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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. Carboniferous paleogeographic and paleoclimatic reconstructions

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

    1992-01-01

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

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

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

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

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

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

    2001-07-01

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

  5. LATE CARBONIFEROUS BRACHIOPODS FROM KARAKORUM, PAKISTAN

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    LUCIA ANGIOLINI

    1999-03-01

    Full Text Available Carboniferous rocks from North Karakorum display sharp lateral variations in lithology and thickness suggesting accumulation in half-grabens during continental rifting between the Karakorum block and northern Gondwana. Different Carboniferous successions, belonging to distinct tectonic units, have been detected. Thin, poorly fossiliferous successions of arenites and crinoidal limestones contrast with very thick terrigenous-carbonate successions comprising two distinct fossiliferous horizons. The lower fossiliferous horizon yielded brachiopods (Pustula sp., Rhipidomella sp., Choristites sp., Martiniopsis sp., Afghanospirifer sp., Gypospirifer sp., Composita sp. of Bashkirian age. The upper fossiliferous horizon, lying about 90 m above the former, contains corals, crinoids and brachiopods (Densepustula cf. losarensis, Dowhatania sulcata n. sp., Brachythyris sp., Rhipidomella sp., Septacamera dowhatensis, Alispirifer middlemissi of Moscovian to Kasimovian age. The Carboniferous brachiopods of North Karakorum are similar to those collected in the Late Carboniferous of Central Afghanistan, Himalaya (Manang, Spiti, Tibet, and Lhasa Block (Xainza area. 

  6. 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...

  7. High-temperature carbidization of carboniferous rocks

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    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.

  8. Carboniferous paleogeographic, phytogeographic, and paleoclimatic reconstructions

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

    1985-01-01

    Two revised paleogeographic reconstructions of the Visean and Westphalian C-D stages are presented based on recent paleomagnetic, phytogeographic, stratigraphic, and tectonic data. These data change the positions of some continental blocks, and allow the definition of several new ones. The most important modifications that have been incorporated in these reconstructions are: (1) a proposed isthmus linking North America and Siberia across the Bering Strait; and (2) the separation of China and Southeast Asia in six major blocks, including South China, North China, Shan Thai-Malaya, Indochina, Qangtang, and Tarim blocks. Evidence is presented that suggests that at least the South China, Shan Thai-Malaya, and Qangtang blocks were derived from the northern margin of Gondwana. Multivariate statistical analysis of phytogeographic data from the middle and late Paleozoic allow definition of a number of different phytogeographic units for four time intervals: (1) the Early Devonian, (2) Tournaisian-early Visean, (3) Visean, and (4) late Visean-early Namurian A. Pre-late Visean-early Namurian A floral assemblages from South China show affinities with northern Gondwana floras suggesting a southerly position and provides additional support for our reconstruction of South China against the northern margin of Gondwana. There is a marked decrease in the diversity of phytogeographic units in the Namurian and younger Carboniferous. This correlates closely with the time of assembly of most of Pangaea. The general pattern of Carboniferous phytogeographic units corresponds well with global distribution of continents shown on our paleogeographic reconstructions. In addition, we have constructed paleoclimatic maps for the two Carboniferous time intervals. These maps stress the distribution of rainfall, as this should be strongly correlated with the floras. There is marked change in the rainfall patterns between the Visean and Westphalian C-D. This change corresponds with the closing of

  9. Carboniferous coprolites from Qinhuangdao of North China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

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

  10. Carboniferous paleogeographic, phytogeographic, and paleoclimatic reconstructions

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

    1985-06-01

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

  11. Plant biodiversity changes in Carboniferous tropical wetlands

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    Cleal, C. J.; Uhl, D.; Cascales-Miñana, B.; Thomas, B. A.; Bashforth, A. R.; King, S. C.; Zodrow, E. L.

    2012-08-01

    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 and Sydney coal basins. In all cases, species richness expansion followed an essentially logistic curve typical of that associated with ecologically closed habitats, with niche saturation being achieved in about three million years. The resulting steady-state ("climax") coal swamp vegetation had a local-scale (within an area of c. 0.1 ha) species diversity in South Wales of 16 ± 7 and Simpson Diversity Indices of 4.53 ± 2.55, which are very similar to values obtained from studies on North American coal swamp vegetation. Landscape diversity (within an area 105 km2) varied between 50 and 100 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 there were a number of intervals of more rapid species turn-over in the early Langsettian, late Duckmantian, early Bolsovian and middle Asturian times, which are recognised today as biozonal boundaries. The swamps were mostly subject to ecological stasis during early and middle Westphalian times, although they contracted locally in response to drying of substrates. Later in Westphalian times, however, the swamps were subject to regional-scale changes in composition and aerial extent, probably in response to climate change. The coal swamps had a much lower species diversity compared to modern-day tropical rain forests.

  12. Identification of Carboniferous (320 million years old) class Ic amber.

    Science.gov (United States)

    Bray, P Sargent; Anderson, Ken B

    2009-10-02

    The presence of amber, the fossil form of the resins produced by many types of higher plants, has been reported from many localities in Mesozoic and Cenozoic rocks. We have found Class I (polylabdanoid) amber in Carboniferous sediments dating to approximately 320 million years ago. This result demonstrates that preconifer gymnosperms evolved the biosynthetic mechanisms to produce complex polyterpenoid resins earlier than previously believed and that the biosynthetic pathways leading to the types of polylabdanoid resins that are now typically found in conifers and those now typically found in angiosperms had already diverged by the Carboniferous.

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

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    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

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

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    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

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

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    Boersma, Kerst Th.

    1973-01-01

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

  16. Three dwarf lycophytes from the Carboniferous of Argentina*)

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    Archangelsky, S.; Azcuy, C.L.; Wagner, R. H.

    1981-01-01

    Impressions of the bark of two small lycophytes, Bumbudendron paganzianum gen. et sp. nov. and Bumbudendron nitidum sp. nov., are described from middle Carboniferous shales in the Sierra de Paganzo. Lepidodendroid leaf cushions with a well-developed leaf scar showing a single trace, and the presence

  17. Archaeocidaris M’Coy (Echinoidea) from the Carboniferous of Egypt

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    Lewis, D.N.; Donovan, S.K.

    2005-01-01

    Collections in museums usually have boxes of specimens which remain ‘undiscovered’ and yet which may be of importance or interest. The recent rediscovery of specimens of Archaeocidaris in the Nationaal Natuurhistorisch Museum, Leiden, from the Carboniferous of Egypt illustrates this point. These spe

  18. 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.

  19. LATE DEVONIAN-CARBONIFEROUS CONODONTS FROM EASTERN IRAN

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    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. 

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

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

  1. Remagnetization of Lower Carboniferous Carbonates, Northeastern Ireland: Preliminary Paleomagnetic Results

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    Pannalal, S. J.; Symons, D. T.; Stanley, G.; Sangster, D. F.

    2004-12-01

    Conodont color alteration index (CAI) values provide indirect paleotemperature estimates for rocks that have been subjected to a thermal event either by burial metamorphism or by hot hydrothermal fluids. Extensive CAI studies have been conducted on the Lower Carboniferous carbonates of Ireland that are host to the major sedimentary lead and zinc deposits in the Irish ore field. The CAI values show that these rocks have been affected by a regional thermal event with a decreasing trend from south (CAI=7.0) to north Ireland (CAI=1). In addition, the relative timing of the regional metamorphic event and ore mineralization in the Irish ore field, critical to the much debated genetic theories for ore genesis, has remained elusive. A paleomagnetic study, that includes thermal and alternating-field demagnetization and isothermal remanence procedures, has been conducted on 235 specimens representing 18 sites from Lower Carboniferous carbonates (CAI age than the A component and may indicate a secondary magnetization, likely the result of weathering of the carbonates by oxidizing fluids. In addition, this regional hydrothermal event may also be related to the observed CAI values in Lower Carboniferous carbonates of northeastern Ireland.

  2. 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.

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

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    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

  4. LATEST TOURNAISIAN (EARLY CARBONIFEROUS CONODONTS FROM THE TABAI LIMESTONE, TIRAH, NORTHWESTERN PAKISTAN

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    FAZL-I-RABBI KHAN

    2004-11-01

    Full Text Available A new stratigraphic unit, the Tabai Limestone of the poorly known Tirah area of northwest Pakistan, is one of several Early Carboniferous carbonate units distributed along the North Gondwana margin, some connected with transgressive interludes. The Tabai Limestone has produced latest Tournaisian (Early Carboniferous conodonts indicative of the middle of the anchoralis-latus Zone.

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

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    Winkler Prins, C.P.

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

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

  7. 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

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    Kotarba, M.J.; Pluta, I. [AGH University of Science & Technology, Krakow (Poland)

    2009-05-15

    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 (CH{sub 4}, small amounts of higher gaseous hydrocarbons, and CO{sub 2}) and microbial (CH{sub 4}, very small amounts of ethane, and CO{sub 2}). 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.

  8. Diagenesis of Cambrian and lower Carboniferous sandstones, southwest Sinai, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Wahab, A.A.; Salem, A.M.K. [Tanta Univ., Kafr El-Sheikh (Egypt); McBride, E.F. [Univ. of Texas, Austin, TX (United States)

    1996-12-31

    Quartzose and feldspathic Cambrian and Lower Carboniferous sandstones (fluvial > marine > eolian) deposited on the Arabian shield in southwestern Sinai were not buried more than 1 to 1.5 km until Late Cretaceous and younger time, when the deepest rocks reached 2.5 km. Porosity was reduced by compaction to about 26%. Grain rearrangement was the main mechanism of compaction; intergranular pressure solution and ductile grain deformation are insignificant. Cementation by iron oxide (5%), quartz (3%), calcite (2%), kaolinite (2%) and K-feldspar (< 1%) reduced porosity to 12-15% except in silcretes and some ferricretes, where porosity was reduced to non-reservoir quality. Cements have no selectivity for certain textures or stratigraphic positions.

  9. Diagenesis of Cambrian and lower Carboniferous sandstones, southwest Sinai, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Wahab, A.A.; Salem, A.M.K. (Tanta Univ., Kafr El-Sheikh (Egypt)); McBride, E.F. (Univ. of Texas, Austin, TX (United States))

    1996-01-01

    Quartzose and feldspathic Cambrian and Lower Carboniferous sandstones (fluvial > marine > eolian) deposited on the Arabian shield in southwestern Sinai were not buried more than 1 to 1.5 km until Late Cretaceous and younger time, when the deepest rocks reached 2.5 km. Porosity was reduced by compaction to about 26%. Grain rearrangement was the main mechanism of compaction; intergranular pressure solution and ductile grain deformation are insignificant. Cementation by iron oxide (5%), quartz (3%), calcite (2%), kaolinite (2%) and K-feldspar (< 1%) reduced porosity to 12-15% except in silcretes and some ferricretes, where porosity was reduced to non-reservoir quality. Cements have no selectivity for certain textures or stratigraphic positions.

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

    Directory of Open Access Journals (Sweden)

    PAUL A. SELDEN

    2016-03-01

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

  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. On two new species of marine Ostracodes in the Carboniferous of Asturias, Spain

    NARCIS (Netherlands)

    Bless, M.J.M.

    1965-01-01

    This note is the result of a preliminary investigation made in the summer of 1964. During that season the author visited the coal-mine ”Villoria” of ”Cementos Fradera S.A.” (Asturias, Spain) in order to collect specimens of Carboniferous ostracodes. Two new species of Hollinella were found and are b

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

    NARCIS (Netherlands)

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

    2015-01-01

    The Paleozoic Dniepr-Donets Basin in Belarus, Ukraine, and Russia forms a major hydrocarbon province. Although well- and seismic data have established a 20 km thick stratigraphy, field-studies of its sediments are scarce. The inverted Donbas segment (Ukraine) exposes the middle Carboniferous part of

  14. The alluvial architecture of the Coevorden Field (Upper Carboniferous), the Netherlands

    NARCIS (Netherlands)

    Kombrink, H.; Bridge, J.S.; Stouthamer, E.

    2007-01-01

    A detailed reconstruction of the alluvial architecture of the Coevorden gas Field (Tubbergen Formation, Upper Carboniferous), which is located in the northeastern part of the Netherlands, is presented. This reconstruction is based on well logs, cross-sections and paleogeographic maps. Sedimentolog

  15. The Permo-Carboniferous genus Sagenodus and the beginning of modern lungfish

    NARCIS (Netherlands)

    Schultze, H.-P.; Chorn, J.

    1997-01-01

    were present in North America ( The lungfish Sagenodus is a widespread Permo-Carboniferous genus found in Europe and North America. Important localities in the U.S.A. include Middle Pennsylvanian coals near Linton, Ohio, Upper Pennsylvanian deposits near Robinson and Hamilton, Kansas, and Peoria, Il

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  18. A new biostratigraphical tool for reservoir characterisation and well correlation in permo-carboniferous sandstones

    NARCIS (Netherlands)

    Garming, J.F.L.; Cremer, H.; Verreussel, R.M.C.H.; Guasti, E.; Abbink, O.A.

    2010-01-01

    Permo-Carboniferous sandstones are important reservoir rocks for natural gas in the Southern North Sea basin. This is a mature area which makes tools for reservoir characterization and well to well correlation important for field optimalisation and ongoing exploration activities. Within the Permo-Ca

  19. 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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

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

  2. Conodont zonation and the Devonian/Carboniferous (Famennian/Tournaisian) boundary in the Naltaş section, eastern Taurides, Turkey

    Science.gov (United States)

    Atakul-Özdemir, Ayşe

    2017-02-01

    Conodont faunas from the Devonian/Carboniferous Naltaş section (eastern Taurides, Turkey) are presented. The faunas include important marker species of the latest Devonian earliest Carboniferous interval, belonging to the genera Siphonodella, Bispathodus, Polygnathus, Pseudopolygnathus, Apatognathus and Branmehla. Four conodont zones, comparable to the standard conodont zonation, are established in the studied succession, from the oldest to the youngest: (1) Bispathodus ultimus, (2) Siphonodella praesulcata Zones (Upper Famennian), (3) Siphonodella sulcata and (4) Siphonodella bransoni Zones (Lower Tournaisian). The Devonian/Carboniferous boundary in the eastern Taurides is recognized by the first appearance of Siphonodella sulcata.

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

    NARCIS (Netherlands)

    Adrichem Boogaert, van H.A.

    1965-01-01

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

  4. 山东省石炭二叠纪沉积岩建造与成矿作用%Formation and Mineralization of Carboniferous-Permian Sedimentary Rocksin Shandong Province

    Institute of Scientific and Technical Information of China (English)

    梁太涛; 李洪奎; 耿科; 禚传源; 王峰; 汤启云

    2014-01-01

    Carboniferous Permian is major coal forming period in Shandong province.Bauxite and hard clay deposit have been formed at the same time.Regarding basic sequence of sedimentary rock as basic principle and sedimentary facies as classification basis,coordinated sedimentary cycle division and lithostratigraphic unit division principle,Carboniferous Permian in Shandong province can be divided into 5 sedimentary rock formations,its characteristics have been introduced,and the relationship between Carboniferous Permian sedimentary rock formation and mineralization has been described.%石炭二叠纪是山东省主要成煤时期,同时期形成的矿产还有铝土矿及硬质粘土矿。根据以沉积岩基本层序为基础原则、以沉积相划分为依据原则、与沉积旋回划分相一致原则、与组级岩石地层单位划分相协调原则等沉积岩建造类型划分原则,将山东省石炭二叠系划分为5个沉积岩建造,介绍了其特征,并阐述了石炭二叠纪沉积岩建造与成矿作用的关系。

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

    Science.gov (United States)

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

    1993-04-01

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

  6. 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.

  7. Impact of a Permo-Carboniferous high O2 event on the terrestrial carbon cycle

    OpenAIRE

    Beerling, D. J.; Berner, R. A.

    2000-01-01

    Independent models predicting the Phanerozoic (past 600 million years) history of atmospheric O2 partial pressure (pO2) indicate a marked rise to approximately 35% in the Permo-Carboniferous, around 300 million years before present, with the strong potential for altering the biogeochemical cycling of carbon by terrestrial ecosystems. This potential, however, would have been modified by the prevailing atmospheric pCO2 value. Herein, we use a process-based terres...

  8. A TRIGONOTARBID ARACHNID FROM THE UPPER CARBONIFEROUS OF THE SAN GIORGIO BASIN, SARDINIA

    Directory of Open Access Journals (Sweden)

    PAUL A. SELDEN

    2009-07-01

    Full Text Available A trigonotarbid arachnid from the Upper Carboniferous (Westphalian D of San Giorgio Basin, Sardinia, is described and referred to Anthracomartus voelkelianus Karsch, 1882, the type genus of the family Anthracomartidae. The occurrence extends the range of this arachnid order outside of the major Euramerican coal basins and into the western Mediterranean region. This is the first pre-Miocene arachnid from Italy to be described. 

  9. Tyloses and Ecophysiology of the Early Carboniferous Progymnosperm Tree Protopitys buchiana

    OpenAIRE

    SCHECKLER, STEPHEN E.; Galtier, Jean

    2003-01-01

    Trunk woods of Early Carboniferous Protopitys buchiana show the earliest example of tylose formation and the first record for a progymnosperm. Protopitys tyloses are more densely located in inner trunk woods and near growth layer boundaries. We suggest, therefore, that an altered physiological state of living ray cells, during dormancy and/or following water stress, was necessary to make the woods vulnerable to tylose formation. Coupled with the distribution and proximity of abundant wood ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-03-01

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

  11. Smart engineering in the mid-carboniferous: how well could palaeozoic dragonflies Fly?

    Science.gov (United States)

    Wootton; Kukalova-Peck; Newman; Muzon

    1998-10-23

    The wings of archaic Odonatoidea from the mid-Carboniferous of Argentina show features analogous to "smart" mechanisms in modern dragonflies that are associated with the agile, versatile flight necessary to catch prey in flight. These mechanisms act automatically in flight to depress the trailing edge and to facilitate wing twisting, in response to aerodynamic loading. The presence of similar features suggests that the earliest known odonatoids were already becoming adapted for high-performance flight in association with a predatory habit.

  12. The influence of diagenesis on the reservoir quality of Cambrian and Carboniferous sandstones, southwest Sinai, Egypt

    Science.gov (United States)

    McBride, Earle F.; Abdel-Wahab, Antar; Salem, Alaa M. K.

    1996-04-01

    The diagenetic influence on hydrocarbon reservoir quality was investigated for the Cambrian and Lower Carboniferous sandstones of southwestern Sinai. These quartzose and feldspathic Palaeozoic sandstones were not buried more than 1 to 1.5 km until Late Cretaceous and more recent times, when the most deeply buried rocks may have reached 25 km. Porosity was reduced by compaction from an assumed original 45% to about 26%. In general, both Cambrian and Carboniferous sandstones lost more porosity by compaction (average of 19% for each) than by cementation (average of 17% and 13%, respectively). There is no significant difference in the degree of compaction shown by Cambrian (older, deeper buried) rather than Carboniferous sandstones. Cementation by iron oxide, quartz, calcite and kaolinite reduced porosity to 12-15%, except in silcretes and some ferricretes where porosity was reduced to <5%. Significant secondary porosity was created (5.8 and 5.1 % for Cambrian and Carboniferous sandstones, respectively ) chiefly by dissolution of feldspar. Kaolinite (maximum of 20%) is the most deleterious cement because it has high microporosity, which causes high residual water saturation, and occurs as tiny crystals that have the potential to break loose during rapid fluid flow and block the pore throats. The present-day porosity in these sandstones averages 19% and ranges from 1.5 to 32%. Many sandstone samples (47% of a total of 178 samples) have permeability values higher than 1000 md. The plot of porosity versus the log of permeability has a good correlation indicating that microporosity, even though locally important, does not significantly influence reservoir quality. In spite of their age and the large volumes of groundwater that probably passed through them, these Palaeozoic sandstones retain sufficient porosity and permeability to possess excellent reservoir quality.

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

    Science.gov (United States)

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

    2015-03-20

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

  14. A revision of tetrapod footprints from the late Carboniferous of the West Midlands, UK

    Directory of Open Access Journals (Sweden)

    Luke E. Meade

    2016-11-01

    Full Text Available A series of sandstone slabs from Hamstead, Birmingham (West Midlands, UK, preserve an assemblage of tetrapod trackways and individual tracks from the Enville Member of the Salop Formation (late Carboniferous: late Moscovian–Kasimovian. This material has received limited previous study, despite being one of the few British sites to preserve Carboniferous tetrapod footprints. Here, we restudy and revise the taxonomy of this material, and document it using 3D models produced using photogrammetry. The assemblage is dominated by large tracks assigned to Limnopus isp., which were made by early amphibians (temnospondyls. A number of similar but smaller tracks are assigned to Batrachichnus salamandroides (also made by temnospondyls. Dimetropus leisnerianus (made by early synapsids and Dromopus lacertoides (made by lizard-like sauropsids such as araeoscelids are also present. This ichnofauna contrasts with a slightly stratigraphically older, more extensive and better-studied assemblage from Alveley (Shropshire, which is dominated by small amphibians with relatively rare reptiliomorphs, but which lacks Dromopus tracks. The presence of Dromopus lacertoides at Hamstead is consistent with the trend towards increasing aridity through the late Carboniferous. It is possible that the assemblage is the stratigraphically oldest occurrence of this important amniote ichnotaxon.

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

    Science.gov (United States)

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

    2015-03-01

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

  16. CARBONIFEROUS FORAMINIFERAL PALEOBIOGEOGRAPHY IN TURKEY AND ITS IMPLICATIONS FOR PLATE TECTONIC RECONSTRUCTIONS

    Directory of Open Access Journals (Sweden)

    JIRÍ KALVODA

    2003-07-01

    Full Text Available Four foraminiferal paleobiogeographic realms are distinguished in the Carboniferous – North Paleotethyan, Perigondwanian, Siberian and North American. The Carboniferous foraminiferal faunas of both the Istanbul and Anatolide-Tauride zones distinctly differ from both Cimmerian terranes (Central Afghanistan, Qiangtang and Libya and Egypt of the Perigondwana Realm and show close relation to the North Paleotethyan Realm, especially to the Fennosarmatian Province of southeastern Laurussia (Moesian and Scythian platforms or to the Central Asiatic Province. A model that best fits with available evidence is that the Anatolide-Tauride Zone was either a part or located close to Laurasia in Carboniferous. The Istanbul Zone represents an equivalent of the Rhenohercynian Zone of the Central Europe and can not be compared with Intra-Alpine or south Variscan terranes which may be correlated with the Anatolide-Tauride Zone. Later, in the Permian, the Anatolide -Tauride Zone may has been separated from the Eurasian mainland by the Karakaya back-arc ocean. 

  17. 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.

  18. 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.

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

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    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.

  20. 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.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-08-01

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

  3. 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.

  4. 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. 

  5. A Carboniferous non-onychophoran lobopodian reveals long-term survival of a Cambrian morphotype.

    Science.gov (United States)

    Haug, Joachim T; Mayer, Georg; Haug, Carolin; Briggs, Derek E G

    2012-09-25

    Lobopodians, a nonmonophyletic assemblage of worm-shaped soft-bodied animals most closely related to arthropods, show two major morphotypes: long-legged and short-legged forms. The morphotype with stubby, conical legs has a long evolutionary history, from the early Cambrian through the Carboniferous, including the living onychophorans and tardigrades. Species with tubular lobopods exceeding the body diameter have been reported exclusively from the Cambrian; the three-dimensionally preserved Orstenotubulus evamuellerae from the uppermost middle Cambrian "Orsten" (Sweden) is the youngest long-legged lobopodian reported thus far. Here we describe a new long-legged lobopodian, Carbotubulus waloszeki gen. et sp. nov., from Mazon Creek, Illinois, USA (∼296 million years ago). This first post-Cambrian long-legged lobopodian extends the range of this morphotype by about 200 million years. The three-dimensionally preserved specimen differs significantly from the associated short-legged form Ilyodes inopinata, of which we also present new head details. The discovery of a Carboniferous long-legged lobopodian provides a more striking example of the long-term survival of Cambrian morphotypes than, for example, the occurrence of a Burgess Shale-type biota in the Ordovician of Morocco and dampens the effect of any major extinction of taxa at the end of the middle Cambrian.

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

    Science.gov (United States)

    Pfefferkorn, Hermann W.; Thomson, Margaret C.

    1982-12-01

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

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

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    D. Korn

    2007-08-01

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

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

    NARCIS (Netherlands)

    Zwan, C.J. van der

    1980-01-01

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

  9. 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

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

    NARCIS (Netherlands)

    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. Furth

  11. 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.

  12. 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

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

    Science.gov (United States)

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

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

  14. Influence of pre-Mississippian paleogeology on Carboniferous Lisburne Group, Arctic National Wildlife refuge, northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.; Carlson, R.; Imm, T.; Gruzlovic, P.; Hanks, C.

    1988-02-01

    The Carboniferous Lisburne Group of northern Alaska formed an extensive carbonate platform, which was later deformed as part of the Brooks Range fold and thrust belt. In the northeast, the Lisburne Group is parautochthonous and analogous to that at Prudhoe Bay. The Lisburne's paleogeography and facies relationships pertain to assessment of the petroleum potential of the Arctic National Wildlife Refuge (ANWR). The Franklinian paleogeology, unconformably underlying the Ellesmerian sequence, has influenced sedimentation patterns in the Lisburne Group. The transgressive Endicott Group (Kekiktuk Conglomerate and Kayak, Shale) and Lisburne Group thin northward over Franklinian basement highs. In the Sadlerochit Mountains, the Katakturuk Dolomite formed a paleotopographic high over which the Endicott Group inched out and the Lisburne Group thinned. Shallow-marine oolitic grainstone developed in the cyclic Pennsylvanian Wahoo Limestone.

  15. 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.

  16. 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

  17. 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. 

  18. The smallest Neoptera (Baryshnyalidae fam. n. from Hagen-Vorhalle (early Late Carboniferous: Namurian B; Germany

    Directory of Open Access Journals (Sweden)

    Jan-Michael Ilger

    2011-09-01

    Full Text Available With Baryshnyala occulta gen. et sp. n. (Baryshnyalidae fam. n. we report a new small species from early Late Carboniferous (Pennsylvanian deposits in Hagen-Vorhalle. It differs in its unique venation pattern and small size from all other Neoptera known from this Lagerstätte and other contemporaneous locations worldwide. With an estimated wing length of <10mm it is by far the smallest species of Neoptera from Hagen-Vorhalle and is less than half as long as Heterologopsis ruhrensis Brauckmann & Koch, 1982 (~25mm. The specimen shows some relations to the earliest Holometabola and may date back the first appearance of holometaboly to the Namurian B (early Bashkirian: Marsdenian. The new species increases the paleo-biodiversity and span of inter-specific variability within the early Neoptera. It shows that very small and tiny specimens and species can easily be overlooked.

  19. Predicting methane accumulations generated from humic Carboniferous coals in the Donbas fold belt (Ukraine)

    Energy Technology Data Exchange (ETDEWEB)

    Alsaab, D.; Elie, M.; Izart, A.; Sachsenhofer, R.F.; Privalov, V.A. [Paradigm Co., Nancy (France)

    2008-08-15

    The numerical modeling of the Ukrainian part of the Donbas fold belt indicates that the coalification pattern was controlled mainly by the maximum burial depth of coal seams and the heat flow (HF) (40-75 mW/m{sup 2}) during the Permian. The coalification pattern was overprinted by magmatic events during the Late Permian in the south syncline (150 mW/m{sup 2}) and during the Permian-Triassic in the north of the Krasnoarmeisk region (120 mW/m{sup 2}). The coalification pattern shows a strong increase in vitrinite reflectance values toward the east and southeastern parts of the study area likely caused by (1) an eastward increase in burial depth, (2) a probable eastward increase in HF, and, (3) probable magmatic activity. An increase in total erosion toward the eastern and southeastern parts was also observed with a maximum erosional amount of approximately 8 km (5 mi) in the southeastern part of the study area. The basin modeling of this area predicts that the main phase of hydrocarbon generation occurred during the Carboniferous-Early Permian subsidence. The magmatic events that occurred during the Permian-Triassic caused renewed pulses of hydrocarbon generation. A large amount of the generated hydrocarbons was lost to the surface because of a lack of seals. However, the numerical simulation predicts accumulations of about 2 tcf (57 billion m{sup 3}) of methane generated from Carboniferous coals in the south and main synclines, where Lower Permian seal rocks are preserved. Finally, this study provides data on methane resources along the northern flank

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

    Science.gov (United States)

    Batkhishig, Bayaraa; Noriyoshi, Tsuchiya; Greg, Bignall

    2010-03-01

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

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

    Science.gov (United States)

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

    2002-11-01

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

  2. Lepidophloios acerosus Lindley and Hutton 1831 in the Carboniferous Cucuiova Formation, “Iron Gates” Natural Park (Banat, Romania

    Directory of Open Access Journals (Sweden)

    Popa Mihai Emilian

    2014-12-01

    Full Text Available The Carboniferous Cucuiova Formation of the Sirinia Basin, Danubian Units, in Almăj Mountains, South Carpathians, yields a highly diverse yet rare compressive flora representing significant heritage values of the “Iron Gates” Natural Park. This flora includes pteridophytes (lycopsids, sphenopsids, filicopsids and gymnosperms (pteridosperms and conifers, some of these representatives being important coal generators during the Late Carboniferous times. The facies features, distribution and paleofloral features of the Cucuiova Formation are discussed in the framework of the Sirinia Basin. The lycopsid Lepidophloios acerosus Lindley and Hutton 1831 is reported for the first time in Romania from the Cucuiova Formation in Dragosela Valley, in the central part of the “Iron Gates” Natural Park.

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

    Science.gov (United States)

    Kodama, K. P.

