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Sample records for junggar basin northwest

  1. Geochemistry of oils from the Junggar basin, northwest China

    USGS Publications Warehouse

    Clayton, J.L.; Yang, J.; King, J.D.; Lillis, P.G.; Warden, A.

    1997-01-01

    The Junggar basin of northwestern China is a structural basin containing a thick sequence of Paleozoic-Pleistocene rocks with estimated oil reserves of as much as 5 billion bbl. Analyses of 19 oil samples from nine producing fields and two oil-stained cores in the Junggar basin revealed the presence of at least five genetic oil types. The geochemistry of the oils indicates source organic matter deposited in fresh to brackish lake and marine environments, including coaly organic matter sources. The volumetrically most important oil type discovered to date is produced from Late Carboniferous-Middle Triassic reservoirs in the giant Karamay field and nearby fields located along the northwestern margin of the Junggar basin. Oil produced from the Mahu field, located downdip in a depression east of the Karamay field, is from a different source than Karamay oils. Unique oil types are also produced from an upper Permian reservoir at Jimusar field in the southeastern part of the basin, and from Tertiary (Oligocene) rocks at Dushanzi field and Lower Jurassic rocks at Qigu field, both located along the southern margin of the basin. Previous studies have demonstrated the presence of Upper Permian source rocks, and the possibility of Mesozoic or Tertiary sources has been proposed, but not tested by geochemical analysis, although analyses of some possible Jurassic coal source rocks have been reported. Our findings indicate that several effective source rocks are present in the basin, including local sources of Mesozoic or younger age for oil accumulations along the southern and southeastern margins of the basin. Future exploration or assessment of petroleum potential of the basin can be improved by considering the geological relationships among oil types, possible oil source rocks, and reservoirs.

  2. Geochemistry of oils from the Junggar basin, northwest China

    SciTech Connect

    Clayton, J.L.; King, J.D.; Lillis, P.G.

    1997-11-01

    The Junggar basin of northwestern China is a structural basin containing a thick sequence of Paleozoic-Pleistocene rocks with estimated oil reserves of as much as 5 billion bbl. Analyses of 19 oil samples from nine producing fields and two oil-stained cores in the Junggar basin revealed the presence of at least five genetic oil types. The geo-chemistry of the oils indicates source organic matter deposited in fresh to brackish lake and marine environments, including coaly organic matter sources. The volumetrically most important oil type discovered to date is produced from Late Carboniferous-Middle Triassic reservoirs in the giant Karamay field and nearby fields located along the northwestern margin of the Junggar basin. Oil produced from the Mahu field, located downdip in a depression east of the Karamay field, is from a different source than Karamay oils. Unique oil types are also produced from an upper Permian reservoir at Jimusar field in the southeastern part of the basin, and from Tertiary (Oligocene) rocks at Dushanzi field and Lower Jurassic rocks at Qigu field, both located along the southern margin of the basin. Previous studies have demonstrated the presence of Upper Permian source rocks, and the possibility of Mesozoic or Tertiary sources has been proposed, but not tested by geochemical analysis, although analyses of some possible Jurassic coal source rocks have been reported. Our findings indicate that several effective source rocks are present in the basin, including local sources of Mesozoic or younger age for oil accumulations along the southern and southeastern margins of the basin. Future exploration or assessment of petroleum potential of the basin can be improved by considering the geological relationships among oil types, possible oil source rocks, and reservoirs.

  3. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

    NASA Astrophysics Data System (ADS)

    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  4. Electrical structures in the northwest margin of the Junggar basin: Implications for its late Paleozoic geodynamics

    NASA Astrophysics Data System (ADS)

    Zhang, Sheng; Xu, Yixian; Jiang, Li; Yang, Bo; Liu, Ying; Griffin, W. L.; Luo, Yong; Huang, Rong; Zhou, Yong; Zhang, Liangliang

    2017-10-01

    Recent geological, geochemical and geophysical data have inclined to support the presence of a remnant Paleozoic oceanic lithosphere beneath the Western Junggar, southwestern Chinese Altaids. However, regional high-resolution geophysical data have been rarely deployed to image its geometry, making it difficult to trace its evolution and final geodynamic setting. Presently, two magnetotelluric (MT) profiles are deployed across the northwest margin of the Junggar basin and the southern Darbut belt to image the electrical structure of the crust and lithospheric mantle. High-quality data at 102 sites and the quasi-2D indications of phase tensor skew angles and impedance phase ellipses for relatively short periods (up to 500 s) allow us to invert the two profile data by a 2-D scheme. The resistivity cross-section of a NW-SE striking LINE2 sheds light on a fossil intraoceanic subduction system, and reveals the Miaoergou intrusions as a bowl-like pluton, indicating that the multi-phase intrusions primarily formed in a post-collisional setting. The resistivity cross-section of striking NE-SW LINE1 reveals a possible oceanic slab with relatively lower resistivity underlying the low-resistivity sedimentary strata and high-resistivity mélange. Given that the profile of LINE1 cuts the out-rise zone of a subducted slab developed during the late Paleozoic, the 2-D resistivity model may thus represent the zone that have experienced heterogeneous deformation, reflecting subduction with barrier variation parallel to the ancient trench. Moreover, as shown in previous results, the new MT data also illustrate that the Darbut Fault is a thin-skinned structure, which has been erased at depths during the subsequent magmatism.

  5. Mesozoic tectonically driven climatic partitioning of the south Junggar and north Tarim basins, northwest China

    SciTech Connect

    Hendrix, M.S.; Graham, S.A.; Brassell, S.C. )

    1991-03-01

    Detailed basin analysis of Mesozoic strata exposed in the south Junggar and north Tarim foreland basin Mesozoic depocenters, northwest China, has documented periodic structural reactivation of the intervening Tian Shan during that era. Coarse alluvial pulses, contained in an otherwise relatively fine-grained section of fluvial lacustrine sediments, were shed off both the north and south flanks of the Tian Shan during the Late Triassic, Latest Jurassic, and late Cretaceous. The lofty modern Tian Shan and associated rain shadow cast over the Tarim basin to the south reflect deformation associated with the early Cenozoic Himalayan collision; so too were the two basins climatically partitioned during the Mesozoic in response to relief produced by orogenesis. During prolonged episodes of relative tectonic quiescence, it appears that Tian Shan relief was too low to confine moisture to the windward side of the range. Most notable is the Middle Jurassic section that is dominated in both basins by a relatively fine-grained series of organic-rich, meandering fluvial, and lacustrine sediments. Pyrolytic analyses of organic-rich mudstones associated with these sediments document high H.I. kerogens, suggesting algal-dominated organic matter typical of anoxic lacustrine settings. However, detailed GC-MS biomarker analysis of the alipaphatic fraction also suggests substantial input from higher land plants in addition to algal sources. Not only are n-alkane distributions typically dominated by high molecular weight compounds with an odd-over-even preference typical of higher land plants, but the abundance of specific diterpenoid biomarker compounds strongly suggests the development of widespread coniferous forests on either side of the range during the Middle Jurassic.

  6. Petroleum source rocks of the Junggar, Tarim, and Turpan basins, northwest China

    SciTech Connect

    Graham, S.A.; Brassell, S.; Carroll, A.R.; McKnight, C.L.; Chu, J.; Hendrix, M.S. ); Xiao, X. ); Demaison, G. ); Liang, Y. )

    1990-05-01

    The sedimentary basins of Xinjiang Uygur Autonomous Region, China, are poorly explored for petroleum. Volumetric adequacy of petroleum source rocks is a critical exploration risk in these basins, particularly because source rock data are limited. However, recent studies provide new source rock data and permit speculative assessment of source rock potential of Xinjiang basins. The Junggar basin, best explored of Xinjiang basins and containing a giant oil field, is underlain over much of its extent by an Upper Permian lacustrine oil-shale sequence that is known for its organic richness and oil source quality. Depending on position in the basin, the Permian section ranges from immature to overmature and is inferred to be the principal source of oil in the basin. Upper Triassic-Middle Jurassic coal measures, including lacustrine rocks, constitute a secondary source rock sequence in the Junggar basin. The smaller intermontane Turpan basin contains a very similar Upper Triassic-Middle Jurassic sequence, which, where sufficiently deeply buried, probably comprises the only significant oil source sequence in the basin. The vast Tarim basin offers the greatest potential variety of petroleum source rocks of all Xinjiang basins, but remains the least well documented. From limited, but geologically planned and focused sampling, Cambrian, Carboniferous, and Permian strata are considered unlikely to be major oil source contributors in the dominantly shallow-marine Paleozoic section of the northern Tarim basin. Only Ordovician black shales appear to have significant oil source potential, and a lower Paleozoic source is confirmed for some Tarim oils by gas chromatography-mass spectrometry analysis. The Upper Triassic-Middle Jurassic sequence of northern Tarim basin, similar to that of the Junggar and Turpan basins in comprising a section rich in coal and lacustrine shale, constitutes another, potentially significant oil source.

  7. Sedimentary record and climatic implications of recurrent deformation in the Tian Shan: Evidence from Mesozoic strata of the north Tarim, south Junggar, and Turpan basins, northwest China

    SciTech Connect

    Hendrix, M.S.; Graham, S.A.; Sobel, E.R.

    1992-01-01

    Detailed stratigraphic, sedimentologic, paleocurrent, and subsidence analyses were conducted on Mesozoic nonmarine sedimentary sections of the south Junggar, north Tarim, and Turpan basins, Xinjang Uygur Autonomous Region, northwest China. These three basins have been foreland basins throughout the Mesozoic and Cenozoic eras, as demonstrated by asymmetrically distributed basinwide sediment accumulations, foreland-style subsidence profiles, and a variety of outcrop and subsurface facies data. Mesozoic paleocurrent indicators measured in the south Junggar and north Tarim basins, as well as Mesozoic sandstone compositions from both basins, indicate that the intervening Tian Shan has existed as a positive physiographic feature partitioning the two basins throughout Mesozoic and Cenozoic time. Paleocurrent, facies, and subsurface isopach data suggest that the Turpan basin was established as a discrete feature by the Early Jurassic period. The timing and style of depositional systems within the north Tarim Mesozoic depocenter, the south Junggar Mesozoic depocenter, and the central Turpan basin are remarkably similar. Upper Triassic strata of each basin consist of alluvial conglomerate and associated braided-fluvial sandstone and siltstone which fine upward into lower through Middle Jurassic, locally organic-rich, meandering-fluvial, and lacustrine strata. Upper Jurassic braided-fluvial red beds in each basin are overlain by a distinct pulse of uppermost Jurassic alluvial conglomerate. Lower Cretaceous exposures consist of fine-grained red beds in north Tarim and Turpan and interbedded red and gray shale with local silty carbonates in south Junggar. Upper Cretaceous strata of the north Tarim and south Junggar basins are composed of alluvial conglomerate with associated braided-fluvial sandstone and siltstone. 94 refs., 17 figs.

  8. Structural geology and tectonic significance of foreland thrust belts, Tarim and Junggar basins, northwest China

    SciTech Connect

    McKnight, C.L.; Chu, J.; Corroll, A.R.; Hendrix, M.S.; Wang, X.; Graham, S.A.; Liang, Y.H.; Wang, Z.X.; Xiao, X.

    1989-03-01

    The Kalpin uplift, located on the northwestern margin of the Tarim basin is characterized by a series of thin, southeast-vergent thrust plates modified by strike-slip faults. Each thrust plate repeats a sedimentary sequence consisting of upper Proterozoic through Permian shallow marine to nonmarine carbonates and clastics. Tertiary rocks as young as Neogene are affected by the deformation. The most basinward thrust sheet abuts the Bachu uplift, an older structural feature trending almost perpendicular to the thrusts. Sedimentary rocks as old as late Proterozoic are exposed in the Bachu uplift, which apparently represents a west-vergent Late Silurian to Early Devonian thrust belt. An unconformable Silurian-Devonian contact, the presence of Devonian red beds, and another unconformable contact separating Devonian from Upper Carboniferous strata support the interpretation of a middle Paleozoic deformational event. Another unconformity, at the Carboniferous-Permian boundary, apparently coincides with the time of collision of the Tarim craton with the southern margin of central Asia. The Shihezi fold trend, located in the southern Junggar basin, consists of three lines of surface anticlines trending parallel to the axis of the Urumqi foredeep. A thick sequence of Mesozoic and Cenozoic nonmarine sedimentary rocks accumulated in the growing foredeep. Mesozoic and Paleogene strata are deformed in the southern foldbelt, with Jurassic rocks forming the cores of these thrusted anticlines. The Qigu oil field is located in this southern belt. Deformed Neogene and Quaternary strata are exposed in the thrusted anticlines of the middle and northern foldbelts. The Dushanzi oil field is located in the northern belt. The episodic development of compressional structures in northwestern China documents the accretion of a number of tectonic units to the growing southern margin of central Asia through time.

  9. Chemical speciation of redox sensitive elements during hydrocarbon leaching in the Junggar Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Zheng, Guodong; Fu, Bihong; Takahashi, Yoshio; Kuno, Akihito; Matsuo, Motoyuki; Zhang, Jindong

    2010-11-01

    Bleaching related to seepage of petroleum fluids and subsurface migration of crude oil and natural gas can alter the chemical and mineralogical properties of rocks, while concurrently depleting hydrocarbon reservoirs. Mud volcanoes constitute one type of petroleum seepage present in several areas on the southern margin of the Junggar Basin in the Xinjiang Uygur Autonomous Region, NW China. The results of XRD, XRF, XANES, and Mössbauer spectroscopy on rock samples collected from areas affected by these mud volcanoes revealed an enrichment of certain minerals and elements, as well changes in mineralogical, molecular, or ionic carrier ("species"). After bleaching, reddish sedimentary rocks showed depletion in silica and enrichment of calcium, magnesium, manganese, and iron. Other elements, including aluminum, potassium, sodium, and titanium, were largely unchanged. Reduced iron and sulfur compounds predominated in the bleached rocks, producing changes in color from the original reddish into green, deep gray, and black. Iron and calcium were associated with carbonates, indicating carbonation of these elements during the bleaching processes. Manganese also appeared to be associated with carbonate, though not with sulfate even though sulfate was present in the bleached rocks. Alkaline conditions were apparently the dominant because reduced manganese would have been absent under acidic condition. The alteration of certain minerals, clay minerals in particular, was also observed in bleached rocks, the alteration of smectite-group minerals to chlorite and muscovite, for example. Mineralogical and geochemical changes in rocks bleached by hydrocarbon fluids could provide a better overall understanding of bleaching processes, and may have applications in surface geochemical exploitation and remote imaging.

  10. Cation exchange capacity (Qv) estimation in shaly sand reservoirs: case studies in the Junggar Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Mao, Zhi-Qiang; Sun, Zhong-Chun; Luo, Xing-Ping; Deng, Ren-Shuang; Zhang, Ya-Hui; Ren, Bing

    2015-10-01

    Cation exchange capacity (Qv) is a key parameter in resistivity-based water saturation models of shaly sand reservoirs, and the accuracy of Qv calculation is crucial to the prediction of saturations of oil and gas. In this study, a theoretical expression of Qv in terms of shaly sand permeability (Kshaly-sand), total porosity (ϕt), and salinity of formation water (S) is deduced based on the capillary tube model and the physics volume model. Meanwhile, the classical Schlumberger-Doll research (SDR) model has been introduced to estimate Kshaly-sand. On this basis, a novel technique to estimate Qv from nuclear magnetic resonance (NMR) logs is proposed, and the corresponding model is also established, whose model parameters are calibrated by laboratory Qv and NMR measurements of 15 core samples from the Toutunhe formation of the Junggar Basin, northwest China. Based on the experimental data sets, this technique can be extended to reservoir conditions to estimate continuous Qv along the intervals. The processing results of field examples illustrate that the Qv calculated from field NMR logs are consistent with the analyzed results, with the absolute errors within the scope of  ±0.1 mmol cm-3 for the majority of core samples.

  11. Carboniferous Proto-type Basin Evolution of Junggar Basin in Northwest China: Implications for the Growth Models of Central Asia Orogenic Belt

    NASA Astrophysics Data System (ADS)

    He, D.

    2016-12-01

    The Junggar Basin locates in the central part of Paleo-Asian Ocean tectonic domain, and records the dynamic processes of the Central Asian Orogenic Belt from subduction-accretion-collision to later intracontinental deformations. Carboniferous is the key period from subduction to closure in the tectonic evolution of Paleo-Asian Ocean. Based on the borehole, outcrop, seismic and gravity and magnetic anomaly data, the paper made analysis of the Carboniferous basin evolution.Geo-chronological results for the borehole volcanic rocks suggest that the Junggar Basin and adjacent area had five periods of volcanic activities, including two periods in the Early Carboniferous (359-347Ma 347-331Ma and 331-324Ma) and three periods in the Late Carboniferous (323-307Ma and 307-300Ma). Regional unconformities divided the Carboniferous into two tectono-stratigraphic sequences: Lower Carboniferous and Upper Carboniferous. The former is characterized by compressional structures and involves massive calc-alkaline basalts, andesites, dacites and rhyolites, whereas the later is mainly controlled by extensional faults and dominated by intermediate-mafic volcanic rocks, with bimodal volcanic rocks in parts. The paper determined four Carboniferous arc-basin belts in the Junggar Basin and adjacent area from north to south: the Saur-Fuhai-Dulate, Heshituoluogai-Wulungu-Yemaquan, Darbut-Luliang-Karamaili, and Zhongguai-Mosuowan-Baijiahai-Qitai, and identified multi-type basins, such as fore-arc basin, retro-arc basin, intra-arc rift basin, foreland basin and passive continental margin basin,etc.. The Carboniferous proto-type basin evolution of the Junggar Basin can be divided into three phases such as, the early to middle Early Carboniferous subduction-related compressional phase, the late Early Carboniferous to middle Late Carboniferous subduction-related extensional phase and the late Late Carboniferous intra-continental fault-sag phase. The study discloses that the Junggar Basin is likely

  12. Sedimentology, organic geochemistry, and petroleum potential of Jurassic coal measures: Tarim, Junggar, and Turpan Basins, Northwest China

    SciTech Connect

    Hendrix, M.S.; Brassell, S.C.; Carroll, A.R.

    1995-07-01

    Lower and Middle Jurassic coal-bearing strata occur widely throughout central Asia and are well developed in northwestern China, where their thicknesses in the southern Junggar, northern Tarim, and Turpan basins exceed 2500, 2300, and 1500 m, respectively. Examination of these strata along 13 transacts across basin margin outcrop belts indicates that they are entirely nonmarine meandering fluvial deposits with local development of braided fluvial and lacustrine deltaic facies. Chinese subsurface data suggest that regional Jurassic lacustrine facies are present down depositional dip, consistent with predictions from global circulation modeling of Early and Middle Jurassic monsoonal precipitation. Laboratory analyses of coals and organic-rich shales show a dominance of terrestrial, higher plant components. Visual kerogen analysis indicates that vitrinite, inertinite, and exinite are the dominant macerals, and elemental analysis characterizes most kerogens as type III. Rock-Eval analyses yield moderate hydrogen index values (50-300) and very low oxygen index values (<20). Jurassic source rock extracts are characterized by odd-over-even normal alkane distributions, high pristane/phytane and high hopane/sterane ratios, dominance of C{sub 29} sterane homologs, local abundance of diterpenoid compounds, and low abundance of tricyclic terpanes. Geochemical correlation with four petroleums from the Junggar, Tarim, and Turpan basins strongly suggests that the Jurassic coaly deposits and their lacustrine equivalents downdip are petroleum source rocks. Pyrolysis-gas chromatography of selected Jurassic samples suggests that they possess potential for liquid hydrocarbon generation. Expulsion of C{sub 15+}, hydrocarbons from Jurassic source rocks appears likely, despite the traditional view that bituminous coals are incapable of expelling long-chain hydrocarbons.

  13. Genesis analysis of high-gamma ray sandstone reservoir and its log evaluation techniques: a case study from the Junggar basin, northwest China.

    PubMed

    Wang, Liang; Mao, Zhiqiang; Sun, Zhongchun; Luo, Xingping; Song, Yong; Liu, Zhen

    2013-01-01

    In the Junggar basin, northwest China, many high gamma-ray (GR) sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs' recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reservoirs with apparent shale content greater than 50% and GR value higher than 110API can be regarded as high GR sandstone reservoir. The high GR sandstone reservoir is mainly and directly caused by abnormally high uranium enrichment, but not the tuff, feldspar or clay mineral. Affected by formation's high water sensitivity and poor borehole quality, the conventional logs can not recognize reservoir and evaluate the physical property of reservoirs. Then, the nuclear magnetic resonance (NMR) logs is proposed and proved to be useful in reservoir recognition and physical property evaluation.

  14. Genesis Analysis of High-Gamma Ray Sandstone Reservoir and Its Log Evaluation Techniques: A Case Study from the Junggar Basin, Northwest China

    PubMed Central

    Wang, Liang; Mao, Zhiqiang; Sun, Zhongchun; Luo, Xingping; Song, Yong; Liu, Zhen

    2013-01-01

    In the Junggar basin, northwest China, many high gamma-ray (GR) sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs' recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reservoirs with apparent shale content greater than 50% and GR value higher than 110API can be regarded as high GR sandstone reservoir. The high GR sandstone reservoir is mainly and directly caused by abnormally high uranium enrichment, but not the tuff, feldspar or clay mineral. Affected by formation's high water sensitivity and poor borehole quality, the conventional logs can not recognize reservoir and evaluate the physical property of reservoirs. Then, the nuclear magnetic resonance (NMR) logs is proposed and proved to be useful in reservoir recognition and physical property evaluation. PMID:24078797

  15. Petroleum in the Junggar basin, northwestern China

    NASA Astrophysics Data System (ADS)

    Taner, Irfan; Kamen-Kaye, Maurice; Meyerhoff, Arthur A.

    The Junggar basin occupies a large triangular area of some 130 000 km 2 in northwestern China. Situated between the Altay Shan (Altay Range) on the northeast and the Tian Shan (Tian Range) on the southwest, and between lesser ranges around the remainder of its periphery, the Junggar basin is completely intermontane. Its history as a basin began in the Permian, and continued as various uplifts and downwarps evolved. Through the Paleozoic the characteristics of the Junggar basin area were largely geosynclinal and marine. Its post-Permian development took place exclusively in continental regimes. Inhabitants of the Junggar basin have known and utilized its numerous oil and asphalt seeps and its spectacular spreads of asphalt for more than 2000 years, especially in the Karamay-Urho thrust belt near the northwestern rim. The first discovery of oil in the modern sense came at Dushanzi, one of the steeply folded anticlines of theÜrümqi foredeep near the southern rim. The first shallow oil in the Karamay-Urho thrust belt came in 1937, followed by commercial production in the Karamay field in 1955. Output continued to be modest until wells were drilled through local thrusts and reverse faults in the early 1980s. By 1985, cumulative production of the Karamay group of fields had reached 42,000,000 t (metric tonnes) (306,000,000 bbl), with a calculated minimum ultimate recovery of 280,000,000 t (2 billion bbl). Principal production comes from Permian and Triassic strata in continental facies. Apart from marine Mid and Upper Carboniferous strata, source rocks occur mainly in fine-grained lacustrine detrital beds of the Permian, the Triassic, the Jurassic and the Tertiary. Several uplifts and downwarps elsewhere in the Junggar basin remain to be drilled comprehensively. Results from such drilling may enhance the very important position that the Junggar already has attained in the hierarchy of China's onshore basins.

  16. Diamondoid Characterization in Condensate by Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometry: The Junggar Basin of Northwest China

    PubMed Central

    Li, Shuifu; Hu, Shouzhi; Cao, Jian; Wu, Ming; Zhang, Dongmei

    2012-01-01

    Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%. PMID:23109861

  17. Diamondoid characterization in condensate by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry: The Junggar Basin of Northwest China.

    PubMed

    Li, Shuifu; Hu, Shouzhi; Cao, Jian; Wu, Ming; Zhang, Dongmei

    2012-01-01

    Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%.

  18. Evaluation of Junggar Basin in China

    SciTech Connect

    Zhou, J.G.

    1996-06-01

    Junggar basin lies in the northwestern comer of China and has an area of about 130,000 km{sup 2}, in a compression tectonic regime, with about 14 suites of source-reservoir-seal assemblages developed from Carboniferous to Eogene. It is a prolific basin with a total hydrocarbon generation of 266.9 billion tons, an upside oil potential of 6.937 billion tons and a gas potential of 1,228.9 billion m{sup 3}. Due to its tuff surface conditions and remoteness, the exploration level is still very low: the proven geological reserve was calculated; the cumulative oil production was 0.123599434 billion tons by year-end 1994. There will be about 5.4 billion tons of oil yet to find in the entire basin. Right now, there are four blocks (Z1, Z2, Z3 and Z4), in the basin, available for bidding. Geologic assessment of the basin indicates these four blocks are located in the favorable potential regions of the basin. Details supporting this evaluation are contained herein. The petroleum potential of each local structure or play depends on its position to certain hydrocarbon sources during geological history and its structural development history as well as fault growth history.

  19. Diagenesis and secondary porosity enhancement from dissolution of analcime cement in reservoir sandstones: The Upper Permian Pingdiquan Formation, Junggar basin, northwest China

    SciTech Connect

    Zhaohui, T.; Longstaffe, F.J. ); Parnell, J. )

    1996-01-01

    The Junggar Basin is one of the largest and most important oil-producing basins in China, in which Upper Permian lacustrine oil shales are among the thickest and richest petroleum source rocks in the world. The Upper Permian Pingdiquan Formation was deposited predominantly in fan-delta sequences within a lacustrine setting. The Pingdiquan Formation sandstones constitute the principal oil reservoirs, whereas the interbedded black shales are the predominant oil source rocks. The early diagenetic mineral assemblage in the sandstones comprises siderite, pyrite, analcime, albite, calcite and authigenic quartz as well as trace amount of halite; By contrast, the late diagenetic minerals are characterized by authigenic K-feldspar, ankerite, and minor amounts of mixed-layer clay minerals. Petrographic, mineralogical and available paleoecological data suggest that early authigenic minerals in the sandstones were controlled by alternating periodic fresh water and saline/alkaline water episodes in a lacustrine environment. The cementation of siderite, analcime, calcite and albite occluded the substantial porosity in the sandstones at an early diagenetic stage. However, extensive dissolution of analcime cement and labile detrital feldspars occurred during burial diagenesis, resulting in a significant secondary porosity enhancement in the sandstones and making them very good quality oil reservoirs. The origin of secondary porosity is related to the generation of various organic acids due to organic maturation of the interbedded exceptionally organic-rich oil shales.

  20. Diagenesis and secondary porosity enhancement from dissolution of analcime cement in reservoir sandstones: The Upper Permian Pingdiquan Formation, Junggar basin, northwest China

    SciTech Connect

    Zhaohui, T.; Longstaffe, F.J.; Parnell, J.

    1996-12-31

    The Junggar Basin is one of the largest and most important oil-producing basins in China, in which Upper Permian lacustrine oil shales are among the thickest and richest petroleum source rocks in the world. The Upper Permian Pingdiquan Formation was deposited predominantly in fan-delta sequences within a lacustrine setting. The Pingdiquan Formation sandstones constitute the principal oil reservoirs, whereas the interbedded black shales are the predominant oil source rocks. The early diagenetic mineral assemblage in the sandstones comprises siderite, pyrite, analcime, albite, calcite and authigenic quartz as well as trace amount of halite; By contrast, the late diagenetic minerals are characterized by authigenic K-feldspar, ankerite, and minor amounts of mixed-layer clay minerals. Petrographic, mineralogical and available paleoecological data suggest that early authigenic minerals in the sandstones were controlled by alternating periodic fresh water and saline/alkaline water episodes in a lacustrine environment. The cementation of siderite, analcime, calcite and albite occluded the substantial porosity in the sandstones at an early diagenetic stage. However, extensive dissolution of analcime cement and labile detrital feldspars occurred during burial diagenesis, resulting in a significant secondary porosity enhancement in the sandstones and making them very good quality oil reservoirs. The origin of secondary porosity is related to the generation of various organic acids due to organic maturation of the interbedded exceptionally organic-rich oil shales.

  1. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, X.; Qi, X.; Zheng, M.

    2015-12-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  2. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, Xiaozhi; He, Dengfa; Qi, Xuefeng

    2016-04-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  3. Formation and Evolution of the Junggar basin basement

    NASA Astrophysics Data System (ADS)

    He, D.

    2015-12-01

    Junggar Basin is located in the central part of the Central Asian Orogenic Belt (CAOB). Its basement nature is a highly controversial scientific topic, involving the basic style and processes of crustal growth.Based on the borehole data from over 300 wells drilled into the Carboniferous System, together with the high-resolution gravity and magnetic data (in a 1:50,000 scale), we made a detailed analysis of the basement structure, formation timing and process and later evolution on basis of core geochemical and isotopic analysis. Firstly, we defined the Mahu Precambrian micro-continental block in the juvenile crust of Junggar Basin according to the Hf isotopic analysis of the Carboniferous volcanic rocks. Secondly, the results of the tectonic setting and basin analysis suggest that the Junggar area incorporates three approximately E-W trending island arc belts (from north to south: Yemaquan-Wulungu-Chingiz, Jiangjunmiao-Luliang-Darbut and Zhongguai-Mosuowan-Baijiahai-Qitai respectively) and intervened three approximately E-W trending retro-arc or inter-arc basin belts from north to south, such as Santanghu-Suosuoquan-Emin, Wucaiwan-Dongdaohaizi-Mahu (Mahu block sunk as a bathyal basin during this phase) and Fukang-western well Pen1 accordingly. Thirdly, the closure of these retro-arc or inter-arc basins gradually toward the south led to the occurrence of collision and amalgamation of the above-mentioned island arcs during the Carboniferous, constituting the basic framework of the Junggar "block". Fourthly, the emplacement of large-scale mantle-derived magmas occurred in the latest Carboniferous or Early Permian. For instance, the well Mahu 5 penetrate the latest Carboniferous basalts with a thickness of over 20m, and these mantle-derived magmas concreted the above-mentioned island arc-collaged body. Therefore, the Junggar basin basement mainly comprises pre-Carboniferous collaged basement, and its formation is characterized by two-stage growth model, involving the

  4. Fluvial sedimentology of a Mesozoic petrified forest assemblage, Shishu Formation, Junggar foreland basin, Xinjiang, China

    SciTech Connect

    McKnight, C.L.; Gan, O.; Carroll, A.R.; Dilcher, D.; Zhao, M.; Liang, Y.H.; Graham, S.A.

    1988-02-01

    The Upper Jurassic(.) Shishu Formation of the eastern Junggar basin, Xinjiang, northwest China, is a fluvial sand unit containing an important assemblage of well-preserved, silicified tree trunks and rooted stumps. Numerous logs, up to 83 ft (25.5 m) long, occur at several levels within a 33.6-ft (10.3 m) stratigraphic section of fluvial sand, gravel, and mud and several paleosol horizons. The uppermost logbearing layer includes a number of rooted tree stumps in growth position, with diameters of up to 8 ft (2.5 m). The maximum root length observed is 40 ft (12.3 m). The trees have been identified by Chinese paleontologists as Cupressinoxylon. The petrified forest assemblage is preserved on the northeast margin of the Mesozoic Junggar foreland basin, a large continental basin subsiding under thrust loading from the south. Logs found within channel gravel units are oriented with their log axes parallel to the channel axis. Sedimentary structures, including epsilon and trough cross-stratification and imbricated channel gravels, indicate paleocurrent flow generally to the south, toward the basin center. The size of the logs suggests the presence of a major fluvial system. The epsilon cross-sets suggest a channel depth of 26 ft (8 m). The oriented silicified logs and their enclosing clastic sediments provide important information on the depositional systems active on the northeastern margin of the Junggar basin in the Late Jurassic(.) time. Hopefully, further detailed study of the fossil trees, including the spacing of the rooted stumps, will provide new information on the paleoecology of Mesozoic forests and the climatic conditions prevailing in the region at the time of deposition.

  5. Tectonic controls on Upper Permian lacustrine oil shales in the Junggar basin, NW China

    SciTech Connect

    Carroll, A.R.; Brassell, S.C.; Graham, S.A. )

    1991-03-01

    Collision of the Tarim craton with the southern margin of Asia during the Late Carboniferous-Early Permian resulted in uplift of an ancestral Tian Shan range and geographic isolation of the previously marine Junggar basin. Dramatic shifts from marine to nonmarine sedimentation took place in both the southern Junggar and northern Tarim basins during the Permina. Paleocurrent analysis indicate that by the Late Permian, coarse-grained sediments in both basins were being supplied predominantly from the area of the Tian Shan. During the Late Permian, the southern Junggar received in excess of 5,000 m of nonmarine sediments, including approximately 1,000 m of laminated, highly organic-rich lacustrine mudstones (oil shales). These deposits commonly have TOCs of 20-30%, and Rock-Eval pyrolitic yields reaching 2,000 mg/g, ranking them among the most prolific petroleum source rocks in the world. Based on a comparison of the distribution of steranes and extended tricyclic terpanes, these Upper Permian oil shales appear to be the primary source of oils in the giant Karamay field in the northwestern Junggar basin. Ancestral uplift of the Tian Shan thus produced a complex tectono-hydrologic partitioning of the Late Permina Junggar basin, which exerted a strong influence on the character of petroleum source rocks deposited within the basin.

  6. Biomarker analysis of Upper Permian lacustrine oil shales, Junggar basin, NW China

    SciTech Connect

    Carroll, A. )

    1990-05-01

    Upper Permian lacustrine oil shales containing up to 34% TOC (total organic carbon) underlie approximately 50,000 km{sup 2} of the Junggar basin in western China, and appear to be the principal source of oils in the giant Karamay field in the northwestern Junggar and in several recent discoveries in other areas of the basin. The siliceous oil shales were deposited in a sediment-starved foreland basin during a period of predominantly humid climate. Previous biomarker studies of crude oils from Karamay field have documented an abundance of {beta}-carotane (which in some cases dominates the aliphatic hydrocarbon distribution) and gammacerane, suggesting a source bed deposited under hypersaline conditions. However, relatively complete outcrop exposures of finely laminated oil shales in the southern Junggar conspicuously lack evaporites, extensive dessication horizons, or other sedimentological evidence of playa lake environments. Indeed, the aliphatic hydrocarbon distribution in bitumen extracts from southern Junggar oil shales appear characteristic of freshwater to brakish water deposition of organic matter in an anoxic lake. Normal alkanes show a slight odd-over-even preference with relatively low levels of the C{sub 22}, n-alkane, pristane/phytane ratios close to unity, low {beta}-carotane and gammacerane levels, and the absence of C{sub 34}-C{sub 35} hopanes. This apparent difference in source bed depositional environments may be due to tectonic partitioning between separate depocenters of the Late Permian Junggar basin. Alternatively, hypersaline oil shale facies may be limited to deeper basinal areas, whereas upslope southern Junggar sediments record highstands in lake level or influx of fresh water from the adjacent drainage areas.

  7. Assessment of Permian tight oil and gas resources in the Junggar basin of China, 2016

    USGS Publications Warehouse

    Potter, Christopher J.; Schenk, Christopher J.; Tennyson, Marilyn E.; Klett, Timothy R.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.; Finn, Thomas M.; Brownfield, Michael E.; Pitman, Janet K.; Mercier, Tracey J.; Le, Phuong A.; Drake, Ronald M.

    2017-04-05

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 764 million barrels of oil and 3.5 trillion cubic feet of gas in tight reservoirs in the Permian Lucaogou Formation in the Junggar basin of northwestern China.

  8. Arbuscular mycorrhizal status of spring ephemerals in the desert ecosystem of Junggar Basin, China.

    PubMed

    Shi, Z Y; Feng, G; Christie, P; Li, X L

    2006-06-01

    A survey was made of the arbuscular mycorrhizal (AM) status of 73 spring ephemeral plant species that grow in the desert ecosystem of Junggar Basin, northwest China. The proportion of AM colonization ranged from 7 to 73% with a mean value of 30%. A total of 65 plant species studied were AM with coils/arbuscules or vesicles and the remaining eight species were possibly AM with no coils/arbuscules or vesicles but with fungal mycelia in the root cortex. AM fungal spores were isolated from rhizosphere samples of all 73 plant species and identified. The mean spore density was 22 per 20 ml of air-dried soil, ranging from 0 to 120. Colonization and spore density of perennials were slightly higher than of annuals and varied among different plant families. A total of 603 AM fungal spore (or sporocarp) specimens were isolated belonging to six genera, Acaulospora, Archaeopora, Entrophospora, Glomus, Paraglomus, and Scutellospora; Glomus was the dominant genus. We conclude that spring ephemerals may be highly dependent on AM associations for survival in the very infertile and arid soils of this desert ecosystem.

  9. [Study on the spatial and temporal distribution of animal plague in Junggar Basin plague focus].

    PubMed

    Guo, Rong; Dai, Xiang; Cao, Hanli; Xia, Lianxu; Abuli, Miti; Abuli, Kemu; Wang, Xinhui; Aza, Ti; Jiang, Wei; Li, Bing; Zhang, Xiaobing; Lei, Gang; Wang, Qiguo; Luo, Tao; Meng, Weiwei; Buren, Mingde; Re, Na; Chen, Yan; Zhang, Yujiang

    2014-02-01

    To explore the spatial and temporal distributions of animal plague in Junggar Basin natural plague focus. Data regarding plague antibody (F1) in serum of Great Gerbil (Rhombomys opimus, R. opimus) which were collected from 2005 to 2012 in Junggar Basin and analyzed. The changing rates on the positivity of F1 that appeared spatially and temporally were also analyzed. A total of 4 825 R. opimus serum samples were collected in 13 administrative regions in Junggar Basin. showed that plague R. opimus existed in two areas-Gurbantonggut desert in the eastern-center and the clay desert of western Junggar Basin. However, in these two areas, the intensity of animal plague prevalence was different. In the former region where Yesinia pestis positive serum was detected from R. opimus, the detected rate of R. opimus was 8.39%. However, in the latter areas, the average positive rate was 1.56%. The changing trends of R. opimus plague prevalence were also varied annually. In the western Junggar Basin, the trend showed a slowly downward profile. The serum positive rate of R. opimus for Yesinia pestis decreased, from 7.59% in 2005 to 0.61% in 2008, and appeared as a resting state that none of the positive sample could be found since then. However, in the eastern-center Junggar Basin area-also named as Gurbantonggut desert which had been divided into 3 segments(western, central and eastern, according to related geographical characteristics), the changing trends of animal plague seemed quite complex. In the western segment, the animal plague had two epidemic peaks-in 2006 and 2010, with the interval of 4 years, with the higher peak of all the three geographic segments as 45.65% in 2010 and the positive serum of R. opimus for plague could be detected each year from 2006 to 2012. However, there were 3 epidemic peaks in the same period in the central and eastern segments. In the central segment, the peaks appeared in 2006, 2009 and 2011, with the intervals as 2.5 years and the average

  10. Overpressure and Its Relation to Petroleum Accumulation in Southern Edge of Junggar Basin

    NASA Astrophysics Data System (ADS)

    Zhao, G.

    2014-12-01

    Abstract: Measured formation pressure, well- log and mud weight data show that there are overpressures in the southern edge of Junggar basin. Vertically, overpressure distribution is not direct ly related to the burial depth, it is mainly controlled by stratigraphic horizons, especially the lower Tertiary Anjihaihe Formation has the most evident control over the overpressures. Horizontally, overpressure occur in the 3 structural belts in southern edge of the basin, but there are differences in the east and in the west : in the eastern part overpressures occur in the Anjihaihe Formation only, while in the western part, they occur not only in the Anjihaihe Formation, but also in the Shawan and Ziniguanzi Formation. Analyzing the relationship between the well test data and overpressures in the southern edge of Junggar basin, it can be found that the distribution of oil and gas reservoirs are closely related to the overpressures. Being affected by faulting, and due to the differences in mechanism of relationship between overpressures and preservation of oil and gas reservoirs, the distribution of overpressures and oil and gas reservoirs cannot be corresponding to one another. As a whole, however, oil and gas would be ready to be reservoired in the normally pressured zone below the moderately abnormal pressured or overpressures zone, which would, therefore, be the favorable target of petroleum exploration; while the overpressured zone with relatively high formation pressure coefficient is unfavorable for oil/ gas reservoiring.

  11. Two-stage formation model of the Junggar basin basement: Constraints to the growth style of Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    He, Dengfa

    2016-04-01

    Junggar Basin is located in the central part of the Central Asian Orogenic Belt (CAOB). Its basement nature is a highly controversial scientific topic, involving the basic style and processes of crustal growth. Some researchers considered the basement of the Junggar Basin as a Precambrian continental crust, which is not consistent with the petrological compositions of the adjacent orogenic belts and the crust isotopic compositions revealed by the volcanic rocks in the basin. Others, on the contrary, proposed an oceanic crust basement model that does not match with the crustal thickness and geophysical characteristics of the Junggar area. Additionally, there are several viewponits, such as the duplex basement with the underlying Precambrian crystalline rocks and the overlying pre-Carboniferous folded basement, and the collaged basement by the Precambrian micro-continent block in the central part and the Hercynian accretionary folded belts circling it. Anyway, it is necessary to explain the property of basement rock, its strong inhomogeneous compositions as well as the geophysical features. In this paper, based on the borehole data from more than 300 industry wells drilled into the Carboniferous System, together with the high-resolution gravity and magnetic data (in a scale of 1:50,000), we made a detailed analysis of the basement structure, formation timing and processes and its later evolution on a basis of core geochemical and isotopic analysis. Firstly, we defined the Mahu Pre-Cambrian micro-continental block in the juvenile crust of Junggar Basin according to the Hf isotopic analysis of the Carboniferous volcanic rocks. Secondly, the results of the tectonic setting and basin analysis suggest that the Junggar area incorporates three approximately E-W trending island arc belts (from north to south: Yemaquan- Wulungu-Chingiz, Jiangjunmiao-Luliang-Darbut and Zhongguai-Mosuowan- Baijiahai-Qitai island arcs respectively) and intervened three approximately E-W trending

  12. Provenance of the southern Junggar Basin in the Jurassic: Evidence from detrital zircon geochronology and depositional environments

    NASA Astrophysics Data System (ADS)

    Fang, Yanan; Wu, Chaodong; Guo, Zhaojie; Hou, Kejun; Dong, Lin; Wang, Luxin; Li, Linlin

    2015-01-01

    The goal of this paper is to study the provenance of the southern Junggar Basin during the late Triassic to early Cretaceous, based on the detrital U-Pb geochronology, petrography and depositional environments. Eight sandstone samples from the Upper Triassic to Lower Cretaceous were collected for detrital zircon U-Pb dating. A total of 794 effective U-Pb ages was obtained and divided into four groups: 488-2537 Ma (basement zircons), 328-482 Ma (subduction-related magmatic zircons), 254-322 Ma (post-collisional magmatic zircons), and 135-250 Ma (syndepositional magmatic zircons). These ages relate to three stages of basin evolution. (1) From the early to middle Jurassic, Tian Shan experienced continued exhumation, accompanied by progressive southward expansion of the Junggar Basin, and a peneplain was formed by the time Xishanyao Formation was deposited. Organic-rich sediments formed in a delta environment were well-developed in the southern Junggar Basin, with source rocks gradually switching from post-collisional volcanic rocks (295-307 Ma with a peak age of 300 Ma) of the southern North Tian Shan to post-collisional volcanic rocks of the Central Tian Shan (280-320 Ma with a peak age of 316 Ma) and then to subduction-related island arc rocks (402-423 Ma with a peak age of 415 Ma) of the Central Tian Shan. (2) During deposition of the Toutunhe and Qigu Formations, large scale volcanic activities occurred along the North Tian Shan Fault. Source rocks at this time include syndepositional volcanic rocks (151-161 Ma), and post-collisional volcanic rocks (290-320 Ma) of the North Tian Shan. By the time of deposition of the Kalazha Formation, Tian Shan experienced rapid tectonic uplift, leading to rapid lake regression. Alluvial fans were well developed in the southern Junggar Basin with source rocks being the underlying sedimentary strata of the north margin of the North Tian Shan. (3) During the early Cretaceous, exhumation of the Tian Shan and lake transgression in

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    This study investigates the mechanism of dolostone formation and establishes a dolomitization model in the Permian strata on the northwestern margin of Junggar Basin, China. Dolomitic rock samples are collected from the Permian Fengcheng Formation in Urho area and then characterized by petrological, mineralogical, carbon and oxygen isotope, and trace element geochemical analyses. Results show that the major types of dolomitic rocks include dolomitic mudstone, dolomitic siltstone, dolomitized tuffaceous siltstone, and dolomitized tuffaceous mudstone. The dolomitized rocks are dominated by euhedral or subhedral powder- and fine-crystal dolomites formed by replacement lacustrine argilla-calcareous and siliceous (tuffaceous) components and commonly filled with residual and late calcite cements. The parameters of dolomitic rocks show great variations, including the V/Ni ratio (1.02-4.88), Sr content (95.9-783.6 μg/g), Mg/Ca ratio (0.68-5.13), degree of ordering (0.39-1.00), δ18OPDB (-14.8‰ to 3.2‰), and δ13CPDB (-1‰ to 5.2‰). The dolomitic rocks have multi-stage origins and were formed in a semi-closed continental brackish-saltwater bay with weak hydrodynamic processes, deep water bodies, and relatively quiet conditions. In the Permian depositional stage, a combination of complex tectonic activities, fault development, hot subtropical climate, and frequent volcanic activities provided not only Mg2+ source for dolomitization but also channels for rapid flow and seepage of Mg-rich fluids. The origins of dolostones in the study area include penecontemporaneous dolomitization, burial dolomitization, and hydrothermal dolomitization. This study lays a foundation for further studies on dolomite formation and dolomite reservoir, and provides effective methods for researching complex dolostone (tuffaceous, shale and silty dolomite) formation.

  14. Mesozoic hydrocarbon source rock studies of north Tarim, south Junggar, and Turpan basins, Xinjiang Uygur autonomous region, northwestern China

    SciTech Connect

    Hendrix, M.S.; Xiao, Z.; Liang, Y.; Graham, S.A.; Carroll, A.R.; Chu, J.; McKnight, C.

    1989-03-01

    Ongoing outcrop and accompanying pyrolysis studies of Mesozoic strata of the north Tarim, south Junggar, and Turpan retroarc foreland basins, northwestern China, have demonstrated the existence of potential oil-prone and gas-prone petroleum source rocks. Lithologies include Jurassic coals from all three basins and Triassic coals from Tarim. Jurassic coals collected from the Mesozoic depocenters of the Junggar and Tarim basins are oil prone, yielding S/sub 2//S/sub 2+3/ values that range from 0.80 to 0.99 and average 0.96, hydrogen index (HI) values that range from 117.9 to 213.4 and average 150.8, and oxygen index (OI) values that range from 1.1 to 31.6 and average 7.67. In contrast, Triassic coals of Tarim and Jurassic coals of Turpan contain more conventional type III gas-prone kerogens and yield S/sub 2//S/sub 2+3/ values ranging from 0.04 to 0.52 and averaging 0.22, HI values ranging from 3.2 to 130.2 with a mean of 33.6, and OI values ranging from 30.9 to 223.7 and averaging 115.9. Coals of all three basins are slightly immature to mature with respect to oil generation, as indicated by T/sub max/ values ranging from 425/degrees/ to 449/degrees/C (average = 343/degrees/C) and vitrinite reflectance values ranging from 0.51 to 0.64 (average = 0.57). Thus, given the widespread abundance and significant thicknesses of Mesozoic and especially Jurassic coals in all three basins, it is very likely that Mesozoic contributions to Xinjiang's oil and gas reserves are significant. This is particularly important in the north Tarim basin, where recent Chinese oil and gas discoveries have been made and the existence of significant pre-Mesozoic source beds remains unproven.

  15. The spatial distribution and movement of the spring soil moisture in the hinter land of Junggar Basin

    NASA Astrophysics Data System (ADS)

    Zhao, Congju; Lei, Jiaqiang; Wang, Xueqin; Jiang, Jin

    2003-07-01

    The exploitation of resources and an increase in civil engineering projects in the Junggar Basin has caused major environmental disturbance to the fragile desert eco-system. It is a serious problem that attracts global attention on how to restore and reconstruct the stable natural eco-system. Understanding soil moisture content and lateral water movement in arid areas, at a shallow depth, is of practical importance. On the one hand, lateral flow can be expected to reduce the groundwater recharge rate. On the other hand, it may result in a strong variability of water resources over short distances, thus affecting the distribution and composition of the vegetal cover. The eolian soil moisture condition is the primary factor that affects desert plant-cover in the hinter land of Junggar Basin, especially in spring (from March to May). With neutron probe, through field calibration, the soil moisture changes in different terrain parts, which are the crest, slope, the foot of the natural and disturbed dunes and the interdune land were measured. The data shows that the spatial distribution of the soil moisture in spring is closely related to the sun radiation, the depth of snow in winter, landscape position, the depth of soil, plant cover condition (cover-degree, plant species), and human impact. The data also provides scientific information and instruction for restoring and reconstructing the eco-system that has been damaged by engineering disturbance.

  16. [Community structure of Great Gerbils (Rhombomys opimus) parasitic fleas in Junggar Basin focus and related epizootiological characteristics on plague].

    PubMed

    Zhang, Yu-jiang; A, Zati; Luo, Tao; Abu, Likemu; Wang, Qi-guo; Abu, Limiti; Li, Bing; Meng, Wei-wei; Guo, Rong; Dai, Xiang; Cao, Han-li

    2013-11-01

    To understand the community structure of Rhombomys opimus parasitic fleas in the natural plague focus in Junggar Basin, so as to explain the relationship between the community structure and the prevalence of animal plague in this area. The body fleas of R.opimus which were collected in 2005-2010 from the Junggar Basin was analysed by community ecology method, an each clustered flea community was compared with information of pathogenic and serological indicators of animal plague epidemic by statistic method. The community structure of R. opimus parasitic fleas included 19 species and was very complicated, with only 3 were identified as 'common' species but the others belonged to 'rare' species. Both the average richness and diversity of flea community were higher, as 1.66 and 1.5556, with dominance not obvious (0.332) and the homogeneity as moderate (0.5283). The community structure of R. opimus parasitic fleas could be changed by the following factors as: the rates of flea parasitic/flea index and the proportions of main fleas etc. The flea community could be divided into 5 clusters according to the above said elements. All these data showed that the fleas of R. opimus parasitic fleas possess the nature of multi-parasitism. The community of R. opimus parasitic fleas existed heterogeneous of geographic region, and this phenomenon associated with the animal plague epidemic strength.

  17. A new genus of aplodontid rodent (Mammalia, Rodentia) from the late Oligocene of northern Junggar Basin, China.

    PubMed

    Bi, Shundong; Meng, Jin; McLean, Sarah; Wu, Wenyu; Ni, Xijun; Ye, Jie

    2013-01-01

    A new genus and species of aplodontid rodent, Proansomys dureensis, from the late Oligocene of the northern Junggar Basin of China is described. The new genus is referred to as Ansomyinae because the ectoloph on the upper cheek teeth, although not fully crested, has attained the same characteristic bucket-handle-shaped configuration as other members of the subfamily. It represents the earliest record of the subfamily yet discovered in Asia and is more plesiomorphic than species of the genus Ansomys in having a partly crested ectoloph, a lower degree of lophodonty, and less complex tooth basins (lacking accessory lophules). Proansomys has transitional features between Prosciurus and Ansomys, suggesting that the Ansomyinae derived from a group of aplodontids related to Prosciurus, as did other advanced aplodontid rodents. This provides new light on the paleobiogeography of the Ansomyinae.

  18. Tectonic evolution of the West Junggar Region, Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Coleman, R. G.; Tilton, G.; Xiao, X.

    1989-08-01

    The West Junggar region of northwestern China consists of a Hercynian-age fold belt occupying a late Paleozoic zone of convergence between three major Eurasian plates: Siberian, Tarim, and Kazakhstan. The northern part of the West Junggar area includes part of the Irtysh-Zaysan fold belt that extends to the northwest into the USSR, where it marks a broad boundary between the Siberian and Kazakhstan plates. The central part of the West Junggar area includes the southeastern extension of the Chingiz-Tarbgatay early Paleozoic island arc sequence. The southern part of the West Junggar area is truncated by the deep fundamental Junggar-Alakol fault that has brought the Yili microplate into juxtaposiition with the West Junggar region in the vicinity of Ebin Nur Lake. To the east the Junggar area is covered by sediments of the Junggar Basin. Paleogeographic reconstructions and geologic evidence indicates that these plates began converging in the Middle Carboniferous, and by Late Carboniferous alkali granites began invading the imbricated leading edges of the coalescing plates. Paleomagnetic data reveals that the plates continued to move along strike-slip faults, bringing the Tarim plate and Yili microplate into their present positions sometime in the early Mesozoic. Six separate ophiolite occurrences in the West Junggar region are strongly tectonized and dismembered. The Tangbale ophiolite is considered to be Late Cambrian (508 ± 20 Ma.) and represents the earliest known oceanic crust in Western China. Petrologic and chemical data indicate that the Tangbale ophiolite represents a possible back arc or forearc tectonic setting situated close to a developing island arc. The Darbut ophiolite has been tectonized to a melange and is overlain by Late Devonian flysch. Ages of the radiolaria in the cherts associated with the pillow lavas indicate that it formed in the Middle Devonian. Other occurrences of ophiolite melange in the northern part of the West Junggar region may be as

  19. Late Paleozoic tectonic evolution of the Central Asian Orogenic Belt: Constraints from multiple arc-basin systems in Altai-Junggar area, NW China

    NASA Astrophysics Data System (ADS)

    Li, D.

    2015-12-01

    In this study, we report results from integrated geological, geophysical and geochemical investigations on the Wulungu Depression of the Junggar Basin to understand the Late Paleozoic continental growth of the Junggar area and its amalgamation history with the Altai terrane, within the broad tectonic evolution of the Altai-Junggar area. Based on seismic and borehole data, the Wulungu Depression can be divided into two NW-trending tectonic units by southward thrust faults. The Suosuoquan Sag is composed of gray basaltic andesite, andesite, tuff, tuffaceous sandstone and tuffite, and the overlying Early Carboniferous volcano-sedimentary sequence with lava gushes and marine sediments from a proximal juvenile provenance, compared to the andesite in the Hongyan High. The SIMS Zircon U-Pb ages for andesites from Late Paleozoic strata indicate that these volcanics in Suosuoquan Sag and Hongyan High erupted at 376.3Ma and 313.4Ma, respectively. Most of the intermediate-mafic volcanic rocks exhibit calc-alkaline affinity, low initial 87Sr/86Sr and positive ɛNd(t) and ɛHf(t) values. Furthermore, these rocks have high Th/Yb and low Ce/Pb and La/Yb ratios as well as variable Ba/Th and Ba/La ratios. These features imply that the rocks were derived from partial melting of a mantle wedge metasomatized by subduction-related components in an island arc setting. The basin filling pattern and the distribution of island arc-type volcanics and their zircon Hf model ages with the eruptive time suggest that the Wulungu Depression represents an island arc-basin system with the development of a Carboniferous retro-arc basin. The gravity and magnetic anomaly data suggest that Altai-Junggar area incorporates three arc-basin belts from north to south: the Karamaili-Luliang-Darbut, Yemaquan-Wulungu, and Dulate-Fuhai-Saur. The recognition of the Wulungu arc-basin system demonstrates that the northern Junggar area is built by amalgamation of multiple Paleozoic linear arcs and accretionary

  20. Late paleozoic tectonic amalgamation of northwestern China. Sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar basins

    SciTech Connect

    Carroll, A.R.; Graham, S.A.; Hendrix, M.S.; Ying, D.; Zhou, D.

    1995-05-01

    This study focuses on areas adjacent to the Tian Shan (shan is Chinese for mountains) in Xinjiang Uygur Autonomous Region, northwestern China, and provides new field data on Carboniferous and Permian outcrop exposures of sedimentary rocks of the southern Junggar, northwestern Turpan, and northern Tarim basins that bear directly on the history of late Paleozoic tectonic amalgamation. We present here a multifaceted sedimentary basin analysis, including sedimentary facies, paleocurrent, and sandstone provenance analyses, and reconstructions of late Paleozoic basin subsidence. These data provide a unique record not only of the basins themselves, but also of the evolution of the adjacent orogenic belts. This study is based on fieldwork during the summers of 1987, 1988, 1991, and 1992 by workers from Stanford University, the Chinese Academy of Geological Sciences, and the Xinjiang Bureau of Geology and Mineral Resources. Although reconnaissance in nature, the data presented here provide a basis for evaluating alternative hypotheses for the evolution of northwestern China and provide a starting point for more comprehensive future studies. 72 refs., 18 figs., 1 tab.

  1. A retreating fan-delta system in the Northwestern Junggar Basin, northwestern China-Characteristics, evolution and controlling factors

    NASA Astrophysics Data System (ADS)

    Jia, Haibo; Ji, Hancheng; Li, Xinwei; Zhou, Hang; Wang, Linsheng; Gao, Yan

    2016-06-01

    In this study, we use seismic reflection, logging and core data to investigate the depositional systems and their controlling factors in the lower Triassic in the northwestern margin of Junggar basin. The succession shows strong lateral and vertical facies variation. The facies associations indicate the development of conglomeratic fan-delta system, with characteristics of fining-upward and landward migration of facies belts. A critical balance between progradation, aggradation, and retrogradation controlled the evolution of delta successions within an overall transgressive regime. Migration of the locus of active faulting exerted the primary control on fan-delta thickness. Variations on the sandy component and gravel type within the fan-delta system among different units indicate the control of provenance. The climate significantly influenced the mode of sediment transfer from the feeder system to the basin. The significant climate change from arid to humid played a primary role in controlling the fan-delta architecture. Our study suggests that in tectonic-active basin, the controls of tectonics on the sequence stratigraphy are still fundamental. However, during the tectonic quiescence or rift-depression transition stage, significant changes of climate would play a primary role in controlling the sediment dispersal. The current study reveals that the hydrocarbon reservoir shows a landward migration trend within a retreating fan-delta system.

  2. Mantle-derived helium in foreland basins in Xinjiang, Northwest China

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Zheng, Guodong; Zheng, Jianjing; Zhou, Shixin; Shi, Pilong

    2017-01-01

    Hydrocarbon-rich natural gases from the Tarim, Junggar, Turpan-Hami and Santanghu basins in Xinjiang, Northwest China have measured 3He/4He ratios from 0.01 to 0.6 times higher than the atmospheric value, indicating 0-7% helium derived from the mantle. The mantle-derived helium is high in foreland basins associated with the Tianshan, Kunlun and Zhayier-Halalate orogenic mountains, but low towards the center of basins. This spatial distribution suggests that the mantle-derived helium originates either from fluids or small scale melts in the upper asthenospheric or lithospheric mantle which have found pathways into the root zones of the major faults defining these mountains, but do not significantly move into the basins themselves. During upward transport to near the surface, the mantle-derived helium is significantly diluted by radiogenic helium produced in the crust. Despite the lack of recent magmatic activity or extensional tectonics within the basins, this pattern shows strong evidence that the major faults play an important role in mantle-derived components degassing from the mantle to the surface.

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  4. [Contamination Assessment and Sources Analysis of Soil Heavy Metals in Opencast Mine of East Junggar Basin in Xinjiang].

    PubMed

    Liu, Wei; Yang, Jian-jun; Wang, Jun; Wang, Guo; Cao, Yue-e

    2016-05-15

    The opencast mine of East Junggar Basin in Xinjiang is the largest self-contained coalfield in China, and the ecological environment of the opencast is very fragile because of its arid climate and poor soil. In this study, 50 soil samples (from 0 to 30 cm depth soil at intervals of 10 cm) in opencast Mine of East Junggar Basin in Xinjiang were collected in order to explore the heavy metals contamination of the coal mining. The contents of zinc (Zn), copper (Cu), cadmium (Cr), lead (Pb), mercury (Hg) and arsenic (As) were measured and the degree of pollution was assessed by Nemerow index, geo-accumulation (Igeo) index and potential ecological risk index. In addition, the layered comparison, dust fall and the distance between coal mine and samples location were used to analyze the source of heavy metals contamination. The results showed that value of As surpassed the Chinese soil quality standard class I (GB 15618-1995) mostly severely, followed by Cr, a relatively lower surpass was obtained by Hg and Cu, while Zn and Pb did not surpass the standard. According to the standard, the soil heavy metals content of research region was in light pollution status and the pollution index for each heavy metal followed the order of As (2.07) > Cr (0.95) > Cu (0.55) > Zn (0.48) > Hg (0.45) > Pb (0.38), which demonstrated a heavy pollution of As and clean status of others. Additionally, an Igeo value of 1.14 for Hg reflected a moderated pollution. The major contribution factor was Hg with a risk index of 251.40. The source analysis showed that the content of Pb in the surface soil (10-20 cm) was different from that in the deep layer (20-30 cm), which may be caused by coal combustion and other human activities. The sources of Hg and As were similar and may come from coal combustion. The distance to the mining area was not the major factor affecting the diffusion of heavy metals, other candidate factors included terrain, aspect and wind direction, etc.

  5. Geochemical characterization of Lucaogou Formation and its correlation of tight oil accumulation in Jimsar Sag of Junggar Basin, Northwestern China.

    PubMed

    Qu, Jiangxiu; Ding, Xiujian; Zha, Ming; Chen, Hong; Gao, Changhai; Wang, Zimeng

    2017-01-01

    With the constant consumption of conventional oil and gas resources, unconventional oil and gas resources with great resource potential such as tight oil have gradually been valued and become the new exploration area. Jimsar Sag is the key tight oil exploration and development block in Junggar Basin of Northwestern China. Based on the data sets of geology, oil production test, logging, rock thin section, and geochemistry of Permian Lucaogou Formation (LCG), we studied the geochemical characteristics of hydrocarbon source rocks and their relation to the tight oil accumulation. Organic matter abundance of source rocks is high, the types of organic matter are mainly type I and type II, and the organic matter maturation is in the low mature stage to mature stage. Results of oil source correlation showed that the crude oil of sweet spots was mainly derived from the source rocks in the interior of the sweet spots. The LCG tight oil is mainly distributed in the plane where the source rocks have great thickness and the TOC is higher than 3.5%. It shows that the source rocks have obvious controlling on the occurrence and accumulation of tight oil.

  6. Origin of dolomitic rocks in the lower Permian Fengcheng formation, Junggar Basin, China: evidence from petrology and geochemistry

    NASA Astrophysics Data System (ADS)

    Zhu, Shifa; Qin, Yi; Liu, Xin; Wei, Chengjie; Zhu, Xiaomin; Zhang, Wei

    2017-04-01

    Although dolomitization of calcite minerals and carbonatization of volcanic rocks have been studied widely, the extensive dolomitic rocks that originated from altered volcanic and volcaniclastic rocks have not been reported. The dolomitic rocks of the Fengcheng Formation in the Junggar Basin of China appear to be formed under unusual geologic conditions. The petrological and geochemical characteristics indicate that the dolomitizing host rock is devitrified volcanic tuff. After low-temperature alteration and calcitization, these tuffaceous rocks are replaced by Mg-rich brine to form massive dolomitic tuffs. We propose that the briny (with -2 ‰ 6 ‰ of δ13CPDB and -5 ‰ 4 ‰ of δ18OPDB) and Mg-rich marine formation water (with 0.7060 0.7087 of 87Sr/86Sr ratio), the thick and intermediate-mafic volcanic ashes, and the tectonically compressional movement may have favored the formation of the unusual dolomitic rocks. We conclude that the proposed origin of the dolomitic rocks can be extrapolated to other similar terranes with volcaniclastic rocks, seabed tuffaceous sediment, and fracture filling of sill.

  7. Origin of dolomitic rocks in the lower Permian Fengcheng formation, Junggar Basin, China: evidence from petrology and geochemistry

    NASA Astrophysics Data System (ADS)

    Zhu, Shifa; Qin, Yi; Liu, Xin; Wei, Chengjie; Zhu, Xiaomin; Zhang, Wei

    2016-09-01

    Although dolomitization of calcite minerals and carbonatization of volcanic rocks have been studied widely, the extensive dolomitic rocks that originated from altered volcanic and volcaniclastic rocks have not been reported. The dolomitic rocks of the Fengcheng Formation in the Junggar Basin of China appear to be formed under unusual geologic conditions. The petrological and geochemical characteristics indicate that the dolomitizing host rock is devitrified volcanic tuff. After low-temperature alteration and calcitization, these tuffaceous rocks are replaced by Mg-rich brine to form massive dolomitic tuffs. We propose that the briny (with -2 ‰ ~ 6 ‰ of δ13CPDB and -5 ‰ ~ 4 ‰ of δ18OPDB) and Mg-rich marine formation water (with 0.7060 ~ 0.7087 of 87Sr/86Sr ratio), the thick and intermediate-mafic volcanic ashes, and the tectonically compressional movement may have favored the formation of the unusual dolomitic rocks. We conclude that the proposed origin of the dolomitic rocks can be extrapolated to other similar terranes with volcaniclastic rocks, seabed tuffaceous sediment, and fracture filling of sill.

  8. Study on the application of seismic sedimentology in a stratigraphic-lithologic reservoir in central Junggar Basin

    NASA Astrophysics Data System (ADS)

    Yu, Yixin; Xia, Zhongmou

    2017-06-01

    This paper discusses the research idea of description for stratigraphic-lithologic reservoir based on seismic sedimentology methods. The sandstone reservoir of Jurrassic XiShanyao Formation in Junggar Basin is studied according to the theory and approaches of seismic sedimentology. By making full use of borehole data, the technologies of layer correlation based on the stratigraphic sequence framework, the forward seismic modeling, the stratal slicing and lithologic inversion are applied. It describes the range of denudation line, the distribution characteristics of sedimentary facies of the strata, the vertical and horizontal distribution of sand bodies and the favourable oil-gas bearing prospective area. The results shows that study area are dominated braided delta deposition including underwater distributary channel and distributary bay microfacies, the nip-out lines of the formation are northeast to southwest from north to south, the second Middle Jurassic sand body is the most widely distributed one among three sand bodies, the prospective oil-gas bearing area located in the south part and around the YG2 well area. The study result is effective on the practice of exploration in study area.

  9. Reconstructing multiple arc-basin systems in the Altai-Junggar area (NW China): Implications for the architecture and evolution of the western Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Li, Di; He, Dengfa; Tang, Yong

    2016-05-01

    The Altai-Junggar area in northwestern China is a critical region to gain insights on the tectonic framework and geological evolution of the western Central Asian Orogenic Belt (CAOB). In this study, we report results from integrated geological, geochemical and geophysical investigations on the Wulungu Depression of the Junggar Basin to determine the basement nature of the basin and understand its amalgamation history with the Chinese Altai, within the broad tectonic evolution of the Altai-Junggar area. Based on borehole and seismic data, the Wulungu Depression is subdivided into two NW-trending tectonic units (Suosuoquan Sag and Hongyan High) by southward-vergent thrust faults. The Suosuoquan Sag consists of the Middle-Late Devonian basaltic andesite, andesite, dacite, tuff, tuffaceous sandstone and tuffite, and the overlying Early Carboniferous volcano-sedimentary sequence with lava flows and shallow marine sediments from a proximal juvenile provenance (zircon εHf(t) = 6.0-14.9), compared to the Late Carboniferous andesite and rhyolite in the Hongyan High. Zircon SIMS U-Pb ages for dacites and andesites indicate that these volcanics in the Suosuoquan Sag and Hongyan High erupted at 376.3 Ma and 313.4 Ma, respectively. The Middle-Late Devonian basaltic andesites from well LC1 are calc-alkaline and exhibit primitive magma-like MgO contents (7.9-8.6%) and Mg# values (66-68), with low initial 87Sr/86Sr (0.703269-0.704808) and positive εNd(t) values (6.6-7.6), and relatively high Zr abundance (98.2-116.0 ppm) and Zr/Y ratios (5.1-5.4), enrichment in LREEs and LILEs (e.g., Th and U) and depletion in Nb, Ta and Ti, suggesting that they were probably derived from a metasomatized depleted mantle in a retro-arc extensional setting. The well LC1 andesitic tuffs, well L8 dacites, well WL1 dacitic tuffs and well L5 andesites belong to calc-alkaline and metaluminous to peraluminous (A/CNK = 0.8-1.7) series, and display low Mg# values (35-46) and variably positive εNd(t) (4

  10. Geochemical characteristics of crude oil from a tight oil reservoir in the Lucaogou Formation, Jimusar Sag, Junggar Basin

    NASA Astrophysics Data System (ADS)

    Cao, Z.

