, J.

    2002-01-01

    In this paper we present a wavelet based algorithm that is able to detect superimposed periodic signals in data with low signal-noise ratio. In this context, the results given by classical period determination methods highly depend on the intrinsic characteristics of each periodic signal, like amplitude or profile. It is then difficult to detect the different periods present in the data set. The results given by the wavelet based method for period determination we present here are independent...

  6. Thyrotoxic Hypokalemic Periodic Paralysis: A Case Report

    OpenAIRE

    Tuna, Mazhar Muslum; Aycicek Dogan, Bercem; Nasiroglu Imga, Narin; Karakilic, Ersen; Karadeniz, Mine; Tutuncu, Yasemin; Isik, Serhat; Berker, Dilek; Guler, Serdar

    2014-01-01

    AbstractHypokalemic periodic paralysis is a rare disorder characterized by reversible attacks of muscle weakness accompanied by episodic hypokalemia. The most common causes of hypokalemic periodic paralysis (HPP) are familial periodic paralysis, thyrotoxic periodic paralysis (TPP) and sporadic periodic paralysis, respectively. There are generally some precipitating factors such as stress, vigorous exercise and high carbohydrate food consumption which all ease the occurrence of attacks. The du...

  7. Aperiodic and semi-periodic perfect maps

    OpenAIRE

    Mitchell, Chris

    1995-01-01

    Paterson [1] has recently shown that the trivial necessary conditions are sufficient for the existence of a (binary) perfect map. These periodic structures can be transformed very simply into corresponding aperiodic and semi-periodic perfect maps. However, aperiodic and semi-periodic perfect maps can exist for parameter sets for which the corresponding periodic perfect maps cannot. In this paper it is shown, by construction, that (binary) aperiodic and semi-periodic perfect maps exist for all...

  8. Periodic Poisson Solver for Particle Tracking

    CERN Document Server

    Dohlus, M

    2015-01-01

    A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics, this approach allows to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudo-periodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.

  9. Crystallography beyond periodic Crystal perfection

    International Nuclear Information System (INIS)

    Full text: The discovery of the quasi-crystals [D. Schechtman et. Al., Phys.] Rev. Lett. [53, 1951-1953 (1984)] made very narrow definition of the crystalline state based on the periodicity of a local arrangement of atoms. Since the definition of this State has been a matter of much controversy [G.R. Desiraju, Nature 423, 485 (2003); S. van Smaalen, IUCR Aperiodic Commission Reports. August 7, 2002; International Union of Crystallography. Report of the Executive Committee for 1991; ACTA Cryst. A48, 922-946 (1992)]. We will make a presentation of the current time of the crystallography in this regard from the conceptual point of view. We show the use of the formalism of algorithmic complexity or Kolmogorov [M. Li and P. Vitanyi, An Introduction to Kolmogorov Complexity and Its Applications (Springer Verlag, Heidelberg, 1993), W.H. Zurek, Phys.] Rev. 40, 4731 (1989); Nature 341, 119-124 (1989)] provides a different perspective on the nature of the Crystallographic order. Infinite crystals can be considered solid with zero algorithmic complexities by atom. Show statistical analysis of inorganic compounds [J.L.C. Daams et al., Atlas of Crystal Structure Types for Intermetallic Phases (ASM International, Ohio, 1991), Fachinformationszentrum/NIST Inorganic Crystal Structure Database, Karlsruhe (2003) icsd.fkf.mpg.de] demonstrating that the minimization of complexity is a trend in the crystalline arrangement. We will then compare the degree of disorder of some typical solids according to their algorithmic complexity. Finally, space diffraction will be studied from this same perspective and will be discussed that zero algorithmic complexities by point in space of diffraction does not necessarily imply the same thing for the Atomic arrangement. The discrete portion of the diffraction pattern is a fingerprint of the underlying order but not the actual existence of long-range order. Experimental results will be showcased [E. Estévez-Rams et al., Physical Review B, 63 (2001

  10. The Galois coaction on $\\phi^4$ periods

    CERN Document Server

    Panzer, Erik

    2016-01-01

    We report on calculations of Feynman periods of primitive log-divergent $\\phi^4$ graphs up to eleven loops. The structure of $\\phi^4$ periods is described by a series of conjectures. In particular, we discuss the possibility that $\\phi^4$ periods are a comodule under the Galois coaction. Finally, we compare the results with the periods of primitive log-divergent non-$\\phi^4$ graphs up to eight loops and find remarkable differences to $\\phi^4$ periods. Explicit results for all periods we could compute are provided in ancillary files.

  11. 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

  12. 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

  13. US Forest Service Periodical Cicada Broods

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service on the www depicting periodical cicada distribution and expected year of emergence by cicada brood and county. The periodical cicada emerges in...

  14. Genetics Home Reference: hypokalemic periodic paralysis

    Science.gov (United States)

    ... paralysis Patient Support and Advocacy Resources (2 links) Muscular Dystrophy Association Resource list from the University of Kansas Medical Center GeneReviews (1 link) Hypokalemic Periodic Paralysis Genetic Testing Registry (3 links) Hypokalemic periodic paralysis Hypokalemic ...

  15. Periodic solutions of nonlinear vibrating beams

    Directory of Open Access Journals (Sweden)

    J. Berkovits

    2003-01-01

    Full Text Available The aim of this paper is to prove new existence and multiplicity results for periodic semilinear beam equation with a nonlinear time-independent perturbation in case the period is not prescribed. Since the spectrum of the linear part varies with the period, the solvability of the equation depends crucially on the period which can be chosen as a free parameter. Since the period of the external forcing is generally unknown a priori, we consider the following natural problem. For a given time-independent nonlinearity, find periods T for which the equation is solvable for any T-periodic forcing. We will also deal with the existence of multiple solutions when the nonlinearity interacts with the spectrum of the linear part. We show that under certain conditions multiple solutions do exist for any small forcing term with suitable period T. The results are obtained via generalized Leray-Schauder degree and reductions to invariant subspaces.

  16. Financial Innovation in Multi-Period Economies

    OpenAIRE

    Enrique Kawamura

    2003-01-01

    I present an attempt to construct multi-period, finite horizon extensions to the well -known two- period financial innovations literature. I first extend the definition of competitive equilibrium with innovations. It is shown that, with a dominating house

  17. Periodic Poisson model for beam dynamics simulation

    Science.gov (United States)

    Dohlus, M.; Henning, Ch.

    2016-03-01

    A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary condition is realized. In beam physics, this approach allows us to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle-mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudoperiodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.

  18. The Middle Islamic and Crusader Periods

    DEFF Research Database (Denmark)

    Walmsley, Alan George

    2008-01-01

    The book chapter presents a critical review of the archaeology of Jordan in the middle Islamic periods (8th - 17th centuries CE), presenting a new evaluation of settlement and culture in the period, and assesses the errors of past appraoches.......The book chapter presents a critical review of the archaeology of Jordan in the middle Islamic periods (8th - 17th centuries CE), presenting a new evaluation of settlement and culture in the period, and assesses the errors of past appraoches....

  19. Local Extrema of Periodic Function's Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    FAN Qi-bin; SONG Xiao-yan

    2005-01-01

    The theory of detecting ridges in the modulus of the continuous wavelet transform is presented as well as reconstructing signal by using information on ridges. To periodic signal we suppose Morlet wavelet as basic wavelet, and research the local extreme point and extrema of the wavelet transform on periodic function for the collection of signal's instantaneous amplitude and period.

  20. 77 FR 73452 - Grace Period Study

    Science.gov (United States)

    2012-12-10

    ... Patent and Trademark Office Grace Period Study ACTION: Proposed collection; comment request. SUMMARY: The...Collection@uspto.gov . Include ``0651- 00xx Grace Period Study comment'' in the subject line of the message... are not fully understood. Few studies in the past ten years have dealt with the grace period, and...

  1. 32 CFR 37.1325 - Periodic audit.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Periodic audit. 37.1325 Section 37.1325 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1325 Periodic audit. An audit of... awards. Appendix C to this part describes what such an audit may cover. A periodic audit of a...

  2. 21 CFR 573.240 - Calcium periodate.

    Science.gov (United States)

    2010-04-01

    ... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used...

  3. 49 CFR 236.588 - Periodic test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic test. 236.588 Section 236.588..., Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.588 Periodic test. Except as provided in § 236.586, periodic test of the automatic train stop, train control, or cab signal...

  4. 27 CFR 70.244 - Payroll period.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Payroll period. 70.244... Excise and Special (Occupational) Tax Limitations § 70.244 Payroll period. For purpose of determining the... established calendar period regularly used by the employer or other person levied upon for payroll or...

  5. Almost Periodic Time Scales and Almost Periodic Functions on Time Scales

    OpenAIRE

    Yongkun Li; Bing Li

    2015-01-01

    We propose some new concepts of almost periodic time scales and almost periodic functions on time scales and give some basic properties of these new types of almost periodic time scales and almost periodic functions on time scales. We also give some comments on a recent paper by Wang and Agarwal (2014) concerning a new almost periodic time scale.

  6. Volcanismo calcoalcalino neopaleozoico en la Precordillera de La Rioja. Petrología y caracterización litoestratigráfica de la Formación Punta del Agua (Carbonífero Superior-Pérmico Inferior Late Palaeozoic calc-alkaline volcanism in the Precordillera of La Rioja: petrology and lithostratigraphical characterization of the Punta del Agua Formation (Late Carboniferous - Early Permian

    Directory of Open Access Journals (Sweden)

    M. Remesal

    2004-09-01

    Pampeanas. The unit consists of interbedded lava flows, pyroclastic flows and clastic sedimentary deposits. The lava flows have been divided according to their composition and textural characteristics; a dacitic sill is also included. Pyroclastic flows consist of block- and ash-flow deposits and reoignimbrites. Between periods of volcanicity, conglomerates, lithic sandstones and scarce mudstones were deposited in lenticular bodies that reflect the irregular morphology of the volcanic area. Twelve samples of the volcanic rocks, obtained from both flanks of the Punta del Agua syncline were geochemically analysed. The variation in chemical composition ranges from basaltic andesites to rhyolites, but andesitic compositions dominate. The calc-alkaline character of these rocks and the abundance of K in the andesites, suggest that these magmas originated by subduction with crystal fractionation and contamination processes. The age of the Punta del Agua Formation was established on the basis of its stratigraphical relations and radiometric dating. Both suggest a Late Carboniferous age, although an Early Permian age for the uppermost part of the sequence cannot be disregarded.

  7. Counterexamples to mean square almost periodicity of the solutions of some SDEs with almost periodic coefficients

    Directory of Open Access Journals (Sweden)

    Omar Mellah

    2013-04-01

    Full Text Available We show that, contrarily to what is claimed in some papers, the nontrivial solutions of some stochastic differential equations with almost periodic coefficients are never mean square almost periodic (but they can be almost periodic in distribution.

  8. A highly specific test for periodicity

    International Nuclear Information System (INIS)

    We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series

  9. A highly specific test for periodicity

    Energy Technology Data Exchange (ETDEWEB)

    Ansmann, Gerrit, E-mail: gansmann@uni-bonn.de [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14–16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53175 Bonn (Germany)

    2015-11-15

    We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series.

  10. 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

  11. Gabor systems on discrete periodic sets

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Due to its good potential for digital signal processing, discrete Gabor analysis has interested some mathematicians. This paper addresses Gabor systems on discrete periodic sets, which can model signals to appear periodically but intermittently. Complete Gabor systems and Gabor frames on discrete periodic sets are characterized; a sufficient and necessary condition on what periodic sets admit complete Gabor systems is obtained; this condition is also proved to be sufficient and necessary for the existence of sets E such that the Gabor systems generated by χE are tight frames on these periodic sets; our proof is constructive, and all tight frames of the above form with a special frame bound can be obtained by our method; periodic sets admitting Gabor Riesz bases are characterized; some examples are also provided to illustrate the general theory.

  12. Discovery of periodic patterns in spatiotemporal sequences

    OpenAIRE

    Cao, H.; Mamoulis, N; Cheung, DW

    2007-01-01

    In many applications that track and analyze spatiotemporal data, movements obey periodic patterns; the objects follow the same routes (approximately) over regular time intervals. For example, people wake up at the same time and follow more or less the same route to their work everyday. The discovery of hidden periodic patterns in spatiotemporal data could unveil important information to the data analyst. Existing approaches for discovering periodic patterns focus on symbol sequences. However,...

  13. Topological Chaos in Spatially Periodic Mixers

    OpenAIRE

    Finn, Matthew D.; Thiffeault, Jean-Luc; Gouillart, Emmanuelle

    2005-01-01

    Topologically chaotic fluid advection is examined in two-dimensional flows with either or both directions spatially periodic. Topological chaos is created by driving flow with moving stirrers whose trajectories are chosen to form various braids. For spatially periodic flows, in addition to the usual stirrer-exchange braiding motions, there are additional topologically-nontrivial motions corresponding to stirrers traversing the periodic directions. This leads to a study of the braid group on t...

  14. Periodic boundary conditions on the pseudosphere

    OpenAIRE

    Sausset, François; Tarjus, Gilles

    2007-01-01

    30 pages, minor corrections, accepted to J. Phys. A International audience We provide a framework to build periodic boundary conditions on the pseudosphere (or hyperbolic plane), the infinite two-dimensional Riemannian space of constant negative curvature. Starting from the common case of periodic boundary conditions in the Euclidean plane, we introduce all the needed mathematical notions and sketch a classification of periodic boundary conditions on the hyperbolic plane. We stress the ...

