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Sample records for basins north central

  1. 137Cs vertical distribution at the deep basins of the North and Central Aegean Sea, Greece

    International Nuclear Information System (INIS)

    Large volume seawater samples were collected for the determination of 137Cs concentration along with depth in the deep basins of North and Central Aegean Sea. The vertical 137Cs distribution showed maximum concentration at the bottom of the basins, while the minimum values corresponded to the intermediate layer, where Levantine water exists. The surface 137Cs activity is found to lie between the two limits and is originated from the Black Sea waters. The typical oceanographic advection–diffusion balance model is modified to a diffusion-settling-decay balance model to better understand the vertical distribution and variation of the 137Cs concentration in the deep basins. In addition, the diffusivity of each basin, as well as the settling speed of particulate 137Cs is also estimated. The results are compared with theoretical approach as well as with previous data. - Highlights: • Three deep basins were studied using 137Cs as a tracer. • Deep waters constitute 137Cs repositories due to deep water formation followed Chernobyl accident. • Diffusivities, as well as particulate 137Cs settling speeds are estimated

  2. Estimation of evapotranspiration in the Rainbow Springs and Silver Springs basins in North-Central Florida

    Science.gov (United States)

    Knowles, Leel, Jr.

    1996-01-01

    Estimates of evapotranspiration (ET) for the Rainbow and Silver Springs ground-water basins in north-central Florida were determined using a regional water-~budget approach and compared to estimates computed using a modified Priestley-Taylor (PT) model calibrated with eddy-correlation data. Eddy-correlation measurements of latent 0~E) and sensible (H) heat flux were made monthly for a few days at a time, and the PT model was used to estimate 3,E between times of measurement during the 1994 water year. A water-budget analysis for the two-basin area indicated that over a 30-year period (196594) annual rainfall was 51.7 inches. Of the annual rainfall, ET accounted for about 37.9 inches; springflow accounted for 13.1 inches; and the remaining 0.7 inch was accounted for by stream-flow, by ground-water withdrawals from the Floridan aquifer system, and by net change in storage. For the same 30-year period, the annual estimate of ET for the Silver Springs basin was 37.6 inches and was 38.5 inches for the Rainbow Springs basin. Wet- and dry-season estimates of ET for each basin averaged between nearly 19 inches and 20 inches, indicating that like rainfall, ET rates during the 4-month wet season were about twice the ET rates during the 8-month dry season. Wet-season estimates of ET for the Rainbow Springs and Silver Springs basins decreased 2.7 inches, and 3.4 inches, respectively, over the 30-year period; whereas, dry-season estimates for the basins decreased about 0.4 inch and1.0 inch, respectively, over the 30-year period. This decrease probably is related to the general decrease in annual rainfall and reduction in net radiation over the basins during the 30-year period. ET rates computed using the modified PT model were compared to rates computed from the water budget for the 1994 water year. Annual ET, computed using the PT model, was 32.0 inches, nearly equal to the ET water-budget estimate of 31.7 inches computed for the Rainbow Springs and Silver Springs basins

  3. Paleomagnetism of the Plio-Pleistocene continental sediments from the north -eastern edge of the Fucino basin (Central Italy)

    OpenAIRE

    F. Galadini; L. Sagnotti; L. Alfonsi

    1995-01-01

    The paleomagnetism of the Plio-Pleistocene continental sediments cropping out at the north-eastern edge of the Fucino extensionaI basin (Italy, Central Apennines) was investigated. The area is characterized by strong neo-tectonic activity and the original purpose was to investigate possibIe verticaI axis rotations in Plio-Pleisto- cene sediments, in order to improve the understanding of the recent geodynamic processes. Scarcity of suit- able outcrops limited sampling at 8 sites (83 specimens)...

  4. Gravity modeling constraints on the Gatun-Chagres Basin and tectonic evolution of north-central Panama

    Science.gov (United States)

    Mynhier, Kelci

    The Oligocene-Miocene collision between Panama and South America significantly influenced ocean currents, global climate, and species diversification. Intraplate deformation of the Panama Block also played an important role in the evolution of this tectonic system, but is not well understood. A high-resolution gravity survey, coupled with geologic observations, was conducted in north-central Panama to better constrain the processes responsible for the Isthmus' modern configuration. Approximately 110 gravity stations were collected from Colon to Nombre de Dios, Panama and merged with existing data. Subsequently, four 2.5-D gravity models were produced to constrain the geometry of the Gatun-Chagres Basin using different sedimentary densities (1.8, 2.0, and 2.2 g/cm 3) to produce a realistic range of basin thicknesses. Overall, models with an average basin density of 2.0 g/cm3 are most consistent with offshore seismic profiles and field evidence, suggesting basin thickness is ~3.0--3.5 km. Previous seismic reflection data and geochemical analyses of Miocene arc volcanic rocks delineate a zone of extension in the Panama Canal Region, and gravity analysis from this study supports this hypothesis. Field evidence of multiple NW-facing normal faults suggests that they separate the basin from uplifted arc basement rocks east of the Canal, resulting in a 60 mGal gravity gradient. Beneath the basin, gravity models indicate ~5--10 km of crustal thinning. 3-D reconstruction of the 2.5-D models show a northward thickening basin and two depocenters that correspond to the Rio Indio and Toro facies of the Chagres Formation. This analysis suggests two directional extension of the Gatun-Chagres Basin; an east-west direction corresponding to the initial formation of the basin, and a modern northwest-southeast direction. To the northeast, gravity modeling indicates that there is a ~150 m-thick, Cretaceous-Holocene sedimentary basin present from Portobelo to Nombre de Dios. Sedimentary

  5. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard

    2005-04-15

    The principal research effort for the first six months of Year 2 of the project has been petroleum system characterization. Understanding the burial and thermal maturation histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in petroleum system characterization. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and thermal maturation and hydrocarbon expulsion modeling indicate that an effective regional petroleum source rock in the onshore interior salt basins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was the Upper Jurassic Smackover lime mudstone. The Upper Cretaceous Tuscaloosa shale was an effective local petroleum source rock in the Mississippi Interior Salt Basin and a possible local source bed in the North Louisiana Salt Basin. Hydrocarbon generation and expulsion was initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin. Hydrocarbon generation and expulsion was initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Reservoir rocks include Jurassic, Cretaceous and Tertiary siliciclastic and carbonate strata. Seal rocks include Jurassic, Cretaceous and Tertiary anhydrite and shale beds. Petroleum traps include structural and combination traps.

  6. Paleomagnetism of the Plio-Pleistocene continental sediments from the north -eastern edge of the Fucino basin (Central Italy

    Directory of Open Access Journals (Sweden)

    F. Galadini

    1995-06-01

    Full Text Available The paleomagnetism of the Plio-Pleistocene continental sediments cropping out at the north-eastern edge of the Fucino extensionaI basin (Italy, Central Apennines was investigated. The area is characterized by strong neo-tectonic activity and the original purpose was to investigate possibIe verticaI axis rotations in Plio-Pleisto- cene sediments, in order to improve the understanding of the recent geodynamic processes. Scarcity of suit- able outcrops limited sampling at 8 sites (83 specimens from the north-eastern edge of the basin, in clay-rich intervals beIonging to two different sedimentary cycIes. The paleomagnetic resuIts pointed out a peculiar mag- netic behaviour common to the whole set of studied samples. The Natural Remanent Magnetization (NRM is dominated by a vigcous normal component acquired under the influence of the present geomagnetic field, stable only below 200°C. Another (reverse very weak component, stable at higher temperatures (up to 400°C, is present in most of the samples. This component can be precisely isolated for only 7 specimens from 3 different sites and therefore the information gained is not statistically sufficient for any tectonic reconstruction. Rock magnetism analyses showed a variable magnetic mineralogy j but the NRM carriers are not well represented in the artificial remanences produced in the laboratory. Results suggest that the natural viscous remanence is most likeIy carried by coarse multi-domain magnetite.

  7. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2005-10-28

    The principal research effort for Year 2 of the project has been petroleum system characterization and modeling. Understanding the burial, thermal maturation, and hydrocarbon expulsion histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in hydrocarbon resource assessment. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and initial thermal maturation and hydrocarbon expulsion modeling indicated that an effective regional petroleum source rock in the onshore interior salt basins and subbasins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was Upper Jurassic Smackover lime mudstone. The initial modeling also indicated that hydrocarbon generation and expulsion were initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin and that hydrocarbon generation and expulsion were initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Refined thermal maturation and hydrocarbon expulsion modeling and additional petroleum source rock analysis have confirmed that the major source rock in the onshore interior salt basins and subbasins is Upper Jurassic Smackover lime mudstone. Hydrocarbon generation and expulsion were initiated in the Early to Late Cretaceous and continued into the Tertiary.

  8. Export of dissolved organic carbon from the Penobscot River basin in north-central Maine

    Science.gov (United States)

    Huntington, Thomas G.; Aiken, George R.

    2013-01-01

    Dissolved organic carbon (DOC) flux from the Penobscot River and its major tributaries in Maine was determined using continuous discharge measurements, discrete water sampling, and the LOADEST regression software. The average daily flux during 2004–2007 was 71 kg C ha−1 yr−1 (392 Mt C d−1), an amount larger than measured in most northern temperate and boreal rivers. Distinct seasonal variation was observed in the relation between concentration and discharge (C–Q). During June through December (summer/fall), there was a relatively steep positive C–Q relation where concentration increased by a factor of 2–3 over the approximately 20-fold range of observed stream discharge for the Penobscot River near Eddington, Maine. In contrast, during January through May (winter/spring), DOC concentration did not increase with increasing discharge. In addition, we observed a major shift in the C–Q between 2004–2005 and 2006–2007, apparently resulting from unprecedented rainfall, runoff, and soil flushing beginning in late fall 2005. The relative contribution to the total Penobscot River basin DOC flux from each tributary varied dramatically by season, reflecting the role of large regulated reservoirs in certain basins. DOC concentration and flux per unit watershed area were highest in tributaries containing the largest areas in palustrine wetlands. Tributary DOC concentration and flux was positively correlated to percentage wetland area. Climatic or environmental changes that influence the magnitude or timing of river discharge or the abundance of wetlands will likely affect the export of DOC to the near-coastal ocean.

  9. Cenozoic stratigraphic development in the north Chilean forearc: Implications for basin development and uplift history of the Central Andean margin

    Science.gov (United States)

    Hartley, Adrian J.; Evenstar, Laura

    2010-11-01

    Analysis of the Cenozoic stratigraphic development of the forearc of northern Chile between 18°S and 23°30'S, allows constraints to be placed on the timing and nature of basin formation and the uplift history of the Central Andes. Chronostratigraphic charts have been constructed from 20 lithostratigraphic sections distributed throughout the forearc. Sections were taken from the Longitudinal Valley, Central Depression, Calama Basin, Salar de Atacama, Precordillera and the western flank of the Western Cordillera. Correlation and timing of events is largely based on the presence of dated volcanic horizons in all the studied sections. Three chronostratigraphic units are defined based upon the presence of regional unconformities. Deposition of the Late Eocene to Early Miocene chronostratigraphic unit (38-19 Ma) commenced across an irregular unconformity surface between ˜ 38 and 30 Ma with alluvial fan and fluvial sediments derived from the east interbedded with rhyolitic ignimbrites. Aggradation after 25 Ma resulted in development of a large broad basin over much of northern Chile that expanded eastwards through onlap onto basement. Deposition terminated around 19 Ma with the development of an angular unconformity over much, but not all of the study area. During deposition of the Early to Late Miocene chronostratigraphic unit (18-10 Ma) emergent volcanic source areas to the east provided catchments for large fluvial systems that drained westwards into endorheic ephemeral lacustrine basins. Fold growth affected sedimentation restricting accommodation space to small intra-thrust basins in the Precordillera and localised disruption and unconformity development in the Longitudinal Valley. The Late Miocene to present day chronostratigraphic unit (10-0 Ma) followed the development of a regional angular unconformity at 10 Ma. Sedimentation was restricted to a series of thrust-bounded endorheic basins in both the Central Depression and the Precordillera sourced from the east

  10. An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

    Science.gov (United States)

    Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

    2013-12-01

    Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as

  11. Deformation History of the Haymana Basin: Structural Records of Closure-Collision and Subsequent Convergence (Indentation) Events at the North-Central Neotethys (Central Anatolia, Turkey)

    Science.gov (United States)

    Gülyüz, Erhan; Özkaptan, Murat; Kaymakcı, Nuretdin

    2016-04-01

    Gondwana- (Tauride Platfrom and Kırşehir Block) and Eurasia (Pontides) - derived continental blocks bound the Haymana basin, in the south and north, respectively. Boundaries between these blocks are signed by İzmir-Ankara-Erzincan and debatable Intra-Tauride Suture zones which are straddled by the Haymana Basin in the region. In this regard, deformation recorded in the upper Cretaceous to middle Eocene deposits of the basin is mainly controlled by the relative movements of these blocks. Therefore, understanding the structural evolution of the Haymana Basin in a spatio-temporal concept is crucial to shed some light on some debatable issues such as ; (1) timing of late stage subduction histories of various branches of Neotethys and subsequent collision events, (2) effects of post-collisional tectonic activity in the Haymana region. Fault kinematic analyses (based on 623 fault-slip data from 73 stations) indicate that the basin was subjected to initially N-S to NNE-SSW extension until middle Paleocene and then N-S- to NNE-SSW- directed continuous compression and coeval E-W to ESE-WNW extension up to middle Miocene. These different deformation phases correspond to the fore-arc (closure) and foreland (collision and further convergence) stages of the basin. Additionally, fold analyses (based on 1017 bedding attitudes) and structural mapping studies show that development of folds and major faults are coeval and they can be explained by principle stress orientations of the second deformation phase. The Haymana basin is, based on the trends of E-W- and WNW-ESE- directed structures at the south-eastern and the north-western parts of the basin, respectively, divided into two structural segments. The balanced cross-sections also indicate ~4% and ~25% shortening at the north-western and south-eastern segments, respectively. The differences in amounts of shortenings are explained by reduce in effectiveness zone of basin-bounding thrust faults towards west. On the other hand

  12. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard

    2004-10-28

    The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification.

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

    Science.gov (United States)

    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

  14. RESOURCE ASSESSMENT OF THE IN-PLACE AND POTENTIALLY RECOVERABLE DEEP NATURAL GAS RESOURCE OF THE ONSHORE INTERIOR SALT BASINS, NORTH CENTRAL AND NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2004-04-16

    The University of Alabama and Louisiana State University have undertaken a cooperative 3-year, advanced subsurface methodology resource assessment project, involving petroleum system identification, characterization and modeling, to facilitate exploration for a potential major source of natural gas that is deeply buried (below 15,000 feet) in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas. The project is designed to assist in the formulation of advanced exploration strategies for funding and maximizing the recovery from deep natural gas domestic resources at reduced costs and risks and with minimum impact. The results of the project should serve to enhance exploration efforts by domestic companies in their search for new petroleum resources, especially those deeply buried (below 15,000 feet) natural gas resources, and should support the domestic industry's endeavor to provide an increase in reliable and affordable supplies of fossil fuels. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification. The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The project objectives will be achieved through a 3-year effort. First, emphasis is on petroleum system identification and characterization in the

  15. An isotopic approach to the functioning of multi-layered aquifer systems in central Tunisia: The cases of North Gafsa and Hajeb el Aioun-Djelma basins

    International Nuclear Information System (INIS)

    In central Tunisia, the hydrogeological behaviour of numerous multilayered aquifers is controlled by tectonics, because major faults act as natural underground hydraulic sills. This tectonic complexity limits the application of the classical hydrogeological methods and it appeared interesting to examine how environmental isotopes techniques could contribute to the knowledge of such systems. Two aquifer systems, corresponding to the North Gafsa and Hajeb el Aioun-Djelma basins, were selected because they are particularly affected by water management problems, such as a lowering of piezometric levels probably due to overexploitation of the aquifers. The behaviour of the environmental isotopes used in this study (18O, 2H, 3H, 14C and 13C) are quite different in the two systems. In the North Gafsa basin, the modern/recent recharge (evidenced by tritium contents) is largely spread all over the basin and is locally identified in the different aquifer levels, even close to the main outlet of the system ('Gafsa sill'). Moreover, since groundwaters seem to be stratified in this region, it is difficult to reconstruct in details the lateral evolution of ionic and isotopic contents. On the opposite, in the multilayered system of the Hajeb el Aioun-Djelma basin, the evolution of the environmental tracers is quite continuous, showing a relay between the different aquifer levels from the recharge areas towards the main outlet ('Hajeb sill'). Present-day water uptakes from the aquifers are likely to exceed recent recharge; however, the comparison between the results obtained in the present study and those from a previous work, in 1972, shows that overexploitation is limited in comparison with the reserves stored in the system. (author)

  16. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2006-09-30

    The objectives of the study were: (1) to perform resource assessment of the thermogenic gas resources in deeply buried (>15,000 ft) natural gas reservoirs of the onshore interior salt basins of the north central and northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling; and (2) to use the petroleum system based resource assessment to estimate the volume of the deep thermogenic gas resource that is available for potential recovery and to identify those areas in the interior salt basins with high potential for this thermogenic gas resource. Petroleum source rock analysis and petroleum system characterization and modeling, including thermal maturation and hydrocarbon expulsion modeling, have shown that the Upper Jurassic Smackover Formation served as the regional petroleum source rock in the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin. Thus, the estimates of the total hydrocarbons, oil, and gas generated and expelled are based on the assumption that the Smackover Formation is the main petroleum source rock in these basins and subbasins. The estimate of the total hydrocarbons generated for the North Louisiana Salt Basin in this study using a petroleum system approach compares favorably with the total volume of hydrocarbons generated published by Zimmermann (1999). In this study, the estimate is 2,870 billion barrels of total hydrocarbons generated using the method of Schmoker (1994), and the estimate is 2,640 billion barrels of total hydrocarbons generated using the Platte River software application. The estimate of Zimmermann (1999) is 2,000 to 2,500 billion barrels of total hydrocarbons generated. The estimate of gas generated for this basin is 6,400 TCF using the Platte River software application, and 12,800 TCF using the method of Schmoker (1994). Barnaby (2006) estimated that the total gas volume generated for this basin ranges from 4,000 to 8,000 TCF. Seventy

  17. Basin development and petroleum prospects of central New Hebrides arc

    Energy Technology Data Exchange (ETDEWEB)

    Greene, H.G.; Wong, F.L.; Falvey, D.A.; MacFarlane, A.

    1986-07-01

    Two extensive intra-arc basins, the Central basin of Vanuatu and the Vanikolo basin, have recently been mapped in detail and appear to have developed in the last 3 m.y. primarily from subduction and arc-polarity reversal. The Central basin of Vanuatu is being modified by the ridge-arc collision and is still accumulating sediment, whereas the Vanikolo basin has no physiographic expression and is completely filled with sediment. Quaternary volcanism has separated the Central basin of Vanuatu into two physiographic basins (North Aoba and South Aoba basins). The Central basin is flanked on the west by five smaller insular basins associated with the islands of Malakula and Espiritu Santo. Although North and South Aoba basins lie in water depths as great as 3 km, migration paths into the shallower water basins appear to be present, and structures that could trap hydrocarbons occur. More than 5 km of sediment of Miocene and younger age were deposited in the deeper basins, whereas 2-km thick sediments of late Miocene and younger age occur near the islands. The most promising hydrocarbon basin is Malakula basin, which lies on the eastern shelf of Malakula Island, where onshore source rock analyses indicated potential gas concentrations. North of the Central basin of Vanuatu lies the largest basin in the region, the Vanikolo basin, covering more than 14,000 km/sup 2/ and containing more than 6 km of probablen Miocene and younger sediment. Water depths are more than 2 km in the deepest part of this basin, but much of the margins lie in water less than 1 km deep. Structures along the margins could trap hydrocarbons, especially along the western side, and are accessible to drilling. More work must be done in Vanikolo basin to assess hydrocarbon source rocks, migration, and heat flow before a comprehensive hydrocarbon evaluation can be made.

  18. North Central Thailand

    Science.gov (United States)

    1998-01-01

    This radar image shows the dramatic landscape in the Phang Hoei Range of north central Thailand, about 40 kilometers (25 miles) northeast of the city of Lom Sak. The plateau, shown in green to the left of center, is the area of Phu Kradung National Park. This plateau is a remnant of a once larger plateau, another portion of which is seen along the right side of the image. The plateaus have been dissected by water erosion over thousands of years. Forest areas appear green on the image; agricultural areas and settlements appear as red and blue. North is toward the lower right. The area shown is 38 by 50 kilometers (24 by 31 miles) and is centered at 16.96 degrees north latitude, 101.67 degrees east longitude. Colors are assigned to different radar frequencies and polarizations as follows: red is L-band horizontally transmitted and horizontally received; green is L-band horizontally transmitted and vertically received; blue is C-band horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar on October 3, 1994, when it flew aboard the space shuttle Endeavour. SIR-C/X-SAR is a joint mission of the U.S./German and Italian space agencies.Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA

  19. Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile

    OpenAIRE

    Strauch, G; R. Oyarzún; F. Reinstorf; J. Oyarzún; M. Schirmer; K. Knöller

    2009-01-01

    For sustainable water resource management in semi-arid regions, sound information is required about interactions between the different components of the water system: rain/snow precipitation, surface/subsurface run-off, groundwater recharge. Exemplarily, the Huasco and Limarí river basins as water stressed river catchments have been studied by isotope and hydrochemical methods for (i) the origin of water, (ii) water quality, (iii) relations of surface and groundwater.

    App...

  20. Hydrochemical and isotopic patterns in a calc-alkaline Cu- and Au-rich arid Andean basin: The Elqui River watershed, North Central Chile

    International Nuclear Information System (INIS)

    Highlights: ► Major ions are provided by rock weathering and NaCl recycling. ► Aridity and cal-alkaline lithology effects abate acid drainage. ► Factors affecting hydrochemistry in mineral rich zone are addressed. ► Stable isotopes confirm the meteoric origin of groundwaters. ► High sulfate contents are explained by widespread sulfide minerals. - Abstract: The geochemistry of surface water and groundwater from the Elqui River basin, North-Central Chile, was studied in spring 2007 and fall 2008 to obtain a general understanding of the factors and mechanisms controlling the water chemistry of steep rivers located in mineral-rich, arid to semi arid zones. Besides its uniform intermediate igneous lithology, this basin is known for acid drainage and high As contents in the El Indio Au–Cu–As district, in its Andean head. Abundant tailings deposits are present in the middle part of the basin, where agricultural activities are important. According to the results, the chemical and isotopic composition of the Elqui basin surface water and groundwater is related to uniform calc-alkaline lithology and the major polluting system of the chemically reactive, but closed El Indio mining district. The resulting compositional imprints in surface and ground-water are, (a) high SO4 levels, reaching about 1000 mg/L in the Toro River water, directly draining the mining area; (b) a major depletion of Fe and pollutant metals in surface water after the confluence of the Toro and La Laguna rivers; (c) similar chemical composition of surface and ground-waters that differ in H and O isotopic composition, reflecting the effect of differential evaporation processes downstream of the Puclaro dam; and (d) seasonal variations of Fe, Mn, Cu and Zn in surface water. In contrast, the groundwater chemistry exhibits moderate seasonal changes, mainly in HCO3- content. In spite of the acid drainage pollution, water quality is adequate for human consumption and irrigation. This is a

  1. Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile

    Directory of Open Access Journals (Sweden)

    G. Strauch

    2009-10-01

    Full Text Available For sustainable water resource management in semi-arid regions, sound information is required about interactions between the different components of the water system: rain/snow precipitation, surface/subsurface run-off, groundwater recharge. Exemplarily, the Huasco and Limarí river basins as water stressed river catchments have been studied by isotope and hydrochemical methods for (i the origin of water, (ii water quality, (iii relations of surface and groundwater.

    Applying the complex multi-isotopic and hydrochemical methodology to the water components of the Huasco and Limarí basins, a differentiation of water components concerning subsurface flow and river water along the catchment area and by anthropogenic impacts are detected. Sulphate and nitrate concentrations indicate remarkable input from mining and agricultural activities along the river catchment.

    The 2H-18O relations of river water and groundwater of both catchments point to the behaviour of river waters originated in an arid to semi-arid environment.

    Consequently, the groundwater from several production wells in the lower parts of the catchments is related to the rivers where the wells located, however, it can be distinguished from the river water. Using the hydrological water balance and the isotope mixing model, the interaction between surface and subsurface flows and river flow is estimated.

  2. The Pliocene-Quaternary Buffalo Valley volcanic field, Nevada: Post-extension, intraplate magmatism in the north-central Great Basin, USA

    Science.gov (United States)

    Cousens, Brian; Wetmore, Stacey; Henry, Christopher D.

    2013-12-01

    The Buffalo Valley volcanic field consists of Pliocene through Quaternary lava flows and spatter cones located south of Battle Mountain and adjacent to the Fish Creek Mountains, north-central Nevada. The volcanic rocks are split into two groups by age and geochemistry. The Pliocene sequence (4.02 to 2.75 Ma) consists of olivine- and plagioclase-bearing alkali basaltic lava flows with minor pyroclastic deposits, found primarily along the south flank of Battle Mountain and also at the north end of the Fish Creek Mountains and within the Fish Creek Mountains caldera. The Quaternary series (1.99 to 1.14 Ma) includes nearly a dozen trachybasaltic spatter cones with short lava flows erupted along the northwest flank of the Fish Creek Mountains. Normalized rare earth element and incompatible element plots for both groups are light rare earth and Nb-Ta enriched, resembling alkali basalts from ocean islands, but the Quaternary lavas are more light rare earth element-enriched and cross the Pliocene basalt patterns at Eu. Radiogenic and stable isotope ratios are consistent with an asthenospheric mantle source, and the rare earth element patterns indicate a shift from melting in the spinel to garnet peridotite field with time. Basaltic rocks from other intraplate fields in the Great Basin, including the Lunar Crater and Cima fields, only include lavas that originated at depth in the garnet peridotite field. Buffalo Valley is located at the margin of a proposed lithospheric drip (delamination) and within a zone of lithospheric thinning that extends across northern Nevada, both of which may control where melting in the asthenosphere may occur. The proximity to the edge of Precambrian-Phanerozoic lithosphere boundary may also be a factor in melt generation.

  3. Biostratigraphy and sedimentology of the Fluviatile Untere Serie (Early and Middle Miocene) in the central part of the North Alpine Foreland Basin: implications for palaeoenvironment and climate

    Science.gov (United States)

    Prieto, J.; Böhme, M.; Maurer, H.; Heissig, K.; Abdul Aziz, H.

    2009-10-01

    The Early to Middle Miocene Fluviatile Untere Serie lithostratigraphic unit of the Upper Freshwater Molasse (UFM) in the North Alpine Foreland Basin (NAFB) crops out in a 40 m long section at Untereichen-Altenstadt (central part of the NAFB). This section yields a unique superposition of two vertebrate assemblages belonging to different biostratigraphic units: early part OSM C + D (Karpatian) and OSM E (Early Badenian). Detailed taxonomic analyses reveal different diversity patterns in the two assemblages. Nine small mammal and six ectothermic vertebrate taxa occur in the older level UA 540 m, while 20 small mammal and 23 ectothermic vertebrate taxa are recorded for the younger level UA 565 m. From the latter locality comes a small-sized representative of the biostratigraphically significant Megacricetodon lappi lineage. This evolutionary level has not been documented previously for the eastern part of the NAFB. Bioclimatic analysis combined with lithofacies and architectural element analysis indicates that significant changes in the fluvial sedimentation style, surface-water runoff and tectonics occurred between the Early Karpatian and Early Badenian. A meandering fluvial system (marly unit) is erosively overlain by sandy braided river deposits (sandy unit). Overbank deposits of the marly unit revealed that the older vertebrate fossil assemblage (UA 540 m) is deposited in an animal burrow that was presumably produced by owls. Both reptilian and mammalian taxa are indicative of a relatively open environment and dry, probably semi-arid climate. Conversely, vertebrates from the sandy unit (UA 565 m), which are accumulated in channel fill deposits, suggest closed as well as open habitats with a subtropical humid climate and mean annual rainfall of about 1,000 mm. According to the sequence stratigraphic analysis the marly unit is interpreted as a highstand-system-tract of the TB 2.2 global 3rd order sequence. The new results add support to the hypothesis that the

  4. Methane leakage during the evolution of petroleum systems in the Western Canada Sedimentary Basin and the Central Graben area of the North Sea

    Science.gov (United States)

    Berbesi, L. A.; di Primio, R.; Anka, Z.; Horsfield, B.

    2012-04-01

    Around 500 to 600 Tg (1 Tg = 1012 g) of methane enter the atmosphere every year, mainly as product of microbial processes and combustion of fossil fuels and burning biomass. The importance of another source, the geologic emissions of methane, is up to now only loosely constrained. In this study, we addressed the potential methane emissions during the geological evolution of the Western Canada sedimentary basin (WCSB), which holds the largest oil sand accumulations in the world, and the Central Graben area of the North Sea. In the case of the WCSB, thermogenic gas generation and leakage at the sediment surface were addressed through 3D petroleum systems modeling. In this basin, the accumulated oil experienced intense biodegradation that resulted in large masses of biogenic methane. We quantified this latter mass though a two-step mass balance approach. Firstly, we estimated the rate of petroleum degradation and the magnitude of petroleum loss. After this, we calculated the mass of biogenic methane generated using a model that assumes hexadecane (C16H34) as representative of the saturated compounds (Zengler et al., 1999). Our 3D model suggests that 90000-150000 Tg of dry gas (mostly methane) could have leaked during the interval from 80 Ma to 60 Ma. Therefore, uniform leakage rates would have been in the order of 10-3-10-2 Tg yr-1. Biogenic methane generation could have taken place at rates of 10-4 to 10-2 Tg yr-1. However, the effective mass of thermogenic and biogenic methane reaching the atmosphere might have been up to 90% lower than calculated here due to methanotrophic consumption in soils (Etiope and Klusman, 2002). We addressed the thermogenic gas generation and leakage in the Central Graben through two different methods. The first is based on a previous 3D petroleum system modeling of the region (Neumann, 2006). The second consisted of calculating the mass of generated petroleum based on source rock extension and properties (Schmoker, 1994), and then

  5. Vulnerability in north- central Vietnam

    DEFF Research Database (Denmark)

    Casse, Thorkil; Milhøj, Anders; Nguyen, Thao Phuong

    2015-01-01

    This article examines changes in livelihood strategies in response to flooding. It does so on the basis of a household survey which was undertaken in three provinces in north central Vietnam. All households in the survey were regularly affected by flooding, but only poor households experience...

  6. Mesozoic basins and associated palaeogeographic evolution in North China

    Institute of Scientific and Technical Information of China (English)

    Yong-Qing Liu; Hong-Wei Kuang; Nan Peng; Huan Xu; Peng Zhang; Neng-Sheng Wang; Wei An

    2015-01-01

    In North China, the Mesozoic terrestrial basins, sedimentary palaeogeography and tectonic settings involved ifve evolutionary stages:(1) the Early-Middle Triassic, (2) the Late Triassic to Early-Middle Jurassic, (3) the Late Jurassic to early Early Cretaceous, (4) the middle-late Early Cretaceous and (5) the Late Cretaceous. The regional punctuated tectonic events occurred during these evolutionary stages. During the Early-Middle Triassic (stage 1), the Xingmeng Orogenic Belt (XMOB, i.e., east-ern part of Central Asia Orogenic Belt, CAOB) of the northern North China was settled in the transition of tectonic environment from syn-orogenic compression to post-orogenic extension with intensive uplifting. It is a main provenance in the uniifed Ordos-North China Basin.The united continental plate of China and the Qinling-Dabie-Sulu Orogenic Belt formed due to convergence and collision between the North China Plate and the Yangtze Plate along two suture zones of the Mianlue and the Shangdan in the terminal Middle Triassic. During the Late Triassic to the Early-Middle Jurassic (stage 2), the Late Triassic maifc or alkaline rocks and intrusions occurred on the northern and southern margins of North China Craton (NCC) and XMOB, implying that intensiifed extension happened all over the North China (early phase of stage 2). Additionally, in the late phase of stage 2, the basic volcanic-iflling faulted basins were widely distributed in the northeastern North China during the Early-Middle Jurassic, including a series of small-to medium-sized basins with coal-bearing strata and some volcanic rocks in other areas of North China, which was the result of subduction of the Palaeo-Paciifc Plate during the Early-Middle Jurassic. An active continental margin with accretionary complex developed in the eastern Heilongjiang of China, Japan and the Far East of Russia at that time. However, in the end of the Early-Middle Jurassic, because of the Yan-shanian orogeny characterized by

  7. Tectonic and thermal history of the western Serrania del Interior foreland fold and thrust belt and Guarico Basin, north central Venezuela: Implications of new apatite fission track analysis and seismic interpretation

    Science.gov (United States)

    Perez de Armas, Jaime Gonzalo

    Structural analysis, interpretation of seismic reflection lines, and apatite fission-track analysis in the Western Serrania del Interior fold and thrust belt and in the Guarico basin of north-central Venezuela indicate that the area underwent Mesozoic and Tertiary-to-Recent deformation. Mesozoic deformation, related to the breakup of Pangea, resulted in the formation of the Espino graben in the southernmost portion of the Guarico basin and in the formation of the Proto-Caribbean lithosphere between the diverging North and South American plates. The northern margin of Venezuela became a northward facing passive margin. Minor normal faults formed in the Guarico basin. The most intense deformation took place in the Neogene when the Leeward Antilles volcanic island arc collided obliquely with South America. The inception of the basal foredeep unconformity in the Late Eocene-Early Oligocene marks the formation of a perisutural basin on top of a buried graben system. It is coeval with minor extension and possible reactivation of Cretaceous normal faults in the Guarico basin. It marks the deepening of the foredeep. Cooling ages derived from apatite fission-tracks suggest that the obduction of the fold and thrust belt in the study area occurred in the Late Oligocene through the Middle Miocene. Field data and seismic interpretations suggest also that contractional deformation began during the Neogene, and specifically during the Miocene. The most surprising results of the detrital apatite fission-track study are the ages acquired in the sedimentary rocks of the easternmost part of the study area in the foreland fold and thrust belt. They indicate an Eocene thermal event. This event may be related to the Eocene NW-SE convergence of the North and South American plates that must have caused the Proto-Caribbean lithosphere to be shortened. This event is not related to the collision of the arc with South America, as the arc was far to the west during the Eocene.

  8. REE Compositions of Lower Ordovician Dolomites in Central and North Tarim Basin, NW China: A Potential REE Proxy for Ancient Seawater

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuefeng; HU Wenxuan; JIN Zhijun; ZHANG Juntao; QIAN Yixiong; ZHU Jingquan; ZHU Dongya; WANG Xiaolin; XIE Xiaomin

    2008-01-01

    Rare earth dement compositions of Lower Ordovician dolomites in the Central and Northern Tarim Basin are studied. Most dolomite samples are more or less contaminated by clay minerals. Their rare earth element compositions have been consequently changed, showing both seawater-like and non-seawater-like features. The clay contamination should be disposed before the REE data are used. Through ICP-MS and ICP-AES analyses, the REE features are well documented. The clay contamination is quantitatively determined by microscopic investigation, trace elements and REE contents. The dolomites, at least in the Tarim Basin, are thought to be pure when their total LREE contents are less than 3x10-6. Through comparison, the pure dolomites show similarities in REE patterns but differences in REE contents with co-existing pure limestone, which indicates that dolomitization may slightly change the REE compositions. Nevertheless, whatever the change is, the pure dolomites may act as a potential REE proxy for Ordovician seawater, which would be significant for ancient massive dolomite strata that lack limestone.

  9. Petrology of seamounts in the Central Indian Ocean Basin: Evidence for near-axis origin

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Batiza, R.; Iyer, S.D.

    ; and Caribbean Basin, Atlantic Ocean (Castillo et al. 1985) and North Central Indian Ocean (Y. Neprochnov personal communication 1995). Information on seamount generation in the Indian Ocean is generally lacking. To test the relation between kinematics...

  10. Structure and dynamics of basin forested wetlands in North America

    International Nuclear Information System (INIS)

    Freshwater basin wetlands are found in depressions of various depths, generally in areas where precipitation exceeds evapotranspiration or where the depression intersects the water table creating groundwater seeps or springs. Forested basins are those that contain woody vegetation with the potential for reaching tree stature; they do not include woody shrub wetlands. In North America these areas are mainly in the central and eastern region. Pertinent information and reviews on the distribution, floristic composition, structure and dynamics of basin forested wetlands are summarized. The major emphasis is on freshwater wetlands, but data for saltwater wetlands mainly from Florida and tropical America are included. The external factors affecting basin wetlands or the important components of a wetlands energy signature are described as well as the distribution and floristic composition of representative basin wetlands. Sections on structural characteristics, organic matter dynamics, and nutrient cycling comprise the bulk of quantitative information. The effects of disturbances, both natural and human induced, with varying degrees of impact depending upon the intensity and on the part of the ecosystem to which the stressor is applied are evaluated. Examples of stressors in basin wetlands include water impoundment, water diversion, thermal stress from hot water, sedimentation, addition of toxic substances, addition of wastewater, oil spills, and harvesting. 86 refs., 5 figs., 11 tabs

  11. Geochemistry of the Obey River Basin, north-central Tennessee: a case of acid mine water in the Karst drainage system

    International Nuclear Information System (INIS)

    The East Fork of the Obey River, a tributary of the Cumberland River, drains a 523 km2 basin along the western margin of the Cumberland Plateau. The upper basin lies on clastic rocks that include coals that were mined earlier in this century. The lower basin is drained through a deep gorge where the East Fork has cut downward into the Mississippian carbonate rocks. The lower basin is karstic, with a 9 km length of the river and most of its tributaries underdrained by conduit systems. Many of the upper basin tributaries of the East Fork are contaminated by acid mine drainage and have high levels of acidity, sulfate, iron and aluminium. As the acid mine waters sink in the limestone portions of the basin, they are buffered but acidity is not rapidly reduced and acid water appears at a large spring deep in the karst having survived 5 km of transport. Sulfate waters gradually convert to bicarbonate waters as more tributaries from carbonate rocks enter the system. Aluminium in solution decreases with increasing pH, and precipitates as colloidal sized particles. Although alkalinity increases in the lower reaches of the basin, most of the waters remain highly undersaturated with respect to calcite

  12. Evidence for Badenian local sea level changes in the proximal area of the North Croatian Basin

    OpenAIRE

    Bakrač, Koraljka; Hajek-Tadesse, Valentina; MIKNIĆ, Mirjana; Grizelj, Anita; Hećimović, Ivan; Kovačić, Marijan

    2010-01-01

    Quantitative analysis of palynomorphs, foraminifera and ostracods enabled the recognition of biotic events and the reconstruction of environmental change in the Badenian sediments from the Vrhovčak section of Mt. Samoborsko gorje (NW Croatia). During the Middle Miocene the investigated area of Mt. Samoborska gora was located at the south-western margin of the North Croatian Basin, which represents the south-western edge of the Pannonian Basin System and the Central Paratethys Basin. This marg...

  13. Tectonic control on turbiditic sedimentation: The Late Cretaceous-Eocene successions in the Sinop-Boyabat Basin of north-central Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Janbu, Nils Erik

    2004-07-01

    The aim of this study: Tectonics is widely recognized by geologists as the single most important factor controlling the development, filling and deformation of sedimentary basins. In general terms, the role of tectonics seems rather ''obvious'' to most geologists, because we know reasonably well as what tectonics ''can do'' as the agent of structural deformation. Therefore, the role of tectonics is often invoked as a kind of ballpark variable - as the obvious cause of ''subsidence'' or ''uplift'' - and seems to some authors even too obvious to mention. Relatively little attempt has been in sedimentological and stratigraphic studies to recognize as to what effects exactly the tectonic activity had on sedimentation in a particular basin. The principal aim of the present study has been to improve our understanding of how tectonic activity can affect deep-water turbiditic sedimentation in a particular basin, including its ''external'' influences (basin geometry, basin-margin configuration, sediment source/supply and relative sea-level change) and ''internal'' effects (basin-floor subsidence, seafloor deformation). Foreland basins are some of the most active tectonically, and the Sinop- Boyabat Basin is a fascinating case of a rift converted into a foreland basin and increasingly deformed. Summary of papers: The main part of the field study, concerned with the sedimentology and facies analysis of the turbiditic succession, is summarized in Papers 1-3, which put special emphasis on the physical character and morphodynamic evolution of the depositional systems and on the tectonic control on their development. Paper 4 focuses on the frequency distribution of bed thickness data collected by detailed logging of various turbiditic assemblages: siliciclastic deposits of nonchannelized currents (lobe and overbank facies); siliciclastic deposits of poorly

  14. Tectonic control on turbiditic sedimentation: The Late Cretaceous-Eocene successions in the Sinop-Boyabat Basin of north-central Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Janbu, Nils Erik

    2004-07-01

    The aim of this study: Tectonics is widely recognized by geologists as the single most important factor controlling the development, filling and deformation of sedimentary basins. In general terms, the role of tectonics seems rather ''obvious'' to most geologists, because we know reasonably well as what tectonics ''can do'' as the agent of structural deformation. Therefore, the role of tectonics is often invoked as a kind of ballpark variable - as the obvious cause of ''subsidence'' or ''uplift'' - and seems to some authors even too obvious to mention. Relatively little attempt has been in sedimentological and stratigraphic studies to recognize as to what effects exactly the tectonic activity had on sedimentation in a particular basin. The principal aim of the present study has been to improve our understanding of how tectonic activity can affect deep-water turbiditic sedimentation in a particular basin, including its ''external'' influences (basin geometry, basin-margin configuration, sediment source/supply and relative sea-level change) and ''internal'' effects (basin-floor subsidence, seafloor deformation). Foreland basins are some of the most active tectonically, and the Sinop- Boyabat Basin is a fascinating case of a rift converted into a foreland basin and increasingly deformed. Summary of papers: The main part of the field study, concerned with the sedimentology and facies analysis of the turbiditic succession, is summarized in Papers 1-3, which put special emphasis on the physical character and morphodynamic evolution of the depositional systems and on the tectonic control on their development. Paper 4 focuses on the frequency distribution of bed thickness data collected by detailed logging of various turbiditic assemblages: siliciclastic deposits of nonchannelized currents (lobe and overbank facies); siliciclastic deposits of poorly

  15. Seismic stratigraphic framework of deep central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Shaub, F.J.; Buffler, R.T.; Parsons, J.G.

    1984-11-01

    The deep Gulf of Mexico basin is underlain by up to 10 km (33,000 ft) of Jurassic(.) to Holocene layered sedimentary rocks. The multichannel reflection seismic record from the deep Gulf of Mexico was divided into six seismic stratigraphic units for study of the geologic history of this accumulation. The basal Challenger unit (Jurassic (.) to middle Cretaceous) is considered coeval with early basin formation. We interpret it as a deep marine sequence overlying oceanic crust in the central basin and as continental and shallow through deep marine rocks, including thick evaporites, over adjacent transitional crust. The next three units, Campeche, Lower Mexican Ridges and Upper Mexican Ridges, indicate that from the Late Cretaceous through middle Miocene the basin filled progressively from the west and north, most probably with siliceous turbidites interlayered with pelagic deposits. By the late Tertiary, however, salt and shale deformation within thick sedimentary sections along the western and northern margins trapped much of the incoming sediment supply on the shelves and upper slopes. The late Miocene to Pliocene Cinco de Mayo unit, therefore, represents a relatively starved interval. In contrast, the uppermost, or Sigsbee unit, includes the Mississippi Fan, an accumulation up to 3 km (10,000 ft) thick of mainly mass-transported deposits that bypassed the shelf and slope and were deposited directly onto the abyssal plain. In the western and southwestern portions of the deep basin, beyond the fan pinchout, the Pleistocene section is largely a continuation of the Pliocene suspension deposits.

  16. On the Origin of One Basin-Multiple Mountain Couplings in the Mesozoic-Cenozoic Basin-Range Area in Eastern North China

    Institute of Scientific and Technical Information of China (English)

    NIU Shuyin; SHAO Ji'an; HOU Quanlin; WANG Baode; XU Chuanshi

    2004-01-01

    The basin-range coupling relation is a leading subject of the modern geology. In geometry, relations of this type include couplings between stretched orogenic belt and down-faulted basin, compressional orogenic belt and foreland basin, strike-slip orogenic belt and strike-slip basin and so on. Fault chains are the key for these couplings and there are typical examples for all these cases. The North China down-faulted basin is coupled west with the Tathang uplift, east with the Jiao-Liao Mountains, north with the Yanshan orogenic belt and south with the Dabie orogenic belt,that is to say, the central down-faulted basin and the surrounding orogenic belts bear a coupling relation within a uniform dynamistic system. Study shows that the central down-faulted basin and the North China mantle sub-plume structure have a close relation during their formation. Owing to intensive mantle sub-plume uplifting, the bottom of the lithosphere suffered from resistance, which caused the lithosphere of the eastern North China to be heated, thinned and fault-depressed. Meanwhile, mantle rocks that were detached outwards in the shape of mushroom was dissected by surrounding ductile shearing zones, which lead to decompression and unloading to generate hypomagmas, and a series of mantle-branch structures were formed around the down-faulted basin. There is an obvious comparability among these mantle branch structures (orogenic belts), and they have basin-range coupling relations with the central down-faulted basins.

  17. Salt movements within the Central European basin system

    Energy Technology Data Exchange (ETDEWEB)

    Maystrenko, Yuriy; Bayer, Ulf; Scheck-Wenderoth [GeoForschungsZentrum (GFZ), Potsdam (Germany); Littke, Ralf [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    2010-04-15

    Evolution of salt structures in relation to tectonic events within central part of the Central European Basin System is described by summarizing results which have been obtained and published in frame of the research project DFG-SPP 1135. These results illustrate main phases of salt tectonics within the basin system from the Triassic to present day. During the Buntsandstein and Muschelkalk, extension triggered raft tectonics and salt movements within the Ems Trough, the Glueckstadt and the Horn Grabens. The next phase of salt movements occurred in response to a Middle-Late Keuper regional extensional event which was strongest within the Triassic depocenters of the Central European Basin System, such as the Horn Graben, the Glueckstadt Graben, the Ems and the Rheinsberg Troughs. Regional erosion truncated the study area during the Late Jurassic-Early Cretaceous time. The magnitude of Late Jurassic-Early Cretaceous erosion is declining towards southern margin of the basin system where a dextral transtensional regime was established in the Lower Saxony Basin and neighboring areas during the Late Jurassic-Early Cretaceous. The late Early Cretaceous-early Late Cretaceous is characterized by a relative tectonic quiescence without strong salt movements. The Late Cretaceous-Early Cenozoic inversion provocated renewed salt movements, causing the thick-skinned salt tectonics along the Elbe Fault System and the thin-skinned character of salt movements towards the north from the area of strain localisation. Post-inversion Cenozoic subsidence was accompanied by salt movements, related either to diapiric rise due to regional shortening and/or to local almost E-W directed extension. (orig.)

  18. Structural Architecture and Evolution of Kumkuli Basin, North Tibet

    Institute of Scientific and Technical Information of China (English)

    He Bizhu; Xu Zhiqin; Jiao Cunli; Cui Junwen; Wang Shenglang; Wang Gonghuai; Li Zhaoyang; Qiu Zhuli

    2009-01-01

    Utilizing the new data of gravity, magnetic, and magnetotelluric survey, we analyzed the characteristics of the three geophysical attribute (gravity, magnetic, and resistivity) interfaces and the deep architecture and structure of Kumkuli basin. The research results can provide basic data for early basin structural study. From coupled basin and mountain system, analysis of the structure, and evolution of Knmknli basin, we found that there was zoning from north to south and from west to east. Kumkuli basin has three structural architecture layers including metamorphic crystallization basement, fold basement and sedimentary cover. Knmkuli basin can be divided into three structural units, two depressions, and one uplift. Structural evolution of the Kumkuli basin can be divided into five evolution stages, including Kumkuli microcontinent formed in Sinian-Ordovician, suture around Kumkuli basin formed in Eopaleozoic, retroarc foreland basin formed in Neopaleozoic, rejuvenated foreland hasin developed in Mesozoic, and strike slip and compression basin developed in Cenozoic.

  19. Pull-apart origin of the Satpura Gondwana basin, central India

    Indian Academy of Sciences (India)

    Chandan Chakraborty; Sanjoy Kumar Ghosh

    2005-06-01

    The Gondwana basins of peninsular India are traditionally considered as extensional-rift basins due to the overwhelming evidence of fault-controlled synsedimentary subsidence. These basins indeed originated under a bulk extensional tectonic regime, due to failure of the attenuated crust along pre-existing zones of weakness inherited from Precambrian structural fabrics. However, disposition of the basins and their structural architecture indicate that the kinematics of all the basins cannot be extensional. To maintain kinematic compatibility with other basins as well as the bulk lateral extension, some basins ought to be of strike-slip origin. The disposition, shape and structural architecture of the Satpura basin, central India suggest that the basin could be a pull-apart basin that developed above a releasing jog of a left-stepping strike-slip fault system defined by the Son-Narmada south fault and Tapti north fault in consequence to sinistral displacement along WSW-ENE. Development of a sedimentary basin under the above-mentioned kinematic condition was simulated in model experiments with sandpack. The shape, relative size, stratigraphic and structural architecture of the experimental basin tally with that of the Satpura basin. The experimental results also provide insights into the tectono-sedimentary evolution of the Satpura basin in particular and pull-apart basins in general.

  20. Correlation and migration studies of North Central Sumatra oils

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, R.J. [Chevron Texaco Energy Research Technology Company, Richmond, CA (United States); Heidrick, T.; Mertani, B.; Qivayanti [PT Caltex Pacific Indonesia, Rumbai (Indonesia); Li, M. [Geological Survey of Canada, Calgary (China)

    2002-12-01

    The Central Sumatra Basin (CSB) is a profile petroleum-producing basin and its petroleum systems have been extensively studied. The widely occurring Tertiary lacustrine shale, Brown Shale, has long been recognized as the main source rock for tens of billions of barrels of oil in place. The oils produced from different fields display significant variation in source characteristics that have been attributed to variation in source facies. Despite this generalized recognition of the oil source, the links between major oil accumulations and many possible source kitchens throughout the basin have not been established as detailed oil-source correlation, and oil migration routes are not well defined. For continued exploration in the region, detailed genetic grouping and migration routes of the oils were evaluated through geochemical characterization of numerous oils from various fields in the northern part of Central Sumatra. Biomarker and carbon isotopic data indicate that the oils are quite similar geochemically but form several genetic groups on the basis of subtle but persistent differences in source facies. The groupings appear geographically meaningful and show association of the different oil groups with various troughs. Carbazole distributions show consistency in suggesting differences in relative migration distance among the oils within each genetic group. By combining the oil grouping and carbazole distributions with geological data, models of migration directions and pathways for oils in North Central Sumatra have been constructed. (author)

  1. Artesian pressures and water quality in Paleozoic aquifers in the Ten Sleep area of the Bighorn Basin, north-central Wyoming

    Science.gov (United States)

    Cooley, M.E.

    1985-01-01

    Major Paleozoic artesian aquifers in the southeastern Bighorn Basin of Wyoming area, in descending order, the Tensleep Sandstone; the Madison Limestone and Bighorn Dolomite, which together form the Madison-Bighorn aquifer; and the Flathead Sandstone. Operating yields commonly are more than 1,000 gallons per minute from flowing wells completed in the Madison-Bighorn aquifer. The initial test of one well indicated a flow of 14,000 gallons per minute. Wellhead pressures range from less than 50 to more than 400 pounds per square inch. Transmissivities are 500-1,900 feet squared per day for the Madison-Bighorn aquifer and 90-325 feet squared per day for the Tensleep and Flathead Sandstones. Despite extensive development for irrigation there have been few decreases in pressure. Some decreases in pressure have occurred in wells completed in the Flathead Sandstone. Fractures along linear structural features result in significant secondary permeability and allow upward interformational movement of water that affects the altitude of the potentiometric surfaces in the Tensleep Sandstone and Madison-Bighorn aquifer. Upward-moving water from the Tensleep and other formations discharges at the land surface as springs along or near these lineations. Water from the aquifers generally contains minimal concentrations of dissolved solids and individual constituents but has excessive hardness. The water is satisfactory for irrigation and other purposes when hardness is not a detrimental factor. Wellhead temperatures range from 11 degrees to 27.5 degrees C, giving a geothermal gradient of about 0.44 degrees C per 100 feet. (USGS)

  2. Ferromanganese nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.; Pattan, J.N.

    In order to delineate a mine site for ferromanganese nodules, extensive surveys were conducted in Central Indian Ocean Basin. Mapping of the basin by multibeam swath bathymetry (Hydrosweep) has revealed many new bottom relief features...

  3. Landslide Inventory for the Little North Santiam River Basin, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase is an inventory of existing landslides in the Little North Santiam River Basin, Oregon (2009). Each landslide feature shown has been classified...

  4. Detailed bathymetric surveys in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.; KameshRaju, K.A.; Ramprasad, T.; George, P.; Jaisankar, S.

    Over 420,000 line kilometers of echo-sounding data was collected in the Central Indian Basin. This data was digitized, merged with navigation data and a detailed bathymetric map of the Basin was prepared. The Basin can be broadly classified...

  5. Paleogene Sediment Character of Mountain Front Central Sumatra Basin

    Directory of Open Access Journals (Sweden)

    P. A. Suandhi

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.164The SE-NW trending Mountain Front of Central Sumatra Basin is located in the southern part of the basin. The Mountain Front is elongated parallel to the Bukit Barisan Mountain, extending from the Regencies of North Padang Lawas (Gunung Tua in the northwest, Rokan Hulu, Kampar, Kuantan Singingi, and Inderagiri Hulu Regency in the southeast. The Palaeogene sediments also represent potential exploration objectives in Central Sumatra Basin, especially in the mountain front area. Limited detailed Palaeogene sedimentology information cause difficulties in hydrocarbon exploration in this area. Latest age information and attractive sediment characters based on recent geological fieldwork (by chaining method infer Palaeogene sediment potential of the area. The Palaeogene sedimentary rock of the mountain front is elongated from northwest to southeast. Thickness of the sedimentary unit varies between 240 - 900 m. Palynology samples collected recently indicate that the oldest sedimentary unit is Middle Eocene and the youngest one is Late Oligocene. This latest age information will certainly cause significant changes to the existing surface geological map of the mountain front area. Generally, the Palaeogene sediments of the mountain front area are syn-rift sediments. The lower part of the Palaeogene deposit consists of fluvial facies of alluvial fan and braided river facies sediments. The middle part consists of fluvial meandering facies, lacustrine delta facies, and turbidity lacustrine facies sediments. The upper part consists of fluvial braided facies and transitional marine facies sediments. Volcanism in the area is detected from the occurrence of volcanic material as lithic material and spotted bentonite layers in the middle part of the mountain front area. Late rifting phase is indicated by the presence of transitional marine facies in the upper part of the Palaeogene sediments.

  6. Bundled slaty cleavage in laminated argillite, north-central minnesota

    Science.gov (United States)

    Southwick, D.L.

    1987-01-01

    Exceptional bundled slaty cleavage (defined herein) has been found in drill cores of laminated, folded, weakly metamorphosed argillite at several localities in the early Proterozoic Animikie basin of north-central Minnesota. The cleavage domains are more closely spaced within the cleavage bundles than outside them, the mean tectosilicate grain size of siltstone layers, measured normal to cleavage, is less in the cleavage bundles than outside them, and the cleavage bundles are enriched in opaque phases and phyllosilicates relative to extra-bundle segments. These facts suggest that pressure solution was a major factor in bundle development. If it is assumed that opaque phases have been conserved during pressure solution, the modal differences in composition between intra-bundle and extra-bundle segments of beds provide a means for estimating bulk material shortening normal to cleavage. Argillite samples from the central part of the Animikie basin have been shortened a minimum of about 22%, as estimated by this method. These estimates are similar to the shortening values derived from other strain markers in other rock types interbedded with the argillite, and are also consistent with the regional pattern of deformation. ?? 1987.

  7. Sedimentary record of mid-Miocene seismotectonic activity in the Sinop Peninsula, north-central Turkey

    OpenAIRE

    Ayhan ILGAR

    2014-01-01

    The middle Miocene shallow-marine siliciclastic succession in the Sinop Peninsula, north-central Turkey, bears a well-preserved sedimentary record of syndepositional deformation associated with the buried escarpment of an oblique-slip dextral reverse fault and attributed to seismotectonic activity. The deposition occurred in a marginal trough at the edge of a tectonically inverted retroarc foreland basin of the Central Pontides. The synsedimentary deformation involved contemporaneous shorefac...

  8. Structural influences on seismic stratigraphy of Nias forearc basin, west of central Sumatra

    Energy Technology Data Exchange (ETDEWEB)

    Matson, R.G.; Moore, G.F.

    1988-02-01

    The Nias forearc basin is a 250-km long, 100-km wide bathyal depression located between the mainland of west-central Sumatra and the island of Nias. A grid of multichannel reflection seismic data covering the basin and adjacent shelves was used to map Neogene structure and to delineate the Neogene seismic stratigraphy. Six major structural features, including the continental margin, strike-slip faults traversing the forearc, and uplifts within the accretionary wedge, were mapped, while 11 seismic sequences were identified within Neogene reflectors. Positive correlations between the structure and seismic facies distributions indicate structure has influenced subsidence and depositional patterns through the developmental history of the basin. From a developmental standpoint, the Nias forearc basin can be subdivided into two smaller basins, the Singkel basin to the north and the Pini basin to the south. During the Miocene and early Pliocene, distinct facies distributions indicate that these two basins developed independently of each other. Subsidence in the Singkel basis was initiated between two parallel strike-slip faults that traverse the forearc. The geometry of the Pini basin, on the other hand, was controlled by the local character of the continental margin and by the uplift of the developing accretionary wedge. In the late Pliocene, a more unified facies distribution across the study area indicates subsidence of a more regional character and an increased regional structural influence over the entire Nias basin area.

  9. Soil indigenous knowledge in North Central Namibia

    Science.gov (United States)

    Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

    2016-04-01

    Mapping and classifying soils is part of an important learning process to improve soil management practices, soil quality and increase productivity. In order to assess soil quality improvement related to an ongoing land reform in North-Central Namibia, the characteristics that determine soil quality in the local land use context were determined in this study. To do so, we collated the indigenous soil knowledge in North-Central Namibia where the Ovakwanyama cultivate pearl millet for centuries. Local soil groups are defined mostly based on their productivity potential, which varies depending on the rainfall pattern. The morphological criteria used by the farmers to differentiate the soil groups (colour, consistence) were supported by a conventional analysis of soil physical and chemical properties. Now, they can be used to develop a soil quality assessment toolbox adapted to the regional use. The characteristics of the tool box do not directly indicate soil quality, but refer to local soils groups. The quality of these groups is relatively homogenous at the local scale. Our results show that understanding of indigenous soil knowledge has great potential to improve soil quality assessment with regards to land use. The integration of this knowledge with the conventional soil analysis improves the local meaning of such a "scientific" assessment and thus facilitates dialog between farmers and agronomists, but also scientists working in different regions of the world, but in similar conditions. Overall, the integration of indigenous knowledge in international classification systems (e.g. WRB) as attempted in this study has thus a major potential to improve soil mapping in the local context.

  10. North Central Project: Environment act proposal

    International Nuclear Information System (INIS)

    Manitoba Hydro proposes to construct a power transmission and distribution line system to connect 12 northern Manitoba communities to the utility's central power grid. The purpose of this North Central Project (NCP) is to provide reliable and unrestricted electric service to remote communities now largely receiving limited diesel-generated power. The NCP is composed of a 138-kV transmission line running ca 350 km from the Kelsey Generating Station, ca 160 km of 25-kV distribution lines, new transformer stations at four communities, upgraded internal distribution systems within the communities, removal of existing diesel stations and restoration of the sites, modifications and additions to the Kelsey switchyard, and a communications system. The NCP is described in detail, including proposed line routes and transformer station locations, rationales for site and route selection, projected impacts on the environment and local societies, and consultations with the communities to be affected. Potential impacts are expected to be modest, with few unmitigable adverse impacts and a number of potentially significant positive benefits. Impact management measures are proposed to prevent or mitigate adverse effects and to create or enhance positive impacts such as local employment of native peoples. 49 figs., 1 tab

  11. New occurrences of Australasian microtektites in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.

    Thirty-three microtektites have been recovered from four different sites in the Central Indian Basin. Based on their physical properties, geographical occurrence and chemical composition, they are identified as belonging to the Australasian tektite...

  12. Glacier characteristics and changes in the Sary-Jaz River Basin (Central Tien Shan, Kyrgyzstan) – 1990–2010

    OpenAIRE

    Osmonov, Azamat; Bolch, Tobias; Xi, Chen; Kurban, Alishir; Guo, Wanqing

    2013-01-01

    The water discharge from the heavily glacierized Sary-Jaz River Basin (Eastern Kyrgyzstan) is of high importance for the very arid Tarim Basin located in Xinjiang (north-western China). We investigated glacier changes in the entire Sary-Jaz River Basin, which covers a large part of the Central Tien Shan, for the period from 1990 to 2010 based on Landsat ‘TM’/‘ETM+’data. We found 1310 glaciers (>0.1 km²), which covered 2055 ± 41.1 km² (∼18% of the entire basin) in 1990. The glaciers shrank by ...

  13. North American Natural Gas Outlook: Basin-on-basin competition

    International Nuclear Information System (INIS)

    Long-term trends and their impacts on the Canadian and American natural gas industry were examined, together with an assessment of the expected evolution of the natural gas markets in North America from 1995 to the year 2010. A strong growth of the natural gas markets in the U.S. and Canada was projected for the period. Demand in the two countries is expected to rise by about a third as a result of general economic growth, competitive gas prices, and efficiency and environmental advantages of gas relative to other fuels. In the U.S., much of this growth is related in some way to electricity: increased use of gas to fuel power generation facilities, a rise in the use of gas for industrial cogeneration and the displacement of electricity by gas in commercial cooling markets. In Canada however, increases in industrial gas demand, including the petrochemical sector, are expected to lead the growth in gas consumption. Canadian gas exports to the U.S. are projected to increase steadily over the period to reach 3.7 Tcf by 2010. While Alberta continues to account for over 80% of Canadian gas production, British Columbia experiences the strongest rate of production growth. In the U.S., the Gulf Coast area continues to be the dominant supply region, accounting for almost 50% of the production over the period. One of the greatest uncertainties over the period results from the deregulation of electricity markets in both the U.S. and Canada. Two other uncertainties that were identified were natural gas supply costs and the incremental tolling of pipeline expansions. 10 figs., 30 tabs., 29 refs

  14. Tectonics and sedimentary evolution of the Sandino forearc basin off Nicaragua, Central America

    Science.gov (United States)

    Costa Pisani, P.; Silver, E.; McIntosh, K.; Ahmed, I.; Ranero, C. R.; Taylor, B.

    2003-04-01

    The Sandino basin is the Nicaragua sector of the Central American forearc, where the Cocos plate subducts beneath the Middle America trench. Recently, Ranero et al. have interpreted a seismic section across the margin and proposed a history of formation of the forearc which is constrained by industry drilling in the basin. They suggested a late Cretaceous to Paleocene accretion event, followed by later subduction erosion processes. The margin wedge consists of the ophiolitic Nicoya complex. The seismic units, unconformities and tectonic features record a rich history of both local and regional vertical movements occurring since the Middle Eocene, which are linked to the evolution of the Pacific convergent margin. During June, 2000, 2800 kms of multichannel seismic reflection data were collected on the R/V Ewing off Nicaragua. Analysis of the 240 channels dataset indicates rapid changes along strike in the Sandino basin. The basin is relatively thin in the southern part, thinning quite rapidly southward against the Nicoya complex of the Santa Elena peninsula of Costa Rica. The forearc sediments thickness approaches and locally exceeds 10 kms in the central and northern parts of the Sandino basin. The oldest units (Upper Cretaceous-Middle Eocene) are very thick off northern Nicaragua, with relatively thin middle to late Cenozoic deposits. However, off central Nicaragua the latter units (Middle-Upper Miocene) attain great thicknesses and the older units appear to thin. This pattern suggests a history of successive deepening of the basin from north to south, after the convergent system evolved from accretion to subduction erosion processes. Present efforts are devoted to quantifying this change in development and using it to understand the dynamics of forearc basin evolution offshore of Central America.

  15. Hydrogeological study and modeling of the Central-North aquifer in Quito

    International Nuclear Information System (INIS)

    The Quito aquifer is composed of two sub-basins: one in the South and the second in the Central- North area. Due to the characteristics of the city, the local water company gave priority to the study of the Central-North sub-basin, where most of the recent studies have been carried out. Since 1991, when the Papallacta project was implemented, EMAAP-Q stopped groundwater extraction from the Quito aquifer, and due to natural recharge, large volumes of groundwater have been recharged, leading to the progressive rising of the water level, up to the surface. The current situation has forced the exploitation of the aquifer as a contribution to the water supply of the Metropolitan District of Quito, with a flow-rate above 800 L·s-1. This pumping will lead to the lowering of the water table, limiting the consequences of the high water levels to the basement of buildings, and at the same time, groundwater will became an strategic alternative of water supply, especially in cases of natural disasters or when surface water systems are not operative. After compilation and evaluation of the hydrological information, the main characteristics of the Quito aquifer, mainly the Central-North sub-basin, were defined after completing a research programme. (author)

  16. Seasonal forecasting of intense tropical cyclones over the North Atlantic and the western North Pacific basins

    Science.gov (United States)

    Choi, Woosuk; Ho, Chang-Hoi; Jin, Chun-Sil; Kim, Jinwon; Feng, Song; Park, Doo-Sun R.; Schemm, Jae-Kyung E.

    2016-02-01

    Intense tropical cyclones (TCs) accompanying torrential rain and powerful wind gusts often cause substantial socio-economic losses in the regions around their landfall. This study analyzes intense TCs in the North Atlantic (NA) and the western North Pacific (WNP) basins during the period 1982-2013. Different intensity criteria are used to define intense TCs for these two basins, category 1 and above for NA and category 3 and above for WNP, because the number of TCs in the NA basin is much smaller than that in the WNP basin. Using a fuzzy clustering method, intense TC tracks in the NA and the WNP basins are classified into two and three representative patterns, respectively. On the basis of the clustering results, a track-pattern-based model is then developed for forecasting the seasonal activities of intense TCs in the two basins. Cross-validation of the model skill for 1982-2013 as well as verification of a forecast for the 2014 TC season suggest that our intense TC model is applicable to operational uses.

  17. Evidence for recent hydrothermal activity in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; ShyamPrasad, M.; Gupta, S.M.; Charan, S.N.