    2015-12-01

    Jimusar Sag, which lies in the Junggar Basin,is one of the most typical tight oil study areas in China. However, the properties and origin of the crude oil and the geochemical characteristics of the tight oil from the Lucaogou Formation have not yet been studied. In the present study, 23 crude oilsfrom the Lucaogou Formation were collected for analysis, such as physical properties, bulk composition, saturated hydrocarbon gas chromatography-mass spectrometry (GC-MS), and the calculation of various biomarker parameters. In addition,source rock evaluation and porosity permeability analysis were applied to the mudstones and siltstones. Biomarkers of suitable source rocks (TOC>1, S1+S2>6mg/g, 0.7%basin modeling was performed. The oil-filling history was also defined by means of basin modeling and microthermometry. The results indicated the presence of low maturity to mature crude oils originating from the burial of terrigenous organic matter beneath a saline lake in the source rocks of mainly type II1kerogen. In addition, a higher proportion of bacteria and algae was shown to contribute to the formation of crude oil in the lower section when compared with the upper section of the Lucaogou Formation. Oil-source correlations demonstrated that not all mudstones within the Lucaogou Formation contributed to oil accumulation.Crude oil from the upper and lower sections originated from thin-bedded mudstones interbedded within sweet spot sand bodies. A good coincidence of filling history and hydrocarbon generation history indicated that the Lucaogou reservoir is a typical in situ reservoir. The mudstones over or beneath the sweet spot bodies consisted of natural caprocks and prevented the vertical movement of oil by capillary forces. Despite being thicker, the thick-bedded mudstone between the upper and lower sweet spots had no obvious contribution to

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

    NASA Astrophysics Data System (ADS)

    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

  12. Thermal history of the periphery of the Junggar Basin, Northwestern China

    USGS Publications Warehouse

    King, J.D.; Yang, J.; Pu, F.

    1994-01-01

    Geochemical analysis of rock core samples show that the basin periphery has experienced low thermal stress; present-day heat flows are in the range of 25-35 mW/m2 and have not been significantly higher than the worldwide mean of approx. 63 mW/m2 since the mid-Permian. Present day heat flows were determined from corrected borehole temperatures and rock thermal conductivities. Paleo-heat flows were determined by first-order reaction kinetic modeling of several geochemical paleothermometers (vitrinite reflectance, clay mineral diagenesis and relative proportions of sterane and hopane biological marker diastereomers). ?? 1994.

  13. Thermal history of the periphery of the Junggar Basin, Northwestern China

    USGS Publications Warehouse

    King, J. David; Yang, Jianqiang; Pu, Fan

    1994-01-01

    Geochemical analysis of rock core samples show that the basin periphery has experienced low thermal stress; present-day heat flows are in the range of 25–35 mW/m2 and have not been significantly higher than the worldwide mean of approx. 63 mW/m2 since the mid-Permian. Present day heat flows were determined from corrected borehole temperatures and rock thermal conductivities. Paleo-heat flows were determined by first-order reaction kinetic modeling of several geochemical paleothermometers (vitrinite reflectance, clay mineral diagenesis and relative proportions of sterane and hopane biological marker diastereomers).

  14. [Experimental observation on the histopathological and ultrastructural pathology of Great Gerbils (Rhombomys opimus) in the Junggar Basin by subcutaneous injecting of Yersinia pestis].

    PubMed

    Li, B; Azhati, Rehemu; Meng, W W; Luo, T; Li, B; Abulimiti, Maituohuti; Wang, X H; Dai, X; Zhang, Y J

    2017-02-06

    Objective: To understand the histopathological and ultrastructural pathology changes of great gerbils in the Junggar Basin to Yersinia pestis infection. Methods: Forty captured great gerbils from the Junggar Basin that tested negative for anti-F1 antibodies were infected. The Y. pestis strain 2504, isolated from a live great gerbil in the natural plague foci of the Junggar Basin in 2005 with a median lethal dose (LD(50)) of <10 CFU/ml, was used in this study. Forty great gerbils were divided into seven infection groups and were subcutaneously infected with 7.4×10(5), 7.4×10(6), 7.4×10(7), 7.4×10(8), 7.4×10(9), 7.4×10(10), or 3.0×10(11) CFU/ml of 2504. One milliliter of physiological saline was injected in the noninfected group as a control. We collected the liver, spleen, heart, and lung from all animals for histopathologic and ultrastructural pathology examination. Results: Great gerbils in the 7.4×10(8)-3.0×10(11) CFU/ml groups did not survive and exhibited pathological changes and altered ultrastructural pathology. The liver tissue of infected great gerbils showed spotty necrosis and fatty degeneration, intranuclear canaliculi with increased hepatocytes, and uneven distribution of organelles. Additionally, reactive proliferation of lymphoid tissue in the spleen, blood sinusoid lacunae with neutrophil infiltration, and phagocytosed bacteria in phagocyte cells were observed. Myocardial fiber hypertrophy and interstitial indistinction, nuclear matrices decreased in cardiac myocytes, and loose arrangement of myogenic fibers in myocardial cells were also observed. Angiectasia, capillary congestion, and tissue necrosis were found in the lung. No significant difference in histopathological and ultrastructural pathology in the parenchymal organ was observed between the 7.4×10(5)-7.4×10(7) CFU/ml groups and the 7.4×10(8)-3.0×10(11) CFU/ml groups, and no specific death caused by Y. pestis infection was apparent in the 7.4×10(5)-7.4×10(7) CFU/ml groups

  15. View northwest, discharge basin, floor, showing cement cross beams built ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northwest, discharge basin, floor, showing cement cross beams built on stone bases - Glens Falls Feeder, Sluice, Along south side of Glens Falls Feeder between locks 10 & 20, Hudson Falls, Washington County, NY

  16. Organic petrology and geochemistry of mudrocks from the lacustrine Lucaogou Formation, Santanghu Basin, northwest China: Application to lake basin evolution

    USGS Publications Warehouse

    Hackley, Paul C.; Fishman, Neil; Wu, Tao; Baugher, Gregory

    2016-01-01

    Exploration for tight oil in the frontier Santanghu Basin of northwest China has resulted in recent commercial discoveries sourced from the lacustrine Upper Permian Lucaogou Formation, already considered a “world class source rock” in the Junggar Basin to the west. Here we apply an integrated analytical program to carbonate-dominated mudrocks from the Lucaogou Formation in Santanghu Basin to document the nature of organic matter (OM) in the context of an evolving lake system. The organic-rich samples (TOC 2.8–11.4 wt%; n = 10) were widely spaced from an ~ 200 m cored section, interpreted from textural and mineralogical evidence to document transition from a lower under-filled to an overlying balanced-filled lake. Organic matter is dominated by moderate to strongly fluorescent amorphous material with Type I geochemical signature (HI values 510–755; n = 10) occurring in a continuum from lamellar stringers, 10–20 μm thick, some ≥ 1 mm in length (possible microbial mat; preserved only in lower under-filled section) to finely-disseminated amorphous groundmass intimately intermixed with mineral matrix. Biomarkers for methanotrophs and photosynthetic cyanobacteria indicate a complex microbial consortium. A unicellular prasinophyte green alga(?), similar to Tasmanites in marine rocks, is present as discrete flattened discs 50–100 μm in diameter. Type III OM including vitrinite (some fluorescent) and inertinite also is abundant. Solid bitumen, indicating local kerogen conversion, fills voids and occurs throughout the cored section. Vitrinite reflectance values are 0.47–0.58%, consistent with strong OM fluorescence but may be “suppressed”. Other proxies, e.g., biomarker parameters, indicate the Lucaogou Formation is in the early oil window at this location. On average, slightly more amorphous OM and telalginite are present in the lower section, consistent with a shallow, stratified, saline environment with low sediment dilution. More

  17. 64. View from northwest corner of Printz Basin, showing dike ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. View from northwest corner of Printz Basin, showing dike along south side of basin, looking southeast. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  18. 6. Aerial view, looking northwest, showing former boat basin on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Aerial view, looking northwest, showing former boat basin on east side of island, A-Frame of sidewheeler Minerva Ex Jane Moseley (vessel 53) to left, and package freighter (vessel 54) in center Charles Wisniewski, photographer, January 1985 - Shooters Island, Ships Graveyard, Newark Bay, Staten Island (subdivision), Richmond County, NY

  19. Triassic-Jurassic climate in continental high-latitude Asia was dominated by obliquity-paced variations (Junggar Basin, Ürümqi, China).

    PubMed

    Sha, Jingeng; Olsen, Paul E; Pan, Yanhong; Xu, Daoyi; Wang, Yaqiang; Zhang, Xiaolin; Yao, Xiaogang; Vajda, Vivi

    2015-03-24

    Empirical constraints on orbital gravitational solutions for the Solar System can be derived from the Earth's geological record of past climates. Lithologically based paleoclimate data from the thick, coal-bearing, fluvial-lacustrine sequences of the Junggar Basin of Northwestern China (paleolatitude ∼60°) show that climate variability of the warm and glacier-free high latitudes of the latest Triassic-Early Jurassic (∼198-202 Ma) Pangea was strongly paced by obliquity-dominated (∼40 ky) orbital cyclicity, based on an age model using the 405-ky cycle of eccentricity. In contrast, coeval low-latitude continental climate was much more strongly paced by climatic precession, with virtually no hint of obliquity. Although this previously unknown obliquity dominance at high latitude is not necessarily unexpected in a high CO2 world, these data deviate substantially from published orbital solutions in period and amplitude for eccentricity cycles greater than 405 ky, consistent with chaotic diffusion of the Solar System. In contrast, there are indications that the Earth-Mars orbital resonance was in today's 2-to-1 ratio of eccentricity to inclination. These empirical data underscore the need for temporally comprehensive, highly reliable data, as well as new gravitational solutions fitting those data.

  20. Triassic–Jurassic climate in continental high-latitude Asia was dominated by obliquity-paced variations (Junggar Basin, Ürümqi, China)

    PubMed Central

    Sha, Jingeng; Olsen, Paul E.; Pan, Yanhong; Xu, Daoyi; Wang, Yaqiang; Zhang, Xiaolin; Yao, Xiaogang; Vajda, Vivi

    2015-01-01

    Empirical constraints on orbital gravitational solutions for the Solar System can be derived from the Earth’s geological record of past climates. Lithologically based paleoclimate data from the thick, coal-bearing, fluvial-lacustrine sequences of the Junggar Basin of Northwestern China (paleolatitude ∼60°) show that climate variability of the warm and glacier-free high latitudes of the latest Triassic–Early Jurassic (∼198–202 Ma) Pangea was strongly paced by obliquity-dominated (∼40 ky) orbital cyclicity, based on an age model using the 405-ky cycle of eccentricity. In contrast, coeval low-latitude continental climate was much more strongly paced by climatic precession, with virtually no hint of obliquity. Although this previously unknown obliquity dominance at high latitude is not necessarily unexpected in a high CO2 world, these data deviate substantially from published orbital solutions in period and amplitude for eccentricity cycles greater than 405 ky, consistent with chaotic diffusion of the Solar System. In contrast, there are indications that the Earth–Mars orbital resonance was in today’s 2-to-1 ratio of eccentricity to inclination. These empirical data underscore the need for temporally comprehensive, highly reliable data, as well as new gravitational solutions fitting those data. PMID:25759439

  1. Obliquity-Dominated High-Latitude Continental Triassic-Jurassic Climate, from the Coal-Bearing Junggar Basin, (Ürümqi, China)

    NASA Astrophysics Data System (ADS)

    Olsen, P. E.; Sha, J.; Pan, Y.; Xu, D.; Yao, X.; Wang, Y.; Zhang, X.

    2014-12-01

    Sedimentary facies-based climate proxy data from the thick, coal-bearing, fluvial-lacustrine Haojiagou and Badaowan fms. of the high-paleolatitude (55-65° N) Junggar Basin of northwestern China show that Late Triassic and Early Jurassic (~210-190 Ma) high latitude climate variability was strongly paced by obliquity cycle-dominated (~40-50 ky) orbital variations (1), based on an age model using the 405 ky cycle of eccentricity and the end-Triassic extinction tie point (2,3). In contrast, contemporaneous low-latitude continental climate was nearly exclusively paced by climatic precession, with virtually no hint of obliquity (4). While obliquity-dominance at high latitude is not necessarily unexpected, the envelope of variability of eccentricity, as well as its period (for cycles > 405 ky) at both high and low latitudes deviate in major ways from the expectations of current numerical solutions of orbital variations (5), but is consistent with chaotic diffusion of the Solar System (6), while our preliminary data also suggest that the Earth-Mars orbital secular resonance was in today's 2-to-1 ratio of eccentricity to inclination periods (5). Previously unknown, this obliquity-dominated, non-analog climate variation in the apparently warm and glacier-free high-latitudes of Pangea, coupled with documented low-latitude climatic precession-dominated climate variation, provides a glimpse of an empirical basis for mapping the behavior of the Solar System during times when its behavior was significantly different than present day. This is a contribution to IGCP 632 (Continental crises of the Jurassic). 1, Sha+, 2010, Earth Sci. Frontiers 17:22; 2, Sha+, 2011, Acta Geol. Sinica 85:421; 3, Blackburn+, 2013, Science 340:941; 4, Olsen & Kent, 1996, Palaeogeo. Palaeoclim. Palaeoeco. 122:1; 5, Laskar+, 2011, A&A 532:A89 DOI:10.1051/0004-6361/201116836; 6, Laskar, 1999, Phil. Trans. Roy. Soc. London A 357:1735.

  2. The southern Bonaparte Gulf, northwest Australia - A basin model

    SciTech Connect

    Dauzacker, M.V. Durrant, J.M.; France, R. ); Nilsen, T. )

    1990-05-01

    The Bonaparte Gulf basin Palaeozoic rift is an extension of the Petrel subbasin-Sahul syncline trend forming one arm of a rift triple junction, Salt tectonics developed in this rift setting are fundamental to a new model of the basin and have influenced the development of three Palaeozoic megasequences defined in the model. Megasequence I (MS-I), Silurian-Devonian restricted, synrift sedimentation was associated with extensive evaporitic systems which developed rich source rocks and massive halites. Early basinward salt withdrawal influenced sediment distribution and structuring, localizing shallow-water carbonates above deep salt ridges. Megasequence II (MS-Il) Late Devonian-Late Carboniferous sedimentation is restricted to subbasins formed by continued basinward salt withdrawal. Turbidites were channelled and stacked along subbasin axes during active subsidence (Milligans Formation), and shallow-water carbonate banks continued to develop on basin highs. As subsidence eased, eustatically controlled deltaic sedimentation filled the subbasins, culminating in deposition of a regional shallow-water carbonate (Tanmurra Formation). Continued salt withdrawal in the north produced a carbonate shelf break evidenced by the apparent termination of the Tanmurra Formation seismic reflector, coincident with the carbonate complex development which exhibits continued growth until this period. An overlying unit (Point Spring Sandstone) marks the transition to the next megasequence. Megasequence III (MS-Ill) Late Carboniferous-Late Permian marginal marine/fluvial sedimentation is associated with renewed rifting in the northwest. Associated driving subsidence produced northwest tilting, which was reinforced by Mesozoic-Cenozoic passive margin subsidence following the Late Jurassic continental breakup and abandonment of the northwest-southeast Paleozoic rift arm.

  3. Remote sensing studies of the terrain northwest of Humorum basin

    NASA Technical Reports Server (NTRS)

    Hawke, B. R.; Peterson, Chris A.; Lucey, Paul G.; Taylor, G. J.; Blewett, David T.; Campbell, Bruce A.; Coombs, Cassandra R.; Spudis, Paul D.

    1993-01-01

    We have used near-infrared reflectance spectra and Earth-based radar data to investigate the composition and origin of the various geologic units northwest of Humorum basin as well as the stratigraphy of the Humorum preimpact target site. The results of our spectral analysis indicate that at least a portion of the inner, mare-bounding ring is composed of pure anorthosite. Other highlands units in the region are dominated by noritic anorthosite. The anorthosites on the inner ring may have been derived from a layer of anorthosite that exists at depth beneath a more pyroxene-rich unit. Both Gassendi G and F craters expose mare material from beneath a highlands-rich surface unit that was emplaced as a result of the Letronne, Gassendi, and other impact events. This ancient basalt unit was emplaced after the formation of Humorum basin but prior to the Orientale impact.

  4. Paleozoic archipelagic tectonic evolution of Western Junggar, NW China: implications for continental growth of southern Altaids

    NASA Astrophysics Data System (ADS)

    Zhang, Jien; Xiao, Wenjiao; Han, Chunming; Ma, Chong; Song, Dongfang

    2013-04-01

    The Western Junggar, NW China, a dominant site for continental growth in Southern Altaids, bridges the Circum-Balkhash and Junggar belts and exposes ophiolite, igneous rocks and strata from Cambrian to Carboniferous. Recent updated data on structure, geochronology, geochemisty and paleomagnetism, integrated with previous data, present a newly Paleozoic spatial and temporal framework of Western Junggar. In Cambrian, the Western Junggar begins to birth at the Tangbale area to south, where occurs Ordovician blueschist and top-to-south vergence structures, indicating north-dipping subduction. This event triggers intra-arc extension to generate Ordovician island arc in the Hongguleleng-Xiemisitai area to north and seamount in the Mayile area, middle of Western Junggar. Until Silurian, a southeastward subduction begins in the extended back-arc basin to west of Mayile, occurring blueschist at the Barleik trench and the Nalunsuo magmatic arc, at the rear of which generates Devonian back-arc basin around the Durbut area. Meanwhile, a Silurian Xiemisitai magmatic arc has been developed at the northern part of Western Junggar, along which a northward subduction has emplaced the Tarbahatai ophiolite and generates the Carboniferous Sawur magmatic arc. At the middle part of Western Junggar, the coeval adakite and sanukitic dykes, charnockite, multiple properties of ophiolite and plutons, SSZ-like andesite, dacite and rhyolite and regional structures suggest that there develop double-subduction systems with ridge-trench interaction in Carboniferous. These features suggest that the Western Junggar experiences rollback, intra-oceanic extension and subduction polarity reversal/flip in back-arc basin settings. Furthermore, positive ɛNd(t) values and no huge movements of blocks suggest that the Western Junggar is amalgamated by juvenile elements with different orientations. Therefore, we conclude that the Western Junggar enlarges from an island arc to Paleozoic tectonic regime with

  5. Geochemical characteristics of fault core and damage zones of the Hong-Che Fault Zone of the Junggar Basin (NW China) with implications for the fault sealing process

    NASA Astrophysics Data System (ADS)

    Liu, Yin; Wu, Kongyou; Wang, Xi; Pei, Yangwen; Liu, Bo; Guo, Jianxun

    2017-08-01

    Faults may have a complex internal structure, including fault core and damage zone, and can act as major conduits for fluid migration. The migration of fluids along faults is generally associated with strong fluid-rock interaction, forming large amounts of cement that fill in the fractures. The cementation of the fault fractures is considered to be one of the important parameters of fault sealing. The different components of faults have diverse geochemical features because of varying physical characteristics. The investigation of the geochemical characteristics of the fault and damage zones could provide important information about the fault sealing process, which is very important in oil and gas exploration. To understand the fault-cemented sealing process, detailed geochemical studies were conducted on the fault and damage zones of the Hong-Che Fault of the northwestern Junggar Basin in China. The major and trace element data of our study suggest that the fault core is characterized by higher loss on ignition (LOI), potassium loss, Chemical Index of Alteration (CIA), and Plagioclase Index of Alteration (PIA) values and lower high field strength element (HFSE), large-ion lithosphile element (LILE), and rare earth element (REE) concentrations compared with the damage zone, implying more serious elemental loss and weathering of the fault core compared with the damage zone during faulting. The carbon and oxygen isotope data reveal that the cement of the Hong-Che Fault Zone formed due to multiple sources of fluids. The fault core was mainly affected by deep sources of hydrothermal fluids. In combination with previous studies, we suggest a potential fault-cemented sealing process during the period of fault movement. The fault core acts as the fluid conduit during faulting. After faulting, the fault core is cemented and the damage zone becomes the major conduit for fluid migration. The cementation firstly occurs on two sides of the damage zone in the upper part of the

  6. Remote sensing-based analysis on temporal and spatial changes about environmental elements in the northwest of Junggar basin, China

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Nannan, Zhang; Wentong, Dong; Liqun, Zou; Shanghong, Huang

    2016-11-01

    This paper presents a study of revealing the environmental elements change during the process of local industrialization based on remote sensing technique in the western part of China. Spatio-temporal evolution of vegetation cover derived from NDVI and land surface water distribution was analyzed by time-series analysis of MSS and Landsat data from 1977 to 2011. Results show that remote sensing provide a way for monitoring the influence of local industrialization on regional environment elements in gobi region.

  7. Sedimentary basin framework of Exmouth Plateau, northwest Australia

    SciTech Connect

    Boyd, R.; Exon, N.; Williamson, P.

    1987-05-01

    The Exmouth Plateau is a marginal plateau lying off northwest Australia. Water depths range between 800 m and 4000 m, and the area shallower than 2000 m covers approximately 150,000 km/sup 2/. The plateau consists of rifted and deeply subsided continental crust, with a Phanerozoic sedimentary sequence around 10 km thick, deposited in the Canning and Carnarvon basins. The plateau is separated from the Northwest Shelf by the Kangaroo syncline and is bounded to the north, west, and south by oceanic crust of Cretaceous and Jurassic age. The present structural configuration of Exmouth Plateau was initiated by rifting in the Triassic to Middle Jurassic, followed by northwest-oriented sea floor spreading. The western margin has a normal rifted structure, while the southern margin structure was dominated by transform motion. The complex rifted and sheared northern margin contains at least one crustal block of post-breakup igneous origin. Below a rift onset unconformity of Neocomian age lies a thick Triassic paralic sequence to the south, while farther north the unconformity is of Callovian age and overlies a Jurassic sequence of Tethyan carbonates, coal measures, and volcanics. The post-breakup sequence consists of Late Jurassic-Cenomanian deltaic and shelf clastics, overlain by thin Late Cretaceous-Tertiary shallow marine to pelagic carbonates. Exmouth Plateau therefore represents classic rift to mature ocean stage development of a sediment-starved passive margin. The large fault blocks in the rifted Triassic-Jurassic sequences and large areal closures in the Cretaceous deltas encouraged petroleum exploration over the last two decades. The rifted section was shown to be gas prone, while the overlying section proved to be largely immature.

  8. Subsidence modeling of the Sabah Basin, a foreland basin, Northwest Borneo, Malaysia

    SciTech Connect

    Azim-Ibrahim, N. ); White, N. )

    1994-07-01

    The Sabah Basin is located on the northwestern side of Borneo. It is a piggy back northeast-southwest-trending basin, riding on a north-westward directed imbricate thrust system. The basin contains approximately 10 to 12 km of sediment in the deepest part deposited in two main episodes of basin development; (1) a pre-early middle Miocene phase of generally deep-marine clastic deformation, which was later subjected to compression and (2) a post-early middle Miocene episode of clastic deposition, comprising bathyal to upper coastal plain sediments. Tectonic subsidence of the post-middle Miocene sequence was determined using the 1-D Airy and 2-D flexure backstripping techniques and wells and selected dip profiles, where the effects of compaction and sediment loading were removed. Variation in paleowater depth was also taken into account. The results show an extremely rapid subsidence phase dominating the earlier part of the basin history, with the later part corresponding to passive basin infilling. The boundary between these two phases becomes younger toward the northwest. The rapid subsidence phase is attributed to tectonic loading, possibly as a result of continuing thrusting at the basin margin. The results also imply that sedimentary sequences formed during the earlier phase were tectonically controlled and marked by transgressive events, while those deposited during the later phase bear the imprints of both tectonic and eustasy.

  9. History of hydrocarbon generation in Tembungo Area, Northwest Sabah Basin

    SciTech Connect

    Hoesni, M.J.; Mood, M.N.C. )

    1994-07-01

    Tembungo field in Sabah Basin produces oil from upper Miocene turbidite reservoirs. The oil, with low sulfur and wax contents and API gravity of 38-40[degrees], was derived from terrigenous source rock of mainly land-plant origin. The history of hydrocarbon generation in the Tembungo area - that is, the burial, fluid pressure and fluid-flow, thermal, hydrocarbon generation, and migration history - has been studied with the help of a two-dimensional finite difference basin model. Backstripping shows that high sedimentation rates occurred during middle to late Miocene. The Tembungo structure itself began to grow in late Miocene (7.24 Ma), with an accelerated growth rate in the early Pliocene. A constant basement heat flow of 55 mW/m[sup 2] was determined for the area. The faults are known to be sealing, with very low associated permeabilities. The presence of barrier faults and thick shales resulted in development of overpressure in the area. Contribution of hydrocarbon generation to overpressure is insignificant. Maturation models based on kinetic chemical reaction indicate that upper Miocene sediments underlying the reservoir section in the adjacent syncline to the northwest and west began to enter the hydrocarbon generation window at 8.4 Ma and that the hydrocarbons began to be trapped in the Tembungo structure in the late Miocene (6.0 Ma). The oils most likely were sourced from these upper Miocene sediments underlying the reservoirs. Hydrocarbons sourced in middle Miocene sediments were largely retained due to thick overlying shales, and they eventually were cracked to gas.

  10. Seismic refraction studies in the San Juan Basin, Northwest New Mexico

    USGS Publications Warehouse

    Evans, D.H.; Jaksha, L.H.

    1984-01-01

    The U.S. Geological Survey is studying some of the features of the earth's crust in the San Juan Basin region, northwest New Mexico. As a part of this study seismic refraction-reflection measurements were made in and around the basin using explosions and earthquakes as energy sources. Record sections and traveltime tables were derived from the measurements.

  11. Maturation history modeling of Sufyan Depression, northwest Muglad Basin, Sudan

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Liu, Luofu; An, Fuli; Wang, Hongmei; Pang, Xiongqi

    2016-08-01

    The Sufyan Depression is located in the northwest of Muglad Basin and is considered as a favorable exploration area by both previous studies and present oil shows. In this study, 16 wells are used or referred, the burial history model was built with new seismic, logging and well data, and the thermal maturity (Ro, %) of proved AG source rocks was predicted based on heat flow calculation and EASY %Ro modeling. The results show that the present heat flow range is 36 mW/m2∼50 mW/m2 (average 39 mW/m2) in 13 wells and 15 mW/m2∼55 mW/m2 in the whole depression. Accordingly, the geothermal gradient is 20 °C/km∼26 °C/km and 12 °C/km∼30 °C/km, respectively. The paleo-heat flow has three peaks, namely AG-3 period, lower Bentiu period and Early Paleogene, with the value decreases from the first to the last, which is corresponding to the tectonic evolution history. Corresponding to the heat flow distribution feature, the AG source rocks become mature earlier and have higher present marurity in the south area. For AG-2_down and AG-3_up source rocks that are proved to be good-excellent, most of them are mature with Ro as 0.5%-1.1%. But they can only generate plentiful oil and gas to charge reservoirs in the middle and south areas where their Ro is within 0.7%-1.1%, which is consistent with the present oil shows. Besides, the oil shows from AG-2_down reservoir in the middle area of the Sufyan Depression are believed to be contributed by the underlying AG-3_up source rock or the source rocks in the south area.

  12. Assessment of undiscovered conventional oil and gas resources of Bonaparte Basin, Browse Basin, Northwest Shelf, and Gippsland Basin Provinces, Australia, 2011

    USGS Publications Warehouse

    Pollastro, Richard M.; Brownfield, Michael E.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.; Kirschbaum, Mark A.; Pitman, Janet K.; Schenk, Christopher J.

    2012-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 4.7 billion barrels of undiscovered oil and 227 trillion cubic feet of undiscovered natural gas in three major offshore petroleum basins of northwest Australia and in the Gippsland Basin of southeast Australia.

  13. Mesoscale variability of deep currents in the Northwest Pacific Basin

    NASA Astrophysics Data System (ADS)

    Miyamoto, M.; Oka, E.; Yanagimoto, D.; Fujio, S.; Kurogi, M.; Hasumi, H.

    2014-12-01

    mooring observations conducted near 30°N, 146°40'E in the late 1970's. In the Northwest Pacific Basin, simulated EKE was highest at the Kuroshio Extension, and a high-EKE area extended about 500 km north and south of it.

  14. Tectonic evolution of the Tualatin basin, northwest Oregon, as revealed by inversion of gravity data

    USGS Publications Warehouse

    McPhee, Darcy K.; Langenheim, Victoria E.; Wells, Ray; Blakely, Richard J.

    2014-01-01

    The Tualatin basin, west of Portland (Oregon, USA), coincides with a 110 mGal gravity low along the Puget-Willamette lowland. New gravity measurements (n = 3000) reveal a three-dimensional (3-D) subsurface geometry suggesting early development as a fault-bounded pull-apart basin. A strong northwest-trending gravity gradient coincides with the Gales Creek fault, which forms the southwestern boundary of the Tualatin basin. Faults along the northeastern margin in the Portland Hills and the northeast-trending Sherwood fault along the southeastern basin margin are also associated with gravity gradients, but of smaller magnitude. The gravity low reflects the large density contrast between basin fill and the mafic crust of the Siletz terrane composing basement. Inversions of gravity data indicate that the Tualatin basin is ∼6 km deep, therefore 6 times deeper than the 1 km maximum depth of the Miocene Columba River Basalt Group (CRBG) in the basin, implying that the basin contains several kilometers of low-density pre-CRBG sediments and so formed primarily before the 15 Ma emplacement of the CRBG. The shape of the basin and the location of parallel, linear basin-bounding faults along the southwest and northeast margins suggest that the Tualatin basin originated as a pull-apart rhombochasm. Pre-CRBG extension in the Tualatin basin is consistent with an episode of late Eocene extension documented elsewhere in the Coast Ranges. The present fold and thrust geometry of the Tualatin basin, the result of Neogene compression, is superimposed on the ancestral pull-apart basin. The present 3-D basin geometry may imply stronger ground shaking along basin edges, particularly along the concealed northeast edge of the Tualatin basin beneath the greater Portland area.

  15. An integrated multiscale river basin observing system in the Heihe River Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Li, X.; Liu, S.; Xiao, Q.; Ma, M.; Jin, R.; Che, T.

    2015-12-01

    Using the watershed as the unit to establish an integrated watershed observing system has been an important trend in integrated eco-hydrologic studies in the past ten years. Thus far, a relatively comprehensive watershed observing system has been established in the Heihe River Basin, northwest China. In addition, two comprehensive remote sensing hydrology experiments have been conducted sequentially in the Heihe River Basin, including the Watershed Allied Telemetry Experimental Research (WATER) (2007-2010) and the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) (2012-2015). Among these two experiments, an important result of WATER has been the generation of some multi-scale, high-quality comprehensive datasets, which have greatly supported the development, improvement and validation of a series of ecological, hydrological and quantitative remote-sensing models. The goal of a breakthrough for solving the "data bottleneck" problem has been achieved. HiWATER was initiated in 2012. This project has established a world-class hydrological and meteorological observation network, a flux measurement matrix and an eco-hydrological wireless sensor network. A set of super high-resolution airborne remote-sensing data has also been obtained. In addition, there has been important progress with regard to the scaling research. Furthermore, the automatic acquisition, transmission, quality control and remote control of the observational data has been realized through the use of wireless sensor network technology. The observation and information systems have been highly integrated, which will provide a solid foundation for establishing a research platform that integrates observation, data management, model simulation, scenario analysis and decision-making support to foster 21st-century watershed science in China.

  16. Northwest Basin and Range tectonic deformation observed with the Global Positioning System, 1999-2003

    USGS Publications Warehouse

    Hammond, W.C.; Thatcher, W.

    2005-01-01

    We use geodetic velocities obtained with the Global Positioning System (GPS) to quantify tectonic deformation of the northwest Basin and Range province of the western United States. The results are based on GPS data collected in 1999 and 2003 across five new quasi-linear networks in northern Nevada, northeast California, and southeast Oregon. The velocities show ???3 mm/yr westward movement of northern Nevada with respect to stable North America. West of longitude 119??W the velocities increase and turn northwest, parallel to Sierra Nevada/Great Valley microplate motion, and similar to velocities previously obtained to the south. The observations are explained by a kinematic model with three domains that rotate around Euler poles in eastern Oregon and western Idaho. Northeast California experiences internal dextral shear deformation (11.2 ?? 3.6 nstrain/yr) subparallel to Pacific/North America motion. Relative motions of the domains imply 2-5 mm/yr approximately east-west extension in northwest Nevada and 1-4 mm/yr approximately north-south contraction near the California/Oregon border. The northward decreasing approximately east-west extension in northwest Nevada is consistent with the northern termination of Basin and Range deformation, faulting and characteristic topography. No significant extension is detected in the Oregon Basin and Range. The Oregon Cascade arc moves north at ???3.5 mm/yr and is possibly influenced by the approximately eastward motion of the Juan de Fuca plate. These results disagree with secular northwest trenchward motion of the Oregon forearc inferred from paleomagnetic rotations. South of latitude 43??, however, trenchward motion exists and is consistent with block rotations, approximately east-west Basin and Range extension, and northwest Sierra Nevada translation. Copyright 2005 by the American Geophysical Union.

  17. The crustal structure from the Altai Mountains to the Altyn Tagh fault, northwest China

    USGS Publications Warehouse

    Wang, Y.; Mooney, W.D.; Yuan, X.; Coleman, R.G.

    2003-01-01

    We present a new crustal section across northwest China based on a seismic refraction profile and geologic mapping. The 1100-km-long section crosses the southern margin of the Chinese Altai Mountains, Junggar Accretional Belt and eastern Junggar basin, easternmost Tianshan Mountains, and easternmost Tarim basin. The crustal velocity structure and Poisson's ratio (??), which provide a constraint on crustal composition, were determined from P and S wave data. Despite the complex geology, the crustal thickness along the entire profile is nearly uniform at 50 km. The thickest crust (56 km) occurs at the northern end of the profile beneath the Altai Mountains and the thinnest (46 km) crust is beneath the Junggar basin. Beneath surficial sediments, the crust is found to have three layers with P wave velocities (Vp) of 6.0-6.3, 6.3-6.6, and 6.9-7.0 km/s, respectively. The southern half of the profile, including the eastern Tianshan Mountains and eastern margin of the Tarim basin, shows low P wave velocities and ?? = 0.25 to a depth of 30 km, which suggests a quartz-rich, granitic upper crustal composition. The northern half of the profile below the Altai Mountains and Junggar Accretional Belt has a higher Poisson's ratio of ?? = 0.26-0.27 to a depth of 30 km, indicative of an intermediate crustal composition. The entire 1100-km-long profile is underlain by a 15-30 km thick high velocity (6.9-7.0 km/s; ?? = 0.26-0.28) lower-crustal layer that we interpret to have a bulk composition of mafic granulite. At the southern end of the profile, a 5-km-thick midcrustal low-velocity layer (Vp = 5.9 km/s, ?? = 0.25) underlies the Tianshan and the region to the south, and may be indicative of a near-horizontal detachment interface. Pn velocities are ???7.7-7.8 km/s between the Tianshan and the Junggar basin, and ???7.9-8.0 km/s below the Altai Mountains and eastern margin of the Tarim basin. We interpret the consistent three-layer stratification of the crust to indicate that the crust

  18. The Termination Of The Northwest Basin And Range Into A Northwest Trending Extensional Fault System

    NASA Astrophysics Data System (ADS)

    Trench, D.; Meigs, A.

    2007-12-01

    Extensional provinces terminate along-strike where extension dissipates to zero, at transform faults, or at triple junctions. Termination of the northern Basin and Range province in western North America has long been thought to be controlled by an intracontinental transform fault, the Brothers Fault zone (BFz). New mapping in the boundary region between a major Basin and Range fault, the Hart Mountain fault system (HFz), and the BFz was conducted to test this model and to determine the structural and temporal relationship between the two fault zones. Stratigraphic separation and topography were used to determine fault orientations, displacement gradients, and sense of motion in the two fault zones. N-S trending faults of the HFz show predominantly normal displacement. Displacement in the HFz decreases northward from a maximum of ~940 m at Hart Mountain to ~173 m to 0 m at the BFz. Fault orientations smoothly change from the N-S Basin and Range trend in the south to the NW BFz trend in the north. Topography and stratigraphic separation indicate that the BFz is a series of isolated faults with maximum slip of ~106 m and lengths of up to a few kilometers. Piercing points within the BFz indicate that down-to-the-north motion predominates with the fault system and that strike-slip motion is minimal. Uncertainty on observed fault displacements is + 5m. Stratigraphic separation of the Rattlesnake Tuff indicates that activity on the NW trending fault system post-dates the 7 Ma tuff. That displacement along the HFz effectively goes to zero at the BFz suggests Basin and Range faults have propagated northward into an existing northeast- facing extensional province represented by the BFz.

  19. Transfer structures in the Northern Tarim Basin, Northwest China

    SciTech Connect

    Guang-Ya Zhang; Shi-Xia Gao

    1996-03-01

    The fold-thrust tectonics of the Northern Tarim Basin, oriented roughly parallel to the South Tianshan orogenic belt, consists of two large-scale tectonic regimes: (1) the foreland-basin, thin-skinned deformation belt; and (2) the foreland-craton, thick-skinned-dominated (i.e., basement-involved) deformation belt. Variations in the degree of deformation in these tectonic belts and style along the regional tectonic strike can be accounted for by longitudinal (progressive transfer or transverse (abrupt) transfer). Longitudinal transfer maintains the overall displacement or shortening within the fold-thrust belts as uniform or with gradual change along the tectonic strike. This includes the tectonic transfer between en echelon master thrusts and from the individual master thrust to terminal fold(s) or distributive thrusts. Transverse transfer resulted from an abrupt change in overall displacement or shortening along the tectonic strike. Within the transverse transfer zone, various tectonics-such as strike-slip faults, strike-slip thrusts, transverse anticlines, and en echelon folds-are developed. The development of longitudinal transfer zones can be attributed to the gradual variation of intrinsic and extrinsic and extrinsic deformational conditions along the tectonic strike. The initiation of transverse transfer may be related to variations in the thickness of sedimentary layers, detachment-layer distribution limits, and variation along strike of the degree and mode of the South Tianshan orogenic belt`s effect on the basin, as well as the variation of the boundary conditions of the deformation, such as in the geometry of plate margins. 15 refs., 8 figs.

  20. Occurrence and geochemistry of natural gases, Piceance Basin, northwest Colorado

    USGS Publications Warehouse

    Johnson, R.C.; Rice, D.D.

    1990-01-01

    The Piceance Basin is a hydrocarbon-rich province that has natural gas production from reservoirs ranging in age from Late Jurassic to Eocene and large undeveloped resources of natural gas in coal beds and tight sandstone reservoirs of Cretaceous age. Gases from all producing intervals are of predominantly thermal origin and become isotopically heavier and chemically drier with increasing thermal maturity of reservoirs. Based on chemical and isotopic composition, three major types of gases can be distinguished: those generated from mixed type II and III kerogens, those from dispersed type III kerogen, and those from coal. A fourth, distinct type of isotopically light thermogenic gas occurs in immature reservoirs of the Eocene Green River Formation. This gas is inferred to have migrated from unidentified deeper, more mature source rocks. -from Authors

  1. Gas occurrence property in shales of Tuha basin northwest china

    NASA Astrophysics Data System (ADS)

    Chen, Jinlong; Huang, Zhilong

    2017-04-01

    Pore of rock under formation condition must be fulfilled by gas, oil, or water, so the volume of water and gas is equation to porous volume in shale gas. The occurrences states of gas are free gas, solution gas, and absorbed gas. Field analysis is used to obtain total gas content by improved lost gas recover method. Free gas content acquired by pore proportion of gas, which use measured pore volume minus water and oil saturation, convert gas content of standard condition by state equation. Water saturation obtain from core water content, oil saturation obtain from extract carbohydrate. Solution gas need gas solubility in oil and water to calculate solution gas content in standard condition. Absorbed gas, introduce Absorbed Gas Saturation ɛ, which acquire from isothermal adsorption volume vs field analysis gas content in many basins of published paper, need isothermal adsorption and Absorbed Gas Saturation to obtain absorbed gas content. All of the data build connect with logging value by regression equation. The gas content is 0.92-1.53 m3/t from field analysis, evaluate gas content is 1.33 m3/t average, free gas proportion is about 47%, absorbed gas counter for 49%, and solution gas is average 4%.

  2. Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

    NASA Astrophysics Data System (ADS)

    Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

    2015-05-01

    Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

  3. Tectonic evolution of the offshore Sarawak and Sabah Basins, Northwest Borneo

    SciTech Connect

    Hazebroek, H.; Tan, D.; Swinburn, P. )

    1994-07-01

    The offshore Sarawak and Sabah Basins, northwest Borneo, contain up to 12 km of Oligocene to Holocene sediments. On the basis of marked different structural styles and stratigraphy, these basins can be divided into 13 tectono-stratigraphic provinces. Many of these, e.g., Balingian southwest Luconia, central Luconia, Baram delta, inboard belt, and outboard belt, are proven hydrocarbon provinces. Stratigraphically, these provinces generally become younger toward the northwest and/or northeast, with the older provinces overlying unconformably the Paleogene Rajang Group deep-marine sediments in the south. There is a great variation in structural styles. However, general structural trends can be recognized in that the older provinces in the southeast, e.g., Balingian, updip part of Baram delta, Rajang Group fold and thrust belt, inboard belt, and outboard belt, have been subjected to strong compressional tectonics, whereas the younger provinces in the northwest, e.g., central Luconia, north Luconia, southwest Luconia, and the central part of the Baram delta, have undergone predominantly extensional tectonics. The tectonic evolution of these provinces from late Eocene to Holocene, relative to the postulated subduction zones and major tectonic lineations recognized in the region, are discussed.

  4. Modeled effects of irrigation on surface climate in the Heihe River Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Zhang, Xuezhen; Xiong, Zhe; Tang, Qiuhong

    2017-08-01

    In Northwest China, water originates from the mountain area and is largely used for irrigation agriculture in the middle reaches. This study investigates the local and remote impact of irrigation on regional climate in the Heihe River Basin, the second largest inland river basin in Northwest China. An irrigation scheme was developed and incorporated into the Weather Research and Forecasting (WRF) model with the Noah-MP land surface scheme (WRF/Noah-MP). The effects of irrigation is assessed by comparing the model simulations with and without consideration of irrigation (hereafter, IRRG and NATU simulations, respectively) for five growth seasons (May to September) from 2009 to 2013. As consequences of irrigation, daily mean temperature decreased by 1.7°C and humidity increased by 2.3 g kg-1 (corresponding to 38.5%) over irrigated area. The temperature and humidity of IRRG simulation matched well with the observations, whereas NATU simulation overestimated temperature and underestimated humidity over irrigated area. The effects on temperature and humidity are generally small outside the irrigated area. The cooling and wetting effects have opposing impacts on convective precipitation, resulting in a negligible change in localized precipitation over irrigated area. However, irrigation may induce water vapor convergence and enhance precipitation remotely in the southeastern portion of the Heihe River Basin.

  5. Simulations of the ENSO Hydroclimate Signals in the Pacific Northwest Columbia River Basin

    SciTech Connect

    Leung, Lai R.; Hamlet, Alan F.; Lettenmaier, Dennis P.; Kumar, Arun

    1999-11-01

    Natural fluctuations in the atmosphere–ocean system related to the El Niño–Southern Oscillation (ENSO) induce climate variability over many parts of the world that is potentially predictable with lead times from seasons to decades. This study examines the potential of using a model nesting approach to provide seasonal climate and streamflow forecasts suitable for water resources management. Two ensembles of perpetual January simulations were performed with a regional climate model driven by a general circulation model (GCM), using observed climatological sea surface temperature (SST) and the mean SST of the warm ENSO years between 1950 and 1994. The climate simulations were then used to drive a macroscale hydrology model to simulate streamflow. The differences between the two ensembles of simulations are defined as the warm ENSO signals. The simulated hydroclimate signals were compared with observations. The analyses focus on the Columbia River basin in the Pacific Northwest. Results show that the global and regional models simulated a warming over the Pacific Northwest that is quite close to the observations. The models also correctly captured the strong wet signal over California and the weak dry signal over the Pacific Northwest during warm ENSO years. The regional climate model consistently performed better than the GCM in simulating the spatial distribution of regional climate and climate signals. When the climate simulations were used to drive a macroscale hydrology model at the Columbia River basin, the simulated streamflow signal resembles that derived from hydrological simulations driven by observed climate. The streamflow simulations were considerably improved when a simple bias correction scheme was applied to the climate simulations. The coupled regional climate and macroscale hydrologic simulations demonstrate the prospect for generating and utilizing seasonal climate forecasts for managing reservoirs.

  6. Rifting to India-Asia Reactivation: Multi-phase Structural Evolution of the Barmer Basin, Rajasthan, northwest India

    NASA Astrophysics Data System (ADS)

    Kelly, M. J.; Bladon, A.; Clarke, S.; Najman, Y.; Copley, A.; Kloppenburg, A.

    2015-12-01

    The Barmer Basin, situated within the West Indian Rift System, is an intra-cratonic rift basin produced during Gondwana break-up. Despite being a prominent oil and gas province, the structural evolution and context of the rift within northwest India remains poorly understood. Substantial subsurface datasets acquired during hydrocarbon exploration provide an unrivalled tool to investigate the tectonic evolution of the Barmer Basin rift and northwest India during India-Asia collision. Here we present a structural analysis using seismic datasets to investigate Barmer Basin evolution and place findings within the context of northwest India development. Present day rift structural architectures result from superposition of two non-coaxial extensional events; an early mid-Cretaceous rift-oblique event (NW-SE), followed by a main Paleocene rifting phase (NE-SW). Three phases of fault reactivation follow rifting: A transpressive, Late Paleocene inversion along localised E-W and NNE-SSW-trending faults; a widespread Late Paleocene-Early Eocene inversion and Late Miocene-Present Day transpressive strike-slip faulting along NW-SE-trending faults and isolated inversion structures. A major Late Eocene-Miocene unconformity in the basin is also identified, approximately coeval with those identified within the Himalayan foreland basin, suggesting a common cause related to India-Asia collision, and calling into question previous explanations that are not compatible with spatial extension of the unconformity beyond the foreland basin. Although, relatively poorly age constrained, extensional and compressional events within the Barmer Basin can be correlated with regional tectonic processes including the fragmentation of Gondwana, the rapid migration of the Greater Indian continent, to subsequent collision with Asia. New insights into the Barmer Basin development have important implications not only for ongoing hydrocarbon exploration but the temporal evolution of northwest India.

  7. STP K Basin Sludge Sample Archive at the Pacific Northwest National Laboratory FY2014

    SciTech Connect

    Fiskum, Sandra K.; Smoot, Margaret R.; Schmidt, Andrew J.

    2014-06-01

    The Pacific Northwest National Laboratory (PNNL) currently houses 88 samples (~10.5 kg) of K Basin sludge (81 wet and seven dry samples) on behalf of the Sludge Treatment Project (STP), which is managed for the U.S. Department of Energy (DOE) by the CH2M Hill Plateau Remediation Company (CHPRC). Selected samples are intended to serve, in part, as sentinels to enhance understanding of sludge properties after long-term storage, and thus enhance understanding of sludge behavior following transfer to sludge transfer and storage containers (STSCs) and storage at the Hanford 200 Area central plateau. In addition, remaining samples serve in contingency for future testing requirements. At PNNL, the samples are tracked and maintained under a prescriptive and disciplined monthly sample-monitoring program implemented by PNNL staff. This report updates the status of the K Basin archive sludge sample inventory to April 2014. The previous inventory status report, PNNL 22245 (Fiskum et al. 2013, limited distribution report), was issued in February of 2013. This update incorporates changes in the inventory related to repackaging of 17 samples under test instructions 52578 TI052, K Basin Sludge Sample Repackaging for Continued Long Term Storage, and 52578 TI053, K Basin Sludge Sample Repackaging Post-2014 Shear Strength Measurements. Note that shear strength measurement results acquired in 2014 are provided separately. Specifically, this report provides the following: • a description of the K Basin sludge sample archive program and the sample inventory • a summary and images of the samples that were repackaged in April 2014 • up-to-date images and plots of the settled density and water loss from all applicable samples in the inventory • updated sample pedigree charts, which provide a roadmap of the genesis and processing history of each sample in the inventory • occurrence and deficiency reports associated with sample storage and repackaging

  8. The role of small-scale extensional faulting in the evolution of basin geometries. An example from the late Palaeozoic Petrel Sub-basin, northwest Australia

    NASA Astrophysics Data System (ADS)

    Baxter, K.

    1998-03-01

    During continental extension, the kinematic collapse of the hangingwall of major normal faults and the subsequent isostatic response imposes a strong control on the evolving basin geometry. The interaction of the flexural wavelength. and the magnitude and location of faults may allow the development of basin geometries which deviate from a classic half-graben style, particularly if some of this deformation is below the scale of observation (commonly seismic reflection data). In particular the development of a lateral partitioning between large- and small-scale faults within a basin may exert a significant control on the resulting basin geometry. Using the Petrel Sub-basin in northwest Australia as an example, it is demonstrated that an extensional basin geometry consisting of a classic half-graben can be overprinted by a significant 'sag' geometry which can be related to the lateral offset of sub-resolution faulting. This lateral partitioning and resulting basin geometry may also have an application to other extensional basins, particularly if a mechanism is present to allow this partitioning of fault styles to develop. In the Petrel Sub-basin this has been related to the presence of older basement features of the Halls Creek Mobile Zone beneath the axis of the basin. However, a comparison with physical models also suggests that this may be applicable to basins formed by oblique rifting (a component of which may also be present within the Petrel Sub-basin), particularly if this is imposed upon a weak zone or suture within the upper mantle.

  9. Numerical simulation of groundwater flow in the Peshawar intermontane basin, northwest Himalayas

    NASA Astrophysics Data System (ADS)

    Yousafzai, Asim; Eckstein, Yoram; Dahl, Peter

    2008-11-01

    The hypothesis that abnormal fluid pressure is generated in basins under tectonic compression is tested. The study site, between the Main Karakoram Thrust (MKT), Main Mantle Thrust (MMT), Main Central Thrust (MCT), Main Boundary Thrust (MBT) and Salt Range Thrust (SRT) in northwest Pakistan, is experiencing a tectonic compression of 90 MPa. The Peshawar basin is a broad, oval depression comprising a thick sequence of lacustrine, deltaic and fluvial sediments overlain by loess and alluvial deposits dated at 2.8-0.6 Ma. It is surrounded by the Precambrian and Tertiary intrusive and metamorphic rocks on the north and sedimentary rocks of Paleogene and Neogene to the south. The basin was divided into four hydrostratigraphic units for numerical simulations using the three-dimensional finite-element model FEMWATER within groundwater modeling system (GMS) ver. 5.1. Simulated pressure head data have been compared with the field measurements of hydraulic heads. Transient simulations indicate that topography alone is not sufficient to induce the pressure heads observed in the field, generating consistently positive residuals 0.98-2.90 m over the topography-driven flow. The residuals disappeared after inclusion of the elastic properties of the four hydrostratigraphic units in the model, suggesting the effect of tectonic compression.

  10. Effects of climate change on water resources in Tarim River Basin, Northwest China.

    PubMed

    Chen, Ya-ning; Li, Wei-hong; Xu, Chang-chun; Hao, Xin-ming

    2007-01-01

    Based on hydrology, temperature, and precipitation data from the past 50 years, the effects of climate change on water resources in Tarim River Basin in Northwest China were investigated. The long-term trends of the hydrological time series were detected using both parametric and nonparametric techniques. The results showed that the increasing tendency of the temperature has a 5% level of significance, and the temperature increased by nearly 1 degree C over the past 50 years. The precipitation showed a significant increase in the 1980s and 1990s, and the average annual precipitation exhibited an increasing trend with a magnitude of 6.8 mm per decade. A step change occurred in both the temperature and precipitation time series around 1986. The streamflow from the headwater of the Tarim River exhibited a significant increase during the last 20 years. The increase in temperature, precipitation, and streamflow may be attributed to global climate change.

  11. Groundwater circulation and hydrogeochemical evolution in Nomhon of Qaidam Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Xiao, Yong; Shao, Jingli; Cui, Yali; Zhang, Ge; Zhang, Qiulan

    2017-03-01

    In this study, analysis of hydrogeological conditions, as well as hydrochemistry and isotopic tools were used to get an insight into the processes controlling mineralization, recharge conditions, and flow pattern of groundwater in a typical arid alluvial-lacustrine plain in Qaidam Basin, northwest China. Analysis of the dissolved constituents reveals that groundwater evolves from fresh water (TDS =300-1000 mg/l) to saline water (TDS ≥5000 mg/l) along the flow paths, with the water type transiting from HCO 3ṡCl-Na ṡMg to HCO 3ṡCl-Na, and eventually to Cl-Na. Groundwater chemical evolution is mainly controlled by water-rock interaction and the evaporation-crystallization process. Deuterium and oxygen-18 isotopes in groundwater samples indicate that the recharge of groundwater is happened by meteoric water and glacier melt-water in the Kunlun Mountains, and in three different recharge conditions. Groundwater ages, estimated by the radiogenic (3H and 14C) isotope data, range from present to Holocene (˜28 ka). Based on groundwater residence time, hydrogeochemical characteristics, field investigation, and geological structure distribution, a conceptual groundwater flow pattern affected by uplift structure is proposed, indicating that shallow phreatic water is blocked by the uplift structure and the flow direction is turned to the northwest, while high pressure artesian water is formed in the confined aquifers at the axis of the uplift structure.

  12. Tectonics, basin analysis and organic geochemical attributes of Permian through Mesozoic deposits and their derivative oils of the Turpan-Hami basin, northwestern China

    NASA Astrophysics Data System (ADS)

    Greene, Todd Jeremy

    The Turpan-Hami basin is a major physiographic and geologic feature of northwest China, yet considerable uncertainty exists as to the timing of its inception, its late Paleozoic and Mesozoic tectonic history, and the relationship of its petroleum systems to those of the nearby Junggar basin. Mesozoic sedimentary fades, regional unconformities, sediment dispersal patterns, and sediment compositions within the Turpan-Hami and southern Junggar basins suggest that these basins were initially separated between Early Triassic and Early Jurassic time. Prior to separation, Upper Permian profundal lacustrine and fan-delta fades and Triassic coarse-grained braided-fluvial/alluvial fades were deposited across a contiguous Junggar-Turpan-Hami basin. Permian through Triassic fades were derived mainly from the Tian Shan to the south as indicated by northward-directed paleocurrent directions and geochemical provenance of granitoid cobbles. Lower through Middle Jurassic strata begin to reflect ponded coal-forming, lake-plain environments within the Turpan-Hami basin. A sharp change in sedimentary-lithic-rich Lower Jurassic sandstone followed by a return to lithic volcanic-rich Middle Jurassic sandstone points to the initial uplift and unroofing of the largely andesitic Bogda Shan range, which first shed its sedimentary cover as it emerged to become the partition between the Turpan-Hami and southern Junggar basins. In Turpan-Hami, source rock age is one of three major statistically significant discriminators of effective source rocks in the basin. A newly developed biomarker parameter appears to track conifer evolution and can distinguish Permian rocks and their correlative oils from Jurassic coals and mudrocks, and their derivative oils. Source fades is a second key control on petroleum occurrence and character. By erecting rock-to-oil correlation models, the biomarker parameters separate oil families into end-member groups: Group 1 oils---Lower/Middle Jurassic peatland

  13. Reservoir development in Brahaney northwest and Patricia fields, northern Midland basin, Texas

    SciTech Connect

    Mazzullo, L.J.

    1990-02-01

    Porous pay zones in the Silurian-Devonian section of the northern Midland basin, Texas, vary stratigraphically, as well as structurally, with their locations beneath the pre-Woodford unconformity. These variations are related to at least two major periods of widespread pre-Woodford tectonism and erosion. A major unconformable surface, present at the top of the Lower Silurian Fusselman formation, was later modified by tectonism and erosion immediately preceding deposition of the Woodford Shale. In places where the Fusselman subcrops beneath the Woodford, its capacity for reservoir development is dependent upon the severity of geologic events that affected the formation during the two major tectonic/erosional events. Where the Wristen and Thirtyone formations subcrop, their reservoir capacity depends upon the extent of structuring and subsequent erosion immediately prior to Woodford deposition. Two pre-Woodford oil fields in the northern Midland basin illustrate geologic complexity that bears on the successful application of subsurface mapping in defining potential pay zones. Brahaney Northwest field in Yoakum County is productive from fractured, coarse crystalline Silurian-Devonian dolomites on subtle, fault-bounded structures. These structures, defined seismically on the base of the Woodford, do not reveal the more complex structural and stratigraphic variations within the reservoir itself. Patricia field in Dawson County is productive from Fusselman carbonates where upper Fusselman structural and topographic relief coincides with post-Woodford faulting and low-relief anticlinal closure as defined at the base of the Woodford.

  14. Groundwater evolution and recharge determination of the Quaternary aquifer in the Shule River basin, Northwest China

    NASA Astrophysics Data System (ADS)

    He, Jianhua; Ma, Jinzhu; Zhao, Wei; Sun, Shuang

    2015-12-01

    Groundwater recharge and evolution in the Shule River basin, Northwest China, was investigated by a combination of hydrogeochemical tracers, stable isotopes, and radiocarbon methods. Results showed the general chemistry of the groundwater is of SO4 2- type. Water-rock reactions of halite, Glauber's salt, gypsum and celestite, and reverse ionic exchange dictated the groundwater chemistry evolution, increasing concentrations of Cl-, Na+, SO4 2-, Ca2+, Mg2+ and Sr2+ in the groundwater. The δ18O and δ2H values of groundwater ranged from -10.8 to -7.7 and -74.4 to -53.1 ‰, respectively. Modern groundwater was identified in the proluvial fan and the shallow aquifer of the fine soil plain, likely as a result of direct infiltration of rivers and irrigation returns. Deep groundwater was depleted in heavy isotopes with 14C ages ranging from 3,000 to 26,000 years, suggesting palaeowater that was recharged during the late Pleistocene and middle Holocene epochs under a cold climate. These results have important implications for groundwater management in the Shule River basin, since large amounts of groundwater are effectively being mined and a water-use strategy is urgently needed.

  15. Minimal groundwater leakage restricts salinity in a hydrologically terminal basin of northwest Australia

    NASA Astrophysics Data System (ADS)

    Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline

    2016-04-01

    The Fortescue Marsh (FM) is one of the largest wetlands of arid northwest Australia (~1200 km2) and is thought to act as a terminal basin for the Upper Fortescue River catchment. Unlike the playa lake systems that predominate in most arid regions, where salinity is driven by inflow and evaporation of groundwater, the hydrological regime of the FM is driven by inundation from irregular cyclonic events [1]. Surface water of the FM is fresh to brackish and the salinity of the deepest groundwater (80 m b.g.l.) does not exceed 160 g/L; salt efflorescences are rarely present on the surface [2]. In this study, we tested the hypothesis that persistent but low rates of groundwater outflow have restricted the accumulation of salt in the FM over time. Using hydrological, hydrochemical data and dimensionless time evaporation modelling along with the water and salt budget, we calculated the time and the annual groundwater discharge volume that would be required to achieve and maintain the range of salinity levels observed in the Marsh. Groundwater outflow from alluvial and colluvial aquifers to the Lower Fortescue catchment is limited by an extremely low hydraulic gradient of 0.001 and is restricted to a relatively small 'alluvial window' of 0.35 km2 because of the elevation of the basement bedrock at the Marsh outflow. We show that if the Marsh was 100% "leakage free" i.e., a true terminal basin for the Upper Fortescue Catchment, the basin water would have achieved salt saturation after ~45 ka. This is not the case and only a very small outflow of saline groundwater of <2 GL/yr (<0.03% of the FM water volume) is needed to maintain the current salinity conditions. The minimum time required to develop the current hydrochemical composition of the water in the Marsh and the steady-state conditions for salt concentration is between 58 and 164 ka. This is a minimum age of the Marsh but it can be much older as nearly steady-state conditions could be maintained infinitely. Our

  16. Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

    NASA Astrophysics Data System (ADS)

    Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline F.

    2016-11-01

    Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (∼1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of <0.0001 and a small 'alluvial outlet' of 0.35 km2 because of relatively high bedrock elevation. However, FM groundwater salinity is far below saturation with respect to halite (TDS < 160 g/L), episodic flood water is fresh to brackish, and salt efflorescences are very sparse and evident only when the FM is dry. We show that if the FM was 100% ;leakage free; i.e., a true terminal basin, groundwater would have achieved halite saturation (>300 g/L) after ∼45 ka. We calculated that only a very small seepage of ∼2G L/yr (∼0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ∼60 to ∼165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.

  17. Sandstone type uranium deposits in the Ordos Basin, Northwest China: A case study and an overview

    NASA Astrophysics Data System (ADS)

    Akhtar, Shamim; Yang, Xiaoyong; Pirajno, Franco

    2017-09-01

    This paper provides a comprehensive review on studies of sandstone type uranium deposits in the Ordos Basin, Northwest China. As the second largest sedimentary basin, the Ordos Basin has great potential for targeting sandstone type U mineralization. The newly found and explored Dongsheng and Diantou sandstone type uranium deposits are hosted in the Middle Jurassic Zhilou Formation. A large number of investigations have been conducted to trace the source rock compositions and relationship between lithic subarkose sandstone host rock and uranium mineralization. An optical microscopy study reveals two types of alteration associated with the U mineralization: chloritization and sericitization. Some unusual mineral structures, with compositional similarity to coffinite, have been identified in a secondary pyrite by SEM These mineral phases are proposed to be of bacterial origin, following high resolution mapping of uranium minerals and trace element determinations in situ. Moreover, geochemical studies of REE and trace elements constrained the mechanism of uranium enrichment, displaying LREE enrichment relative to HREE. Trace elements such as Pb, Mo and Ba have a direct relationship with uranium enrichment and can be used as index for mineralization. The source of uranium ore forming fluids and related geological processes have been studied using H, O and C isotope systematics of fluid inclusions in quartz veins and the calcite cement of sandstone rocks hosting U mineralization. Both H and O isotopic compositions of fluid inclusions reveal that ore forming fluids are a mixture of meteoric water and magmatic water. The C and S isotopes of the cementing material of sandstone suggest organic origin and bacterial sulfate reduction (BSR), providing an important clue for U mineralization. Discussion of the ore genesis shows that the greenish gray sandstone plays a crucial role during processes leading to uranium mineralization. Consequently, an oxidation-reduction model for

  18. Hydroclimate temporal variability in a coastal Mediterranean watershed: the Tafna basin, North-West Algeria

    NASA Astrophysics Data System (ADS)

    Boulariah, Ouafik; Longobardi, Antonia; Meddi, Mohamed

    2017-04-01

    One of the major challenges scientists, practitioners and stakeholders are nowadays involved in, is to provide the worldwide population with reliable water supplies, protecting, at the same time, the freshwater ecosystems quality and quantity. Climate and land use changes undermine the balance between water demand and water availability, causing alteration of rivers flow regime. Knowledge of hydro-climate variables temporal and spatial variability is clearly helpful to plan drought and flood hazard mitigation strategies but also to adapt them to future environmental scenarios. The present study relates to the coastal semi-arid Tafna catchment, located in the North-West of Algeria, within the Mediterranean basin. The aim is the investigation of streamflow and rainfall indices temporal variability in six sub-basins of the large catchment Tafna, attempting to relate streamflow and rainfall changes. Rainfall and streamflow time series have been preliminary tested for data quality and homogeneity, through the coupled application of two-tailed t test, Pettitt test and Cumsum tests (significance level of 0.1, 0.05 and 0.01). Subsequently maximum annual daily rainfall and streamflow and average daily annual rainfall and streamflow time series have been derived and tested for temporal variability, through the application of the Mann Kendall and Sen's test. Overall maximum annual daily streamflow time series exhibit a negative trend which is however significant for only 30% of the station. Maximum annual daily rainfall also e exhibit a negative trend which is intend significant for the 80% of the stations. In the case of average daily annual streamflow and rainfall, the tendency for decrease in time is unclear and, in both cases, appear significant for 60% of stations.

  19. Estimating exploration potential in mature producing area, northwest shelf of Delaware Basin, New Mexico

    SciTech Connect

    Kumar, N.

    1985-11-01

    The case history presented here describes an investigation of the Northwest shelf of the Delaware basin carried out in 1979 for estimating the potential of finding new reserves and a follow-up study to measure predictions against results. A total of 191 new-field wildcats had been drilled during 1974-1979 in the study area. An analysis of target zones and success ratios showed that the best chances of drilling a successful test were in the San Andres (Permian) and Silurian-Devonian. However, cumulative frequency plots of existing fields in these two intervals showed that the chance of finding a field larger than 1 million bbl (159,000 m/sup 3/) in either of these zones was relatively low. As a result of the 1979 analysis, three prospective areas representing 8% of the total study area were high graded, or rated as having a higher potential than other parts of the study area. The 1980-1983 drilling results show that the original high-graded areas contain 52% of the 21 successful San Andres tests and the only discovery in the Silurian-Devonian. However, as predicted by the analysis, all of these discoveries appear to be small. 12 figures, 2 tables.

  20. Estimating exploration potential in mature producing area, Northwest shelf of Delaware basin, New Mexico

    SciTech Connect

    Kumar, N.

    1985-11-01

    The case history presented here describes an investigation of the Northwest shelf of the Delaware basin carried out in 1979 for estimating the potential of finding new reserves and a follow-up study to measure predictions against results. A total of 191 new-field wildcats had been drilled during 1974-1979 in the study area. An analysis of target zones and success ratios showed that the best chances of drilling a successful test were in the San Andres (Permian) and SilurianDevonian. However, cumulative frequency plots of existing fields in these two intervals showed that the chance of finding a field larger than 1 million bbl (159,000 mT) in either of these zones was relatively low. As a result of the 1979 analysis, three prospective areas representing 8% of the total study area were high graded, or rated as having a higher potential than other parts of the study area. The 1980-1983 drilling results show that the original high-graded areas contain 52% of the 21 successful San Andres tests and the only discovery in the SilurianDevonian. However, as predicted by the analysis, all of these discoveries appear to be small.

  1. Source identification and hazardous risk delineation of heavy metal contamination in Yanqi basin, northwest China.

    PubMed

    Mamat, Zulpiya; Yimit, Hamid; Ji, Rou Zi A; Eziz, Mamattursun

    2014-09-15

    A total of 469 surface soil samples were collected from the Yanqi basin in northwest China and evaluated for levels of ten heavy metals. Multivariate statistical analyses were used to study sources of and map the spatial distribution of heavy metals, as well as determine the relationship between land use types and soil source materials. It was found that: (1) the average amounts of ten heavy metals in the Yanqi basin were all below the national soil environmental quality standards of China (GB15618-1998), but the average amount of Cd, Hg, Mn, Ni, Pb, and Zn all exceeded the heavy metal background levels of soil in Xinjiang, China and exhibited accumulation. The ten heavy metals analyzed in this study can be categorized into four principal components as follows: Principal component 1 was Co, Cr, Mn, Ni, and Zn, and principal component 3 was As and Cu. Both of these originated from a natural geological background. Principal component 2 consisted of Cd and Pb and originated from industrial, agricultural and transportation influences. Principal component 4 consisted of Hg and was due to industrial influences. Our study found that Pb and Zn were a large part in the principal components 1 and 3 and were influenced by a combination of geologic background and human activity. (2) Heavy metals Cd and Hg were at high levels in construction land and farmland, while Co, Cr, Cu, Mn, and Ni were significantly higher in lacustrine deposits than in sandy shale from weathered material, coarse crystalline rock weathered material, and diluvial material. The land use types correlated significantly with the accumulation of Cd and Hg, and the soil parent material was the major factor for the accumulation of As, Co, Cr, Cu, Mn, and Ni. (3) The single element, element integration and the corresponding principal component presented similar spatial patterns of hazardous risk. Following comprehensive assessment of all elements, the high risk regions were found to be located in densely

  2. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

    USGS Publications Warehouse

    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  3. Provenance and pathways of late Quaternary turbidites in the deep-water Agadir Basin, northwest African margin

    NASA Astrophysics Data System (ADS)

    Frenz, Michael; Wynn, Russell B.; Georgiopoulou, Aggeliki; Bender, Vera B.; Hough, Gayle; Masson, Douglas G.; Talling, Peter J.; Cronin, Bryan T.