  15. The periodic table of elementary particles

    OpenAIRE

    Chung, Ding-Yu

    2000-01-01

    All leptons, quarks, and gauge bosons can be placed in the periodic table of elementary particles. The periodic table is derived from dualities of string theory and a Kaluza-Klein substructure for the six extra spatial dimensions. As a molecule is the composite of atoms with chemical bonds, a hadron is the composite of elementary particles with hadronic bonds. The masses of elementary particles and hadrons can be calculated using the periodic table with only four known constants: the number o...

  16. Casimir electromotive force in periodic configurations

    OpenAIRE

    Fateev, Evgeny G.

    2016-01-01

    The possibility in principle of the existence of Casimir electromotive force (EMF) is shown for nonparallel nanosized metal plates arranged in the form of a periodic structure. It is found that EMF does not appear in strictly periodic structures with parallel plates. However, when the strict periodicity is disturbed in nonparallel plates, EMF is generated, and its value is equal to the number of pairs of plates in a configuration. Moreover, there are some effective parameters of the configura...

  17. Do triatomic molecules echo atomic periodicity?

    Energy Technology Data Exchange (ETDEWEB)

    Hefferlin, R., E-mail: hefferln@southern.edu; Barrow, J. [Southern Adventist University, PO Box 370, Collegedale, Tennessee 37315 (United States)

    2015-03-30

    Demonstrations of periodicity among triatomic-molecular spectroscopic constants underscore the role of the periodic law as a foundation of chemistry. The objective of this work is to prepare for another test using vibration frequencies ν{sub 1} of free, ground-state, main-group triatomic molecules. Using data from four data bases and from computation, we have collected ν{sub 1} data for molecules formed from second period atoms.

  18. Periodic boundary conditions on the pseudosphere

    Energy Technology Data Exchange (ETDEWEB)

    Sausset, F; Tarjus, G [Laboratoire de Physique Theorique de la Matiere Condensee, Universite Pierre et Marie Curie, Paris 6, UMR CNRS 7600, 4 place Jussieu, 75252 Paris Cedex 05 (France)

    2007-10-26

    We provide a framework for building periodic boundary conditions on the pseudosphere (or hyperbolic plane), the infinite two-dimensional Riemannian space of constant negative curvature. Starting from the common case of periodic boundary conditions in the Euclidean plane, we introduce all the required mathematical notions and sketch a classification of periodic boundary conditions on the hyperbolic plane. We stress the possible applications in statistical mechanics for studying the bulk behavior of physical systems, and illustrate how to implement such periodic boundary conditions in two examples, the dynamics of particles on the pseudosphere and the study of classical spins on hyperbolic lattices.

  19. [Hypokalemic periodic paralysis. A case report].

    Science.gov (United States)

    Areta-Higuera, J D; Algaba-Montes, M; Oviedo-García, A Á

    2014-01-01

    Periodic paralysis is a rare disorder that causes episodes of severe muscle weakness that can be confused with other diseases, including epilepsy or myasthenia gravis. Hyperkalemic and hypokalemic paralysis are included within these diseases, the latter being divided into periodic paralysis (familial, thyrotoxic or sporadic) and non-periodic paralysis. In this regard, we present a case of familial hypokalemic periodic paralysis in an eighteen year-old female who was diagnosed with epilepsy in childhood, as well as a subclinical hypothyroidism (for which she received replacement therapy) months ago. The diagnosis was made by the anamnesis and the confirmation of hypokalemia. PMID:24360869

  20. Measuring Stellar Rotation Periods with Kepler

    DEFF Research Database (Denmark)

    Nielsen, M. B.; Gizon, L.; Schunker, H.;

    2012-01-01

    We measure rotation periods for 12151 stars in the Kepler field, based on photometric variability caused by stellar activity. Our analysis returns stable rotation periods over at least six out of eight quarters of Kepler data. This large sample of stars enables us to study rotation periods as a...... function of spectral type. We find good agreement with previous studies and v sin i measurements for F, G, and K stars. Combining rotation periods, (B-V) color, and gyrochronology relations, we find that cool stars in our sample are predominantly younger than ˜ 1 Gyr....

  1. Casimir electromotive force in periodic configurations

    CERN Document Server

    Fateev, Evgeny G

    2016-01-01

    The possibility in principle of the existence of Casimir electromotive force (EMF) is shown for nonparallel nanosized metal plates arranged in the form of a periodic structure. It is found that EMF does not appear in strictly periodic structures with parallel plates. However, when the strict periodicity is disturbed in nonparallel plates, EMF is generated, and its value is equal to the number of pairs of plates in a configuration. Moreover, there are some effective parameters of the configuration (angles between plates, plate lengths and length to length ratios), at which the EMF generation per unit of the length of the periodic structure is maximal.

  2. Bifurcations of Periodic Orbits and Uniform Approximations

    CERN Document Server

    Schomerus, H; Schomerus, Henning; Sieber, Martin

    1997-01-01

    We derive uniform approximations for contributions to Gutzwiller's periodic-orbit sum for the spectral density which are valid close to bifurcations of periodic orbits in systems with mixed phase space. There, orbits lie close together and give collective contributions, while the individual contributions of Gutzwiller's type would diverge at the bifurcation. New results for the tangent, the period doubling and the period tripling bifurcation are given. They are obtained by going beyond the local approximation and including higher order terms in the normal form of the action. The uniform approximations obtained are tested on the kicked top and are found to be in excellent agreement with exact quantum results.

  3. Exact analysis of bi-periodic structures

    CERN Document Server

    Cai, C W; Chan, H C

    2002-01-01

    By using the U-transformation method, it is possible to uncouple linear simultaneous equations, either algebraic or differential, with cyclic periodicity. This book presents a procedure for applying the U-transformation technique twice to uncouple the two sets of unknown variables in a doubly periodic structure to achieve an analytical exact solution. Explicit exact solutions for the static and dynamic analyses for certain engineering structures with doubly periodic properties - such as a continuous truss with any number of spans, cable network and grillwork on supports with periodicity, and g

  4. In Sample of L’Illustration Magazine, Militarism in World War II Period Periodical Advertising

    OpenAIRE

    BOYRAZ, Burak

    2015-01-01

    World War II (1939-1945) which is one of the most bloody and deathful wars of history is also the period militarism was involved in daily life most intensively. In this study named; In Sample of L’Illustration Magazine, Militarism in World War II Period Periodical Advertising, said characteristics of militarism has been, within the scope of a literature review, scrutinized over periodicals and periodical advertising. Accordingly, in the first section of the study where L’Illustration, one of ...

  5. 28 CFR 524.75 - Periodic review.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Periodic review. 524.75 Section 524.75... TRANSFER CLASSIFICATION OF INMATES Central Inmate Monitoring (CIM) System § 524.75 Periodic review. The Warden shall ensure that the status of an inmate's CIM assignment is considered at each program...

  6. How Sensitively Timed Are Sensitive Periods?

    Science.gov (United States)

    Zener, Rita Schaefer

    2003-01-01

    Reviews Maria Montessori's view of sensitive periods and examines the kinds of help needed from adults: an open mind, specific help from a prepared learning environment, and challenges presented at the right time. Stresses the universality of sensitive periods and their connection to brain development. Focuses on the unconscious nature and…

  7. Studying the Nazi Period: Some Considerations.

    Science.gov (United States)

    Molnar, Alex; And Others

    1984-01-01

    Students should be taught how to make well-reasoned and analytic judgments about the Nazis. The process of arriving at judgments about the Nazi period should be characterized by a factual knowledge of the Nazi era within a general historical knowledge of the period, sympathy, and an open mind. (RM)

  8. Undulating periodization models for strength training & conditioning

    Directory of Open Access Journals (Sweden)

    A. Jiménez

    2009-01-01

    Full Text Available Periodized strength training refers to varying the training program at regular time intervals in an attempt to bring about optimal resistance gains. The main aim of this paper was to present a short review of the diferent aspects of training periodization and its effects with performance. as well as the differential effect of alternate periodization models on other populations, and specially the need for further research regarding the effectiveness of the undulating model as compared with the linear model. A focussed literature review reveals that most studies that examined strength training periodization utilized young males as their subject population, and the research has mainly focused on differences between periodized and non-periodized programs. Furthermore, the periodization training programs are designed and developed according to two different models: the linear model and the non-linear model. The Linear Model is characterized by high initial training volume and low and intensity. The Non-Linear Model enables variation in intensity and volume within each 7-10 day cycle by rotating different protocols to train various components of the neuromuscular system. The results showed at the scientific literature encourage researchers and exercise professionals to include non-linear (undulating periodization models during resistance training.

  9. 20 CFR 655.205 - Recruitment period.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Recruitment period. 655.205 Section 655.205... Agricultural Employment § 655.205 Recruitment period. (a) If the OFLC Administrator determines that the... carry out the assurances contained in § 655.203 with respect to the recruitment of U.S. workers....

  10. Periodicity of Rauzy scheme and substitutional systems

    CERN Document Server

    Kanel-Belov, Alexei

    2011-01-01

    In the paper the notion of {\\em Rauzy scheme} is introduced. From Rauzy graph Rauzy Scheme can be obtaining by uniting sequence of vertices of ingoing and outgoing degree 1 by arches. This notion is a tool to describe Rauzy graph behavior. For morphic superword we prove periodicity of Rauzy schemes. This is generalization of fact that quadratic irrationals have periodic chain fractions.

  11. Multi-periodic nanostructures for photon control

    DEFF Research Database (Denmark)

    Kluge, Christian; Adam, Jost; Barié, Nicole; Jakobs, Peter-Jürgen; Guttmann, Markus; Gerken, Martina

    We propose multi-periodic nanostructures yielded by superposition of multiple binary gratings for wide control over photon emission in thin-film devices. We present wavelength- and angle-resolved photoluminescence measurements of multi-periodically nanostructured organic light-emitting layers. Th...

  12. Almost periodic Hamiltonians: an algebraic approach

    International Nuclear Information System (INIS)

    We develop, by analogy with the study of periodic potential, an algebraic theory for almost periodic hamiltonians, leading to a generalized Bloch theorem. This gives rise to results concerning the spectral measures of these operators in terms of those of the corresponding Bloch hamiltonians

  13. The periodic table of elementary particles

    International Nuclear Information System (INIS)

    It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs

  14. Online Periodic Table: A Cautionary Note

    Science.gov (United States)

    Izci, Kemal; Barrow, Lloyd H.; Thornhill, Erica

    2013-01-01

    The purpose of this study was (a) to evaluate ten online periodic table sources for their accuracy and (b) to compare the types of information and links provided to users. Limited studies have been reported on online periodic table (Diener and Moore 2011; Slocum and Moore in "J Chem Educ" 86(10):1167, 2009). Chemistry students'…

  15. 24 CFR 886.332 - Rehabilitation period.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Rehabilitation period. 886.332... Assistance Program for the Disposition of HUD-Owned Projects § 886.332 Rehabilitation period. (a) Immediate start of rehabilitation after sales closing. After the execution of the Agreement and the sales...

  16. 42 CFR 441.58 - Periodicity schedule.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Periodicity schedule. 441.58 Section 441.58 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... schedule. The agency must implement a periodicity schedule for screening services that— (a)...

  17. Periodicity of d-cluster-tilted algebras

    CERN Document Server

    Dugas, Alex

    2010-01-01

    It is well-known that any maximal Cohen-Macaulay module over a hypersurface has a periodic free resolution of period 2. Auslander, Reiten and Buchweitz have used this periodicity to explain the existence of periodic projective resolutions over certain finite-dimensional algebras which arise as stable endomorphism rings of Cohen-Macaulay modules. These algebras are in fact periodic, meaning that they have periodic projective resolutions as bimodules and thus periodic Hochschild cohomology as well. The goal of this article is to generalize this construction of periodic algebras to the context of Iyama's higher AR-theory. We start by considering projective resolutions of functors on a maximal (d-1)-orthogonal subcategory C of an exact Frobenius category B. If C is fixed by the d-th syzygy functor of B, then we show that this d-th syzygy functor induces the (2+d)-th syzygy on the category of finitely presented functors on the stable category of C. If C has finite type, i.e., if C = add(T) for a d-cluster tilting ...

  18. The dispersion of period spacing for DAVstars

    Science.gov (United States)

    Chen, Y. H.

    2016-05-01

    Three groups of DAV star models are evolved with time-dependent element diffusion by WDEC. The core compositions of these models are directly from white dwarf models evolved by MESA, which are results of thermonuclear burning. Based on these DAV star models, we try to study the dispersion of period spacing. The thickness of hydrogen atmosphere can seriously affect the deviation degree of minimal period spacings. The minimal period spacings dominate the dispersion of period spacing. The thinner the hydrogen atmosphere, basically, the more dispersive the period spacing. Standard deviations are used to analyse the dispersion of period spacing. Studying the dispersion of period spacing on a DAV star KUV03442+0719 preliminarily, we suggest that log(MH/M*) is from -8.5 to -5.5. In addition, modes partly trapped in C/O core are found based on those DAV star models. The identified modes and average period spacings indicate that KUV03442+0719 may be the first star to `observe' modes partly trapped in C/O core.

  19. BIVARIATE REAL-VALUED ORTHOGONAL PERIODIC WAVELETS

    Institute of Scientific and Technical Information of China (English)

    Qiang Li; Xuezhang Liang

    2005-01-01

    In this paper, we construct a kind of bivariate real-valued orthogonal periodic wavelets. The corresponding decomposition and reconstruction algorithms involve only 8 terms respectively which are very simple in practical computation. Moreover, the relation between periodic wavelets and Fourier series is also discussed.