    /89 and SS10/657 were mounted in epoxy, ground and polished to expose the internal features, and then sputter Hydrothermal activity in the Central Indian Basin 1169 8”Oo’. 16”0( Fig. 1. Physiographic features of the Central Indian Basin. FZ 1... determined with pure Ni and pyrite standards, respectively. The polished sections of the spherules were analysed on a flat surface with an accuracy of 0.1%. The ochrous sediments, due to their porous nature, gave lesser totals and hence only those totals...

  18. Neogene dinocyst zonation for the eastern North Sea Basin, Denmark

    DEFF Research Database (Denmark)

    Dybkjær, Karen; Piasecki, Stefan

    2010-01-01

    A dinocyst zonation for the Neogene succession in the eastern part of the North Sea Basin (Denmark) is presented. The zonation is based on an extensive database comprising data from more than fifty onshore and offshore boreholes and about twenty five outcrops. Most of the nineteen dinocyst zones...... method allowed the previous last occurrence of Cordosphaeridium cantharellus (one of the zonal index fossils) dated as between 17.95 My and 19.5 My in previous studies, to be assigned a new dating of 18.4 My. The timespan of the zones range from 2.6 My for the Amiculospharea umbraculum Zone to 0.4 My for...

  19. The Norwegian Danish Basin: A key to understanding the Cenozoic in the eastern North Sea

    Science.gov (United States)

    Rasmussen, Thomas L.; Clausen, Ole R.; Andresen, Katrine J.; Goledowski, Bartosz

    2015-04-01

    The Danish part of Norwegian-Danish Basin, which constitutes the eastern part of the North Sea Basin, has been the key area for sequence stratigraphic subdivision and analysis of the Cenozoic succession since the mid 1990's. Widespread 3D seismic data, in the central parts of the North Sea Basin, as well as more scattered 3D seismic data in the Danish part of the Norwegian-Danish Basin, have given a more detailed understanding of the sequences and indicate that climate is tenable for the origin of Cenozoic sequence boundaries. The previous sequence stratigraphic interpretations have been an integrated part of an ongoing debate concerning vertical movements of the Fennoscandian shield versus the impact of climate and erosion. A newly accessed coherent regional 2D and reprocessed 3D seismic data set, in the Norwegian part of the Norwegian-Danish Basin, constitute the database for a new sequence stratigraphic analysis of the entire area. The objective of the new study is to test previous subdivisions and introduce a coherent 3D sequence stratigraphic analysis and depositional model for the entire Norwegian-Danish Basin. This analysis is necessary to get out of the stalemate with the uplift discussion. The study shows that the original subdivision by Michelsen et al. (1995, 1998) stands. However, revision of few a sequence boundaries may have to be adjusted due to new biostratigraphic information published. Furthermore, high-angle clinoforms and geomorphological transport complexes observed in the Danish North Sea Basin can be traced into the Norwegian sector. This together with the recognition of several other high-angle clinoform complexes, and their associated seismic facies distribution maps and thickness-maps, enhances the level of detail and constrains the previous published paleogeographic reconstructions of the Cenozoic. The geometry of the Cenozoic infill, in the Norwegian part of the Norwegian-Danish Basin, is here interpreted to be controlled by relative sea

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

    International Nuclear Information System (INIS)

    The basin is located in the Precambrian insular shelf limited to the North. East and South. The North (Brazil) and south (Uruguay) edge are constituted by the insular shelf ancient nucleus which dates from 2000 million years.

  1. Anthropogenic warming has decreased water supply in North Central Texas

    Science.gov (United States)

    Brikowski, T. H.

    2015-12-01

    North Central Texas, including Dallas-Ft. Worth, the 4th largest metropolitan area in the U.S., has been in a state of drought for most of this 21st Century. Seven million residents there depend almost exclusively on surface water resources, and net water storage declined precipitously until record rainfall in early 2015. Part of the decline in water availability can be attributed to reduced runoff, where despite slightly above normal precipitation, natural basin runoff has declined almost 20% since its peak in the mid-1990's. These changes have coincided with 0.85oC warming above the historical 20th Century mean. Prevalent Vertisol (cracking) soils in the region make runoff especially sensitive to climate variations, and make it difficult to apply traditional hydrologic models to investigate climate-runoff links. Non-parametric (empirical) runoff elasticity methods circumvent these limitations, and are applied here, focusing on the Upper Trinity River basin (UTB). Diagrammatic assessment of UTB temperature-precipitation (T-Pr) runoff elasticity indicates persistent warming greatly increases the risk of reduced runoff, based on historical experience. Evaluation of individual parameter elasticity indicates dry periods since 2000 have primarily been T-driven, in contrast to the Pr-driven 1951-6 drought of record. Observed decline in runoff during 2000-2010 is entirely attributable to increased T. Additional runoff declines from 2011-14 were driven by reduced Pr, augmenting the T-driven reductions. These T effects are most prominent to the west, and decline to minimal extent just east of the UTB. The observed warming can be related to anthropogenic CO2 increase with >95% certainty based on comparison of CMIP5 climate model results for the UTB with and without CO2 forcing. UTB runoff fraction of Pr decreased after 1980 with >97.5% certainty. These results strongly indicate that 21st Century 20% decline in runoff from previous century norms is largely attributable to

  2. Evolutionary model of the oblique rift basins- Central African Rifts

    Science.gov (United States)

    Yang, Kenn-Ming; Cheng, I.-Wen; Wu, Jong-Chang

    2016-04-01

    The geometry of oblique-rifting basin is strongly related with the angle (α) between the trend of rift and that of regional major extensional stress. The main purpose of this study is to investigate characteristics of geometry and kinematics of structure and tectono-stratigraphy during basin evolution of Central African Rifts (CAS). In this study, we simulated the formation of oblique-rifting basin with Particle Flow Code 3-Dimensions-(PFC 3D) and compared the simulation results with the tectonic settings of a series of basin in CAS. CAS started to develop in Early Cretaceous (130Ma) and lasted until the Late Cretaceous (85Ma-80Ma). The following collision between the African and Eurasian plates imposed compressional stress on CAS and folded the strata in the rift basins. Although the characteristics of rift basin formation remain controversial, palinspastic sections constructed in this study show that, in the Early Cretaceous, the rift basins are mainly characterized by normal faults and half-grabens. In the Late Cretaceous, the morphology of the rift basins was altered by large-scaled tectonic compression with the active Borogop Fault of regional scale. Also, en echelon trend of normal faults in the basins were measured and the angles between the trend with that of the rift axes of each basin were demonstrated, indicating that the development of CAS was affected by the regional extensional stress with a dextral component during the rifting process and, therefore, the rift basins were formed by oblique-rifting. In this study, we simulated the oblique-rifting basin model of various α with Particle Flow Code 3-Dimensions-(PFC 3D). The main theory of PFC 3D is based on the Discrete Element Method (DEM), in which parameters are applied to every particle in the models. We applied forces acting on both sides of rift axis, which α are 45°, 60°, 75° and 90° respectively, to simulate basin formation under oblique-rifting process. The study results of simulation

  3. North Central regional environmental characterization report: executive summary - final

    International Nuclear Information System (INIS)

    This Executive Summary of the final North Central Regional Environmental Characterization Report (RECR) is issued primarily for public information purposes and provides a general overview of the report. The complete RECR presents available regional environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the States within the North Central Region, information is provided on the environmental disqualifying factors and the environmental regional screening variables to be used in region-to-area screening

  4. Central Coast Region South District Basin Planning & Habitat Mapping Project

    OpenAIRE

    Watson, Jessica; Casagrande, Julie; Watson, Fred

    2008-01-01

    This is a report to the California Department of Fish and Game. Between 2003 and 2008, the Foundation of CSUMB produced fish habitat maps and GIS layers for CDFG based on CDFG field data. This report describes the data entry, mapping, and website construction procedures associated with the project. Included are the maps that have been constructed. This report marks the completion of the Central Coast region South District Basin Planning and Habitat Mapping Project. (Document contains 40 pages)

  5. Geochemistry of polymetallic nodules from the Central Indian Ocean basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Khadge, N.H.; Desa, J.A.E.

    ; \\[\\] > l0 cm. Pacific Ocean; A nodules; x sediments. Average shale values from Piper (1974). POLYMETALLIC NODULES FROM THE CENTRAL INDIAN OCEAN BASIN TABLE 3A Inter-element relationship in the CIOB nodules Moisture Mn Fe Cu Ni Co Cu + Ni + Co Moisture...-242. Lyle, M., 1982. Estimating growth rates of ferromanganese nodules from chemical composition: implications for nodule formation processes. Geochim. Cosmochem. Acta., 46: 2301- 2306. Piper, D.Z., 1974. Rare earth elements and the sedimentary cycle: A...

  6. An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

    Science.gov (United States)

    Wilson, Robert M.

    2009-01-01

    An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

  7. CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN

    Institute of Scientific and Technical Information of China (English)

    YIN Fuguang

    2004-01-01

    The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extensional stress field. The extensional structure and detachment fault are formed under the influence of the losing stabilized gravitation. In the deformation area in both the upper part and the lower part, an extensional deposition area would be formed, and this is the generation of a new basin.The metamorphic core complex of the central uplift is comprised of gneiss, which is itself overlain by non-metamorphic to weakly metamorphic covering strata intersected by faults.

  8. Palaeoenvironmental changes across the Danian–Selandian boundary in the North Sea Basin

    DEFF Research Database (Denmark)

    Clemmensen, Anne; Thomsen, Erik

    2005-01-01

    southern and eastern part of the North Sea Basin resulted in a huge influx of reworked Cretaceous chalk and an almost complete stop of carbonate production. Finally, later in the early Selandian, in connection to a general sea-level rise and a reduction in the gateway between the North Sea Basin and the...

  9. Suggestion of a dynamic model of North China basin-range system

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It is found from preliminary studies that previous basin-range models have difficulties in explaining the formation of the Mesozoic North-China basin-range system. This work suggests a new model-"tectonic thermal erosion" model, which considers the North China basin of Late Mesozoic and its peripheral ranges as a unified system, identifies relationship between upwelling and lateral spreading of the asthenolith with horizontal movement and deformation of the upper crust in the system, clarifies the effects of underplating erosion on the crustal evolution, and tries to establish an earth-dynamic model of the North China Mesozoic basin-range supported by numerical simulation.

  10. Hydrogeological mapping of north-central Madagascar using limited data

    OpenAIRE

    Davies, Jeffrey

    2009-01-01

    North-central Madagascar is well endowed with surface-water. Due to soil erosion and pollution, rivers can no longer provide year round clean water supplies. Shallow aquifers are being developed to provide sustainable rural and urban water supplies. A survey of water sources located 2760 boreholes, wells, ponds and springs in the area, but understanding of groundwater occurrence remains poor. The area comprises four hydrogeological zones: the dry Central High Plateau with erosi...

  11. CHARACTERISTICS OF FARMLAND LEASING IN THE NORTH CENTRAL UNITED STATES

    OpenAIRE

    Patterson, Brian; Hanson, Steven D.; Robison, Lindon J.

    1998-01-01

    Leasing behavior differs across the North Central United States. Survey data is used to characterize leasing activity in the region. Data is collected on the amount of leased farmland, amount of cash and share leased land, and common output share levels. Factors influencing leasing and arrangements are also identified.

  12. World and experiences of AIDS orphans in north central Namibia

    NARCIS (Netherlands)

    Brug, van der M.

    2007-01-01

    How do young AIDS orphans deal with the loss of their parents and their changed circumstances? This thesis discusses the social environment, experiences and perceptions of fourteen orphans in north central Namibia. The author followed the children for five months from September 2003 until March 2004

  13. New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

    Science.gov (United States)

    Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

    2014-05-01

    In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional

  14. Typical basin-fill sequences and basin migration in Yanshan, North China--Response to Mesozoic tectonic transition

    Institute of Scientific and Technical Information of China (English)

    LI; Zhong; LIU; Shaofeng; ZHANG; Jinfang; WANG; Qingchen

    2004-01-01

    Basin-fill sequences of Mesozoic typical basins in the Yanshan area, North China may be divided into four phases, reflecting lithosphere tectonic evolution from flexure (T3), flexure with weak rifting (J1+2), tectonic transition (J3), and rifting (K). Except the first phase, the other three phases all start with lava and volcaniclastic rocks, and end with thick coarse clastic rocks and/or conglomerates, showing cyclic basin development rather than simple cyclic rift mechanism and disciplinary basin-stress change from extension to compression in each phase. Prototype basin analysis, based on basin-fill sequences, paleocurrent distribution and depositional systems, shows that single basin-strike and structural-line direction controlling basin development had evidently changed from east-west to northeast in Late Jurassic in the Yanshan area, although basin group still occurred in east-west zonal distribution. Till Early Cretaceous, main structural-line strike controlling basins just turned to northeast by north in the studied area.

  15. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    Science.gov (United States)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  16. Storing CO2 under the North Sea Basin - A key solution for combating climate change

    International Nuclear Information System (INIS)

    This report represents the first deliverable of the North Sea Basin Task Force, which Norway and the UK established in November 2005 to work together on issues surrounding the transport and storage of CO2 beneath the North Sea. The North Sea represents the best geological opportunity for storing our CO2 emissions away from the atmosphere for both the UK and Norway

  17. Stratigraphy, sedimentology and paleontology of lower Eocene San Jose formation, central San Juan basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, S.G.; Smith, L.N. (New Mexico Museum of Natural History, Albuquerque (USA))

    1989-09-01

    The lower Eocene San Jose Formation in the central portion of the San Juan basin (Gobernador-Vigas Canyon area) consists of the Cuba Mesa, Regina, Llaves, and Tapicitos Members. Well log data indicate that, from its 100-m thickness, the Cuba Mesa Member thins toward the basin center and pinches out to the northeast by lat. 36{degree}40'N, long. 107{degree}19'W. The Regina Member has the most extensive outcrops in the central basin, and it decreases in sandstone/mud rock ratio to the north. The Llaves and Tapicitos Members occur only at the highest elevations, are thin due to erosion, and are not mappable as separate units. Well log data and 1,275 m of measured stratigraphic section in the Regina, Llaves, and Tapicitos Members indicate these strata are composed of approximately 35% medium to coarse-grained sandstone and 65% fine-grained sandstone and mud rock. Sedimentology and sediment-dispersal patterns indicate deposition by generally south-flowing streams that had sources to the northwest, northeast, and east. Low-sinuosity, sand-bedded, braided( ) streams shifted laterally across about 1 km-wide channel belts to produce sheet sandstones that are prominent throughout the San Jose Formation. Subtle levees separated channel environments from floodplain and local lacustrine areas. Avulsion relocated channels periodically to areas on the floodplain, resulting in the typically disconnected sheet sandstones within muddy overbank deposits of the Regina Member.

  18. Well installation, single-well testing, and particle-size analysis for selected sites in and near the Lost Creek Designated Ground Water Basin, north-central Colorado, 2003-2004

    Science.gov (United States)

    Beck, Jennifer A.; Paschke, Suzanne S.; Arnold, L. Rick

    2011-01-01

    This report describes results from a groundwater data-collection program completed in 2003-2004 by the U.S. Geological Survey in support of the South Platte Decision Support System and in cooperation with the Colorado Water Conservation Board. Two monitoring wells were installed adjacent to existing water-table monitoring wells. These wells were installed as well pairs with existing wells to characterize the hydraulic properties of the alluvial aquifer and shallow Denver Formation sandstone aquifer in and near the Lost Creek Designated Ground Water Basin. Single-well tests were performed in the 2 newly installed wells and 12 selected existing monitoring wells. Sediment particle size was analyzed for samples collected from the screened interval depths of each of the 14 wells. Hydraulic-conductivity and transmissivity values were calculated after the completion of single-well tests on each of the selected wells. Recovering water-level data from the single-well tests were analyzed using the Bouwer and Rice method because test data most closely resembled those obtained from traditional slug tests. Results from the single-well test analyses for the alluvial aquifer indicate a median hydraulic-conductivity value of 3.8 x 10-5 feet per second and geometric mean hydraulic-conductivity value of 3.4 x 10-5 feet per second. Median and geometric mean transmissivity values in the alluvial aquifer were 8.6 x 10-4 feet squared per second and 4.9 x 10-4 feet squared per second, respectively. Single-well test results for the shallow Denver Formation sandstone aquifer indicate a median hydraulic-conductivity value of 5.4 x 10-6 feet per second and geometric mean value of 4.9 x 10-6 feet per second. Median and geometric mean transmissivity values for the shallow Denver Formation sandstone aquifer were 4.0 x 10-5 feet squared per second and 5.9 x 10-5 feet squared per second, respectively. Hydraulic-conductivity values for the alluvial aquifer in and near the Lost Creek Designated

  19. Petroleum generation and migration in the Ghadames Basin, north Africa: A two-dimensional basin-modeling study

    OpenAIRE

    Underdown, R; Redfern, J

    2008-01-01

    The Ghadames Basin contains important oil- and gas-producing reservoirs distributed across Algeria, Tunisia, and Libya. Regional two-dimensional (2-D) modeling, using data from more than 30 wells, has been undertaken to assess the timing and distribution of hydrocarbon generation in the basin. Four potential petroleum systems have been identified: (1) a Middle-Upper Devonian (Frasnian) and Triassic (Triassic Argilo Greseux lnferieur [TAG-I]) system in the central-western basin; (2) a Lower Si...

  20. Flash heat simulation events in the north Mediterranean basin

    Science.gov (United States)

    Mazon, Jordi; Pino, David

    2013-04-01

    According to the definition of flash heat event proposed by Mazon et al. in the European Meteorology Meeting (2011 and 2012) from the studied case produced in the Northeast of the Iberian peninsula on 27th August 20120, some other flash heat events have been detected by automatic weather stations around the in the Mediterranean basin (South Italy, Crete island, South Greece and the northeast of the Iberian peninsula). Flash heat event covers those events in which a large increase of temperature last a spatial and temporal scale between heat wave (defined by the WMO as a phenomenon in which the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5°C, with respect to the 1961-1990 period) and heat burst (defined by the AMS as a rare atmospheric event characterized by gusty winds and a rapid increase in temperature and decrease in humidity that can last some minutes). Thus flash heat event may be considered as a rapid modification of the temperature that last several hours, lower than 48 hours, but usually less than 24 hours. Two different flash heat events have been simulated with the WRF mesoscale model in the Mediterranean basin. The results show that two different mechanisms are the main causes of these flash heat events. The first one occurred on 23rd March 2008 in Crete Island due to a strong Foehn effect caused by a strong south and southeast wind, in which the maximum temperature increased during some hours on the night at 32°C. The second one occurred on 1st August 2012 in the northeast of the Iberian Peninsula, caused by a rapid displacement of warm a ridge from North Africa that lasted around 24 hours.

  1. High-resolution seismic analysis of the coastal Mecklenburg Bay (North German Basin): the pre-Alpine evolution

    Science.gov (United States)

    Zöllner, H.; Reicherter, K.; Schikowsky, P.

    2008-09-01

    The pre-Alpine structural and geological evolution in the northern part of the North German Basin have been revealed on the basis of a very dense reflection seismic profile grid. The study area is situated in the coastal Mecklenburg Bay (Germany), part of the southwestern Baltic Sea. From the central part of the North German Basin to the northern basin margin in the Grimmen High area a series of high-resolution maps show the evolution from the base Zechstein to the Lower Jurassic. We present a map of basement faults affecting the pre-Zechstein. The pre-Alpine structural evolution of the region has been determined from digital mapping of post-Permian key horizons traced on the processed seismic time sections. The geological evolution of the North German Basin can be separated into four distinct periods in the Rerik study area. During Late Permian and Early Triassic evaporites and clastics were deposited. Salt movement was initiated after the deposition of the Middle Triassic Muschelkalk. Salt pillows, which were previously unmapped in the study area, are responsible for the creation of smaller subsidence centers and angular unconformities in the Late Triassic Keuper, especially in the vicinity of the fault-bounded Grimmen High. In this area, partly Lower Jurassic sediments overlie the Keuper unconformably. The change from extension to compression in the regional stress field remobilized the salt, leading to a major unconformity marked at the base of the Late Cretaceous.

  2. Depositional sequences in a foreland basin (north-western domain of the continental Duero basin, Spain)

    Science.gov (United States)

    Herrero, Antonio; Alonso-Gavilán, Gaspar; Colmenero, Juan Ramón

    2010-01-01

    The Cenozoic record of the north-western domain of the Duero basin is articulated at the surface through a set of continental depositional sequences called, from base to top, the Vegaquemada sequence, the Candanedo sequence, and the Barrillos sequence. These depositional sequences were deposited in continental sedimentary environments. The deposition of the first sequence occurred through a fluvial system with floodplains cut by low-sinuosity channels. The Vegaquemada sequence was developed between the Middle Eocene and the Early Agenian. The second sequence was formed by a set of highly efficient transport alluvial fans that evolved laterally towards fluvial systems with low-sinuosity fluvial channels and an extensive floodplain, where several types of palaeosols were formed. This sequence developed between the Early Agenian and the Late Vallesian. The third unit-the Barrillos sequence (between the Late Vallesian and the Turolian/Ruscinian transition), was generated by a set of highly efficient transport alluvial fans dominated by low-sinuosity fluvial channels. In subsurface geology, seismic and well data are used to rebuild the stratigraphic architecture. The two basal depositional sequences can be identified with two seismic units: the Palaeogene Seismic Unit (PgSU) and the Neogene Seismic Unit (NgSU), respectively. In the present work, we obtained the isovelocity, isochron, and isobath maps for the top and base of the two Cenozoic units. The Palaeozoic (PzSU) and Mesozoic (MzSU) seismic units are found under these two units. Through study of the logs of the various boreholes, it was only possible to analyse the upper 700 m of the Candanedo Sequence (NgSU), without encompassing the total thickness of the unit. Several middle-order sequences were differentiated, in general showing a sequential fining-upwards evolutionary character. Additionally, for the boreholes analysed two main types of electrofacies were identified, both representing fluvial channels and

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

    Science.gov (United States)

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

    2015-04-01

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

  4. Slope instability in the Bastardo Basin (Umbria, Central Italy) ? The landslide of Barattano

    OpenAIRE

    Cencetti, C.; Conversini, P.

    2003-01-01

    The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben) with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological). The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to landslides of the Apenninic intermontane basins. In par...

  5. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-05-26

    The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and shallow shelf sandstone facies; and carbonate shoal, shelf and reef facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary. Hydrocarbon

  6. Double-saloon-door tectonics in the North Fiji Basin

    Science.gov (United States)

    Martin, A. K.

    2013-07-01

    Fiji Platform rotated counter clockwise from at least 10.2 Ma until 1.56 Ma, while Vanuatu Arc rotated clockwise from 12/10 Ma until the present. A revised model incorporating these opposite rotations explains the distribution of magnetic anomalies in the North Fiji Basin (NFB). The conjugate margin of southwest Fiji Platform is southeast Vanuatu Arc. Previous models which associate NW-oriented anomalies off southwest Fiji with similarly oriented anomalies northeast of Vanuatu Arc are therefore wrong. Secondly, these models propose a NW-oriented spreading ridge extending to 19°S, 177.5°E, almost 500 km southeast of the mapped extension of rifted island-arc crust on Vanuatu Arc. This creates an unacceptable overlap with Fiji Platform in pre-rift reconstructions. Thirdly, anomalies off SW Fiji which are NW-oriented in their present-day position were oriented NNE during initial breakup. Rather than aligning with NW-oriented anomalies in the western NFB, they are matched by NNE-oriented anomalies off SE Vanuatu Arc. With further rotation, these conjugate anomaly sets form a fan shape in the southern NFB. Fourthly, previous models which recognise a triple junction only from 3 Ma do not explain early WNW-ESE separation of Vanuatu Arc and Fiji Platform required by well-documented opposite rotations. NFB characteristics which match the double-saloon-door tectonic model include opposite rotations of island arc terranes, backarc seafloor spreading which is both arc-parallel and arc-perpendicular, and rifts propagating north, south, northeast and northwest. Features which do not match the double-saloon-door model include the North Fiji Fracture Zone and the West Fiji spreading centre. Both initiated post-1.5 Ma, when Fiji Platform stopped rotating, and only one terrane, Vanuatu Arc, continued to rotate. The NFB developed via double saloon door tectonics from 12/10 Ma until 1.5 Ma, whereas post-1.5 Ma opening constitutes single saloon door rotation.

  7. Estimating the Length of the North Atlantic Basin Hurricane Season

    Science.gov (United States)

    Wilson, Robert M.

    2012-01-01

    For the interval 1945-2011, the length of the hurricane season in the North Atlantic basin averages about 130 +/- 42 days (the +/-1 standard deviation interval), having a range of 47 to 235 days. Runs-testing reveals that the annual length of season varies nonrandomly at the 5% level of significance. In particular, its trend, as described using 10-yr moving averages, generally has been upward since about 1979, increasing from about 113 to 157 days (in 2003). Based on annual values, one finds a highly statistically important inverse correlation at the 0.1% level of significance between the length of season and the occurrence of the first storm day of the season. For the 2012 hurricane season, based on the reported first storm day of May 19, 2012 (i.e., DOY = 140), the inferred preferential regression predicts that the length of the current season likely will be about 173 +/- 23 days, suggesting that it will end about November 8 +/- 23 days, with only about a 5% chance that it will end either before about September 23, 2012 or after about December 24, 2012.

  8. Timber Harvest Change in the Little North Santiam River Basin, Oregon, 1995 to 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Using available aerial photos from approximately a 15-year period, changes in timber harvest were mapped in the Little North Santiam River Basin, Oregon. Timber...

  9. Head Scarp Boundary for the Landslides in the Little North Santiam River Basin, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Polygons represent head scarps and flank scarps associated with landslide deposits in the Little North Santiam River Basin, Oregon. This work was completed as part...

  10. Landslide Deposit Boundaries for the Little North Santiam River Basin, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This layer is an inventory of existing landslides deposits in the Little North Santiam River Basin, Oregon (2009). Each landslide deposit shown on this map has been...

  11. Location of Photographs Showing Landslide Features in the Little North Santiam River Basin, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data points represent locations of photographs taken of landslides in the Little North Santiam River Basin, Oregon. Photos were taken in spring of 2010 during field...

  12. Paleoseismological investigations and Geomorphology on the Gaenserndorf Terrace in the central Vienna Basin (Austria)

    Science.gov (United States)

    Weissl, Michael; Hintersberger, Esther; Lomax, Johanna; Decker, Kurt

    2016-04-01

    In the central Vienna Basin normal faults define the eastern and western margins of Pleistocene Danube terraces north of Vienna. The terrace body is built up of coarse sandy gravel and sand. Locally the terrace surface is covered with eolian and alluvial sediments of the last glacial revealing OSL/IRSL ages of about 15-16 ka. High resolution digital terrain models (LIDAR) show relicts of a periglacial landscape in the northern part of the Middle Pleistocene (MIS 8) terrace. Large elongated depressions in the northern parts of the terrace are interpreted as the basins of former thermokarst lakes due to analogies in recent periglacial zones. Draining valleys corrugate the fault scarps indicating advanced subsidence of the Aderklaa and Obersiebenbrunn Quaternary basins before the last Glacial. Obviously the periglacial morphology is only preserved in the elevated parts of the terrace which is located in the footwall of the bounding normal faults. In the hanging wall Quaternary basins are filled with up to 40 m thick Pleistocene and Holocene growth strata. During the last decade three faults were investigated by trenching. In contrast to the earlier trench sites on the Markgrafneusiedl Fault and the Vienna Basin Transform Fault it was not possible to provide clear evidence for offset on the Aderklaa-Bockfliess fault because cryoturbation deformed the covering fluvial sediments together with the underlying Gaenserndorf terrace gravels. However it was possible to localize this fault precisely applying an electrical resistivity tomography. The resulting ERT-section shows an offset of the 200-300 ky old terrace and the underlying Miocene sediments of about 9-10 meters suggesting a vertical slip rate of 0.03 - 0.05 mm/a.

  13. Nouvelles données biostratigraphiques et sédimentologiques des formations carbonifères de la région de Bouqachmir (Maroc central). Implications sur la paléogéographie des bassins carbonifères nord-mésétiensNew biostratigraphic and sedimentological data of the Carboniferous formations in the Bouqachmir area (central Morocco). Implications on the palaeogeography of the north Mesetian Carboniferous basins

    Science.gov (United States)

    Izart, Alain; Tahiri, Abdelfatah; El Boursoumi, Abdou; Vachard, Daniel; Saidi, Mariam; Chèvremont, Philippe; Berkhli, Mostafa

    2001-02-01

    New Visean formations and biozones of foraminifera were defined on the Bouqachmir map. The new biozonation concerns the Moroccan biozone, Cfm1, which is subdivided into two subzones, Cfm1a and Cfm1b. This map exhibited, from north-west to south-east, the Tilouine, Bouqachmir-Tougouroulmès and Fourhal turbiditic basins. The first one, from Tournaisian to Late Visean, was the equivalent of the Sidi Bettache basin, located westwards. The second extended the Tilouine basin eastwards during the Visean. The third was a basin from Visean to Westphalian. They were separated by the Zaer-Oulmes and El Hammam horsts, else emerged or immersed, bordered by faults and with materials feeding chaotic deposits.

  14. Slope instability in the Bastardo Basin (Umbria, Central Italy) – The landslide of Barattano

    OpenAIRE

    Cencetti, C.; Conversini, P.

    2002-01-01

    The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben) with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological). The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to ...

  15. Estimation of hydrothermal deposits location from magnetization distribution and magnetic properties in the North Fiji Basin

    Science.gov (United States)

    Choi, S.; Kim, C.; Park, C.; Kim, H.

    2013-12-01

    The North Fiji Basin is belong to one of the youngest basins of back-arc basins in the southwest Pacific (from 12 Ma ago). We performed the marine magnetic and the bathymetry survey in the North Fiji Basin for finding the submarine hydrothermal deposits in April 2012. We acquired magnetic and bathymetry datasets by using Multi-Beam Echo Sounder EM120 (Kongsberg Co.) and Overhouser Proton Magnetometer SeaSPY (Marine Magnetics Co.). We conducted the data processing to obtain detailed seabed topography, magnetic anomaly, reduce to the pole(RTP), analytic signal and magnetization. The study areas composed of the two areas(KF-1(longitude : 173.5 ~ 173.7 and latitude : -16.2 ~ -16.5) and KF-3(longitude : 173.4 ~ 173.6 and latitude : -18.7 ~ -19.1)) in Central Spreading Ridge(CSR) and one area(KF-2(longitude : 173.7 ~ 174 and latitude : -16.8 ~ -17.2)) in Triple Junction(TJ). The seabed topography of KF-1 existed thin horst in two grabens that trends NW-SE direction. The magnetic properties of KF-1 showed high magnetic anomalies in center part and magnetic lineament structure of trending E-W direction. In the magnetization distribution of KF-1, the low magnetization zone matches well with a strong analytic signal in the northeastern part. KF-2 area has TJ. The seabed topography formed like Y-shape and showed a high feature in the center of TJ. The magnetic properties of KF-2 displayed high magnetic anomalies in N-S spreading ridge center and northwestern part. In the magnetization distribution of KF-2, the low magnetization zone matches well with a strong analytic signal in the northeastern part. The seabed topography of KF-3 presented a flat and high topography like dome structure at center axis and some seamounts scattered around the axis. The magnetic properties of KF-3 showed high magnetic anomalies in N-S spreading ridge center part. In the magnetization of KF-2, the low magnetization zone mismatches to strong analytic signal in this area. The difference of KF-3

  16. Impact of climate variability on runoff in the north-central United States

    Science.gov (United States)

    Ryberg, Karen R.; Lin, Wei; Vecchia, Aldo V.

    2014-01-01

    Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) to changes in runoff within 25 stream basins. The basins studied were organized into four groups, each one representing basins similar in topography, climate, and historic patterns of runoff. Precipitation, PET, and runoff data were adjusted for near-decadal scale variability to examine longer-term changes. A nonlinear water-balance analysis shows that changes in precipitation and PET explain the majority of multidecadal spatial/temporal variability of runoff and flood magnitudes, with precipitation being the dominant driver. Historical changes in climate and runoff in the region appear to be more consistent with complex transient shifts in seasonal climatic conditions than with gradual climate change. A portion of the unexplained variability likely stems from land-use change.

  17. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman

    2005-05-10

    The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary

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

    International Nuclear Information System (INIS)

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

  19. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2005-03-31

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  20. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2004-11-05

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  1. Lg Coda Variations in North-Central Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Naghavi

    2012-01-01

    Full Text Available Ground motion records in north-central Iran have been used in order to obtain the Lg coda , using stack spectral ratio method. The lateral variations in 0 and its frequency dependence are estimated in the 0.3–7.0 Hz frequency range which led to =267(±32×0.71(±0.14. The observed variations in quality factor show low values of 0 in western part of the study region where bounded by relatively high values in southern and northern parts. Since the seismicity of the study area is quite shallow the obtained results can be attributed to the upper 30 km of the crust. The Damavand volcano and its surrounding region also exhibit variations in the value of 0 which result in low and intermediate values of 0 in western and eastern parts, respectively. Current seismicity in Damavand is mostly confined to its southwestern part, whereas our results proved to possess low values of 0. In general, most of factor variations can be attributed to the lateral heterogeneity as well as the severity of the crustal velocity gradient, and as expected the north-central Iran is well inferred as a tectonically active region.

  2. The evolution of the Thuringian Syncline (Central Germany) - an interdisciplinary approach to basin reconstruction

    Science.gov (United States)

    Malz, Alexander; Beyer, Daniel; Donndorf, Stephan; Navabpour, Payman; Voigt, Thomas; Aehnelt, Michaela; Kley, Jonas

    2014-05-01

    The Thuringian Syncline is a shallow synform of mainly Triassic strata in Central Germany. In general, its lithostratigraphic units are similar to that of the North German Basin. On the top of the Paleozoic basement and Permocarboniferous red beds the evaporites of the late Permian Zechstein were deposited. The Triassic super group consists of fluvial to lacustrine sandstones, shale and evaporites of the Buntsandstein group, limestone, marls and evaporites of the marine Muschelkalk group and pelitic to sandy fluvial deposits and evaporite of the Keuper group. Some relicts of Lower Jurassic deposits still cover this succession. A number of NW-SE-trending fault zones with mostly small normal offsets characterize the recent structural configuration of the Thuringian Syncline. From regional correlations, and Lower Jurassic strata affected by normal faults, the extension most likely occurred in Late Jurassic to Early Cretaceous time. Some of these normal faults were reactivated as reverse faults during a phase of contraction in the Late Cretaceous. The unknown original offsets of the normal faults and the absence of syntectonic strata deposited during extension and contraction, however, make reconstruction of the graben inversion difficult to detect. In this study we try to reconstruct the structural evolution of the Thuringian Syncline based on structural observations, detailed map analysis, interpolations of stratigraphic surfaces at depth, cross section balancing and fault slip data analysis. Vitrinite reflectance data are used to estimate the maximum thickness of the eroded overburden. Our study identified a deep, extended and later inverted palaeo-depression in the central part of the Thuringian Syncline. We show that the recent structural configuration cannot explain variations of the thermal maturity without deriving specific thickness variations in the eroded overburden. Taking in consideration that many Central European faults, formerly interpreted as purely

  3. Different sedimentological and thermal evolution of three north-pyrenean basins during their set-up

    Science.gov (United States)

    Chelalou, Roman; Nalpas, Thierry; Bousquet, Romain; Lahfid, Abdeltif

    2015-04-01

    The Pyrenean belt is resulting in the inversion of several lower Cretaceous basins, separating the Iberia micro-plate from the Eurasia plate. The eat-west oriented basins are well known for their high-temperature metamorphism synchronous of the last deposits during Aptian-Albian times. For the first time, we present a combined sedimentological and thermal study of three north pyrenean basins (Boucheville, St Paul-de-Fenouillet and Bas-Agly). With the help of detailed stratigraphic logs of each basin, we propose restored cross-sections for the whole area. North-south sections across Boucheville and St Paul-de-Fenouillet basins show that theses basins have large asymmetrical structure. The Boucheville basin is a large anticline bordered by two isoclinal syncline highly skewed, while the St Paul-de-Fenouillet one is a unique syncline. Detailed sedimentalogical observations show common features for these basins: deposits of white limestones and breccias during the Jurassic time following by black sandstones with a calcareous matrix of lower Cretaceous age. On one hand, Jurassic limestones were deposited on a shelf environment and their thickness is homogeneous all over each basin. On the other hand, sandstones deposits seem to occur at greater depths during the Albian time and are displaying asymmetrical north-south variation of their thickness. The quantification of the temperature overprint occurred in the basin was done using the graphitisation of the carbonaceous material, and was measured by RAMAN spectroscopy (Lahfid et al. 2010). Despite their similar deposits, the mapping of the temperature-peak inside the three basins show contrasted thermal evolution. Then we document a lower temperature overprint around 150-200˚C in the northern basin {St Paul-de-Fenouillet) while the highest overprint up to 600˚C has been reached in the southern basin (Boucheville) in which diopside - scapolite and also probably olivine are occurring. These three north-pyrenean basin turn

  4. Digital assessment of northern and central Appalachian basin coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.F.; Tewalt, S.J.; Braff, L.J.; Wallack, R.N. [US Geological Survey National Center, Reston, VA (US)

    1999-10-01

    The US Geological Survey (USGS) is currently conducting a coal resource assessment of the coalbeds and zones that are projected to provide the bulk of the nation's resources for the next few decades. The Pittsburgh and Upper Freeport coals are the first two beds in the northern and central Appalachian basin region to undergo fully digital coal assessments. The bed-specific assessments are being carried out in partnership with the state geologic surveys of West Virginia, Ohio, Pennsylvania and Maryland. Comprehensive stratigraphic and geochemical data-bases have been developed for both of the beds. The extent of the bed with mined areas, structure contour, isopach, and overburden thickness maps for the Pittsburgh coal bed have been realised as USGS open-file reports. The articles includes several detailed maps showing the export of the Pittsburgh coalbed, ash yield, sulphur contents and calorific value of the coal by county, structure contours, overburden thickness and isopac lines. 10 figs., 2 tabs.

  5. Proceedings of the North Aleutian Basin information status and research planning meeting.

    Energy Technology Data Exchange (ETDEWEB)

    LaGory, K. E.; Krummel, J. R.; Hayse, J. W.; Hlohowskyj, I.; Stull, E. A.; Gorenflo, L.; Environmental Science Division

    2007-10-26

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant ecological and natural resources. The Basin includes most of the southeastern part of the Bering Sea continental shelf including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals including federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012 and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory (Argonne) were contracted to assist the MMS Alaska Outer Continental Shelf (OCS) Region in identifying and prioritizing information needs related to the North Aleutian Basin and potential future oil and gas leasing and development activities. The overall approach focused on three related but separate tasks: (1) identification and

  6. Magnetic anomalies across Bastar craton and Pranhita–Godavari basin in south of central India

    Indian Academy of Sciences (India)

    I V Radhakrishna Murthy; S Bangaru Babu

    2009-02-01

    Aeromagnetic anomalies over Bastar craton and Pranhita –Godavari (P –G)basin in the south of central India could be attributed to NW –SE striking mafic intrusives in both the areas at variable depths.Such intrusions can be explained considering the collision of the Bastar and Dharwar cratons by the end of the Archaean and the development of tensile regimes that followed in the Paleoproterozoic,facilitating intrusions of mafic dykes into the continental crust.The P –G basin area,being a zone of crustal weakness along the contact of the Bastar and Dharwar cratons, also experienced extensional tectonics.The inferred remanent magnetization of these dykes dips upwards and it is such that the dykes are oriented towards the east of the magnetic north at the time of their formation compared to their present NW –SE strike.Assuming that there was no imprint of magnetization of a later date,it is concluded that the Indian plate was located in the southern hemisphere,either independently or as part of a supercontinent,for some span of time during Paleoproterozoic and was involved in complex path of movement and rotation subsequently. The paper presents a case study of the utility of aeromagnetic anomalies in qualitatively deducing the palaeopositions of the landmasses from the interpreted remanent magnetism of buried intrusive bodies.

  7. Radiocarbon age distribution of groundwater in the Konya Closed Basin, central Anatolia, Turkey

    Science.gov (United States)

    Bayari, C. Serdar; Ozyurt, N. Nur; Kilani, Susan

    2009-03-01

    Annual abstraction of 2.6 × 109 m3 of groundwater in the 53,000 km2 Konya Closed Basin of central Turkey has caused a head decline of 1 m/year over the last few decades. Therefore, understanding the hydrogeology of this large endorheic basin, in a semi-arid climate, is important to sustainable resource management. For this purpose, the groundwater’s radiocarbon age distribution has been investigated along a 150-km transect parallel to regional flow. Results show that the groundwater ranges in age from Recent at the main recharge area of the Taurus Mountains in the south, to about 40,000 years around the terminal Salt Lake located in the north. In this predominantly confined flow system, radiocarbon ages increase linearly by distance from the main recharge area and are in agreement with the hydraulic ages. The mean velocity of regional groundwater flow (3 m/year) is determined by the rate of regional groundwater discharge into the Salt Lake. Calcite dissolution, dedolomitization and geogenic carbon dioxide influx appear to be the dominant geochemical processes that determine the carbon isotope composition along the regional flow path. The groundwater’s oxygen-18 content indicates more humid and cooler paleorecharge. A maximum drop of 5°C is inferred for the past recharge temperature.

  8. Statistical Aspects of the North Atlantic Basin Tropical Cyclones: Trends, Natural Variability, and Global Warming

    Science.gov (United States)

    Wilson, Robert M.

    2007-01-01

    Statistical aspects of the North Atlantic basin tropical cyclones for the interval 1945- 2005 are examined, including the variation of the yearly frequency of occurrence for various subgroups of storms (all tropical cyclones, hurricanes, major hurricanes, U.S. landfalling hurricanes, and category 4/5 hurricanes); the yearly variation of the mean latitude and longitude (genesis location) of all tropical cyclones and hurricanes; and the yearly variation of the mean peak wind speeds, lowest pressures, and durations for all tropical cyclones, hurricanes, and major hurricanes. Also examined is the relationship between inferred trends found in the North Atlantic basin tropical cyclonic activity and natural variability and global warming, the latter described using surface air temperatures from the Armagh Observatory Armagh, Northern Ireland. Lastly, a simple statistical technique is employed to ascertain the expected level of North Atlantic basin tropical cyclonic activity for the upcoming 2007 season.

  9. Roadmap to the deployment of offshore wind energy in the Central and Southern North Sea (2020-2030)

    International Nuclear Information System (INIS)

    This Roadmap represents the final deliverable of the WINDSPEED project. It has a dual objective. Firstly, it aims to present an ambitious but realistic target for offshore wind with minimum negative impacts on other sea functions present in the Central and Southern North Sea basin in the time frame to 2030. Secondly, it aims to identify actions and milestones required to achieve this target. The North Sea countries - Belgium, Denmark, Germany, the Netherlands, Norway and the UK - are facing a number of challenges and opportunities in their quest for rapid expansion of offshore wind energy in the Central and Southern North Sea basin. The WINDSPEED project has carried out an assessment of (ambitious but realistic) deployment potentials under different scenarios to gain better insight into how key uncertainties can impact on OWE developments. An early understanding of how different development perspectives influence challenges and opportunities, as well as uncertainties, will allow for better adaptation of policies and approaches to promote large scale offshore wind energy (OWE). This is particularly important at a time when OWE is strongly driven by EU and national policy needs in attempting to reach overall policy goals of a competitive, secure and sustainable energy system. There is ample space in the Central and Southern North Sea. But many attractive areas for developing OWE within reasonable cost ranges are already occupied by other sea users. Moving OWE further from shore and into deeper waters not only drives costs up, but also raises the issue of the availability of deep sea technology components and the need for an offshore grid. To date, the North Sea countries will have developed a capacity of around 2 GW in the North Sea. It has taken a decade to get this far. Important lessons are being learnt and these must be taken into account in the development of OWE towards 2030. The WINDSPEED project concludes that a capacity of 135 GW of OWE in the Central and

  10. North Central Transmission Line: Guidelines for the environmental impact statement

    International Nuclear Information System (INIS)

    Guidelines that Manitoba Hydro must follow in the preparation of the environmental impact statement on the proposed North Central Transmission Line (TCTL) project are presented. The project consists of a 138 kV transmission line, two 25 kV distribution lines, and related ancillary structures and facilities. The review process must be sensitive to cultural and community needs and must involve those most directly affected, and should be grounded in the impacted northern communities. The review should include a project background, the proposal, a description of the existing natural and socio-economic environment, and must address employment, education and training, impacts on renewable resource harvesting, environmental impacts, social impacts and economic impacts, legal/jurisdictional issues, infrastructure, mitigation and compensation, and environmental monitoring and follow-up. 1 fig., 20 tabs

  11. Terrestrial pollution in the Pechora basin, north-eastern European Russia

    OpenAIRE

    Walker, Tony Robert

    2003-01-01

    The chemical composition of snow, terricolous lichens and top-soil along with abundance and diversity of lichen communities were assessed in the Pechora and Usa basins, North-Eastern European Russia. Transects were established through the principal industrial towns of Vorkuta, Inta and Usinsk to assess the spatial extent of acid or alkaline and metal deposition. A further eight sites were selected to assess local impacts of oil and gas operations. In the Usa basin decreases of nitrogen co...

  12. Chronostratigraphy and tectonic deformation of the North Ecuadorian-South Colombian offshore Manglares forearc basin

    OpenAIRE

    Marcaillou, B.; Collot, Jean-Yves

    2008-01-01

    Forearc basins in convergent margins contain a nearly continuous record of sedimentation and deformation. Their chronostratigraphy reflects the manner in which the basin accommodates loads and vertical and horizontal motion caused by eustasy, tectonics and sedimentation during plate convergence. Along the North Ecuador and South Colombia (NESC) Margin (1 degrees-3.5 degrees N), thick Cenozoic sedimentary sequences accumulated over blocks of oceanic basement that accreted between the Late Cret...

  13. On the origin of the Southern Permian Basin, Central Europe

    OpenAIRE

    J.-D. van Wees; Stephenson, R.A.; Ziegler, P. A.; Ulf Bayer; McCann, T; R. Dadlez; Gaupp, R; M. Narkiewicz; F. Bitzer; Scheck, M.;  

    2000-01-01

    A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the Rotliegend-Zechstein development of this basin. The Late Permian-Early Jurassic tectonic subsidence curves are typical for a Permian to Early Triassic extensional stage that is followed by thermal subsidence. Howe...

  14. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns

    Science.gov (United States)

    Wilson, Robert M.

    2009-01-01

    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  15. Cenozoic tectonics of the Tuz Gölü Basin (Central Anatolian Plateau, Turkey)

    OpenAIRE

    FERNÁNDEZ-BLANCO, David; BERTOTTI, Giovanni; ÇİNER, T. Attila

    2013-01-01

    We present a new 3D geologic model for the architecture and Cenozoic tectonic evolution of the Tuz Gölü Basin, a major sedimentary basin in the Central Anatolian orogenic plateau. This model is grounded on 7 depth-converted seismic reflection profiles in combination with the analysis of backstripped subsidence curves, isochore maps, and a palinspastically restored cross-section. Two stages of basin formation are detected during Cenozoic times. During the Palaeogene, around 2 km of basement su...

  16. Australasian microtektites from the Central Indian Basin: Implications for ejecta distribution patterns

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    Microtektites belonging to the Australasian tektite strewn field have been recovered in one (SK-16/176) out of three cores examined from the Central Indian Basin. The microtektites have been identified based on their physical appearance...

  17. Categories used to classify the basin-fill deposits in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the categories used to classify the basin-fill deposits in the Central Valley as either coarse-grained or fine-grained deposits. This...

  18. Variation in size, morphology and chemical composition of polymetallic nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Karisiddaiah, S.M.; Parthiban, G.

    Chemical composition of 613 polymetallic nodules from 150 stations in the Central Indian Ocean Basin (CIOB) are determined and variations in Mn, Fe, Cu, Ni, Co, Zn and moisture content are studied with respect to their size and surface texture...

  19. Diagenetic remobilization of rare earth elements in a sediment core from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Banakar, V.K.

    Rare earth elements (REE) distribution in a 36 cm long sediment box core from the Central Indian Basin is studied. REE concentration is generally higher in the upper oxic zone than in intermediate suboxic zone suggesting REE diffusion upwards...

  20. Benthic disturbance and monitoring experiment in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Nath, B.N.

    Environmental impact assessment studies for deep-sea manganese nodule mining have been initiated in the Central indian Ocean Basin since 1995. As a part of the first phase for collecting the benthic baseline data, echosounding, subbottom profiling...

  1. Changes in geotechnical properties of sediments from the Central Indian Basin induced by disturbance experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    During the Indian Deep-sea Environment Experiment (INDEX) conducted in the Central Indian Basin to simulate nodule mining activity, the sediments were physically disturbed, lifted from the seafloor, and then redeposited to study the effects...

  2. Benthic disturbance and impact experiments in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Nath, B.N.; Valsangkar, A.B.; Parthiban, G.; Sivakholundu, K.M.; Walker, G.A.

    As a part of the Environmental Impact Assessment studies for nodule mining, a long-term program has been initiated in the Central Indian Basin. Multidisciplinary studies on geological, biological, physical and chemical parameters were carried out...

  3. Recovery of deep-sea meiofauna after artificial disturbance in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Goltekar, N.R.; Gonsalves, S.; Ansari, Z.A.

    -1 1 Recovery of Deep-sea Meiofauna after Artificial Disturbance in the Central Indian Basin INGOLE B.S*., R. GOLTEKAR, S. GONSALVES and Z. A. ANSARI Biological Oceanography Division, National Institute of Oceanography, Dona Paula, Goa; 403004...

  4. Quantitative radiolarian assemblages in surface sediments from the central Indian Basin and their paleomonsoonal significance

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.

    The percentage data of 47 radiolarian coarser taxonomic groups in the surface sediments from the central Indian Basin was subjected to cluster and factor analyses. The R-mode cluster analysis resulted in 3 dominant clusters which represent surface...

  5. Physical properties of a sediment core from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    A box core of 7.5 m was collected from the Central Indian Basin for the purpose of geotechnical studies and depthwise variation of physical properties and clay mineralogy. Water content, Atterberg limits, specific gravity are measured at regular...

  6. Marine mineral resources of the Central Indian Basin: Ferromanganese nodules and crusts

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Nair, R.R.

    The morphology, mineralogy and composition of ferromanganese nodules and crusts from the Central Indian Basin and southwestern flank of the Charlsberg Ridge have been characterized from the analyses of data and samples collected at more than 2000...

  7. New ichthyoliths from ferromanganese crusts and nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.

    Ferromanganese encrusted hardgrounds, their intraclasts and the nuclei of manganese nodules collected from the Central Indian Ocean basin have yielded plentiful numbers of ichthyoliths. Forty well-knon ichthyoliths, one new type and 35 new subtypes...

  8. Parasitism of Dasineura oxycoccana (Diptera: Cecidomyiidae) in North Central Florida.

    Science.gov (United States)

    Roubos, Craig R; Liburd, Oscar E

    2013-06-01

    Blueberry gall midge, Dasineura oxycoccana (Johnson), is a key pest of blueberries in Florida. As a larva, this insect feeds in developing flower and leaf buds. Management of D. oxycoccana relies principally on chemical insecticides; however, efficacy is limited because D. oxycoccana is sheltered within the plant during most of its life cycle. Natural enemies, particularly parasitoids, may play an important role in regulating D. oxycoccana populations. To determine the seasonal dynamics and parasitism rates of eulophid and platygastrid wasps parasitizing D. oxycoccana larvae, we sampled D. oxycoccana larvae by collecting infested blueberry leaf buds from a minimally-managed farm in north central Florida. Midge larvae were examined under a microscope to determine parasitism status of host instars. Parasitism rates ranged from 25 to 40% over the 3-yr study. Percent parasitization was significantly higher in third instars than first or second instars. Midge larvae in the centers of leaf buds were significantly less likely to be parasitized than larvae in outer layers of leaf buds. Thirty-seven percent of midge larvae had been parasitized multiple times, suggesting these parasitoids do not discriminate between parasitized and unparasitized hosts. Implications for pesticide use in relation to the conservation of natural enemies and management of D. oxycoccana populations are discussed. PMID:23726050

  9. North Central Regional geologic characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, groundwater resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process. 43 figs., 15 tabs

  10. Revised draft: North Central Regional geologic characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, water resources, groundwater salinity, and state of stress. Information is presented on age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented

  11. Revised draft: North Central Regional environmental characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed federal protected lands, proximity to federal protected lands, existing state protected lands, proximity to state protected lands, population density and distribution, proximity to highly populated areas, national and state forest lands, state wildlife lands, designated critical habitats for threatened and endangered species, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that may be of use at later phases of screening. Also included is a discussion of the relationship between the DOE Siting Guidelines and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  12. North Central Regional environmental characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed Federal-protected lands, proximity to Federal-protected lands, components of national forest lands, existing state-protected lands, proximity to state-protected lands, population density and distribution, proximity to highly populated areas or to 1-mile square areas with 1000 or more persons, national and state forest lands, designated critical habitats for threatened and endangered spcies, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that will be of use at later phases of screening. Also included is a discussion of the relationship between the US Department of Energy Siting Guidelines (10CFR 960) and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  13. The Post-Permian evolution of the Northern Part of the North German Basin

    Science.gov (United States)

    Hansen, M. B.; Huebscher, C.; Lykke-Andersen, H.; Gajewski, D.; Dehghani, A.; Reicherter, K.

    2004-12-01

    In the frame of the Priority Program 1135 of the German Research Foundation (DFG) "Dynamics of sedimentary systems under varying stress conditions by example of the Central European Basin System", the scientific goal of the NeoBaltic project is to describe the post-Permian to recent geological evolution of the entire western Baltic Sea region, with a special emphasis on neotectonic activity and it relation to salt dynamics. The western Baltic Sea comprises the northern part of the North German Basin (NGB), a part of the Central European Basin System (CEBS), and the transitional zone between the NGB and the Baltic Shield. In order to investigate these scientific goals the Universities of Aarhus (Denmark) and Hamburg (Germany) has since 1998 completed seven marine campaigns in the western Baltic Sea, collecting 2D high resolution seismic (HRS), gravity and magnetic data in the entire region during different projects. Since 2003 all these data has been available for the NeoBaltic project. All together the data pool have more than 7000 km HRS, 5000 km gravity and 4000 km magnetic data. Until now the project work has been focused on the completion of the data processing and the digital interpretation of important Mesozoic and Cenozoic markers on the seismic sections from the Bays of Kiel and Mecklenburg. Furthermore, several maps have been completed from the potential field data (gravity and magnetic). As a result of the digital interpretation of the HRS data, the overall geological evolution of the northern part of the NGB can be subdivided into four distinct periods. During the Triassic and the Early Jurassic, E-W extension and the deposition of clastic sediments initiated the movement of the underlying Zechstein evaporites. This is seen by the presence of several salt pillows in the region. The deposition ceased during the Middle Jurassic, when the entire area was uplifted, due to the Mid North Sea Doming. The uplift resulted in a pronounced erosion of Upper Triassic

  14. Response to state comments on the revised draft North Central Regional characterization reports for the Crystalline Repository Project

    International Nuclear Information System (INIS)

    The purpose of this document is to respond to the comments received from the states of the North Central Region on the revised draft North Central Regional Characterization Reports (RCRs). The responses in this document indicate the manner in which the suggestions or comments received have been considered in modifying the revised draft North Central RCRs. Both general comments related to the overall Crystalline Repository Project (CRP) and comments on specific sections of the RCRs are addressed. This document responds to North Central State comments on both the revised draft North Central Regional Geologic Characterization Report (RGCR) and the revised draft North Central Regional Environmental Characterization Report (RECR)

  15. Marine Ingressive Events Recorded in Epicontinental Sequences:Example from the Cretaceous Songliao Basin of NE China in Comparison with the Triassic Central Europe Basin of SW Germany

    Institute of Scientific and Technical Information of China (English)

    WANG Pujun; LIU Wanzhu; YIN Xiuzhen; SCHNEIDER Werner; MATTERN Frank

    2002-01-01

    Songliao Basin is filled predominantly with continental facies sediments including alluvial fan, fluvial plain, fan delta, lacustrine delta, shore - shallow lacustrine, beach salty flat, semi - deep to deep lacustrine, subaqueous gravity flow,lacustrine swamp and pyroclastic sediments. However, some event units were formed during lake - marine linking periods of the Mid - Cretaceous in the basin, which include black shales with high values for salinity (Sr/Ba) , alkalinity ( Ca + Mg)/(Si + Al) , reducibility (Ni + Zn)/Ga and sulfide sulfur as well as heavy isotopes. The Breitenholz -section to be represented for facies comparison with the Cretaceous evaporitic series in Northeast China is localized in Southwest Germany. Stratigraphically it belongs to the Crabfeld Formation of Keuper of the Germanic Triassic corresponding to Ladinian - Carnian of the international reference scale, and is generally called Lower Gipskeuper. The Germanic Triassic was deposited in the epicontinental (cratonic) central Europe Basin. It covered the area in between Great Britain, North Sea, Poland and Southern Germany. It is composed of cyclic deposits of multicolored mudstones, gypsum/anhydrite, and dolomite beds. The two cases of marine ingression - influenced sequences share some common features.

  16. A potential archive of Pleistocene uplift and erosion in the eastern Nete basin, Campine area, north-eastern Belgium

    Science.gov (United States)

    Beerten, Koen; Leterme, Bertrand

    2013-04-01

    From a geodynamic point of view, the Campine area is situated on the crossroads between distinctive tectonic settings: the subsiding North Sea basin and Roer Valley Graben in the north, and the uplifting Brabant Massif and Ardennes in the south. In general, this has led to overall Cenozoic subsidence of the area and sedimentation of unconsolidated marine sands. However, the morphology of the present-day Nete basin, which is situated in the central and eastern part of the Campine area, is a clear example of an erosional feature and shows evidence of up to 30 m of Quaternary erosion. However, the drivers, timing and rate of landscape development in the Nete basin are poorly constrained. Here, we present and describe geological and geomorphological remnants testifying to past landscape development in the Nete basin, that will help understanding the Quaternary geodynamic evolution (uplift) of the Campine area. The Nete basin is located in northern Belgium and is drained by two small rivers, the Kleine Nete and Grote Nete, that merge into the larger Nete river several km before entering the Lower Scheldt basin. The Nete basin can clearly be identified on topographical maps as a depression, ca. 40 km x 40 km, with valley floors ranging between 10-20 m above sea level (a.s.l.). It is bounded in the north, east and south by erosion resistant geological formations at altitudes between 30 m (north) and 60 m (south). The major direction of drainage is from ENE to WSW and the basin thus opens towards the west. The start of basin development is situated after deposition of Rhine sediments (~ 1 Ma) which form the erosion resistant eastern watershed with the Meuse basin at an altitude of ~ 50 m a.s.l. on top of the Campine Plateau. GIS-based landscape analysis of the topography and the contour map of the Quaternary base confirm the observation that the lowering of the relief from the Campine Plateau down to the floodplain of the Kleine Nete and Grote Nete shows a stepwise

  17. Living on the edge: The oxygen isotope record of Eocene Basins at the margin of the Cenozoic North American plateau

    Science.gov (United States)

    Methner, Katharina; Mulch, Andreas; Chamberlain, Page

    2013-04-01

    Topography has a strong impact on atmospheric circulation and precipitation patterns and is a key element in reconstructing the dynamics of mountain building processes. The topographic evolution of the world's major orogens remains one of the most important questions when discussing the interactions among tectonics, climate, and Earth surface processes. Here, we focus on the spatial and temporal development of topography and relief in the western North American Cordillera and how changes in the topography may have affected precipitation patterns and vice versa. In this context, we sampled more than 20 sections in Eocene to Oligocene terrestrial (intermontane?) basins (Chumstick, Swauk, and Chuckanut) in western and central Washington (USA) to the W and E of the modern Cascades. Oxygen isotope analysis of pedogenic carbonate in these sections allows us to reconstruct the isotopic composition of ancient soilwater or groundwater, and ultimately precipitation. Oxygen isotope measurements of pedogenic concretions and calcic horizons interestingly yield uniformly low δ18O values of 10 to 13‰ SMOW despite the proximity of all sections to the Pacific moisture source. These extremely low oxygen isotope values can result from (1) highly 18O-depleted meteoric waters (soil- or groundwater), (2) burial diagenesis at moderate temperatures and interaction with 18O-depleted (ground)water, and (3) high burial temperatures and and exchange with basins brines. Vitrinite reflectance data and preservation of primary soil structures such as rootlets, root casts, burrows, or even preserved wood fragments clearly show that some of the low-d18O sections were not affected by high degrees of burial diagenesis. Thus, we believe that the primary isotopic signal of ancient soil- or groundwater is preserved at least in parts (if not in all) of these basins. Low δ18O values of pedogenic carbonate require highly 18O-depleted meteoric water, which in turn, would require high elevation either at

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

    Science.gov (United States)

    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

  19. Tectono-stratigraphic evolution and crustal architecture of the Orphan Basin during North Atlantic rifting

    Science.gov (United States)

    Gouiza, Mohamed; Hall, Jeremy; Welford, J. Kim

    2016-06-01

    The Orphan Basin is located in the deep offshore of the Newfoundland margin, and it is bounded by the continental shelf to the west, the Grand Banks to the south, and the continental blocks of Orphan Knoll and Flemish Cap to the east. The Orphan Basin formed in Mesozoic time during the opening of the North Atlantic Ocean between eastern Canada and western Iberia-Europe. This work, based on well data and regional seismic reflection profiles across the basin, indicates that the continental crust was affected by several extensional episodes between the Jurassic and the Early Cretaceous, separated by events of uplift and erosion. The preserved tectono-stratigraphic sequences in the basin reveal that deformation initiated in the eastern part of the Orphan Basin in the Jurassic and spread towards the west in the Early Cretaceous, resulting in numerous rift structures filled with a Jurassic-Lower Cretaceous syn-rift succession and overlain by thick Upper Cretaceous to Cenozoic post-rift sediments. The seismic data show an extremely thinned crust (4-16 km thick) underneath the eastern and western parts of the Orphan Basin, forming two sub-basins separated by a wide structural high with a relatively thick crust (17 km thick). Quantifying the crustal architecture in the basin highlights the large discrepancy between brittle extension localized in the upper crust and the overall crustal thinning. This suggests that continental deformation in the Orphan Basin involved, in addition to the documented Jurassic and Early Cretaceous rifting, an earlier brittle rift phase which is unidentifiable in seismic data and a depth-dependent thinning of the crust driven by localized lower crust ductile flow.

  20. Krušné hory Piedmont basins. North Bohemian Lignite (Most) Basin

    Czech Academy of Sciences Publication Activity Database

    Elznic, A.; Macůrek, V.; Dašková, Jiřina; Fejfar, O.; Kvaček, Z.; Mikuláš, Radek; Pešek, J.; Sýkorová, Ivana; Teodoridis, V.

    Prague: Czech Geological Survey, 2014, s. 31-89 ISBN 978-80-7075-862-5 R&D Projects: GA ČR GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  1. Two new species of the bee genus Peponapis, with a key to the North and Central American species (Hymenoptera: Apidae: Eucerini)

    OpenAIRE

    Ricardo Ayala; Terry Griswold

    2012-01-01

    Two new species of squash bees, Peponapis pacifica Ayala and Griswold sp. n. and P. parkeri Griswold and Ayala sp. n., are described and illustrated. Peponapis pacifica is oligolectic on flowers of Schizocarpum longisepalum (Cucurbitaceae) endemic to Mexico, where it is found in the tropical dry forest along the Pacific Coast, between Sonora and Chiapas and in the Balsas River basin; and P. parkeri is known only from the Pacific slope of Costa Rica. A key for the North and Central American sp...

  2. FIRST RECORD OF Alburnus atropatenae (BERG, 1925) (CYPRINIDAE) IN NAMAK BASIN, CENTRAL IRAN

    OpenAIRE

    Somaye Khataminejad; Hamed Mousavi-Sabet; Masud Sattari; Saber Vatandoust

    2013-01-01

    Alburnus atropatenae Berg, 1925 is reported for the first time from the River Ghareh-Chay in the Namak basin, central Iran. Previously, this species has only been reported from the Lake Orumiyeh basin, in northwest Iran. In this report twenty-nine specimens were caught on 8 August 2012. Morphometric and meristic characteristics of the specimens were similar to those reported elsewhere for the species.

  3. Understanding volcanism at the PETM: Abundant volcanic ash layers in the Central Tertiary Basin of Spitsbergen, Svalbard

    Science.gov (United States)

    Jones, Morgan; Eliassen, Gauti; Svensen, Henrik; Jochmann, Malte; Friis, Bjarki; Jerram, Dougal; Planke, Sverre

    2014-05-01

    During the early Tertiary, Svalbard developed a fold-thrust belt on its western margin with an associated foreland basin in the central-south of what is now Spitsbergen. This Central Tertiary Basin (CTB) is a syn-orogenic sedimentary basin in a strike-slip regime. The CTB contains the ~1900 m thick Van Mijenfjorden group, a dominantly sandstone-shale succession that was deposited in a North-South extending basin. Sediments in this group display evidence of major transgressive-regressive cycles related to local tectonics and eustatic sea level change. This basin is ideal for study as it has been extensively cored for coal prospecting, allowing a suite of sedimentary logs across the basin to be considered. Prominent marker beds in this sedimentary sequence are 1-30 cm thick bentonites, formed from the chemical weathering of volcanic tuff deposits. In this study, we focus on 8 sedimentary logs across the CTB, spanning the Palaeocene to lower Eocene in age. Bentonites are common in the Palaeocene cores (Basilika and Grumantbyen formations), while rarer but still occasionally present in the Eocene Frysjaodden formation. The cores had between 3-12 observable bentonite layers that showed large variations in preservation and subsequent reworking. Roots and other finer organic material were common, especially when the bentonites were found next to coal seams. Geochemical affinities between ash layers were investigated to identify basin-wide depositional events, with the aim of elucidating the provenance of these ashes. This sedimentary sequence is of broader interest as it covers the Palaeocene-Eocene thermal maximum (PETM), an extreme global warming event driven by large releases to the atmosphere of CO2 and/or CH4, evidenced by a negative carbon isotope excursion in both the ocean and atmosphere. Potential sources include volcanism and associated gas release from intruded sediments, CH4 hydrate dissociation, and/or the oxidation of organic matter. These formations are

  4. FORMATIVE MECHANISM OF AKAISHI MOUNTAINS AND ENREI BASIN IN CENTRAL JAPAN

    Institute of Scientific and Technical Information of China (English)

    Yasu'uchi KUBOTA; Takao YANO

    2001-01-01

    @@ 1 Introduction It is common in mobile belts that uplifting mountains are neighbored by synchronously subsiding basins.The coupling mechanism of such subsidence and uplift is an important target to clarify the dynamics of mobile belts.We investigate the coupled mountain uplift and basin subsidence in the Central Japan highland,the junction of three island arcs (the Northeast Japan,the Southwest Japan and the Izu-Ogasawara arcs).The highland over 3 000 m in height is composed of mountain ranges,plateaus and intramountain basins (Fig.1).