    2009-06-01

    A series of individual turbidites, correlated over distances >100 km, are present in the recent fill of the Agadir Basin, offshore northwest Africa. The aim here is to unravel multiple turbidite source areas and flow pathways, and show how turbidite provenance studies contribute to interpretation of flow processes. Agadir Basin turbidites are sourced from four main areas, with the majority originating from the siliciclastic Morocco Shelf; their sand-mud distribution is strongly controlled by flow sediment volume, with relatively low-volume flows dying out within the Agadir Basin and large-volume flows bypassing significant sediment volumes to basins further downslope. Two large-volume volcaniclastic turbidites are attributed to a Canary Islands landslide source, while several small mud-dominated turbidites are interpreted to be locally sourced from hemipelagic-draped seamounts (e.g. Turbidite AB10). Finally, Turbidite AB1 (˜1 ka) is only present in the western Agadir Basin, and is linked to recent “re-activation” of the Sahara Slide headwall. The muddy suspension clouds of three large-volume flows, all linked to large-scale landslides, have covered huge areas of seafloor and flowed along or even slightly upslope for long distances. It is proposed that northeastwards-flowing bottom currents have aided transport of these dilute flow fractions into and across the Agadir Basin.

  4. Geochemical evidence for mudstone as the possible major oil source rock in the Jurassic Turpan Basin, Northwest China

    USGS Publications Warehouse

    Chen, J.; Qin, Yelun; Huff, B.G.; Wang, D.; Han, D.; Huang, D.

    2001-01-01

    Geologists and geochemists have debated whether hydrocarbons from Jurassic coal measures are derived from the mudstones or the coals themselves. This paper identifies mudstones as the possible major source rock of hydrocarbons in the Jurassic basins in Northwest China. The Turpan Basin is used as a representative model. Mudstones in the Middle-Lower Jurassic are very well developed in the basin and have an average genetic potential from 2 to 4 mg/g. The vitrinite reflectance of the source rocks ranges from 0.6 to 1.3%, exhibiting sufficient thermal maturity to generate oil and gas. Biomarkers in crude oils from the basin are similar to those in mudstones from the coal-bearing strata, with a low tricyclic terpane (cheilanthane) content, a relatively high content of low carbon number (less than C22) tricyclic terpanes and a low content of high carbon number tricyclic terpanes, relatively high ratios of Ts/Tm, and C29 Ts/17?? (H)-C29 norhopane, and low ratios of Tm/17?? (H)-C30 hopane and 17?? (H)-C31 homohopane/17?? (H)-C30 hopane. These characteristics and the distribution of steranes and terpanes in the crude oil and mudstone differ significantly from those of the Jurassic coals and carbonaceous shales of the basin, indicating mudstone is possibly the major source rock of the oils in the Turpan Basin. ?? 2001 Elsevier Science Ltd. All rights reserved.

  5. Integrated Water and Sanitation Risk Assessment and Modeling in the Upper Sonora River basin (Northwest, Mexico)

    NASA Astrophysics Data System (ADS)

    Mayer, A. S.; Robles-Morua, A.; Halvorsen, K. E.; Vivoni, E. R.; Auer, M. T.

    2011-12-01

    Studies that integrate human dimensions and the biophysical characteristics of watersheds are necessary to meet the challenge of sustainable water resources development. In this project, we integrated perspectives from sociology, hydrology, and environmental engineering to examine and suggest solutions for managing waterborne disease risks associated with wastewater contamination in the Sonora River basin (SRB), a semiarid rural basin in northwest Mexico. This research consisted of four sub-projects. First, we assessed the perceptions of risks associated with wastewater contamination of water resources in rural communities in the SRB through a series of semi-structured interviews Results from this study indicate that there are major differences in risk perceptions among health professionals, government officials, and lay citizens. Government officials and lay citizens tend to underestimate the severity of the problems related to water related risks. Second, a fully distributed hydrologic model was used to make streamflow predictions in the un-gauged SRB. Synthetic flows generated from the hydrologic model were used to evaluate pollutant transport processes associated with wastewater loadings to the Sonora River. The hydrologic model revealed that the high degree of spatio-temporal variability of runoff in the SRB is associated with links between runoff generation mechanisms and land-atmosphere interactions. Third, a surface water quality model was used to assess the impact of wastewater discharges and develop pathogen contamination indicators in two sites along the Sonora River. To parameterize the water quality model, pathogenic indicator loadings and removal rates were estimated, along with their uncertainty. Results from the water quality modeling show regions in the watershed that may be exceeding pathogenic standards, but also that uncertainty in model parameters requires a probabilistic approach for estimating risks. Finally, a workshop was conducted to

  6. Baseflow simulation of SWAT model in an inland river basin in Tianshan Mountains, Northwest China

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Arnold, J.; Allen, P.; Chen, X.

    2011-11-01

    Baseflow is an important component in hydrological modeling. Complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during high-flow period but very slowly during the low-flow period in rivers in arid and cold Northwest China, the current one-reservoir baseflow approach in SWAT (Soil Water Assessment Tool) model was extended by adding a slow reacting reservoir and applied to the Manas River basin in Tianshan Mountains. Meanwhile, a digital filter program was employed to separate baseflow from streamflow records for comparisons. Results indicated that the two-reservoir method yielded much better results than the one-reservoir one in reproducing streamflow processes, and the low-flow estimation was improved markedly. Nash-Sutcliff efficiency values at the calibration and validation stages are 0.68 and 0.62 for the one-reservoir case, and 0.76 and 0.69 for the two-reservoir case, respectively. The filter-based method estimated the baseflow index as 0.60, while the model-based as o.45. The filter-based baseflow responds almost immediately to surface runoff occurrence at onset of rising limb, while the model-based with a delay. In consideration of watershed surface storage retention and soil freezing/thawing effects on infiltration and recharge during initial snowmelt season, a delay response is considered to be more reasonable. However, a more detailed description of freezing/thawing processes should be included in soil modules so as to determine recharge to aquifer during these processes, and thus an accurate onset point of rising limb of the simulated baseflow.

  7. Baseflow simulation using SWAT model in an inland river basin in Tianshan Mountains, Northwest China

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Arnold, J.; Allen, P.; Chen, X.

    2012-04-01

    Baseflow is an important component in hydrological modeling. The complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during the high-flow period but very slowly during the low-flow period in rivers in arid and cold northwest China, the current one-reservoir baseflow approach in SWAT (Soil Water Assessment Tool) model was extended by adding a slow- reacting reservoir and applying it to the Manas River basin in the Tianshan Mountains. Meanwhile, a digital filter program was employed to separate baseflow from streamflow records for comparisons. Results indicated that the two-reservoir method yielded much better results than the one-reservoir one in reproducing streamflow processes, and the low-flow estimation was improved markedly. Nash-Sutcliff efficiency values at the calibration and validation stages are 0.68 and 0.62 for the one-reservoir case, and 0.76 and 0.69 for the two-reservoir case. The filter-based method estimated the baseflow index as 0.60, while the model-based as 0.45. The filter-based baseflow responded almost immediately to surface runoff occurrence at onset of rising limb, while the model-based responded with a delay. In consideration of watershed surface storage retention and soil freezing/thawing effects on infiltration and recharge during initial snowmelt season, a delay response is considered to be more reasonable. However, a more detailed description of freezing/thawing processes should be included in soil modules so as to determine recharge to aquifer during these processes, and thus an accurate onset point of rising limb of the simulated baseflow.

  8. Charting exploration strategy in a mature producing area, Northwest Shelf of Delaware basin, New Mexico

    SciTech Connect

    Kumar, N.

    1984-04-01

    In formulating strategy for mature areas, management has to consider chance factor for success, as well as the chance of finding sizeable reserves. As a case history, we describe an investigation of the Northwest Shelf of Delaware basin carried out in 1979 to locate areas having the best potential of finding new reserves. In 1983, we tabulated the activity since 1980 to compare our predictions against the drilling results. The 1979 study had shown that out of a total of almost 200 wildcats drilled during 1974-79, the largest number (63) had been drilled for San Andres (Permian) objective with a success ratio of 33%. Forty-six wells had been drilled for various Pennsylvanian objectives with a success ratio of 40%, and 25 wells had been drilled for Siluro-Devonian targets with a success ratio of 16%. However, based on wildcat success ratios and cumulative-frequency plots of field sizes, the probability of a wildcat discovering reserves larger than 1 million bbl was only 6% in San Andres, 19% in Pennsylvanian, and 7% in Siluro-Devonian. The 1979 study allowed us to high-grade three blocks representing 5% of the total 5.25 million acres. These blocks were considered to have the best potential for San Andres and Siluro-Devonian objectives. Subsequent analysis of 1980-83 drilling results shows that these blocks contain 55% of the 20 new successful San Andres tests and the only new discovery in the Siluro-Devonian. However, as predicted, all of these have been small discoveries. Such studies allow management to develop a course of action for mature areas.

  9. Distinct groundwater recharge sources and geochemical evolution of two adjacent sub-basins in the lower Shule River Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Wang, Liheng; Dong, Yanhui; Xie, Yueqing; Song, Fan; Wei, Yaqiang; Zhang, Jiangyi

    2016-12-01

    Based on analysis of groundwater hydrogeochemical and isotopic data, this study aims to identify the recharge sources and understand geochemical evolution of groundwater along the downstream section of the Shule River, northwest China, including two sub-basins. Groundwater samples from the Tashi sub-basin show markedly depleted stable isotopes compared to those in the Guazhou sub-basin. This difference suggests that groundwater in the Tashi sub-basin mainly originates from meltwater in the Qilian Mountains, while the groundwater in the Guazhou sub-basin may be recharged by seepage of the Shule River water. During the groundwater flow process in the Tashi sub-basin, minerals within the aquifer material (e.g., halite, calcite, dolomite, gypsum) dissolve in groundwater. Mineral dissolution leads to strongly linear relationships between Na+ and Cl- and between Mg2++ Ca2+ and SO4 2- + HCO3 -, with stoichiometry ratios of approximately 1:1 in both cases. The ion-exchange reaction plays a dominant role in hydrogeochemical evolution of groundwater in the Guazhou sub-basin and causes a good linear relationship between (Mg2++ Ca2+)-(SO4 2- + HCO3 -) and (Na++ K+)-Cl- with a slope of -0.89 and also results in positive chloroalkaline indices CAI 1 and CAI 2. The scientific results have implications for groundwater management in the downstream section of Shule River. As an important irrigation district in Hexi Corridor, groundwater in the Guazhou sub-basin should be used sustainably and rationally because its recharge source is not as abundant as expected. It is recommended that the surface water should be used efficiently and routinely, while groundwater exploitation should be limited as much as possible.

  10. Intrusion versus inversion—a 3D density model of the southern rim of the Northwest German Basin

    NASA Astrophysics Data System (ADS)

    Bilgili, Filiz; Götze, Hans-Jürgen; Pašteka, Roman; Schmidt, Sabine; Hackney, Ron

    2009-04-01

    An unsolved problem of regional importance for both the evolution and structure of the Northwest German Basin is the existence or non-existence of the so-called Bramsche Massif. Explaining the nature of this massif and the cause of a related strong, positive Bouguer anomaly (Bramsche Anomaly) is critical. In the study described here, we tested an existing “intrusion model” against a newer “inversion model” in the southern Northwest German Basin. In the intrusion model, the strongly-positive Bouguer anomaly represents the gravity effect of an intrusion at depths between 6 and 10 km. More recent interpretations invoke tectonic inversion rather than intrusion to explain increased burial and the low level of hydrocarbon maturity found in boreholes. We tested these different interpretations by constructing 3D forward density models to 15 km depth. The intrusion model was updated and adjusted to incorporate recent data and we also modelled pre-Zechstein structures using different scenarios. The final model has a very good fit between measured and modelled gravity fields. Based on currently available seismic and structural models, as well as borehole density measurements, we show that the positive Bouguer anomaly cannot be modeled without a high-density, intrusive-like body at depth. However, further in-sight into the crustal structures of the Bramsche region requires more detailed investigations.

  11. An integrated workflow to assess the remaining potential of mature hydrocarbon basins: a case study from Northwest Germany (Upper Jurassic/Lower Cretaceous, Lower Saxony Basin)

    NASA Astrophysics Data System (ADS)

    Seyfang, Björn; Aigner, Thomas; Munsterman, Dirk K.; Irmen, Anton

    2017-04-01

    Mature hydrocarbon provinces require a high level of geological understanding in order to extend the lives of producing fields, to replace reserves through smaller targets and to reduce the risks of exploring for more and more subtle hydrocarbon traps. Despite a large number of existing wells in the area studied in this paper, the depositional environments and the stratigraphic architecture were still poorly known. In order to improve the geological understanding, we propose a workflow to assess the remaining reservoir potential of mature hydrocarbon areas, integrating cores, cuttings, well-logs, biostratigraphy and seismic data. This workflow was developed for and is exemplified with the northwest of the Lower Saxony Basin (LSB), a mature hydrocarbon province in northwest Germany, but can be applied in a similar fashion to other areas. Systematic integration of lithofacies analysis, chrono- and sequence stratigraphy, combined with electrofacies analysis and modern digital methods like neural network-based lithology determination and 3D facies modelling provides a high-resolution understanding of the spatial facies and reservoir architecture in the study area. Despite widely correlatable litho-units in the Upper Jurassic and Lower Cretaceous in the LSB, complex heterogeneous sedimentary systems can be found in the basin's marginal parts. Two new play types were determined in the study area, showing a remaining potential for stratigraphic hydrocarbon traps. The results of this exploration scale study also provide the basis for re-evaluations on a field development scale. On a basin scale, this study may encourage further data acquisition and re-evaluations to discover previously unknown reservoirs.

  12. An integrated workflow to assess the remaining potential of mature hydrocarbon basins: a case study from Northwest Germany (Upper Jurassic/Lower Cretaceous, Lower Saxony Basin)

    NASA Astrophysics Data System (ADS)

    Seyfang, Björn; Aigner, Thomas; Munsterman, Dirk K.; Irmen, Anton

    2016-06-01

    Mature hydrocarbon provinces require a high level of geological understanding in order to extend the lives of producing fields, to replace reserves through smaller targets and to reduce the risks of exploring for more and more subtle hydrocarbon traps. Despite a large number of existing wells in the area studied in this paper, the depositional environments and the stratigraphic architecture were still poorly known. In order to improve the geological understanding, we propose a workflow to assess the remaining reservoir potential of mature hydrocarbon areas, integrating cores, cuttings, well-logs, biostratigraphy and seismic data. This workflow was developed for and is exemplified with the northwest of the Lower Saxony Basin (LSB), a mature hydrocarbon province in northwest Germany, but can be applied in a similar fashion to other areas. Systematic integration of lithofacies analysis, chrono- and sequence stratigraphy, combined with electrofacies analysis and modern digital methods like neural network-based lithology determination and 3D facies modelling provides a high-resolution understanding of the spatial facies and reservoir architecture in the study area. Despite widely correlatable litho-units in the Upper Jurassic and Lower Cretaceous in the LSB, complex heterogeneous sedimentary systems can be found in the basin's marginal parts. Two new play types were determined in the study area, showing a remaining potential for stratigraphic hydrocarbon traps. The results of this exploration scale study also provide the basis for re-evaluations on a field development scale. On a basin scale, this study may encourage further data acquisition and re-evaluations to discover previously unknown reservoirs.

  13. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China

    PubMed Central

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995–2014) and near future (2015–2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses. PMID:27348224

  14. Basin development and compressional deformation in the central High Atlas Mountains northwest of Errachidia (Morocco) - rejuvenated tectonics

    SciTech Connect

    Brede, R.

    1988-08-01

    The development of the central High Atlas Mountains from the Triassic until today was controlled by a set of pre-existent basement faults which were reactivated in various manners. During the Triassic a graben began to subside at the northwestern border of the African craton. The graben's development was at least temporarily linked to the opening of the Atlantic Ocean. The growing basin was filled by red detrital material from the adjacent elevated regions. Evaporites were only locally formed. Mostly the red beds show an intercalation of basic volcanics. During the early and middle Liassic, a shallow shelf with reefs existed at the southern rim of the Atlas-Gulf, from which much carbonate material was delivered into the basin. This deposition is proved by turbiditic limestones of considerable thickness in the Pliensbachian. After a further deepening of the Atlas-Gulf in the late Liassic and the early Dogger, a trend toward shallowing began in the Bajocian, enabling reefs to grow from the south into the basin. Toward the end of the middle Dogger, the trough began to fill with red detrital material. This period of red-bed sedimentation lasted until the early part of the late Cretaceous and had abundant intercalation of gypsum near the top of the sequence. Due to a transgression a short marine period followed, documented by the Cenomanian-Turonian limestones. This marine period was succeeded again by the deposition of red beds in the middle of late Cretaceous. The Jurassic sediments are sometimes penetrated by small doleritic dikes. The development of the basin was controlled by east-northeast-striking faults. During compression in the Tertiary, the /sigma//sub 3/ direction (north-northwest) of the Mesozoic basin development changed into the /sigma//sub 1/ direction of compressional deformation and the synsedimentary normal faults were reactivated as upthrusts.

  15. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Nan, Z.; Xu, Y.; Li, S.

    2016-12-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystem. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995-2014) and near future (2015-2024), by combining two land use models (i.e. Markov chain model and Dyna-CLUE) with a hydrological model (i.e. SWAT). The potential impacts in the near future were explored using projected land use pattern and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and the decrease in farmland, and meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses.

  16. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China.

    PubMed

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995-2014) and near future (2015-2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses.

  17. The potential for coalbed gas exploration and production in the Greater Green River Basin, southwest Wyoming and northwest Colorado

    SciTech Connect

    Tyler, R.; Kaiser, W.R.; Scott, A.R.; Hamilton, D.S.

    1997-01-01

    Coalbed gas is an important source of natural gas in the United States. In 1993, approximately 740 BCF of coalbed gas was produced in the United States, or about 4.2% of the nation`s total gas production. Nearly 96% of this coalbed gas is produced from just two basins, the San Juan (615.7 BCF; gas in place 84 TCF) and Black Warrior (105 BCF; gas in place 20 TCF), and current production represents only a fraction of the nation`s estimated 675 TCF of in-place coalbed gas. Coal beds in the Greater Green River Basin in southwest Wyoming and northwest Colorado hold almost half of the gas in place (314 TCF) and are an important source of gas for low-permeability Almond sandstones. Because total gas in place in the Greater Green River Basin is reported to exceed 3,000 TCF (Law et al., 1989), the basin may substantially increase the domestic gas resource base. Therefore, through integrated geologic and hydrologic studies, the coalbed gas potential of the basin was assessed where tectonic, structural, and depositional setting, coal distribution and rank, gas content, coal permeability, and ground-water flow are critical controls on coalbed gas producibility. Synergism between these geologic and hydrologic controls determines gas productivity. High productivity is governed by (1) thick, laterally continuous coals of high thermal maturity, (2) basinward flow of ground water through fractured and permeable coals, down the coal rank gradient toward no-flow boundaries oriented perpendicular to the regional flow direction, and (3) conventional trapping of gas along those boundaries to provide additional sources of gas beyond that sorbed on the coal surface.

  18. Air Pollution Over the Ganges Basin and Northwest Bay of Bengal in the Early Postmonsoon Season Based on NASA MERRAero Data

    NASA Technical Reports Server (NTRS)

    Kishcha, Pavel; Da Silva, Arlindo M.; Starobinets, Boris; Alpert, Pinhas

    2014-01-01

    The MERRA Aerosol Reanalysis (MERRAero) has been recently developed at NASA's Global Modeling Assimilation Office. This reanalysis is based on a version of the Goddard Earth Observing System-5 (GEOS-5) model radiatively coupled with Goddard Chemistry, Aerosol, Radiation, and Transport aerosols, and it includes assimilation of bias-corrected aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on both Terra and Aqua satellites. In October over the period 2002-2009, MERRAero showed that AOT was lower over the east of the Ganges basin than over the northwest of the Ganges basin: this was despite the fact that the east of the Ganges basin should have produced higher anthropogenic aerosol emissions because of higher population density, increased industrial output, and transportation. This is evidence that higher aerosol emissions do not always correspond to higher AOT over the areas where the effects of meteorological factors on AOT dominate those of aerosol emissions. MODIS AOT assimilation was essential for correcting modeled AOT mainly over the northwest of the Ganges basin, where AOT increments were maximal. Over the east of the Ganges basin and northwest Bay of Bengal (BoB), AOT increments were low and MODIS AOT assimilation did not contribute significantly to modeled AOT. Our analysis showed that increasing AOT trends over northwest BoB (exceeding those over the east of the Ganges basin) were reproduced by GEOS-5, not because of MODIS AOT assimilation butmainly because of the model capability of reproducing meteorological factors contributing to AOT trends. Moreover, vertically integrated aerosol mass flux was sensitive to wind convergence causing aerosol accumulation over northwest BoB.

  19. Farmers' attitudes toward mandatory water-saving policies: A case study in two basins in northwest China.

    PubMed

    Chang, Genying; Wang, Lu; Meng, Liuyi; Zhang, Wenxia

    2016-10-01

    China began to implement stringent water-saving policies in 2012. Mandatory water-saving measures implemented in arid inland river basins include the measures of allocating surface water among upper, middle and lower beaches, restricting household agricultural water use, closing wells, reducing farmland and increasing water prices. These measures have negative influences on the agricultural production of farmers. This study aimed to reveal the demographic and psychological correlates of farmers' attitudes toward these policies. The participants included 672 farmers in the Heihe River Basin and the Shule River Basin in northwest China. Structural equation analyses showed that farmers' awareness of the beneficial consequences of restricting household agricultural water and their perception of policy enforcement had significant relationships with their attitudes toward water-saving policies, whereas the effects of the New Ecological Paradigm and collectivism on farmers' attitudes were mediated through their awareness of beneficial consequences and their perception of policy enforcement. Multivariable regression analyses revealed that as a whole, there were no significant correlations between demographic variables and farmers' attitudes. Policy implications include propagandizing these policies among local farmers, strengthening open and fair policy enforcement, and cautiously using water prices as an instrument to control irrigation water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The Federal Cylinder Project: A Guide to Field Cylinder Collections in Federal Agencies. Volume 3, Great Basin/Plateau Indian Catalog, Northwest Coast/Arctic Indian Catalog.

    ERIC Educational Resources Information Center

    Gray, Judith A., Ed.

    Two catalogs inventory wax cylinder collections, field recorded among Native American groups, 1890-1942. The catalog for Great Basin and Plateau Indian tribes contains entries for 174 cylinders in 7 collections from the Flathead, Nez Perce, Thompson/Okanagon, Northern Ute, and Yakima tribes. The catalog for Northwest Coast and Arctic Indian tribes…

  1. Estimation of subsurface formation temperature in the Tarim Basin, northwest China: implications for hydrocarbon generation and preservation

    NASA Astrophysics Data System (ADS)

    Liu, Shaowen; Lei, Xiao; Feng, Changge; Hao, Chunyan

    2016-07-01

    Subsurface formation temperature in the Tarim Basin, northwest China, is vital for assessment of hydrocarbon generation and preservation, and of geothermal energy potential. However, it has not previously been well understood, due to poor data coverage and a lack of highly accurate temperature data. Here, we combined recently acquired steady-state temperature logging data with drill stem test temperature data and measured rock thermal properties, to investigate the geothermal regime and estimate the subsurface formation temperature at depth in the range of 1000-5000 m, together with temperatures at the lower boundary of each of four major Lower Paleozoic marine source rocks buried in this basin. Results show that heat flow of the Tarim Basin ranges between 26.2 and 66.1 mW/m2, with a mean of 42.5 ± 7.6 mW/m2; the geothermal gradient at depth of 3000 m varies from 14.9 to 30.2 °C/km, with a mean of 20.7 ± 2.9 °C/km. Formation temperature estimated at the depth of 1000 m is between 29 and 41 °C, with a mean of 35 °C, while 63-100 °C is for the temperature at the depth of 3000 m with a mean of 82 °C. Temperature at 5000 m ranges from 97 to 160 °C, with a mean of 129 °C. Generally spatial patterns of the subsurface formation temperature at depth are basically similar, characterized by higher temperatures in the uplift areas and lower temperatures in the sags, which indicates the influence of basement structure and lateral variations in thermal properties on the geotemperature field. Using temperature to identify the oil window in the source rocks, most of the uplifted areas in the basin are under favorable condition for oil generation and/or preservation, whereas the sags with thick sediments are favorable for gas generation and/or preservation. We conclude that relatively low present-day geothermal regime and large burial depth of the source rocks in the Tarim Basin are favorable for hydrocarbon generation and preservation. In addition, it is found that the

  2. Geologic Mapping Investigations of the Northwest Rim of Hellas Basin, Mars

    NASA Technical Reports Server (NTRS)

    Crown, David A.; Bleamaster, Leslie F., III; Mest, Scott C.; Mustard, John F.

    2009-01-01

    The Hellas impact basin, spanning 2000+ km in the cratered highlands, is the largest well-preserved impact structure on Mars and its deepest depositional sink. The Hellas region is significant for evaluating Mars hydrogeologic and climate histories, given the nature, diversity, and range in ages of potential water- and ice-related landforms [e.g., 1-2], including possible paleolakes on the basin floor [2-4]. The circum-Hellas highlands are of special interest given recent studies of potential localized fluvial/lacustrine systems [2, 5-17] and evidence for phyllosilicates around and within impact craters north of the basin [18-26].

  3. Verification of hydrologic landscape derived basin-scale classifications in the Pacific Northwest

    Treesearch

    Keith Sawicz

    2016-01-01

    The interaction between the physical and climatic attributes of a basin (form) control how water is partitioned, stored, and conveyed through a catchment (function). Hydrologic Landscapes (HLs) were previously...

  4. Assessing the changes in land use and ecosystem services in an oasis agricultural region of Yanqi Basin, Northwest China.

    PubMed

    Wang, Shuixian; Wu, Bin; Yang, Pengnian

    2014-12-01

    The Yanqi Basin, one of the most productive agricultural areas, has a high population density in Xinjiang, Northwest China. Land use changes, mainly driven by oasis expansion, significantly impact ecosystem services and functions, but these effects are difficult to quantify. The valuation of ecosystem services is important to clarify the ecological and environmental changes caused by agriculturalization of oasis. This study aimed to investigate variations in ecosystem services in response to land use changes during oasis agricultural expansion activities in the Yanqi Basin from 1964 to 2009. The methods used were based on formula of ecosystem service value (ESV) and ESV coefficients. Satellite data were combined with the ESV coefficients to quantify land use changes and ecosystem service changes in the study area. Sensitivity analysis determined the effect of manipulating the coefficients on the estimated values. The results show that the total ESVs in the Yanqi Basin were $1,674, $1,692, $1,471, $1,732, and $1,603 million in 1964, 1973, 1989, 1999, and 2009, respectively. The net deline in ESV was $71 million in the past 46 years, but the ESVs of each types of landscape changed significantly. The aggregated ESVs of water areas and wetlands were approximately 80 % of the total ESV. Water supply and waste treatment were the two largest service functions and contributed approximately 65 % of the total ESV. The estimated ESVs in this study were elastic with respect to the value coefficients. Therefore, the estimations were robust in spite of uncertainties on the value coefficients. These significant changes in land use occur within the entire basin over the study period. These changes cause environmental problems, such as land degradation, vegetation degeneracy, and changes in aquatic environment.

  5. Achieving Sustainability in a Semi-Arid Basin in Northwest Mexico through an Integrated Hydrologic-Economic-Institutional Model

    NASA Astrophysics Data System (ADS)

    Munoz-Hernandez, A.; Mayer, A. S.

    2008-12-01

    The hydrologic systems in Northwest Mexico are at risk of over exploitation due to poor management of the water resources and adverse climatic conditions. The purpose of this work is to create and Integrated Hydrologic-Economic-Institutional Model to support future development in the Yaqui River basin, well known by its agricultural productivity, by directing the water management practices toward sustainability. The Yaqui River basin is a semi-arid basin with an area of 72,000 square kilometers and an average precipitation of 527 mm per year. The primary user of water is agriculture followed by domestic use and industry. The water to meet user demands comes from three reservoirs constructed, in series, along the river. The main objective of the integrated simulation-optimization model is to maximize the economic benefit within the basin, subject to physical and environmental constraints. Decision variables include the water allocation to major users and reservoirs as well as aquifer releases. Economic and hydrologic (including the interaction of the surface water and groundwater) simulation models were both included in the integrated model. The surface water model refers to a rainfall-runoff model created, calibrated, and incorporated into a MATLAB code that estimates the monthly storage in the main reservoirs by solving a water balance. The rainfall-runoff model was coupled with a groundwater model of the Yaqui Valley which was previously developed (Addams, 2004). This model includes flow in the main canals and infiltration to the aquifer. The economic benefit of water for some activities such as agricultural use, domestic use, hydropower generation, and environmental value was determined. Sensitivity analysis was explored for those parameters that are not certain such as price elasticities or population growth. Different water allocation schemes were created based on climate change, climate variability, and socio-economic scenarios. Addams L. 2004. Water resource

  6. Seismic Data from the Kane Basin, Northwest Greenland - Insight into a white spot on the map

    NASA Astrophysics Data System (ADS)

    Ehrhardt, Axel; Schnabel, Michael; Damm, Volkmar

    2013-04-01

    The opening history of the Baffin Bay and the possible extent of oceanic crust within the basin is a key question in order to reconstruct the plate tectonic development of the Arctic region. To contribute to the scientific discussion, a multi-component geophysical and geological survey was carried out in 2010 in the area of the Northern Baffin Bay. Because of the fortunate ice conditions we seized the chance to go to the Kane Basin, half way between the Baffin Bay in the South and the Lincoln Sea in the North, one of a series of basins that are aligned along the Nares Strait. In addition the unclear situation within the Baffin Bay the Nares Strait is one of the most disputed areas in the Arctic. As the opening of the Baffin Bay and the formation of oceanic crust must have been compensated somewhere between Greenland and Ellesmere Island a transform fault was proposed. However, in particular land geological data does not support this thesis and let assume moreover that no lateral displacement occurred between Greenland and Ellesmere Island. In order to shed some more light onto the potential transform fault (the Wegener Fault) two reflection seismic lines were shot within the eastern Kane Basin supported by sonobuoys. Furthermore, magnetic and gravity data is acquired. This paper presents first insight into the eastern side of the Kane Basin. The eastern Kane Basin is characterized by a deeper rim and a more shallow central part of the basin. The term basin is probably misleading as most of it is floored by Proterozoic crust without any sedimentary beds on top of it. Only in the western part of the Kane Basin a sedimentary infill can be recorded which terminates with an erosional truncation on to the seafloor. The significant amount of sediments and debris that is washed into the Kane Basin by rivers and glaciers is transported to the Baffin Bay Fan by the considerably strong N-S current through the Nares Strait. A pull-apart development of the Kane Basin can't be

  7. Quaternary glacial, lacustrine, and fluvial interactions in the western Noatak basin, Northwest Alaska

    USGS Publications Warehouse

    Hamilton, T.D.

    2001-01-01

    The 130 km long Noatak basin is surrounded by mountains of the western Brooks Range. Middle and late Pleistocene glaciers flowing southeast into the basin dammed a succession of proglacial lakes defined by shorelines, outlet channels and upper limits of wave erosion. More than 60 bluffs along the Noatak River and its principal tributaries expose glacial and glaciolacustrine sediments that exhibit cut-and-fill relationships with interglacial and interstadial river-channel and floodplain deposits. This report focuses on the western Noatak basin, where high bluffs created by deep postglacial erosion record four major glacial advances. During the Cutler advance, a floating ice tongue terminated in a large proglacial lake that filled the Noatak basin. The retreating glacier abandoned a trough along the valley center that subsequently filled with about 40m of sediment during several younger glaciations and probably two major interglacial episodes. Alluvium that formed near the beginning of the younger interglaciation contains the 140,000 yr old Old Crow tephra. The subsequent closely spaced Okak and Makpik advances are clearly younger than the maximum of the last interglaciation, but they preceded a middle Wisconsin (36-30 ka) nonglacial interval in the Noatak basin. The Okak advance terminated in an extensive lake, whereas glaciers of the Makpik and the subsequent Anisak advances flowed into much narrower lakes that filled only the basin center. The Anisak advance, bracketed by radiocarbon ages of about 35 and 13.6 ka, represents the Last Glacial Maximum (LGM) in the western Noatak basin. Correlations with the oldest and youngest glacial deposits of the central Brooks Range are clear, but relationships to events of intermediate age are more tenuous. Early Pleistocene and older glacial advances from the central Brooks Range must have filled the Noatak basin and overflowed northward through Howard Pass. A younger glacial advance, of inferred middle Pleistoscene

  8. The Occurrence, Sources and Spatial Characteristics of Soil Salt and Assessment of Soil Salinization Risk in Yanqi Basin, Northwest China

    PubMed Central

    Zhaoyong, Zhang; Abuduwaili, Jilili; Yimit, Hamid

    2014-01-01

    In order to evaluate the soil salinization risk of the oases in arid land of northwest China, we chose a typical oasis-the Yanqi basin as the research area. Then, we collected soil samples from the area and made comprehensive assessment for soil salinization risk in this area. The result showed that: (1) In all soil samples, high variation was found for the amount of Ca2+ and K+, while the other soil salt properties had moderate levels of variation. (2) The land use types and the soil parent material had a significant influence on the amount of salt ions within the soil. (3) Principle component (PC) analysis determined that all the salt ion values, potential of hydrogen (pHs) and ECs fell into four PCs. Among them, PC1 (C1-, Na+, SO42-, EC, and pH) and PC2 (Ca2+, K+, Mg2+and total amount of salts) are considered to be mainly influenced by artificial sources, while PC3 and PC4 (CO3- and HCO32-) are mainly influenced by natural sources. (4) From a geo-statistical point of view, it was ascertained that the pH and soil salt ions, such as Ca2+, Mg2+ and HCO3-, had a strong spatial dependency. Meanwhile, Na+ and Cl- had only a weak spatial dependency in the soil. (5) Soil salinization indicators suggested that the entire area had a low risk of soil salinization, where the risk was mainly due to anthropogenic activities and climate variation. This study can be considered an early warning of soil salinization and alkalization in the Yanqi basin. It can also provide a reference for environmental protection policies and rational utilization of land resources in the arid region of Xinjiang, northwest China, as well as for other oases of arid regions in the world. PMID:25211240

  9. Rift kinematics during the incipient stages of continental extension: Evidence from the nascent Okavango rift basin, northwest Botswana

    NASA Astrophysics Data System (ADS)

    Modisi, M. P.; Atekwana, E. A.; Kampunzu, A. B.; Ngwisanyi, T. H.

    2000-10-01

    High-resolution aeromagnetic data from the nascent Okavango rift in northwest Botswana provide an unprecedented view of rift kinematics during the incipient stages of continental extension. Crosscutting relationships between west-northwest trending 180 Ma Karoo dikes and reactivated northeast-trending Proterozoic basement faults are used to document the kinematics of Cenozoic faulting during the initial stages of rifting. Depth estimates to the top of the dikes using three-dimensional Euler deconvolution solutions have produced the following interpretations. (1) The Okavango rift is a half graben with a downthrow of ˜200 300 m. (2) The width of the Okavango rift (100 ± 20 km) is similar to that of more mature continental rifts such as the Tanganyika and Baikal rifts. This suggests that the width of continental rifts is acquired early in their evolution and reflects neither the age and maturity of the rift basin, nor the amount of extension. It is suggested that the cumulative downthrow (sediment infill included) and subsidence may be a better indicator of the relative maturity of rift basins. (3) Preexisting basement faults exert a major control during rifting, and reactivation processes do not occur synchronously along the entire length of preexisting faults. (4) The Okavango rift is defined by normal faults; there is no evidence of major strike-slip faults, thus excluding a pull-apart tectonic model for this nascent continental rift stage. (5) The preexisting Sekaka shear zone terminates the Okavango rift to the south, suggesting that such shear zones represent major barriers during longitudinal propagation of rifts. This probably explains why such shear zones commonly evolve into accommodation or transfer zones during further evolution of continental rifts.

  10. The occurrence, sources and spatial characteristics of soil salt and assessment of soil salinization risk in Yanqi basin, northwest China.

    PubMed

    Zhaoyong, Zhang; Abuduwaili, Jilili; Yimit, Hamid

    2014-01-01

    In order to evaluate the soil salinization risk of the oases in arid land of northwest China, we chose a typical oasis-the Yanqi basin as the research area. Then, we collected soil samples from the area and made comprehensive assessment for soil salinization risk in this area. The result showed that: (1) In all soil samples, high variation was found for the amount of Ca2+ and K+, while the other soil salt properties had moderate levels of variation. (2) The land use types and the soil parent material had a significant influence on the amount of salt ions within the soil. (3) Principle component (PC) analysis determined that all the salt ion values, potential of hydrogen (pHs) and ECs fell into four PCs. Among them, PC1 (C1-, Na+, SO4(2-), EC, and pH) and PC2 (Ca2+, K+, Mg2+and total amount of salts) are considered to be mainly influenced by artificial sources, while PC3 and PC4 (CO3(-) and HCO3(2-)) are mainly influenced by natural sources. (4) From a geo-statistical point of view, it was ascertained that the pH and soil salt ions, such as Ca2+, Mg2+ and HCO3(-), had a strong spatial dependency. Meanwhile, Na+ and Cl- had only a weak spatial dependency in the soil. (5) Soil salinization indicators suggested that the entire area had a low risk of soil salinization, where the risk was mainly due to anthropogenic activities and climate variation. This study can be considered an early warning of soil salinization and alkalization in the Yanqi basin. It can also provide a reference for environmental protection policies and rational utilization of land resources in the arid region of Xinjiang, northwest China, as well as for other oases of arid regions in the world.

  11. Evaluation of relative tectonic perturbations of the Kashmir Basin, Northwest Himalaya, India: An integrated morphological approach

    NASA Astrophysics Data System (ADS)

    Dubey, R. K.; Dar, Javid Ahmad; Kothyari, Girish Ch.

    2017-10-01

    Geomorphic and morphotectonic evaluations of the Kashmir Basin have been carried by implicating different geomorphic indices such as stream-gradient index (SL), hypsometric integral (HI), drainage basin asymmetry (AF), valley floor height and width ratio (Vf), transverse topographic symmetry factor (T), mountain front sinuosity (Smf), drainage basin shape (BS) and sinuosity index (SI) for the categorization of relative index of active tectonics (RIAT) through the use of geographic information systems (GIS) so as to decipher the role of neotectonics in geomorphologic evolution of the basin. The verified RIAT classes through field investigation and validation reveal the traverse of twenty-one active faults in the basin with demarcation of three RIAT classes viz., class-1 (inactive 20.07% of the area), class-2 (moderately active; 36.52% of the area) and class-3 (very active; 43.4% of the area). The observed values of RIAT distribution pattern are well corroborated with field observations. Ultimately, the overall geomorphic outputs and clustering of recent seismicity support the active tectonic control over the Kashmir basin, India.

  12. Tectonic evolution of the East Junggar terrane, CAOB

    NASA Astrophysics Data System (ADS)

    Xu, Xing-Wang

    2016-04-01

    The East Junggar terrane is one of the important tectonic units of the Central Asian Orogenic Belt (CAOB; Zonenshain et al., 1990). Debate surrounds the tectonics of the East Junggar area, including tectonic setting, age, basement nature, subduction polarity and collisional time between the East Junggar terrane and Junggar block (e.g., Xiao et al., 2008, 2011; Long et al., 2012; Huang et al., 2012). Among the two popular models, one suggests that the Junggar is a continental block (e.g. Zhang et al., 1984, 1993; Watson et al., 1987; Xiao et al., 1992; He et al., 1994; Li et al., 2000; Charvet et al., 2001, 2007; Xu et al., 2003; Zhao et al., 2003; Buslov et al., 2004; Xu and Ma, 2004; Dong et al., 2009; Bazhenov et al., 2012; Choulet et al., 2012; Zhang et al., 2012). The other model proposes that the Junggar has a basement of Paleozoic oceanic crust (e.g., Carroll et al., 1990; Zheng et al., 2007) or oceanic island arc complexes (e.g., Coleman, 1989; Chen and Jahn, 2004; Windley et al., 2007) of the Altaid Paleozoic rocks (e.g., Sengör et al., 1993; Sengör and Natal'in, 1996; Allen and Vincent, 1997; Filippova et al., 2001; Xiao et al., 2004a, 2004b, 2008, 2009, 2010a, 2010b, 2012). The tectonics in the Eastern Junggar area are interpreted to be related to late Paleozoic intra-oceanic accretion induced by northward subduction of the Junggar oceanic lithosphere (e.g. Xiao et al., 2008, 2009; Biske and Seltmann, 2010; Wan et al., 2011; Yang et al., 2011) or by the southward subduction of the Paleo-Asian oceanic lithosphere (Zhang et al., 2004; Wong et al., 2010; Su et al., 2012). Recently, we did detailed field survey and petrological, geochemical and chronological analysis of the metamorphosed volcanic rocks and magmatic rocks, and new discovered gneiss and magnetite quartzite enclaves from the Taheir tectonic window in the East Junggar region which is situated between the Zaisan-Erqis-the Main Mongolian Lineament-suture and the Kelameili suture. The new results

  13. Heat flow, deep formation temperature and thermal structure of the Tarim Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Liu, Shaowen; Lei, Xiao; Feng, Changge; Li, Xianglan

    2016-04-01

    Geothermal regime of a sedimentary basin not only provides constraint on understanding the basin formation and evolution, but also offers fundamental parameters for hydrocarbon resources assessment. As one of three Precambrian blocks in China, the Tarim craton is also a current hydrocarbon exploration target where the largest sedimentary basin (Tarim Basin) develops with great potential. Although considerable advancement of geothermal regime of this basin has been made during the past decades, nearly all the temperature data in previous studies are from the exploration borehole formation testing temperatures. Recently, we have conducted the steady-state temperature logging in the Tarim basin, and measured abundant rock thermal properties, enabling us to re-visit the thermal regime of this area with more confidence. Our results show that the present-day geothermal gradients for the Tarim Basin vary from 23 K/km to 27 K/km, with a mean of 22 K/km; the values of heat flow range from 40 mW/m2 to 49 mW/m2, with a mean of 43 mW/m2. These new data confirmed that the Tarim Basin has relatively low heat flow and shares similar geothermal regime with other Precambrian cratons in the world. In addition, the new temperatures from the steady-state logs are larger than the bottom hole temperatures (BHT) as 22 degree Celsius, indicating the thermal non-equilibrium for the BHTs used in previous studies. Spatial distribution of the estimated formation temperatures-at-depth of 1~5km within the basin is similar and mainly controlled by crystalline basement pattern. Generally, the temperatures at the depth of 1km range from 29 to 41 degree Celsius, with a mean of 35 degree Celsius; while the temperatures at 3km vary from 63 to 100 degree Celsius, and the mean is 82 degree Celsius; at 5km below the surface, the temperatures fall into a range between 90 and 160 degree Celsius, with a mean of 129 degree Celsius. We further proposed the long-term low geothermal background and large burial

  14. Towards a digital watershed, with a case study in the Heihe River Basin of northwest China

    NASA Astrophysics Data System (ADS)

    Li, X.; Cheng, G.-D.; Ma, M.-G.; Lu, L.; Ge, Y.-C.

    2003-04-01

    Integrated watershed study and river basin management needs integrated database and integrated hydrological and water resource models. We define digital watershed as a web-based information system that integrates data from different sources and in different scales through both information technology and hydrological modeling. In the last two years, a “digital basin” of the Heihe River Basin, which is a well-studied in-land catchment in China’s arid region was established. More than 6 Gb of in situ observation data, GIS maps, and remotely sensed data have been uploaded to the Heihe web site. Various database and dynamic web techniques such as PHP, ASP, XML, VRML are being used for data service. In addition, the DIAL (Data and Information Access Link), IMS (Internet Map Server) and other Web-GISs are used to make GIS and remote sensing datasets of the Heihe River Basin available and accessible on the Internet. We also have developed models for estimating the evapotranspiration, bio-physical parameters, and snow runoff. These methods can be considered as the elements to build up the integrated watershed model that can be used for integrated management of the Heihe River Basin. The official domain name of the digital Heihe River Basin is heihe.westgis.ac.cn

  15. An integrated analysis of agricultural water-use efficiency: A case study in the Heihe River Basin in Northwest China

    NASA Astrophysics Data System (ADS)

    Wang, Guofeng; Chen, Jiancheng; Wu, Feng; Li, Zhihui

    The water-use efficiency has direct impacts on the water consumption of agriculture production and is vital to water conservation at both local and regional extent. The agricultural water-use efficiency is a critical indicator that reflects the effective water allocation and water productivity improvement among different agricultural sectors. Taking the Heihe River Basin as the case study area, this study explores the changing trajectories of agricultural water use based on the input-output data of 2003-2012, and estimates the water-use efficiency with Data Envelopment Analysis, Malmquist Total Productivity Index and the decomposition of total factor productivity. Further, the influence of driving factors on the water-use efficiency is analyzed with the Tobit model. The research results indicate that the average agricultural water-use efficiency in different counties is all lower than 1 during 2003-2012, indicating that there is still improvement space in the agricultural water-use efficiency. In addition, there is obvious heterogeneity in the agricultural water-use efficiency among different counties, especially prior to 2009. The research results from the Tobit model indicate that agricultural investment and production, economic growth, industrial restructuring and agricultural plants structural adjustment have significant influence on the agricultural water-use efficiency. The research results can provide significant references for agricultural water-use management in the middle reaches of the Heihe River Basin and other similar regions in Northwest China.

  16. Analysis of Agricultural Land Use Change in the Middle Reach of the Heihe River Basin, Northwest China

    PubMed Central

    Fu, Li; Zhang, Lanhui; He, Chansheng

    2014-01-01

    The Heihe River Basin (HRB) is the second largest inland river basin in arid Northwest China. The expanding agricultural irrigation, growing industrialization, and increasing urban development in the middle reach have depleted much of the river flow to the lower reach, degrading the corresponding ecosystems. Since the enactment of the State Council of China’s new HRB water allocation policy in 2000 tremendous land use and land cover (LULC) changes have taken place to reduce water consumption in the middle reach and deliver more water downstream. This paper analyzes LULC changes during the period of 2000–2009 to understand how the changing land use patterns have altered water resource dynamics in the region. Results, while yet to be further verified in the field, show that from 2000 to 2009, urban, agricultural land, rangeland, and forest areas have increased, and barren area has decreased. Within the cropland, rice (a high water consumption crop) planting area decreased, while corn and wheat (relatively lower water consumption crops) planting areas increased. These changes in land use patterns, especially in the agricultural zones, have ensured the discharge of the required amount of water to the lower reach. PMID:24599043

  17. Managing stakeholders' conflicts for water reallocation from agriculture to industry in the Heihe River Basin in Northwest China.

    PubMed

    Wang, Xiaojun; Yang, Hong; Shi, Minjun; Zhou, Dingyang; Zhang, Zhuoying

    2015-02-01

    Along with the accelerating process of industrialization and urbanization, water reallocation from agriculture to industry will be an inevitable trend in most developing countries. In the inland river basin, inter-sectoral water transfer is likely to result in reallocation of water resources between upstream and downstream regions, and further triggers frictions and conflicts between regions. Designing effective policy measures to coordinate these conflicts among stakeholders is crucial for the successful implementation of water reallocation. This study established a participatory multi-attribute decision support model to seek a widely acceptable water allocation alternative in the Heihe River Basin, an arid region in Northwest China. The results indicate that: (1) intense conflicts arise not only among stakeholder groups but also between upstream and downstream regions in the process of water reallocation from agriculture to industry; (2) among the options which respectively emphasize on equity, efficiency, and sustainability, the combination of equity and efficiency is the least controversial alternative for the majority of stakeholder groups, although it is not the most desirable one in the performance of all sub-objectives; (3) the multi-attribute value theory (MAVT) approach is a useful technique to elicit stakeholder values and to evaluate water reallocation options. The technique can improve the transparency and credibility of decision making in the water management process.

  18. Geologic and engineering implications of production history from five Mesaverde wells in central Piceance Creek Basin, northwest Colorado

    SciTech Connect

    Chancellor, R.E.; Johnson, R.C.

    1988-06-01

    Five gas wells completed in low-permeability rocks of the Upper Cretaceous Williams Ford and Iles formations in the central part of the Piceance Creek basin, northwest Colorado, have been on continuous production for about 2 years. A general comparison is made between these wells and the Dept. of Energy's Multiwell Experiment (DOE MWX) wells about 30 miles (48 km) to the southeast. The five wells were completed with gelled KCl water/sand fractures in various intervals over a 3,000-ft (910-m) section of largely fluvial and paludal rocks of the Williams Fork and Iles formations of the Mesaverde group. Flow has apparently stabilized at low flowing tubing pressures at a rate of 30 to 125 Mcf/D (0.84 to 3.5 x 10/sup 3/ m/sup 3//d) per well, with minor water and variable condensate volumes. On the basis of production information to date, attempts to select intervals with better-than-average effective permeabilities by state-of-the-art techniques were not successful. The study points out several important differences in the Mesaverde group between the area of the five wells and the MWX site. The differences in the Mesaverde group between the MWX site and the area of the five wells point out the need to expand the MWX data base to include other gas-producing areas in the Piceance Creek basin.

  19. Northwest Arid Lands : an introduction to the Columbia Basin shrub-steppe

    SciTech Connect

    O'Connor, Georganne P. ); Wieda, Karen J. )

    2001-04-15

    This book explores the rich variety of life in shrub-steppe lands of the Columbia River Basin. It describes, for a non-technical audience, the flora, fauna, and geology of the lower Columbia Basin in and around the Tri-Cities, Washington. Features include color photos and maps of shrub-steppe plants and animals; lists and illustration of common plants, mammals, reptiles, amphibians, birds, fish, and species of conservation concern; tips on places to see wildflowers and wildlife; geological travel logs from the Tri-Cities to Seattle and Spokane; and a comprehensive bibliography and definition of ecological terms.

  20. Testing the Origins of Nonmarine Stratigraphic Sequences, Iglesia Basin, Northwest Argentina

    NASA Astrophysics Data System (ADS)

    Ruskin, B. G.; Jordan, T.

    2003-12-01

    The Iglesia Basin is an entirely nonmarine Andean foreland basin consisting of approximately 3.5 km of Tertiary strata unconformably overlying Paleozoic basement. Best described as a wedge-top basin, Iglesia Basin is located in San Juan Province, Argentina at S 30-31\\deg between the Frontal Cordillera and Precordillera fold-thrust belt. Interpretations of seismic reflection profiles and field reconnaissance have suggested basin-wide stratigraphic sequences. Additionally, radiometric and magnetostratigraphic data constrain sequence deposition between approximately 17 and 4 Ma. However, a fundamental question remains unanswered: temporal variability of which control caused development of unconformity-bound nonmarine sequences? Prior to this work, hypotheses about the factors at play, notably tectonism and climate change, remained untested, and fieldwork provided only localized information about the nature of the sequences. The present study examines basin lithofacies more broadly and will independently constrain discharge history (a proxy for climate) and intrabasinal tectonics. Thus far, fuller knowledge of the sedimentation patterns, structural expression, and volcanic history of Iglesia Basin is supplied by information from new outcrop localities near the northern paleomargin and basin center, and from reinterpretation of previously studied localities. A substantial volcanic component to the history of the oldest sequences is inferred from age relationships and continuity of deposits in proximity to the Cerro Negro intrabasinal andesitic center. Reassessment of field-assigned sequence boundaries in terms of continuity and expression, both along-strike and across intrabasinal faults, suggests that lithofacies shifts are more prevalent than erosive surfaces. Radiometric dating of additional tuffaceous units in the Tertiary sequences will allow more conclusive correlation among discontinuous outcrops. Floodplain assemblages of Aridosols and Inceptisols indicate

  1. Linear and nonlinear characteristics of the runoff response to regional climate factors in the Qira River basin, Xinjiang, Northwest China.

    PubMed

    Xue, Jie; Gui, Dongwei

    2015-01-01

    The inland river watersheds of arid Northwest China represent an example of how, in recent times, climatic warming has increased the complexity of Earth's hydrological processes. In the present study, the linear and nonlinear characteristics of the runoff response to temperature and precipitation were investigated in the Qira River basin, located on the northern slope of the Kunlun Mountains. The results showed that average temperature on annual and seasonal scales has displayed a significantly increasing trend, but this has not been reflected in accumulated precipitation and runoff. Using path analysis, a positive link between precipitation and runoff was found both annually and in the summer season. Conversely, it was found that the impact of temperature on runoff has been negative since the 1960s, attributable to higher evaporation and infiltration in the Qira River basin. Over the past 50 years, abrupt changes in annual temperature, precipitation and runoff occurred in 1997, 1987 and 1995, respectively. Combined with analysis using the correlation dimension method, it was found that the temperature, precipitation and runoff, both annually and seasonally, possessed chaotic dynamic characteristics, implying that complex hydro-climatic processes must be introduced into other variables within models to describe the dynamics. In addition, as determined via rescaled range analysis, a consistent annual and seasonal decreasing trend in runoff under increasing temperature and precipitation conditions in the future should be taken into account. This work may provide a theoretical perspective that can be applied to the proper use and management of oasis water resources in the lower reaches of river basins like that of the Qira River.

  2. Linear and nonlinear characteristics of the runoff response to regional climate factors in the Qira River basin, Xinjiang, Northwest China

    PubMed Central

    Xue, Jie

    2015-01-01

    The inland river watersheds of arid Northwest China represent an example of how, in recent times, climatic warming has increased the complexity of Earth’s hydrological processes. In the present study, the linear and nonlinear characteristics of the runoff response to temperature and precipitation were investigated in the Qira River basin, located on the northern slope of the Kunlun Mountains. The results showed that average temperature on annual and seasonal scales has displayed a significantly increasing trend, but this has not been reflected in accumulated precipitation and runoff. Using path analysis, a positive link between precipitation and runoff was found both annually and in the summer season. Conversely, it was found that the impact of temperature on runoff has been negative since the 1960s, attributable to higher evaporation and infiltration in the Qira River basin. Over the past 50 years, abrupt changes in annual temperature, precipitation and runoff occurred in 1997, 1987 and 1995, respectively. Combined with analysis using the correlation dimension method, it was found that the temperature, precipitation and runoff, both annually and seasonally, possessed chaotic dynamic characteristics, implying that complex hydro-climatic processes must be introduced into other variables within models to describe the dynamics. In addition, as determined via rescaled range analysis, a consistent annual and seasonal decreasing trend in runoff under increasing temperature and precipitation conditions in the future should be taken into account. This work may provide a theoretical perspective that can be applied to the proper use and management of oasis water resources in the lower reaches of river basins like that of the Qira River. PMID:26244113

  3. Tectonic development of the Northwest Bonaparte Basin, Australia by using Digital Elevation Model (DEM)

    NASA Astrophysics Data System (ADS)

    Wahid, Ali; Salim, Ahmed Mohamed Ahmed; Ragab Gaafar, Gamal; Yusoff, AP Wan Ismail Wan

    2016-02-01

    The Bonaparte Basin consist of majorly offshore part is situated at Australia's NW continental margin, covers an area of approx. 270,000km2. Bonaparte Basin having a number of sub-basins and platform areas of Paleozoic and Mesozoic is structurally complex. This research established the geologic and geomorphologic studies using Digital Elevation Model (DEM) as a substitute approach in morphostructural analysis to unravel the geological complexities. Although DEMs have been in practice since 1990s, they still have not become common tool for mapping studies. The research work comprised of regional structural analysis with the help of integrated elevation data, satellite imageries, available open topograhic images and internal geological maps with interpreted seismic. The structural maps of the study area have been geo-referenced which further overlaid onto SRTM data and satellite images for combined interpretation which facilitate to attain Digital Elevation Model of the study area. The methodology adopts is to evaluate and redefine development of geodynamic processes involved in formation of Bonaparte Basin. The main objectives is to establish the geological histories by using digital elevation model. The research work will be useful to incorporate different tectonic events occurred at different Geological times in a digital elevation model. The integrated tectonic analysis of different digital data sets benefitted substantially from combining them into a common digital database. Whereas, the visualization software facilitates the overlay and combined interpretation of different data sets which is helpful to reveal hidden information not obvious or accessible otherwise for regional analysis.

  4. A surprising discovery of American pika sites in the northwest Great Basin

    Treesearch

    Mackenzie R. Jeffress; K. Jane Van Gunst; Constance I. Millar

    2017-01-01

    Although the American pika (Ochotona princeps) continues to receive attention due to documented declines and range retractions, particularly in the Great Basin, thorough range inventories have yet to be completed in many parts of the region. Here we report on recently discovered populations in northwestern Nevada in areas not suspected to support...

  5. Paleo-heat flow evolution of the Tabei Uplift in Tarim Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Li, Meijun; Wang, Tieguan; Chen, Jianfa; He, Faqi; Yun, Lu; Akbar, Sadik; Zhang, Weibiao

    2010-01-01

    The paleo-heat flow evolution of the Tabei Uplift in the Tarim Basin is investigated based on burial and thermal history reconstruction of 14 wells and using basin modeling. Numerous geological parameters, such as, temperature data and missing sediment thickness by erosion were used in the modeling. The basin model was calibrated using 460 measured vitrinite reflectance (% VRo) and vitrinite-like maceral reflectance (% VLMRo) values to constrain the validity of the maturity model. The heat flow history of the Tabei Uplift, Tarim Basin shows the following characteristics: (1) the highest paleo-heat flow was predicted to have occurred in the Early Ordovician as 65 ± 5 mW/m 2, and gradually decreased to 55 ± 5 mW/m 2 during the Late Carboniferous; (2) a thermal kick was modeled to have occurred in the Permian as suggested by an abrupt rise in the heat flow; (3) the heat flow gradually decreased since the Triassic; (4) the present day heat flow was predicted to be as low as 38 mW/m 2. This heat flow history honors the geologic and tectonic evolution history of the Tabei Uplift and is suggested as the best case heat flow model.

  6. Tectonostratigraphic history of the Neogene Maimará basin, Northwest Argentina

    NASA Astrophysics Data System (ADS)

    Galli, Claudia I.; Coira, Beatriz L.; Alonso, Ricardo N.; Iglesia Llanos, María P.; Prezzi, Claudia B.; Kay, Suzanne Mahlburg

    2016-12-01

    This paper presents the tectonostratigraphic evolution of the Maimará Basin and explores the relationship between the clastic sediments and pyroclastic deposits in the basin and the evolution of the adjacent orogeny and magmatic arc. The sedimentary facies in this part of the basin include, in ascending order, an ephemeral fluvial system, a deep braided fluvial system and a medial to distal ephemeral fluvial system. We interpret that Maimará Formation accumulated in a basin that has developed two stages of accumulation. Stage 1 extended from 7 to 6.4 Ma and included accelerated tectonic uplift in the source areas, and it corresponds to the ephemeral fluvial system deposits. Stage 2, which extended from 6.4 to 4.8 Ma, corresponds to a tectonically quiescent period and included the development of the deep braided fluvial system deposits. The contact between the Maimará and Tilcara formations is always characterized by a regional unconformity and, in the study area, also shows pronounced erosion. Rare earth element and other chemical characteristics of the tuff intervals in the Maimará Formation fall into two distinct groups suggesting the tuffs were erupted from two distinct late Miocene source regions. The first and most abundant group has characteristics that best match tuffs erupted from the Guacha, Pacana and Pastos Grandes calderas, which are located 200 and 230 km west of the study area at 22º-23º30‧S latitude. The members the second group are chemically most similar to the Merihuaca Ignimbrite from the Cerro Galán caldera 290 km south-southwest of the studied section. The distinctive geochemical characteristics are excellent tools to reconstruct the stratigraphic evolution of the Neogene Maimará basin from 6.4 to 4.8 Ma.

  7. Organic geochemistry and petroleum geology, tectonics and basin analysis of southern Tarim and northern Qaidam basins, northwest China

    NASA Astrophysics Data System (ADS)

    Hanson, Andrew Dean

    Organic geochemistry of oils from the Tarim basin, NW China, distinguish at least seven genetic groups of oils. The largest group are derived from Middle-Upper Ordovician anoxic slope-facies marls coincident with the margins of structural uplifts. Other groups include non-marine derived oils in the Luntai uplift, from southwest Tarim, in the Kuqa depression, and west of the Bachu uplift. A seep sample from west of Kashi clusters with Luntai oils. These results suggest that numerous source-rock horizons occur, but they are really restricted. Organic geochemistry of oils from northern Qaidam defines a family of hypersaline, anoxic lacustrine derived oils. Cenozoic outcrop samples from northern Qaidam are too organic lean to be of source quality, but dark laminated upper Oligocene mudstones from the Shi 28 well are of fair to good quality. Biomarkers provide a good correlation between the oils and the core samples. Organic matter is from algae and bacteria and lacks terrestrial material. Hydrocarbons are contained in upper Oligocene, Miocene, and Pliocene reservoirs. Eight oils are from NW Qaidam, but one sample comes from NE Qaidam, an area previously believed to only produce oils derived from Jurassic source rocks. Thus an unidentified Cenozoic source rock occurs in NE Qaidam. Thermal modeling indicates generation occurred in northwestern Qaidam within the last 3 million years, agreeing with observed low maturity biomarker parameters. Cenozoic stratigraphy in northern Qaidam and southern Tarim basins record the tectonic history of the surrounding structural/topographic elements. Paleocurrents record flow away from adjacent ranges from the Miocene to the present. Provenance data tie sediments to adjacent structural elements. Petrography indicates increasingly immature sandstones in Miocene and younger sediments relative to pre-Miocene samples. Apatite fission-track results from southeastern Tarim yield a cooling age of 17 +/- 1 Ma indicative of unroofing since at

  8. Stratigraphic and Tectonic Evolution of the Jurassic Hazelton Trough-Bowser Basin, Northwest British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Gagnon, Jean-Francois

    The Hazelton trough--Bowser basin is a large sedimentary basin that developed on volcanic arc rocks of the Stikine terrane in northern British Columbia, Canada. Its fill mostly consists of the Lower to Middle Jurassic Hazelton Group and the Middle Jurassic to Lower Cretaceous Bowser Lake Group. Regional correlations indicate that the Hazelton Group can be divided in two distinct lithostratigraphic intervals separated in most places by an unconformity. The lower Hazelton Group (LHG) is dominated by arc-related volcanic rocks, whereas the upper Hazelton Group (UHG) contains mainly fine-grained clastic rocks and lesser bimodal rift-related volcanic rocks. Lowermost coarse-grained strata of the UHG, including the bioturbated and fossiliferous units of the Smithers Formation and the Spatisizi River Formation, record a transgressive trend consistent with thermal subsidence and relative sea-level rise. Transgression of the Stikine arc culminated with the establishment of deep-water conditions in the Late Toarcian-Early Aalenian, and deposition of the Quock Formation. Interbedded siliceous mudstone and rusty-weathered tuff of the Quock Formation are correlated throughout most of the basin, except in the Iskut River area on the northwestern margin of the basin, where contemporaneous strata of the Iskut River Formation are dominated by rift-related volcanic rocks and conglomerates. Inception of rifting in the Iskut River area constitutes an independent extensional event on Stikinia, and could be related to reorganization of tectonic plates during a protracted period of terrane accretion in the Middle Jurassic. Obduction of the Cache Creek terrane over Stikinia in early Middle Jurassic provided a new source of sediment, which led to accumulation of the Bowser Lake Group. The second pulse of subsidence observed at Todagin Mountain can be explained by sediment loading of the accommodation previously generated during extension of the Hazelton trough in Early Jurassic time.

  9. Significance of loessite in the Maroon Formation (Middle Pennsylvanian to Lower Permian), Eagle Basin, northwest Colorado

    USGS Publications Warehouse

    Johnson, S.Y.

    1989-01-01

    The Maroon Formation includes a siltstone-dominated facies interpreted as loessite (lithified loess) along its downwind basin margin. The section of inferred loessite is locally at least 490 m thick and consists in large part of structureless and nearly structureless beds of homogeneous sandy siltstone. Bed contacts are generally planar to undulatory and are either horizontal or are characterized by gentle relief. Deposition of the Maroon Formation was probably strongly affected by cyclic climatic changes synchronous with fluctuations in late Paleozoic continental ice sheets. -from Author

  10. Age and tectonic evolution of the northwest corner of the West Philippine Basin

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Yeh, Yi-Ching; Tsai, Ching-Hui; Chang, Ching-Ming

    2015-09-01

    To understand the tectonic characteristics and age of the northwestern part of the West Philippine Basin (WPB), multi-beam bathymetry and geomagnetic data have been collected and analyzed. The seafloor morphology obviously shows NW-SE trending seafloor fabrics and NE-SW trending fracture zones, indicating a NE-SW seafloor spreading direction. An overlapping spreading center near 22°20'N and 125°E is identified. Besides, numerous seamounts indicate an excess supply of magma during or after the oceanic crust formation. A V-shaped seamount chain near 21°52'N and 124°26'E indicates a southeastward magma propagation and also indicates the location of the seafloor spreading ridge. On the basis of the newly collected geomagnetic data, the magnetic anomaly shows NW-SE trending magnetic lineations. Both bathymetry and geomagnetic data reveal NE-SW seafloor spreading features between the Gagua Ridge and the Luzon Okinawa fracture zone (LOFZ). Our magnetic age modeling indicates that the age of the northwestern corner of the WPB west of the LOFZ is between 47.5 to 54 Ma (without including overlapping spreading center), which is linked to the first spreading phase of the WPB to the east of the LOFZ. In addition, the age of the Huatung Basin is identified to be between 33 to 42 Ma, which is similar to the second spreading phase of the WPB.

  11. [Geochemistry of surface and ground water in the Lijang basin, Northwest Yunnan].

    PubMed

    Pu, Tao; He, Yuan-Qing; Zhu, Guo-Feng; Zhang, Wei; Cao, Wei-Hong; Chang, Li; Wang, Chun-Feng

    2012-01-01

    The study focused on the chemical element compositions of river water and groundwater in Lijiang Basin. Water samples were collected in Baishui, Sanshu, Geji and Shuhe rivers in Lijiang Basin to analyze pH, conductivity and ion concentration, in order to understand the contributions of anthropogenic activities and rock weathering to river solutes. The results show that all water samples are mildly alkaline and are rich in Ca2+ and HCO3-, which account for 54.8 and 92.4 percentage of total ion concentration respectively. Obvious variations have been perceived during monsoon and westward wind season. The ion concentration of river water is lower than that of groundwater. With decreasing elevation, the ion concentrations are found to increase considerably in the study region. According to source study of major ions, water chemistry is mainly influenced by precipitation rock weathering and dissolving processes. In addition, precipitation is an important factor in monsoon seasons whereas the anthropogenic inputs have lead to light pollution on water in residential district.

  12. Significance and effect of ecological rehabilitation project in inland river basins in northwest China.

    PubMed

    Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

    2013-07-01

    The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.

  13. Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

    2017-06-01

    Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

  14. Transpiration and canopy conductance variations of shelterbelt in an arid inland river basin of northwest China

    NASA Astrophysics Data System (ADS)

    Gao, G.