  20. Lightcurve and period determination for 582 Olympia

    Science.gov (United States)

    Higgins, David; Menke, John; Pozzoli, Valentino; Sheridan, Edwin; Dymock, Roger

    2004-03-01

    Minor planet 582 Olympia was observed over a period of 40 days from 9 February to 20 March 2003. More than 3000 data points from 42 sessions were obtained by 5 observers. The lightcurve obtained shows a rotational (synodic) period of 72.0 ± 0.5 hrs with amplitude of 0.20 ± 0.05 mag.

  1. 10 CFR 603.1295 - Periodic audit.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Periodic audit. 603.1295 Section 603.1295 Energy... Used in this Part § 603.1295 Periodic audit. An audit of a participant, performed at an agreed-upon... Federal awards in compliance with the terms of those awards. Appendix A to this part describes what...

  2. 46 CFR 403.115 - Accounting period.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Accounting period. 403.115 Section 403.115 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE UNIFORM ACCOUNTING SYSTEM General § 403.115 Accounting period. Each Association subject to this part shall...

  3. 18 CFR 367.5 - Accounting period.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Accounting period. 367.5 Section 367.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... Instructions § 367.5 Accounting period. Each service company must keep its books on a monthly basis so that...

  4. 75 FR 47717 - Content of Periodicals Mail

    Science.gov (United States)

    2010-08-09

    ... Periodicals Mail'' published by the Federal Register on July 20, 2010 (75 FR 41989-41991) is revised to... March 27, 1995, the Postal Service published a final rule in the Federal Register (60 FR 10021-10029... Part 111 Content of Periodicals Mail AGENCY: Postal Service\\TM\\ ACTION: Final rule; revised....

  5. Automatically identifying periodic social events from Twitter

    NARCIS (Netherlands)

    Kunneman, F.A.; Bosch, A.P.J. van den

    2015-01-01

    Many events referred to on Twitter are of a periodic nature, characterized by roughly constant time intervals in between occurrences. Examples are annual music festivals, weekly television programs, and the full moon cycle. We propose a system that can automatically identify periodic events from Twi

  6. 24 CFR 221.775 - Option period.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Option period. 221.775 Section 221.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... § 221.775 Option period. The mortgagee may exercise its option to assign within one year following...

  7. Hiss emissions during quiet and disturbed periods

    Indian Academy of Sciences (India)

    D K Singh; R P Singh

    2002-10-01

    The characteristic features of VLF hiss emissions during quiet and disturbed conditions observed at ground stations and on-board satellites are summarized. The increased intensity of the hiss emissions during magnetic storm period is explained by considering the enhanced flux of energetic electrons during magnetic storm period. The generation and propagation mechanism of VLF hiss are also briefly discussed.

  8. Numerical bifurcation of Hamiltonian relative periodic orbits

    DEFF Research Database (Denmark)

    Wulff, Claudia; Schilder, Frank

    2009-01-01

    Relative periodic orbits (RPOs) are ubiquitous in symmetric Hamiltonian systems and occur, for example, in celestial mechanics, molecular dynamics, and the motion of rigid bodies. RPOs are solutions which are periodic orbits of the symmetry-reduced system. In this paper we analyze certain symmetry...

  9. Monotone periodic orbits for torus homeomorphisms

    OpenAIRE

    Parwani, Kamlesh

    2005-01-01

    Let f be a homeomorphism of the torus isotopic to the identity and suppose that there exists a periodic orbit with a non-zero rotation vector (p/q,r/q), then f has a topologically monotone periodic orbit with the same rotation vector.

  10. Nonlinear quasimodes near elliptic periodic geodesics

    CERN Document Server

    Albin, Pierre; Marzuola, Jeremy L; Thomann, Laurent

    2011-01-01

    We consider the nonlinear Schr\\"odinger equation on a compact manifold near an elliptic periodic geodesic. Using a geometric optics construction, we construct quasimodes to a nonlinear stationary problem which are highly localized near the periodic geodesic. We show the nonlinear Schr\\"odinger evolution of such a quasimode remains localized near the geodesic, at least for short times.

  11. Locally periodic homogenization of reflected diffusion

    Directory of Open Access Journals (Sweden)

    Aboubakary Diakhaby

    2006-01-01

    Full Text Available We study the homogenization of reflected SDEs with locally periodic coefficients and highly oscillating drift. Our method is entirely probabilistic, and builds upon earlier works of Tanaka, Benchérif-Madani and Pardoux, and Bensoussan et al We extend, to Tanaka's theorem locally periodic case.

  12. Sensitivity analysis of periodic matrix population models.

    Science.gov (United States)

    Caswell, Hal; Shyu, Esther

    2012-12-01

    Periodic matrix models are frequently used to describe cyclic temporal variation (seasonal or interannual) and to account for the operation of multiple processes (e.g., demography and dispersal) within a single projection interval. In either case, the models take the form of periodic matrix products. The perturbation analysis of periodic models must trace the effects of parameter changes, at each phase of the cycle, on output variables that are calculated over the entire cycle. Here, we apply matrix calculus to obtain the sensitivity and elasticity of scalar-, vector-, or matrix-valued output variables. We apply the method to linear models for periodic environments (including seasonal harvest models), to vec-permutation models in which individuals are classified by multiple criteria, and to nonlinear models including both immediate and delayed density dependence. The results can be used to evaluate management strategies and to study selection gradients in periodic environments. PMID:23316494

  13. Period meter output during startup transients

    International Nuclear Information System (INIS)

    The time response of a period meter whose input signal comes from an ionization chamber may be calculated using a Ferranti Mercury digital computer programme. Details of the programme are given. The type of period meter considered is the one for which the input time constant is determined by the input capacity and the logarithmic element. The input excitation is a terminated ramp of reactivity. Other reactivity inputs may be treated. In particular the step change of reactivity may be used as the input excitation. Allowance is taken of the power dependent time constant associated with the logarithmic element and of the differentiating and integrating time constants in the period meter. The programme may be used by period meter designers to assess the performance of their instruments and may also be used by those carrying out safety and operations studies on reactors which use this type of period meter. An example of the use of the programme is given. (author)

  14. Periodicity of the earth's magnetic reversals

    Science.gov (United States)

    Stothers, R. B.

    1986-01-01

    Results are presented from an attempt to perform a relatively comprehensive analysis of the evidence for a periodicity, with harmonics, of the observed regular reversals of the earth's magnetic field. The database considered covers 296 reversals over the past 165 Myr. Histograms with bins 1 Myr apart reveal only 30 Myr reversal patterns. The reversal dates are fitted to a linear periodic function and a spectrum is computed for the residuals at the adopted dates. The possible presence of multiple periodicities is evaluated and over various time intervals. The analysis shows that a recently observed 15 Myr periodicity is probably a harmonic of the 29.5-30.5 Myr period. The calculations do not confirm an inherent magnetic reversal property of the earth. The reversals may arise from tectonic events or from impacts from extraterrestrial objects.

  15. Relating geodynamic setting to periods of crustal growth and reworking as illustrated by the Phanerozoic granitoids of the Eastern Cordillera of South Peru

    Science.gov (United States)

    Reitsma, M.; Schaltegger, U.; Spikings, R.; Ulianov, A.; Gerdes, A.; Chiaradia, M.

    2012-04-01

    The granitoids that form the backbone of the Eastern Cordillera of Peru between 12 and 14°S, are the ideal material for a case study to relate geodynamic setting to crustal growth over the period of a Wilson cycle. Extension related plutons were emplaced in the back-arc region of the Western Gondwana margin during the Ordovician, Permo-Carboniferous, Triassic and Early Jurassic. With the onset of the Andean cycle in the Middle Jurassic the South American margin was under compression, the plutonic record of this period is in the study area restricted to the Eocene and Miocene. The Ordovician to Triassic back-arc related plutons share many geochemical characteristics that point to dominant crustal reworking as the main process during their formation. These are 1) their mainly felsic and peraluminous nature; 2) the similarity of whole rock REE and trace element compositions compared to those of average continental crust; 3) the presence of negative Nb-Ta anomalies only in the more evolved samples which indicates that these excursions have been obtained by crustal melting rather than from a slab fluid and 4) the presence of significant amounts of xenocrystic cores in zircon. According to the literature the last major episode of juvenile crust formation was during the Grenvillian age Sunsas event (1.2 - 0.9 Ga) related to the collision of Laurentia and south-western Amazonia during the assembly of Rodinia. Hf-isotopes on zircons from the Ordovician, Permo-Carboniferous and Triassic plutons confirm their origin as mainly crustal melts generated by reworking of Sunsas-age crust. Under these geodynamic conditions it is mainly the crust that melts due to an elevated geothermal gradient as the result of crustal thinning. However, data from Jurassic nepheline bearing syenite and Eocene hornblende diorite and monzonite have epsilon Hfi values well above those of Sunsas crust, indicating an important mantle component in the melts. The Jurassic geodynamic setting is interpreted

  16. Periodicity of extinction: A 1988 update

    Science.gov (United States)

    Sepkowski, J. John, Jr.

    1988-01-01

    The hypothesis that events of mass extinction recur periodically at approximately 26 my intervals is an empirical claim based on analysis of data from the fossil record. The hypothesis has become closely linked with catastrophism because several events in the periodic series are associated with evidence of extraterrestrial impacts, and terrestrial forcing mechanisms with long, periodic recurrences are not easily conceived. Astronomical mechanisms that have been hypothesized include undetected solar companions and solar oscillation about the galactic plane, which induce comet showers and result in impacts on Earth at regular intervals. Because these mechanisms are speculative, they have been the subject of considerable controversy, as has the hypothesis of periodicity of extinction. In response to criticisms and uncertainties, a data base was developed on times of extinction of marine animal genera. A time series is given and analyzed with 49 sample points for the per-genus extinction rate from the Late Permian to the Recent. An unexpected pattern in the data is the uniformity of magnitude of many of the periodic extinction events. Observations suggest that the sequence of extinction events might be the result of two sets of mechanisms: a periodic forcing that normally induces only moderate amounts of extinction, and independent incidents or catastrophes that, when coincident with the periodic forcing, amplify its signal and produce major-mass extinctions.

  17. Radial and nonradial periods of Delta Scuti

    International Nuclear Information System (INIS)

    Five periods have been discussed by Smith (1981) for the prototype variable star delta Scuti. The main one, at 0.193772 day, has long been identified as the radial fundamental mode. The others have not been clearly understood, but the second radial overtone is probably the correct identification for the 0.116366 day period. The other three at 0.186891, 0.189435, and 0.211157 day seem to be nonradial modes because of their long periods. The first of these seems to have l = 2 and m = -2 as observed by Smith. Table 1 gives these observed periods. Based on the Fitch (1981) nonradial pulsation constants, the 4.48 hour (.187 day) period seems to be a p1 mode, but as we shall see, we find that this identification is not very certain. The goal of this paper is to use our nonradial nonadiabatic computing program to predict periods in this range for a model matching the observed parameters of delta Scuti and to identify all five periods

  18. Reliability, return periods, and risk under nonstationarity

    Science.gov (United States)

    Read, Laura K.; Vogel, Richard M.

    2015-08-01

    Water resources design has widely used the average return period as a concept to inform management and communication of the risk of experiencing an exceedance event within a planning horizon. Even though nonstationarity is often apparent, in practice hydrologic design often mistakenly assumes that the probability of exceedance, p, is constant from year to year which leads to an average return period To equal to 1/p; this expression is far more complex under nonstationarity. Even for stationary processes, the common application of an average return period is problematic: it does not account for planning horizon, is an average value that may not be representative of the time to the next flood, and is generally not applied in other areas of water planning. We combine existing theoretical and empirical results from the literature to provide the first general, comprehensive description of the probabilistic behavior of the return period and reliability under nonstationarity. We show that under nonstationarity, the underlying distribution of the return period exhibits a more complex shape than the exponential distribution under stationary conditions. Using a nonstationary lognormal model, we document the increased complexity and challenges associated with planning for future flood events over a planning horizon. We compare application of the average return period with the more common concept of reliability and recommend replacing the average return period with reliability as a more practical way to communicate event likelihood in both stationary and nonstationary contexts.

  19. 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.

  20. Optimal glucose management in the perioperative period.

    Science.gov (United States)

    Evans, Charity H; Lee, Jane; Ruhlman, Melissa K

    2015-04-01

    Hyperglycemia is a common finding in surgical patients during the perioperative period. Factors contributing to poor glycemic control include counterregulatory hormones, hepatic insulin resistance, decreased insulin-stimulated glucose uptake, use of dextrose-containing intravenous fluids, and enteral and parenteral nutrition. Hyperglycemia in the perioperative period is associated with increased morbidity, decreased survival, and increased resource utilization. Optimal glucose management in the perioperative period contributes to reduced morbidity and mortality. To readily identify hyperglycemia, blood glucose monitoring should be instituted for all hospitalized patients. PMID:25814110

  1. Quantification of rats' behavior during reinforcement periods

    OpenAIRE

    Gunn, Kenneth P.

    1983-01-01

    What is treated as a single unit of reinforcement often involves what could be called a reinforcement period during which two or more acts of ingestion may occur, and each of these may have associated with it a series of responses, some reflexive, some learned, that lead up to ingestion. Food-tray presentation to a pigeon is an example of such a “reinforcement period.” In order to quantify this behavior, a continuous-reinforcement schedule was used as the reinforcement period and was chained ...

  2. Periodicity in Age-Resolved Populations

    Science.gov (United States)

    Esipov, Sergei

    We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

  3. Turkish Foreign Policy during Adnan Menderes Period

    OpenAIRE

    Dagci, Gül Tuba; Diyarbakirlioglu, Kaan

    2013-01-01

    Adnan Menderes is a unique personality who has an important role within Turkish political life.DemocraticParty founded in 1946 by Menderes and his three friends has taken the power from People's Republican Party in 22 May 1950. Hence they have ended the single party period and opened the multi-party period in political life. This study examines the Turkish foreign policy of Menderes period between 1950-1960 as a whole. And it concludes that the most important motives of the Turkish foreign po...