  5. FORMATIVE MECHANISM OF AKAISHI MOUNTAINS AND ENREI BASIN IN CENTRAL JAPAN

    Institute of Scientific and Technical Information of China (English)

    Yasu'uchi; KUBOTA; Takao; YANO

    2001-01-01

    1 Introduction  It is common in mobile belts that uplifting mountains are neighbored by synchronously subsiding basins.The coupling mechanism of such subsidence and uplift is an important target to clarify the dynamics of mobile belts.We investigate the coupled mountain uplift and basin subsidence in the Central Japan highland,the junction of three island arcs (the Northeast Japan,the Southwest Japan and the Izu-Ogasawara arcs).The highland over 3 000 m in height is composed of mountain ranges,plateaus and intramountain basins (Fig.1).……

  6. Oxygen and hydrogen isotope exchange of geopressured thermal water in the central Guanzhong basin

    Institute of Scientific and Technical Information of China (English)

    YU Juan; MA Zhi-yuan; WANG Zhao-wei; LI Wei-liang; SU Yan

    2009-01-01

    Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the pc-rimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geo-pressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of thssolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.

  7. Basin formation and inversion of the back-arc, Niigata basin, central Japan: New insight from deep seismic profiling

    Science.gov (United States)

    Sato, Hiroshi; Abe, Susumu; Kawai, Nobuo; Saito, Hideo; Kato, Naoko; Shiraishi, Kazuya; Ishiyama, Tatsuya; Fukasawa, Hikaru; Inaba, Mitsuru

    2010-05-01

    Associated with the opening of the Japan Sea, rift-basins have been developed along the Japan Sea coast of northern Honshu. The Niigata basin, central Japan, is one of the such basins and filled by thick (faulting. Due to thick Neogene sediments, relationship between active faults/folds at near the surface and deep-sited seismogenic source faults is poorly understood. To reveal the crustal structure, in particular geometry of source faults, onshore-offshore integrated deep seismic profiling was undertaken along the two seismic lines in 2008 and 2009. The 2009 Aizu-Sado seismic line is a 135-km-long, onshore-offshore seismic line across Niigata basin and Sado island, which is located in the eastern part of Japan Sea. The 2008 Sanjo-Yahiko seismic line (Sato et al., 2009) is located 20 km south of the seismic line and trending parallel to it. The seismic source was air-gun (3020 cu. inch), four vibroseis trucks and explosives (cables, cable-connected-recording system and offline recorders, forming a maximum 2400 channels receiver array. The basin fill consists of early to middle Miocene volcaniclastic rocks and overlying Neogene sedimentary rocks showing upward coarsening facies deposited under bathyal to fluvial environment. Main features of basin development, such as early Miocene normal faulting, associated with the formation of Japan Sea, and shortening deformation since Pliocene, are well demonstrated on the seismic sections. Particularly, boundary between pre-Tertiary meta-sedimentary rocks and Miocene volcanics were identified by velocity profile deduced by diving wave tomography and it enabled us to identify the geometry of extensional rift-basin. It is very difficult to distinguish meta-sedimentary rocks from volcaniclastic rocks by seismic facies or pattern of reflections. Fault reactivation of Miocene normal faulting to reverse faulting is common style of deformation. The fault reactivation processes of the eastern boundary fault of the Nagaoka plane

  8. A tektite fragment discovered in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Mislankar, P.G.; Charan, S.N.; Prasad, K.

    ) and the largest encompassing 1/10 of the Earth's surface. Tektites of this strewn field exhibit morphological differences in different geographic domains, such as the blocky, layered Muong Nongtype tektites in the Indo-China region in the north, splash form types...

  9. Kernel Density Estimation of Tropical Cyclone Frequencies in the North Atlantic Basin

    OpenAIRE

    Timothy A. Joyner; Robert V. Rohli

    2010-01-01

    Previous research has identified specific areas of frequent tropical cyclone activity in the North Atlantic basin. This study examines long-term and decadal spatio-temporal patterns of Atlantic tropical cyclone frequencies from 1944 to 2009, and analyzes categorical and decadal centroid patterns using kernel density estimation (KDE) and centrographic statistics. Results corroborate previous research which has suggested that the Bermuda-Azores anticyclone plays an integral role in the directio...

  10. Top of Head Scarp and Internal Scarps for Landslide Deposits in the Little North Santiam River Basin, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data points represent head scarps, flank scarps, and minor internal scarps (linear) associated with landslide deposits in the Little North Santiam River Basin,...

  11. Tropical Cyclone Exposure for U.S. waters within the North Atlantic Ocean basin, 1900-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent modeled, historical exposure of U.S. offshore and coastal waters to tropical cyclone activity within the North Atlantic Ocean basin. BOEM Outer...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-03-23

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

  13. Life history of the striped newt at a north-central Florida breeding pond

    Science.gov (United States)

    Johnson, S.A.

    2002-01-01

    I studied the life history of Striped Newts (Notophthalmus perstriatus) at a breeding pond in north-central Florida. Newts were captured in pitfall traps at a drift-fence as they migrated into and out of the pond basin. During the 2-year study, I recorded 10,290 captures (8,127 individuals) of newts at the drift-fence. Newts were active during each month of the study, but there were four peak activity periods, each of which included immigration and emigration events. Immigration events were almost exclusively comprised of adults, whereas emigration events were comprised of adults and recently transformed larvae. I documented 5,296 recently transformed, immature larvae (efts) and 435 recently transformed mature larvae (paedomorphs) during four distinct periods of emigration. Efts matured in the uplands before returning to the pond to breed. In the uplands, male efts (n = 16) grew 0.0183 mm/day on average, whereas average female (n = 24) growth was 0.0167 mm/day. Immigrating adults of both sexes were significantly smaller than emigrating adults. Emigrating efts were smallest, followed by emigrating paedomorphs, immigrating adults, then emigrating adults. The overall adult sex ratio was 1:1.25 (m:f). Sex ratio of emigrating paedomorphs was highly skewed towards females, with one male for every 4.43 females. Newts tended to move during wetter periods, and captures were significantly correlated with rainfall, but rainfall was a poor predictor of the magnitude of newt movements.

  14. Reservoir heterogeneity in Carter Sandstone, North Blowhorn Creek oil unit and vicinity, Black Warrior Basin, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, R.L.; Pashin, J.C.

    1992-05-01

    This report presents accomplishments made in completing Task 3 of this project which involves development of criteria for recognizing reservoir heterogeneity in the Black Warrior basin. The report focuses on characterization of the Upper Mississippian Carter sandstone reservoir in North Blowhorn Creek and adjacent oil units in Lamar County, Alabama. This oil unit has produced more than 60 percent of total oil extracted from the Black Warrior basin of Alabama. The Carter sandstone in North Blowhorn Creek oil unit is typical of the most productive Carter oil reservoirs in the Black Warrior basin of Alabama. The first part of the report synthesizes data derived from geophysical well logs and cores from North Blowhorn Creek oil unit to develop a depositional model for the Carter sandstone reservoir. The second part of the report describes the detrital and diagenetic character of Carter sandstone utilizing data from petrographic and scanning electron microscopes and the electron microprobe. The third part synthesizes porosity and pore-throat-size-distribution data determined by high-pressure mercury porosimetry and commercial core analyses with results of the sedimentologic and petrographic studies. The final section of the report discusses reservoir heterogeneity within the context of the five-fold classification of Moore and Kugler (1990).

  15. Pre-Variscan back-arc extension of Avalonia: The genesis of the Southern North Sea Basin

    Science.gov (United States)

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

    2016-04-01

    The Devonian-Early Carboniferous was a period of intense rifting in the Avalonia microplate in between the Caledonian and the Hercynian-Alleghanian collision phases. This rifting phase created the typical horst-and-graben structure of much of East Avalonia's crust that is best known from the UK and Ireland where the horsts and the graben infill are located at or near the surface. In the Southern North Sea, the Netherlands and northwest Germany, the Late Devonian-Early Carboniferous rift structure and units are obliterated by the thick cover of Late Carboniferous-to-Recent basin fill and by the recurrent fault reactivation. Although this rifting created the basis for 350 Ma of lithospheric memory, its dynamics remains relatively unknown. Major open questions include the mode and total amount of extension as well as the age and origin of the Central Graben and the relation between structures located east and west of it. This study addresses these issues by integrating existing data from lithosphere to basin scales and a map-view restoration. We have revised the crustal map of the Thor Suture Zone. The newly defined northern margin of Avalonia and the Thor Suture Zone are key elements in the reconstruction of Devonian-Carboniferous rifting of Avalonian lithosphere. We present a revised map of Devonian-Carboniferous basin structures including the main horsts and grabens and the governing faults east of the Central Graben. Based on these maps, we present a new paleotectonic reconstruction and a novel geodynamic scenario for the Devonian- Carboniferous rifting. These findings are key for better understanding of long-lived tectonic compartmentalisation and post-rifting deformation phases.

  16. Slope instability in the Bastardo Basin (Umbria, Central Italy – The landslide of Barattano

    Directory of Open Access Journals (Sweden)

    C. Cencetti

    2003-01-01

    Full Text Available The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological. The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to landslides of the Apenninic intermontane basins. In particular lithological, stratigraphical and hydrogeological conditions are analysed under which a landslide near village of Barattano has developed. This mass movement, at different times, produced partial or total occlusion of the torrent Puglia. Here geognostic investigations together with laboratory tests and subsequent monitoring of landslide area were carried out.  A back analysis, based on limit equilibrium solutions for the factor of safety of the slope, provided the residual strenght properties of the soil mass along the sliding surface.   The landslide of Barattano is representative of a very frequent situation (in terms of type, factors and causes of the movement, possible development of the movement not only within Bastardo Basin, but in general within Apenninic intermontane basins, too.  The study of landslide and the design of appropriate remedial measures are of great importance in terms of prevention and mitigation of geologic-hydraulic risk in Apenninic intermontane basins.

  17. Tectonic structure, seismic stratigraphy and hydrocarbon potential of the North Kara Basin (Russian Arctic)

    Science.gov (United States)

    Verzhbitsky, V.; Kosenkova, N.; Murzin, R.; Vasilyev, V.; Malysheva, S.; Komissarov, D.; Ananyev, V.; Roslov, Yu.; Khudoley, A.

    2012-04-01

    North Kara shelf represents one of the remote and still poorly studied sedimentary megabasins of Russian West Arctic. North Kara area lacks any offshore wells so the understanding of its structure is based on the geology of adjacent East Barents Basin, as well as surrounding land areas (Taimyr, Severnaya and Novaya Zemlya fold belts) and stratigraphic columns of the scattered Arctic Islands. It is widely believed that North Kara shelf is mostly composed of Riphean-Paleozoic sedimentary units, underlain by Precambrian basement (North Kara massif), and represents one of the most promising areas of the Russian Arctic for hydrocarbon (mostly oil) discoveries. Our study is based on the reinterpretation of several regional seismic lines acquired by Sevmorgeo. We used the main Paleozoic and Mesozoic tectonic events known for Severnaya Zemlya Archipelago and Taimyr Peninsula for interpretation of the age of main seismic complexes/boundaries within the North Kara sedimentary cover (first of all within the Priseverozemelsky Trough). We correlated the sharp angular unconformity in the lower part of sedimentary succession with Cambrian/Ordovician unconformity described earlier on the nearby Severnaya Zemlya onshore domain. It is likely that the pre-Ordovician tectonic event corresponds to the Late Baikalian (Timanian) orogeny, which took place on Timan-Pechora and Novaya Zemlya areas. Above the unconformity we proposed the occurrence of Ordovician-Silurian shelfal sedimentary sequence of ~ 2 km thickness. This strata are overlain by thick (~3-4 km) progradational unit. It is likely that this sequence should correspond to molassic deposits of old red sandstones, related to the regional Caledonian orogeny. We believe that general structural pattern of the North Kara region was formed in Late Carboniferous-Early Permian time as a result of Kara massif/Siberian Craton collision-related Hercynian orogeny of Taimyr-Severnaya Zemlya domain. This event led to gentle folding of the

  18. Systematic and integrated approach to tropical cyclone track forecasting in the eastern and central North Pacific

    OpenAIRE

    White, Sean R.

    1995-01-01

    This study is the application of the meteorological framework in the Systematic Approach to tropical cyclone track forecasting of Carr and Elsberry to the eastern and central North Pacific tropical cyclones. All eastern and central North Pacific tropical cyclones from 1990-1993 are examined using 500 mb Navy Operational Global Atmospheric Prediction System streamline and isotach analyses, geostationary satellite imagery, and the tropical cyclone best track information. Application of the Syst...

  19. Quaternary landscape evolution driven by slab-pull mechanisms in the Granada Basin (Central Betics)

    Science.gov (United States)

    Pérez-Peña, J. V.; Azañón, J. M.; Azor, A.; Booth-Rea, G.; Galve, J. P.; Roldán, F. J.; Mancilla, F.; Giaconia, F.; Morales, J.; Al-Awabdeh, M.

    2015-11-01

    The Granada Basin is one of the largest Neogene-Quaternary intramontane basins of the Betic Cordillera in SE Spain. The landscape evolution in this basin is complex and does not respond to a simple model of headward erosion following river capture of a former endorheic catchment. In the NE border of the basin, the drainage network is highly incised and reveals two different stages of river development since the Pleistocene. The older drainage network presents low incision, being locally controlled by ENE-WSW open folds. The present-day drainage network features deep incised valleys with a well-defined local base-level controlled by NW-SE normal faults. The ENE-WSW open folds were generated by compressional stresses and affect a geomorphic surface that caps the local sedimentary sequence. These folds are thought to reactivate a Pliocene roll-over formed in the hanging wall of ENE-WSW normal faults that bound the Granada Basin to the north and the deepest Pliocene depocenter. On the contrary, Quaternary depocenters are located in the hanging wall of the NW-SE-oriented normal faults that control the present-day drainage network (NW-SE oriented). The activity of these faults also contributes to the erosion of the Pliocene depocenter located to the north, thus suggesting a southwestward migration of the loci of extension to the center of the basin. The broad-scale scenario envisaged to explain the Pliocene-Quaternary evolution of the NE border of the Granada Basin is one dominated by mantle slab-pull coeval with the Africa-Iberia continuous convergence.

  20. Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

    Science.gov (United States)

    Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

    2009-04-01

    repeated permafrost heaving from small declustered frozen mounds to recovery of palsa plateaus due to growing and merging of isolated mounds. It was shown that satellite altimetry, which was applied for the first time in permafrost zone in the framework of Russian-French project CAR-WET-SIB, is a prospective method to study lakes and khasyreis state and dynamic. References [1] Kirpotin S.N., Naumov A .V., Vorobiov S.N., Mironycheva-Tokareva N.P., Kosych N.P., Lapshina E.D., Marquand J., Kulizhski S.P., Bleuten W. 2007. Western-Siberian Peatlands: Indicators of Climate Change and Their Role in Global Carbon Balance. Chapter 33 in Climate Change and Terrestrial Carbon Sequestration in Central Asia / edited by R.Lal, M.Suleimenov, B.A.Stewart, D.O.Hansen, and P.Doraiswamy, Taylor and Francis, Amsterdam, Holland, pp. 453-472. [2] Kirpotin S., Polishchuk Yu., Zakharova E., Shirokova L., Pokrovsky O., Kolmakova M., Dupre B. 2008. One of Possible Mechanisms of Thermokarst Lakes Drainage in West-Siberian North // International Journal of Environmental Studies. Vol.65, No 5, October 2008, 631-635. [3] Smith, L.C., Sheng, Y., McDonald, G.M., Hinzman, L.D. 2005. Disappearing Arctic Lakes, Science, 308, 1429 [4] Hinkel, K.M., Eisner, W.R., Bockheim, J.G., Nelson, F.E., Peterson, K.M., and Dai, X. 2003. Spatial Extent, Age, and Carbon Stoks in Drained Thaw Lake Basins on the Barrow Peninsula. Alaska. Arctic, Antarctic, and Alpine Research, 35, 3, 291-300.

  1. Interpretation of magnetotelluric data: Pasco Basin, south central Washington

    International Nuclear Information System (INIS)

    The purpose of this project was to review, evaluate, and interpret magnetotelluric (MT) data collected in support of the Basalt Waste Isolation Project. The integrated interpretation presented is related to regional and site-specific geology and associated borehole, gravity, and magnetic data. The MT interpretation procedure placed strong reliance on computer models based upon the inferred physical parameters of the subsurface materials and their anticipated variability. Much of the MT data is of poor quality by current standards; however, significant qualitative observations can be made. The quantification of these observations, including the procedures and assumption utilized, are discussed in detail. Problems related to ambiguities inherent in the MT method are discussed as related to the Pasco Basin MT data. 117 refs., 77 figs., 3 tabs

  2. Literature and information related to the natural resources of the North Aleutian Basin of Alaska.

    Energy Technology Data Exchange (ETDEWEB)

    Stull, E.A.; Hlohowskyj, I.; LaGory, K. E.; Environmental Science Division

    2008-01-31

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant natural resources. The Basin includes most of the southeastern part of the Bering Sea Outer Continental Shelf, including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals, including several federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, 'Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012' and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory were contracted to assist MMS with identifying and prioritizing information needs related to potential future oil and gas leasing and development activities in the North Aleutian Basin. Argonne focused on three related tasks: (1) identify and gather relevant literature published since 1996, (2) synthesize and

  3. Availability of water resources in the rio Bermudez micro-basin. Central Region of Costa Rica

    International Nuclear Information System (INIS)

    The Rio Bermudez micro-basin makes up part of the principal hydrological resource area in the Central Region of Costa Rica. For this reason a study was done to determine the availability of hydrological resources in said micro-basin to identify areas with potential water availability problems. A monthly water balance was calculated using land use, geomorphology and climate parameters. From these water balance studies, the amount of available water was calculated and classified into four categories, however, in this micro-basin, only three categories were identified: high, medium and moderate water availability. No areas were identified with low water availability, indicating availability is sufficient; however, there is increasing demand on water resources because over half of the micro-basin area is classified as having moderate water availability. (Author)

  4. Assessing and addressing the re-eutrophication of Lake Erie: central basin hypoxia

    Science.gov (United States)

    Scavia, Donald; Allan, J. David; Arend, Kristin K.; Bartell, Steven; Beletsky, Dmitry; Bosch, Nate S.; Brandt, Stephen B.; Briland, Ruth D.; Daloğlu, Irem; DePinto, Joseph V.; Dolan, David M.; Evans, Mary Anne; Farmer, Troy M.; Goto, Daisuke; Han, Haejin; Höök, Tomas O.; Knight, Roger; Ludsin, Stuart A.; Mason, Doran; Michalak, Anna M.; Richards, R. Peter; Roberts, James J.; Rucinski, Daniel K.; Rutherford, Edward; Schwab, David J.; Sesterhenn, Timothy M.; Zhang, Hongyan; Zhou, Yuntao

    2014-01-01

    Relieving phosphorus loading is a key management tool for controlling Lake Erie eutrophication. During the 1960s and 1970s, increased phosphorus inputs degraded water quality and reduced central basin hypolimnetic oxygen levels which, in turn, eliminated thermal habitat vital to cold-water organisms and contributed to the extirpation of important benthic macroinvertebrate prey species for fishes. In response to load reductions initiated in 1972, Lake Erie responded quickly with reduced water-column phosphorus concentrations, phytoplankton biomass, and bottom-water hypoxia (dissolved oxygen 2) requires cutting total phosphorus loads by 46% from the 2003–2011 average or reducing dissolved reactive phosphorus loads by 78% from the 2005–2011 average. Reductions to these levels are also protective of fish habitat. We provide potential approaches for achieving those new loading targets, and suggest that recent load reduction recommendations focused on western basin cyanobacteria blooms may not be sufficient to reduce central basin hypoxia to 2000 km2.

  5. Volcanic ash and its enigma: A case study from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.

    An ash layer occurs between 10-35 cm depth in sediment cores from the Central Indian Ocean basin. Morphology, major, trace and rare earth element composition of glass shards from the ash layer suggest that the Youngest Toba Tuff of ~74 ka from...

  6. Do manganese nodules grow or dissolve after burial? Results from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.P.S.

    Fifty buried manganese nodules at different depth intervals were recovered in 12 sediment cores from the Central Indian Ocean Basin (CIOB). A maximum of 15 buried nodules were encountered in one sediment core (AAS-22/GC-07) and the deepest nodule...

  7. Distribution of baroduric, psychrotrophic and culturable nitrifying and denitrifying bacteria in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; PradeepRam, A.S.; Nair, S.; Nath, B.N.; Chandramohan, D.

    The abundance of baroduric, culturable nitrifying and denitrifying bacteria in the deep-sea cores of Central Indian Basin (CIB) at ca 5000 m depth was investigated. Analysis of 8 cores, sampled between 10 degrees 00 minutes S and 75 degrees 55...

  8. AN INTERDISCIPLINARY APPROACH TO RIPARIAN MEADOW CHARACTERIZATION AND PRIORITIZATION, CENTRAL GREAT BASIN

    Science.gov (United States)

    The Great Basin Ecosystem Management Research group has described the hydrological, geophysical, and geomorphic conditions that lead to the formation and maintenance of riparian meadows of central Nevada. Previous work on these systems has focused on understanding a few study mea...

  9. Impacts on surface productivity during sediment dispersal experiment in Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Nath, B.N.; Ingole, B.S.; Parthiban, G.; Matondkar, S.G.P.; Raghukumar, C.; Khadge, N.H.; Valsangkar, A.B.; Suryanarayana, A.; Jaisankar, S.; Sharma, R.

    (SEDEX) was conducted in Central Indian Basin (CIB). A total of 675 liters of slurry prepared from 225 kg of wet sediment (330 g . l sup(-1)) was discharged on the surface during the experiment. Water samples were collected before and after the discharge...

  10. Distribution of deep-sea benthos in the proposed mining area of Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.

    During the first stage of the project work on the Indian Deep-Sea Environment Experiment (INDEX), the abundance and distribution of deep-sea benthos were surveyed in the Central Indian Basin for the collection of baseline data. The deep...

  11. Slope angle studies from multibeam sonar data on three seamounts in Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

    is presented here. The slope angle grid can be used to create the slope angle map. Morphology of three seamounts from Central Indian Basin and the slope angle data on them are described. The seamounts are of the heights 1000-1200 m and occupy area up to 300 sq...

  12. Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Hazra, S.

    The Central Indian Ocean Basin (CIOB) basalts are plagioclase-rich, while olivine and pyroxene are very few. The analyses of 41 samples reveal high FeO sup(T) (approx. 10-18 wt percent) and TiO sub(2) (approx. 1.4-2.7 wt percent) indicating a...

  13. Comparison of internal features and microchemistry of ferromanganese crusts from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    SEM/probe analyses of two ferromanganese crusts from the Central Indian Basin, formed on basalt substrate, reveal botryoids and cusps. The botryoids composed of delta-MnOs2, are enriched in Co, and the cusps and laminations with todorokite...

  14. Geological evolution, regional perspectives and hydrocarbon potential of the northwest Phu Khanh Basin, offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael Bryld Wessel; Nielsen, Lars H.; Boldreel, Lars Ole;

    2009-01-01

      Seismic stratigraphic and structural analyses of the northwest Phu Khanh Basin, offshore Central Vietnam, based on 2-D seismic data, indicate that the initial rifting began during the latest Cretaceous? or Palaeogene controlled by left-lateral transtension along the East Vietnam Boundary Fault ...

  15. Regional variability in occurrence and distribution of polymetallic nodules in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A; Rebello, J.M.S.

    Regional scale morphological studies on different-sized polymetallic nodules from the Central Indian Basin show that only 2–5 cm sized nodules have highest occurrence per station (92–94% along latitudes; 88–94% along longitudes). A nodule size shows...

  16. Geotechnical properties of deep-sea sediments from central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Physical and geotechnical properties of 2 sediment cores from the nodule rich area of the Central Indian Ocean Basin are studied to know the sediment characteristics. Average water content of sediment from 2 deep-sea cores is 289% with 151...

  17. Preliminary geotechnical properties of deepsea sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Geotechnical properties of the Plio-Pleistocene sediments from nodule bearing area in the Central Indian Basin have been studied to know shear strength and water content variation with depth. It reveals that surface sediments have low (less than 1 k...

  18. Middle Miocene chitons (Polyplacophora from the Slovak part of the Vienna Basin and the Danube Basin (Central Paratethys

    Directory of Open Access Journals (Sweden)

    Ruman Andrej

    2015-12-01

    Full Text Available We describe species-rich chiton assemblages from the Middle Miocene of the Slovak part of the Vienna Basin and the Danube Basin (Central Paratethys. They were found at five localities, including Devínska Nová Ves brickyard, Devínska Nová Ves-Útočnica, Rohožník clay pit, Kúty-45 borehole and Dubová. Thirteen species belong to eight genera from the families Leptochitonidae, Hanleyidae, Callochitonidae, Chitonidae, Tonicellidae and Acanthochitonidae. They occur predominantly in redeposited, moderately-sorted rhodolith-rich or well-sorted bioclastic layers of the Late Badenian age, and belong to lineages that presently inhabit warm-temperate and tropical regions.

  19. Geotechnical properties of siliceous sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    COMMUNICATIONS CURRENT SCIENCE, VOL. 82, NO. 3, 10 FEBRUARY 2002 Geotechnical properties of siliceous sediments from the Central Indian B a sin N. H. Khadge National Institute of Oceanography, Dona Paula, Goa 403 004, India Indian Deep - sea... , for baseline data collec - tion. A NW - SE trending strip of 3000 m length and RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 82, NO. 3, 10 FEBRUARY 2002 339 200 m width was selected for carrying out simulated disturbance studies in this area...

  20. Perchlorate in pleistocene and holocene groundwater in North-Central New Mexico

    Science.gov (United States)

    Plummer, L.N.; Böhlke, J.K.; Doughten, M.W.

    2006-01-01

    Groundwater from remote parts of the Middle Rio Grande Basin in north-central New Mexico has perchlorate (ClO4-) concentrations of 0.12-1.8 ??g/L Because the water samples are mostly preanthropogenic in age (0-28 000 years) and there are no industrial sources in the study area, a natural source of the ClO4- is likely. Most of the samples have Br-, Cl-, and SO42- concentrations that are similar to those of modern bulk atmospheric deposition with evapotranspiration (ET) factors of about 7-40. Most of the ET values for Pleistocene recharge were nearly twice that for Holocene recharge. The NO3-/Cl- and ClO4-/Cl- ratios are more variable than those of Br -/Cl- or SO42-/Cl-. Samples thought to have recharged under the most arid conditions in the Holocene have relatively high NO3-/Cl- ratios and low ??15N values (+1 per mil (???)) similar to those of modern bulk atmospheric N deposition. The ??18O values of the NO 3- (-4 to 0 ???) indicate that atmospheric N0 3- was not transmitted directly to the groundwater but may have been cycled in the soils before infiltrating. Samples with nearly atmospheric NO3-/Cl- ratios have relatively high ClO4- concentrations (1.0-1.8 ??g/L) with a nearly constant ClO4-/Cl- mole ratio of (1.4 ?? 0.1) ?? 10-4, which would be consistent with an average ClO 4- concentration of 0.093 ?? 0.005 ??g/L in bulk atmospheric deposition during the late Holocene in north-central NM. Samples thought to have recharged underwetter conditions have higher ??15N values (+3 to +8 ???), lower N03-/Cl- ratios, and lower ClO4-/Cl- ratios than the ones most likely to preserve an atmospheric signal. Processes in the soils that may have depleted atmospherically derived NO3- also may have depleted ClO4- to varying degrees prior to recharge. If these interpretations are correct, then ClO4- concentrations of atmospheric origin as high as 4 ??g/L are possible in preanthropogenic groundwater in parts of the Southwest where ET approaches a factor of 40. Higher ClO4

  1. Aerosol optical depth over central north Asia based on MODIS-Aqua data

    Science.gov (United States)

    Avgousta Foutsi, Athina; Korras Carraca, Marios Bruno; Matsoukas, Christos; Biskos, George

    2016-04-01

    Atmospheric aerosols, both natural and anthropogenic, can affect the regional and global climate through their direct, indirect, and semi-direct effects on the radiative energy budget of the Earth-atmosphere system. To quantify these effects it is important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). The central Asia region (mainly the Caspian and Aral sea basins), the arid and semi-arid regions of Western China as well as Siberia are of great interest due to the significant natural sources of mineral aerosols originating from local deserts and biomass burning from wildfires in boreal forests. What is of particular interest in the region is the phenomenal shrinking and desertification of the Aral Sea that drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions with important implications in regional air quality. Anthropogenic particles are also observed due to fossil-fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Here we investigate the spatial and temporal variability of the AOD at 550 nm over central Asia, Siberia and western China, in the region located between 35° N - 65° N and 45° E - 110° E. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest collection (006), available in a 1°×1° resolution (ca. 100 km × 100 km) over the period 2002-2014. Our results indicate a significant spatial variability of the aerosol load over the study region. The highest AODs are observed over the Aral Sea year-round, with extreme values reaching 2.1 during July. In the rest of our study region a clear seasonal cycle with highest AOD values (up to 1.2 over the Taklamakan Desert) during spring and summer is observed. The arid parts of central north Asia are characterized by larger aerosol loads during spring, lower but still high AOD in summer and much lower values in autumn and spring

  2. Project plan-Surficial geologic mapping and hydrogeologic framework studies in the Greater Platte River Basins (Central Great Plains) in support of ecosystem and climate change research

    Science.gov (United States)

    Berry, Margaret E.; Lundstrom, Scott C.; Slate, Janet L.; Muhs, Daniel R.; Sawyer, David A.; Van Sistine, Darren R.

    2011-01-01

    The Greater Platte River Basin area spans a central part of the Midcontinent and Great Plains from the Rocky Mountains on the west to the Missouri River on the east, and is defined to include drainage areas of the Platte, Niobrara, and Republican Rivers, the Rainwater Basin, and other adjoining areas overlying the northern High Plains aquifer. The Greater Platte River Basin contains abundant surficial deposits that were sensitive to, or are reflective of, the climate under which they formed: deposits from multiple glaciations in the mountain headwaters of the North and South Platte Rivers and from continental ice sheets in eastern Nebraska; fluvial terraces (ranging from Tertiary to Holocene in age) along the rivers and streams; vast areas of eolian sand in the Nebraska Sand Hills and other dune fields (recording multiple episodes of dune activity); thick sequences of windblown silt (loess); and sediment deposited in numerous lakes and wetlands. In addition, the Greater Platte River Basin overlies and contributes surface water to the High Plains aquifer, a nationally important groundwater system that underlies parts of eight states and sustains one of the major agricultural areas of the United States. The area also provides critical nesting habitat for birds such as plovers and terns, and roosting habitat for cranes and other migratory birds that travel through the Central Flyway of North America. This broad area, containing fragile ecosystems that could be further threatened by changes in climate and land use, has been identified by the USGS and the University of Nebraska-Lincoln as a region where intensive collaborative research could lead to a better understanding of climate change and what might be done to adapt to or mitigate its adverse effects to ecosystems and to humans. The need for robust data on the geologic framework of ecosystems in the Greater Platte River Basin has been acknowledged in proceedings from the 2008 Climate Change Workshop and in draft

  3. Comparative Study of Basins within Palaeogene Seaway in East China and Cretaceous Seaway in North America and Its Reservoir Significance

    Institute of Scientific and Technical Information of China (English)

    Wu Xiantao

    2007-01-01

    The well known Cretaceous seaway in North America was recognized in the middle of the last century and the Palaeogene seaway in East China was proposed by the author recently. The two seaways located on the opposite sides of North Pacific Ocean may be not a coincidence,and a comparative study was made in this paper. The results show that the two seaways inundated basins share several similarities particularly in basin origin,filling processes and reservoir facies. It is suggested that reservoir facies of estuarine sandstone and shelf bar sandstone related to sea level fluctuation,which are well developed in the Cretaceous seaway covered basins in North America might have been also developed here in Palaeogene seaway inundated basins in East China. Therefore it is worth paying more attention to finding these new reservoir facies on this side of the Pacific ocean. Evidences of sedimentology and ichnology indicate that good prospects are likely.

  4. The Sulfur content and origin of the North Thrace Basin coals, Turkey

    Science.gov (United States)

    Erarslan, Cemile; Örgün, Yüksel; Çelik Balcı, Nurgül

    2016-04-01

    Sulfur (S) is one of the major and hazardous components of the coal, and it may be originated from different sources depending on coal formation. The defined main sulfur types in the coal are pyritic sulfur, organic sulfur and sulfate sulfur. Thrace basin which have approximately 2 billion tons coal reserves is one of the most important coal basins of Turkey and Edirkoy (Saray-Tekirdaǧ) is the largest coal production site in north of Thrace basin. The obtained results show that the total S contents in the Edirköy coal samples vary from 3.21 to 14.1%. According to this result, the coal in Edirköy field is in the form of high -sulfur coal and the sulfur types analysis indicate that the ratio of pyritic sulfur vary from 0.78 to 5.25%, the organic sulfur vary from 1.1 to 7.47 % and the sulfate sulfur vary from 0.54 to 1.38% in the field. It was revealed that the ratio of organic sulfur in the coal increase towards the north of the field. In this study, the sulfur content and origin of the coal in Edirköy field will be discussed with sulfur isotope data.

  5. Storing CO{sub 2} under the North Sea Basin - A key solution for combating climate change

    Energy Technology Data Exchange (ETDEWEB)

    Skogen, T; Morris, B; Agerup, M; Svenningsen, S Oe; Kropelien, K F; Solheim, M; Northmore, B; Dixon, T; O' Carroll, K; Greaves, A; Golder, J; Selmer-Olsen, S; Sjoeveit, A; Kaarstad, O; Riley, N; Wright, I; Mansfield, C

    2007-06-15

    This report represents the first deliverable of the North Sea Basin Task Force, which Norway and the UK established in November 2005 to work together on issues surrounding the transport and storage of CO{sub 2} beneath the North Sea. The North Sea represents the best geological opportunity for storing our CO{sub 2} emissions away from the atmosphere for both the UK and Norway

  6. Central Wind Forecasting Programs in North America by Regional Transmission Organizations and Electric Utilities: Revised Edition

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.; Porter, K.

    2011-03-01

    The report and accompanying table addresses the implementation of central wind power forecasting by electric utilities and regional transmission organizations in North America. The first part of the table focuses on electric utilities and regional transmission organizations that have central wind power forecasting in place; the second part focuses on electric utilities and regional transmission organizations that plan to adopt central wind power forecasting in 2010. This is an update of the December 2009 report, NREL/SR-550-46763.

  7. Evidence for a broadly distributed Samoan-plume signature in the northern Lau and North Fiji Basins

    Science.gov (United States)

    Price, Allison A.; Jackson, Matthew G.; Blichert-Toft, Janne; Hall, Paul S.; Sinton, John M.; Kurz, Mark D.; Blusztajn, Jerzy

    2014-04-01

    enrichment of lavas in the northern Lau Basin may reflect the influx of Samoan-plume mantle into the region. We report major and trace element abundances and He-Sr-Nd-Hf-Pb-isotopic measurements for 23 submarine volcanic glasses covering 10 locations in the northern Lau and North Fiji Basins, and for three samples from Wallis Island, which lies between Samoa and the Lau Basin. These data extend the western limit of geochemical observations in the Basins and improve the resolution of North-South variations in isotopic ratios. The Samoan hot spot track runs along the length of the northern trace of the Lau and North Fiji Basins. We find evidence for a Samoan-plume component in lavas as far West as South Pandora Ridge (SPR), North Fiji Basin. Isotopic signatures in SPR samples are similar to those found in Samoan Upolu shield lavas, but show a slight shift toward MORB-like compositions. We explain the origin of the enriched signatures by a model in which Samoan-plume material and ambient depleted mantle undergo decompression melting during upwelling after transiting from beneath the thick Pacific lithosphere to beneath the thin lithosphere in the northern Lau and North Fiji Basins. Other lavas found in the region with highly depleted isotopic signatures may represent isolated pockets of depleted mantle in the basins that evaded this enrichment process. We further find that mixing between the two components in our model, a variably degassed high-3He/4He Samoan component and depleted MORB, can explain the diversity among geochemical data from the northern Lau Basin.

  8. Composition of macrobenthos from the central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pavithran, S.; Ingole, B.S.; Nanajkar, M.; Raghukumar, C.; Nath, B.N.; Valsangkar, A.B.

    nodules (Prasad 2007). However, of the three oceans, the Indian Ocean is the least studied in terms of deep sea fauna. Benthic organisms play an important role as food for large carnivores and some sediment-dwelling forms influence the mixing of organic... distribution; Central Indian Ocean. J. Earth Syst. Sci. 118, No. 6, December 2009, pp. 689–700 © Indian Academy of Sciences 689 690 S Pavithran et al Figure 1. (a) CIOB and (b) depth contours (meters) and box core locations in the CIOB. available organic carbon...

  9. Preliminary Results From the CAUGHT Experiment: Investigation of the North Central Andes Subsurface Using Receiver Functions and Ambient Noise Tomography

    Science.gov (United States)

    Ryan, J. C.; Ward, K. M.; Porter, R. C.; Beck, S. L.; Zandt, G.; Wagner, L. S.; Minaya, E.; Tavera, H.

    2011-12-01

    Jamie Ryan, Kevin M. Ward, Ryan Porter, Susan Beck, George Zandt, Lara Wagner, Estela Minaya, and Hernando Tavera The University of Arizona The University of North Carolina San Calixto Observatorio, La Paz, Bolivia IGP, Lima, Peru In order to investigate the interplay between crustal shortening, lithospheric removal, and surface uplift we have deployed 50 broadband seismometers in northwestern Bolivia and southern Peru as part of the interdisciplinary Central Andean Uplift and Geodynamics of High Topography (CAUGHT) project. The morphotectonic units of the central Andes from west to east, consist of the Western Cordillera, the active volcanic arc, the Altiplano, an internally drained basin (~4 km elevation), the Eastern Cordillera, the high peaks (~6 km elevation) of an older fold and thrust belt, the Subandean zone, the lower elevation active fold and thrust belt, and the foreland Beni basin. Between northwestern Bolivia and southern Peru, the Altiplano pinches out north of Lake Titicaca as the Andes narrow northward. The CAUGHT seismic instruments were deployed between 13° to 18° S latitudes to investigate the crust and mantle lithosphere of the central Andes in this transitional zone. In northwest Bolivia, perpendicular to the strike of the Andes, there is a total of 275 km of documented upper crustal shortening (15° to 17°S) (McQuarrie et al, 2008). Associated with the shortening is crustal thickening and possibly lithospheric removal as the thickening lithospheric root becomes unstable. An important first order study is to compare upper crustal shortening estimates with present day crustal thickness. To estimate crustal thickness, we have calculated receiver functions using an iterative deconvolution method and used common conversion point stacking along the same profile as the geologically based shortening estimates. In our preliminary results, we observed a strong P to S conversion corresponding to the Moho at approximately 60-65 km depth underneath the

  10. From the North-Iberian Margin to the Alboran Basin: A lithosphere geo-transect across the Iberian Plate

    Science.gov (United States)

    Carballo, A.; Fernandez, M.; Jiménez-Munt, I.; Torne, M.; Vergés, J.; Melchiorre, M.; Pedreira, D.; Afonso, J. C.; Garcia-Castellanos, D.; Díaz, J.; Villaseñor, A.; Pulgar, J. A.; Quintana, L.

    2015-11-01

    A ~ 1000-km-long lithospheric transect running from the North-Iberian Margin to the Alboran Basin (W-Mediterranean) is investigated. The main goal is to image the changes in the crustal and upper mantle structure occurring in: i) the North-Iberian margin, whose deformation in Alpine times gave rise to the uplift of the Cantabrian Mountains related to Iberia-Eurasia incipient subduction; ii) the Spanish Meseta, characterized by the presence of Cenozoic basins on top of a Variscan basement with weak Alpine deformation in the Central System, and localized Neogene-Quaternary deep volcanism; and iii) the Betic-Alboran system related to Africa-Iberia collision and the roll-back of the Ligurian-Tethyan domain. The modeling approach, combines potential fields, elevation, thermal, seismic, and petrological data under a self-consistent scheme. The crustal structure is mainly constrained by seismic data whereas the upper mantle is constrained by tomographic models. The results highlight the lateral variations in the topography of the lithosphere-asthenosphere boundary (LAB), suggesting a strong lithospheric mantle strain below the Cantabrian and Betic mountain belts. The LAB depth ranges from 180 km beneath the Cantabrian Mountains to 135-110 km beneath Iberia Meseta deepening again to values of 160 km beneath the Betic Cordillera. The Central System, with a mean elevation of 1300 m, has a negligible signature on the LAB depth. We have considered four lithospheric mantle compositions: a predominantly average Phanerozoic in the continental mainland, two more fertile compositions in the Alboran Sea and in the Calatrava Volcanic Province, and a hydrated uppermost mantle in the North-Iberian Margin. These compositional differences allowed us to reproduce the main trends of the geophysical observables as well as the inferred P- and S-wave seismic velocities from tomography models and seismic experiments available in the study transect. The high mean topography of Iberia can be

  11. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    K. ANTONAKAKIS

    2012-12-01

    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  12. Petroleum source rocks of western and central Africa : the examples of the marine Tarfaya Basin, Morocco and the continental Congo Basin, Democratic Republic of Congo

    OpenAIRE

    Sachse, Victoria Frederike

    2011-01-01

    This study comprises newly collected organic geochemical and petrological data on quality, quantity, maturity as well as the depositional environment of various organic matter-rich stratigraphic units in Morocco and the Central Congo Basin, DRC. In addition, 1D modeling was carried out for one locality in northern Morocco (Aït Moussa) and for two wells from the Central Congo Basin to obtain information on burial thermal and maturation history. For the Aït Moussa model, specific bulk kinetic p...

  13. Sup(14)C activity of dissolved organic carbon fractions in the north-central Pacific and Sargasso Sea

    International Nuclear Information System (INIS)

    Radiocarbon measurements of dissolved organic carbon (DOC) oxidizable by ultraviolet irradiation (DOCuv) yielded apparent ages of ∼6,000 yr in the deep waters of the oligotrophic north-central Pacific gyre. Recent reports of a potentially larger pool of DOC as measured by high-temperature catalytic combustion (DOChtc) using discrete injections of sea water have led to speculation that 'younger', more recently produced DOC could contribute significantly to overall oceanic organic carbon fluxes, owing to its suspected greater biological lability. Here we present a comparison of Δ14C (the deviation in parts per thousand from the 14C activity of nineteenth-century wood) of the DOChtc, DOCuv and humic substances in profiles from the oligotrophic north-central Pacific and Sargasso Sea. For each ocean, the Δ14C values of all three fractions are remarkably similar, yielding no evidence for a component of DOC that is cycled through the system on timescales shorter than several thousands of years. We observe an age difference between the two oceans of ∼2,000 yr for the deepest DOC, which can largely be accounted for by differences in the Δ14C of the DOC sources to the deep basins, and by the different deep-water circulation patterns and transit times in the two oceans. (author)

  14. Contribution of cephalopod prey to the diet of large pelagic fish predators in the central North Atlantic Ocean

    Science.gov (United States)

    Logan, John M.; Toppin, Rebecca; Smith, Sean; Galuardi, Benjamin; Porter, Julie; Lutcavage, Molly

    2013-10-01

    Trophic studies documenting the importance of cephalopod prey for large pelagic fish predators have been performed recently for open ocean ecosystems in the Pacific and Indian oceans, but similar data for the central North Atlantic Ocean have been lacking. A series of longline sampling cruises targeting large pelagic fish species was undertaken in the central North Atlantic Ocean in 2001-2002, and stomach samples were analyzed from a variety of tuna, shark, and billfish species to help fill this data gap. Stomach samples were collected from nine species (n=170 non-empty stomachs), with the majority of stomachs from Atlantic swordfish (Xiphias gladius; n=69), yellowfin tuna (Thunnus albacares; n=31), and albacore tuna (Thunnus alalunga; n=28). Ommastrephid squids were the most ubiquitous prey group across predator species and sampling years. Secondary cephalopod prey included octopods, histioteuthids, and architeuthids. Mesopelagic fishes and Sargassum-associated fishes were also identified as important prey. Diet composition varied spatially and prey size increased with predator size for swordfish and yellowfin tuna. Our results support findings in other ocean basins that demonstrate the importance of squid to large pelagic fishes and highlight the need for more research on their ecological and biophysical dynamics.

  15. Anthropogenic soils on spoil rock banks in North Bohemian Coal Basin, Czech Republic

    International Nuclear Information System (INIS)

    The area of the North Bohemian Coal Basin is devastated by the extensive exploitation of brown coal by open pit mining. Knowledge of newly formed soils, their properties, development and contamination is important from the point of view of biological regeneration of the landscape. The mineralogy of anthropogenic soils from the mining area is presented together with the geochemistry of nutrients and trace elements. Attention is paid to the soil-forming processes in the non-reclaimed spoil rock banks with the development of spontaneous vegetation. 3 refs., 1 fig., 4 tabs

  16. Aksaray and Ecemis faults - Diapiric salt relationships: relevance to the hydrocarbon exploration in the Tuz Golu (Salt Lake) Basin, Central Anatolia, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Coskun, Bulent [Ankara Univ., Dept. of Geology, Tandogan (Turkey)

    2004-09-15

    Due to activity of the Aksaray and Ecemis Faults, volcanic intrusion and westward movement of the Anatolian plate, diapiric salt structures were occurred in the Tuz Golu (Salt Lake) basin in central Anatolia, Turkey. With the collisions of the Arabian and Anatolian plates during the late Cretaceous and Miocene times, prominent ophiolitic obduction occurred in the Pontides and Taurides along the North Anatolian Fault (NAF) and East Anatolian Fault (EAF). The NAF and EAF intersect each other in the Karliova region, in eastern Turkey. At this point, due to the northward movement of the Arabian plate in SE Turkey, the Anatolian plate shifted toward the west and south along the fault zones. The same geological tectonic model is proposed at the intersection point of the Aksaray Fault (AF) and Ecemis Fault (EF) in central Anatolia. The westward movement of the Anatolian plate between these two faults resulted in the formation of the diapiric salt structures, volcanic intrusions and overpressure zones in the study area. Paleogeological reconstructions of the Tuz Golu basin indicate that the salient positive structures in the basin were formed during late Eocene-Oligocene times. These structures, like the Yeniceoba-Bezirci and Karapinar-Kochisar trends, are oriented in a NW-SE or N-S directions between the Kirsehir and Sivrihisar-Bozdag massifs. The subsidence rate and Paleogeographic evolutions in the basin show that the southeastern sector of the Tuz Golu basin remained shallower relative to the central and northwestern regions. Based on the paleostructural, subsidence and geothermal reconstructions, it has been concluded that the oil generation and migration zones and geothermal trends are oriented in a NW-SE direction in the Tuz Golu basin. (Author)

  17. Statistical Aspects of Tropical Cyclone Activity in the North Atlantic Basin, 1945-2010

    Science.gov (United States)

    Wilson, Robert M.

    2012-01-01

    Examined are statistical aspects of the 715 tropical cyclones that formed in the North Atlantic basin during the interval 1945-2010. These 715 tropical cyclones include 306 storms that attained only tropical storm strength, 409 hurricanes, 179 major or intense hurricanes, and 108 storms that struck the US coastline as hurricanes. Comparisons made using 10-year moving average (10-yma) values between tropical cyclone parametric values and surface air and ENSO-related parametric values indicate strong correlations to exist, in particular, against the Armagh Observatory (Northern Ireland) surface air temperature, the Atlantic Multi-decadal Oscillation (AMO) index, the Atlantic Meridional Mode (AMM) index, and the North Atlantic Oscillation (NAO) index, in addition to the Oceanic Ni o index (ONI) and Quasi-Biennial Oscillation (QBO) indices. Also examined are the decadal variations of the tropical cyclone parametric values and a look ahead towards the 2012 hurricane season and beyond.

  18. Cation export by overland flow in a recently burnt forest area in north-central Portugal.

    Science.gov (United States)

    Machado, A I; Serpa, D; Ferreira, R V; Rodríguez-Blanco, M L; Pinto, R; Nunes, M I; Cerqueira, M A; Keizer, J J

    2015-08-15

    The current fire regime in the Mediterranean Basin constitutes a serious threat to natural ecosystems because it drastically enhances surface runoff and soil erosion in the affected areas. Besides soil particles themselves, soil cations can be lost by fire-enhanced overland flow, increasing the risk of fertility loss of the typically shallow and nutrient poor Mediterranean soils. Although the importance of cations for land-use sustainability is widely recognized, cation losses by post-fire runoff have received little research attention. The present study aimed to address this research gap by assessing total exports of Na(+), K(+), Ca(2+) and Mg(2+) in a recently burnt forest area in north-central Portugal. These exports were compared for two types of planted forest (eucalypt vs. maritime pine plantations), two types of parent materials (schist vs. granite) and for two spatial scales (micro-plot vs. hill slope). The study sites were a eucalypt plantation on granite (BEG), a eucalypt plantation on schist (BES) and a maritime pine plantation on schist (BPS). Overland flow samples were collected during the first six months after the wildfire. Cation losses differed strikingly between the two forest types on schist, being higher at the eucalypt than pine site. This difference was evident at both spatial scales, and probably due to the extensive cover of a needle cast from the scorched pine crowns. The role of parent material in cation export was less straightforward as it varied with spatial scale. Cation losses were higher for the eucalypt plantation on schist than for that on granite at the micro-plot scale, whereas the reverse was observed at the hill slope scale. Finally, cation yields were higher at the micro-plot than slope scale, in agreement with the general notion of scaling-effect in runoff generation. PMID:25897728

  19. Evaluation of water resources in part of north-central Texas

    International Nuclear Information System (INIS)

    Water resources within the North-Central Texas Region which lies in the Brazos, Red, Sulphur, Sabine, and Trinity River basins, were evaluated. The geologic formations underlying the study area range in age from Paleozoic to Recent. The principal water-bearing formations are the Antlers, Twin Mountains, and Paluxy Formations of the Trinity Group, and the Woodbine Group, all of Cretaceous age. Extensive cones of depression have developed in the piezometric surface of each of the region's principal aquifers, coinciding with areas of large groundwater withdrawals. During the 13-year period 1976 to 1989, water level declines of 25 ft were common in the aquifers studied. The study identified a number of existing and potential water quality problems. Some of these are naturally occurring and are related to geologic structure. Elevated levels of some chemical constituents suggest contamination related to oil-field activities and other industrial sources. The projected water demands for the study area by the year 2010 total over 1.4 million acre-ft. Existing surface-water reservoirs can supply 1.6 million acre ft of water under 2010 conditions. The amount of groundwater currently pumped exceeds the estimated annual effective recharge to the area's aquifers; a portion of the water pumped is drawn from aquifer storage resulting in water level declines. Even though the study area has sufficient surface water to meet projected needs through 2010, rural areas that depend on a groundwater supply could face shortages before 2010 due to the limited availability of groundwater and the high cost of converting to a surface water supply. 93 refs., 19 figs., 3 tabs

  20. A Geochemical Transect Across the Lau and North Fiji Basins: New Evidence for the Distribution of Multiple Mantle Plume Components

    Science.gov (United States)

    Price, A. A.; Jackson, M. G.; Blichert-Toft, J.; Arculus, R. J.; Conatser, C. S.; Konter, J. G.; Koppers, A. A. P.; Blusztajn, J.

    2014-12-01

    The Lau and North Fiji backarc basins are located in a tectonically complex region of the South Pacific, where the upper mantle may have been modified by up to five hotspots (Samoa, Rurutu, Rarotonga, Macdonald, and Louisville), each with distinct geochemical fingerprints. We present new Hf, Nd, Sr, and Pb isotopic data for basaltic samples dredged from seven areas along an east-west transect spanning the Lau and North Fiji basins to determine the possible influence and distribution of these various hotspot sources. We find that the isotope ratios of nearly all samples can be explained by mixing a depleted mantle component, which is ubiquitous in the Lau Basin, with a component similar to that found in Samoan shield (EMII) and/or rejuvenated (EMI) lavas. Lavas as far southwest as the Fiji Triple Junction (North Fiji Basin) show enriched geochemical signatures (87Sr/86Sr and 206Pb/204Pb up to 0.7037 and 18.635 respectively, and 143Nd/144Nd and 176Hf/177Hf down to 0.51285 and 0.283023, respectively) trending toward Samoa. This observation extends the range of Samoan influence into the North Fiji Basin 400 km south of its previous observed extent at South Pandora Ridge. The few samples that cannot be explained solely by incorporation of Samoan material are from the northeastern Lau Basin (Falloon et al., 2007) and host a dilute HIMU component that may relate to the incorporation of material from the Rurutu hotspot. This component is not observed further to the west in the Lau and North Fiji basins. A ubiquitous EMI signature in the region may be linked to the Rarotonga hotspot. New dredges from the northeast Lau Basin may give clearer signals that will reveal the identity of the enriched plume component.

  1. Impacts of global change on water-related sectors and society in a trans-boundary central European river basin - Part 1: project framework and impacts on agriculture

    Science.gov (United States)

    Hattermann, F. F.; Gömann, H.; Conradt, T.; Kaltofen, M.; Kreins, P.; Wechsung, F.

    2007-06-01

    Central Europe, the focus region of this study, is a region in transition, climatically from maritime to continental and politically from formerly more planning-oriented to more market-oriented management regimes, and in terms of climate change from regions of increasing precipitation in the west and north of Europe to regions of decreasing precipitation in central and southern Europe. The Elbe basin, a trans-boundary catchment flowing from the Czech Republic through Germany into the North Sea, was selected to investigate the possible impacts of global change on crop yields and water resources in this region. For technical reasons, the paper has been split into two parts, the first showing the overall model concept, the model set-up for the agricultural sector, and first results linking eco-hydrological and agro-economic tools for the German part of the basin. The second part describes the model set-up for simulating water supply and demand linking eco-hydrological and water management tools for the entire basin including the Czech part.

  2. Meso-Cenozoic Tectono-Thermal Evolution History in Bohai Bay Basin, North China

    Institute of Scientific and Technical Information of China (English)

    Yinhui Zuo; Nansheng Qiu; Jiawei Li; Qingqing Hao; Xiongqi Pang; Zhongying Zhao; Qi Zhu

    2015-01-01

    The thermal history of sedimentary basins is a key factor for hydrocarbon accumula-tion and resource assessment, and is critical in the exploration of lithospheric tectono-thermal evo-lution. In this paper, the Cenozoic thermal histories of nearly 200 wells and the Mesozoic thermal histories of 15 wells are modeled based on the vitrinite reflectance and apatite fission track data in Bohai Bay Basin, North China. The results show that the basin experienced Early Cretaceous and Paleogene heat flow peaks, which reveals two strong rift tectonic movements that occurred in the Cretaceous and the Paleogene in the basin, respectively. The thermal evolution history in Bohai Bay Basin can be divided into five stages including (1) the low and stable heat flow stage from the Trias-sic to the Jurassic, with the heat flow of 53 to 58 mW/m2;(2) the first heat flow peak from the Early Cretaceous to the middle of the Late Cretaceous, with a maximum heat flow of 81 to 87 mW/m2;(3) the first post-rift thermal subsidence stage from the middle of the Late Cretaceous to the Paleocene, with the heat flow of 65 to 74 mW/m2 at the end of the Cretaceous; (4) the second heat flow peak from the Eocene to the Oligocene, with a maximum heat flow of 81 to 88 mW/m2;and (5) the second thermal subsidence stage from the Neogene to present, with an average heat flow of 64 mW/m2.

  3. The spatial variability of Chernobyl-derived 137Cs inventories in a small agricultural drainage basin in central Russia

    International Nuclear Information System (INIS)

    Little information currently exists regarding the small-scale spatial variability of Chernobyl radiocaesium fallout and associated inventories. This contribution reports the results of a study of the variability of 137Cs inventories within the 2.18-km2 Lapki balka catchment located near Tula in central Russia. The local area was characterized by 137Cs inventories in excess of 200 kBq m-2 immediately after the Chernobyl accident and pre-existing bomb-derived inventories can be ignored in view of their very low magnitude. Field sampling and measurements included both collection of soil cores for subsequent laboratory analysis and in situ field measurements using a CORAD portable detector. The results obtained show evidence of a systematic south-north increase in the reference inventory across the basin, which must be taken into account when interpreting subsequent radiocaesium redistribution within the basin. Random spatial variability of 137Cs inventories of a similar magnitude to that reported for bomb-derived fallout was also documented. The extent of random spatial variability varied between different geomorphological units. Maximum variability, with coefficients of variation up to 20%,was associated with areas of sediment accumulation within the balka bottoms. Substantial variability (cv. typically ca. 15%) was found within flat cultivated areas and undisturbed areas both on the interfluves and on the balka sides, all of which could serve as reference sites. Minimum variability (cv. typically ca. 12%) was associated with the cultivated slopes with no evidence of sediment accumulation

  4. Plate tectonic reconstructions and paleogeographic maps of the central and North Atlantic oceans

    OpenAIRE

    Sibuet, Jean-Claude; Rouzo, Stephane; Srivastava, Shiri

    2012-01-01

    We have established a new plate kinematic model of the central and North Atlantic oceans between North America, Africa, Meseta, Iberia, Flemish Cap, and Galicia Bank from Late Triassic to Late Cretaceous to better understand the nature and timing of rifting of Nova Scotia and Morocco conjugate continental margins since Late Triassic. The maps of salt distributions at the Sinemurian-Pliensbachian limit (190 Ma; after salt deposition) and in middle Bajocian (170 Ma) show that an area of the Nov...

  5. Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T. [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K. [Phillips Petroleum Co., Bartlesville, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States)

    1998-12-31

    The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

  6. Evolution of physical and biological characteristics of mesoscale eddy in north-central Red Sea

    KAUST Repository

    Zarokanellos, Nikolaos

    2015-04-01

    Eddies appear to be important to both the physical and biogeochemical dynamics of the Red Sea. Numerical simulations of physical dynamics and remote sensing studies of chlorophyll concentration and sea surface height in the Red Sea indicate their importance to the upper portions of the sea (Raitsos et al., 2013; Yao et al., 2014; Zhan et al., 2014). Despite their apparent importance, process studies of these eddies have been lacking. In March 2013 we began an extended observational study of the north-central Red Sea (NCRS) where anticyclonic eddies have been observed. The study began with a ship-based characterization of the eddy and was followed by a three-month observational time series using an autonomous glider equipped with a CTD, oxygen sensor, and optical sensors for chlorophyll, CDOM and optical backscatter. The ship-based study captured an initial snapshot of an anticyclonic eddy and it\\'s associated biological and bio-optical distributions. Initially, chlorophyll distributions tended to mirror the density distribution, with deeper isopycnals and chlorophyll maximum depth in the anticyclonic eddy center. The anticyclone eddy in March had an along basin diameter of 150 km, penetrated vertically less than 150 m and elevated near surface chlorophyll concentrations appeared along its outer boundary. The shallowing of the pycnocline of the outer boundaries of the anticyclone eddy on March may elevate nutrients into the lower euphotic zone, contributing to phytoplankton productivity and biomass within the eddy. This eddy contains most of the kinetic energy of the region with the maximum velocities up to 30 - 35 cm/s. The eddy appeared to interact with the coastal reefs where exchange particulate and dissolved matter may occur. The autonomous glider provided the spring-to-summer progression of the system with increasing stratification, shallowing of the subsurface chlorophyll maximum, and fluctuations in the position and intensity of the eddy. Our glider effort

  7. Late Miocene biogeography and paleoclimatology of the central North Atlantic

    Science.gov (United States)

    Poore, R.Z.

    1981-01-01

    Quantitative analyses of planktonic foraminiferal assemblages from Deep Sea Drilling Project (DSDP) Holes 334 and 410 demonstrate that subpolar and subtropical faunal provinces existed in the North Atlantic during the late Miocene. Climatic oscillations are clearly recorded in Hole 410 by variations in abundance of the Neogloboquadrina subpolar assemblage. These climatic oscillations have a period of about 1 m.y. Higher frequency oscillations with a periodicity of one to several hundred thousand years are evident from about 6.5 to 7.5 m.y. and are probably present throughout the entire late Miocene. A revised age of 7.0 m.y. is proposed for the first occurrence of the calcareous nannofossil Amaurolithus primus (the Amaurolithus datum). ?? 1981.

  8. Drivers of summer oxygen depletion in the central North Sea

    Science.gov (United States)

    Queste, Bastien Y.; Fernand, Liam; Jickells, Timothy D.; Heywood, Karen J.; Hind, Andrew J.

    2016-02-01

    In stratified shelf seas, oxygen depletion beneath the thermocline is a result of a greater rate of biological oxygen demand than the rate of supply of oxygenated water. Suitably equipped gliders are uniquely placed to observe both the supply through the thermocline and the consumption of oxygen in the bottom layers. A Seaglider was deployed in the shallow (≍ 100 m) stratified North Sea in a region of known low oxygen during August 2011 to investigate the processes regulating supply and consumption of dissolved oxygen below the pycnocline. The first deployment of such a device in this area, it provided extremely high-resolution observations, 316 profiles (every 16 min, vertical resolution of 1 m) of conductivity, temperature, and depth (CTD), dissolved oxygen concentrations, backscatter, and fluorescence during a 3-day deployment.The high temporal resolution observations revealed occasional small-scale events (North Sea. However, the glider data show a net oxygen consumption rate of 2.8 ± 0.3 µmol dm-3 day-1, indicating a localized or short-lived (< 200 m or 6 h) increase in oxygen consumption rates. This high rate of oxygen consumption is indicative of an unidentified oxygen sink. We propose that this elevated oxygen consumption is linked to localized depocentres and rapid remineralization of resuspended organic matter.The glider proved to be an excellent tool for monitoring shelf sea processes despite challenges to glider flight posed by high tidal velocities, shallow bathymetry, and very strong density gradients. The direct observation of these processes allows more up to date rates to be used in the development of ecosystem models.

  9. Age and paleoenvironmental reconstruction of partially remagnetized lacustrine sedimentary rocks (Oligocene Aktoprak basin, central Anatolia, Turkey)

    Science.gov (United States)

    Meijers, Maud J. M.; Strauss, Becky E.; Özkaptan, Murat; Feinberg, Joshua M.; Mulch, Andreas; Whitney, Donna L.; Kaymakçı, Nuretdin

    2016-03-01

    The age and paleoenvironmental record of lacustrine deposits in the Aktoprak basin of south-central Turkey provides information about the evolution of topography, including the timing of development of an orographic rain shadow caused by uplift of the mountain ranges fringing the Central Anatolian Plateau. New magnetostratigraphy-based age estimates, in combination with existing biostratigraphic ages, suggest that the partially remagnetized Kurtulmuş Tepe section of the basin is Chattian (Upper Oligocene). The mean carbon and oxygen stable isotope ratios (δ18O= 24.6 ± 2.0 ‰, δ13C= -4.9 ± 1.1‰) are largely constant through the section and indicative of a subtropical, open freshwater lake. These isotopic values are also similar to those of the Chattian Mut basin to the south, on the Mediterranean side of the modern orographic barrier (Tauride Mountains), and indicate absence of an orographic barrier during Late Oligocene basin deposition. Post-depositional partial remagnetization occurred after tilting of the basin sequence and was mineralogically controlled, affecting grey, carbonate-rich rocks (average %CaCO3= 82), whereas interlayered pink carbonate-poor rocks (average %CaCO3= 38) carry a primary, pretilt magnetization. The pink rocks are rich in clay minerals that may have reduced the permeability of these rocks that carry a primary magnetization, concentrating basinal fluid flow in the carbonate-rich grey layers and leading to the removal and reprecipitation of magnetic minerals. The normal and reverse polarities recorded by the remagnetized rocks suggest that remagnetization occurred over a protracted period of time.

  10. Tectono-climatic implications of Eocene Paratethys regression in the Tajik basin of central Asia

    Science.gov (United States)

    Carrapa, Barbara; DeCelles, Peter G.; Wang, Xin; Clementz, Mark T.; Mancin, Nicoletta; Stoica, Marius; Kraatz, Brian; Meng, Jin; Abdulov, Sherzod; Chen, Fahu

    2015-08-01

    Plate tectonics and eustatic sea-level changes have fundamental effects on paleoenvironmental conditions and bio-ecological changes. The Paratethys Sea was a large marine seaway that connected the Mediterranean Neotethys Ocean with Central Asia during early Cenozoic time. Withdrawal of the Paratethys from central Asia impacted the distribution and composition of terrestrial faunas in the region and has been largely associated with changes in global sea level and climate such as cooling associated with the Eocene/Oligocene transition (EOT). Whereas the regression has been dated in the Tarim basin (China), the pattern and timing of regression in the Tajik basin, 400 km to the west, remain unresolved, precluding a test of current paleogeographic models. Here we date the Paratethys regression in Tajikistan at ca. 39 million years ago (Ma), which is several million years older than the EOT (at ca. 34 Ma) marking the greenhouse to icehouse climate transition of the Cenozoic. Our data also show a restricted, evaporitic marine environment since the middle-late Eocene and establishment of desert like environments after ca. 39 Ma. The overall stratigraphic record from the Tajik basin and southern Tien Shan points to deposition in a foreland basin setting by ca. 40 Ma in response to active tectonic growth of the Pamir-Tibet Mountains at the same time. Combined with the northwestward younging trend of the regression in the region, the Tajik basin record is consistent with northward growth of the Pamir and suggests significant tectonic control on Paratethys regression and paleoenvironmental changes in Central Asia.

  11. Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

    Science.gov (United States)

    Yin, A.; Yu, X.; Shen, Z.

    2014-12-01

    Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

  12. Progress and outlook of uranium exploration in meso-cenozoic basins in north China

    International Nuclear Information System (INIS)

    Through the efforts in last decades on the research of geology setting and regional assessment for uranium exploration in the Meso-Cenozoic basins in North China, rich accomplishment have been gotten in metallogenic theory, temporal and spatial distribution pattern, zone division, Classification, mineralization of different type, ore-controlling factors, metallogenic model, principle of valuation and prognostication, exploration criteria and great breakthrough in the prospecting of key areas. However, the extensive territory make the effort limited only to some region, the exploration level is fairly lower in the whole country, and there is wide space for uranium exploration. The further exploration should be basically guided by 'highlighting the exploration of key areas, strengthening the evaluation of regional potential and accelerating the implementation of new reserve bases' and persisted in principle of 'deployment with different level and execution according to region' and oriented with different types of deposit by 'wholly evaluation and systematic exploration'. By deploying the new effort frame in large base exploration, regional evaluation and solving the important geological and geophysical problem, we can put forward the uranium exploration in Meso-Cenozoic basins in North China. (author)

  13. An Estimate of the North Atlantic Basin Tropical Cyclone Activity for the 2011 Hurricane Season

    Science.gov (United States)

    Wilson, Robert M.