    2015-12-01

    The knowledge of plant water use characteristics under changing environmental conditions is essential for ecosystem management and water resources distribution in water-stressed environments. This study was conducted to quantify variations in transpiration and canopy conductance in a shelterbelt in the middle of the Heihe River Basin, China. Sap flow of eight Gansu Poplar trees (Populus gansuensis) with different diameters at breast height (DBH) was measured over three consecutive growing seasons (2012-2014). The evapotranspiration of groundwater via plant use was estimated by the White method, with diurnal water table fluctuations. Results showed that mean sap flow density varied between 30.62 ±11.44 and 101.88 ±28.98 kg m-2 h-1, and it increased linearly with the DBH. Variations of sap flow density were mainly controlled by meteorological factors in addition to water table depth. Average stand transpiration during the growing season was about 4.85 mm day-1, and it had a logarithmic relationship with reference crop evapotranspiration. Precipitation increased stand transpiration, but not at a statistically significant level (p>0.05). The recharge of soil water by irrigation significantly accelerated stand transpiration (p<0.05). Stand transpiration and canopy conductance increased by 27% and 31%, respectively, when soil water conditions changed from dry to wet. Canopy conductance decreased logarithmically with vapor pressure deficit, whereas there was no apparent relationship between canopy conductance and solar radiation. The sensitivity of canopy conductance to vapor pressure deficit decreased under dry soil conditions. Groundwater evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71). During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelts, and might

  15. Structural and stratigraphic mapping from satellite imagery, Kalpin uplift, northwestern Tarim basin, northwest China

    SciTech Connect

    McKnight, C.L.; Carroll, A.R.; Chu, J.; Hendrix, M.S.; Graham, S.A.; Lyon, R.J.P. )

    1990-05-01

    The Kalpin uplift, located on the northwestern margin of the Tarim craton, northwest China, exposes a complete Paleozoic cratonal stratigraphic sequence. The lack of vegetative cover and the visible color contrasts between stratigraphic units afford an optimal situation for detailed geologic mapping from Landsat Multispectral Scanner imagery at a scale of 1:250,000. Field work in the eastern Kalpin uplift constrains the geologic interpretation of the satellite imagery. Exposed basement rock in the Kalpin uplift consists of deformed and metamorphosed upper Proterozoic strata cut by unmetamorphosed mafic dikes. The overlying sedimentary section was deposited primarily in shallow marine to nonmarine environments and includes Sinian (latest Proterozoic to early Cambrian) siliciclastics and carbonates; Cambrian and Ordovician carbonates; Silurian green shales; Devonian red beds; Carboniferous siliciclastics and carbonates; and Permian carbonates, siliciclastics, and subaerial basalt flows. Paleozoic strata are exposed in a series of low, parallel, curvilinear ranges located at the leading edges of low-angle, southeast-vergent thrust sheets. The regular thrust repetition of the entire Paleozoic section suggests the presence of a detachment horizon within the Cambrian section. These southeast-vergent thrust sheets override an older structural trend on the craton, the Bachu uplift, at right angles, folding as they do so. Strike-slip faults cutting the thrust sheets along the same trend as the Bachu uplift suggest the location of buried lateral ramps associated with the Bachu uplift. The young deformation in the Kalpin uplift is a response to compressive stresses produced by the northward movement of the Indian plate. Major faults in the Tian Shan mountain range to the north have been reactivated, resulting in southward-directed thrusting over the Tarim craton.

  16. The influence of paleogeography in epicontinental seas: A case study based on Middle Devonian strata from the MacKenzie Basin, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Corlett, Hilary; Jones, Brian

    2011-08-01

    The history of Middle Devonian sea level changes are recorded in the Chinchaga Formation, Lonely Bay Formation, Horn Plateau Formation, and the Horn River Formations that originated in the MacKenzie Basin, which is located in the southern Northwest Territories, Canada. These strata record an almost consistent sea-level rise throughout the Middle Devonian with punctuated deepenings. Deposition began in the MacKenzie Basin in the Eifelian with restricted shallow water evaporites and dolomites of the Chinchaga Formation. Overlying the Chinchaga Formation are the open-marine carbonates belonging to the Lonely Bay Formation, which were overlain by the Horn Plateau Formation buildups. Pelagic shales of the Horn River Formation in the Late Givetian/Early Frasnian later covered these buildups. During the Early and Middle Devonian many continental basins in North America had limited interactions with open ocean waters. These restricted shallow-water basins were vulnerable to the effects of clastic shedding and evaporitic drawdown that commonly caused local lowstands. Several of these shallow basins, including the MacKenzie Basin, have been used to construct Devonian sea-level curves. Comparison of the Middle Devonian strata that formed in the MacKenzie Basin with well-established sea level curves shows that the Late-Givetian regression interpreted from some of those successions is not evident in the succession found in the MacKenzie Basin. This probably reflects the fact that the Mackenzie Basin was directly linked to the open ocean and was not influenced by the changes in sea level that affected many of the enclosed basins.

  17. Semi-natural areas of Tarim Basin in northwest China: Linkage to desertification.

    PubMed

    Liu, Fang; Zhang, Hongqi; Qin, Yuanwei; Dong, Jinwei; Xu, Erqi; Yang, Yang; Zhang, Geli; Xiao, Xiangming

    2016-12-15

    Semi-natural lands are not intensively managed lands, which have ecological significance in protecting artificial oasis and preventing desertification in arid regions. The significant shrinkage and degradation of semi-natural lands in the land-use intensification process have caused severe desertification. However, there is a knowledge gap regarding the spatio-temporal pattern and detailed classification of semi-natural lands and its quantitative relationship with desertification. Taking the Tarim Basin as an example, we proposed a comprehensive classification system to identify semi-natural lands for 1990, 2000, and 2010, respectively, using multi-source datasets at large scales. Spatio-temporal changes of semi-natural lands were then characterized by map comparisons at decade intervals. Finally, statistical relationships between semi-natural lands and desertification were explored based on 241 watersheds. The area of semi-natural lands in Tarim Basin was 10.77×10(4)km(2) in 2010, and desert-vegetation type, native-oasis type, artificial-oasis type, saline type and wetland type accounted for 59.59%, 14.65%, 11.25%, 9.63% and 4.88% of the total area, respectively. A rapid loss of semi-natural lands (9769.05km(2)) was demonstrated from 1990 to 2010. In the fragile watersheds, the semi-natural lands were mainly converted to desert; while in the watersheds with advanced oasis agriculture, artificial-oasis type reclaimed to arable land was the major change. The occurrence of desertification was closely related to the type, area proportion and combination patterns of semi-natural lands. Desertification was prone to occur in regions abundant in desert-vegetation type and saline type, while less serious desertification was observed in regions with high proportion of artificial-oasis type and wetland type. Policy intervention and reasonable water resource allocation were encouraged to prevent the substantial loss of semi-natural lands, especially for the water

  18. Geophysical evidence for fluid flow in the Laminaria High, Bonaparte basin, Northwest shelf of Australia

    NASA Astrophysics Data System (ADS)

    Abdulkareem, Lamees; Hobbs, Richard; Imber, Jonathan

    2016-04-01

    Seismic amplitude anomalies ("bright spots") can result from changes in acoustic impedance caused by the presence of fluids and/or lateral changes in lithology. In this study, 3D seismic interpretation and well log data is used to investigate the nature and causes of seismic amplitude anomalies within the shallow subsurface on the Laminaria High on the north-west shelf of Australia. Here, the anomalies are associated with active faults that cut the seabed. Previous studies suggest that fault reactivation and fault geometry have an important role in causing hydrocarbon leakage from a deeper reservoir and that bends on the larger faults will influence the localization of shear strain, increasing the risk of leakage. However, these studies did not examine the influence of fault growth during reactivation on fluid migration, or how post-rift and syn-rift sedimentation may have influenced fluid leakage. In our study, preliminary results suggest that not all active faults are associated with amplitude anomalies or dry/partially-filled hydrocarbon traps at depth, implying that there could be a different mechanism for the creation of the amplitude anomaly observed on the Laminaria High. Specifically, these anomalies may be the result of preferential cementation, or the presence of gas trapped within sediments at or near the seabed, possibly originating from gas generation due to biogenic activity in recently deposited sediment. Detailed amplitude maps are extracted from syn- and pre- faulting seismic horizons down to the top reservoir level in order to understand the spatial extent of the high amplitude anomalies within the stratigraphic succession. The first two amplitude maps for the seismic horizons beneath the seabed show high amplitude anomalies associated with the same active faults that are present on the seabed, but with some different characteristics along these faults. Then we extract number of deeper amplitude maps to the top of reservoir, to reveal whether the

  19. The Timan-Pechora Basin province of northwest Arctic Russia; Domanik, Paleozoic total petroleum system

    USGS Publications Warehouse

    Lindquist, Sandra J.

    1999-01-01

    The Domanik-Paleozoic oil-prone total petroleum system covers most of the Timan-Pechora Basin Province of northwestern Arctic Russia. It contains nearly 20 BBOE ultimate recoverable reserves (66% oil). West of the province is the early Precambrian Eastern European craton margin. The province itself was the site of periodic Paleozoic tectonic events, culminating with the Hercynian Uralian orogeny along its eastern border. The stratigraphic record is dominated by Paleozoic platform and shelf-edge carbonates succeeded by Upper Permian to Triassic molasse siliciclastics that are locally present in depressions. Upper Devonian (Frasnian), deep marine shale and limestone source rocks ? with typically 5 wt % total organic carbon ? by middle Mesozoic time had generated hydrocarbons that migrated into reservoirs ranging in age from Ordovician to Triassic but most focused in Devonian and Permian rocks. Carboniferous structural inversions of old aulacogen borders, and Hercynian (Permian) to Early Cimmerian (Late Triassic to Early Jurassic) orogenic compression not only impacted depositional patterns, but also created and subsequently modified numerous structural traps within the province.

  20. [Effects of land use change on landscape pattern vulnerability in Yinchuan Basin, Northwest China].

    PubMed

    Ren, Zhi-yuan; Zhang, Han

    2016-01-01

    Landscape pattern vulnerability reflects the instability and sensitivity of ecological system to external disturbances and helps to understand the status and trend of ecological environment. This paper used landscape sensitivity index and landscape adaptability index to construct the landscape pattern vulnerability index of Yinchuan Basin, and got the distribution of the landscape pattern vulnerability in 2001 and 2013. Our study explored the effect of the land use degree composite index, the integrated land use dynamic degree, the importance index of land use change and various types of land transfer on landscape pattern vulnerability. Results showed that the land use degree composite index was mainly caused by the increase of the arable land, forest and the construction land. The higher proportion of the arable land or forest, the lower the vulnerability was, and the construction land had the opposite effect. With the increase of integrated land use dynamic degree, the construction land significantly increased the vulnerability, followed by grassland, and the forest significantly decreased the vulnerability, followed by the arable land. As the importance index of land use change increasing, the arable land could significantly decrease the vulnerability, followed by the forest, the grassland had a weaker trend with no obvious pattern, and the construction land significantly increased the vulnerability. When the arable land, forest and the grassland were the maintypes of land use transfer, the increasing proportion of the construction land increased the vulnerability. When the construction land was the main type of land use transfer, the grassland and forest improved the vulnerability and the arable land had the opposite effect. Changes in the number of land use types influenced the spatial structure of land use to a certain extent, which could offer a reference on using and developing the land resources scientifically. The ternary diagram could reflect the impact

  1. Testing fault growth models with low-temperature thermochronology in the northwest Basin and Range, USA

    NASA Astrophysics Data System (ADS)

    Curry, Magdalena A. E.; Barnes, Jason B.; Colgan, Joseph P.

    2016-10-01

    Common fault growth models diverge in predicting how faults accumulate displacement and lengthen through time. A paucity of field-based data documenting the lateral component of fault growth hinders our ability to test these models and fully understand how natural fault systems evolve. Here we outline a framework for using apatite (U-Th)/He thermochronology (AHe) to quantify the along-strike growth of faults. To test our framework, we first use a transect in the normal fault-bounded Jackson Mountains in the Nevada Basin and Range Province, then apply the new framework to the adjacent Pine Forest Range. We combine new and existing cross sections with 18 new and 16 existing AHe cooling ages to determine the spatiotemporal variability in footwall exhumation and evaluate models for fault growth. Three age-elevation transects in the Pine Forest Range show that rapid exhumation began along the range-front fault between approximately 15 and 11 Ma at rates of 0.2-0.4 km/Myr, ultimately exhuming approximately 1.5-5 km. The ages of rapid exhumation identified at each transect lie within data uncertainty, indicating concomitant onset of faulting along strike. We show that even in the case of growth by fault-segment linkage, the fault would achieve its modern length within 3-4 Myr of onset. Comparison with the Jackson Mountains highlights the inadequacies of spatially limited sampling. A constant fault-length growth model is the best explanation for our thermochronology results. We advocate that low-temperature thermochronology can be further utilized to better understand and quantify fault growth with broader implications for seismic hazard assessments and the coevolution of faulting and topography.

  2. Testing fault growth models with low-temperature thermochronology in the northwest Basin and Range, USA

    USGS Publications Warehouse

    Curry, Magdalena A. E.; Barnes, Jason B.; Colgan, Joseph P.

    2016-01-01

    Common fault growth models diverge in predicting how faults accumulate displacement and lengthen through time. A paucity of field-based data documenting the lateral component of fault growth hinders our ability to test these models and fully understand how natural fault systems evolve. Here we outline a framework for using apatite (U-Th)/He thermochronology (AHe) to quantify the along-strike growth of faults. To test our framework, we first use a transect in the normal fault-bounded Jackson Mountains in the Nevada Basin and Range Province, then apply the new framework to the adjacent Pine Forest Range. We combine new and existing cross sections with 18 new and 16 existing AHe cooling ages to determine the spatiotemporal variability in footwall exhumation and evaluate models for fault growth. Three age-elevation transects in the Pine Forest Range show that rapid exhumation began along the range-front fault between approximately 15 and 11 Ma at rates of 0.2–0.4 km/Myr, ultimately exhuming approximately 1.5–5 km. The ages of rapid exhumation identified at each transect lie within data uncertainty, indicating concomitant onset of faulting along strike. We show that even in the case of growth by fault-segment linkage, the fault would achieve its modern length within 3–4 Myr of onset. Comparison with the Jackson Mountains highlights the inadequacies of spatially limited sampling. A constant fault-length growth model is the best explanation for our thermochronology results. We advocate that low-temperature thermochronology can be further utilized to better understand and quantify fault growth with broader implications for seismic hazard assessments and the coevolution of faulting and topography.

  3. Stratigraphy and Geochemistry of the Lower Permian Esayoo Volcanics, Northwest Ellesmere Island: Insights into Sverdrup Basin Paleogeography

    NASA Astrophysics Data System (ADS)

    Morris, N. J.; Beauchamp, B.; Cuthbertson, J. P.; Chau, Y.

    2012-12-01

    The Esayoo Volcanics consist of altered Lower Permian basalts that outcrop on northwest Ellesmere Island and northeast Axel Heiberg, within the Sverdrup Basin, Arctic Canada. Rifting in the Sverdrup Basin initiated in the Early Carboniferous and ceased during the Early Permian. The Esayoo volcanics geochemically classify as alkaline to transitional within-plate-basalts, with high Ti/Y and Zr/Y ratios. Eruptions are coincident with two rifting pulses of Sakmarian and Kungurian age. During the 2011 July field season, ten stratigraphic sections of the Esayoo Volcanics were measured at four locations on northwest Ellesmere Island: Borup Fiord Pass, Oobloyah Bay, Ricker Glacier and Mount Leith. The Esayoo Volcanics reach a maximum thickness of 450 m near Oobloyah Bay, and thin west, east and north of Oobloyah Bay with respective thicknesses of 140 m, 69 m and 75 m. At Oobloyah Bay, volcanic rocks occur at two stratigraphic levels. The lower Esayoo unit lies within the Raanes Formation, a mixed clastic-carbonate, and further west at Ricker Glacier within the upper Hare Fiord Formation, a black siliceous shale-siltstone. The upper Esayoo unit is below the Assistance Formation, carbonate-rich to clean quartz sandstone, and below the Sabine Bay Formation, a clean quartz sandstone with abundant cross-beds. Thin 1 to 2 m shales that indicate maximum flooding surfaces overlie both the upper and lower Esayoo units. Each measured section was divided into individual flow units that averaged 7 m thick. Dominant textures observed within individual flow units include: thin 2-3 cm thick amygdule-rich bases transitioning into thick 2-10 m thick massive flow interiors; frothy, amygdule-rich flow tops 1-3 m thick; and chaotic vesicular units with amygdules ranging from 0.5-3 cm in width and pervasive cross-cutting calcite veins and stringers. The lower level at Oobloyah Bay is composed of a laminated volcaniclastic rock that is rich in heterozoan marine bioclasts, with associated pillow

  4. Characteristics and formation mechanism of composite flower structures in the Shuntuo area, Tarim Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Han, X.; Tang, L.; Cao, Z.

    2016-12-01

    The Shuntuo area, located in the north part of the northern slope of Tazhong Uplift, is one of the key areas of Tarim Basin with great exploration potentials. Based on detailed 3D seismic interpretations of the Shuntuo area, the characteristics and formation mechanisms of the strike-slip faults were investigated. The research results show that a series of sinistral strike-slip faults, which cut through the basement strata and straight up to the Middle Devonian strata, developed in the study area. On the 3D seismic profiles, the strike-slip fault shows complex geometric features that consists of a lower convex strata deformation (positive flower structure) and an upper concave-shaped strata deformation (negative flower structure) that bounded by the Late Ordovician strata. Systematic research on the distribution, geometry and kinematics of the composite flower structures suggests that they are completely different fault systems formed in different time and controlled by different factors. According to fault open horizon and fault throw changes, the development history of the strike-slip faults may be divided into two stages including the Middle Caledonian and the Early Hercynian. On the seismic coherency maps, the lower strike-slip faults show NE linear extension. In the Middle Caledonian, the Tazhong Uplift experienced a strong compression from Ancient Kunlun ocean subducting in NE direction and Arkin ocean subducting in NW direction, which resulted in the formation of NE-trending strike-slip faults. The upper strike-slip faults are NW trending and present right-order en-echelon arrangements. During Early Hercynian, with the termination of the Kunlun Caledonian collision orogeny, the Tazhong Uplift was in the stress relaxation stage. The stress condition of the Shuntuo area transformed from compression to extension. Based on the lower strike-slip faults, the upper strike-slip faults were developed under the control of previous basement weak zones. Since the strike

  5. Groundwater mixing and mineralization processes in a mountain-oasis-desert basin, northwest China: hydrogeochemistry and environmental tracer indicators

    NASA Astrophysics Data System (ADS)

    Ma, Bin; Jin, Menggui; Liang, Xing; Li, Jing

    2017-09-01

    Hydrogeochemistry and environmental tracers (2H, 18O, 87Sr/86Sr) in precipitation, river and reservoir water, and groundwater have been used to determine groundwater recharge sources, and to identify mixing characteristics and mineralization processes in the Manas River Basin (MRB), which is a typical mountain-oasis-desert ecosystem in arid northwest China. The oasis component is artificial (irrigation). Groundwater with enriched stable isotope content originates from local precipitation and surface-water leakage in the piedmont alluvial-oasis plain. Groundwater with more depleted isotopes in the north oasis plain and desert is recharged by lateral flow from the adjacent mountains, for which recharge is associated with high altitude and/or paleo-water infiltrating during a period of much colder climate. Little evaporation and isotope exchange between groundwater and rock and soil minerals occurred in the mountain, piedmont and oasis plain. Groundwater δ2H and δ18O values show more homogeneous values along the groundwater flow direction and with well depths, indicating inter-aquifer mixing processes. A regional contrast of groundwater allows the 87Sr/86Sr ratios and δ18O values to be useful in a combination with Cl, Na, Mg, Ca and Sr concentrations to distinguish the groundwater mixing characteristics. Two main processes are identified: groundwater lateral-flow mixing and river leakage in the piedmont alluvial-oasis plain, and vertical mixing in the north oasis plain and the desert. The 87Sr/86Sr ratios and selected ion ratios reveal that carbonate dissolution and mixing with silicate from the southern mountain area are primarily controlling the strontium isotope hydrogeochemistry.

  6. Postglacial relative sea-level changes in northwest Iceland: Evidence from isolation basins, coastal lowlands and raised shorelines

    NASA Astrophysics Data System (ADS)

    Brader, Martin D.; Lloyd, Jeremy M.; Barlow, Natasha L. M.; Norðdahl, Hreggviður; Bentley, Michael J.; Newton, Anthony J.

    2017-08-01

    Relative sea-level (RSL) data provide constraints on land uplift associated with former ice loading and can be used to differentiate between contrasting ice unloading scenarios. Isolation basin, coastal lowland and geomorphological evidence is employed to reconstruct RSL changes in northwest (NW) Iceland, which may have experienced contrasting uplift patterns. Under local (NW) uplift, highest RSL would be expected in central Vestfirðir, whereas highest RSL would be closest to the main ice-loading centre under regional (central Iceland) uplift. Four new RSL records are presented based on 16 sea-level index points and 4 limiting ages from sites principally focussed along a transect away from central Iceland. The new RSL records highlight spatial variability of Holocene RSL changes and provide constraints on deglaciation. There is an increase in marine limit elevation with proximity to the proposed principal ice loading centre in central Iceland. Highest recorded marine limit shorelines are found in Hrútafjörður-Heggstaðanes (southeast), the lowest in Hlöðuvík and Rekavík bak Látrum (north), and at an intermediate elevation in Reykjanes-Laugardalur (central Vestfirðir). Evidence from Breiðavik-Látrar records early rapid deglaciation in Breiðafjörður or a complex interplay of multiple uplift centres. RSL fell rapidly following deglaciation in several locations as a result of the quick response of the Icelandic lithosphere to unloading. The RSL data along the transect show an uplift pattern consistent with extensive regional glaciation emanating from central Iceland, which could have implications for ice sheet configuration and patterns of deglaciation, glacio-isostatic adjustment modelling and the volume of meltwater input into the North Atlantic.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  8. Architecture, Kinematics, and Development of Widespread Late Oligocene to Early Miocene East-Northeast and West-Northwest Trending Extensional Basins during North-South Extension in the Central and Southern Walker Lane, Western Great Basin

    NASA Astrophysics Data System (ADS)

    Kerstetter, S. R.; Katopody, D. T.; Oldow, J. S.

    2016-12-01

    In the central and southern Walker Lane, a network of seven east-northeast and west-northwest trending half-grabens, spanning an area of 4000 km2, controlled the spatial distribution and thickness of late Oligocene to early Miocene volcanic and volcaniclastic rocks. The basins range from 10 to 20 km long, are 4 to 7 km wide, and from 0.5 to 1.5 km deep. Internally, the basins are segmented by north-northeast and north-northwest striking transfer faults that accommodated along-axis changes in basin geometry and across-axis dog-leg steps of up to 15 km. The basin-fill consists of synextensional rhyolite tuff, andesite, and volcaniclastic rocks that form asymmetric stratal wedges that thicken to the north and south into basin-bounding faults. In several locations, the bounding faults are overlapped by post-extensional deposits of tuff and andesite. Locally, east-west and east-northeast striking andesitic dikes intrude the basin-fill sequences and are consistent with emplacement during north-south extension. In the southern central Walker Lane, half-grabens controlled deposition of rhyolite tuff ranging in age from 28 to 21 Ma and andesite dated at 19 to 15 Ma. Individual faults were variously sealed by 23 Ma rhyolite tuff and mid-Miocene volcanic and sedimentary rocks. In the northern part of the southern Walker Lane, half-grabens localized the deposition of late Oligocene rhyolite tuff dated at 26 Ma and early Miocene andesite, and are sealed by mid-to-Upper Miocene volcanic rocks. Half graben development ceased by the mid-to-late Miocene and the basins were subsequently dissected by Late Miocene to Quaternary faults. Analysis of over 1000 fault-slip measurements collected within late Cenozoic and pre-Cenozoic rocks along major basin-controlling faults indicates the half-grabens formed in a period of regional north-south extension and predated northwest extension associated with Pliocene to contemporary transtensional deformation.

  9. The impact of the winter North Atlantic Oscillation on the frequency of spring dust storms over Tarim Basin in northwest China in the past half-century

    NASA Astrophysics Data System (ADS)

    Zhao, Yong; Huang, Anning; Zhu, Xinsheng; Zhou, Yang; Huang, Ying

    2013-06-01

    The relationship between the frequency of spring dust storms over Tarim Basin in northwest China and the winter North Atlantic Oscillation (NAO) is investigated by using the observed dust storm frequency (DSF) and the 10 m wind velocity at 36 stations in Tarim Basin and the National Centers for Environment Prediction/National Center for Atmospheric Research reanalysis data for the period 1961-2007. The spring DSF (winter NAO) index shows a clear decreasing (increasing) linear trend over 1961-2007. The winter NAO correlates well with the subsequent spring DSF over Tarim Basin on both interannual and interdecadal time scales and its interannual to interdecadal variation plays an important role in the spring DSF. Two possible physical mechanisms are identified. One is related to the large scale anomalous circulations in spring in the middle to high troposphere modulated by the winter NAO, providing the background of dynamical conditions for the dust storm occurrences. The other is related to the shifts in the local horizontal sea level pressure (SLP) gradients and 10 m wind speed, corresponding to changes in the large scale circulations in spring. The decrease in the local 10 m wind speed due to the reduced horizontal SLP gradients over Tarim Basin during the strong winter NAO years contributes to the decline of the DSF in the subsequent spring.

  10. Subsurface structure and stratigraphy of the northwest end of the Turkana Basin, Northern Kenya Rift, as revealed by magnetotellurics and gravity joint inversion

    NASA Astrophysics Data System (ADS)

    Abdelfettah, Yassine; Tiercelin, Jean-Jacques; Tarits, Pascal; Hautot, Sophie; Maia, Marcia; Thuo, Peter

    2016-07-01

    In order to understand the subsurface stratigraphy and structure of the northwest end of the Turkana Basin, Northern Kenya Rift, we used 2-D joint inversion of magnetotelluric (MT) and gravity data acquired along 3 profiles perpendicular to the main Murua Rith-Lapur Rift Border Fault. The regional geology is characterized by a basement of Precambrian age overlain by a ≤500-m thick sandstone formation named the Lapur Sandstone of upper Cretaceous-lower Eocene in age, covered by thick rhyolitic and basaltic lavas of late Eocene-middle Miocene age, known as the "Turkana Volcanics". Final interpretation of the resistivity and density models, until 5 km depth, obtained by the joint inversion approach confirms the previous general knowledge about the half-graben geometry of the northern part of the Turkana Basin. The main Murua Rith-Lapur Rift Border Fault is well identified by both gravity and MT. At least, two other important secondary faults without surface expression are also identified. A new small half-graben basin, named the Kachoda Basin, parallel to the main Turkana Basin and filled by 1.5 km of sediments, has been also characterized. This study also highlights strong thickness variations of the three main geological units that could be expected in the subsurface of the Turkana Basin. For example, the sedimentary Nachukui and Kibish Formations reach up to >3 km in thickness at the eastern end of the north and central profiles. Lateral variations of the topography of the Precambrian basement are also evidenced. Conceptual geological models, which result from the combination of the obtained density and resistivity models as well as from geological and reflection seismic data, are proposed. In such an area of intensive and promising oil exploration, these models are essential in terms of identification of reservoirs, source rocks and trapping mechanisms.

  11. The Early Miocene-Early Pliocene Vegetation and Climate Changes at the north to northwest Çankırı -Çorum Basin (Central Anatolian Plateau)

    NASA Astrophysics Data System (ADS)

    Atalar, Müge; Kováčová, Marianna; Sezgül Kayseri Ozer, Mine; Utescher, Torsten; Mazzini, Ilaria; Gliozzi, Elsa; Cosentino, Domenico

    2016-04-01

    The ALErT project targets on climate and tectonic hazards in the densely populated regions in the Central Anatolian Plateau (CAP), within the framework of the Marie Curie FP7-PEOPLE-2013-ITN program, The CAP extends in a wide area in between zone the Aegean extensional zone and Bitlis /Zagros compressional zone. Çankırı Basin (in the middle CAP) is a key to understand aridification plateau interior and it was a deep pelagic Basin from Late Cretaceous -Early Tertiary as a result of the closure of Neo- Tethyan till the Middle Eocene. North to south of the Çankırı Basin; the Plio - Quaternary Deǧim formation (fluvial deposits) consist of massive mudstones and sandstones and it unconformable overlies the Bozkır formation (lacustrine deposits). That is a Messinian succession mainly by a 200 m-thick cyclic sequence of continental gypsum layers, clays and sandy clays in gypsum with different thicknesses crops. Bozkır formation, the lower being the contact with the Süleymanlı formation. It is overlay the Tuǧlu formation with uncomformably, which is an Upper Miocene succession mainly composed of dark grey silty and organic rich clays. Following formation, which outcrops in the northwest of Çankırı basin, is Hançili formation. The unit is covered by grey sediments of the Hançili Formation, showing alternations of channel sandstones and clay stones over 100 m thick in Early - Middle Miocene in the Çankırı basin. In this study, samples were analyzed for biotic proxy data (palynology) to figure the paleo-environmental and paleoclimate changes. Additionally only for Bozkir formation (longest section in the study area) were sampled for geochemical (δ18O - δ13C isotopes analyses and CaCO3) analysis and the rest of the formations were interpreted using the previous study. In the most pollen spectra the herbs and shrubs prevail: in Deǧim formation (50%), in Bozkır formation (75%), in Süleymanlı formation (47%), in Tuǧlu formation (60%) and in Han

  12. Organic geochemistry and hydrocarbon potential contrasts among lithologically different source rocks in the Qingxi Sag, Jiuquan Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Zhang, Weiwei; Huang, Zhilong; Gao, Gang; Yin, Yue; Li, Tianjun

    2017-04-01

    Jiuquan Basin, located in the eastern part of Hexi Corridor, is a medium- to small-sized superimposed basin in northwest China. Situated in the southwest of the basin is the Qingxi sag, in which the development of large sets of argillaceous dolomite dominate (lithological assemblage named as LSA) and dolomitic mudstone (LSB), partially being mudstone. From electronical and seismic profile features, the Lower Cretaceous can be divided into the Chijinpu Formation, Xiagou Formation, and Zhonggou Formation in the Qingxi Sag. Moreover, the Xiagou Formation can be divided into four members, represented as K1g0, K1g1, K1g2, and K1g3. The given lithological assemblages and occurrence of particular mineralogical combinations indicate that it is the product of hydrothermal deposition. Lithologically, the argillaceous dolomite and dolomitic mudstone are diametrically different in both mineral contents and types. The integration of field outcrop observation and sampling with laboratory analyses, including solvent extract, Rock-Eval (S1, S2, and Tmax), organic petrography (lithological identification, cement, grain, mineral, and maceral observation), and laboratory modeling of hydrocarbon generation, show that both LSA and LSB contains good hydrocarbon potentials but rather different mineralogical compositions. The concurrence of LSA and LSB indicates the alternate interaction between the hydrothermal deposition and normal lacustrine deposits. The LSA mainly contains Type I kerogen and much lower Pr/Ph ratio, indicating parental material sourced from lacustrine algae and bacteria and much stronger reduction depostional environment. However, the LSB mainly contains Type III kerogen, containing parental material mainly sourced from terrestrial higher plant. And in the mudstone, there is almost no Type I kerogen, indicating no substantial input of lacustrine phytoplankton. The LSA contains TOC value of 1.2-3.2% (wt), averaging 2.1% (wt); while the LSB contains 0.8-2.4% (wt) with

  13. Evaluation of the pollution and human health risks posed by heavy metals in the atmospheric dust in Ebinur Basin in Northwest China.

    PubMed

    Abuduwailil, Jilili; Zhaoyong, Zhang; Fengqing, Jiang

    2015-09-01

    Recently, a large amount of research assessing pollution levels and the related health risks posed by atmosphere dust has been undertaken worldwide. However, little work has been done in the oases of the arid regions of Northwest China. In this paper, we studied the pollution and health risks over a year of seven heavy metals in the atmospheric dust of Ebinur Basin, a typical oasis in Northwest China. The results showed the following: (1) The annual amount of atmospheric deposition in Ebinur Basin was 298.23 g m(-2) and the average monthly atmospheric deposition was 25.06 g m(-2). The average and maximum values of the seven heavy metals measured were all below the National Soil Environmental Quality Standards (2nd). (2) Heavy metals of Cu, Cr, and As in the atmospheric deposition mainly originated from the natural geological background, while Zn came from human activity. This study also showed that among the seven measured heavy metals, the ratios of the no-pollution status of Pb, Cd, and Hg were higher than those of others with moderate degrees of pollution also accounting for a certain ratio. (3) The carcinogenic risks from As, Cd, and Cr were all lower than the corresponding standard limit values, and these metals are considered not harmful to the health of the basin. However, there is a relatively high risk of exposure for children from hand-to-mouth intake, which is worthy of attention. This research showed that both human activity and natural factors, such as wind and altitude, influenced the heavy metal contents in the atmospheric dust of the study area. Furthermore, recent human activity in the study area had the most negative influence on the accumulation of the heavy metals and the corresponding health risks, especially for Hg, Pb, and Cd, which is worthy of attention.

  14. StreamNet; Northwest Aquatic Resource Information Network - Status of Salmon and Steelhead in the Columbia River Basin, 1995 Final Report.

    SciTech Connect

    Anderson, Duane A.; Beamesderfer, Raymond C.; Woodard, Bob

    1996-04-01

    Information on fish populations, fisheries, and fish habitat is crucial to the success of ongoing program to protect, recover, enhance, and manage fish resources in the Columbia River Basin. However, pertinent data are often difficult to locate because it is scattered among many agencies and is often unpublished. The goal of this annual report is to bring many diverse data types and sources into a single comprehensive report on the status of anadromous fish runs in the Columbia River Basin and the environmental conditions that may affect that status. Brief summaries are provided to identify the type and scope of available information. This synopsis is intended to complement other more detailed reports to which readers are referred for comprehensive treatment of specific subjects. This first report focuses mainly on anadromous salmon and steelhead (primarily through 1994) but the authors intend to expand the scope of future issues to include resident species. This is the first of what the authors intend to be an annual report. They welcome constructive suggestions for improvements. This report is a product of the StreamNet (formerly Coordinated Information System and Northwest Environmental Data Base) project which is a part of the Bonneville Power Administration`s program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The project is called for in the Fish and Wildlife Program of the Northwest Power Planning Council. The project`s objective is to promote exchange and dissemination of information in a standardized electronic format throughout the basin. This project is administered by the Pacific States Marine Fisheries Commission with active participation by tribal, state, and federal fish and wildlife agencies.

  15. Relating seasonal dynamics of enhanced vegetation index to the recycling of water in two endorheic river basins in north-west China

    NASA Astrophysics Data System (ADS)

    Matin, M. A.; Bourque, C. P.-A.

    2015-08-01

    This study associates the dynamics of enhanced vegetation index in lowland desert oases to the recycling of water in two endorheic (hydrologically closed) river basins in Gansu Province, north-west China, along a gradient of elevation zones and land cover types. Each river basin was subdivided into four elevation zones representative of (i) oasis plains and foothills, and (ii) low-, (iii) mid-, and (iv) high-mountain elevations. Comparison of monthly vegetation phenology with precipitation and snowmelt dynamics within the same basins over a 10-year period (2000-2009) suggested that the onset of the precipitation season (cumulative % precipitation > 7-8 %) in the mountains, typically in late April to early May, was triggered by the greening of vegetation and increased production of water vapour at the base of the mountains. Seasonal evolution of in-mountain precipitation correlated fairly well with the temporal variation in oasis-vegetation coverage and phenology characterised by monthly enhanced vegetation index, yielding coefficients of determination of 0.65 and 0.85 for the two basins. Convergent cross-mapping of related time series indicated bi-directional causality (feedback) between the two variables. Comparisons between same-zone monthly precipitation amounts and enhanced vegetation index provided weaker correlations. Start of the growing season in the oases was shown to coincide with favourable spring warming and discharge of meltwater from low- to mid-elevations of the Qilian Mountains (zones 1 and 2) in mid-to-late March. In terms of plant requirement for water, mid-seasonal development of oasis vegetation was seen to be controlled to a greater extent by the production of rain in the mountains. Comparison of water volumes associated with in-basin production of rainfall and snowmelt with that associated with evaporation seemed to suggest that about 90 % of the available liquid water (i.e. mostly in the form of direct rainfall and snowmelt in the mountains

  16. Small rural communities in the inland Northwest: an assessment of small communities in the interior and upper Columbia River basins.

    Treesearch

    Charles C. Harris; William McLaughlin; Greg Brown; Dennis R. Becker

    2000-01-01

    An assessment of small rural communities in the interior and upper Columbia River basin was conducted for the Interior Columbia Basin Ecosystem Management Project (ICBEMP). The characteristics and conditions of the rural communities in this region, which are complex and constantly changing, were examined. The research also assessed the resilience of the region’s...

  17. A Model for Interpreting 10Be Basin-Wide Erosion Rates in Post-Glacial Environments, Northwest Scotland

    NASA Astrophysics Data System (ADS)

    Fame, M. L.; Owen, L. A.; Balco, G.; Spotila, J. A.

    2015-12-01

    Meaningful interpretation of in-situ cosmogenic 10Be basin-wide erosion rates in slowly eroding postglacial catchments is complicated because 10Be is inherited through shifts between glacial and fluvial regimes and ice shielding prevents 10Be production. Such environments do not attain isotopic and landscape steady state, conditions necessary for the current method of calculating basin-wide erosion rates. We propose an alternate set of assumptions, specific to postglacial regions, which make it possible to calculate basin-wide erosion rates in the post-glacial Highlands of NW Scotland. From 20 Scottish basins basin-wide 10Be concentrations range from 2.129 x 104 to 4.870 x 104 atoms/g qtz. Average 10Be concentrations from shallow till and bank deposits within the basins are 2.856 x 104 atoms/g qtz, similar to the basin-wide concentrations, whereas average bedrock concentrations in the basins are 1.747 x 105 atoms/g qtz. This suggests that during the postglacial time most active sediment is derived from reworked deposits rather then sub-aerially eroded bedrock. Therefore, we make the simplifying assumption that most bedrock erosion occurs during glaciation. A deeply buried till that has experienced no nuclide production since deglaciation has a 10Be concentration of 6.810 x 103 atoms/g qtz and allows us to estimate how much of the 10Be in basin-wide samples was produced since deglaciation. A glacial ice thickness of only 2 m would shield all 10Be production; therefore we assume that no 10Be production occurred during glacial periods and that all production occurs during interglacial periods. Using 100 ka as the approximate duration of a Pleistocene glacial-interglacial cycle, comprised of a 15 ka interglacial period and an 85 ka glacial period, and the aforementioned assumptions we have derived a numerical model to calculate basin-wide glacial erosion rates in NW Scotland.

  18. Bio- and chemostratigraphy of the Early Aptian Oceanic Anoxic Event 1a within the mid-latitudes of northwest Europe (Germany, Lower Saxony Basin)

    NASA Astrophysics Data System (ADS)

    Heldt, Matthias; Mutterlose, Joerg; Berner, Uli; Erbacher, Jochen

    2013-04-01

    The Mid-Cretaceous period was characterised by a series of prominent anoxic events, one of these was the late Early Aptian Oceanic Anoxic Event 1a (OAE 1a). The Fischschiefer horizon is the regional sedimentary expression of this event in a small epicontinental sea in northwest Europe (Germany, Lower Saxony Basin). In the present study, two sediment cores of Lower to Upper Aptian age (Hoheneggelsen KB 9 and 40) from the Brunswick area, north Germany, have been investigated in detail with respect to their lithostratigraphy, geochemistry (CaCO3, TOC), biostratigraphy (coccoliths, nannoliths) and high-resolution chemostratigraphy (^13Ccarb and ^13Corg). Together with separately published new planktonic foraminifer data of the cores it was possible to establish a detailed time frame and to recognise the OAE 1a. The ^13C data enabled us to subdivide the deposits into isotope segments (C2-C7), which are commonly used as stratigraphic markers in coeval sediments around the world. The carbon isotope curves are compared to recently published Aptian curves from other parts of the Lower Saxony Basin, all of which record the prominent carbon isotope anomaly of the OAE 1a. A high-resolution correlation of the typical isotope trends of OAE 1a (segments C3-6) across the Lower Saxony Basin appears difficult due to an early diagenetic overprint of the primary isotope signal. These alterations can be explained by the temporary establishment of euxinic conditions the Lower Saxony Basin during OAE 1a as consequence of an interplay of different factors, such as global warming, restricted palaeogeography, increased fluvial input and intensified stable water stratification, which is supported by several lines of regional evidence.

  19. Late Paleozoic vertical crustal growth of Western Junggar, Xinjiang in China: evidence from petrology and Nd isotope in charnockites and alkaline granites

    NASA Astrophysics Data System (ADS)

    Xian, W. S.; Sun, M.; Zhang, L. F.; Zhao, G. C.; Malpas, J.

    2003-04-01

    This abstract reports our new petrographic, mineralogical, geochemical and Nd isotope studies on the charnockites and alkaline granites in the western Junggar of Xinjiang, China. During the 1997 field excursion, we for the first time discovered charnockites in the Miaergou alkaline granite batholith, one of the six largest intrusive A-type bodies in the western Junggar of Xinjiang, Northwest China. The batholith is located in the southwestern part of the East-Central Asian Orogenic Belt, which is characterized by the presence of voluminous Paleozoic to Mesozoic granitoids with positive ɛNd(t) values. In spatial distribution, the batholith occurs as a ring-like igneous complex, which intrudes the early-Carboniferous volcanic sedimentary rocks of low-grade metamorphism. It is mainly composed of charnockite, quartz diorite, alkaline granite, potash feldspar granite, syenite and rare tourmaline-bearing intermediate-mafic dykes. Charnockites occur only within the diorite. A large amount of gabbroic, dioritic and leucogranitic enclaves are found in a zone between the alkaline granite and diorite. Petrographic and mineralogical studies indicate that the charnockites were derived from partial melting of the lower crust and crystallized under P-T conditions of 5.44˜5.63 ± 1.0 kbar and 700˜800^oC. Zircons from a charnockite sample and an alkaline granite sample yielded concordant U-Pb TIMS ages of 305.3 ± 1. 1 Ma and 274.1 ± 2.9 Ma, respectively, interpreted as the age of the emplacement of the charnockites and alkaline granites. Two-pyroxene granulites, biotite-spinel-cordierite gneisses and sillimanlite-biotite gneisses occur as enclaves within the charnockites. The two-pyroxene granulite enclaves are considered to be restites of partial melting of the previous lower crust at ˜845^oC, whereas the xenoliths of biotite-spinel-cordierite and sillimanlite-biotite gneisses were metamorphosed at low-pressure amphibolite- to granulite-facies, which were related to the

  20. Inclusion of glacier processes for distributed hydrological modeling at basin scale with application to a watershed in Tianshan Mountains, northwest China

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Arnold, Jeff; Liu, Shiyin; Wang, Xiuying; Chen, Xi

    2013-01-01

    SummaryIn this paper we proposed: (1) an algorithm of glacier melt, sublimation/evaporation, accumulation, mass balance and retreat; (2) a dynamic Hydrological Response Unit approach for incorporating the algorithm into the Soil and Water Assessment Tool (SWAT) model; and (3) simulated the transient glacier retreat and its impacts on streamflow at basin scale. Application of the enhanced SWAT model in the Manas River Basin (MRB) in the Tianshan Mountains in northwest China, shows that the approach is viable as evidenced by a Nash-Sutcliff efficiency of 0.65 and a percent bias of -3.7% for daily streamflow and water balance, respectively. The results indicate that the glacier area decreased by 11% during the simulation period from 1961 to 1999, which is within the range of records from other glaciers. On average, glacier melt contributed 25% to streamflow, although glacier area accounts for only 14% of the catchment drainage area in the MRB. Glacier melt was positively correlated to temperature change (R2 = 0.70, statistical significance P < 0.001) and negatively correlated to precipitation (R2 = 0.20, statistical significance P < 0.005). The results indicate that glacier melt was more sensitive to temperature change than to precipitation change, implying that modeling the effects of climate change with increasing temperatures and decreasing precipitation should be further studied.

  1. Soil erosion rates in two karst peak-cluster depression basins of northwest Guangxi, China: Comparison of the RUSLE model with 137Cs measurements

    NASA Astrophysics Data System (ADS)

    Feng, Teng; Chen, Hongsong; Polyakov, Viktor O.; Wang, Kelin; Zhang, Xinbao; Zhang, Wei

    2016-01-01

    Reliable estimation of erosion in karst areas is difficult because of the heterogeneous nature of infiltration and sub-surface drainage. Understanding the processes involved is a key requirement for managing against karst rock desertification. This study used the revised Universal Soil Loss Equation (RUSLE) to estimate the annual soil erosion rates on hillslopes and compared them with 137Cs budget in the depressions at two typical karst peak-cluster depression basins in northwest Guangxi, southwestern China. Runoff plots data were used to calibrate the slope length factor (L) of the RUSLE model by adjusting the accumulated area threshold. The RUSLE model was sensitive to the value of the threshold and required DEMs with 1 m resolution, due to the discontinuous nature of the overland flow. The average annual soil erosion rates on hillslopes simulated by the RUSLE were 0.22 and 0.10 Mg ha- 1 y- 1 during 2006 through 2011 in the partially cultivated GZ1 and the undisturbed GZ2 basins, respectively. The corresponding deposition rates in the depressions agreed well with the 137Cs records when recent changes in precipitation and land use were taken into consideration. The study suggests that attention should be given to the RUSLE-L factor when applying the RUSLE on karst hillslopes because of the discontinuous nature of runoff and significant underground seepage during storm events that effectively reduces the effects of slope length.

  2. Estimation of water consumption for ecosystems based on Vegetation Interfaces Processes Model: A case study of the Aksu River Basin, Northwest China.

    PubMed

    Yang, Peng; Xia, Jun; Zhan, Chesheng; Mo, Xingguo; Chen, Xuejuan; Hu, Shi; Chen, Jie

    2017-09-12

    Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) - Normalized Difference Vegetation Index (NDVI), the Vegetation Interfaces Processes (VIP) model simulated the spatio-temporal patterns of actual evapotranspiration (ET) and the water consumption of different ecosystems in the Aksu River Basin, Northwest China between 2000 and 2015. The results revealed that: (1) the applicability of the VIP model was confirmed, with good agreement (R(2)=0.79, P<0.05) between the VIP-ET and water balance model (WB)-ET in the Aksu River Basin; (2)arable land showed the highest annual actual ET per unit pixel (362.4mm/pixel), followed by forest (159.6mm/pixel), and grass land (142.8mm/pixel); (3) water consumption for arable, forest, and grass land were determined as 19.45×10(8), 1.94×10(8), and 28×10(8)m(3)/a, respectively; and (4) there was a significant trend (P<0.05) of increasing water consumption of 0.379×10(8)m(3)/a in the artificial ecosystem, but there was no significant trend in the time series of the natural ecosystem. Overall, the study demonstrated that the VIP model is able to supply important information for water resource management at the catchment-scale. Copyright © 2017. Published by Elsevier B.V.

  3. The land use change characteristics and its driving force analysis of Shiyang river basin in northwest China

    NASA Astrophysics Data System (ADS)

    Han, Tao; Xie, Yaowen; Jiang, Youyan

    2015-12-01

    In the paper, the use of 1994 and 2005 Landsat TM data monitors the land use and changes of the Shiyang river basin with remote sensing classification comparison under the support of GIS. The result shows that from 1994 to 2005, the area of farmland and settlement land increased greatly and that of grass and forest reduces obviously in this basin; Minqin which is in the lower reaches of Shiyang river basin has a serious desertification with low grass coverage degradation into desert. With a comprehensive analysis about the driving factors of nature and human, population pressure and irrational use of water resource are the key factors of the Land use change and between the natural factor and human factor, human acts leading role.

  4. Effects of groundwater lateral flow on land surface processes: a case study in Heihe River Basin, north-west of China

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Zeng, Y.; Yu, Y.

    2015-12-01

    As an important component of hydrologic cycle, groundwater is affected by topography, vegetation, climate condition, and anthropogenic activity. Groundwater horizontal convergence and divergence and vertical interaction with soil water result in variations of soil moisture, water and energy exchanges between the land surface and the atmosphere, which ultimately influences climate. In this work, a two-dimensional groundwater lateral flow scheme based on groundwater mass equation, is developed and incorporated into the land surface model CLM4.5 to investigate effects of groundwater lateral flow on land surface processes in a river basin. A 30-year simulation with groundwater lateral flow and a control run without the horizontal movement are conducted over Heihe River Basin, north-west China, from 1979 to 2012 using the developed model. Results show that with groundwater lateral flow, equilibrium distribution of groundwater table shows more spatial variability following topography rather than the water balance between local precipitation and evapotranspiration, and are much closer to well observations especially over middle reaches area. Along with shallower groundwater table over piedmont areas in the middle reaches, increased soil moisture is shown which alleviates the underestimation of CLM4.5 at here. Changes in evapotranspiration are occurred and it is mainly controlled by the variation of local surface soil moisture, since water is the major limitation factor of evapotranspiration over this arid area. Besides, groundwater lateral flow can change the distribution of surface runoff by changing the saturated area fraction of each model grid cell. Energy cycle also responds to the changes of hydrological cycle which redistributes the sensible heat flux and latent heat flux in the entire basin.

  5. [Ecology-economy harmonious development based on the ecological services value change in Yanqi Basin, Northwest China].

    PubMed

    Mamat, Zulpiya; Halik, Umut; Aji, Rouzi; Nurmemet, Ilyas; Anwar, Mirigul; Keyimu, Maierdang

    2015-03-01

    In this paper, we used land use/cover ecosystem service value estimation model and ecological economic coordination degree model to analyze the changes of the ecosystem service value by the land use/cover changes during 1985, 1990, 1996, 2000, 2005 and 2011 in Yanqi Basin, Xin-jiang. Then we evaluated the ecology-economy harmony and the regional differences. The results showed that during 1985-2011, there was an increasing trend in the areas of waters, wetland, sand, cultivated land and construction land in Yanqi Basin. In contrast, that of the saline-alkali land, grassland and woodland areas exhibited a decreasing trend. The ecosystem service value in Yanqi Basin during this period presented an increasing trend, among which the waters and cultivated land contributed most to the total value of ecosystem services, while the grassland and the woodland had obviously declined contribution to the total value of ecosystem services. The research showed that the development of ecological economy in the study area was at a low conflict and low coordination level. So, taking reasonable and effective use of the regional waters and soil resources is the key element to maintain the ecosystem service function and sustainable and harmonious development of economy in Yanqi Basin.

  6. Slope-apron deposition in an ordovician arc-related setting: The Vuelta de Las Tolas Member (Suri Formation), Famatina Basin, northwest Argentina

    USGS Publications Warehouse

    Mangano, M.G.; Buatois, L.A.

    1997-01-01

    The Ordovician Suri Formation is part of the infill of the Famatina Basin of northwest Argentina, which formed in an active setting along the western margin of early Paleozoic Gondwana. The lower part of this formation, the Vuelta de Las Tolas Member, records sedimentation on a slope apron formed in an intra-arc basin situated on a flooded continental arc platform. The coincidence of a thick Arenig-Llanvirn sedimentary succession and volcanic-plutonic arc rocks suggests an extensional or transtensional arc setting, and is consistent with evidence of an extensional regime within the volcanic arc in the northern Puna region. The studied stratigraphic sections consist of volcanic rocks and six sedimentary facies. The facies can be clustered into four facies associations. Association 1, composed of facies A (laminated siltstones and mudstones) and B (massive mudstones and siltstones), is interpreted to have accumulated from silty-muddy high-and low-density turbidity currents and highly fluid, silty debris flows, with subsequent reworking by bottom currents, and to a lesser extent, hemipelagic suspension in an open-slope setting. Facies association 2 is dominated by facies C (current-rippled siltstones) strata. These deposits are interpreted to record overbank sedimentation from fine-grained turbidity currents. Facies E (matrix-supported volcanic breccias) interbedded with andesitic lava units comprises facies association 3. Deposition was contemporaneous with subaqueous volcanic activity, and accumulated from cohesive debris flows in a coarse-grained wedge at the base of slope. Facies association 4 is typified by facies D (vitric fine-grained sandstones and siltstones) and F (channelized and graded volcanic conglomerates and breccias) deposits. These strata commonly display thinning-and fining-upward trends, indicating sedimentation from highly-concentrated volcaniclastic turbidity currents in a channelized system. The general characteristics of these deposits of fresh

  7. Geology and coal resources of Zonguldak basin (Northwest Turkey) as a potential source for coal bed methane

    SciTech Connect

    Yalcin, M.N. )

    1991-03-01

    The Carboniferous clastic sequence of Zonguldak basin contains several coal seams that have been mined since 1848 by underground methods. Coal seams are located in a Namurian to Westfalian D progradational delta and fluid plain sequence that is approximately 3,500 m thick. These units are affected by Hercynian orogenic movements. Related tectonism and uplift led to a widespread erosion. Consequently, younger units, mainly Cretaceous shallow-marine carbonates, rest unconformably on different sections of the Carboniferous strata. There exist up to 8 coal seams in Namurian, 20 to 26 in Westfalian A, and up to 8 coal seams in Westfalian B, C, and D. The average combined thickness values are 8 m, 34 m, and 7 m, respectively. However, due to the lateral changes in seam thickness and due to the erosion, both the number and combined thickness of coal seams may change remarkably. Majority of the coals in the exploitation area are of highly volatile C to A bituminous rank. Vitrinite reflectance values range from 0.6 to 1.2% (R{sub 0} mean). Methane content of some coal seams is determined by desorption data which indicate a methane content of 5 to 16 m{sup 3} per ton of coal. In addition to classical methods, data from some deep wells have been used to determine the thermal history by the method of basin modeling. Amount of gas generated in coals is then computed with the help of a kinetic approach. Furthermore, timing of gas generation has also been determined, which enabled consideration of migrational and diffusional gas losses. Data from coal geology, geochemistry, and modeling are combined to evaluate the coal bed methane potential of the basin in an integrated and quantitative manner.

  8. Evaluation of ecosystem services: A case study in the middle reach of the Heihe River Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Li, Hongji; Li, Zhihui; Li, Zhaohua; Yu, Jing; Liu, Bing

    Ecosystem services evaluation aims at understanding the status of ecosystem services on different spatial and temporal scale. In this paper, we selected the middle reach of the Heihe River Basin (HRB), which is the second largest inland river basin in China, as one of the typical area to estimate the ecosystem services values (ESVs) corresponding to the land use changes. Based on the land use data and ecosystem service value coefficients, the total ecosystem services values (TESVs) of the middle reach of the HBR are quantitatively calculated, which were 9.244 × 108, 9.099 × 108, 9.131 × 108 and 9.146 × 108 USD in 1988, 2000, 2005 and 2008 respectively. During 1988-2008, the decrease of grassland, forest land, water area and unused land contributed 148.94%, 57.85%, 87.87% and 16.42% respectively to the net loss of TESVs, while the dramatic increase of cultivated land improved the TESVs with contribution of -211.08% to the net loss of TESVs. Expansion of cultivated land, which especially caused the loss of grassland and forest land, directly exerted negative impacts on the provision of ecosystem services in the study area. The findings of this research indicated that land use change was an important form of human activities, which had a strong impact on ecosystem services.

  9. Ichnological constraints on the depositional environment of the Sawahlunto Formation, Kandi, northwest Ombilin Basin, west Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Zonneveld, J.-P.; Zaim, Y.; Rizal, Y.; Ciochon, R. L.; Bettis, E. A.; Aswan; Gunnell, G. F.

    2012-02-01

    A low diversity trace fossil assemblage is described from the Oligocene Sawahlunto Formation near Kandi, in the northwestern part of the Ombilin Basin in western Sumatra, Indonesia. This trace fossil assemblage includes six ichnogenera attributed to invertebrate infaunal and epifaunal activities ( Arenicolites, Diplocraterion, Planolites, Monocraterion/ Skolithos and Coenobichnus) and two ichnotaxa attributed to vertebrate activity (avian footprints: two species of Aquatilavipes). Arenicolites, Diplocraterion and Monocraterion/ Skolithos record the suspension feeding activities of either arthropods (most likely amphipods) or vermiform organisms. Planolites reflects the presence of an infaunal deposit feeder. Coenobichnus records the walking activities of hermit crabs. Both the Coenobichnus and the avian footprints record the surficial detritus scavenging of epifaunal organisms within a subaerial setting. These traces occur within a fine-grained sandstone succession characterized by planar laminae and low-relief, asymmetrical, commonly mud-draped (locally bidirectional) ripples. The presence of traces attributable to suspension feeders implies deposition in a subaqueous setting. Their occurrence (particularly the presence of Arenicolites and Diplocraterion) in a sandstone bed characterized by mud-draped and bidirectional ripples implies emplacement in a tidally-influenced marine to marginal marine setting. Co-occurrence of these traces with well-preserved avian footprints ( Aquatilavipes) further implies periodic subaerial exposure. Thus, it is most likely that the Sawahlunto Formation near Kandi records deposition within an intertidal flat setting. Definitive evidence of marine influences in the Oligocene interval of the Ombilin Basin implies a more complex tectono-stratigraphic history than has previously been implied.

  10. Temporal variations of CO2 concentration near land surface and its response to meteorological variables in Heihe River Basin, northwest China.

    PubMed

    Chen, Ren-sheng; Kang, Er-si; Ji, Xi-bin; Yang, Jian-ping; Zhang, Zhi-hui; Yang, Yong

    2006-01-01

    Atmospheric CO2 concentration (CC) near land surface and meteorological variables have been measured at four sites, named Yeniugou (alpine meadow and permafrost), Xishui (mountainous forest), Linze (oasis edge) and Ejina (lower desert), respectively, in Heihe River Basin, northwest China. The results showed that, the half hourly CC at night was larger than in daytime, and the daily averaged CC was the largest in winter. The averaged CC of 932 d at the Linze was about 418 ppm, was about 366 ppm in the 762 d at the Ejina. In the same period from September 23 to November 9, 2004, the averaged CC was about 625, 334, 436 and 353 ppm, at Yeniugou, Xishui, Linze and Ejina, respectively. The linear relationship between daily averaged CC and air temperature T was negative, between CC and relative humidity (RH) was positive. The linear CC-atmospheric pressure (AP) relationship was negative at the Linze and Yeniugou, was positive at the Ejina. The relationship between CC and global radiation R was exponent, and soil temperature Ts was negative linear, and soil water content was complex. The correlation between CC and wind speed was not existent. Using meteorological variables together to simulate CC, could give good results.

  11. Cyclic sedimentation, depositional environments, and facies distribution of the Permian Paddock member of the Yeso Formation, Vacuum (Glorieta) field, northwest shelf of the Permian basin

    SciTech Connect

    Burnham, D.E. ); Womochel, D.R. )

    1992-04-01

    The Vacuum (Glorieta) field is located on the northwest shelf of the Permian basin in central Lea County, New Mexico. Cumulative oil production of 62 MMBO is primarily from the upper 100 ft of the Leonardian Paddock Member of the Yeso Formation. Cores from 10 wells were examined to identify lithologies and facies relationships. Five lithofacies were identified: (1) fine-grained quartz sandstone/siltstone facies, (2) pelletoid mudstone facies, (3) skeletal packstone/wackestone facies, (4) oolitic-pelletoid grainstone facies, and (5) crystalline dolomite facies. These lithofacies occur sequentially in four shoaling-upward cycles that can be correlated throughout much of the study area. Three major depositional environments are recognized in the Paddock Member of the Yeso Formation: (1) a subtidal open-marine environment in which the oolitic grainstone facies was deposited, (2) a subtidal protected shallow-marine environment where the skeletal packstone/wackestone facies was deposited, and (3) a subtidal to supratidal restricted shallow-marine environment where the pelletoid mudstone facies accumulated. Facies analysis indicates that the Paddock Member was deposited on a broad shallow-marine shelf. Numerous shoaling-upward cycles are possibly related to worldwide Permian sea level fluctuations. Porosity development is enhanced at the upper surface of each shoaling-upward cycle by dissolution of fossil fragments and grains.

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

    NASA Astrophysics Data System (ADS)

    Collins, Dylan R.

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

  13. Rates of landscape change in discontinuous permafrost terrain inferred from Goose Lake sediments, Scotty Creek Basin, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Cockburn, J.; Baltzer, J.; Quinton, W. L.

    2012-12-01

    Changes to the Taiga Plain regions of the world due to recent permafrost thaw and a general warming trend has significant impacts on hydrology, ecology and carbon sequestration in these regions. Furthermore, the rates of these changes may prove to be positive feedbacks within the cryosphere. The recent sedimentary record from Goose Lake, NWT (61° 18' N, 121° 18' W) reveals changes in lake and adjacent landscape productivity, likely coincident with degrading permafrost through the late Holocene and noticeable shifts within the last half of the 20th century. Using short-cores retrieved in August 2012, this study presents preliminary models of late Holocene landscape changes. Shifts in the rates of change are due to recent thaw as evidenced by the sedimentary record and supported through process work completed in the region. Goose Lake is situated in the Taiga Plains, approximately 50 km south of Fort Simpson, in the lower Liard River basin. This small, lake (~2.5 m deep, 200 ha) in the Scotty Creek watershed headwaters is primarily fed through small fens. The Scotty Creek basin has had over a decade of permafrost and peatland hydrological monitoring (i.e., Quinton et al., 2009). As well, the Scotty Creek basin is the location of ongoing peatland ecological and hydrological monitoring programs. The monitoring work suggests that there is a cycle of bog - fen - plateau (ice-rich) landscape changes and that perhaps the rate of these cycles may be increasing as permafrost degradation increases. The lake sediment work aims to estimate the rates of these cycles through the late Holocene and potentially link to larger scale models of change within the Taiga Plains. A shift in cycling would have substantial impacts on carbon storage, ecosystem diversity and potentially change the overall hydrology of this peatland area. If Goose Lake is indicative of other small lakes in the Taiga Plains, combined with the hydrological and ecological observations, this system will be a

  14. Groundwater quality and its suitability for drinking and agricultural use in the Yanqi Basin of Xinjiang Province, Northwest China.

    PubMed

    Wang, Shuixian

    2013-09-01

    The Yanqi Basin in Xinjiang Province is an important agricultural area with a high population density. The extensive agricultural activities in the Yanqi Basin started in the 1950s with flood irrigation techniques. Since then, the groundwater table was raised because of the absence of an efficient drainage system. This obstacle is a crucial factor that restricts sustainable socioeconomic development. Hydrochemical investigations were conducted in the Yanqi Basin, Northwestern China, to determine the chemical composition of groundwater. Sixty groundwater samples were collected from different wells to monitor the water chemistry of various ions. The results of the chemical analysis indicate that the groundwater in the area is generally neutral to slightly alkaline and predominantly contains Na(+) and Ca(2+) cations as well as HCO3(-) and SO4 (2+) anions. High positive correlations between HCO3 (-)-Mg(2+) + Ca(2+), SO 4 (2-)-Mg(2+), SO4 (2-)-Na(+) + K(+), and Cl(-)-Na(+) + K(+) were obtained. The total dissolved solids (TDS) mainly depend on the concentration of major ions such as HCO3(-), SO4 (2-), Cl(-), Ca(2+), Mg(2+), and Na(+) + K(+). The dominant hydrochemical facies for groundwater are Ca(2+)-Mg(2+)-HCO3(-), Mg(2+)-Ca(2+)-SO4 (2-)-Cl(-), Na(+)-K(+)-Cl(-)-SO4 (2-), and Na(+)-K(+)-Mg(2+)-Cl(-)-HCO3(-) types. The hydrochemical processes are the main factors that determine the water quality of the groundwater system. These processes include silicate mineral weathering, dissolution, ion exchange, and, to a lesser extent, evaporation, which seem to be more pronounced downgradient of the flow system. The saturation index (SI), which is calculated according to the ionic ratio plot, indicates that the gypsum-halite dissolution reactions occur during a certain degree of rock weathering. SI also indicates that evaporation is the dominant factor that determines the major ionic composition in the study area. The assessment results of the water samples using various methods

  15. Geochemical and stable isotope indicators of paleoenvironmental and climatic conditions from Cenozoic dolocretes in the Hamersley Basin of northwest Australia

    NASA Astrophysics Data System (ADS)

    Mather, Caroline; Skrzypek, Grzegorz; Dogramaci, Shawan; Grierson, Pauline

    2017-04-01

    Extensive shallow groundwater carbonate deposits composed of dolomite (dolocretes) are ubiquitous within the semi-arid Hamersley Basin of NW Australia. However, dolomite is relatively rare within surficial terrestrial carbonate deposits as precipitation is strongly controlled by reaction kinetics and is inhibited at surface temperatures and pressures. The presence of dolomite within the Hamersley Basin carbonate deposits indicates that specific hydrochemical conditions occurred to overcome kinetic barriers to precipitation, namely elevated Mg/Ca and high salinity and alkalinity. We investigated the sedimentology, geochemistry and stable isotope compositions of dolocrete and groundwater chemistry from several locations in the Hamersley Basin to better understand dolocrete formation processes and produce a multi-proxy archive of the paleoenvironmental conditions. Petrographic and mineralogical analysis is consistent with channel dolocrete formation where dolomite has largely replaced host channel sediments. Authigenic palygorskite was also present in all samples, indicative of the Mg-rich environment. Modelling of the δ18O of paleogroundwater from oxygen isotope compositions of carbonates revealed dolomite precipitated from groundwater with considerably higher δ18O (median = -2.0‰) values compared to modern alluvial groundwater (-8.02 ± 0.83‰). As groundwater δ18O values are strongly correlated (R2=0.93) with salinity, this finding suggests that dolocrete formed from highly saline groundwaters and in an arid climate that prevailed for sufficient time to form dolocrete bodies of tens of metres thick. This ancient dolocrete formation can be constrained by host sediments ages to forming since the mid-late Miocene. In contrast, modern alluvial groundwater is relatively fresh and unlikely to precipitate dolomite. A further indication of a more recent (likely Holocene) shift to fresher waters is the dedolomitization and precipitation of calcite within shallow

  16. The Crustal Deformation Revealed by GPS and InSAR in the Northwest Corner of the Tarim Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Qiao, Xuejun; Yu, Pengfei; Nie, Zhaosheng; Li, Jie; Wang, Xiaoqiang; Kuzikov, Sergey I.; Wang, Qi; Yang, Shaomin

    2017-03-01

    The Northwestern Corner of the Tarim Basin (hereinafter the NOCTB) is surrounded by the Pamir salient, the south Tian Shan Mountains, and the Tarim Basin. The tectonic settings of these three structures dominate the crustal deformation patterns and seismic events in the NOCTB and its adjacent regions. We integrated the GPS and InSAR measurements to derive a large-scale three-dimensional velocity map of the NOCTB. The GPS data obtained during 38 campaigns between 1992 and 2013 were used to derive a horizontal velocity field. 149 Envisat ASAR images observed along four satellite tracks between 2003 and 2011 were processed to get a line of sight rate map based on the small baseline subset time series analysis method and a homogeneous isotropic model. Finally, we modeled the dip angle, slip rate, and locking depth of selected faults. The results indicate that the crustal convergence is not uniformly distributed across the NOCTB: more than 50% of the N-S shortening is absorbed by the Tian Shan Mountains in the southwest, whereas the N-S shortening rates are low and therefore the strain accommodations are smaller in the east of the NOCTB. The vertical displacement rates in the NOCTB range from -2 to 3 mm/year with different magnitudes in different areas. The main uplift areas are located on the junction region between frontal MPT and the southwestern STT including the Kazkeaerte fault, Aikenerte fault, the Southern Artux fault, and part areas in north of the Kalping fault. The main subsident areas are located on central belt of STT including the Totgumbaz-Alpaleh fault, Nothern Artux fault, the southwestern Karatieke fault, and the north of Puchang/Piqiang fault. Compared with the substantial N-S shortening rate of 10 mm/year, the vertical rate across each fault ranges from approximately -1 to 1 mm/year, suggesting that vertical movement in NOCTB area is relatively moderate at present. Both the horizontal and vertical rates show obvious changes across the Kazkeaerte

  17. The depositional setting of the Late Quaternary sedimentary fill in southern Bannu basin, Northwest Himalayan fold and thrust belt, Pakistan.

    PubMed

    Farid, Asam; Khalid, Perveiz; Jadoon, Khan Zaib; Jouini, Mohammed Soufiane

    2014-10-01

    Geostatistical variogram and inversion techniques combined with modern visualization tools have made it possible to re-model one-dimensional electrical resistivity data into two-dimensional (2D) models of the near subsurface. The resultant models are capable of extending the original interpretation of the data to depict alluvium layers as individual lithological units within the 2D space. By tuning the variogram parameters used in this approach, it is then possible to visualize individual lithofacies and geomorphological features for these lithologic units. The study re-examines an electrical resistivity dataset collected as part of a groundwater study in an area of the Bannu basin in Pakistan. Additional lithological logs from boreholes throughout the area have been combined with the existing resistivity data for calibration. Tectonic activity during the Himalayan orogeny uplifted and generated significant faulting in the rocks resulting in the formation of a depression which subsequently has been filled with clay-silt and dirty sand facies typical of lacustrine and flood plain environments. Streams arising from adjacent mountains have reworked these facies which have been eroded and replaced by gravel-sand facies along channels. It is concluded that the sediments have been deposited as prograding fan shaped bodies, flood plain, and lacustrine deposits. Clay-silt facies mark the locations of paleo depressions or lake environments, which have changed position over time due to local tectonic activity and sedimentation. The Lakki plain alluvial system has thus formed as a result of local tectonic activity with fluvial erosion and deposition characterized by coarse sediments with high electrical resistivities near the mountain ranges and fine sediments with medium to low electrical resistivities towards the basin center.