  4. On the periods of generalized Fibonacci recurrences

    Science.gov (United States)

    Brent, Richard P.

    We give a simple condition for a linear recurrence (mod 2^w) of degree r to have the maximal possible period 2^(w-1).(2^r-1). It follows that the period is maximal in the cases of interest for pseudo-random number generation, i.e. for 3-term linear recurrences defined by trinomials which are primitive (mod 2) and of degree r > 2. We consider the enumeration of certain exceptional polynomials which do not give maximal period, and list all such polynomials of degree less than 15.

  5. New Realization of Periodic Cycled Separation

    DEFF Research Database (Denmark)

    Toftegard, Bjarne; Clausen, Charlotte H.; Jørgensen, Sten B.; Abildskov, Jens

    2016-01-01

    A new realization of periodic cycled gas/liquid separation is presented. Separation factors and column efficiencies are compared for a column stripping ammonia from water with air, using three different sets of internals: conventional sieve trays, Sulzer BX gauze packings, and periodically cycled...... drained sequentially rather than simultaneously, such that the vapor flow is not interrupted during the liquid drainage. For different ratios of counter-current vapor/liquid flow rates, column efficiencies for periodically cycled columns are shown experimentally to be two times greater than those for...

  6. Attractors of the periodically forced Rayleigh system

    Directory of Open Access Journals (Sweden)

    Petre Bazavan

    2011-07-01

    Full Text Available The autonomous second order nonlinear ordinary differential equation(ODE introduced in 1883 by Lord Rayleigh, is the equation whichappears to be the closest to the ODE of the harmonic oscillator withdumping.In this paper we present a numerical study of the periodic andchaotic attractors in the dynamical system associated with the generalized Rayleigh equation. Transition between periodic and quasiperiodic motion is also studied. Numerical results describe the system dynamics changes (in particular bifurcations, when the forcing frequency is varied and thus, periodic, quasiperiodic or chaotic behaviour regions are predicted.

  7. Estimates on the minimal period for periodic solutions of nonlinear second order Hamiltonian systems

    International Nuclear Information System (INIS)

    In this paper, we prove a sharper estimate on the minimal period for periodic solutions of autonomous second order Hamiltonian systems under precisely Rabinowitz' superquadratic condition. (author). 20 refs, 1 fig

  8. Spectral properties of almost-periodic Hamiltonians

    International Nuclear Information System (INIS)

    We give a description of some spectral properties of almost-periodic hamiltonians. We put the stress on some particular points of the proofs of the existence of absolutely continuous or pure point spectrum

  9. Transversally periodic solitary gravity-capillary waves.

    Science.gov (United States)

    Milewski, Paul A; Wang, Zhan

    2014-01-01

    When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity-capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity-capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles. PMID:24399922

  10. UNVEILING THE PHENOMENON OF DOUBLE PERIODIC VARIABLES

    Directory of Open Access Journals (Sweden)

    R. E. Mennickent

    2009-01-01

    Full Text Available In this paper we give a brief report of our recent research on Double Periodic Variables (DPVs, including the discovery of DPVs in the Galaxy and some insights on the nature of their long-cycle variability.

  11. Neutron transport with periodic boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Angelescu, N.; Marinescu, N.; Protopopescu, V.

    1976-01-01

    The initial value problem for monoenergetic neutron transport in homogeneous nonmultiplying, nonabsorbing medium with isotropic scattering and periodic boundary conditions. One completely determines the structure of the spectrum of the transport operator both in plane and parallelepipedic geometries.

  12. Extracting periodic driving signal from chaotic noise

    Institute of Scientific and Technical Information of China (English)

    MU Jing; TAO Chao; DU Gonghuan

    2003-01-01

    After periodic signals pass through some nonlinear systems, they are usually transformed into noise-like and wide-band chaotic signals. The discrete spectrums of the original periodic signals are often covered by the chaotic spectrums. Recovering the periodic driving signals from the chaotic signals is important not only in theory but also in practical applications. Based on the modeling theory of nonlinear dynamic system, a "polynomial-simple harmonic drive" non-autonomous equation (P-S equation) to approximate the original system is proposed and the approximation error between P-S equation and the original system is obtained. By changing the drive frequency, we obtain the curve of the approximation error vs. drive frequency. Based on the relation between this curve and the spectrums of the original periodic signals, the spectrum of the original driving signal is extracted and the original signal is recovered.

  13. Early and Periodic Screening, Diagnosis and Treatment

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit provides comprehensive and preventive health care services for children under age 21 who...

  14. The Detection of Hidden Periodicities in EEG

    Institute of Scientific and Technical Information of China (English)

    YOU Rong-yi

    2007-01-01

    Abstract.A novel method for detecting the hidden periodicities in EEG is proposed.By using a width-varying window in the time domain, the structure function of EEG time series is defined. It is found that the minima of the structure function, within a finite window width, can be found regularly, which indicate that there are some certain periodicities associated with EEG time series. Based on the structure function, a further quadratic structure function of EEG time series is defined. By quadratic structure function, it can be seen that the periodicities of EEG become more obvious, moreover, the period of EEG can be determined accurately. These results will be meaningful for studying the neuron activity inside the human brain.

  15. Global bioevents and the question of periodicity

    Science.gov (United States)

    Sepkoski, J. John

    The hypothesis of periodicity in extinction is an empirical claim that extinction events, while variable in magnitude, are regular in timing and therefore are serially dependent upon some single, ultimate cause with clocklike behavior. This hypothesis is controversal, in part because of questions regarding the identity and timing of certain extinction events and because of speculations concerning possible catastrophic extraterrestrial forcing mechanisms. New data on extinctions of marine animal genera are presented that display a high degree of periodicity in the Mesozoic and Cenozoic as well as a suggestion of nonstationary periodicity in the late Paleozoic. However, no periodicity is evident among the as yet poorly documented extinction events of the early and middle Paleozoic.

  16. Broiler adaptation to post-hatching period

    Directory of Open Access Journals (Sweden)

    Maiorka Alex

    2006-01-01

    Full Text Available In the latest years more attention has been given to mechanisms for bird adaptation at post-hatching period by management of environmental conditions and formulations of diets offered during this period when digestive, immune, and thermo-regulating systems suffer slight changes. In post-hatching period, digestive system is anatomically complete, but its functionality is still immature in relation to adult birds. The chick immunity depends on maternal antibodies transferred to egg just before laying. In addition, variations within thermal comfort zone might affect initial development of chick. For example, high temperatures may induce hyperthermia with dehydration, while low temperatures may lead to hypothermia responsible by pulmonary hypertension syndrome. In conclusion, productivity might be enhanced when good conditions are offered to chicks during the period from last embryo development to first days after hatching.

  17. Toward an Organic Chemist's Periodic Table.

    Science.gov (United States)

    Hall, H. K., Jr.

    1980-01-01

    An analogy between electron transfer reactions of the elements and those of organic molecules is offered. Examples of organic electron transfer reactions are presented. The rationale of constructing an organic chemists' periodic table is also discussed. (HM)

  18. Theodore William Richards and the Periodic Table

    Science.gov (United States)

    Conant, James B.

    1970-01-01

    Discusses the contribution of Theodore Richards to the accurate determination of atomic weights of copper and other elements; his major contribution was to the building of the definitive periodic table of the elements. (BR)

  19. A new pattern of the periodic table

    Directory of Open Access Journals (Sweden)

    Brajendra Nath Tripathi

    1962-07-01

    Full Text Available A new pattern of the Periodic Table is described which incorporates all the points for which various models of two or three dimensional tables have been proposed from time to time.

  20. Ecological periodic tables: In principle and practice

    Science.gov (United States)

    The chemical periodic table, the Linnaean system of classification and the Hertzsprung-Russell diagram are iconic information organizing structure in chemistry, biology and astronomy, respectively, because they are simple, exceptionally useful and they foster the expansion of sci...

  1. Voltage Sensors in Hypokalemic Periodic Paralysis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-06-01

    Full Text Available Researchers at the National Hospital, Queen Square, London, UK, conducted automated DNA sequencing of the S4 regions of CACNA1S and SCN4A in 83 patients with hypokalemic periodic paralysis (HypoPP.

  2. 40 CFR 264.96 - Compliance period.

    Science.gov (United States)

    2010-07-01

    ....96 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Releases From Solid Waste Management Units § 264.96 Compliance period. (a) The Regional Administrator...

  3. Coping with Common Period Problems (For Teens)

    Science.gov (United States)

    ... and your period — is excessive exercising , usually distance running, ballet, or gymnastics, combined with a poor diet. For exercise to be excessive, it means more than just playing soccer a few times a week or working out ...

  4. Periodic words connected with the Fibonacci words

    Directory of Open Access Journals (Sweden)

    G. M. Barabash

    2016-06-01

    Full Text Available In this paper we introduce two families of periodic words (FLP-words of type 1 and FLP-words of type 2 that are connected with the Fibonacci words and investigated their properties.

  5. Subcortical cytoskeleton periodicity throughout the nervous system.

    Science.gov (United States)

    D'Este, Elisa; Kamin, Dirk; Velte, Caroline; Göttfert, Fabian; Simons, Mikael; Hell, Stefan W

    2016-01-01

    Superresolution fluorescence microscopy recently revealed a ~190 nm periodic cytoskeleton lattice consisting of actin, spectrin, and other proteins underneath the membrane of cultured hippocampal neurons. Whether the periodic cytoskeleton lattice is a structural feature of all neurons and how it is modified when axons are ensheathed by myelin forming glial cells is not known. Here, STED nanoscopy is used to demonstrate that this structure is a commonplace of virtually all neuron types in vitro. To check how the subcortical meshwork is modified during myelination, we studied sciatic nerve fibers from adult mice. Periodicity of both actin and spectrin was uncovered at the internodes, indicating no substantial differences between unmyelinated and myelinated axons. Remarkably, the actin/spectrin pattern was also detected in glial cells such as cultured oligodendrocyte precursor cells. Altogether our work shows that the periodic subcortical cytoskeletal meshwork is a fundamental characteristic of cells in the nervous system and is not a distinctive feature of neurons, as previously thought. PMID:26947559

  6. Electrons and photons in periodic structures

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor

    This thesis concerns various theoretical proposals for engineering dispersion relations of photons and electrons for particular applications. The common concept is the use of a periodic modulation to induce new phenomena on length scales comparable with the periodicity of the modulation. In...... applications both in terms of spontaneous emission control and for slow light propagation. We first consider antidot lattices, periodic modulations of the potential of an electron gas. We demonstrate that such structures may serve as an interesting platform for quantum information processing. In particular, we...... semiconductor, paving the way for graphene transistors. Photonic band gaps can be engineered using structures with a periodic modulations of the refractive index, commonly referred to as photonic crystal. We discuss the application of photonic crystals to slow light phenomena, where advantage is taken of the...

  7. Stability of Periodic Locomotion in Potential Flow

    CERN Document Server

    Jing, Fangxu

    2013-01-01

    Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. In this paper, we examine the stability of periodic locomotion due to sideways flapping in unbounded potential flow. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. Here, we consider a simplified model where the swimmer is a planar elliptic body undergoing prescribed periodic heaving and pitching. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping. We obtain closed-form solutions for the locomotion and efficiency for small flapping a...

  8. DOREMI - Interim Progress Report (Period 2)

    OpenAIRE

    Rial, Michela; Benvenuti, Chiara; Vozzi, Federico; Parodi, Oberdan; Fortunati, Luigi; Palumbo, Filippo

    2015-01-01

    The DOREMI Scientific and Technological objectives of this period is: 1.2 . Development of preliminary version for the WSN environment, smart environment for context awareness and gamified environment (MS4, M18)

  9. Positive periodic solutions of periodic neutral Lotka-Volterra system with state dependent delays

    Science.gov (United States)

    Li, Yongkun

    2007-06-01

    By using a fixed point theorem of strict-set-contraction, some new criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with state dependent delays where (i,j=1,2,...,n) are [omega]-periodic functions and (i=1,2,...,n) are [omega]-periodic functions with respect to their first arguments, respectively.

  10. Inflation and the Trade Credit Period

    OpenAIRE

    Moshe Ben-Horim; Haim Levy

    1982-01-01

    Management of accounts receivable and trade credit policy should often be adjusted to reflect changing interest rates due to changing inflation. Firms can respond to inflation by either increasing the discount for cash payments or by shortening the credit period. This paper investigates the policy of shortening the credit period in response to changing inflation rates. We first assume that inflation is fully anticipated, and later we extend the analysis to incorporate inflation risk.

  11. Periodicity and Immortality in Reversible Computing

    OpenAIRE

    Kari, Jarkko; Ollinger, Nicolas

    2008-01-01

    Additional material available on the web at http://www.lif.univ-mrs.fr/~nollinge/rec/gnirut/ We investigate the decidability of the periodicity and the immortality problems in three models of reversible computation: reversible counter machines, reversible Turing machines and reversible one-dimensional cellular automata. Immortality and periodicity are properties that describe the behavior of the model starting from arbitrary initial configurations: immortality is the property of having at ...

  12. Ground states for nonuniform periodic Ising chains

    OpenAIRE

    Martínez-Garcilazo, J. P.; Ramírez, C.

    2014-01-01

    We give a generalization of Morita's works on ground states of Ising chains, for chains with a periodic structure with different spins, and distant neighbor interactions. The main assumption is translational invariance. The length of the irreducible blocks is a multiple of the period of the chain. In the case of parity invariance, it restricts the length in general only in the diatomic case. There are degenerated states and under certain circumstances there could be nonregular ground states. ...