    2011-01-01

    Estimates are presented for the expected level of tropical cyclone activity for the 2011 North Atlantic Basin hurricane season. It is anticipated that the frequency of tropical cyclones for the North Atlantic Basin during the 2011 hurricane season will be near to above the post-1995 means. Based on the Poisson distribution of tropical cyclone frequencies for the current more active interval 1995-2010, one computes P(r) = 63.7% for the expected frequency of the number of tropical cyclones during the 2011 hurricane season to be 14 plus or minus 3; P(r) = 62.4% for the expected frequency of the number of hurricanes to be 8 plus or minus 2; P(r) = 79.3% for the expected frequency of the number of major hurricanes to be 3 plus or minus 2; and P(r) = 72.5% for the expected frequency of the number of strikes by a hurricane along the coastline of the United States to be 1 plus or minus 1. Because El Nino is not expected to recur during the 2011 hurricane season, clearly, the possibility exists that these seasonal frequencies could easily be exceeded. Also examined are the effects of the El Nino-Southern Oscillation phase and climatic change (global warming) on tropical cyclone seasonal frequencies, the variation of the seasonal centroid (latitude and longitude) location of tropical cyclone onsets, and the variation of the seasonal peak wind speed and lowest pressure for tropical cyclones.

  14. An Estimate of North Atlantic Basin Tropical Cyclone Activity for 2008

    Science.gov (United States)

    Wilson, Robert M.

    2008-01-01

    The statistics of North Atlantic basin tropical cyclones for the interval 1945-2007 are examined and estimates are given for the frequencies of occurrence of the number of tropical cyclones, number of hurricanes, number of major hurricanes, number of category 4/5 hurricanes, and number of U.S. land-falling hurricanes for the 2008 hurricane season. Also examined are the variations of peak wind speed, average peak wind speed per storm, lowest pressure, average lowest pressure per storm, recurrence rate and duration of extreme events (El Nino and La Nina), the variation of 10-yr moving averages of parametric first differences, and the association of decadal averages of frequencies of occurrence of North Atlantic basin tropical cyclones against decadal averages of Armagh Observatory, Northern Ireland, annual mean temperature (found to be extremely important for number of tropical cyclones and number of hurricanes). Because the 2008 hurricane season seems destined to be one that is non-El Nino-related and is a post-1995 season, estimates of the frequencies of occurrence for the various subsets of storms should be above long-term averages.

  15. Circumpolar oil-and-gas-bearing basins of the arctic part of the North American continent

    Science.gov (United States)

    Zabanbark, A.; Lobkovsky, L. I.

    2015-09-01

    Major geotectonic elements of the reviewed territory of the Arctic part of the North American continent are the Hyperborean Precambrian Platform, the Franklin folding belt, the northern part of the Precambrian Canadian platform, and the Mesozoic folding belt of Canada and Alaska. The rise of the Arctic slope of Alaska, the Beaufort Sea, and the Sverdrup basin are located in the southern margins of the Hyperborean Platform. The structure and peculiarities of development of these structural elements are genetically related to the evolution of this platform, as well as the current state of petroleum potential of the most promising exploration region of Arctic in the 21st century. The forced exploration of the Arctic regions of the United States and Canada has become an important milestone in the current development of the world energetics. Up to 100 oil, gas, and gas condensate fields have been discovered as a result of violent studies, and the potential oil and gas reserves in the Arctic part of the North American continent have been estimated to 30 billiion t and 50 trillion cubic meters, respectively. Many prospects are related to the continental slopes of all three above-mentioned basins; the total potential reserves of slopes are estimated as 10-12 billion t of oil and 20-25 trillion cubic meters of gas.

  16. Influences of North Atlantic climate variability on low-flows in the Connecticut River Basin

    Science.gov (United States)

    Steinschneider, Scott; Brown, Casey

    2011-10-01

    SummaryConnections between summertime, ecologically relevant low-flow indicators and both winter and spring climate phenomena are explored for the Connecticut River Basin, with an emphasis on assessing forecast potential. Low-flow streamflow statistics deemed important for ecological health, including minimum 1-day mean flows, minimum 7-day mean flows, and monthly streamflow averages from June to September, are derived from 61 years of continuous, daily streamflow data at 15 United States Geological Survey streamflow gauging stations across the basin. Relationships between the ecological flow indicators with leading sea-surface temperature and sea-level pressure are investigated using correlation and composite analysis. Results suggest lagged relationships of up to 5 months between summer streamflow and the wintertime North Atlantic Oscillation, springtime east coast pressure trough, and springtime North Atlantic Tripole. These climate states have been linked to shifts between zonal and meridonal airflow as well as sea-surface temperature anomalies off the coast of the eastern US, both of which have implications for the movement of moisture systems over the study region. This study suggests that residual influences on airflow and sea-surface temperature persist into the summer following these earlier climate states, influencing low-flow hydrology in the region. As eco-hydrologic flow targets often conflict with other stakeholder objectives within a watershed, reservoir operators may utilize such lagged teleconnection patterns to predict annual low-flow characteristics in the region and help negotiate tradeoffs between traditional water management objectives and those emphasizing ecological conservation.

  17. Spatio-Temporal Identification of Areas Suitable for West Nile Disease in the Mediterranean Basin and Central Europe.

    Directory of Open Access Journals (Sweden)

    Annamaria Conte

    Full Text Available West Nile virus (WNV is a mosquito-transmitted Flavivirus belonging to the Japanese encephalitis antigenic complex of the Flaviviridae family. Its spread in the Mediterranean basin and the Balkans poses a significant risk to human health and forces public health officials to constantly monitor the virus transmission to ensure prompt application of preventive measures. In this context, predictive tools indicating the areas and periods at major risk of WNV transmission are of paramount importance. Spatial analysis approaches, which use environmental and climatic variables to find suitable habitats for WNV spread, can enhance predictive techniques. Using the Mahalanobis Distance statistic, areas ecologically most suitable for sustaining WNV transmission were identified in the Mediterranean basin and Central Europe. About 270 human and equine clinical cases notified in Italy, Greece, Portugal, Morocco, and Tunisia, between 2008 and 2012, have been considered. The environmental variables included in the model were altitude, slope, night time Land Surface Temperature, Normalized Difference Vegetation Index, Enhanced Vegetation Index, and daily temperature range. Seasonality of mosquito population has been modelled and included in the analyses to produce monthly maps of suitable areas for West Nile Disease. Between May and July, the most suitable areas are located in Tunisia, Libya, Egypt, and North Cyprus. Summer/Autumn months, particularly between August and October, characterize the suitability in Italy, France, Spain, the Balkan countries, Morocco, North Tunisia, the Mediterranean coast of Africa, and the Middle East. The persistence of suitable conditions in December is confined to the coastal areas of Morocco, Tunisia, Libya, Egypt, and Israel.

  18. Spatio-Temporal Identification of Areas Suitable for West Nile Disease in the Mediterranean Basin and Central Europe.

    Science.gov (United States)

    Conte, Annamaria; Candeloro, Luca; Ippoliti, Carla; Monaco, Federica; De Massis, Fabrizio; Bruno, Rossana; Di Sabatino, Daria; Danzetta, Maria Luisa; Benjelloun, Abdennasser; Belkadi, Bouchra; El Harrak, Mehdi; Declich, Silvia; Rizzo, Caterina; Hammami, Salah; Ben Hassine, Thameur; Calistri, Paolo; Savini, Giovanni

    2015-01-01

    West Nile virus (WNV) is a mosquito-transmitted Flavivirus belonging to the Japanese encephalitis antigenic complex of the Flaviviridae family. Its spread in the Mediterranean basin and the Balkans poses a significant risk to human health and forces public health officials to constantly monitor the virus transmission to ensure prompt application of preventive measures. In this context, predictive tools indicating the areas and periods at major risk of WNV transmission are of paramount importance. Spatial analysis approaches, which use environmental and climatic variables to find suitable habitats for WNV spread, can enhance predictive techniques. Using the Mahalanobis Distance statistic, areas ecologically most suitable for sustaining WNV transmission were identified in the Mediterranean basin and Central Europe. About 270 human and equine clinical cases notified in Italy, Greece, Portugal, Morocco, and Tunisia, between 2008 and 2012, have been considered. The environmental variables included in the model were altitude, slope, night time Land Surface Temperature, Normalized Difference Vegetation Index, Enhanced Vegetation Index, and daily temperature range. Seasonality of mosquito population has been modelled and included in the analyses to produce monthly maps of suitable areas for West Nile Disease. Between May and July, the most suitable areas are located in Tunisia, Libya, Egypt, and North Cyprus. Summer/Autumn months, particularly between August and October, characterize the suitability in Italy, France, Spain, the Balkan countries, Morocco, North Tunisia, the Mediterranean coast of Africa, and the Middle East. The persistence of suitable conditions in December is confined to the coastal areas of Morocco, Tunisia, Libya, Egypt, and Israel. PMID:26717483

  19. Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America

    Science.gov (United States)

    Neff, K. L.; Meixner, T.; Ajami, H.; De La Cruz, L.

    2015-12-01

    For water-scarce communities in the western U.S., it is critical to understand groundwater recharge regimes and how those regimes might shift in the face of climate change and impact groundwater resources. Watersheds in the Basin and Range Geological Province are characterized by a variable precipitation regime of wet winters and variable summer precipitation. The relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation recharge dominant in the northern parts of the region, and recharge from summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon (NAM) extends its influence. Stable water isotope data of groundwater and seasonal precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to estimate and compare groundwater recharge seasonality throughout the region. Contributions of winter precipitation to annual recharge vary from 69% ± 41% in the southernmost Río San Miguel Basin in Sonora, Mexico, to 100% ± 36% in the westernmost Mojave Desert of California. The Normalized Seasonal Wetness Index (NSWI), a simple water budget method for estimating recharge seasonality from climatic data, was shown to approximate recharge seasonality well in several winter precipitation-dominated systems, but less well in basins with significant summer precipitation.

  20. Climate change adaptation in a highly urbanized snowmelt dominated basin in Central Chile

    Science.gov (United States)

    Vicuna, S.; Bustos, E.; Merino, P.; Henriquez Dole, L. E.; Jansen, S.; Gil, M.; Ocampo, A.; Poblete, D.; Tosoni, D.; Meza, F. J.; Donoso, G.; Melo, O.

    2015-12-01

    The Maipo river basin holds 40% of Chile's total population and produces almost half of the country's Gross Domestic Product. The basin is located in the semiarid and snowmelt dominated central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river basin faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements, natural ecosystems, and economic activities including agriculture, mining and hydropower production. In 2012 a research project, called MAPA (Maipo Plan de Adaptacion), began with the objective of articulating a climate variability and climate change adaptation plan for the Maipo river basin. The project engaged at the beginning a group of relevant water and land use stakeholders which allowed for a good representation of critical aspects of an adaptation plan such as the definition of objectives and performance indicators, future land use scenarios, modeling of the different components of the system and design of adaptation strategies. The presentation will highlight the main results of the research project with a special focus on the upper catchments of the basin. These results include the assessment of impacts associated with future climate and land use scenarios on key components of the hydrologic cycle including snowmelt and glacier contribution to runoff and subsequent impacts on water availability for the operation of hydropower facilities, satisfaction of instream (recreation and aquatic ecosystem) uses and provision of water for the city of Santiago (7 million people) and to irrigate more than 100,000 hectares of high value crops. The integrative approach followed in this project including different perspectives on the use of water in the basin provides a good opportunity to test the varying degree of impacts that could be associated with a given future scenario and also understand

  1. Sustainable Transformations of Water Supply Regimes. The Cuvelai-Etosha Basin in Central Northern Namibia.

    OpenAIRE

    Zimmermann, Martin

    2013-01-01

    In this thesis, an interdisciplinary modelling approach for water resources management and its application is presented that is able to deal with socio-technical systems that are characterised by a multiplicity of variables, interdependencies, and actors. The case study area is the Cuvelai-Etosha Basin, which is located in central northern Namibia. Approximately 850,000 people or 40 % of the Namibian population live in this area, which comprises only about 14 % of the country’s area. The regi...

  2. 10Be variation in surficial sediments of the Central Indian Basin

    International Nuclear Information System (INIS)

    Distribution of 10Be in systematically collected (degree x degree interval at 10 to 16 deg. S; 73.5 to 76.5 deg. E) surficial siliceous ooze, siliceous clay and pelagic clay sediments (top 2 cm) from the abyssal Central Indian Basin and the Andaman Sea is used to evaluate sources and to decipher the transport pathways of sediment particles, demarcate sediment depocenters and erosional areas. While 10Be concentrations display a wide variation (0.12-5.56 x 109 atoms g-1) with an average of 3.58 x 109 atoms g-1 in the Central Indian Basin, the values in the Andaman Sea are uniform with an average of 1.49 x 109 atoms g-1. The 10Be/9Be values in the Central Indian Basin sediments range between 0.06 and 2.99 x 10-8 atoms atoms-1 and average to ∼1.56 x 10-8 atoms atoms-1. Correlation of 10Be data with some selected major (Al, Mn, Ti) and trace (Rb and Ba) elements suggest that large part of the isotope has been supplied through direct atmospheric fallout from the water column and minor part from lithogenic detrital flux. Significantly lower 10Be accumulation rates in the Central Indian Basin and an order of magnitude higher in the Andaman Sea sediments compared to the estimated global average production rates indicate removal of the isotopes at the continental margins. Bottom topography seems to exert control on local 10Be variation, where sediments deposited in valleys or topographic depressions contain higher 10Be concentrations in contrast to the probably erosion-dominated areas at the slopes and troughs

  3. Hydrological Modeling in an Ungauged Basin of Central Vietnam Using SWAT Model

    OpenAIRE

    Rafiei Emam, Ammar; Kappas, Martin; Hoang Khanh Nguyen, Linh; Renchin, Tsolmon

    2016-01-01

    Hydrological modeling of ungauged basins which have a high risk of natural hazards (e.g., flooding, droughts) is always imperative for policymakers and stakeholders. The Aluoi district in Hue province is a representative case study in Central Vietnam, as it is under extreme pressure of natural and anthropogenic factors. Flooding, soil erosion and sedimentation are the main hazards in this area, which threaten socio-economic activities not only in this district but also those of the area downs...

  4. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    OpenAIRE

    Pan Chen; Lan Li; Hongbin Zhang

    2015-01-01

    Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA), the cluster analysis (CA) and the discriminant analysis (DA) were used to assess the water pollutio...

  5. Hydrovolcanic activity in the Central Indian Ocean Basin. Does nature mimic laboratory experiments?

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; ShyamPrasad, M.; Gupta, S.M.; Charan, S.N.; Mukherjee, A.D.

    ’ ’ National Institute of Oceanography, Dona Paula, Goa 403 004, India b National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, India ’ School of Oceanographic Studies, Department of Geological Sciences, Jadavpur University, Calcutta 700 032... (communicated). 220 S.D. Iyer et al. /Joumai of Volcanology and Geothermal Research 78 (19971209-220 Iyer, S.D., Sudhakar, M., 1993. A new report on the occurrence of zeolitites in the abyssal depths of the Central Indian Basin. Sediment. Geol. 84, 169...

  6. Cooling ponds and small rivers in north central United States

    International Nuclear Information System (INIS)

    An attempt is made to review those Commonwealth Edison (Ceco) programs related directly or indirectly to compensation and stock manipulation in fish populations. The direct stocking of sport fish fingerlings for mitigation is one method of stock manipulation. There are, however, two other, less common manipulative approaches to enhancing local fish stocks. First is the use of cooling ponds as off-stream nursery areas for forage and sport species. Second is the use of waste heat to modify habitat temperatures and permit or improve overwintering survival of select species such as gizzard or threadfin shad in north-temperate waters that are naturally too cold to sustain strong populations. This, in turn, will increase the abundance of these species as forage in subsequent years. There are four different Ceco projects which are discussed. These are: Fish releases in Pool 14 of the Mississippi River; Studies of endemic and stock fishes at the Collins and Dresden Cooling Ponds; Fish and water quality monitoring of the Des Plaines and Upper Illinois Rivers; and Proposed walleye, muskellunge and striped bass x white bass hybrid stocking in the Rock River. 7 references

  7. Salar de Atacama basin: A record of compressional tectonics in the central Andes since the mid-Cretaceous

    Science.gov (United States)

    Arriagada, Cesar; Cobbold, Peter R.; Roperch, Pierrick

    2006-02-01

    The Salar de Atacama basin lies in the inner fore arc of northern Chile. Topographically and structurally, it is a first-order feature of the central Andes. The sedimentary fill of the basin constrains the timing and extent of crustal deformation since the mid-Cretaceous. We have studied good exposures along the western edge of the basin and have correlated them with seismic reflection sections and data from an exploration well. Throughout most of its history, the basin developed in a foreland setting, during periods of thin-skinned and thick-skinned thrusting. Growth strata provide evidence for coeval sedimentation and thrust motions during mid-Cretaceous, Paleogene, and Neogene times. Pre-Neogene deformation was significant in the basin and in surounding areas of the early central Andes. Models that attempt to explain the current thickness of the central Andes should consider Late Cretaceous and Paleogene shortening, as well as the more obvious Neogene and Quaternary shortening.

  8. Hydrogeologic subdivision of the Wolfcamp series and Pennsylvanian system of eastern Texas Panhandle, north-central Texas, and southwestern Oklahoma

    International Nuclear Information System (INIS)

    The Pennsylvanian-Wolfcamp section in the Palo Duro Basin includes brine aquifers that are considered to be the most important ground-water flow paths in the deep-basin system. This report is the fifth in a series providing summary documentation of studies that subdivide the section into hydrogeologic units based on their judged relative capacities for transmitting water. This report extends the hydrogeologic study area to the eastern Texas Panhandle, north-central Texas, and southwestern Oklahoma. It includes 37 counties in Texas and Oklahoma. Underground patterns of rock distribution are delineated from a hydrologic perspective and at a level of detail appropriate for numerical modeling of regional ground-water flow. Hydrogeologic units are defined and characterized so that appropriate porosity and permeability values can be assigned to each unit during construction of the numerical models (not part of this study), and so that modelers can combine units where necessary. In this study, hydrogeologic units have been defined as mappable, physically continuous rock bodies that function in bulk as water-transmitting or water-retarding units relative to adjacent rocks. Interpretations are made primarily from geophysical logs. Hydrologic characteristics are assessed on the basis of properties typically associated with certain lithologies (e.g., sandstones are more pervious than shales) and on the basis of gross variations in effective porosity (particularly in carbonate sequences). 44 refs., 32 figs., 1 tab

  9. The U.S. Geological Survey`s National Coal Resource Assessment: The Northern and Central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Bragg, L.; Tewalt, S. [Geological Survey, Reston, VA (United States)

    1996-09-01

    The US Geological Survey (USGS) Energy Resource Surveys Program is currently conducting a five-year National Coal Resource Assessment project. Primary focus is on the quality and quantity of top-producing coal beds and coal zones in five of the nine major coal producing regions in the US. These regions include the (1) Northern and Central Appalachian Basin, (2) Gulf Coastal Plain, (3) Illinois Basin, (4) Colorado Plateau, and (5) Powder River Basin and Northern Great Plains.

  10. Palaeomagnetic secular variation and relative field intensity in pleistocene lacustrine sediments in the U.S. great basin as chronologic tools for dating climate in western north America

    International Nuclear Information System (INIS)

    Complete text of publication follows. Since the end of the 19th Century when first it was reported that large pluvial lakes formed during the Pleistocene in the U.S. Great Basin (Russell, 1885), the sediments deposited by some of those lakes have been used to study climate in western North America back about 3 m.y. (Smith et al., 1983, Morrison, 1991: many others). That research includes mineralogic, isotopic, geochemical, and sedimentologic data; radiometric dates; lacustrine fossils; volcanic ashes; and a record of long-term behaviour (secular variation) and excursions (Pringle Falls, Laschamp, and Mono Lake) of the palaeomagnetic field. In an attempt to establish an accurate chronology for the palaeoclimate in western North America during the past approximately 50,000 years, I will compare the records of palaeomagnetic directions for Pyramid Lake (the remnant of Lake Lahontan in northwestern Nevada)(Benson et al., 2008), Mono Lake (the remnant of Lake Russell in east-central California)(Lund et al., 1988; Zimmerman et al., 2006), and Searles Lake in the southeastern Great Basin (Liddicoat et al., 2008) with other records of palaeomagnetic field behaviour, especially the relative palaeomagnetic field intensity for the North and South Atlantic oceans (Laj et al., 2000; Stoner et al., 2004). This is possible because large- and small-scale fluctuations occur in the records that are distinctive and often are common to all.

  11. Climatology, hydrology, and simulation of an emergency outlet, Devils Lake basin, North Dakota

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, A.V.; Osborne, Leon; Wood, Carrie M.; Fay, James T.

    2000-01-01

    Devils Lake is a natural lake in northeastern North Dakota that is the terminus of a nearly 4,000-square-mile subbasin in the Red River of the North Basin. The lake has not reached its natural spill elevation to the Sheyenne River (a tributary of the Red River of the North) in recorded history. However, geologic evidence indicates a spill occurred sometime within the last 1,800 years. From 1993 to 1999, Devils Lake rose 24.5 feet and, at the present (August 2000), is about 13 feet below the natural spill elevation. The recent lake-level rise has caused flood damages exceeding $300 million and triggered development of future flood-control options to prevent further infrastructure damage and reduce the risk of a potentially catastrophic uncontrolled spill. Construction of an emergency outlet from the west end of Devils Lake to the Sheyenne River is one flood-control option being considered. This report describes the climatologic and hydrologic causes of the recent lake level rise, provides information on the potential for continued lake-level rises during the next 15 years, and describes the potential effectiveness of an emergency outlet in reducing future lake levels and in reducing the risk of an uncontrolled spill. The potential effects of an outlet on downstream water quantity and quality in the upper Sheyenne River also are described.

  12. DISTRIBUTION, ABUNDANCE AND ENTRAINMENT STUDIES OF LARVAL FISHES IN THE WESTERN AND CENTRAL BASINS OF LAKE ERIE

    Science.gov (United States)

    To assess the impact of entrainment of larval fishes at steam generating electrical power plants, samples were collected in Lake Erie. In 1975, 1976 and 1977 the Western Basin was sampled and in 1978 the sampling was concentrated in the Central Basin. The 1975, 1976 sampling perm...

  13. The nitrogen budget for different forest types in the central Congo Basin

    Science.gov (United States)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

    2016-04-01

    Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

  14. Fate of copper complexes in hydrothermally altered deep-sea sediments from the Central Indian Ocean Basin.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Sander, S.G.; Jayachandran, S.; Nath, B.N.; Nagaraju, G.; Chennuri, K.; Vudamala, K.; Lathika, N.; Mascarenhas-Pereira, M.B.L.

    -EDTA complexes. The speciation of Cu indicates that hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may not significantly contribute to the global Cu flux. However, increasing lability of Cu-sediment complexes with increasing depth...

  15. Assessing the distribution and abundance of seabed minerals from seafloor photographic data in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Khadge, N.H.; JaiSankar, S.

    estimation of a deposit from photographic data in conjunction with sounding and sampling data in the Central Indian Ocean Basin. Data from more than 20,000 photos were analysed and correlated with geological features such as bathymetry, sediment thickness...

  16. Thermohaline circulation in the Central Indian Ocean Basin (CIB) during austral summer and winter periods of 1997

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Suryanarayana, A.; Murty, V.S.N.

    As a part of Indian Deep Sea Environment Experiment (INDEX) aimed at assessing the environmental impact of manganese nodule mining in the Central Indian Basin (CIB), a study on baseline physical conditions of water column viz. potential temperature...

  17. Bacterial standing stock, meiofauna and sediment-nutrient characteristics: Indicators of benthic disturbance in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; LokaBharathi, P.A.; Ansari, Z.A.; Nair, S.; Ingole, B.S.; Sheelu, G.; Mohandass, C.; Nath, B.N.; Rodrigues, N.

    As a part of the environmental impact assessment studies for polymetallic nodule mining, the effect of simulated "benthic disturbance" caused by a benthic hydraulic disturber was studied in the Central Indian Basin (CIB). The abundance...

  18. Nature and distribution of manganese nodules from three sediment domains of the Central Indian Basin, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Mukhopadhyay, R.

    Manganese nodules from the Central Indian Basin (5 degrees-10 degrees S) vary in abundance, morphology, mineralogy, and chemistry with water depth and sediment type. Nodules from the southern region, dominatEd. by siliceous sediment, differ markedly...

  19. DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

    Science.gov (United States)

    This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

  20. Open-Country Poverty in a Relatively Affluent Area - The East North Central States.

    Science.gov (United States)

    Fitzwilliams, Jeanette

    Poverty among open-country households in the East North Central States (11%) was slightly above the incidence found among U.S. whites in general. Incidence of poverty was greatest among the aged, disabled, and small farmers of all ages who made farming their major source of earnings. Of the respondent households in this 1967 survey, 87% had…

  1. Sweet corn growth and yield responses to planting dates of the north central U.S.

    Science.gov (United States)

    Sweet corn is planted over a three-month period in the north central U.S. in order to extend availability for fresh market and processing; however, the extent to which development and growth of sweet corn changes during this period is unreported. Field experiments were conducted in 2006 and 2007 to...

  2. Residual Weeds of Processing Sweet Corn in the North Central Region

    Science.gov (United States)

    Knowledge of weed community structure in vegetable crops of the North Central Region (NCR) is poor. To characterize weed composition of species persisting in sweet corn to harvest, hereafter called residual weeds, 175 sweet corn fields were surveyed in Illinois, Minnesota, and Wisconsin from 2005 to...

  3. Lawn Weeds and Their Control. North Central Regional Extension Publication No. 26.

    Science.gov (United States)

    Purdue Univ., Lafayette, IN. Cooperative Extension Service.

    This publication discusses lawn weed control for the twelve state north central region of the country. Written for use by homeowners, the publication focuses on weed identification and proper herbicide selection and application. Identification of weeds and safe and appropriate herbicide use are emphasized. Forty-six weed and turf plants are…

  4. Hydrologic response of a high altitude glacierized basin in the central Tibetan Plateau

    Science.gov (United States)

    Li, Binquan; Yu, Zhongbo; Liang, Zhongmin; Acharya, Kumud

    2014-07-01

    Hydrologic cycles of most high altitude glacierized watersheds in the Tibetan Plateau are not closely monitored due to their inaccessibility. Understanding the hydrologic cycle in such a basin may provide insight into the role climate plays on changes in glacier mass. Thus, hydrologic simulations with a physical perspective in the Tibetan glacierized watershed are of great significance. A high altitude glacierized basin in the central Tibetan Plateau, Qugaqie basin, was investigated with an energy-balance based glacier-melt model and the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model. With these two models, glacier mass balance was estimated and basin runoff from glaciers was simulated at a daily time step. Results from the simulation period (October 1, 2006-September 30, 2011) demonstrated that the glaciers experienced a large negative surface mass balance with the cumulative value of - 300 cm w.e.. In other words, up to 13.93 × 106 m3 water volume was melting out from the glaciers during these five years. In the 2007/08 year, however, the glaciers experienced a surplus mass balance because of the low air temperature and increased precipitation in the summer season. Infiltration, evapotranspiration (ET), and overland flow were also calculated using the GSSHA model. Results showed that precipitation, the main water source, contributed roughly 95% to the total mass gain of the annual water balance in the Qugaqie basin during the study period, while the glacial runoff (snow/ice melting) contributed 5% water balance. In the water loss, 17% of annual water volume was consumed by the ET process. As a result, the remaining water volume (83%) converted to the basin river flow to the Lake Nam Co. In the summertime, the glacial runoff accounted for 15% of the total basin runoff volume, while this contribution increased in the upstream portion to 46% due to a large percentage of glacierized area. The analysis showed that the glacial runoff contributions to the

  5. Pre-Alpine evolution of a segment of the North-Gondwanan margin: Geochronological and geochemical evidence from the central Serbo-Macedonian Massif

    OpenAIRE

    Antić, Milorad; Peytcheva, Irena; Von Quadt, Albrecht; Kounov, Alexandre; Trivić, Branislav; Serafimovski, Todor; Tasev, Goran; GERDJIKOV, IANKO; Wetzel, Andreas

    2016-01-01

    The Serbo-Macedonian Massif (SMM) represents a composite crystalline belt within the Eastern European Alpine orogen, outcropping from the Pannonian basin in the north, to the Aegean Sea in the south. The central parts of the massif (i.e. southeastern Serbia, southwestern Bulgaria, eastern Macedonia) consist of the medium- to high-grade Lower Complex, and the low-grade Vlasina Unit. New results of U–Pb LA-ICP-MS analyses, coupled with geochemical analyses of Hf isotopes on magmatic and d...

  6. Helium Isotope Variations in the Northern Lau and North Fiji Basins

    Science.gov (United States)

    Lupton, J. E.; Arculus, R. J.; Jenner, F. E.; Evans, L.; Greene, R.

    2012-12-01

    Recent measurements of submarine basalts from the Northern Lau Basin exhibit a fascinating pattern in the helium isotopes. In particular, basalts along the NW Lau Spreading Center and the Rochambeau Rifts (NWLSC-RR) all have elevated 3He/4He ratios ranging from 11 to 28 Ra, much higher than the MORB-like values of 7 - 9 Ra that might be expected for a typical back-arc spreading center (Lupton et al, GRL 2009) (R = 3He/4He and Ra = Rair = 1.39E-6). This has been interpreted as indicating the presence of a mantle plume component, possibly from the Samoan hotspot, which has somehow intruded into the northern Lau Basin. Furthermore, neon isotopes analyzed in this same suite of basalts exhibit enrichments in 21Ne/22Ne and 20Ne/22Ne distinct from MORB neon and similar to neon isotopes measured in Samoan lavas (Lupton et al., GRL, 2012), further evidence for intrusion of a Samoan plume component. Surprisingly, this hotspot component is only evident along the NWLSC-RR, while samples from seafloor basalts and submarine hydrothermal fluids in the NE Lau Basin have MORB-like values or lower, varying from 6.5 to 8.5 Ra. However, very few samples have been collected to the west of the NWLSC-RR, and the question thus remains as to the origin and extent of this 3He-rich component in the northern Lau Basin. Recently, expedition SS2012 of the R/V Southern Surveyor collected submarine rock samples from the volcanic zones in the northwestern Lau Basin and North Fiji Basin. These samples have 3He/4He ratios ranging from 9.0 up to 14.6 Ra, above the range for normal MORBs. Of particular interest is the zone immediately to the west of the Rochambeau Rifts. Samples from the SE Futuna Volcanic Zone and from the Futuna Spreading Center have 3He/4He varying from 9.2 to 10.6 Ra. Farther west, samples from the West Cikobia Volcanic Zone due north of the Fiji Islands have helium with 9.3 up to 12.2 Ra. Still farther west in the Fiji Basin at 17S, 174E, samples dredged from the NE Fiji Triple

  7. Tropical Cyclone Activity in the North Atlantic Basin During the Weather Satellite Era, 1960-2014

    Science.gov (United States)

    Wilson, Robert M.

    2016-01-01

    This Technical Publication (TP) represents an extension of previous work concerning the tropical cyclone activity in the North Atlantic basin during the weather satellite era, 1960-2014, in particular, that of an article published in The Journal of the Alabama Academy of Science. With the launch of the TIROS-1 polar-orbiting satellite in April 1960, a new era of global weather observation and monitoring began. Prior to this, the conditions of the North Atlantic basin were determined only from ship reports, island reports, and long-range aircraft reconnaissance. Consequently, storms that formed far from land, away from shipping lanes, and beyond the reach of aircraft possibly could be missed altogether, thereby leading to an underestimate of the true number of tropical cyclones forming in the basin. Additionally, new analysis techniques have come into use which sometimes has led to the inclusion of one or more storms at the end of a nominal hurricane season that otherwise would not have been included. In this TP, examined are the yearly (or seasonal) and 10-year moving average (10-year moving average) values of the (1) first storm day (FSD), last storm day (LSD), and length of season (LOS); (2) frequencies of tropical cyclones (by class); (3) average peak 1-minute sustained wind speed () and average lowest pressure (); (4) average genesis location in terms of north latitudinal () and west longitudinal () positions; (5) sum and average power dissipation index (); (6) sum and average accumulated cyclone energy (); (7) sum and average number of storm days (); (8) sum of the number of hurricane days (NHD) and number of major hurricane days (NMHD); (9) net tropical cyclone activity index (NTCA); (10) largest individual storm (LIS) PWS, LP, PDI, ACE, NSD, NHD, NMHD; and (11) number of category 4 and 5 hurricanes (N4/5). Also examined are the December-May (D-M) and June-November (J-N) averages and 10-year moving average values of several climatic factors, including the (1

  8. Georesistivity structure in the central part of North-Eastern Japan Arc; Tohoku chiho chubu chiiki no denki dendodo kozo

    Energy Technology Data Exchange (ETDEWEB)

    Fujinawa, Y. [National Research Institute for Disaster Prevention, Tsukuba (Japan); Kawakami, N. [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Ueshima, M. [The University of Tokyo, Tokyo (Japan). Earthquake Research Institute; Honkura, Y. [Tokyo Institute of Technology, Tokyo (Japan)

    1998-03-13

    MT measurement of transects was made in the central part of North-Eastern Japan Arc to clarify tectonics of subduction zones. 1-D, 2-D and 3-D resistivity structures are observed in surface layers, and zones shallower and deeper than a Conrad surface, respectively. A main structure direction is S-N or NNE-SSW. Ishinomaki-Chokai tectonic line and low- resistivity zones due to Quaternary volcanos (Naruko, Onikobe) exist in a backbone range region. Resistivity is 100{Omega}{center_dot}m or less by Bostick Inversion except Mesozoic and Palaeozoic layers in the southern Kitakami mountainous region, resulting in a good agreement with previous results in a north transect. Resistivity is several {Omega}{center_dot}m and depth is several km around Shinjo basin and in surface layers of Kitakami River region. The backbone range region shows complex resistivity structures because of volcanic activity and wide-area hot water activity. High-resistivity layers correspond to stable Mesozoic and Palaeozoic land layers. Seismic velocity increases in the low-resistivity zone. Earthquake generally occurs at the boundary between resistivity structures. 68 refs., 9 figs., 2 tabs.

  9. Structure of the Cordillera de la Costa Belt, North-Central Venezuela: Implications for plate tectronic models

    Energy Technology Data Exchange (ETDEWEB)

    Ave Lallemant, H.G.; Sisson, V.B.; Wright, J.E. (Rice Univ., Houston, TX (United States))

    1993-02-01

    Preliminary results of an on-going study of the Cordillera de la Costa belt between Puerto Cabello and Choroni, north-central Venezuela, indicate that the deformational history is far more complicated than expected from simple plate-tectonic models. The Cordillera de la Costa belt consists of oceanic rocks (e.g., serpentinites, amphibilites, with lenses of eclogite and blueschist) intimately intermixed with metamorphosed continental margin deposits (e.g., mica and graphite schist, quartzite, marble). Locally, large granitic (basement ) complexes of Lower Paleozoic age are included as well. In late Cretaceous time, the entire belt was involved in four synmetamorphic deformations phases (D[sub 1a] to D[sub 1d]); the first (D[sub 1a]) occurred at depths of at 35-40 km and the later ones at successively shallower depths. This deformation occurred in a subduction zone, related to right-oblique convergence of the Farallon and Atlantic plates. The most penetrative structures resulted from (all in present coordinates) north-south contraction and east-west dextral simple shear (D[sub 1b]). During an Early Tertiary ( ) event (D[sub 2]), the belt was emplaced southward onto the South American continental margin. Subsequent deformational structures (D[sub 3]) resulted in cross folds and faults (with small pull-apart basins) which are consistent with the eastward passage of the Caribbean past the South American plate.

  10. Disentangling Middle Paleozoic sea level and tectonic events in cratonic margins and cratonic basins of North America

    Science.gov (United States)

    Bond, Gerard C.; Kominz, Michelle A.

    1991-04-01

    The cratonic margins and basins of North America contain evidence of distinct changes in relative sea level, one of the most intriguing of which occurred in middle Paleozoic time. The change in relative sea level began in Frasnian time (Late Devonian) and continued through Visean time (Middle Mississippian) in the Cordilleran miogeocline, in the Southern Oklahoma Aulacogen, in the Appalachian miogeocline and in the Michigan, Illinois, and Williston basins. The synchroneity and wide geographic distribution of this event are striking and would seem to argue for an eustatic mechanism. An estimate of the middle Paleozoic sea level rise relative to the stable craton in Iowa suggests that while a large sea level rise occurred, it is smaller than the magnitude of subsidence in the cratonic basins and margins. Flexural foreland basin models do not appear to account for the all of the events in the cratonic margins, and thermal subsidence mechanisms do not seem appropriate for the subsidence in the cratonic basins. The middle Paleozoic stratigraphic record from the North American craton and its margins, therefore, poses a basic problem of identifying a mechanism for producing a large-amplitude rise in sea level relative to the stable craton at the same time as a synchronous onset of tectonic subsidence in widespread basinal and marginal settings of diverse tectonic origin. One plausible mechanism for the tectonic subsidence in the basins and margins is a pulse of intraplate compressive stress. The origin of the large sea level rise relative to the stable craton could reflect an unusually large eustatic sea level change, but we cannot eliminate the possibility of a small component of subsidence or change in dynamic topography of the North American craton. The synchroneity of the sea level rise relative to the craton with the subsidence of basins and margins may be fortuitous, but it is also predicted by recent mantle convection models for the early stages of accretion of

  11. Climate Change Impacts on Runoff Regimes at a River Basin Scale in Central Vietnam

    Directory of Open Access Journals (Sweden)

    Do Hoai Nam

    2012-01-01

    Full Text Available Global warming has resulted in significant variability of global climate especially with regard to variation in temperature and precipitation. As a result, it is expected that river flow regimes will be accordingly varied. This study presents a preliminary projection of medium-term and long-term runoff variation caused by climate change at a river basin scale. The large scale precipitation projection at the middle and the end of the 21st century under the A1B scenario simulated by the CGCM model (MRI & JMA, 300 km resolution is statistically downscaled to a basin scale and then used as input for the super-tank model for runoff analysis at the upper Thu Bon River basin in Central Vietnam. Results show that by the middle and the end of this century annual rainfall will increase slightly; together with a rising temperature, potential evapotranspiration is also projected to increase as well. The total annual runoff, as a result, is found to be not distinctly varied relative to the baseline period 1981 - 2000; however, the runoff will decrease in the dry season and increase in the rainy season. The results also indicate the delay tendency of the high river flow period, shifting from Sep-Dec at present to Oct-Jan in the future. The present study demonstrates potential impacts of climate change on streamflow regimes in attempts to propose appropriate adaptation measures and responses at the river basin scales.

  12. Determination of hydrocarbon prospective areas in the Tuzgolu (Saltlake) Basin, central Anatolia, by using geophysical data

    Energy Technology Data Exchange (ETDEWEB)

    Aydemir, Attila [Turkiye Petrolleri A.O. Mustafa Kemal Mah. 2.Cad. No: 86, 06100 Sogutozu, Ankara (Turkey); Ates, Abdullah [Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100, Besevler, Ankara (Turkey)

    2008-09-15

    Tuzgolu Basin is the largest interior basin in Central Anatolia, Turkey, with significant hydrocarbon indications in outcrops and exploration wells. However, there is no commercial discovery since 1959 which is the beginning year of exploration activities. Because of the poor seismic quality, all available geological-geophysical data and methods should be used in integration with each other to carry out exploration activities. In previous studies, the basin was modeled three dimensionally (3D) using gravity data by the authors of this paper and results of the modeling study were published recently. The model results can be evaluated to determine probable hydrocarbon generation zones. Gravity anomalies in this region exhibit many inflections that could be prospective locations for hydrocarbons. In this study, the gravity data were subjected to the vertical derivative in order to isolate inflections and to determine concealed structurally high areas in the subsurface that could have hydrocarbon potential. These potential subsurface structures were also compared with the Analytical Signal map produced from the aeromagnetic anomalies to reveal if they are originated from a magmatic intrusion. Finally, it was determined that all exploration wells were drilled off-structure and none of these potential subsurface structures was tested. According to correlation of the previous well locations and determined subsurface structures in or around the hydrocarbon generation zones, it is possible to claim that the Tuzgolu Basin with no previous discovery remains prospective for hydrocarbon exploration activities in the future. (author)

  13. Holocene mammalian change in the central Columbia Basin of eastern Washington state, USA

    Science.gov (United States)

    Lyman, R. Lee

    2016-08-01

    Predictions of changes in the Holocene mammalian fauna of the central Columbia Basin in eastern Washington (USA) based on environmental changes are largely met. Taxonomic richness is greatest during periods of cool-moist climate. Rates of input of faunal remains to the paleozoological record may suggest greater mammalian biomass during periods of greater moisture but are difficult to interpret without data on sampling intensity in the form of volume of sediment excavated. Abundances of leporids and grazing ungulates fluctuate in concert with abundance of grass. Several biogeographic records are tantalizing but require additional study and data before being accepted as valid. Records of red fox (Vulpes vulpes) indicate this species was present in the central basin during the Holocene contrary to historic records and recent suggestions modern foxes there are escapees from fur farms. Bison (Bison bison) and bighorn sheep (Ovis canadensis) underwent diminution of body size during the Holocene. Modern efforts to conserve the Columbia Basin ecosystem are advised to consider the Holocene record as indicative of what may happen to that ecosystem in the future.

  14. Seismic stratigraphy and clay mineral distribution in shallow-marine siliciclastic deposits, central Mississippi sound, North-central Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Harper, G.G.; Manley, F.H.; Staheli, A.C.

    1983-03-01

    Three north-south high-resolution (7 kHz) seismic profiles and 16 20-foot cores taken at shot-point locations in central Mississippi Sound were utilized to determine: (1) any meaningful seismic reflector configurations in the subsurface; (2) the clay species dispersal pattern and its relation to transport systems that move sediment into the depositional basin; (3) any change in clay mineral species that has occurred through time with respect to deposition of 5 to 6 m (16 to 20 ft) of sediment. Interpretation of shallow seismic events (20 m (66 ft)) and clay mineral analysis indicates that extrinsic factors largely determined the clay mineral species and geologic history of Pleistocene and Holocene sedimentation in central Mississippi Sound. Trend surface maps, residual maps, profiles of the smectite (montmorillonite) to kaolinite ratios, and seismic profiles illustrate that: (1) Mississippi Sound has been influenced by transgressions and regressions associated with proglacial and interglacial stages; (2) a toplap seismic reflection configuration forms the probable Pleistocene-Holocene boundary; (3) at least one ancient barrier island is located inside the Holocene barrier system; (4) there is a late date for sea level reaching its present location (2500 years B.P.); (5) the influence of the Mississippi River system on sedimentation is soon after inundation of Mississippi Sound; (6) the longshore currents and flood tides supplied sediment rich in kaolinite to the study area; (7) the drainage systems emptying into the study area have local influence on clay mineral distribution; and (8) the dredging of ship channels affects the clay-mineral distribution within the sediments immediately below the sediment-water interface in central Mississippi Sound.

  15. Assessment of Undiscovered Oil and Gas Resources of the Williston Basin Province of North Dakota, Montana, and South Dakota, 2008

    Science.gov (United States)

    Anna, Lawrence O.; Pollastro, Richard M.; Gaswirth, Stephanie B.; Lewan, Michael D.; Lillis, Paul G.; Roberts, Laura N.R.; Schenk, Christopher J.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.

    2008-01-01

    Using a geology-based assessment method, the U.S. Geological Survey estimated mean undiscovered volumes of 3.8 billion barrels of undiscovered oil, 3.7 trillion cubic feet of associated/dissolved natural gas, and 0.2 billion barrels of undiscovered natural gas liquids in the Williston Basin Province, North Dakota, Montana, and South Dakota.

  16. A new age model for the early-middle Miocene in the North Alpine Foreland Basin

    Science.gov (United States)

    Reichenbacher, Bettina; Krijgsman, Wout; Pippèrr, Martina; Sant, Karin; Kirscher, Uwe

    2016-04-01

    The establishment of high-resolution age models for sedimentary successions is crucial for numerous research questions in the geosciences and related disciplines. Such models provide an absolute chronology that permits precise dating of depositional episodes and related processes such as mountain uplift or climate change. Recently, our work in the Miocene sediments of the North Alpine Foreland Basin (NAFB) has revealed a significantly younger age (16.6 Myr) for sediments that were thought to have been deposited 18 Myr ago. This implies that a fundamentally revised new age model is needed for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB (20 to 15-Myr). Our new data also indicate that previously published reconstructions of early-middle Miocene palaeogeography, sedimentation dynamics, mountain uplift and climate change in the NAFB all require a critical review and revision. Further, the time-span addressed is of special interest, since it encompasses the onset of a global warming phase. However, it appears that a fundamentally revised new age model for the entire suite of lower-middle Miocene sedimentary rocks in the NAFB can only be achieved based on a 500 m deep drilling in the NAFB for which we currently seek collaboration partners to develop a grant application to the International Continental Deep Drilling Program (ICDP). Reference: Reichenbacher, B., W. Krijgsman, Y. Lataster, M. Pippèrr, C. G. C. Van Baak, L. Chang, D. Kälin, J. Jost, G. Doppler, D. Jung, J. Prieto, H. Abdul Aziz, M. Böhme, J. Garnish, U. Kirscher, and V. Bachtadse. 2013. A new magnetostratigraphic framework for the Lower Miocene (Burdigalian/Ottnangian, Karpatian) in the North Alpine Foreland Basin. Swiss Journal of Geosciences 106:309-334.

  17. Stratigraphy, geochronology, geochemistry and tectonic setting of the Mesozoic Nazas Formation, north-central Mexico

    Science.gov (United States)

    Bartolini, Claudio

    Late Triassic to Middle Jurassic volcanic-sedimentary sequences that were part of the Mesozoic continental-margin of western North America are exposed in northern and central Mexico. These sequences have been grouped into the Nazas Formation and crop out in the states of Durango, Coahuila, Zacatecas, and San Luis Potosi. The Nazas Formation consists of 2,500 m or more of volcanic and pyroclastic rocks and interbedded clastic sedimentary rocks that were deposited in alluvial fan and fluvial depositional systems that developed in intra-arc basins, mainly fault-bound grabens and topographic depressions within an extending Mesozoic volcanic arc. Major and trace element geochemistry of volcanic rocks suggests that the volcanic suite is calc-alkaline and includes rhyolite, dacite, rhyodacite, andesite, trachyandesite and rare basalt. Pyroclastic rocks are basically air-fall tuffs and volcanic breccias. The sedimentary strata include conglomerate, sandstone, shale, and siltstone, locally red in color. Geochronology (Ar-Ar, K-Ar and Rb-Sr) and field evidence indicate that the age of the Nazas Formation ranges from Late Triassic to Middle Jurassic, but the peak of arc volcanism appears to be Early and Middle Jurassic. The Mesozoic magmatic arc in Mexico has a northwest trend and extends from Sonora to Chiapas. The arc structure is more than 2,000 km long, and possibly up to 150 km wide. The width of the arc is uncertain due to the limited number of surface outcrops, however, it did not extend east into the Gulf of Mexico. Arc-related magmatism began in latest Triassic time, but the peak of arc evolution occurred during the Early and Middle Jurassic. By Oxfordian time, the arc was deeply dissected and eroded, and magmatic activity had ceased. A marine transgression from the Gulf of Mexico covered most of the Nazas arc, depositing the initial sediments of the Oxfordian Zuloaga Limestone in the Mexican Geosyncline. Jurassic crustal extension in the Gulf of Mexico was

  18. Geological characteristics and prospecting potential of sandstone-type uranium deposits in the north margin of Qaidam basin

    International Nuclear Information System (INIS)

    The north margin of Qaidam Basin is composed with rift trough and Oulongbuluke landmass which is clamped by Qilian Mountain and Qaidam block Suture zone. The two activities provide a rich source of uranium for the basin area. The coal-bearing rocks as stratums of medium and lower Jurassic, is the main exploration target zones of sandstone-type uranium ore. Through geological survey and drilling, we think that the interlayer oxidation zone. being primary factors of sandstone-type uranium, can be divided into ancient type and modern type. The ancient interlayer oxidation zone type uranium deposit is the main prospecting types in the north margin of Qaidam Basin. Combined with analysis on geological conditions of sandstone-type uranium mineralization, we propose that eastern edge of Yuqia, southern edge of Lucao Mountain, Beidatan and northwest edge of Ulan depression are good prospects. (authors)

  19. Study on relationship between deep and shallow structures along north boundary fault of Yanqing-Fanshan basin

    Institute of Scientific and Technical Information of China (English)

    于贵华; 徐锡伟; 朱艾澜; 马文涛; 刁桂苓; 张四昌; 张先康; 刘保金; 孙振国

    2004-01-01

    Based on the results of surface geology, shallow and deep seismic survey, features of micro-earthquake activity along the north boundary fault of Yanqing-Fanshan sub-basin and their relationship with the surface active faults and the deep-seated crustal structure are analyzed using the recordings from the high-resolution digital seismic network. The focal mechanism solutions of micro-earthquakes, whose locations are precisely determined by the seismic network, have confirmed the structural characteristics to be the rotational planar normal fault and demonstrated the surface traces of the north boundary fault of Yanqing-Fanshan sub-basin. By using the digital recordings of earthquakes with the high resolutions and analyzing the mechanism solutions, our study has revealed the relationship between the geological phenomena in the shallow and deep structures in Yanqing-Huailai basin and the transition features from the brittle to ductile deformation with the crustal depth.

  20. Federally owned coal and Federal lands in the northern and central Appalachian Basin coal regions

    Energy Technology Data Exchange (ETDEWEB)

    Susan J. Tewalt

    2002-02-01

    The US Geological Survey (USGS) assessed five coals beds or coal zones in the northern and central Appalachian Basin coal regions for the National Coal Resource Assessment: the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay coal zone, the Pond Creek coal zone, and the Pocahontas No. 3 coal bed. The assessment produced stratigraphic and geochemical databases and digital coal maps, or models, which characterized the coal beds and coal zones. Using the assessment models, the USGS estimated original and remaining (unmined) resources for these coal beds or zones. The Appalachian Basin assessment was conducted in collaboration with the State geological surveys of West Virginia, Pennsylvania, Ohio, Maryland, Kentucky, and Virginia. 3 refs., 7 figs.

  1. Coal resources of selected coal beds and zones in the northern and central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Ruppert; Susan Tewalt; Linda Bragg

    2002-02-01

    The U.S. Geological Survey (USGS) is completing a National Coal Resource Assessment of five coal-producing regions of the United States, including the Appalachian Basin. The USGS, in cooperation with the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia, has completed a digital coal resource assessment of five of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions -- the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay and Pond Creek coal zones, and the Pocahontas No. 3 coal bed. Of the 93 billion short tons of original coal in these units, about 66 billion short tons remain. 2 refs., 5 figs., 2 tabs.

  2. Revision of the biostratigraphy of the Chatham Group (Upper Triassic), Deep River basin, North Carolina, USA

    Science.gov (United States)

    Litwin, R.J.; Ash, S.R.

    1993-01-01

    Paleontological evidence from the Upper Triassic Chatham Group in the three subbasins of the Deep River basin (North Carolina, USA) supports a significant revision of the ages assigned to most of this non-marine continental sedimentary sequence. This study confirms an early(?) or mid-Carnian age in the Sanford subbasin for the base of the Pekin Formation, the lowest unit of the Chatham Group. However, diagnostic late Carnian palynomorphs have been recovered from coals in the lower part of the Cumnock Formation in the Sanford subbasin, and from a sample of the Cumnock Formation equivalent in the Wadesboro subbasin. Plant megafossils and fossil verebrates from rocks in the Sanford subbasin also support a late Carnian age for the Cumnock Formation and its equivalents. The overlying Sanford Formation, which has not yet been dated paleontologically, probably includes beds of Norian age, as over 1000 m of strata may be present between the Cumnock Formation coals (dated here as late Carnian) and the top of the Sanford Formation. This chronostratigraphic interval appears similar to, but slightly longer than, that preserved in the Dan River-Danville and Davie County basins 100 km to the northwest. Our evidence, therefore, indicates that the Chatham Group was deposited over a much longer time interval [early(?) to mid-Carnian through early Norian] than previously was believed. ?? 1993.

  3. Persistent Localized Microseism Source in Kyushu Island, North Fiji basin and Gulf of Guniea

    Science.gov (United States)

    Zeng, X.; Xia, Y.; Ni, S.; Shi, Y.

    2012-12-01

    The ambient noise tomography (ANT) has been widely applied to investigating crust and upper mantle seismic structure on different scales. The assumptions (diffusivity of noise wave field, homogeneity of noise sources etc) in the validity of ANT are different from realistic ambient noises which leads to studies about microseism source distribution and excitation mechanism. Most microseism in the band of 1s-100s is considered to be generated in ocean by nonlinear interaction between atmosphere, ocean and solid Earth. Besides such sources, the monochromic signals observed in regional and global seismic networks which are excited by persistent localized (PL) sources also play important role in ANT study. The Noise Cross-correlation Function provides opportunity to detect weak microseism signal generated by localized sources. We report a new 10s PL source in Kyushu Island, Japan to interpret strong precursor signals in NCFs between East Asia seismic stations. The 26s microseism signals in NCFs are employed to investigate source location in Gulf of Guinea and Fiji basin. Difference in location, spectrum and temporal variation support an independent 26s microseism source which situates in North Fiji basin. Narrow band-passed NCFs also reveal twin 26s microseism sources in Gulf of Guinea. Although the excitation mechanism of PL sources is still unclear, the coincidences in location and frequency with volcanic long-period-tremor suggest that magma activity is a potential excitation mechanism of PL sources.

  4. Preliminary description of hydrologic characteristics and contaminant transport potential of rocks in the Pasco Basin, south-central Washington

    International Nuclear Information System (INIS)

    This report aims at consolidating existing data useful in defining the hydrologic characteristics of the Pasco Basin within south-central Washington. It also aims at compiling the properties required to evaluate contaminant transport potential within individual subsurface strata in this basin. The Pasco Basin itself is a tract of semi-arid land covering about 2,000 square miles in south-central Washington. The regional geology of this basin is dominated by tholeiitic flood basalts of the Columbia Plateau. The surface hydrology of the basin is dominated by the Yakima, Snake, and Columbia rivers. Short-lived ephemeral streams may flow for a short period of time after a heavy rainfall or snowmelt. The subsurface hydrology of the Pasco Basin is characterized by an unconfined aquifer carrying the bulk of the water discharged within the basin. This aquifer overlies a series of confined aquifers carrying progressively smaller amounts of groundwater as a function of depth. The hydraulic properties of the various aquifers and non-water-bearing strata are characterized and reported. A summary of the basic properties is tabulated. The hydrochemical data obtained are summarized. The contaminant transport properties of the rocks in the Pasco Basin are analyzed with emphasis on the dispersion and sorption coefficients and the characteristics of the potential reactions between emplaced waste and the surrounding medium. Some basic modeling considerations of the hydrogeologic systems in the basin with a brief discussion of model input requirements and their relationship to available data are presented

  5. A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

    Science.gov (United States)

    Foxgrover, Amy C.; Barnard, Patrick L.

    2012-01-01

    A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

  6. Linking carbon storage with functional diversity in tropical rainforest in the central Congo Basin

    Science.gov (United States)

    Verbeeck, Hans; Kearsley, Elizabeth; Bauters, Marijn; Beeckman, Hans; Huygens, Dries; Steppe, Kathy; Boeckx, Pascal

    2015-04-01

    This presentation will show an overview of results of the COBIMFO project (Congo basin integrated monitoring for forest carbon mitigation and biodiversity). In the framework of this project we have established 21 permanent 1 ha sampling plots in different forest types in the Yangambi reserve. This UNESCO Man and Biosphere reserve has an area of more than 6000 km² and is located in the heart of the Congo Basin near the Yangambi research station (DR Congo). Analysis of the inventory data of these plots revealed that carbon stocks in mature forests in this area of the Congo Basin are significantly lower (24%) than stocks recorded in the outer regions of the basin. These lower stocks are attributed to a lower maximal tree height (Kearsley et al. 2013). In addition to the carbon inventories we collected leaf and wood samples on all species within 95% basal area of each of the Yangambi plots. A total of 995 individuals were sampled, covering 123 tree species. On the samples we measured 15 traits related to leaf and wood morphology and functioning. In the presented study, relationships between the observed functional diversity and biomass are analysed. One of the remarkable results of our analysis is that species with a high functional distinctiveness have a low contribution to the basal area and the carbon stocks. In contrast, species with a high contribution to the carbon stock have a low contribution to the functional diversity. Similar patterns have been observed elsewhere (e.g. Amazon basin), but are now for the first time confirmed for central African rainforest. Finally, we also present the first results of an analysis of carbons stocks and functional diversity in tropical plantations from a unique 70-years old tree diversity experiment that was established during the colonial period at the Yangambi research station. Kearsley, E., de Haulleville, T., Hufkens, K., Kidimbu, A., Toirambe, B., Baert, G., Huygens, D., Kebede, Y., Defourny, P., Bogaert, J., Beeckman, H

  7. Effective Stress-Porosity Relationship above and Within the Oil Window in the North Sea Basin

    Directory of Open Access Journals (Sweden)

    Kenneth S. Okiongbo

    2011-01-01

    Full Text Available This study investigates the effective stress - porosity relationship above and within the oil window in the Kimmeridge Clay Formation (KCF in the North Sea Basin (UK using effective stress and porosity determined from wireline logs and pore pressure data. Porosity was determined from an empirical porosity - sonic transit - time transform, calibrated using shale and mudstone core porosity measurements from Jurassic shales in the North Sea. Effective stress was determined from the total overburden stress and pore pressure. The total overburden stress was calculated by integration of the density log. The results show that porosity range between ~11-20% in the pre-generation zone but decreased to <5% within the oil window. Compaction coefficient ($ values above the oil window vary from ~0.08-0.09 M/Pa, but vary from ~0.05-0.06 M/Pa within the oil window implying that deeper burial and a high degree of chemical precipitation and cementation has created a stiff matrix giving rise to low $ values. The effective stress-porosity relationship above and within the oil window reflects a possible decrease in effective stress occasioned by increase in porosity in the pregeneration zone.

  8. Watcr Security Situation in Haihc Rivcr Basin after South-to-North Watcr Transfer Project

    Institute of Scientific and Technical Information of China (English)

    JIA Shaofeng; YAN Tingting; LUE Aifeng

    2012-01-01

    The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×10^8m^3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×10^8m^3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: firstly, water transfer project will bring to the Basin 60x108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low- income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.

  9. Origin and time-space distribution of hydrothermal systems in east-central Australian sedimentary basins: Constraints from illite geochronology and isotope geochemistry.

    Science.gov (United States)

    Uysal, I. Tonguç

    2016-04-01

    Some well-known precious mineral deposits and hydrocarbon resources occur extensively in east-central Australian sedimentary Basins. The metal occurrences are abundant in northwestern and eastern part of Queensland, whereas no significant deposits are known in large areas further south, which may, however, be hidden beneath the Jurassic-Cretaceous sedimentary basins. Important hydrocarbon resources exist within the Jurassic-Cretaceous sedimentary rocks at relatively shallow depths, of which the distribution represent zones of high paleo-geothermal gradients. This study examines the time-space distribution in relation to the regional tectonic history of concealed metal deposits and areas of high paleo-geothermal gradient leading to hydrocarbon maturation. To this end, authigenic illitic clay minerals representing various locations and stratigraphic depths in east-central Australia were investigated, of which the Rb-Sr and Ar-Ar geochronology and stable isotope geochemistry assist in delineating zones of hydrothermal systems responsible for hydro-carbon maturation/migration and potentially ore deposition. The Late Carboniferous - Early Permian crustal extension that affected large areas of eastern Australia and led to the epithermal mineralisations (e.g., the Drummond Basin) is also recorded in northern South Australia and southwest Queensland. A Late Triassic - Early Jurassic tectonic event being responsible for coal maturation and gas generation in the Bowen Basin and the epithermal mineralisation in the North Arm goldfield in SE Queensland likewise affected the areas much further west in Queensland. Some illites from the basement in outback Queensland and fault gouges from the Demon Fault in NE New South Wales yield younger Rb-Sr and Ar-Ar ages indicating the effect of hydrothermal processes as a result of a Middle-Upper Jurassic tectonic event. The majority of illite samples from the crystalline basement rocks, Permian Cooper Basin, and Jurassic

  10. IODP expedition 347: Baltic Sea basin paleoenvironment and biosphere

    DEFF Research Database (Denmark)

    Andrén, T; Jørgensen, Bo Barker; Cotterill, Carol;

    2015-01-01

    microbiology. The sites covered the gateway to the North Sea and Atlantic Ocean, several sub-basins in the southern Baltic Sea, a deep basin in the central Baltic Sea, and a river estuary in the north. The waxing and waning of the Scandinavian ice sheet has profoundly affected the Baltic Sea sediments. During...

  11. Evidence for an Upper Palaeozoic North-Palaeotethyan succession in Central Iran: The Siah Godar Complex of Jandaq

    Science.gov (United States)

    Berra, Fabrizio; Zanchi, Andrea; Malaspina, Nadia; Javadi, Hamid Reza; Koohpeyma, Meysam; Angiolini, Lucia; Vachard, Daniel; Zanchetta, Stefano

    2014-05-01

    ., Orulgania sp. , Cleiothyridina sp., Deltachania sp.), corals, smaller foraminifers and fusulinids (Bradyina cf. magna, Pseudoacutella, cf. grozdilovae; Ozawainella sp., Neostaffella ozawai; Fusulinella (Moellerites?) sp., Profusulinella (Ovatella?) sp. and Eoschubertella/Schubertellina sp.) of Moscovian (Kashirian) age. Despite the discontinuity of the outcrops, two different lithological assemblages can be identified: the older is dominated by carbonates with volcanic layers (southern and central outcrops), whereas the younger consists of siliciclastic litharenitic deposits. Fusulinids and brachiopods indicate a North-Palaeotethyan affinity as they are mostly similar to assemblages from Spain, the Donbass, the Urals, as well as the Yukon Territory, Canada, documenting deposition along the northern margin of the Palaeotethys. This confirms the palaeogeographic interpretation by Bagheri & Stampfli (2008), based on the occurrence of several foraminiferal taxa, especially Quasiendothyra kobeitusana (determination D. Vachard). For the moment, this taxon was not recovered in the successions under study, but our assemblages confirm a North-Palaeotethyan origin Despite the outcrop discontinuity, the occurrence of 1) North Palaeotethyan type fossils and 2) of a succession with lithological associations and petrographic composition (northern outcrop), significantly different from the classical upper Palaeozoic succession of Gondwanan affinity of Central Iran, is documented. These data support a complex palaeogeographic evolution for the studied outcrops with respect to the surrounding regions, suggesting a more complex evolution than expected for the Iranian block (e.g., collision of different terranes, preserved arc-related basins, displacement of blocks by transform faults). Bagheri, S. & Stampfli, G.M. 2008. The Anarak, Jandaq and Posht-e-Badam metamorphic complexes in central Iran: New geological data, relationships and tectonic implications. Tectonophysics, 451, 123

  12. Post-Panafrican late Proterozoic basins in the Central Anti-Atlas (Morocco): their influence on the Variscan contractional structures.

    Science.gov (United States)

    Guimerà, Joan; Arboleya, María. Luisa

    2010-05-01

    Located South of the High Atlas, in Morocco, The Anti-Atlas is a 700 km-long chain trending NE-SW. In the Central Anti-Atlas region, between Warzazat and Taznakht, the Proterozoic Pan-African basement (X1 to X2-3) crops out in isolated areas (boutonnières), where it is overlaid by late to post Pan-African Upper Proterozoic and Palaeozoic rocks. Late to post Pan-African Upper Proterozoic rocks (X3) have been classically divided into three units (X3i, X3m and X3s) which include volcanic rocks — mainly rhyolites— and continental siliciclastic rocks, the older units intruded by late granites (Choubert, 1952 and Choubert et al., 1970). Rocks belonging to the upper unit of post Pan-African Upper Proterozoic rocks (X3s) were deposited in basins bounded by faults with a dominant dip-slip normal motion; as a result, this unit have a variable thickness, being locally absent in the uplifted blocks. Uppermost Proterozoic (Adoudounian) and Palaeozoic rocks deposited unconformable on the older rocks in the Anti-Atlas. The Central Anti-Atlas was slightly deformed during the Variscan orogeny by folds and high-angle thrusts. Two areas are selected to study the post Pan-African to Variscan evolution of the area: the Tiwiyyine basin and the Anti-Atlas Major Fault. Tiwiyyine basin This basin is delimited by kilometric-scale normal faults. Three of them can be observed in the field: two striking NE-SW (NW and SE boundaries) and one striking NW-SE (SW boundary), while the NE boundary is covered by Cenozoic rocks. The basin fill reaches 725 m and has been divided into three units: 1. X3s1: Coarse conglomerates with basal breccias. 2. X3s2: Laminated dolomites at the base, red pelites and conglomerates. 3. X3s3: Conglomerates with interbedded andesites. Unit X3s2 passes laterally to the SW to unit X3s1. The thickness of the basin fill diminishes to the SE. This is specially visible at the basal X3s1 unit. At both sides of the two NE-SW-striking faults, only the upper X3s3 unit is

  13. Late Pliocene and Early Pleistocene Temperature Reconstructions from Paleolakes of the West Turkana and North Awash Basins, East Africa

    Science.gov (United States)

    Castañeda, I. S.; Thompson-Munson, M.; Lupien, R.; Russell, J. M.

    2015-12-01

    The Hominin Sites and Paleolakes Drilling Project (HSPDP) aims to reconstruct past environments of the East African Rift Valley from locations in close proximity to some of the world's most important fossil hominin and artifact sites. In this study, we investigate sediments from the West Turkana and North Awash Basins, which were recently drilled as part of the HSPDP. The North Awash Basin contains abundant early hominin fossils and the lakebeds of the Hadar Formation (~3.6 to ~2.9 Ma) will provide a record of climate variability during the Pliocene, prior to the intensification of Northern Hemisphere glaciation at ~2.7 Ma. The lakebeds of the Turkana Basin are Early Pleistocene in age (~1.9 to ~1.45 Ma) and span the interval that includes some the earliest fossils of Homo rudolfensis and H. ergaster/erectus. Here we examine the organic geochemistry of West Turkana and North Awash Basin sediments and investigate the use of proxies based on isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs) to reconstruct temperature, including TEX86 and the methylation and cyclization (MBT and CBT) ratios and relative abundances of branched GDGTs. We also examine variability in the abundances and ratios of plant leaf waxes (n-alkanes) to provide insight into past vegetation changes on the East African landscape.