    2004-05-01

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

  4. A Devonian to Carboniferous intra-oceanic subduction system in Western Junggar, NW China

    Science.gov (United States)

    Zhang, Ji'en; Xiao, Wenjiao; Han, Chunming; Mao, Qigui; Ao, Songjian; Guo, Qianqian; Ma, Chong

    2011-07-01

    The Devonian and Carboniferous rock assemblages in Western Junggar, southern Altaids, include ophiolitic mélanges and coherent units. At Baijiantan, Yeyagou and Dagun Devonian gabbros and one group of volcanic rocks (type I lava) generally crop out as blocks in a matrix of ultramafic rocks and/or mudstone. They have a depleted light rare earth element (LREE) and mid-oceanic ridge basalt (MORB)-like signature with a small negative Nb anomaly, suggesting formation in a back-arc basin. Another group of volcanic rocks (type II lava) from Baijiantan, Yeyagou, Western Karamay and Maliya includes alkaline basalt, basanite, andesite, dacite and trachyte that contain microphenocrysts of clinopyroxene-plagioclase, amygdales filled with chalcedony and calcite, and accessory pyrite and ilmenite. The type II lavas are further subdivided into five sub-types: (1) Type II1 lava is strongly enriched in LREE with incompatible trace element ratios similar to oceanic island basalt (OIB), suggesting derivation from enriched mantle. (2) Type II2 lava and tuff are slightly LREE-enriched, with a marked negative Nb anomaly and Th/Yb-enrichment indicating that they were generated in a supra-subduction zone (SSZ). (3) Type II3 lava is also moderately enriched in LREE suggesting derivation from a more-enriched MORB mantle. (4) Type II4 lava is enriched in LREE and has high Nb/Yb values close to those of OIB. It is extensively depleted in Nb suggesting a source containing a mixture of enriched and SSZ mantle. (5) Type II5 lava has MORB-like REE patterns, and Nb/Yb and Th/Yb ratios. Based on field structural data, and the contemporaneity of the Baogutu adakite, a high-Mg diorite dike and the Miaoergou charnockite, these enriched and depleted magmatic features suggest generation in an intra-oceanic subduction zone influenced by ridge-trench interaction. The Altaids in Western Junggar are characterized by multiple intra-oceanic subduction systems, which may have continued to operate to the late

  5. 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.

    2016-12-01

    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

  6. A Late Carboniferous-Early Permian slab window in the West Junggar of NW China: Geochronological and geochemical evidence from mafic to intermediate dikes

    Science.gov (United States)

    Yin, Jiyuan; Long, Xiaoping; Yuan, Chao; Sun, Min; Zhao, Guochun; Geng, Hongyan

    2013-08-01

    The Late Carboniferous to Early Permian is a critical period for the formation of particular high-temperature magmatic associations in West Junggar, NW China and the geodynamic processes of ridge subduction and related slab windows in the Central Asian Orogenic Belt. Mafic to intermediate dikes, exposed in the central and southeastern West Junggar extensively, mainly consist of Nb-enriched and magnesian suites. The Nb-enriched dikes (305 Ma) are characterized by high Nb contents (5.63-9.08 ppm) and large variations of major element contents, exhibiting high-K to medium-K calc-alkaline characteristics with high Na2O/K2O (1.33-3.85) and low Sr/Y (9-32) ratios. The dikes have moderate Mg# (44.6-52.9), LREE-rich and sub-horizontal HREE patterns ((La/Yb)N = 3.05-7.18; (Gd/Yb)N = 1.43-1.78) with weak Eu anomalies (Eu*/Eu = 0.81-1.10) and positive εNd (t) values (+ 5.2 to + 8.0), and likely originate from partial melting of mantle peridotite that was metasomatized by subducted sediment-derived melts and slab fluids. The medium-K magnesian dikes (305 Ma) are characterized by high MgO (3.05-7.28 wt.%), Cr (22.3-311 ppm) and Ni (32.6-199 ppm) contents and all plot in the field of high-Mg andesite. Some have very high Mg numbers (Mg# > 60), suggesting a primitive melt composition. These samples display positive Ba, Sr, K and negative Nb-Ta-Ti anomalies as well as strongly-depleted HREE patterns with weak positive Eu anomalies. They have high Sr/Y (27-126) and relatively high εNd (t) values (+ 6.0 to + 8.3), which suggest a similar petrogenesis as the Nb-enriched dikes, but were metasomatized by adakitic melts. The high-K magnesian dikes (284 Ma) are high-K calc-alkaline and have lower MgO (3.63-5.57 wt.%) compared with the medium-K suite. They have high Sr (422-819 ppm), Sr/Y (26-62) ratios and εNd (t) values (+ 7.0 to + 7.1) with relatively flat REE patterns ((La/Yb)N = 2.4-5.5), probably originating from partial melting of K-enriched mantle wedge peridotite metasomatized

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

    Science.gov (United States)

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

    2012-08-01

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

  8. 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.

  9. The role of tidal-velocity asymmetries in the deposition of silty tidal rhythmites (Carboniferous, Eastern Interior Coal Basin, U.S.A.)

    Energy Technology Data Exchange (ETDEWEB)

    Archer, A.W. [Kansas State Univ., Manhattan, KS (United States). Dept. of Geology; Kuecher, G.J. [Argonne National Lab., IL (United States). Energy Systems Div.; Kvale, E.P. [Indiana Univ., Bloomington, IN (United States). Indiana Geological Survey

    1995-04-03

    Laminated to thin-bedded siltstones directly overlie Carboniferous coals at several localities in the Eastern Interior Coal Basin. Because lamina thicknesses show cyclical variations, the siltstones have been termed tidal rhythmites. The rhythmites commonly show a repetitive thick-thin pairing of the laminae, and these two-lamina rhythmites have been interpreted as the result of the asymmetry of flood and ebb velocities that affected sedimentation in a diurnal paleotidal system. Alternatively, the pairing has been interpreted to be related to a pronounced difference in height between successive high tides in a semidiurnal system. This explanation suggests deposition in a mixed, predominantly semidiurnal system with a marked diurnal inequality. In addition to the two-lamina rhythmites described originally, subsequent examination of drill cores indicates the occurrence of relatively rare, more complex three- and four-lamina rhythmites. A variety of mathematical techniques are used herein to analyze lamina-thickness data extracted from these rhythmites. Processing techniques include: (1) comparing the linear relationship between the thicknesses of the thinner and thicker laminae and comparing these relationships to modern tidal systems; (2) analyses of thickness periodicities and comparison with modern neap-spring tidal cycles; and (3) extraction of lamina-thickness inequalities and comparison to the diurnal inequalities that occur in semidiurnal tidal systems. These tests indicate that reasonable conclusions can be made for the type of originating paleotidal system. For the cases analyzed herein, the paleotidal signature suggests a mixed, predominantly semidiurnal system with a marked diurnal inequality.

  10. 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.

  11. Influence of pre-Mississippian paleogeology on Carboniferous Lisburne Group, Arctic National Wildlife Refuge, northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.; Carlson, R.; Imm, T.; Gruzlovic, P.; Hanks, C.

    1988-01-01

    The Carboniferous Lisburne Group of northern Alaska formed an extensive carbonate platform, which was later deformed as part of the Brooks Range fold and thrust belt. In the northeast, the Lisburne Group is parautochthonous and analogous to that at Prudhoe Bay. The Lisburne's paleogeography and facies relationships pertain to assessment of the petroleum potential of the Arctic National Wildlife Refuge (ANWR). The Franklinian paleogeology, unconformably underlying the Ellesmerial sequence, has influenced sedimentation patterns in the Lisburne Group. The transgressive Endicott Group (Kekiktuk conglomerate and Kayak Shale) and Lisburne Group thin northward over Franklinian basement highs. In the Sadlerochit Mountains, the Katakturuk Dolomite formed a paleotopographic high over which the Endicott Group pinched out and the Lisburne Group thinned. Shallow-marine oolitic grainstone developed in the cyclic Pennsylvanian Wahoo Limestone. To the south in the Shublik Mountains, a repeated sequence of Katakturuk Dolomite and the Nanook Limestone were lower, so the Endicott Group lapped over the area and was later overlain by comparable Lisburne Group rocks. In the Fourth Range, the Lisburne Group is thicker and limestones also occur in the upper Endicott Group. Oolitic grainstone in the Wahoo Limestone is rare, and broad ooid shoals apparently pinched out into deeper water carbonates on a southward sloping carbonate ramp.

  12. Single well multidisciplinary facies reconstruction (De Lute-6 Upper Carboniferous, Netherlands)

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Zwan, C.J. (Nederlandse Aardolie Maatschappij B.V., Assen (Netherlands)); Van De Laar, J.G.M.; Pagnier, H.J.M.; Van Amerom, H.W.J. (Geological Survey of the Netherlands, Heerlen (Netherlands))

    1993-09-01

    De Lutte-6 is a key well situated in onshore Netherlands. A cored lithological sequence from the Upper Carboniferous has been investigated by means of palynology, palynofacies, paleobotany, and sedimentology. Paleobotanical data suggest a late Westphalian C to late Westphalian D Age. Palynological assemblages have a late Westphalian D-Stephanian character. This discrepancy suggests that the local paleobotanical remains allow for a more precise age determination, whereas the palynological data provide information about the regional facies development. Palynofacies analyses combined with palynoflora data indicate a gradual transition from a waterlogged flood plain characterized by a diverse lycopod/cordait palynoflora, to well-drained flood plain with an impoverished cordait/conifer palynoflora. The sedimentological data, combined with the palynological and the paleobotanical data, suggest that the flood plains alternate with swamp and lake deposits. The transition from a waterlogged flood plain to a well-drained flood plain coincides with transition from intervals characterized by seat-earth soils (indicating humid conditions) to intervals characterized by immature calcie soils (witnessing semihumid to semi-arid conditions).

  13. 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.

  14. 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.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  17. Tyloses and ecophysiology of the early carboniferous progymnosperm tree Protopitys buchiana.

    Science.gov (United States)

    Scheckler, Stephen E; Galtier, Jean

    2003-05-01

    Trunk woods of Early Carboniferous Protopitys buchiana show the earliest example of tylose formation and the first record for a progymnosperm. Protopitys tyloses are more densely located in inner trunk woods and near growth layer boundaries. We suggest, therefore, that an altered physiological state of living ray cells, during dormancy and/or following water stress, was necessary to make the woods vulnerable to tylose formation. Coupled with the distribution and proximity of abundant wood ray parenchyma to large xylem conducting cells, the positions of conduits filled with tyloses can be interpreted as ecophysiological responses of the plant to changes in local environment. In addition, some xylem conducting cells might have functioned as vessels. Fungal hyphae are present in some tracheary cells and in some areas with tyloses, but there is no evidence for wood trauma; we conclude, therefore, that these particular cases of tyloses are probably not induced by wound trauma. Protopitys buchiana wood thus shows structure/function similarities to modern woods with vessels, such as those of dicot angiosperms. This implies that ancient and modern plant ecophysiological responses correlate well with the physical parameters of their cellular construction.

  18. In situ ion microprobe U-Pb dating and REE abundances of a carboniferous conodont

    Science.gov (United States)

    Sano, Yuji; Terada, Kentaro

    We report here in situ ion microprobe U-Pb dating of a conodont micro-fossil using an ion microprobe method. Thirteen spots on the single fragment of the Carboniferous conodont (size: approximately 800 µm × 100 µm) yield a 238U/206Pb isochron age of 323±36 Ma and a Tera-Wasserburg concordia intercept age of 332±44 Ma in a three-dimensional 238U/206Pb-207Pb/206 Pb-204Pb/206Pb diagram. These ages are consistent with the depositional and early diagenetic ages of the fossil in its host Mississippian sedimentary sequence within experimental error. The success of the method depends on the chemical fractionation of U from Pb within a hundred-µm length scale and the consequent variations in Pb isotopic compositions due to radioactive decay. Shale-normalized rare earth element (REE) abundances of two spots on the same sample show flat patterns from light REE to middle REE and decreases from middle REE to heavy REE with negative anomalies of both Ce and Eu. The REE characteristics are significantly different from those of Devonian conodonts reported by other workers, suggesting discrepant redox states and/or formation environments.

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

    Science.gov (United States)

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

    2013-02-01

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

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

    Science.gov (United States)

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

    1997-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    卢进才; 陈高潮; 魏仙样; 李玉宏; 魏建设

    2011-01-01

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

  2. 准噶尔盆地中拐地区石炭—二叠纪火山岩特征及构造环境分析%Geochemical characteristics and tectonic setting of the Carboniferous-Permian volcanic rocks in Zhongguai area northwestern Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    孙国强; 史基安; 张顺存; 陈吉; 贾艳艳

    2012-01-01

    中拐地区位于准噶尔盆地西北缘,是在石炭纪—早二叠世挤压应力场作用下形成的宽缓鼻状古隆起.石炭—二叠纪火山岩是主要的含油层系之一,到目前为止已发现了多个油气藏和出油气点,显示出良好的勘探前景.根据系统、精细的地震资料解释,中拐地区在石炭—二叠纪时期主要存在4期构造运动,分别对应4个不整合面:1)石炭系与二叠系之间;2)二叠系佳木河组与下乌尔禾组之间;3)二叠系下乌尔禾组与上乌尔禾组之间;4)二叠系上乌尔禾组与三叠系百口泉组之间.通过对中拐地区石炭—二叠纪火山岩的全岩元素分析表明,该区域主要为中-酸性的安山岩、英安岩和流纹岩及火山角砾岩和凝灰岩为主,其中SiO2的含量普遍较高,平均含量达到了67%,判定中拐地区的石炭—二叠纪火山岩喷发环境应位于岛弧体系的大陆内侧,在喷发过程中经历过陆壳的熔融作用.结合前人对周缘火山岩的研究,认为石炭—二叠纪时期中拐地区由岛弧环境逐渐进入陆内演化阶段,三叠纪开始进入稳定的沉积演化时期.%Zhong-Guai area is located in the Northwest margin of Junggar Basin, it is a broad nose palaeohigh formed in compressional stress field of Carboniferous Early Permain Period. Carboniferous-Permain volcanic rock is one of the mainly oil-bearing series, until now many hydrocarbon reservoirs and oil entry points are discovered, and showing good exploration prospects. According to systematic and elaborate seismic data interpretation, Zhong-Guai area have four tectonic movements in the Carboniferous-Permian period, corresponding to four unconformity respectively: 1 ) Between the Carboniferous and Permian system; 2) Between the Jiamuhe and Xiawuerhe Formation of Permian system; 3 ) Between the Xiawuerhe and Shangwuerhe Formation of Permian system; 4) Between the Xiawuerhe Formation of Permian system and Baikouquan Formation of

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

    Science.gov (United States)

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

    2011-01-01

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

  4. 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

  5. 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

  6. 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

  7. Late Carboniferous tectonic subsidence in South Wales: implications for Variscan basin evolution and tectonic history in SW Britain

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, P.M.; Gayer, R.A. [University of Cardiff, Cardiff (United Kingdom). Dept. of Earth Sciences

    2000-01-01

    Detailed stratigraphic data were used to backstrip seven sections from the Carboniferous South Wales coal basin. Resulting tectonic subsidence curves for the interval 319-305 Ma (Namurian-Westphalian D) are convex-up, indicating increasing subsidence rate with time, with rates between 130 and 250 m Ma{sup -1} suggesting a foreland basin setting. Forward modelling of subsidence due to flexural loading in front of a propagating orogenic wedge shows that an orogenic load migrating in a north-northeasterly direction across SW England between 319 and 305 Ma could have generated the backstripped subsidence patterns. Sensitivity tests show that while many of the forward model parameters are poorly constrained, and the model results non-unique, backstripped subsidence patterns allow reasonable constraint on the different model cases, so that model predictions can be treated as one possibility in a limited range. The predicted load evolution is consistent with current knowledge of tectonic and stratigraphic features of SW England. These results suggest that subsidence in other Late Carboniferous UK basins may also have been influenced by flexure due to a propagating orogenic load.

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

    Science.gov (United States)

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

    2011-01-01

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

  9. 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.

    2017-01-01

    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

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

  11. Early post-metamorphic, Carboniferous blastoid reveals the evolution and development of the digestive system in echinoderms.

    Science.gov (United States)

    Rahman, Imran A; Waters, Johnny A; Sumrall, Colin D; Astolfo, Alberto

    2015-10-01

    Inferring the development of the earliest echinoderms is critical to uncovering the evolutionary assembly of the phylum-level body plan but has long proven problematic because early ontogenetic stages are rarely preserved as fossils. Here, we use synchrotron tomography to describe a new early post-metamorphic blastoid echinoderm from the Carboniferous (approx. 323 Ma) of China. The resulting three-dimensional reconstruction reveals a U-shaped tubular structure in the fossil interior, which is interpreted as the digestive tract. Comparisons with the developing gut of modern crinoids demonstrate that crinoids are an imperfect analogue for many extinct groups. Furthermore, consideration of our findings in a phylogenetic context allows us to reconstruct the evolution and development of the digestive system in echinoderms more broadly; there was a transition from a straight to a simple curved gut early in the phylum's evolution, but additional loops and coils of the digestive tract (as seen in crinoids) were not acquired until much later.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    Ben Thuy

    2015-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-01

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

  15. An Extended Paleozoic Apparent Polar Wander Path for Baltica: new Permo-Carboniferous Paleopoles From the Donbas Region (Ukraine)

    Science.gov (United States)

    Hamers, M. F.; Meijers, M. J.; van Hinsbergen, D. J.; van der Meer, D. G.; Langereis, C. G.; Stephenson, R. A.

    2007-12-01

    An improved Paleozoic apparent polar wander (APW) path for Baltica is presented here on the basis of six new paleopoles that have been determined from samples collected in the Donbas region in the Dniepr-Donets basin in south-eastern Ukraine. Constructing APW paths allows improving paleogeographic reconstructions that reach further back in time than 200 Ma, where the use of oceanic isochrons and hotspot track has limited applicability. The absence of penetrative regional deformation and the subparallel trending bedding attitudes across the basin suggest that our sites did not suffer from local rotations and their results are interpreted as representative for Baltica. The data presented here improve the paleogeographic reconstruction of Baltica within the collage of the supercontinent Pangea. The six new paleopoles cover a time span from earliest Carboniferous (~356 Ma) to early Permian (~295 Ma). In our reconstruction, Baltica was located at a constant latitude of ~5°N during a major part of the Carboniferous, while at ~310 Ma it started to move gradually northward, reaching a paleolatitude of ~13°N at 295 Ma. From ~355 Ma to 295 Ma Baltica experienced a net ~20° clockwise rotation. Our new data differ with the APW path from Torsvik et al. (submitted) in the time span from ~320-300 Ma, wherein they propose a northward movement from more southerly latitudes. From 300 Ma onwards, our path fits the reference path from Torsvik et al. A possible Permian remagnetization of our sites is not likely, considering the rotational differences in the various time spans, and rockmagnetic analyses that have been performed. We also discuss the usage of the TK03 model (Tauxe and Kent (2004), Geoph. Mon. 145, pp 101-116) that allows for the correction of inclination error caused by compaction during burial, which is insignificant for most sites. This suggest that the NRM has been acquired after compaction.

  16. 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.

  17. Chemotaxonomy for naturally macerated tree-fern cuticles (Medullosales and Marattiales), Carboniferous Sydney and Mabou Sub-Basins, Nova Scotia, Canada

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2001-01-01

    Naturally macerated cuticles (NMC) and one synangium, representing medullosalean and marattialean tree-fern species, from two Carboniferous coalfields in Nova Scotia, Canada, are investigated. The samples were analyzed by infrared spectroscopy (FTIR), and by pyrolysis-gas chromatograph/mass spectrometry (py-Gc/Ms) techniques in search for chemical signatures that would help in developing a chemotaxonomic classification of Carboniferous fern species, assuming genetically dependent make-up of cuticles. FTIR-derived CH2/CH3 ratios, in conjunction with contributions from carboxyl groups, demonstrated a better potential for discriminating between medullosalean genera and species than molecular signatures obtained by py-Gc/Ms. However, the latter provided better data for differentiating medullosalean from marattialean tree ferns as a group. Changes in the chemical make-up of naturally macerated cuticles due to sample preparation are discussed. ?? 2001 Elsevier Science B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Thomas Rainer

    2002-12-01

    Full Text Available 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. Carboniferous deposits are late diagenetic to anchimetamorphic. Mesozoic deposits cover the range from middle diagenesis to the anchizone. Triassic to Cretaceous rocks in the SB and the Sava Folds reach the anchizone. Differences in diagenesis/metamorphism are mainly due to different maximumburial in Paleogene time.

  19. Internal structure and depositional environment of Late Carboniferous mounds from the San Emiliano Formation, Cármenes Syncline, Cantabrian Mountains, Northern Spain

    OpenAIRE

    2005-01-01

    Well-exposed mounds are common in limestone of the Late Carboniferous San Emiliano Formation, Cantabrian Mountains (Northern Spain). They occur as obvious primary topographic features. Careful study of the mound intervals and surrounding strata revealed the internal structures of mounds and the factors controlling their growth. The substrate (2–3 m) of the mounds consists of greyish to reddish, bedded oolitic and oncolithic packstone and grainstone. Crinoids, fragments of the alga Epimastopor...

  20. Petrogenesis and tectonic implications of the Early Carboniferous to the Late Permian Barleik plutons in the West Junggar (NW China)

    Science.gov (United States)

    Liu, Bo; Han, Bao-Fu; Ren, Rong; Chen, Jia-Fu; Wang, Zeng-Zhen; Zheng, Bo

    2017-02-01

    The Paleozoic accretionary orogenesis and continental crustal growth in Central Asia are thought to have close relationship with the evolution of the Paleo-Asian Ocean (PAO). The well-exposed plutons in the northern Barleik Mountains of the West Junggar region, NW China, may provide essential insights into the evolution of the Junggar Ocean, a branch of the PAO, and mechanism of continental crustal growth. Our work on the Barleik plutons indicates an early suite of 324-320 Ma diorite and a late suite of 314-259 Ma quartz syenite and granitic porphyry. All the plutons are characterized by high-K calc-alkaline to shoshonitic signatures, varying depletion in Nb, Ta, Sr, P, Eu, and Ti, low initial 87Sr/86Sr ratios (0.70241-0.70585), strongly positive εNd(t) values (+ 5.7-+7.7), and young one-stage Nd model ages (390-761 Ma), suggesting that they resulted from different batches of magma that were produced by fractional crystallization of a metasomatized mantle source with minor crustal contamination. The diorite is coeval with the youngest arc magmatic rocks, indicating a subduction-related origin. By contrast, the quartz syenite and granitic porphyry are geochemically similar to A2-type granites, with high Zr, Ga, and FeOT/[FeOT + MgO], and are coeval with the widespread plutons in the West Junggar. This, together with the occurrence of Late Carboniferous fluvial deposits and the lack of < 320 Ma ophiolitic and subduction-related metamorphic lithologies, definitively indicates a post-collisional setting after the closure of the Junggar Ocean. Slab breakoff accompanied by asthenospheric upwelling and basaltic underplating is a possible geodynamic process that is responsible for the post-collisional magmatism and vertical crustal growth in the region. Thus a tectonic switch from subduction to post-collision started at the end of the Early Carboniferous ( 320 Ma), probably as a result of the final closure of the Junggar Ocean.

  1. Detrital zircon U-Pb geochronology and provenance of the Carboniferous-Permian glaciomarine pebbly slates in the Tibetan Plateau

    Science.gov (United States)

    Wang, Q.; Zhu, D.; Zhao, Z.; Chung, S.; Li, C.; Sui, Q.; Fu, X.; Mo, X.

    2011-12-01

    Glaciomarine diamictites (including pebbly slate, pebbly siltstone, and pebbly sandstone) in the Tibetan Plateau are widely interpreted to have been associated with the deglaciation of the Indian continent. Guiding by zircon cathodoluminescence images, we determined U-Pb ages for detrital zircons from five typical Carboniferous-Permian pebbly slate samples from the Qiangtang, Lhasa, and Tethyan Himalaya of the Tibetan Plateau. The age distributions of detrital zircons from two samples (180 analyses) from Qiwu and Gangma Tso of the Qiangtang Terrane are similar, with two main age peaks ca. 579 and ca. 816 Ma and one minor age peak ca. 2490 Ma. Two samples (177 analyses) from Jiangrang and Damxung of the Lhasa Terrane define similar age distributions with two main age peaks ca. 539 and ca. 1175 Ma. Ages of detrital zircons from one sample (110 analyses) from Kangmar of the Tethyan Himalaya display main age peaks ca. 535, ca. 949, and ca. 2490 Ma. The ca. 816-Ma detrital zircons from the Qiangtang Terrane were most likely derived from the Lesser Himalaya, and the ca. 950-Ma detrital zircons from the Tethyan Himalaya might have been sourced from the High Himalaya, Eastern Ghats Province of the Indian plate and the Rayner Province of East Antarctica. The distinctive ca. 1175-Ma age population characteristic of zircons in the pebbly slates from the Lhasa Terrane is identical to the detrital zircons from the late Paleozoic sandstones (Zhu et al., 2011a) and the inherited zircons from the Mesozoic peraluminous granites (Zhu et al., 2011b) in this terrane, but significantly absent in the pebbly slates from both the Qiangtang and the Tethyan Himalayan terranes. The ca. 1175-Ma detrital zircons in the Lhasa Terrane were most likely sourced from the Albany-Fraser-Wilkes in southwestern Australia and East Antarctica. These new data obtained in this study reveal a distinct difference of detrital zircon provenance for the coeval Carboniferous-Permian glaciomarine pebbly slates

  2. Period Pain

    Science.gov (United States)

    ... You may also have other symptoms, such as lower back pain, nausea, diarrhea, and headaches. Period pain is not ... Taking a hot bath Doing relaxation techniques, including yoga and meditation You might also try taking over- ...

  3. Irregular Periods

    Science.gov (United States)

    ... blood become too low or too high. Some women have irregular periods because their bodies produce too much androgen, which is a hormone that causes increased muscle mass, facial hair, and deepening of the voice in males and ...

  4. Redescription and phylogenetic relationships of Solenodonsaurus janenschi Broili, 1924, from the Late Carboniferous of Nýřany, Czech Republic

    Directory of Open Access Journals (Sweden)

    M. Danto

    2012-08-01

    Full Text Available The basal tetrapod Solenodonsaurus janenschi Broili, 1924, from Nýřany (Westphalian D, Late Carboniferous, Czech Republic, is redescribed and its phylogenetic position reevaluated. A distinct groove at the base of the maxillary teeth is regarded as an autapomorphic character, which is present in both the large and small specimens. Other characteristic features, which are not unique to S. janenschi, are: an extension of the lacrimal that forms the anteroventral margin of the orbit; a long posterior extension of the jugal; spool-shaped vertebrae, and small, wedge-like intercentra. A phylogenetic analysis based on the data matrix of Ruta, Coates and Quicke suggests that S. janenschi is the sister taxon of the Lepospondyli. Shared characters include the shape of the vertebrae, non-swollen neural arches, and absence of an intertemporal. Although nested within the amniote stem, S. janenschi is not as closely related to basal amniotes as previously suggested. A rather long, slender humerus argues for a predominantly terrestrial mode of life, and the curved, slender ribs, as well as the comparatively small skull, suggest costal ventilation of the lungs similar to that in amniotes, rather than buccal pumping. The morphology of the shallow squamosal embayment in which an ossified dorsal margin is absent, renders the presence of a tympanum unlikely. doi:10.1002/mmng.201200003

  5. CYP1A2 phenotype and genotype in a population from the Carboniferous Region of Coahuila, Mexico.

    Science.gov (United States)

    Castorena-Torres, Fabiola; Mendoza-Cantú, Ania; de León, Mario Bermúdez; Cisneros, Bulmaro; Zapata-Pérez, Omar; López-Carrillo, Lizbeth; Salinas, Juan E; Albores, Arnulfo

    2005-04-28

    CYP1A2 regulation by polycyclic aromatic hydrocarbons (PAHs) exposure and polymorphism was investigated in 46 male volunteers from the Carboniferous Region in northern Coahuila, Mexico. PAH exposure was estimated by the urinary excretion of 1-hydroxypyrene (1-OHP), whereas the regulatory effects were assessed by the caffeine metabolic ratio (CMR). Genotype was evaluated by determining 5'-flanking region (-2964) and intron I (734) polymorphisms. A statistically significant difference in the urinary 1-OHP geometric means of Barroterán, Cloete and Juárez (2.30, 0.45 and 0.04, respectively) was observed. As for the genotype, the intron I distribution was 0% C/C, 46% C/A and 54% A/A, whereas that of the 5'-flanking region was 26% G/G, 42% G/A and 32% A/A. Both distributions were in agreement with the Hardy-Weinberg equilibrium model. A greater enzyme activity was observed in the A/A compared to C/A individuals according to the CMR (P<0.001), whereas the 5'-flanking region polymorphism showed no effect on CYP1A2 enzymatic activity. These results suggest that intron I polymorphism and PAH exposure are relevant factors that modulate CYP1A2 enzymatic activity.

  6. 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.

  7. Correlation of Upper Devonian and Lower Carboniferous Depositional Sequences in Different Facies Belts on Southern Margin of Upper Yangtze Platform

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A fundamental problem in sequence stratigraphy is whether the sequences are global in extent and whether the sea level changes are eustatic in nature. Study on the Upper Devonian and Lower Carboniferous depositional sequences in different facies belts on the southern margin of the Upper Yangtze platform shows that different orders of sequences possess distinctive distribution and correlation in space, although the sea level changes in various orders of sequences may be primarily global in nature. The present paper regards the distribution in space, especially in different facies belts, as a criterion for defining and recognizing the various orders of sequences. The orthosequence (third-order sequence) is probably global in nature, which may be discerned in various depositional facies belts on the continental margin and can be correlated over long distances, sometimes maybe worldwide. Commonly, correlation of the subsequences (fourth-order sequences with time interval of 0.5 Ma to 1.5 Ma) is difficult in different facies belts, although some of them are probably also worldwide in distribution. A subsequence should be distinguishable and correlatable within at least one facies belt. The higher-order sequences, including parasequences (fifth-order sequences) and microsequences (sixth-order sequences), are regional or local in distribution. They may have reflected the longer and shorter Milankovitch cycles respectively. Orthosequences and subsequences are usually recognizable in different facies belts, while parasequences and microsequences may be distinguished only in shallow marine deposits, but not in slope and basin facies deposits.