  13. Discrete periodic geodesics in a surface

    OpenAIRE

    Linnér, Anders; Renka, Robert

    2005-01-01

    An alternative to the traditional curve-straightening flow on periodic curves in surfaces is introduced. The implementation of this flow produces periodic geodesics in minutes rather than hours. The flow is also simpler to initiate since its use of a penalty method permits initial curves that are not necessarily in the surface. Compact and noncompact examples are provided as well as examples with trivial and nontrivial free homotopy classes. The explicit curve-straightening flow on circles in...

  14. Periodic Exponential Shear of Complex Fluids

    OpenAIRE

    Kalelkar, Chirag; McKinley, Gareth

    2012-01-01

    We define a class of flows with exponential kinematics termed Periodic Exponential Shear (PES) flow which involve periodic exponential stretching of fluid elements along with their rotation. We exhibit analytical and numerical results for PES flow by using the Oldroyd-B model for viscoelastic fluids. We calculate the growth in the shear and the normal stresses analytically as well as demonstrate that repeated application of the flow leads to stable oscillatory shear and normal stresses. We de...

  15. Land Prices During Periods of Rapid Change

    OpenAIRE

    Schurle, Bryan; Featherstone, Allen; Wilson, Christine; Crossan, Dylan

    2013-01-01

    Accurate information on land values is a consequential concern when prices are changing rapidly. This study compares USDA data and sales data from 1971-2011. While the land prices from these series move in similar patterns, there are periods of substantial differences. These periods show a pattern where differences are larger when prices are changing rapidly, and where USDA prices lag sales data prices. The spread in prices in sales data is also examined. While the standard deviation of price...

  16. Periodic EEG complexes in infectious mononucleosis encephalitis.

    OpenAIRE

    Greenberg, D A; Weinkle, D J; Aminoff, M. J.

    1982-01-01

    The presence of periodic EEG complexes in patients with an acute viral encephalitis is generally held to suggest that infection is due to herpes simplex. We now report a patient with clinical and laboratory findings of infectious mononucleosis, and neurologic involvement manifested by lymphocyte meningitis, coma, seizures, aphasia, hemiparesis and hemianopsia. Serial EEGs showed periodic, predominantly left-sided slow wave complexes occurring every 4 to 5 seconds, which disappeared with clini...

  17. Filtering Characteristics of Doubly Sinusoidal Periodic Media

    Science.gov (United States)

    Dong, Tian-Lin; Chen, Ping

    2006-03-01

    Dispersion and filtering characteristics of doubly sinusoidal periodic (DSP) medium is investigated. Based on its feature different from singly sinusoidal periodic medium, a novel dual-band filter model is realized and measured. The results show that even a single unit cell of DSP medium can provide rather good filtering performance. And the filter is of perfect compatibility with regular waveguide and substrate integrated waveguide technology.

  18. Periodic Table for Floquet Topological Insulators

    OpenAIRE

    Roy, Rahul; Harper, Fenner

    2016-01-01

    Dynamical phases with novel topological properties are known to arise in driven systems of free fermions. In this paper, we obtain a `periodic table' to describe the phases of such time-dependent systems, generalizing the periodic table for static topological insulators. Using K-theory, we systematically classify Floquet topological insulators from the ten Altland-Zirnbauer symmetry classes across all dimensions. We find that the static classification scheme described by a group $G$ becomes $...

  19. IUPAC Periodic Table of the Isotopes

    Science.gov (United States)

    Holden, N.E.; Coplen, T.B.; Böhlke, J.K.; Wieser, M.E.; Singleton, G.; Walczyk, T.; Yoneda, S.; Mahaffy, P.G.; Tarbox, L.V.

    2011-01-01

    For almost 150 years, the Periodic Table of the Elements has served as a guide to the world of elements by highlighting similarities and differences in atomic structure and chemical properties. To introduce students, teachers, and society to the existence and importance of isotopes of the chemical elements, an IUPAC Periodic Table of the Isotopes (IPTI) has been prepared and can be found as a supplement to this issue.

  20. Thyrotoxic Periodic Paralysis: A Case Report

    OpenAIRE

    Morović-Vergles, Jadranka; Ostrički, Branko; Galešić, Krešimir; Škoro, Mirko; Zelenika, Dijana

    2002-01-01

    A case of thyrotoxic periodic paralysis in a 24-year-old male with hyperthyroidism is presented. Clinical manifestations included progressive symmetrical weakness that led to flaccid paralysis due to hypokalemia with concurrent thyrotoxicosis. Intravenous administration of potassium chloride resulted in complete regression of the symptoms of muscle weakness and paralysis. Hypokalemic periodic paralysis is an uncommon complication of thyrotoxicosis, which primarily occurs in Orientals, with a ...

  1. How periodic orbit bifurcations drive multiphoton ionization

    OpenAIRE

    Huang, S.; Chandre, C; Uzer, T.

    2006-01-01

    The multiphoton ionization of hydrogen by a strong bichromatic microwave field is a complex process prototypical for atomic control research. Periodic orbit analysis captures this complexity: Through the stability of periodic orbits we can match qualitatively the variation of experimental ionization rates with a control parameter, the relative phase between the two modes of the field. Moreover, an empirical formula reproduces quantum simulations to a high degree of accuracy. This quantitative...

  2. Family of almost periodic Schroedinger operators

    International Nuclear Information System (INIS)

    Bellisard et al., introduced a one-dimensional, almost-periodic, discrete Schroedinger operator which is defined by a parameter lambda. We allow this parameter to become complex and develop a geometric formalism to control the operator. The support of the spectrum of this operator is the Julia set of the mapping x2 - lambda → x. We prove that the almost-periodicity holds over wide regions of the complex lambda-plane, even though Hermiticity fails. 14 references

  3. Energy minimization, periodic sets and spherical designs

    CERN Document Server

    Coulangeon, Renaud

    2010-01-01

    We study energy minimization for pair potentials among periodic sets in Euclidean spaces. We derive some sufficient conditions under which a point lattice locally minimizes the energy associated to a large class of potential functions. This allows in particular to prove a local version of Cohn and Kumar's conjecture that $\\mathsf{A}_2$, $\\mathsf{D}_4$, $\\mathsf{E}_8$ and the Leech lattice are globally universally optimal, regarding energy minimization, and among periodic sets of fixed point density.

  4. Depression in Pregnancy and Postpartum Period

    OpenAIRE

    Sood, Mamta; Sood, A. K.

    2003-01-01

    This prospective study was carried out in a service hospital, with the aim to study the prevalence and incidence of depression in pregnancy and postpartum period. Eighty Four consecutive patients attending the antenatal outpatient in the Obstetrics & Gynaecology department in their last trimester of pregnancy were recruited for the study. They were assessed on Beck Depression Inventory thrice viz. during third trimester of pregnancy, within 3 days of delivery (early postpartum period) & withi...

  5. Quantum cohomology and the periodic Toda lattice

    International Nuclear Information System (INIS)

    We describe a relation between the periodic one-dimensional Toda lattice and the quantum cohomology of the periodic flag manifold (an infinite-dimensional Kaehler manifold). This generalizes a result of Givental and Kim relating the open Toda lattice and the quantum cohomology of the finite-dimensional flag manifold. We derive a simple and explicit ''differential operator formula'' for the necessary quantum products, which applies both to the finite-dimensional and to the infinite-dimensional situations. (orig.)

  6. 15. 7-min periodicity in OJ287

    Energy Technology Data Exchange (ETDEWEB)

    Valtaoja, E.; Lehto, H.; Teerikorpi, P.; Korhonen, T.; Valtonen, M.; Teraesranta, H.; Salonen, E.; Urpo, S.; Tiuri, M.; Piirola, V.; Saslaw, W.C.

    1985-03-14

    The BL Lac-type object OJ287, with a redshift z = 0.306 and a luminosity exceeding 10/sup 47/ erg s/sup -1/ at maximum light, is among the brightest and most violently variable objects of its class. Rapid variations, with timescales of a few hours or less, have been reported over a wide range of wavelengths and also in polarization, imposing strong constraints on the size and dynamics of the source. The detection of periodic variations in OJ287, or in any other compact extragalactic source, would be even more important, as these could be related to rotation or orbital motion in the source. So far the only searches sensitive to periodic variations shorter than 1 h are the photometric observations of Visvanathan and Elliot, Frohlich et al. and Kiplinger, in which a 40-min period in OJ287 was respectively found, confirmed and not detected. Here the detection of a 15.7-min periodic flux variation in OJ287 in April 1981 at 37 GHz is reported. The source has been subsequently monitored for 265 h at 22 and 37 GHz, as well as in optical photometry, and the same period has been seen in simultaneous observations. The peak-peak amplitude of the variation is 1-10% of the total intensity. Other periods may also exist. 17 references, 3 figures.

  7. Periodic Table Target: A Game that Introduces the Biological Significance of Chemical Element Periodicity

    Science.gov (United States)

    Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…

  8. The Discrete Beverton-Holt Model with Periodic Harvesting in a Periodically Fluctuating Environment

    Directory of Open Access Journals (Sweden)

    Ziyad AlSharawi

    2010-01-01

    Full Text Available We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better option, especially for sufficiently large initial populations. Also, we investigate the combinatorial structure of the periodic sequence of carrying capacities and its effect on the maximum sustainable yield. Finally, we leave some questions worth further investigations.

  9. Charged particle periodicity in the Saturnian magnetosphere

    International Nuclear Information System (INIS)

    The low energy charged particles (LECP) experiments on the Voyager 1 and 2 spacecraft performed measurements of electrons (approx.22 keV to approx.20 MeV) and ions (approx.28 keV to approx.150 MeV) during the Saturn encounters in 1980 and 1981. Count rate ratios of two of the low energy electron (22 to 35 keV and 183 to 500 keV) and ion (43 to 80 keV and 137 to 215 keV) channels exhibit an approximation 10 hour periodicity in the outer Saturnian magnetosphere beyond the orbit of Titan. Electron ratios vary from approx.50 to approx.300; ion ratios vary from approx.3 to approx.20. Similar but less pronounced periodicities are observed for higher and lower energy electron and ion spectral indices. Three complete cycles were observed during the Voyager 2 outbound portion of the encounter from which were determined an electron ratio period of 10/sup h/21/sup m/ +- 48/sup m/ and an ion ratio period of 9/sup h/49/sup m/ +- 59/sup m/. Using Saturn Kilometric Radiation (SKR) and Saturn Electrostatic Discharge (SED) periods, extrapolation backward from Voyager 2 to Voyager 1 suggests that the periodicities are Saturnian rather than Jovian in nature, and that they persist in phase for time intervals at least as long as 287 days. Ratio minima, or spectral hardenings, occur in the same hemisphere as do auroral brightenings, SKR activity, and spoke enhanement. We interpret the observations as prima facie evidence of an asymmetry in the Saturian magnetic field and the root cause of the observed SKR periodicity

  10. Dynamics of Coulombic and gravitational periodic systems

    Science.gov (United States)

    Kumar, Pankaj; Miller, Bruce N.

    2016-04-01

    We study the dynamics and the phase-space structures of Coulombic and self-gravitating versions of the classical one-dimensional three-body system with periodic boundary conditions. We demonstrate that such a three-body system may be reduced isomorphically to a spatially periodic system of a single particle experiencing a two-dimensional potential on a rhombic plane. For the case of both Coulombic and gravitational versions, exact expressions of the Hamiltonian have been derived in rhombic coordinates. We simulate the phase-space evolution through an event-driven algorithm that utilizes analytic solutions to the equations of motion. The simulation results show that the motion exhibits chaotic, quasiperiodic, and periodic behaviors in segmented regions of the phase space. While there is no evidence of global chaos in either the Coulombic or the gravitational system, the former exhibits a transition from a completely nonchaotic phase space at low energies to a mixed behavior. Gradual yet striking transitions from mild to intense chaos are indicated with changing energy, a behavior that differentiates the spatially periodic systems studied in this Rapid Communication from the well-understood free-boundary versions of the three-body problem. Our treatment of the three-body systems opens avenues for analysis of the dynamical properties exhibited by spatially periodic versions of various classes of systems studied in plasma and gravitational physics as well as in cosmology.

  11. The period-age relation for cepheids

    International Nuclear Information System (INIS)

    The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x107 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

  12. [Hypokalemic periodic paralysis provoked by "Ambene"].

    Science.gov (United States)

    Wessel, K; Schumm, F; Peiffer, J; Schlote, W

    1985-12-01

    The case of a 42-year-old man is reported, who on four occasions developed a hypokalaemic periodic paralysis after an intramuscular injection of "Ambene". The detailed examination of this patient shows, that it is the primary, autosomal dominant inherited form of hypokalaemic periodic paralysis, and not the secondary form, which is caused by a renal or gastrointestinal loss of potassium. Clinical and electrophysiological, as well as histopathological and electron microscopic findings are presented, showing the typical vacuolar myopathy with submicroscopic tubular structures. In the literature there is evidence for an increased sensitivity of the muscle membrane to insulin with an increased potassium-shift inside the cell in hypokalaemic periodic paralysis. "Ambene" is a combination, which contains amongst other substances dexamethasone and the local anaesthetic drug lidocain. In the present case the paresis was possibly caused by a combined effect of dexamethasone with a consequent hyperglycaemia and lidocain with a change in the excitability of the muscle membrane. The pathophysiological mechanism of hypokalaemic periodic paralysis is discussed in terms of the release by the combination of these two drugs. It has not previously been reported that "Ambene" can provoke a hypokalaemic periodic paralysis. This is a severe side effect because of the resulting cardiac and respiratory problems. PMID:2936967

  13. On the Sensitivity of Period Searches

    Science.gov (United States)

    Schwarzenberg-Czerny, A.