  18. Responses of shelterbelt stand transpiration to drought and groundwater variations in an arid inland river basin of Northwest China

    NASA Astrophysics Data System (ADS)

    Shen, Qin; Gao, Guangyao; Fu, Bojie; Lü, Yihe

    2015-12-01

    Plant water use characteristics and transpiration responses under dry conditions are considered essential for effective and sustainable ecosystem management in arid areas. This study was conducted to evaluate the response of shelterbelt stand transpiration to precipitation, soil drought and groundwater variations in an oasis-desert ecotone in the middle of the Heihe River Basin, China. Sap flow was measured in eight Gansu Poplar trees (Populus Gansuensis) with different diameter at breast height over three consecutive growing seasons (2012-2014). The groundwater evapotranspiration via plant use was estimated by the White method with diurnal water table fluctuations. The results showed that precipitation increased the stand transpiration but not statistically significant (paired t-test, p > 0.05). The recharge of soil water by irrigation caused stand transpiration acceleration significantly (t-test, p < 0.05). Stand transpiration and canopy conductance increased by 27% and 31%, respectively, when soil water conditions changed from dry to wet. Canopy conductance decreased logarithmically with vapor pressure deficit, while there was no apparent relationship between canopy conductance and solar radiation. The sensitivity of canopy conductance to vapor pressure deficit decreased under dry soil conditions. Groundwater evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71), and these two variables had similar variability. During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelt, and might provide the basis for the development of water requirement schemes for shelterbelt growth in arid inland river basins.

  19. Granites in the Sawuer region of the west Junggar, Xinjiang Province, China: Geochronological and geochemical characteristics and their geodynamic significance

    NASA Astrophysics Data System (ADS)

    Zhou, Taofa; Yuan, Feng; Fan, Yu; Zhang, Dayu; Cooke, David; Zhao, Guochun

    2008-12-01

    The Sawuer region is located in the west Junggar, Jimunai County of Altay district and Hefeng County of Tacheng district, Xinjiang Autonomous Region, in northwest China. In the study area granitic intrusions are widespread and can be subdivided into I-type granites (Tasite pluton, Sentasi pluton, Wokensala pluton and Kaerjia pluton) and A-type (A 2) granites (Kuoyitasi pluton and Qiaqihai pluton). The I-type granites consist of granite, adamelite, granodiorite, and the A-type granites are mainly represented by alkali granite. SHRIMP U-Pb dating results indicate that the granites in Sawuer region were formed between 337 Ma and 290.7 Ma (late Carboniferous and early Permian), with the I-type granites being formed between 337 Ma and 302.6 Ma, and the A-type between 297.9 and 290.7 Ma. From the older to the youngest granites, their composition changes from calc-alkalic to high-K calc-alkalic, to alkali series, and from I-type to A-type, based on the characteristics of whole rock trace element and rare earth elements geochemistry. This compositional range is the result of a change in the geodynamic regime from compressional to tensional during the late Paleozoic. Strontium, Nd, Pb, O isotope systematics suggest that both the I-type and A-type granites in Sawuer were sourced from the mantle (DM), but with some crustal contamination for the Kuoyitasi pluton. The I-type granites were formed by equilibrium partial melting, while the A-type granites were formed mainly by fractional crystallization. Based on the Rb-Y + Nb and Nb-Y-Ce discrimination criteria by Eby [Eby G.N., 1992. Chemical subdivision of the A-type granitoids: Petrogenetic and tectonic implications. Geology 20, 641-644] and Pearce [Pearce J.A., 1996. Sources and settings of granitic rocks. Episodes 19, 120-125] and comparisons with granites in other regions of northern Xinjiang, the I-type granites were emplaced during a transition from compressional to extensional settings in a post-collision regime, whereas

  20. Temperature as a tracer to identify surface water-groundwater exchanges in the Heihe River Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Liu, J.; Yao, Y.; Liu, C.; Xiao, H.; Zheng, C.; Li, W.

    2013-12-01

    The Heihe River Basin (HRB) is the second largest inland river basin in the arid region of northwestern China. Under natural conditions, the Heihe River recharges to groundwater in the piedmont areas after coming out of the Qilian Mountains. In the front edge of the alluvial and fluvial fans in the middle HRB, groundwater discharges to the surface in the form of springs and then flows into the Heihe River and ends up at the terminal lakes in the lower HRB. The surface water-groundwater interactions are frequent and dynamic along the Heihe River, and the understanding of these interactions is essential for conjunctive use and management of water resources and is fundamental to ensuring ecosystem health of the HRB. Among the various methods used to study surface water-groundwater interactions, those based on temperature have some distinct advantages because of the obvious temperature differences between surface water and groundwater and also because of the simplicity and low cost of temperature measurement. Fiber-optic distributed temperature sensing (DTS) can measure temperature at very high spatial and temporal resolutions and has led to important insights into the processes of groundwater and surface water interactions. In this study, DTS was applied to measure high-resolution temperature variations in the river water with a 0.25 m spatial interval and a 15 minute temporal frequency in a total distance of 5 km along two sections of the Heihe River. A statistical approach was used to discern the spatial distribution and the size of groundwater discharge zones and hyporheic zones, respectively. The exchange flux was then estimated using 1-D hydrodynamic model, which calculates the inflow flux in the study area by comparing the simulated temperatures with the measured ones. In addition, temperature data, combined with more traditional hydrological data such as hydraulic heads and fluxes, can provide independent constraints for calibrating the coupled surface water

  1. Paleoenvironmental reconstruction based on palynofacies analyses of the Cansona Formation (Late Cretaceous), Sinú-San Jacinto Basin, northwest Colombia

    NASA Astrophysics Data System (ADS)

    Juliao-Lemus, Tatiana; Carvalho, Marcelo de Araujo; Torres, Diego; Plata, Angelo; Parra, Carlos

    2016-08-01

    To reconstruct the paleoenvironments of the Cansona Formation, a Cretaceous succession in Colombia that has controversial paleoenvironmental interpretation, occasionally deep marine and occasionally shallow marine, palynofacies analyses were conducted on 93 samples from four sections of the Sinú San Jacinto Basin in the north, midwest, and southwest sectors. For the palynofacies analyses, the kerogen categories were counted and subjected to cluster analyses. Four palynofacies associations were revealed for the four sections: Palynofacies Association I (PA I), which consisted of microforaminiferal linings, scolecodonts, dinoflagellate cysts, pollen grains, and fungi hyphae; PA II, which consisted of phytoclast translucent non-biostructured and biostructured, opaque phytoclasts (equidimensional and lath shaped); PA III, which consisted of pseudoamorphous particles, cuticles, resin, and fungal spores; and PA IV, which consisted of fluorescent and non-fluorescent amorphous organic matter and the fresh-water algae Botryococcus. In contrast to early studies that suggested a generalization of the depositional environment for the Cansona Formation (deep or shallow conditions), this study suggests that the formation reflects conspicuous stratigraphic and lateral changes and hence different depositional environments. The Cerro Cansona (CC4 section) and Chalán (AP section) areas are a more marine proximal settings (Early Campanian-Maastrichtian), and there is an intermediate setting for the Lorica area (SC section) and deeper conditions for the Montería area (CP2 section).

  2. Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin)

    NASA Astrophysics Data System (ADS)

    Plaza-Morlote, Maider; Rey, Daniel; Francisco Santos, Jose; Ribeiro, Sara; Heslop, David; Bernabeu, Ana M.; Mohamed, Kais J.; Rubio, Belen; Martins, Virginia

    2017-04-01

    The reconstruction of circum-Atlantic ice-sheet instabilities is of great importance to understanding the mechanisms that force abrupt climate changes. We have used enviromagnetic and geochemical data to explore these issues, providing a continuous and well-dated record of the evolution of glacial/interglacial sedimentation in the Galician Interior Basin (GIB) during the last glacial period covering the last six Heinrich Stadials. Our results show sediments of European provenance that have been related to meltwater pre-events during the initial stages of HS1, HS2, and HS4 corroborating the Channel River depositional history. Therefore, this study provides insight into one of the potential forcing mechanisms for Heinrich Events and, by inference, for Heinrich Stadials. The GIB records are an important element in the discussion of EIS-LIS-AMOC dynamics. Their significant distance from these ice-sheets is such that they have only recorded the most catastrophic ice shelves collapse events and/or meltwater discharges, acting as a low-amplitude filter to the interrelated dynamics and instabilities of the North Atlantic ice sheets. Our results demonstrate that European-sourced sediments arrived earlier at this site than Laurentide-sourced icebergs. This implies greater EIS freshwater discharges resulting from the deglacial activation of EIS palaeorivers for HS1 and from glacial instabilities during the course of the EIS' progression to its LGM position for HS2 and HS4. This supports the idea of synchronous collapse of the EIS and LIS. The data also suggest that these discharges acted as a positive feedback mechanism that further weakened the AMOC, accelerating LIS and EIS collapse.

  3. 3D Structural and Stratigraphic Architecture of the Northwest Santa Barbara Basin: Implications for Slope Stability and Submarine Landslide Occurrence

    NASA Astrophysics Data System (ADS)

    Wright, A.; Brothers, D. S.; Kluesner, J.; Johnson, S. Y.

    2016-12-01

    Multiple submarine landslides have been documented on the north flank of the Santa Barbara Basin and such failures are considered capable of generating local tsunami hazards to the Santa Barbara region. Past 2D seismic reflection data has provided a general view of the regional framework geology resulting from north-south compression, but fails to identify along-strike variations of faults and folds. This study uses industry 3D seismic reflection data encompassing the slope surrounding the 3.8 km2-Gaviota submarine landslide to investigate structural and stratigraphic controls of slope failure in this region. The 3D depth-migrated volume shows a complex network of faults that result in both broad and local zones of compression, folding, and uplift along the slope. One localized zone of enhanced anticlinal folding and uplift associated with small-scale thrust faults is located directly beneath the Gaviota slide, while another is beneath a seafloor fissure west of the slide inferred to represent incipient failure. New high-resolution 2D transects constrain the character of shallow deformation above the locally uplifted blocks. 3D isopach maps indicate the seafloor fissures trend along a key threshold of thickness between the seafloor and a shallow horizon; the fissures are also coincide with an apparent zone of shallow, gas-charged strata that onlap the steeply dipping flanks of local anticlinal deformation. Because the seafloor gradient near the Gaviota slide is significantly lower than the internal friction angle for fine-grained marine sediments, we propose that a combination of active deformation, sediment compaction, and gas charging acted to precondition the slope of the Gaviota landslide for failure by reducing the shear strength. Similar factors occur beneath intact sections of the slope adjacent to the slide, which should be considered prone to future landsliding.

  4. Cenomanian Turonian organic sedimentation in North-West Africa: A comparison between the Tarfaya (Morocco) and Senegal Basins

    NASA Astrophysics Data System (ADS)

    Nzoussi-Mbassani, P.; Khamli, N.; Disnar, J. R.; Laggoun-Défarge, F.; Boussafir, M.

    2005-06-01

    The Cenomanian-Turonian Oceanic Anoxic Event was recognised in North Western Africa in various depositional settings from abyssal areas to continental shelves. To derive information on environmental conditions in these different settings and define a depositional model, a petrographical and geochemical study of the organic matter was performed on sediments from the Tarfaya (Morocco) and Senegal Basins. The results obtained for these two locations were compared to those of previous studies, namely from DSDP wells. Petrographic and geochemical data allow the differentiation of two main organofacies: a shallow depositional facies (continental shelf) is characterised by low total organic carbon (TOC) contents (< 4%). As attested by low hydrogen index (HI) values (100 to 400 mg HC/g TOC), the organic matter (OM) is moderately preserved. Petrographically, this facies is composed of mixed OM with high proportions of reworked vitrinite indicating detrital material influence. The depositional environment is typical of dysoxic conditions (S/C < 0.36) exposed to high mineral inputs and oxygenated water currents. The second organofacies deposited in the deep marine environment (slope and abyssal) shows a high TOC content (> 7%). The predominance of fluorescing amorphous OM combined with high HI values suggests good preservation conditions. The S/C ratio (> 0.36) and abundance of organic-sulphur compounds support this interpretation and indicate a development of anoxic conditions. To explain the organic contrast between both environments a depositional model has been developed which is based on limited water exchange between both depositional settings. The main factor which has determined black shale sedimentation is the restricted water circulation related to the presence of isolated depositional environment during Atlantic Ocean opening. Compared to present upwelling zones, the palaeoproductivity in the studied area was relatively moderate during Cenomanian-Turonian and seems

  5. High-resolution precipitation data derived from dynamical downscaling using the WRF model for the Heihe River Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Zhang, Xuezhen; Xiong, Zhe; Zheng, Jingyun; Ge, Quansheng

    2017-01-01

    The community of climate change impact assessments and adaptations research needs regional high-resolution (spatial) meteorological data. This study produced two downscaled precipitation datasets with spatial resolutions of as high as 3 km by 3 km for the Heihe River Basin (HRB) from 2011 to 2014 using the Weather Research and Forecast (WRF) model nested with Final Analysis (FNL) from the National Center for Environmental Prediction (NCEP) and ERA-Interim from the European Centre for Medium-Range Weather Forecasts (ECMWF) (hereafter referred to as FNLexp and ERAexp, respectively). Both of the downscaling simulations generally reproduced the observed spatial patterns of precipitation. However, users should keep in mind that the two downscaled datasets are not exactly the same in terms of observations. In comparison to the remote sensing-based estimation, the FNLexp produced a bias of heavy precipitation centers. In comparison to the ground gauge-based measurements, for the warm season (May to September), the ERAexp produced more precipitation (root-mean-square error (RMSE) = 295.4 mm, across the 43 sites) and more heavy rainfall days, while the FNLexp produced less precipitation (RMSE = 115.6 mm) and less heavy rainfall days. Both the ERAexp and FNLexp produced considerably more precipitation for the cold season (October to April) with RMSE values of 119.5 and 32.2 mm, respectively, and more heavy precipitation days. Along with simulating a higher number of heavy precipitation days, both the FNLexp and ERAexp also simulated stronger extreme precipitation. Sensitivity experiments show that the bias of these simulations is much more sensitive to micro-physical parameterizations than to the spatial resolution of topography data. For the HRB, application of the WSM3 scheme may improve the performance of the WRF model.

  6. BASINS

    EPA Pesticide Factsheets

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.

  7. Soil carbon content and CO2 flux along a hydrologic gradient in a High-Arctic tundra lake basin, Northwest Greenland

    NASA Astrophysics Data System (ADS)

    McKnight, J.; Klein, E. S.; Welker, J. M.; Schaeffer, S. M.; Franklin, M.

    2015-12-01

    High Arctic landscapes are composed of watershed basins that vary in size and ecohydrology, but typically have a plant community complex that ranges from dry tundra to moist tundra to wet sedge systems along water body shorelines. The spatial extent of these plant communities reflects mean annual soil moisture and temperature, and is vulnerable to changes in climate conditions. Soil moisture and temperature significantly influence organic matter microbial activity and decomposition, and can affect the fate of soil carbon in tundra soils. Consequently, due to the unique soil carbon differences between tundra plant communities, shifts in their spatial extent may drive future High Arctic biosphere-atmosphere interactions. Understanding this terrestrial-atmosphere trace gas feedback, however, requires quantification of the rates and patterns of CO2 exchange along soil moisture gradients and the associated soil properties. In summer of 2015, soil CO2 flux rate, soil moisture and temperature were measured along a soil moisture gradient spanning three vegetation zones (dry tundra, wet tundra, and wet grassland) in a snow melt-fed lake basin near Thule Greenland. Mean soil temperature during the 2015 growing season was greater in dry tundra than in wet tundra and wet grassland (13.0 ± 1.2, 7.8 ± 0.8, and 5.5 ± 0.9°C, respectively). Mean volumetric soil moisture differed among all three vegetation zones where the soil moisture gradient ranged from 9 % (dry tundra) to 34 % (wet tundra) to 51 % (wet grassland). Mean soil CO2 flux was significantly greater in the wet grassland (1.7 ± 0.1 μmol m-2 s-1) compared to wet tundra (0.9 ± 0.2 μmol m-2 s-1) and dry tundra (1.2 ± 0.2 μmol m-2 s-1). Soil CO2 flux increased and decreased with seasonal warming and cooling of soil temperature. Although soil temperature was an important seasonal driver of soil CO2 flux rates, differences in mean seasonal soil CO2 flux rates among vegetation zones appeared to be a function of the

  8. Lower Eocene alluvial paleosols (Willwood Formation, Northwest Wyoming, U.S.A.) and their significance for paleoecology, paleoclimatology, and basin analysis

    USGS Publications Warehouse

    Bown, T.M.; Kraus, M.J.

    1981-01-01

    The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed. Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless. All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency

  9. Lower Eocene alluvial paleosols (Willwood Formation, Northwest Wyoming, U.S.A.) and their significance for paleoecology, paleoclimatology, and basin analysis

    USGS Publications Warehouse

    Bown, Thomas M.; Kraus, M.J.

    1981-01-01

    The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed.Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless.All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency of

  10. Morphologies and depositional/erosional controls on evolution of Pliocene-Pleistocene carbonate platforms: Northern Carnarvon Basin, Northwest Shelf of Australia

    NASA Astrophysics Data System (ADS)

    Goktas, P.; Austin, J. A.; Fulthorpe, C. S.; Gallagher, S. J.

    2016-08-01

    The detailed morphologies, evolution and termination of latest Neogene tropical carbonate platforms in the Northern Carnarvon Basin (NCB), on the passive margin of the Northwest Shelf (NWS) of Australia, defined based upon mapping using 3D seismic images, reveal the history of local/regional oceanographic processes, fluctuations in relative sea-level and changing climate. Cool-water carbonate deposition, dominant during the early-middle Miocene, was followed by a siliciclastic influx, which prograded across the NWS beginning in the late-middle Miocene, during a period of long-term global sea-level fall. The resulting prograding clinoform sets, interpreted as delta lobes, created relict topographic highs following Pliocene termination of the siliciclastic influx. These highs constituted multiple favorable shallow-water environments for subsequent photozoan carbonate production. Resultant platform carbonate development, in addition to being a response to cessation of siliciclastic influx and the existence of suitable shallow-water substrate, was also influenced by development of the warm-water Leeuwin Current (LC), flowing southwestward along this margin. Four flat-topped platforms are mapped; each platform top is a sequence boundary defined by reflection onlap above and truncation below. Successive platforms migrated southwestward through time, along margin strike. All platforms exhibit predominantly progradational seismic geometries. Mapped tops are ≥10 km wide. Seismic evidence of karst on three of four platform tops, e.g., v-shaped troughs up to 50 m deep and ~1 km wide, and broader basins with areas up to 20 km2, suggests episodic subaerial exposure that may have contributed to platform demise. Platform 4, the most recent, is unique in having interpreted biohermal build-ups superimposed on the progradational platform base. The base of these interpreted patch reefs now lies at a water depth of ~153 m; therefore, we suggest that these reefs developed post

  11. Assessments of carbon and water cycling in multiple agricultural ecosystems in the Inland Pacific Northwest using eddy covariance flux measurements and integrated basin-crop model simulation

    NASA Astrophysics Data System (ADS)

    Chi, J.; Maureira, F.; Waldo, S.; O'Keeffe, P.; Pressley, S. N.; Stockle, C. O.; Lamb, B. K.

    2014-12-01

    Local meteorology, crop management practices and site characteristics have important impacts on carbon and water cycling in agricultural ecosystems. This study focuses on carbon and water fluxes measured using eddy covariance (EC) methods and crop simulation models in the Inland Pacific Northwest (IPNW), in association with the Regional Approaches to Climate Change (REACCH) program. The agricultural ecosystem is currently challenged by higher pressure on water resources as a consequence of population growth and increasing exposure to impacts associated with different types of crop managements. In addition, future climate projections for this region show a likely increase in temperature and significant reductions in precipitation that will affect carbon and water dynamics. This new scenario requires an understanding of crop management by assessing efficient ways to face the impacts of climate change at the micrometeorological level, especially in regards to carbon and water flow. We focus on three different crop management sites. One site (LIND) under crop-fallow is situated in a low-rainfall area. The other two sites, one no-till site (CAF-NT) and one conventional tillage site (CAF-CT), are located in an area of high-rainfall with continuous cropping. In this study, we used CropSyst micro-basin model to simulate the responses in carbon and water budgets at each site. Based on the EC processed results for net ecosystem exchange (NEE) of CO2, the CAF-NT site was a carbon sink during 2013 when spring garbanzo was planted; while the paired CAF-CT site, under similar crop rotation and meteorological conditions, was a carbon source during the same period. The LIND site was also a carbon sink where winter wheat was growing during 2013. Model results for CAF-NT showed good agreement with the EC carbon and water flux measurements during 2013. Through comparisons between measurements and modeling results, both short and long term processes that influence carbon and water

  12. Microfacies and depositional environments of the Late Ordovician Lianglitage Formation at the Tazhong Uplift in the Tarim Basin of Northwest China

    NASA Astrophysics Data System (ADS)

    Gao, Da; Lin, Changsong; Yang, Haijun; Zuo, Fanfan; Cai, Zhenzhong; Zhang, Lijuan; Liu, Jingyan; Li, Hong

    2014-04-01

    The Late Ordovician Lianglitage Formation comprises 13 microfacies (Mf1-Mf13) that were deposited on a carbonate platform at the Tazhong Uplift of the Tarim Basin in Northwest China. Each type of microfacies indicates a specific depositional environment with a certain level of wave energy. Four primary groups of microfacies associations (MA1-MA4) were determined. These associations represent different depositional facies, including reef-shoal facies in the platform margin (MA1), carbonate sand shoal facies (MA2) and oncoid shoal (MA3) on open platforms, and lagoon and tidal flat facies (MA4) in the platform interior. Each microfacies association was generated in a fourth-order sedimentary sequence developing within third-order sequences (SQ1, SQ2, and SQ3, from bottom to top), showing a shallowing-upward trend. High-frequency sequences and facies correlation between wells suggests that the reef-shoal facies more successively developed in the southeastern part of the platform margin, and high-energy microfacies were more strictly confined by the top boundary of fourth-order sequences in the northwestern part of the platform. The highstand systems tract (HST) of the SQ2 is characterized by reef-shoals that developed along the platform margin and tidal flats and lagoons that developed in the platform interior, while the SQ3 is characterized by the oncoid shoal facies that generally developed on the uplift due to a regionally extensive transgression that occurred during the latter part of the Late Ordovician. The results of this study can be used for investigating the development and distribution of potential reservoirs; the reservoirs in southeastern part of the platform margin may be of premium quality because the high-energy microfacies were best preserved there.

  13. Tectonically controlled relief evolution in the Northern Tien Shan and Junggar Alatau from the Eocene to the Present

    NASA Astrophysics Data System (ADS)

    Seib, N.; Kley, J.; Voigt, T.; Kober, M.

    2012-04-01

    The Cenozoic Tien Shan and Junggar Alatau mountains developed on the southern part of the Paleozoic Altaid orogen as a far-field effect of the collision of the Indian and Eurasian plates. Highland terrain, active seismicity, and fast GPS-derived motions are evidence of rapid ongoing mountain growth today. Variations in relief energy, hight-to-width ratio of ranges and apatite fission track (AFT) exhumation ages suggest they rose at different times. The strong dissection of the higher ridges (heights of up to 2km), indicates an earlier onset and higher rates of uplift. At the other end of the spectrum are low, little dissected ridges. According to AFT ages, exhumation in the Junggar Range began at 9 Ma (Jolivet et al., 2010), circa 11 Ma in the central Kyrgyz Range (Sobel et al., 2006) and 10 Ma in the Terskey Alatau. An AFT age of the low Sogety range is 77 Ma, suggesting that the Cenozic exhumation of the ridge was insufficient to expose rocks from below c.3 km depth. The synclinal lows between the basement highs preserve Cenozoic strata of Eocene to Quaternary age, probably deposited in a once continuous basin (the Ili Basin) and recording the entire history of Tien Shan uplift. Facies pattern of proximal alluvial fans are strictly related to the recent higher mountain areas in the north and in the south. During Middle Miocene, a large lake developed in the basin center. Up to the Middle Miocene sedimentation was accompanied by normal faulting of small magnitude. The main Cenozoic folding and thrusting occurred after that time and before deposition of the Chorgos formation. Shortening was accommodated by reactivation of inherited basement structures, by a switch to reverse or strike-slip motion on normal faults, and the nucleation of new thrusts. The majority of faults which emplace basement rocks over upper Cenozoic sediments dip steeply at angles of 60-70˚, and some have throws of more than 200 m. They are marked by topographic steps and contrasting morphology

  14. The disastrous effects of salt dust deposition on cotton leaf photosynthesis and the cell physiological properties in the Ebinur Basin in Northwest China.

    PubMed

    Abuduwaili, Jilili; Zhaoyong, Zhang; Feng qing, Jiang; Dong wei, Liu

    2015-01-01

    Salt dust in rump lake areas in arid regions has long been considered an extreme stressor for both native plants and crops. In recent years, research on the harmful effects of salt dust on native plants has been published by many scholars, but the effect on crops has been little studied. In this work, in order to determine the impact of salt dust storms on cotton, we simulated salt dust exposure of cotton leaves in Ebinur Basin in Northwest China, and measured the particle sizes and salt ions in the dust, and the photosynthesis, the structure and the cell physiological properties of the cotton leaves. (1) Analysis found that the salt ions and particle sizes in the salt dust used in the experiments were consistent with the natural salt dust and modeled the salt dust deposition on cotton leaves in this region. (2) The main salt cations on the surface and inside the cotton leaves were Na+, Ca2+, Cl- and SO42-, while the amounts of CO3- and HCO3- were low. From the analysis, we can order the quantity of the salt cations and anions ions present on the surface and inside the cotton leaves as Na+>Ca2+>Mg2+>K+ and Cl->SO42->HCO3->CO3-, respectively. Furthermore, the five salt dust treatment groups in terms of the total salt ions on both the surface and inside the cotton leaves were A(500g.m-2)>B(400g.m-2)>C(300g.m-2)>D(200g.m-2)>E(100g.m-2)>F(0g.m-2). (3)The salt dust that landed on the surface of the cotton leaves can significantly influence the photosynthetic traits of Pn, PE, Ci, Ti, Gs, Tr, WUE, Ls, φ, Amax, k and Rady of the cotton leaves. (4)Salt dust can significantly damage the physiological functions of the cotton leaves, resulting in a decrease in leaf chlorophyll and carotenoid content, and increasing cytoplasmic membrane permeability and malondialdehyde (MDA) content by increasing the soluble sugar and proline to adjust for the loss of the cell cytosol. This increases the activity of antioxidant enzymes to eliminate harmful materials, such as the intracellular

  15. Investigations of illite and small scale fluid-rock interaction in Upper Carboniferous reservoir sandstones from the Lower Saxony Basin, Northwest Germany

    NASA Astrophysics Data System (ADS)

    Bock, Susanne; Zwingmann, Horst; Aehnelt, Michaela; Gaupp, Reinhard

    2013-04-01

    Illite is one of the most important minerals concerning the exploration of hydrocarbons. It is known, that illite reduces significantly porosity and permeability and deteriorates reservoir quality. Therefore the formation conditions are an issue of special interest. The Upper Carboniferous sandstones from the Lower Saxony Basin (LSB) show intense mechanical compaction and thus low porosity values (3-12 Vol.-%) and very low permeability values (0.001-0.1 mD). Petrographic observations indicate that fluid pathways must be hampered, but illite occurs in variable amounts. This study was intended to get a better understanding of the controlling factors of the illite formation in the LSB. This investigation, funded by the RWE Dea Germany, compares 18 samples of Upper Carboniferous sandstones (Westphalian C & D). These samples originate from three different study areas with varying burial histories within the Lower Saxony Basin (LSB), Northwest Germany. The southern margin offers a deep burial during Cretaceous with subsequent uplift/inversion. The center of the deepest burial is situated north of the southern margin and shows also a post-Cretaceous, but more intense uplift. Also the northern part with shallower burial depths was investigated. The locations have different initial thermal histories and resulting conditions for illite formation. Petrographic analyses revealed a consistent modal composition, which describes sublitharenitic sandstones. Most common authigenic phases are quartz, carbonate cements, and phyllosilicates like illite, kaolinite and locally chlorite. Several investigation methods were applied to detect differences between the illites from the locations. The age of last illite precipitation was determined by conventional K-Ar dating of clay fractions (< 2 µm). Using the burial history (known from literature) the illite age can be linked to the burial depth and related p-T conditions at this time. Additional vitrinite reflectance measurements provide

  16. U-Pb detrital zircon ages to determine the provenance signature of late Quaternary paleo-channel systems in the western Indo-Gangetic basin, northwest India

    NASA Astrophysics Data System (ADS)

    Singh, A.; Carter, A.; Gupta, S.; Sinha, R.; Murray, A. S.; Buylaert, J.; Thomsen, K.; Jain, M.; Paul, D.

    2011-12-01

    An extensive set of paleo-river channels are present in the shallow subsurface of the alluvial plains of the western Indo-Gangetic basin in northwest India as evidenced by the analysis of satellite imagery. There has been considerable interest in paleochannels in the doab between the present-day courses of the Sutlej and Yamuna rivers in particular because of the hypothesized relationship between the distribution of Harappan settlements and paleo-river courses. Specifically, the Ghaggar-Hakra paleo-channel has been the focus of attention because of the occurrence of archaeological Harappan sites along its course. Several studies link the end of the Harappan urban phase ~3500 BP to paleo-river drying or drainage diversion. However, no detailed scientific study has been done to establish the sub-surface stratigraphy and/or the provenance of alluvial sediments of the Ghaggar-Hakra paleo-channel. Some of the major questions are: (1) What is the provenance of the sediments that form the paleo-channels?; (2) Do they represent major Himalayan-sourced paleo-rivers or smaller rivers derived from the frontal Himalayan ranges? We investigated the provenance of river sediments retrieved through core-drilling, down to ~50 m depth, along three transects across the paleo-valleys on the Ghaggar and Sutlej plains. Drill core litho-stratigraphy shows ~20-25 m thick micaceous coarse- to medium-sand bodies at variable depths below ~10 m. U-Pb detrital zircon ages were determined for the fluvial sand bodies, in five drill-cores, using the LA-ICPMS technique available at University College of London. We selected 3-7 number of samples from each core and performed heavy mineral separation to extract zircon grains, which were then dated by U-Pb technique. Further to establish provenance links we determined the U-Pb ages of detrital zircons from modern river sands along this sector of the Himalayan front, i.e., the major Himalayan rivers such as the modern Sutlej, the Yamuna, and the Ganges

  17. The Disastrous Effects of Salt Dust Deposition on Cotton Leaf Photosynthesis and the Cell Physiological Properties in the Ebinur Basin in Northwest China

    PubMed Central

    Abuduwaili, Jilili; Zhaoyong, Zhang; Feng qing, Jiang; Dong wei, Liu

    2015-01-01

    Salt dust in rump lake areas in arid regions has long been considered an extreme stressor for both native plants and crops. In recent years, research on the harmful effects of salt dust on native plants has been published by many scholars, but the effect on crops has been little studied. In this work, in order to determine the impact of salt dust storms on cotton, we simulated salt dust exposure of cotton leaves in Ebinur Basin in Northwest China, and measured the particle sizes and salt ions in the dust, and the photosynthesis, the structure and the cell physiological properties of the cotton leaves. (1) Analysis found that the salt ions and particle sizes in the salt dust used in the experiments were consistent with the natural salt dust and modeled the salt dust deposition on cotton leaves in this region. (2) The main salt cations on the surface and inside the cotton leaves were Na+, Ca2+, Cl- and SO42-, while the amounts of CO3- and HCO3- were low. From the analysis, we can order the quantity of the salt cations and anions ions present on the surface and inside the cotton leaves as Na+>Ca2+>Mg2+>K+ and Cl->SO42->HCO3->CO3-, respectively. Furthermore, the five salt dust treatment groups in terms of the total salt ions on both the surface and inside the cotton leaves were A(500g.m-2)>B(400g.m-2)>C(300g.m-2)>D(200g.m-2)>E(100g.m-2)>F(0g.m-2). (3)The salt dust that landed on the surface of the cotton leaves can significantly influence the photosynthetic traits of Pn, PE, Ci, Ti, Gs, Tr, WUE, Ls, φ, Amax, k and Rady of the cotton leaves. (4)Salt dust can significantly damage the physiological functions of the cotton leaves, resulting in a decrease in leaf chlorophyll and carotenoid content, and increasing cytoplasmic membrane permeability and malondialdehyde (MDA) content by increasing the soluble sugar and proline to adjust for the loss of the cell cytosol. This increases the activity of antioxidant enzymes to eliminate harmful materials, such as the intracellular

  18. Magnetotelluric imaging of a fossil paleozoic intraoceanic subduction zone in western Junggar, NW China

    NASA Astrophysics Data System (ADS)

    Xu, Yixian; Yang, Bo; Zhang, Sheng; Liu, Ying; Zhu, Lupei; Huang, Rong; Chen, Chao; Li, Yongtao; Luo, Yinhe

    2016-06-01

    The fate of subducted oceanic slabs can provide important clues to plate reconstruction through Earth history. Since oceanic slabs in continental collision zones are typically not well preserved, ancient subduction zones have rarely been imaged by geophysical techniques. Here we present an exception from the Darbut belt in the Junggar accretionary collage in the southern Altaids of Asia. We deployed a 182 km long magnetotelluric (MT) profile including 60 broadband sounding sites across the belt. Quality off-diagonal impedances were inverted by a three-dimensional scheme to image resistivities beneath the profile. The resistivity model along with MT impedance phase ellipses and induction vectors were tested and interpreted in detail. Combining geological and geophysical observations, mineral physical experiment, and geodynamic modeling results, the MT transect suggests a fossil intraoceanic subduction zone during the Late Paleozoic in the western Junggar that has been well preserved due to lack of significant subsequent tecto-thermal events.

  19. Walled Sedimentary Basins of China: Perpetrators or Victims of Plateau Growth?

    NASA Astrophysics Data System (ADS)

    Carroll, A. R.; Graham, S. A.; Smith, M. E.

    2004-12-01

    Western China and adjacent areas of central Asia are characterized by low relief, internally drained sedimentary basins that are divided by actively uplifting mountain ranges. The margins of these basins often show evidence for extensive contractional deformation, yet their interiors are surprisingly stable. Basins such as the Tarim and Junggar also exhibit long and apparently continuous histories of closed drainage in the same approximate location (over 250 my in the case of Junggar). In contrast to traditional foreland basins, these basins are not uniquely associated with a specific thrust belt, nor do they show evidence for underlying decollements. We therefore propose the new term "walled basin", in recognition of the essential role of peripheral orogenic walls in creating and maintaining closed drainage and impounding sediments. Walled basins in Asia currently are restricted to areas that receive less than 40 cm/yr precipitation, suggesting that aridity plays a role in preventing fluvial breach of the basin walls (cf., Sobel et al., 2003). Entrapment of sediment within the closed Qaidam basin in the northeast Tibetan plateau has been implicated as a potential mechanism of plateau growth, based on the observations that the basin retains mass within the orogen and creates level topography. However, we propose that the Qaidam instead represents a walled basin that has been elevated due to underplating of the plateau, and is fated to eventual destruction as deformation continues. Several lines of reasoning support this conclusion. First, DEM analysis shows that modern drainage divides for the Qaidam and other walled basins never rise more than 1-2 km above the basin floors, limiting the amount of possible topgraphic infill. Second, the Tarim and Junggar basins presently remain well below 2000 m and probably have never been higher, despite receiving large influxes of detritus from adjacent ranges. Third, the Qaidam basin, like the Tarim and Junggar basins, has an

  20. Formation mechanism of the Qiongdongnan basin northwest of the South China Sea-dating the sinistral slip of the Red River Fault Zone

    NASA Astrophysics Data System (ADS)

    Sun, Z.; Jiang, J.; Xie, W.

    2010-12-01

    Locating on the northwestern margin of the South China Sea, the Qiongdongnan basin is a NE-trending rift zone in general. Bounding with the NW-trending Yinggehai basin and the Red River- East Vietnam Fault Zone to the west, the evolution of the Qiongdongnan basin bears large amounts of information about the slip of the Red River Fault zone. Combined the geological analysis with analogue modeling experiments, we suggest that the evolution of the Qiongdongnan is controlled not only by the southeastward to south southeastward extension, but also by the sinistral slip of the Red River Fault zone. The central depression of the Qiongdongnan basin is controlled mainly by the southeastward to south southeastward extension, while the southern depression developed under the combined stress filed of southeastward extension and the dextral slip along the NNW-trending Red River fault zone. The northern depression was formed by the combined effect of the sinistral slip along the Red River Fault Zone and the southeastward extension. According to the age of the shear fault starting to develop in the southwest of the Qiongdongnan basin, as well as the age for the northwestern part to develop, the sinistral slip of the Red River Fault zone began around early oligocene, later than the rifting of the Qiongdongnan basin. The sinistral slip rate of the Red River Fault zone during early Oligocene may be smaller than the displacement rate of the Qiongdongnan basin, but become reversed thereafter, which in turn caused tectonic inversion and folding along the western segment of the Qiongdongnan basin, and NW- to NNW-trending Rediel faults from late Oligocene to middle Miocene. Through the deformation history of the Qiongdongnan basin, we defined the sinistral slip stage Indochina along the Red River Fault zone from about 36Ma to 16Ma, and further a rapid slip occurring after 30Ma.

  1. Distribution and erosion of the Paleozoic tectonic unconformities in the Tarim Basin, Northwest China: Significance for the evolution of paleo-uplifts and tectonic geography during deformation

    NASA Astrophysics Data System (ADS)

    Lin, Changsong; Yang, Haijun; Liu, Jingyan; Rui, Zhifeng; Cai, Zhenzhong; Zhu, Yongfeng

    2012-03-01

    The distribution and erosional features of the Paleozoic major tectonic unconformities in the Tarim Basin, and their genetic relation to the development of paleo-uplifts as well as the evolution of geodynamic settings, are documented in this paper based on the integral analysis of seismic, drilling, and outcrop data. During the Paleozoic, the Tarim Basin underwent three major tectonic deformation stages, which resulted in three angular unconformities and in significant changes in basin geomorphology and paleogeography. The tectonic deformation at the end of the Middle Ordovician was characterized by development of the southern central paleo-uplift, the northern depression, and the southeastern Tangguzibasi depression in the basin. The thickest denudation belts of the unconformity (Tg5-2) are distributed mainly along the thrust structural highs. A stronger deformation event took place at the end of the Late Ordovician and formed a huge uplift along the southwestern and southeastern basin margins and the western part of the Tabei uplift along the northern basin margin, producing an extensive angular unconformity (Tg5) with maximum erosion thickness of 1500-2000 m. This tectonic event resulted in an abrupt change in overall geography of the basin, from a deepwater marine environment at the late stages of the Late Ordovician to a littoral and neritic basin in the Early Silurian. The deformation that occurred at the end of the Middle Devonian was the strongest in the Paleozoic. It generated the most widespread angular unconformity (Tg3) within the basin and led to extensive erosion, with maximum denudation thickness of 3000-5000 m in the northern and northeastern parts of the basin. The topography of the basin during the late Devonian was characterized by a high in the northeast and a low in the southwest, forming an embayment basin opening to the southwest during the Early Devonian to Carboniferous. The transgression in general from southwest to northeast deposited

  2. Use of satellite data in runoff forecasting in the heavily forested, cloud-covered Pacific Northwest. [Upper Snake, Boise, Dworshak, Libby and Hungry Horse River Basins

    NASA Technical Reports Server (NTRS)

    Dillard, J. P.; Orwig, C. F. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. Satellite-derived snow cover data improves forecasts of stream flow but not at a statistically significant amount and should not be used exclusively because of persistent cloud cover. Based upon reconstruction runs, satellite data can be used to augment snow-flight data in the Upper Snake, Boise, Dworshak, and Hungry Horse basins. Satellite data does not compare well with aerial snow-flight data in the Libby basin.

  3. Geochronology and Geochemistry of Igneous Rocks from the Laoshankou District, North Xinjiang: Implications for the Late Paleozoic Tectonic Evolution and Metallogenesis of East Junggar

    NASA Astrophysics Data System (ADS)

    Liang, Pei; Chen, Huayong; Hollings, Pete; Wu, Chao; Xiao, Bing; Bao, Zhiwei; Xu, Deru

    2016-12-01

    The Fe-Cu mineralization of the Laoshankou district is located in the Dulate Late Paleozoic island arc at the northern margin of East Junggar terrane, Northwest China and is hosted by volcanic rocks of the Middle Devonian Beitashan Formation. LA-ICP-MS U-Pb dating of zircon constrains the timing of crystallization of biotite diorites and quartz syenites in the Laoshankou district to 379 ± 2 Ma and 376 ± 2 Ma, respectively. The volcanic rocks are calc-alkaline in composition and are characterised by LILE and LREE enrichments and HFSE depletions, consistent with a subduction-related affinity. The relatively depleted Nb, Ta, Zr, Hf and Th, enriched Sr and Ba, elevated Mg#, positive εNd(t) values (5.5 and 5.6), low (87Sr/86Sr)i ratios (0.7042 and 0.7044) and MORB-like Pb-isotope characters all suggest that they were derived from a depleted mantle wedge metasomatized by slab-derived fluids, without crustal contamination. The biotite diorite shows slightly metaluminous compositions and is geochemically similar to the volcanic rocks, suggesting that they were derived from the same depleted mantle source. The lack of correlation between SiO2 and initial Sr, Nd ratios suggests that fractional crystallization dominated the petrogenesis of the biotite diorite with only weak crustal contamination. The geochemical characteristics of the quartz syenite are distinct from the volcanic rocks and the biotite diorite. The positive εHf(t), εNd(t), high Th/La (0.17-0.53), Th/Yb (1.62-4.39), low Ce/Th (2.87-10.13) ratios and positive trends of SiO2 versus (87Sr/86Sr)i and (143Nd/144Nd)i indicate the quartz syenite is likely the product of a depleted mantle wedge metasomatized by slab-derived fluids and subducted sediment-derived melts that underwent crustal contamination during passage through the crust. The low abundance of Th, Yb, Ta and La, indicate that all the intrusive rocks from 379 to 376 Ma in the Laoshankou district formed in an island arc rather than a continental margin

  4. Combined multivariate statistical techniques, Water Pollution Index (WPI) and Daniel Trend Test methods to evaluate temporal and spatial variations and trends of water quality at Shanchong River in the Northwest Basin of Lake Fuxian, China.

    PubMed

    Wang, Quan; Wu, Xianhua; Zhao, Bin; Qin, Jie; Peng, Tingchun

    2015-01-01

    Understanding spatial and temporal variations in river water quality and quantitatively evaluating the trend of changes are important in order to study and efficiently manage water resources. In this study, an analysis of Water Pollution Index (WPI), Daniel Trend Test, Cluster Analysis and Discriminant Analysis are applied as an integrated approach to quantitatively explore the spatial and temporal variations and the latent sources of water pollution in the Shanchong River basin, Northwest Basin of Lake Fuxian, China. We group all field surveys into 2 clusters (dry season and rainy season). Moreover, 14 sampling sites have been grouped into 3 clusters for the rainy season (highly polluted, moderately polluted and less polluted sites) and 2 clusters for the dry season (highly polluted and less polluted sites) based on their similarities and the level of pollution during the two seasons. The results show that the main trend of pollution was aggravated during the transition from the dry to the rainy season. The Water Pollution Index of Total Nitrogen is the highest of all pollution parameters, whereas the Chemical Oxygen Demand (Chromium) is the lowest. Our results also show that the main sources of pollution are farming activities alongside the Shanchong River, soil erosion and fish culture at Shanchong River reservoir area and domestic sewage from scattered rural residential area. Our results suggest that strategies to prevent water pollutionat the Shanchong River basin need to focus on non-point pollution control by employing appropriate fertilizer formulas in farming, and take the measures of soil and water conservation at Shanchong reservoir area, and purifying sewage from scattered villages.

  5. Combined Multivariate Statistical Techniques, Water Pollution Index (WPI) and Daniel Trend Test Methods to Evaluate Temporal and Spatial Variations and Trends of Water Quality at Shanchong River in the Northwest Basin of Lake Fuxian, China

    PubMed Central

    Wang, Quan; Wu, Xianhua; Zhao, Bin; Qin, Jie; Peng, Tingchun

    2015-01-01

    Understanding spatial and temporal variations in river water quality and quantitatively evaluating the trend of changes are important in order to study and efficiently manage water resources. In this study, an analysis of Water Pollution Index (WPI), Daniel Trend Test, Cluster Analysis and Discriminant Analysis are applied as an integrated approach to quantitatively explore the spatial and temporal variations and the latent sources of water pollution in the Shanchong River basin, Northwest Basin of Lake Fuxian, China. We group all field surveys into 2 clusters (dry season and rainy season). Moreover, 14 sampling sites have been grouped into 3 clusters for the rainy season (highly polluted, moderately polluted and less polluted sites) and 2 clusters for the dry season (highly polluted and less polluted sites) based on their similarities and the level of pollution during the two seasons. The results show that the main trend of pollution was aggravated during the transition from the dry to the rainy season. The Water Pollution Index of Total Nitrogen is the highest of all pollution parameters, whereas the Chemical Oxygen Demand (Chromium) is the lowest. Our results also show that the main sources of pollution are farming activities alongside the Shanchong River, soil erosion and fish culture at Shanchong River reservoir area and domestic sewage from scattered rural residential area. Our results suggest that strategies to prevent water pollutionat the Shanchong River basin need to focus on non-point pollution control by employing appropriate fertilizer formulas in farming, and take the measures of soil and water conservation at Shanchong reservoir area, and purifying sewage from scattered villages. PMID:25837673

  6. The influence of precipitation and temperature input schemes on hydrological simulations of a snow and glacier melt dominated basin in Northwest China

    NASA Astrophysics Data System (ADS)

    Ji, X.; Luo, Y.

    2013-01-01

    Basins with glaciers and snow provide water storage and supply for downstream irrigated farmland, but their hydrology is often poorly known because there are limited observation networks in high mountain regions. Large uncertainties in hydrological simulations also arise from errors associated with meteorological forcing data. The influence of precipitation and temperature forcing data on hydrological simulations in rain/snow dominated watershed is well documented, but less so in basins with glaciers. We analyzed the impacts and reliability of precipitation/temperature input solutions on hydrological simulations in the glacier/snow dominated Manas River Basin, showing that precipitation pattern has significant impact on snow accumulation and melt, and further impacts on simulated glacier melt behavior. The temperature inputs affect not only the timing of discharge but also the total water yield. The uncertainty associated with simple estimated input data propagates and is amplified through the modeling process. We suggest that the impacts of forcing data on hydrological simulations in basins with glaciers are more complex than in common rain/snow dominated watersheds. Glacier melt behavior may conceal uncertainties that are actually derived from input data. Assessment of hydrological model performance should include investigation of key processes involved in the hydrologic cycle individually, not just comparisons of simulated and observed discharge.

  7. Evolution of the groundwater system under the impacts of human activities in middle reaches of Heihe River Basin (Northwest China) from 1985 to 2013

    NASA Astrophysics Data System (ADS)

    Mi, Lina; Xiao, Honglang; Zhang, Jianming; Yin, Zhenliang; Shen, Yongping

    2016-06-01

    Investigation of the evolution of the groundwater system and its mechanisms is critical to the sustainable management of water in river basins. Temporal and spatial distributions and characteristics of groundwater have undergone a tremendous change with the intensity of human activities in the middle reaches of the Heihe River Basin (HRB), the second largest arid inland river basin in northwestern China. Based on groundwater observation data, hydrogeological data, meteorological data and irrigation statistical data, combined with geostatistical analyses and groundwater storage estimation, the basin-scaled evolution of the groundwater levels and storage (from 1985 to 2013) were investigated. The results showed that the unbalanced allocation of water sources and expanded cropland by policy-based human activities resulted in the over-abstraction of groundwater, which induced a general decrease in the water table and groundwater storage. The groundwater level has generally fallen from 4.92 to 11.49 m from 1985 to 2013, especially in the upper and middle parts of the alluvial fan (zone I), and reached a maximum depth of 17.41 m. The total groundwater storage decreased by 177.52 × 108 m3; zone I accounted for about 94.7 % of the total decrease. The groundwater balance was disrupted and the groundwater system was in a severe negative balance; it was noted that the groundwater/surface-water interaction was also deeply affected. It is essential to develop a rational plan for integration and management of surface water and groundwater resources in the HRB.

  8. High-quality intensity data from Argentina: archeomagnetic study of pottery fragments from the Guayatayoc-Miraflores basin (Puna de Jujuy, Northwest Argentina)

    NASA Astrophysics Data System (ADS)

    Gomez-Paccard, M.; Chauvin, A.; Albeck, M. E.; Zaburlín, M. A.; Basso, D. M.

    2015-12-01

    Improving geomagnetic field reconstructions clearly poses a high-priority challenge in geomagnetic research today. A better characterization of the geomagnetic field strength in the southern hemisphere is particularly crucial as the limited number of reliable intensity records from this area hamper a meaningful analysis of dipole moment past variations. Here we present the first archeointensity results obtained from several collections of pottery fragments from four agropastoral sites from the Puna of Jujuy (Northwest Argentina), an area never studied before. The ages of the studied sites, dated by radiocarbon analysis, range from the XIII to the XVII centuries. The classical Thellier method with regular partial Thermoremanent magnetization (pTRM) checks and TRM anisotropy and cooling rate corrections has been used for archeointensity determination. From the 82 specimens analysed, 63 gave reliable results. This high success rate indicates that potteries from agropastoral sites of the Puna of Jujuy provide a unique opportunity to further recover past geomagnetic field intensity changes in Northwest Argentina. The new data obtained are the first archeointensity data from this region. The differences observed between the new data, other available archeointensity data from nearby regions, and archeointensity variation curves derived from global models (ARCH3k and SHA.DIF.14), highlights the need for new high-quality data to better constrain the evolution of the Earth magnetic field strength in central South America.

  9. Late Paleozoic tectonic evolution and concentrated mineralization in Balkhash and West Junggar, western part of the Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Dong, Shuwen; Chen, Xuanhua; Chen, Zhengle

    2016-04-01

    The Central Asia Orogenic Belt (CAOB) is an important area with significant growth of the crust and metallogeny in the Late Paleozoic. The Balkhash-Junggar tectono-metallogenic belt consists of the Balkhash, the West Junggar, and the East Junggar tectono-metallogenic belts in western part of the Central Asian Orogenic Belt (CAOB). According to the structural geological relationship, the East Junggar, the West Junggar, and the Balkhash belts are considered to be once a continuous E-W-trending tectono-metallogenic belt in Late Carboniferous. The West Junggar belt is featured with NE-trending left-lateral strike-slip faulting tectonic system (WJTS), while the left-lateral strike-slip faults are E-W-trending in the Balkhash belt. The WJTS consists of the Darabut, the Mayile, and the Baerluke faults, and the blocks among them. All these left-lateral strike-slip faults are forming due to the transition of tectonic settings from syn-collisional orogeny to post-collisional extension during the closure of the ocean (the Junggar Sea) in Late Carboniferous, with significant intrusion of batholiths and crust growth occurred in this period. These faults are truncated by the right-lateral strike-slip faults, such as the Chingiz-Junggar fault, and the Central Balkhash fault in Mesozoic. The Balkhash-Junggar tectono-metallogenic belt is important for the occurrence of many well-known super-large and large porphyry Cu-Mo deposits (such as the Kounrad, the Aktogai, the Borly, and the Baogutu deposits), large skarn Cu deposits (in the Sayak ore-filed), large rare metal deposits (such as the East Kounrad, the Zhanet, and the Akshatau deposits), and large gold deposits (such as the Hatu deposit). Zircon U-Pb ages, Re-Os isotopic dating of molybdenites, 40Ar/39Ar thermochronology of hornblendes, muscovites, biotites, and K-feldspars, and zircon and apatite fission track (FT) and (U-Th)/He dating and thermal history modeling, provide a multidisciplinary approach to constrain the whole

  10. Tectonic evolution of West Junggar (NW China): implications for accretionary orogens processes in Central Asia

    NASA Astrophysics Data System (ADS)

    Choulet, Flavien; Faure, Michel; Chen, Yan; Cluzel, Dominique; Wang, Bo; Lin, Wei

    2014-05-01

    Understanding the development and evolution of accretionary orogens is crucial for characterizing continental crust growth in time and space. In the Altaids tectonic collage of Central Asia, conflicting geodynamic models have been proposed about the Paleozoic evolution, during which juvenile continental crust has been extensively formed. This study focuses on West Junggar (NW China), a key region that has not been extensively studied yet. A multidisciplinary approach, including detrital zircon provenance study, geochemistry, field structural analysis and paleomagnetism provides new constraints on the Paleozoic evolution of West Junggar. Oceanic subduction predominates in Early Paleozoic time, as indicated by ophiolitic mélanges, fore-arc volcaniclastic turbidites and magmatic arc suites. However, the development of an olistostrome supplied by a sub-contemporaneous carbonate platform, the occurrence of continental molasse, and the chronology and geochemistry of magmatic events reveal interruptions of subduction. Discrete collisions of volcanic arcs and micro-continent are inferred from the tectonic structure of the belt, which displays allochthonous units rooted in the suture zone. Early Paleozoic magmatic and sedimentary rocks of West Junggar bear some resemblance to contemporaneous analogues in Eastern Kazakhstan, and suggest a lateral connection. During Late Paleozoic, tectonic features that develop in response to plate convergence are strongly controlled by geometry of two new subduction zones. A Carboniferous accretionary complex composed of fore-arc sedimentary rocks and ophiolitic mélanges has been identified. The occurrence of quasi-synchronous upright folds and folds with vertical axes suggests that transpression plays a significant role in the Late Paleozoic tectonic evolution of the West Junggar. Latest Carboniferous (ca. 300 Ma) alkaline plutons postdate this early phase of folding, which was synchronous with accretion of the Carboniferous complex. The

  11. Southernmost evidence of large European Ice Sheet-derived freshwater discharges during the Heinrich Stadials of the Last Glacial Period (Galician Interior Basin, Northwest Iberian Continental Margin)

    NASA Astrophysics Data System (ADS)

    Plaza-Morlote, M.; Rey, D.; Santos, J. F.; Ribeiro, S.; Heslop, D.; Bernabeu, A.; Mohamed, K. J.; Rubio, B.; Martíns, V.

    2017-01-01

    Reconstruction of circum-Atlantic ice-sheet motion and instabilities is crucial to understanding the mechanisms that triggered and/or enhanced abrupt climate changes. Using enviromagnetic and geochemical data, we provide a continuous and well-dated record of the evolution of glacial/interglacial sedimentation on the Northwest Iberian Margin during the last glacial period, covering the last six Heinrich Stadials. The record shows European sediments that were related to meltwater pre-events during the initial stages of HS1, HS2, and HS4 that corroborate the Channel River depositional history. The record also includes IRD from the Laurentide Ice Sheet and the European Ice Sheet during the final stages of these stadials, i.e., Heinrich Events. Therefore, this study provides insight into one of the potential forcing mechanisms for Heinrich Events and, by inference, for Heinrich Stadials.

  12. Analyzing the effect of cryosphere processes on catchment hydrology through a modeling approach: a case study in the Heihe River basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Yang, D.; Gao, B.; Wang, Y.

    2015-12-01

    Understanding the changes in cryosphere processes on river discharge under climate change is very important for the water resources management in the high altitude cold regions. A distributed eco-hydrological model was developed and cryosphere processes were coupled with hydrological processes in the model simulation. Model validation shows that the model shows high skill in simulating the river discharge, soil moisture, soil temperature and heat flux. The study area is the Heihe River basin, the second largest inland river basin in China. Numerical experiment shows that the soil freezing/thawing shows significant impact of hydrological processes and it reduced base flow and increased peak flow. Hydrological changes of the past 50 years in the Heihe River were analyzed based on model simulation. Soil temperature was found to be increased and melting depth shows significant increasing trend. Due to the limited areas, glacier melting shows little impact on the runoff changes. However, the changes in frozen soil and the snow melting shows significant effects on the river discharge changes. The results highlights the importance of study of the cryosphere hydrology in understanding the hydrological changes in the high altitude cold regions. Key words: the Heihe River basin, hydrological changes, Cryosphere processes

  13. Pacific Northwest AGU Meeting

    NASA Astrophysics Data System (ADS)

    Engebretson, David C.; Beck, Myrl E., Jr.

    1984-04-01

    The 30th AGU Pacific Northwest Regional Meeting was held September 29 to October 1, 1983, on the campus of Western Washington University, Bellingham, Wash. Approximately 125 attended the meeting, and 36 papers were presented. The meeting included two fields trips, five special symposia, and a banquet where keynote speaker Don Swanson presented “Dome building on Mt. St. Helens.”The meeting highlights included a symposium on Tertiary sedimentary basins of Washington and Oregon which revealed the importance of sedimentological studies for deciphering the timing and nature of accretionary processes in tectonically active areas. Geological and geophysical studies on the recent tectonics of the Juan de Fuca plate and nearby continent were presented by workers from the United States and Canada as well as ongoing studies for the evolution and character of the crystalline North Cascades of Washington and British Columbia.

  14. Spatial-temporal framework for the closure of the Junggar Ocean in central Asia: New SIMS zircon U-Pb ages of the ophiolitic mélange and collisional igneous rocks in the Zhifang area, East Junggar

    NASA Astrophysics Data System (ADS)

    Xu, Xing-Wang; Jiang, Neng; Li, Xian-Hua; Wu, Chu; Qu, Xun; Zhou, Gang; Dong, Lian-Hui

    2015-11-01

    The closure time of the Junggar Ocean is one of the hottest topics surrounding the tectonic evolution of the Central Asian Orogenic Belt (CAOB). This paper reports SIMS zircon U-Pb ages of the ophiolitic mélange and collisional igneous rocks in the Zhifang area, East Junggar. Our new results reveal the following evidence: (1) the West Hill ophiolitic mélange in the Zhifang area contains segments of the 371 Ma MORB-type layered rocks and 363 Ma oceanic islands, which were intruded by the 348 Ma syn-collisional quartz diorites; (2) the ophiolitic mélange and 348 Ma syn-collisional quartz diorites are overlain by the 342 Ma andesitic tuffs; and (3) the 342 Ma andesitic tuffs and successive 332 Ma granodiorites-gabbro were formed at late-collisional setting, whereas the 314 Ma granitic porphyry at post-collisional setting. We suggest that the Junggar Ocean in the Zhifang area was opened before 371 Ma and 363 Ma, and possibly closed before 348 Ma. By combining the published U-Pb ages of the Mayile-Tangbale-Darbute-Kalamaili-Zhifang-Daheishan (MTDKZD) ophiolite belt, Early-Carboniferous volcanic rocks unconformably overlying the MTDKZD ophiolite belt, bimodal volcanic rocks and granitoids within and adjacent to the MTDKZD ophiolite belt, it is suggested that the Junggar Ocean was possibly opened scissors-like from the Neoproterozoic-Ordovician Mayile-Tangbale ocean eastwards through the Silurian-Devonian Darbute-Karamay ocean finally to the Devonian-Early-Carboniferous Kalamaili-Zhifang ocean, and closed scissors-like from the Zhifang-Kalamaili area in the eastern segment westwards to the Darbute-Karamay area in the western segment. Tectonic collage between the Yemaquan-Xiemisitai arc and Junggar block occurred at approximately 343-348 Ma. The Junggar orogenic belt went through late-collisional stage at 343-330 Ma, post-collisional period after 330 Ma, and post-collisional extensional regime after 320 Ma with an intensive stage at around 303 Ma.

  15. FUTURE OF PACIFIC NORTHWEST SALMON: SCIENCE AND POLICY IN ACTION

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon stocks (a group of interbreeding individuals that is roughly equivalent to a "population") have declined and some have disappear...

  16. PACIFIC NORTHWEST SALMON: FORECASTING THEIR STATUS IN 2100

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon stocks (a group of interbreeding individuals that is roughly equivalent to a "population") have declined and some have disappear...

  17. FUTURE OF PACIFIC NORTHWEST SALMON: SCIENCE AND POLICY IN ACTION

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon stocks (a group of interbreeding individuals that is roughly equivalent to a "population") have declined and some have disappear...

  18. PACIFIC NORTHWEST SALMON: FORECASTING THEIR STATUS IN 2100

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon stocks (a group of interbreeding individuals that is roughly equivalent to a "population") have declined and some have disappear...

  19. RESTORING WILD SALMON TO THE PACIFIC NORTHWEST: CHASING AN ILLUSION?

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon "stocks" (a group of interbreeding individuals that is roughly equivalent to a "population) have declined and some have been e...

  20. RESTORING WILD SALMON TO THE PACIFIC NORTHWEST: CHASING AN ILLUSION

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon "stocks" (a group of interbreeding individuals that is roughly equivalent to a "population") have declined and some have been ...

  1. RESTORING WILD SALMON TO THE PACIFIC NORTHWEST: CHASING AN ILLUSION?

    EPA Science Inventory

    Throughout the Pacific Northwest (northern California, Oregon, Idaho, Washington, and the Columbia Basin portion of British Columbia), many wild salmon "stocks" (a group of interbreeding individuals that is roughly equivalent to a "population) have declined and some have been e...

  2. Using the nonlinear aquifer storage-discharge relationship to simulate the baseflow of glacier and snowmelt dominated basins in Northwest China

    NASA Astrophysics Data System (ADS)

    Gan, R.; Luo, Y.

    2013-04-01

    Baseflow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage-discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of baseflow estimates in rivers dominated by snow and/or glacier melt in arid and cold northwestern China, a nonlinear storage-discharge relationship for use in SWAT (Soil Water Assessment Tools) modeling was developed and applied to the Manas River basin in the Tianshan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of flow recession curves from 78 river gauge stations revealed variation in the coefficients of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flows. The highest Nash-Sutcliff efficiency and lowest Percent Bias were obtained when compared to the one- or two-linear reservoir approach. The exponent b of the aquifer storage-discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

  3. Using the nonlinear aquifer storage-discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

    NASA Astrophysics Data System (ADS)

    Gan, R.; Luo, Y.

    2013-09-01

    Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage-discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage-discharge relationship for use in SWAT (Soil Water Assessment Tool) modeling was developed and applied to the Manas River basin in the Tian Shan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of recession curves from 78 river gauge stations revealed variation in the parameters of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flow period. The higher Nash-Sutcliffe efficiency, logarithmic efficiency, and volumetric efficiency, and lower percent bias were obtained when compared to the one-linear reservoir approach. The parameter b of the aquifer storage-discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

  4. Population structure and effective/census population size ratio in threatened three-spined stickleback populations from an isolated river basin in northwest Spain.

    PubMed

    Pérez-Figueroa, A; Fernández, C; Amaro, R; Hermida, M; San Miguel, E

    2015-08-01

    Variability at 20 microsatellite loci was examined to assess the population genetic structure, gene flow, and effective population size (N(e)) in three populations of three-spined stickleback (Gasterosteus aculeatus) from the upper basin of the Miño River in Galicia, NW Spain, where this species is threatened. The three populations showed similar levels of genetic diversity. There is a significant genetic differentiation between the three populations, but also significant gene flow. N(e) estimates based on linkage disequilibrium yielded values of 355 for the Miño River population and 241 and 311 for the Rato and Guisande Rivers, respectively, although we expect that these are overestimates. N(e) estimates based on temporal methods, considering gene flow or not, for the tributaries yielded values of 30-56 and 47-56 for the Rato and Guisande Rivers, respectively. Estimated census size (N(c)) for the Rato River was 880 individuals. This yielded a N(e)/N(c) estimate of 3-6 % for temporal estimation of N(e), which is within the empirical range observed in freshwater fishes. We suggest that the three populations analyzed have a sufficient level of genetic diversity with some genetic structure. Additionally, the absence of physical barriers suggests that conservation efforts and monitoring should focus in the whole basin as a unit.

  5. Description of two ubiquitous species of Desmosomatidae (Isopoda: Asellota) from the Northwest Pacific Basin east of the Kuril-Kamchatka Trench.

    PubMed

    Golovan, Olga A

    2015-11-05

    Two new species of Desmosomatidae, Eugerdella kurabyssalis sp. nov. and Parvochelus serricaudis sp. nov., are described from the Northwest Pacific open abyssal plain to the east of the Kuril-Kamchatka Trench. These species constituted about one fourth of all collected desmosomatid specimens of the KuramBio expedition (2012), indicating it may be the most abundant species of the family in this area. E. kurabyssalis sp. nov. is rather similar to E. minutula Mezhov, 1986 and E. theodori Brix, 2007, resembling them in the shape of its body segments and appendages, including the absence of the mandibular palp and morphology of the pereopod I. The new species can be distinguished from the mentioned species by the number of cusps of the mandibular incisor process and lacinia mobilis, the relatively stouter pereopods and different setation of the pereopod I ischium. P. serricaudis sp. nov. is the second species of the genus Parvochelus Brix & Kihara, 2015 (see Brix et al. 2015) and the first record of the genus from the Pacific Ocean and from the Northern Hemisphere. P. serricaudis sp. nov. can be distinguished from P. russus Brix & Kihara, 2015 by its relatively stouter pereopod I, presence of the mandibular palp and the shape of the maxilliped palp articles and female operculum. A discussion of the taxonomic characters and the modified diagnosis of the genus Parvochelus are presented.

  6. Petrography and diagenesis of reservoir and non-reservoir sandstones in Shattuck Member of Queen Formation, northwest shelf of Permian basin

    SciTech Connect

    Malicse, A.; Siegel, J.; Mazzullo, J.

    1988-02-01

    The Shattuck Member is a thick (6-20 m) sandstone that defines the top of the Queen Formation (Permian, Guadalupian) and is a major hydrocarbon reservoir on the Northwestern shelf of the Permian basin. The Shattuck was deposited in desert dune and interdune, dry and wet sand sheet, and sandy sabkha environments during a lowstand of sea level. The desert dune, interdune, and dry sand sheet deposits constitute the producing horizons in the Shattuck, whereas the wet sand sheet and sabkha deposits are generally non-productive. The purposes of this study are to examine the petrographic characteristics of the producing and non-producing horizons with petrographic and scanning electron microscopes, and to determine their provenance and diagenetic history.

  7. Approximation of continuity of lenticular Mesaverde sandstone lenses, utilizing close-well correlations, Piceance Basin, northwest, Colorado. Western Gas Sands Project

    SciTech Connect

    Not Available

    1982-11-01

    Mesaverde Group sandstone units in 13 closely-spaced wells in the central and southern Piceance Basin of Colorado were correlated utilizing wireline log response quantitatively and qualitatively. Based on these correlations, the environmental subdivisions of the Mesaverde Group were characterized as follows. Paralic (upper mixed-marine) zone, occurring in the uppermost Mesaverde, includes thick sandstone units which are interpreted to be regionally continuous. Fluvial zone, containing point-bars 20 to 30+ ft thick, is interpreted to be correlatable to a maximum of 6800 ft. Paludal zone, which has insufficient data to adequately characterize the sand units. However, 63 percent of the units are correlatable across at least 139 ft. An approximation of the dimensional characteristics of Mesaverde sandstone units has potential applications in designing hydraulic fracturing treatments and estimating gas reserves more accurately. 16 figures, 2 tables

  8. Participatory Modeling Processes to Build Community Knowledge Using Shared Model and Data Resources and in a Transboundary Pacific Northwest Watershed (Nooksack River Basin, Washington, USA)

    NASA Astrophysics Data System (ADS)

    Bandaragoda, C.; Dumas, M.