  14. Wildlife use of existing culverts and bridges in North Central Pennsylvania

    OpenAIRE

    Brudin, Carl O. III

    2003-01-01

    The Pennsylvania Department of Transportation (PENNDOT) District 3-0 initiated a study in North Central Pennsylvania evaluating existing bridges and culverts for use as underpasses by wildlife. This project was a two-phase study to investigate animal passage through existing drainage box culverts, arch culverts and bridges on existing highway systems. The objective of this study was to (1) determine whether wildlife are using existing structures as passageways based on wildlife sign and remot...

  15. Credit Growth in the Middle East, North Africa, and Central Asia Region

    OpenAIRE

    Joe Crowley

    2008-01-01

    Rapid private sector credit growth in the Middle East, North Africa, and Central Asia has been a result of strong economic growth, financial deepening, and banks’ willingness to explore consumer credit markets. Economic growth, the initial ratio of private sector credit to GDP, price volatility, and nonoil exports are found to be significant explanatory variables, while oil exports and spillovers from oil exporting neighbors were not found to have any significance. The credit growth has finan...

  16. Radiological health assessment of natural radioactivity in the vicinity of Obajana cement factory, North Central Nigeria

    OpenAIRE

    Omoniyi Matthew Isinkaye; Jibiri, Nnamdi N.; Adebowale A Olomide

    2015-01-01

    Measurements of activity concentrations of natural radionuclides in and around Obajana cement factory, North Central Nigeria have been carried out in this study to determine the activity levels of natural radionuclides in different environmental matrices in order to assess the radiological health hazards associated with the use of these matrices by the local population. A low-background Pb-shielded gamma spectroscopic counting assembly utilizing NaI (Tl) detector was employed for the measurem...

  17. Imperial Japanese Army Intelligence in North and Central China During the Second Sino-Japanese War

    OpenAIRE

    2014-01-01

    The Japanese today seek to improve their national intelligence apparatus, particularly in relation to human intelligence assets and higher echelon coordination. To be successful, Japan must examine its wartime past in the intelligence field. The Imperial Japanese Army maintained a prolific intelligence presence in North and Central China during the Second World War. Its intelligence apparatus encompassed all aspects of information collection, with considerable overlap between intelligence org...

  18. Strategic Planning for Activation and Operation of the North Central Superpave Center (NCSC): Interim Report

    OpenAIRE

    Olek, J.; McDaniel, Rebecca

    1997-01-01

    The North Central Superpave Center (NCSC) was established to serve the needs of the states and industry in ten states and two Canadian provinces as they implement the Superpave system. Accomplishing this goal requires the cooperation and active support of a number of people and organizations. Organizational and operational issues related to infrastructure, personnel, equipment and finances also needed to be resolved. This project was designed to address those issues, develop a comprehensive s...

  19. Epidemilogical Profile of Speech and Language Disorder in North Central Nigeria

    OpenAIRE

    Aremu, Shuaib K.; Afolabi, Olushola A; Alabi, Biodun S; Elemunkan, Isiah O.

    2011-01-01

    Background: Speech-language pathologists/Otolaryngologists recognize high prevalence of speech and language disorder among children. The aim of the study is to find out the epidemiological profile of speech and language disorder in north central Nigeria. Method: A five year retrospective review of all referral to speech and language therapy unit ENT Department between January 2005 and December 2009. Information retrieved and analysed included bio-data, clinical presentation and diagnosis of t...

  20. Primary infertility associated with schitosoma mansoni: a case report from the Jos plateau, north central Nigeria

    OpenAIRE

    Adisa, J; Egbujo, EM; Yahaya, BA; Echejoh, G

    2012-01-01

    Testicular schistosomiasis caused by Schistosoma mansoni is very rare and more so when associated with primary infertility. A 40 years old man from the Jos Plateau, North Central Nigeria presented with primary infertility after ten years of marriage. Sperm count revealed oligospermia and he also complained of inability to sustain erection. Testicular biopsy revealed several ova of Schistosoma mansoni in the connective tissue of the testes. Cases of infertility in endemic areas especially when...

  1. Assessment of undiscovered oil and gas resources of the Sud Province, north-central Africa

    Science.gov (United States)

    Brownfield, M.E.; Klett, T.R.; Schenk, C.J.; Charpentier, R.R.; Cook, T.A.; Pollastro, R.M.; Tennyson, M.E.

    2011-01-01

    The Sud Province located in north-central Africa recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 7.31 billion barrels of oil, 13.42 trillion cubic feet of natural gas, and 353 million barrels of natural gas liquids.

  2. Drinking water and pregnancy outcome in central North Carolina: source, amount, and trihalomethane levels.

    OpenAIRE

    Savitz, D A; Andrews, K W; Pastore, L M

    1995-01-01

    In spite of the recognition of potentially toxic chemicals in chlorinated drinking water, few studies have evaluated reproductive health consequences of such exposure. Using data from a case-control study of miscarriage, preterm delivery, and low birth weight in central North Carolina, we evaluated risk associated with water source, amount, and trihalomethane (THM) concentration. Water source was not related to any of those pregnancy outcomes, but an increasing amount of ingested water was as...

  3. Factors That Affect Tax Compliance among Small and Medium Enterprises (SMEs) in North Central Nigeria

    OpenAIRE

    Ojochogwu Winnie Atawodi; Stephen Aanu Ojeka

    2012-01-01

    Tax is an important stream of revenue for government’s development projects. However, tax compliance amongSMEs is poor. Therefore, this study was conducted using SMEs in Zaria, North-Central Nigeria to evaluate andrank the factors that encourage non-compliance with tax obligation by SMEs. It was found that high tax rates andcomplex filing procedures are the most crucial factors causing non-compliance of SMEs. Other factors likemultiple taxation and lack of proper enlightenment affect tax comp...

  4. Extensional fault-bend folding and synrift deposition: An example from the Central Sumatra basin, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.H.; Hook, S.C. [Texaco Exploration and Production Technology Dept., Houston, TX (United States); Sitohang, E.P. [PT CALTEX Pacific Indonesia, Pekanbaru (Indonesia)

    1997-03-01

    We describe an analytical method for interpreting the geometry and structural history of asymmetric half grabens in rift basins with extensional fault-bend fold theory. Using seismic reflection profiles from the Central Sumatra basin and balanced forward models, we show how local variations in tectonic subsidence relative to deposition rates yield distinctive patterns of folded synrift strata and unconformities that record basin history. If the deposition rate exceeds the local subsidence rate, folded growth strata form upwardly narrowing kink bands that have been described previously as growth triangles. In contrast, if the deposition rate is less than or equals the local subsidence rate, growth strata are folded and truncated at the surface on half-graben margins. Subsequent increases in deposition rate relative to subsidence rate form angular unconformities near the half-graben margins. These unconformities develop without the necessity of erosion and are folded by continuing fault slip. Strata above and below the unconformities are concordant in the deeper parts of the half grabens. Thus, angular unconformities on half-graben margins are helpful for defining sequence boundaries that may reflect changes in deposition and tectonic subsidence rates. In addition, fault-bend fold interpretations yield fault geometry and measures of horizontal extension, both of which control three-dimensional half-graben geometry and accommodation space. We show how along-strike variations in fault geometry produce intrabasinal structures that may form prospective fair-ways or local depocenters.

  5. Sedimentology and diagenesis of a rift basin lacustrine sandstone: Pematang group, central Sumatra, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Janks, J.S.; Kelley, P.A.; Williams, H.H.

    1986-05-01

    The Central Sumatra basin is a back-arc basin that formed during the Paleocene as a series of half-graben structures. These early formed half-graben structures were filled with nonmarine clastics and lacustrine sediments of the Pematang Group, sourced from local highland areas. The Pematang Group consists of the Lower Red Beds, Brown Shale, Coal Zone Member, and Lake Fill Formation (in ascending order). The Pematang Group sedimentology is intimately related to the regional and basinal tectonic development and history. Sandstones of the Pematang Group are predominantly sublitharenites and litharenites; feldspars are rare. Sandstone diagenesis is relatively uniform regardless of the depositional environment. Diagenetic modifications include compaction, early calcite and dolomite cementation, quartz overgrowth formation, unstable rock-fragment dissolution, kaolinite precipitation, siderite formation, and local illite formation. Secondary porosity accounts for up to 50% of the effective porosity and was created by rock-fragment dissolution. This dissolution is probably caused by the organic acids released during kerogen maturation. Stable isotope data from diagenetic siderite are presented.

  6. The changing climate and human vulnerability in north-central Namibia

    Directory of Open Access Journals (Sweden)

    Margaret N. Angula

    2016-01-01

    Full Text Available North-central Namibia is more vulnerable to effects of climate change and variability. Combined effects of environmental degradation, social vulnerability to poverty and a changing climate will compromise subsistence farming in north-central Namibia (NCN. This will make subsistence and small-scale farmers in the region more vulnerable to projected changes in the climate system. Thus, the aim of this article was to examine factors contributing to subsistence farmers’ vulnerability to impacts of climate change. The article further discusses different aspects of human vulnerability and existing adaptation strategies in response to impacts of climate related disasters experienced over the past three to four decades in NCN. Qualitative and quantitative research approaches and methodology were employed to obtain information from subsistence farmers in north-central Namibia. The sociodemographic characteristics of Ohangwena, Oshana and Omusati Region reveals high levels of unemployment, high adult and elderly population and high dependency on agricultural livelihood system. These indicators help understand levels of household vulnerability. The study concludes that households interviewed revealed low levels of adaptive capacity due to exposure to climate risks and combined effects of social, political and cultural factors. This article provided an understanding that is required to inform the adaptation pathways relevant for NCN.

  7. Difference in full-filled time and its controlling factors in the Central Canyon of the Qiongdongnan Basin

    Institute of Scientific and Technical Information of China (English)

    SHANG Zhilei; XIE Xinong; LI Xushen; ZHANG Daojun; HE Yunlong; YANG Xing; CUI Mingzhe

    2015-01-01

    Based on the interpretation of high resolution 2D/3D seismic data, sedimentary filling characteristics and full-filled time of the Central Canyon in different segments in the Qiongdongnan Basin of northwestern South China Sea have been studied. The research results indicate that the initial formation age of the Central Canyon is traced back to 11.6 Ma (T40), at which the canyon began to develop due to the scouring of turbidity currents from west to east. During the period of 11.6–8.2 Ma (T40–T31), strong downcutting by gravity flow occurred, which led to the formation of the canyon. The canyon fillings began to form since 8.2 Ma (T31) and were dominated by turbidite deposits, which constituted of lateral migration and vertical superposition of turbidity channels during the time of 8.2–5.5 Ma. The interbeds of turbidity currents deposits and mass transport deposits (MTDs) were developed in the period of 5.5–3.8 Ma (T30–T28). After then, the canyon fillings were primarily made up of large scale MTDs, interrupted by small scale turbidity channels and thin pelagic mudstones. The Central Canyon can be divided into three types according to the main controlling factors, geomorphology-controlled, fault-controlled and intrusion-modified canyons. Among them, the geomorphology-controlled canyon is developed at the Ledong, Lingshui, Songnan and western Baodao Depressions, situated in a confined basin center between the northern slope and the South Uplift Belt along the Central Depression Belt. The fault-controlled canyon is developed mainly along the deep-seated faults in the Changchang Depression and eastern Baodao Depression. Intrusion-modified canyon is only occurred in the Songnan Low Uplift, which is still mainly controlled by geomorphology, the intrusion just modified seabed morphology. The full-filled time of the Central Canyon differs from west to east, displaying a tendency of being successively late eastward. The geomorphology-controlled canyon was

  8. Ethiopian Central Rift Valley basin hydrologic modelling using HEC-HMS and ArcSWAT

    Science.gov (United States)

    Pascual-Ferrer, Jordi; Candela, Lucila; Pérez-Foguet, Agustí

    2013-04-01

    An Integrated Water Resources Management (IWRM) shall be applied to achieve a sustainable development, to increase population incomes without affecting lives of those who are highly dependent on the environment. First step should be to understand water dynamics at basin level, starting by modeling the basin water resources. For model implementation, a large number of data and parameters are required, but those are not always available, especially in some developing countries where different sources may have different data, there is lack of information on data collection, etc. The Ethiopian Central Rift Valley (CRV) is an endorheic basin covering an area of approximately 10,000 km2. For the period 1996-2005, the average annual volume of rainfall accounted for 9.1 Mm3, and evapotranspiration for 8 Mm3 (Jansen et al., 2007). From the environmental point of view, basin ecosystems are endangered due to human activities. Also, poverty is widespread all over the basin, with population mainly living from agriculture on a subsistence economy. Hence, there is an urgent need to set an IWRM, but datasets required for water dynamics simulation are not too reliable. In order to reduce uncertainty of numerical simulation, two semi-distributed open software hydrologic models were implemented: HEC-HMS and ArcSWAT. HEC-HMS was developed by the United States Army Corps of Engineers (USACoE) Hydrologic Engineering Center (HEC) to run precipitation-runoff simulations for a variety of applications in dendritic watershed systems. ArcSWAT includes the SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) model developed for the USDA Agricultural Research Service into ArcGIS (ESRI®). SWAT was developed to assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time (Neitsch et al., 2005). According to this, ArcSWAT would be the best option for IWRM implementation in the basin. However

  9. Minibasins and salt canopy in foreland fold-and-thrust belts: The central Sivas Basin, Turkey

    Science.gov (United States)

    Kergaravat, Charlie; Ribes, Charlotte; Legeay, Etienne; Callot, Jean-Paul; Kavak, Kaan Sevki; Ringenbach, Jean-Claude

    2016-06-01

    The Sivas Basin in the Central Anatolian Plateau (Turkey), which formed in the context of a foreland fold-and-thrust belt (FTB), exhibits a typical wall and basin (WAB) province characterized by symmetric minibasins separated by continuous steep-flanked walls and diapirs. Extensive fieldwork including regional and detailed local mapping of the contacts and margins of minibasins, and interpretation of a set of 2-D regional seismic lines, provide evidence for the development of a shallow evaporite level separating two generations of minibasins within the WAB province. Here beds of symmetric exposed minibasins along diapir flank are younger than minibasins observed over autochthonous evaporites. Laterally away from the WAB province, increase in wavelength of the tectonic structures suggests a deepening of the decollement level. We interpret that a shallower evaporite level developed in the form of an evaporite canopy, triggered by significant lateral shortening. The Upper Eocene-Lower Oligocene autochthonous Tuzhisar evaporite level was remobilized by the northward migrating sedimentary load and the tilting of the southern basin margin during propagation of the foreland fold-and-thrust belt. Asymmetric and symmetric primary minibasins were overrun by an allochthonous sheet forming a canopy. A second generation of salt withdrawal minibasins subsided into the allochthonous salt sheet. The polygonal pattern of the WAB province influences the growing fold-and-thrust belt system during the late stage of the secondary minibasins development. The Sivas FTB basin is the result of the interaction between fold-and-thrust belt propagation, evaporite remobilization, and interaction between evaporite flow and sedimentation in the minibasins.

  10. Analysis of trends in streamflow and its linkages with rainfall and anthropogenic factors in Gomti River basin of North India

    Science.gov (United States)

    Abeysingha, N. S.; Singh, Man; Sehgal, V. K.; Khanna, Manoj; Pathak, Himanshu

    2016-02-01

    Trend analysis of hydro-climatic variables such as streamflow, rainfall, and temperature provides useful information for effective water resources planning, designing, and management. Trends in observed streamflow at four gauging stations in the Gomti River basin of North India were assessed using the Mann-Kendall and Sen's slope for the 1982 to 2012 period. The relationships between trends in streamflow and rainfall were studied by correlation analyses. There was a gradual decreasing trend of annual, monsoonal, and winter seasonal streamflow ( p design streamflow restoration strategies for sustainable water management planning of the Gomti River basin.

  11. Vesta's north pole quadrangle Av-1 (Albana): Geologic map and the nature of the south polar basin antipodes

    Science.gov (United States)

    Blewett, David T.; Buczkowski, Debra L.; Ruesch, Ottaviano; Scully, Jennifer E.; O'Brien, David P.; Gaskell, Robert; Roatsch, Thomas; Bowling, Timothy J.; Ermakov, Anton; Hiesinger, Harald; Williams, David A.; Raymond, Carol A.; Russell, Christopher T.

    2014-12-01

    As part of systematic global mapping of Vesta using data returned by the Dawn spacecraft, we have produced a geologic map of the north pole quadrangle, Av-1 Albana. Extensive seasonal shadows were present in the north polar region at the time of the Dawn observations, limiting the ability to map morphological features and employ color or spectral data for determination of composition. The major recognizable units present include ancient cratered highlands and younger crater-related units (undivided ejecta, and mass-wasting material on crater floors). The antipode of Vesta's large southern impact basins, Rheasilvia and Veneneia, lie within or near the Av-1 quadrangle. Therefore it is of particular interest to search for evidence of features of the kind that are found at basin antipodes on other planetary bodies. Albedo markings known as lunar swirls are correlated with basin antipodes and the presence of crustal magnetic anomalies on the Moon, but lighting conditions preclude recognition of such albedo features in images of the antipode of Vesta's Rheasilvia basin. “Hilly and lineated terrain,” found at the antipodes of large basins on the Moon and Mercury, is not present at the Rheasilvia or Veneneia antipodes. We have identified small-scale linear depressions that may be related to increased fracturing in the Rheasilvia and Veneneia antipodal areas, consistent with impact-induced stresses (Buczkowski, D. et al. [2012b]. Analysis of the large scale troughs on Vesta and correlation to a model of giant impact into a differentiated asteroid. Geol. Soc. of America Annual Meeting. Abstract 152-4; Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre.20123). The general high elevation of much of the north polar region could, in part, be a result of uplift caused by the Rheasilvia basin-forming impact, as predicted by numerical modeling (Bowling, T.J. et al. [2013]. J. Geophys. Res. - Planets, 118. http://dx.doi.org/10.1002/jgre

  12. Polyphase tectonic subsidence evolution of the Vienna Basin inferred from quantitative subsidence analysis of the northern and central parts

    Science.gov (United States)

    Lee, Eun Young; Wagreich, Michael

    2016-04-01

    The Vienna Basin is a tectonically complex Neogene basin situated at the Alpine-Carpathian transition. This study analyzes a detailed quantification of subsidence in the northern and central parts of the Vienna Basin to understand its tectonic subsidence evolution. About 200 wells were used to arrange stratigraphic setting, and wells reaching the pre-Neogene basement were analyzed for subsidence. To enhance the understanding of the regional subsidences, the wells were sorted into ten groups based on their position on major fault blocks. In the Early Miocene, subsidence was slow and along E-W to NE-SW trending axis, indicating the development of thrust-controlled piggyback basins. During the late Early Miocene data show abruptly increasing subsidence, making the initiation of the Vienna pull-apart basin system. From the Middle Miocene, the tectonic subsidence curves show regionally different patterns. The tectonic subsidence during the Middle Miocene varies laterally across the Vienna Basin, and the differential subsidence can be related to the changing tensional regime of weakening transtension and strengthening extension toward the late Middle Miocene. From the late Middle Miocene to the Late Miocene, the tectonic subsidence occurred dominantly along the regional active faults, and corresponds to the axis of E-W trending extension of the western parts of the Pannonian Basin system. In the Quaternary the Vienna Basin has been reactivated, and resulted in subsidence along the NE-SW trending Vienna Basin transfer fault system.

  13. Basin-floor fans in the North Sea: Sequence stratigraphic models vs. sedimentary facies

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G.; Bloch, R.B. [Mobil Research and Development Corp., Dallas, TX (United States); Mitchell, S.M. [Mobil Exploration and Producing US, Inc., Dallas, TX (United States); Beamish, G.W.J.; Shields, K.E. [Mobil North Sea Ltd., London (United Kingdom); Hodgkinson, R.J.; Straume, T.; Syvertsen, S.E. [Mobil Exploration Norway, Inc., Stavanger (Norway); Damuth, J.E. [Univ. of Texas, Arlington, TX (United States)

    1995-04-01

    Examination of nearly 12,000 feet (3658m) of conventional core from Paleogene and Cretaceous deep-water sandstone reservoirs cored in 50 wells in 10 different areas or fields in the North Sea and adjacent regions reveals that these reservoirs are predominantly composed of mass-transport deposits, mainly sandy slumps and sandy debris flows. Sedimentary features indicating slump and debris-flow origin include sand units with sharp upper contacts; slump folds; discordant, steeply dipping layers (up to 60{degrees}); glide planes; shear zones; brecciated clasts; clastic injections; floating mudstone clasts; planar clast fabric; inverse grading of clasts; and moderate-to-high matrix content (5-30%). This model predicts that basin-floor fans are predominantly composed of sand-rich turbidites with laterally extensive, sheetlike geometries. However, calibration of sedimentary facies in our long (400-700 feet) cores with seismic and wire-line-log signatures through several of these basin-floor fans (including the Gryphon-Forth, Frigg, and Faeroe areas) shows that these features are actually composed almost exclusively of mass-transport deposits consisting mainly of slumps and debris flows. Distinguishing deposits of mass-transport processes, such as debris flows, from those of turbidity currents has important implications for predicting reservoir geometry. Debris flows, which have plastic flow rheology, can form discontinuous, disconnected sand bodies that are harder to delineate and less economical to develop than deposits of fluidal turbidity currents, which potentially produce more laterally continuous, interconnected sand bodies. Process sedimentological interpretation of conventional core is commonly critical for determining the true origin and distribution of reservoir sands.

  14. Herbarium specimens reveal the footprint of climate change on flowering trends across north-central North America.

    Science.gov (United States)

    Calinger, Kellen M; Queenborough, Simon; Curtis, Peter S

    2013-08-01

    Shifting flowering phenology with rising temperatures is occurring worldwide, but the rarity of co-occurring long-term observational and temperature records has hindered the evaluation of phenological responsiveness in many species and across large spatial scales. We used herbarium specimens combined with historic temperature data to examine the impact of climate change on flowering trends in 141 species collected across 116,000 km(2) in north-central North America. On average, date of maximum flowering advanced 2.4 days °C(-1), although species-specific responses varied from - 13.5 to + 7.3 days °C(-1). Plant functional types exhibited distinct patterns of phenological responsiveness with significant differences between native and introduced species, among flowering seasons, and between wind- and biotically pollinated species. This study is the first to assess large-scale patterns of phenological responsiveness with broad species representation and is an important step towards understanding current and future impacts of climate change on species performance and biodiversity. PMID:23786499

  15. Modeling the Nd isotopic composition in the North Atlantic basin using an eddy-permitting model

    Science.gov (United States)

    Arsouze, T.; Treguier, A. M.; Peronne, S.; Dutay, J.-C.; Lacan, F.; Jeandel, C.

    2010-09-01

    Boundary Exchange (BE - exchange of elements between continental margins and the open ocean) has been emphasized as a key process in the oceanic cycle of neodymium (Nd) (Lacan and Jeandel, 2005a). Here, we use a regional eddy-permitting resolution Ocean General Circulation Model (1/4°) of the North Atlantic basin to simulate the distribution of the Nd isotopic composition, considering BE as the only source. Results show good agreement with the data, confirming previous results obtained using the same parameterization of the source in a coarse resolution global model (Arsouze et al., 2007), and therefore the major control played by the BE processes in the Nd cycle on the regional scale. We quantified the exchange rate of the BE, and found that the time needed for the continental margins to significantly imprint the chemical composition of the surrounding seawater (further referred as characteristic exchange time) is of the order of 0.2 years. However, the timescale of the BE may be subject to large variations as a very short exchange time (a few days) is needed to reproduce the highly negative values of surface waters in the Labrador Sea, whereas a longer one (up to 0.5 years) is required to simulate the radiogenic influence of basaltic margins and distinguish the negative isotopic signatures of North Atlantic Deep Water from the more radiogenic southern origin water masses. This likely represents geographical variations in erosion fluxes and the subsequent particle load onto the continental margins. Although the parameterization of the BE is the same in both configurations of the model, the characteristic exchange time in the eddy-permitting configuration is significantly lower than the previous evaluations using a low resolution configuration (6 months to 10 years), but however in agreement with the available seawater Nd isotope data. This results highlights the importance of the model dynamics in simulating the BE process.

  16. Cob biomass supply for combined heat and power and biofuel in the north central USA

    International Nuclear Information System (INIS)

    Corn (Zea mays L.) cobs are being evaluated as a potential bioenergy feedstock for combined heat and power generation (CHP) and conversion into a biofuel. The objective of this study was to determine corn cob availability in north central United States (Minnesota, North Dakota, and South Dakota) using existing corn grain ethanol plants as a proxy for possible future co-located cellulosic ethanol plants. Cob production estimates averaged 6.04 Tg and 8.87 Tg using a 40 km radius area and 80 km radius area, respectively, from existing corn grain ethanol plants. The use of CHP from cobs reduces overall GHG emissions by 60%–65% from existing dry mill ethanol plants. An integrated biorefinery further reduces corn grain ethanol GHG emissions with estimated ranges from 13.9 g CO2 equiv MJ−1 to 17.4 g CO2 equiv MJ−1. Significant radius area overlap (53% overlap for 40 km radius and 86% overlap for 80 km radius) exists for cob availability between current corn grain ethanol plants in this region suggesting possible cob supply constraints for a mature biofuel industry. A multi-feedstock approach will likely be required to meet multiple end user renewable energy requirements for the north central United States. Economic and feedstock logistics models need to account for possible supply constraints under a mature biofuel industry. - Highlights: • Corn cob biomass was estimated for the north central United States region. • Cobs were evaluated for combined heat and power generation and bioethanol. • Co-located ethanol plants showed a reduction in greenhouse gas emissions. • Biomass supply constraints may occur under a mature cellulosic ethanol scenario

  17. Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, NE China: evidence from basin provenance and geochronology

    Science.gov (United States)

    Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei

    2010-05-01

    The main part of Jiamusi Block, named as Huanan-Uplift, is located in the northeastern Heilongjiang, China. The Huanan-Uplift is surrounded by many relatively small Mesozoic-Cenozoic basins, e.g. Sanjiang Basin, Hulin Basin, Boli Basin, Jixi Basin, Shuangyashan Basin and Shuanghua Basin. However previous research works were mainly focused on stratigraphy and palaeontology of the basins, therefore, the coupling relation between the uplift and the surrounding basins have not been clear. Based on the field investigations, conglomerate provenance studies of the Houshigou Formation in Boli Basin, geochronology of the Huanan-Uplift basement, we have been studied the relationships between Huanan-Uplift and the surrounding basins. The regional stratigraphic correlations indicates that the isolated basins in the area experienced the same evolution during the period of the Chengzihe and the Muling Formations (the Early Cretaceous). The paleogeography reconstructions suggest that the area had been a large-scale basin as a whole during the Early Cretaceous. The Huanan-Uplift did not exist. The paleocurrent directions, sandstone and conglomerate provenance analyses show that the Huanan-Uplift started to be the source area of the surrounding basins during the period of Houshigou Formation (early Late Cretaceous), therefore, it suggests that the Jiamusi Block commenced uplift in the early Late Cretaceous. The granitic gneisses in Huanan-Uplift give 494-415 Ma monazite U-Th-total Pb ages, 262-259 Ma biotite and 246-241 Ma K-feldspar 40Ar/39Ar ages. The cooling rates of 1-2 ℃/Ma from 500-260 Ma and 10-11 ℃/Ma from 260-240 Ma have been calculated based on the ages. This suggests that the Jiamusi Block had a rapid exhumation during late Permian, which should be related to the closure of the Paleo-Asian Ocean between the Siberian and North China continents. It is concluded that during the late Paleozoic the Jiamusi Block was stable with a very slow uplifting. With the closure of

  18. Long-term geochemical connections between the Samoan hotspot and the northern Lau and North Fiji Basins

    Science.gov (United States)

    Price, A. A.; Jackson, M. G.; Blichert-Toft, J.; Hall, P. S.; Sinton, J. M.; Kurz, M. D.; Blusztajn, J.

    2013-12-01

    The Lau and North Fiji Basins provide a unique environment for the study of upper mantle flow around a subducting slab due to the juxtaposition of the Tonga Trench and the Samoan hotspot (Hart et al., 2004). Both geochemical and geophysical data suggest that material from the Samoan hotspot is leaking southward into the adjacent Lau Basin, but the direction and rate of mantle flow are difficult to constrain.Spatial variations in the isotope geochemistry of igneous rocks from the Lau Basin can provide a useful window on flow in the upper mantle. For example, some lavas from the Samoan hotspot exhibit high 3He/4He, and the observation of elevated 3He/4He at Rochambeau Bank in the nearby northern Lau Basin has been interpreted as the result of a 'finger-like' intrusion of Samoan-plume mantle into the region. However, high 3He/4He is rare even in Samoan lavas, so other geochemical signatures including radiogenic 87Sr/86Sr and Pb-isotopic compositions unique to the Samoan hotspot are useful for characterizing the spatial distribution of the Samoan component within the northern Lau and North Fiji Basins. We present analyses of a combination of geochemical tracers (He-Hf-Nd-Sr-Pb isotopes, major, and trace elements) measured on glasses from the northern Lau Basin and the North Fiji Basin. The samples have 3He/4He ratios that vary between 6 and 10.5 times atmospheric. The samples also show arange in isotopic values from extremely depleted (87Sr/86Sr=0.702892, 143Nd/144Nd=0.513218 and 176Hf/177Hf=0.283510 on a ridge 100km North of Fiji) to moderately enriched (87Sr/86Sr=0.703598, 143Nd/144Nd=0.512884 and 176Hf/177Hf=0.283082 in lavas fromPandora Ridge). Notably, moderately enriched isotopic compositions in Pandora Ridge lavas plot near Samoa's Upolu Island in isotope space, but are slightly shifted isotopically towards a depleted MORB mantle component. The new data suggestthat the western extent of the Samoan plume's influence in the region extends into both the

  19. Structural control of the basement in the central portion of the Santos Basin-Brazil; Controle estrutural do embasamento na porcao central da Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Izeli, Maira G.B.; Morales, Norberto; Souza, Iata A. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

    2008-07-01

    New discoveries of oil in deep water and ultra-deep water in Santos Basin suggest that it needs to be studied to better understanding of basement structures and their role in the basin control and configuration. This study characterizes the main tectonic structures of a portion at the central area of this basin, looking for their relation to the geological basement framework. The study is based on the integration of the geological and geophysical data from subsurface (offshore) and surface of the adjacent continent. These analyses include the continental structures that continue in direction of this basin (Guapiara Lineament and Ponta Grossa Arc), checking their possible influence on the basin evolution and deformation. To achieve the proposed goals, the Precambrian basement lineaments were extracted from the offshore area using remote sensing, as result was obtained strong NW-SE structural trend. According to the interpretation of seismic sections, it is possible to observe that this portion of the basin presents main NE-SW structural trend, and most of the structures are typical of passive margin and halokintics process. It is possible to see that some recognized faults in the rift deposits may be coinciding with the main continental guidelines which are projected into the basin. (author)

  20. Evapotranspiration from the Lower Walker River Basin, West-Central Nevada, Water Years 2005-07

    Science.gov (United States)

    Allander, Kip K.; Smith, J. LaRue; Johnson, Michael J.

    2009-01-01

    Evapotranspiration is the ultimate path of outflow of nearly all water from the Lower Walker River basin. Walker Lake is the terminus of the topographically closed Walker River basin, and the lake level has been declining at an average rate of about 1.6 feet per year (ft/yr) since 1917. As a result of the declining lake level, dissolved-solids concentrations are increasingly threatening the fishery and ecosystem health of the lake. Uncertainties in the water budget components of the Lower Walker River basin led the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, to undertake an investigation to refine estimates of the water budget. Evapotranspiration from the Lower Walker River basin represents a major component of this water budget. The specific objectives of this report are to provide estimates of total and net evapotranspiration for water years 2005-07 for areas in the Lower Walker River basin in which annual evapotranspiration exceeds annual precipitation, and to summarize these results for areas of similar vegetation and soil characteristics, hydrographic subareas, and Walker Lake and Weber Reservoir. The three hydrographic subareas include the area along Walker River north of Walker Lake, the area of and adjacent to Walker Lake, and the area south of Walker Lake. Areas of annual evapotranspiration exceeding annual precipitation were identified and mapped in the field and were further delineated using remote-sensing analysis. These areas were classified into 10 evapotranspiration units. A network of 11 evapotranspiration stations was operated in natural and agricultural vegetation and on Walker Lake. Measured evapotranspiration rates ranged from 0.5 ft/yr at a sparsely vegetated desert shrub site to 5.0 ft/yr from Walker Lake. The greatest evapotranspiration rate on land was 4.1 ft/yr at an irrigated alfalfa field, and the greatest rate for natural vegetation was 3.9 ft/yr in a riparian community along Walker River. At an

  1. Surface uplift and convective rainfall along the southern Central Andes (Angastaco Basin, NW Argentina)

    Science.gov (United States)

    Pingel, Heiko; Mulch, Andreas; Alonso, Ricardo N.; Cottle, John; Hynek, Scott A.; Poletti, Jacob; Rohrmann, Alexander; Schmitt, Axel K.; Stockli, Daniel F.; Strecker, Manfred R.

    2016-04-01

    Stable-isotopic and sedimentary records from the orogenic Puna Plateau of NW Argentina and adjacent intermontane basins to the east furnish a unique late Cenozoic record of range uplift and ensuing paleoenvironmental change in the south-central Andes. Today, focused precipitation in this region occurs along the eastern, windward flanks of the Eastern Cordillera and Sierras Pampeanas ranges, while the orogen interior constitutes high-elevation regions with increasingly arid conditions in a westward direction. As in many mountain belts, such hydrologic and topographic gradients are commonly mirrored by a systematic relationship between the oxygen and hydrogen stable isotope ratios of meteoric water and elevation. The glass fraction of isotopically datable volcanic ash intercalated in sedimentary sequences constitutes an environmental proxy that retains a signal of the hydrogen-isotopic composition of ancient precipitation. This isotopic composition thus helps to elucidate the combined climatic and tectonic processes associated with topographic growth, which ultimately controls the spatial patterns of precipitation in mountain belts. However, between 25.5 and 27°S present-day river-based hydrogen-isotope lapse rates are very low, possibly due to deep-convective seasonal storms that dominate runoff. If not accounted for, the effects of such conditions on moisture availability in the past may lead to misinterpretations of proxy-records of rainfall. Here, we present hydrogen-isotope data of volcanic glass (δDg), extracted from 34 volcanic ash layers in different sedimentary basins of the Eastern Cordillera and the Sierras Pampeanas. Combined with previously published δDg records and our refined U-Pb and (U-Th)/He zircon geochronology on 17 tuff samples, we demonstrate hydrogen-isotope variations associated with paleoenvironmental change in the Angastaco Basin, which evolved from a contiguous foreland to a fault-bounded intermontane basin during the late Mio

  2. Mineralogical and geochemical characters of surface sediments from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.

    and siliceous sediments of the northern part of the basin indicate the influence of continental influx. This influence, however, decreases in the southern part of the basin where smectite is predominant, indicating volcanic input. The basinal sediments...

  3. Diagenetic Evolution and Reservoir Quality of Sandstones in the North Alpine Foreland Basin: A Microscale Approach.

    Science.gov (United States)

    Gross, Doris; Grundtner, Marie-Louise; Misch, David; Riedl, Martin; Sachsenhofer, Reinhard F; Scheucher, Lorenz

    2015-10-01

    Siliciclastic reservoir rocks of the North Alpine Foreland Basin were studied focusing on investigations of pore fillings. Conventional oil and gas production requires certain thresholds of porosity and permeability. These parameters are controlled by the size and shape of grains and diagenetic processes like compaction, dissolution, and precipitation of mineral phases. In an attempt to estimate the impact of these factors, conventional microscopy, high resolution scanning electron microscopy, and wavelength dispersive element mapping were applied. Rock types were established accordingly, considering Poro/Perm data. Reservoir properties in shallow marine Cenomanian sandstones are mainly controlled by the degree of diagenetic calcite precipitation, Turonian rocks are characterized by reduced permeability, even for weakly cemented layers, due to higher matrix content as a result of lower depositional energy. Eocene subarkoses tend to be coarse-grained with minor matrix content as a result of their fluvio-deltaic and coastal deposition. Reservoir quality is therefore controlled by diagenetic clay and minor calcite cementation.Although Eocene rocks are often matrix free, occasionally a clay mineral matrix may be present and influence cementation of pores during early diagenesis. Oligo-/Miocene deep marine rocks exhibit excellent quality in cases when early cement is dissolved and not replaced by secondary calcite, mainly bound to the gas-water contact within hydrocarbon reservoirs. PMID:26365327

  4. Numerical modeling of fracking fluid migration through fault zones and fractures in the North German Basin

    Science.gov (United States)

    Pfunt, Helena; Houben, Georg; Himmelsbach, Thomas

    2016-04-01

    Gas production from shale formations by hydraulic fracturing has raised concerns about the effects on the quality of fresh groundwater. The migration of injected fracking fluids towards the surface was investigated in the North German Basin, based on the known standard lithology. This included cases with natural preferential pathways such as permeable fault zones and fracture networks. Conservative assumptions were applied in the simulation of flow and mass transport triggered by a high pressure boundary of up to 50 MPa excess pressure. The results show no significant fluid migration for a case with undisturbed cap rocks and a maximum of 41 m vertical transport within a permeable fault zone during the pressurization. Open fractures, if present, strongly control the flow field and migration; here vertical transport of fracking fluids reaches up to 200 m during hydraulic fracturing simulation. Long-term transport of the injected water was simulated for 300 years. The fracking fluid rises vertically within the fault zone up to 485 m due to buoyancy. Progressively, it is transported horizontally into sandstone layers, following the natural groundwater flow direction. In the long-term, the injected fluids are diluted to minor concentrations. Despite the presence of permeable pathways, the injected fracking fluids in the reported model did not reach near-surface aquifers, either during the hydraulic fracturing or in the long term. Therefore, the probability of impacts on shallow groundwater by the rise of fracking fluids from a deep shale-gas formation through the geological underground to the surface is small.

  5. An Estimate of the North Atlantic Basin Tropical Cyclone Activity for the 2010 Hurricane Season

    Science.gov (United States)

    Wilson, Robert M.

    2010-01-01

    Estimates are presented for the tropical cyclone activity expected for the 2010 North Atlantic basin hurricane season. It is anticipated that the 2010 season will be more active than the 2009 season, reflecting increased frequencies more akin to that of the current more active phase that has been in vogue since 1995. Averages (+/- 1 sd) during the current more active phase are 14.5+/-4.7, 7.8+/-3.2, 3.7+/-1.8, and 2+/- 2, respectively, for the number of tropical cyclones (NTC), the number of hurricanes (NH), the number of major hurricanes (NMH), and the number of United States (U.S.) land-falling hurricanes (NUSLFH). Based on the "usual" behavior of the 10-yma parametric first differences, one expects NTC = 19+/-2, NH = 14+/-2, NMH = 7+/-2, and NUSLFH = 4+/-2 for the 2010 hurricane season; however, based on the "best guess" 10-yma values of surface-air temperature at the Armagh Observatory (Northern Ireland) and the Oceanic Nino Index, one expects NTC > or equals 16, NH > or equals 14, NMH > or equals 7, and NUSLFH > or equals 6.

  6. Determination of faults parameters controlling the Petroleum Systems Elements in the northern North Sea by using 3D basin Modelling

    OpenAIRE

    Andriamihaja, Spariharijaona

    2011-01-01

    3D basin modelling of the northern North Sea region covering 4886km2 is performed in order to understand the petroleum system elements within the area. The approach used to obtain the most likely model is to analyze and determine quantitatively the faults properties controlling the hydrocarbons accumulations in the Gullfaks, Visund, Kvitebjørn, and Huldra fields. This approach is made by varying the faults properties defined by shale gauge ratio until the reserves in place in the four fields ...

  7. GIS-analysis of gully erosion susceptibility: a key study in north-central Sicily, Italy

    Science.gov (United States)

    Agnesi, Valerio; Angileri, Silvia; Cappadonia, Chiara; Conoscenti, Christian; Costanzo, Dario; Maerker, Michael; Rotigliano, Edoardo

    2010-05-01

    Erosion by water is responsible for severe geo-environmental problems in semi-humid to arid Mediterranean areas. Large sectors of Sicily are affected by intense soil erosion phenomena leading to severe damages in agriculture lands that, in some cases, experience high soil loss rates. An important contribution to sediment yield from these areas is given by gully erosion phenomena; the latter, in the last decades, attracted attention of many researches that developed and applied methods to quantify soil loss volumes and to evaluate proneness of territory to this process. The present research aims to assess gully erosion susceptibility in the basin of the San Giorgio torrent, a mountain stream flowing in north-central Sicily and draining an area of about 9.5 km2; the watershed, which is mainly covered by arable lands, has highly erodible slopes characterized by the outcropping of clays and marls. In order to predict gully erosion susceptibility, a multivariate geostatistical approach is adopted here. In particular, the method is based on the definition of spatial relationships between the geographical variability of a set of controlling factors and the occurrence of gullies on slopes; the linear density of gullies computed on homogeneous domains is selected as the probabilistic function expressing how proneness to gully erosion spatially changes in the studied area. Available thematic maps, which were integrated by field and remote surveys, and a high quality DEM, were used to derive eight layers of terrain variables, selected according to geomorphological criteria and expressing both soil erodibility (bedrock lithology, land use) and erosivity of flowing waters (slope angle, Stream Power Index, SL-factor, Topographic Wetness Index, plan and profile curvature). All the parameters were computed for homogeneous spatial domains, created by intersecting a grid of 50m square polygons and a layer of slope units automatically derived from DEM; therefore, the eight layers

  8. Discussions on the sedimentary-tectonic event and tectonic setting of the North Tarim Basin in Cryogenian-Cambrian

    Science.gov (United States)

    Zhou, X. B.; Li, J. H.; Li, W. S.

    2012-04-01

    Across the Tarim Basin, limited surface outcrops of Cryogenian to Cambrian sedimentary succession are completely exposed in the vicinity of Aksu area(Northwest Tarim), Kuruktag(Northeast Tarim)and Southwest Tarim, thus provides a unique, well preserved and accessible means by which to study the early development of the north Tarim Basin. Based on the field geological investigation in the northwestern and northeastern of Tarim Basin, with the referencing of paleomagnetism mapping and previous research, basin evolution process in Cryogenian-Cambrian is discussed according to sedimentary-tectonic event and other evidences. The major lithological types of Cryogenian-Cambrian system in Northeast Tarim are: tillite, clastic rocks(rich in organic matter) and carbonate ,with interbeds of volcanic rocks while in Northwest Tarim, the calstic rocks and carbonate are the common rock type, with tillite and volcanic interbeds in a small amount. The north margin of Tarim Block, which was a part of Rodinia supercontinent, neighboring the northwestern margin of Australia, was deeply rifted in Cryogenian-Ediacaran and developed into two rifts in the northwestern and northeastern margin, while formed a thick layer of the rift-passive margin deposits and the layer in the northwestern rift was not completely developed as the northeastern. The deepest rift-passive magin sediment which can be observed is Cryogenian-Middle Ordovician strata, and the period can be divided into Cryogenian faulted period (supercontinent rifting stage) and Ediacaran-Middle Ordovician subsidence period (plate drifting stage).

  9. Moho geometry along a north-south passive seismic transect through Central Australia

    Science.gov (United States)

    Sippl, Christian

    2016-04-01

    Receiver functions from a temporary deployment of 25 broadband stations along a north-south transect through Central Australia are used to retrieve crustal and uppermost mantle structural constraints from a combination of different methods. Using H-K stacking as well as receiver function inversion, overall thick crust with significant thickness variation along the profile (40 to ≥ 55 km) is found. Bulk crustal vp/vs values are largely in the felsic to intermediate range, with the southernmost stations on the Gawler Craton exhibiting higher values in excess of 1.8. A common conversion point (CCP) stacking profile shows three major discontinuities of the crust-mantle boundary: (1) a two-sided Moho downwarp beneath the Musgrave Province, which has previously been associated with the Neoproterozoic to early Cambrian Petermann Orogeny, (2) a Moho offset along the Redbank Shear Zone further north attributed to the Middle to Late Paleozoic Alice Springs Orogeny, and (3) another Moho offset further north, located at the boundary between the Davenport and Warramunga Provinces, which has not been imaged before. In all cases, the difference in crustal thickness between the two sides of the offset is > 8-10 km. Unlike the two southern Moho offsets, the northernmost one does not coincide with a prominent gravity anomaly. Its location and the absence of known reactivation events in the region make it likely that it belongs to a Proterozoic suture zone that marks a previously unknown block boundary within the North Australian Craton.

  10. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins.

    Science.gov (United States)

    McTaggart, Lisa R; Brown, Elizabeth M; Richardson, Susan E

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  11. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins

    Science.gov (United States)

    McTaggart, Lisa R.; Brown, Elizabeth M.; Richardson, Susan E.

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  12. Dissolved organic matter and terrestrial-lotic linkages in the Central Amazon Basin of Brazil

    Science.gov (United States)

    McClain, Michael E.; Richey, Jeffrey E.; Brandes, Jay A.; Pimentel, Tania P.

    1997-09-01

    We evaluate the hypothesis that decomposition and adsorption reactions operating in upland soils of headwater catchments control the concentration and composition of dissolved and fine particulate organic matter in rivers of the Amazon basin. In two contrasting first-order catchments characteristic of the central Amazon basin, we analyzed plant, litter, soil, groundwater, and stream water chemistry. Our results indicate that clear and persistent differences exist in the concentration and elemental composition of dissolved organic matter (DOM) in stream waters and groundwaters from the two catchments, due mainly to corresponding differences in soil texture and chemistry. Within the more oxide and clay rich Oxisols underlying terra firme forest, groundwater DOM concentrations were uniformly low (120 μMC) and C/N ratios averaged 10. Conversely, within the oxide and clay deficient Spodosols underlying campinarana forest, groundwater DOM concentrations were greatly elevated (3000 μMC), and C/N ratios averaged near 60. We found that, in the terra firme/Oxisol terrain, the majority of DOM contributions to the stream derived from the riparian zone, while in the campinarana/Spodosol terrain, upland groundwater contributions could account for the concentration and composition of DOM in the stream. The implications of our findings are that in the terra firme terrains which dominate the region, upland soil profiles are not the site of definitive processes which impart compositional signatures to organic matter carried by the largest rivers of the Amazon basin, as was hypothesized. Instead, we suggest that definitive reactions are focused primarily in the river corridor.

  13. Seismic stratigraphy of middle Cretaceous unconformity (MCU) in central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Faust, M.J.

    1986-05-01

    A widespread high-amplitude reflector seen on seismic data throughout the Gulf of Mexico has been called the middle Cretaceous unconformity (MCU). This reflector seems to be a major stratigraphic boundary in the Gulf of Mexico basin. It is believed to correspond to Vail's type 1 unconformity of middle Cenomanian age (97 Ma), which records an eustatic drop in sea level of approximately 200 m. This study area includes the entire Gulf of Mexico, except areas of thick, highly deformed salt where following the MCU with any degree of confidence becomes impossible. The MCU is easy to follow in multichannel seismic reflection profiles collected by the Institute for Geophysics of the University of Texas at Austin in the Gulf of Mexico. In central, deeper part of the gulf, reflectors above and below the MCU are parallel. In the southern and eastern rims of the gulf, along the Campeche and Florida escarpments, reflectors are truncated below the MCU and show onlap relationships above it. Therefore, the MCU may be interpreted as representing an unconformity along the southern and eastern rims of the Gulf of Mexico basin. The unconformity appears to die out and grade into a conformable section toward the center of the basin, and channeling is common along the Campeche and Florida escarpments. These channels can be projected back into canyons in the escarpments, which were probably initiated by subaerial exposure of the top of the escarpments during the middle Cretaceous lowstand. The downslope channels, being sourced by the canyons, were cut in deep water.

  14. Two new species of the bee genus Peponapis, with a key to the North and Central American species (Hymenoptera: Apidae: Eucerini) Dos especies nuevas de abejas del género Peponapis, con una clave para las especies de América del Norte y Central (Hymenoptera: Apidae: Eucerini)

    OpenAIRE

    Ricardo Ayala; Terry Griswold

    2012-01-01

    Two new species of squash bees, Peponapis pacifica Ayala and Griswold sp. n. and P. parkeri Griswold and Ayala sp. n., are described and illustrated. Peponapis pacifica is oligolectic on flowers of Schizocarpum longisepalum (Cucurbitaceae) endemic to Mexico, where it is found in the tropical dry forest along the Pacific Coast, between Sonora and Chiapas and in the Balsas River basin; and P. parkeri is known only from the Pacific slope of Costa Rica. A key for the North and Central American sp...

  15. Correlation of the oldest Toba Tuff to sediments in the central Indian Ocean Basin

    Indian Academy of Sciences (India)

    J N Pattan; M Shyam Prasad; E V S S K Babu

    2010-08-01

    We have identified an ash layer in association with Australasian microtektites of ∼0.77Ma old in two sediment cores which are ∼450 km apart in the central Indian Ocean Basin (CIOB). Morphology and chemical composition of glass shards and associated microtektites have been used to trace their provenance. In ODP site 758 from Ninetyeast Ridge, ash layer-D (13 cm thick, 0.73–0.75 Ma) and layer-E (5 cm thick, 0.77–0.78 Ma) were previously correlated to the oldest Toba Tuff (OTT) eruptions of the Toba caldera, Sumatra. In this investigation, we found tephra ∼3100 km to the southwest of Toba caldera that is chemically identical to layer D of ODP site 758 and ash in the South China Sea correlated to the OTT. Layer E is not present in the CIOB or other ocean basins. The occurrence of tephra correlating to layer D suggests a widespread distribution of OTT tephra (∼3.6 × 107 km2), an ash volume of at least ∼1800 km3, a total OTT volume of 2300 km3, and classification of the OTT eruption as a super-eruption.

  16. Paleoclimatic variations in Maknassy Basin (central Tunisia) during the Holocene period using multidisciplinary approaches

    International Nuclear Information System (INIS)

    The signature of humid climatic episodes in the Holocene paleoclimatic history of Tunisia are evident in outcroppings along riverbanks almost all over the Tunisian drainage network. Previous multidisciplinary studies have already identified some sites where these remnants can contribute valuable information for reconstruction of paleoenvironmental and paleoclimatic variations in the presently hyper-arid zone of the Northern Sahara. Sedimentary deposits outcropping on Wadi Leben and Wadi Ben Sellam banks, in the Maknassy Basin (Central Tunisia), have been sampled. Multidisciplinary studies, including prehistory, sedimentology, mineralogy, ecology and radiochronology have been conducted to improve palaeoenvironmental interpretations and to determine a precise chronological history of humid episodes during the Holocene in Tunisia. This paper deals with the interpretation of results obtained from the Maknassy Basin in comparison with some other Tunisian sites in order to highlight Holocene humid episodes. Establishment of a precise chronological framework is prerequisite to exploring potential relationships between the occurrence of humid phases and recharge of aquifers located in this area. (author)

  17. Quaternary Geology and Geomorphology of Terna River Basin in West Central India

    Directory of Open Access Journals (Sweden)

    Mohammad Babar

    2012-12-01

    Full Text Available This paper presents the morphostratigraphy, lithostratigraphy and sedimentary structures of Terna River basin in the Deccan Basaltic Province (DBP of West Central India. These Quaternary deposits have been divided into three informal formations (i dark grey silt formation – Late Holocene, (ii Light grey silt formations – Early Holocene, (iii Dark grayish brown silt formation – Late Pleistocene with the older Quaternary Alluvial deposits of Upper Pleistocene age. The fine clay and silt formations in the lower reaches reflect that the streams are of low gradient and more sinuous. The river shows evidences of channel movement by avulsion, largely controlled by lineaments. Palaeo-levees, in the form 4–5 m high ridges exist along the Terna River floodplain, specifically in the Ter, Killari, Sastur, Dhuta and Makni villages. Several lineaments occur along NE-SW, NW-SE, E-W and WNW-ESE directions, which control the basement structure in the study area. The values of the Topographic Sinuosity Index (TSI indicate rejuvenation of the area leading to the dominance of topography on the sinuosity of the river channels. The break in slope in the long profile is also indication of the Quaternary tectonic uplift of the area. Radiocarbon dating of some charcoal fragments collected from folded beddings indicates that paleoseismic activity might have taken place along the basin between AD 120 and AD 1671.

  18. The organic geochemistry of the Eocene-Oligocene black shales from the Lunpola Basin, central Tibet

    Science.gov (United States)

    Sun, Tao; Wang, Chengshan; Duan, Yi; Li, Yalin; Hu, Bin

    2014-01-01

    This paper reports on the depositional paleoenvironment and the potential hydrocarbons of the Eocene-Oligocene black shales from the Dingqinghu and Niubao Formations in the Lunpola Basin, central Tibet. Nineteen samples from two outcrop profiles were analysed. The contents of the total organic carbon (TOC) and sulphur were measured; other analyses included Rock-Eval pyrolysis, solvent extraction and gas chromatography-mass spectrometer (GC-MS). The results indicated that the shales from the Dingqinghu and Niubao Formations are thermally immature. The pyrolysis data show that the shales contain Type I organic matter and that lacustrine algal are the main organic matter sources. The low pristane to phytane ratios and the high gammacerane indices indicate that the shales were deposited in a reducing, stratified, and hypersaline palaeo-lake, which is consistent with the climate information provided by the development history of palaeo-lakes from the Eocene to the Oligocene epochs.

  19. Group classification of mixed oils in central Junggar Basin, Northwest China and their migration

    Institute of Scientific and Technical Information of China (English)

    WANG Xulong; SHI Xinpu; CAO Jian; LAN Wenfang; TAO Guoliang; HU Wenxuan; YAO Suping

    2010-01-01

    The produced oils in central Junggar Basin are commonly mixed in origin. In this paper, in order to reveal this complexity and thereby provide valuable clues to the study of oil source and formation mechanism, genetic groups of the mixed oils were classified and their migration/accumulation was investigated. Based on the artificial oil mixing experiments, some representative biomarkers of the mixed oils showed varying tendencies according to mixing ratios of the oils. Hence, these biomarkers are useful for determining the origin of the mixed oils. According to the criteria, oils in the area were divided into four basic groups, i.e., the Lower Permian Fengcheng oil, the Middle Permian Lower Wuerhe oil, the Jurassic source derived oil, and the mixed oil (including the Lower and Middle Permian mixed oil and the Permian and Jurassic mixed oil). Oil migration and accumulation were discussed in combination with the geological background.

  20. Macrofossil evidence for pre-settlement vegetation of Central Otago's basin floors and gorges

    International Nuclear Information System (INIS)

    Composition of pre-settlement vegetation communities in the semi-arid Central Otago lowlands has been one of New Zealand's long-standing ecological puzzles. Uncertainty is due largely to a paucity of fossil data. Here, we provide new evidence for pre-settlement vegetation in the region based on analyses of plant macrofossils from 15 late Pleistocene and Holocene lowland sites. The assemblages represent two habitat types: wooded or partially wooded intermontane basin-floor wetlands, and low forest and/or shrubland habitats in the Kawarau and Clutha River gorges. In both habitat types, plant communities appear to have been predominantly woody, with significant components of herbaceous dicotyledons but few grasses. Both habitats seem to have undergone major post-settlement vegetation transformation. Several presently common taxa were rare or absent before human settlement, but others (including threatened spring annuals), now rare or extinct in the region, were formerly more common. (author). 57 refs., 5 figs., 3 tabs

  1. Elemental composition of air masses under different altitudes in Azores, central north Atlantic

    International Nuclear Information System (INIS)

    Between 8th July 2002 and 18th June 2004, aerosol samples were collected in Azores. Their inorganic composition was obtained by neutron activation analysis in order to study the differences of aerosols in two atmospheric altitudes of the central north Atlantic: (1) PICO-NARE observatory (Lower Free Troposphere-LFT) at Pico mountain summit (38,470 deg N, 28,404 deg W, 2,225 m a.s.l.) in Pico Island, Azores, where air masses from the surrounding continents (Africa, Europe, Central and North America) pass through, carrying aerosols with anthropogenic (Sb, Br, Mo, U, Se and Tb) and/or natural emissions (Fe, Co, La, Na, Sm, Cr, Zn, Hf, K and Th); (2) TERCEIRA-NARE station (Marine Boundary Layer) at Serreta (38,69 deg N, 27,36 deg W, 50 m a.s.l.), in Terceira Island, Azores, where natural aerosols (I, Cl, Na, Br and other soil related elements) are predominant. However, a combined interpretation of the data points out to a co-existence of the anthropogenic elements Sb and Mo, eventually with similar origins as the ones passing Pico Mountain summit. Very high concentrations and enrichment factors for Sb, Mo and Br in LFT, higher than the ones found in other areas, confirm atmospheric long-range transport mainly from the west boundary of north Atlantic; this may indicate eventual accumulation and persistence of those elements in the area due to the presence of Azores high pressures or the Hadley cells effect. A significant correlation between Fe and Yb and the enrichment of rare earth elements (La, Sm, Tb and Yb) and Th in LFT aerosols, both reflect a mineral dust intrusions from north Africa (Sahara and Sahel region). (author)

  2. From Flysch to Molasse-Sedimentary and Tectonic Evolution of Late Caledonian-Early Hercynian Foreland Basin in North Qilian Mountains

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Late Caledonian to Early Hercynian North Qilian orogenic belt in northwestern China is an elongate tectonic unit situated between the North China plate in the north and the Qaidam plate in the south. North Qilian started in the latest Proterozoic to Cambrian as a rift basin on the southern margin of North China, and evolved later to an archipelagic ocean and active continental margin during the Ordovician and a foreland basin from Silurian to the Early and Middle Devonian. The Early Silurian flysch and submarine alluvial fan, the Middle to Late Silurian shallow marine to tidal flat deposits and the Early and Middle Devonian terrestrial molasse are developed along the corridor Nanshan. The shallowing-upward succession from subabyssal flysch, shallow marine, tidal flat to terrestrial molasse and its gradually narrowed regional distribution demonstrate that the foreland basin experienced the transition from flysch stage to molasse stage during the Silurian and Devonian time.

  3. Interpretation of seismic reflection data, Central Palo Duro Basin: Technical report

    International Nuclear Information System (INIS)

    Seismic reflection data from the Central Palo Duro Basin, Texas, were studied to identify and characterize geologic structure, potential hydrocarbon traps, and anomalies suggesting adverse features such as salt dissolution or diapirism. The data included seismic reflection data, geologic and geophysical data controlled by Stone and Webster Engineering Corporation, and data from the literature. These data comprised approximately 590 line-mi of seismic profiles over approximately 4000 mi2, plus well logs from 308 wells. The study addressed the section from shallow reflectors down to basement. Structural contour maps were prepared for the Upper San Andres, Near Top of Glorieta, Wolfcamp, and Precambrian horizons. Isopach maps were prepared for intervals between the Upper and Lower San Andres and between the Upper San Andres and the Wolfcamp. Interpretation indicates southeasterly dips in the northwest part of the mapped area and southwesterly dips in the southwest part. Geologic structures show a generally northwest alignment. Faults at the Precambrian level and geologic structures show a generally northwest alignment. Faulting in the area is largely limited to the Precambrian, but interpretation is uncertain. Evidence of post-Wolfcampian faulting is not recognized. Seismic data delineating the San Andres section indicate a stable section throughout the area. Anomalous reflection events possibly associated with subsurface salt dissolution were seen at the 800- to 1200-ft level in Swisher County. Other anomalies include an overthickened zone northwest of Westway and carbonate buildup in the Wolfcamp and Pennsylvanian in Randall County. Mississippian to Middle Pennsylvanian diastrophism resulting in the Amarillo Uplift and Matador Arch is not manifested structurally in the central Palo Duro Basin. Subsidence or gentle uplift contributed to some structural deformation

  4. Evaluating regional differences in macroinvertebrate communities from forested depressional wetlands across eastern and central North America.

    Energy Technology Data Exchange (ETDEWEB)

    Batzer, Darold, P.; Dietz-Brantley, Susan E.; Taylor, Barbera E.; DeBiase, Adrienne E.

    2005-02-12

    Batzer, Darold, P., Susan E. Dietz-Brantley, Barbera E. Taylor, and Adrienne E. DeBiase. 2005. Evaluating regional differences in macroinvertebrate communities from forested depressional wetlands across eastern and central North America. J. N. Am. Benthol. Soc. 24(2):403-414. Abstract. Forested depressional wetlands are an important seasonal wetland type across eastern and central North America. Macroinvertebrates are crucial ecosystem components of most forested depressional wetlands, but community compositions can vary widely across the region. We evaluated variation in macroinvertebrate faunas across eastern and central North America using 5 published taxa lists from forested depressional wetlands in Michigan, Ontario, Wisconsin, Florida, and Georgia. We supplemented those data with quantitative community descriptions generated from 17 forested depressional wetlands in South Carolina and 74 of these wetlands in Minnesota. Cluster analysis of presence/absence data from these 7 locations indicated that distinct macroinvertebrate communities existed in northern and southern areas. Taxa characteristic of northern forested depressionalwetlands included Sphaeriidae, Lumbriculidae, Lymnaeidae, Physidae, Limnephilidae, Chirocephalidae, and Hirudinea (Glossophoniidae and/or Erpodbellidae) and taxa characteristic of southern sites included Asellidae, Crangonyctidae, Noteridae, and Cambaridae. Quantitative sampling in South Carolina and Minnesota indicated that regionally characteristic taxa included some of the most abundant organisms, with Sphaeriidae being the 2nd most abundant macroinvertebrate in Minnesota wetlands and Asellidae being the 2nd most abundant macroinvertebrate in South Carolina wetlands. Mollusks, in general, were restricted to forested depressional wetlands of northern latitudes, a pattern that may reflect a lack of Ca needed for shell formation in acidic southern sites. Differences in community composition probably translate into region

  5. Plio-Pleistocene changes in the vegetation of central North Africa

    Science.gov (United States)

    Castaneda, I. S.; Phu, V.; Urann, B.

    2013-12-01

    The area of central North Africa (including the Sahara and the Sahel) is sensitive to migrations of the intertropical rainbelt and has experienced dramatic, and possibly abrupt, shifts between wet and arid conditions in the past. For example, during the humid period of the early Holocene, the region that is presently the Sahara desert was vegetated and contained permanent lakes, and was occupied by human populations (e.g. Kuper and Kröpelin, 2006). In this study, we investigate the hydrology of central North Africa during the Plio-Pleistocene (4-0.5 Ma), a period during which a number of key steps in hominin evolution occurred. ODP site 660 is located in the tropical NE Atlantic Ocean (offshore West Africa) and receives dust from central North Africa, which is transported offshore by the African Easterly Jet. Plant leaf waxes (n-alkanes) contained in this dust provide information on the type of vegetation present , which in turn, can be used to examine hydrological variability because in tropical Africa the large scale distribution of vegetation utilizing the C3 (mainly trees) vs. C4 (grasses and warm season sedges) photosynthetic pathways mainly depends on aridity (precipitation) (e.g. Schefuss et al., 2003). Here, we examine the carbon (δ13C) and deuterium (δD) isotopic composition of plant leaf waxes, proxies for vegetation type (C3 vs. C4 plants) and precipitation amount, respectively. We also examine sea surface temperature variability using the alkenone Uk'37 Index as several studies have demonstrated close ties between sea surface temperature variability and hydrological conditions in N Africa during the late Pleistocene and Holocene. Results of this study further support a close link between SST and hydrological conditions in the Sahel during the past 4 Ma while also highlighting regional differences in aridity between Plio-Pleistocene records of western, eastern and southern Africa.

  6. Extensional Basins in a Convergent Margin: Oligocene-Early Miocene Salar de Atacama and Calama basins, Central Andes

    Science.gov (United States)

    Jordan, T. E.; Mpodozis, C.; Blanco, N.; Pananont, P.; Dávila, F.

    2004-12-01

    The Salar de Atacama Basin (SdAB) is the largest and most persistent sedimentary basin of northern Chile, accumulating nonmarine sediment from Cretaceous to modern times. Its northwestern neighbor, the Calama, was a Cenozoic basin. Although SdAB was in the backarc zone early in the Andean orogeny, both are now forearc basins. Others demonstrated that the basins overlie anomalously cold, strong, and dense crust and lithosphere. We focus on an extensional Oligocene basin stage. Interpretation of the basin-controlling faults is based on seismic reflection studies supported by field relations. The SdAB is limited to the west by the NNE-trending, steeply east-dipping, Paciencia Fault (PF). The PF experienced 5-7 km of down-to-the-east offset during the Oligocene-early Miocene. Syntectonic strata, an arid succession of siliciclastics and evaporites, are asymmetric, with thicknesses of 5000 m and abundant halite adjacent to the PF, and of 1000 m with fine detrital clastic strata 25 km farther east. Relations in conglomeratic growth strata that overlap the PF also demonstrate normal displacement during sediment accumulation. Seismic data reveal that a buried normal fault with 1-1.5 km down-to-the-east displacement limits the western margin of the Oligocene-Miocene Calama siliciclastic basin fill. Regionally, Oligocene-early Miocene margin-parallel strike-slip deformation dominated northwest of the basins, contributing sinistral offset (West Fissure Fault) to the northern segment of the long-lived Domeyko Fault System. The new SdAB and Calama data reveal that a 20,000 km2 domain of extensional basins existed within the dominantly strike-slip region. Even if PF and the fault in the Calama Basin were transtensional, the proportion of extension to strike-slip displacement is much greater in these basins than elsewhere in northern Chile. Further study is required to understand what combination of factors caused this kinematic distinction as well as delayed the onset of CVZ

  7. Implementation of MAR within the Rio Grande Basin of Central New Mexico, USA

    Science.gov (United States)

    Marley, Robert; Blandford, T. Neil; Ewing, Amy; Webb, Larry; Yuhas, Katherine

    2014-05-01

    The U.S. Bureau of Reclamation has identified the Rio Grande basin within Central New Mexico as one of several regions where water supplies are over-allocated and future conflicts over the inadequate resource are highly likely. Local water providers have consistently identified managed aquifer recharge (MAR) as an important tool to provide conjunctive management of surface-water, groundwater, and reclaimed water sources in order to extend the useful life of existing water sources. However, MAR projects have been slow to take root partly due to rigorous demonstration requirements, groundwater quality protection concerns, and ongoing water right uncertainties. At first glance the several thousand meters of unconsolidated basin-fill sediments hosting the regional aquifer appear to provide an ideal environment for the subsurface storage of surplus water. However, the basin has a complex structural and depositional history that impacts the siting and overall effectiveness of MAR systems. Several recharge projects are now in various stages of implementation and are overcoming site specific challenges including source water and ambient groundwater compatibility, low-permeability sediments and compartmentalization of the aquifer by extensive faulting, well clogging, and overall water quality management. This presentation will highlight ongoing efforts of these water providers to develop full-scale recharge facilities. The performance of natural in-channel infiltration, engineered infiltration galleries, and direct injection systems designed to introduce from 500 to 5,000 mega-liters per annum to target intervals present from 150 to 600 meters below ground surface will be described. Source waters for recharge operations include inter-basin transferred surface water and highly treated reclaimed water sources requiring from minor to extensive treatment pre-recharge and post-recovery. Operational complexities have raised concerns related to long-term operation and maintenance

  8. Latest Permian to Middle Triassic cyclo-magnetostratigraphy from the Central European Basin, Germany: Implications for the geomagnetic polarity timescale

    OpenAIRE

    Michael Szurlies

    2007-01-01

    In Central Germany, the about 1 km thick mainly clastic Germanic Lower Triassic (Buntsandstein) consists of about 60 sedimentary cycles, which are considered to reflect variability in precipitation within the epicontinental Central European Basin, most probably due to solar-induced short eccentricity cycles. They provide a high-resolution cyclostratigraphic framework that constitutes the base for creating a composite geomagnetic polarity record, in which this paper presents a Middle Buntsands...