    2012-04-01

    Astronomical time series are special in that time sampling in them is uneven yet often with periodic gaps due to daytime, moon and seasons. There is therefore a need for special-purpose time-series analysis (TSA) methods. The emergence of massive CCD photometric surveys from the ground and space raises the question of an automatic period search in >> 105 light curves. We caution that already at the planning stage it is important to account for the effects of time sampling and analysis methods on the sensitivity of detections. We present a transparent scheme for the classification of period-search methods. We employ tools for evaluating the performance of those methods, according to the type of light curves investigated. In particular we consider sinusoidal and non-sinusoidal oscillations as well as eclipse or transit light curves. From these considerations we draw recommendations for the optimum analysis of astronomical time series. We present briefly the capability of an automatic period-search package Tatry. Finally we discuss the role of Monte Carlo simulations in the analysis of detection sensitivity. As an example, we demonstrate a practical method to account for the bandwidth (multi-trial) penalty in the statistical evaluation of detected periods.

  14. Dipole interactions in doubly-periodic domains

    CERN Document Server

    Tsang, Alan Cheng Hou

    2013-01-01

    We consider the interactions of finite dipoles in a doubly-periodic domain. A finite dipole is a pair of equal and opposite strength point vortices separated by a finite distance. The dynamics of multiple finite dipoles in an unbounded inviscid uid was first proposed by Tchieu, Kanso & Newton in [1] as a model that captures the "far- field" hydrodynamic interactions in fish schools. In this paper, we formulate the equations of motion governing the dynamics of finite-dipoles in a doubly-periodic domain. We show that a single dipole in a doubly-periodic domain exhibits periodic and aperiodic behavior, in contrast to a single dipole in an unbounded domain. In the case of two dipoles in doubly-periodic domain, we identify a number of interesting trajectories including collision, collision avoidance, and passive synchronization of the dipoles. We then examine two types of dipole lattices: rectangular and diamond. We verify that these lattices are in a state of relative equilibrium and show that the rectangular...

  15. Policy Uncertainty, Investment and Commitment Periods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Today's investment decisions in key sectors such as energy, forestry or transport have significant impacts on the levels of greenhouse gas (GHG) emissions over the coming decades. Given the economic and environmental long-term implications of capital investment and retirement, a climate mitigation regime should aim to encourage capital investment in climate-friendly technologies. Many factors affect technology choice and the timing of investment, including investor expectations about future prices and policies. Recent international discussions have focused on the importance of providing more certainty about future climate policy stringency. The design of commitment periods can play a role in creating this environment. This paper assesses how the length of commitment periods influences policy uncertainty and investment decisions. In particular, the paper analyses the relationship between commitment period length and near term investment decisions in climate friendly technology.

  16. Effective propagation in a perturbed periodic structure

    International Nuclear Information System (INIS)

    In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sanchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions

  17. Periodic and Chaotic Flapping of Insectile Wings

    CERN Document Server

    Huang, Yangyang

    2015-01-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the desired energy level, insects can maintain periodic flapping mechanically for a range of operating condit...

  18. Superconducting insertion devices with switchable period length

    International Nuclear Information System (INIS)

    Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they offer the possibility to enhance the tuning range and functionality significantly by period length switching. Period length switching can be realized by employing two or more individually powerable subsets of superconducting coils and reverse the current in a part of the winding. So far, the first demonstration mock-up coil allowing period length tripling was fabricated and tested successfully (A. Grau et al., accepted for publication in IEEE Transactions on Applied Superconductivity). Here, we report on the feasibility of a superconducting switch implemented as proposed by A. Madur et al., Proc. of the 10th International Conference on Synchrotron Radiation Instrumentation 2009, Melbourne, Australia.

  19. Superconducting insertion devices with switchable period length

    Energy Technology Data Exchange (ETDEWEB)

    Holubek, Tomas; Baumbach, Tilo; Casalbuoni, Sara; Gerstl, Stefan; Grau, Andreas; Hagelstein, Michael; Saez de Jauregui, David [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Boffo, Cristian; Walter, Wolfgang [Babcock Noell GmbH, Wuerzburg (Germany)

    2011-07-01

    Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they offer the possibility to enhance the tuning range and functionality significantly by period length switching. Period length switching can be realized by employing two or more individually powerable subsets of superconducting coils and reverse the current in a part of the winding. So far, the first demonstration mock-up coil allowing period length tripling was fabricated and tested successfully (A. Grau et al., accepted for publication in IEEE Transactions on Applied Superconductivity). Here, we report on the feasibility of a superconducting switch implemented as proposed by A. Madur et al., Proc. of the 10th International Conference on Synchrotron Radiation Instrumentation 2009, Melbourne, Australia.

  20. Local electrostatic moments and periodic boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, P.A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    1999-07-01

    Electronic structure calculations frequently invoke the supercell approximation and solve for electrostatic potentials within periodic boundary conditions. For systems that are electronically charged, or contain dipole (or higher) moments, this artifice introduces spurious potentials due to interactions between the system and multipole moments of its periodic images in aperiodic directions. I describe a method to handle properly the multipole moments of the electron density in electronic structure calculations using supercells. The density is divided into two pieces. A model local density is constructed to match multipole moments of the full density. The potential from this piece is obtained treating this density as isolated. With the density of this local-moment countercharge removed from the full density, the remainder density no longer contains moments with long-range potentials, and its electrostatic potential can be evaluated accurately using periodic boundary conditions. {copyright} {ital 1999} {ital The American Physical Society}

  1. Quantum periods of Calabi-Yau fourfolds

    CERN Document Server

    Gerhardus, Andreas

    2016-01-01

    In this work we study the quantum periods together with their Picard-Fuchs differential equations of Calabi-Yau fourfolds. In contrast to Calabi-Yau threefolds, we argue that the large volume points of Calabi-Yau fourfolds generically are regular singular points of the Picard-Fuchs operators of non-maximally unipotent monodromy. We demonstrate this property in explicit examples of Calabi-Yau fourfolds with a single Kahler modulus. For these examples we construct integral quantum periods and study their global properties in the quantum Kahler moduli space with the help of numerical analytic continuation techniques. Furthermore, we determine their genus zero Gromov-Witten invariants, their Klemm-Pandharipande meeting invariants, and their genus one BPS invariants. In our computations we emphasize the features attributed to the non-maximally unipotent monodromy property. For instance, it implies the existence of integral quantum periods that at large volume are purely worldsheet instanton generated. To verify ou...

  2. Using periodicity to mitigate ground vibration

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    filters for wave propagation, effectively reducing the transmission of energy in certain frequency bands known as stop bands or band gaps, thus only allowing propagation in the so-called pass bands. In this paper, a stratified ground with two soil layers is considered and two types of periodicity is...... of energy transmission can be obtained within the medium and high frequency ranges, barriers are a poor solution at low frequencies. As an alternative, a periodic change in the properties of the soil can be introduced—to the geometry and/or to the material. Periodic structures are known to act as......Introduction of trenches, barriers and wave impeding blocks on the transmission path between a source and receiver can be used for mitigation of ground vibration. However, to be effective a barrier must have a depth of about one wavelength of the waves to be mitigated. Hence, while great reductions...

  3. Krsko NPP Periodic Safety Review program

    International Nuclear Information System (INIS)

    The need for conducting a Periodic Safety Review for the Krsko NPP has been clearly recognized both by the NEK and the regulator (SNSA). The PSR would be highly desirable both in the light of current trends in safety oversight practices and because of many benefits it is capable to provide. On January 11, 2001 the SNSA issued a decision requesting the Krsko NPP to prepare a program and determine a schedule for the implementation of the program for 'Periodic Safety Review of NPP Krsko'. The program, which is required to be in accordance with the IAEA safety philosophy and with the EU practice, was submitted for the approval to the SNSA by the end of March 2001. The paper summarizes Krsko NPP Periodic Safety Review Program [1] including implemented SNSA and IAEA Expert Mission comments.(author)

  4. The incubation periods of Dengue viruses.

    Directory of Open Access Journals (Sweden)

    Miranda Chan

    Full Text Available Dengue viruses are major contributors to illness and death globally. Here we analyze the extrinsic and intrinsic incubation periods (EIP and IIP, in the mosquito and human, respectively. We identified 146 EIP observations from 8 studies and 204 IIP observations from 35 studies. These data were fitted with censored Bayesian time-to-event models. The best-fitting temperature-dependent EIP model estimated that 95% of EIPs are between 5 and 33 days at 25°C, and 2 and 15 days at 30°C, with means of 15 and 6.5 days, respectively. The mean IIP estimate was 5.9 days, with 95% expected between days 3 and 10. Differences between serotypes were not identified for either incubation period. These incubation period models should be useful in clinical diagnosis, outbreak investigation, prevention and control efforts, and mathematical modeling of dengue virus transmission.

  5. Symmetry and Resonance in Periodic FPU Chains

    Science.gov (United States)

    Rink, Bob

    The symmetry and resonance properties of the Fermi Pasta Ulam chain with periodic boundary conditions are exploited to construct a near-identity transformation bringing this Hamiltonian system into a particularly simple form. This ``Birkhoff-Gustavson normal form'' retains the symmetries of the original system and we show that in most cases this allows us to view the periodic FPU Hamiltonian as a perturbation of a nondegenerate Liouville integrable Hamiltonian. According to the KAM theorem this proves the existence of many invariant tori on which motion is quasiperiodic. Experiments confirm this qualitative behaviour. We note that one can not expect this in lower-order resonant Hamiltonian systems. So the periodic FPU chain is an exception and its special features are caused by a combination of special resonances and symmetries.

  6. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

  7. Detecting series periodicity with horizontal visibility graphs

    CERN Document Server

    Núñez, Angel M; Valero, Eusebio; Gómez, Jose Patricio; Luque, Bartolo

    2011-01-01

    The horizontal visibility algorithm has been recently introduced as a mapping between time series and networks. The challenge lies in characterizing the structure of time series (and the processes that generated those series) using the powerful tools of graph theory. Recent works have shown that the visibility graphs inherit several degrees of correlations from their associated series, and therefore such graph theoretical characterization is in principle possible. However, both the mathematical grounding of this promising theory and its applications are on its infancy. Following this line, here we address the question of detecting hidden periodicity in series polluted with a certain amount of noise. We first put forward some generic properties of horizontal visibility graphs which allow us to define a (graph theoretical) noise reduction filter. Accordingly, we evaluate its performance for the task of calculating the period of noisy periodic signals, and compare our results with standard time domain (autocorre...

  8. Spinor Structure and Modulo 8 Periodicity

    CERN Document Server

    Varlamov, V V

    2015-01-01

    Spinor structure is understood as a totality of tensor products of biquaternion algebras, and the each tensor product is associated with an irreducible representation of the Lorentz group. A so-defined algebraic structure allows one to apply modulo 8 periodicity of Clifford algebras on the system of real and quaternionic representations of the Lorentz group. It is shown that modulo 8 periodic action of the Brauer-Wall group generates modulo 2 periodic relations on the system of representations, and all the totality of representations under this action forms a self-similar fractal structure. Some relations between spinors, twistors and qubits are discussed in the context of quantum information and decoherence theory.

  9. Intermittence and roughening of periodic elastic media

    International Nuclear Information System (INIS)

    We analyze intermittence and roughening of an elastic interface or domain wall pinned in a periodic potential, in the presence of random-bond disorder in 1+1 and 2+1 dimensions. Though the ensemble average behavior is smooth, the typical behavior of a large sample is intermittent, and does not self-average to a smooth behavior. Instead, large fluctuations occur in the mean location of the interface and the onset of interface roughening is via an extensive fluctuation which leads to a jump in the roughness of order λ, the period of the potential. Analytical arguments based on extreme statistics are given for the number of the minima of the periodicity visited by the interface and for the roughening crossover, which is confirmed by extensive exact ground state calculations

  10. Short-Term Periodicities in Solar Indices

    Science.gov (United States)

    Kane, R. P.

    2005-03-01

    The purpose of the present communication is to identify the short-term (few tens of months) periodicities of several solar indices (sunspot number, Caii area and K index, Lyman α, 2800 MHz radio emission, coronal green-line index, solar magnetic field). The procedure used was: from the 3-month running means (3m) the 37-month running means (37m) were subtracted, and the factor (3m - 37m) was examined for several parameters. For solar indices, considerable fluctuations were seen during the ± 4 years around sunspot maxima of cycles 18-23, and virtually no fluctuations were seen in the ± 2 years around sunspot minima. The spacings between successive peaks were irregular but common for various solar indices. Assuming that there are stationary periodicities, a spectral analysis was carried out which indicated periodicities of months: 5.1 5.7, 6.2 7.0, 7.6 7.9, 8.9 9.6, 10.4 12.0, 12.8 13.4, 14.5 17.5, 22 25, 28 (QBO), 31 36 (QBO), 41 47 (QTO). The periodicities of 1.3 year (15.6 months) and 1.7 years (20.4 months) often mentioned in the literature were seen neither often nor prominently. Other periodicities occurred more often and more prominently. For the open magnetic flux estimated by Wang, Lean, and Sheeley (2000) and Wang and Sheeley (2002), it was noticed that the variations were radically different at different solar latitudes. The open flux for 45∘ solar latitudes had variations anti-parallel to the sunspot cycle. The open fluxes, interplanetary magnetic field and cosmic rays, all showed periodicities similar to those of solar indices. Many peaks (but not all) matched, indicating that the open flux for < 45∘ solar latitudes was at least partially an adequate carrier of the solar characteristics to the interplanetary space and thence for galactic cosmic ray modulation.