    2014-12-01

    As with many western US watersheds, the Nooksack River Basin faces strong pressures associated with climate variability and change, rapid population growth, and deep-rooted water law. This transboundary basin includes contributing areas in British Columbia, Canada, and has a long history of joint data collection, model development, and facilitated communication between governmental (federal, tribal, state, local), environmental, timber, agricultural, and recreational user groups. However, each entity in the watershed responds to unique data coordination, information sharing, and adaptive management regimes and thresholds, further increasing the complexity of watershed management. Over the past four years, participatory methods were used to compile and review scientific data and models, including fish habitat (endangered salmonid species), channel hydraulics, climate data, agricultural, municipal and industrial water use, and integrated watershed scale distributed hydrologic models from over 15 years of projects (from jointly funded to independent shared work by individual companies, agencies, and universities). A specific outcome of the work includes participatory design of a collective problem statement used for guidance on future investment of shared resources and development of a data-generation process where modeling results are communicated in a three-tiers for 1) public/decision-making, 2) technical, and 3) research audiences. We establish features for successful participation using tools that are iteratively developed, tested for usability through incremental knowledge building, and designed to provide rigor in modeling. A general outcome of the work is ongoing support by tribal, state, and local governments, as well as the agricultural community, to continue the generation of shared watershed data using models in a dynamic legal and regulatory setting, where two federally recognized tribes have requested federal court resolution of federal treaty rights

  9. Impacts of SST anomalies in the Indian-Pacific basin on Northwest Pacific tropical cyclone activities during three super El Niño years

    NASA Astrophysics Data System (ADS)

    Zhan, Ruifen; Chen, Baode; Ding, Yihui

    2017-07-01

    This study investigated the impact of sea surface temperature (SST) in several important areas of the Indian-Pacific basin on tropical cyclone (TC) activity over the western North Pacific (WNP) during the developing years of three super El Niño events (1982, 1997, and 2015) based on observations and numerical simulations. During the super El Niño years, TC intensity was enhanced considerably, TC days increased, TC tracks mostly recurved along the coasts, and fewer TCs made landfall in China. These characteristics are similar to the strong ENSO-TC relationship but further above the climatological means than in strong El Niño years. It indicates that super El Niño events play a dominant role in the intensities and tracks of WNP TCs. However, there were clear differences in both numbers and positions of TC genesis among the different super El Niño years. These features could be attributed to the collective impact of SST anomalies (SSTAs) in the tropical central-eastern Pacific and East Indian Ocean (EIO) and the SST gradient (SSTG) between the southwestern Pacific and the western Pacific warm pool. During 2015, the EIO SSTA was extremely warm and the anomalous anticyclone in the western WNP was enhanced, resulting in fewer TCs than normal. In 1982, the EIO SSTA and spring SSTG showed negative anomalies, followed by an increased anomalous cyclone in the western WNP and equatorial vertical wind shear. This intensified the conversion of eddy kinetic energy from large-scale flows, favorable for the westward shift of TC genesis. Consequently, anomalous TC activities during the super El Niño years resulted mainly from combined SSTA impacts of different key areas over the Indian-Pacific basin.

  10. Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, northwest Alaska

    USGS Publications Warehouse

    Lenz, Josefine; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey M. Walter; Bobrov, Anatoly; Wulf, Sabine; Wetterich, Sebastian

    2016-01-01

    Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyse a ~ 4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemical, geochronological, micropalaeontological (ostracoda, testate amoebae) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by the deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP and drained catastrophically in spring 2005. The present study emphasises that Arctic lake systems and periglacial landscapes are highly dynamic and that permafrost formation as well as degradation in central Beringia was controlled by regional to global climate patterns as well as by local disturbances.

  11. Spatial-temporal variability of soil water content in a cropland-shelterbelt-desert site in an arid inland river basin of Northwest China

    NASA Astrophysics Data System (ADS)

    Shen, Qin; Gao, Guangyao; Hu, Wei; Fu, Bojie

    2016-09-01

    Knowledge of the spatial-temporal variability of soil water content (SWC) is critical for understanding a range of hydrological processes. In this study, the spatial variance and temporal stability of SWC were investigated in a cropland-shelterbelt-desert site at the oasis-desert ecotone in the middle of the Heihe River Basin, China. The SWC was measured on 65 occasions to a depth of 2.8 m at 45 locations during two growing seasons from 2012 to 2013. The standard deviation of the SWC versus the mean SWC exhibited a convex upward relationship in the shelterbelt with the greatest spatial variation at the SWC of around 22.0%, whereas a linearly increasing relationship was observed for the cropland, desert, and land use pattern. The standard deviation of the relative difference was positively linearly correlated with the SWC (p < 0.05) for the land use pattern, whereas such a relationship was not found in the three land use types. The spatial pattern of the SWC was more time stable for the land use pattern, followed by desert, shelterbelt, and cropland. The spatial pattern of SWC changed dramatically among different soil layers. The locations representing the mean SWC varied with the depth, and no location could represent the whole soil profile due to different soil texture, root distribution and irrigation management. The representative locations of each soil layer could be used to estimate the mean SWC well. The statistics of temporal stability of the SWC could be presented equally well with a low frequency of observation (30-day interval) as with a high frequency (5-day interval). Sampling frequency had little effect on the selection of the representative locations of the field mean SWC. This study provides useful information for designing the optimal strategy for sampling SWC at the oasis-desert ecotone in the arid inland river basin.

  12. Pacific Northwest

    NASA Image and Video Library

    2017-09-28

    The Rocky, Cascade, and Coast Mountain Ranges dominate the landscape of the Pacific Northwest in this image created June 11-17, 2012 from the Visible-Infrared Imager/Radiometer Suite (VIIRS) instrument aboard the Suomi National Polar-orbiting Partnership or Suomi NPP satellite, a partnership between NASA and the National Oceanic and Atmospheric Administration, or NOAA. Potato and other agriculture can be seen in the bottom center of the image, as the Rockies transition to the plains of Idaho. High values of Normalized Difference Vegetation Index, or NDVI, represent dense green functioning vegetation and low NDVI values represent sparse green vegetation or vegetation under stress from limiting conditions, such as drought. Credit: NASA/NOAA To read more go to: www.nasa.gov/mission_pages/NPP/news/vegetation.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  13. Sensitive response of desert vegetation to moisture change based on a near-annual resolution pollen record from Gahai Lake in the Qaidam Basin, northwest China

    NASA Astrophysics Data System (ADS)

    Zhao, Yan; Yu, Zicheng; Chen, Fahu; Liu, Xiuju; Ito, Emi

    2008-05-01

    We present a 50-year pollen record at near-annual resolution from Gahai Lake in the Qaidam Basin on the northeastern Tibetan Plateau. Chronology of a 22-cm short core was established by 210Pb and 137Cs analysis. The pollen results at 0.5 cm intervals show large changes in Artemisia/Chenopodiaceae (A/C) ratios from < 0.2 to 0.95 in the last 50 years. High (low) A/C ratios represent increase (decrease) in steppe pollen production, which correspond to high (low) relative humidity observed at nearby Delingha weather station. On the basis of good correspondence with instrumental records and carbonate content from Gahai Lake, we conclude that A/C ratio is sensitive to moisture change and can be a very useful index in reconstructing paleoclimate of arid regions. Comparison with pollen and snow accumulation data from Dunde ice core suggests that effective moisture at low and high elevations shows the opposite relationship when mountain precipitation was extremely high, possibly due to topography-induced uplifting and subsiding air dynamics.

  14. Late Paleozoic to Jurassic tectonic evolution of the Bogda area (northwest China): Evidence from detrital zircon U-Pb geochronology

    NASA Astrophysics Data System (ADS)

    Tang, Wenhao; Zhang, Zhicheng; Li, Jianfeng; Li, Ke; Chen, Yan; Guo, Zhaojie

    2014-06-01

    Since the Cenozoic, the Tian Shan is rejuvenated by crustal shortening related to the ongoing India-Asia collision. However, the tectonic process prior to the Cenozoic remains ambiguous, especially in the Bogda area of the eastern Tian Shan. The continuous Late Paleozoic-Mesozoic sequences in the Bogda area record abundant information about the basin-mountain interaction. U-Pb (LA-ICP-MS) dating of detrital zircons from seven sandstone samples from Permian to Jurassic was used to investigate the changes of provenance and basin-mountain interaction in the Bogda area. During the Permian, proximal and synchronous pyroclastic materials were the major source. The Late Paleozoic magmatic belt in the North Tian Shan (NTS) had gradually become one of the main sources by the Late Permian, which implies the uplift and exhumation in the NTS area. This is interpreted in terms of near-source sedimentation in basin developing in a post-orogenic extension setting. The large range of U-Pb ages of detrital zircons observed in the Early-Middle Jurassic sediments encompasses most of the available sources implying a wide drainage pattern developing on a rather flat topography. Re-emergence of the Early Permian peak in the spectrum implies that the Bogda Mountains has existed as a gentle positive relief and began to provide materials to the submountain regions. The southern Junggar Basin extended towards to the south and evolved as a passively subsiding basin from the Middle Triassic to the Middle Jurassic. However, the synchronous pyroclastic (tuff) and the exhumed late Paleozoic detrital materials from the uplifted Bogda Mountains were the major component of the Upper Jurassic sediments. Associated to the conglomerate in the Kalaza Formation, the basin-range evolution entered a compression uplift stage. The basin pattern evolution of the Bogda area is consistent with that of the southern Junggar Basin.

  15. Agricultural crop mapping and classification by Landsat images to evaluate water use in the Lake Urmia basin, North-west Iran

    NASA Astrophysics Data System (ADS)

    Fazel, Nasim; Norouzi, Hamid; Madani, Kaveh; Kløve, Bjørn

    2016-04-01

    Lake Urmia, once one of the largest hypersaline lakes in the world has lost more than 90% of its surface body mainly due to the intensive expansion of agriculture, using more than 90% of all water in the region. Access to accurate and up-to-date information on the extent and distribution of individual crop types, associated with land use changes and practices, has significant value in intensively agricultural regions. Explicit information of croplands can be useful for sustainable water resources, land and agriculture planning and management. Remote sensing, has been proven to be a more cost-effective alternative to the traditional statistically-based ground surveys for crop coverage areas that are costly and provide insufficient information. Satellite images along with ground surveys can provide the necessary information of spatial coverage and spectral responses of croplands for sustainable agricultural management. This study strives to differentiate different crop types and agricultural practices to achieve a higher detailed crop map of the Lake Urmia basin. The mapping approach consists of a two-stage supervised classification of multi-temporal multi-spectral high resolution images obtained from Landsat imagery archive. Irrigated and non-irrigated croplands and orchards were separated from other major land covers (urban, ranges, bare-lands, and water) in the region by means of maximum Likelihood supervised classification method. The field data collected during 2015 and land use maps generated in 2007 and Google Earth comparisons were used to form a training data set to perform the supervised classification. In the second stage, non-agricultural lands were masked and the supervised classification was applied on the Landsat images stack to identify seven major croplands in the region (wheat and barley, beetroot, corn, sunflower, alfalfa, vineyards, and apple orchards). The obtained results can be of significant value to the Urmia Lake restoration efforts which

  16. Integration of seismic interpretation and petrophysical studies on Hawaz Formation in J-field NC-186 concession, Northwest Murzuq basin, Libya

    NASA Astrophysics Data System (ADS)

    Mohamed, A. K.; Selim, E. I.; Kashlaf, A.

    2016-12-01

    This study has been carried out by the integration of seismic interpretations and the well-logging analysis of ten wells distributed in J-field of concession NC-186, Murzuq basin, Libya. Twenty (3D) seismic lines and ten wells have been analyzed. The results of this study indicated that, the main reservoir in this concession is Hawaz Formation. Hawaz has been split into 8 units with a subdivision of Hawaz H4 into three subunits with the objective of better characterization of the three general fine upward intervals. The lower interval of H4 zone presents the better reservoir properties. The depth of reflector H4 ranges from 4100 ft in the northwestern part of the study area and increases to 4600 ft in the southeastern part of the study area. In this study, the outline of the Hawaz paleohighs which is NC-186 Field "J" is generally trending in the NW-SE direction. The well logging analysis particularly quick look interpretation indicates that Hawaz Formation in the studied wells is mainly oil-bearing with some water-bearing sand levels at the horizons from H4 to and H6 which are potentially the main reservoirs. The water bearing zones are beyond these horizons starting from the sub-horizon H6c and the oil water contact is probably at depth 4495 ft. The crossplot of porosity-saturation for H5 and H6b indicates firmly that these horizons are indeed at irreducible state and will produce mainly oil as indicated in J4-NC186 well, while the crossplot of H8 shows wide scattering of points which is the main characteristic for water producing horizon. The depth of Hawaz Formation H4 is more than 4160 ft in J4, J12 and J16 wells in the northwestern parts of this field and increases to 4400 in the central part of the concession at well J1.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Parana basin

    SciTech Connect

    Zalan, P.V.; Wolff, S.; Conceicao, J.C.J.; Vieira, I.S.; Astolfi, M.A.; Appi, V.T.; Zanotto, O.; Neto, E.V.S.; Cerqueira, J.R.

    1987-05-01

    The Parana basin is a large intracratonic basin in South America, developed entirely on continental crust and filled with sedimentary and volcanic rocks ranging in age from Silurian to Cretaceous. It occupies the southern portion of Brazil (1,100,000 km/sup 2/ or 425,000 mi/sup 2/) and the eastern half of Paraguay (100,000 km/sup 2/ or 39,000 mi/sup 2/); its extension into Argentina and Uruguay is known as the Chaco-Parana basin. Five major depositional sequences (Silurian, Devonian, Permo-Carboniferous, Triassic, Juro-Cretaceous) constitute the stratigraphic framework of the basin. The first four are predominantly siliciclastic in nature, and the fifth contains the most voluminous basaltic lava flows of the planet. Maximum thicknesses are in the order of 6000 m (19,646 ft). The sequences are separated by basin wide unconformities related in the Paleozoic to Andean orogenic events and in the Mesozoic to the continental breakup and sea floor spreading between South America and Africa. The structural framework of the Parana basin consists of a remarkable pattern of criss-crossing linear features (faults, fault zones, arches) clustered into three major groups (N45/sup 0/-65/sup 0/W, N50/sup 0/-70/sup 0/E, E-W). The northwest- and northeast-trending faults are long-lived tectonic elements inherited from the Precambrian basement whose recurrent activity throughout the Phanerozoic strongly influenced sedimentation, facies distribution, and development of structures in the basin. Thermomechanical analyses indicate three main phases of subsidence (Silurian-Devonian, late Carboniferous-Permian, Late Jurassic-Early Cretaceous) and low geothermal gradients until the beginning of the Late Jurassic Permian oil-prone source rocks attained maturation due to extra heat originated from Juro-Cretaceous igneous intrusions. The third phase of subsidence also coincided with strong tectonic reactivation and creation of a third structural trend (east-west).

  19. 17. VIEW OF SETTLING BASIN, SHOWING FLUME TRACK SPUR CROSSING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VIEW OF SETTLING BASIN, SHOWING FLUME TRACK SPUR CROSSING OVER SETTLING BASIN, SPARE BENT MATERIAL IN RIGHT-HAND FOREGROUND, BYPASS FLUME, AND SHACK #6 IN BACKGROUND, LOOKING NORTHWEST - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  20. 2. CATCH BASIN, INFLOW PIPES AT CENTER, COLD FLOW LABORATORY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CATCH BASIN, INFLOW PIPES AT CENTER, COLD FLOW LABORATORY AT LEFT, VIEW TOWARDS NORTHWEST. - Glenn L. Martin Company, Titan Missile Test Facilities, Catch Basin, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  1. Three-dimensional audio-frequency magnetotelluric imaging of Akebasitao granitic intrusions in Western Junggar, NW China

    NASA Astrophysics Data System (ADS)

    Yang, Bo; Zhang, Anqi; Zhang, Sheng; Liu, Ying; Zhang, Shengye; Li, Yongtao; Xu, Yixian; Wang, Qinyan

    2016-12-01

    An audio-frequency magnetotelluric (AMT) array was deployed here to map the resistivity structure of the Akebasitao intrusions and the surrounding area in Western Junggar, China. High quality AMT data were acquired at 463 sites that covered the whole Akebasitao intrusions. The latest 3D electromagnetic inversion system, ModEM, was employed to invert the AMT dataset. A high resolution resistivity model was recovered by using a nonlinear conjugate-gradient scheme. The Akebasitao intrusions, the most pronounced resistive features in the preferred model, are clearly imaged from shallow depths to more than 10 km, with some conductive zones and spots in and surrounding it. The shape of the Akebasitao pluton is asymmetrical mushroom-like, suggesting an extension stress environment at its forming age (the Late Carboniferous to the Early Permian) in Western Junggar. Our explanation is consistent with the subducting spreading ridge tectonic model for Western Junggar in the Late Carboniferous, with a paleo-Asia ocean plate subducting northwestward beneath Karamay arc, as former studies proposed. The upwelling channel of the Akebasitao pluton seems to be located at its center. The Darbut Fault has been clearly imaged as a subvertical narrow conductive zone extending from the surface to 3-5 km or deeper. The most prominent conductors are two elongate zones in depths deeper than 500 m. Other conductive zones can also be identified surrounding the boundaries of the Akebasitao pluton, which can be interpreted as pyrometasomatic metamorphism relating to magmatic activities. Because the ophiolitic rocks outcrop as some lens along these two boundaries, and as previous studies showed that the serpentine metamorphosed from peridotite with well-connected magnetite possessing high conductivity, the conductors may therefore also represent their sources in depth.

  2. 16. CONSTRUCTION DETAIL (NORTHWEST LOWER FOOT OF CRANE), LOOKING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. CONSTRUCTION DETAIL (NORTHWEST LOWER FOOT OF CRANE), LOOKING NORTHWEST - Cabot Station Electric Generating Plant, Gantry Crane, Montague City Road, Turners Falls vicinity, Montague, Franklin County, MA

  3. PACIFIC NORTHWEST CYBER SUMMIT

    SciTech Connect

    Lesperance, Ann M.; Matlock, Gordon W.; Becker-Dippmann, Angela S.; Smith, Karen S.

    2013-08-07

    On March 26, 2013, the Snohomish County Public Utility District (PUD) and the U.S. Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) jointly hosted the Pacific Northwest Cyber Summit with the DOE’s Office of Electricity Delivery and Energy Reliability, the White House, Washington State congressional delegation, Washington State National Guard, and regional energy companies.

  4. Kaiser Permanente Northwest

    Cancer.gov

    Kaiser Permanente Northwest's Center for Health Research was created to study health maintenance organizations by scientists were recruited from a variety of fields to study a range of health and medical care issues.

  5. VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 (SECOND BASING FROM THE EAST) SHOWING CRANEWAY AND GALLERY BETWEEN BASINS NO. 4 AND 5. GENERAL WAREHOUSE IS IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  6. Georgia Basin-Puget Sound Airshed Characterization Report 2014

    EPA Science Inventory

    The Georgia Basin - Puget Sound Airshed Characterization Report, 2012 was undertaken to characterize the air quality within the Georgia Basin/Puget Sound region,a vibrant, rapidly growing, urbanized area of the Pacific Northwest. The Georgia Basin - Puget Sound Airshed Characteri...

  7. Georgia Basin-Puget Sound Airshed Characterization Report 2014

    EPA Science Inventory

    The Georgia Basin - Puget Sound Airshed Characterization Report, 2012 was undertaken to characterize the air quality within the Georgia Basin/Puget Sound region,a vibrant, rapidly growing, urbanized area of the Pacific Northwest. The Georgia Basin - Puget Sound Airshed Characteri...

  8. 8. VIEW NORTHWEST, CORNER DETAIL OF NORTHWEST CORNER OF BRIDGE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW NORTHWEST, CORNER DETAIL OF NORTHWEST CORNER OF BRIDGE, WITH PORTAL BRACING FROM BRIDGE SURFACE - Jeffersonville Bridge, Spanning Lamoille River on Vermont Route 15, Cambridge, Lamoille County, VT

  9. 13. VIEW NORTHWEST, WEST TRUSS, DETAIL OF CONNECTION AT NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW NORTHWEST, WEST TRUSS, DETAIL OF CONNECTION AT NORTHWEST END POST AND TOP CHORD - Osborn Avenue Bridge, Spanning New Jersey Transit Raritan Valley Line at Tuttle Parkway (formerly Osborn Avenue), Westfield, Union County, NJ

  10. FACING NORTHWEST OF NORTHWEST CORNER OF CANDLER PARK Candler ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACING NORTHWEST OF NORTHWEST CORNER OF CANDLER PARK - Candler Park Historic District, Roughly bounded by Moreland, Dekalb, McLendon & Harold Avenues, Matthews Street & Clifton Terrace, Atlanta, Fulton County, GA

  11. 3. NORTHWEST INTERIOR VIEW OF NORTHWEST ROOM WITH EQUIPMENT FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. NORTHWEST INTERIOR VIEW OF NORTHWEST ROOM WITH EQUIPMENT FROM CENTER INTERIOR - Juniata Mill Complex, Assay Office, 22.5 miles Southwest of Hawthorne, between Aurora Crater & Aurora Peak, Hawthorne, Mineral County, NV

  12. Northwest Washington State

    NASA Image and Video Library

    1973-06-22

    SL2-05-458 (22 June 1973) --- Portions of northwest Washington State (48.0N, 122.5) can be seen in this view as well as portions of British Columbia, Canada. The snow covered Cascade Mountains are on the eastern side of the scene. Vancouver Island is visible in the northeast corner of the photo. The strait of Juan de Fuca separates Vancouver Island from the northwest corner of Washington. Seattle is near the center and the snow covered Olympic Mountains are to the east. Photo credit: NASA

  13. Cenozoic basin development in Hispaniola

    SciTech Connect

    Mann, P.; Burke, K.

    1984-04-01

    Four distinct generations of Cenozoic basins have developed in Hispaniola (Haiti and Dominican Republic) as a result of collisional or strike-slip interactions between the North America and Caribbean plates. First generation basins formed when the north-facing Hispaniola arc collided with the Bahama platform in the middle Eocene; because of large post-Eocene vertical movements, these basins are preserved locally in widely separated areas but contain several kilometers of arc and ophiolite-derived clastic marine sediments, probably deposited in thrust-loaded, flexure-type basins. Second generation basins, of which only one is exposed at the surface, formed during west-northwesterly strike-slip displacement of southern Cuba and northern Hispaniola relative to central Hispaniola during the middle to late Oligocene; deposition occurred along a 5-km (3-mi) wide fault-angle depression and consisted of about 2 km (1 mi) of submarine fan deposits. Third generation basins developed during post-Oligocene convergent strike-slip displacement across a restraining bend formed in central Hispaniola; the southern 2 basins are fairly symmetrical, thrust-bounded ramp valleys, and the third is an asymmetrical fault-angle basin. Fourth generation basins are pull-aparts formed during post-Miocene divergent strike-slip motion along a fault zone across southern Hispaniola. As in other Caribbean areas, good source rocks are present in all generations of basins, but suitable reservoir rocks are scarce. Proven reservoirs are late Neogene shallow marine and fluvial sandstones in third generation basins.

  14. Northwest Coast Indian Art.

    ERIC Educational Resources Information Center

    Manning, Thomas; Knecht, Elizabeth

    The visual art forms of the Northwest Coast Indian Tribes of Alaska (Haida, Tlingit, and Tsimshian) share common distinctive design elements (formline, ovoid, U-form, and curvilinear shapes) which are referred to as the "Northern Style." Designs represent events or characters taken from the oral tradition of song and legend.…

  15. Northwest Coast Indian Art.

    ERIC Educational Resources Information Center

    Manning, Thomas; Knecht, Elizabeth

    The visual art forms of the Northwest Coast Indian Tribes of Alaska (Haida, Tlingit, and Tsimshian) share common distinctive design elements (formline, ovoid, U-form, and curvilinear shapes) which are referred to as the "Northern Style." Designs represent events or characters taken from the oral tradition of song and legend.…

  16. Suicide in Northwest Alaska.

    ERIC Educational Resources Information Center

    Travis, Robert

    1983-01-01

    Between 1975 and 1979 the Alaskan Native suicide rate (90.9 per 100,000) in Northwest Alaska was more than seven times the national average. Alienation, loss of family, low income, alcohol abuse, high unemployment, and more education were factors related to suicidal behavior. Average age for suicidal behavior was 22.5. (Author/MH)

  17. Pacific Northwest geothermal - Review and outlook

    NASA Astrophysics Data System (ADS)

    Youngquist, W.

    1980-11-01

    Activities associated with geothermal exploration and development in the states of Idaho, Oregon, and Washington are reviewed. A geothermal electric plant on the Raft River is almost operational. Tests for space heating projects at Rexburg and in the City of Boise continue. The State of Oregon conducts its regional temperature gradient drilling program, and a number of shallow wells were drilled in 1979 and 1980. Deep well drilling (projected to 5,000 to 7,000 ft.) is pursued at Mount Hood. The eruption of Mount St. Helens has increased interest in the geothermal resources in Washington. A study of the warm and hot water potential on the northwest flank of Mount Ranier is negotiated. Possible space heating sources in 22 cities, towns, and hamlets in the Columbia Basin have been identified. Deleterious environmental impact on the forest regions of the Pacific Northwest is one reason for the Federal leasing problems. The electric power situation will be critical in the Northwest in 1983, as no additional power will probably be available to utilities from the Bonneville Power Administration. Indigenous U.S. energy sources can be developed and exploration activity can be increased if federal lease processing is greatly expedited.

  18. Buried-euxenic-basin model sets Tarim basin potential

    SciTech Connect

    Hsu, K.J. )

    1994-11-28

    The Tarim basin is the largest of the three large sedimentary basins of Northwest China. The North and Southwest depressions of Tarim are underlain by thick sediments and very thin crust. The maximum sediment thickness is more than 15 km. Of the several oil fields of Tarim, the three major fields were discovered during the last decade, on the north flank of the North depression and on the Central Tarim Uplift. The major targets of Tarim, according to the buried-euxenic-basin model, should be upper Paleozoic and lower Mesozoic reservoirs trapping oil and gas condensates from lower Paleozoic source beds. The paper describes the basin and gives a historical perspective of exploration activities and discoveries. It then explains how this basin can be interpreted by the buried-euxenic-basin model. The buried-euxenic-basin model postulates four stages of geologic evolution: (1) Sinian and early Paleozoic platform sedimentation on relic arcs and deep-marine sedimentation in back-arc basins in Xinjiang; (2) Late Paleozoic foreland-basin sedimentation in north Tarim; (3) Mesozoic and Paleogene continental deposition, subsidence under sedimentary load; and (4) Neogene pull-apart basin, wrench faulting and extension.

  19. 18. VIEW OF SETTLING BASIN FROM UPSTREAM TRESTLE, SHOWING BULKHEAD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF SETTLING BASIN FROM UPSTREAM TRESTLE, SHOWING BULKHEAD ON RIGHT AND SAND BANK ON LEFT, LOOKING NORTHWEST - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  20. 29. CIRCULAR WASH BASIN, TOILETS ABOVE ROOF PANEL STORAGE AREA. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. CIRCULAR WASH BASIN, TOILETS ABOVE ROOF PANEL STORAGE AREA. VIEW TO WEST-NORTHWEST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  1. Intra-Crater Structure in NW Hellas Basin, Mars

    NASA Image and Video Library

    2010-05-05

    This image from NASA Mars Reconnaissance Orbiter covers a small portion of the northwest quadrant of Hellas Basin, or Hellas Planitia, on southern Mars; Hellas is one of the largest impact craters in the solar system.

  2. Proceedings from a Workshop on Ecological Carrying Capacity of Salmonids in the Columbia River Basin : Measure 7.1A of the Northwest Power Planning Council`s 1994 Fish and Wildlife Program : Report 3 of 4, Final Report.

    SciTech Connect

    Johnson, Gary E.; Neitzel, D.A.; Mavros, William V.

    1996-05-01

    This report contains the proceedings of a workshop held during 1995 in Portland, Oregon. The objective of the workshop was to assemble a group of experts that could help us define carrying capacity for Columbia River Basin salmonids. The workshop was one activity designed to answer the questions asked in Measure 7.1A of the Council`s Fish and Wildlife Program. Based, in part, on the information we learned during the workshop we concluded that the approach inherent in 7.1A will not increase understanding of ecology, carrying capacity, or limiting factors that influence salmon under current conditions. Measure 7.1A requires a definition of carrying capacity and a list of determinants (limiting factors) of capacity. The implication or inference then follows that by asking what we know and do not know about the determinants will lead to research that increases our understanding of what is limiting salmon survival. It is then assumed that research results will point to management actions that can remove or repair the limiting factors. Most ecologists and fisheries scientists that have studied carrying capacity clearly conclude that this approach is an oversimplification of complex ecological processes. To pursue the capacity parameter, that is, a single number or set of numbers that quantify how many salmon the basin or any part of the basin can support, is meaningless by itself and will not provide useful information.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Injection of supercritical CO2 for enhanced oil recovery (EOR) presents an opportunity to evaluate the effects of CO2 on reservoir properties and formation waters during geologic carbon sequestration. Produced water from oil wells tapping a carbonate-hosted reservoir at an active EOR site in the Permian Basin of Texas both before and after injection were sampled to evaluate geochemical and isotopic changes associated with water-rock-CO2 interaction. Produced waters from the carbonate reservoir rock are Na-Cl brines with TDS levels of 16.5-34 g/L and detectable H2S. These brines are potentially diluted with shallow groundwater from earlier EOR water flooding. Initial lithium isotope data (δ7Li) from pre-injection produced water in the EOR field fall within the range of Gulf of Mexico Coastal sedimentary basin and Appalachian basin values (Macpherson et al., 2014, Geofluids, doi: 10.1111/gfl.12084). Pre-injection produced water 87Sr/86Sr ratios (0.70788-0.70795) are consistent with mid-late Permian seawater/carbonate. CO2 injection took place in October 2013, and four of the wells sampled in May 2014 showed CO2 breakthrough. Preliminary comparison of pre- and post-injection produced waters indicates no significant changes in the major inorganic constituents following breakthrough, other than a possible drop in K concentration. Trace element and isotope data from pre- and post-breakthrough wells are currently being evaluated and will be presented.

  4. Petrogenesis of the Yangzhuang Nb- and Ta-rich A-type granite porphyry in West Junggar, Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Mao, Wei; Li, Xiaofeng; Wang, Guo; Xiao, Rong; Wang, Mou; Li, Yanlong; Ren, Manchuan; Bai, Yanping; Yang, Feng

    2014-06-01

    West Junggar is featured with a wide spread of Late Carboniferous-Early Permian A-type granites. Systematic comparison of the Yangzhuang granite porphyry and the regional coeval A-type granites (RCAG) shows that: (1) all the Late Carboniferous-Early Permian A-type granites are of the A2 group except the Yangzhuang granite porphyry; (2) the Nb and Ta contents of the Yangzhuang granite porphyry are nearly 10 times that of the RCAG while Ti content is more depleted; (3) εNd (t) of the Yangzhuang granite porphyry is slightly lower and the Sr isotope has a wider range relative to the RCAG. Previous research revealed that highly incompatible elements including Nb and Ta can be transferred into the mantle wedge by precipitation of amphibole from the ascending fluids generated by dehydration of subducted slab. It is inferred that enhanced heat flux brought by the Late Carboniferous ridge subduction decomposed amphibole in the mantle wedge to generate Nb and Ta-rich melt and finally produced the Yangzhuang granite porphyry.

  5. Tectonic framework of Turkish sedimentary basins

    SciTech Connect

    Yilmaz, P.O. )

    1988-08-01

    Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary. The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very little in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide. The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in mesozoic and Tertiary. The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.

  6. Holocene paleoenviroments of northwest Iowa

    SciTech Connect

    Baker, R.G.; Bettis, E.A. III; Schwert, D.P.

    1996-05-01

    This paper presents the biotic, sedimentary, geomorphic, and climatic history of the upper part of the Roberts Creek Basin, northeastern Iowa for the late-glacial and Holocene, and compares these records with a C-O isotopic sequence from Coldwater Cave, 60 km northwest of Roberts Creek. the biotic record (pollen, vascular plant and bryophyte macrofossils, and insects) is preserved in floodplain alluvium that underlies three constructional surfaces separated by low scarps. Each surface is underlain by a lithologically and temporally distinct alluvial fill. The highest surface is underlain by the Gunder Member of the Deforest Formation, dating from 11,000 to 4000 yr BP; beneath the intermediate level is the Roberts Creek Member, dating from 4000 to 400 yr BP; and the lowest level is underlain by the Camp Creek Member, deposited during the last 380 yr. Pollen and plant macrofossils in the alluvial fill show that a typical late-glacial spruce forest was replaced by Quercus and Ulmus in the early Holocene. This early-to-middle Holocene forest became dominated by medic elements such as Acer saccharum, Tila americana, Ostyra virginiana, and Carpinus caroliniana as late as 5500 yr BP; in contrast, the closest sites to the west and north were at their warmest and driest were covered by prairie vegetation between 6500 and 5500 yr BP. After 5500 yr BP, the forest in the roberts Creek area was replaced by prairie, as indicated by a rich assemblage of plant macrofossils, although only Ambrosia and Poaceae became abundant in the pollen record. The return of Quercus {approx} 3000 BP (while nonarboreal pollen percentages remained relatively high) indicates the oak savanna prevailed with little change until settlement time. 83 refs., 17 figs., 5 tabs.

  7. Plio-Pleistocene facies environments from the KBS Member, Koobi Fora Formation: implications for climate controls on the development of lake-margin hominin habitats in the northeast Turkana Basin (northwest Kenya).

    PubMed

    Lepre, Christopher J; Quinn, Rhonda L; Joordens, Josephine C A; Swisher, Carl C; Feibel, Craig S

    2007-11-01

    Climate change is hypothesized as a cause of major events of Plio-Pleistocene East African hominin evolution, but the vertically discontinuous and laterally confined nature of the relevant geological records has led to difficulties with assessing probable links between the two. High-resolution sedimentary sequences from lacustrine settings can provide comprehensive data of environmental changes and detailed correlations with well-established orbital and marine records of climate. Hominin-bearing deposits from Koobi Fora Ridge localities in the northeast Turkana Basin of Kenya are an archive of Plio-Pleistocene lake-margin sedimentation though significant developmental junctures of northern African climates, East African environments, and hominin evolution. This study examines alluvial channel and floodplain, nearshore lacustrine, and offshore lacustrine facies environments for the approximately 136-m-thick KBS Member (Koobi Fora Formation) exposed at the Koobi Fora Ridge. Aspects of the facies environments record information on the changing hydrosedimentary dynamics of the lake margin and give insights into potential climatic controls. Seasonal/yearly climate changes are represented by the varve-like laminations in offshore mudstones and the slickensides, dish-shaped fractures, and other paleosol features overprinted on floodplain strata. Vertical shifts between facies environments, however, are interpreted to indicate lake-level fluctuations deriving from longer-term, dry-wet periods in monsoonal rainfall. Recurrence periods for the inferred lake-level changes range from about 10,000 to 50,000 years, and several are consistent with the average estimated timescales of orbital precession ( approximately 20,000 years) and obliquity ( approximately 40,000 years). KBS Member facies environments from the Koobi Fora Ridge document the development of lake-margin hominin habitats in the northeast Turkana Basin. Environmental changes in these habitats may be a result of

  8. Zircon U-Pb ages and Hf isotopes of the Askot klippe, Kumaun, northwest India: Implications for Paleoproterozoic tectonics, basin evolution and associated metallogeny of the northern Indian cratonic margin

    NASA Astrophysics Data System (ADS)

    Mandal, Subhadip; Robinson, Delores M.; Kohn, Matthew J.; Khanal, Subodha; Das, Oindrila; Bose, Sukhanjan

    2016-04-01

    Throughout the Himalayan thrust belt, klippen of questionable tectonostratigraphic affinity occur atop Lesser Himalayan rocks. Integrated U-Pb ages, Hf isotopic, and whole rock trace element data establish that the Askot klippe, in northwest India, is composed of Paleoproterozoic lower Lesser Himalayan rocks, not Greater Himalayan rocks, as previously interpreted. The Askot klippe consists of 1857 ± 19 Ma granite-granodiorite gneiss, coeval 1878 ± 19 Ma felsic volcanic rock, and circa 1800 Ma Berinag quartzite, representing a small vestige of a Paleoproterozoic (circa 1850 Ma) continental arc, formed on northern margin of the north Indian cratonic block. Detrital zircon from Berinag quartzite shows ɛHf1850 Ma values between -9.6 and -1.1 (an average of -4.5) and overlaps with ɛHf1850 Ma values of the Askot klippe granite-granodiorite gneiss (-5.5 to -1.2, with an average of -2.7) and other Paleoproterozoic arc-related Lesser Himalayan granite gneisses ( -4.8 to -2.2, with an average of -4.0). These overlapping data suggest a proximal arc source for the metasedimentary rocks. Subchondritic ɛHf1850 Ma values (-5.5 to -1.2) of granite-granodiorite gneiss indicate existence of a preexisting older crust that underwent crustal reworking at circa 1850 Ma. A wide range of ɛHf1850 Ma values in detrital zircon (-15.0 to -1.1) suggests that a heterogeneous crustal source supplied detritus to the northern margin of India. These data, as well as the presence of a volcanogenic massive sulphide deposit within the Askot klippe, are consistent with a circa 1800 Ma intra-arc extensional environment.

  9. Northwest Area Science

    USGS Publications Warehouse

    Fuentes, Tracy L.; van Heeswijk, Marijke; Grossman, Eric E.

    2010-01-01

    Northwest Area Facts * Population about 12 million * 43 federally recognized Tribes * Hydropower provides about two-thirds of electricity supply * 78 federally listed threatened and endangered species * 12 active or potentially active volcanoes * Columbia River system drains more than 260,000 square miles, an area about the size of Texas * More than 175 square miles covered by glaciers * More than 900 miles of Pacific Ocean coastline * More than 2,300 miles of greater Puget Sound coastline * Some forests store more carbon per unit area than any other area in the world, including the tropics * 51 percent federal lands * Significant lead, zinc, silver, and phosphate deposits

  10. Pacific Northwest election results

    NASA Astrophysics Data System (ADS)

    Qamar, Anthony

    Six AGU members have been elected members of the Regional Committee of the AGU Pacific Northwest Region. Their terms are July 1, 1986, to June 30, 1988. The Regional Committee, which directs the activities of the branch, is composed of a representative of each of the AGU sections taking part in branch activities.Those elected are Robert M. Ellis, Tectonophysics Section; Stephen L. Gillett, Geomagnetism and Paleomagnetism Section; Tark S. Hamilton, Volcanology, Geochemistry, and Petrology Section; Renner B. Hofmann, Seismology Section; Charles W. Slaughter, Hydrology Section; and Richard E. Thomson, Ocean Sciences Section.

  11. Geodynamic scenario and structural styles of Mesozoic and Cenozoic basins in China

    SciTech Connect

    Hefu, L.

    1986-04-01

    The continental lithosphere of China is situated at the junction of the Marginal-Pacific and Tethys-Himalayan tectonic domains. The most manifest tectonic movements responsible for the deformation of the continental lithosphere of China are taphrogenic, collisional, and shearing. These movements played an important role in the Mesozoic and Cenozoic tectonic evolution of China and formed various types of Mesozoic and Cenozoic basins in China. The Marginal-Pacific crust in eastern China was attenuated by rifting and developed north-northeast-trending Mesozoic and Cenozoic basins, e.g., the Songliao, Bohai Bay, and Jianghan basins. Rifting mainly followed preexisting lineaments or shear zones in the basement. Then basin-range (graben-horst) structures and large fault-bounded basins developed. Extensional structural styles have prevailed in Mesozoic and Cenozoic basins in eastern China, with listric faults and tilted blocks in the basement, and detached faults, growth faults, and rollover anticlines or drape folds in the cover rocks. These structures are favorable for hydrocarbon accumulation; thus, the famous Daqing and Zhongyuan oil fields formed in Songliao basin and Bohai Bay basin, respectively. In western China the continental crust thickened by collision and formed a series of Mesozoic and Cenozoic intermontane and foreland basins, such as the Junggar (Dzungaria), Tarim, and Qaidam basins. Contraction structural styles are predominant in Mesozoic and Cenozoic basins in western China, with shortened fault blocks and ramps in basement, and thrust faults and folds in the cover rocks. The Kelamayi and Laojunmiao oil fields formed in these compressional basins. 22 figures, 1 table.

  12. Caribbean basin framework, 3: Southern Central America and Colombian basin

    SciTech Connect

    Kolarsky, R.A.; Mann, P. )

    1991-03-01

    The authors recognize three basin-forming periods in southern Central America (Panama, Costa Rica, southern Nicaragua) that they attempt to correlate with events in the Colombian basin (Bowland, 1984): (1) Early-Late Cretaceous island arc formation and growth of the Central American island arc and Late Cretaceous formation of the Colombian basin oceanic plateau. During latest Cretaceous time, pelagic carbonate sediments blanketed the Central American island arc in Panama and Costa Rica and elevated blocks on the Colombian basin oceanic plateau; (2) middle Eocene-middle Miocene island arc uplift and erosion. During this interval, influx of distal terrigenous turbidites in most areas of Panama, Costa Rica, and the Colombian basin marks the uplift and erosion of the Central American island arc. In the Colombian basin, turbidites fill in basement relief and accumulate to thicknesses up to 2 km in the deepest part of the basin. In Costa Rica, sedimentation was concentrated in fore-arc (Terraba) and back-arc (El Limon) basins; (3) late Miocene-Recent accelerated uplift and erosion of segments of the Central American arc. Influx of proximal terrigenous turbidites and alluvial fans in most areas of Panama, Costa Rica, and the Colombian basin marks collision of the Panama arc with the South American continent (late Miocene early Pliocene) and collision of the Cocos Ridge with the Costa Rican arc (late Pleistocene). The Cocos Ridge collision inverted the Terraba and El Limon basins. The Panama arc collision produced northeast-striking left-lateral strike-slip faults and fault-related basins throughout Panama as Panama moved northwest over the Colombian basin.

  13. Northwester upstairs room of northwest wing looking southeast through stair ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Northwester upstairs room of northwest wing looking southeast through stair landing and hallway to southeast room. note far floorboard with smoke damage between historic joists; modern joists in stair landing. - Scheetz Farm, House, 7161 Camp Hill Road, Fort Washington, Montgomery County, PA

  14. Northwest Climate Risk Assessment

    NASA Astrophysics Data System (ADS)

    Mote, P.; Dalton, M. M.; Snover, A. K.

    2012-12-01

    As part of the US National Climate Assessment, the Northwest region undertook a process of climate risk assessment. This process included an expert evaluation of previously identified impacts, their likelihoods, and consequences, and engaged experts from both academia and natural resource management practice (federal, tribal, state, local, private, and non-profit) in a workshop setting. An important input was a list of 11 risks compiled by state agencies in Oregon and similar adaptation efforts in Washington. By considering jointly the likelihoods, consequences, and adaptive capacity, participants arrived at an approximately ranked list of risks which was further assessed and prioritized through a series of risk scoring exercises to arrive at the top three climate risks facing the Northwest: 1) changes in amount and timing of streamflow related to snowmelt, causing far-reaching ecological and socioeconomic consequences; 2) coastal erosion and inundation, and changing ocean acidity, combined with low adaptive capacity in the coastal zone to create large risks; and 3) the combined effects of wildfire, insect outbreaks, and diseases will cause large areas of forest mortality and long-term transformation of forest landscapes.

  15. Atlantic marginal basins of Africa

    SciTech Connect

    Moore, G.T.

    1988-02-01

    The over 10,000-km long Atlantic margin of Africa is divisible into thirty basins or segments of the margin that collectively contain over 18.6 x 10/sup 6/ km/sup 3/ of syn-breakup and post-breakup sediments. Twenty of these basins contain a sufficiently thick volume of sediments to be considered prospects. These basins lie, at least partially, within the 200 m isobath. The distribution of source rocks is broad enough to give potential to each of these basins. The sedimentation patterns, tectonics, and timing of events differ from basin to basin and are related directly to the margin's complex history. Two spreading modes exist: rift and transform. Rifting dates from Late Triassic-Early Jurassic in the northwest to Early Cretaceous south of the Niger Delta. A complex transform fault system separated these two margins. Deep-water communication between the two basins became established in the middle Cretaceous. This Mesozoic-Cenozoic cycle of rifting and seafloor spreading has segmented the margin and where observable, basins tend to be bounded by these segments.

  16. Tectonic model for Eocene Formation of the Columbia basin

    SciTech Connect

    Fisk, L.H. ); Fritts, S.G. )

    1990-05-01

    Evidence suggests that a major sedimentary basin underlies the Columbia plateau in Oregon and Washington; however, the Miocene Columbia River Basalts conceal critical structural relationships between adjacent exotic terranes. To date, no interpretations have been published that adequately address the three related questions of the architecture, age, and mechanism of formation of the Columbia basin. The authors interpret residual gravity and aerial photographic data to show, within the basin, a pattern of deep fault architecture consistent with northwest-southeast-oriented rifting. Paleotectonic reconstructions for the Pacific Northwest suggest that rifting may have begun during the Cretaceous, as interpreted previously, but stratigraphic, geophysical and well data point to an early Eocene age for initiation of dramatic rifting and basin subsidence resulting from oblique subduction of the Farallon plate. Their tectonic model for Eocene formation of rift basins underlying the Columbia River Basalt addresses important, previously unanswered questions regarding the tectonics of the Pacific Northwest and rationally relates tectonics and sedimentation over the full extent of the basin from north-central Washington to north-central Oregon. The rifting event(s) they propose explain that the formation of the Columbia basin is consistent in timing and geometry with tectonic events in areas adjacent to the Columbia basin, and thus is but a part of a much larger picture of dramatic extension affecting the entire Pacific Northwest in the Eocene.

  17. Educational Needs in Northwest Schools.

    ERIC Educational Resources Information Center

    Nelson, Steven R.; Hegg, Lauren

    This needs assessment identified six educational needs and issues of schools in the Northwest region, prioritized Northwest Regional Educational Laboratory (NWREL) areas of emphasis, evaluated research/development strategies to address these needs and priorities, and applied assessment results to NWREL program planning activities. Assessment…

  18. Physics Northwest: An Academic Alliance

    ERIC Educational Resources Information Center

    Hicks, James L.

    2007-01-01

    It's a weekday in mid-October, late at night and with another teaching assignment not far below the horizon. Yet 40 teachers are laughing, joking, and sharing in the fun that is associated with physics teaching. The event: a Physics Northwest (PNW) meeting, an organization that is in its 20th year and thriving. "Physics Northwest meetings are…

  19. Physics Northwest: An Academic Alliance

    ERIC Educational Resources Information Center

    Hicks, James L.

    2007-01-01

    It's a weekday in mid-October, late at night and with another teaching assignment not far below the horizon. Yet 40 teachers are laughing, joking, and sharing in the fun that is associated with physics teaching. The event: a Physics Northwest (PNW) meeting, an organization that is in its 20th year and thriving. "Physics Northwest meetings are…

  20. 76 FR 13438 - Amended Columbia River Basin Fish and Wildlife Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-11

    ... POWER AND CONSERVATION PLANNING COUNCIL Amended Columbia River Basin Fish and Wildlife Program AGENCY... Council's Columbia River Basin Fish and Wildlife Program. SUMMARY: Pursuant to Section 4(h) of the Northwest Power Act, the Council has amended its Columbia River Basin Fish and Wildlife Program to add...

  1. 75 FR 64752 - Amended Columbia River Basin Fish and Wildlife Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... POWER AND CONSERVATION PLANNING COUNCIL Amended Columbia River Basin Fish and Wildlife Program AGENCY... Council's Columbia River Basin Fish and Wildlife Program. SUMMARY: Pursuant to Section 4(h) of the Northwest Power Act, the Council has amended its Columbia River Basin Fish and Wildlife Program to add...

  2. 76 FR 13676 - Amended Columbia River Basin Fish and Wildlife Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... POWER AND CONSERVATION PLANNING COUNCIL Amended Columbia River Basin Fish and Wildlife Program AGENCY... Council's Columbia River Basin Fish and Wildlife Program. SUMMARY: Pursuant to Section 4(h) of the Northwest Power Act, the Council has amended its Columbia River Basin Fish and Wildlife Program to add...

  3. Northwest corner of Wyoming

    NASA Image and Video Library

    1974-02-01

    SL4-138-3846 (February 1974) --- A near vertical view of the snow-covered northwest corner of Wyoming as seen from the Skylab space station in Earth orbit. A Skylab 4 crewman used a hand-held 70mm Hasselblad camera to take this picture. A small portion of Montana and Idaho is seen in this photograph also. The dark area is Yellowstone National Park. The largest body of water is Yellowstone Lake. The Absaroka Range is immediately east and northeast of Yellowstone Lake. The elongated range in the eastern part of the picture is the Big Horn Mountain range. The Wind River Range is at bottom center. The Grand Teton National Park area is almost straight south of Yellowstone Lake. Approximately 30 per cent of the state of Wyoming can be seen in this photograph. Photo credit: NASA

  4. Perspective of gas exploration in Ying-Qiong Basin

    SciTech Connect

    He, Hanyi; Zhongtiang Hu )

    1996-01-01

    The Yinggehai and Qiongdongnan Basin (Ying-Qiong Basin) in the northwest part of the South China Sea is a Cenozoic sedimentary basin, which has fast-subsiding and thick sediments. The maximum Cenozoic sediments in the center part of the basin is 20,000 m. Six sets of source rocks with prevailing Type III kerogen were developed in the basin, which has a great potential for gas generation. Different types of reservoirs and traps, leading to different assemblages of source rocks, reservoirs, and cap rocks, form good gas pools. Abnormal high temperature and high pressure in the basin resulted in many mud diapirs and made the generation, migration, and accumulation of gas more colorful. Up to now, four gas fields have been discovered in the basin. A large number of anticlines and stratigraphic-lithologic traps in the basin provide an extensive area for gas exploration. The perspective of gas exploration in the basin is vast and bright.

  5. Perspective of gas exploration in Ying-Qiong Basin

    SciTech Connect

    He, Hanyi; Zhongtiang Hu

    1996-12-31

    The Yinggehai and Qiongdongnan Basin (Ying-Qiong Basin) in the northwest part of the South China Sea is a Cenozoic sedimentary basin, which has fast-subsiding and thick sediments. The maximum Cenozoic sediments in the center part of the basin is 20,000 m. Six sets of source rocks with prevailing Type III kerogen were developed in the basin, which has a great potential for gas generation. Different types of reservoirs and traps, leading to different assemblages of source rocks, reservoirs, and cap rocks, form good gas pools. Abnormal high temperature and high pressure in the basin resulted in many mud diapirs and made the generation, migration, and accumulation of gas more colorful. Up to now, four gas fields have been discovered in the basin. A large number of anticlines and stratigraphic-lithologic traps in the basin provide an extensive area for gas exploration. The perspective of gas exploration in the basin is vast and bright.

  6. The long wavelength topography of Beethoven and Tolstoj basins, Mercury

    NASA Astrophysics Data System (ADS)

    André, Sarah L.; Watters, Thomas R.; Robinson, Mark S.

    2005-11-01

    Topography derived from Mariner 10 stereo images is used to characterize the interior structure of two mercurian basins, Beethoven and Tolstoj. Beethoven and Tolstoj basins are shallow (~2.5 km and ~2 km deep, respectively) and relatively flat-floored. Beethoven basin has an interior topographic rise near the northwest margin. The topography of Beethoven and Tolstoj basins is similar to that of lunar mare-filled basins. Well-developed basin-concentric wrinkle ridges and arcuate graben associated with lunar mascons are absent in both Beethoven and Tolstoj basins. The lack of mascon tectonic features suggests that either 1) the mercurian basins have a relatively thin veneer of fill material, 2) Mercury's elastic lithosphere was too strong for significant lithospheric flexure and subsidence to occur, or 3) the basin fill material has little or no density contrast with the surrounding crust and thus exerts little net load on the mercurian lithosphere.

  7. Kandik basin stratigraphy, sedimentology, and structure

    SciTech Connect

    Wiley, T.J.; Howell, D.G.; Kauffman-Linam, L.; Boundy-Sanders, S.; Murray, R.W.; Jones, D.L.

    1987-05-01

    East-central Alaska's Kandik basin is a structural remnant of a larger Permian to Cretaceous basin. Permian shallow-water Tahkandit Limestone and Step Conglomerate at the base of the sequence rest unconformably on Paleozoic chert-pebble conglomerate, siliceous shale, and limestone. These Permian rocks are overlain by Triassic to Lower Cretaceous open-ocean Glenn Shale, which grades upward into Lower Cretaceous (Valanginian) hummocky cross-bedded (outer shelf to upper slope) Keenan Quartzite. The quartzite grades upward into fine-grained north-northeast-flowing turbidites of the Biederman Argillite (undated). East-northeast-flowing pebbly turbidites of the Kathul Graywacke (undated) overlie Biederman strata. Locally, Cretaceous (Albian and younger) through Paleogene nonmarine rocks unconformably overlie the Kandik basin sequence. The Mesozoic part of the sequence is similar to that of Manley basin, northwest Yukon Territory, and much of the North Slope. East-directed flow for Kandik basin strata may require paleogeographic reconstructions involving local to large-scale palinspastic rotations or a western source of chert detritus. Deformation of the Mesozoic sequence in Kandik basin west of the US-Canada border shows northwest-southeast shortening. Shaly units are tightly folded with well-developed cleavage striking northeast. Strikes of beds swing from northeast to east in the extreme southwestern part of the basin, suggesting clockwise rotation. Thrust faults, reverse faults, and fold axes trend east to northeast; normal faults trend northwest. These relations are all consistent with, and probably are closely related to, right slip on the west-northwest-trending Tintina fault.

  8. Global warming: A Northwest perspective

    SciTech Connect

    Scott, M.J.; Counts, C.A.

    1990-02-01

    The Northwest Power Planning Council convened a symposium in Olympia, Washington, on the subject of global climate change ( the greenhouse effect'') and its potential for affecting the Pacific Northwest. The symposium was organized in response to a need by the Power Council to understand global climate change and its potential impacts on resource planning and fish and wildlife planning for the region, as well as a need to understand national policy developing toward climate change and the Pacific Northwest's role in it. 40 figs., 15 tabs.

  9. Perspective view of the library, looking northwest from the northwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perspective view of the library, looking northwest from the northwest corner of the administration building: central and east parts of the original south front are sunlit at the left, and the east side is at the right. The north part of the 1962 addition is built in to the central part of the south front. - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  10. Sedimentation of shelf sandstones in Queen Formation, McFarland and Means fields, central basin platform of Permian basin

    SciTech Connect

    Malicse, A.; Mazzullo, J.; Holley, C.; Mazzullo, S.J.

    1988-01-01

    The Queen Formation is a sequence of carbonates, evaporites, and sandstones of Permian (Guadalupian) age that is found across the subsurface of the Central Basin platform of the Permian basin. The formation is a major hydrocarbon reservoir in this region, and its primary reservoir facies are porous shelf sandstones and dolomites. Cores and well logs from McFarland and Means fields (on the northwest margin of the Central Basin platform) were examined to determine the sedimentary history of the shelf sandstones.

  11. Caribbean basin framework, 4: Maracaibo basin, northwestern Venezuela

    SciTech Connect

    Lugo, J. )

    1991-03-01

    The Maracaibo basin is presently located in a topographic depression on the Maracaibo block, a triangular, fault-bounded block within the Caribbean-South America plate boundary of northwestern Venezuela. Intense oil exploration over the last 50 years has produced a large amount of seismic and well data that can be used to constrain four Jurassic to Recent tectonic and depositional events that affected the region: (1). Late Jurassic rift phase and subsidence along normal faults striking north-northeast across the floor of the basin; (2) Cretaceous to early Eocene subsidence recorded by shallow to deep marine carbonate and clastic rocks that thicken from south to north and completely cover Permian rocks of the Merida arch; (3) Eocene folding, thrusting, and initial reactivation of Jurassic normal faults as convergent strike-slip and reverse faults. Eocene clastic sediments are thickest in a narrow northwest-trending foredeep on the northeastern margin of the basin; (4) Late Miocene to Recent northwest-southeast convergence is marked by continued reactivation of Jurassic normal faults as reverse and left-lateral strike-slip faults, uplift of mountain ranges bordering the basin, and deposition of up to 10 km of clastic sediment.

  12. Research, monitoring and evaluation of fish and wildlife restoration projects in the Columbia River Basin: Lessons learned and suggestions for large-scale monitoring programs.

    Treesearch

    Lyman L. McDonald; Robert Bilby; Peter A. Bisson; Charles C. Coutant; John M. Epifanio; Daniel Goodman; Susan Hanna; Nancy Huntly; Erik Merrill; Brian Riddell; William Liss; Eric J. Loudenslager; David P. Philipp; William Smoker; Richard R. Whitney; Richard N. Williams

    2007-01-01

    The year 2006 marked two milestones in the Columbia River Basin and the Pacific Northwest region's efforts to rebuild its once great salmon and steelhead runs: the 25th anniversary of the creation of the Northwest Power and Conservation Council and the 10th anniversary of an amendment to the Northwest Power Act that formalized scientific peer review of the council...

  13. Mississippian facies relationships, eastern Anadarko basin, Oklahoma

    SciTech Connect

    Peace, H.W. ); Forgotson, J.M. )

    1991-08-01

    Mississippian strata in the eastern Anadarko basin record a gradual deepening of the basin. Late and post-Mississippian tectonism (Wichita and Arbuckle orogenies) fragmented the single large basin into the series of paired basins and uplifts recognized in the southern half of Oklahoma today. Lower Mississippian isopach and facies trends (Sycamore and Caney Formations) indicate that basinal strike in the study area (southeastern Anadarko basin) was predominantly east-west. Depositional environment interpretations made for Lower Mississippian strata suggest that the basin was partially sediment starved and exhibited a low shelf-to-basin gradient. Upper Mississippian isopach and facies trends suggest that basinal strike within the study area shifted from dominantly east-west to dominantly northwest-southeast due to Late Mississippian and Early Pennsylvanian uplift along the Nemaha ridge. Within the study area, the Chester Formation, composed of gray to dove-gray shales with interbedded limestones deposited on a carbonate shelf, thins depositionally into the basin and is thinnest at its facies boundary with the Springer Group and the upper portion of the Caney Formation. As basin subsidence rates accelerated, the southern edge of the Chester carbonate shelf was progressively drowned, causing a backstepping of the Chester Formation calcareous shale and carbonate facies. Springer Group sands and black shales transgressed northward over the drowned Chester Formation shelf.

  14. Methane origin and oxygen-fugacity evolution of the Baogutu reduced porphyry Cu deposit in the West Junggar terrain, China

    NASA Astrophysics Data System (ADS)

    Shen, Ping; Pan, HongDi

    2015-12-01

    Most porphyry copper deposits worldwide contain magnetite, hematite, and anhydrite in equilibrium with hypogene copper-iron sulfides (chalcopyrite, bornite) and have fluid inclusions with CO2 >> CH4 that are indicative of high fO2. In contrast, the Baogutu porphyry Cu deposit in the West Junggar terrain (Xinjiang, China) lacks hematite and anhydrite, contains abundant pyrrhotite and ilmenite in equilibrium with copper-iron sulfides (chalcopyrite), and has fluid inclusions with CH4 >> CO2 that are indicative of low fO2. The mineralized intrusive phases at Baogutu include the main-stage diorite stock and minor late-stage diorite porphyry dikes. The main-stage stock underwent fractional crystallization and country-rock assimilation-contamination, and consists of dominant diorite and minor gabbro and tonalite porphyry. The country rocks contain organic carbons (0.21-0.79 wt.%). The δ13CvPDB values of the whole rocks (-23.1 to -25.8 ‰) in the wall rocks suggest a sedimentary organic carbon source. The δ13CvPDB values of CH4 (-28.2 to -36.0 ‰) and CO2 (-6.8 to -20.0 ‰) in fluid inclusions require an organic source of external carbon and equilibration of their Δ13CCO2-CH4 values (8.2-25.0 ‰) at elevated temperatures (294-830 °C) suggesting a significant contribution of thermogenic CH4. Mineral composition data on the main-stage intrusions, such as clinopyroxene, hornblende, biotite, magnetite, ilmenite, sphene, apatite, and pyrrhotite, suggest that the primary magma at Baogutu was oxidized and became reduced after emplacement by contamination with country rocks. Mineral compositions and fluid inclusion gas compositions suggest that the redox state of the system evolved from log fO2 > FMQ + 1 in the magma stage, to log fO2 < FMQ as a consequence of country rocks assimilation-contamination, to log fO2 > FMQ in the hydrothermal stage. Though oxidized magma was emplaced initially, assimilation-contamination of carbonaceous country rocks decreased its fO2 such that

  15. Timber resources of northwest Oregon.

    Treesearch

    Mary A. Mei

    1979-01-01

    This report presents statistics from a 1976 timber resource inventory of 10 counties in northwest Oregon: Clackamas, Clatsop, Columbia, Hood River, Marion, Multnomah, Polk, Tillamook, Washington, and Yamhill. Tables presented are of forest area, timber volume, growth, mortality, and harvest.

  16. Rice Cultivation in Northwest Italy

    NASA Image and Video Library

    2005-06-08

    The lowlands of Lombardy and Piedmont in northwest Italy are some of the most highly developed irrigation areas in the world. These views of the region were acquired on May 8, 2005, by NASA Terra spacecraft.

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

    NASA Astrophysics Data System (ADS)

    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

  18. Diagenesis of niagaran (middle silurian) pinnacle reefs, northwest Michigan

    NASA Astrophysics Data System (ADS)

    Cercone, K. R.

    The presence of geothermal gradients 10 to 20 C higher than the current average gradient (25 C/km), and of one kilometer of now eroded overburden in the Michigan Basin during the Paleozoic can be inferred from the high organic maturity of basin strata using the Lopatin method. These data are used to reconstruct the burial history of a single pinnacle reef from northwest Michigan, allowing absolute time constraints to be placed on reef diagenesis. Partial dolomitization occurred during subaerial exposure just after reef growth; regional dolomitization occurred between the late Silurian and the Devonian; and late mineralization by calcite, dolomite and pyrite occurred after Mississippian hydrocarbon emplacement and before the end of the Jurassic. There is no evidence that a well-developed fresh-water lens was ever present in this reef. Regional controls on carbonate diagenesis in this northwest reef trend include: size and hydraulic conductivity of reefs, thickness and lithology of adjacent and overlying evaporites, migration paths of late gypsum-derived and basinal brines, and the timing of anaerobic fermentation in organic-rich carbonates.

  19. Provenance and basin evolution, Zhada basin, southwestern Tibet

    NASA Astrophysics Data System (ADS)

    Saylor, J.; Decelles, P.; Gehrels, G.; Kapp, P.

    2007-12-01

    The Zhada basin is a late Miocene - Pliocene intermontane basin situated at high elevations in the Himalayan hinterland. The fluvial and lacustrine sediments of the Zhada formation are undeformed and sit in angular unconformity above the deformed Tethyan Sedimentary Sequence (TSS). The basin sits just south of the Indus suture in a structural position occupied elsewhere in the Himalayan orogen by some of the highest mountains on earth, including Everest. The occurrence of a basin at this location demands explanation. Currently, the Sutlej River flows parallel to the structural grain of the Himalaya, westward through the basin, towards the Leo Pargil (Qusum) range. Near the range front it takes a sharp southward turn, cuts across the structural grain of the Himalaya and out into the Gangetic foreland. Palaeocurrent indicators in the lower part of the Zhada formation show that the basin originated as a northwest flowing axial river. Palaeocurrent indicators are consistently northwest oriented, even to within to within 10 km of the Leo Pargil range front in the north-western end of the basin. This implies that at the onset of sedimentation in Zhada basin the Leo Pargil range was not a barrier as it is today. In the upper part of the Zhada formation, palaeocurrent indicators are generally directed towards the centre of the basin. In the central and southern portions of the basin this indicates a transition from an axial, northwest flowing river to prograding fluvial and alluvial fans. However, in the north-western part of the basin the change between lower and upper Zhada formation involves a complete drainage reversal. This change in palaeocurrent orientation is also reflected in the detrital zircon signal from basin sediments. Low in the Zhada formation the detrital zircon signal is dominated by zircons from the Kailash (Gangdese) batholith (or associated extrusives, see below). However, higher in the sections, a local source, either from the TSS or the core of the

  20. DELUGE AND WATER RECLAMATION BASIN BELOW TEST STAND 1A. Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DELUGE AND WATER RECLAMATION BASIN BELOW TEST STAND 1-A. Looking north northwest - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Flame Deflector Water System, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  1. Caloris Basin

    NASA Image and Video Library

    1999-12-07

    Caloris Basin on Mercury, is one of the largest basins in the solar system, its diameter exceeds 1300 kilometers and is in many ways similar to the great Imbrium basin on the Moon. This image is from NASA Mariner 10 spacecraft which launched in 1974.

  2. BPA Committed to Northwest Values

    SciTech Connect

    2010-09-01

    The Columbia River has been called the “crown jewel” of the Pacific Northwest. There is no question it is among the region’s greatest assets — supplying low-cost clean hydropower, making deserts bloom thanks to irrigation and providing navigation, recreation and a home for many species of fish and wildlife. The Bonneville Power Administration is proud to be a steward of this great resource. Our mission is to serve the people and environment of the Pacific Northwest. We sell wholesale power from Grand Coulee Dam and 30 other Northwest federal dams to Northwest utilities, including public utility districts, rural electric cooperatives and municipal utility departments, as well as investor-owned utilities. We operate three-fourths of the region’s high voltage transmission system that delivers that power. But, as a federal agency, we are not just a power marketer. We have public responsibilities that include, among many, promoting energy efficiency, facilitating development of renewable power, protecting fish and wildlife affected by hydro development, honoring treaty obligations to tribes and promoting a reliable energy future through collaboration and partnerships. This document describes our responsibilities to citizens in the Pacific Northwest.

  3. Radioactive air emissions notice of construction for the 105N Basin Stabilization

    SciTech Connect

    Coenenberg, E.T.

    1994-05-01

    The 105N Basin (basin) Stabilization will place the basin in a radiologically and environmentally safe condition so that it can be decommissioned at a later date. The basin is in the 105N Building, which is located in the 100N Area. The 100N Area is located in the Northern portion of the Hanford Site approximately 35 miles northwest of the city of Richland, Washington. The basin stabilization objectives are to inspect for Special Nuclear Material (SNM) (i.e., fuel assemblies and fuel pieces), remove the water from the basin and associated pits, and stabilize the basin surface. The stabilization will involve removal of basin hardware, removal of basin sediments, draining of basin water, and cleaning and stabilizing basin surfaces to prevent resuspension of radioactive emissions to the air. These activities will be conducted in accordance with all applicable regulations.

  4. Abiogenic Fischer-Tropsch synthesis of methane at the Baogutu reduced porphyry copper deposit, western Junggar, NW-China

    NASA Astrophysics Data System (ADS)

    Cao, MingJian; Qin, KeZhang; Li, GuangMing; Evans, Noreen J.; Jin, LuYing

    2014-09-01

    Methane is widely developed in hydrothermal fluids from reduced porphyry copper deposits, but its origin remains enigmatic. The occurrence of methane in fluid inclusions at the Late Carboniferous Baogutu reduced porphyry copper deposit in western Junggar, Xinjiang, NW-China, presents an excellent opportunity to address this problem. A systematic study including fluid inclusion Laser-Raman and CO2-CH4 carbon isotope analyses, igneous and hydrothermal mineral H-O isotope analyses, and in situ major, trace element and Sr isotopic analyses of hydrothermal epidote was conducted to constrain the origin of CH4 and CH4-rich fluids. The δ2H and δ18O of water in equilibrium with igneous biotite ranges from -65.0‰ to -66.0‰ and +7.2‰ to +7.4‰, respectively, indicating notable degassing of probably supercritical fluids in the magma chamber. The wide range of δ2H (-58.0‰ to -107.0‰, n = 23) for water within quartz suggests the existence of significant hydrothermal fluid boiling. Water-rock interaction is the most likely mechanism leading to the wide range of δ18O values for water in vein quartz with water/rock ratios (wt.% in O) of 0.15 to 0.75 and 0.13 to 0.46 for a closed and open system, respectively. Detailed Laser-Raman analyses indicate CO2 in apatite included in granodiorite porphyry phenocrystic biotite that records the carbon species of the early stage magmatic stage, whereas later hydrothermal fluids containing CH4 with trace or without CO2 are found in inclusions of vein quartz. We propose that CH4 is probably transformed from CO2 by Fischer-Tropsch type reactions at 500 °C, assumed from CO2-CH4 C isotope equilibrium. The (87Sr/86Sr)i of hydrothermal epidote yields values of 0.70369-0.70404, consistent with that reported for the whole rocks. The δ13CCH4 (-28.6‰ to -22.6‰) and δ2HCH4 (-108.0‰ to -59.5‰) are characteristic of abiogenic methane. The measured δ13CCO2 shows a slightly depleted 13C (-13.5‰ to -7.2‰) relative to upper mantle

  5. Irradiation of Northwest agricultural products

    SciTech Connect

    Eakin, D.E.; Tingey, G.L.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  6. Seismic stratigraphy or Cape Sorell Basin, Tasmania

    SciTech Connect

    Bellow, T.L.