  9. A review of tectonics and sedimentation in a forearc setting: Hellenic Thrace Basin, North Aegean Sea and Northern Greece

    Science.gov (United States)

    Maravelis, A. G.; Boutelier, D.; Catuneanu, O.; Seymour, K. St.; Zelilidis, A.

    2016-04-01

    Exposure of the forearc region of the North Aegean Sea, Greece, offers insight into evolving convergent margins. The sedimentary fill of the Thrace Basin during the Late Eocene to Oligocene time provides a record of subduction-driven processes, such as growth of magmatic arcs and construction of accretionary complexes. This large sediment repository received sediment from two sources. The southern (outboard) basin margin reflects the active influence of the exhumed accretionary prism (e.g. Pindic Cordillera or Biga peninsula), while the northern (inboard) margin records the effect of the magmatic arc in the Rhodope region. The forearc basin sedimentary fills shoal upward into shallow-marine strata but are dominated mainly by deep-marine facies. The depositional trend and stacking pattern are dominated by progradational patterns. This trend, which is observed in both basin margins, is related to tectonic deformation rather than sea-level fluctuations. Additional evidence for this tectonic uplift comes from the backstripping analysis. The accretionary complex provided material into the forearc basin. This material was transported northeast and formed a sand-rich turbidity system that evolved upslope into shallow-marine deposits. Stratigraphic data indicate that this turbidity system exhibits a successive landward (inboard) migration of the depocenter. Provenance data utilizing sandstone petrography, conglomerate clast composition, and bulk-rock geochemistry suggest that this system reflects an increased influx of mafic material into the basin. Volcanic arc-derived material was transported south and east and accumulated in deep-marine settings. Both stratigraphic and provenance data indicate a seaward (outboard) migration of the basin depocenter and a significant increase in felsic detritus into the forearc.

  10. The implications of geology, soils, and vegetation on landscape morphology: Inferences from semi-arid basins with complex vegetation patterns in Central New Mexico, USA

    Science.gov (United States)

    Yetemen, Omer; Istanbulluoglu, Erkan; Vivoni, Enrique R.

    2010-04-01

    This paper examines the relationship between land surface properties (e.g. soil, vegetation, and lithology) and landscape morphology quantified by the catchment descriptors: the slope-area (S-A) relation, curvature-area (C-A) relation, and the cumulative area distribution (CAD), in two semi-arid basins in central New Mexico. The first site is composed of several basins located in today's desert elevations with mesic north-facing and xeric south-facing hillslopes underlain by different lithological formations. The second site is a mountainous basin exhibiting vegetation gradients from shrublands in the lower elevations to grasslands and forests at higher elevations. All three land surface properties were found to have significant influences on the S-A and C- A relations, while the power-law exponents of the CADs for these properties did not show any significant deviations from the narrow range of universal scaling exponents reported in the literature. Among the three different surface properties we investigated, vegetation had the most profound impact on the catchment descriptors. In the S-A diagrams of the aspect-controlled ecosystems, we found steeper slopes in north-facing aspects than south-facing aspects for a given drainage area. In elevation-controlled ecosystems, forested landscapes exhibited the steepest slopes for the range of drainage areas examined, followed by shrublands and grasslands in all soil textures and lithologies. In the C-A diagrams, steeper slopes led to a higher degree of divergence on hillslopes and a higher degree of convergence in the valleys than shallower slopes. The influence of functional types of vegetation detected on observed topography provided some initial understanding of the potential impacts of life on the organization of topography. This finding also emphasizes the critical role of climate in catchment development. We suggest that climatic fluctuations that are capable of replacing vegetation communities could lead to highly

  11. Geoelectric investigation to delineate groundwater potential and recharge zones in Suki river basin, north Maharashtra

    Science.gov (United States)

    Gupta, Gautam; Patil, S. N.; Padmane, S. T.; Erram, Vinit C.; Mahajan, S. H.

    2015-10-01

    Suki river basin of Raver sub-division is located towards the northeastern part of Jalgaon district in Maharashtra State. The existing land use pattern of the region clearly shows that more than 60% of the area is utilized for agricultural sector. Groundwater is the major source of irrigation and domestic purposes. To assess the overall water resources development of Raver area for better environment in future, investigation was carried out with the help of geophysical indicators. Vertical electrical sounding studies were conducted at 17 stations in the study area using Wenner configuration. The study was aimed at characterizing the aquifer in the area as well as assessing its potential risk to contaminant seepage in terms of protective capacity of the overburden rock materials using Dar- Zarrouk (D-Z) parameters, viz., the transverse resistance ( T), longitudinal conductance ( S), transverse resistivity ( ρ t ) and longitudinal resistivity ( ρ l ). These were computed to generate the resistivity regime of freshwater-bearing formations and its movement. The central-western part of the study area reflects very good to good protective capacity rating as can be seen from the high longitudinal conductance values. The low value of the protective capacity in the eastern part is making the aquifer system in the area highly vulnerable to surface contamination. This indicates that the ground water quality may have been deteriorated in the area and borehole water samples should be randomly sampled for contaminant loads based on this analysis.

  12. Regional analysis of changes in snow pack in mountainous basins in the central Danube region

    Science.gov (United States)

    Balint, Gabor; Juričeková, Katarina; Gauzer, Balazs; Hlavčová, Kamila; Kohnová, Silvia; Szolgay, Jan; Zsideková, Beata

    2013-04-01

    Accurate estimation of the volume of water stored in the snow pack and its rate of release is essential to predict the flow during the snowmelt period. In mountainous drainage basins water stored in the snow pack represents an important component of the water budget. Two modelling tools are compared. The first, HOLV snowmelt model is developed by the Hungarian National Hydrological Forecasting Service (VITUKI NHFS) for regional assessment of snow accumulation and ablation of the central Danube. The model originates from the early 80's and it is under continuous development, while its recent distributed version over a grid with 0.1 degree resolution is in use. The snowmelt model has a flexible structure; it is able to change its own structure in function of data availability. In case when only precipitation and air temperature data are available temperature index method is used. When also other data are accessible (cloudiness, dew point, wind speed) using of energy balance model is to be preferred. If there are suitable data available for calculation of the energy terms, the energy balance method can be applied. The second semi-distributed Hron model, developed at the Slovak University of Technology was applied to a smaller sub-basin to represent spatial distribution of snow cover by simulated snow water equivalent. The upper Hron river basin with an area of 1766 km2 is located in central Slovakia. The conceptual semi-distributed tool applied contains three basic storage components with 15 calibrated parameters, as the flow routing component the cascade of linear reservoirs is used as opposed to the original simple triangular routing function. The snow sub-model uses the temperature index (degree-day) method for snow accumulation and snowmelt calculations. Uncertainty of model parameters was reduced by multi-calibration on the mean daily discharges in the basin outlet and measured stations data of snow water equivalent. Changes in the model parameters during the

  13. Lava and Life: New investigations into the Carson Volcanics, lower Kimberley Basin, north Western Australia

    Science.gov (United States)

    Orth, Karin; Phillips, Chris; Hollis, Julie

    2014-05-01

    The Carson Volcanics are the only volcanic unit in the Paleoproterozoic Kimberley Basin and are part of a poorly studied Large Igneous Province (LIP) that was active at 1790 Ma. New work focussing on this LIP in 2012 and 2013 involved helicopter-supported traverses and sampling of the Carson Volcanics in remote areas near Kalumburu in far north Western Australia's Kimberley region. The succession is widespread and flat lying to gently dipping. It consists of three to six basalt units with intercalated sandstone and siltstone. The basalts are 20-40 m thick, but can be traced up to 60 km along strike. The basalt can be massive or amygdaloidal and commonly display polygonal to subhorizontal and rare vertical columnar jointing. Features of the basalt include ropy lava tops and basal pipe vesicles consistent with pahoehoe lavas. The intercalated cross-bedded quartzofeldspathic sandstone and siltstone vary in thickness up to 40 m and can be traced up to 40 km along strike. Peperite is common and indicates interaction between wet, unconsolidated sediment and hot lava. Stromatolitic chert at the top of the formation represents the oldest life found within the Kimberley region. Mud cracks evident in the sedimentary rocks, and stromatolites suggest an emergent broad tidal flat environment. The volcanics were extruded onto a wide marginal margin setting subject to frequent flooding events. Thickening of the volcanic succession south and the palaeocurrents in the underlying King Leopold Sandstone and the overlying Warton Sandstone suggest that this shelf sloped to the south. The type of basalt and the basalt morphology indicate a low slope gradient of about 1°.

  14. Assessment of the impact of moving fluids on the regional thermal field for the area of Brandenburg (North German Basin)

    Science.gov (United States)

    Noack, V.; Scheck-Wenderoth, M.; Cacace, M.; Lewerenz, B.

    2012-04-01

    We present results from numerical simulations of the 3D thermal field for the area of Brandenburg in the North German Basin. The study area encompasses a part of the basin centre in the north, whereas to the south the basin margin is enclosed. Starting with Permocarboniferous volcanic rocks the basin fill is represented by Permian to Cenozoic sediments. A thick layer of mobilized salt (Zechstein, Upper Permian) generated elevated structures such as salt pillows and diapirs. Especially where diapirs pierce their overburden, the overlying deposits are strongly influenced in their thickness and distribution. This special configuration of the Zechstein salt is relevant for the thermal calculations due to the fact that salt has a distinctly higher thermal conductivity than the surrounding sediments and is impermeable to fluid flow. Therefore, the Zechstein salt acts as a conductive chimney for heat and a hydraulic decoupling horizon between the Pre-Permian and the Mesozoic-Cenozoic strata. The latter are characterized by two further quasi-impervious sediment complexes, the Rupelian-clay and the Muschelkalk. These two divide the Post-Permian strata in three main aquifer systems: the Buntsandstein, Keuper to Pre-Rupelian and the Post-Rupelian complex. Based on results from purely conductive modelling we additionally analyse the influence of moving fluids on the shallow temperature field above the Zechstein salt. Therefore coupled fluid flow and heat transfer numerical simulations are carried out to investigate the hydrothermal field. The 3D simulations for the heat transport processes are based on the finite element method. The results indicate that the distribution of thermal conductivities in the basin fill controls the short-wavelength pattern of the temperature distribution whereas the long wavelength pattern results from interaction between the highly conductive crust and low conductive sediments. Furthermore, the results reveal that the shallow temperature field

  15. Roaming Earthquakes in North China and Central-Eastern US: How and Why?

    Science.gov (United States)

    Liu, M.; Stein, S. A.; Wang, H.

    2014-12-01

    Large earthquakes in mid-continents often occur in unexpected places. In North China, large earthquakes roamed between distant fault systems in the past 2000 years such that no large events ruptured the same fault segment twice during this period. In the central-eastern US, although historic earthquake records only go back a few hundred years, increasing paleoseismic evidence reveals large events in places of little seismicity today. Such spatiotemporal patterns of mid-continental earthquakes differ significantly from those at plate boundary zones, where relative plate motion loads the plate boundary faults steadily at relatively high rates, leading to localized seismicity with some arguable quasi-periodicity. In mid-continents, tectonic loading is slow and accommodated collectively by a complex system of interacting faults, each of which can be active for a short period after long dormancy. The mechanics of fault interaction in mid-continents remain to be fully understood. Besides the well studied Coulomb stress perturbations due to dislocation on the fault planes, property changes of fault zones by a large rupture may cause redistribution of regional stress and strain fields in mid-continents. Further studies of fault interaction and the resulting spatiotemporal occurrence of large earthquakes in mid-continents are imperative for improving earthquake hazard assessment in North China, central-eastern US, and other highly populated and earthquake-prone mid-continents.

  16. A synoptic climatology of derecho producing mesoscale convective systems in the North-Central Plains

    Science.gov (United States)

    Bentley, Mace L.; Mote, Thomas L.; Byrd, Stephen F.

    2000-09-01

    Synoptic-scale environments favourable for producing derechos, or widespread convectively induced windstorms, in the North-Central Plains are examined with the goal of providing pattern-recognition/diagnosis techniques. Fifteen derechos were identified across the North-Central Plains region during 1986-1995. The synoptic environment at the initiation, mid-point and decay of each derecho was then evaluated using surface, upper-air and National Center for Atmospheric Research (NCAR)/National Center for Environmental Prediction (NCEP) reanalysis datasets.Results suggest that the synoptic environment is critical in maintaining derecho producing mesoscale convective systems (DMCSs). The synoptic environment in place downstream of the MCS initiation region determines the movement and potential strength of the system. Circulation around surface low pressure increased the instability gradient and maximized leading edge convergence in the initiation region of nearly all events regardless of DMCS location or movement. Other commonalities in the environments of these events include the presence of a weak thermal boundary, high convective instability and a layer of dry low-to-mid-tropospheric air. Of the two corridors sampled, northeastward moving derechos tend to initiate east of synoptic-scale troughs, while southeastward moving derechos form on the northeast periphery of a synoptic-scale ridge. Other differences between these two DMCS events are also discussed.

  17. Neospora caninum infection in beef cattle reared under grazing conditions in north-central Mexico

    Directory of Open Access Journals (Sweden)

    Karina Mondragón-Zavala

    2011-05-01

    Full Text Available Objetive. To determine the seroprevalence of N. caninum antibodies and prevalence of parasite DNA in blood, and estimate the association between seroprevalence and the potential risk of some factors in beef cattle under grazing conditions in north-central Mexico. Materials and methods. Blood samples from 139 cows and only 10 bulls belonging to 13 farms were collected and evaluated by ELISA test to detect antibodies against N. caninum. Furthermore, to determine the presence of parasite DNA, nested PCR probe was performed on blood samples. Association between potential risk factors and seroprevalence was estimated. Results. Overall seroprevalence was 23% (35/149 samples, while the prevalence of parasite DNA in blood was 28% (42/149 samples. Of the 149 animals examined 28 (19% were positive to both tests (25 cows and 3 bulls. Concordance between tests was k = 0.63. All herds had seropositive animals with positive parasite DNA detection in blood. The only risk factor identified was the presence of dogs (OR= 2.65. Conclusions. This study showed that bovine neospososis should be considered as an important infectious disease in north-central Mexico herds. Therefore, an epidemiological control should be taken into consideration to avoid the negative effect of this disease on mexican beef industry.

  18. Forest Owners’ Organizations in North and Central Portugal – Assessment of Success

    Directory of Open Access Journals (Sweden)

    Diana Feliciano

    2011-06-01

    Full Text Available Background and Purpose: The emergence of forest owners’ organizations (FOOs in Portugal occurred in the 1990s. Fifteen years later there were 173 FOOs providing services to the private forest owners and also to the whole of society. This study aims to evaluate the success of FOOs in increasing their membership and the quantity of services provided. Material and Methods: Eight FOOs from the North and Central Portugal were chosen as case studies. Quantitative data on membership numbers and number of services provided by the eight case studies were collected from the archives of FORESTIS or directly at the FOOs headquarters. Qualitative data from newsletters, annual reports, local newspapers and letters were also collected to be further analysed. Secondary data collected cover a period of ten years (1994-2005. In addition, eight interviews to members of staff or FOOs directors were conducted in 2005. It was hypothesised that the number of members and the quantity of services provided may be interrelated and that the turnover of staff and their productivity influence the success of FOOs in increasing their membership and providing technical advice services. Results and Conclusion: The study showed that although most FOOs were successful in making their membership grow, there were big differences in the number of members, in the forest area covered by them and in the quantity of services provided. It was concluded that human capital, financial capital and path dependence were the factors that most constrained the success FOOs in North and Central Portugal.

  19. Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

    Directory of Open Access Journals (Sweden)

    Y. Jun Xu

    2013-04-01

    Full Text Available Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004 river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen, nitrate + nitrite nitrogen (NO3 + NO2, total phosphorous (TP, and total organic carbon (TOC through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB acted as a significant sink for TKN (annual retention: 24%, TP (41%, and TOC (12%, but a source for NO3 + NO2 nitrogen (6%. On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise.

  20. Provenance analysis of the Guaritas Group (RS conglomeratic sandstones: implications for the paleoclimate and paleogeography of the Eocambrian Central Camaquã sub-basin

    Directory of Open Access Journals (Sweden)

    Antonio Romalino Santos Fragoso-Cesar

    2013-06-01

    Full Text Available The Camaquã Supergroup, located in the central-south region of Rio Grande do Sul, Brazil, constitutes a rift-type post-orogenicsedimentary basin, whose deposition occurred in a continental environment between the Ediacaran and the Eocambrian.The upper succession of the Camaquã Supergroup is represented by the Guaritas Group, a unit formed by fluvial, eolian andalluvial fan deposits that keeps important records of the sedimentation right after the end of the neoproterozoic orogenesis thatgave rise to the Gondwana supercontinent. The objective of the present work was to apply sedimentary provenance analysis inconglomeratic arenites and conglomerates of the Guaritas Group, in order to explore the climatic and tectonic evolution historyof this unit. Based on the pebble compositional data, two main source areas were recognized for the deposits of this unit,a more distal one located to the north, related with a trunk river system parallel to the basin main axis, and a more proximalone located to the east, related to transversal fluvial systems and alluvial fans at the border of the basin. The comparison of theprovenance data with previous studies on facies and paleocurrents suggests that, during the entire evolution of the east borderof the basin, there was a same transversal fluvial system, whose catchment area suffered significative reductions due to thereactivation of the east border fault during the deposition of the Varzinha and Pedra Pintada Formations. The Serra do ApertadoFormation, the upper unit of Guaritas Group, shows a high correlation between the variation of quartzose and non quartzosepebbles composition, and it was attributed to a variation between more humid and more arid climatic conditions.

  1. Modal composition of the central water in the North Atlantic subtropical gyre

    Directory of Open Access Journals (Sweden)

    A. Cianca

    2009-10-01

    Full Text Available The modal composition of the Central Water in the North Atlantic subtropical gyre is not clearly defined, as there are some uncertainties related to mode identification, as well as modes which are not well documented. This study shows that eastern North Atlantic Central Water (eastern NACW in the subtropical gyre is composed of three modes: The North Atlantic Subpolar Mode Water (NASPMW σt=27.1 to 27.3, the Madeira Mode Water (MMW σt=26.4 to 26.6, and the mode water with a σt near 27.0, which is currently not well documented. We confirmed this mode based on the similarities found between it and the mode waters already reported. The similarities were determined from comparative analyses of the temperature/salinity standard curves and the gradients of the potential density anomalies of two concurrent data sets from two subtropical time-series stations (Bermuda Atlantic Time-series Study, BATS, in the west, and European Station for Time-series in the Ocean Canary Islands, ESTOC, in the east. In order to establish the outcropping regions, the corresponding pycnostads were determined using another climatologic data set (World Ocean Database, WOD2005. In this case, the pycnostads were located based on the presence of standard deviation minima from the average density anomalies. Finally, we confirmed that the pycnostads corresponded to the temperature values related to the modes by overlaying the characteristic modal isotherm of each of the modes in the geographic distribution of the pycnostads. Sea surface temperature data (SST from the Ocean Pathfinder Program (OPP were used to estimate the isotherms. The results showed a clear correspondence between the modal isotherms and the pycnostads, for both the modes that have already been documented and the mode confirmed in this study.

  2. Groundwater flow functioning in arid zones with thick volcanic aquifer units: North-Central Mexico

    International Nuclear Information System (INIS)

    Population increase in arid zones of Mexico has created the presence of 450% new cities with more that 50,000 inhabitants, as related to the 1950s. Due to the arid nature of the environment, the once sufficient spring and shallow water are becoming inadequate for the supply of those cities. An answer to this problem lies with the sustainable development of deep groundwater. The geological features of the country include fractured volcanic aquifer units that are more than 1,500 m thick, and are regionally continuous over of several hundred thousands of square kilometres. Groundwater development decisions need to consider, in the long span, inter-basin groundwater flow and the need to prevent environmental impacts in distant sites hydraulically connected with extraction centres. Radiocarbon is an excellent tool that initially has been applied to characterize groundwater in thick aquifer units in central Mexico to provide evidence on the hierarchy of flow (local/regional) and water age from where the distance of regional recharge was inferred. Radiocarbon also helps constrain flow path length which can then be used to characterize inter-basin groundwater communication. Radiocarbon has a large potential for future expansion of research and water management application. (author)

  3. An investigation of basin effects on flood discharges in North Dakota

    Science.gov (United States)

    Crosby, Orlo A.

    1974-01-01

    An investigation of the relationship of peak discharge to causative storm variables and drainage-basin characteristics was made to provide guidelines for future analyses of frequency and magnitudes of floods from small drainage areas. The procedure used was (l) to estimate peak discharges on the ll study basins from multiple-regression models developed from the storm variables and (2) to relate the peak discharges to the basin characteristics through regression or correlation with particular attention given to the effect of basin shape.

  4. Occurrence of major sequence stratigraphic boundaries in relation to basin development in Cenozoic deposits of the southeastern North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Michelsen, O.; Danielsen, M.; Heilmann-Clausen, C.; Jordt, H.; Laursen, G.V.; Thomsen, E.

    1995-05-01

    The post-Danian Cenozoic succession in the southeastern North Sea is subdivided into seven informal `major sequence stratigraphic units`, comprising twenty-one sequences. The boundaries of the units are easily recognized seismic sections over the entire study area. The North Sea is an epicontinental basin. It underwent considerable changes during the Cenozoic as regards subsidence rates, direction of sediment transport, and position of depocentres. The six unit boundaries are interpreted to reflect some of the major events in the development of the basin. The boundary between units 1 and 2 (lowermost Eocene) is associated with a regional hiatus followed by a large relative sea-level rise, whereas the boundary between units 2 and 3 (Lower Eocene) coincides with a shift in the direction of sediment transport from north to west. The boundary between units 3 and 4 (Eocene-Oligocene transition) marks an important change in the depositional environment of the North Sea with a shift in the direction of sediment transport from west to mainly northeast. In the northeastern part of the study area, thick prograding deposits of unit 4 are situated on distal deposits of units 1, 2 and 3. The transition between units 4 and 5 (uppermost Oligocene) shows a pronounced basinward shift in onlap, and it is interpreted to reflect a major fall in the relative sea level. The boundary between units 6 and 7 (Middle Miocene) is identified on a shift from a prograding reflection pattern to an aggrading pattern. The lower part of unit 7 is interpreted to represent a starved depositional environment, related to a pronounced increase in subsidence rate. The North Sea sequences are correlated with the Danish onshore deposits. The sequence boundaries generally coincide with an unconformity in the Danish deposits. A glauconitic horizon characterises the initial deposits overlying each of the unconformities. (au) (29 refs.)

  5. Assessment of the invasive status of newly recorded cactus species in the central Tugela River basin

    Directory of Open Access Journals (Sweden)

    Michael D. Cheek

    2015-03-01

    Full Text Available Background: Current distribution information on cacti in the Tugela River basin in KwaZulu-Natal, South Africa, is scant. Accordingly, surveys in this region substantially improve our understanding of regional invasions by this succulent group. The identification of new or extended invasions requires (reassessments of their invasion status and consideration of possible management interventions.Objectives: To identify and collect cacti either not previously recorded or poorly known in the central Tugela River basin, and to assess their invasion status.Method: A 40 km section of tertiary road was travelled through the topocadastral square 2830 CC, from the R74 main road northward across the Bloukrans River towards the Tugela River. Herbarium specimens were collected to vouch for new instances of naturalisation of cacti, the colony sizes of which were estimated and invasion stages determined. An applicable weed risk assessment model was used to determine the threat status of one cactus species not previously evaluated for South Africa. Based on the South African Plant Invaders Atlas database records and field observations, management recommendations were suggested for six cacti species.Results: The first naturalised population of Opuntia microdasys in KwaZulu-Natal was detected, as was the first confirmed South African record of Echinopsis oxygona. Four populations of Peniocereus serpentinus were also found, ranging in size from several square metres to 0.4 ha. Echinopsis oxygona generated a score that falls into the reject category of the risk assessment model used.Conclusion: It is recommended that E. oxygona be added to the Species Under Surveillance for Possible Eradication or Containment Targeting list to investigate whether this species requires formal legal listing and the development of a specific eradication plan. Immediate action from local authorities is recommended for the manual removal of P. serpentinus and O. microdasys populations.

  6. The Last Glacial Maximum in the central North Island, New Zealand: palaeoclimate inferences from glacier modelling

    Science.gov (United States)

    Eaves, Shaun R.; Mackintosh, Andrew N.; Anderson, Brian M.; Doughty, Alice M.; Townsend, Dougal B.; Conway, Chris E.; Winckler, Gisela; Schaefer, Joerg M.; Leonard, Graham S.; Calvert, Andrew T.

    2016-04-01

    Quantitative palaeoclimate reconstructions provide data for evaluating the mechanisms of past, natural climate variability. Geometries of former mountain glaciers, constrained by moraine mapping, afford the opportunity to reconstruct palaeoclimate, due to the close relationship between ice extent and local climate. In this study, we present results from a series of experiments using a 2-D coupled energy balance-ice flow model that investigate the palaeoclimate significance of Last Glacial Maximum moraines within nine catchments in the central North Island, New Zealand. We find that the former ice limits can be simulated when present-day temperatures are reduced by between 4 and 7 °C, if precipitation remains unchanged from present. The spread in the results between the nine catchments is likely to represent the combination of chronological and model uncertainties. The majority of catchments targeted require temperature decreases of 5.1 to 6.3 °C to simulate the former glaciers, which represents our best estimate of the temperature anomaly in the central North Island, New Zealand, during the Last Glacial Maximum. A decrease in precipitation of up to 25 % from present, as suggested by proxy evidence and climate models, increases the magnitude of the required temperature changes by up to 0.8 °C. Glacier model experiments using reconstructed topographies that exclude the volume of post-glacial ( < 15 ka) volcanism generally increased the magnitude of cooling required to simulate the former ice limits by up to 0.5 °C. Our palaeotemperature estimates expand the spatial coverage of proxy-based quantitative palaeoclimate reconstructions in New Zealand. Our results are also consistent with independent, proximal temperature reconstructions from fossil groundwater and pollen assemblages, as well as similar glacier modelling reconstructions from the central Southern Alps, which suggest air temperatures were ca. 6 °C lower than present across New Zealand during the Last

  7. Morphostructural characterization of the Charco basin and its surrounding areas in the Chihuahua segment of north Mexican Basin and Range Province

    Science.gov (United States)

    Troiani, Francesco; Menichetti, Marco

    2014-05-01

    The Chihuahua Basin and Range (CBR) is the eastern branch of the northern Mexican Basin and Range Province that, from a morphostructural point of view, presently is one amongst the lesser-known zones of the southern portion of the North America Basin and Range Province. The study area covers an approximately 800 km2-wide portion of the CBR and encompasses the fault-bounded Charco basin and its surrounding areas. The bedrock of the area pertains to the large siliceous-igneous province of the Sierra Madre Occidental and consists of volcanoclastic rocks including Oligocene dacite, rhyolite, rhyolitic tuffs, and polimitic conglomerates. The region is characterized by a series of NW-SE oriented valleys delimited by tilted monoclinal blocks bounded by high angle, SW-dipping, normal faults. Abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins are the main morphological elements of the area. The valleys correspond to structural grabens filled with Plio-Pleistocene continental sediments. These grabens are about 10 km wide, while the extensional fault system extend over a distance of more than 15 km. The mountain ranges are in most cases continuous over distances that range from 10 to 70 km including different branches of the extensional and transfer faults. The morphogenesis is mainly erosive in character: erosional landforms (such as rocky scarps, ridges, strath-terraces, erosional pediment, reverse slopes, landslide scar zones, litho-structural flat surfaces) dominate the landscape. In contrast, Quaternary depositional landforms are mainly concentrated within the flat valleys or basins. The Quaternary deposits consist of wide alluvial fans extending to the foot of the main ridges, fluvial and debris-slope deposits. The morphostructural characterization of the area integrated different methodologies, including: i) geomorphological and structural field analyses; ii) remote sensing and geo-morphometric investigations

  8. A key continental archive for the last 2 Ma of climatic history of the central Mediterranean region: A pilot drilling in the Fucino Basin, central Italy

    Science.gov (United States)

    Giaccio, B.; Regattieri, E.; Zanchetta, G.; Wagner, B.; Galli, P.; Mannella, G.; Niespolo, E.; Peronace, E.; Renne, P. R.; Nomade, S.; Cavinato, G. P.; Messina, P.; Sposato, A.; Boschi, C.; Florindo, F.; Marra, F.; Sadori, L.

    2015-12-01

    An 82 m long sedimentary succession was retrieved from the Fucino Basin, the largest intermountain tectonic depression of the central Apennines. The basin hosts a succession of fine-grained lacustrine sediments (ca. 900 m-thick) possibly continuously spanning the last 2 Ma. A preliminary tephrostratigraphy study allows us to ascribe the drilled 82 m long record to the last 180 ka. Multi-proxy geochemical analyses (XRF scanning, total organic/inorganic carbon, nitrogen and sulfur, oxygen isotopes) reveal noticeable variations, which are interpreted as paleohydrological and paleoenvironmental expressions related to classical glacial-interglacial cycles from the marine isotope stage (MIS) 6 to present day. In light of the preliminary results, the Fucino sedimentary succession is likely to provide a long, continuous, sensitive, and independently dated paleoclimatic archive of the central Mediterranean area.

  9. Late Neogene and active orogenic uplift in the Central Pontides associated with the North Anatolian Fault; implications for the northern margin of the Central Anatolian Plateau, Turkey

    OpenAIRE

    Yildirim, C.; Schildgen, T.F.; Helmut Echtler; H. Melnick; Strecker, M. R.

    2011-01-01

    Surface uplift at the northern margin of the Central Anatolian Plateau (CAP) is integrally tied to the evolution of the Central Pontides (CP), between the North Anatolian Fault (NAF) and the Black Sea. Our regional morphometric and plate kinematic analyses reveal topographic anomalies, steep channel gradients, and local high relief areas as indicators of ongoing differential surface uplift, which is higher in the western CP compared to the eastern CP and fault-normal components of geodetic sl...

  10. Hydrological impact of rainwater harvesting in the Modder river basin of central South Africa

    Directory of Open Access Journals (Sweden)

    W. A. Welderufael

    2011-05-01

    Full Text Available Along the path of water flowing in a river basin are many water-related human interventions that modify the natural systems. Rainwater harvesting is one such intervention that involves harnessing of water in the upstream catchment. Increased water usage at upstream level is an issue of concern for downstream water availability to sustain ecosystem services. The upstream Modder River basin, located in a semi arid region in the central South Africa, is experiencing intermittent meteorological droughts causing water shortages for agriculture, livestock and domestic purpose. To address this problem a technique was developed for small scale farmers with the objective of harnessing rainwater for crop production. However, the hydrological impact of a wider adoption of this technique by farmers has not been well quantified. In this regard, the SWAT hydrological model was used to simulate the hydrological impact of such practices. The scenarios studied were: (1 Baseline scenario, based on the actual land use of 2000, which is dominated by pasture (combination of natural and some improved grass lands (PAST; (2 Partial conversion of Land use 2000 (PAST to conventional agriculture (Agri-CON; and (3 Partial conversion of Land use 2000 (PAST to in-field rainwater harvesting which was aimed at improving the precipitation use efficiency (Agri-IRWH.

    SWAT was calibrated using observed daily mean stream flow data of a sub-catchment (419 km2 in the study area. SWAT performed well in simulating the stream flow giving Nash and Sutcliffe (1970 efficiency index of 0.57 for the monthly stream flow calibration. The simulated water balance results showed that the highest peak mean monthly direct flow was obtained on Agri-CON land use (18 mm, followed by PAST (12 mm and Agri-IRWH land use (9 mm. These were 19 %, 13 % and 11 % of the mean annual rainfall, respectively. The Agri-IRWH scenario reduced direct flow by 38 % compared to Agri-CON. On the other

  11. Participatory and decentralized water resources management: challenges and perspectives for the North Paraíba River Basin committee - Brazil.

    Science.gov (United States)

    Ribeiro, M A F M; Vieira, Z M C L; Ribeiro, M M R

    2012-01-01

    The Brazilian Water Resources Policy (Law 9433/1997) establishes participatory and decentralized management, involving civil society, water users and governmental bodies, with the basin committees as the basis of this process. Fifteen years after its implementation, it is possible to perceive accomplishments, but, at the same time, there are some difficulties in regards to the operation of the basin committees in the country. Considering the North Paraíba River Basin - which is completely included in the State of Paraíba, Northeastern Brazil, and presents great social and economic importance for the state - this article analyzes the process of formation, installation and functioning of its Basin Committee (CBH-PB), focusing on its composition, the reasons for the mobilization and demobilization of its members, the intra-relations between segments, and the inter-relations between the CBH-PB and other entities of the State Water Management System (the Water Executive Agency and the State Water Resources Council). The level of decentralization and the quality of participatory management (as it is being performed at the CBH-PB) are discussed and guidelines are suggested in order to allow greater effectiveness to the committee. PMID:22925876

  12. Timing and Kinematics of Cretaceous to Paleogene inversion at the SE margin of the Central European Basin System: Part 2, Thermochronology

    Science.gov (United States)

    Hoffmann, V.-E.; Dunkl, I.; von Eynatten, H.; Jähne, F.; Voigt, T.; Kley, J.

    2009-04-01

    During the Late Cretaceous to Early Tertiary some parts of the Central European Basin System (CEBS) were uplifted along NW-SE to WNW-ESE striking compressive fault systems. As a result Pre-Zechstein (Permian) basement is exposed at the southern border of the CEBS from Central Germany to the sudetes still further east (e.g. Harz Mountains, Thuringian Forest). Thrust-related basins like the Subhercynian Cretaceous Basin (SCB) in the foreland of the Harz Mountains accumulated up to 2500m of siliciclastic and chemical sediments in only 10 million years (Late Turonian to Lower Campanian, Voigt et al., 2006). By means of low-temperature thermochronology it is possible to characterise these basin inversion processes with respect to timing, pattern and rates of cooling and exhumation. Differed authors have already applied Apatite Fission Track analysis (AFT) in certain areas of the southern margin of CEBS. Thomson and Zeh (2000) published AFT apparent ages of 69 to 81 Ma for the Ruhla Crystalline Complex in the Thuringian Forest. Similar AFT-ages (73-84 Ma) of granitoids from the Harz Mountains were reported by Thomson et al. (1997). The late Carboniferous felsic volcanic rocks near Halle yield a much broader range of AFT apparent ages (75-108 Ma; Jacobs and Breitkreuz, 2003). Comparable AFT-ages (84-90 Ma) had been also observed for gabbros from the north-eastern part of the Mid German Crystalline High (Ventura et al. 2003). The present study tries to bridge some of the major gaps in the regional distribution of thermochronological data by analysing samples from central and southern parts of the CEBS. Overall almost 50 AFT-ages from Saxony-Anhalt, Lower Saxony, Thuringia, Hesse and North Rhine-Westphalia were measured. Emphasis is placed on the regions from the Harz Mountains to the Rhenish Uplands and the Thuringian Forest and its foreland. Furthermore, apatite (U-Th)/He thermochronology is used to better constrain the time-temperature history models. Apart from some

  13. Optimum combination of water drainage, water supply and eco-environment protection in coal-accumulated basin of North China

    Institute of Scientific and Technical Information of China (English)

    武强; 董东林; 石占华; 武雄; 孙卫东; 叶责钧; 李树文; 刘金韬

    2000-01-01

    The conflict among water drainage, water supply and eco-environment protection is getting more and more serious due to the irrational drainage and exploitation of ground water resources in coal-accumulated basins of North China. Efficient solutions to the conflict are to maintain long-term dynamic balance between input and output of the ground water basins, and to try to improve resourcification of the mine water. All solutions must guarantee the eco-environment quality. This paper presents a new idea of optimum combination of water drainage, water supply and eco-environment protection so as to solve the problem of unstable mine water supply, which is caused by the changeable water drainage for the whole combination system. Both the management of hydraulic techniques and constraints in economy, society, ecology, environment, industrial structural adjustments and sustainable developments have been taken into account. Since the traditional and separate management of different departments of water drainage,

  14. Phosphorus fluxes in headwater streams draining non-research poultry-pasture operations in north-central Georgia, USA

    Science.gov (United States)

    Romeis, J. J.; Jackson, C. R.; Radcliffe, D. E.; Risse, M. L.; Bryant, J.

    2007-12-01

    Poultry production is the largest agricultural commodity in Georgia, USA. Due to inefficient utilization of the phosphorus (P) in poultry feed, the manure contains high concentrations of P. When used as fertilizer for crops and pasture, poultry manure may be washed from the soil surface and increase eutrophication risks to downstream lakes and reservoirs. Long term application of poultry manure may result in P saturation of the soils. In the upper Etowah River basin in north-central Georgia, a long history of poultry farming has resulted in high P levels in soils receiving regular poultry manure applications. Few studies to date have been performed on the estimation of P fluxes from operational commercial poultry farms in Georgia. In Fall 2006, a 20-month surface water quality monitoring program was completed that was aimed at estimating P and suspended sediment fluxes in nine headwater streams draining poultry-pasture operations in the upper Etowah River basin. The nine catchments differed in terms of land use history, soil P levels, best management practices and other factors. An additional three streams draining U.S. National Forest were also monitored to provide reference concentrations and loads. Monitoring data included continuous (5-minute) streamflow, rainfall, and water quality samples. Water quality samples included biweekly grab samples plus storm samples collected using conventional autosamplers. Storm sampling using autosamplers included collection of discrete samples and composite samples. In particular instances, the two types of storm sample were collected simultaneously. Discrete storm sampling methods enabled collection of both rising and falling hydrograph limb samples to identify potential hysteretic water quality effects. Water samples were analyzed for total P, filterable reactive P, and total suspended solids. We are using this data to compare different flux estimation methods with emphasis on regression models that utilize laboratory results

  15. A comprehensive approach to the 3D geological modelling of sedimentary basins: example of Latvia, the central part of the Baltic Basin

    Directory of Open Access Journals (Sweden)

    Konrāds Popovs

    2015-05-01

    Full Text Available This paper presents a semi-automatic approach adapted to the modelling of the geological structure of sedimentary basins. The modelling approach is based on developing the algorithm of the main geological processes so that the geometrical relationship is automatically defined between model elements. The algorithm is based on the assumption that sedimentary basins are formed as a result of the repeated sequence of sedimentation, faulting and erosion. This approach allows of successful modelling of the geological structure of the sedimentary basins with limited data coverage: stratigraphic intervals from well logs describing the thicknesses of sedimentary strata and a limited amount of structural data. Sedimentary layers are handled by modelling assuming non-eroded thickness distribution and using geometrical adjustment from the known fault displacements. As a result geometrical relationships of the model layers are deduced automatically in the presence of unconformities. An application of this methodology, a 3D geological model of Latvia, the central part of the Baltic Basin, is presented. The results show that this model is geologically reasonable for achieving the structural and stratigraphic concepts.

  16. Hydrocarbon seep-carbonates of a Miocene forearc (East Coast Basin), North Island, New Zealand

    Science.gov (United States)

    Campbell, Kathleen A.; Francis, David A.; Collins, Mike; Gregory, Murray R.; Nelson, Campbell S.; Greinert, Jens; Aharon, Paul

    2008-02-01

    An ancient hydrocarbon seep province of 14 isolated, authigenic carbonate deposits has been identified in fine-grained, deep-marine siliciclastic strata of the Miocene East Coast Basin, North Island, New Zealand. These forearc sediments have been uplifted and complexly deformed into accretionary ridges, adjacent to the still-active Hikurangi convergent margin. Older active and passive margin strata (mid-Cretaceous to Oligocene in age) underlie the Neogene sequence, and contain oil- and gas-prone source rocks. Older Mesozoic meta-sedimentary rocks constitute the backstop against which the current phase of subduction-related sedimentation has accumulated (~ 24 Ma-present). The seep-carbonates (up to 10 m thick, 200 m across) archive methane signatures in their depleted carbon isotopes (to δ13C -51.7‰ PDB), and contain chemosynthesis-based paleocommunities (e.g. worm tubes, bathymodioline mussels, and vesicomyid, lucinid and thyasirid bivalves) typical of other Cenozoic and modern seeps. Northern and southern sites are geographically separated, and exhibit distinct lithological and faunal differences. Structural settings are variable. Seep-associated lithologies also are varied, and suggest carbonate development in sub-seafloor, seafloor and physically reworked (diapiric expansion, gas explosion, gravity slide or debris flow) settings, similar to Italian Apennine seep deposits of overlapping ages. Peculiar attributes of the New Zealand Miocene seep deposits are several, including digitate thrombolites of clotted microbial micrite encased in thick, isopachous horizons and botryoids of aragonite. Seep plumbing features are also well-exposed at some sites, displaying probable gas-explosion breccias filled with aragonite, tubular concretions (fluid conduits), and carbonate-cemented, thin sandstone beds and burrows within otherwise impermeable mudstones. A few seeps were large enough to develop talus-debris piles on their flanks, which were populated by lucinid bivalves

  17. Evaluating Religious Influences on the Utilization of Maternal Health Services among Muslim and Christian Women in North-Central Nigeria

    OpenAIRE

    Maryam Al-Mujtaba; Cornelius, Llewellyn J.; Hadiza Galadanci; Salome Erekaha; Joshua N. Okundaye; Adeyemi, Olusegun A.; Sam-Agudu, Nadia A.

    2016-01-01

    Introduction. Uptake of antenatal services is low in Nigeria; however, indicators in the Christian-dominated South have been better than in the Muslim-dominated North. This study evaluated religious influences on utilization of general and HIV-related maternal health services among women in rural and periurban North-Central Nigeria. Materials and Methods. Targeted participants were HIV-positive, pregnant, or of reproductive age in the Federal Capital Territory and Nasarawa. Themes explored we...

  18. Sedimentary characteristics of tide-dominated estuary in Donghetang Formation(Upper Devonian), central Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The Donghetang Formation (Upper Devonian) in central Tarim Basin has been thought an important oil and gas reservoir since the abundant oil and gas resources were found in the wells W16, W20, W34, and other fields. However, the sedimentary environment of the Donghetang Formation has been disputed because it suffered from both tidal and fluvial actions and there were not rich fossils in the sandstone. After the authors analyzed sedimentary features by means of drill cores, well logging data, paleosols, and with SEM obseruations, three kinds of sedimentary environments were distinguished: alluvial fan, tide-dominated estuary, and shelf. Particularly, the sedimentary features of tide-dominated estuary were studied in detail. Besides, the authors discussed sedimentary characteristics of the Donghetang Formation which was divided into two fourth-order sequences and five system tracts. At the same time, according to the forming process of five system tracts, the whole vertical evolution and lateral transition of tide-dominated estuary were illustrated clearly. Finally, the reservoir quality was evaluated based on porosity and permeability.

  19. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    Directory of Open Access Journals (Sweden)

    Pan Chen

    2015-05-01

    Full Text Available Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA, the cluster analysis (CA and the discriminant analysis (DA were used to assess the water pollution status and analyze its spatio-temporal variation. Ten sites were classified by the high pollution (HP region and the low pollution (LP region, while 12 months were divided into the wet season and the dry season. It was found that the HP region was mainly in the small tributaries with small drainage areas and low average annual discharges, and it was also found that most of these rivers went through urban areas with industrial and domestic sewages input into the water body. Principal component analysis/factor analysis (PCA/FA was applied to reveal potential pollution sources, whereas absolute principal component score-multiple linear regression (APCS-MLR was used to identify their contributions to each water quality variable. The study area was found as being generally affected by industrial and domestic sewage. Furthermore, the HP region was polluted by chemical industries, and the LP region was influenced by agricultural and livestock sewage.

  20. Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

    Science.gov (United States)

    Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J.-H.; Zell, C. I.; Mortillaro, J.-M.; Meziane, T.; Moreira-Turcq, P.; Sinninghe Damsté, J. S.

    2016-01-01

    In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indicator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derived OM contribution was observed along the gradient of increasing open waters - i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

  1. Characterization of photoautotrophic picoplankton assemblages in turbid, alkaline lakes of the Carpathian Basin (Central Europe

    Directory of Open Access Journals (Sweden)

    Lajos VÖRÖS

    2009-08-01

    Full Text Available The photoautotrophic picoplankton (PPP of ten shallow, hyposaline soda lakes located in three different geographical regions in the Carpathian Basin (Central Europe was characterized. These lakes, which frequently dry out completely, are extremely rich in PPP. Epifluorescence microscopy was applied to determine picocyanobacterial and picoeukaryotic cell abundance and PCR-based molecular techniques (denaturing gradient gel electrophoresis and cloning with phylospecies delineation to identify the members of PPP. Most of these lakes were eu- and hypertrophic with varying contribution of picocyanobacteria to the total PPP cell number. We found an unusually high PPP abundance with peaks of 8.16 × 106 cells mL-1 for picoeukaryotes and 1.78 × 107 cells mL-1 for picocyanobacteria. The majority of the retrieved PPP sequences belonged to picocyanobacteria (nonmarine Synechococcus/ Cyanobium, while others showed similarity to eukaryotic algal plastids (close to Trebouxiophycean isolates. Molecular analysis revealed significant genetic diversity in the PPP fraction of these lakes and showed that the closest relatives of our picocyanobacterial clones were recovered from different habitats, indicating seemingly no correlation between the 'saline' ecotypes and their phylogenetic position. Our results also confirmed that PPP might exploit different aquatic ecosystems and be successful even in the case of abrupt changes of environmental parameters (in our case, salinity. According to our knowledge, this is the first survey focusing on the identification of the PPP community members in turbid and alkaline lakes with extraordinarily high picoplankton productivity.

  2. Evolution of the Moxizhuang Oil Field, Central Junggar Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    Zou Huayao; Zhang Yuanchun; Liu Jianzhang; Shi Jiannan

    2008-01-01

    Current oil saturation in the Moxizhuang (莫西庄) Oil Field in central Janggar (准噶尔) basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by graln-containing-oil inclusion (GOI) analysis.The pay zones in this field have low oil saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values (up to 38%), suggesting high paleo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low oil-saturation field evolved from a high oil-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for oil loss in the Moxizhuang Oil Field.The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paleo-oil zones (current water zones).

  3. Changes in Diversity of Fish Fauna of the Chu River Basin (Central Asia

    Directory of Open Access Journals (Sweden)

    Eleonora Byrlykzhanovna Kozhabaeva

    2015-11-01

    Full Text Available The Chu River originates in the Central Tien Shan Mountains and dissipates into the Muyunkum desert. The first information about the fish of the river was received in the middle 19-th century. Several expeditions collected data during 20-th century. Results of our investigations last decade in comparison with previous data allow tracking changes in the fish fauna after growing human impact. In the main, our data concern of the Kazakhstan part of the river. About 34 species and subspecies were discovered here; about 19 species between them are native. Origin or taxonomy of some species are disputable. In the last publications of the XX-th century 38 fish species and subspecies were mentioned. Native fish species as Aral barbel Barbus brachycephalus and Bulatmai barbel Barbus capito, Chu sharpray Capoetobrama kuschakewitschii and alien Sea trout Salmo trutta, Sevan trout Salmo ischchan were not found last decade in the Kazakhstan part of the river. Distribution area of native Balkhash marinka Schizothorax argentatus and alien Balkhash perch Perca schrenkii were reduced. The most widespread and numerous fish species are native roach, carp, dace, gudgeon and alien stone moroco. Native fishes like pike, asp, Aral ide, striped bystranka, golden spiny loach, southern ninespine stickleback and others were found only in certain sites. Fish species composition for each investigated site was not stable during recent years. Significant variations in fish composition were observed between different water bodies of the basin too. It reflects diversity of human impacts and unsteady water regimen here.

  4. Late quaternary pollen records from the middle caqueta river basin in central colombian amazon

    International Nuclear Information System (INIS)

    Three pollen records are presented from the Pantano de Monica region (0 degrade 42' S, 72 degrade 04' W, 160 m elevation) on the lower terrace of Caqueta River of the central Colombian Amazonas. Ten radiocarbon dates from three cores indicate that the deposits are of Holocene age, but the pollen data suggest that also the record may contain the late glacial. The core Pantano de Monica 1 covers the time interval from 11,150 BP (extrapolated) to 4730 BP during the late glacial and early Holocene this swamp was smaller in size and water were more shallow than today, with abundant Mauritia palm trees. This indicates that the lower terrace of the Caqueta River was better drained than today, which might be related to changes in the drainage system and/or drier conditions during that time. Late glacial and early Holocene vegetation changes in the rain forests surrounding the swamp Pantano de Monica indicate successional stages, probably related to on changes in the drainage system and/or climate changes. Presence of Podocarpus pollen grains up to 2.6% of the total sum (and influx of 78 grains cm2 yr1) point to regional presence of Podocarpus at the beginning of the Holocene. evidence of Podocarpus during glacial times in other pollen records from the Amazon Basin has been taken as indicative of cooling

  5. Hydrogeochemical investigations in a drained lake area: the case of Xynias basin (Central Greece).

    Science.gov (United States)

    Charizopoulos, Nikos; Zagana, Eleni; Stamatis, Georgios

    2016-08-01

    In Xynias drained Lake Basin's area, central Greece, a hydrogeochemical research took place including groundwater sampling from 30 sampling sites, chemical analysis, and statistical analysis. Groundwaters present Ca-Mg-HCO3 as the dominant hydrochemical type, while their majority is mixed waters with non-dominant ion. They are classified as moderately hard to hard and are characterized by oxidizing conditions. They are undersaturated with respect to gypsum, anhydrite, fluorite, siderite, and magnesite and oversaturated in respect to calcite, aragonite, and dolomite. Nitrate concentration ranges from 4.4 to 107.4 mg/L, meanwhile 13.3 % of the samples exceed the European Community (E.C.) drinking water permissible limit. The trace elements Fe, Ni, Cr, and Cd present values of 30, 80, 57, and 50 %, respectively, above the maximum permissible limit set by E.C. Accordingly, the majority of the groundwaters are considered unsuitable for drinking water needs. Sodium adsorption ratio values (0.04-3.98) and the electrical conductivity (227-1200 μS/cm) classify groundwaters as suitable for irrigation uses, presenting low risk and medium soil alkalization risk. Factor analysis shows that geogenic processes associated with the former lacustrine environment and anthropogenic influences with the use of fertilizers are the major factors that characterized the chemical composition of the groundwaters. PMID:27450374

  6. Rainfall and land use empirically coupled to forecast landslides in the Esino river basin, central Italy

    Science.gov (United States)

    Gioia, E.; Carone, T.; Marincioni, F.

    2015-06-01

    A coupled empirical approach to highlight relationships between rainfall, vegetation segmentation, and landslide occurrence is discussed. To reveal such links, two important rainfall events, which occurred over the Esino river basin in central Italy in November 2013 and May 2014, were analysed. The correlation between rainfall and landslides was evaluated by applying an intensity-duration (ID) threshold method, whereas the correlation between vegetation segmentation and landslides was investigated using morphological spatial pattern analysis (MSPA). This coupled approach represents an attempt to find both timing and location of landslide occurrence through an empirical (black box) analysis. Results showed: (i) the ID minimum threshold proposed in a previous study (Gioia et al., 2015) to be verified as an effective equation to assess the rainfall conditions likely to trigger landslides in the study area ("when"), and (ii) the core areas and the fragmented vegetation structures defined by the MSPA to be the most affected by slope failures ("where"). These encouraging findings prompt additional testing and the application of such a coupled empirical approach so that it is possible to achieve an integrated basis for landslide forecasting.

  7. Parascolymia (Scleractinia: Lobophylliidae) in the Central Paratethys Sea (Vienna Basin, Austria) and its possible biogeographic implications.

    Science.gov (United States)

    Reuter, Markus; Wiedl, Thomas; Piller, Werner E

    2015-01-01

    Palaeobiogeographical and palaeodiversity patterns of scleractinian reef corals are generally biased due to uncertain taxonomy and a loss of taxonomic characters through dissolution and recrystallization of the skeletal aragonite in shallow marine limestones. Herein, we describe a fossil lobophylliid coral in mouldic preservation from the early middle Miocene Leitha Limestone of the Central Paratethys Sea (Vienna Basin, Austria). By using grey-scale image inversion and silicone rubber casts for the visualization of the original skeletal anatomy and the detection of distinct micromorphological characters (i.e. shape of septal teeth, granulation of septocostae) Parascolymia bracherti has been identified as a new species in spite of the dissolved skeleton. In the recent era, Parascolymia like all Lobophylliidae is restricted to the Indo-Pacific region, where it is represented by a single species. The new species proves the genus also in the Miocene Mediterranean reef coral province. A review of the spatio-temporal relationships of fossil corals related to Parascolymia indicates that the genus was probably rooted in the Eastern Atlantic‒Western Tethys region during the Paleocene to Eocene and reached the Indo-Pacific region not before the Oligocene. The revealed palaeobiogeographical pattern shows an obvious congruence with that of Acropora and tridacnine bivalves reflecting a gradual equatorwards retreat of the marine biodiversity center parallel to the Cenozoic climate deterioration. PMID:26201071

  8. Digital resource modeling of the northern and central Appalachian Basin coal regions: Top producing coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Tewalt, S.; Bragg, L.; Wallack, R.; Jenkins, J.; Tully, J. [Geological Survey, Reston, VA (United States)

    1998-12-31

    The US Geological Survey is currently conducting a coal resource assessment of the coal beds and zones that are expected to provide the bulk of the Nation`s coal resources for the next few decades. In partnership with the state geologic surveys of Kentucky, Tennessee, West Virginia, Virginia, Pennsylvania, Ohio, and Maryland, six coal beds will be digitally assessed in the northern and central Appalachian Basin coal region. In ascending stratigraphic order, the beds which range from the Lower Pennsylvanian Pocahontas Formation to the Upper Pennsylvanian Monongahela Group are the Pocahontas No. 3, Pond Creek, Fire Clay, Lower Kittanning, Upper Freeport, and Pittsburgh coals. Comprehensive stratigraphic and geochemical databases have been developed for the coal beds. Maps that show the extent and mined areas of the beds, structure contour, isopach, and overburden thickness have been compiled for the Pittsburgh coal bed and are in preparation for the other coal beds. The resource model for the Pittsburgh coal bed indicates that of the original 33.6 billion short tons (30.5 billion tonnes) of Pittsburgh coal, approximately 15.9 billion short tons (14.4 billion tonnes) remain. The remaining coal is, however, higher in ash and sulfur, and generally thinner and under thicker overburden cover.

  9. Investigaton of ÇINARCIK Basin and North Anatolian Fault Within the Sea of Marmara with Multichannel Seismic Reflection Data

    Science.gov (United States)

    Atgın, O.; Çifçi, G.; Sorlien, C.; Seeber, L.; Steckler, M.; Sillington, D.; Kurt, H.; Dondurur, D.; Okay, S.; Gürçay, S.; Sarıtaş, H.; Küçük, H. M.

    2012-04-01

    The Sea of Marmara is becoming a natural laboratory for structure, sedimentation, and fluid flow within the North Anatolian fault (NAF) system. Much marine geological and geophysical data has been collected there since the deadly 1999 M=7.2. Izmit earthquake. The Sea of Marmara occupies 3 major basins, with the study area located in the eastern Cinarcik basin near Istanbul. These basins are the results of an extensional component in releasing segments between bends in this right-lateral tranmsform. It is controversial whether the extensional component is taken up by partitioned normal slip on separate faults, or instead by oblique right-normal slip on the non-vertical main northern branch of the NAF. High resolution multichannel seismic reflection (MCS) and multibeam bathymetry data collected by R/V K.Piri Reis and R/V Le-Suroit as part of two different projects respectively entitled "SeisMarmara", "TAMAM" and "ESONET". 3000 km of multichannel seismic reflection profiles were collected in 2008 and 2010 using 72, 111, and 240 channels of streamer with a 6.25 m group interval. The generator-injector airgun was fired every 12.5 or 18.75 m and the resulting MCS data has 10-230 Hz frequency band. The aim of the study is to investigate continuation of North Anatolian Fault along the Sea of Marmara, in order to investigate migration of depo-centers past a fault bend. We also test and extend a recently-published age model, quantify extension across short normal faults, and investigate whether a major surface fault exists along the southern edge of Çınarcık Basin. MCS profiles indicate that main NAF strand is located at the northern boundary of Çınarcık Basin and has a large vertical component of slip. The geometry of the eastern (Tuzla) bend and estimated right-lateral slip rates from GPS data requires as much of ten mm/yr of extension across Çınarcık Basin. Based on the published age model, we calculate about 2 mm/yr of extension on short normal faults in the

  10. A comparison of plastic and plankton in the North Pacific central gyre

    Energy Technology Data Exchange (ETDEWEB)

    Moore, C.J.; Moore, S.L. [Algalita Marine Research Foundation, Long Beach, CA (United States); Leecaster, M.K.; Weisberg, S.B. [Southern California Coastal Water Research Project, Westminster, CA (United States)

    2001-07-01

    The potential for ingestion of plastic particles by open ocean filter feeders was assessed by measuring the relative abundance and mass of neustonic plastic and zooplankton in surface waters under the central atmospheric high-pressure cells of the North Pacific Ocean. Neuston samples were collected at 11 random sites, using a manta trawl lined with 333 u mesh. The abundance and mass of neustonic plastic was the largest recorded anywhere in the Pacific Ocean at 334271 pieces km{sup 2} and 5114gkm{sup 2}, respectively. Plankton abundance was approximately five times higher than that of plastic, but the mass of plastic was approximately six times that of plankton. The most frequently sampled types of identifiable plastic were thin films, polypropylene/monofilament line and unidentified plastic, most of which were miscellaneous fragments. Cumulatively, these three types accounted for 98% of the total number of plastic pieces. (Author)

  11. Review of DOE's proposal for Crystalline bedrock disposal of radioactive waste, north-central area

    International Nuclear Information System (INIS)

    The DOE's Region-to-Area Screening Methodology for the Crystalline Repository Project (DOE/CH-1), the Final North-Central Region Geologic Characterization Report (DOE/CH-8(1)), and the Draft Area Recommendation Report for the Crystalline Repository Project (DOE/CH-15), with the associated maps, were reviewed. The review has focused on all general information regarding geologic topics and all site-specific data for DOE sites NC-10 and NC-3. This report contains two parts: (1) a point-by-point critique of perceived errors, omissions, or other shortcomings in each of the three documents; and (2) a discussion of the feasibility of crystalline bedrock as a suitable host medium for high-level radioactive waste

  12. Factors That Affect Tax Compliance among Small and Medium Enterprises (SMEs in North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Ojochogwu Winnie Atawodi

    2012-06-01

    Full Text Available Tax is an important stream of revenue for government’s development projects. However, tax compliance amongSMEs is poor. Therefore, this study was conducted using SMEs in Zaria, North-Central Nigeria to evaluate andrank the factors that encourage non-compliance with tax obligation by SMEs. It was found that high tax rates andcomplex filing procedures are the most crucial factors causing non-compliance of SMEs. Other factors likemultiple taxation and lack of proper enlightenment affect tax compliance among the SMEs surveyed only to alesser extent. Therefore, it is recommended that SMEs should be levied lower percentage of taxes to allowenough funds for business development and better chances of survival in a competitive market. The governmentshould also consider increasing tax incentives such as exemptions and tax holidays as these will not onlyencourage voluntary compliance but also attract investors who are potential viable tax payers in the future.

  13. Bedload exports in a forest catchment following wildfire and terracing, north-central Portugal

    Science.gov (United States)

    Martins, Martinho A. S.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob

    2014-05-01

    In Portugal, the occurrences of wildfires are frequently, on average, affects some 100.000 ha of rural lands each year, but in extreme years such as 2003 and 2005 the burnt areas can go over 300.000 ha. Studies in various parts of the world, including Portugal, have well-documented a strong and sometimes extreme response in overland flow generation and associated soil losses following wildfire. Over the last two decades, the construction of terraces in preparation of a new eucalypt plantation has become increasingly common in the mountain areas of north-central Portugal, including in recently burnt areas. Terraces are traditionally viewed as a soil conservation technique, however, the present authors have measured high splash and inter-rill erosion on recent terraces and have frequently observed gully formation connecting the terraces over the full hill slope length, as well as within the adjacent unsealed roads. The present study was carried out in a forest catchment in the north-central Portugal that was burnt by a wildfire during the summer of 2010 and logged and then terraced with a bulldozer during the winter 2010. The burnt catchment of roughly 25 ha was instrumented with two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. The bed load that deposited in the smallest flume was removed and weighted in the field at regular intervals during the subsequent three years. The records are being now analyzed, nonetheless preliminary results suggested that, besides the wildfire effects, also post-fire land management played an important role on bedload exports.

  14. Climatic Forcing of Glacier Surface Mass Balance Changes Along North-Central Peru: A Modeling Perspective

    Science.gov (United States)

    Mark, B. G.; Fernandez, A.

    2015-12-01

    Most tropical glaciers are Peru, where they are key water sources for communities in mountain environments and beyond. Thus, their sustained shrinkage portrays these glaciers as archetype of global warming impacts on the local scale. However, there is still no deep understanding on the mechanism connecting temperature and these glaciers. Among others, the effect of temperature on the glacier surface mass balance (GSMB) can be expressed within accumulation regimes and hence in surface albedo, or in ablation dynamics through incoming longwave energy (LE). Here, we report a study combining statistical analyses of reanalysis data (~30km grid-cell), regional climate modeling and glacier mass balance simulations at high resolution (2km) to analyze long-term (30 years) and seasonal GSMB along north-central Peru. Our goal is to mechanistically understand climate change impact on these glaciers. Results suggest temperature as the main factor controlling GSMB changes through the lapse rate (LR). Correlations of GSMB with LR, humidity and zonal wind point to vertical homogenization of temperature, causing LE to increase, despite this flux always remaining negative. This "less negative" LE multiplies the impact of the seasonal fluctuation in albedo, thereby enhancing total ablation. As this mechanism only needs a relative increase in temperature, it may even occur in subfreezing conditions. Model output also indicates that turbulent fluxes are small, largely cancelling out. This suggests that the impact of LE is more likely to occur compared to either turbulent fluxes changes or shifts in the proportion of sublimation versus melt, which we find to be regionally stable. These findings imply that glaciers in north-central Peru are sensitive to subtle changes in temperature. We discuss the implications for process-based understanding and how this non-linear and somewhat hidden effect of temperature reduces the skill of temperature index models to simulate GSMB in the Tropics.

  15. Characterization of smallholder pig breeding practices within a rural commune of North Central Vietnam.

    Science.gov (United States)

    Ieda, Nahoko; Van Bui, Quang; Nguyen, Nga Thi Duong; Lapar, Lucy; Marshall, Karen

    2015-08-01

    This case study focused on a pig production system in a rural area of North Central Vietnam, with a focus on describing household pig breeding practices and estimating herd demographic parameters, particularly on reproduction. One hundred five households undertaking small-scale piglet production were surveyed, with information gathered on 3268 individual pigs. Pig keeping contributed variably to the overall household livelihood portfolio, with female household members as the main decision makers, contributors to labor, and beneficiaries of income from the pig enterprise. All households kept between one and four young or adult sows, with 69% of these sows of a local breed type (predominantly Mong Cai), 28% a cross between a local sow and an exotic sow (predominantly Large White), and the remainder (3%) as exotic sows. Eighty-eight percent of the piglets produced were cross-bred, while 12% were local breed. No adult males were kept by the surveyed households, reflecting the common use of artificial insemination for mating purposes. The most common breeding system practiced-the keeping of Mong Cai females and production of cross-bred piglets-capitalizes on the small body size and high fecundity of the sows and the fast growth rate and leanness of the cross-bred piglets. The survey tool used, which was based on farmer recall of events over the preceding 12-month period, appeared to give reasonable results although some recall bias could be detected. This case study will serve as an entry point to planned broader scale characterization and development of pig breeding systems in North Central Vietnam. PMID:25947237

  16. Mediterranean climate patterns and wine quality in North and Central Italy.

    Science.gov (United States)

    Dalu, John David; Baldi, Marina; Marta, Anna Dalla; Orlandini, Simone; Maracchi, Gianpiero; Dalu, Giovanni; Grifoni, Daniele; Mancini, Marco

    2013-09-01

    Results show that the year-to-year quality variation of wines produced in North and Central Italy depends on the large-scale climate variability, and that the wine quality improvement in the last four decades is partially due to an increase of temperature and to a decrease of precipitation in West and Central Mediterranean Europe (WME; CME). In addition, wine quality is positively correlated with air temperature throughout the entire active period of the grapevine, weakly negatively correlated with precipitation in spring, and well negatively correlated in summer and fall. The month-to-month composites of the NAO anomaly show that, in years of good quality wine, this anomaly is negative in late spring, oscillates around zero in summer, and is positive in early fall; while, in years of bad quality wine, it is positive in late spring and summer, and negative in early fall, i.e. its polarity has an opposite sign in spring and fall in good versus bad years. The composite seasonal maps show that good wines are produced when the spring jet stream over the Atlantic diverts most of the weather perturbations towards North Europe, still providing a sufficient amount of rainwater to CME; when summer warming induced by southerly winds is balanced by the cooling induced by westerly winds; and when a positive geopotential anomaly over WME shelters CME from fall Atlantic storms. Bad quality wines are produced when the jet stream favors the intrusion of the Atlantic weather perturbations into the Mediterranean. Results suggest that atmospheric pattern persistencies can be used as precursors for wine quality forecast. PMID:23152193

  17. Changing central Pacific El Niños reduce stability of North American salmon survival rates.

    Science.gov (United States)

    Kilduff, D Patrick; Di Lorenzo, Emanuele; Botsford, Louis W; Teo, Steven L H

    2015-09-01

    Pacific salmon are a dominant component of the northeast Pacific ecosystem. Their status is of concern because salmon abundance is highly variable--including protected stocks, a recently closed fishery, and actively managed fisheries that provide substantial ecosystem services. Variable ocean conditions, such as the Pacific Decadal Oscillation (PDO), have influenced these fisheries, while diminished diversity of freshwater habitats have increased variability via the portfolio effect. We address the question of how recent changes in ocean conditions will affect populations of two salmon species. Since the 1980s, El Niño Southern Oscillation (ENSO) events have been more frequently associated with central tropical Pacific warming (CPW) rather than the canonical eastern Pacific warming ENSO (EPW). CPW is linked to the North Pacific Gyre Oscillation (NPGO), whereas EPW is linked to the PDO, different indicators of northeast Pacific Ocean ecosystem productivity. Here we show that both coho and Chinook salmon survival rates along western North America indicate that the NPGO, rather than the PDO, explains salmon survival since the 1980s. The observed increase in NPGO variance in recent decades was accompanied by an increase in coherence of local survival rates of these two species, increasing salmon variability via the portfolio effect. Such increases in coherence among salmon stocks are usually attributed to controllable freshwater influences such as hatcheries and habitat degradation, but the unknown mechanism underlying the ocean climate effect identified here is not directly subject to management actions. PMID:26240365

  18. The economics of CO2-EOR cluster developments in the UK Central North Sea

    International Nuclear Information System (INIS)

    Studies to date have generally shown that individual CO2-EOR offshore projects are uneconomic except under questionable assumptions. The present study is based on an interconnected cluster of nine oilfields in the Central North Sea linked to an onshore CO2 collection hub by a set of existing and new pipelines. Monte Carlo simulation modelling was undertaken of the prospective returns to investments in CO2-EOR in the fields. Relatively high oil prices were employed for the study period (2020–2050) and two contrasting CO2 transfer price scenarios, the first being the Carbon Price Floor (CPF) introduced by the UK Government and the second being relatively low negotiated prices reflecting recent and prospective levels under the EU-ETS. At CPF prices the investment returns were all found to be negative, but at prices averaging £10 per tonne positive returns were generally achieved. The study emphasises the importance of CO2 prices and the taxation system in determining the viability of the investments. - Highlights: • Detailed modelling of CO2 EOR in nine North Sea oil fields. • Overall investment risks are demonstrated to be very high. • Sharing of pipelines in network and cluster of CO2-EOR fields significantly reduces investment costs. • Range of plausible CO2 prices paid by investor results in very wide range of returns from CO2-EOR. • CO2 pricing and tax arrangements for EOR need further attention by policy makers

  19. Naturalization of central European plants in North America: species traits, habitats, propagule pressure, residence time.