  11. Periodicity in bimodal atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chia-Yun; Santos, Sergio, E-mail: santos-en@yahoo.com; Chiesa, Matteo [Laboratory for Energy and NanoScience (LENS), Institute Center for Future Energy (iFES), Masdar Institute of Science and Technology, Abu Dhabi (United Arab Emirates); Barcons, Victor [Departament de Disseny i Programació de Sistemes Electrònics, UPC - Universitat Politècnica de Catalunya, Av. Bases, 61, 08242 Manresa (Barcelona) (Spain)

    2015-07-28

    Periodicity is fundamental for quantification and the application of conservation principles of many important systems. Here, we discuss periodicity in the context of bimodal atomic force microscopy (AFM). The relationship between the excited frequencies is shown to affect and control both experimental observables and the main expressions quantified via these observables, i.e., virial and energy transfer expressions, which form the basis of the bimodal AFM theory. The presence of a fundamental frequency further simplifies the theory and leads to close form solutions. Predictions are verified via numerical integration of the equation of motion and experimentally on a mica surface.

  12. Periodicity in the isotope chemistry of hydrogen

    OpenAIRE

    Bigeleisen, Jacob

    1981-01-01

    Periodicities and regularities are established among the deuterium to protium isotopic reduced partition function ratios, ln(s/s′)f, of 39 diatomic and 19 polyatomic hydrides. It is shown that ln(s/s′)f for diatomic hydrides can be correlated with the position in the periodic table of the element X in the hydride HX. A similar analysis is made for the contributions from X—H stretching motion in the polyatomic hydrides HnX. It is shown that the contributions from stretching motions to ln(s/s′)...

  13. Rotation Period Determination for 871 Amneris

    Science.gov (United States)

    Pilcher, Frederick; Benishek, Vladimir; Oey, Julian

    2016-07-01

    From a total of 44 sessions of photometric measurements of asteroid 871 Amneris, a principal synodic rotation period of 78.71 ± 0.01 hours and amplitude 0.60 ± 0.05 magnitudes is found for its lightcurve. The individual sessions in the composite lightcurve show considerable variation that may be due to changes in phase angle and phase angle bisector through the long interval of observation. These changes are suggestive of shadowing within significant concavities or that some secondary "tumbling" period might be involved. However a careful search of the data reveals no evidence for the latter.

  14. Stochastic dynamics of a periodical reactor

    International Nuclear Information System (INIS)

    The dynamics of a pulsed periodical reactor (PPR) are analyzed beyond the region of stability on the basis of a discrete model is analyzed. It is shown that at a certain power lewel PPR with negative temperature coefficient will inevitably feature the stochastic behaviour of power pulse energy, the so called determinated chaos. The nature of transition to the chaos depends on the nature of feedback and specific model of dynamics. Feingenbaum transition in the most likely one when the random motion occurs after an infinite sequence of bifureations of oscillation period doubling. It also shown that PPR transition to chaos may be considered as a safe one. 16 refs.; 10 figs

  15. Modification and expansion of Mendeleev's periodic table

    International Nuclear Information System (INIS)

    The periodic table of the chemical elements has provided guidance for the discovery of many elements since its formulation as a guiding principle 125 years ago. It has misled investigators on occasion into temporary excursions along erroneous routes to new elements. Even these tortuous paths, however, have eventually led to the correct destination. It is described, the part that the periodic table has played in the discovery of the man-made elements, especially the transuranium elements, and its possible future role. (author). 7 refs., 6 figs

  16. The electrostatic surface term: (I) periodic systems.

    Science.gov (United States)

    Herce, Henry David; Garcia, Angel Enrique; Darden, Thomas

    2007-03-28

    The authors propose a new approach to understand the electrostatic surface contributions to the interactions of large but finite periodic distributions of charges. They present a simple method to derive and interpret the surface contribution to any electrostatic field produced by a periodic distribution of charges. They discuss the physical and mathematical interpretations of this term. They present several examples and physical details associated with the calculation of the surface term. Finally, they provide a simple derivation of the surface contribution to the virial. This term does not disappear even if tinfoil boundary conditions are applied. PMID:17411107

  17. Stochastic dynamics of a periodic pulsed reactor

    International Nuclear Information System (INIS)

    A periodical pulsed reactor (PPR) dynamics far beyond stability is analyzed using the discrete nonlinear model as a basic one. It is shown that a PPR with negative temperature reactivity effect inevitably comes up to a stochastic chaos. A way by which a reactor goes to chaos is defined by a time dependence of feedback and by a kind of dynamics model. The most usual case is the Feigenbaum transition the matter of which is that the chaotic motion will appear after the PPR passes through the infinite cascade of oscillation period doubling. The transition of PPR to chaotic behaviour must be considered to be safe. 16 refs.; 7 figs

  18. Periodicity in bimodal atomic force microscopy

    International Nuclear Information System (INIS)

    Periodicity is fundamental for quantification and the application of conservation principles of many important systems. Here, we discuss periodicity in the context of bimodal atomic force microscopy (AFM). The relationship between the excited frequencies is shown to affect and control both experimental observables and the main expressions quantified via these observables, i.e., virial and energy transfer expressions, which form the basis of the bimodal AFM theory. The presence of a fundamental frequency further simplifies the theory and leads to close form solutions. Predictions are verified via numerical integration of the equation of motion and experimentally on a mica surface

  19. Periodic optimization of continuous microbial growth processes.

    Science.gov (United States)

    Abulesz, E M; Lyberatos, G

    1987-06-01

    Steady-state operation of continuous bioreactors is not necessarily the optimum type of operation. The method of pi-criterion is used in this work to determine whether periodic variation of the dilution rate can enhance the performance of continuous fermentation processes. It is found that the presence of time delay in the dynamic response of the chemostat renders a periodic operation of bioreactors, used for biomass production, superior to any steady-state operation. Also, employing Williams' structured model it is shown that cycling improves the average protein productivity. PMID:18576558

  20. Quantum cohomology and the periodic Toda lattice

    Energy Technology Data Exchange (ETDEWEB)

    Guest, M.A. [Tokyo Metropolitan Univ. (Japan). Dept. of Mathematics; Otofuji, T. [Tokyo Inst. of Tech. (Japan). Dept. of Mathematics

    2001-03-01

    We describe a relation between the periodic one-dimensional Toda lattice and the quantum cohomology of the periodic flag manifold (an infinite-dimensional Kaehler manifold). This generalizes a result of Givental and Kim relating the open Toda lattice and the quantum cohomology of the finite-dimensional flag manifold. We derive a simple and explicit ''differential operator formula'' for the necessary quantum products, which applies both to the finite-dimensional and to the infinite-dimensional situations. (orig.)

  1. Periodization of the early postnatal development in the rat with particular attention to the weaning period

    Czech Academy of Sciences Publication Activity Database

    Ošťádalová, Ivana; Babický, A.

    2012-01-01

    Roč. 61, Suppl.1 (2012), S1-S7. ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GAP303/12/1162 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat * ontogenic development * presuckling period * suckling period * weaning period Subject RIV: ED - Physiology Impact factor: 1.531, year: 2012

  2. Comparative study of thyrotoxic periodic paralysis from idiopathic hypokalemic periodic paralysis: An experience from India

    OpenAIRE

    Kalita, J; G Goyal; Bhoi, S. K.; Chandra, S.; Misra, U K

    2012-01-01

    Objective: There is paucity of reports on thyrotoxic periodic paralysis (TPP) from India. We report the patients with TPP and compare them with idiopathic hypokalemic periodic paralysis (IHPP). Materials and Methods: Patients with hypokalemic periodic paralysis (HPP) treated during the past 11 years were evaluated retrospectively. Their demographic parameters, family history, clinical features, precipitating factors, severity of weakness, laboratory parameters and rapidity of recovery were re...

  3. Lumping Processes of Periodic ARMA Processes

    OpenAIRE

    Smadi, Abdullah A. [عبد الله الصمادي

    2004-01-01

    In this article various lumping processes are defined for periodic ARMA (PARMA) processes, namely, the forward, the backward and the cyclic lumping processes. The inter-relations between the parameters of these lumping processes are obtained. It is then proved that stationarity of any lumped process implies sta¬tionarity of all other lumped processes.

  4. Period Determination for (15337) 1993 VT2

    Science.gov (United States)

    Alvarez, Eduardo Manuel

    2013-04-01

    Lightcurve analysis for asteroid (15337) 1993 VT2 was performed from observations during its 2012 favorable opposition. The previously unknown synodic rotation period was found to be 3.338 ± 0.001 h and the lightcurve amplitude was 0.27 ± 0.04 mag.

  5. 17 CFR 290.2 - Periodic reports.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Periodic reports. 290.2 Section 290.2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) Schedule A to Part 285 GENERAL RULES AND REGULATIONS PURSUANT TO SECTION 9(a) OF THE EUROPEAN BANK...

  6. Chandler's period in the mean sea level

    OpenAIRE

    Jessen, Axel

    2011-01-01

    The constants of the Chandlerian oscillation in the mean sea level are calculated for nine ports and the results compared with those of the International Latitude Service. The Chandler period is clearly observed and the amplitudes are large enough. The phase differences greatly depend upon the selected localities.DOI: 10.1111/j.2153-3490.1964.tb00186.x

  7. Periodicity in wide-band time series

    OpenAIRE

    Bullock, T.H.; McClune, M.C.; Enright, J.T.

    2002-01-01

    Summary: To test the hypotheses that (i) electroencephalograms (EEGs) are largely made up of oscillations at many frequencies and (ii) that the peaks in the power spectra represent oscillations, we applied a new method, called the Period Specific Average (PSA) to a wide sample of EEGs. Both hypotheses can be rejected.

  8. PHYSICAL EDUCATION AND SPORTS IN PRESCHOOL PERIOD

    OpenAIRE

    Arzu ÖZYÜREK; ÖZKAN, İsa; Zuhal BEGDE; N. Ferah YAVUZ

    2015-01-01

    Early childhood is known as a critical period for development and fundamental movement skills. Growing and development of children have an effect on gaining fundamental movement skills. Besides, the opportu nities and movement education provided for the students play an essential role on developing fundamental movement skills poisedly. In preschool education, physical training is the leading activity given the least i...

  9. Clustering of periodic orbits in chaotic systems

    International Nuclear Information System (INIS)

    In the framework of the semiclassical approach, the universal spectral correlations in Hamiltonian systems with classical chaotic dynamics can be attributed to the systematic correlations between the actions of periodic orbits which (up to the switch in the momentum direction) pass through approximately the same points of the phase space. By considering symbolic dynamics of the system one can introduce a natural ultrametric distance between periodic orbits and organize them into clusters of orbits approaching each other in the phase space. We study the distribution of cluster sizes for the baker's map in the asymptotic limit of long trajectories. This problem is equivalent to the one of counting degeneracies in the length spectrum of the de Bruijn graphs. Based on this fact, we derive the probability Pk that k randomly chosen periodic orbits belong to the same cluster. Furthermore, we find asymptotic behaviour of the largest cluster size |Cmax| and derive the probability P(t) that a random periodic orbit belongs to a cluster smaller than t|Cmax|, t ∈ [0, 1]. (paper)

  10. 12 CFR 226.7 - Periodic statement.

    Science.gov (United States)

    2010-01-01

    ... cards; (C) Lines of credit accessed by check-guarantee cards or by debit cards that can be used only at... not apply to periodic statements provided solely for charge card accounts. (12) Minimum payment—(i) General disclosure requirements. Except as provided in paragraph (b)(12)(v) of this section, a card...

  11. Periodically forced ferrofluid pendulum: effect of polydispersity

    CERN Document Server

    Leschhorn, A

    2006-01-01

    We investigate a torsional pendulum containing a ferrofluid that is forced periodically to undergo small-amplitude oscillations. A homogeneous magnetic field is applied perpendicular to the pendulum axis. We give an analytical formula for the ferrofluid-induced ``selfenergy'' in the pendulum's dynamic response function for monodisperse as well as for polydisperse ferrofluids.

  12. Culture and Cooperation during the Interwar Period

    OpenAIRE

    Anişoara Popa

    2015-01-01

    Starting from the most important Publications of the International Institute for Intellectual Cooperation (1925-1946) we will explore the ideas concerning culture and personalities involved in the intellectual cooperation during the Interwar Period. Pointing out the role that the International Institute of Intellectual Cooperation had and the Romanian contribution to this cooperation is another purpose of this article.

  13. Multispacecraft observations of quasi-periodic emissions

    Science.gov (United States)

    Nemec, Frantisek; Picket, Jolene S.; Santolik, Ondrej

    2014-05-01

    Quasi-periodic (QP) emissions are VLF electromagnetic waves in the frequency range of about 0.5-5 kHz which exhibit a periodic time modulation of the wave intensity. The modulation period is usually on the order of a few tens of seconds. The generation mechanism of these emissions is still not understood, but at least in some cases it appears to be related to ULF magnetic field pulsations which result in periodic modifications of the resonant conditions in the source region. We use multipoint measurements of QP emissions by the 4 Cluster spacecraft. The observations are obtained close to the equatorial region at radial distances of about 4 Earth radii, i.e. close to a possible generation region. A combined analysis of the high resolution data obtained by the WBD instruments and the ULF magnetic field data obtained by the FGM instruments allows for a detailed case-study analysis of these unique emissions. The presented analysis benefits from the recent close-separation configuration of three of the Cluster spacecraft (≡20-100 km) and a related timing analysis, which would be impossible otherwise.