  8. Late Carboniferous palaeobotany of the upper Bideford Formation, north Devon: a coastal setting for a Coal Measures flora

    Energy Technology Data Exchange (ETDEWEB)

    Cleal, C.J.; Thomas, B.A. [Natural Museums & Galleries Wales, Cardiff (United Kingdom)

    2004-07-01

    The Culm Seams are thin coals in the Upper Carboniferous upper Bideford Formation of north Devon. Clastic sedimentary rocks associated with the coals have yielded a fossil macroflora dominated by the remains of the Calamostachyales and Medullosales, together with subsidiary lycophytes, sphenophylls, ferns, lagenostomaleans, rare cordaites, and a possible early cycad. The flora is probably early Langsettian in age, which is in agreement with the evidence of the non-marine bivalves and marine bands. It is broadly similar in composition to contemporaneous macrofloras from South Wales. It is unlikely to represent an assemblage formed from plant remains subject to long-distance transportation. Rather, it was probably preserved in the lower reaches of a 'bird-foot' delta that had temporarily transgressed into the Culm Basin. The distal margin of this delta would represent a comparable habitat to the levees of the rivers further inland, and thus would have supported vegetation similar to that which generated the more usual Coal Measures macrofloras.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    F. Witzmann

    2010-08-01

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

  11. Periodic behaviors

    CERN Document Server

    Napp, Diego; Shankar, Shiva

    2010-01-01

    This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R^n. These properties - in particular the Nullstellensatz describing the Willems closure - are closely related to integral and rational points on affine algebraic varieties.

  12. PERIODIC BEHAVIORS

    NARCIS (Netherlands)

    Napp, Diego; Put, Marius van der; Shankar, Shiva

    2010-01-01

    This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R(n). These properties-in particular the Nullste

  13. 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.

  14. 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.

  15. Carboniferous rifted arcs leading to an archipelago of multiple arcs in the Beishan-Tianshan orogenic collages (NW China)

    Science.gov (United States)

    Tian, Zhonghua; Xiao, Wenjiao; Windley, Brian F.; Zhang, Ji'en; Zhang, Zhiyong; Song, Dongfang

    2016-12-01

    The Beishan and East Tianshan Orogenic Collages in the southernmost Central Asian Orogenic Belt (CAOB) record the final stages of evolution of the Paleo-Asian Ocean. These collages and their constituent arcs have an important significance for resolving current controversies regarding their tectonic setting and age, consequent accretionary history of the southern CAOB, and the closure time of the Paleo-Asian Ocean. In this paper, we present our work on the southern Mazongshan arc and the northern Hongyanjing Basin in the Beishan Orogenic Collage (BOC), and our comparison with the Bogda arc and associated basins in the East Tianshan Orogenic Collage. Field relationships indicate that the Pochengshan fault defines the boundary between the arc and basin in the BOC. Volcanic rocks including basalts and rhyolites in the Mazongshan arc have bimodal calc-alkaline characteristics, an enrichment in large ion lithophile elements such as Rb, Ba, and Pb and depletion in high field-strength elements (e.g., Nb and Ta), which were probably developed in a subduction-related tectonic setting. We suggest that these bimodal calc-alkaline volcanic rocks formed in rifted arcs instead of post-orogenic rifts with mantle plume inputs. By making detailed geochemical comparisons between the Mazongshan arc and the Bogda arc to the west, we further propose that they are similar and both formed in arc rifts, and helped generate a Carboniferous archipelago of multiple arcs in the southern Paleo-Asian Ocean. These data and ideas enable us to postulate a new model for the tectonic evolution of the southern CAOB.

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

    Science.gov (United States)

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

    2010-06-01

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

  17. Late Carboniferous to early Permian sedimentaryetectonic evolution of the north of Alxa, Inner Mongolia, China:Evidence from the Amushan Formation

    Institute of Scientific and Technical Information of China (English)

    Haiquan Yin; Hongrui Zhou; Weijie Zhang; Xiaoming Zheng; Shengyu Wang

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Haiquan Yin

    2016-09-01

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

  19. Rasnitsynala sigambrorum gen. et sp. n., a small odonatopterid (“Eomeganisoptera”, “Erasipteridae” from the early Late Carboniferous of Hagen-Vorhalle (Germany

    Directory of Open Access Journals (Sweden)

    Wolfgang Zessin

    2011-09-01

    Full Text Available Besides Erasipteroides valentini (Brauckmann in Brauckmann, Koch & Kemper, 1985, Zessinella siope Brauckmann, 1988, and Namurotypus sippeli Brauckmann & Zessin, 1989, Rasnitsynala sigambrorum gen. et sp. n. is the fourth species of the Odonatoptera from the early Late Carboniferous (Early Pennsylvanian: Namurian B, Marsdenian deposits of the important Hagen-Vorhalle Konservat-Lagerstätte in Germany. With its wing-span of about 55mm it is unusually small even for the “Eomeganisoptera”. Its venation resembles other small “Eomeganisoptera”, in particular Z. siope. This is why it is here assigned to the probably paraphyletic “Erasipteridae” Carpenter, 1939.

  20. Rasnitsynala sigambrorum gen. et sp. n., a small odonatopterid ("Eomeganisoptera", "Erasipteridae") from the early Late Carboniferous of Hagen-Vorhalle (Germany).

    Science.gov (United States)

    Zessin, Wolfgang; Brauckmann, Carsten; Gröning, Elke

    2011-01-01

    Besides Erasipteroides valentini (Brauckmann in Brauckmann, Koch & Kemper, 1985), Zessinella siope Brauckmann, 1988, and Namurotypus sippeli Brauckmann & Zessin, 1989, Rasnitsynala sigambrorumgen. et sp. n. is the fourth species of the Odonatoptera from the early Late Carboniferous (Early Pennsylvanian: Namurian B, Marsdenian) deposits of the important Hagen-Vorhalle Konservat-Lagerstätte in Germany. With its wing-span of about 55 mm it is unusually small even for the "Eomeganisoptera". Its venation resembles other small "Eomeganisoptera", in particular Zessinella siope. This is why it is here assigned to the probably paraphyletic "Erasipteridae" Carpenter, 1939.

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

    Institute of Scientific and Technical Information of China (English)

    张建东

    2012-01-01

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

  2. The drowning of a carbonate platform: an example from the Devonian-Carboniferous of the southwestern Holy Cross Mountains, Poland

    Science.gov (United States)

    Szulczewski, M.; Belka, Z.; Skompski, S.

    1996-10-01

    The broad Middle Devonian carbonate platform of the Holy Cross Mountains was fragmented during the Frasnian and afterwards submerged as isolated blocks and transformed into a topographic depression. The section exposed in the Ostrowka quarry illustrates a well-documented drowning of the last small fragment (seamount) of this carbonate platform which submerged during Late Devonian and Early Carboniferous times. The recognized facies succession reflects a progressive, stepwise lowering of the sediment surface through time from a peritidal, lagoonal environment to a deep-water, anoxic basin. The Frasnian shallow-water carbonate platform is represented by lagoonal facies with peritidal sediments. Small-scale deepening-upward cycles punctuated with emersion surfaces are a feature of this stage. They resulted from a combination and continuous balance between carbonate production, subsidence and low-order, eustatic sea-level fluctuations. The carbonate platform aggraded at rates around 100-125 m/Ma. The shallow-water peritidal carbonates are separated from the post-platform deposits by an unconformity surface developed during subaerial exposure. The flooding of the faulted block of Galezice in the pre-late marginifera time and the subsequent initial drowning resulted primarily from a rapid sea-level rise. Small dimension of the seamount and its cemented upper surface were the most important factors that facilitated the sediment removal and thus suppressed the sediment accumulation. A condensed section was deposited on the top of the seamount. Its stratigraphic succession and rare cephalopod storm beds account for a model of redistribution of sediment over the swell, disintegrated by small-scale faulting. During drowning, the seamount traversed down through the photic zone at an average rate not higher than 20-25 m/Ma. Transformation of the swell into a basin accelerated in the late Tournaisian anchoralis Zone. It is manifested by an increase of deposition rate and by a

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  4. Cyclostratigraphy of Uppermost Carboniferous-to-Lower Triassic Terrestrial Deposits in Bogda Mountains, NW China - A Potential Astrostratigraphic Proxy Section

    Science.gov (United States)

    Yang, W.; Tabor, N. J.; Crowley, J. L.; Miggins, D. P.; Obrist, J.

    2012-12-01

    Lithologic and stratigraphic evidence from the uppermost Carboniferous-Lower Triassic fluvial-lacustrine deposits in the Tarlong-Taodonggou half-graben of southern Bogda Mountains, NW China shows 3 orders of depositional cyclicity. The section is thick (~1,700 m), relatively complete, and well-constrained by radiometric ages, as a potential candidate for Permo-Triassic astrostratigraphy in the mid-latitude of NE Pangea. 10 low-order cycles (LCs) are defined by their dominant depositional environments and prominent cycle boundaries. Upper Gzhelian-mid Sakamarian Lower, Middle, and Upper Daheyan LCs are composed mainly of meandering and braided stream deposits, formed during initial and early rifting. The Upper Daheyan LC contains mature Calcisols, indicating a subhumid-semi-arid climatic change. They were transgressed conformably by lake-margin, deltaic, and profundal deposits of the mid-Sakamarian-Artinskian Lucaogou and Hongyanchi LCs, indicating rapid graben subsidence. Contrasting lithologies suggest highly-fluctuating arid-subhumid conditions at the intermediate and high-order cycle scales. The two LCs are separated by a fluvial-incision and correlative deltaic downlap surface, indicating an uplifting event. Lake regression and fluvial peneplanation at the end of Hongyanchi LC is indicated by fluvial erosion and deposition of the thin (1-10s m) Lower Quanzijie LC, suggesting a tectonic uplift and/or climatic change. The basal two mature Calcisols and top Gleysols of the Upper Quanzijie LC containing fluvial and loess (?) deposits indicate an arid-to-humid climatic change. The two Quanzijie LCs span over Kungurian (?)-Capitanian ages and signify the beginning of late rifting. The humid condition magnified in overlying thick (~800 m) Lopingian-lower Induan Wutonggou LC, composed of deltaic, lake-margin, and meandering stream deposits. The overlying fluvial-lake margin deposits of the Induan Jiucaiyuan LC indicate a combination of tectonic uplift and a climatic

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

    Institute of Scientific and Technical Information of China (English)

    宋到福; 何登发; 王书荣; 李涤; 王志勇; 黄卫东

    2012-01-01

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

  6. 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

  7. Mid-Carboniferous conglomerates in southwestern Europe record early Variscan intracontinental convergence: evidence that channels were exhumed before thermal weakening of the lithosphere

    Science.gov (United States)

    Martinez, Francisco J.; Dietsch, Craig; Aleinikoff, John; Cirès, Jordi

    2010-05-01

    The early part of the intracontinental geodynamic evolution of the Variscan chain in southwestern Europe is recorded by polymict conglomerates found in flysch basins paired with exhumed crystalline massifs. The conglomerates contain pebbles and cobbles of deformed granite and mid- to lower-crustal metamorphic rock, and in southern France and northeastern Spain have been assigned a Visean-Namurian age based on biostratigraphy. In the Catalan Coastal Ranges, where Alpine deformation and metamorphism are absent, conglomerates are deformed, cross-cut by granite, and contact metamorphosed to andalusite-cordierite grade. Foliation in the pebbles and cobbles is not coplanar with foliation in their pelitic matrix: the conglomerates record exhumation of crust that was already deformed, metamorphosed, and exhumed before the Visean. In the Guilleries massif of NE Spain, gneisses were exhumed ≈10 km before 324 Ma. Conglomerate samples from eight flysch basins, from north to south: Montagne Noire, Mouthoumet massif, SE Pyrenees, and five localities in the Catalan Coastal Ranges, were collected for detrital zircon age determinations using the USGS/Stanford SHRIMP-RG. The flysch basins have principal sources of pre-Cadomian, Cadomian, Cambro-Ordovician, Devonian, and Carboniferous ages. The dominance of Paleozoic ages indicates local orthogneiss and Variscan granite as primary sources, implying intra-Carboniferous exhumation rates as high as 5-10 mm/a. The maximum depositional age of each flysch conglomerate may show a trend of younging to the south [330 Ma (Montagne Noire) - 340 Ma (Mouthoumet) - 324 Ma (Poblet) -328 (Perinet)], suggesting deposition in front of advancing thrust nappes. In the Pineda basin, a dike of undeformed granite which cross-cuts conglomerate is 304 ± 2 Ma (SHRIMP U-Pb zircon data), providing a minimum age constraint on the time of deposition. In the Montagne Noire and the Mouthoumet massif, flysch basins are deformed by structures related to nappe

  8. 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.

  9. 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.

  10. 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.

  11. Comparison of hydrocarbon gases (C{sub 1}-C{sub 5}) production from Carboniferous Donets (Ukraine) and Cretaceous Sabinas (Mexico) coals

    Energy Technology Data Exchange (ETDEWEB)

    Alsaab, D.; Elie, M.; Izart, A.; Martinez, L. [G2R, Nancy - Universite, CNRS, CREGU, BP-239, 54506 Vandoeuvres-les-Nancy (France); Sachsenhofer, R.F. [Institut fuer Geowissenschaften, Montanuniversitaet Leoben, Peter-Tunner-Strasse 5, A-8700 Leoben (Austria); Privalov, V.A. [Donetsk National Technical University, Artem str., 58, UA-83000 Donetsk (Ukraine); Suarez-Ruiz, I. [Instituto Nacional del Carbon - (INCAR) - CSIC. Ap.Co., 73, 33080-Oviedo (Spain)

    2008-04-03

    The main purpose of this contribution is to compare the ability of Carboniferous coals from the Donets Basin of the Ukraine and Cretaceous coal from the Sabinas Basin of the Mexico to generate hydrocarbon gases (C{sub 1}-C{sub 5}). Two bituminous coals from the Donets Basin (2c10YD and 1l1Dim; 0.55 and 0.65%R{sub r} respectively) and one bituminous coal from the Sabinas Basin (Olmos, 0.92%R{sub r}) were studied using heating experiments in a confined-pyrolysis system. The highest rank reached during the heating experiments corresponds to the anthracite stage (2.78 and 2.57%R{sub r}) for the 2c10YD and 1l1Dim coals and (2.65%R{sub r}) for the Olmos coal. The composition of the generated (C{sub 1}-C{sub 5}) gases was evaluated using a thermodesorption-multidimensional gas chromatography. The results show that the Carboniferous Donets coals produced more wet gas and methane during pyrolysis than the Cretaceous Olmos coal. This is probably due to their higher liptinite (6-20%) and collodetrinite content and to the loss of a major part of the petroleum potential of the Olmos coal during natural coalification. C{sub 2}-C{sub 5} compounds are mainly derived from the cracking of liquid hydrocarbons. Ethane is the most stable compound and formed from the cracking of higher hydrocarbon component. Large amounts of methane (up to 81 mg/g coal for the Donets coals and 50 mg/g coal for the Sabinas coal) were formed at high temperatures by cracking of previously formed heavier hydrocarbons and by dealkylation of the coal matrix. A linear relationship was observed between methane generation and the maturity level of both coal types. (author)

  12. 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.

  13. Plagioclase-mantled K-feldspar in the Carboniferous porphyritic microgranite of Altenberg-Frauenstein, Eastern Erzgebirge/Krusné Hory

    Directory of Open Access Journals (Sweden)

    Axel Müller

    2002-01-01

    Full Text Available The Upper Carboniferous porphyritic microgranite of Altenberg-Frauenstein, formerly known as Granitporphyr (Dalmer 1896 and here abbreviated as GP, forms a 36 km long and up to 18 km wide complex of ring dykes related to the Teplice-Altenberg caldera in the German–Czech border region of the Eastern Erzgebirge/Krusné Hory. The microgranites are characterized by the occurrence of plagioclase-mantled K-feldspar phenocrysts. The microgranite varieties representtwo main stages of intrusion evolved from acid (GP I to intermediaterocks (GP II within the intrusion. The most acid rock (GP Icum occurs as enclaves in GP I and GP II and is interpreted as a cumulate of K-feldspar and quartz phenocrysts. The porphyritic microgranites show field, textural and geochemical evidence suggesting that some of them have formed as a result of interaction between felsic and mafic magmas. Mixing features are abundant in the porphyriticquartz-feldspar-hornblende microgranite (GP II interpreted as a hybrid rock. They are less discrete in the early phase (GP I and not obvious in the acid enclaves (GP Icum. This trend seems to reflect a continuous deflation of the magma chamber from the top to the bottom. According to the definition of rapakivi granites after Haapala and Rämö (1992, the porphyritic microgranite of Altenberg-Frauenstein may be considered as rapakivi granite although ovoid alkali feldspar megacrysts typical of classical rapakivi granites are not recorded.However, due to its Carboniferous age and being the only known granitewith rapakivi texture in the German–Czech part of the Variscan belt, the microgranite of Altenberg-Frauenstein is exceptional.

  14. Sedimentologic and paleoclimatic reconstructions of carbonate factory evolution in the Alborz Basin (northern Iran) indicate a global response to Early Carboniferous (Tournaisian) glaciations

    Science.gov (United States)

    Sardar Abadi, Mehrdad; Kulagina, Elena I.; Voeten, Dennis F. A. E.; Boulvain, Frédéric; Da Silva, Anne-Christine

    2017-03-01

    The Lower Carboniferous Mobarak Formation records the development of a storm-sensitive pervasive carbonate factory on the southern Paleo-Tethyan passive margin following the opening of the Paleo-Tethys Ocean into the Alborz Basin along the northern margin of Gondwana. Its depositional facies encompass inner ramp peritidal environments, peloidal to crinoidal shoals, storm to fair-weather influenced mid-ramps, proximal to distal shell beds and low energy outer ramps. Sedimentological analyses and foraminiferal biostratigraphy reveal four events affecting carbonate platform evolution in the Alborz Basin during the Lower Carboniferous: (1) A transgression following global temperature rise in the Early Tournaisian (middle Hastarian) caused the formation of thick-bedded argillaceous limestones. This interval correlates with Early Tournaisian nodular to argillaceous limestones in the Moravia Basin (Lisen Formation, Czech Republic), the Dinant Basin (Pont d'Arcole Formation, Belgium), and at the Rhenish Slate Mountains (Lower Alum shale, Germany). (2) Late Hastarian-early Ivorian glaciations previously identified in Southern Gondwana but had not yet recognized in Northern Gondwana were recorded through a sequence boundary. (3) During the Late Tournaisian-Early Visean?, a differential block faulting regime along the basin's margin caused uplift of the westernmost parts of the Alborz Basin and resulted in subsidence in the eastern part of the central basin. This tectonically controlled shift in depositional regime caused vast sub-aerial exposure and brecciation preserved in the top of the Mobarak Formation in the western portion of the Central Alborz Basin. (4) Tectonic activity coinciding with a progressive, multiphase sea level drop caused indirectly by the Viséan and Serpukhovian glaciations phases ultimately led to the stagnation of the carbonate factory. Paleothermometry proxies, the presence of foraminiferal taxa with a northern Paleo-Tethyan affinity and evidence for

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

    Science.gov (United States)

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

    2016-07-01

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

  16. Gas Drilling Technology for Carboniferous Nappe in Northern Huoshaoshan%火烧山北部石炭系推覆体气体钻井技术

    Institute of Scientific and Technical Information of China (English)

    石建刚; 杨虎; 周鹏高; 乾彬

    2014-01-01

    火烧山北部(简称火北)石炭系推覆体厚度超过1000 m ,机械钻速低,为了提高钻速,在火北021井和火北022井进行了气体钻井技术试验。为了确保气体钻井的顺利实施,利用邻井钻井/测井资料建立了地层三压力剖面,根据地层三压力剖面进行了井眼稳定性评价,通过优选井身结构封隔不稳定地层,利用环空钻屑传输比计算最佳注气量。试验结果表明,火北地区石炭系推覆体适用于气体钻井技术,气体钻井的平均机械钻速达到5.37 m/h ,较邻井同井段常规钻井提高4倍左右,钻井周期大幅缩短。这表明,火北地区应用气体钻井技术可以提高钻速,能为加快该地区致密油的勘探进程提供技术保障,同时也为准噶尔盆地火山岩地层钻井提速积累了宝贵经验。%The carboniferous nappe in northern Huoshaoshan is over 1 000 m in thickness ,which poses low penetration rate problem in drilling .In order to speed up well drilling ,test of gas drilling was conduc-ted in Well Huobei 021 and Huobei 022 .To ensure the successful implementation of gas drilling ,drilling and & logging data of offset wells were used to predict pore pressure ,fracturing pressure and borehole col-lapse pressureset up the three formation pressure of the carboniferous nappe interval ,borehole stability was evaluated based on these pressure profiles ;formations with potential stability problems were sealed through optimizing casing program ;optimum gas injection rate was calculated by using annular drilling cutting transport ratio .The test showed that gas drilling technique is suitable for carboniferous nappe in Northern Huoshaoshan ,w here average penetration rate of gas drilling reached 5.37 m/h ,about 4 times higher than conventional drilling at the same interval ,resulting in significant reduction in drilling cycled .This showed that gas drilling in Huobei Area could increase drilling speed ,which not

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    裴立新; 高岗; 王绪龙; 枊广弟; 张越千; 唐勇

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    彭向东; 林英铴

    2001-01-01

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

  20. 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

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Subduction-related Late Carboniferous to Early Permian Magmatism in the Eastern Pontides, the Camlik and Casurluk plutons: Insights from geochemistry, whole-rock Sr-Nd and in situ zircon Lu-Hf isotopes, and U-Pb geochronology

    Science.gov (United States)

    Karsli, Orhan; Dokuz, Abdurrahman; Kandemir, Raif

    2016-12-01

    Late Carboniferous to early Permian granitoid rocks represent a volumetrically minor component of the Eastern Pontide lithosphere, but they preserve useful information about the region's tectonomagmatic history. The Casurluk and Camlik plutons primarily consist of gabbro, gabbroic diorite, diorite, monzogabbro, monzodiorite and monzonite, which intrude early to middle Carboniferous granitic basement rocks in the region. In this study, we use in situ zircon U-Pb ages and Lu-Hf isotopic values, whole-rock Sr-Nd isotopic values, and mineral chemistry and geochemistry of these plutons to determine petrogenesis and crustal evolution; we also discuss geodynamic implications. LA-ICP-MS zircon U-Pb dating of magmatic zircons from the rocks suggests that the plutons were emplaced during the late Carboniferous to early Permian (302 Ma). The metaluminous and I-type intrusive rocks belong to the high-K calc-alkaline series. In addition, they are relatively enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs); they are depleted in heavy rare earth elements (HREEs) and high field strength elements (HFSEs), such as Nb and Ti. All of the samples have homogeneous initial ISr values (0.70675 to 0.70792) and low εNd (t) values (- 5.1 to - 3.3). Zircons from the rocks of both plutons have uniform negative to slightly positive εHf (t) values (- 3.5 to 1.4) and old Hf two-stage model ages (1323 to 1548 Ma), implying that they have the same source, as well as suggesting the involvement of old enriched lithospheric mantle materials during their magma genesis. These results, combined with the εHf (t) values and two-stage model ages, demonstrate that the primary magmas were derived from partial melting of old lithospheric mantle material metasomatized by subduction-related fluids. Considering other regional geological data from the Sakarya Zone where these plutons formed, we conclude that late Carboniferous to early Permian magmatism in the area

  3. Provenance analysis of sandstone of the Upper Carboniferous to Middle Permian in Ordos Basin%鄂尔多斯盆地上石炭统-中二叠统砂岩物源分析

    Institute of Scientific and Technical Information of China (English)

    陈全红; 李文厚; 刘昊伟; 李克永; 庞军刚; 郭艳琴; 袁珍

    2009-01-01

    Based on comprehensive study of regional geology, stratigraphic contact relations, sandstone fragment components, heavy mineral and trace elements, the Upper Carboniferous to Middle Permian provenance area for the north Ordos Basin mainly come from recycling orogeny area, and can be divided into three provenance areas that are Wuhai-Yinchuan, Hangjinqi-Dongsheng, Zhungeer-Fugu. But affected by variation provenance and bounded by Hangjinqi-Dongsheng, the distribution of quartz sandstone of Ordos Basin that was derived from Alashan ancient land has obvious west-east trending divisional feature and is mainly distributed in west Ordos Basin, but lithic sandstone that came from Yin Mountains mainly distributed in east Ordos Basin. South and southwest trending source sandstone that came from steady tectonic area and recycling orogeny area are strongly related to the evolution of Qin-Qi orogenic belt, and has the duplex characteristic of activity and stabilization. So the south provenance can be divided into three provenance areas that are Haiyuan and Tongxin-Zhongwei, Pingliang-Guyuan and Huaixian, Yaoxian-Yijun and Fuxian. The catchment area of south and north provenance with NWW trending shoestring extension is located in Huanxian-Fuxian-Xianning area, and the catchment area gradually transfers to south Ordos Basin during Shanxi to He-8 period. Until He-8 period, the west provenance began to supply coarse clastic sediments. In Liuyehe Basin, Zhouzhi, as the outer margin of Ordos Basin, which is the intermontane basin of Qinling orogenic belt and has continuous transitional relationship between them, the Upper Carboniferous to Middle Permian sandstone came from recycling orogeny area and continental blocks.%对区域地质、地层接触关系、砂岩组分、重矿物及微量元素等的综合分析与研究结果表明,鄂尔多斯盆地北部上石炭统-中二叠统砂岩的物源区主要为再旋回造山带物源区,并可划分出乌海-银川、杭锦

  4. 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

  5. Comparison of generative capacities for bitumen and gas between Carboniferous coals from Donets Basin (Ukraine) and a Cretaceous coal from Sabinas-Piedras Negras Basin (Mexico) during artificial maturation in confined pyrolysis system

    Energy Technology Data Exchange (ETDEWEB)

    Alsaab, D.; Elie, M.; Izart, A.; Martinez, L. [UMR CNRS 7566-G2R Universite H. Poincare, BP-239, 54506 Vandoeuvre-les-Nancy, Cedex (France); Suarez-Ruiz, I. [Instituto Nacional del Carbon - (INCAR) - CSIC. Ap.Co., 73, 33080-Oviedo (Spain)

    2007-06-01

    The goal of this work is to study the ability of two immature Carboniferous coals from Donets Basin (Ukraine) to act as source for oil. Heating experiments in confined medium were performed to compare the thermal behavior of these coals, 1l1 Dim (%R{sub r} = 0.55; H/C at. = 0.79) and 2c10YD (%R{sub r} = 0.65; H/C at. 0.80), relative to a mature Cretaceous coal from Sabinas Basin (Olmos, %R{sub r} 0.92, H/C at. = 0.77). Macerals analysis carried out on starting materials showed that Olmos is exhausted in liptinite contrary to 2c10YD (20 vol.%) and 1l1Dim (6 vol.%). The vitrinite content is lower for 2c10YD (59 vol.%) than for Olmos (84 vol.%) and 1l1Dim (80 vol.%). Solid bitumen occurs often dispersed in the raw coals. Both petrographic and geochemical analyses on starting materials revealed that the selected Carboniferous Donets coals have better potentialities for bitumen generation than the Cretaceous Sabinas coal. The presence of long chain n-alkanes (> n-C{sub 8}) in the pyrolysis-GC chromatograms indicates that the two raw Carboniferous coals from Donets Basin can yield non-volatile hydrocarbons under further thermal maturation. It is speculated that some vitrinite macerals present in hydrogen-rich Carboniferous coals from Donets Basin can act as source rocks for oil. As a matter of fact, results showed that the 'oil window' occurs between {proportional_to} 1.0%R{sub r} and {proportional_to} 2.0%R{sub r} for both Cretaceous Sabinas and Carboniferous Donets coals during confined pyrolysis. As expected from geochemical and petrographic analyses of starting samples, the Carboniferous Donets coals yielded more bitumen and hydrocarbons than Cretaceous Sabinas coal during artificial maturation. Low proportions of solid bitumen (< 12 vol.%) are also formed between 1.1%R{sub r} and 1.5%R{sub r} during confined pyrolysis of coals. Two solid bitumen groups have been identified, which correspond to distinct phases of neo-formation. The drop in the solid bitumen

  6. Hyperkalemic periodic paralysis

    Science.gov (United States)

    Periodic paralysis - hyperkalemic; Familial hyperkalemic periodic paralysis; HyperKPP; HyperPP; Gamstorp disease ... factors include having other family members with periodic paralysis. It affects men more often than women.