    1990-05-01

    Because large new exploration areas have become scarce, the Cape Sorell basin has become an increasingly attractive frontier area. Cape Sorell basin, located along the western passive continental margin of Tasmania formed as a result of the breakup of eastern Gondwanaland 95{plus minus}5 Ma. An extensional fault system trending west-northwest with dip-slip movement down to the south-southwest forms the northern boundary and a second fault system trending north-northwest with oblique slip down to the south-southwest creates the basin. Second order extensional faults within the basin have created wrench-type flower structures, which are potential migration pathways for hydrocarbons. Nine distinct depositional sequences identified within the Cape Sorell basin record the evolution of this passive continental margin. Late Cretaceous-early Paleocene sequences were deposited as the rifting ceased and clastic progradation over the rift terrain began. Relative lowering of sea level occurred during the Paleocene, resulting in extensive channeling of the Late Cretaceous-early Paleocene sequences. A subsequent rise in relative sea level resulted in canyon-fill deposition during the early Paleocene to early Eocene. During the Eocene, sedimentation sufficiently increased to produce a downlapping sediment progradation characterized by deltaic depositional environment. Although interrupted several times by changes in relative sea level and shifting sediment sources, deltaic deposition continued until the late Oligocene. As the rate of clastic sedimentation slowed, carbonate shelf deposition began and has typified the basin since late the Oligocene.

  7. Irradiation of northwest agricultural products

    NASA Astrophysics Data System (ADS)

    Eakin, D. E.; Tingey, G. I.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect ocntrol procedures are developed and followed. Due to the recognized potential benefits of irradiation, this program was conducted to evaluate the benefits of using irradiation on Northwest agricultural products. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  8. 75 FR 23823 - Sixth Northwest Electric Power and Conservation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... From the Federal Register Online via the Government Publishing Office PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Sixth Northwest Electric Power and Conservation Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council (Northwest Power and Conservation...

  9. The Northwest Environmental Education Center

    ERIC Educational Resources Information Center

    Ryan, Roberta

    1971-01-01

    Two part narration of the development of the Northwest Environmental Education Center (NEEC) is presented. Part I outlines its 13-year history relating problems and procedures of fund raising and organizational endorsement. Part II enumerates the program, its philosophy, evolution, and present status. (BL)

  10. The Northwest Territories and Nunavut.

    ERIC Educational Resources Information Center

    O'Donoghue, Fiona; Lupart, Judy

    2003-01-01

    This article focuses primarily on the relevant joint history and initiatives for students who are at-risk in the Northwest Territories and Nunavut, which became separate territories in April 1999. It describes programs and services for students who are at-risk, challenges that need to be overcome, and future directions. (Contains references.) (CR)

  11. Northwest Outward Bound Instructor's Manual.

    ERIC Educational Resources Information Center

    Northwest Outward Bound School, Portland, OR.

    Instructor responsibilities, procedures for completing activities safely, and instructional methods and techniques are outlined to assist instructors in the Northwest Outward Bound School (Portland, Oregon) as they strive for teaching excellence. Information is organized into six chapters addressing: history and philosophy of Outward Bound; course…

  12. Forest statistics for northwest Oregon.

    Treesearch

    Melvin E. Metcalf; John W. Hazard

    1964-01-01

    This publication summarizes the results of the latest reinventory of 10 counties in northwest Oregon: Clackamas, Clatsop, Columbia, Hood River, Marion, Multnomah, Polk, Tillamook, Washington, and Yamhill. This block of counties is one of 10 such blocks set up in the States of Oregon and Washington by the Forest Survey to facilitate orderly reinventories of the timber...

  13. Northwest Forest Plan research synthesis.

    Treesearch

    Richard W. Haynes; Gloria E. Perez; [tech. eds.].

    2000-01-01

    This document synthesizes research accomplishments initiated and funded under the Northwest Forest Plan or the President’s Forest Plan (hereafter referred to as the Forest Plan) since its inception in 1994. Three major parts in this document cover, the context for this effort, eight Forest Plan research accomplishments, and a synthesis. The eight accomplishments...

  14. Hispanics in the Pacific Northwest.

    ERIC Educational Resources Information Center

    Cook, Annabel Kirschner

    Sources of diversity in the Pacific Northwest's Spanish origin population, up 79.7% since 1970, was the subject of research based on 1980 Census data. Census information for Whites and Hispanics from metropolitan and nonmetropolitan counties with 400 or more persons of Spanish origin was compared on the basis of age, family/household structure,…

  15. The Pacific Northwest Research Station.

    Treesearch

    Forest Service. U.S. Department of Agriculture

    1937-01-01

    The research organization of the United States Forest Service in the North Pacific Region is the Pacific Northwest Forest and Range Experiment Station, one of the 12 regional experiment stations maintained by the service. This station, which has headquarters in Portland, Oregon, is making studies and surveys in the fields of economics, forest management, forest...

  16. Northwest Outward Bound Instructor's Manual.

    ERIC Educational Resources Information Center

    Northwest Outward Bound School, Portland, OR.

    Instructor responsibilities, procedures for completing activities safely, and instructional methods and techniques are outlined to assist instructors in the Northwest Outward Bound School (Portland, Oregon) as they strive for teaching excellence. Information is organized into six chapters addressing: history and philosophy of Outward Bound; course…

  17. New interpretation of Clarks Fork field, northern Bighorn basin, Montana

    SciTech Connect

    Johnson, J.S.; Lindsley-Griffin, N.

    1986-08-01

    Clarks Fork field is located at the northern edge of the Bighorn basin (T9S, R22E) in Carbon County, Montana. Production was first established in 1944 by General Petroleum Corporation in the Cretaceous Peay Sandstone (basal Frontier) and was later extended to the Cretaceous Greybull (1949) and Lakota (1956) sandstones by British American. Total cumulative hydrocarbons from this field are 1,1789,193 bbl of oil and 3,061,522 mcf of gas, with Lakota sandstones being most productive. Lakota production occurs from a structural-stratigraphic trap in an east-west-trending channel on the axis of Clarks Fork anticline, geographically near the center of the township. Our structural reinterpretation of Clarks Fork field suggests that Elk Basin anticline is a northwest extension of the Elk Basin field anticline. The Elk Basin thrust truncates the north limb of the fold and does not strike to the northwest, as shown by earlier interpretations. They interpret a northwest-striking thrust in the center of the township as a splay off the Elk Basin thrust, and have named it the Clarks Fork thrust. The Clarks Fork anticline is located on the hanging wall of Clarks Fork thrust. Subsurface maps indicate the Clarks Fork area has not been fully developed. Stratigraphic traps in the Lakota and Greybull sandstones are present in several areas of the township. Structural traps in the center and northwest portions of the township may also exist.

  18. A classification of Meso-Cenozoic continental basins and their oil-gas potentials in China

    SciTech Connect

    Wu Changlin ); Xue Shuhao )

    1991-03-01

    Most of the oilfields in China are located in Mesozoic-Cenozoic continental basins. Characteristics of continental sediments are controlled by such factors as paleoclimatic zones, distance from oceans, paleogeomorphic features, and tectonic settings. Based on paleoclimatic zonation, the continental basins in China can be divided into humid, arid, and humid-arid transitional types. Furthermore, based on the distances from oceans, they can be classified into inland and onshore types, and based on regional geomorphic features, they can be classified into faulted and depressional types. According to three factors, the Mesozoic-Cenozoic continental petroliferous basins in China can be grouped under ten types as follows: (1) onshore humid faulted type such as Zhujiangkou (Pearl River Mouth; E); (2) onshore humid depressional type such as Songliao (K); (3) inland humid faulted type such as Baise (E); (4) inland humid depressional type such as Ordos (T); (5) onshore arid-humid faulted type such as Bohai Bay (E); (6) inland arid-humid faulted type such as Jiuxi (K); (7) inland arid-humid depressional type such as Junggar (E); (8) onshore arid depressional type such as Tarim (E); (9) inland arid faulted type such as Jianghan (E); and (10) inland arid depressional type such as Tsaidam (E-N). Sedimentary systems in different basins have different depositional characteristics and petroliferous potentials. Onshore basins in humid zone and arid-humid transitional zone have best petroleum prospects, and inland basins in humid and arid-humid transitional zones are second while the basins in arid zone are third.

  19. Petrogenesis of Late Paleozoic volcanics from the Zhaheba depression, East Junggar: Insights into collisional event in an accretionary orogen of Central Asia

    NASA Astrophysics Data System (ADS)

    Li, Di; He, Deng-fa; Santosh, M.; Tang, Jie-yun

    2014-01-01

    The Carboniferous to Permian period marks an important transition from accretion to collision in the East Junggar terrane, NW China. Field and Well Fuqian-1 well core data from the Zhaheba depression provide a better window for understanding the magmatic process during this period and its implications for the continental growth of Central Asia. Field investigations reveal structural features characterized by NE-SW compression, with lithology composed of basic and intermediate-felsic volcanic rocks and pyroclastic rocks. The core samples from Well Fuqian-1 show dominantly basalt, basaltic andesite, dacite and minor pyroclastic rocks. We report zircon SHRIMP U-Pb ages of 276.0-279.8 Ma from rhyolites and zircon LA-ICP-MS U-Pb ages of 315.4-317.4 Ma from dacite and basaltic andesite. Our data suggest that the volcanic rocks from surface exposures and the well cores of Well Fuqian-1 formed in the Early Permian and the Late Carboniferous, respectively. The Late Carboniferous mafic rocks have geochemical characteristics similar to the intercalated Early Permian felsic rocks. The mafic rocks show low initial 87Sr/86Sr (0.703162-0.703783) and high ɛNd(t) (5.5-7.5), enrichment in LREE and some LILEs (such as Rb and Th) as well as HFSEs (such as Zr, Y), and depletion in Nb, Ta and Ti. Furthermore, they also display lower Sm/Th (1.6-8.4) and higher Th/Y (0.03-0.12) ratios than those of MORB, and variable Th/Zr (0.004-0.016), Ba/Th (61-839), Ba/La (6.13-48.77) and Ba/Nb (10-101) ratios. The geochemical data suggest that these rocks were derived dominantly from a 5-10% partial melting of a mainly garnet-rich with minor spinel-bearing Iherzolite mantle source metasomatized by slab-derived fluids. The felsic rocks are rich in silica (SiO2 = 57.43-78.07%) and alkalis (K2O + Na2O = 5.33-9.28%) and possess high TFe2O3 (0.70-6.95%) contents and Ga/Al ratios, and low CaO (0.18-5.11%) and MgO (0.13-2.02%) contents. They represent typical high-medium-K calc-alkaline A-type rhyolite

  20. Seasonal hydrologic responses to climate change in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Vano, Julie A.; Nijssen, Bart; Lettenmaier, Dennis P.

    2015-04-01

    Increased temperatures and changes in precipitation will result in fundamental changes in the seasonal distribution of streamflow in the Pacific Northwest and will have serious implications for water resources management. To better understand local impacts of regional climate change, we conducted model experiments to determine hydrologic sensitivities of annual, seasonal, and monthly runoff to imposed annual and seasonal changes in precipitation and temperature. We used the Variable Infiltration Capacity (VIC) land-surface hydrology model applied at 1/16° latitude-longitude spatial resolution over the Pacific Northwest (PNW), a scale sufficient to support analyses at the hydrologic unit code eight (HUC-8) basin level. These experiments resolve the spatial character of the sensitivity of future water supply to precipitation and temperature changes by identifying the seasons and locations where climate change will have the biggest impact on runoff. The PNW exhibited a diversity of responses, where transitional (intermediate elevation) watersheds experience the greatest seasonal shifts in runoff in response to cool season warming. We also developed a methodology that uses these hydrologic sensitivities as basin-specific transfer functions to estimate future changes in long-term mean monthly hydrographs directly from climate model output of precipitation and temperature. When principles of linearity and superposition apply, these transfer functions can provide feasible first-order estimates of the likely nature of future seasonal streamflow change without performing downscaling and detailed model simulations.

  1. Climate change impacts and adaptation in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Lettenmaier, D. P.

    2008-12-01

    The University of Washington Climate Impacts Group (CIG) is an interdisciplinary research group that studies the impacts of natural climate variability and change on the U.S. Pacific Northwest (PNW). Through research and interaction with regional stakeholders, the CIG works to increase the resilience of the Pacific Northwest to fluctuations and long-term changes in climate. The CIG's research focuses on four key sectors of the PNW environment: water resources, aquatic ecosystems, forests, and coasts. This talk focuses specifically on the water resources sector of CIG, and its work addressing potential climate change impacts on the region's hydrology being undertaken under an ongoing statewide climate impacts assessment (known as HB 1303). In the Pacific Northwest, as in most of the western U.S., warming temperatures are expected to result in lower winter snowpack, thus shifting seasonal runoff peaks earlier in the year, and increasing the duration of the summer and fall low flow period. The ongoing HB1303 work is based on IPCC 2007 climate scenarios. Hydrologic scenarios have been generated by downscaling GCM scenarios to 1/16 degree latitude-longitude spatial resolution, and using these downscaled scenarios to force the macroscale Variable Infiltration Capacity (VIC) model. We describe the range of hydrologic projections recently performed for 16 downscaled GCMs and 2 global emissions scenarios for the next 100 years, with particular attention on reservoir systems serving water supply needs in the Puget Sound basin and irrigation water in the Yakima River basin. We also evaluate implications of the changing climate for the Columbia River reservoir system, both in terms of the tradeoff between reservoir releases made for salmonid protection and restoration and hydropower generation, and for flood control.

  2. Climate change impacts and adaptation in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Lettenmaier, D. P.

    2008-05-01

    The University of Washington Climate Impacts Group (CIG) is an interdisciplinary research group that studies the impacts of natural climate variability and change on the U.S. Pacific Northwest (PNW). Through research and interaction with regional stakeholders, the CIG works to increase the resilience of the Pacific Northwest to fluctuations and long-term changes in climate. The CIG's research focuses on four key sectors of the PNW environment: water resources, aquatic ecosystems, forests, and coasts. This talk focuses specifically on the water resources sector of CIG, and its work addressing potential climate change impacts on the region's hydrology, and the potential for adaptation of water management, primarily through changes in reservoir operating policies, in response to projected effects of climate change. In the Pacific Northwest, as in most of the western U.S., warming temperatures are expected to result in lower winter snowpack, thus shifting seasonal runoff peaks earlier in the year, and increasing the duration of the summer and fall low flow period. The CIG is currently conducting a statewide assessment of the impacts of climate change for the State of Washington based on IPCC 2007 climate scenarios. Hydrologic scenarios have been generated by downscaling GCM scenarios to 1/16 degree latitude-longitude spatial resolution, and using these downscaled scenarios to force the macroscale Variable Infiltration Capacity (VIC) model. We describe the range of hydrologic projections recently performed for 16 downscaled GCMs and 2 global emissions scenarios for the next 100 years, with particular attention on the Puget Sound basin and the Yakima River basin. We also evaluate implications of the changing climate for the Columbia River reservoir system, both in terms of the tradeoff between reservoir releases made for salmonid protection and restoration and hydropower generation, and for flood control.

  3. National emission standards for hazardous air pollutants application for approval to stabilize the 105N Basin

    SciTech Connect

    Not Available

    1994-05-01

    The 105N Basin (basin) Stabilization will place the basin in a radiologically and environmentally safe condition so that it can be decommissioned at a later date. The basin stabilization objectives are to inspect for Special Nuclear Material (SNM) (i.e., fuel assemblies and fuel pieces), remove the water from the basin and associated pits, and stabilize the basin surface. The stabilization will involve removal of basin hardware, removal of basin sediments, draining of basin water, and cleaning and stabilizing basin surfaces-to prevent resuspension of radioactive emissions to the air. These activities will be conducted in accordance with all applicable regulations. The basin is in the 105N Building, which is located in the 100N Area. The 100N Area is located in the Northern portion of the Hanford Site approximately 35 miles northwest of the city of Richland, Washington. The basin is a reinforced unlined concrete structure 150 feet long, 50 feet wide, and 24 feet deep. The basin is segregated into seven areas sharing a common pool of water; the Discharge/Viewing (``D``) Pit, the fuel segregation pit (including a water tunnel that connects the ``D`` pit and segregation pit), two storage basins designated as North Basin and South Basin, two cask load-out pits, and a fuel examination area. The North Basin floor is entirely covered and the South Basin is partly covered by a modular array of cubicles formed by boron concrete posts and boron concrete panels.

  4. Columbia Basin Fish and Wildlife Authority Project Abstracts; May 25-27, Portland, Oregon, 1997 Annual Review.

    SciTech Connect

    Allee, Brian J.

    1997-06-26

    Abstracts are presented from the 1997 Columbia Basin Fish and Wildlife Program Review of Projects. The purpose was to provide information and education on the approximate 127 million dollars in Northwest electric ratepayer fish and wildlife mitigation projects funded annually.

  5. Forest resources in Northwest Florida

    Treesearch

    I.F. Eldredge

    1938-01-01

    Northwest Florida is the long arm of the State that extends along the Gulf Coast south of Georgia and Alabama and includes the 16 counties west of the Aucilla River (see map, fig. 1). It is a rather sparsely settled area in which only 26 percent of the total population of 254,000 (1930 Census) live in cities of 2,500 population or larger; most of the inhabitants live...

  6. Northwest Africa - A Climatological Study,

    DTIC Science & Technology

    1996-08-01

    A climatological study of NorthwestAfrica, includingAlgeria, Tunisia, Morocco , Western Sahara, and the northern parts of Mauritania, Mali, and Niger...additional hazards. 14. Subject Terms: CLIMATOLOGY, METEOROLOGY, WEATHER, GEOGRAPHY, AFRICA, ALGERIA, MOROCCO , TUNISIA, WESTERN SAHARA, MAURITANIA, MALI, NIGER...line where mean annual rainfall exceeds 250 boundary. This zone includes most of Morocco , mm (the area south of this line is described in and the

  7. Mineral resources prospecting by synthetic application of TM/ETM+, Quickbird and Hyperion data in the Hatu area, West Junggar, Xinjiang, China

    PubMed Central

    Liu, Lei; Zhou, Jun; Jiang, Dong; Zhuang, Dafang; Mansaray, Lamin R.; Hu, Zhijun; Ji, Zhengbao

    2016-01-01

    The Hatu area, West Junggar, Xinjiang, China, is situated at a potential gold-copper mineralization zone in association with quartz veins and small granitic intrusions. In order to identify the alteration zones and mineralization occurrences in this area, the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+), Quickbird, Hyperion data and laboratory measured spectra were combined in identifying structures, alteration zones, quartz veins and small intrusions. The hue-saturation-intensity (HSI) color model transformation was applied to transform principal component analysis (PCA) combinations from R (Red), G (Green) and B (Blue) to HSI space to enhance faults. To wipe out the interference of the noise, a method, integrating Crosta technique and anomaly-overlaying selection, was proposed and implemented. Both Jet Propulsion Laboratory Spectral Library spectra and laboratory-measured spectra, combining with matched filtering method, were used to process Hyperion data. In addition, high-resolution Quickbird data were used for unraveling the quartz veins and small intrusions along the alteration zones. The Baobei fault and a SW-NE-oriented alteration zone were identified for the first time. This study eventually led to the discovery of four weak gold-copper mineralized locations through ground inspection and brought new geological knowledge of the region’s metallogeny. PMID:26911195

  8. Mineral resources prospecting by synthetic application of TM/ETM+, Quickbird and Hyperion data in the Hatu area, West Junggar, Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Zhou, Jun; Jiang, Dong; Zhuang, Dafang; Mansaray, Lamin R.; Hu, Zhijun; Ji, Zhengbao

    2016-02-01

    The Hatu area, West Junggar, Xinjiang, China, is situated at a potential gold-copper mineralization zone in association with quartz veins and small granitic intrusions. In order to identify the alteration zones and mineralization occurrences in this area, the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+), Quickbird, Hyperion data and laboratory measured spectra were combined in identifying structures, alteration zones, quartz veins and small intrusions. The hue-saturation-intensity (HSI) color model transformation was applied to transform principal component analysis (PCA) combinations from R (Red), G (Green) and B (Blue) to HSI space to enhance faults. To wipe out the interference of the noise, a method, integrating Crosta technique and anomaly-overlaying selection, was proposed and implemented. Both Jet Propulsion Laboratory Spectral Library spectra and laboratory-measured spectra, combining with matched filtering method, were used to process Hyperion data. In addition, high-resolution Quickbird data were used for unraveling the quartz veins and small intrusions along the alteration zones. The Baobei fault and a SW-NE-oriented alteration zone were identified for the first time. This study eventually led to the discovery of four weak gold-copper mineralized locations through ground inspection and brought new geological knowledge of the region’s metallogeny.

  9. Mineral resources prospecting by synthetic application of TM/ETM+, Quickbird and Hyperion data in the Hatu area, West Junggar, Xinjiang, China.

    PubMed

    Liu, Lei; Zhou, Jun; Jiang, Dong; Zhuang, Dafang; Mansaray, Lamin R; Hu, Zhijun; Ji, Zhengbao

    2016-02-25

    The Hatu area, West Junggar, Xinjiang, China, is situated at a potential gold-copper mineralization zone in association with quartz veins and small granitic intrusions. In order to identify the alteration zones and mineralization occurrences in this area, the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+), Quickbird, Hyperion data and laboratory measured spectra were combined in identifying structures, alteration zones, quartz veins and small intrusions. The hue-saturation-intensity (HSI) color model transformation was applied to transform principal component analysis (PCA) combinations from R (Red), G (Green) and B (Blue) to HSI space to enhance faults. To wipe out the interference of the noise, a method, integrating Crosta technique and anomaly-overlaying selection, was proposed and implemented. Both Jet Propulsion Laboratory Spectral Library spectra and laboratory-measured spectra, combining with matched filtering method, were used to process Hyperion data. In addition, high-resolution Quickbird data were used for unraveling the quartz veins and small intrusions along the alteration zones. The Baobei fault and a SW-NE-oriented alteration zone were identified for the first time. This study eventually led to the discovery of four weak gold-copper mineralized locations through ground inspection and brought new geological knowledge of the region's metallogeny.

  10. Long term mean annual water temperature for stream reaches in Pacific Northwest United States

    USGS Publications Warehouse

    ,

    2012-01-01

    Long-term mean annual water temperature (degrees Celsius) was estimated for the E2RF1 stream network (Brakebill and Terziotti, 2011) located within the Pacific Northwest region of the United States (HUC2 = 17; the Columbia River basin, the Puget Sound watershed, the coastal drainages of Washington and Oregon, and the closed basins in southern Oregon). Multiple linear regressions were used to select reach-scale watershed attributes (explanatory variables) for predicting the long-term mean annual water temperature (dependent variable) at a set of USGS water-quality monitoring stations. The results from the multiple linear regressions were used to predict the long-term mean water temperature for the Pacific Northwest reaches in the E2RF1 network.

  11. Petroleum systems of the Northwest Java Province, Java and offshore southeast Sumatra, Indonesia

    USGS Publications Warehouse

    Bishop, Michele G.

    2000-01-01

    Mature, synrift lacustrine shales of Eocene to Oligocene age and mature, late-rift coals and coaly shales of Oligocene to Miocene age are source rocks for oil and gas in two important petroleum systems of the onshore and offshore areas of the Northwest Java Basin. Biogenic gas and carbonate-sourced gas have also been identified. These hydrocarbons are trapped primarily in anticlines and fault blocks involving sandstone and carbonate reservoirs. These source rocks and reservoir rocks were deposited in a complex of Tertiary rift basins formed from single or multiple half-grabens on the south edge of the Sunda Shelf plate. The overall transgressive succession was punctuated by clastic input from the exposed Sunda Shelf and marine transgressions from the south. The Northwest Java province may contain more than 2 billion barrels of oil equivalent in addition to the 10 billion barrels of oil equivalent already identified.

  12. 8. View, fuel waste tanks and containment basin associated with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View, fuel waste tanks and containment basin associated with Components Test Laboratory (T-27) located uphill to the left, looking northwest. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  13. Managing the Columbia Basin for Sustainable Economy, Society, Environment

    EPA Science Inventory

    The Columbia River Basin (CRB) is a vast region of the Pacific Northwest covering parts of the United States, Canada and Tribal lands. As the Columbia River winds its way from Canada into the US, the river passes through numerous multi-purpose reservoirs and hydroelectric genera...

  14. View of Lake Sabrina Dam and dry Lake Sabrina Basin ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Lake Sabrina Dam and dry Lake Sabrina Basin with the upstream side of the outlet structure visible at photo center, view to north-northwest - Bishop Creek Hydroelectric System, Plant 2, Lake Sabrina Dam, Bishop Creek, Bishop, Inyo County, CA

  15. Managing the Columbia Basin for Sustainable Economy, Society, Environment

    EPA Science Inventory

    The Columbia River Basin (CRB) is a vast region of the Pacific Northwest covering parts of the United States, Canada and Tribal lands. As the Columbia River winds its way from Canada into the US, the river passes through numerous multi-purpose reservoirs and hydroelectric genera...

  16. BASINS Publications

    EPA Pesticide Factsheets

    Although BASINS has been in use for the past 10 years, there has been limited modeling guidance on its applications for complex environmental problems, such as modeling impacts of hydro modification on water quantity and quality.

  17. Basin analysis

    SciTech Connect

    Lerche, I. )

    1989-01-01

    The exploration for oil is a high-risk game. Worldwide drilling success is around 5-10%, the average cost of drilling is around $1000 a foot, and the average well is now around 15,000 feet deep. Over the years, two fundamental avenues of attack have been developed: methods designed to locate oil in situ from direct measurement ahead of the drill and methods focusing on the dynamic evolution of a sedimentary basin in relation to the timing of hydrocarbon generation, migration, and accumulation to provide an assessment of which areas in a basin might be the most prospective for oil accumulations today. This volume addresses the problem of quantitative basin analysis in relation to oil accumulations. Emphasis is placed on the uncertainties and resolution limits of basin analysis given constraints derived from surface and downhole data and the sensitivity to model input parameters and assumptions.

  18. Validation Efforts of the Pacific Northwest River Restoration Database

    NASA Astrophysics Data System (ADS)

    McFall, J. M.; Katz, S. L.; Morehead, M. D.

    2005-12-01

    The improvement of science in river restoration relies heavily on the evaluation of previously established projects in order to assess the ecosystem response and project outcome (Bernhard et al, 2005). To facilitate this, there needs to be competent project tracking and documentation of outcomes. In the Pacific Northwest, the National Marine Fisheries Service's Northwest Fisheries Science Center has compiled a database containing over 26,000 restoration actions at 36,000 locations in Oregon, Washington, Idaho, and Montana (Katz, et al. in review). Recent efforts have been undertaken to validate this database through selection of random samples for telephone interviews and field site visits. 47 project managers were interviewed via telephone regarding their restoration activities within four project category intents. In addition, six Columbia River sub-basins were selected for site validation sampling of 170 projects. The basins included for site validations are the Lemhi and Pahsimeroi Rivers in Idaho, the Methow and Entiat Rivers in Washington, and the Upper and Lower John Day Rivers in Oregon. Survey results are presented with statistical estimators to validate the database. Regional trends in river restoration were found to exist and differences were found between reporting agencies and on the smaller, local scale. The implementation of restoration activities is examined to see if projects are being instigated as intended and case studies are examined to reveal lessons learned from practitioners. In general, the effectiveness of various river restoration activities in the Pacific Northwest would be better charted through standardization in project tracking and documentation. References Bernhardt, E. S., Palmer, M. A., Allan, J. D., Alexander, G., Barnas, K., Brooks, S., Carr, J., Clayton, S., Dahm, C., Follstad-Shah, J., Galat, D., Gloss, S., Goodwin, P., Hart, D., Hassett, B., Jenkinson, J., Katz, S., Kondolf, G. M., Lake, P. S., Lave, R., Meyer, J. L., O

  19. Callisto basin

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This picture of a multi=ring basin on Callisto was taken the morning of March 6, 1979, from a distance of about 200,000 km. The complicated circular structure seen at left center is similar to the large circular impact basins that dominate the surface of the Earth's moon and also the planet Mercury. The inner parts of these basins are generally surrounded by radially lineated ejecta and several concentric mountainous ring structures that are thought to form during the impact event. This multi-ring basin on Callisto consists of light floored central basin some 300 k m in diameter surrounded by at least eight to ten discontinuous rhythmically spaced ridges. No radially lineated ejecta can be seen. The ring structures on Moon and Mercury have been likened to ripples produced on a pond by a rock striking the water. The great number of rings observed around this basin on Callisto is consistent with its low planetary density and probable low internal strength. JPL manages and controls the Voyager project for NASA's Office of Space Science.

  20. Invasive crayfish in the Pacific Northwest

    USGS Publications Warehouse

    Pearl, Christopher A.; McCreary, Brome; Adams, Michael

    2011-01-01

    Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areas where invasion is advanced, crayfish pose major economic and ecological problems. Crayfish have been widely introduced for aquaculture and can become established in a wide range of habitat conditions. They also may be spread by anglers who use them as bait. Several non-native crayfish are established in the PNW, but the extent of their invasion is not well known. At least two groups are known from scattered sites in the PNW, and both have proven problematic for native species in other parts of the world: Red swamp crayfish (Procambarus clarkii) and several members of the genus Orconectes. Both groups are native to areas of the eastern United States. Both are identified globally as invasives of high concern and appear on the Oregon Department of Fish and Wildlife's "10 Most Unwanted" and the U.S. Forest Service's "Primary Species of Concern" lists for stream systems in the PNW. Despite the presence of introduced crayfish in the PNW and their high potential for negative effects, the scope of their invasion and effects on aquatic systems are not well known. The U.S. Geological Survey (USGS), along with local groups and state agencies, is working to clarify crayfish distribution and to outline which basins may not yet be invaded. Other goals are to improve understanding of habitat associations of invasive crayfish and their potential effects on native crayfish.

  1. Sediment Evaluation Framework for the Pacific Northwest

    EPA Pesticide Factsheets

    The Sediment Evaluation Framework provides a regional framework for assessment, characterization and management of sediments in the Pacific Northwest to determine suitability for unconfined in-water disposal.

  2. Links Related to Northwest Indiana Area (Indiana)

    EPA Pesticide Factsheets

    Northwest Indiana of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  3. Pacific Northwest Resources Inventory Demonstration

    NASA Technical Reports Server (NTRS)

    Nichols, J. D.

    1976-01-01

    The Pacific Northwest Land Resource Inventory Demonstration project is designed to demonstrate to users from state and local agencies in Washington, Oregon, and Idaho the cost effective role that Landsat derived information can play in natural resource planning and management when properly supported by ground and aircraft data. The project has been organized into five main phases: (1) maps and overlays, (2) early digital image analysis, (3) demonstration of applications using interactive image analysis, (4) Landsat products and land resources information systems, and (5) documentation. The demonstration project has been applied to Washington forestry, water inventory in southern Idaho, and monitoring of tansy ragwort in western Oregon.

  4. Progress and prospects of climate change impacts on hydrology in the arid region of northwest China.

    PubMed

    Chen, Yaning; Li, Zhi; Fan, Yuting; Wang, Huaijun; Deng, Haijun

    2015-05-01

    The arid region of Northwest China, located in the central Asia, responds sensitively to global climate change. Based on the newest research results, this paper analyzes the impacts of climate change on hydrology and the water cycle in the arid region of Northwest China. The analysis results show that: (1) In the northwest arid region, temperature and precipitation experienced "sharply" increasing in the past 50 years. The precipitation trend changed in 1987, and since then has been in a state of high volatility, during the 21st century, the increasing rate of precipitation was diminished. Temperature experienced a "sharply" increase in 1997; however, this sharp increasing trend has turned to an apparent hiatus since the 21st century. The dramatic rise in winter temperatures in the northwest arid region is an important reason for the rise in the average annual temperature, and substantial increases in extreme winter minimum temperature play an important role in the rising average winter temperature; (2) There was a significant turning point in the change of pan evaporation in the northwest arid area in 1993, i.e., in which a significant decline reversed to a significant upward trend. In the 21st century, the negative effects of global warming and increasing levels of evaporation on the ecology of the northwest arid region have been highlighted; (3) Glacier change has a significant impact on hydrology in the northwest arid area, and glacier inflection points have appeared in some rivers. The melting water supply of the Tarim River Basin possesses a large portion of water supplies (about 50%). In the future, the amount of surface water will probably remain at a high state of fluctuation.

  5. Seismic Characterization of the Jakarta Basin

    NASA Astrophysics Data System (ADS)

    Cipta, A.; Saygin, E.; Cummins, P. R.; Masturyono, M.; Rudyanto, A.; Irsyam, M.

    2015-12-01

    Jakarta, Indonesia, is home to more than 10 million people. Many of these people live in seismically non-resilient structures in an area that historical records suggest is prone to earthquake shaking. The city lies in a sedimentary basin composed of Quaternary alluvium that experiences rapid subsidence (26 cm/year) due to groundwater extraction. Forecasts of how much subsidence may occur in the future are dependent on the thickness of the basin. However, basin geometry and sediment thickness are poorly known. In term of seismic hazard, thick loose sediment can lead to high amplification of seismic waves, of the kind that led to widespread damage in Mexico city during the Michoacan Earthquake of 1985. In order to characterize basin structure, a temporary seismograph deployment was undertaken in Jakarta in Oct 2013- Jan 2014. A total of 96 seismic instrument were deployed throughout Jakarta were deployed throughout Jakarta at 3-5 km spacing. Ambient noise tomography was applied to obtain models of the subsurface velocity structure. Important key, low velocity anomalies at short period (<8s) correspond to the main sedimentary sub-basins thought to be present based on geological interpretations of shallow stratigraphy in the Jakarta Basin. The result shows that at a depth of 300 m, shear-wave velocity in the northern part (600 m/s) of the basin is lower than that in the southern part. The most prominent low velocity structure appears in the northwest of the basin, down to a depth of 800 m, with velocity as low as 1200 m/s. This very low velocity indicates the thickness of sediment and the variability of basin geometry. Waveform computation using SPECFEM2D shows that amplification due to basin geometry occurs at the basin edge and the thick sediment leads to amplification at the basin center. Computation also shows the longer shaking duration occurrs at the basin edge and center of the basin. The nest step will be validating the basin model using earthquake events

  6. Pacific Northwest regional AGU meeting

    NASA Astrophysics Data System (ADS)

    Bentley, R.; Hinthome, J.

    The 28th Annual Pacific Northwest Regional American Geophysical Union Meeting, September 13-20, 1981, was hosted by the Department of Geology at Central Washington University, Ellensburg, Washington. A total of 31 papers was presented to the 91 registrants in two general sessions. Topics included seismology, general geophysics, volcanology, hydrology, oceanography, and two special symposia: Tectonics of the Columbia Plateau and Neogene —Quaternary Faults of the Pacific Northwest' and ‘Studies of the Eruption of Mount Saint Helens.’ Before and after the formal meetings, several field conferences were conducted to examine the Neogene tectonics of the Coast Range (Bob Bentley, Al Niem, and Ray Wells, leaders); the Columbia River Gorge (Bob Bentley, Marv Beeson, and Terry Tolan, leaders); the western Columbia Plateau northsouth transect (Bob Bentley and Jim Anderson, leaders); Quaternary structures of the Toppenish Ridge anticline (Don Tahkeal, Newell Campbell, and Bob Bentley, leaders); the Umtanum imbricate fault zone and pre-Saddle Mountains unconformity near Priest Rapids Dam (Ed Price and Bob Bentley, leaders); and the Yakima anticlines in the Cle Elum-Wallula deformed zone between Ellensburg and Yakima (Bob Bentley, leader).

  7. 76 FR 5796 - Gas Transmission Northwest Corporation; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ... Energy Regulatory Commission Gas Transmission Northwest Corporation; Notice of Application January 26, 2011. Take notice that on January 14, 2011, Gas Transmission Northwest Corporation (GTN), 717 Texas..., Manager, Project Determinations & Regulatory Administration, Gas Transmission Northwest Corporation,...

  8. 77 FR 40565 - Northwest Forest Plan Provincial Advisory Committees

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... Forest Service Northwest Forest Plan Provincial Advisory Committees AGENCY: Forest Service, USDA. ACTION: Notice of Administrative Meetings for the Northwest Forest Plan Provincial Advisory Committees. SUMMARY... up under the Northwest Forest Plan. The PIECs facilitate the successful implementation of the...

  9. The Northwest Ordinance. A Special Issue.

    ERIC Educational Resources Information Center

    Sheehan, Bernard W., Ed.; And Others

    1988-01-01

    Eight articles discuss different aspects of the Northwest ordinances. W. W. Abbot emphasizes George Washington's enduring, complex, and deep involvement with the west and its land. Robert V. Remini points out the value of the Articles of Confederation by emphasizing that it was the Congress under the Articles that passed the Northwest Ordinance.…

  10. Nuisance Aquatic Macrophyte Growth in the Northwest,

    DTIC Science & Technology

    1980-12-12

    were often selected, such as protected bays, shoals or areas of nutrient input. The " Flora of the Pacific Northwest" was accepted as the taxonomic...Press, Madison. 405pp 1957. 3. Hitchcock, D. L., and A. Cronquist. Flora of the Pacific Northwest, an illustrated manual. Univ. of Washington Press

  11. Delimiting communities in the Pacific Northwest.

    Treesearch

    Ellen M. Donoghue

    2003-01-01

    The paper presents an approach for delimiting communities in the Northwest Forest Plan (NWFP) region of the Pacific Northwest that responds to the need to assess impacts and issues associated with broad-scale ecosystem management. Census block groups are aggregated to provide an alternative to more commonly used geographic delimitations of communities, specifically...

  12. Identifying block structure in the Pacific Northwest, USA

    USGS Publications Warehouse

    Savage, James C.; Wells, Ray E.

    2015-01-01

    We have identified block structure in the Pacific Northwest (west of 116°W between 38°N and 49°N) by clustering GPS stations so that the same Euler vector approximates the velocity of each station in a cluster. Given the total number k of clusters desired, the clustering procedure finds the best assignment of stations to clusters. Clustering is calculated for k= 2 to 14. In geographic space, cluster boundaries that remain relatively stable as k is increased are tentatively identified as block boundaries. That identification is reinforced if the cluster boundary coincides with a geologic feature. Boundaries identified in northern California and Nevada are the Central Nevada Seismic Belt, the west side of the Northern Walker Lane Belt, and the Bartlett Springs Fault. Three blocks cover all of Oregon and Washington. The principal block boundary there extends west-northwest along the Brothers Fault Zone, then north and northwest along the eastern boundary of Siletzia, the accreted oceanic basement of the forearc. East of this boundary is the Intermountain block, its eastern boundary undefined. A cluster boundary at Cape Blanco subdivides the forearc along the faulted southern margin of Siletzia. South of Cape Blanco the Klamath Mountains-Basin and Range block extends east to the Central Nevada Seismic Belt and south to the Sierra Nevada-Great Valley block. The Siletzia block north of Cape Blanco coincides almost exactly with the accreted Siletz terrane. The cluster boundary in the eastern Olympic Peninsula may mark permanent shortening of Siletzia against the Intermountain block.

  13. An index of biological integrity (IBI) for Pacific Northwest rivers

    USGS Publications Warehouse

    Mebane, C.A.; Maret, T.R.; Hughes, R.M.

    2003-01-01

    The index of biotic integrity (IBI) is a commonly used measure of relative aquatic ecosystem condition; however, its application to coldwater rivers over large geographic areas has been limited. A seven-step process was used to construct and test an IBI applicable to fish assemblages in coldwater rivers throughout the U.S. portion of the Pacific Northwest. First, fish data from the region were compiled from previous studies and candidate metrics were selected. Second, reference conditions were estimated from historical reports and minimally disturbed reference sites in the region. Third, data from the upper Snake River basin were used to test metrics and develop the initial index. Fourth, candidate metrics were evaluated for their redundancy, variability, precision, and ability to reflect a wide range of conditions while distinguishing reference sites from disturbed sites. Fifth, the selected metrics were standardized by being scored continuously from 0 to 1 and then weighted as necessary to produce an IBI ranging from 0 to 100. The resulting index included 10 metrics: number of native coldwater species, number of age-classes of sculpins Cottus spp., percentage of sensitive native individuals, percentage of coldwater individuals, percentage of tolerant individuals, number of alien species, percentage of common carp Cyprinus carpio individuals, number of selected salmonid age-classes, catch per unit effort of coldwater individuals, and percentage of individuals with selected anomalies. Sixth, the IBI responses were tested with additional data sets from throughout the Pacific Northwest. Last, scores from two minimally disturbed reference rivers were evaluated for longitudinal gradients along the river continuum. The IBI responded to environmental disturbances and was spatially and temporally stable at over 150 sites in the Pacific Northwest. The results support its use across a large geographic area to describe the relative biological condition of coolwater and

  14. [Spatiotemporal characteristics of reference crop evapotranspiration in inland river basins of Hexi region].

    PubMed

    Lü, Xiao-Dong; Wang, He-ling; Ma, Zhong-ming

    2010-12-01

    Based on the 1961-2008 daily observation data from 17 meteorological stations in the inland river basins in Hexi region, the daily reference crop evapotranspiration (ET0) in the basins was computed by Penman-Monteith equation, and the spatiotemporal characteristics of seasonal and annual ET0 were studied by GIS and IDW inverse-distance spatial interpolation. In 1961-2008, the mean annual ET0 (700-1330 mm) increased gradually from southeast to northwest across the basins. The high value of mean annual ET0 in Shule River basin and Heihe River basin declined significantly (P < 0.05), with the climatic trend rate ranged from -53 to -10 mm (10 a)(-1), while the low value of mean annual ET0 in Shiyang River basin ascended slightly. The ET0 in the basins had a significant annual fluctuation, which centralized in Linze and decreased toward northwest and southeast. The ET0 in summer and autumn contributed most of a year, and the highest value of ET0 all the year round always appeared in Shule River basin. The climatic trend rate was in the order of summer > spring > autumn > winter. Wind speed and maximum temperature were the primary factors affecting the ET0 in the basins. Furthermore, wind speed was the predominant factor of downward trend of ET0 in Shule and Heihe basins, while maximum temperature and sunshine hours played an important role in the upward trend of ET0 in Shiyang basin.

  15. Tectonic development of Michigan basin

    SciTech Connect

    Prouty, C.E.

    1986-08-01

    The general form of the Michigan basin and surrounding frame structures - the Findlay, Kankakee, and Wisconsin arches - was inherited from the Precambrian. An ongoing study has provided new information on present basin configuration and the evolution of intrabasinal structures during the Paleozoic. This study involves: (1) isopach, structure contour, depocenter, and lithofacies map preparation; (2) diagenetic and epigenetic dolomitization processes and patterns; (3) Landsat imagery and lineament interpretation; (4) recognition of shearing mechanics and the resulting shear faulting and folding; and (5) the recognition of radial faults in contrast to shear faults. Monitoring of the above throughout the Paleozoic indicates that tectonic events within the basin were episodic in nature. Stresses are recognized as external and, through Fourier analysis of lineaments (shear faults), may be demonstrated as from the southeast, probably the Appalachian mobile belt. Shear faults are seated in Precambrian rocks, although they are probably not of that age. The faults occur with accompanying shear folds in rocks possibly as early as the Late Ordovician or Middle Silurian, but definitely by the Middle Devonian with the principal faulting and folding during the post-Osage Mississippian. Local shifting of the depocenter within the general Saginaw Bay area occurred during the early Paleozoic with a major shift westward to the present central basin position accompanied by the development of the present north-northwest ellipticity of the basin during the post-Osage, pre-Meramecian Mississippian. Barrier separation of the West Michigan Lagoon occurred in the Middle Ordovician and Middle and Late Devonian. Radial structures can be demonstrated in at least the Upper Silurian and Upper Devonian.

  16. Aleutian basin oceanic crust

    USGS Publications Warehouse

    Christeson, Gail L.; Barth, Ginger A.

    2015-01-01

    We present two-dimensional P-wave velocity structure along two wide-angle ocean bottom seismometer profiles from the Aleutian basin in the Bering Sea. The basement here is commonly considered to be trapped oceanic crust, yet there is a change in orientation of magnetic lineations and gravity features within the basin that might reflect later processes. Line 1 extends ∼225 km from southwest to northeast, while Line 2 extends ∼225 km from northwest to southeast and crosses the observed change in magnetic lineation orientation. Velocities of the sediment layer increase from 2.0 km/s at the seafloor to 3.0–3.4 km/s just above basement, crustal velocities increase from 5.1–5.6 km/s at the top of basement to 7.0–7.1 km/s at the base of the crust, and upper mantle velocities are 8.1–8.2 km/s. Average sediment thickness is 3.8–3.9 km for both profiles. Crustal thickness varies from 6.2 to 9.6 km, with average thickness of 7.2 km on Line 1 and 8.8 km on Line 2. There is no clear change in crustal structure associated with a change in orientation of magnetic lineations and gravity features. The velocity structure is consistent with that of normal or thickened oceanic crust. The observed increase in crustal thickness from west to east is interpreted as reflecting an increase in melt supply during crustal formation.

  17. Temporal and spatial variations of precipitation in Northwest China during 1960-2013

    NASA Astrophysics Data System (ADS)

    Yang, Peng; Xia, Jun; Zhang, Yongyong; Hong, Si

    2017-01-01

    Based on the precipitation data from 96 weather stations in Northwest China (NWC) during 1960-2013, the Continuous Wavelet Transform (CWT) and the Mann-Kendall (MK) test were applied to analyze the precipitation spatiotemporal variations at different time scales. The relationships between the original precipitation and different periodic components were investigated. The results indicated that the annual precipitation was significantly increasing (P < 0.01) at the rate of 0.55 mm/a in the NWC. In terms of seasonal precipitation, the summer original precipitation significantly increased (P < 0.05) in the Southern Altay Mountain Basin (SAMB), Qaidam Basin (QB), Qiang Tang Plateau Basin (QTPB), Turpan-Hami Basin (THB), Tarim Desert Basin (TDB), Northern Tianshan Mountain Basin (NTMB) and NWC. For the winter original precipitation, except the Inner Mongolia Inland Rivers Basin and Northern Kunlun Mountain Basin, the significant increases (P < 0.05) were detected in the other sub-basins. In terms of monthly precipitation, significant increases were detected in January in the SAMB, NTMB and NWC, and July in the QB, Headstreams of Tarim River Basin (HTRB) and N. Additionally, most of the increasing and decreasing trends began in the mid-1980s or mid-1990s. Moreover, the periodic components were not always similar to the original data with the significant trends. The dominant scale of the original data from the periodic components was different in spatiotemporal distribution. Meanwhile, the relationship between the precipitation and El Niño-Southern Oscillation (ENSO) was different from period to period and from time scale to time scale. This study will help to develop better management measures to account for climate change and the supply/demand of water.

  18. The economic impact on the forest sector of critical habitat delineation for salmon in the Columbia and Snake River basins.

    Treesearch

    R.W. Haynes; N.A. Bolon; D.T. Hormaechea

    1992-01-01

    Economic implications of critical habitat designation (CHD) for salmon in the Columbia River basin were estimated in advance of actual designation and recovery plan development. Economic impacts on Pacific, Northwest, Intermountain, and Northern Region National Forests' range, recreation, timber, and mineral programs in the Columbia and Snake River basins were...

  19. LODGEPOLE BRIDGE, FACING NORTHWEST Generals Highway, Lodge Pole Bridge, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LODGEPOLE BRIDGE, FACING NORTHWEST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  20. 47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  1. Thermal conditions in the Anadarko basin, Oklahoma

    SciTech Connect

    Kelley, S.A.; Gallardo, J.D.; Carter, L.C.; Blackwell, D.D. )

    1991-03-01

    Heat flow, bottom-hole temperature (BHT), and thermal conductivity data are used to evaluate the present thermal conditions in the Anadarko basin. Heat flow values decrease from 54-62 mWm{sup {minus}2} in the northern part of the basin to 39-53 mWm{sup {minus}2} in the southern portion of the basin. The variation in the regional conductive heat flow is controlled by basin geometry and by the distribution of radiogenic elements in the basement. The heat flow, thermal conductivity, and lithologic information were combined to construct a 3-D model of the temperature structure of the Anadarko basin. The highest temperatures sedimentary rocks older than Pennsylvanian are offset 35 km north-northwest of the deepest part of the basin. This offset is related to the regional increase in heat flow to the north and to the presence of high thermal conductivity granite wash adjacent to the Wichita Mountains. A plot of the temperature difference between the equilibrium temperatures estimated from the model and the measured BHTs as a function of depth is remarkably similar to the published correction curve for BHTs for wells in Oklahoma. Vitrinite reflectance and apatite fission-track (FT) data are used to estimate the paleogeothermal conditions in the basin. Published vitrinite reflectance values are consistent with a past geographic temperature distribution comparable to the observed distribution with the maximum values offset from the basin axis. FT analysis of sandstones from wells in the southeastern portion of the basin indicates that subsurface temperatures were at least 30C higher than at present, suggest the possibility of substantial erosion in this area.

  2. Evidence for Right-lateral Shear Along the Northwest Margin of the Eastern Snake River Plain, Idaho

    NASA Astrophysics Data System (ADS)

    Payne, S. J.; McCaffrey, R.; King, R. W.

    2007-12-01

    Previous investigators have proposed that extension within the eastern Snake River Plain (ESRP) is accommodated by intrusion of dikes at a rate similar to the rate of extension in the surrounding Basin and Range. This hypothesis is primarily based on the lack of strike-slip offset along the northwest physiographic boundary of the ESRP, the lack of seismicity within the ESRP relative to the surrounding active Basin and Range, and the presence of NW-trending volcanic rift zones within the ESRP. The ESRP is a 400-km long region within the track of the Yellowstone Hotspot that extends from southern Idaho northeast into northwestern Wyoming. GPS data compiled for this study are used to test this hypothesis. Several institutions including the Idaho National Laboratory, National Geodetic Survey, Rensselaer Polytechnic Institute, and University of Utah observed GPS stations from 1994 to 2007 within the ESRP and surrounding region. The GPS velocities show the average orientation of horizontal GPS velocities in the adjacent northwest Basin and Range region is similar to the average orientation for the ESRP (N113°W vs N91°W, respectively), but the average magnitude of horizontal GPS velocities in the Basin and Range (1.4 ± 0.3 mm/yr) is less than that for the ESRP (2.2 ± 0.3 mm/yr). Additionally, the adjacent northwest Basin and Range extends at about 9 x 10-9 /yr with most of the deformation localized along three NW-trending normal faults (Lost River, Lemhi, and Beaverhead). In contrast, the ESRP extends at a rate that is an order of magnitude lower than the adjacent northwest Basin and Range and we see little indication of extension along the Great Rift or other volcanic rift zones over the 400 km length. The GPS differential motion along the region of the ESRP adjacent to the northwest Basin and Range indicates a NE-trending zone of right-lateral shear. Preliminary inversions of GPS velocities, earthquakes, faults, and volcanic features indicate this zone of right

  3. Pacific Northwest Laboratory CALIOPE overview

    SciTech Connect

    McDowell, R.S.; Kelly, J.F.; Sharpe, S.W.

    1995-03-01

    This overview covers progress in the following areas in which Pacific Northwest Laboratory contributes to the CALIOPE Program: (1) Fabrication of electro-optic modulators to generate FM-coding on IR lasers in the 8-12 and 3-5 {mu}m regions. (2) IR spectroscopy of signature species, abnormal isotopic distributions, hydrolysis and kinetics of effluents interacting with the atmosphere, and reflectance measurements of natural surfaces. (3) Systems analysis of FM-DIAL concepts, including lateral phase coherence and MTF measurements, and laboratory tests of detector technology and demodulation methods. (4) Field tests of FM-DIAL, covering field validation of portable diode laser concepts, FM-CO{sub 2} interrogation of Hanford sites, and signal returns from natural specular surfaces. (5) Ancillary matters: ground-truthing at Hanford (and RSTR?), countermeasures, and new laser design concepts.

  4. 1997 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1997-12-01

    The 1997 White Book is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. Data detailing Pacific Northwest non-utility generating (NUG) resources is also available upon request. This analysis updates the 1996 pacific Northwest Loads and Resources Study, published in December 1996. In this loads and resources study, resource availability is compared with a medium forecast of electricity consumption. This document analyzes the Pacific Northwest`s projected loads and available generating resources in two parts: (1) the loads and resources of the Federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional power system which includes loads and resources in addition to the Federal system. This study presents the Federal system and regional analyses for the medium load forecast. This analysis projects the yearly average energy consumption and resource availability for Operating Years (OY) 1998--99 through 2007--08.

  5. 1993 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1993-12-01

    The Loads and Resources Study is presented in three documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The forecasted future electricity demands -- firm loads -- are subtracted from the projected capability of existing and {open_quotes}contracted for{close_quotes} resources to determine whether Bonneville Power Administration (BPA) and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, and additional conservation, contract purchases, or generating resources will be needed to meet load growth. The Pacific Northwest Loads and Resources Study analyzes the Pacific Northwest`s projected loads and available generating resources in two parts: (1) the loads and resources of the Federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional power system, which includes loads and resource in addition to the Federal system. The loads and resources analysis in this study simulates the operation of the power system under the Pacific Northwest Coordination Agreement (PNCA) produced by the Pacific Northwest Coordinating Group. This study presents the Federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for Operating Years (OY) 1994--95 through 2003--04.

  6. [Ecological and economic harmony evaluation and spatial evolution of the Hexi corridor, northwest China].

    PubMed

    Liu, Hai-long; Shi, Pei-ji; Li, Sheng-mei; Tong, Hua-li; Nie, Xiao-ying; Wei, Wei

    2014-12-01

    The relationship between economic development and environment and the evolution characteristics of spatial pattern in Hexi Corridor of Northwest China were analyzed based on Landsat images in 1985, 1995, 2000 and 2011 with twenty counties in Hexi Corridor chosen as the basic research units. The ecological economic harmony during 1985-2011 was estimated according to ESV (ecosystem services value) and EEH (ecological and economic harmony) index with the ecosystem services value estimation methods. The results showed that the land type of the study area dramatically changed during the study period, the grassland decreased badly, and the construction land and cultivated land increased quickly. The ESV showed an overall downward trend, especially in the Shiyang River basin and the middle of Heihe River. The ESV in the Shule River basin in this period. After 2000, the economic growth speeded up visibly in the study area. The economic development concentrated in the resource-based cities and regional central cities, and declined from the center of corridor to the both sides. The ecological-economic relation in Hexi Corridor experienced a transformation of "preliminary deterioration--further deterioration--low grade coordination". The EEH had large changes in the Shiyang River basin and the middle of Heihe River, which experienced a transformation of "conflict--more conflicts--less conflicts", however, there was little change in Shule River basin. The development mode and the comprehensive reclamation of Shiyang River basin and Heihe River basin had a significant influence on the regional ecological and economic harmony.

  7. Lightning Behaviour in the Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Kochtubajda, B.; Flannigan, M. D.; Gyakum, J. R.; Stewart, R. E.; Way, A.

    2003-12-01

    Thunderstorms play an important role in the cycling of water and energy over the boreal ecosystem of the Northwest Territories (NWT) of Canada during the warm season. Associated lightning activity can also initiate forest fires. Global distributions of lightning derived from satellite observations indicate that this region experiences a relatively large amount of lightning, given its high latitude location. However, no previous work has been directly applied to the NWT. A variety of data sets have been used to study lightning activity, cloud and convective processes in the water cycle and their impacts on the forests of the NWT for the 1994-1999 fire seasons. These include the archived strike data from the lightning detection network operating in the NWT, fire data from the Canadian Forest Service's national Large Fire Database, surface and upper-air station data, and historical gridded data from the Environment Canada and the National Centers for Environmental Prediction (NCEP) digital archives. Lightning activity over the NWT is linked with its geographic alignment, large scale flows, and diurnal heating cycle. The convective storm season and resultant lightning activity is characterized as short but intense with a strong peak in cloud-to-ground lightning during June and July. The maximum area of lightning activity varies in space and in time and is influenced by local moisture sources (such as wetland areas and small lakes) and by topography. The diurnal distribution of strikes indicates that most of the lightning is linked with daytime-heating initiated thunderstorms. There was a relatively low amount of lightning activity during the 1994-95 seasons but an unusually high fraction of positive lightning strikes during 1995. The positive ground strikes may have been influenced by the presence of smoke from fires. Lightning-initiated fire occurrence peaks during July, while much of the burned area occurs in June. Events with an especially large number of lightning

  8. Hydrocarbon habitat of the Tuz Golu basin, central Anatolia, Turkey

    SciTech Connect

    More, C.; Bird, P.R.; Clark-Lowes, D.D. )

    1988-08-01

    The Tuz Golu basin (TGB) of central Anatolia has been interpreted as a northwest-southeast-aligned terraced forearc basin that accumulated a Maastrichtian to Holocene, predominantly terrigenous, sedimentary succession. Evidence is presented from an integrated study incorporating all seismic, gravity, and well data for the following basin evolution. (1) Late Cretaceous sedimentation on the west of the Kirsehir block with a diverse assemblage of facies including terrestrial, possible sabkha, shallow marine carbonate and turbidite deposits; (2) eastward subduction of Neotethys beginning in the Maastrichtian and development of the Tuz Golu as a forearc basin; (3) deposition of a thick Paleocene to Eocene flysch succession; (4) late Eocene inversion of the thick flysch section along the central axis of the basin and development of flanking shallow basins; (5) late Eocene-Oligocene emergence with deposition of evaporites and red beds in a restricted basin, followed by suturing of continental blocks, uplift, and erosion; (6) dextral displacement along the Kochisar fault; (7) Oligocene-Miocene diapirism of Eocene salt along major faults in the western shallow basin; and (8) terrestrial and lacustrine sedimentation in the neotectonic TGB. Of the 22 wells drilled in the TGB, four contained oil or gas shows from formations of Paleocene to Miocene age. Potential shale source rocks occur in the Upper Cretaceous, Paleocene, and Eocene sections. Cretaceous rudist reefs and Paleocene/Eocene sandstones provide target reservoirs, while Eocene salt represents an ideal seal. Late Eocene deformation created the major trap-forming structures of the basin.

  9. Substantial inorganic carbon sink in closed drainage basins globally

    NASA Astrophysics Data System (ADS)

    Li, Yu; Zhang, Chengqi; Wang, Naiang; Han, Qin; Zhang, Xinzhong; Liu, Yuan; Xu, Lingmei; Ye, Wangting

    2017-07-01

    Arid and semi-arid ecosystems are increasingly recognized as important carbon storage sites. In these regions, extensive sequestration of dissolved inorganic carbon can occur in the terminal lakes of endorheic basins--basins that do not drain to external bodies of water. However, the global magnitude of this dissolved inorganic carbon sink is uncertain. Here we present isotopic, radiocarbon, and chemical analyses of groundwater, river water, and sediments from the terminal region of the endorheic Shiyang River drainage basin, in arid northwest China. We estimate that 0.13 Pg of dissolved inorganic carbon was stored in the basin during the mid-Holocene. Pollen-based reconstructions of basin-scale productivity suggest that the mid-Holocene dissolved inorganic carbon sink was two orders of magnitude smaller than terrestrial productivity in the basin. We use estimates of dissolved inorganic carbon storage based on sedimentary data from 11 terminal lakes of endorheic basins around the world as the basis for a global extrapolation of the sequestration of dissolved organic carbon in endorheic basins. We estimate that 0.152 Pg of dissolved inorganic carbon is buried per year today, compared to about 0.211 Pg C yr-1 during the mid-Holocene. We conclude that endorheic basins represent an important carbon sink on the global scale, with a magnitude similar to deep ocean carbon burial.

  10. Timing of Cenozoic Basin Formation in Northern Sundaland, Southeast Asia

    SciTech Connect

    Liew, K.K. )

    1994-07-01

    The present shorelines of northern Sundaland show preferential northwest-southeast elongation. This trend is parallel for subparallel to major faults and suture in this region. Continental wrench/shear basins developed on the western portion of this region and back-arc basins developed on the western portion of this region and back-arc basins in the rest of the region are also aligned to this trend. Different basin geometries and structural patterns among Cenozoic basins in northern Sundaland indicate different origins and/or timing of basin formation. Wrench faulting has played a significant role in the formation of these Cenozoic basins. The continued collision of the Indian subplate with the Eurasian plate during early Cenozoic has caused a redistribution of stress within this region. Zones of weakness have been reactivated or created with large lateral displacements by these changes, thus initiating the subsidence of these basins. The episodic initiation of Cenozoic basins may have begun as early as Jurassic and continued till Oligocene.

  11. Energy for the Future. The Draft 1991 Northwest Power Plan.

    ERIC Educational Resources Information Center

    Clearing, 1991

    1991-01-01

    The Northwest Power Plan, developed by the Northwest Power Planning Council to deal with the increasing demands for energy by the Pacific Northwest, is discussed. An idea of how sufficient energy could be produced as well as preserve the qualities of life that make the Pacific Northwest special is presented. (KR)

  12. Polyphase deformation in Marathon basin, west Texas

    SciTech Connect

    Sims, D.; Morris, A.

    1989-03-01

    Marathon basin, Texas, is the westernmost window into the Ouachita orogene. Interpreted as a result of northwest-southeast compression, intermittent orogenic pulses began in the Mississippian and continued into the Early Permian (Wolfcampian). However, the northeastern portion of the basin contains structures that could not have resulted from a single compression orientation and indicate that deformation continued to affect Wolfcampian and Leonardian rocks. Their work confirms the protracted nature of upper Paleozoic deformation and indicates that late- and postorogenic events were not related to the northwest-southeast compression manifest throughout the Marathon basin. The northeastern part of the basin exposes Morrowan( )-Desmoinesian rocks. The authors recognize a duplex thrust system, traceable for 10 km, rooted in the uppermost Morrowan( ) Tesnus Formation and creating a double thickness of (Morrowan-Atokan) Dimple Limestone. The duplex is folded by 50 to 2000-m half-wavelength northwestverging folds which plunge gently southwestward. Dimple thickness is further increased by a large number of contraction faults, each with up to 2 m of stratigraphic throw. Superimposed upon these structures are southeast-plunging, 10-20-m half-wavelength open kinks with vergence sympathetic with the regional trend variation apparent in this part of the basin. The superimposed structures are the result of a northeast-southwest compressive event. North of the Ouachita exposure, rocks containing lower Leonardian fusulinids are deformed into gentle east-west-trending 500-m half-wavelength folds which are likely the result of another distinct compression orientation trending north-south. Pervasive east-west extension in all Pennsylvania-age rocks is indicated by subvertical, calcite-filled veins.

  13. Using the stratigraphic record to document tectonic-geomorphologic interactions in a foreland basin setting: outcrop study of the Ainsa Basin, Spain

    NASA Astrophysics Data System (ADS)

    Pyles, D. R.; Moody, J.; Gordon, G.; Hoffman, M.; Moss-Russell, A.; Silalahi, H.; Setiawan, P.; Clark, J.; Bracken, B.; Guzofski, C.

    2013-12-01

    Eocene strata of the Ainsa Basin (Spain) contain clastic and carbonate strata deposited in a relatively small (100 km^2), structurally active piggyback foreland basin. The basin is bounded by the Mediano Anticline to the east and the Boltana Anticline to the west. Clastic strata were sourced by an eastern fluvial-deltaic system whereas carbonate strata were sourced from shallow-water carbonate systems that rimmed the southern and western margins of the basin. Four time-stratigraphic units, which form an upward transect through the basin-fill succession, were studied in detail: Ainsa, Morillo, Guaso, Sobrarbe-Escanilla. The study uses the stratigraphic record to document linkages between progressive uplift of the basin-bounding structures, spatial-temporal changes in the amount and location of subsidence, and temporal changes in the landscape. The Ainsa unit contains submarine channels that entered the basin from the east and exited the basin to the northwest, although some channels locally transfer to lobes near the northwest end of the basin. The Morillo unit contains submarine channels that entered the basin from the east, dispersed onto the basin floor, then converged at the western end of the basin where they continued onto the longitudinally adjacent Jaca Basin. The Guaso unit contains submarine channels that entered the basin from the east and transfer to a ponded distributive submarine fan at the center of the basin. The Escanilla-Sobrarbe unit contains a linked shelf-to-basin system that prograded from south to north and records the final filling of the basin. Four lines of evidence collectively support the basin-fill succession was deposited during structural growth. First, the depocenter, which is interpreted to reflect the position of maximum subsidence during deposition, of the systems systematically shifted westward as the basin filled. Second, the axial part of the clastic sediment systematically shifted southward as the basin filled. Third, the

  14. 1994 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1994-12-01

    The 1994 Pacific Northwest Loads and Resources Study presented herein establishes a picture of how the agency is positioned today in its loads and resources balance. It is a snapshot of expected resource operation, contractual obligations, and rights. This study does not attempt to present or analyze future conservation or generation resource scenarios. What it does provide are base case assumptions from which scenarios encompassing a wide range of uncertainties about BPA`s future may be evaluated. The Loads and Resources Study is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates the 1993 Pacific Northwest Loads and Resources Study, published in December 1993. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The Federal system and regional analyses for medium load forecast are presented.

  15. Acid Precipitation in the Pacific Northwest.

    ERIC Educational Resources Information Center

    Baldwin, John; Kozak, David

    1988-01-01

    Discusses the causes, sources, and problems associated with acid deposition in the Pacific Northwest. Includes a learning activity about acid rain, "Deadly Skies," which was adapted from the Project WILD Aquatic Supplement. (TW)

  16. Photo Gallery for Northwest Indiana Area (Indiana)

    EPA Pesticide Factsheets

    Northwest Indiana Area (Indiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  17. Acid Precipitation in the Pacific Northwest.

    ERIC Educational Resources Information Center

    Baldwin, John; Kozak, David

    1988-01-01

    Discusses the causes, sources, and problems associated with acid deposition in the Pacific Northwest. Includes a learning activity about acid rain, "Deadly Skies," which was adapted from the Project WILD Aquatic Supplement. (TW)

  18. Program Contacts for Northwest Indiana Area (Indiana)

    EPA Pesticide Factsheets

    Northwest Indiana Area (Indiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  19. Forest management challenged in the Pacific Northwest

    SciTech Connect

    Heilman, P.E. )

    1990-11-01

    This article discusses the US Forest Service Pacific Northwest and current management practice in the light of increasingly cynical public questions about forest policy. Policy challenges to the Service include clearcutting, sustainability, diversity, and ecosystem preservation.

  20. Definition of basin phases in the Petrel Sub-basin (Australia): Implications for the development of Palaeozoic petroleum systems

    SciTech Connect

    Blevin, J.E.; Colwell, J.B.; Kennard, J.M. , Canberra )

    1996-01-01

    An study of the Petrel Sub-basin (Bonaparte Basin) on Australia's northwest margin has identified seven main phases of basin development spanning the Early Cambrian to Tertiary. Each phase was initiated and terminated by distinct, primarily tectonic events that have controlled the structural and stratigraphic evolution of the basin and the development of petroleum systems. These phases include periods of major extension (Early Cambrian, Middle Devonian to early Carboniferous) and compression (Early Devonian, mid-Triassic), as well as rapid and slow subsidence phases in the Early to Late Carboniferous and Late Carboniferous to Triassic, respectively. Basin inversion in the mid-Triassic has been critical in controlling the development of broad anticlinal features that presently reservoir the large, but as yet undeveloped gas/condensate fields Petrel and Tern. An earlier period of minor compression during the late Carboniferous initiated limited movement of Paleozoic salt within the deeper basin, forming salt-cored, low amplitude anticlines in the predominantly carbonate Tanmurra Formation, a play which remains untested. In the southern Petrel Sub-basin, early phases of hydrocarbon generation and fluid migration associated with salt movement are poorly understood. Preliminary results of geochemical studies indicate that there are at least two oil families in Devonian and Carboniferous reservoirs. This suggests multiple source intervals within the deeper flanks of the basin, thus the understanding of sedimentation during early basin phases may be critical in evaluating petroleum systems.