    Science.gov (United States)

    Pyšek, Petr; Manceur, Ameur M; Alba, Christina; McGregor, Kirsty F; Pergl, Jan; Stajerová, Katerina; Chytrý, Milan; Danihelka, Jiří; Kartesz, John; Klimesova, Jitka; Lucanova, Magdalena; Moravcová, Lenka; Nishino, Misako; Sadlo, Jiri; Suda, Jan; Tichy, Lubomir; Kühn, Ingolf

    2015-03-01

    The factors that promote invasive behavior in introduced plant species occur across many scales of biological and ecological organization. Factors that act at relatively small scales, for example, the evolution of biological traits associated with invasiveness, scale up to shape species distributions among different climates and habitats, as well as other characteristics linked to invasion, such as attractiveness for cultivation (and by extension propagule pressure). To identify drivers of invasion it is therefore necessary to disentangle the contribution of multiple factors that are interdependent. To this end, we formulated a conceptual model describing the process of invasion of central European species into North America based on a sequence of "drivers." We then used confirmatory path analysis to test whether the conceptual model is supported by a statistical model inferred from a comprehensive database containing 466 species. The path analysis revealed that naturalization of central European plants in North America, in terms of the number of North American regions invaded, most strongly depends on residence time in the invaded range and the number of habitats occupied by species in their native range. In addition to the confirmatory path analysis, we identified the effects of various biological traits on several important drivers of the conceptualized invasion process. The data supported a model that included indirect effects of biological traits on invasion via their effect on the number of native range habitats occupied and cultivation in the native range. For example, persistent seed banks and longer flowering periods are positively correlated with number of native habitats, while a stress-tolerant life strategy is negatively correlated with native range cultivation. However, the importance of the biological traits is nearly an order of magnitude less than that of the larger scale drivers and highly dependent on the invasion stage (traits were associated

  20. The economic feasibility of sugar beet biofuel production in central North Dakota

    International Nuclear Information System (INIS)

    This study examines the financial feasibility of producing ethanol biofuel from sugar beets in central North Dakota. Under the Energy Independence and Security Act (EISA) of 2007, biofuel from sugar beets uniquely qualifies as an 'advanced biofuel'. EISA mandates production of 21 billion gallons of advanced biofuels annually by 2022. A stochastic simulation financial model was calibrated with irrigated sugar beet data from central North Dakota to determine economic feasibility and risks of production for 0.038 hm3y-1 (or 10 MGY (Million Gallon per Year) and 0.076 hm3y-1 (or 20 MGY) ethanol plants. Study results indicate that feedstock costs, which include sugar beets and beet molasses, account for more than 70 percent of total production expenses. The estimated breakeven ethanol price for the 0.076 hm3y-1 plant is $400 m-3 ($1.52 per gallon) and $450 m-3 ($1.71 per gallon) for the 0.038 hm3y-1 plant. Breakeven prices for feedstocks are also estimated and show that the 0.076 hm3y-1 plant can tolerate greater ethanol and feedstock price risks than the 0.038 hm3y-1 plant. Our results also show that one of the most important factors that affect investment success is the price of ethanol. At an ethanol price of $484.21 m-3 ($1.84 per gallon), and assuming other factors remain unchanged, the estimated net present value (NPV) for the 0.076 hm3y-1 plant is $41.54 million. By comparison, the estimated NPV for the 0.038 hm3y-1 plant is only $8.30 million. Other factors such as changes in prices of co-products and utilities have a relatively minor effect on investment viability. -- Highlights: → Sugar beets and beet molasses costs account for more than 70 percent of total production expenses. → The estimated breakeven ethanol prices for the 0.076 hm3y-1 and 0.038 hm3y-1ethanol plants are $400 m-3 and $450 m-3 respectively. → The price of ethanol will be one of the most important factors for determining the future feasibility of a sugar-beet-based ethanol plant in North

  1. Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data

    OpenAIRE

    Jiu Jimmy Jiao; Xiaotao Zhang; Yi Liu; Xingxing Kuang

    2015-01-01

    Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan ...

  2. Managing drought risk with a computer model of the Raritan River Basin water-supply system in central New Jersey

    Science.gov (United States)

    Dunne, Paul; Tasker, Gary

    1996-01-01

    The reservoirs and pumping stations that comprise the Raritan River Basin water-supply system and its interconnections to the Delaware-Raritan Canal water-supply system, operated by the New Jersey Water Supply Authority (NJWSA), provide potable water to central New Jersey communities. The water reserve of this combined system can easily be depleted by an extended period of below-normal precipitation. Efficient operation of the combined system is vital to meeting the water-supply needs of central New Jersey. In an effort to improve the efficiency of the system operation, the U.S. Geological Survey (USGS), in cooperation with the NJWSA, has developed a computer model that provides a technical basis for evaluating the effects of alternative patterns of operation of the Raritan River Basin water-supply system. This fact sheet describes the model, its technical basis, and its operation.

  3. Evolution of Meso-Cenozoic lithospheric thermal-rheological structure in the Jiyang sub-basin, Bohai Bay Basin, eastern North China Craton

    Science.gov (United States)

    Xu, Wei; Qiu, Nansheng; Wang, Ye; Chang, Jian

    2016-07-01

    The Meso-Cenozoic lithospheric thermal-rheological structure and lithospheric strength evolution of the Jiyang sub-basin were modeled using thermal history, crustal structure, and rheological parameter data. Results indicate that the thermal-rheological structure of the Jiyang sub-basin has exhibited obvious rheological stratification and changes over time. During the Early Mesozoic, the uppermost portion of the upper crust, middle crust, and the top part of the upper mantle had a thick brittle layer. During the early Early Cretaceous, the top of the middle crust's brittle layer thinned because of lithosphere thinning and temperature increase, and the uppermost portion of the upper mantle was almost occupied by a ductile layer. During the late Early Cretaceous, the brittle layer of the middle crust and the upper mantle changed to a ductile one. Then, the uppermost portion of the middle crust changed to a thin brittle layer in the late Cretaceous. During the early Paleogene, the thin brittle layer of the middle crust became even thinner and shallower under the condition of crustal extension. Currently, with the decrease in lithospheric temperature, the top of the upper crust, middle crust, and the uppermost portion of the upper mantle are of a brittle layer. The total lithospheric strength and the effective elastic thickness (T e) in Meso-Cenozoic indicate that the Jiyang sub-basin experienced two weakened stages: during the late Early Cretaceous and the early Paleogene. The total lithospheric strength (approximately 4-5 × 1013 N m-1) and T e (approximately 50-60 km) during the Early Mesozoic was larger than that after the Late Jurassic (2-7 × 1012 N m-1 and 19-39 km, respectively). The results also reflect the subduction, and rollback of Pacific plate is the geodynamic mechanism of the destruction of the eastern North China Craton.

  4. Structural style of the Appalachian Plateau fold belt, north-central Pennsylvania

    Science.gov (United States)

    Mount, Van S.

    2014-12-01

    New seismic and well data from hydrocarbon exploration and development activity associated with the Marcellus Formation shale gas play in north-central Pennsylvania provide insight to the structural style of the Appalachian Plateau fold belt in the region north and northwest of the Allegheny structural front in Potter, Tioga, Bradford, Sullivan, Lycoming, Clinton and Centre counties. The Plateau fold belt in this area developed over a detachment in Upper Silurian Salina Group evaporites during the Permian Alleghanian Orogeny in response to north-northwest directed shortening. At the Allegheny structural front, a deep detachment in Cambrian shales that underlies the Valley and Ridge province to the south-southeast, ramps up-section through Cambro-Ordovician carbonates and Lower-Middle Silurian clastics to a shallow detachment in Upper Silurian evaporites. At the northeastern plunge of the Nittany Anticline (south and east of Williamsport, PA), only a small amount of slip is interpreted to have been transmitted into the foreland on the shallow Upper Silurian detachment. Instead most slip was consumed in fault-propagation folds immediately north of the Allegheny structural front. The Plateau fold belt, developed above the Upper Silurian evaporites, can be divided into structural domains based on fold characteristics. Domain 1 folds have short wavelengths and low amplitudes. Domain 2 salt-cored anticlines have long wavelengths and large amplitudes. Domain 3 comprises large synclines, located between Domain 2 anticlines. Halite originally beneath Domain 3 synclines is interpreted to have been mobilized, or evacuated, into the cores of adjacent Domain 2 anticlines during folding. Seismic data indicate that the base of the salt detachment underlying Plateau folds is a non-planar, stepped surface. Possible scenarios for the development of the non-planar detachment include: 1) mobilization of halite from an evaporite sequence that contained an originally non

  5. Tectono-sedimentary evolution of the Tertiary Piedmont Basin (NW Italy) within the Oligo-Miocene central Mediterranean geodynamics

    Science.gov (United States)

    Maino, Matteo; Decarlis, Alessandro; Felletti, Fabrizio; Seno, Silvio

    2013-06-01

    analyze the tectono-sedimentary and thermochronometric constraints of the Tertiary Piedmont Basin (TPB) and its adjoining orogen, the Ligurian Alps, providing new insights on the basin evolution in response to a changing geodynamic setting. The geometry of the post-metamorphic faults of the Ligurian belt as well as the fault network that controlled the Oligo-Miocene TPB deposition has been characterized through a detailed structural analysis. Three main faulting stages have been distinguished and dated thanks to the relationships among faults and basin stratigraphy and thermochronometric data. The first stage (F1, Rupelian-Early Chattian) is related to the development of extensional NNW-directed faults, which controlled the exhumation of the orogen and the deposition of nearshore clastics. During the Late Chattian, the basin drowning is marked by mudstones and turbidites, which deposition was influenced by the second faulting stage (F2). This phase was mainly characterized by NE- to ENE-striking faults developed within a transtensional zone. Since the Miocene, the whole area was dominated by transpressive tectonics. The sedimentation was represented by a condensed succession followed by a very thick, turbiditic complex. At the regional scale, this succession of events reflects the major geodynamic reorganization in the central Mediterranean region during the Oligo-Miocene times, induced by the late-collisional processes of the Alps, by the eastward migration of the Apennines subduction and by the opening of extensional basins (i. e., the Liguro-Provençal Ocean).

  6. Concave slab out board of the Tonga subduction zone caused by opposite toroidal flows under the North Fiji Basin

    Science.gov (United States)

    Martin, A. K.

    2014-05-01

    An alternative scenario is proposed for the origin of a concave NE-facing slab under the North Fiji Basin between the Tonga subduction slab and Vanuatu Arc. During rollback of the Australian Plate, Vanuatu Arc rotated clockwise, whereas Fiji Platform rotated counterclockwise from 12/10 Ma until 1.5 Ma ago. Thereafter, only Vanuatu Arc rotated until the present. During the period of opposite rotations, toroidal flows entered the mantle around the northwest slab edge of Vanuatu Arc and from the northeast slab edge of Fiji Platform. The latter lies close to the northern end of the Tonga slab where arc-parallel flows are shown by volcanic geochemistry and mantle anisotropy. Opposite toroidal flows with upwelling and downwelling components generate the concave form of the combined Vanuatu/Fiji Platform slab, match its extent to mapped deep seismicity, explain its position overlying the Tonga slab, provide a mechanism for high heat flow in the North Fiji Basin as well as enriched MORB and OIB basalts in the northern NFB, and obviate slab collisions invoked to produce slab curvature.

  7. Ecological and environmental water demand of the lakes in the Haihe-Luanhe Basin of North China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The purpose of this paper is to present a brief concept of the ecological and environmental water demand of lake. The present situation and affecting factors of lake ecological system in the Haihe-Luanhe Basin of North China was analyzed. The calculating method of the ecological and environmental water demand of the lake basis on the water body and the calculating method of the ecological and environmental water demand of the lake basis on the aquatic ecosystem, wetland and vegetation were compared and discussed. As the examples of Baiyangdian Lake and Beidagang Lake in Haihe-Luanhe river basin, the ecological and environmental water demand of the two lakes was calculated to be 27× 108m3 . It is 6.75 times to the water demand according to the calculating method of the ecological and environmental water demand of the lake basis on the water body. The research result indicated: ( 1 ) The calculating methods of the ecological and environmental water demand of the lake basis on the aquatic ecosystem should be better than only basis on the water body of lake. (2) The data, such as area of the vegetation kind around and in the lake, the vegetation coefficient, the evaporating amount of the vegetation and the vegetation water demand itself around and in the lake are lack and urgent need. Some suggestions for controlling and regulating the water resource of the lake in North China were proposed.

  8. Quantitative and qualitative vulnerability of the Makutupora basin aquifer Dodoma, central Tanzania

    International Nuclear Information System (INIS)

    The rapid development of Dodoma town has raised demand for water for domestic, irrigation and industrial use. Uncontrolled human activities pose threat of contamination of the well field and damage to recharge areas of Makutupora basin. Monitoring data collected over the years indicate that the basin is overpumped in dry years and that peripheral boreholes register high nitrate levels from nearby settlements and intensive use of agrochemicals on farms within the basin

  9. A note on chemical composition and origin of ferromanganese oxide coated and uncoated pumice samples from central Indian Ocean basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.; Moraes, C.; Rajalakshmi, R.; Lekshmi, S.; Athira, S.; JaiSankar, S.

    the physical properties of pumice such as density, specific gravity, porosity, void ratio and degree of saturation. Detailed studies related to chemical composition of both coated and uncoated pumice from CIOB are rare (Pattan et al, 2008). The objective..., N. G., IYER, S. D. and ILANGOVAN, D. (2011) Physical properties, morphology and petrological characteristics of pumices from the Central Indian Ocean Basin. Acta Geologica Sinica., v. 85, pp. 826-839. KAY, S. M. (2001) Tertiary to Recent...

  10. A coupled empirical approach for rainfall and land use correlation to landslide occurrence in the Esino river basin, central Italy

    OpenAIRE

    E. Gioia; T. Carone; F. Marincioni

    2015-01-01

    A coupled empirical approach for studying possible correlations among rainfall, vegetation segmentation and landslide occurrence is discussed. To reveal such links two important rainfall events, occurred over the Esino river basin in central Italy, in November 2013 and May 2014, were analysed. The correlation between rainfall and landslides was carried out applying an intensity–duration (ID) threshold method, whereas the correlation between vegetation segmen...

  11. Geochemical characteristics of basaltic rocks from the Nain ophiolite (Central Iran); constraints on mantle wedge source evolution in an oceanic back arc basin and a geodynamical model

    Science.gov (United States)

    Ghazi, Javad Mehdipour; Moazzen, Mohssen; Rahgoshay, Mohammad; Shafaii Moghadam, Hadi

    2012-10-01

    The Nain ophiolitic complex is situated at the north west of the Central Iran Micro-continent (CIM) block. The basaltic rocks of this complex consist of both mantle and crustal suites and include pegmatitic and isotropic gabbros, gabbroic-dibasic dykes, dyke swarm complex and pillow lavas. The chondrite-normalized rare earth element (REE) patterns of most of these rocks show LREE depletion and the primary mantle-normalized incompatible elements indicate depletion in HFSEs (Nb, Ta) and enrichment in LILEs. The rocks show characters of island arc tholeiite/mid-ocean ridge basalt magma types. Whole rock chemistry of the rocks shows that they are originated in an oceanic back arc basin, and subsequently have been enriched by slab-derived fluids. Abundances of HFSE and HREE in most of the basaltic samples, suggest a slow subduction rate. Opening of Nain-Baft Ocean, which was probably a marginal basin, occurred during Lower Jurassic. After generation of an inter-oceanic island arc in the Nain-Baft Ocean during the Late Jurassic, a second rifting phase started within the inter-ocean island arc during Late Cretaceous (Cenomanian-Senonian). The inter-ocean island arc was developed and formed an oceanic back arc basin, the site of generation of most of the Nain ophiolitic rocks. The Nain-Baft Ocean finally closed in Maastrichtian. According to the new tectono-magmatic evolution model proposed here, the arc volcanic-like magmas were produced at the early stage (producing gabbros, gabbroic-diabasic dykes and dyke swarm complex) and then MORB-like basalts (producing pillow lavas) were generated at the later stage of evolution of the Nain ophiolitic complex.

  12. Neogene north American-Caribbean plate boundary across Northern Central America: Offset along the polochic fault

    Science.gov (United States)

    Burkart, Burke

    1983-12-01

    The Polochic fault was a segment of the North American-Caribbean plate boundary across Central America in the Neogene. Its 130 km of left slip was previously determined by matching structures and stratigraphie outcrop patterns of northwest and central Guatemala across the fault. Additional support for the model and the youthfulness of the recorded offset comes from an essentially perfect match of major geomorphic features across the fault. A reconstruction process which eliminates 123 km of left slip brings together rivers and drainage divides that existed before the Polochic became active. With the reconstruction carried across the isthmus on an east-west fault the regional structural geology assumes the coherent pattern of a continuous orogenic belt whose geometry is compatible with the model of collisional tectonics centered on the Motagua "suture zone". Confined within this belt, narrowed to some 60 km by the reconstruction, lie the major Laramide thrusts, folds and tectonically emplaced serpentinites of Guatemala. Crystalline rocks of Guatemala re-join the Chiapas Massif and Paleozoic sedimentary rocks, exposed in the core of an almost-continuous anticlinorium, extend from southern Chiapas to Lake Izabal. The Polochic does not bend in eastern Guatemala but continues eastward to the Motagua fault where it dies. Westward drift of the northern block resulted in rifting which extended from eastern Guatemala into the Caribbean along the Cayman trough. The Honduras depression may represent an element of a triple junction along with the Polochic and Izabal-Cayman rift. The Polochic continues westward into the Pacific Ocean and offsets the Middle America trench. The Polochic has offset the Miocene volcanic belt of northern Central America, confirming the previous estimate of a Neogene time of movement. About 300 km of relative east-west Neogene displacement has been recorded on the Mid-Cayman rise, only 130 km of which can be accounted for across the Polochic. It is

  13. Vectors and malaria transmission in deforested, rural communities in north-central Vietnam

    Directory of Open Access Journals (Sweden)

    Do Manh Cuong

    2010-09-01

    Full Text Available Abstract Background Malaria is still prevalent in rural communities of central Vietnam even though, due to deforestation, the primary vector Anopheles dirus is uncommon. In these situations little is known about the secondary vectors which are responsible for maintaining transmission. Basic information on the identification of the species in these rural communities is required so that transmission parameters, such as ecology, behaviour and vectorial status can be assigned to the appropriate species. Methods In two rural villages - Khe Ngang and Hang Chuon - in Truong Xuan Commune, Quang Binh Province, north central Vietnam, a series of longitudinal entomological surveys were conducted during the wet and dry seasons from 2003 - 2007. In these surveys anopheline mosquitoes were collected in human landing catches, paired human and animal bait collections, and from larval surveys. Specimens belonging to species complexes were identified by PCR and sequence analysis, incrimination of vectors was by detection of circumsporozoite protein using an enzyme-linked immunosorbent assay. Results Over 80% of the anopheline fauna was made up of Anopheles sinensis, Anopheles aconitus, Anopheles harrisoni, Anopheles maculatus, Anopheles sawadwongporni, and Anopheles philippinensis. PCR and sequence analysis resolved identification issues in the Funestus Group, Maculatus Group, Hyrcanus Group and Dirus Complex. Most species were zoophilic and while all species could be collected biting humans significantly higher densities were attracted to cattle and buffalo. Anopheles dirus was the most anthropophilic species but was uncommon making up only 1.24% of all anophelines collected. Anopheles sinensis, An. aconitus, An. harrisoni, An. maculatus, An. sawadwongporni, Anopheles peditaeniatus and An. philippinensis were all found positive for circumsporozoite protein. Heterogeneity in oviposition site preference between species enabled vector densities to be high in both

  14. Imaging of the seismogenic source fault in the fold-and-thrust belt, Niigata basin, central Japan

    Science.gov (United States)

    Kato, N.; Sato, H.; Abe, S.; Kawai, N.; Saito, H.; Iwasaki, T.; Shiraishi, K.; Ishiyama, T.; Inaba, M.

    2010-12-01

    Associated with the opening of the Japan Sea, volcanic rift-basins have been developed along the Japan Sea coast of northern Honshu. The Niigata basin, central Japan, is one of such basins and filled by thick (faulting. Due to thick Neogene sediments, relationship between active faults/folds at near the surface and deep-sited seismogenic source faults is poorly understood. To reveal the crustal structure, in particular geometry of source faults, onshore-offshore integrated deep seismic profiling was undertaken along the three seismic lines in 2008, 2009 and 2010. The 2009 Aizu-Sado Seismic line is a 135-km-long, onshore-offshore seismic line across Niigata basin and Sado island, which is located in the eastern part of Japan Sea. The 2008 Sanjo-Yahiko Seismic line is located 20 km south of the seismic line and trending parallel to it. The 2010 Higashiyama-Mishima seismic line cut through the northern part of the epicentral area of the 2007 Chuetsu-oki earthquake. The seismic sources were air-gun (3020 cu. inch), four vibroseis trucks and explosives (cables, cable-connected-recording system and offline recorders, forming a maximum 2400 channels receiver array. The basin fill consists of early to middle Miocene volcaniclastic rocks and overlying Neogene sedimentary rocks showing upward coarsening facies deposited under bathyal to fluvial environment. Main features of basin development, such as early Miocene normal faulting, associated with the formation of Japan Sea, and shortening deformation since the Pliocene, are well demonstrated on the seismic sections. Particularly, boundary between pre-Tertiary meta-sedimentary rocks and Miocene felsic volcanics were identified by velocity profiles deduced by diving wave tomography and they enabled us to identify the geometry of extensional rift-basin. Fault reactivation of Miocene normal faulting to subsequent reverse faulting is common style of deformation. The fault reactivation processes of the eastern boundary fault of

  15. Mineral-magnetic signal of long-term climatic variation in Pleistocene fluvio-lacustrine sediments, Nihewan Basin (North China)

    Science.gov (United States)

    Ao, Hong

    2010-11-01

    The Nihewan Basin (around 40°N, North China) is a major focus of investigations into hominid occupation in the eastern Asia during the early Pleistocene, thus the paleoenvironmental evolution in this area is crucial for understanding of early human habitation at high northern latitudes of East Asia. To retrieve reliable long-term paleoenvironmental signals from the Nihewan fluvio-lacustrine sequences, I conduct an environmental magnetic investigation on the Pleistocene Xiantai fluvio-lacustrine sequence at the eastern margin of the Nihewan Basin. Results suggest that there exist an up-section decreasing trend in magnetic mineral concentration and grain size, which is attributed to a long-term decrease in abundance of magnetic minerals in the catchments and in transportation of detrital magnetic minerals into the Nihewan paleolake. I further reveal that these long-timescale variations are related to a long-term decrease in East Asian monsoon precipitation and humidity in the Nihewan Basin during the Pleistocene. This paleoclimate inference is consistent with the increasing aridification in Asian mainland during the Pleistocene, an important climate response to increasing global ice volume.

  16. Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    Science.gov (United States)

    Andreani, L.; Gloaguen, R.

    2016-01-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. We intend to characterize and understand the complex tectonic setting that produced an intricate pattern of landscapes using tectonic geomorphology, as well as available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in a transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low-amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes. Lower reaches adjust to new base-level conditions and are characterized by multiple knickpoints. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos forearc sliver and (2) the compression along the northern tip of the Central American volcanic arc. Although most of the shortening between the Cocos forearc sliver and the North American Plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén Basin.

  17. Geomorphic analysis of transient landscapes from the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    Science.gov (United States)

    Andreani, L.; Gloaguen, R.

    2015-09-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. The complex tectonic setting produced an intricate pattern of landscapes that we try to systemize using remote sensing tectonic geomorphology and available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes while lower segments characterized by multiple knickpoints, that adjust to new base-level conditions. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos fore-arc sliver, and (2) the compression along the northern tip of the Central America Volcanic Arc. Although most of the shortening between the Cocos fore-arc sliver and the North American plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén basin.

  18. Statistical prediction of seasonal discharge in the Naryn basin for water resources planning in Central Asia

    Science.gov (United States)

    Apel, Heiko; Gafurov, Abror; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Merkushkin, Aleksandr; Merz, Bruno

    2016-04-01

    The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt water of the rivers originating in the mountains provides the only water resource available for agricultural production but also for water collection in reservoirs for energy production in winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources.. In fact, seasonal forecasts are mandatory tasks of national hydro-meteorological services in the region. Thus this study aims at a statistical forecast of the seasonal water availability, whereas the focus is put on the usage of freely available data in order to facilitate an operational use without data access limitations. The study takes the Naryn basin as a test case, at which outlet the Toktogul reservoir stores the discharge of the Naryn River. As most of the water originates form snow and glacier melt, a statistical forecast model should use data sets that can serve as proxy data for the snow masses and snow water equivalent in late spring, which essentially determines the bulk of the seasonal discharge. CRU climate data describing the precipitation and temperature in the basin during winter and spring was used as base information, which was complemented by MODIS snow cover data processed through ModSnow tool, discharge during the spring and also GRACE gravimetry anomalies. For the construction of linear forecast models monthly as well as multi-monthly means over the period January to April were used to predict the seasonal mean discharge of May-September at the station Uchterek. An automatic model selection was performed in multiple steps, whereas the best models were selected according to several performance measures and their robustness in a leave-one-out cross validation. It could be shown that the seasonal discharge can be predicted with

  19. Tomographic images of subducted oceans matched to the accretionary records of orogens - Case study of North America and relevance to Central Asia

    Science.gov (United States)

    Sigloch, Karin; Mihalynuk, Mitchell G.; Hosseini, Kasra

    2016-04-01

    Accretionary orogens are the surface record of subduction on the 100-million-year timescale; they aggregate buoyant crustal welts that resisted subduction. The other record of subduction is found in the deep subsurface: oceanic lithosphere preserved in the mantle that records ocean basin closure between successive generations of arcs. Seismic tomography maps out these crumpled paleo-oceans down to the core-mantle boundary, where slab accumulates. One such accumulation of enormous scale is under Eastern Asia, recording the assembly of the Central Asian Orogenic Belt (CAOB). Deep CAOB slab has hardly been explored because tomographic image resolution in the lowermost mantle is limited, but this is rapidly improving. We present new images of the CAOB slabs from our P-wave tomography that includes core-diffracted waves as a technical novelty. The previous slab blur sharpens into the type of elongated geometries expected to trace paleo-trench lines. Since the North American Cordillera is younger than the CAOB (mostly 10,000 km long. North America converged on the two microcontinents by westward subduction of two intervening basins (which we name Mezcalera and Angayucham oceans), culminating in diachronous suturing between ~150 Ma and ~50 Ma. Hence geophysical subsurface evidence negates the widely accepted "Andean-style" model of Farallon-beneath-continent subduction since at least 180 Ma, and supports a Jura-Cretaceous paleogeography closer to today's Southwestern Pacific, or to the Paleozoic CAOB. Though advocated since the 1970's by a minority of geologists, this scenario had not gained wide acceptance due to a record obscured by overprinting, margin-parallel translation, and oroclinal bending. The new subsurface evidence provides specific indications where to seek the decisive Mezcalera-Angayucham suture. The suture is evident in a trail of collapsed Jura-Cretaceous basin relics that run the length of the Cordillera. Reference: Sigloch, K., & Mihalynuk, M. G. (2013

  20. Sources and the flux pattern of dissolved carbon in rivers of the Yenisey basin draining the Central Siberian Plateau

    International Nuclear Information System (INIS)

    Frequent measurements of dissolved organic (DOC) and inorganic (DIC) carbon concentrations in rivers during snowmelt, the entire ice-free season, and winter were made in five large watersheds (15 000–174 000 km2) of the Central Siberian Plateau (Yenisey River basin). These differ in the degree of continuous permafrost coverage, mean annual air temperature, and the proportion of tundra and forest vegetation. With an annual DOC export from the catchment areas of 2.8–4.7 gC m−2 as compared to an annual DIC export of 1.0–2.8 gC m−2, DOC was the dominant component of terrigenous C released to rivers. There was strong temporal variation in the discharge of DOC and DIC. Like for other rivers of the pan-arctic and boreal zones, snowmelt dominated annual fluxes, being 55–71% for water runoff, 64–82% for DOC and 37–41% for DIC. Likewise, DOC and DIC exhibited also a strong spatial variation in C fluxes, with both dissolved C species decreasing from south to north. The rivers of the southern part of the plateau had the largest flow-weighted DOC concentrations among those previously reported for Siberian rivers, but the smallest flow-weighted DIC concentrations. In the study area, DOC and DIC fluxes were negatively correlated with the distribution of continuous permafrost and positively correlated with mean annual air temperature. A synthesis of literature data shows similar trends from west to east, with an eastward decrease of dissolved C concentrations and an increased proportion of DOC in the total dissolved C flux. It appears that there are two contemporary limitations for river export of terrigenous C across Siberia: (1) low productivity of ecosystems with respect to potentially mobilizable organic C, slow weathering rates with concomitant small formation of bicarbonate, and/or wildfire disturbance limit the pools of organic and inorganic C that can be mobilized for transport in rivers (source-limited), and (2) mobilization of available pools of C is

  1. Miocene Bahean stratigraphy in the Longzhong Basin,northern central China and its implications in environmental change

    Institute of Scientific and Technical Information of China (English)

    LI; Jijun; ZHANG; Jun; SONG; Chunhui; ZHAO; Zhijun; ZHANG; Yong; WANG; Xiuxi; ZHANG; Jianming; CUI; Qiaoyu

    2006-01-01

    Fossil mammal-riched Neogene strata are widely distributed in the southeast corner of the huge Longzhong Basin at Tianshui,Gansu Province,northern central China.Hipparion weihoense,a typical member of late Middle Miocene Bahean stage,was recently excavated at Yaodian along a well-exposed outcrop.Owing to the importance of the Bahean stage in the mammalian evolution and its potential for environmental change,we suggested a name of Yaodian Formation for the stratigraphy,which is correlated to the Bahe Formation at Lantian,Shaanxi.High resolution paleomagnetic dating of the section shows that the Yaodian Formation covers the period between 11.67 Ma and 7.43 Ma,with the site bearing Hipparion weihoense being estimated at about 10.54-10.30 Ma,providing first magnetostratigraphic chronology for the Bahean Stage.The Yaodian Formation consists of fluvial channel deposits (11.67-10.40 Ma) at the bottom,floodplain deposits in the middle (10.40-9.23 Ma) and shallow lake sediments at the top (9.23-7.43 Ma).This upward fining sequence suggests that the relief in nearby mountain ranges such as West Qinling to the south and Huajia Ling to the north was greatly reduced after long-term denudation,fluvial transport capacity was low,and finally the drainage system was disintegrated,replaced with broad-shallow lakes in which only fine sediments like mud and marlite were deposited,indicating an old stage of development of a planation surface.A remarkable shift in ecology and climatic environment was found at 7.4-7.7 Ma when paleoclimate changed from early warm humid to late dry as indicated by sedimentary facies changed from early shallow lake sequence to late eolian red clays and a former coniferous-deciduous mixed forest was replaced by grassland,leading to great growth of Hipparion Fauna of Baodean stage in the region.Therefore,it is estimated that the present high relief of Qinling and drainage pattern did not come into being until Late Pliocene in response to intensive

  2. Relationship between chemical composition and magnetic susceptibility in sediment cores from Central Indian Ocean Basin

    Indian Academy of Sciences (India)

    J N Pattan; G Parthiban; V K Banakar; A Tomer; M Kulkarni

    2008-04-01

    Three sediment cores in a north–south transect (3°N to 13°S) from different sediment types of the Central Indian Ocean Basin (CIOB) are studied to understand the possible relationship between magnetic susceptibility () and Al, Fe, Ti and Mn concentrations. The calcareous ooze core exhibit lowest (12.32 × 10-7m3 kg−1), Al (2.84%), Fe (1.63%) and Ti (0.14%), terrigenous clay core with moderate (29.9 × 10-7 m3 kg−1) but highest Al (6.84%), Fe (5.20%) and Ti (0.44%), and siliceous ooze core with highest (38.06 × 10-7 m3 kg−1) but moderate Al (4.49%), Fe (2.80%) and Ti (0.19%) contents. The distribution of and detrital proxy elements (Al, Fe, and Ti) are identical in both calcareous and siliceous ooze. Interestingly, in terrigenous core, the behaviour of is identical to only Ti content but not with Al and Fe suggesting possibility of Al and Fe having a non-detrital source. The occurrence of phillipsite in terrigenous clay is evident by the Al-K scatter plot where trend line intersects K axis at more than 50% of total K suggesting excess K in the form of phillipsite. Therefore, the presence of phillipsite might be responsible for negative correlation between and Al ( = −0.52). In siliceous ooze the strong positive correlations among , Alexc and Feexc suggest the presence of authigenic Fe-rich smectite. High Mn content (0.5%) probably in the form of manganese micronodules is also contributing to in both calcareous and siliceous ooze but not in the terrigenous core where mean Mn content (0.1%) is similar to crustal abundance. Thus, systematically records the terrigenous variation in both the biogenic sediments but in terrigenous clay it indirectly suggests the presence of authigenic minerals.

  3. Monoterpene Compositions of Three Forested Ecosystems in the Central Amazon Basin

    Science.gov (United States)

    Jardine, A.; Fuentes, J. D.; Manzi, A. O.; Higuchi, N.; Chambers, J. Q.; Jardine, K.

    2014-12-01

    Monoterpenes play fundamental roles as secondary metabolites in forested ecosystems and as gas and liquid phase secondary organic aerosol (SOA) precursors in their surrounding atmospheres. While the chemical pathways involved in ozonolysis driven SOA formation from individual monoterpene precursors is known, local and regional chemical transport models are still lacking observations of speciated monoterpenes from forested atmospheres. Here, we present high vertically resolved mixing ratio profiles of speciated monoterpenes from the ambient air of three neighboring forested ecosystems in the central Amazon Basin. Two well-drained plateau primary forests and one seasonally flooded valley forest were sampled during the afternoon hours (13:00 - 16:30) on walkup towers from the initiation of the 2013-14 wet season through the onset of the 2014 dry season (Nov 2013 - Jul 2014). Ambient mixing ratios in all three ecosystems were greatest in the upper canopy with secondary sources of some monoterpenes within the sub-canopies. Relative vertical compositions of monoterpenes did not change significantly throughout the seasons for either ecosystem type. Both ecosystem types were dominated by d-limonene (up to 1.6 ppb) with equally strong mixing ratios of alpha-pinene in the valley compared to the much weaker a-pinene mixing ratios on the plateaus (up to 200 ppt). The highly reactive cis- and trans-beta-ocimene were consistently present in both ecosystems (up to 250 ppt) with the addition of equally high camphene mixing ratios in the valley forest (up to 200 ppt) which is present in the plateau ecosystems in low quantities (50 ppt). With respect to clean atmosphere mixing ratios of 10 ppb ozone, lifetimes are below 2 hours for camphene and below 30 minutes for ocimene, suggesting a potentially large impact on local and possibly regional ozonolysis and subsequent SOA composition.

  4. A LEPS approach to the predictability of intense rain storms in the Central Mediterranean basin

    Directory of Open Access Journals (Sweden)

    S. Federico

    2008-04-01

    Full Text Available This study investigates a method for best member selection of a Limited area model Ensemble Prediction System (LEPS with the goal to increase quantitative precipitation forecast. A case study that occurred between 22-24 May 2002 over Calabria, southern Italy, is discussed.

    Mediterranean storms often develop under upper level disturbances which are usually associated with high values of potential vorticity. Anomalously high values of potential vorticity can be identified by the METEOSAT water vapor channel centered around 6.3 μm because they are associated with dark band on the METEOSAT image. This signature offers a chance to identify the upper level disturbance that can be exploited in data void countries as Calabria.

    The working hypothesis is that the uncertainty in the representation of the upper-level disturbance has a major impact on the precipitation forecast. This issue is utilized in an ensemble forecast where member forecasts are compatible with the analysis and forecast errors. These members are grouped in five clusters by a hierarchical clustering technique which utilizes the height of the dynamical tropopause to compute distances between members. Therefore the members of a cluster have a similar representation of the upper level disturbance. For each cluster a representative member is selected and its pseudo water vapor image is compared with the corresponding METEOSAT 7 water vapor image at a specific time, antecedent to the rain occurrence over Calabria. The subjective evaluation of the comparison allows to gain physical insight in the storm evolution and to select representative members which are more in agreement with the METEOSAT image.

    Results, even if for a case study, show the feasibility of the methodology that, if confirmed by further investigations, could be valuable in data void countries as the central Mediterranean basin.

  5. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  6. Multiple ash layers in late Quaternary sediments from the Central Indian Basin

    Science.gov (United States)

    Mascarenhas-Pereira, M. B. L.; Nagender Nath, B.; Iyer, S. D.; Borole, D. V.; Parthiban, G.; Jijin, R.; Khedekar, V.

    2016-04-01

    We have investigated three sediment cores collected from water depths > 5000 m along the transect 76°30‧E in close proximity to a fracture zone in the Central Indian Basin (CIB). The cores yielded five volcanic horizons of which four have visual and dispersed shards. Rhyolitic glass shards of bubble wall, platy, angular and blocky types were retrieved from various stratigraphic horizons in the cores. The abundance of glass shards, composition of bulk sediments, and 230Thexcess ages of the host sediments were used to distinguish the volcanic horizons. Of the four volcanic horizons, three are now newly reported and correspond to ages of ~ 85, 107-109 and 142-146 ka while the fourth horizon is of 70-75 ka. By using trace element ratios and Cr and Nb-based normative calculations, cryptotephra has been identified for the first time from the CIB sediment. The cryptotephra forms the fifth ash horizon and is of ~ 34 ka. A comparison with the published data on volcanic tephra in and around the Indian Ocean indicate the shard rich horizon (SRH) of 70-75 ka to resemble the Younger Toba Tuffs (YTT), while the other volcanic horizons that were deposited during different time periods do not correlate with any known marine or terrestrial records. These tephra layers have produced a tephrostratigraphic framework across the tectonically and volcanically complex regions of the CIB. Due to the lack of terrestrial equivalents of these tephra, it is hypothesized that the newly found volcanic horizons may have been derived from submarine volcanic eruptions. Multiple layers of submarine volcaniclastic deposits found at water depths as great as 5300 m reaffirm the growing belief that submarine phreatomagmatic eruptions are much more common in the intraplate region of the Indian Ocean than previously reported.

  7. Clays of volcanic – detrititus strata of North the Bohemian coal basin as a raw material for the preparation of natural mineral pigments

    Directory of Open Access Journals (Sweden)

    Pavel Rucký

    2005-11-01

    Full Text Available Raw materials which are suitable for the preparation of mineral pigments are found in the area of the North Bohemian brown coal basin. Set Experiments on a hydrocyclone were realized as a part of the technological research of the suitability of “bolus” and ochres from the North Bohemian brown coal basin to be applicated as ecological pigments. It was found that this method of processing is suitable for the preparation of the product which can serve as a mineral pigment. Produced pigments were examined concerning their application in the area of paint pigments with a positive result.

  8. Landscape Based Modeling of Nonpoint Source Nitrogen Loading in the Neuse River Basin, North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T.

    2001-01-11

    The objective of this research was to arrive at a quantitative and qualitative assessment of nonpoint sources of potential excess N under different land use/land cover (LULC) categories in the Neuse River Basin on a seasonal time scale. This assessment is being supplied to EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, for inclusion in a hydrologic model to predict seasonal fluxes of N from the terrestrial landscape to surface receiving waters and groundwater in the Neuse River Basin. The analysis was performed in the following five steps: (1) development of a conceptual model to predict potential excess N on land, (2) a literature review to parameterize N fluxes under LULC categories found in the Neuse River Basin, (3) acquisition of high resolution (15-m pixel) LULC data from EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, (4) acquisition of a soil N inventory map for the Neuse River Basin, (5) calculations of potential excess N on a seasonal basis for the entire Neuse River Basin.

  9. An experimental peri-urban basin in North-western France

    Science.gov (United States)

    Chancibault, K.; Rodriguez, F.; Mosini, M.-L.; Furusho, C.; Bocher, E.; Palaccio, M.; Palma-Lopes, S.; Letellier, L.; Benot, R.; Andrieu, H.

    2009-04-01

    Basins located in the suburbs, known as peri-urban basins, face a quick land-use change, increasing pollution and flood risks. Being neither urban nor rural basins, they have been left apart by hydrologists. Improving hydrological models taking into account both natural and anthropogenic surfaces and pathways is the objective of the French project AVuPUR. One of the two peri-urban basins chosen for this project is the Chézine basin, located in northwestern France, in the suburbs of Nantes. The Chézine basin is subject to an oceanic climate and has a quite flat topography. Whereas the upstream part of the catchment remains essentially rural, the urbanization is dense in the downstream part and under development in the medium part. The mean urbanization over the basin is about 18%. A first part of the project consists of collecting geographical and hydrological data, followed by a first hydrological data analysis. Then different spatial segmentation methods are tested based on a geomorphological analysis and ultimately hydrological models well adapted for these particular basins will be developed. Nantes Metropole supplies geographical data as roads, buildings, land-use, sewer networks, Digital Elevation Model, etc. They also have monitored Chézine basin since 2001, with a water level recorder and a rain gauge. The outlet, at the water level recorder, defines a 29 km² basin with a 15km long river. During summer 2008, additional recorders were installed, in the medium part of the basin, at the outlet of the rural subcatchment : a rain gauge and a flow meter. This will help to analyse the hydrological behaviour of the catchment, by characterizing the rainfall spatial variability over the basin and by pointing out the rural surface contribution. In autumn 2008, a geophysical experimental study was carried out, using different geophysical methods: ground penetrating radar, DC-electrical resistivity tomography and EM31 electromagnetic profiling method. The aim of this

  10. Re-Engineering Vocational and Technical Education (VTE) for Sustainable Development in North Central Geo-Political Zone, Nigeria

    Science.gov (United States)

    Sofoluwe, Abayomi Olumade

    2013-01-01

    The purpose of the study is to re-engineer vocational and technical education for sustainable development in the North Central Geo-Political Zone in Nigeria. The research design adopted was a survey inferential type. Stratified random was used to select 36 schools out of 98 schools while 920 students out of 3680 students were sampled. The data…

  11. In search of the latest danian event in a paleobathymetric transect off Kasserine Island, north-central Tunisia

    NARCIS (Netherlands)

    Sprong, J.; Kouwenhoven, T.J.; Bornemann, A.; Dupuis, C.; Speijer, R.P.; Stassen, P.; Steurbaut, E.

    2013-01-01

    Danian (lower Paleocene) sequences in north-central Tunisia are dominantly composed of marls and shales but a conspicuous, indurated glauconite-bearing marker bed is associated with the P3a–P3b transition. This glauconite bed is considered to correlate with the Latest Danian Event (LDE) described fr

  12. Tectonics of North-Central Switzerland: interpretation on the basis on regional seismics, surface geology and deep boreholes

    International Nuclear Information System (INIS)

    This report presents the methodology and results of a geological interpretation of Nagra's reflection seismic data (1982-1984) for North-Central Switzerland. The area under investigation, which is covered by the entire network of reflection seismics lines, is outlined by the towns of Schaffhausen/ Zuerich in the east and Saeckingen/Olten in the west. (author) figs., tabs., 439 refs

  13. Geochemical signatures of stream sediments within the main geological domains and terranes of North and Central Madagascar

    OpenAIRE

    Scheib, A.J.; Lapworth, D. J.; Pitfield, P.E.J.; Ralison, A.V.; Randriamananjara, T.; Rabarimanana, M.; Rafahatelo, J.-M.; Bejoma, M.

    2012-01-01

    Geochemical mapping of North and Central Madagascar was carried out using stream sediments at an average density of one sample per 11 km2. Over 50 elements were determined from some 13,300 stream sediments using a sample size fraction of

  14. 78 FR 50441 - Iowa Wetland Management District, 35 Counties in North-Central and Northwest Iowa; Environmental...

    Science.gov (United States)

    2013-08-19

    ..., which we began by publishing a notice of intent in the Federal Register (75 FR 7289) on February 18... Fish and Wildlife Service Iowa Wetland Management District, 35 Counties in North-Central and Northwest... comprehensive conservation plan (CCP) for the Iowa Wetland Management District (district, WMD) for public...

  15. "El Miedo y El Hambre": Understanding the Familial, Social, and Educational Realities of Undocumented Latino Families in North Central Indiana

    Science.gov (United States)

    Viramontez Anguiano, Ruben P.; Lopez, Anayeli

    2012-01-01

    This study explored how different ecological factors, within and outside the family, affected the educational success of the children of undocumented families. The sample consisted of 63 immigrant Latino parents (40 families) who resided in North Central Indiana. This study utilized an ethnographic research design. Findings demonstrated that…

  16. Application of ICT (Information and Communication Technology) in the Management of Universities in the North-Central State of Nigeria

    Science.gov (United States)

    Oboegbulem, Angie Ijeoma; Godwin, Ochai

    2013-01-01

    This study investigated the application of ICT (information and communication technology) in the management of universities in the north-central Nigeria. The study was a descriptive survey. The population of the study comprised 1,294 respondents in federal and state universities (763 in federal and 531 in state universities). The sample size…

  17. Central-north China precipitation as reconstructed from the Qing dynasty: Signal of the Antarctic Atmospheric Oscillation

    Science.gov (United States)

    Wang, Huijun; Fan, Ke

    2005-12-01

    Based on the long-term Central-north China precipitation (CNCP) time series reconstructed from the Qing Dynasty Official Document, the relationship between CNCP and the Antarctic Atmospheric Oscillation (AAO) in June-July is examined. The analysis yields a (significant) negative correlation of -0.22. The signal of AAO in CNCP is further studied through analyses of the atmospheric general circulation variability related to AAO. It follows that AAO-related variability of convergence and convection over the tropical western Pacific can exert impact on the circulation condition and precipitation in north China (actually, the precipitation in the Yangtze River Valley as well) through atmospheric teleconnection known as the East Asia-Pacific (or Pacific-Japan) teleconnection wave pattern. There is also an AAO-connected wave train in the vorticity field at high troposphere over Eurasia, providing an anti-cyclonic circulation in central-north China favorable to the decline of precipitation in positive phase of AAO.

  18. Suspended-sediment transport in the Big Eau Pleine River Basin, central Wisconsin

    Science.gov (United States)

    Hindall, S.M.

    1978-01-01

    Suspended-sediment yields in the Big Eau Pleine River basin are low to moderate in comparison with other drainage basins in Wisconsin. Average annual yield in the Big Eau Pleine River near Stratford is 32.tons per square mile, with an annual yield ranging from 1.0 to 64 tons per square mile. Fenwood Creek at Bradley and Freeman Creek at Halder, two smaller tributary basins, have average annual yields of 3.3 and 7.9 tons per square mile, respectively. Suspended-sediment concentrations in the basin ranged from 0 to 960 milligrams per liter, with a median concentration at the Stratford site of 13 milligrams per liter. Ninety percent of the material transported by the streams of the Big Eau Pleine basin is finer than sand and is made up of about equal percentages of silt and clay.

  19. Geochemical fractionation of Ni, Cu and Pb in the deep sea sediments from the Central Indian Ocean Basin: An insight into the mechanism of metal enrichment in sediment

    Digital Repository Service at National Institute of Oceanography (India)

    Sensarma, S.; Chakraborty, P.; Banerjee, R.; Mukhopadhyay, S.

    Metal speciation study in combination with major element chemistry of deep sea sediments provided possible metal enrichment pathways in sediments collected from environmentally different locations of Central Indian Ocean Basin (CIB). Metal...

  20. Relationship between size and geochemistry of polymetallic nodules from the Central Indian Ocean Basin: Significance in selection of high grade nodules

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Ambre, N.V.

    Morphological, mineralogical and geochemical studies on nodules of different sizes collected from the Central Indian Ocean Basin (CIOB) show two suits of nodule formation by oxic diagenetic and hydrogenous process resulting into distinct properties...

  1. Fine-scale distribution modeling of avian malaria vectors in north-central Kansas.

    Science.gov (United States)

    Ganser, Claudia; Gregory, Andrew J; McNew, Lance B; Hunt, Lyla A; Sandercock, Brett K; Wisely, Samantha M

    2016-06-01

    Infectious diseases increasingly play a role in the decline of wildlife populations. Vector-borne diseases, in particular, have been implicated in mass mortality events and localized population declines are threatening some species with extinction. Transmission patterns for vector-borne diseases are influenced by the spatial distribution of vectors and are therefore not uniform across the landscape. Avian malaria is a globally distributed vector-borne disease that has been shown to affect endemic bird populations of North America. We evaluated shared habitat use between avian malaria vectors, mosquitoes in the genus Culex and a native grassland bird, the Greater Prairie-Chicken (Tympanuchus cupido), by (1) modeling the distribution of Culex spp. occurrence across the Smoky Hills of north-central Kansas using detection data and habitat variables, (2) assessing the occurrence of these vectors at nests of female Greater Prairie-Chickens, and (3) evaluating if shared habitat use between vectors and hosts is correlated with malarial infection status of the Greater Prairie-Chicken. Our results indicate that Culex occurrence increased at nest locations compared to other available but unoccupied grassland habitats; however the shared habitat use between vectors and hosts did not result in an increased prevalence of malarial parasites in Greater Prairie-Chickens that occupied habitats with high vector occurrence. We developed a predictive map to illustrate the associations between Culex occurrence and infection status with malarial parasites in an obligate grassland bird that may be used to guide management decisions to limit the spread of vector-borne diseases. PMID:27232133

  2. An assessment of the SSC impact on the training and employment needs of North Central Texas

    International Nuclear Information System (INIS)

    The Texas Higher Education Coordinating Board has funded the Navarro College/Dallas County Community College Districe SSC Technical Training Project to determine the direct and inderect manpower needs in the eighteen-county North Cenbtral Texas area surrounding the Superconducting Super Collider Laboratory (SSCL) and to identify training programs to be developed by local community colleges. The tasks of this project were specifically designed to maximize the use of existing informatiion resources of various organizations and agencies concerned with lobor force development issues to provide custom databases focusied upon the SSCL. The labor market informataion (LMI) resources developed in this project provide a strong foundation for examining the impacts of the SSCL on the training and employment needs of the North Central Texas region. The direct and indirect effects of the SSCL are analyzed to the smallest level of occupational detail feasible. Regional labor demand estimates and forecasts were updated and expanded, county level demand data was developed, statewide vocational education programs were inventoried and lists of affected regional employers were extracted. All of the data developed in this project is available in standard Dbase disk files, formatted to be compatible with other LMI resources such as INTERLINK's LMIS. Further, a custom version of INTERLINK's PC-based LMIS software was developed for the SSC Technical Training Project to provide the greatest access to and linkage between the labor demand and supply data developed in this study. Future efforts to develop additional information resources relevant to the event of the SSCL must focus upon comparative analyses of similar projects, such as Fermilab and others, to provide more detail to the products developed in this project

  3. 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

    Science.gov (United States)

    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

  4. Integrated well log and 2-D seismic data interpretation to image the subsurface stratigraphy and structure in north-eastern Bornu (Chad) basin

    Science.gov (United States)

    Isyaku, Aminu A.; Rust, Derek; Teeuw, Richard; Whitworth, Malcolm

    2016-09-01

    Structural and stratigraphic mapping within the Bornu Basin in north east Nigeria was commonly carried out using traditional field geological methods. However, such traditional approaches remain inadequate in the semi-arid region characterised by topographically flat areas and lack of continuous bedrock outcrops that are mostly concealed beneath sand cover. Previous studies in the north-eastern part of the basin carried out using ditch cuttings from few wells and disconnected seismic data were largely inadequate and the resulting stratigraphic analyses were more often generalised. This paper presents an integrated structural and stratigraphic study of the basin using combined subsurface geophysical datasets. A Combined Log Pattern (CLP) method is a well log analysis, which utilises various well log data including gamma ray, resistivity, bulk density and sonic logs to identify lithology and stratigraphic boundaries of subsurface formations. This method is applied to constrain the subsurface stratigraphy of the north-eastern part of the Bornu Basin bordering the Lake Chad. In addition to qualitative combined well log analysis, the time-depth relationship of the sonic log and seismic data was quantitatively determined by tying a well with an intersecting seismic section to validate the stratigraphic facies horizons identified. Four well log facies and their environments of deposition were characterised from the combined well log analysis of the different log types. It is discovered that the Cretaceous basement structural features controlled the deposition of overlying formations in the basin. Without intact core data, the shallower wells were discovered to have bottomed over subsurface horst features while deeper wells penetrated into the basal facies contained mainly within the grabens. Main subsurface structural lineaments in the area include NW-SE, NE-SW and NNW-SSE trending faults, which mainly formed the horst and graben features. Some stratigraphic formations

  5. GIS Representation of Coal-Bearing Areas in North, Central, and South America

    Science.gov (United States)

    Tewalt, Susan J.; Kinney, Scott A.; Merrill, Matthew D.

    2008-01-01

    Worldwide coal consumption and international coal trade are projected to increase in the next several decades (Energy Information Administration, 2007). A search of existing literature indicates that in the Western Hemisphere, coal resources are known to occur in about 30 countries. The need exists to be able to depict these areas in a digital format for use in Geographic Information System (GIS) applications at small scales (large areas) and in visual presentations. Existing surficial geology GIS layers of the appropriate geologic age have been used as an approximation to depict the extent of coal-bearing areas in North, Central, and South America, as well as Greenland (fig. 1). Global surficial geology GIS data were created by the U.S. Geological Survey (USGS) for use in world petroleum assessments (Hearn and others, 2003). These USGS publications served as the major sources for the selection and creation of polygons to represent coal-bearing areas. Additional publications and maps by various countries and agencies were also used as sources of coal locations. GIS geologic polygons were truncated where literature or hardcopy maps did not indicate the presence of coal. The depicted areas are not adequate for use in coal resource calculations, as they were not adjusted for geologic structure and do not include coal at depth. Additionally, some coal areas in Central America could not be represented by the mapped surficial geology and are shown only as points based on descriptions or depictions from scientific publications or available maps. The provided GIS files are intended to serve as a backdrop for display of coal information. Three attributes of the coal that are represented by the polygons or points include geologic age (or range of ages), published rank (or range of ranks), and information source (published sources for age, rank, or physical location, or GIS geology base).

  6. Hydrologic Sensitivities of Upper Indus Basin (North Pakistan) Rivers to Multi-Decadal Climatic Variability

    Science.gov (United States)

    Farhan, S. B.; Zhang, Y.; Ma, Y.; Haifeng, G.; Jilani, R.; Hashmi, D.; Rasul, G.

    2014-12-01

    Thermal inputs play a vital role in the management and seasonal distribution of stream-flows particularly in snow and glacier fed basins, therefore the signatures of the recent climate trends can also be observed in various hydrological variables in those basins. Upper Indus Basin (UIB) is located in the western part of Tibetan Plateau, and most of its flows are dependent on snow- and glacier-melt produced water, thus the analyses of historical stream-flows and climatic indicators in the snow-melt dominated rivers of UIB was carried out, which points towards an advance in the spring flow onset time over the past few decades. Trend results reveal that warm temperature spells in spring have occurred much earlier in recent years, which explains in part the trend in the timing of spring peak stream-flows owing to earlier occurrence of snow melt onset. The observed increase in spring stream-flows and decrease in summer stream-flows suggests a broad shift of snow-melt yield and spring peak flows. These trends are found to be strongest at lower elevations basins where winter temperatures are closer to the melting point, even modest variation in temperatures are capable to enforce large shifts in the basin hydrologic feedback. In addition, it appears that in recent years due to winter and spring warming, more of the precipitation is falling as rain rather than snow particularly in late winter and early spring seasons, consequently it is speculated that this shift in precipitation ratio (snow vs rain) and early warming spells might also affect local (basin-scale) Albedo via early recession and systematic decrease of snow cover area, which tends in lowering Albedo from an increased fraction of snow-free area, which instigate positive feedback on radiative balance that can perhaps causes local-scale heat redistribution, which collectively in turn augmented winter and early spring stream-flows in those basins. These observed hydro-climatological trends over UIB can have

  7. Groundwater recharge history and hydrogeochemical evolution in the Minqin Basin, North West China

    International Nuclear Information System (INIS)

    The Minqin Basin is a type area for examining stress on groundwater resources in the Gobi Desert, and has been investigated here using a combination of isotopic, noble gas and chemical indicators. The basin is composed of clastic sediments of widely differing grain size and during the past half century over 10 000 boreholes have been drilled with a groundwater decline of around 1 m a-1. Modern diffuse recharge is unlikely to exceed 3 mm a-1, as determined using unsaturated zone profiles and Cl- mass balance. A small component of modern (3H-3He data, probably from irrigation returns. A clear distinction is found between modern waters with median δ 18O values of 6.5 ± 0.5 per mille and most groundwaters in the basin with more depleted isotopic signatures. Radiocarbon values as pmc range from 0.6% to 85% modern, but it is difficult to assign absolute ages to these, although a value of 20% modern C probably represents the late Pleistocene to Holocene transition. The δ 13C compositions remain near-constant throughout the basin (median value of -8.1 per mille δ 13C) and indicate that carbonate reactions are unimportant and also that little reaction takes place. There is a smooth decrease in 14C activity accompanied by a parallel increase in 4He accumulations from S-N across the basin, which define the occurrence of a regional flow system. Noble gas temperatures indicate recharge temperatures of about 5.6 deg. C for late Pleistocene samples, which is some 2-3 deg. C cooler than the modern mean annual air temperature and the recharge temperature obtained from several Holocene samples. Groundwaters in the Minqin Basin have salinities generally below 1 g/L and are aerobic, containing low Fe but elevated concentrations of U, Cr and Se (mean values of 27.5, 5.8 and 5.3 μg L-1, respectively). Nitrate is present at baseline concentrations of around 2 mg L-1 but there is little evidence of impact of high NO3 from irrigation returns. Strontium isotope and major ion ratios

  8. Rock-Eval pyrolysis and vitrinite reflectance results from the Sheep Creek 1 well, Susitna basin, south-central Alaska

    Science.gov (United States)

    Stanley, Richard G.; Lillis, Paul G.; Pawlewicz, Mark J.; Haeussler, Peter J.

    2014-01-01

    We used Rock-Eval pyrolysis and vitrinite reflectance to examine the petroleum source potential of rock samples from the Sheep Creek 1 well in the Susitna basin of south-central Alaska. The results show that Miocene nonmarine coal, carbonaceous shale, and mudstone are potential sources of hydrocarbons and are thermally immature with respect to the oil window. In the samples that we studied, coals are more organic-rich and more oil-prone than carbonaceous shales and silty mudstones, which appear to be potential sources of natural gas. Lithologically similar rocks may be present in the deeper parts of the subsurface Susitna basin located west of the Sheep Creek 1 well, where they may have been buried deeply enough to generate oil and (or) gas. The Susitna basin is sparsely drilled and mostly unexplored, and no commercial production of hydrocarbons has been obtained. However, the existence of potential source rocks of oil and gas, as shown by our Rock-Eval results, suggests that undiscovered petroleum accumulations may be present in the Susitna basin.

  9. Hydrogeology and hydrogeochemistry at a site of strategic importance: the Pareja Limno-reservoir drainage basin (Guadalajara, central Spain)

    Science.gov (United States)

    Molina-Navarro, Eugenio; Sastre-Merlín, Antonio; Vicente, Rosa; Martínez-Pérez, Silvia

    2014-08-01

    A small calcareous basin in central Spain was studied to establish the role of groundwater in the Pareja Limno-reservoir. Limno-reservoirs aim to preserve a constant water level in the riverine zone of large reservoirs to mitigate the impacts arising from their construction. Groundwater flow contribution (mean 60 %) was derived by recharge estimation. In situ measurements (spring discharge, electrical conductivity and sulfate) were undertaken and spring discharge was compared with a drought index. Twenty-eight springs were monitored and three hydrogeological units (HGUs) were defined: a carbonate plateau (HGU1), the underlying aquitard (HGU2), and the gypsum-enriched HGU3. HGU1 is the main aquifer and may play a role in the preservation of the limno-reservoir water level. Hydrogeochemical sampling was conducted and the code PHREEQC used to describe the main geochemical processes. Weathering and dissolution of calcite and gypsum seem to control the hydrogeochemical processes in the basin. Water progresses from Ca2+-HCO3 - in the upper basin to Ca2+-SO4 2- in the lower basin, where HGU3 outcrops. A clear temporal pattern was observed in the limno-reservoir, with salinity decreasing in winter and increasing in summer. This variation was wider at the river outlet, but the mixing of the river discharge with limno-reservoir water buffered it.

  10. Paleomagnetic and Anisotropy of Magnetic Susceptibility (AMS analyses of the Plio-Pleistocene extensional Todi basin, Central Italy

    Directory of Open Access Journals (Sweden)

    L. Alfonsi

    1997-06-01

    Full Text Available In the last few years paleomagnetic investigations within the Apennine chain have revealed that the area is characterized by a complex pattern of deformation, not linkable to a simple and homogeneous process. In order to estimate the amount, sense and timing of vertical axis rotations within the Central Apennines, Neogene continental basins have been investigated for paleomagnetic studies. The paleomagnetic results obtained in the Plio-Pleistocene Todi basin showed that the Upper Pliocene-Lower Pleistocene evolution, associated with major dip-slip tectonics, has not involved vertical axis rotation since that time. The Anisotropy of Magnetic Susceptibility analysis (AMS, carried out on the same samples treated for paleomagnetic determination, revealed the presence of two groups of specimens characterized by different magnetic lineation directions. One direction trends NE-SW and is parallel to the orientation of the regional extension stress typical of the area. This direction is observed throughout the northern basin. The other, restricted to the southern basin, trends N-S and shows no links with the tectonic, hydrological-sedimentary conditions of the area. The results of the AMS analysis will be presented and discussed in the light of the rock magnetic results and the tectonic framework of the area.

  11. Constraints on the development of Proterozoic basins in central India from 40Ar/39Ar analysis of authigenic glauconitic minerals

    Science.gov (United States)

    Conrad, J.E.; Hein, J.R.; Chaudhuri, A.K.; Patranabis-Deb, S.; Mukhopadhyay, J.; Deb, G.K.; Beukes, N.J.

    2011-01-01

    Ages of some key stratigraphic sequences in central Indian Proterozoic basins are based predominantly on lithostratigraphic relationships that have been constrained by only a few radioisotopic dates. To help improve age constraints, single grains of glauconitic minerals taken from sandstone and limestone in two Proterozoic sequences in the Pranhita-Godavari Valley and the Chattisgarh basin were analyzed by the 40Ar/39Ar incremental heating method. Analysis of the age spectra distinguishes between ages that are interpreted to reflect the time of glauconite formation, and anomalous ages that result from inherited argon or postcrystallization heating. The analyses indicate an age of 1686 ± 6 Ma for the Pandikunta Limestone and 1566 ± 6 Ma for the Ramgundam Sandstone, two units in the western belt of Proterozoic sequences in Pranhita-Godavari Valley. Glauconite from the Chanda Limestone, in the upper part of this sequence, contains inherited 40Ar but is interpreted to reflect an age of ca. 1200 Ma. Glauconite from the Somanpalli Group in the eastern belt of the Pranhita-Godavari Valley gives an age of 1620 ± 6 Ma. In the Chattisgarh basin, glauconite from two units gives disturbed ages that suggest a period of regional heating in the Chattisgarh basin at ca. 960–1000 Ma. These new ages indicate that these sequences are 200–400 m.y. older than previously recognized, which has important implications for geochemical studies of Mesoproterozoic ocean redox conditions in addition to providing important constraints on regional tectonics and lithostratigraphy.

  12. Geodynamic Drivers of Vertical Crustal Motion: Integrating Paleoaltimetry with Basin Development in the Central Andean Plateau of Southern Peru

    Science.gov (United States)

    Sundell, K. E., II; Saylor, J. E.; Lapen, T. J.; Villarreal, D. P.; Styron, R. H.; Horton, B. K.; Cardenas, J.