  7. The effect of water saturation on methane breakthrough pressure: An experimental study on the Carboniferous shales from the eastern Qaidam Basin, China

    Science.gov (United States)

    Zhang, Cheng; Yu, Qingchun

    2016-12-01

    Breakthrough pressure plays an important role in shale gas flow, mining, and caprock evaluation. A series of breakthrough experiments were conducted under different water saturation conditions for four shales taken from the Carboniferous Hoit Taria Formation in the eastern Qaidam Basin, China to investigate the influence of water saturation on breakthrough pressure. Relevant geochemical tests (mineral composition, clay content, total organic carbon, thermal maturity and vitrinite reflectance) and micro structural characteristics of micro pores were also conducted. Breakthrough pressures under at least five different water saturations (from 0 to 100%) were obtained and relationship between breakthrough pressure and water saturation was fitted for each sample. We found that breakthrough pressure increases exponentially with water saturation. The decrease in effective pore diameter caused by both the bound water films and the swelling of the clay minerals resulted in the increase in the breakthrough pressure. After water saturation reached about 60%, breakthrough pressure increased rapidly from connectivity reduction, caused by the sealing off of smaller pores and partial water saturation of the macropores. By analyzing the correlation between breakthrough pressure and pore structure characteristics, breakthrough pressure is inversely related to porosity, and is primarily affected by macropores. Because macropores consist of many microfractures with lengths up to dozens of micrometers, they determine the porosity and then affect the connectivity of the rock. Correlation analysis between the mineral compositions and breakthrough pressure showed that TOC content exhibits a positive correlation with breakthrough pressure, but neither quartz content nor the clay mineral content exhibits a correlation. By combining this information with Field Emission Scanning Electron Microscope results, we found that microfractures are easily created where the TOC (total organic carbon

  8. Deformation patterns of the Carboniferous, illustrated by the example of the Harpstedt district in Northern Germany; Deformationsstile des Karbon am Beispiel des Gebietes Harpstedt, Norddeutschland

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, H. von [Niedersaechsisches Landesamt fuer Bodenforschung, Hannover (Germany)

    1999-07-01

    The Carboniferous basin of North West Germany is part of the piedmont basin north of the Variscides stretching from Ireland and England to France, Germany, and Poland. In the West German part of the piedmont basin, the Prepermian Jurassic and Cretacious took part in the development of the Lower Saxon basin and tectogenic. This results in a highly complex seismic deformation picture. For example, in the Harz mountains, deformations of the former piedmont basin are developed in the Culm facies, but the further direction of deformation remains unclear. Hydrocabon explorations in the North West German basin also developed the Prepermian underground strata. 3D seismic exploration provided a three-dimensional image of the region. A 3D seismic measurement made aAt the southern edge of Pompeckj's block was evaluated in order to obtain information on the deformation pattern and its interdependence with a Variscan piedmont basin deformation. [German] Das Nordwestdeutsche Karbonbecken ist Teil des noerdlich des variszischen Orogens vorgelagerten Vorlandbeckens. Dieses Becken erstreckt sich von Irland und England ueber Frankreich, Deutschland bis nach Polen. Im westdeutschen Teil des Vorlandbeckens wird das praepermische Stockwerk im Jura und in der Kreide in die Entwicklung des Niedersaechsischen Beckens und des Niedersaechsischen Tektogens einbezogen. Hierdurch werden aeltere Deformationen ueberpraegt und die seismische Abbildung so komplex, dass kaum noch Aussagen ueber einen frueheren Deformationszustand gemacht werden koennen. Im Harz ist die Deformationen des ehemaligen Vortiefenbeckens z.B. in der Kulmfazies aufgeschlossen. Der weitere Verlauf der Deformation in Richtung Vorland ist jedoch unklar. Durch die Kohlenwasserstoffexploration im Nordwestdeutschen Becken wurde auch der praepermische Untergrund erschlossen. Die 3D-Seismik ermoeglicht es, sich ein dreidimensionales Bild dieses Gebietes zu verschaffen. Am suedlichen Rand der Pompeckjschen Scholle wurde eine

  9. Coal and oil shale of Early Carboniferous age in northern Canada - significance for paleoenvironmental and paleoclimatic interpretations. [Canada - Northwest Territories and Yukon Territory

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, A.R.; Goodarzi, F.; Potter, J. (Geological Survey of Canada, Calgary, AB (Canada))

    1994-01-01

    Lower Carboniferous (Mississippian) coal beds and oil shale occur at several locations in northern Canada. In the northern Yukon Territory coal of semi-anthracite/anthracite rank occurs in the Kayak Formation in the British Mountains and at Hoidahl Dome near the headwaters of Blow River. Farther south in the Liard Basin, Northwest Territories, coals of high volatile bituminous rank occur in the Mattson Formation. In the Arctic Islands thicker beds of the Emma Fiord Formation, the oldest unit in the Sverdrup Basin, contain thin coal seams and oil shale on Devon Island, near the southern edge of the basin and on Axel Heiberg and Ellesmere islands on the north side of the basin. Organic matter in the Devon Island section is at a low maturity level (R[sub o, max] % 0.26-0.50), whereas that from Ellesmere and Axel Heiberg has reached the level of meta-anthracite. Depositional environments for these carbonaceous sediments were different. The coal-bearing Kayak strata accumulated in a coastal plain setting overlain transgressively by younger marine beds. The Mattson coal beds appear to have formed in a prograding delta, but coal and oil shale in the Emma Ford were deposited in lacustrine environments in a rift basin. These Canadian occurrences resemble penecontemporaneous deposits in Svalbard and elsewhere, adjacent to the present-day Arctic Ocean. They formed at low latitudes where conditions were favourable for the preservation of carbonaceous matter. Prior to the opening of the Arctic Ocean basin in Mesozoic times, sites on the mainland were undoubtedly closer to sites in the Arctic Islands than they are today.

  10. 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.

  11. 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

  12. Inverse periodic shadowing properties

    CERN Document Server

    Osipov, Alexey V

    2011-01-01

    We consider inverse periodic shadowing properties of discrete dynamical systems generated by diffeomorphisms of closed smooth manifolds. We show that the $C^1$-interior of the set of all diffeomorphisms having so-called inverse periodic shadowing property coincides with the set of $\\Omega$-stable diffeomorphisms. The equivalence of Lipschitz inverse periodic shadowing property and hyperbolicity of the closure of all periodic points is proved. Besides, we prove that the set of all diffeomorphisms that have Lipschitz inverse periodic shadowing property and whose periodic points are dense in the nonwandering set coincides with the set of Axiom A diffeomorphisms.

  13. ON PERIODIC DYNAMICAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    LU WENLIAN; CHEN TIANPING

    2004-01-01

    The authors investigate the existence and the global stability of periodic solution for dynamical systems with periodic interconnections, inputs and self-inhibitions. The model is very general, the conditions are quite weak and the results obtained are universal.

  14. 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…

  15. Community College Periodicals.

    Science.gov (United States)

    Pederson, Eldor O.

    Drawing from an examination of community college periodicals, their availability and characteristics, the academic affiliations of contributing authors, and the topics of their articles, this paper discusses the minor role which community college periodicals appear to play. A list of 35 periodicals dealing primary with community college education…

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

    Institute of Scientific and Technical Information of China (English)

    赵省民; 陈登超; 邓坚; 李锦平

    2011-01-01

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

  17. 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

  18. Rare Carboniferous and Permian glacial and non-glacial bryophytes and associated lycophyte megaspores of the Paraná Basin, Brazil: A new occurrence and paleoenvironmental considerations

    Science.gov (United States)

    Ricardi-Branco, Fresia; Rohn, Rosemarie; Longhim, Marcia Emilia; Costa, Juliana Sampaio; Martine, Ariel Milani; Christiano-de-Souza, Isabel Cortez

    2016-12-01

    Fossil bryophytes are rare because their preservation is compromised by the presence of a thin cuticle (if any) and a lack of lignin. Except for the occurrence of one bryophyte in the glacial Dwyka Group of the Karoo Basin, the other rare Late Paleozoic records in Gondwana are notably from the Paraná Basin in Southeast/South Brazil. Four bryophyte sites (including a newly discovered one) were found in the lower part of the thick Permo-Carboniferous glacial succession of the Itararé Group, and one was found in the Guadalupian Teresina Formation, which was roughly assigned to an epeiric sea (or "lake") dominated by a warm, semi-arid climate. This study describes the fossils from the new occurrence from the Itararé Group and discusses the context in which the bryophyte beds originated in the basin. The new samples confirm that all of the bryophytes of the Itararé Group can be classified as Dwykea araroii Ricardi-Branco et al. (a possible pleurocarp) and are associated with the lycophyte megaspore Sublagenicula brasiliensis (Dijkstra) Dybová-Jachowicz. In the much younger Teresina Formation, the bryophytes are Yguajemanus yucapirus Cristiano-de-Souza et al. and Capimirinus riopretensis Cristiano-de-Souza et al., and abundant charophytes and rare dwarf lycophyte stems and bracts are present in the same layers. Although the two stratigraphic units represent distinct paleoenvironments and climates, they seem to share some characteristics: a) the bryophyte assemblages were transported very little; b) they were deposited in very calm environments; c) they were the main components (along with some lycophytes) of local or poorly diversified regional vegetation. The low number of species, which is characteristic of opportunistic communities, can be explained by local or regional conditions that would have been stressful for the vascular plants in other areas. During the deposition of the Itararé Group, the main control was probably the cold climate in addition to a

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

    Science.gov (United States)

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

    2012-01-01

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

  20. 安徽宿松上石炭统碳酸盐岩台地沉积物定量分析与海平面变化%Quantitative analysis of carbonate platform sediments and sea-level changes of the Upper Carboniferous in Susong area,Anhui Province

    Institute of Scientific and Technical Information of China (English)

    芦艳琳; 李双应; 赵大千; 王冰; 稽在飞

    2014-01-01

    The Upper Carboniferous carbonate rocks,with 1 00meters thickness and abundant fos-sils,were well developed in Susong area of Anhui Province.These rocks belonged to the typical shallow carbonate platform deposits.The grains quantitative analysis showed that the lithofacies mainly included grainstones and packstones with the content of 81.2% and 69.6% respectively;and shallow marine bio-clasts predominated.Moreover, there were wackstones and lime mudstones with the grains content of 26.4%and 4.1%respectively.The open-marine platform facies and tidal flat facies were mainly developed in study area, which could be divided into five types of subfacies including intra-platform shoal, intra-platform basin,intra-platform flat and inter-tidal flat and supra-tidal flat.Combining the above characteris-tics,three long-term transgressive-regressive cycles could be recognized from the Upper Carboniferous. The sea-level changes were characterized by the high frequency short-term sea-level fluctuations superimpo-sing on a long-term sea-level fall.These three cycles were roughly corresponding to the long-term trans-gressive-regressive cycles in other areas of Yangtze Plate and the same-time strata in Euramerican Plate.It also indicated that the sea-level changes were influenced by alternation of the glacial period and non-glacial period in Gondwana.%安徽宿松地区上石炭统碳酸盐岩发育,厚约100m,化石丰富,属于比较典型的浅海碳酸盐岩台地沉积。定量分析显示,研究区岩石类型主要为颗粒灰岩和泥粒灰岩,颗粒平均含量分别为81.2%和69.6%,以浅海生物碎屑为主;其次为粒泥灰岩和泥晶灰岩,颗粒平均含量分别为26.4%和4.1%。依据岩石学特征,研究区主要发育开阔台地相和潮坪相,并可进一步划分出5种沉积亚相,分别是台内滩、台内盆、台内坪、潮间坪和潮上坪。在研究区上石炭统中共识别出3个长期的海进-海退旋回

  1. Bott periodicity of inclusions

    CERN Document Server

    Mare, Augustin-Liviu

    2011-01-01

    When looking at Bott's original proof of his periodicity theorem for the stable homotopy groups of the orthogonal and unitary groups, one sees in the background a differential geometric periodicity phenomenon. We show that this geometric phenomenon extends to the standard inclusion of the orthogonal group into the unitary group. This explains the periodicity of the group homomorphisms between stable homotopy groups which are induced by the inclusion map. Standard inclusions between other classical Riemannian symmetric spaces are also discussed.

  2. 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.

  3. Painful menstrual periods

    Science.gov (United States)

    Menstruation - painful; Dysmenorrhea; Periods - painful; Cramps - menstrual; Menstrual cramps ... related activities for a few days during each menstrual cycle. Painful menstruation is the leading cause of ...

  4. Second Period Access Report

    DEFF Research Database (Denmark)

    Maisondieu, Christophe; Giebhardt, Jochen; Tetu, Amelie

    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....

  5. 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…

  6. On some periodicity effects

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2015-01-01

    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 o...

  7. Latent Period of Relaxation.

    Science.gov (United States)

    Kobayashi, M; Irisawa, H

    1961-10-27

    The latent period of relaxation of molluscan myocardium due to anodal current is much longer than that of contraction. Although the rate and the grade of relaxation are intimately related to both the stimulus condition and the muscle tension, the latent period of relaxation remains constant, except when the temperature of the bathing fluid is changed.

  8. Periods and Nori motives

    CERN Document Server

    Huber, Annette

    2017-01-01

    This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...

  9. 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

  10. Mean-periodic functions

    Directory of Open Access Journals (Sweden)

    Carlos A. Berenstein

    1980-01-01

    Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.

  11. 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,

  12. New advances in the study of Carboniferous-Permian paleontology in Guoganjianianshan-Rongma area of Qiangtang region, Tibetan Plateau%青藏高原羌塘地区果干加年山-荣玛乡一带石炭纪-二叠纪古生物研究新进展

    Institute of Scientific and Technical Information of China (English)

    耿全如; 彭智敏; 张璋

    2012-01-01

    of Gondwana and Tethys biota in Carboniferous and Permian period, and there exists no obvious boundary of the biological region. It is thus inferred that the ocean basin represented by the Longmucuo-Shuanghu ophiolitic zone was a small marginal basin in southern Tethyan archipelago.

  13. 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

  14. Optimal periodic control

    CERN Document Server

    Colonius, Fritz

    1988-01-01

    This research monograph deals with optimal periodic control problems for systems governed by ordinary and functional differential equations of retarded type. Particular attention is given to the problem of local properness, i.e. whether system performance can be improved by introducing periodic motions. Using either Ekeland's Variational Principle or optimization theory in Banach spaces, necessary optimality conditions are proved. In particular, complete proofs of second-order conditions are included and the result is used for various versions of the optimal periodic control problem. Furthermore a scenario for local properness (related to Hopf bifurcation) is drawn up, giving hints as to where to look for optimal periodic solutions. The book provides mathematically rigorous proofs for results which are potentially of importance in chemical engineering and aerospace engineering.

  15. Extremal periodic wave profiles

    Directory of Open Access Journals (Sweden)

    E. van Groesen

    2007-01-01

    Full Text Available As a contribution to deterministic investigations into extreme fluid surface waves, in this paper wave profiles of prescribed period that have maximal crest height will be investigated. As constraints the values of the momentum and energy integrals are used in a simplified description with the KdV model. The result is that at the boundary of the feasible region in the momentum-energy plane, the only possible profiles are the well known cnoidal wave profiles. Inside the feasible region the extremal profiles of maximal crest height are "cornered" cnoidal profiles: cnoidal profiles of larger period, cut-off and periodically continued with the prescribed period so that at the maximal crest height a corner results.

  16. On semi-periods

    CERN Document Server

    Avram, A C; Jancic, D; Uni, H; Uni, Humboldt

    1995-01-01

    The periods of the three-form on a Calabi-Yau manifold are found as solutions of the Picard-Fuchs equations; however, the toric varietal method leads to a generalized hypergeometric system of equations which has more solutions than just the periods. This same extended set of equations can be derived from symmetry considerations. Semi-periods are solutions of this extended system. They are obtained by integration of the three-form over chains; these chains can be used to construct cycles which, when integrated over, give periods. In simple examples we are able to obtain the complete set of solutions for the extended system. We also conjecture that a certain modification of the method will generate the full space of solutions in general.

  17. Familial Periodic Paralyses

    Science.gov (United States)

    ... and less severe than the hypokalemic form. Muscle spasms are common. × Definition Familial periodic paralyses are a ... and less severe than the hypokalemic form. Muscle spasms are common. View Full Definition Treatment Treatment of ...

  18. 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)

  19. 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)

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

    Institute of Scientific and Technical Information of China (English)

    蒋宜勤; 高岗; 柳广弟; 王绪龙; 裴立新; 向宝力; 唐勇

    2012-01-01

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

  1. 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

  2. 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.

  3. Efficient Exploration and Development of Carboniferous Volcanic Gas Field in Kelameili Area in Junggar Basin%克拉美丽石炭系火山岩气田的高效勘探开发

    Institute of Scientific and Technical Information of China (English)

    董雪梅; 徐怀民; 贺陆明; 任军民; 吴静

    2012-01-01

    Volcanic oil-gas exploration in Junggar basin started in 1950's.In recent years,through comprehensive researches of hydrocarbon accumulation conditions of the Carboniferous volcanic reservoirs,Ludong-Wucaiwan area is chosen as major exploration target to carry out systematic studies and make technological breakthrough,thus deepening the knowledge of volcanic reservoir,establishing the exploration thought of reservoir controls dominated by volcanic rock body,based on which the matched technologies were developed,and the breakthroughs have been made in drilling of volcanic rock body as main target in Dinan bulge.A hundred billion cubic meters of Kelameili gas field with both source and reservoir in Carboniferous system was proved in two years and the first large-scale integrated volcanic gas field in Junggar basin is discovered.Up to now,it has been brought into the scale and efficient production.The Carboniferous volcanic reservoirs have become an important domain for oil-gas exploration in Junggar basin.%准噶尔盆地火山岩油气勘探始于20世纪50年代,近年来通过准噶尔盆地石炭系油气成藏条件综合研究,优选陆东—五彩湾地区作为勘探主战场,展开针对石炭系火山岩的系统研究和技术攻关,不断深化成藏认识,确立了以火山岩岩体控藏的勘探思路,研发了与之相应的配套技术,在滴南凸起上以火山岩岩体为主要目标展开钻探获得突破,探明了千亿方的石炭系自生自储的克拉美丽气田,形成准噶尔盆地第一个大型整装火山岩气田,并已实现规模高效开发。石炭系火山岩已经成为准噶尔盆地油气勘探的重要领域。

  4. 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...... over time and theoretical implications are discussed, notably by introducing a new approach to autobiographical memory, Transition Theory, which assumes that autobiographical memory is organized by transitional events that can be selfinitiated or externally imposed - historically defined...

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

    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. Thyrotoxic periodic paralysis

    Directory of Open Access Journals (Sweden)

    Rojith Karandode Balakrishnan

    2011-01-01

    Full Text Available This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.

  7. Periodic Ising Correlations

    CERN Document Server

    Hystad, Grethe

    2010-01-01

    In this paper, we first rework B. Kaufman's 1949 paper, "Crystal Statistics. II. Partition Function Evaluated by Spinor Analysis", by using representation theory. Our approach leads to a simpler and more direct way of deriving the spectrum of the transfer matrix for the finite periodic Ising model. We then determine formulas for the spin correlation functions that depend on the matrix elements of the induced rotation associated with the spin operator in a basis of eigenvectors for the transfer matrix. The representation of the spin matrix elements is obtained by considering the spin operator as an intertwining map. We exhibit the "new" elements V+ and V- in the Bugrij-Lisovyy formula as part of a holomorphic factorization of the periodic and anti-periodic summability kernels on the spectral curve associated with the induced rotation for the transfer matrix.

  8. 天山石炭纪火山岩系中含有富Nb岛弧玄武岩吗?%Do the Tianshan Carboniferous volcanic successions contain Nb-enriched arc basalts?

    Institute of Scientific and Technical Information of China (English)

    夏林圻; 夏祖春; 徐学义; 李向民; 马中平

    2009-01-01

    中国西北部天山石炭纪-早二叠世裂谷火山作用代表了一个新近被认可的大火成岩省.有人认为,在天山石炭纪火山岩系中发育有富Nb岛弧玄武岩、埃达克岩和高镁安山岩组合.然而,该岩石组合具有与典型富Nb岛弧玄武岩、埃达克岩和高镁安山岩不同的化学和同位素特点,表明其并非是岛弧岩石组合.这一推断的岛弧岩石组合实际上是大陆板内火山岩组合,由未遭受地壳混染、受到地壳轻微混染和遭受地壳强烈混染的大陆火山岩组成.%The Tianshan Carboniferous-Early Permian rift-related volcanism in northwestern China represents a newly recognized large igneous province. It has been deemed that an assemblage of Nb-enriched arc basalt, adakite and high-Mg andesite occurred in the Tianshan Carboniferous volcanic successions. Divergent chemical and isotopic characteristics between this rock assemblage and the typical Nb-enriched arc basalts, adakites and high-Mg andesites reveal that the former is not arc related. This postulated arc-related assemblage is indeed an intracontinental volcanic assemblage that consists of crustally uncontaminated, less-contaminated and strongly contaminated continental volcanic rocks.

  9. 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 (plate. In contrast, the Early Permian mafic magmatism exhibits typical within-plate basalt affinities, such as high TiO2 (2.7-3.2 wt.%) contents, elevated Ti/V (86.0-115.1) and Zr/Y (4.9-9.3) ratios, OIB-like trace element patterns and high εNd(t) (+ 1.1 to + 4.5) and zircon εHf(t) (+ 3.0 to + 9.8) values. In association with previous investigations, we suggest that their protoliths were most probably derived from the partial melting of an asthenospheric mantle source in the garnet stability field, plausibly induced by asthenosphere upwelling during the slab break-off of the Junggar oceanic plate, which agrees well with the linear distributions of Permian mafic-ultramafic rocks in the Eastern Tianshan. Collectively, our data pinpoint a tectonic transition from oceanic subduction to post-collisional extension during Late Carboniferous to Early Permian time, probably triggered by the closure of the Junggar Ocean and subsequent arc-continent collision between the Central Tianshan and Junggar terranes that gave rise to the final assembly of the Eastern Tianshan.

  10. Petrogenesis of Late Carboniferous to Early Permian Granitoid Plutons in the Chinese South Tianshan: Implications for Crustal Accretion%中国南天山晚石炭世一早二叠世花岗质侵入岩的岩石成因与地壳增生

    Institute of Scientific and Technical Information of China (English)

    黄河; 张招崇; 张东阳; 杜红星; 马乐天; 康建丽; 薛春纪

    2011-01-01

    regions and temperature and pressure conditions under which magma evolves, which reflect the development process of tectonic environment during that period. In this paper, seven granitoid plutons in the Chinese South Tianshan orogenic belt, including Tielieke pluton, Mangqisu pluton, Yingmailai pluton, Chuanwulu pluton, Baleigong pluton, Huoshibulake pluton and Mazhashan pluton, were chosen for geochronological, petrological, and geochemical investigations. The Tielieke and Mangqisu plutons are Late Carboniferous I-type granites and the magmas formed due to partial melting of the metaigneous rocks in the lower crust under the condition of the syn-collisional tectonics. The Early Permian S-type granite is represented by the Yingmailai pluton, which was the result of remelting of Mesoproterozoic metasedimentary rocks induced by the radiogenic heating. Felsic rocks in the Chuanwulu pluton are Early Permian I-type granites, representing the hybrid magmas derived from the lower part of the thickened continental crust. The mafic rocks in the Chuanwulu pluton represent underplating mantle-derived magma resulted from partial melting of enrichment metasomatized lithospheric mantle. The Yingmailai and Chuanwulu plutons formed in a transition stage of tectonic regimes from syn-collisional compression to post-collisional extension. A-type granites forming at - 275 Ma represents a high temperature granitic magma, which resulted from the interaction between asthenosphere and lower crust under a condition of low pressures. The Baleigong pluton is A2-type granite representing the epilogue of the post-collisional setting. The Huoshibulake and Mazhashan plutons, however, are Al-type granite indicative of intra-plate rifting regime.

  11. Periodically poled silicon

    Science.gov (United States)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

    2010-02-01

    Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

  12. Oscillations following periodic reinforcement.

    Science.gov (United States)

    Monteiro, Tiago; Machado, Armando

    2009-06-01

    Three experiments examined behavior in extinction following periodic reinforcement. During the first phase of Experiment 1, four groups of pigeons were exposed to fixed interval (FI 16s or FI 48s) or variable interval (VI 16s or VI 48s) reinforcement schedules. Next, during the second phase, each session started with reinforcement trials and ended with an extinction segment. Experiment 2 was similar except that the extinction segment was considerably longer. Experiment 3 replaced the FI schedules with a peak procedure, with FI trials interspersed with non-food peak interval (PI) trials that were four times longer. One group of pigeons was exposed to FI 20s PI 80s trials, and another to FI 40s PI 160s trials. Results showed that, during the extinction segment, most pigeons trained with FI schedules, but not with VI schedules, displayed pause-peck oscillations with a period close to, but slightly greater than the FI parameter. These oscillations did not start immediately after the onset of extinction. Comparing the oscillations from Experiments 1 and 2 suggested that the alternation of reconditioning and re-extinction increases the reliability and earlier onset of the oscillations. In Experiment 3 the pigeons exhibited well-defined pause-peck cycles since the onset of extinction. These cycles had periods close to twice the value of the FI and lasted for long intervals of time. We discuss some hypotheses concerning the processes underlying behavioral oscillations following periodic reinforcement.

  13. 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)

  14. 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…

  15. 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

  16. Chaotic period doubling

    NARCIS (Netherlands)

    Chandramouli, V. V. M. S.; Martens, M.; De Melo, W.; Tresser, C. P.

    2009-01-01

    The period doubling renormalization operator was introduced by Feigenbaum and by Coullet and Tresser in the 1970s to study the asymptotic small-scale geometry of the attractor of one-dimensional systems that are at the transition from simple to chaotic dynamics. This geometry turns out not to depend

  17. Thyrotoxic periodic paralysis

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro, J.E.; Arguelles, D.J.; Rams, H. Jr.

    1986-01-01

    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.

  18. The postanesthetic period. Complications.

    Science.gov (United States)

    Malamed, S F

    1987-01-01

    Postanesthetic complications can occur even in the best of circumstances. Proper preparation of the staff, aggressive monitoring of the recovering patient, and early recognition and management of the complications are essential if the outcome is to be successful. In reviewing postanesthetic complications, two factors are present in the overwhelming majority of situations--hypoxia and hypercarbia--often the direct result of inadequate monitoring during the postanesthetic period. The anesthetic procedure is not over once the anesthetic agents are discontinued. The skillful anesthetist is aware of the possibilities of postoperative complications and prevents problems by employing enhanced monitoring techniques during the recovery phase.

  19. Periods of Hecke characters

    CERN Document Server

    Schappacher, Norbert

    1988-01-01

    The starting point of this Lecture Notes volume is Deligne's theorem about absolute Hodge cycles on abelian varieties. Its applications to the theory of motives with complex multiplication are systematically reviewed. In particular, algebraic relations between values of the gamma function, the so-called formula of Chowla and Selberg and its generalization and Shimura's monomial relations among periods of CM abelian varieties are all presented in a unified way, namely as the analytic reflections of arithmetic identities beetween Hecke characters, with gamma values corresponding to Jacobi sums. The last chapter contains a special case in which Deligne's theorem does not apply.

  20. Periodic truss structures

    Science.gov (United States)

    Zok, Frank W.; Latture, Ryan M.; Begley, Matthew R.

    2016-11-01

    Despite the recognition of the enormous potential of periodic trusses for use in a broad range of technologies, there are no widely-accepted descriptors of their structure. The terminology has been based loosely either on geometry of polyhedra or of point lattices: neither of which, on its own, has an appropriate structure to fully define periodic trusses. The present article lays out a system for classification of truss structure types. The system employs concepts from crystallography and geometry to describe nodal locations and connectivity of struts. Through a series of illustrative examples of progressively increasing complexity, a rational taxonomy of truss structure is developed. Its conceptual evolution begins with elementary cubic trusses, increasing in complexity with non-cubic and compound trusses as well as supertrusses, and, finally, with complex trusses. The conventions and terminology adopted to define truss structure yield concise yet unambiguous descriptions of structure types and of specific (finite) trusses. The utility of the taxonomy is demonstrated by bringing into alignment a disparate set of ad hoc and incomplete truss designations previously employed in a broad range of science and engineering fields. Additionally, the merits of a particular compound truss (comprising two interpenetrating elementary trusses) is shown to be superior to the octet truss for applications requiring high stiffness and elastic isotropy. By systematically stepping through and analyzing the finite number of structure types identified through the present classification system, optimal structures for prescribed mechanical and functional requirements are expected to be ascertained in an expeditious manner.

  1. 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

  2. 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...

  3. 阿尔泰南缘晚石炭世淡色花岗岩的发现及其构造意义%Discovery of the Late Carboniferous Leucogranite in the Southern Altay Range and its Tectonic Implications

    Institute of Scientific and Technical Information of China (English)

    沈晓明; 张海祥; 马林

    2013-01-01

    在阿尔泰南缘的多摩拉克布拉克地区,新发现含石榴子石和白云母的淡色花岗岩侵入于早石炭世南明水组火山沉积地层中。LA-ICP-MS锆石U-Pb测年结果表明,淡色花岗岩形成于311±3 Ma的晚石炭世早期。该淡色花岗岩的发现及其年龄的确定,结合区域岩浆岩、变质岩和沉积学等资料分析,表明阿尔泰造山带南缘在~311 Ma前完成碰撞过程,并从此进入后碰撞时代。该发现为进一步研究阿尔泰造山带晚古生代构造演化提供了新的证据。%The time frame for the collision between Siberia Plate and Kazakhstan-Junggar Plate and the initiation of post-collision of the Southern Altay Range in the Late Paleozoic remain controversial. Paleozoic granitoid magmatism played an important role in the tectonic evolution of the Southern Altay Range and various origins of granitoids have been found in this region, including I-, S-, A-and M-type granitoids. Here, we report the newly discovered Duomolakebulake garnet-and muscovite-bearing leucogranite which intruded the Early Carboniferous Nanmingshui volcanic-sedimentary formation in the southern Altay Range. LA-ICP-MS zircon U-Pb dating indicates that the leucogranite was generated in the early Late Carboniferous (311±3 Ma). As an important rock type for tectonic implications, leucogranite is considered to be generated in a post-collision setting. In combination with lithology data in this region, we suggest that the collision ended prior to~311 Ma in the southern Altay Range, and then evolved into the post-collisional stage. This new discovery may shed lights on the tectonic evolution of the Altay Range in the Late Paleozoic.

  4. Depositional environments and cyclo- and chronostratigraphy of uppermost Carboniferous-Lower Triassic -lacustrine deposits, southern Bogda Mountains, NW China - A terrestrfluvialial paleoclimatic record of mid-latitude NE Pangea

    Science.gov (United States)

    Yang, W.; Feng, Q.; Liu, Yajing; Tabor, N.; Miggins, D.; Crowley, J.L.; Lin, J.; Thomas, S.