  1. Definition of basin phases in the Petrel Sub-basin (Australia): Implications for the development of Palaeozoic petroleum systems

    SciTech Connect

    Blevin, J.E.; Colwell, J.B.; Kennard, J.M.

    1996-12-31

    An study of the Petrel Sub-basin (Bonaparte Basin) on Australia`s northwest margin has identified seven main phases of basin development spanning the Early Cambrian to Tertiary. Each phase was initiated and terminated by distinct, primarily tectonic events that have controlled the structural and stratigraphic evolution of the basin and the development of petroleum systems. These phases include periods of major extension (Early Cambrian, Middle Devonian to early Carboniferous) and compression (Early Devonian, mid-Triassic), as well as rapid and slow subsidence phases in the Early to Late Carboniferous and Late Carboniferous to Triassic, respectively. Basin inversion in the mid-Triassic has been critical in controlling the development of broad anticlinal features that presently reservoir the large, but as yet undeveloped gas/condensate fields Petrel and Tern. An earlier period of minor compression during the late Carboniferous initiated limited movement of Paleozoic salt within the deeper basin, forming salt-cored, low amplitude anticlines in the predominantly carbonate Tanmurra Formation, a play which remains untested. In the southern Petrel Sub-basin, early phases of hydrocarbon generation and fluid migration associated with salt movement are poorly understood. Preliminary results of geochemical studies indicate that there are at least two oil families in Devonian and Carboniferous reservoirs. This suggests multiple source intervals within the deeper flanks of the basin, thus the understanding of sedimentation during early basin phases may be critical in evaluating petroleum systems.

  2. Analogue modeling of arc and backarc deformation in the New Hebrides arc and North Fiji Basin

    NASA Astrophysics Data System (ADS)

    Schellart, W. P.; Lister, G. S.; Jessell, M. W.

    2002-04-01

    In most backarc basins, extension is perpendicular to the arc. Thus individual spreading ridges extend approximately parallel to the arc. In the North Fiji Basin, however, several ancient and active spreading ridges strike 70° 90° to the New Hebrides arc. These high- angle spreading ridges relocated southward during the asymmetric opening of the North Fiji Basin. We have simulated the structural development of the North Fiji Basin and the New Hebrides arc with scaled analogue models, and the results have inspired us to come to several tentative conclusions. We interpret the orientation of the high-angle spreading ridges to be related to the asymmetric opening of the backarc basin around a hinge, where they form close to the hinge. Relocation of these spreading ridges is most likely related to subduction of the West Torres Plateau along the New Hebrides Trench. This resulted in localized collision, retarded rollback of the subducting slab along the northwest corner of the trench, and reduced extension and shearing in the northwest corner of the North Fiji Basin. Backarc extension continued in the rest of the North Fiji Basin owing to continued rollback of the southern part of the subducting slab. Here, active extension was separated from the slightly or nonextending northwest corner by a zone striking at high angle to the New Hebrides arc, i.e., the Hazel Holme extensional zone. Moreover, impingement of the d'Entrecasteaux Ridge into the overriding plate led to local deformation and fragmentation of the arc.

  3. Petroleum prospectivity of the Canada Basin, Arctic Ocean

    USGS Publications Warehouse

    Grantz, A.; Hart, P.E.

    2012-01-01

    Reconnaissance seismic reflection data indicate that Canada Basin is a >700,000 sq. km. remnant of the Amerasia Basin of the Arctic Ocean that lies south of the Alpha-Mendeleev Large Igneous Province, which was constructed across the northern part of the Amerasia Basin between about 127 and 89-83.5 Ma. Canada Basin was filled by Early Jurassic to Holocene detritus from the Beaufort-Mackenzie Deltaic System, which drains the northern third of interior North America, with sizable contributions from Alaska and Northwest Canada. The basin contains roughly 5 or 6 million cubic km of sediment. Three fourths or more of this volume generates low amplitude seismic reflections, interpreted to represent hemipelagic deposits, which contain lenses to extensive interbeds of moderate amplitude reflections interpreted to represent unconfined turbidite and amalgamated channel deposits.Extrapolation from Arctic Alaska and Northwest Canada suggests that three fourths of the section in Canada Basin is correlative with stratigraphic sequences in these areas that contain intervals of hydrocarbon source rocks. In addition, worldwide heat flow averages suggest that about two thirds of Canada Basin lies in the oil or gas windows. Structural, stratigraphic and combined structural and stratigraphic features of local to regional occurrence offer exploration targets in Canada Basin, and at least one of these contains bright spots. However, deep water (to almost 4000 m), remoteness from harbors and markets, and thick accumulations of seasonal to permanent sea ice (until its possible removal by global warming later this century) will require the discovery of very large deposits for commercial success in most parts of Canada Basin. ?? 2011 Elsevier Ltd.

  4. Pleural calcification in northwest Greece

    SciTech Connect

    Bazas, T.; Oakes, D.; Gilson, J.C.; Bazas, B.; McDonald, J.C.

    1985-12-01

    Mass miniature radiography in 1969 detected a high prevalence of pleural calcification in three villages in northwest Greece. In 1980 a survey of a 15% sample of the population over the age of 10 was carried out with a 80% response rate. Full-size radiographs, ventilatory capacity measurements, and a detailed questionnaire on respiratory symptoms, type of work, and residence were used. Independent classification of the 408 films by two readers using the ILO/UC scheme showed very few small opacities but a very high prevalence of pleural calcification first evident in young adults and rising to 70% in the elderly. The overall prevalence was 34.7% in men and 21.5% in women. A comparison with the 1969 survey showed a progression rate of 5% per annum. In neither sex was there a significant relation of pleural calcification to smoking, ventilatory capacity, nor type of work, though those classified as field croppers had a slightly higher prevalence. There was no obvious evidence of increased lung cancer or mesothelioma in the village. The agent responsible for this apparently benign condition was not identified.

  5. Air Pollution over North-West Bay of Bengal in the Early Post-Monsoon Season Based on NASA MERRAero Data

    NASA Technical Reports Server (NTRS)

    Kishcha, Pavel; DaSilva, Arlindo M.; Starobinets, Boris; Alpert, Pinhas

    2013-01-01

    The MERRA Aerosol Reanalysis (MERRAero) has been recently developed at NASA's Global Modeling Assimilation Office (GMAO). This reanalysis is based on a version of the GEOS-5 model radiatively coupled with GOCART aerosols, and it includes assimilation of bias-corrected Aerosol Optical Thickness (AOT) from the MODIS sensor on both Terra and Aqua satellites. Our main finding is that, in October, in the absence of aerosol sources in north-west Bay of Bengal (BoB), MERRAero showed increasing AOT trends over north-west BoB exceeding those over the east of the Ganges basin. The Ganges basin is characterized by significant population growth accompanied by developing industry, agriculture, and increasing transportation: this has resulted in declining air quality. MERRAero data for the period 2002-2009 was used to study AOT trends over north-west Bay of Bengal (BoB) in the early post-monsoon season. This season is characterized by aerosol transport from the Ganges basin to north-west BoB by prevailing winds; and still significant rainfall of over 150 mmmonth. Different aerosol components showed strong increasing AOT trends over north-west BoB. The following factors contributed to the increasing AOT trend over the area in question in October: an increasing number of days when prevailing winds blew from land to sea, resulting in a drier environment and an increase in air pollution over north-west BoB; wind convergence was observed over north-west BoB causing the accumulation of aerosol particles over that region, when prevailing winds blew from land to sea. MERRAero aerosol reanalysis can be used on a global scale.

  6. Global climate change and effects on Pacific Northwest salmonids: An exploratory case study

    SciTech Connect

    Shankle, S.A.

    1990-09-01

    Recently, a number of papers have addressed global warming and freshwater fisheries. The recent report to Congress by the US Environmental Protection Agency included an analysis of potential effects of global warming on fisheries of the Great Lakes, California, and the Southeast. In California, the report stated that salinity increases in the San Francisco Bay could enhance the abundance of marine fish species, while anadromous species could be adversely affected. This paper discusses global climate changes and the effects on Pacific Northwest Salmonids. The impacts of climate change or Spring Chinook production in the Yakima Sub-basin was simulated using a computer modeling system developed for the Northwest Power planning council. 35 refs., 1 fig., 1 tab.

  7. Development of sedimentary cycles on the east Sahara craton since Silurian time (northwest Sudan/southwest Egypt)

    SciTech Connect

    Wycisk, P. )

    1988-08-01

    The sedimentary succession of southwest Egypt and northwest Sudan, formerly called the Nubia(n) Sandstone, has been subdivided into a number of formations. The predominantly fluvial sediments which characterize Silurian to Upper Cretaceous strata of this region were repeatedly interrupted by marine transgressions that rapidly progressed toward the south since Ordovician time. Thin, shallow marine sequences of different ages can be traced for more than 1,000 km within the studied area. The development of the sedimentary cycles will be pointed out by surface and subsurface data along a cross section from the southern Dakhla basin in the north to the Misaha trough and Abyad basin in the south.

  8. San Mateo Creek Basin

    EPA Pesticide Factsheets

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  9. Tectonic evolution of northwest Siberia

    SciTech Connect

    Natapov, L.P. )

    1993-09-01

    The ancient Siberian continent was split from early Pangen in early Riphean. The newly formed continent drifted from the southern to the northern hemisphere, reaching high altitudes only in the Late Paleozoic. Up to the Early Carboniferous, a typical passive margin of the Atlantic type, prograding to the ocean, developed along the present northern and eastern boundaries of this continent. In Upper Paleozoic, Triassic, and Jurassic, the carbonate sedimentation was replaced by the accumulation of thick terrigenous complexes along the northern and southern margins. Large submarine plains were formed by the merging of fans, while eustatic lowering of the ocean level enlarged the source area of detrital material. Distal facies, with time, were moving into the ocean. Rifting, penetrating inside the continent, conditioned for formation of large sedimentary basins. The development of the Sukhanskaya syneclise is associated with Riphean rifting, and Vilyuiskaya with Upper Devonian rifting. In the Upper Mesozoic, the covergent boundaries of lithospheric plates existed along the northern and eastern boundaries of the Siberian continent. As a result of the final collision of the continental margin with blocks of different nature (microcontinents, island arcs, etc.) transported by the Kula plate, and with chukchi and north Taimyr arctic blocks, Verkhoyansk and Taimyr fold belts appeared in the Upper Cretaceous. They were over-thrusted on clastic wedges, putting into shape the present-day structure of foredeeps. In the paper, principal attention is devoted to peculiarities of structure and development of sedimentary basins, formation of oil-producing complexes, and structures favorable for accumulation of hydrocarbons. All these features are analyzed at the background of this plate tectonic scenario.

  10. Compendium of Low-Cost Pacific Salmon and Steelhead Trout Production Facilities and Practices in the Pacific Northwest.

    SciTech Connect

    Senn, Harry G.

    1984-09-01

    The purpose was to research low capital cost salmon and steelhead trout production facilities and identify those that conform with management goals for the Columbia Basin. The species considered were chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and steelhead trout (Salmo gairdneri). This report provides a comprehensive listing of the facilities, techniques, and equipment used in artificial production in the Pacific Northwest. (ACR)

  11. Effects of climate change on Pacific Northwest water-related resources: Summary of preliminary findings

    SciTech Connect

    Scott, M.J.; Sands, R.D.; Vail, L.W.; Chatters, J.C.; Neitzel, D.A.; Shankle, S.A.

    1993-12-01

    The Pacific Northwest Case Study is a multi-agency analysis of atmospheric/climatic change impacts on the Pacific Northwest (which includes Washington, Oregon, Idaho, and portions of the Columbia River Basin in Western Montana). The purpose of the case study, which began in fiscal year 1991, was to develop and test analytical tools, as well as to develop an assessment of the effects of climate change on climate-sensitive natural resources of the Pacific Northwest and economic sectors dependent on them. The overall study, jointly funded by the US Department of Energy (DOE) and the US Environmental Protection Agency, was a broad-based, reconnaissance-level study to identify potential climate impacts on agriculture, coastal resources, forest resources, and irrigation in the Pacific Northwest. DOE participated in the reconnaissance study, with responsibility for hydroelectric and water supply issues. While this report briefly discusses a broader array of water issues, attention is mainly focused on three aspects of the water study: (1) the effects of the region`s higher temperatures on the demand for electric power (which in turn puts additional demand on hydroelectric resources of the region); (2) the effects of higher temperatures and changes, both in precipitation amounts and seasonality, on river flows and hydroelectric supply; and (3) the effect of higher temperatures and changed precipitation amounts and seasonality on salmonid resources -- particularly the rearing conditions in tributaries of the Columbia River Basin. Because the meaning of regional climate forecasts is still quite uncertain, most of the preliminary findings are based on sensitivity analyses and historical analog climate scenarios.

  12. The Northwest Indiana Robotic Telescope

    NASA Astrophysics Data System (ADS)

    Slavin, Shawn D.; Rengstorf, A. W.; Aros, J. C.; Segally, W. B.

    2011-01-01

    The Northwest Indiana Robotic (NIRo) Telescope is a remote, automated observing facility recently built by Purdue University Calumet (PUC) at a site in Lowell, IN, approximately 30 miles from the PUC campus. The recently dedicated observatory will be used for broadband and narrowband optical observations by PUC students and faculty, as well as pre-college students through the implementation of standards-based, middle-school modules developed by PUC astronomers and education faculty. The NIRo observatory and its web portal are the central technical elements of a project to improve astronomy education at Purdue Calumet and, more broadly, to improve science education in middle schools of the surrounding region. The NIRo Telescope is a 0.5-meter (20-inch) Ritchey-Chrétien design on a Paramount ME robotic mount, featuring a seven-position filter wheel (UBVRI, Hα, Clear), Peltier (thermoelectrically) cooled CCD camera with 3056 x 3056, square, 12 μm pixels, and off-axis guiding. It provides a coma-free imaging field of 0.5 degrees square, with a plate scale of 0.6 arcseconds per pixel. The observatory has a wireless internet connection, local weather station which publishes data to an internet weather site, and a suite of CCTV security cameras on an IP-based, networked video server. Control of power to every piece of instrumentation is maintained via internet-accessible power distribution units. The telescope can be controlled on-site, or off-site in an attended fashion via an internet connection, but will be used primarily in an unattended mode of automated observation, where queued observations will be scheduled daily from a database of requests. Completed observational data from queued operation will be stored on a campus-based server, which also runs the web portal and observation database. Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0736592.

  13. The Paleozoic tectonic evolution and metallogenesis of the northern margin of East Junggar, Central Asia Orogenic Belt: Geochronological and geochemical constraints from igneous rocks of the Qiaoxiahala Fe-Cu deposit

    NASA Astrophysics Data System (ADS)

    Liang, Pei; Chen, Huayong; Hollings, Pete; Xiao, Bing; Wu, Chao; Bao, Zhiwei; Cai, Keda

    2016-11-01

    The East Junggar terrane (NW China) is an important constituent of the Central Asian Orogenic Belt (CAOB). From the Devonian to Permian, regional magmatism evolved from mainly calc-alkaline (I-type) to alkaline (A-type). The Qiaoxiahala Fe-Cu deposit, located in the Late Paleozoic Dulate island arc (northern margin of the East Junggar), is hosted in the volcanic rocks of the Middle Devonian Beitashan Formation. Two magmatic stages were identified in the deposit, the Qiaoxiahala diorite porphyry (380 ± 4.0 Ma) and a younger aplite (331 ± 3.1 Ma). The (high-K) calc-alkaline Beitashan Formation basaltic rocks are characterized by LILE and LREE enrichments and HFSE depletions, pointing to a subduction-related affinity. The high Mg# (42-75), elevated Ce/Th and Ba/Th, depleted Nb, positive εNd(t) (6.6), low (87Sr/86Sr)i (0.7037) and MORB-like Pb isotope characters all suggest an origin involving partial melting of a MORB-like depleted mantle wedge (metasomatized by slab-derived fluids) with little evidence of crustal contamination. The calc-alkaline (I-type) diorite porphyry, characterized by LILE and LREE enrichments and HFSE depletions, may have formed from fractional crystallization of the basaltic rocks, with its parental magma derived from the same depleted mantle wedge. The negative εHf(t) (-8.26), Hf model age (TDMC) of 1406 Ma and the presence of inherited zircons (ca. 470 and 506 Ma) indicate that the diorite has assimilated older crustal material. The alkaline, metaluminous (A-type) aplite is characterized by HFSE enrichment and depletions in Sr, P and Ti, distinct from the basaltic rocks and diorite porphyry at Qiaoxiahala. The low Mg# (35-38), positive Zr and Hf, positive εHf(t) (4.77-9.75) and εNd(t) (6.85-6.86) and low T2DM (538-520 Ma) suggest a juvenile lower crustal source due to partial melting of basaltic lower crust as a result of underplating of mantle-derived melts and accompanied by magma mixing. The tectonic evolution of the Paleozoic East

  14. Hydrogeology of the West Siberian Basin

    SciTech Connect

    Hoover, K.A.; Foley, M.G.; Bradley, D.J.

    1996-12-31

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in significant contamination of the environment in western Siberia. The radioactive releases to surface waters and the surficial environment from the Mayak site are the largest known in the world. However, they are dwarfed by the amounts of liquid wastes injected into the subsurface at Tomsk and Krasnoyarsk since the early 1960s. This paper provides the status of efforts by Pacific Northwest National Laboratory to quantify the regional hydrogeologic context for potential contaminant migration from areas in western Siberia. The West Siberian Basin is the largest platformal basin and region of low relief on earth. Ground water in the West Siberian Basin is contained in a single geologic structure (i.e., a single basin). Hydrogeologic cross sections indicate that freshwater wedges are present in both unconfined and confined aquifers (as well as in Paleozoic rocks) in the highland regions that rim the basin. The authors developed a 13-layer, finite-element computer model of the West Siberian Basin primarily based on GIS integration of data from geologic studies. The top of the hydrologic system was assumed to coincide with a water table derived from smoothed topography and surface-water occurrences; precipitation supplied the water, and the topographic gradient of the water table supplied the driving force for ground-water flow. The general directions of calculated ground-water flow suggest that (1) the major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks; and (2) ground-water divides that penetrate the entire thickness of the model are evident between the major rivers. Their results suggest that contaminants entering the confined aquifer system may eventually migrate to the surface, discharging within major rivers, rather than remaining confined for long travel distances within the basin sediments.

  15. Cretaceous may hold promise in Majunga basin, Madagascar

    SciTech Connect

    Lalaharisaina, J.V. ); Ferrand, N.J. )

    1994-08-01

    Recent drilling in the Majunga basin of northwestern Madagascar revealed unexpected light oil shows in excellent quality reservoir sands of Mid-Cretaceous age. Regional reconstructions show the development of a prograding clastic shelf from the Aptian until the Mid-Turonian that extended laterally from the northwest costs of Madagascar into Northwest India and Southeast Pakistan. Six untested play concepts have been identified in Cretaceous reservoirs of the Majunga basin. These plays offer multiple objectives in the depth range of 800--2,500 m within a well defined area. Further untested plays exist for Tertiary and Dogger objectives. The paper describes the geologic setting, exploration history the Cretaceous reservoirs, source rocks, and other potential plays. Political changes in Madagascar the last four years have led to an open door policy for foreign investment. Favorable terms are on offer for investment in the petroleum sector, and high potential exists for development on this island continent.

  16. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... northwest of an imaginary line between two points: 28°24′57.88″ N, 080°37′25.69″ W to 28°24′37.48″ N, 080°37... arrival of a cruise ship at the West Basin of Port Canaveral Harbor during MARSEC Levels 2 and 3 or when... will not be deactivated until the departure of all cruise ships from the West Basin. The zone is...

  17. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... northwest of an imaginary line between two points: 28°24′57.88″ N, 080°37′25.69″ W to 28°24′37.48″ N, 080°37... arrival of a cruise ship at the West Basin of Port Canaveral Harbor during MARSEC Levels 2 and 3 or when... will not be deactivated until the departure of all cruise ships from the West Basin. The zone is...

  18. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... northwest of an imaginary line between two points: 28°24′57.88″ N, 080°37′25.69″ W to 28°24′37.48″ N, 080°37... arrival of a cruise ship at the West Basin of Port Canaveral Harbor during MARSEC Levels 2 and 3 or when... will not be deactivated until the departure of all cruise ships from the West Basin. The zone is...

  19. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... northwest of an imaginary line between two points: 28°24′57.88″ N, 080°37′25.69″ W to 28°24′37.48″ N, 080°37... arrival of a cruise ship at the West Basin of Port Canaveral Harbor during MARSEC Levels 2 and 3 or when... will not be deactivated until the departure of all cruise ships from the West Basin. The zone is...

  20. MODELING WILDLIFE HABITAT SUITABILITY IN THE WILLAMETTE BASIN: A COMPARISON OF PAST, PRESENT AND A RANGE OF POSSIBLE FUTURES (CA. 2050)

    EPA Science Inventory

    The effects of three possible land use futures in the Willamette Basin are evaluated with respect to present and historic conditions of wildlife habitat. Basin wide land use/land cover maps were developed by the Pacific Northwest Ecosystem Research Consortium (PNW-ERC) in coopera...

  1. MODELING WILDLIFE HABITAT SUITABILITY IN THE WILLAMETTE BASIN: A COMPARISON OF PAST, PRESENT AND A RANGE OF POSSIBLE FUTURES (CA. 2050)

    EPA Science Inventory

    The effects of three possible land use futures in the Willamette Basin are evaluated with respect to present and historic conditions of wildlife habitat. Basin wide land use/land cover maps were developed by the Pacific Northwest Ecosystem Research Consortium (PNW-ERC) in coopera...

  2. Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; McCreary, Brome

    2013-01-01

    Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1852) by two invaders. We found invasive Procambarus clarkii (Girard, 1852), in 51 of 283 sites and in all three hydrographic basins. We found invasive Orconectes n. neglectus (Faxon, 1885) at 68% of sites in the Rogue basin and provide first documentation of their broad distribution in the Umpqua basin. We found P. clarkii in both lentic and lotic habitats, and it was positively associated with manmade sites. P. leniusculus was positively associated with lotic habitats and negatively related to manmade sites. In the Rogue and Umpqua basins, O. n. neglectus and P. leniusculus were similar in their habitat associations. We did not find a negative relationship in site occupancy between O. n. neglectus and P. leniusculus. Our data suggest that P. clarkii has potential to locally displace P. leniusculus. There is still time for preventive measures to limit the spread of the invasive crayfish in this region.

  3. Evolution of the elevated passive margin of northwest Greenland

    NASA Astrophysics Data System (ADS)

    Spiegel, Cornelia; Reiter, Wolfgang; Lisker, Frank; Damm, Volkmar

    2015-04-01

    The geomorphic evolution of high-standing passive continental margins is still controversially discussed. This is particularly true for the elevated margins of Greenland. They have alternatively been explained by resulting from prolonged very slow erosion following Paleozoic orogeny, resulting from rifting and opening of ocean basins adjacent to the Greenland continental margins, or as young geomorphic features only formed during the Cenozoic. This study focuses on the northwestern margin of Greenland, north of the Melville Bugt at the northern end of Baffin Bay, using a combination of apatite fission track and (U-Th-Sm)/He thermochronology. Opening and formation of oceanic crust of Baffin Bay took place during the Late Cretaceous. The study area is also situated at the southern termination of the postulated Wegener Fault, a controversially discussed large-scale strike-slip fault system supposedly active during the Paleogene, which has been described as one of the last problems of global plate tectonic reconstructions. Our data show that several normal faults dissecting the northwest Greenland margin were active during or after the Cretaceous, presumably related to extension associated with the opening of Baffin Bay. Also, our data show a clear - although not very pronounced - cooling signal at the end of the Cretaceous, which we interpret as reflecting initial formation of an elevated margin during and after continental breakup. Margin formation was followed by subsidence, with maximum burial at c. 30 Ma, again followed by a period of relatively rapid exhumation associated with net denudation of 2 - 3 km. This post-30 Ma denudation period may be related to tectonic activity associated with ongoing northward movement of Greenland, or to climatic changes such as early glaciation of the Arctic realm. In any case, our data imply that the present morphologic expression of the northwest Greenland margin results from young Cenozoic processes unrelated to earlier

  4. Cenozoic pull-apart basins in southwest Montana

    SciTech Connect

    Ruppel, E.T. )

    1991-06-01

    Faults and fault zones bounding the mountain ranges of southwest Montana commonly have been described as normal faults, and the region has been considered to be a northern extension of the Basin and Range. New geologic mapping suggests, however, that Cenozoic movements along most of the zones of steep faults in southwest Montana and in east-central Idaho have been strike-slip, and the intermontane basins appear to be pull-aparts. The principal fault zones trend about north, northwest, east, and north-northeast; the north-trending zones are Cenozoic in age, but the others are of Archean ancestry and are rooted in basement rocks. These faults break the region into rhomboidal mountain blocks separated by broad basins with parallel sides. The basins are as much as 5,000 m deep, and their floors are deeply indented by centers of subsidence wherre they are crossed by major fault zones. The basins are floored by Archean or Proterozoic rocks and are filled with tuffaceous sedimentary rocks of late Oligocene to late Miocene age. The Big Hole basin and the smaller basins in upper Grasshopper Creek and Horse Prairie are interpreted to be pull-aparts between zones of east-trending right-lateral faults. The cratonic basins farther east in southwest Montana are interpreted to be basement-floored openings between mountain blocks that have been separated by subcrustal flow to the northwest. The interpretations suggest that significant accumulations of oil or gas are not likely to be found in this region.

  5. Climatic and Hydrologic Modeling in the Yellow River Basin in China Dr. Shourong Wang wangsr@cma.gov.cn China Meteorological Administration No.46, Zhongguancun Nandajie, Haidian District, Beijing 100081, China Dr. Ruby LEUNG, Pacific Northwest National Laboratory, Richland, Washington 99352, USA

    NASA Astrophysics Data System (ADS)

    Wang, S.

    2012-12-01

    In order to enhance climatic and hydrologic prediction and assessment ability in the Yellow River Basin, the climatic and hydrologic modeling system is developed based on a joint international research. The system includes three sub-modeling systems, the seasonal climatic modeling system, the climate change modeling system, and the hydrologic modeling system. The seasonal climatic modeling system is composed of a regional climate model WRF3.3.1 developed by PNNL in 2011, with domain cover whole China and surrounding areas and horizontal resolution of 30 km, the Global general circulation models (GCMs) developed by China National Climate Center (NCC), providing lateral boundary conditions to WRF3.3.1, and both dynamic and statistic downscaling tools for providing detail modeling results in the Yellow River Basin. The climate change modeling system is composed of a regional climate model RegCM4.0 modified by NCC, with domain and horizontal resolution similar to WRF3.3.1, four GCMs MIROC3.2, ECHAM5, HadCM3 and NCC-CSM1.1, providing lateral boundary conditions to RegCM4.0, respectively, for comparing the nest modeling results, and also the downscaling tools. The hydrologic modeling system is composed of a large scale semi-distributed hydrologic mode VIC(Variable Infiltration Capacity) modified by PNNL, with domain cover whole Yellow River Basin and horizontal resolution of 50 km, and a distributed hydrologic mode DHSVM3.0 (Distributed Hydrology-Soil-vegetation Mode) also modified by PNNL, with domain cover the headstream of Yellow River Basin and horizontal resolution of 0.5 km. Both VIC and DHSVM3.0 are driven by the outputs of WRF3.3.1 and RegCM4.0, and provide seasonal hydrologic predictions and future hydrologic projections under IPCC AR5 climate change scenarios SRES RCP8.5 and RCP4.5. Now the simulated seasonal climatic and hydrologic results are compared and verified by recorded data sets, and VIC and DHSVM3.0 are running for the future hydrologic simulation

  6. The Northwest Passage opens for bowhead whales.

    PubMed

    Heide-Jørgensen, Mads Peter; Laidre, Kristin L; Quakenbush, Lori T; Citta, John J

    2012-04-23

    The loss of Arctic sea ice is predicted to open up the Northwest Passage, shortening shipping routes and facilitating the exchange of marine organisms between the Atlantic and the Pacific oceans. Here, we present the first observations of distribution overlap of bowhead whales (Balaena mysticetus) from the two oceans in the Northwest Passage, demonstrating this route is already connecting whales from two populations that have been assumed to be separated by sea ice. Previous satellite tracking has demonstrated that bowhead whales from West Greenland and Alaska enter the ice-infested channels of the Canadian High Arctic during summer. In August 2010, two bowhead whales from West Greenland and Alaska entered the Northwest Passage from opposite directions and spent approximately 10 days in the same area, documenting overlap between the two populations.

  7. 1996 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1996-12-01

    The Pacific Northwest Loads and Resources Study (White Book) is published annually by BPA and establishes the planning basis for supplying electricity to customers. It serves a dual purpose. First, the White Book presents projections of regional and Federal system load and resource capabilities, along with relevant definitions and explanations. Second, the White Book serves as a benchmark for annual BPA determinations made pursuant to the 1981 regional power sales contracts. Specifically, BPA uses the information in the White Book for determining the notice required when customers request to increase or decrease the amount of power purchased from BPA. Aside from these purposes, the White Book is used for input to BPA`s resource planning process. The White Book compiles information obtained from several formalized resource planning reports and data submittals, including those from the Northwest Power Planning Council (Council) and the Pacific Northwest Utilities Conference Committee (PNUCC). 11 figs., 12 tabs.

  8. The Northwest Passage opens for bowhead whales

    PubMed Central

    Heide-Jørgensen, Mads Peter; Laidre, Kristin L.; Quakenbush, Lori T.; Citta, John J.

    2012-01-01

    The loss of Arctic sea ice is predicted to open up the Northwest Passage, shortening shipping routes and facilitating the exchange of marine organisms between the Atlantic and the Pacific oceans. Here, we present the first observations of distribution overlap of bowhead whales (Balaena mysticetus) from the two oceans in the Northwest Passage, demonstrating this route is already connecting whales from two populations that have been assumed to be separated by sea ice. Previous satellite tracking has demonstrated that bowhead whales from West Greenland and Alaska enter the ice-infested channels of the Canadian High Arctic during summer. In August 2010, two bowhead whales from West Greenland and Alaska entered the Northwest Passage from opposite directions and spent approximately 10 days in the same area, documenting overlap between the two populations. PMID:21937490

  9. Tectonic differences between eastern and western sub-basins of the Qiongdongnan Basin and their dynamics

    NASA Astrophysics Data System (ADS)

    Liu, Jianbao; Sun, Zhen; Wang, Zhenfeng; Sun, Zhipeng; Zhao, Zhongxian; Wang, Zhangwen; Zhang, Cuimei; Qiu, Ning; Zhang, Jiangyang

    2015-03-01

    The central depression of the Qiongdongnan Basin can be divided into the eastern and western sub-basins by the Lingshui-Songnan paleo-uplift. To the northwest, the orientation of the faults turns from NE, to EW, and later to NW; In the southwest, the orientation of the faults turns from NE, to NNE, and then to NW, making the central depression much wider towards the west. In the eastern sub-basin, the NE-striking faults and the EW-striking faults made up an echelon, making the central depression turn wider towards the east. Fault activity rates indicate that faulting spreads gradually from both the east and west sides to the middle of the basin. Hence, extensional stress in the eastern sub-basin may be related to the South China Sea spreading system, whereas the western sub-basin was more under the effect of the activity of the Red River Fault. The extreme crustal stretching in the eastern sub-basin was probably related to magmatic setting. It seems that there are three periods of magmatic events that occurred in the eastern sub-basin. In the eastern part of the southern depression, the deformed strata indicate that the magma may have intruded into the strata along faults around T60 (23.3 Ma). The second magmatic event occurred earlier than 10.5 Ma, which induced the accelerated subsidence. The final magmatic event commenced later than 10 Ma, which led to today's high heat flow. As for the western sub-basin, the crust thickened southward, and there seemed to be a southeastward lower crustal flow, which happened during continental breakup which was possibly superimposed by a later lower crustal flow induced by the isostatic compensation of massive sedimentation caused by the right lateral slipping of the Red River Fault. Under the huge thick sediment, super pressure developed in the western sub-basin. In summary, the eastern sub-basin was mainly affected by the South China Sea spreading system and a magma setting, whereas the western sub-basin had a closer

  10. Natural phosphorus sources for the Pacific Northwest

    USGS Publications Warehouse

    Johnson, Hank

    2011-01-01

    Phosphorus is a naturally occurring element found in all rocks; the amount varies by the type of rock. The amount of phosphorus in sediments is expected to be correlated with the amount of phosphorus in the parent rocks. Streambed sediment collected by the National Uranium Resource Evaluation (NURE) Program were used to estimate the variation of phosphorus across the Pacific Northwest. This file provides an estimate of the mean concentration of phosphorus in soils for each incremental catchment of the USGS Pacific Northwest SPARROW model.

  11. 15. The 183Filter Plant with settling basins in January 1945. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. The 183-Filter Plant with settling basins in January 1945. The 182-B Reservoir and Pump House is on the left in the background, and the coal storage pond for the 184-B Power House is in the upper right. View is to the northwest. P-8012 - B Reactor, Richland, Benton County, WA

  12. Development of a Willingness to Pay Survey for Willamette Basin Spring Chinook and Winter Steelhead Recovery

    EPA Science Inventory

    Salmon fisheries are a high-profile icon of the Pacific Northwest. Spring Chinook and winter-run steelhead are both listed as federally endangered species in the Willamette basin, the most populated and developed watershed in Oregon. Despite being a high profile issue, there are ...

  13. Development of a Willingness to Pay Survey for Willamette Basin Spring Chinook and Winter Steelhead Recovery

    EPA Science Inventory

    Salmon fisheries are a high-profile icon of the Pacific Northwest. Spring Chinook and winter-run steelhead are both listed as federally endangered species in the Willamette basin, the most populated and developed watershed in Oregon. Despite being a high profile issue, there are ...

  14. Salmonid Gamete Preservation in the Snake River Basin, 1998 Annual Report.

    SciTech Connect

    Armstrong, Robyn; Kucera, Paul A.

    1999-03-01

    Steelhead (Oncorhynchus mykiss) and salmon (Oncorhynchus tshawytscha)populations in the Northwest are decreasing. The Nez Perce Tribe (Tribe) was funded in 1998 by the Bonneville Power Administration to coordinate gene banking of male gametes from Endangered Species Act (ESA) listed steelhead and spring and summer chinook salmon in the Snake River basin.

  15. EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL STORAGE BUILDING (CPP-603). PHOTO TAKEN LOOKING NORTHWEST. INL PHOTO NUMBER HD-54-19-1. Mike Crane, Photographer, 8/2005 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  16. Stratigraphic analysis of the carboniferous rocks of the Central Appalachian Basin

    SciTech Connect

    Chesnut, D.R. Jr.

    1988-01-01

    A series of seven cross sections was constructed across part of the Central Appalachian Basin in Kentucky, Tennessee, Virginia, West Virginia, and Ohio. Information used to make these sections included well logs, coal-company core descriptions, measured sections, and mapped surface geology. Newly discovered surface and subsurface structural features such as faults, folds, and flexures, are described. A new, unofficial lithostratigraphic nomenclature was introduced to illustrate the stratigraphic framework, and a regional unconformity was interpreted to occur between the Pennsylvanian Pocahontas Formation and the Pennsylvanian New River Formation. The cross sections reveal that sequential truncation of formations below the unconformity occurs t the northwest in the basin. A regional unconformity and biostratigraphic evidence indicate that the Carboniferous rocks were deposited in a series of several small-scale environmental continua. Pennsylvanian rocks overlying the regional unconformity sequentially overlap the underlying rocks to the northwest in the basin. Belts of quartzose sandstones (Lee Formation) within the overlying rocks, are oriented northeast-southwest. Succeeding sandstone belts onlap the unconformity to the northwest within the basin. A fluvial origin is suggested for the quartzose, conglomeratic sands of the Lee Formation. The source for these sands may have been reworked sediments derived from the Old Red Sandstone continent to the northwest in Canada. The remaining Pennsylvanian coal-bearing clastic rocks (Breathitt Group) were deposited as clastic wedges derived from the east and southeast on coastal lowlands.

  17. Washington Phase II Fish Diversion Screen Evaluations in the Yakima River Basin, 1998.

    SciTech Connect

    Blanton, S.L.; McMichael, Geoffrey A.; Neitzel, D.A.

    1999-12-01

    Pacific Northwest National Laboratory (PNNL) evaluated 19 Phase II screen sites in the Yakima River Basin as part of a multi-year study for the Bonneville Power Administration (BPA) on the effectiveness of fish screening devices. The sites were examined to determine if they were being effectively operated and maintained to provide fish a safe, efficient return to the Yakima River.

  18. WILLAMETTE RIVER BASIN TRAJECTORIES OF ENVIRONMENTAL AND ECOLOGICAL CHANGE: A PLANNING ATLAS

    EPA Science Inventory

    The Pacific Northwest Ecosystem Research Consortium, consisting of scientists at EPA-WED, Oregon State University, and the University of Oregon, completed a planning atlas for the Willamette River Basin in western Oregon. The atlas describes ecological conditions and human activ...

  19. Groundwater Treatment Study for South Plants and Basin a Neck, Task 26

    DTIC Science & Technology

    1986-12-01

    3.1-2 Generalized Cross Section Looking Northwest through 3-7 Basin A Neck 3.1-3 Paleogeologic (Subcrop) Map of Volcaniclastics 3-8 3.1-4 Generalized...Source: May at ol., 1983. Prepared for: FIGURE 3.1- 3 Program Manager’s Office far Paleogeologic (Subcrop) Map of Rocky Mountain Arsenal Cleanup

  20. Evolution of the San Jorge basin, Argentina

    SciTech Connect

    Fitzgerald, M.G. ); Uliana, M.A. ); Biddle, K.T. ); Mitchum, R.M. Jr.

    1990-06-01

    The San Jorge basin, although small, is the most important hydrocarbon-producing basin in Argentina. Remaining untested potential is high because of the presence of good source rock, favorable structural complexity, and multiple reservoirs. Reservoir quality is commonly low because of the highly tuffaceous sandstones. The sedimentary fill of the basin is closely related to its tectonic history. Northwest-southeast-trending grabens formed and filled during a Triassic and Early Jurassic early rift phase, climaxing with a pervasive Middle Jurassic volcanic episode; continued growth and filling of the basin occurred during a Late Jurassic-earliest Cretaceous late rift phase and Cretaceous early and late sag phases. Late Cretaceous-early Tertiary extension set up many of the present-day structural traps along normal faults. Middle Tertiary Andean compression produced the narrow, north-south San Bernardo structural belt, which exhibits reversed movement on older, normal, graben-bounding faults and on local, low-angle thrust faults. Marked early to middle Tertiary erosion produced a significant unconformity within Cretaceous beds around basin margins. Origin of Upper Jurassic and lowermost Cretaceous sedimentary fill is primarily lacustrine or fluvial in origin. Lacustrine, organic-rich black shales are fringed by oolitic and other limestones and fluvial-deltaic sandstones derived mostly from the north. A significant southern source of sand existed during the Valanginian. Interbedded marine shales occur mostly to the west toward a presumed marine seaway connection to the northern Magallanes basin. Middle to Upper Cretaceous sedimentary rocks, sourced mostly from the north, are mainly fluvial sandstone-shale successions with some minor lacustrine influence. Reservoir quality glauconitic sands were deposited during a Late Cretaceous-early Tertiary marine incursion from the Atlantic.

  1. Tectonic history of the Illinois basin

    SciTech Connect

    Kolata, D.R.; Nelson, J.W. )

    1990-05-01

    The Illinois basin began as a failed rift that developed during breakup of a supercontinent approximately 550 Ma. A rift basin in the southernmost part of the present Illinois basin subsided rapidly and filled with about 3,000 m of probable Early and Middle Cambrian sediments. By the Late Cambrian, the rift-bounding faults became inactive and a broad relatively slowly subsiding embayment, extending well beyond the rift and open to the Iapetus Ocean, persisted through most of the Paleozoic Era. Widespread deformation swept through the proto-Illinois basin beginning in the latest Mississippian, continuing to the end of the Paleozoic Era. Uplift of basement fault blocks resulted in the formation of many major folds and faults. The timing of deformation and location of these structures in the forelands of the Ouachita and Alleghanian orogenic belts suggest that much of the deformation resulted from continental collision between North America and Gondwana. The associated compressional stress reactivated the ancient rift-bounding faults, upthrusting the northern edge of a crustal block approximately 1,000 m within the rift. Concurrently, dikes (radiometrically dated as Early Permian), sills, and explosion breccias formed in or adjacent to the reactivated rift. Subsequent extensional stress, probably associated with breakup of Pangea, caused the crustal block within the rift to sink back to near its original position. High-angle, northeast- to east-west-trending normal faults, with as much as 1,000 m of displacement, formed in the southern part of the basin. These faults displace some of the northwest trending Early Permian dikes. Structural closure of the southern end of the Illinois basin was caused by uplift of the Pascola arch sometime between the Late Pennsylvanian and Late Cretaceous.

  2. 2. Northwest circular bastion, seen from edge of southwest circular ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Northwest circular bastion, seen from edge of southwest circular bastion wall. Metal roof beams extend up to form peak. World War II gun installation at right. - Fort Hamilton, Northwest Circular Bastion, Rose Island, Newport, Newport County, RI

  3. FEATURE 4, ARMCO HUT, INTERIOR , VIEW FACING NORTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 4, ARMCO HUT, INTERIOR , VIEW FACING NORTHWEST. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-ARMCO Hut, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  4. 5. Light tower and keeper's house, view southeast, northwest and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Light tower and keeper's house, view southeast, northwest and southwest sides - Pumpkin Island Light Station, Pumpkin Island, at northern end of Eggemoggin Beach, off northwest end of Little Deer Island, Eggemoggin, Hancock County, ME

  5. 7. Light tower, interior from entrance, looking northwest Pumpkin ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Light tower, interior from entrance, looking northwest - Pumpkin Island Light Station, Pumpkin Island, at northern end of Eggemoggin Beach, off northwest end of Little Deer Island, Eggemoggin, Hancock County, ME

  6. 6. Keeper's house, southeast parlor, looking northwest Pumpkin Island ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Keeper's house, southeast parlor, looking northwest - Pumpkin Island Light Station, Pumpkin Island, at northern end of Eggemoggin Beach, off northwest end of Little Deer Island, Eggemoggin, Hancock County, ME

  7. 3. Keeper's house, view northwest, southeast and northeast sides ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Keeper's house, view northwest, southeast and northeast sides - Pumpkin Island Light Station, Pumpkin Island, at northern end of Eggemoggin Beach, off northwest end of Little Deer Island, Eggemoggin, Hancock County, ME

  8. Photocopy of original blackandwhite silver gelatin print, VIEW FROM NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of original black-and-white silver gelatin print, VIEW FROM NORTHWEST CORNER, April 1, 1929, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

  9. SOUTHEAST FRONT AND NORTHEAST SIDE. Looking northwest from top of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SOUTHEAST FRONT AND NORTHEAST SIDE. Looking northwest from top of protective berm - Edwards Air Force Base, South Base Sled Track, Water Pump Station, Area "O" at east end, northwest of fuel storage, Lancaster, Los Angeles County, CA

  10. 3. BARRACKS, NEXT TO BASKETBALL COURT, LEFT SIDE, LOOKING NORTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. BARRACKS, NEXT TO BASKETBALL COURT, LEFT SIDE, LOOKING NORTHWEST. - NIKE Missile Base SL-40, Barracks No. 1, North end of base, southest of Basketball Court & northwest of Barracks No. 2, Hecker, Monroe County, IL

  11. INTERIOR OF VESTIBULE OF STANDARDIZING MAGNETIC OBSERVATORY, LOOKING NORTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF VESTIBULE OF STANDARDIZING MAGNETIC OBSERVATORY, LOOKING NORTHWEST. - Carnegie Institution of Washington, Department of Terrestrial Magnetism, Standardizing Magnetic Observatory, 5241 Broad Branch Drive Northwest, Washington, District of Columbia, DC

  12. 1. OVERVIEW OF DECK AND EAST ELEVATION. Looking northwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW OF DECK AND EAST ELEVATION. Looking northwest. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  13. 47. CRANE AND FREIGHT ELEVATOR DOOR, NORTHWEST CORNER OF SECOND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. CRANE AND FREIGHT ELEVATOR DOOR, NORTHWEST CORNER OF SECOND FLOOR WAREHOUSE. VIEW TO NORTHWEST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  14. 55. Downstream face of diversion dam looking northwest. Photographer Mark ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. Downstream face of diversion dam looking northwest. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  15. 11. FIRST FLOOR, NORTHWEST ROOM, GENERAL VIEW OF PARLOR LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. FIRST FLOOR, NORTHWEST ROOM, GENERAL VIEW OF PARLOR LOOKING NORTHWEST TOWARDS CORNER FIREPLACE (THERE WAS ORIGINALLY A WALL BETWEEN THESE FIREPLACES) - Open Gate Farm, House, Ridge Road, 1 mile East of Elephant Road, Perkasie, Bucks County, PA

  16. 5. SHAFT HOUSE, EAST ELEVATION; VIEW TO THE NORTHWEST; (WASTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. SHAFT HOUSE, EAST ELEVATION; VIEW TO THE NORTHWEST; (WASTE ROCK/SPOIL PILE IN THE FOREGROUND). - Joker Mine, Shafthouse, Medicine Bow National Forest, Northwest of Keystone, Keystone, Albany County, WY

  17. 14. VIEW TO NORTHWEST, SMALL ROASTER (DISMANTLED). Vanadium Corporation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW TO NORTHWEST, SMALL ROASTER (DISMANTLED). - Vanadium Corporation of America (VCA) Naturita Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  18. 1. VIEW TO NORTHWEST, FRONT AND SIDE. Vanadium Corporation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW TO NORTHWEST, FRONT AND SIDE. - Vanadium Corporation of America (VCA) Naturita Mill, Mill Warehouse, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  19. 46. AUXILIARY CHAMBER (EAST END), LOOKING NORTHWEST AT STEAM AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. AUXILIARY CHAMBER (EAST END), LOOKING NORTHWEST AT STEAM AND FEEDWATER PIPING AND PRESSURIZER AND FLASH/BLOWOFF TANK ROOMS (LOCATION EEE) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  20. View of the northwest corner of the Justice Department Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the northwest corner of the Justice Department Building at Tenth Street and Pennsylvania Avenue - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  1. 8. VIEW FROM NORTHWEST OF CONDENSATE STORAGE TANK (LEFT), PRIMARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW FROM NORTHWEST OF CONDENSATE STORAGE TANK (LEFT), PRIMARY WATER STORAGE TANK (CENTER), CANAL WATER STORAGE TANK (RIGHT) (LOCATIONS E,F,D) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  2. INTERIOR ELEVATION LOOKING TOWARD THE LEANTO OF THE NORTHWEST SIDE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR ELEVATION LOOKING TOWARD THE LEAN-TO OF THE NORTHWEST SIDE. VIEW FACING NORTHWEST. - U.S. Naval Base, Pearl Harbor, Seaplane Hangar, Lexington Boulevard, south of Enterprise Street, Pearl City, Honolulu County, HI

  3. 2. Southeast side of addition. View to northwest. Offutt ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Southeast side of addition. View to northwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  4. 6. General interior overview of addition. View to northwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. General interior overview of addition. View to northwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  5. 3. Northwest side and southwest rear of addition. View to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Northwest side and southwest rear of addition. View to east. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  6. View of northwest elevation of Building No. 42. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of northwest elevation of Building No. 42. Parking Area No. 28 at front right. Looking southeast - Easter Hill Village, Building No. 42, Northwest corner of Foothill Avenue & South Twenty-eighth Street, Richmond, Contra Costa County, CA

  7. 2. SOUTH VIEW OF NORTHWEST AND NORTHEAST SIDES (NORTH CORNER). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SOUTH VIEW OF NORTHWEST AND NORTHEAST SIDES (NORTH CORNER). NORTHWEST SIDE OF ASSAY OFFICE ON LEFT - Juniata Mill Complex, Mine Office, 22.5 miles Southwest of Hawthorne, between Aurora Crater & Aurora Peak, Hawthorne, Mineral County, NV

  8. 3. Interior view southeast to northwest showing space heater in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Interior view southeast to northwest showing space heater in northwest corner - Fort Hood, World War II Temporary Buildings, Dispatcher House, North of Park Avenue at Forty-ninth Street, Killeen, Bell County, TX

  9. INTAKE, CLOSE UP OF RACKS; FACING NORTHWEST Shoshone Falls ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTAKE, CLOSE UP OF RACKS; FACING NORTHWEST - Shoshone Falls Hydroelectric Project, Intake, North Bank of Snake River, immediately West/Northwest of the Shoshone Falls Hydroelectric Project Dam No. 1, Tipperary Corner, Jerome County, ID

  10. LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING NORTHWEST Generals Highway, Lodge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LODGEPOLE BRIDGE, SOUTH ELEVATION, FACING NORTHWEST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  11. 45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, LOOKING WEST BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  12. Foreland normal fault control on northwest Himalayan thrust front development

    NASA Astrophysics Data System (ADS)

    Blisniuk, Peter M.; Sonder, Leslie J.; Lillie, Robert J.

    1998-10-01

    In the Trans-Indus Ranges along the western part of the northwest Himalayan thrust front, unconformities, changes in paleocurrent directions, and locally derived conglomerates in synorogenic foreland basin deposits provide evidence for major local deformation at ≥3.5 Ma. The tectonic history of the Trans-Indus Ranges has previously been described in terms of a single episode of major thrusting at ≤1 Ma, thus our work implies that there were two distinct phases of deformation. In conjunction with published evidence in the Salt Range to the east for two phases of deformation (˜6 to 5 Ma, and ˜2.5 Ma to present), this study demonstrates that these two phases of deformation are regionally significant and probably correlative along the entire present-day NW Himalayan thrust front. Reconstruction of possible source areas for the locally derived conglomerates shows that the earlier deformation is probably related to normal faulting. These results suggest that the tectonic evolution of the area along the present-day thrust front is characterized by (1) latest Miocene to early Pliocene formation of north dipping normal fault zones (total throw ≥ 600 m) within the foreland basin, related to syn-orogenic flexure of the Indian plate, and (2) late Pliocene to early Pleistocene initiation of south directed thrusting along the present-day thrust front, related to outward growth of the NW Himalayan thrust wedge. The location of the present-day thrust front appears to be controlled by north dipping normal faults and monoclines that formed during the earlier deformation and subsequently localized structural ramps during later thrusting.

  13. Fluvial drainage basins, outflow channels, and valley networks: Margaritifer Sinus, Mars

    SciTech Connect

    Boothroyd, J.C.; Grant, J.A.

    1985-01-01

    The fluvial drainage basins of the Margaritifer Sinus Quadrangle (MC-19) are dominated by Capri and Eos Chasma and associated chaos on the northwest, by Ladon Basin in the center, and by Noachis Basin to the southeast. Laadon and Noachis are ancient, multi-ringed impact structures. The Uzboi/Ladon outflow channels are the principal drainage into Ladon Basin contributing to a major sediment sink on the central Basin plain (18/sup 0/S,29/sup 0/W). Osuga Valles outflow system (16S,39W), and some valley networks, have been beheaded by the formation of Eos Chasma. Flow out of Ladon Basin to the northeast is obscured by Margaritifer Chaos collapse. Two major longitudinal valley networks, Samara/Himera to the west and Parana/Loire to the east, dominate the drainage of eastern Margaritifer Sinus. These networks, through-going to the northwest, cross the outer ring hills of Ladon to debouch into etched terrain near Margaritifer Chaos. The Parana multi-digitate network flows into a small impact basin with a sediment sink characterized by positive relief chaos (22S,12W). Loire Valles heads in this basin; thus the authors treat Parana/Loire as a single system. Mapping with stereo pairs has allowed not only the delineation of major drainage basins, but also the identification of sub-basins, areas of internal drainage between larger basins, and determination of drainage-basin area. This mapping demonstrates that an integrated series of drainage systems with a complex fluvial history encompasses a large part of Margaritifer Sinus.

  14. Cross folding in southern Bighorn basin

    SciTech Connect

    Gubbels, T.L.

    1986-08-01

    Analysis of Landsat Thematic Mapper imagery coupled with surface structural investigations of well-exposed folds in the southern Bighorn basin have revealed two northwest-trending folds that have been refolded. The eastern boundary of the Owl Creek Mountains is characterized by a well-defined alignment of folds that extend north-northwest from the Owl Creek thrust front. Bridger monocline, Wildhorse Butte anticline, and Red Hole anticline lie along this trend. Initial Laramide folding, probably during latest Cretaceous time, resulted in a single, continuous, north-northwest-trending anticline with a southwestward vergence. This anticline was progressively unfolded from south to north as the Owl Creek Range was thrust southward over the Wind River basin in earliest Eocene time; scissors-like vertical motion along this flexure rotated the axial surface of the early formed Bridger anticline, resulting in a monocline with a reversed vergence (northeastward). Formation of the Thermopolis/East Warm Springs anticline parallel to the north flank of the range accompanied thrusting and effectively refolded the northern end of the Wildhorse Butte anticline along an east-west axis. Faulting of the oversteepened south limb of the Red Hole cross fold was contemporaneous with folding. Cross-cutting fold axes in this area and the Mud Creek area to the west are best explained by a counterclockwise change in stress direction during the latest phase of the Laramide orogeny. Vertical movement along the eastern side of the Owl Creek Range results from differential motion in the hanging wall of the crystalline thrust sheet.

  15. Sedimentary sequence evolution in a Foredeep basin: Eastern Venezuela

    SciTech Connect

    Bejarano, C.; Funes, D.; Sarzalho, S.; Audemard, F.; Flores, G.

    1996-08-01

    Well log-seismic sequence stratigraphy analysis in the Eastern Venezuela Foreland Basin leads to study of the evolution of sedimentary sequences onto the Cretaceous-Paleocene passive margin. This basin comprises two different foredeep sub-basins: The Guarico subbasin to the west, older, and the Maturin sub-basin to the east, younger. A foredeep switching between these two sub-basins is observed at 12.5 m.y. Seismic interpretation and well log sections across the study area show sedimentary sequences with transgressive sands and coastal onlaps to the east-southeast for the Guarico sub-basin, as well as truncations below the switching sequence (12.5 m.y.), and the Maturin sub-basin shows apparent coastal onlaps to the west-northwest, as well as a marine onlap (deeper water) in the west, where it starts to establish. Sequence stratigraphy analysis of these sequences with well logs allowed the study of the evolution of stratigraphic section from Paleocene to middle Miocene (68.0-12.0 m.y.). On the basis of well log patterns, the sequences were divided in regressive-transgressive-regressive sedimentary cycles caused by changes in relative sea level. Facies distributions were analyzed and the sequences were divided into simple sequences or sub- sequences of a greater frequencies than third order depositional sequences.

  16. Amplification of seismic waves by the Seattle basin, Washington State

    USGS Publications Warehouse

    Pratt, T.L.; Brocher, T.M.; Weaver, C.S.; Creager, K.C.; Snelson, C.M.; Crosson, R.S.; Miller, K.C.; Trehu, A.M.

    2003-01-01

    Recordings of the 1999 Mw 7.6 Chi-Chi (Taiwan) earthquake, two local earthquakes, and five blasts show seismic-wave amplification over a large sedimentary basin in the U.S. Pacific Northwest. For weak ground motions from the Chi-Chi earthquake, the Seattle basin amplified 0.2- to 0.8-Hz waves by factors of 8 to 16 relative to bedrock sites west of the basin. The amplification and peak frequency change during the Chi-Chi coda: the initial S-wave arrivals (0-30 sec) had maximum amplifications of 12 at 0.5-0.8 Hz, whereas later arrivals (35-65 sec) reached amplifications of 16 at 0.3-0.5 Hz. Analysis of local events in the 1.0- to 10.0-Hz frequency range show fourfold amplifications for 1.0-Hz weak ground motion over the Seattle basin. Amplifications decrease as frequencies increase above 1.0 Hz, with frequencies above 7 Hz showing lower amplitudes over the basin than at bedrock sites. Modeling shows that resonance in low-impedance deposits forming the upper 550 m of the basin beneath our profile could cause most of the observed amplification, and the larger amplification at later arrival times suggests surface waves also play a substantial role. These results emphasize the importance of shallow deposits in determining ground motions over large basins.

  17. Promise seen in Petrel sub-basin off northwestern Australia

    SciTech Connect

    Maung, T.U.; Passmore, V. )

    1995-01-30

    The Australian government during the past 11 years has been regularly releasing vacant areas on the Australian continental shelf for exploration. Although Australia's offshore basins cover an area of 12 million sq km, only about 1,100 exploration and development wells have been drilled, and most of the basins are underexplored by world standards. One of these areas is the Petrel sub-basin of the Bonaparte basin in water shallower than 100 m off Northwest Australia. The government recently released six areas in the southern offshore Petrel subbasin for petroleum exploration. The results of a study by the Petroleum Resources Branch of the bureau of Resource Sciences have been synthesized into a Petrel Sub-basin Bulletin, some selections of which are discussed in this article. Although there are over 44,000 km of seismic data recorded in the sub-basin, the quality of pre-1979 data is very poor to poor, and only 15,800 km of data recorded between 1980--94 (including 1,000 km of 3D seismic data over the Barnett structure) are of fair to good quality. The paper describes the regional geology, reservoir and seals, source rocks, and types of geologic traps. The study identified over 30 structures and leads in the offshore southern Petrel sub-basin. Significant opportunities exist for delineation and definition of drillable prospects in this promising Australian petroleum province.

  18. Source rocks of the Sub-Andean basins

    SciTech Connect

    Raedeke, L.D. )

    1993-02-01

    Seven source rock systems were mapped using a consistent methodology to allow basin comparison from Trinidad to southern Chile. Silurian and Devonian systems, deposited in passive margin and intracratonic settings, have fair-good original oil/gas potential from central and northern Bolivia to southern Peru. Kerogens range from mature in the foreland to overmature in the thrust belt. Permian to Carboniferous deposition in local restricted basins formed organic-rich shales and carbonates with very good original oil/gas potential, principally in northern Bolivia and southern Peru. Late Triassic to early Jurassic marine shales and limestones, deposited in deep, narrow, basins from Ecuador to north-central maturity. Locally, in the Cuyo rift basin of northern Argentina, a Triassic lacustrine unit is a very good, mature oil source. Early Cretaceous to Jurassic marine incursions into the back-arc basins of Chile-Argentina deposited shales and limestones. Although time transgressive (younging to the south), this system is the principal source in southern back-arc basins, with best potential in Neuquen, where three intervals are stacked A late Cretaceous marine transgressive shale is the most important source in northern South America. The unit includes the La Luna and equivalents extending from Trinidad through Venezuela, Colombia, Ecuador, and into northern Peru. Elsewhere in South America upper Cretaceous marine-lacustrine rocks are a possible source in the Altiplano and Northwest basins of Bolivia and Argentina. Middle Miocene to Oligocene source system includes shallow marine, deltaic, and lacustrine sediments from Trinidad to northern Peru.

  19. Three-Dimensional Geologic Characterization of a Great Basin Geothermal System: Astor Pass, Nevada

    SciTech Connect

    Mayhew, Brett; Siler, Drew L; Faulds, James E

    2013-09-30

    The Great Basin, western USA, exhibits anomalously high heat flow (~75±5 mWm-2) and active faulting and extension, resulting in ~430 known geothermal systems. Recent studies have shown that steeply dipping normal faults in transtensional pull-aparts are a common structural control of these Great Basin geothermal systems. The Astor Pass blind (no surface expression) geothermal system, Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Across this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range, resulting in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and northerly striking normal faults. Previous studies indicate that Astor Pass was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal-dextral fault bounding the western side of the Terraced Hills. Drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming a blind geothermal system. Expanding upon previous work and employing interpretation of 2D seismic reflection data, additional detailed geologic mapping, and well cuttings analysis, a 3-dimensional geologic model of the Astor Pass geothermal system was constructed. The 3D model indicates a complex interaction/intersection area of three discrete fault zones: a northwest-striking dextral-normal fault, a north-northwest-striking normal-dextral fault, and a north-striking west-dipping normal fault. These two discrete, critically-stressed intersection areas plunge moderately to steeply to the NW-NNW and probably act as conduits for upwelling geothermal fluids.

  20. Structure and geologic history of late Cenozoic Eel River basin, California

    SciTech Connect

    Clarke, S.H. Jr.

    1988-03-01

    The Eel River basin formed as a late Cenozoic forearc basin floored by late Mesozoic and early Cenozoic allochthonous terranes (central and coastal belts of the Franciscan complex). Regionally, basement rocks are unconformably overlain on land by a sedimentary sequence as much as about 4200 m thick that comprises the Bear River Formation (early and middle Miocene) and the Wildcat Group (late Miocene to middle Pleistocene) and offshore by broadly coeval upper Tertiary and Quaternary deposits as much as 3300 m thick. Offshore, the southern part of the basin is typified by the seaward extensions of youthful northeast-dipping thrust and reverse faults and northwest-trending anticlines. The latest period of deformation in this part of the basin began during the middle Pleistocene and probably reflects north-northwestward migration of the Mendocino triple junction and encroachment of the Pacific plate. Farther north, the western basin margin and adjacent upper continental slope are separated from the axial part of the offshore basin by a narrow zone of north-northwest-trending, right-stepping en echelon folds. These folds indicate that northeast-southwest compression characteristic of the southern part of the basin is accompanied toward the north by right-lateral shear between the accretionary complex to the west and the basin to the east. The northeastern margin of the offshore basin is cut by north to north-northwest-trending high-angle reverse faults that vertically offset basement rocks as much as 1300 m, west side down. These faults, which may merge northward, coincide with older terrane boundaries and locally show evidence of late Cenozoic reactivation with possible right-lateral slip.

  1. The Northwest Ordinance, 1787: A Bicentennial Handbook.

    ERIC Educational Resources Information Center

    Taylor, Robert M., Jr., Ed.

    The essays and annotations in this publication provide an opportunity for citizens and students to consider not only the history of the Northwest Ordinance but also basic and enduring issues in U.S. political life. The book is divided into three main parts. The first part provides a background to the Ordinance and its passage by the Confederation…

  2. Verticillium wilt in the Pacific Northwest

    USDA-ARS?s Scientific Manuscript database

    Verticillium wilt is a serious disease of many economically important agricultural and horticultural crops in the Pacific Northwest (PNW). The disease affects herbaceous annuals and perennials as well as woody trees and shrubs. Plants affected by Verticillium wilt exhibit chlorosis, wilting, defolia...

  3. Forest statistics for Northwest Florida, 1979

    Treesearch

    Raymond M. Sheffield

    1979-01-01

    This report highlights the principal findings of the fifth forest survey of Northwest Florida. Fieldwork began in September 1978 and was completed in June 1979. Four previous surveys, completed in 1934, 1949, 1959, and 1969, provide statistics for measuring changes and trends over the past 45 years. The primary emphasis in this report is on the changes and trends since...

  4. The Northwest Territories. Reference Series No. 35.

    ERIC Educational Resources Information Center

    Department of External Affairs, Ottawa (Ontario).

    This booklet, one of a series featuring the Canadian provinces, presents a brief overview of Northwest Territories and is suitable for teacher reference or student reading. Separate sections discuss geography, history and people, land claims, the economy, the government, and recreation and the arts. Specific topics include the expansive size and…

  5. Endangered Species in the Pacific Northwest.

    ERIC Educational Resources Information Center

    Clearing: Nature and Learning in the Pacific Northwest, 1985

    1985-01-01

    Suggests that students can learn how society works by studying threatened and endangered plant and animal species which occur in the local environments. Pictures, descriptions, habitats, and niche information are given for 21 threatened or endangered species of the Pacific Northwest. (DH)

  6. Forest statistics for Northwest Florida, 1969

    Treesearch

    Herbert A. Knight

    1969-01-01

    This report highlights the principal findings of the fourth Forest survey of the timber resource in Northwest Florida. The survey was started in July 19 68 and completed in March 1969. Findings of the three previous surveys, completed in 1934, 1949, and 1959, provide the basis for measuring changes that have occurred and trends that have developed over the past 35...

  7. The Designated Tournament: A Northwest Experiment.

    ERIC Educational Resources Information Center

    Bartanen, Michael D.

    The Northwest Forensic Conference (NFC) was created in response to decreasing budgets and fewer schools participating in forensics. The basis of the NFC is the designated tournament and yearly divisional sweepstakes awards. Special features of designated tournaments include oral critiques and seminars on forensic issues. Initially, it was assumed…

  8. Northwest Educational Cooperative Participant Policy Manual.

    ERIC Educational Resources Information Center

    Northwest Educational Cooperative, Des Plaines, IL.

    This policy manual provides guidelines for participants in the Northwest Educational Cooperative's (NEC's) Hospitality Industry Training Program. It sets forth the program expectations that participants must meet before they are sent on interviews. Topics covered include: attendance and punctuality; attitude, including respect for others,…

  9. Solar Energy for Pacific Northwest Buildings.

    ERIC Educational Resources Information Center

    Reynolds, John S.

    Data presented in this report indicate that solar space and water heating are possible in the Pacific Northwest. The first section of the report contains solar records from several stations in the region illustrating space heating needs that could be met, on an average daily basis, by solar energy. The data are summarized, and some preliminary…

  10. Northwest forest plants defeat pests and diseases!

    Treesearch

    Natasha Vizcarra; Rick Kelsey; Joe. Karchesy

    2017-01-01

    Societies use biologically active chemicals as medicines and pesticides to protect human and agricultural health. But widespread use of synthetic compounds raises concerns about their safety, and resistance development in targeted pests.To find safer alternatives, scientists turned to native plants and trees in Pacific Northwest forests...

  11. Solar Energy for Pacific Northwest Buildings.

    ERIC Educational Resources Information Center

    Reynolds, John S.

    Data presented in this report indicate that solar space and water heating are possible in the Pacific Northwest. The first section of the report contains solar records from several stations in the region illustrating space heating needs that could be met, on an average daily basis, by solar energy. The data are summarized, and some preliminary…

  12. The Northwest Ordinance, 1787: A Bicentennial Handbook.

    ERIC Educational Resources Information Center

    Taylor, Robert M., Jr., Ed.

    The essays and annotations in this publication provide an opportunity for citizens and students to consider not only the history of the Northwest Ordinance but also basic and enduring issues in U.S. political life. The book is divided into three main parts. The first part provides a background to the Ordinance and its passage by the Confederation…

  13. Planting native oak in the Pacific Northwest

    Treesearch

    Warren D. Devine; Constance A. Harrington

    2010-01-01

    The extent of oak woodland and savanna habitat in the Pacific Northwest has been dramatically reduced since settlement in the mid-1800s. This report presents a practical guide for landowners and managers who are interested in reestablishing native oak by planting seedlings. Keys to successful establishment are (1) planting quality...

  14. Raindrop Characteristics in the Pacific Northwest

    USDA-ARS?s Scientific Manuscript database

    The U.S. Pacific Northwest, influenced by maritime air masses for most of the year, generally exhibits low rainfall intensities. The drop-size characteristics of such low-intensity storms are rarely studied. An investigation of natural drop sizes and their distribution was conducted at the Palouse ...

  15. SCIENCE, POLITICS, AND PACIFIC NORTHWEST SALMON RECOVERY

    EPA Science Inventory

    Throughout the Pacific Northwest, since 1850, all wild salmon runs have declined and some have disappeared. Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline. Each year, hundreds of millions of dollars continue to be spent in variou...

  16. The Pacific northwest stream quality assessment

    USGS Publications Warehouse

    Van Metre, Peter C.; Morace, Jennifer L.; Sheibley, Rich W.

    2015-01-01

    The Pacific Northwest study will be the third regional study by the NAWQA program, and it will be of similar design and scope as the first two—the Midwest in 2013 and the Southeast in 2014 (Van Metre and others, 2012, 2014).