  14. A Compact Expression for Periodic Instantons

    CERN Document Server

    Cherkis, Sergey A; Zaitsev, Dmitri

    2015-01-01

    Instantons on various spaces can be constructed via a generalization of the Fourier transform called the ADHM-Nahm transform. An explicit use of this construction, however, involves rather tedious calculations. Here we derive a simple formula for instantons on a space with one periodic direction. It simplifies the ADHM-Nahm machinery and can be generalized to other spaces.

  15. Unique solution to periodic boundary value problems

    Directory of Open Access Journals (Sweden)

    Yong Sun

    1991-01-01

    Full Text Available Existence of unique solution to periodic boundary value problems of differential equations with continuous or discontinuous right-hand side is considered by utilizing the method of lower and upper solutions and the monotone properties of the operator. This is subject to discussion in the present paper.

  16. Theory of Periodic Conjugate Heat Transfer

    CERN Document Server

    Zudin, Yuri B

    2012-01-01

    This book presents the theory of periodic conjugate heat transfer in a detailed way. The effects of thermophysical properties and geometry of a solid body on the commonly used and experimentally determined heat transfer coefficient are analytically presented from a general point of view. The main objective of the book is a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body. At the body surface, the true heat transfer coefficient is composed of two parts: the true mean value resulting from the solution of the steady state heat transfer problem and a periodically variable part, the periodic time and length to describe the oscillatory hydrodynamic effects. The second edition is extended by (i) the analysis of stability boundaries in helium flow at supercritical conditions in a heated channel with respect to the interaction between a solid body and a fluid; (ii) a periodic model and a method of heat transfer sim...

  17. Periodic singular problem with quasilinear differential operator

    Czech Academy of Sciences Publication Activity Database

    Rachůnková, I.; Tvrdý, Milan

    2006-01-01

    Roč. 131, č. 3 (2006), s. 321-336. ISSN 0862-7959 R&D Projects: GA ČR(CZ) GA201/04/1077 Institutional research plan: CEZ:AV0Z1019905 Keywords : second order nonlinear ordinary differential equation with impulses * periodic solutions * lower and upper functions Subject RIV: BA - General Mathematics

  18. Multiwavelength periodicity study of Markarian 501

    CERN Document Server

    Roedig, Constanze; Elbracht, Oliver; Spanier, Felix

    2009-01-01

    Context: Active Galactic Nuclei are highly variable emitters of electromagnetic waves from the radio to the gamma-ray regime. This variability may be periodic, which in turn could be the signature of a binary black hole. Systems of black holes are strong emitters of gravitational waves whose amplitude depends on the binary orbital parameters as the component mass, the orbital semi-major-axis and eccentricity. Aims: It is our aim to prove the existence of periodicity of the AGN Markarian 501 from several observations in different wavelengths. A simultaneous periodicity in different wavelengths provides evidence for bound binary black holes in the core of AGN. Methods: Existing data sets from observations by Whipple, SWIFT, RXTE, VERITAS and MAGIC have been analysed with the Lomb-Scargle method, the epoch folding technique and the SigSpec software. Results: Our analysis shows a 72-day period, which could not be seen in previous works due to the limited length of observations. This does not contradict a 23-day p...

  19. Periodic and in-service inspection programs

    International Nuclear Information System (INIS)

    Periodic and in-service inspection programs for Cernavoda NPP consists of periodic inspections of CANDU NPP components CSAN N-285.4 and CSAN N-285.4, in-service inspections and repair and modifications general inspection. Periodic inspection program document (PIPD) determines the systems and components subject to inspection, the category of the inspection, techniques, areas and other details.The current status of the inspection programs is presented, including containment , erosion/corrosion, pressure vessel support and snubbers, main steam lines inspection programs. Qualification program in Cernavoda NPP involves equipment qualification in the on-site laboratory, yearly certification, special equipment qualification in the National Institute of Metrology. All procedures are approved by the ISCIR (regulatory body for pressure vessel and lifting equipment) and CNCAN (National Commission on Nuclear Activities Control). Qualification of the personnel is performed according to the ISCIR Technical prescription CR 11/82 for up to 3 year period. Final qualification and licensing is performed by CNCAN

  20. Symmetry and resonance in periodic FPU chains

    NARCIS (Netherlands)

    Rink, B.

    2001-01-01

    The symmetry and resonance properties of the Fermi Pasta Ulam chain with periodic boundary conditions are exploited to construct a nearidentity transformation bring ing this Hamiltonian system into a particularly simple form This BirkhoGustavson normal form retains the symmetries of the original sy

  1. Quantum Transport Calculations Using Periodic Boundary Conditions

    OpenAIRE

    Wang, Lin-Wang

    2004-01-01

    An efficient new method is presented to calculate the quantum transports using periodic boundary conditions. This method allows the use of conventional ground state ab initio programs without big changes. The computational effort is only a few times of a normal ground state calculations, thus is makes accurate quantum transport calculations for large systems possible.

  2. 49 CFR 232.611 - Periodic maintenance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic maintenance. 232.611 Section 232.611 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... maintenance. (a) In addition to the maintenance requirements contained in § 232.303(b) through (d), a...

  3. The Different Periodic Tables of Dmitrii Mendeleev

    Science.gov (United States)

    Laing, Michael

    2008-01-01

    Between 1869 and 1905 the Russian chemist Dmitrii Mendeleev published several tables with different arrangements of the chemical elements. Four of these are compared with periodic tables by Russian scientists from 1934 and 1969. The difficulties caused by the lanthanoid elements are clearly seen in the table of 1905, which satisfactorily includes…

  4. Relating Functional Groups to the Periodic Table

    Science.gov (United States)

    Struyf, Jef

    2009-01-01

    An introduction to organic chemistry functional groups and their ionic variants is presented. Functional groups are ordered by the position of their specific (hetero) atom in the periodic table. Lewis structures are compared with their corresponding condensed formulas. (Contains 5 tables.)

  5. Ecological periodic tables for estuarine habitats

    Science.gov (United States)

    Southwood (1977; J Anim Ecol 46: 337-365) compared the situation in ecology to that in chemistry before the development of the periodic table when each fact, for example, the solubility or reactivity of a chemical element, had to be discovered independently and remembered in isol...

  6. Hyperinflation in periodic and quasiperiodic chains

    Science.gov (United States)

    Odagaki, Takashi; Aoyama, Hideaki

    1988-08-01

    A hyperinflation rule is found, which relates one-dimensional systems with different periodicity or quasiperiodicity determined by a parameter α. Physical systems described by transfer matrices are analyzed and the hyperinflation rule is shown to give rise to self-similarity in the space spanned by parameters of the system and α.

  7. On Burnett coefficients in periodic media

    Science.gov (United States)

    Conca, Carlos; Orive, Rafael; Vanninathan, Muthusamy

    2006-03-01

    The aim of this work is to demonstrate a curious property of general periodic structures. It is well known that the corresponding homogenized matrix is positive definite. We calculate here the next order Burnett coefficients associated with such structures. We prove that these coefficients form a tensor which is negative semidefinite. We also provide some examples showing degeneracy in multidimension.

  8. Periodic and recurrent variations of cosmic rays

    International Nuclear Information System (INIS)

    The new results achieved in the field of periodic and recurrent variations of the intensity of 109 to 1013 eV cosmic rays are reviewed. Particular emphasis is given to developments in understanding the fluctuations of corotation-type anisotropies as well as to the structure of the heliosphere and its temporal changes. (author)

  9. Obesity and exercise in adoloscent period

    Directory of Open Access Journals (Sweden)

    Eda Mendeş

    2011-10-01

    Full Text Available Adolescence period is a special period during which fastest growth and development occur in humans and which includes transition from childhood to adulthood. World Health Organization (WHO define 10-19 age-group individuals as adolescence and 15- 24 age-group individuals as youthood. That today’s community lacks knowledge of workout, inadequate awareness of the benefits of workout to human health and acceptance of the continuity of sedentary life gives rise to the incidence of lots of chronic diseases such as high-blood pressure, cardio-pulmonary diseases, obesity and diabetes.In recent years, childhood and adolescence obesity has become an important health problem as a result of the decline in physical activities. In this context, workout along with balanced diet is one of the precautions that can be suggested in terms of the prevention of obesity. The purpose of this study (compilation is to provide information on keeping human health by means of an awareness of workout in adolescence period which is the most important stage preceding adulthood; to summarize the issue in relation to the written documents existing in the relevant literature, and to make suggestions about healthy future generations through workout in adolescence period.In conclusion, successful results regarding the treatment of obesity in adolescence can be achieved through aerobics along with low-calorie diet.

  10. Six Online Periodical Databases: A Librarian's View.

    Science.gov (United States)

    Willems, Harry

    1999-01-01

    Compares the following World Wide Web-based periodical databases, focusing on their usefulness in K-12 school libraries: EBSCO, Electric Library, Facts on File, SIRS, Wilson, and UMI. Search interfaces, display options, help screens, printing, home access, copyright restrictions, database administration, and making a decision are discussed. A…

  11. NPP Krsko Periodic Safety Review action plan

    International Nuclear Information System (INIS)

    In the current, internationally accepted, safety philosophy Periodic Safety Reviews (PSRs) are comprehensive reviews aimed at the verification that an operating NPP remains safe when judged against current safety objectives and practices and that adequate arrangements are in place to maintain an acceptable level of safety. These reviews are complementary to the routine and special safety reviews. They are long time-scale reviews intended to deal with the cumulative effects of plant ageing, modifications, operating experience and technical developments, which are not so easily comprehended over the shorter time-scale routine of safety reviews. The review was completed in 2005 and the next period will see the implementation of the action plan including some plant upgrades. The action plan lists issues that should be implemented at NPP Krsko together with associated milestones. The milestones were assumed based on best estimate resource availability and their ends can be potentially floated. In some cases, multiple corrective measures may be postulated to provide resolution for a given safety issue. The Slovenian Nuclear Safety Administration by decree approved the first periodic safety review and the implementation plan of activities arising from it. The entire implementation plan must be carried out by 15 October 2010. Report on the second periodic safety review must be submitted by the NEK not later than 15 December 2013. (author)

  12. QS Spiral: Visualizing Periodic Quantified Self Data

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Cuttone, Andrea; Jørgensen, Sune Lehmann

    2013-01-01

    In this paper we propose an interactive visualization technique QS Spiral that aims to capture the periodic properties of quantified self data and let the user explore those recurring patterns. The approach is based on time-series data visualized as a spiral structure. The interactivity includes ...

  13. 7 CFR 981.73 - Periodic reports.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Periodic reports. 981.73 Section 981.73 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... prescribed by the Board for use in redetermination of kernel weight and marketing policy considerations....

  14. Quantum fields, periods and algebraic geometry

    OpenAIRE

    Kreimer, Dirk

    2014-01-01

    We discuss how basic notions of graph theory and associated graph polynomials define questions for algebraic geometry, with an emphasis given to an analysis of the structure of Feynman rules as determined by those graph polynomials as well as algebraic structures of graphs. In particular, we discuss the appearance of renormalization scheme independent periods in quantum field theory.

  15. Localization length of nearly periodic layered metamaterials

    CERN Document Server

    del Barco, O

    2015-01-01

    We have analyzed numerically the localization length of light $\\xi$ for nearly periodic arrangements of homogeneous stacks (formed exclusively by right-handed materials) and mixed stacks (with alternating right and left-handed metamaterials). Layers with index of refraction $n_1$ and thickness $L_1$ alternate with layers of index of refraction $n_2$ and thickness $L_2$. Positional disorder has been considered by shifting randomly the positions of the layer boundaries with respect to periodic values. For homogeneous stacks, we have shown that the localization length is modulated by the corresponding bands and that $\\xi$ is enhanced at the center of each allowed band. In the limit of long-wavelengths $\\lambda$, the parabolic behavior previously found in purely disordered systems is recovered, whereas for $\\lambda \\ll L_1 + L_2$ a saturation is reached. In the case of nearly periodic mixed stacks with the condition $|n_1 L_1|=|n_2 L_2|$, instead of bands there is a periodic arrangement of Lorenztian resonances, ...

  16. Ultrasound periodic inspections of reactor pressure vessels

    International Nuclear Information System (INIS)

    Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)

  17. Dysfunctional uterine bleedings of a climacteric period

    International Nuclear Information System (INIS)

    Climacteric period of some women is complicated by dysfunctional uterine bleedings (DUB). Bearing in mind the fact that DUBS are caused by disorder of estrin rhysmic secretion, the paper presents the methods of differential diagnostics for investigations into functional disorders in the hypothalamus -hypophysis - ovaries - uterus system. The preference is given to roentgenologic and radioimmunologic diagnostic methods

  18. Amorites in the Early Old Babylonian Period

    NARCIS (Netherlands)

    Boer, Rients de

    2014-01-01

    The Amorites are known throughout the history of the Ancient Near East: they occur in texts from the Ur III empire (2100–2000 bc), but also in the Bible. In the Old Babylonian period (2000–1600 bc), several dynasties of Amorite kings ruled all over the Middle East. They came to power in the early Ol

  19. Periodic orbits in hyperchaotic Chen systems

    Directory of Open Access Journals (Sweden)

    Susanna Maza

    2015-08-01

    Full Text Available In this work, we show a zero-Hopf bifurcation in a Hyperchaotic Chen system. Using averaging theory, we prove the existence of two periodic orbits bifurcating from the zero-Hopf equilibria located at the origin of the Hyperchaotic Chen system.

  20. Adams operations and periodic cyclic cohomology

    International Nuclear Information System (INIS)

    The properties of Bismut's equivariant Chern character lead to the study of certain periodic cyclic cohomology groups. We compute these cohomology groups and construct a new A∞-algebra structure on the associated complexes, well suited for applications to the theory of equivariant characteristic classes. (author)