    2010-01-01

    Two uppermost Carboniferous-Lower Triassic fluvial-lacustrine sections in the Tarlong-Taodonggou half-graben, southern Bogda Mountains, NW China, comprise a 1834. m-thick, relatively complete sedimentary and paleoclimatic record of the east coast of mid-latitude NE Pangea. Depositional environmental interpretations identified three orders (high, intermediate, and low) of sedimentary cycles. High-order cycles (HCs) have five basic types, including fluvial cycles recording repetitive changes of erosion and deposition and lacustrine cycles recording repetitive environmental changes associated with lake expansion and contraction. HCs are grouped into intermediate-order cycles (ICs) on the basis of systematic changes of thickness, type, and component lithofacies of HCs. Nine low-order cycles (LCs) are demarcated by graben-wide surfaces across which significant long-term environmental changes occurred. A preliminary cyclostratigraphic framework provides a foundation for future studies of terrestrial climate, tectonics, and paleontology in mid-latitude NE Pangea.Climate variabilities at the intra-HC, HC, IC, and LC scales were interpreted from sedimentary and paleosol evidence. Four prominent climatic shifts are present: 1) from the humid-subhumid to highly-variable subhumid-semiarid conditions at the beginning of Sakamarian; 2) from highly-variable subhumid-semiarid to humid-subhumid conditions across the Artinskian-Capitanian unconformity; 3) from humid-subhumid to highly-variable subhumid-semiarid conditions at early Induan; and 4) from the highly-variable subhumid-semiarid to humid-subhumid conditions across the Olenekian-Anisian unconformity. The stable humid-subhumid condition from Lopingian to early Induan implies that paleoclimate change may not have been the cause of the end-Permian terrestrial mass extinction. A close documentation of the pace and timing of the extinction and exploration of other causes are needed. In addition, the semiarid-subhumid conditions

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

    Institute of Scientific and Technical Information of China (English)

    杨大勇; 巩恩普; 孙宝亮; 陈晓红; 关长庆; 张永利

    2013-01-01

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

  6. Geochronology and geochemistry of late Carboniferous-middle Permian I- and A-type granites and gabbro-diorites in the eastern Jiamusi Massif, NE China: Implications for petrogenesis and tectonic setting

    Science.gov (United States)

    Bi, Jun-Hui; Ge, Wen-Chun; Yang, Hao; Wang, Zhi-Hui; Xu, Wen-Liang; Yang, Jin-Hui; Xing, De-He; Chen, Hui-Jun

    2016-12-01

    Late Carboniferous-middle Permian magmatism in the Jiamusi Massif of northeast China, in the eastern segment of the Central Asian Orogenic Belt (CAOB), provides critical evidence regarding the tectonic history and geodynamic processes in the region. The gabbro-diorites of the Longtouqiao pluton and two groups of coeval granite in the study area comprise a bimodal magmatic suite. 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). Group I granites have high SiO2 (70.75-77.04 wt.%) and K2O (3.65-5.89 wt.%) contents, are enriched in LILEs (e.g., Rb, Th, and U) relative to HFSEs and LREEs, and have negative Nb, Ta, P, and Ti anomalies, which collectively indicate affinities with subduction-related magmas. Group II granites are weakly peraluminous (A/CNK = 1.03-1.07) and are characterized by enrichment in alkalis (Na2O + K2O = 8.22-8.90 wt.%), low MgO (0.04-0.09 wt.%) and P2O5 (0.01-0.04 wt.%) contents, high Zr and Nb contents, high 10,000 × Ga/Al ratios, and they are geochemically similar to aluminous A-type granites. All the magmatic zircons in these granitoids have great variations of εHf(t) (+ 7.89 to - 5.60) and two-stage Hf model ages (TDM2) of 0.8-1.7 Ga, which suggest that the precursor magmas originated from a heterogeneous source that involved juvenile components derived from a depleted mantle source during magma generation. The aluminous A-type granite magmas were probably derived by high-temperature partial melting of a felsic crustal source, whereas the other granite magmas probably resulted from partial melting of a mafic lower crust. 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 large positive anomalies in Ba, K, and Pb. These features reflect a limited degree of crustal contamination associated with the subduction-related magmatic processes. These data

  7. DISCOVERY OF PETROMICTIC CONGLOMERATE BETWEEN EARLY AND IRATE CARBONIFEROUS STRATA IN THE TONGLING AREA, ANHUI PROVINCE%安徽铜陵地区早、晚石炭世地层之间砾岩的发现

    Institute of Scientific and Technical Information of China (English)

    杜森官; 杜建国; 许卫; 孙乘云; 吴礼彬

    2012-01-01

    The quartzose conglomerate and lithic conglomerate occur between Early and I.ate Carboniferous strata at muhiple sections in the Tongling, Nanling. and Jingxian regions, indicating a sea level drop, erosion, and weathering in these regions that led to stratigraphic incompleteness in the Early Carboniferous. The lithostratigraphic difference between quartzose conglomerate and lithic conglomerate allows a differen- tiation between the upper and lower Zhexi Formation. Quartzose conglomerate of the lower Zhexi Forma lion can be incomplete at some sections because of erosion during later fluvial fan development. Stratigraphic thickness and clast size varies in both vertical and horizontal directions, and this variation was controlled by paleogeographic, paleoclimatic and tectonic factors.%通过一系列地层剖面的测制,在铜陵、南陵、泾县地区早、晚石炭世地层之间发现了沉积石英质砾岩和岩屑砾岩,肯定了本区在早、晚石炭世之间曾经历一次海平面下降和风化剥蚀作用,致使早石炭世地层在许多地方残缺不全,由于石英质砾岩与岩屑砾岩在岩性、沉积特征、成因等方面有明显的不同,分别称为浙溪组下段和浙溪组上段。早期的石英质砾岩由于受到后期的冲积扇沉积环境的影响,在一些剖面上表现为缺失。岩屑砾岩的沉积厚度、砾石大小等在纵、横向上变化较大,明显受古地理、古气候、古构造的控制。

  8. [Childhood periodic syndromes].

    Science.gov (United States)

    Cuvellier, J-C; Lépine, A

    2010-01-01

    This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis

  9. Near periodicity in dynamical systems

    Institute of Scientific and Technical Information of China (English)

    陈文成

    1995-01-01

    The notion of near periodicity is shown to be equivalent to that of weak near periodicity in dynamical systems. A sufficient condition for the positive near periodicity of a point in dynamical systems is given. The structure of nearly periodic dynamical systems is discussed, and a condition is proved to be necessary and sufficient for a dynamical system on a local compact space to be positively nearly periodic.

  10. THE WAVELET TRANSFORM OF PERIODIC FUNCTION AND NONSTATIONARY PERIODIC FUNCTION

    Institute of Scientific and Technical Information of China (English)

    刘海峰; 周炜星; 王辅臣; 龚欣; 于遵宏

    2002-01-01

    Some properties of the wavelet transform of trigonometric function, periodic function and nonstationary periodic function have been investigated. The results show that the peak height and width in wavelet energy spectrum of a periodic function are in proportion to its period. At the same time, a new equation, which can truly reconstruct a trigonometric function with only one scale wavelet coefficient, is presented. The reconstructed wave shape of a periodic function with the equation is better than any term of its Fourier series. And the reconstructed wave shape of a class of nonstationary periodic function with this equation agrees well with the function.

  11. Carboniferous 'green shales' of the Solimoes Basin: volcanic ashes (K-bentonites); 'Folhelhos verdes' carboniferos da Bacia do Solimoes: cinzas vulcanicas (K-bentonitas)

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Daisy Barbosa [PETROBRAS S.A., Rio de de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Sedimentologia e Petrologia], E-mail: daisy@petrobras.com.br; Vaz, Pekim Tenorio

    2005-11-15

    Several K-bentonite beds have been found intercalated with sedimentary rocks of the Jurua Formation (Namurian) in the Solimoes Basin, northern part of Brazil. These beds are only 1 to 15 cm-thick, but are spread over a wide area, comprising Rio Urucu, East of Urucu and Jurua oil and gas fields. They exhibit sharp contacts with the adjacent layers (carbonates, shales or even sandstones) and can be easily identified by their typical apple green color, homogeneous texture and smooth silky touch. These K-bentonites are composed almost exclusively of either a type of ordered illite-smectite mixed-layer or of discrete illite (1M polytype) - both clay minerals formed from the alteration of Carboniferous volcanic ashes. Unknown previously, such beds point out to an additional clastic source to the basin at this time. Due to their specific origin, they can therefore become stratigraphic markers; which can be useful for local and regional correlations along of the Solimoes Basin. (author)

  12. 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 aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH

  13. 天山南缘石炭系-三叠系碎屑岩成分及其对物源区大地构造属性的指示%Compositions of Carboniferous-Triassic clastic rocks in the southern margin of the Tianshan, Northwest China: Implications for the evolution of the provenance tectonic attributes

    Institute of Scientific and Technical Information of China (English)

    王松; 李双应; 杨栋栋; 何刚; 赵大千

    2012-01-01

    Our research focuses on the composition and provenance tectonic evolution of the Carboniferous-Triassic clastic rocks in the southern margin of the Tianshan. Analysis of petrology and geochemistry of detrital rocks shows that the Carboniferous and Triassic sandstones have a low compositional, textural maturity and high matrix content. The unstable component of sandstones increases from the Carboniferous to the Triassic. The Carboniferous and Permian have a similar characteristic of REE abundances, which is obviously higher than that in the Triassic. The fractionation degree of light and heavy rare earth elements and the ratios of La/Th and La/Y descend from the Carboniferous to the Triassic and the Th/U ratio increases, which implicate the increase of recycled sediments. According to the distinction of detrital composition, major elements, rare earth elements and trace elements, the provenance tectonic settings of the Carboniferous were continental island arcs, active continental margin and passive continental margin, and the Permian's was continental island arcs and the provenance of the Triassic was more similar to continental island arcs and ancient sedimentary geological bodies. The carboniferous has a more complex provenance compared with Permian and Triassic provenances, which may be related to the collision between the Central Tianshan-Yili block and the Tarim block.%本文通过对天山南缘石炭系-三叠系碎屑岩岩石学特征和地球化学特征的分析,揭示了研究区石炭系-三叠系碎屑岩的物质组分特征及其物源区的大地构造背景.碎屑岩的岩石学、地球化学分析表明,天山南缘石炭系、三叠系砂岩成分成熟度和结构成熟度均不高,杂基含量较高,从石炭系至三叠系砂岩不稳定组分依次增加.石炭系、二叠系具有相似的稀土元素含量特征,三叠系稀土元素含量明显低于石炭系和二叠系,石炭系-三叠系轻、重稀土元素分馏

  14. Periodic feedback stabilization for linear periodic evolution equations

    CERN Document Server

    Wang, Gengsheng

    2016-01-01

    This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

  15. Doubly Resonant Optical Periodic Structure.

    Science.gov (United States)

    Alagappan, G; Png, C E

    2016-02-08

    Periodic structures are well known in various branches of physics for their ability to provide a stopband. In this article, using optical periodic structures we showed that, when a second periodicity--very closed to the original periodicity is introduced, large number of states appears in the stopband corresponding to the first periodicity. In the limit where the two periods matches, we have a continuum of states, and the original stopband completely disappears. This intriguing phenomena is uncovered by noticing that, regardless of the proximities of the two periodicities, there is an array of spatial points where the dielectric functions corresponding to the two periodicities interfere destructively. These spatial points mimic photonic atoms by satisfying the standards equations of quantum harmonic oscillators, and exhibit lossless, atom-like dispersions.

  16. 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...

  17. Periodic review and continuous ordering

    OpenAIRE

    Prak, Dennis R.J.; Teunter, Ruud; Riezebos, Jan

    2014-01-01

    There exist many inventory control studies that consider either continuous review & continuous ordering, or periodic review & periodic ordering. Mixtures of the two are hardly ever studied. However, the model with periodic review and continuous ordering is highly relevant in practice, as information on the actual inventory level is not always up to date while making ordering decisions. This paper will therefore consider this case of periodic review and continuous ordering. Assuming zero fixed...

  18. Periodic review and continuous ordering

    NARCIS (Netherlands)

    Prak, Dennis; Teunter, Ruud; Riezebos, Jan

    2015-01-01

    Many inventory control studies consider either continuous review and continuous ordering, or periodic review and periodic ordering. Mixtures of the two are hardly ever studied. However, the model with periodic review and continuous ordering is highly relevant in practice, as information on the actua

  19. Periodic review and continuous ordering

    NARCIS (Netherlands)

    Prak, Dennis R.J.; Teunter, Ruud; Riezebos, Jan

    2014-01-01

    There exist many inventory control studies that consider either continuous review & continuous ordering, or periodic review & periodic ordering. Mixtures of the two are hardly ever studied. However, the model with periodic review and continuous ordering is highly relevant in practice, as information

  20. 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.

  1. 广西隆安下石炭统都结微生物岩微相特征与沉积环境研究%Sedimentary Environment and Microfacies Analysis of the Lower Carboniferous Microbial Carbonates in the Dujie Village, Long’an County,Guangxi

    Institute of Scientific and Technical Information of China (English)

    苗卓伟; 张永利; 巩恩普; 关长庆; 阮氏梅香; 黄文韬; 王邓

    2016-01-01

    microbial carbonates have 3 developmental stages;③ the sea level shows a falling trend roughly,although it changes within a narrow range.Dujie microbial carbonates develop on the eve of the Late Paleozoic ice age and the Serpukhovian (Carboniferous ) mass extinction.With the enrichment of microbial carbonates and the lack of metazoan reefs,the biological composition in marine ecosystems has changed significantly during the period from late Visean to Serpukhovian.Based on the above,the effects of the glaciation in Gondwanal and on the low latitudes of the Northern Hemisphere from the perspective of microbial carbonates is analysised preliminary in the present study.%广西隆安县都结乡发育的微生物岩产于下石炭统都安组中—上部地层,分布广、厚度大,是中国南方早石炭世报道较少的碳酸盐岩建造类型,具有较高的研究价值。该微生物岩以颗粒灰岩和粘结岩为主,生物含量丰富,包括微生物、有孔虫、棘皮类、钙球、腕足等。通过岩相分析,可识别出以下8种微相类型:MF1含亮晶胶结物的泥晶包壳生屑灰岩、MF2含腕足似球粒灰岩、MF3无纹层似球粒颗粒灰岩、MF4集合颗粒灰岩、MF5细密纹层状粘结岩、MF6内碎屑鲕粒灰岩、MF7鲕粒灰岩、MF8白云质鲕粒灰岩。伴随海平面升降变化,都结微生物岩沉积环境先后经历了FZ1台地边缘浅滩相、FZ2开阔台地相与FZ3局限台地相这三种沉积相带之间往复变化的沉积相模式。结合前人基础地质资料,该沉积相模式表明该微生物岩发育于低纬度孤立碳酸盐岩台地浅水环境,并经历了初期、主体时期和消亡期3个发育阶段,海平面虽伴有小幅波动,但整体呈下降趋势。微生物岩发育于晚古生代冰期与谢尔普霍夫生物灭绝事件前夕,该时期南盘江盆地微生物岩的富集与后生动物礁的缺失相耦合,海洋生态系统中生物组成发生显著变化。在

  2. 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.

  3. 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

  4. [Periodic breathing with periodic oxygen variation in infancy].

    Science.gov (United States)

    von Czettritz, G; Bax, R T; Eckardt, T; Springer, S; Emmrich, P

    1996-01-01

    Oxycardiorespirographies, recording arterial oxygen saturation (SaO2), breathing movements, heart rate and ECG with a mean recording time of 22.3 hours, were performed on 85 preterm (mean postconceptional age: 38 weeks) and 81 term infants (mean postconceptional age 42.4 weeks). 83% of the preterm infants showed periodic breathing (PB), in 97% of them this was accompanied by periodic variations of arterial oxygen saturation (PVO). Periodic breathing occurred in 61% of the term infants, 84% of them showed PVO during periodic breathing. The mean variation of oxygen saturation was between 92.8 and 96.8% (+/- 1.7) for preterm and between 92.9 and 96.0% (+/- 2.2) for term infants. In some infants the peak to peak amplitude of the SaO2 cycles was up to 22%, sometimes a further fall of SaO2 occurred. There was a strong correlation of the PVO both at the beginning and end of the episode as well as with the PB-cycle periodicity itself. The fall of the oxygen saturation occurred 3.1 to 7.8 s after the beginning of the first apnea of an episode of periodic breathing, the minimum SaO2 was reached approximately 4.2 to 8.6 s later. This periodic rapid fall of SaO2 from a high oxygenation level cannot be explained by the apneas of a rather short duration during periodic breathing. It is discussed that PVO during periodic breathing may be caused by an ideopathic right to left shunting across fetal circulation pathways which occurs intermittently and periodically. This mechanism could-via patterns of reaction exhibited during the fetal and neonatal time period-lead to acute hypoxemia, as found in apparently life threatening events (ALTE) and as postulated in sudden infant death (SID).

  5. Analytical modeling of mercury injection in high-rank coalbed methane reservoirs based on pores and microfractures: a case study of the upper carboniferous Taiyuan Formation in the Heshun block of the Qinshui Basin, central China

    Science.gov (United States)

    Gu, Yang; Ding, Wenlong; Yin, Shuai; Wang, Ruyue; Mei, Yonggui; Liu, Jianjun

    2017-03-01

    The coalbed gas reservoirs in the Qinshui Basin in central China are highly heterogeneous; thus, the reservoir characteristics are difficult to assess. Research on the pore structure of a reservoir can provide a basis for understanding the occurrence and seepage mechanisms of coal reservoirs, rock physics modeling and the formulation of rational development plans. Therefore, the pore structure characteristics of the coalbed gas reservoirs in the high rank bituminous coal in the No. 15 coal seam of the Carboniferous Taiyuan Group in the Heshun coalbed methane (CBM) blocks in the northeastern Qinshui Basin were analyzed based on pressure mercury and scanning electron microscopy data. The results showed that the effective porosity system of the coal reservoir was mainly composed of pores and microfractures and that the pore throat configuration of the coal reservoir was composed of pores and microthroats. A model was developed based on the porosity and microfractures of the high rank coal rock and the mercury injection and drainage curves. The mercury injection curve model and the coal permeability are well correlated and were more reliable for the analysis of coal and rock pore system connectivity than the mercury drainage curve model. Coal rocks with developed microfractures are highly permeable; the production levels are often high during the initial drainage stages, but they decrease rapidly. A significant portion of the natural gas remains in the strata and cannot be exploited; therefore, the ultimate recovery is rather low. Coal samples with underdeveloped microfractures have lower permeabilities. While the initial production levels are lower, the production cycle is longer, and the ultimate recovery is higher. Therefore, the initial production levels of coal reservoirs with poorly developed microfractures in some regions of China may be low. However, over the long term, due to their higher ultimate recoveries and longer production cycles, the total gas

  6. 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.…

  7. 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.

  8. Latino Periodicals: A Selection Guide.

    Science.gov (United States)

    Guerena, Salvador, Ed.; Pisano, Vivian M., Ed.

    This guide is a collection development tool of national scope for librarians who need in-depth coverage of Latino periodicals suitable for public, school, and academic libraries. Periodicals evaluated include general interest and popular magazines and newspapers that appeal to Spanish-speaking, bilingual, and English-speaking library patrons and…

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

    Institute of Scientific and Technical Information of China (English)

    白建科; 李智佩; 徐学义; 茹艳娇; 李婷

    2011-01-01

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

  10. 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.

  11. Autism: a "critical period" disorder?

    Science.gov (United States)

    LeBlanc, Jocelyn J; Fagiolini, Michela

    2011-01-01

    Cortical circuits in the brain are refined by experience during critical periods early in postnatal life. Critical periods are regulated by the balance of excitatory and inhibitory (E/I) neurotransmission in the brain during development. There is now increasing evidence of E/I imbalance in autism, a complex genetic neurodevelopmental disorder diagnosed by abnormal socialization, impaired communication, and repetitive behaviors or restricted interests. The underlying cause is still largely unknown and there is no fully effective treatment or cure. We propose that alteration of the expression and/or timing of critical period circuit refinement in primary sensory brain areas may significantly contribute to autistic phenotypes, including cognitive and behavioral impairments. Dissection of the cellular and molecular mechanisms governing well-established critical periods represents a powerful tool to identify new potential therapeutic targets to restore normal plasticity and function in affected neuronal circuits.

  12. Measuring Scars of Periodic Orbits

    CERN Document Server

    Kaplan, L

    1999-01-01

    The phenomenon of periodic orbit scarring of eigenstates of classically chaotic systems is attracting increasing attention. Scarring is one of the most important ``corrections'' to the ideal random eigenstates suggested by random matrix theory. This paper discusses measures of scars and in so doing also tries to clarify the concepts and effects of eigenfunction scarring. We propose a new, universal scar measure which takes into account an entire periodic orbit and the linearized dynamics in its vicinity. This measure is tuned to pick out those structures which are induced in quantum eigenstates by unstable periodic orbits and their manifolds. It gives enhanced scarring strength as measured by eigenstate overlaps and inverse participation ratios, especially for longer orbits. We also discuss off-resonance scars which appear naturally on either side of an unstable periodic orbit.

  13. Periodicities in photospheric magnetic flux

    Institute of Scientific and Technical Information of China (English)

    SONG; Wenbin; WANG; Jingxiu

    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.

  14. Period-doubling cascades galore

    OpenAIRE

    Sander, Evelyn; Yorke, James A.

    2009-01-01

    The appearance of numerous period-doubling cascades is among the most prominent features of {\\bf parametrized maps}, that is, smooth one-parameter families of maps $F:R \\times {\\mathfrak M} \\to {\\mathfrak M}$, where ${\\mathfrak M}$ is a smooth locally compact manifold without boundary, typically $R^N$. Each cascade has infinitely many period-doubling bifurcations, and it is typical to observe -- such as in all the examples we investigate here -- that whenever there are any cascades, there are...

  15. Period Integrals and Tautological Systems

    CERN Document Server

    Lian, Bong H; Yau, Shing-Tung

    2011-01-01

    We study period integrals of CY hypersurfaces in a partial flag variety. We construct a holonomic system of differential equations which govern the period integrals. By means of representation theory, a set of generators of the system can be described explicitly. The results are also generalized to CY complete intersections. The construction of these new systems of differential equations have lead us to the notion of a tautological system.

  16. Periodic billiard trajectories in polyhedra

    CERN Document Server

    Bedaride, Nicolas

    2011-01-01

    We consider the billiard map inside a polyhedron. We give a condition for the stability of the periodic trajectories. We apply this result to the case of the tetrahedron. We deduce the existence of an open set of tetrahedra which have a periodic orbit of length four (generalization of Fagnano's orbit for triangles), moreover we can study completly the orbit of points along this coding.

  17. Jupiter and Saturn Rotation Periods

    CERN Document Server

    Helled, Ravit; Anderson, John D

    2009-01-01

    Anderson & Schubert (2007, Science,317,1384) proposed that Saturn's rotation period can be ascertained by minimizing the dynamic heights of the 100 mbar isosurface with respect to the geoid; they derived a rotation period of 10h 32m 35s. We investigate the same approach for Jupiter to see if the Jovian rotation period is predicted by minimizing the dynamical heights of its isobaric (1 bar pressure level) surface using zonal wind data. A rotation period of 9h 54m 29s is found. Further, we investigate the minimization method by fitting Pioneer and Voyager occultation radii for both Jupiter and Saturn. Rotation periods of 9h 55m 30s and 10h 32m 35s are found to minimize the dynamical heights for Jupiter and Saturn, respectively. Though there is no dynamical principle requiring the minimization of the dynamical heights of an isobaric surface, the successful application of the method to Jupiter lends support to its relevance for Saturn. We derive Jupiter and Saturn rotation periods using equilibrium theory in ...

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

    Institute of Scientific and Technical Information of China (English)

    高永利

    2014-01-01

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

  19. CHARACTERISTICS OF CARBONIFEROUS VOLCANIC RESERVOIRS IN THE 6th AND 7th AREAS OF KARAMAY OIL FIELD%克拉玛依油田六七区石炭系火山岩储层特征

    Institute of Scientific and Technical Information of China (English)

    罗雪; 罗明高; 林军; 袁述武; 乐园; 陈忠云

    2013-01-01

    Characteristics of lithology,physical and pore structure of the Carboniferous volcanic rocks in the 6th and the 7th districts of Karamay oil field are studied through observation and analysis of drilling cores of 665.56 meters long from 32 drilling wells,470 thin sections,666 physical analysis samples and 82 drilling wells logging data.It is showed that burial depth of layers,lithology and fractures are 3 main factors influencing the reservoirs in this area,and the most favorable reservoir is located in the south of the 6 district and the middle of the 7 district.Pyroclastic rock and sedimentary rock are the main rock types in the area and the major lithology of volcanic rock reservoir is breccias lava and basalt characteristic of low porosity and permeability.Reservoir space is dominated by stoma,intercrystal pore,vug and pre-existing fractures.The favorable reservoir mainly distributes in the south and northwest of 6 district and in the middle of 7 district.%针对32口井665.56 m岩心、470块岩矿薄片、666个物性分析样品以及82口井测井等资料,对克拉玛依油田六七区石炭系火山岩的岩性、物性以及孔隙结构特征进行了研究,结果表明该区影响火山岩储层的主要因素主要有地层埋深、岩性以及裂缝影响,最有利的储集区位于六区南部和七中区.研究区岩石类型主要为火山熔岩类、火山碎屑岩类和沉积岩类,火山岩储层主要岩性为角砾熔岩和玄武岩;孔隙度、渗透率较低;储集空间以气孔、晶间孔、溶蚀孔和原生裂缝为主;有利火山岩储层主要分布于六区南部、西北部以及七中区.

  20. Periodic Sweep Coverage Scheme Based on Periodic Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Li Shu

    2014-03-01

    Full Text Available We provide a sweep coverage algorithm for routing mobile sensors that communicate with a central data sink. This algorithm improves on its predecessors by reducing the number of unnecessary scans when different points of interest (POIs have different requirements for the time interval within which they must be scanned (sweep period. Most sweep coverage algorithms seek to minimize the number of sensors required to cover a given collection of POIs. When POIs have different sweep period requirements, existing algorithms will produce solutions in which sensors visit some POIs much more frequently than is necessary. We define this as the POI Over-Coverage problem. In order to address this problem we develop a Periodic Sweep Coverage (PSC scheme based on a well-known solution to the Periodic Vehicle Routing Problem (PVRP. Our algorithm seeks a route for the mobile sensors that minimizes the number of unnecessary visits to each POI. To verify and test the proposed scheme we implemented a C++ simulation and ran scenarios with a variety of POI topologies (number and distribution of the POIs and the speed at which sensors could travel. The simulation results show that the PSC algorithm outperforms other sweep coverage algorithms such as CSweep and Vehicle Routing Problem Sweep Coverage (VRPSC on both the average number of sensors in a solution and in the computational time required to find a solution. Our results also demonstrate that the PSC scheme is more suitable for the sweep coverage scenarios in which higher speed mobile sensors are used.

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

    Institute of Scientific and Technical Information of China (English)

    张雄华; 黄兴; 陈继平; 廖群安; 段先锋

    2012-01-01

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

  2. 塔里木盆地北缘上石炭统砂岩碎屑组分及其对物源类型和构造属性的指示%Detrital composition of Upper Carboniferous sandstone in northern Tarim basin and its implications for provenance and tectonic attributes

    Institute of Scientific and Technical Information of China (English)

    杨栋栋; 李双应; 王松; 万秋; 赵大千; 徐锦龙

    2011-01-01

    Since the late Paleozoic, the south Tianshan Mountain has gone through a series of collision and micro-plate collage events, which have had obvious reflection in the sedimentation and tectonic evolution of northern Tarim basin. The analysis of depositional provenance is an important method for understanding basin evolution and interpreting tectonic background, and is also the first prerequisite for confirming the evolution of the basin. The variation in the composition of depositional provenances reflects the relationship between the uplift of basin margin orogen and the basin subsidence. With the improvement of modem analytical techniques, the provenance analytical methods have increased in number, become gradually perfected in quality and complemented each other. Based on Dickinson's provenance analytical method, the authors studied and analyzed sandstone detrital composition and source rocks of Upper Carboniferous sandstone along different geological sections in northern Tarim basin. The results show that the major types of the Upper Carboniferous sandstone are quartz sandstone and lithic quartz sandstone, with low compositional maturity, and the average Q/(F+ L) in Cedaya, Dashankou hydropower station and Bayinbuluke geological section are respectively 1.80, 3.11, 3.32. The detrital composition is mainly quartz and subordinately feldspar and some rock debris, with minor organic matrix or biotite. According to the study of sandstone detrital compositions, sandstone of Upper Carboniferous Ayilihe Formation in northern Tarim basin is composed averagely of 70.7% quartz (53%~86%), 7.1% feldspar (5%~17%), and22.5 % rock debris (20%~30%). Metamorphic debris and sedimentary debris are mainly existent in this area, while in Cedaya, volcanic debris possesses 42%. On the basis of Dickinson's triangular plot and the characteristics of rock debris, the Upper Carboniferous provenance in northern Tarim basin is characterized by the recycled orogen type, and the primary

  3. 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.

  4. Inflation from periodic extra dimensions

    CERN Document Server

    Higaki, Tetsutaro

    2016-01-01

    We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing $T^2/{\\mathbb Z}_2$ orbifold. We show also predictions of cosmic observables by numerical analyzes.

  5. Periodicity and repeatability in data

    Science.gov (United States)

    Southwood, D.

    Using magnetic data from the first two years in Saturn orbit, the basic periodicity of apparent is examined with the aim of elucidating the `cam' shaft model of Espinosa et al. (2003) identifying the nature of the `cam' and giving a definitive period for its rotation. An initial hypothesis, supported by the spectral analysis of analysis of the first 8 months in orbit Gianpieri et al. (2006), is made that the source of the period is linked to something inside the planet and therefore that the source inertia means that the period effectively does not change over the 2 years. Moreover one expects that the source phase is fixed. Using this approach, not only can the period identified by spectral analysis (647.1 + 0.6 min.) be verified but also by phase analysis between successive passes over the 2 years the period can be refined to 647.6 + 0.1 min. The signal itself is remarkably reproducible from pass to pass. It appears in all three components of the field and its polarisation is unambiguously not attributable to direct detection of an internal field. Not only does the signal not decay rapidly with distance from the planet, but although it has the m=1 symmetry of a tilted dipole, the field lines diverge from the planet indicating an exterior source. This feature led to the `cam' model. The polarisation and comparisons of passes with different latitude profiles show a surprising north-south symmetry in the azimuthal field. The absence of asymmetry with respect to the magnetic equator rules out a direct magnetospheric-ionospheric interaction source. Accordingly, it is proposed that the basic `cam' effect is generated by a single hemisphere anomaly which creates hemisphere to hemisphere field aligned currents. The existence of Saturn phase related anomaly appears to produce a basic asymmetry in the inner magnetosphere that sets the phase of both an inflowing and outflowing sector in a rotating circulation system.

  6. Sigmoid Volvulus Complicating Postpartum Period

    Science.gov (United States)

    Blake, Erin; Gonzalez, Eduardo; Pieracci, Frederic

    2017-01-01

    Background. Sigmoid volvulus is a rare complication of pregnancy and the puerperium. Case. A 19-year-old patient, gravida 1 para 0 at 41 0/7 weeks of gestation, admitted for late-term induction of labor underwent an uncomplicated primary low transverse cesarean delivery for arrest of descent. Her postoperative period was complicated by sudden onset of abdominal pain and the ultimate diagnosis of sigmoid volvulus. Conclusion. Prompt surgical evaluation of an acute abdomen in the postpartum period is essential; delayed diagnosis and treatment can lead to significant maternal morbidity and mortality.

  7. Hydrogen purification by periodic adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br

    2000-07-01

    The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)

  8. 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.

  9. Soliton Management in Periodic Systems

    CERN Document Server

    Malomed, Boris A

    2006-01-01

    During the past ten years, there has been intensive development in theoretical and experimental research of solitons in periodic media. This book provides a unique and informative account of the state-of-the-art in the field. The volume opens with a review of the existence of robust solitary pulses in systems built as a periodic concatenation of very different elements. Among the most famous examples of this type of systems are the dispersion management in fiber-optic telecommunication links, and (more recently) photonic crystals. A number of other systems belonging to the same broad class of spatially periodic strongly inhomogeneous media (such as the split-step and tandem models) have recently been identified in nonlinear optics, and transmission of solitary pulses in them was investigated in detail. Similar soliton dynamics occurs in temporal-domain counterparts of such systems, where they are subject to strong time-periodic modulation (for instance, the Feshbach-resonance management in Bose-Einstein conde...

  10. Quasi-Periodic Spatiotemporal Filtering

    NARCIS (Netherlands)

    Burghouts, G.J.; Geusebroek, J.M.

    2006-01-01

    This paper presents the online estimation of temporal frequency to simultaneously detect and identify the quasi-periodic motion of an object. We introduce color to increase discriminative power of a reoccurring object and to provide robustness to appearance changes due to illumination changes. Spati

  11. Quantifying Periodicity in Omics Data

    Directory of Open Access Journals (Sweden)

    Cornelia eAmariei

    2014-08-01

    Full Text Available Oscillations play a significant role in biological systems, with many examples in the fast, ultradian, circadian, circalunar and yearly time domains. However, determining periodicity in such data can be problematic. There are a number of computational methods to identify the periodic components in large datasets, such as signal-to-noise based Fourier decomposition, Fisher's g-test and autocorrelation. However, the available methods assume a sinusoidal model and do not attempt to quantify the waveform shape and the presence of multiple periodicities, which provide vital clues in determining the underlying dynamics. Here, we developed a Fourier based measure that generates a de-noised waveform from multiple significant frequencies. This waveform is then correlated with the raw data from the respiratory oscillation found in yeast, to provide oscillation statistics including waveform metrics and multi-periods. The method is compared and contrasted to commonly used statistics. Moreover we show the utility of the program in the analysis of noisy datasets and other high-throughput analyses, such as metabolomics and flow cytometry, respectively.

  12. Periodic solutions and slow manifolds

    NARCIS (Netherlands)

    Verhulst, F.

    2006-01-01

    After reviewing a number of results from geometric singular perturbation theory, we give an example of a theorem for periodic solutions in a slow manifold. This is illustrated by examples involving the van der Pol-equation and a modified logistic equation. Regarding nonhyperbolic transitions we disc

  13. Glass Waveguides for Periodic Poling

    DEFF Research Database (Denmark)

    Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin

    2005-01-01

    Planar silica-based waveguide devices have been developed for second-harmonic generation by poling with periodic electrodes. We show that detrimental charge transport can occur along interfaces, but with proper choice of fabrication, high-quality devices are obtained....

  14. Periodic progress report, 6 months

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Nielsen, Jakob Skov

    This is the first progress report of the BriteEuram project named "High Power Laser Cutting for Heavy Industry" ("Powercut"). The report contains a summary of the objectives of the first period, an overview of the technical progress, a comparison between the planed and the accomplished work...

  15. Coupling light to periodic nanostructures

    NARCIS (Netherlands)

    Driessen, Eduard Frans Clemens

    2009-01-01

    This thesis describes coupling of light to periodic structures. A material is patterned with a regular pattern on a length scale comparable to the wavelength of light. With these structures, light can be manipulated very precisely. The structures find applications in semiconductor lasers, light emit

  16. 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.

  17. 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.

  18. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    is 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...

  19. 76 FR 80312 - Periodic Reporting

    Science.gov (United States)

    2011-12-23

    ... of the Business Reply Mail cost model in periodic reporting of service performance measurement... initiate a rulemaking proceeding to address the current methodology used to develop the avoided cost.... SUMMARY: The Commission is establishing a docket to consider new measurement of Flats Sequencing...

  20. System Optimization by Periodic Control.

    Science.gov (United States)

    1979-09-30

    extended re- sults are now contained in a single report [3] which will appear as a regular paper in the December, 1979 issue of the IEEE Transactions on Automatic Control . The...Test Revisited, " to appear in the IEEE Transactions on Automatic Control . 4. D. J. Lyons, "Improved Aircraft Cruise by Periodic Control," Ph. D

  1. Hyperkalemic periodic paralysis associated with multiple sleep onset REM periods.

    Science.gov (United States)

    Iranzo, A; Santamaria, J

    1999-12-15

    A 24-year-old man with sporadic hyperkalemic periodic paralysis (HPP) presented with moderate excessive daytime sleepiness and transitory episodes of weakness which occurred during and after sleep. Multiple sleep latency test (MSLT) demonstrated the presence of five sleep onset REM periods (SOREMPs) and a sleep latency of five minutes. Treatment with a diuretic which decreases serum potassium resolved all the clinical symtomps and a new MSLT showed the absence of SOREMPs and a sleep latency of 13.5 minutes. To our knowledge, the patient herein reported is the first case that associates sleep abnormalities and multiple SOREMPs with HPP. Furthermore, the present case suggests that SOREMPs may be explained by an increased extracellular potassium conductance related to HPP.

  2. Carboniferous Fusulinids from the Cantabrian Mountains (Spain)

    NARCIS (Netherlands)

    Ginkel, van A.C.

    1965-01-01

    Fusulinid faunas from various locations spread throughout the Cantabrian mountains are described as belonging to about 180 species including 17 new species and 11 new subspecies of 18 genera. The latter are Staffella (with 3 new species), Parastaffella (with 3 new species and 2 new subspecies), Mill

  3. 7 CFR 1160.113 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Fiscal period. 1160.113 Section 1160.113 Agriculture... Definitions § 1160.113 Fiscal period. Fiscal period means the initial period of up to 30 months that this subpart is effective. Thereafter, the fiscal period shall be such annual period as the Board may...

  4. 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.

  5. Exploration of Periodically Varying Graphs

    CERN Document Server

    Flocchini, Paola; Santoro, Nicola

    2009-01-01

    We study the computability and complexity of the exploration problem in a class of highly dynamic graphs: periodically varying (PV) graphs, where the edges exist only at some (unknown) times defined by the periodic movements of carriers. These graphs naturally model highly dynamic infrastructure-less networks such as public transports with fixed timetables, low earth orbiting (LEO) satellite systems, security guards' tours, etc. We establish necessary conditions for the problem to be solved. We also derive lower bounds on the amount of time required in general, as well as for the PV graphs defined by restricted classes of carriers movements: simple routes, and circular routes. We then prove that the limitations on computability and complexity we have established are indeed tight. In fact we prove that all necessary conditions are also sufficient and all lower bounds on costs are tight. We do so constructively presenting two worst case optimal solution algorithms, one for anonymous systems, and one for those w...

  6. Regular and Periodic Tachyon Kinks

    OpenAIRE

    Bazeia, D.; Menezes, R.; Ramos, J. G.

    2004-01-01

    We search for regular tachyon kinks in an extended model, which includes the tachyon action recently proposed to describe the tachyon field. The extended model that we propose adds a new contribution to the tachyon action, and seems to enrich the present scenario for the tachyon field. We have found stable tachyon kinks of regular profile, which may appropriately lead to the singular kink found by Sen sometime ago. Also, under specific conditions we may find periodic array of kink-antikink co...

  7. 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.

  8. Constituents of Doubly Periodic Instantons

    CERN Document Server

    Ford, C; Ford, Chris; Pawlowski, Jan M.

    2002-01-01

    Using the Nahm transform we investigate doubly periodic charge one SU(2) instantons with radial symmetry. Two special points where the Nahm zero modes have softer singularities are identified as constituent locations. To support this picture, the action density is computed analytically and numerically within a two dimensional slice containing the two constituents. For particular values of the parameters the torus can be cut in half yielding two copies of a twisted charge 1/2 instanton. Such objects comprise a single constituent.

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

    Science.gov (United States)

    Budzyń, Bartosz; Jastrzębski, Mirosław; Stawikowski, Wojciech

    2014-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Fernando Pagani Possamai

    2007-03-01

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

  11. 7 CFR 955.113 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 955.113 Section 955.113 Agriculture... and Regulations § 955.113 Fiscal period. Pursuant to § 955.13, fiscal period shall mean the period beginning January 1 and ending December 31 of each year, except that the fiscal period that began...

  12. 7 CFR 929.106 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 929.106 Section 929.106 Agriculture... LONG ISLAND IN THE STATE OF NEW YORK Rules and Regulations § 929.106 Fiscal period. The fiscal period... include the period of August 1, through August 31, 1968. Thereafter, the fiscal period will begin...

  13. Periodic roads and quantized wheels

    Science.gov (United States)

    de Campos Valadares, Eduardo

    2016-08-01

    We propose a simple approach to determine all possible wheels that can roll smoothly without slipping on a periodic roadbed, while maintaining the center of mass at a fixed height. We also address the inverse problem that of obtaining the roadbed profile compatible with a specific wheel and all other related "quantized wheels." The role of symmetry is highlighted, which might preclude the center of mass from remaining at a fixed height. A straightforward consequence of such geometric quantization is that the gravitational potential energy and the moment of inertia are discrete, suggesting a parallelism between macroscopic wheels and nano-systems, such as carbon nanotubes.

  14. A model for periodic blazars

    CERN Document Server

    Sobacchi, Emanuele; Stamerra, Antonio

    2016-01-01

    We describe a scenario to explain blazar periodicities with timescales of $\\sim$ few years. The scenario is based on a binary super-massive black hole (SMBH) system in which one of the two SMBH carries a jet. We discuss the various mechanisms that can cause the jet to precess and produce corkscrew patterns through space with a scale of $\\sim$ few pc. It turns out that the dominant mechanism responsible for the precession is simply the imprint of the jet-carrying SMBH orbital speed on the jet. Gravitational deflection and Lense-Thirring precession (due to the gravitational field of the other SMBH) are second order effects. We complement the scenario with a kinematical jet model which is inspired to the spine-sheath structure observed in M87. One of the main advantages of such a structure is that it allows the peak of the synchrotron emission to scale with frequency according to $\

  15. A periodic table for cancer.

    Science.gov (United States)

    Epstein, Richard J

    2015-01-01

    Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.

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

    Institute of Scientific and Technical Information of China (English)

    徐锦龙; 贾志海; 王伟; 罗雷; 李俊青

    2012-01-01

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

  18. 7 CFR 955.13 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 955.13 Section 955.13 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Definitions § 955.13 Fiscal period. Fiscal period means the 12-month period beginning on September 16...

  19. 7 CFR 953.122 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 953.122 Section 953.122 Agriculture... STATES Rules and Regulations Change in Date for Completing Nominations, Term of Office, and Fiscal Period § 953.122 Fiscal period. The fiscal period, pursuant to § 953.9, which began on April 1, 1976, shall...

  20. 7 CFR 947.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 947.9 Section 947.9 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Definitions § 947.9 Fiscal period. Fiscal period means the period beginning and ending on the dates...

  1. 7 CFR 923.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 923.7 Section 923.7 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Definitions § 923.7 Fiscal period. Fiscal period is synonymous with fiscal year and means the 12-month period ending on March 31 of each year or such...

  2. 7 CFR 966.16 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 966.16 Section 966.16 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 966.16 Fiscal period. Fiscal period means the period beginning August 1...

  3. 7 CFR 948.10 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 948.10 Section 948.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Definitions § 948.10 Fiscal period. Fiscal period means the period...

  4. 7 CFR 922.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 922.7 Section 922.7 Agriculture... IN WASHINGTON Order Regulating Handling Definitions § 922.7 Fiscal period. Fiscal period is synonymous with fiscal year and means the 12-month period ending on March 31 of each year or such...

  5. 7 CFR 1221.10 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1221.10 Section 1221.10 Agriculture... INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.10 Fiscal period. Fiscal period means the 12-month period ending on December 31 or such other consecutive 12-month...

  6. 7 CFR 1230.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1230.9 Section 1230.9 Agriculture... CONSUMER INFORMATION Pork Promotion, Research, and Consumer Information Order Definitions § 1230.9 Fiscal period. Fiscal period means the 12-month period ending on December 31 or such other consecutive...

  7. 7 CFR 1220.111 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1220.111 Section 1220.111 Agriculture... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.111 Fiscal period. The term fiscal period means the calendar year or such other annual period as the Board may determine with...

  8. 7 CFR 924.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 924.7 Section 924.7 Agriculture... COUNTIES IN WASHINGTON AND IN UMATILLA COUNTY, OREGON Order Regulating Handling Definitions § 924.7 Fiscal period. Fiscal period is synonymous with fiscal year and means the 12-month period ending on March 31...

  9. 7 CFR 948.103 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 948.103 Section 948.103 Agriculture... Rules and Regulations General § 948.103 Fiscal period. Pursuant to § 948.10, the fiscal periods for each... following year, both dates inclusive. The 1986-87 fiscal period which began July 1, 1986, will be...

  10. 7 CFR 946.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 946.9 Section 946.9 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Definitions § 946.9 Fiscal period. Fiscal period means the period beginning...

  11. 7 CFR 1218.8 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1218.8 Section 1218.8 Agriculture... INFORMATION ORDER Blueberry Promotion, Research, and Information Order Definitions § 1218.8 Fiscal period. Fiscal period means a calendar year from January 1 through December 31, or such other period as...

  12. 7 CFR 929.6 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 929.6 Section 929.6 Agriculture... LONG ISLAND IN THE STATE OF NEW YORK Order Regulating Handling Definitions § 929.6 Fiscal period. Fiscal period is synonymous with fiscal year and crop year and means the 12-month period...

  13. 7 CFR 956.113 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 956.113 Section 956.113 Agriculture... VALLEY OF SOUTHEAST WASHINGTON AND NORTHEAST OREGON Rules and Regulations § 956.113 Fiscal period. Pursuant to § 956.13, fiscal period shall mean the period beginning January 1 and ending December 31...

  14. 7 CFR 927.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 927.9 Section 927.9 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Definitions § 927.9 Fiscal period. Fiscal period means the period...

  15. 7 CFR 959.16 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 959.16 Section 959.16 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 959.16 Fiscal period. Fiscal period means the annual period beginning...

  16. 7 CFR 917.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 917.9 Section 917.9 Agriculture... CALIFORNIA Order Regulating Handling Definitions § 917.9 Fiscal period. Fiscal period is synonymous with fiscal year and means the 12-month period ending on the last day of February of each year, or such...

  17. 7 CFR 945.12 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 945.12 Section 945.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Fiscal period. Fiscal period means the period beginning and ending on the dates approved by the...

  18. 7 CFR 958.12 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 958.12 Section 958.12 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Definitions § 958.12 Fiscal period. Fiscal period means the period beginning and ending on the dates approved by the Secretary pursuant...

  19. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito

    1990-01-01

    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

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

    Institute of Scientific and Technical Information of China (English)

    孙宝亮; 巩恩普; 李金梅; 关长庆; 张永利

    2012-01-01

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

  1. 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.

  2. 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

  3. Periodic Control of Power Electronic Converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Danwei, Wang; Yang, Yongheng

    Advanced power electronic converters convert, control and condition electricity. Power converters require control strategies for periodic signal compensation to assure good power quality and stable power system operation. This comprehensive text presents the most recent internal model principle...... based periodic control technology, which offers the perfect periodic control solution for power electronic conversion. It also provides complete analysis and synthesis methods for periodic control systems, and plenty of practical examples to demonstrate the validity of proposed periodic control...... technology for power converters. It proposes a unified framework for housing periodic control schemes for power converters, and provides a general proportional-integral-derivative control solution to periodic signal compensation in extensive engineering applications. Periodic Control of Power Electronic...

  4. 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 massive...

  5. 7 CFR 1205.20 - Representative period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Representative period. 1205.20 Section 1205.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING... period means the 2006 calendar year....

  6. 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.

  7. Periodic Solution of the Hematopoiesis Equation

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2013-01-01

    Full Text Available Wu and Liu (2012 presented some results for the existence and uniqueness of the periodic solutions for the hematopoiesis model. This paper gives a simple approach to find an approximate period of the model.

  8. The period functions' higher order derivatives

    CERN Document Server

    Sabatini, Marco

    2012-01-01

    We prove a formula for the $n$-th derivative of the period function $T$ in a period annulus of a planar differential system. For $n = 1$, we obtain Freire, Gasull and Guillamon formula for the period's first derivative \\cite{FGG}. We apply such a result to hamiltonian systems with separable variables and other systems. We give some sufficient conditions for the period function of conservative second order O.D.E.'s to be convex.

  9. Prediction Theory of Periodically Correlated Stochastic Processes

    Science.gov (United States)

    2015-05-12

    in order to do a reliable forecasting of periodically correlated sequences with large period (or continuous time processes) the standard method of...aimed at sequences with large periods. It has been known already for years that in order to do a reliable forecasting of periodically correlated...we showed that this technique is very efficient. We successfully used it to study structure, regularity, autoregressive representation, innovation

  10. 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....

  11. Cepheids : the period-luminosity relation

    NARCIS (Netherlands)

    Beaulieu, JP

    1997-01-01

    The Cepheids are relatively young, bright, periodic supergiant variable stars showing a correlation between their periods and luminosities. Since the beginning of the century, the Cepheid Period-Luminosity relation has been the corner stone of distance determination, and of the measure of the correl

  12. 7 CFR 920.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 920.7 Section 920.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Definitions § 920.7 Fiscal period. Fiscal period is synonymous with fiscal year and means a 12-month...

  13. 32 CFR 552.80 - Suspension period.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Suspension period. 552.80 Section 552.80 National... Suspension period. All solicitation privileges suspended by installation commanders will be for a specific time. Normally, it will not exceed 2 years. When the suspension period expires, the agent may...

  14. 12 CFR 561.6 - Audit period.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Audit period. 561.6 Section 561.6 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY DEFINITIONS FOR REGULATIONS AFFECTING ALL SAVINGS ASSOCIATIONS § 561.6 Audit period. The audit period of a savings association means the...

  15. 47 CFR 27.13 - License period.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false License period. 27.13 Section 27.13... COMMUNICATIONS SERVICES Applications and Licenses § 27.13 License period. (a) 2305-2320 MHz and 2345-2360 MHz... beyond the end of the license term if no broadcast service had been provided, whichever period is...

  16. 47 CFR 78.29 - License period.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false License period. 78.29 Section 78.29... SERVICE Applications and Licenses § 78.29 License period. Licenses for CARS stations will be issued for a period not to exceed five (5) years. On and after February 1, 1966, licenses for CARS stations...

  17. 47 CFR 5.71 - License period.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false License period. 5.71 Section 5.71...) Applications and Licenses § 5.71 License period. (a) The regular license period for stations in the Experimental Radio Service is either 2 or 5 years. An applicant desiring to apply for a 5-year license...

  18. 7 CFR 945.111 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 945.111 Section 945.111 Agriculture... DESIGNATED COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Rules and Regulations Definitions § 945.111 Fiscal period. The fiscal period that began June 1, 1981, shall end July 31, 1982. Each year thereafter...

  19. 7 CFR 947.114 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 947.114 Section 947.114 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Definitions § 947.114 Fiscal period. The fiscal period shall begin July 1 of each year and end June 30 of...

  20. 7 CFR 905.11 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 905.11 Section 905.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... TANGELOS GROWN IN FLORIDA Order Regulating Handling Definitions § 905.11 Fiscal period. Fiscal period...

  1. 7 CFR 1205.307 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1205.307 Section 1205.307 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Research and Promotion Order Definitions § 1205.307 Fiscal period. Fiscal period is the 12-month...

  2. 7 CFR 1150.107 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Fiscal period. 1150.107 Section 1150.107 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Definitions § 1150.107 Fiscal period. Fiscal period means the calendar year or such other...

  3. 7 CFR 959.104 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 959.104 Section 959.104 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulations General § 959.104 Fiscal period. The fiscal period shall begin August 1 of each year and end...

  4. 7 CFR 930.107 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 930.107 Section 930.107 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Miscellaneous Provisions § 930.107 Fiscal period. Pursuant to § 930.7, fiscal period shall mean the...

  5. 7 CFR 916.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 916.7 Section 916.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 916.7 Fiscal period. Fiscal period is synonymous with fiscal year and...

  6. 7 CFR 925.12 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 925.12 Section 925.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... SOUTHEASTERN CALIFORNIA Definitions § 925.12 Fiscal period. Fiscal period is synonymous with fiscal year...

  7. 7 CFR 1250.303 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1250.303 Section 1250.303 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Research and Promotion Order Definitions § 1250.303 Fiscal period. Fiscal period means the calendar...

  8. 7 CFR 953.9 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 953.9 Section 953.9 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Order Regulating Handling Definitions § 953.9 Fiscal period. Fiscal period means the...

  9. 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.

  10. CICATRIZATION OF WOUNDS : XI. LATENT PERIOD.

    Science.gov (United States)

    Carrel, A; du Noüy, P L

    1921-09-30

    1. The latent period of cicatrization varies generally from 5 to 7 days. 2. It stops abruptly and contraction starts with its maximum velocity. 3. The formula of du Noüy applies to the beginning of the contraction period as well as to the subsequent periods.

  11. Generalized periodic and generalized Boolean rings

    Directory of Open Access Journals (Sweden)

    Howard E. Bell

    2001-01-01

    Full Text Available We prove that a generalized periodic, as well as a generalized Boolean, ring is either commutative or periodic. We also prove that a generalized Boolean ring with central idempotents must be nil or commutative. We further consider conditions which imply the commutativity of a generalized periodic, or a generalized Boolean, ring.

  12. 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...

  13. 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... an audit may cover. A periodic audit of a participant differs from an award-specific audit of...

  14. 5 CFR 9901.411 - Appraisal period.

    Science.gov (United States)

    2010-01-01

    ....411 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS... PERSONNEL SYSTEM (NSPS) Performance Management § 9901.411 Appraisal period. (a) Except as provided in... period, an employee has not met the minimum period of performance, management may extend the...

  15. 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...

  16. 38 CFR 3.17 - Disability and death pension; Mexican border period and later war periods.

    Science.gov (United States)

    2010-07-01

    ... pension; Mexican border period and later war periods. 3.17 Section 3.17 Pensions, Bonuses, and Veterans... Compensation General § 3.17 Disability and death pension; Mexican border period and later war periods. In... service which began before and extended into the Mexican border period or ended during World War I,...

  17. Quasi-Periodically Driven Quantum Systems

    Science.gov (United States)

    Verdeny, Albert; Puig, Joaquim; Mintert, Florian

    2016-10-01

    Floquet theory provides rigorous foundations for the theory of periodically driven quantum systems. In the case of non-periodic driving, however, the situation is not so well understood. Here, we provide a critical review of the theoretical framework developed for quasi-periodically driven quantum systems. Although the theoretical footing is still under development, we argue that quasi-periodically driven quantum systems can be treated with generalisations of Floquet theory in suitable parameter regimes. Moreover, we provide a generalisation of the Floquet-Magnus expansion and argue that quasi-periodic driving offers a promising route for quantum simulations.

  18. Correspondence Between Astronomical Periods and Sedimentary Cycles

    Institute of Scientific and Technical Information of China (English)

    Cheng Rihui; You Haitao

    2000-01-01

    It is shown from detailed study that there are some genetic relationships between outer events of celestial bodies and inner geological events of the earth, such as some kinds of correspondences between astronomical periods and sedimentary cycles. The time spans of movement periods of the solar system around the center of the galaxy and cross the plain of the galaxy, the periods of the earth orbit (Milankovitch period) and periods of sunspot are coincided with that of respective sedimentary cycles. It is suggested that the gravity and magnetic changes of the earth leading up to the global climatic and sea level changes are the dynamics of sedimentary cycles.

  19. 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.

  20. Uniformly Almost Periodic Functions and Almost Periodic Solutions to Dynamic Equations on Time Scales

    Directory of Open Access Journals (Sweden)

    Yongkun Li

    2011-01-01

    Full Text Available Firstly, we propose a concept of uniformly almost periodic functions on almost periodic time scales and investigate some basic properties of them. When time scale T=ℝ or ℤ, our definition of the uniformly almost periodic functions is equivalent to the classical definitions of uniformly almost periodic functions and the uniformly almost periodic sequences, respectively. Then, based on these, we study the existence and uniqueness of almost periodic solutions and derive some fundamental conditions of admitting an exponential dichotomy to linear dynamic equations. Finally, as an application of our results, we study the existence of almost periodic solutions for an almost periodic nonlinear dynamic equations on time scales.

  1. Periods of weed interference in cowpea

    Directory of Open Access Journals (Sweden)

    Maria José Pinheiro Corrêa

    2015-12-01

    Full Text Available This work aimed to determine the periods weed interference in cowpea. The experimental design was randomized blocks, and the treatments consisted of periods of control or coexistence with the culture. The periods of control or weed coexistence after culture emergence were: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60 and 0 – 80 days after crop emergence. The main weed density were: AlternantheratenellaColla,CyperusrotundusL., Digitariaciliaris(Retz. Koeler, Eleusineindica(L.Gaertn,MollugoverticillataL.Considering 5% of tolerance in cowpea yield reduction, the period prior interference was 8 days after emergence (DAE, total period of interference prevention was 53 DAE and critical period of interference prevention between 8 and 53 DAE. Weed interference reduced the grainyield up to 46%.

  2. 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.

  3. Gabor systems on discrete periodic sets

    Institute of Scientific and Technical Information of China (English)

    LI YunZhang; LIAN QiaoFang

    2009-01-01

    Due to its good potential for digital signal processing,discrete Gabor analysis has inter ested 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 XE 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.

  4. Cyclical period changes in Z Chamaeleontis

    CERN Document Server

    Baptista, R; Oliveira, E; Vrielmann, S; Woudt, P A; Catalan, M S

    2002-01-01

    We report the identification of cyclical changes in the orbital period of the eclipsing dwarf nova Z Cha. We used times of mid-eclipse collected from the literature and our new eclipse timings to construct an observed-minus-calculated diagram covering 30 years of observations (1972-2002). The data present cyclical variations that can be fitted by a linear plus sinusoidal function with period 28+/-2 yr and amplitude 1.0+/-0.2 minute. The statistical significance of this period by an F-test is larger than 99.9%. The derived fractional period change, Delta P/P= 4.4 x 10^{-7}, is comparable to that of other short-period cataclysmic variables (CVs), but is one order of magnitude smaller than those of the long-period CVs. Separate fits to the first and second half of the data lead to ephemerides with quite different cycle periods and amplitudes, indicating that the variation is not sinusoidal or, most probably, is not strictly periodic. The observed cyclical period change is possibly caused by a solar-type magnetic...

  5. 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

  6. Measuring stellar rotation periods with Kepler

    CERN Document Server

    Nielsen, M B; Schunker, H; Karoff, C

    2015-01-01

    We measure rotation periods for 12151 stars in the Kepler field, based on the 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 the rotation periods as a function of spectral type. We find good agreement with previous studies and vsini measurements for F, G and K stars. Combining rotation periods, B-V color, and gyrochronology relations, we find that the cool stars in our sample are predominantly younger than ~1Gyr.

  7. Periodic Motion near the Surface of Asteroids

    CERN Document Server

    Jiang, Yu; Li, Hengnian

    2015-01-01

    We are interested in the periodic motion and bifurcations near the surface of an asteroid. The gravity field of an irregular asteroid and the equation of motion of a particle near the surface of an asteroid are studied. The periodic motions around the major body of triple asteroid 216 Kleopatra and the OSIRIS REx mission target asteroid 101955 Bennu are discussed. We find that motion near the surface of an irregular asteroid is quite different from the motion near the surface of a homoplastically spheroidal celestial body. The periodic motions around the asteroid 101955 Bennu and 216 Kleopatra indicate that the geometrical shapes of the orbits are probably very sophisticated. There exist both stable periodic motions and unstable periodic motions near the surface of the same irregular asteroid. This periodic motion which is unstable can be resonant or non resonant. The period doubling bifurcation and pseudo period doubling bifurcation of periodic orbits coexist in the same gravity field of the primary of the t...

  8. 38 CFR 3.252 - Annual income; pension; Mexican border period and later war periods.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Annual income; pension; Mexican border period and later war periods. 3.252 Section 3.252 Pensions, Bonuses, and Veterans' Relief... Dependency, Income and Estate § 3.252 Annual income; pension; Mexican border period and later war periods....

  9. Uniformly Asymptotic Stability and Existence of Periodic Solutions and Almost Periodic Solutions

    Institute of Scientific and Technical Information of China (English)

    林发兴

    1994-01-01

    We introduce the concepts of uniformly stable solutions and uniformly-asymptotically stable solutions, and then give the relation between Lyapunov function and those concepts. Furthermore, we establish the theorem that an almost periodic system or periodic system has uniformly-asymptotically stable solutions and Lipschitz’ condition has an almost periodic solution or periodic solution.

  10. Project 2nd Periodic Report - Section 2

    DEFF Research Database (Denmark)

    Healy, Mark; Knowles, Emma; Johnstone, Cameron

    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....

  11. Selecting Full-Text Undergraduate Periodicals Databases.

    Science.gov (United States)

    Still, Julie M.; Kassabian, Vibiana

    1999-01-01

    Examines how libraries and librarians can compare full-text general periodical indices, using ProQuest Direct, Periodical Abstracts (via Ovid), and EBSCOhost as examples. Explores breadth and depth of coverage; manipulation of results (email/download/print); ease of use (searching); and indexing quirks. (AEF)

  12. 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...

  13. 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...

  14. 17 CFR 285.2 - Periodic reports.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Periodic reports. 285.2 Section 285.2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS PURSUANT TO SECTION 15(a) OF THE BRETTON WOODS AGREEMENTS ACT § 285.2 Periodic reports. (a)...

  15. 14 CFR 23.49 - Stalling period.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Stalling period. 23.49 Section 23.49... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.49 Stalling period. (a) VSOand VS1are the stalling speeds or the minimum steady flight speeds, in knots (CAS),...

  16. Modeling of laser induced periodic surface structures

    NARCIS (Netherlands)

    Skolski, J.Z.P.; Römer, G.R.B.E.; Huis in 't Veld, A.J.; Mitko, V.S.; Obona, J.V.; Ocelik, V.; Hosson, J.T.M. de

    2010-01-01

    In surfaces irradiated by short laser pulses, Laser Induced Periodic Surface Structures (LIPSS) have been observed on all kind of materials for over forty years. These LIPSS, also referred to as ripples, consist of wavy surfaces with periodicity equal or smaller than the wavelength of the laser radi

  17. 12 CFR 226.7 - Periodic statement.

    Science.gov (United States)

    2010-01-01

    ... telephone numbers and the Web site operated by or on behalf of the Federal Reserve Board. A small depository... period and calendar year to date, using a format substantially similar to Sample G-18(A) in appendix G to... period and calendar year to date, using a format substantially similar to Sample G-18(A) in appendix...

  18. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase ...

  19. Dry period length of dairy cows :

    NARCIS (Netherlands)

    Vries, de Ruben

    2017-01-01

    A dry period of dairy cows is historically seen as a period during which the cow can restore its body condition and regenerate its mammary epithelium in order to be high yielding in the successive lactation. Recent work has indicated that high yielding cows generally experience a severe negative ene

  20. 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.

  1. 47 CFR 24.15 - License period.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false License period. 24.15 Section 24.15 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Applications and Licenses General Filing Requirements § 24.15 License period. Licenses for...

  2. Multi-periodic nanostructures for photon control

    DEFF Research Database (Denmark)

    Kluge, Christian; Adam, Jost; Barié, Nicole;

    2014-01-01

    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...

  3. 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)

  4. 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.

  5. 7 CFR 956.13 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 956.13 Section 956.13 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... VALLEY OF SOUTHEAST WASHINGTON AND NORTHEAST OREGON Definitions § 956.13 Fiscal period. Fiscal...

  6. 7 CFR 958.112 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 958.112 Section 958.112 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Rules and Regulations § 958.112 Fiscal period. The...

  7. 7 CFR 1212.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1212.7 Section 1212.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS..., Consumer Education, and Industry Information Order Definitions § 1212.7 Fiscal period. “Fiscal...

  8. 7 CFR 925.112 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 925.112 Section 925.112 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... SOUTHEASTERN CALIFORNIA Rules and Regulations § 925.112 Fiscal period. Beginning January 1, 1988, fiscal...

  9. 7 CFR 906.15 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 906.15 Section 906.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Definitions § 906.15 Fiscal period. Fiscal...

  10. 7 CFR 1206.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Fiscal period. 1206.7 Section 1206.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... INFORMATION Mango Promotion, Research, and Information Order Definitions § 1206.7 Fiscal period. Fiscal...

  11. 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'…

  12. 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...

  13. Asymptotically periodic solutions of Volterra integral equations

    Directory of Open Access Journals (Sweden)

    Muhammad N. Islam

    2016-03-01

    Full Text Available We study the existence of asymptotically periodic solutions of a nonlinear Volterra integral equation. In the process, we obtain the existence of periodic solutions of an associated nonlinear integral equation with infinite delay. Schauder's fixed point theorem is used in the analysis.

  14. Local field effects in periodic metamaterials

    Science.gov (United States)

    Porvatkina, O. V.; Tishchenko, A. A.; Strikhanov, M. N.

    2016-08-01

    In this article we investigate dielectric and magnetic properties of periodic metamaterials taking into account the so-called local field effect, caused by interaction between single particles the material consists of. We also consider the spatial dispersion effects. As a result, generalized Clausius-Mossotti techniques have been extended to the case of periodic metamaterials; permittivity tensor and permeability tensor were obtained.

  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. 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

  17. 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.

  18. David's Understanding of Functions and Periodicity

    Science.gov (United States)

    Gerson, Hope

    2008-01-01

    This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David engaged…

  19. Short Periodicities in Latitudinal Variation of Sunspots

    Science.gov (United States)

    Kim, Bang-Yeop; Chang, Heon-Young

    2011-06-01

    The latitudinal variation of sunspots appearing during the period from 1874 to 2009 has been studied in terms of centerof- latitude (COL). The butterfly diagram has been used to study the evolution of the magnetic field and the dynamics at the bottom of the solar convection zone. Short-term periodicities have been of particular interest, in that they are somehow related to the structure and dynamics of the solar interior. We thus have focused our investigation on shortterm periodicities. We first calculated COL by averaging the latitude of sunspots with the weight function in area. Then, we analyzed the time series of COL using the wavelet transform technique. We found that a periodicity of ~5 years is the most dominant feature in the time series of COL, with the exception of the ~11 year solar cycle itself. This periodicity can be easily understood by considering small humps between the minima in the area-weighted butterfly diagram. However, we find that periodicities of ~1.3 (0.064), ~1.5 (0.056), or ~1.8 (0.046) years ( 1/ month ), which have been previously suggested as evidence of links between the changing structure of the sunspot zone and the tachocline rotation rate oscillations, are insignificant and inconsistent. We therefore conclude that the only existing short-term periodicity is of ~5 years, and that periodicities of ~1.3, ~1.5, or ~1.8 years are likely to be artifacts due to random noise of small sunspots.

  20. New Realization of Periodic Cycled Separation

    DEFF Research Database (Denmark)

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

    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...... trays. The proposed new periodic trays are shown to be advantageous compared to their continuous alternatives. It is demonstrated experimentally that periodic tray efficiencies of up to 300% are achievable. With the proposed new tray design, a new operation form is also introduced in which the trays...... are 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...

  1. Bounded Correctors in Almost Periodic Homogenization

    Science.gov (United States)

    Armstrong, Scott; Gloria, Antoine; Kuusi, Tuomo

    2016-10-01

    We show that certain linear elliptic equations (and systems) in divergence form with almost periodic coefficients have bounded, almost periodic correctors. This is proved under a new condition we introduce which quantifies the almost periodic assumption and includes (but is not restricted to) the class of smooth, quasiperiodic coefficient fields which satisfy a Diophantine-type condition previously considered by Kozlov (Mat Sb (N.S), 107(149):199-217, 1978). The proof is based on a quantitative ergodic theorem for almost periodic functions combined with the new regularity theory recently introduced by Armstrong and Shen (Pure Appl Math, 2016) for equations with almost periodic coefficients. This yields control on spatial averages of the gradient of the corrector, which is converted into estimates on the size of the corrector itself via a multiscale Poincaré-type inequality.

  2. On Orbital Period Changes in Nova Outbursts

    CERN Document Server

    Martin, Rebecca G; Schaefer, Bradley E

    2011-01-01

    We propose a new mechanism that produces an orbital period change during a nova outburst. When the ejected material carries away the specific angular momentum of the white dwarf, the orbital period increases. A magnetic field on the surface of the secondary star forces a fraction of the ejected material to corotate with the star, and hence the binary system. The ejected material thus takes angular momentum from the binary orbit and the orbital period decreases. We show that for sufficiently strong magnetic fields on the surface of the secondary star, the total change to the orbital period could even be negative during a nova outburst, contrary to previous expectations. Accurate determinations of pre- and post-outburst orbital periods of recurrent nova systems could test the new mechanism, in addition to providing meaningful constraints on otherwise difficult to measure physical quantities. We apply our mechanism to outbursts of the recurrent nova U Sco.

  3. On the Rotation Period of (90377) Sedna

    CERN Document Server

    Gaudi, B S; Hartman, J D; Holman, M J; McLeod, B A; Stanek, Krzysztof Z.; Hartman, Joel D.; Holman, Matthew J.; Leod, Brian A. Mc

    2005-01-01

    We present precise, ~1%, r-band relative photometry of the unusual solar system object (90377) Sedna. Our data consist of 143 data points taken over eight separate nights in October 2004 and January 2005. The RMS variability over the longest contiguous stretch of five nights of data spanning nine days is only ~1.3%. This subset of data alone constrain the amplitude of any long-period variations with period P to be A10 days, unless the intrinsic light curve has significant and comparable power on multiple timescales, which we argue is difficult. A sinusoidal fit yields a number of viable solutions, with a best-fit period of P=(10.273+/-0.003) hours and semi-amplitude of A=(1.0 +/- 0.1)%. Our results indicate that the period of Sedna is likely consistent with typical rotation periods of solar system objects, thus obviating the need for a massive companion to slow its rotation.

  4. Wave propagation in axially moving periodic strings

    Science.gov (United States)

    Sorokin, Vladislav S.; Thomsen, Jon Juel

    2017-04-01

    The paper deals with analytically studying transverse waves propagation in an axially moving string with periodically modulated cross section. The structure effectively models various relevant technological systems, e.g. belts, thread lines, band saws, etc., and, in particular, roller chain drives for diesel engines by capturing both their spatial periodicity and axial motion. The Method of Varying Amplitudes is employed in the analysis. It is shown that the compound wave traveling in the axially moving periodic string comprises many components with different frequencies and wavenumbers. This is in contrast to non-moving periodic structures, for which all components of the corresponding compound wave feature the same frequency. Due to this "multi-frequency" character of the wave motion, the conventional notion of frequency band-gaps appears to be not applicable for the moving periodic strings. Thus, for such structures, by frequency band-gaps it is proposed to understand frequency ranges in which the primary component of the compound wave attenuates. Such frequency band-gaps can be present for a moving periodic string, but only if its axial velocity is lower than the transverse wave speed, and, the higher the axial velocity, the narrower the frequency band-gaps. The revealed effects could be of potential importance for applications, e.g. they indicate that due to spatial inhomogeneity, oscillations of axially moving periodic chains always involve a multitude of frequencies.

  5. 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.

  6. 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.

  7. Numerical bifurcation of Hamiltonian relative periodic orbits

    DEFF Research Database (Denmark)

    Wulff, Claudia; Schilder, Frank

    2009-01-01

    that the family of choreographies rotating around the $e^2$-axis bifurcates to the family of rotating choreographies that connects to the Lagrange relative equilibrium. Moreover, we compute several relative period-doubling bifurcations and a turning point of the family of planar rotating choreographies, which...... to symmetry-breaking/symmetry-increasing pitchfork bifurcations or to period-doubling/period-halving bifurcations. We apply our methods to the family of rotating choreographies which bifurcate from the famous figure eight solution of the three-body problem as angular momentum is varied. We find...

  8. The Jovian period in the Sun?

    Science.gov (United States)

    Kotov, V. A.

    2015-09-01

    The 41-year measurements of the Doppler effect of the photosphere performed at the Crimean Astrophysical Observatory, discovered two periods of global oscillations of the Sun: 9600.606(12) s and 9597.929(15) s. Their beat period, 398.4(2.9) d, well agrees with a synodic orbital period of Jupiter, PJ = 398.9 d, raising a new problem for solar physics, cosmogony and cosmology. A hypothesis is advanced that the PJ beating of the Sun is induced by gravitation of Jupiter, revolving in a privileged reference system "the Sun - the Earth".

  9. Periodicity effects on compound guided waves

    Science.gov (United States)

    Chiadini, Francesco; Fiumara, Vincenzo; Scaglione, Antonio; Lakhtakia, Akhlesh

    2016-09-01

    Surface waves of different types can be compounded when a homogeneous layer is sandwiched between two half spaces filled with dissimilar periodically non-homogeneous dielectric materials and the intermediate layer is sufficiently thin. We solved the boundary-value problem for compound waves guided by a layer of a homogeneous and isotropic (metal or dielectric) material sandwiched between a structurally chiral material (SCM) and a periodically multi-layered isotropic dielectric material. We found that the periodicity of the SCM is crucial to excite a multiplicity of compound guided waves with strong coupling between the two interfaces.

  10. Investigation of periodic Ni–Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Veres, T., E-mail: veres.tamas@wigner.mta.hu [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Cser, L. [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Bodnarchuck, V.; Ignatovich, V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie st. 6, Dubna, Moscow Reg. 141980 (Russian Federation); Horváth, Z.E. [Research Centre for Natural Sciences, Institute for Technical Physics and Materials Science, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary); Nagy, B. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest H-1121, Konkoly-Thege út 29.-33. (Hungary)

    2013-07-01

    In order to improve the quality of neutron supermirrors periodic multilayers of various periods were prepared. The reflectivity properties of these systems were investigated using neutron and X-ray reflectometry. The obtained experimental results were compared with the calculated ones. The deviations from the proposed structure and calculated scattering length densities were investigated. In first approximation, the results proved the main features of the calculations. The roughness of different interfaces was also investigated. - Highlights: • Periodic Ni(Mo)/Ti multilayer samples were prepared by dc sputtering. • X-ray and neutron reflectivity measurements on the samples • Fitting and comparison with the proposed structure.

  11. Weight effects on the periodic ambiguity function

    Science.gov (United States)

    Getz, Benjamin; Levanon, Nadav

    1995-01-01

    CW radar signals and processors are discussed. The use of the periodic ambiguity function (PAF) to analyze the delay-Doppler performance of CW signals and their corresponding correlation receivers, is extended to include weight function effects. This work provides tools which can predict the delay-Doppler response of almost any phase-coded CW radar. Examples demonstrate that a combination of CW signals having perfect periodic autocorrelation, a matched reference signal with a large number of modulation periods and a smooth weight function, can create a delay-Doppler response with extremely low sidelobes, strongly resembling the response of a coherent pulse train.

  12. Diffraction Theory and Almost Periodic Distributions

    Science.gov (United States)

    Strungaru, Nicolae; Terauds, Venta

    2016-09-01

    We introduce and study the notions of translation bounded tempered distributions, and autocorrelation for a tempered distribution. We further introduce the spaces of weakly, strongly and null weakly almost periodic tempered distributions and show that for weakly almost periodic tempered distributions the Eberlein decomposition holds. For translation bounded measures all these notions coincide with the classical ones. We show that tempered distributions with measure Fourier transform are weakly almost periodic and that for this class, the Eberlein decomposition is exactly the Fourier dual of the Lebesgue decomposition, with the Fourier-Bohr coefficients specifying the pure point part of the Fourier transform. We complete the project by looking at few interesting examples.

  13. Periodic solutions of dissipative systems revisited

    Directory of Open Access Journals (Sweden)

    Górniewicz Lech

    2006-01-01

    Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

  14. Periodic solutions of dissipative systems revisited

    Directory of Open Access Journals (Sweden)

    Lech Górniewicz

    2006-05-01

    Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

  15. Period change in Magellanic Cloud Cepheids

    Energy Technology Data Exchange (ETDEWEB)

    Deasy, H.P.; Wayman, P.A. (Dunsink Observatory, Castleknock (Ireland))

    1985-01-15

    The data for period change in some 115 Cepheid variable stars in the Magellanic Clouds are presented. The accuracy of each determination is estimated and for all but three of the stars it is possible to estimate whether the rate of change of period prior to 1966/67 is maintained subsequently. About 40 per cent of the stars show period variations, similar to the percentage estimated for galactic Cepheids by a previous author. About half of these variations cannot be regarded as being constant in rate.

  16. Periodic Solutions of Periodic Delay Predator-Prey System with Nonmonotonic Functional Response

    Institute of Scientific and Technical Information of China (English)

    宋永利; 韩茂安

    2003-01-01

    By using the continuation theorem of coincidence degree theory, sufficient conditions are obtained for theexistence of positive periodic solutions of a delayed predator-prey system with nonmonotonic functional response ina periodic environment.

  17. EXISTENCE AND UNIQUENESS OF PERIODIC SOLUTIONS TO A HIGHER DIMENSIONAL PERIODIC SYSTEM WITH DELAY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper, using fixed point theorem, we discuss a higher dimensional nonautonomous periodic system with delay and give some suffcient criteria for the existence and uniqueness of periodic solution. Our results extend and improve some results in previous researches.

  18. 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.

  19. 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.

  20. 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.

  1. A method to compute periodic sums

    CERN Document Server

    Gumerov, Nail A

    2013-01-01

    In a number of problems in computational physics, a finite sum of kernel functions centered at $N$ particle locations located in a box in three dimensions must be extended by imposing periodic boundary conditions on box boundaries. Even though the finite sum can be efficiently computed via fast summation algorithms, such as the fast multipole method (FMM), the periodized extension is usually treated via a different algorithm, Ewald summation, accelerated via the fast Fourier transform (FFT). A different approach to compute this periodized sum just using a blackbox finite fast summation algorithm is presented in this paper. The method splits the periodized sum in to two parts. The first, comprising the contribution of all points outside a large sphere enclosing the box, and some of its neighbors, is approximated inside the box by a collection of kernel functions ("sources") placed on the surface of the sphere or using an expansion in terms of spectrally convergent local basis functions. The second part, compri...

  2. Quantum Chemistry via the Periodic Law.

    Science.gov (United States)

    Blinder, S. M.

    1981-01-01

    Describes an approach to quantum mechanics exploiting the periodic structure of the elements as a foundation for the quantum theory of matter. Indicates that a quantum chemistry course can be developed using this approach. (SK)

  3. Cascade of period doublings of tori

    Science.gov (United States)

    Arneodo, A.; Coullet, P. H.; Spiegel, E. A.

    1983-02-01

    A three-dimensional map is proposed to model the effects of periodic forcing on a system displaying a transition to chaos through a cascade of period-doubling bifurcations. The study outlined here raises the problem of the existence and bifurcation of invariant tori. A principal feature of the simulations of both the differential equations and the discrete dynamical systems is that it is possible to disrupt period-doubling sequences (and inverse sequences as well) by periodic external forcing. Even though the way in which this abortion works is not understood, the mechanism is thought to be associated with the destruction of tori (Aronson et al., 1982) when the system is on the verge of bifurcation. The simulations therefore suggest that in moving farther along the cascade, the tori become more fragile. It is suspected that for arbitrarily weak driving, the cascade will eventually be disrupted after the cascade has proceeded through a sufficient number of steps.

  4. Pole assignment in descriptor periodic systems

    Institute of Scientific and Technical Information of China (English)

    FAN; Hung-Yuan; LIN; Wen-Wei; XU; Shufang

    2005-01-01

    In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

  5. 5 CFR 2634.908 - Reporting periods.

    Science.gov (United States)

    2010-01-01

    ... DISCLOSURE, QUALIFIED TRUSTS, AND CERTIFICATES OF DIVESTITURE Confidential Financial Disclosure Reports § 2634.908 Reporting periods. (a) Incumbents. Each confidential financial disclosure report filed under... disclosure report filed under this part. (b) New entrants. Each confidential financial disclosure...

  6. Coping with Common Period Problems (For Teens)

    Science.gov (United States)

    ... Delayed Puberty Can Birth Control Help With Cramps? Female Athlete Triad Abnormal Uterine Bleeding (AUB) Irregular Periods Endometriosis Gyn Checkups Female Reproductive System All About Menstruation Polycystic Ovary Syndrome ...

  7. 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...

  8. 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...

  9. 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

    2016-03-07

    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.

  10. 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...

  11. 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)

  12. 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.

  13. 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)

  14. 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...

  15. The ACM Periodical Bank: A Retrospective View.

    Science.gov (United States)

    Clarke, Jack A.

    1980-01-01

    Evaluates a cooperative venture in interlibrary lending of periodicals planned and executed by ten midwestern colleges. The study traces the consortium's history from 1967 to the present, describing successes and problems. (RAA)

  16. Periodic orbits of planets in binary systems

    Science.gov (United States)

    Voyatzis, G.

    2017-03-01

    Periodic solutions of the three body problem are very important for understanding its dynamics either in a theoretical framework or in various applications in celestial mechanics. In this paper we discuss the computation and continuation of periodic orbits for planetary systems. The study is restricted to coplanar motion. Starting from known results of two-planet systems around single stars, we perform continuation of solutions with respect to the mass and approach periodic orbits of single planets in two-star systems. Also, families of periodic solutions can be computed for fixed masses of the primaries. When they are linearly stable, we can conclude about the existence of phase space domains of long-term orbital stability.

  17. 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.

  18. Period change in Magellanic Cloud Cepheids

    Science.gov (United States)

    Deasy, H. P.; Wayman, P. A.

    1985-01-01

    The data for period change in some 115 Cepheid variable stars in the Magellanic Clouds are presented. The accuracy of each determination is estimated and for all but three of the stars it is possible to estimate whether the rate of change of period prior to 1966/67 is maintained subsequently. About 40 per cent of the stars show period variations, similar to the percentage estimated for galactic Cepheids by Hoffmeister (1967). About half of these variations cannot be regarded as being constant in rate. Probably the interpretation of the data lies either in small atmospheric changes that produce phase-discontinuities that accumulate or in small luminosity changes that produce random period changes.

  19. Periodicity In The Intervals Between Primes

    Science.gov (United States)

    2015-07-02

    simple proportionality in Eq.(32), such that the basic form of Dc over the range (0,Γ] is repeated in progressively smaller scale over subsequent...striations are an aggregate visual effect that could be produced only from finely-grained periodicity in the δ- dependence of Dp. Figure (6) is a...a randomized analogue of the first 104 primes. indicates a certain ‘Russian dolls’-style self-similarity in the periodicity of the prime intervals

  20. Wavefunction Intensity Statistics from Unstable Periodic Orbits

    CERN Document Server

    Kaplan, L

    1998-01-01

    We examine the effect of short unstable periodic orbits on wavefunction statistics in a classically chaotic system, and find that the tail of the wavefunction intensity distribution in phase space is dominated by scarring associated with the least unstable periodic orbits. In an ensemble average over systems with classical orbits of different instabilities, a power law tail is found, in sharp contrast to the exponential prediction of random matrix theory. The calculations are compared with numerical data and quantitative agreement is obtained

  1. Obesity and exercise in adoloscent period

    OpenAIRE

    2011-01-01

                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 ...

  2. Pulsar PRS 0656 + 14 - Period and spindown

    Science.gov (United States)

    Domingue, D.; Rankin, J. M.; Weisberg, J. M.; Backus, P. R.

    1986-01-01

    Observations from various sources are used to explain the larger-than-expected period noted for pulsar 0656 + 14 on July 7, 1984 (Ashworth and Lyne, 1981). No indication of orbital motion was found, and most of the observations are consistent with a simple secular spindown. The derived period derivative of (54.3 + or - 1.3) x 10 to the -15th at epoch 2444300 is far greater than the previously reported value.

  3. 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.

  4. LOG PERIODIC DIPOLE ARRAY WITH PARASITIC ELEMENTS

    Science.gov (United States)

    The design and measured characteristics of dipole and monopole versions of a log periodic array with parasitic elements are discussed. In a dipole...array with parasitic elements, these elements are used in place of every alternate dipole, thereby eliminating the need of a twisted feed arrangement...for the elements to obtain log periodic performance of the anntenna. This design with parasitic elements lends itself to a monopole version of the

  5. Semiclassical quantization with short periodic orbits

    CERN Document Server

    Vergini, E G; Vergini, Eduardo G.; Carlo, Gabriel

    2000-01-01

    We apply a recently developed semiclassical theory of short peridic orbits to the stadium billiard. We give explicit expresions for the resonances of periodic orbits and for the application of the semiclassical Hamiltonian operator to them. Then, by using the 3 shortest periodic orbits and 2 more living in the bouncing ball region, we obtain the first 25 odd-odd eigenfunctions with surprising accuracy.

  6. Periodic body-and-bar frameworks

    CERN Document Server

    Borcea, Ciprian S; Tanigawa, Shin-ichi

    2011-01-01

    Abstractions of crystalline materials known as periodic body-and-bar frameworks are made of rigid bodies connected by fixed-length bars and subject to the action of a group of translations. In this paper, we give a Maxwell-Laman characterization for generic minimally rigid periodic body-and-bar frameworks. As a consequence we obtain efficient polynomial time algorithms for their recognition based on matroid partition and pebble games.

  7. Reducing or enhancing chaos using periodic orbits.

    Science.gov (United States)

    Bachelard, R; Chandre, C; Leoncini, X

    2006-06-01

    A method to reduce or enhance chaos in Hamiltonian flows with two degrees of freedom is discussed. This method is based on finding a suitable perturbation of the system such that the stability of a set of periodic orbits changes (local bifurcations). Depending on the values of the residues, reflecting their linear stability properties, a set of invariant tori is destroyed or created in the neighborhood of the chosen periodic orbits. An application on a paradigmatic system, a forced pendulum, illustrates the method.

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

    Directory of Open Access Journals (Sweden)

    Massa D.

    2006-11-01

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

  9. The periodicity of the eta Carinae events

    CERN Document Server

    Damineli, A; Hillier, D J; Stahl, O; Levenhagen, R S; Leister, N V; Groh, J H; Teodoro, M; Colombo, J F Albacete; Gonzalez, F; Arias, J; Levato, H; Grosso, M; Morrell, N; Gamen, R; Wallerstein, G; Niemela, V

    2007-01-01

    Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of 2022.7+-1.3 d. Spectroscopic data collected during the last 60 years yield an average period of 2020+-4 d, consistent with the present day period. The period cannot have changed by more than $\\Delta$P/P=0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of HeI 6678 to define the epoch of the Cycle 11 minimum, T_0=JD 2,452,819.8. The next event is predicted to occur on 2009 January 11 (+-2 days). The d...

  10. 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 parti......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...... periodic modulation of an electron gas leads to the emergence of localized defect states with energies within the band gap, where no propagating modes exist. Secondly, the divergence of the photonic density of states near a photonic band gap leads to strongly modified light-matter interactions, which has...... 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 divergence...

  11. Physical explanation of the periodic table.

    Science.gov (United States)

    Ostrovsky, V N

    2003-05-01

    The Periodic Table of the elements, the most important generalization in chemistry, is often considered as a representative special case in the study of the relation between chemistry and physics. Its quantum interpretation was initiated, but not completed, by Niels Bohr. In this paper, post-Bohr conceptual developments are discussed from historical and epistemological points of view. The difference between high-precision numerical calculations for individual atoms and the theory of the periodic system as a whole is emphasized. Periodic laws met in Nature are not restricted to the chemical Periodic Table. A comparative study of these laws makes it possible to single out essential features that define the particular pattern of periodicity. It is shown that the periodic system of neutral ground state atoms now has a firm nonempirical quantum-theoretical basis. Alternative approaches, based on group theory and other mathematical schemes, are briefly discussed. It is argued that, while quantum theory is capable of fully accurate calculations for relatively simple atoms or molecular objects, the complexity of polyatomic molecules and chemical reactions guarantees the flourishing of chemistry as a separate scientific discipline.

  12. Period, Place and Mental Space: Using Historical Scholarship to Develop Year 7 Pupils' Sense of Period

    Science.gov (United States)

    Smith, Dan

    2014-01-01

    What is a sense of period? And how can pupils' sense of period be developed? Questions such as these have troubled history teachers for many years, often revolving around debates over the role played by empathy and imagination in coming to know a period on its own terms. Rather than adopt a comparative approach, Dan Smiths decided in his teaching…

  13. 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…

  14. Frequency selective surfaces with multiple periodic elements

    Science.gov (United States)

    Reed, Jeffrey Alan

    A thorough computer design study using the method of Chen1,2,3 was undertaken for band-pass filters constructed from frequency selective surfaces (FSSs). The FSSs, modeled as thin, perfectly conducting surfaces with periodically arranged apertures, were designed to produce a transmission profile with a bandpass characteristic centered at 10.6 μm and to have various specified bandwidths. The effects of aperture shape and dimensions, configuration and periodicity of the aperture array, and presence of a dielectric substrate were examined in- depth. For comparison purposes, a complimentary array of metallic patches was also examined. The successful design (a thin, planar sheet of aluminum perforated with narrow rectangular apertures in a triangular array configuration on a thick zinc selenide substrate) provided a preliminary set of basic design rules for creating bandpass filters from FSSs. Dual resonance transmission profiles were generated by considering a FSS with a group of apertures as the periodic element. Chen's method1,2,3 was modified to work with periodic groups of up to four rectangular or circular shaped apertures (or metallic patches). Combinations of different length narrow slot apertures, combinations of square and narrow slot apertures, and variation of periodicity along alternating rows of narrow slot apertures, all produced a dual resonance transmission profile in the computer model. For the combination of different length narrow apertures, the dual resonance resulted from the natural resonance associated with the two different length narrow apertures, while for the combination of squares and narrow slots, an enhancement of the Wood's anomaly at the diffraction edge created the second resonance peak. Variation of the periodicity along alternating rows produced a dual resonance because each of the 'superimposed arrays' had a different periodicity. The presence of Wood's anomalies in the transmission profile was also examined. Finally, 'proof of

  15. Comparison of Characteristics of Periodic and Non-Periodic Defected Ground Structures

    Institute of Scientific and Technical Information of China (English)

    LI Yuan; LI Huancai; DING Ronglin

    2006-01-01

    The filter characteristic of defected ground structure(DGS)is analyzed and the equivalent circuit of C-shaped DGS is extracted. The characteristics of non-periodic and periodic DGS with different dimensions are compared. Then the DGS is simulated and optimized with software, and the circuit board is manufactured and measured. The non-periodic structure is simple in structure and small in size and ripple compared with the periodic structure. Though the stop band of the non-periodic structure is narrow, it can meet the requirement of application. The C-shaped structure with two stop bands can select frequency in a special band.

  16. 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.

  17. Comparison of Single Periodical Control With Multiple-Periodical Sporadic Control Using Wavelet Feedback

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It should be pointed out that there are two ways of applying nonlinear control using the wavelet-based feedback control: the single periodical (ΔP =1) control and multiple-periodical sporadic (interval)(ΔP≥2) control for controlling beam halo-chaos.Table 1 shows a comparison of results obtained before and after wavelet-based feedback controller at the 1 800th period. It is seen from table 1 that multiple-periodical sporadic (interval) control can also reach the same good results as the single periodical control, but it has much higher economic impact on practical application.

  18. THE CATALINA SURVEYS PERIODIC VARIABLE STAR CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Drake, A. J.; Graham, M. J.; Djorgovski, S. G.; Mahabal, A. A.; Donalek, C.; Williams, R. [California Institute of Technology, 1200 East California Boulevard, CA 91225 (United States); Catelan, M.; Torrealba, G. [Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Facultad de Física, Av. Vicuña Mackena 4860, 782-0436 Macul, Santiago (Chile); García-Álvarez, D. [Instituto de Astrofísica de Canarias, Avenida Vía Láctea, E-38205 La Laguna, Tenerife (Spain); Prieto, J. L.; Beshore, E. [Department of Astronomy, Princeton University, 4 Ivy Ln., Princeton, NJ 08544 (United States); Larson, S.; Christen sen, E.; Boattini, A.; Gibbs, A.; Hill, R.; Kowalski, R.; Johnson, J. [Department of Planetary Sciences, Lunar and Planetary Laboratory, The University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States); Belokurov, V.; Koposov, S. E. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); and others

    2014-07-01

    We present ∼47,000 periodic variables found during the analysis of 5.4 million variable star candidates within a 20,000 deg{sup 2} region covered by the Catalina Surveys Data Release-1 (CSDR1). Combining these variables with type ab RR Lyrae from our previous work, we produce an online catalog containing periods, amplitudes, and classifications for ∼61,000 periodic variables. By cross-matching these variables with those from prior surveys, we find that >90% of the ∼8000 known periodic variables in the survey region are recovered. For these sources, we find excellent agreement between our catalog and prior values of luminosity, period, and amplitude as well as classification. We investigate the rate of confusion between objects classified as contact binaries and type c RR Lyrae (RRc's) based on periods, colors, amplitudes, metallicities, radial velocities, and surface gravities. We find that no more than a few percent of the variables in these classes are misidentified. By deriving distances for this clean sample of ∼5500 RRc's, we trace the path of the Sagittarius tidal streams within the Galactic halo. Selecting 146 outer-halo RRc's with SDSS radial velocities, we confirm the presence of a coherent halo structure that is inconsistent with current N-body simulations of the Sagittarius tidal stream. We also find numerous long-period variables that are very likely associated within the Sagittarius tidal stream system. Based on the examination of 31,000 contact binary light curves we find evidence for two subgroups exhibiting irregular light curves. One subgroup presents significant variations in mean brightness that are likely due to chromospheric activity. The other subgroup shows stable modulations over more than a thousand days and thereby provides evidence that the O'Connell effect is not due to stellar spots.

  19. Auditory sustained field responses to periodic noise

    Directory of Open Access Journals (Sweden)

    Keceli Sumru

    2012-01-01

    Full Text Available Abstract Background Auditory sustained responses have been recently suggested to reflect neural processing of speech sounds in the auditory cortex. As periodic fluctuations below the pitch range are important for speech perception, it is necessary to investigate how low frequency periodic sounds are processed in the human auditory cortex. Auditory sustained responses have been shown to be sensitive to temporal regularity but the relationship between the amplitudes of auditory evoked sustained responses and the repetitive rates of auditory inputs remains elusive. As the temporal and spectral features of sounds enhance different components of sustained responses, previous studies with click trains and vowel stimuli presented diverging results. In order to investigate the effect of repetition rate on cortical responses, we analyzed the auditory sustained fields evoked by periodic and aperiodic noises using magnetoencephalography. Results Sustained fields were elicited by white noise and repeating frozen noise stimuli with repetition rates of 5-, 10-, 50-, 200- and 500 Hz. The sustained field amplitudes were significantly larger for all the periodic stimuli than for white noise. Although the sustained field amplitudes showed a rising and falling pattern within the repetition rate range, the response amplitudes to 5 Hz repetition rate were significantly larger than to 500 Hz. Conclusions The enhanced sustained field responses to periodic noises show that cortical sensitivity to periodic sounds is maintained for a wide range of repetition rates. Persistence of periodicity sensitivity below the pitch range suggests that in addition to processing the fundamental frequency of voice, sustained field generators can also resolve low frequency temporal modulations in speech envelope.

  20. Estudio geocientífico aplicado a la evaluación de la aptitud para la urbanización en la cuenca carbonífera de Río Turbio, Santa Cruz Geoscientific study applied to the evaluation of urbanisation suitability at the carboniferous basin of Río Turbio, Santa Cruz

    Directory of Open Access Journals (Sweden)

    Fernando Pereyra

    2010-06-01

    Full Text Available Se realizó un estudio geocientífico para la evaluación de la aptitud para la urbanización en la cuenca carbonífera de Río Turbio. Este estudio incluyó la caracterización de los recursos naturales: suelos, agua y paisaje y la evaluación de áreas de riesgo natural y antrópico, la pérdida de espacios verdes y tierras agrícolas. La zona implicada se encuentra localizada en el extremo SO de la provincia de Santa Cruz. Conforma la llamada cuenca carbonífera del Río Turbio. Las localidades de Río Turbio y 28 de Noviembre exhiben el mayor número poblacional. Estas poblaciones se desarrollaron a partir de la actividad minera y ganadera. En función de las características geológicas, geomorfológicas, bióticas, geotécnicas, hidrológicas y edafológicas, se han diferenciado 7 unidades de paisaje. A partir de la información generada previamente y como insumo básico para la producción del plan de desarrollo urbano, se ha realizado un mapa de aptitud para la urbanización del área. Las unidades de paisaje con mejores posibilidades para la expansión urbana son dos: Morenas con estepa herbácea y planicies glacifluviales con estepa mixta. La unidad paisaje erosivo glaciar con bosque y la unidad terrazas fluviales son aceptables para la urbanización, mientras que las unidades: Cañadones y pendientes aluvio-coluviales, serranías poligenéticas terciarias y mallines y bajos, son inapropiadas para la urbanización, por diferentes motivos.A geoscientific study was accomplished to evaluate suitability for urban developments the in carboniferous basin of the Turbio River. This research included the characterization of natural resources: soil, water and landscape; the evaluation of natural and anthropic hazardous areas and the loss of farming and green lands. The implied area is located in the SW end of the Province of Santa Cruz. It is part of the carboniferous basin of the River Turbio. The towns of Rio Turbio and 28 de Noviembre hold

  1. 新疆库鲁克塔格阿訇开里得南石炭纪花岗岩LA-ICP-MS锆石U-Pb定年及其地质意义%Zircon LA-ICP-MS U-Pb dating of South Ahongkailide Carbonifereous granite in Kuruktag of Xinjiang and its geological implications

    Institute of Scientific and Technical Information of China (English)

    尼加提·阿布都逊; 郭瑞清; 帕拉提·阿布都卡迪尔; 贾晓亮; 秦切; 朱志新; 王克卓

    2013-01-01

    对出露于新疆库鲁克塔格地块西段的阿訇开里得南花岗岩进行了详细的岩石学、地球化学及锆石U-Pb定年研究,并探讨了其构造背景及地质意义.岩体LA-ICP-MS锆石U-Pb原位定年获得年龄为340.6Ma±5.7Ma,属于石炭纪花岗岩.地球化学分析显示岩体具高硅、高铝、高钾,贫钠、低钙、低磷、低钛和贫镁的特征,铝饱和指数(A/CNK)为1.14~2.31,CIPW标准刚玉分子大于1%,属高钾钙碱性过铝质花岗岩.在稀土元素球粒陨石标准化配分模式图上,轻稀土元素(LREE)富集、重稀土元素(HREE)亏损,轻重稀土元素分馏明显,Eu出现中等负异常(δEu=0.52~0.62);在微量元素原始地幔标准化蛛网图上,明显富集大离子亲石元素Rb、Ba、Th和K,亏损高场强元素Nb、Ta、Ti.综合分析研究认为,岩体的形成与加厚地壳引起的地壳重熔有关,反映了塔里木板块与伊犁-中天山板块陆-陆碰撞的岩浆活动.%The South Ahongkailide Carboniferous granite is exposed in the west segment of Kuruktag block in Xinjiang. This paper has studied petrographical, geochemical and zircon U-Pb chronolgical characteristics of this granite as well as its petrogenesis and geological significance. Zircon LA-ICP-MS dating yielded the age of 340.6Ma±5.7Ma, implying that the magmatic crystallization epoch of the granite is Carboniferous. Geochemical analyses show that the granite has high SiO2, A12O3, K2O but relatively low CaO, P2O5, TiO2 and MgO. The ratios of A/CNK vary from 1.14 to 2.31, suggesting high-K calc- alkaline peraluminous syn-collision granite. The chondrite-normalized REE patterns show that the granite is enriched in LREE but depleted in HREE, with high fractionations between LREE and HREE and moderate negative Eu anomalies ((δEu=0.52~0.62). In addition, the granite is relatively rich in such LILEs as Rb,Ba.Th and K, but poor in such HFSEs as Nb, Ta and Ti, with relative enrichment of Ce in the primitive mantle

  2. Periodic power spectrum with applications in detection of latent periodicities in DNA sequences.

    Science.gov (United States)

    Yin, Changchuan; Wang, Jiasong

    2016-11-01

    Periodic elements play important roles in genomic structures and functions, yet some complex periodic elements in genomes are difficult to detect by conventional methods such as digital signal processing and statistical analysis. We propose a periodic power spectrum (PPS) method for analyzing periodicities of DNA sequences. The PPS method employs periodic nucleotide distributions of DNA sequences and directly calculates power spectra at specific periodicities. The magnitude of a PPS reflects the strength of a signal on periodic positions. In comparison with Fourier transform, the PPS method avoids spectral leakage, and reduces background noise that appears high in Fourier power spectrum. Thus, the PPS method can effectively capture hidden periodicities in DNA sequences. Using a sliding window approach, the PPS method can precisely locate periodic regions in DNA sequences. We apply the PPS method for detection of hidden periodicities in different genome elements, including exons, microsatellite DNA sequences, and whole genomes. The results show that the PPS method can minimize the impact of spectral leakage and thus capture true hidden periodicities in genomes. In addition, performance tests indicate that the PPS method is more effective and efficient than a fast Fourier transform. The computational complexity of the PPS algorithm is [Formula: see text]. Therefore, the PPS method may have a broad range of applications in genomic analysis. The MATLAB programs for implementing the PPS method are available from MATLAB Central ( http://www.mathworks.com/matlabcentral/fileexchange/55298 ).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-15

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

  4. Period analysis of the Piccardi P test

    Energy Technology Data Exchange (ETDEWEB)

    Majorino, G. (Milan Univ. (Italy). Ist. di Chimica Fisica); Zecca, L. (Milan Univ. (Italy). Ist. di Farmacologia)

    1981-12-01

    The Piccardi P test is a method to evaluate the difference between the sedimentation rate of a colloid under a copper screen and in open air. Three different sets of daily test values, collected in Florence in the period 1955-1972, have been considered. Each set has been analyzed with a 5 component Fourier expansion, varying the T period of the maximum component between 6 and 300 months. The best agreement between experimental and theoretical data has been obtained for T = 12 years. Repeating the computation with a 10 component expansion, this value is modified to T = 22.5 years, and another optimum fit at T = 24 years. Those results confirm the Piccardi hypothesis about the connection between the solar cycle and the P test trend. Further confirmation has been obtained by comparing the Wolf sunspot number trend for the period 1954-1974 with the T values obtained by separately analyzing the periods 1955-1966 and 1966-1972. A more detailed analysis of the short period components stresses the importance of seasonal and annual components.

  5. Visible periodicity of strong nucleosome DNA sequences.

    Science.gov (United States)

    Salih, Bilal; Tripathi, Vijay; Trifonov, Edward N

    2015-01-01

    Fifteen years ago, Lowary and Widom assembled nucleosomes on synthetic random sequence DNA molecules, selected the strongest nucleosomes and discovered that the TA dinucleotides in these strong nucleosome sequences often appear at 10-11 bases from one another or at distances which are multiples of this period. We repeated this experiment computationally, on large ensembles of natural genomic sequences, by selecting the strongest nucleosomes--i.e. those with such distances between like-named dinucleotides, multiples of 10.4 bases, the structural and sequence period of nucleosome DNA. The analysis confirmed the periodicity of TA dinucleotides in the strong nucleosomes, and revealed as well other periodic sequence elements, notably classical AA and TT dinucleotides. The matrices of DNA bendability and their simple linear forms--nucleosome positioning motifs--are calculated from the strong nucleosome DNA sequences. The motifs are in full accord with nucleosome positioning sequences derived earlier, thus confirming that the new technique, indeed, detects strong nucleosomes. Species- and isochore-specific variations of the matrices and of the positioning motifs are demonstrated. The strong nucleosome DNA sequences manifest the highest hitherto nucleosome positioning sequence signals, showing the dinucleotide periodicities in directly observable rather than in hidden form.

  6. The Last Element of Mendeleev's Periodic Table

    Science.gov (United States)

    Khazan, Albert

    2010-02-01

    Despite much achievements of the synthesis for super-heavy elements (10 new elements were obtained during the last 25 years), the experts in Mendeleev's Periodic Table have not answered the most fundamental question: where the Table ends? The calculations produced on the basis of Quantum Mechanics (the physical conditions in micro-scales) do not not answer this question till now. In my study of chemical compounds, I focused onto the physical conditions observed in macro-scales (the subjects of the regular physics and chemistry). Thus, the Law of Hyperboles was discovered in the Periodic Table: given any chemical compound, the contents of any element in it (per 1 gram-atom), including the contents of unknown elements, whose atomic masses can be set up arbitrarily, is described by the equation of a equilateral hyperbola Y=K/X. The tops of all the arcs are distributed along a real axis crossing the line Y=1 in the point of abscissa 411.66, which manifests the actual atomic mass of the last (heaviest) element of the Periodic Table: its location is Period 8, Group 1; its atomic mass is 411.66, its number is 155 (Khazan A. Upper Limit in Mendeleev's Periodic Table --- Element No.155. Svenska fysikarkivet, 2009). )

  7. 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.

  8. Planar glass devices for efficient periodic poling

    DEFF Research Database (Denmark)

    Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin

    2005-01-01

    We demonstrate that frequency-converting devices of high quality can be realised with glass poling. The devices, made with silica-on-silicon technology, are poled with periodic, embedded electrodes, and used for second-harmonic generation. We obtain precise control of the quasi phase-matching wav......We demonstrate that frequency-converting devices of high quality can be realised with glass poling. The devices, made with silica-on-silicon technology, are poled with periodic, embedded electrodes, and used for second-harmonic generation. We obtain precise control of the quasi phase......-matching wavelength and bandwidth, and a normalised conversion efficiency of 1.4×10-3 %/W/cm2 which, to our knowledge, is the highest obtained so far with periodic glass poling....

  9. 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...

  10. Thirty-Year Periodicity of Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Jorge Pérez-Peraza

    2012-01-01

    Full Text Available Cosmogenic isotopes have frequently been employed as proxies of ancient cosmic ray fluxes. On the basis of periodicities of the 10Be time series (using data from both the South and North Poles and the 14C time series (with data from Intercal-98, we offer evidence of the existence of cosmic ray fluctuations with a periodicity of around 30 years. Results were obtained by using the wavelet transformation spectral technique, signal reconstruction by autoregressive spectral analysis (ARMA, and the Lomb-Scargle periodogram method. This 30-year periodicity seems to be significant in nature because several solar and climatic indexes exhibit the same modulation, which may indicate that the 30-year frequency of cosmic rays is probably a modulator agent for terrestrial phenomena, reflecting the control source, namely, solar activity.

  11. 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...

  12. Periodic wrappings in coded aperture imaging

    Science.gov (United States)

    Shutler, Paul M. E.; Springham, Stuart V.; Talebitaher, Alireza

    2014-02-01

    We classify all coded masks onto which cyclic difference sets can be wrapped periodically using a generalization of the Finger and Prince construction. In particular, we establish simple numerical criteria which determine whether any given mask can be wrapped periodically in this way and, for each mask which can, we provide explicit constructions which will produce at least one such wrapping. We show that all periodic wrappings currently reported in the literature are special cases of our explicit constructions, and we often provide simpler alternatives. Using these constructions we show that all Singer cyclic difference sets of practical size and open fraction can be wrapped exactly onto masks which are very nearly as compact and symmetrical as hexagons, without the need for pixel padding.

  13. Periodic solutions of Volterra integral equations

    Directory of Open Access Journals (Sweden)

    M. N. Islam

    1988-01-01

    Full Text Available Consider the system of equationsx(t=f(t+∫−∞tk(t,sx(sds,           (1andx(t=f(t+∫−∞tk(t,sg(s,x(sds.       (2Existence of continuous periodic solutions of (1 is shown using the resolvent function of the kernel k. Some important properties of the resolvent function including its uniqueness are obtained in the process. In obtaining periodic solutions of (1 it is necessary that the resolvent of k is integrable in some sense. For a scalar convolution kernel k some explicit conditions are derived to determine whether or not the resolvent of k is integrable. Finally, the existence and uniqueness of continuous periodic solutions of (1 and (2 are btained using the contraction mapping principle as the basic tool.

  14. Periodic billiard trajectories in polygons: generating mechanisms

    Science.gov (United States)

    Vorobets, Ya B.; Gal'perin, G. A.; Stepin, Anatolii M.

    1992-06-01

    CONTENTSIntroduction §1. Billiard trajectories in a plane domain §2. Fagnano's problem. Mechanical interpretations of periodic trajectories in triangles §3. An extremal property of billiard trajectories. Birkhoff's theorem. The non-existence of a unified construction of periodic trajectories in obtuse triangles §4. 'Perpendicular' trajectories in obtuse triangles of special shape §5. 'Perpendicular' trajectories in rational polygons and polyhedra §6. Stable trajectories §7. Stable perpendicular trajectories §8. Isolated trajectories §9. Isolated trajectories in acute and obtuse triangles. The bifurcation diagram of isolated trajectories (a 'hang-glider' configuration) §10. The density of F-triangles in a neighbourhood of (0, 0) §11. Generalization of the construction of isolated trajectories in obtuse triangles §12. Stable and unstable billiard trajectories in plane Weyl chambers §13. A criterion for the stability of periodic trajectories in a regular hexagonConclusionReferences

  15. Diffraction of limit periodic point sets

    CERN Document Server

    Baake, Michael

    2010-01-01

    Limit periodic point sets are aperiodic structures with pure point diffraction supported on a countably, but not finitely generated Fourier module that is based on a lattice and certain integer multiples of it. Examples are cut and project sets with p-adic internal spaces. We illustrate this by explicit results for the diffraction measures of two examples with 2-adic internal spaces. The first and well-known example is the period doubling sequence in one dimension, which is based on the period doubling substitution rule. The second example is a weighted planar point set that is derived from the classic chair tiling in the plane. It can be described as a fixed point of a block substitution rule.

  16. Periodicity in Delta-modulated feedback control

    Institute of Scientific and Technical Information of China (English)

    Xiaohua XIA; Guanrong CHEN; Rudong GAI; Alan S. I. ZINOBER

    2008-01-01

    The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with "leaky" integration is completely characterized by some interesting groups of polynomials with "sign" coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the "downlink", unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.

  17. Onsager coefficients for systems with periodic potentials

    Science.gov (United States)

    Rosas, Alexandre; Van den Broeck, Christian; Lindenberg, Katja

    2016-11-01

    We carry out the thermodynamic analysis of a Markovian stochastic engine, driven by a spatially and temporally periodic modulation in a d -dimensional space. We derive the analytic expressions for the Onsager coefficients characterizing the linear response regime for the isothermal transfer of one type of work (a driver) to another (a load), mediated by a stochastic time-periodic machine. As an illustration, we obtain the explicit results for a Markovian kangaroo process coupling two orthogonal directions and find extremely good agreement with numerical simulations. In addition, we obtain and discuss expressions for the entropy production, power, and efficiency for the kangaroo process.

  18. The postpartum period in women with epilepsy.

    Science.gov (United States)

    Klein, Autumn

    2012-08-01

    For women with epilepsy (WWE), the postpartum period is a vulnerable time owing to medication alterations, disrupted sleep, increased stress, and the challenges of breastfeeding. Sleep deprivation and the stress of having a new child can be challenging for WWE. Concerns over antiepileptic drugs (AEDs) in breast milk and sleep disruption associated with breastfeeding leads some WWE to discontinue breastfeeding. Adjustment of AEDs in the postpartum period can lead to difficulties in seizure control. Postpartum depression is increased in WWE, and patient education about newborn safety remains a concern. This article covers these important topics in postpartum WWE.

  19. 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.

  20. [Hypoglycaemic periodic paralysis in hyperthyroidism patients].

    Science.gov (United States)

    Kratochvíl, J; Masopust, J; Martínková, V; Charvát, J

    2008-11-01

    Hypokalemic periodic paralysis (HPP) is a rare disorder characterised by acute, potentially fatal atacks of muscle weakness or paralysis. Massive shift of potassium into cells is caused by elevated levels of insulin and catecholamines in the blood. Hypophosphatemia and hypomagnesemia may be also present. Acidobasic status usually is not impaired. HPP occurs as familiar (caused by ion channels inherited defects) or acquired (in patients with hyperthyroidism). On the basis of two clinical cases we present a review of hypokalemic periodic paralysis in hyperthyroid patients. We discuss patogenesis, clinical and laboratory findings as well as the principles of prevention and treatment of this rare disorder.

  1. Chaos, Order Statistics and Unstable Periodic Orbits

    CERN Document Server

    Valsakumar, M C; Kanmani, S

    1999-01-01

    We present a new method for locating unstable periodic points of one dimensional chaotic maps. This method is based on order statistics. The densities of various maxima of the iterates are discontinuous exactly at unstable periodic points of the map. This is illustrated using logistic map where densities corresponding to a small number of iterates have been obtained in closed form. This technique can be applied to the class of continuous time systems where the successive maxima of the time series behave as if they were generated from a unimodal map. This is demonstrated using Lorenz model.

  2. Mathematics of Periodic Tables for Benzenoid Hydrocarbons.

    Science.gov (United States)

    Dias, Jerry Ray

    2007-01-01

    The upper and lower bounds for invariants of polyhex systems based on the Harary and Harborth inequalities are studied. It is shown that these invariants are uniquely correlated by the Periodic Table for Benzenoid Hydrocarbons. A modified periodic table for total resonant sextet (TRS) benzenoids based on the invariants of Ds and r(empty) is presented; Ds is the number of disconnections among the empty rings for fused TRS benzenoid hydrocarbons. This work represents a contribution toward deciphering the topological information content of benzenoid formulas.

  3. Reconstruction of periodic signals using neural networks

    Directory of Open Access Journals (Sweden)

    José Danilo Rairán Antolines

    2014-01-01

    Full Text Available In this paper, we reconstruct a periodic signal by using two neural networks. The first network is trained to approximate the period of a signal, and the second network estimates the corresponding coefficients of the signal's Fourier expansion. The reconstruction strategy consists in minimizing the mean-square error via backpro-pagation algorithms over a single neuron with a sine transfer function. Additionally, this paper presents mathematical proof about the quality of the approximation as well as a first modification of the algorithm, which requires less data to reach the same estimation; thus making the algorithm suitable for real-time implementations.

  4. 7 CFR 247.16 - Certification period.

    Science.gov (United States)

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS COMMODITY SUPPLEMENTAL FOOD PROGRAM § 247.16 Certification period. (a.... However, pregnant women may be certified to participate for the duration of their pregnancy and for up...

  5. Theory of periodic conjugate heat transfer

    CERN Document Server

    Zudin, Yuri B

    2016-01-01

    This book presents the theory of periodic conjugate heat transfer in detail. It offers 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.

  6. Teaching the Hitler Period: History and Morality.

    Science.gov (United States)

    Mork, Gordon R.

    1980-01-01

    Outlines six approaches used in a university history course which address the problems of teaching the Hitler period. The assumption underlying all the approaches is that Americans are not entirely different from Germans and that they may be faced with similar moral choices. The approaches avoid the didactic moralism often taught about this era.…

  7. The Long Period of 2675 Tolkien

    Science.gov (United States)

    Durkee, Russell I.; Brinsfield, James W.; Hornoch, Kamil; Kuönirak, Petr

    2011-10-01

    Lightcurve measurements of 2675 Tolkien from the Shed of Science, Via Capote Observatory, and Ondrejov Observatory were taken on twenty-three nights; a period of P = 1058 ± 30 hrs, A = 0.75 ± 0.1 mag were derived.

  8. 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.

  9. 42 CFR 423.38 - Enrollment periods.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Enrollment periods. 423.38 Section 423.38 Public... material provision of its contract under this part in relation to the individual, including, but not... in marketing the plan to the individual. (ii) The individual meets other exceptional circumstances...

  10. 7 CFR 930.7 - Fiscal period.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Fiscal period. 930.7 Section 930.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TART CHERRIES GROWN IN THE STATES...

  11. Periodic Solutions for Highly Nonlinear Oscillation Systems

    DEFF Research Database (Denmark)

    Ghadimi, M; Barari, Amin; Kaliji, H.D;

    2012-01-01

    In this paper, Frequency-Amplitude Formulation is used to analyze the periodic behavior of tapered beam as well as two complex nonlinear systems. Many engineering structures, such as offshore foundations, oil platform supports, tower structures and moving arms, are modeled as tapered beams...

  12. The Maslov indices of Hamiltonian periodic orbits

    Energy Technology Data Exchange (ETDEWEB)

    Gosson, Maurice de [Blekinge Institute of Technology, SE 371 79 Karlskrona (Sweden); Gosson, Serge de [Vaexjoe University (MSI), SE 351 95 Vaexjoe (Sweden)

    2003-12-05

    We use the properties of the Leray index to give precise formulae in arbitrary dimensions for the Maslov index of the monodromy matrix arising in periodic Hamiltonian systems. We compare our index with other indices appearing in the literature. (letter to the editor)

  13. On the periodic "good" Boussinesq equation

    CERN Document Server

    Farah, Luiz Gustavo

    2009-01-01

    We study the well-posedness of the initial-value problem for the periodic nonlinear "good" Boussinesq equation. We prove that this equation is local well-posed for initial data in Sobolev spaces \\textit{$H^s(\\T)$} for $s>-1/4$, the same range of the real case obtained in Farah \\cite{LG4}.

  14. Forecasting with periodic autoregressive time series models

    NARCIS (Netherlands)

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

    1999-01-01

    textabstractThis paper is concerned with forecasting univariate seasonal time series data using periodic autoregressive models. We show how one should account for unit roots and deterministic terms when generating out-of-sample forecasts. We illustrate the models for various quarterly UK consumption

  15. Pacer cell response to periodic Zeitgebers

    NARCIS (Netherlands)

    Beersma, D.G.M.; Broer, H.W.; Efstathiou, K.; Gargar, K.A.; Hoveijn, I.

    2011-01-01

    Almost all organisms show some kind of time periodicity in their behavior. In mammals, the neurons of the suprachiasmatic nucleus form a biological clock regulating the activity–inactivity cycle of the animal. The main question is how this clock is able to entrain to the natural 24 h light–dark cycl

  16. The periodic complex method in interpolation spaces

    CERN Document Server

    Avni, Eliran

    2012-01-01

    We discuss a question which relates to Calderon's complex interpolation method. More precisely, we will consider the so-called "periodic" complex interpolation method, studied by Peetre. (Which also corresponds to the spaces obtained by Calderon's construction using Banach space valued analytic functions, but defined on an annulus instead of the strip used by Calderon.) Cwikel showed that, using functions with a given period i\\lambda in the complex method mechanism, one obtains the same interpolation spaces as in the original version of the complex method, up to equivalence of norms. He also showed that one of the constants of this equivalence will, in some cases, "blow up" as \\lambda tends to zero. We will show that the equivalence constants tend to 1 as \\lambda tends to infinity. Intuitively, this means that when applying the complex method, it makes a very small difference if one restricts oneself to periodic functions, provided that the period is very large (or the corresponding annulus is very thin).

  17. Obesity and exercise in adoloscent period

    Directory of Open Access Journals (Sweden)

    Eda Mendes

    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.

  18. On the Spectrum of Periodic Signals

    Science.gov (United States)

    Al-Smadi, Adnan

    2004-01-01

    In theory, there are many methods for the representation of signals. In practice, however, Fourier analysis involving the resolution of signals into sinusoidal components is used widely. There are several methods for Fourier analysis available for representation of signals. If the signal is periodic, then the Fourier series is used to represent…

  19. 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…

  20. 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...