    2015-12-01

    Determining the spatial and temporal relationships between surface uplift, tectonic subsidence, and exhumation during periods of oblique crustal shortening is essential to discriminating geodynamic processes controlling formation of high topography in the central Andes. Although subsidence analysis is now a standard tool, paleoelevation estimation remains a challenging task, as estimates based on proxy data can be complicated by uncertainties in the relative controls of tectonics and climate. We therefore adopt an approach of combining established tools of subsidence analysis and detrital geochronology with emerging methods of volcanic glass paleoaltimetry, which enables us to explore a broad range of viable interpretations to understand the development of intermontane basins and their relationship to the development of the central Andean plateau. We investigated a suite of temporally overlapping and spatially separate Cenozoic basins spanning the east-west extent of the central Andean plateau in southern Peru. These basins contain an exceptional record of the vertical movements of this region. We calculate sediment accumulation and subsidence rates through decompaction of measured stratigraphic sections, and reconstruct past environmental conditions based on the stable isotopic composition of ancient waters preserved in hydrated volcanic glass. These data and published records of crustal shortening and exhumation show that although paleoaltimetry data in the study areas may be interpreted in various ways, they are best explained by multiple geodynamic processes driving (i) Eocene-early Miocene development of high topography in the Western Cordillera, then (ii) a pulsed middle Miocene-present building of the central Andean plateau from west to east, consistent with global climate changes as well as regional climate shifts driven by topographic development of the Andean orogen.

  13. Pleistocene pollen stratigraphy from borehole 81/34, devil's hole area, central north sea

    Science.gov (United States)

    Ekman, Sten R.

    1998-09-01

    Twelve pollen assemblage zones are identified in a 229 m deep borehole (BH 81/34) from the Devil's Hole area in the central North Sea (British sector). The sediment from this borehole is Early to Late Pleistocene in age and the observation of massulae from Azolla filiculoides in sediment with reversed polarity indicates an age younger than the Olduvai geomagnetic event for the entire sequence. The Early Pleistocene sediments were at least partly deposited in the vicinity of a river outlet and can be correlated either with the Eburonian or the Menapian cold stage and with the Bavel interglacial and the Linge glacial within the Bavelian stage in the Dutch stratigraphy. The Middle Pleistocene sequence contains an interval rich in Abies, Picea and Pinus, probably deposited during the end of either Cromerian Complex interglacial IV (Noordbergum) or possibly the Holsteinian. The uppermost 80 m of the core contains high frequencies of pre-Quaternary and deteriorated palynomorphs indicating extensive glacial or glaciofluvially reworked sediment.

  14. Radiological health assessment of natural radioactivity in the vicinity of Obajana cement factory, North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Omoniyi Matthew Isinkaye

    2015-01-01

    Full Text Available Measurements of activity concentrations of natural radionuclides in and around Obajana cement factory, North Central Nigeria have been carried out in this study to determine the activity levels of natural radionuclides in different environmental matrices in order to assess the radiological health hazards associated with the use of these matrices by the local population. A low-background Pb-shielded gamma spectroscopic counting assembly utilizing NaI (Tl detector was employed for the measurements. The results show that sediment samples have the highest activity concentrations of all the radionuclides relative to soil, farmland soil, and rock samples. The radium equivalent activity and indoor gamma dose rates together with the corresponding annual effective indoor doses evaluated were found to be lower than their permissible limits. It suffices to say, that contrary to age-long fear of radiation risks to the population in the vicinity of the cement factory, no excessive radiological health hazards either indoors and/or outdoors is envisaged. Therefore, the environmental matrices around the factory could be used without any restrictions.

  15. Forensically important calliphoridae (diptera) associated with pig carrion in rural north-central Florida

    Science.gov (United States)

    Gruner, Susan V.; Slone, D.H.; Capinera, J.L.

    2007-01-01

    A study to determine the relative abundance and seasonality of forensically important blow flies (Diptera: Calliphoridae) in rural north-central Florida was conducted using pig carcasses (Sus scrofa L.) as models for human bodies. Seven species of Calliphoridae were collected: Lucilia coeruleiviridis (=Phoenicia) (Macquart), Cochliomyia macellaria (F.), Chrysomya rufifaces (Macquart), Phormia regina (Meigen), Chrysomya megacephala (F.), and a few specimens of Calliphora livida Hall, and Calliphora vicina Robineau-Desvoidy. Species composition in aerial collections of adult flies, preserved larval collections, and samples of larvae reared to the adult stage were all highly correlated. Relative abundance of the species found was significantly different, with L. coeruleiviridis the most abundant species year-round. The relative abundance of the collected species varied significantly by day of decomposition and by season, with significant interactions between season and day, season and species, and day and species. L. coeruleiviridis, C. macellaria, C. rufifaces, and P. regina were found during the entire year, two C. vicina specimens and 11 C. livida specimens were collected from December to March, whereas C. megacephala was collected only from June through September. ?? 2007 Entomological Society of America.

  16. Bio-optical characterization in an ultra-oligotrophic region: the North central Red Sea

    KAUST Repository

    Kheireddine, Malika

    2015-04-01

    Until recently, satellite-derived ocean color observations have been the only means of evaluating optical variability of the Red Sea. During a cruise in autumn 2014, we investigated the variability of Inherent Optical Properties (IOPs) in the North Central Red Sea (NCRS) with a particular focus on the particulate backscattering coefficient, bbp, and colored dissolved organic matter, CDOM, absorption. To our knowledge, these are some of the measurements of these properties in the Red Sea. The IOPs are derived from the concentration and physical properties of suspended particles in the ocean. They provide a simple description of the influence of these particles on the light within the water column. Bio-optical relationships found for ultra-oligotrophic waters of the six stations sampled significantly depart from the mean standard relationships provided for the global ocean, showing the peculiar character of the Red Sea. These optical anomalies relate to the specific biological and environmental conditions occurring in the Red Sea ecosystem. Specifically, the surface specific phytoplankton absorption coefficients are lower than the values predicted from the global relationships due to a high proportion of relatively large sized phytoplankton. Conversely, bbp values are much higher than the mean standard values for a given chlorophyll-a concentration, Chl a. This presumably results from the influence of highly refractive submicrometer particles of Saharan origin in the surface layer of the water column.

  17. Feeding site selection by woodland caribou in north-central British Columbia

    Directory of Open Access Journals (Sweden)

    Chris J. Johnson

    2000-04-01

    Full Text Available We examined the foraging habits of the northern woodland caribou ecotype {Rangifer tarandus caribou at the scale of the individual feeding site. Field data were collected in north-central British Columbia over two winters (Dec 1996-Apr 1998. We trailed caribou and measured vegetation characteristics (species composition and percent cover, snow conditions (depth, density, and hardness, and canopy closure at terrestrial and arboreal feeding sites, and at random sites where feeding had not occurred. Logistic regression was used to determine the attributes of feeding sites that were important to predicting fine scale habitat selection in forested and alpine areas. In the forest, caribou selected feeding sites that had a greater percent cover of Cladina mitis and Cladonia spp, lower snow depths, and a lower percentage of debris and moss. Biomass of Bryoria spp. at the 1-2 m stratum above the snow significantly contributed to predicting what trees caribou chose as arboreal feeding sites. In the alpine, caribou selected feeding sites with a greater percent cover of Cladina mitis, Cladina rangiferina, Cetraria cucullata, Cetraria nivalis, Thamnolia spp., and Stereocaulon alpinum as well as lower snow depths.

  18. Pollen analysis of natural honeys from the central region of Shanxi, North China.

    Directory of Open Access Journals (Sweden)

    Xiao-Yan Song

    Full Text Available Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010-2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples included Caprifoliaceae (found in 10 samples, Laminaceae (10, Brassicaceae (12, Rosaceae (12, Moraceae (13, Rhamnaceae (15, Asteraceae (17, and Fabaceae (19. In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples, Robinia pseudoacacia (3, Vitex negundo var. heterophylla (2, Sophora japonica (1, Ailanthus altissima (1, Asteraceae type (1, and Fabaceae type (1. The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample suggested that 13 samples belonged to Group I (<20,000 pollen grains, 4 to Group II (20,000-100,000, and 2 to Group III (100,000-500,000. The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants indicated that the honey samples are of good quality and suitable for human consumption.

  19. Carbon Flux of Down Woody Materials in Forests of the North Central United States

    International Nuclear Information System (INIS)

    Across large scales, the carbon (C) flux of down woody material (DWM) detrital pools has largely been simulated based on forest stand attributes (e.g., stand age and forest type). The annual change in forest DWM C stocks and other attributes (e.g., size and decay class changes) was assessed using a forest inventory in the north central United States to provide an empirical assessment of strategic-scale DWM C flux. Using DWM inventory data from the USDA Forest Service's Forest Inventory and Analysis program, DWM C stocks were found to be relatively static across the study region with an annual flux rate not statistically different from zero. Mean C flux rates across the study area were -0.25, -0.12, -0.01, and -0.04 (Mg/ha/yr) for standing live trees, standing dead trees, coarse woody debris, and fine woody debris, respectively. Flux rates varied in their both magnitude and status (emission/sequestration) by forest types, latitude, and DWM component size. Given the complex dynamics of DWM C flux, early implementation of inventory re measurement, and relatively low sample size, numerous future research directions are suggested.

  20. Pharmaceuticals and other organic chemicals in selected north-central and northwestern Arkansas streams

    Science.gov (United States)

    Haggard, B.E.; Galloway, J.M.; Green, W.R.; Meyer, M.T.

    2006-01-01

    Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north-central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para-cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN). ?? ASA, CSSA, SSSA.

  1. Field Features And Mode Of Emplacement Of Pegmatites Of Keffi Area North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Tanko

    2015-04-01

    Full Text Available Abstract The Keffi area of North Central Nigeria hosts numerous pegmatite bodies which are related to the surrounding granitic intrusions islocated about 45 km east of the Federal Capital Territory Abuja Nigeria. Petrological investigation of the pegmatites and surrounding host rocks aimed at characterising and understanding field relations and mode of emplacement of the rocks with a view to assess their mineralisation potentials were carried out. From the field observations the pegmatites were characterised into 1 Pelitic schist-amphibolite hosted pegmatites and 2 Granitoids orthogneisses hosted pegmatites and the granites into 1 the Bakin Ayini biotite granites 2 the Angwan Madugu biotite-muscovite granites and 3 the Sabongida biotite-muscovite granites. It is clear that those discordantly emplaced in pelitic schists varied in shape and size with length and width ranging from 400-2000m and 2-20m respectively some are huge isolated sill-like and flat-lying whilst those hosted in orthogneisses are narrow ranging in length 40-1000m and width 1-4m crosscutting and vertically oriented along shear zones which suggest passive emplacement

  2. Electrifying reviews of the central North Sea area; Elektrisifiseringsvurderinger for midtre Nordsjoe

    Energy Technology Data Exchange (ETDEWEB)

    Husdal, Geir

    2012-06-15

    We conducted a site evaluation of power from land to several fields in the central North Sea. The findings are included Dagny, Edvard Grieg, Draupne and Johan Sverdrup. In addition, an unidentified future field is included in the evaluation. Unclassified cost estimates have been prepared and measures cost is calculated for a main concept based on a set of assumptions and suppositions. To check the robustness of the results and to identify which parameters the results are most sensitive to, we conducted sensitivity analyzes in which key assumptions are changed. The study shows a cost of Nok 412 Nok / tonne reduction in Co2 emissions. This is slightly higher than the sum of the current Co2 tax and quota price, but lower than the Co2 cost proposed in the white paper. Sensitivity calculations show that the cost of measures is very sensitive to investment costs, future energy demand and the price difference between gas sold on the continent and electricity from the grid in Norway. (eb)

  3. Pattern and determinants of morbidity among people living with HIV/AIDS in North Central Nigeria.

    Science.gov (United States)

    Olaleye, Adeniyi; Ogwumike, F O

    2013-02-01

    The study investigated the nature of self-reported morbidity and determinants of health status among people living with HIV/AIDS (PLWHA) in North Central Nigeria. A multi-stage cluster sampling method was used to select 1,056 adult PLWHA from 60 community-based support groups as respondents to a structured questionnaire. Based on health production function, health status was specified as a function of individual/household characteristics, health-related behaviours and genetic endowment. Descriptive statistics showed that more than half (52.8%, n=558) of the PLWHA reported illness in the last four weeks. The poor, widows and divorcees, and those living in rural areas reported illness more than their non-poor, married and urban counterparts. Logistic regression results indicated that self reported mobility was associated with rural residence (p=.005), greater use of condom (p=.013), and lower CD4 count (p=.007). Programs to promote positive living and access to health care services among PLWHA in Nigeria, especially in rural areas, are recommended. PMID:23377732

  4. Organic matter budget in a mixed-hardwood forest in north central Florida

    International Nuclear Information System (INIS)

    Organic-matter flows through a mixed-hardwood forest were analyzed as part of a study of the unusual behavior of 137Cs in Florida ecosystems. The data suggest that rates of organic-matter flow in the mixed-hardwood forest in north central Florida more closely approach those of similar systems in tropical areas than in temperate areas. Annual litterfall was 1069 g/m2; litter turnover, 1.3/year; net daytime productivity of leaves and twigs, 12.4 g m-2 day-1; nighttime respiration, 5.1 g m-2 day-1; and stem respiration, 1.4 g m-2 day-1. Constancy of litter storage (820 g/m2) and leaf fall and lack of net wood deposition indicate that the forest is in steady state. It was concluded that 137Cs accumulation in this forest is probably caused by intrinsic ecosystem processes, as previously suggested, rather than by buildup that might be expected in a successional ecosystem

  5. Hydrology and plant survival in excavated depressions near an earthen dam in north-central Texas

    Science.gov (United States)

    Williams, Lynde L.; Hudak, Paul F.

    2005-09-01

    This investigation examined plant survival and water sources for small depressions excavated to build an earthen dam and nature trail in north-central Texas, USA. These “inadvertent wetlands” occupy part of an outdoor education facility, overlying alluvial deposits of the Trinity River. A large lake behind the earthen dam strongly influences surface water and groundwater levels in the area. Excavated depressions receive direct precipitation, runoff, and groundwater inputs, losing water by seepage and evapotranspiration. Hydroperiods varied with location and water input: excavations receiving groundwater held water year round; others periodically desiccated. Groundwater-fed depressions had higher salinity; however, the highest average value (1,304 μS/cm) was within the freshwater range. A total of 66 to 75% of emergent and floating wetland species planted in three depressions survived after 2 years. The developing wetlands appear viable under hydrologic conditions typical of the study period. Ultimately, variable hydroperiods among wetlands, and water level fluctuations within individual wetlands, may foster diverse plant-species compositions. Depressed lake levels following long-term drought or increased water demands pose the greatest threat to the developing wetlands.

  6. Deleterious Emission Abatement through Structured Energy Use Pattern: A North Central Nigeria Perspective

    Science.gov (United States)

    Ajayi-Banji, Ademola; Omotosho, Olayinka; Amori, Anthony; Alao, Damilola; Igbode, Imoisime; Abimbola, Olufemi

    2016-05-01

    Holistic view of household energy consumption based on greenhouse gas emissions in the North Central cities of Nigeria was examined in this study. Scenarios considered were based on income level of energy users (low and high) and energy metering system (i.e. pre-paid and post-paid energy billing systems). Strong direct nexus was observed between energy use and emissions pattern. Energy utilization by post-paid category had higher weekly average value of 35.09 and 41.70 kWh as against 23.18 and 33.38 kWh for low and high income pre-paid consumers respectively. Energy use and greenhouse gas emissions from both classification followed similar trend. Data obtained and analysed in the study show that global warming and acidification potentials could be reduced by 33.94 and 19.95 % for low and high income category consumers when pre-paid meters are in place. Conclusively, energy system users with pre-paid metering system displayed reasonable level of management decisions that reduce energy wastage and consequently environmental negative impacts.

  7. Fallout 137Cs in cultivated and noncultivated north central United States watersheds

    International Nuclear Information System (INIS)

    The cesium (137Cs) concentrations were measured in the soils and sediments of 14 watersheds, 7 cultivated and 7 noncultivated, in the North Central United States. The 137Cs concentration in watershed soils ranged from 56 to 149 nCi/m2, with cultivated watersheds averaging 75 nCi/m2 and noncultivated watersheds averaging 104 nCi/m2. The 137Cs concentration in the reservoir sediments ranged from 74 to 1,280 nCi/m2, with a mean of 676 nCi/m2 for the cultivated watersheds and 365 nCi/m2 for the noncultivated watersheds. The 137Cs concentrations per unit area in sediments were 0.8 to 18.7 times greater than those found in the contributing watershed soils. This indicated that some 137Cs is moving within the watersheds and that the reservoirs are acting as ''traps'' or ''sinks.'' The factors accounting for the variation in 137Cs concentration in the soils and sediments of the watersheds are (i) the erosion potential of the watershed, (ii) the sites for adsorption of 137Cs, and (iii) the input of radioactivity into the watershed

  8. The performance of poultry egg farms after the 2006 avian influenza outbreak in north central, Nigeria

    Directory of Open Access Journals (Sweden)

    H.Y. Ibrahim

    2011-01-01

    Full Text Available The study assessed the performance of the poultry egg farms after the outbreak of avian influenza in 2006 in the north central part of Nigeria. Seventeen poultry (17 farms were purposefully sampled for the study. The net farm income model, simple descriptive statistics and data envelopment analysis were used as analytical tools. The result shows that the poultry farms are making profits after the losses obtained due to the outbreak of avian influenza (AVI. The revenue from eggs and spent layers constitutes 52.3 % and 47.7 % of the total revenue respectively. The medium size farms are however making higher profits and are more technically efficient than the small size poultry farms. The technical efficiency scores for the small scale farms range from 0.23-1 with a mean of 0.51, while that for the medium size farms range from 0.38-1 with a mean of 0.73. The major constraints affecting poultry egg production include; fluctuations in egg production and high cost of feeds as well as vaccines. The study concluded that the performance of poultry egg farms in Nigeria can be enhanced through improvements in technical efficiency or an increase in scale of operation. The provision of subsidies to poultry farmers by the government was however recommended to ease the high production cost.

  9. Thermocline mixing and vertical oxygen fluxes in the stratified central North Sea

    Science.gov (United States)

    Rovelli, Lorenzo; Dengler, Marcus; Schmidt, Mark; Sommer, Stefan; Linke, Peter; McGinnis, Daniel F.

    2016-03-01

    In recent decades, the central North Sea has been experiencing a general trend of decreasing dissolved oxygen (O2) levels during summer. To understand potential causes driving lower O2, we investigated a 3-day period of summertime turbulence and O2 dynamics in the thermocline and bottom boundary layer (BBL). The study focuses on coupling biogeochemical with physical transport processes to identify key drivers of the O2 and organic carbon turnover within the BBL. Combining our flux observations with an analytical process-oriented approach, we resolve drivers that ultimately contribute to determining the BBL O2 levels. We report substantial turbulent O2 fluxes from the thermocline into the otherwise isolated bottom water attributed to the presence of a baroclinic near-inertial wave. This contribution to the local bottom water O2 and carbon budgets has been largely overlooked and is shown to play a role in promoting high carbon turnover in the bottom water while simultaneously maintaining high O2 concentrations. This process may become suppressed with warming climate and stronger stratification, conditions which could promote migrating algal species that potentially shift the O2 production zone higher up within the thermocline.

  10. Drinking water and pregnancy outcome in central North Carolina: source, amount, and trihalomethane levels.

    Science.gov (United States)

    Savitz, D A; Andrews, K W; Pastore, L M

    1995-06-01

    In spite of the recognition of potentially toxic chemicals in chlorinated drinking water, few studies have evaluated reproductive health consequences of such exposure. Using data from a case-control study of miscarriage, preterm delivery, and low birth weight in central North Carolina, we evaluated risk associated with water source, amount, and trihalomethane (THM) concentration. Water source was not related to any of those pregnancy outcomes, but an increasing amount of ingested water was associated with decreased risks of all three outcomes (odds ratios around 1.5 for 0 glasses per day relative to 1-3 glasses per day, falling to 0.8 for 4+ glasses per day). THM concentration and dose (concentration x amount) were not related to pregnancy outcome, with the possible exception of an increased risk of miscarriage in the highest sextile of THM concentration (adjusted odds ratio = 2.8, 95% confidence interval = 1.1-2.7), which was not part of an overall dose-response gradient. These data do not indicate a strong association between chlorination by-products and adverse pregnancy outcome, but given the limited quality of our exposure assessment and the increased miscarriage risk in the highest exposure group, more refined evaluation is warranted. PMID:7556013

  11. Modeling susceptibility to deforestation of remaining ecosystems in North Central Mexico with logistic regression

    Institute of Scientific and Technical Information of China (English)

    L. Miranda-Aragón; E.J. Trevi(n)o-Garza; J. Jiménez-Pérez; O.A. Aguirre-Calderón; M.A. González-Tagle; M. Pompa-García; C.A. Aguirre-Salado

    2012-01-01

    Determining underlying factors that foster deforestation and delineating forest areas by levels of susceptibility are of the main challenges when defining policies for forest management and planning at regional scale.The susceptibility to deforestation of remaining forest ecosystems (shrubland,temperate forest and rainforest) was conducted in the state of San Luis Potosi,located in north central Mexico.Spatial analysis techniques were used to detect the deforested areas in the study area during 1993-2007.Logistic regression was used to relate explanatory variables (such as social,investment,forest production,biophysical and proximity factors) with susceptibility to deforestation to construct predictive models with two focuses:general and by biogeographical zone.In all models,deforestation has positive correlation with distance to rainfed agriculture,and negative correlation with slope,distance to roads and distance to towns.Other variables were significant in some cases,but in others they had dual relationships,which varied in each biogeographical zone.The results show that the remaining rainforest of Huasteca region is highly susceptible to deforestation.Both approaches show that more than 70% of the current rainforest area has high and very high levels of susceptibility to deforestation.The values represent a serious concern with global warming whether tree carbon is released to atmosphere.However,after some considerations,encouraging forest environmental services appears to be the best alternative to achieve sustainabie forest management.

  12. Sociodemographic Correlates of Choice of Health Care Services in Six Rural Communities in North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Onyemocho Audu

    2014-01-01

    Full Text Available Household expenditure on health has increasingly remained a major source of health care financing in Nigeria despite the introduction of several social health scheme policies provided by the government for meeting the health care costs of patients. Recognizing these limitations, this study assessed the type of health care services people commonly use in various illnesses and the sociodemographic correlates of the preferred health care services by household heads in six rural communities of North Central Nigeria. A cross-sectional community-based descriptive study design was used to study 154 household heads in the settlements using a multistage sampling method. Multiple logistic regressions were performed to investigate independent predictors that had significant chi-square at P<0.05. The leading causes of illness experienced by respondents were medical conditions (42.0% and 41.7% of them sought treatment from patent medicine vendors. The dominant reasons for health-seeking preferences were financial access (53.7% and proximity (48.6%. Age had a higher impact (Beta = 0.892 on the health-seeking preferences of the respondents as compared to their occupation and religion (Beta = 0.368 and −0.746, resp.. Therefore, in order to meet the health care of patients, it is pertinent that the unmet needs of patients are properly addressed by appropriate agencies.

  13. Soil properties in different types of Eucalypt Plantations in a small forested watershed, north-central Portugal

    Science.gov (United States)

    Santos, J. M.; van Beersum, S.; van Hall, I.; Bernard-Jannin, L.; Rial-Rivas, M. E.; Nunes, J. P.; Keizer, J. J.

    2012-04-01

    The main aim of the HIDRIA project is to improve the knowledge and understanding of factors and processes that determine the hydrological behaviour of forested foothills in the Caramulo mountain range, North-Central Portugal. The changes from natural forest cover to Eucalyptus plantations in the last decades in Portugal is present in Serra de Cima catchment, one of the four experimental catchments monitored within the framework of the project. The objectives of the present study are to determine the effects of these changes on soil properties, and to improve the parameterization of the SWAT model to simulate the impact of land-use changes associated with forestry practices on hydrological processes. The study catchment (Serra de Cima) is located in the Águeda Basin, draining the foothills of the Caramulo mountains east of Águeda (40°36'N, -8°20'E). The climate is wet Mediterranean with a mean annual precipitation of about 1600 mm at 445 m a.s.l. Soils are generally Umbric Leptosols (pine forest (27% of the total area). Eucalypts are managed as Short Rotation Coppices, with each stand growing during 30-36 years; trees are cut every 10-12 years and stems re-grow from roots afterwards. The eucalypt stands in the study area differ in tree age, undergoing their first, second or third rotations. Climate, soil moisture and streamflow are monitored at the catchment. The presentation will focus on the results of a field campaign done on June 2011 to characterize soil and vegetation properties for six points on eucalypt stands in different stages of growth, as well as pine stands. The parameters sampled in this campaign were selected based on a sensitivity analysis of the SWAT model, and included: tree density and diameter; Leaf Area Index (LAI); ground cover; profile description; dry bulk density; texture and rock content; organic matter content; intensity of Soil Water Repellency (Molarity of Ethanol Droplet test); and near-saturated hydraulic conductivity (mini

  14. Gamma-ray analysis for U, Th and K on bulk cutting samples from deep wells in the Danish Subbasin and the North German Basin

    International Nuclear Information System (INIS)

    A total of 1329 bulk cutting samples from deep wells in Denmark were analysed for U, Th and K by laboratory gamma-ray analysis. Contamination of the samples by drilling mud additives, mud solids and fall down was studied by means of a wash down experiment and by comparison with the total gamma-ray response from wireline logging. It is concluded that the inorganic geochemistry on bulk cutting samples must be applied with great caution. The data are useful for geochemical characterization of well sections and for regional geochemical correlation. Radioelement abundance logs and radioelement ratio logs are presented from 3 wells in the Danish Subbasin and 2 wells in the North German Basin. The radioelement geochemistry is discussed for the successive lithostratigraphical units and a reference radioelement profile is established for the central part of the Danish Subbasin. Finally, a model describing the relationship between common lithofacies and their U content and Th/U ratio is suggested. The model deliniates the depositional environment and the relative distances to the provenance areas. It is concluded that: (1) Uranium is mobile during deposition, but since then it is fixed by stable mineral phases at depth; (2) Thorium reflects source area characteristics and that any available ions are readily adsorbed by clay minerals. Thorium anomalies may thus serve as lithostratigraphical markers; (3) Potassium occurs in unstable rock forming mineral phases. The present distribution is controlled not only by the clastic mineral assemblage, but also by the diagenetic processes through geologic time

  15. Marine vertebrates from the Santonian coastal carbonates of northwestern Germany - a tool for the reconstruction of a Proto- North Sea Basin intertidal dinosaur-exchange bridge

    Science.gov (United States)

    Diedrich, Cajus G.; Scheer, Udo

    2015-09-01

    A diverse vertebrate fauna, dominated by shark teeth, is recorded from conglomerates within the limestones of the Upper Cretaceous (Santonian) Burgsteinfurt Formation of northwestern Germany. The conglomerate beds comprise carbonatic, glauconitic and phosphate nodules, as well as Triassic, Jurassic and Cretaceous extraclasts. The Burgsteinfurt Formation conglomerates contain fining-upwards parasequences 2-20 cm in thickness, interpreted as tempestite layers within a unit formed by larger-scale Milankovitch Cycles. The presence of the inoceramid Sphenoceramus patootensis and belemnite Gonioteuthis granulata indicate a late Santonian age for the unit. The studied vertebrate fauna from the Weiner Esch locality consists of 20 selachian species (14 macroselachians and 6 microselachians), a few teleosts, rare marine mosasaur remains, and one tooth from a theropod dinosaur. 95% of the vertebrates in the assemblage are depositionally autochthonous, with the remaining material reworked from older underlying Cenomanian-Coniacian (lower Upper Cretaceous) limestones. On the basis of observed sedimentary structures, the scarcity of deep-sea selachians, and the dominance of the Mitsukurinidae (59% of the preserved shark fauna) in the fossil assemblage, the unit is interpreted as a shallow (0-3 metres deep), subtidal, nearshore environment, or even subaerial carbonate-sand islands, located on the southern margin of a submarine swell. The presence of a Santonian theropod in this deposit, and other dinosaur records in northern Germany, together support the interpretation of a short-lived uplift event with strong upwelling influence for the Northwestphalian-Lippe submarine swell north of the Rhenish Massif in the southern Proto- North Sea Basin. A new migration model for dinosaurs moving along carbonate coasts or intertidal zones of shallow carbonate-sand islands in Central Europe is presented, which may explain the scattered distribution of dinosaur remains across Europe in the

  16. 3D seismic geomorphology of mass transport complexes in a foredeep basin: Examples from the Pleistocene of the Central Adriatic Basin (Mediterranean Sea)

    Science.gov (United States)

    Dalla Valle, Giacomo; Gamberi, Fabiano; Rocchini, Patrizia; Minisini, Daniel; Errera, Alessia; Baglioni, Luca; Trincardi, Fabio

    2013-08-01

    Three-dimensional (3D) seismic-reflection data has shed light on the character of a series of mass transport complexes (MTCs) emplaced during the Pleistocene in the Pescara Basin (Central Adriatic Sea, Italy). The Pescara Basin is the Plio-Pleistocene inner foredeep of the Central Apennines orogen, which was filled by a rapidly prograding, margin-scale clinoforms system. Three MTCs punctuate the normal turbiditic and hemipelagic sedimentary succession of the Pescara Basin foredeep. MTC_0 is the oldest one and covers an area of around 74 km2. It is composed of three different mass transport deposits (MTDs) resulting from individual collapses that involved a shelf-edge delta during a period of relative sea level rise. MTC_1, the intermediate age MTC, is the largest one, with an area of 90 km2. It has a 10 km wide cookie-bite headwall region that indents the upper slope and, in places, reaches the continental shelf-break. MTC_1 is made up of four laterally and vertically stacked MTDs which are the result of a composite set of failures that migrated progressively upslope in a sedimentary setting dominated by contourite deposits. MTC_2 is the youngest and the smallest one, with an area of 55 km2. It has a 5 km long headwall confined in correspondence with a sedimentary bulge developed in the upper slope. Its geomorphic setting leads us to consider two different episodes of failure rooted at different depths. The investigation of the MTCs, through the coupling of 3D seismic geomorphology, seismic facies analysis and rollover trajectory analysis, reveals that the type of sedimentary environment, the rate of sediment accumulation, the source region and the depth of rooting of the failure, are the major controlling factors on MTC evolution and emplacement. Each MTC of the Pescara Basin foredeep is generally confined within a discrete clinotheme. Finally, the rollover trajectory analysis has shown that, in the PB foredeep, a sediment failure can possibly occur at any

  17. New insights into the structure of Om Ali-Thelepte basin, central Tunisia, inferred from gravity data: Hydrogeological implications

    Science.gov (United States)

    Harchi, Mongi; Gabtni, Hakim; El Mejri, Hatem; Dassi, Lassaad; Mammou, Abdallah Ben

    2016-08-01

    This work presents new results from gravity data analyses and interpretation within the Om Ali-Thelepte (OAT) basin, central Tunisia. It focuses on the hydrogeological implication, using several qualitative and quantitative techniques such as horizontal gradient, upward continuation and Euler deconvolution on boreholes log data, seismic reflection data and electrical conductivity measurements. The structures highlighted using the filtering techniques suggest that the Miocene aquifer of OAT basin is cut by four major fault systems that trend E-W, NE-SW, NW-SE and NNE-SSW. In addition, a NW-SE gravity model established shows the geometry of the Miocene sandstone reservoir and the Upper Cretaceous limestone rocks. Moreover, the superimposition of the electrical conductivity and the structural maps indicates that the low conductivity values of sampled water from boreholes are located around main faults.

  18. Decadal oscillation of autumn precipitation in Central Vietnam modulated by the East Pacific–North Pacific (EP–NP) teleconnection

    International Nuclear Information System (INIS)

    Autumn precipitation over Central Vietnam is associated with an increase in the occurrence of tropical cyclones that lead to frequent flooding and pose a significant threat to lives and property. The present analyses reveal a pronounced decadal oscillation of autumn precipitation in Central Vietnam within the 8–11 year frequency band that is modulated by the East Pacific–North Pacific (EP–NP) teleconnection. The negative phase of the EP–NP pattern is associated with a positive sea surface temperature (SST) anomaly in the South China Sea (SCS) that induces low-level convergence, enhances convection, and increases precipitation over Central Vietnam and adjacent islands including Hainan (China) and the Philippines. This circulation feature around the SCS is embedded in a large-scale circulation associated with SST anomalies across the Pacific Ocean—i.e., cooling in the Eastern and Central tropical Pacific sandwiched by warming in the North and South Pacific as well as the Western Pacific Ocean. The positive phase of the EP–NP features opposite SST and circulation anomalies, with the result being reduced rainfall in Central Vietnam. This out-of-phase relationship and shared decadal spectral coherence between the EP–NP index and autumn precipitation in Central Vietnam might be useful for future climate predictions and flood management. (letter)

  19. Decadal oscillation of autumn precipitation in Central Vietnam modulated by the East Pacific-North Pacific (EP-NP) teleconnection

    Science.gov (United States)

    Li, R.; Wang, S.-Y.; Gillies, R. R.; Buckley, B. M.; Truong, L. H.; Cho, C.

    2015-02-01

    Autumn precipitation over Central Vietnam is associated with an increase in the occurrence of tropical cyclones that lead to frequent flooding and pose a significant threat to lives and property. The present analyses reveal a pronounced decadal oscillation of autumn precipitation in Central Vietnam within the 8-11 year frequency band that is modulated by the East Pacific-North Pacific (EP-NP) teleconnection. The negative phase of the EP-NP pattern is associated with a positive sea surface temperature (SST) anomaly in the South China Sea (SCS) that induces low-level convergence, enhances convection, and increases precipitation over Central Vietnam and adjacent islands including Hainan (China) and the Philippines. This circulation feature around the SCS is embedded in a large-scale circulation associated with SST anomalies across the Pacific Ocean—i.e., cooling in the Eastern and Central tropical Pacific sandwiched by warming in the North and South Pacific as well as the Western Pacific Ocean. The positive phase of the EP-NP features opposite SST and circulation anomalies, with the result being reduced rainfall in Central Vietnam. This out-of-phase relationship and shared decadal spectral coherence between the EP-NP index and autumn precipitation in Central Vietnam might be useful for future climate predictions and flood management.

  20. Evaluation of carbon dioxide storage potential for the Bohai Basin, North-East China

    OpenAIRE

    Vincent, Ceri; Poulsen, Niels E.; Rongshu, Zeng; Shifeng, Dai; Mingyuan, Li; Guosheng, Ding

    2011-01-01

    The storage potential of selected sites within the Bohai Basin was assessed for the COACH project. The Gangdong oilfield is considered to have a small potential storage capacity (23 Mt) and to be possibly suitable for an enhanced oil recovery or small-scale storage pilot rather than large-scale storage. The Shengli oilfield province is considered to have a great potential storage capacity (472 Mt in eight selected fields), however, these fields, like those of the Gangdong oilfield province, a...

  1. Assessment of Undiscovered Technically Recoverable Oil and Gas Resources of the Bakken Formation, Williston Basin, Montana and North Dakota, 2008

    Science.gov (United States)

    Pollastro, R.M.; Roberts, L.N.R.; Cook, T.A.; Lewan, M.D.

    2008-01-01

    The U.S. Geological Survey (USGS) has completed an assessment of the undiscovered oil and associated gas resources of the Upper Devonian to Lower Mississippian Bakken Formation in the U.S. portion of the Williston Basin of Montana and North Dakota and within the Williston Basin Province. The assessment is based on geologic elements of a total petroleum system (TPS), which include (1) source-rock distribution, thickness, organic richness, maturation, petroleum generation, and migration; (2) reservoir-rock type (conventional or continuous), distribution, and quality; and (3) character of traps and time of formation with respect to petroleum generation and migration. Framework studies in stratigraphy and structural geology and modeling of petroleum geochemistry, combined with historical exploration and production analyses, were used to estimate the undiscovered, technically recoverable oil resource of the Bakken Formation. Using this framework, the USGS defined a Bakken-Lodgepole TPS and seven assessment units (AU) within the system. For the Bakken Formation, the undiscovered oil and associated gas resources were quantitatively estimated for six of these AUs.

  2. Geochemistry of a continental saline aquifer for CO2 sequestration: The Guantao formation in the Bohai Bay Basin, North China

    International Nuclear Information System (INIS)

    The Neogene Guantao formation in the Beitang sag in the Bohai Bay Basin (BBB) of North China, a Mesozoic–Cenozoic sedimentary basin of continental origin, has been chosen as a candidate for a pilot field test of CO2 sequestration. Hydrogeological and geochemical investigations have been carried out to assess its suitability, taking advantage of many existing geothermal wells drilled to 2000 m or greater depths. Water samples from 25 wells and drill cores of three sections of the Guantao formation were collected for measurements of mineralogy, water chemistry and isotopes (δ18O, δD, δ13C, 14C). Formation temperature estimated by chemical geothermometry is in the range of 60–80 °C. Geochemical modeling of water–rock–CO2 interaction predicts a strong geochemical response to CO2 injection. Besides the elevated porosity (33.6–38.7%) and high permeability (1150–1980 mD) of the Ng-III formation and a favorable reservoir–caprock combination, it is also found that the formation contains carbonates that will react with CO2 after injection. The low salinity (TDS 2 solubility. The 14C age of the formation water indicates a quasi-closed saline aquifer system over large time scales, the lateral sealing mechanism for CO2 sequestration requires further investigation. The CO2 storage capacity of the Guantao formation within the Beitang sag is estimated to be 17.03 Mt, assuming pure solubility trapping.

  3. A record of astronomically forced climate change in a late Ordovician (Sandbian) deep marine sequence, Ordos Basin, North China

    Science.gov (United States)

    Fang, Qiang; Wu, Huaichun; Hinnov, Linda A.; Wang, Xunlian; Yang, Tianshui; Li, Haiyan; Zhang, Shihong

    2016-07-01

    The late Ordovician Pingliang Formation on the southwestern margin of the Ordos Basin, North China, consists of rhythmic alternations of shale, limestone, and siliceous beds. To explore the possible astronomical forcing preserved in this lithological record, continuous lithological rank and magnetic susceptibility (MS) stratigraphic series were obtained from a ~ 34 m thick section of the Pingliang Formation at Guanzhuang. Power spectral analysis of the MS and rank series reveal 85.5 cm to 124 cm, 23 cm to 38 cm, and 15 cm to 27 cm thick sedimentary cycles that in ratio match that of late Ordovician short eccentricity, obliquity and precession astronomical cycles. The power spectrum of the MS time series, calibrated to interpreted short orbital eccentricity cycles, aligns with spectral peaks to astronomical parameters, including 95 kyr short orbital eccentricity, 35.3 kyr and 30.6 kyr obliquity, and 19.6 kyr and 16.3 kyr precession cycles. The 15 cm to 27 cm thick limestone-shale couplets mainly represent precession cycles, and siliceous bed deposition may be related to both precession and obliquity forcing. We propose that precession-forced sea-level fluctuations mainly controlled production of lime mud in a shallow marine environment, and transport to the basin. Precession and obliquity controlled biogenic silica productivity, and temperature-dependent preservation of silica may have been influenced by obliquity forcing.

  4. A regional ocean circulation model for the mid-Cretaceous North Atlantic Basin: implications for black shale formation

    Directory of Open Access Journals (Sweden)

    R. P. M. Topper

    2011-03-01

    Full Text Available High concentrations of organic matter accumulated in marine sediments during Oceanic Anoxic Events (OAEs in the Cretaceous. Model studies examining these events invariably make use of global ocean circulation models. In this study, a regional model for the North Atlantic Basin during OAE2 at the Cenomanian-Turonian boundary has been developed. A first order check of the results has been performed by comparison with the results of a recent global Cenomanian CCSM3 run, from which boundary and initial conditions were obtained. The regional model is able to maintain tracer patterns and to produce velocity patterns similar to the global model. The sensitivity of the basin tracer and circulation patterns to changes in the geometry of the connections with the global ocean is examined with three experiments with different bathymetries near the sponges. Different geometries turn out to have little effect on tracer distribution, but do affect circulation and upwelling patterns. The regional model is also used to test the hypothesis that ocean circulation may have been behind the deposition of black shales during OAEs. Three scenarios are tested which are thought to represent pre-OAE, OAE and post-OAE situations. Model results confirm that Pacific intermediate inflow together with coastal upwelling could have enhanced primary production during OAE2. A low sea level in the pre-OAE scenario could have inhibited large scale black shale formation, as could have the opening of the Equatorial Atlantic Seaway in the post-OAE scenario.

  5. Basin evolution during change from convergent to transform continental margin in Central California

    Energy Technology Data Exchange (ETDEWEB)

    Graham, S.A.; Hitzman, M.; McCloy, C.; Turner, R.; Ward, R.

    1984-03-01

    Miocene nonmarine and shallow marine strata exposed east of San Francisco Bay record a change from convergent-margin tectonics to transform margin tectonics. During the middle Miocene, the East Bay area occupied the oceanward side of a shelved forearc basin that was progressively incorporated in the evolving San Andreas strike-slip orogene. Patterns of deposition in the broad forearc basin were relatively simple: andesitic arc-derived detritus was transported the full width of the forearc basin from the Sierras to the East Bay area. In contrast, the wrench-tectonic regime produced complex patterns of sedimentation displaying greater local variability. On the basis of stratigraphic data, we infer that the west-facing slope of the forearc basin in the East Bay area was reversed about 13 Ma with uplift of the area between the eventual traces of the San Andreas and Hayward faults on the site of the present bay. A fluvial clastic wedge was shed eastward into the East Bay area from this uplifted terrane of Mesozoic subduction complex and forearc basin rocks. Initial rupturing along the Hayward fault trend followed the uplift at about 10 Ma. Loci of basaltic volcanism (10-7 Ma) along these fractures interfinger with the clastic wedge. A similar pattern of uplift and drainage reversal apparently presaged the onset of wrenching along the nearby Calaveras trend from 8-6 Ma. Expansion of the strike-slip orogene segmented the outer forearc basin into local basins, some characterized by episodic lacustrine deposition and probable internal drainage. By the end of the Miocene, Sierran arc volcanism waned at the latitude of San Francisco Bay, and arc-derived volcaniclastics were fully supplanted by recycled Coast Range-derived detritus in the East Bay area. Certain of these Coast Range sediment sources, particularly blueschist-bearing Franciscan terranes, permit an estimate of 7-27 km (4-17 mi) of total right slip on the Hayward fault.

  6. Spatiotemporal variability in bigeye tuna ( Thunnus obesus) dive behavior in the central North Pacific Ocean

    Science.gov (United States)

    Howell, Evan A.; Hawn, Donald R.; Polovina, Jeffrey J.

    2010-07-01

    Data from 29 pop-up archival transmission (PAT) tags deployed on commercial-size bigeye tuna ( Thunnus obesus) in the central North Pacific Ocean from 4°N to 32°N were analyzed to describe variability in their dive behavior across space and time. During the day, bigeye tuna generally spent time in the 0-50 m and 300-400 m depth ranges, with spatial and temporal variability in the deep mode. At night, bigeye tuna generally inhabited the 0-100 m depth range. Three daily dive types were defined based on the percentage of time tuna spent in specific depth layers during the day. These three types were defined as shallow, intermediate, and deep and represented 24.4%, 18.8%, and 56.8% of the total number of days in the study, respectively. More shallow and intermediate dive-type behavior was found in the first half of the year, and in latitudes from 14°N to 16°N and north of 28°N. A greater amount of deep-dive behavior was found in the regions south of 10°N and between 18°N and 28°N during the third and fourth quarters of the year. Dive-type behavior also varied with oceanographic conditions, with more shallow and intermediate behavior found in colder surface waters. Intermediate and deep-dive types were pooled to reflect the depths where bigeye tuna may have potential interactions with fishing gear. A Generalized Additive Model was used to quantify the effects of time, space, and sea surface temperature on this pooled dive type. Results from the model showed that while latitude and quarter of the year were important parameters, sea surface temperature had the most significant effect on the pooled intermediate and deep-dive behavior. Model predictions indicated that the largest percentage of potential interaction would occur in the fourth quarter in the region from 18°N-20°N, which corresponds to the time and place of the highest bigeye tuna catch rates by the Hawaii-based long-line fishery. These results suggest that a model framework using these three

  7. Floristic changes at Khersan Glacier Territory, Alamkuh Mountain, Central Alborz, North of Iran

    Directory of Open Access Journals (Sweden)

    KOUROSH KAVOUSI

    2016-02-01

    Full Text Available Abstract. Kavousi K, Nejadsattari T, Asri Y, Ejtehadi H, Khavari-Nejad RA. 2016. Floristic changes at Khersan Glacier Territory, Alamkuh Mountain, Central Alborz, North of Iran. Biodiversitas 17: 11-15. Extensive investigation in subnival-nival area around Khersan glacier moraine introduced 71 vascular plant species. From this list 43 species have been listed in Noroozi (2001 in “ subnival-nival vascular plant species of Iran : a unique high mountain flora and its threat from climate warming ” and the others are new for subnival- nival area of Iran. Among this plant list 31 species had introduced with Kotschy (1861a,b, Bornmuller (1904, Melchior (1937, Klein (1982, european researchers and the other is named for the first time from Khersan glacier territory. Many species such as Astragalus macrosemius, Pseudocamelina kleinii, Crepis multicaulis subsp. congesta, Didymophysa fedtschenkoana and Draba melanopus due to glacier condition have very sensitive habitat, vulnerable and only gathered from restrict area with conservation value. Vegetation change happened in many nival and subnival area with upward movement in the same habitat and movement from lower altitude at alpine towards summit in subnival and nival. Carex oreophila, Campanula stevenii, Bromus barchystachyus, Oxytropis immersa, Erigeron uniflorus,Trachydium pauciradiatum, Scorzonera radicosa and some other species are surprisingly movement to subnival area and many nival and subnival species such as Didymophysa aucheri, Didymophysa fedtschenkoana, Dracocephalum aucheri and Arabis caucasica have come significantly upward in nival. The movement is different in all side of Khersan glacier moraine in north, south and the east (beside moraine tongue slops and limited with presence of soil natural generation and other ecological remarks. Limitation for soil generation starts at different altitude in northern, southern and eastern slopes of Khersan glacier valley. This study examined

  8. Spatial analysis of soil and shallow groundwater physicochemical parameters in El-Mujib Basin-central Jordan

    Science.gov (United States)

    Salman, Abeer; Al-Qinna, Mohammed; Kuisi, Mustafa Al

    2014-01-01

    In this study statistical and geostatistical methods were applied to a monitoring data set in order to assess contamination risk in soil and shallow groundwater. The study covered an area within El-Mujib Basin in central Jordan, where the barren land is dominating with a small number of irrigated areas in the vicinity of Wadi El-Mujib and in the northern part of the basin. A total of 77 soil and 104 water samples were collected randomly and analyzed physically, chemically, statistically and spatially using ordinary and indicator kriging techniques. Phosphate, nitrate, organic matter and effective field capacity in the soil system were spatially investigated and correlated to current landuse. Maximum soil maximum nitrate (125.6 mg/L), phosphate (9.7 mg/L), and organic matter (3%) contents are encountered in the central area at Wadi El-Mujib, Qattrana and Umm Rasas due to the use of fertilizers and existence of solid landfill. The soil has low water holding capacity as it is dominated by coarse texture and therefore subjecting the groundwater for potential risks through the fast soil system. The major cations and anions in the groundwater were mainly concentrated in the Wadi El-Mujib and in the central part of the Basin increases along the groundwater flow direction. Spatial groundwater indicator maps of salinity; nitrate and sulfate contents proves the high susceptibility of the study area to be contaminated. By determining the impacts, more effective (specific to contamination sources) measures for preventing groundwater quality could be implemented.

  9. The tomato borer, Tuta absoluta, invading the Mediterranean Basin, originates from a single introduction from Central Chile.

    Science.gov (United States)

    Guillemaud, Thomas; Blin, Aurélie; Le Goff, Isabelle; Desneux, Nicolas; Reyes, Maritza; Tabone, Elisabeth; Tsagkarakou, Anastasia; Niño, Laura; Lombaert, Eric

    2015-01-01

    The Lepidopteran pest of tomato, Tuta absoluta, is native to South America and is invasive in the Mediterranean basin. The species' routes of invasion were investigated. The genetic variability of samples collected in South America, Europe, Africa and Middle East was analyzed using microsatellite markers to infer precisely the source of the invasive populations and to test the hypothesis of a single versus multiple introductions into the old world continents. This analysis provides strong evidence that the origin of the invading populations was unique and was close to or in Chile, and probably in Central Chile near the town of Talca in the district of Maule. PMID:25667134

  10. Solute load concentrations in some streams in the Upper Osun and Owena drainage basins, central western Nigeria

    Science.gov (United States)

    Jeje, L. K.; Ogunkoya, O. O.; Oluwatimilehin, J. M.

    1999-12-01

    The solute load dynamics of 12 third-order streams in central western Nigeria are presented, during storm and non-storm runoff events. The relevance of the Walling and Foster model for explaining storm period solute load dynamics in the humid tropical environment was assessed and it was found that this model was generally applicable to the study area. Exceptions appear to be streams draining settlements and/or farms where fertilizers are applied heavily. The solute load ranged from 5 mg l -1 to 580 mg l -1 with streams draining basins with tree-crop plantations ( Theobroma cacao, Cola sp.) as the dominant land cover having the highest solute load.

  11. An analysis on the principal control factor of coal reservoir permeability in central and southern Qinshui Basin

    Energy Technology Data Exchange (ETDEWEB)

    Fu, X.; Qin, Y.; Li, G. [China University of Mining and Technology, Xuzhou (China). College of Mineral Resource and Envronment

    2001-06-01

    Macrofractrues were classified into four ranks according to the measurement and statistics of underground coal mine in central and southern Qinshui Basin, and the description and measurement of microfractures were performed with scanning electron microscope. Based on the analysis of relationships among permeability and ground stress/buried depth, fractures, reservoir pressure, and hydro-geological condition, it is pointed out that the ground stress/buried depth is the principal controlling factor. When the buried depth is similar, the other factors would play more important role on permeability. 4 refs., 4 figs., 2 tabs.

  12. Implications of post-disturbance studies on the grain size of the sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    COMMUNICATIONS CURRENT SCIEN CE, VOL. 81, NO. 10, 25 NOVEMBER 2001 1365 e - mail: vals@csnio.ren.nic.in Implications of post - disturbance stu d ies on the grain size of the sediments from the Central Indian Basin Anil B. Valsangkar National... (2 to 4, 8 to 10 cm) of silty clay out of nine at BC - 13. South RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 81, NO. 10, 25 NOVEMBER 2001 Figure 1. a , Selected sample locations in INDEX area for comparative studies. ?, Box...

  13. Open-System Alkaline Magmatism in the Caledonides of North-Central Norway

    Science.gov (United States)

    Barnes, C. G.; Prestvik, T.; Barnes, M. A.

    2002-12-01

    The Caledonian-age Hortavaer intrusion is exposed on small islands and skerries off the coast of north-central Norway. It was emplaced into a range of host rocks that includes calcitic and dolomitic marble to migmatitic gneiss to quartz-rich meta-arenite. The intrusion is unusual relative to Caledonian plutons on the mainland because of its alkaline nature and its possible circa 460-470 Ma age (based on imprecise Sr and Nd isochrones). The intrusion is broadly zoned, with central diorite and outer syenite. Dike-like bodies of monzonite and syenite are also present and are elongate in a NNE-SSW direction. Each lithologic unit is characterized by evidence for magma mingling, particularly by synplutonic dikes and enclaves. In the syenitic zone, mingled magmas ranged from monzonitic (syenitic) to dioritic. In the diorite zone, mingling was dominated by diorite-in-diorite, but composite diorite-syenite dikes are present. The contact between the syenite and diorite units is marked by an approximately 500-m-wide zone of sheeted diorite/syenite dikes that are mutually intrusive. In addition to magma mingling, the complex shows a variety of types of interaction with screens of its host rocks, which are typically subparallel to foliation in the pluton. Some screens were apparently unreactive with the surrounding magma, whereas others resulted in intense reaction and formation of garnet melasyenite, pyroxene-rich monzodiorite, and rare nepheline-bearing rocks. A trend toward Fe enrichment among the dioritic rocks, the low Mg/(Mg+Fe) and Sr contents of the evolved syenites, and curvilinear composition trends for many elements in the suite suggest fractional crystallization was a major control on magma evolution. However, low epsilon Nd (465 Ma) (-3 to -10), moderate initial 87Sr/86Sr (0.705 to 0.710), and high delta18O (+8.3 to +14.0 %) suggest either a crustal source or intense contamination. The presence of primary calcite with delta13C typical of host carbonate rocks

  14. Methods for dating very old groundwater: eastern and central Great Artesian Basin case study. Chapter 13

    International Nuclear Information System (INIS)

    The Great Artesian Basin extends across 1.7 × 106 km2 or one fifth of the Australian continent. Annual rainfall ranges from 100 mm in the arid western parts to a maximum of 600 mm near the main recharge areas along the eastern basin margin. Average annual runoff is less than 10 mm and generally less than 5 mm. Ephemeral rivers dominate the land surface of the basin, except for a few perennial rivers in the most northern, tropical parts of the region. Most interior rivers drain into Lake Eyre (a dry salt pan at 12 m below sea level); however, the river waters often evaporate or infiltrate before reaching Lake Eyre because of the long distances. With little or no surface water present in the dry, hot and harsh climate of Australia’s interior, the ability of the early settlers to explore and exploit the resources of this region were limited.

  15. Geochemical and faunal investigation of shelf/slope environment of north-central Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Healy-Williams, N.; Trainor, D.M.; Williams, D.F.; Jenkins, P. (Univ. of South Carolina, Columbia (United States)); Gary, A. (Unocal, Brea, CA (United States))

    1991-03-01

    The shelf/slope environment of the northern Gulf of Mexico offers a complex pattern of marine and terrestrial derived sediments. The authors have performed geochemical and faunal investigations on approximately 80 box cores from 30 to 1,300 m water depth from the north-central Gulf of Mexico. The geochemical results relate the modern and late Holocene distribution of marine and terrestrial organic carbon to the present day depositional systems of this actively prograding system. Total organic carbon (%TOC) analyses of the surface sediment are used to characterize the distribution of TOC on the Louisiana shelf and slope as a function of distance from the Mississippi delta. Stable carbon isotopic analyses ({sup 13}C/{sup 12}C) of the TOC are used to distinguish marine from terrestrial organic carbon. Higher amounts of terrestrial organic carbon are associated with the western edge of the Mississippi delta. Marine organic carbon increases seaward of the deltaic system. The percentage of fine-grained (< 63 microns) calcium carbonate also increases seaward of the Mississippi delta as well as with lateral distance along the shelf-slope. Percent CaCO{sub 3} and {delta}{sup 13}C of the fine-grained carbonate determinations have been performed in Plio-Pleistocene cores and exploration wells from this region. The authors use this data to examine how the modern/late Holocene patterns of these variables have changed as a function of continental margin evolution. They have also analyzed the benthic foraminiferal distributions in terms of the sedimentary nature of the box cores. They note increased abundances in certain species in relation to deltaic vs nondeltaic environments along with some species altering their depth ranges between the two environments.

  16. The hydrology of a drained topographical depression within an agricutlural field in north-central Iowa

    Science.gov (United States)

    Roth, Jason L.; Capel, Paul D.

    2012-01-01

    North-central Iowa is an agriculturally intensive area comprising the southeastern portion of the Prairie Pothole Region, a landscape containing a high density of enclosed topographical depressions. Artificial drainage practices have been implemented throughout the area to facilitate agricultural production. Vertical surface drains are utilized to drain the topographical depressions that accumulate water. This study focuses on the hydrology of a drained topographical depression located in a 39.5 ha agricultural field. To assess the hydrology of the drained depression, a water balance was constructed for 11 ponding events during the 2008 growing season. Continuous pond and groundwater level data were obtained with pressure transducers. Flows into the vertical surface drain were calculated based on pond depth. Precipitation inflows and evaporative outflows of the ponds were calculated using climatic data. Groundwater levels were used to assess groundwater/pond interactions. Results of the water balances show distinct differences between the inflows to and outflows from the depression based on antecedent conditions. In wet conditions, groundwater inflow sustained the ponds. The ponds receded only after the groundwater level declined to below the land surface. In drier conditions, groundwater was not a source of water to the depression. During these drier conditions, infiltration comprised 30% of the outflows from the depression during declining pond stages. Over the entire study period, the surface drain, delivering water to the stream, was the largest outflow from the pond, accounting for 97% of the outflow, while evapotranspiration was just 2%. Precipitation onto the pond surface proved to be a minor component, accounting for 4% of the total inflows.

  17. Seasonal methane accumulation and release from a gas emission site in the central North Sea

    Science.gov (United States)

    Mau, S.; Gentz, T.; Körber, J.-H.; Torres, M. E.; Römer, M.; Sahling, H.; Wintersteller, P.; Martinez, R.; Schlüter, M.; Helmke, E.

    2015-09-01

    We investigated dissolved methane distributions along a 6 km transect crossing active seep sites at 40 m water depth in the central North Sea. These investigations were done under conditions of thermal stratification in summer (July 2013) and homogenous water column in winter (January 2014). Dissolved methane accumulated below the seasonal thermocline in summer with a median concentration of 390 nM, whereas during winter, methane concentrations were typically much lower (median concentration of 22 nM). High-resolution methane analysis using an underwater mass-spectrometer confirmed our summer results and was used to document prevailing stratification over the tidal cycle. We contrast estimates of methane oxidation rates (from 0.1 to 4.0 nM day-1) using the traditional approach scaled to methane concentrations with microbial turnover time values and suggest that the scaling to concentration may obscure the ecosystem microbial activity when comparing systems with different methane concentrations. Our measured and averaged rate constants (k') were on the order of 0.01 day-1, equivalent to a turnover time of 100 days, even when summer stratification led to enhanced methane concentrations in the bottom water. Consistent with these observations, we could not detect known methanotrophs and pmoA genes in water samples collected during both seasons. Estimated methane fluxes indicate that horizontal transport is the dominant process dispersing the methane plume. During periods of high wind speed (winter), more methane is lost to the atmosphere than oxidized in the water. Microbial oxidation seems of minor importance throughout the year.

  18. Determination of computed tomography diagnostic reference levels in North-Central Nigeria

    International Nuclear Information System (INIS)

    The aim of this study is to estimate computed tomography (CT) dose levels for common CT examinations in North-Central Nigeria. Dose parameters and scan parameters for the most commonly performed CT examinations (head, chest and abdominal CT scans) were surveyed during a four month period in 4 CT centres with Multislice scanning capabilities (4- 64 slices). Data on CT volume index (CTDIvol) and dose length product (DLP) displayed on scanner console was recorded for a minimum of 10 averaged-sized (70±10kg) patients for each facility to estimate the DRLs. The rounded 75th percentile of the distribution was then used to calculate a DRL for each centre and the region by compiling all results from centres surveyed. Data for 226 patients was collected. CT dosimetry software Impact CT patient dosimetry calculator, version 1.0.4 with National Radiation Protection Board SR250 data set was used to validate and compare surveyed scanner generated dose values. Estimated regional DRLs for head, chest and abdominal scans are (60mG and 1024 mGy.cm), (10mGy and 407mGy.cm) and (15mGy and 757mGy.cm) for CTDIvol and DLP respectively. Mean effective dose values are 1.7mSv, 5mSv and 11.9mSv for head, chest and abdominal scan respectively. A wide variation of mean doses was observed across the centres, however, DRLs estimates were lower than EC (1999) values but above UK (2003) DRLs except for chest examination, this indicates a need for optimization. Validation result show unity (‹10% overall variation) between scanner generated and software calculated dose values. (au)

  19. Managing weather and climate risks to agriculture in North America, Central America and the Caribbean

    Directory of Open Access Journals (Sweden)

    Harlan D. Shannon

    2015-12-01

    Full Text Available In recent decades, numerous weather- and climate-related natural disasters have impacted North America, Central America, and the Caribbean, repeatedly demonstrating how vulnerable local agriculture is to extreme episodic events. Given this recent history, and expectations that the frequency and intensity of some episodic events will increase with climate change, it is becoming increasingly important for farmers to proactively manage weather and climate risks to agriculture to protect their livelihoods. Some farmers in this region already apply various strategies to help reduce weather and climate risks and uncertainties, including farming in multiple locations, diversifying crops and varieties, seeking alternative sources of income, and purchasing crop insurance. Such efforts often help farmers maintain a more stable income while also protecting and preserving the productivity of the land. Other farmers, however, have failed to implement basic risk management strategies despite the clear benefits. Reasons for these failures can be attributed to inadequate farmer education and training, a lack of tools to help facilitate the practical application of risk management concepts, and poor communications between the agrometeorological and farming communities. The agrometeorological community can help overcome these obstacles by building upon existing efforts that have successfully educated farmers about weather and climate risks to agriculture and have equipped farmers with the data, tools, and applications necessary to manage these risks. Farmer input is critical to preparing effective educational and training materials and developing user-friendly risk management tools. The agrometeorological community should solicit input from farmers regularly to ensure that farmers are obtaining the information necessary to effectively manage weather and climate risks to agriculture.

  20. Assessing the toxicity and teratogenicity of pond water in north-central Minnesota to amphibians

    Science.gov (United States)

    Bridges, C.; Little, E.; Gardiner, D.; Petty, J.; Huckins, J.

    2004-01-01

    Background. Incidence of amphibian deformities have increased in recent years, especially in the northern region of the United States. While many factors have been proposed as being responsible for generating deformities (e.g., contaminants, ultraviolet radiation [UV], parasites), no single cause has been definitively established. Methods. To determine whether waterborne chemicals are responsible for amphibian deformities in ponds in north-central Minnesota, we deployed semipermeable membrane devices (SPMDs) in an impacted and a reference site to accumulate lipophilic contaminants. We then exposed native tadpoles (northern leopard frogs; Rana pipiens) to the SPMD extracts combined with two agricultural pesticides (atrazine, carbaryl) at two levels of UV radiation. Results and Discussion. UV radiation alone caused a slight increase in hatching success and tadpole growth rate. Deformity rate among hatchlings was high following exposure to SPMD extracts from the reference site in the absence of UV, suggesting that chemicals present at this site are broken down by UV to less harmful forms, or become less bioavailable. Conversely, impacted site SPMD extracts caused hatchling deformities only in the presence of UV, suggesting that UV potentiates the teratogenicity of the compounds present there. Impacted site SPMD extracts significantly increased the number of bony triangles among metamorphs, a common deformity observed at this site. The incidence of skin webbings increased significantly with SPMD extracts from both sites as well as with our pesticide control containing atrazine and carbaryl alone. Conclusions. Higher deformity rates among tadpoles reared in the presence of UV radiation and SPMD extracts from sites where deformities are common indicates a chemical compound (or compounds) in the water at this site may be causing the deformities. Recommendations and Outlook. It is important to examine the effects of chemical Stressors in the presence of other natural

  1. Using LiDAR datasets to improve HSPF water quality modeling in the Red River of the North Basin

    Science.gov (United States)

    Burke, M. P.; Foreman, C. S.

    2013-12-01

    The Red River of the North Basin (RRB), located in the lakebed of ancient glacial Lake Agassiz, comprises one of the flattest landscapes in North America. The topography of the basin, coupled with the Red River's direction of flow from south to north results in a system that is highly susceptible to flooding. The magnitude and frequency of flood events in the RRB has prompted several multijurisdictional projects and mitigation efforts. In response to the devastating 1997 flood, an International Joint Commission sponsored task force established the need for accurate elevation data to help improve flood forecasting and better understand risks. This led to the International Water Institute's Red River Basin Mapping Initiative, and the acquisition LiDAR Data for the entire US portion of the RRB. The resulting 1 meter bare earth digital elevation models have been used to improve hydraulic and hydrologic modeling within the RRB, with focus on flood prediction and mitigation. More recently, these LiDAR datasets have been incorporated into Hydrological Simulation Program-FORTRAN (HSPF) model applications to improve water quality predictions in the MN portion of the RRB. RESPEC is currently building HSPF model applications for five of MN's 8-digit HUC watersheds draining to the Red River, including: the Red Lake River, Clearwater River, Sandhill River, Two Rivers, and Tamarac River watersheds. This work is being conducted for the Minnesota Pollution Control Agency (MPCA) as part of MN's statewide watershed approach to restoring and protecting water. The HSPF model applications simulate hydrology (discharge, stage), as well as a number of water quality constituents (sediment, temperature, organic and inorganic nitrogen, total ammonia, organic and inorganic phosphorus, dissolved oxygen and biochemical oxygen demand, and algae) continuously for the period 1995-2009 and are formulated to provide predictions at points of interest within the watersheds, such as observation gages

  2. Gender, Sexual Health Seeking Behavior, and HIV/AIDS Among Tarok Women in North-Central Nigeria.

    Science.gov (United States)

    Orisaremi, Titilayo Cordelia

    2016-06-01

    In this study, which was part of a larger project I undertook in North-central Nigeria, I explored the differences in the sexual health seeking behavior of Tarok women and men and how these differences affect the spread of HIV. With the help of three research assistants, I conducted 16 in-depth interviews and 24 focus group discussions in four Tarok communities in North-central Nigeria. I found certain negative effects of gender inequality on women's sexual health seeking behavior in particular, a situation that has adverse implications for HIV acquisition and transmission. I therefore concluded that addressing the challenges of gender inequality is imperative for a sustained fight against HIV and AIDS in Nigeria. PMID:25365697

  3. Effects of terrace construction on runoff and erosion in a recently burnt forest area in north-central Portugal

    OpenAIRE

    M.A.S. Martins; D. Serpa; A.I. Machado; R.F.H. de Lenne; A.G.v.d. Linden; S.R. Faria; R.S.V. Ferreira; I. Skulska; S.A. Prats; M.E.T. Varela; J.J. Keizer

    2013-01-01

    In present-day Portugal, wildfires are a common phenomenon that, on average, affects some 100.000 ha of forest lands each year. Fires can markedly increase runoff generation and the associated sediment transport, nevertheless the magnitude of these impacts strongly depends on post-fire forestry management practices. This study evaluates the effect of terrace construction on runoff and erosion at micro-plot and catchment scale, six months after a wildfire in a forest area in north central Port...

  4. Optical dating of perennially frozen deposits associated with preserved ancient plant and animal DNA in north-central Siberia

    DEFF Research Database (Denmark)

    Arnold, L.J.; Roberts, R.G.; Macphee, R.D.E.;

    2008-01-01

    We present chronological constraints on a suite of permanently frozen fluvial deposits which contain ancient DNA (aDNA) from the Taimyr Peninsula of north-central Siberia. The luminescence phenomenology of these samples is first discussed, focusing on the optically stimulated luminescence (OSL) d...... of providing a reliable chronometric framework for sedimentary aDNA records in permafrost environments. (C) 2007 Elsevier Ltd. All rights reserved Udgivelsesdato: 2008...

  5. Specialized consultant in radiological safety to the clinical north central hospital of high speciality, PEMEX. IV. - December of 2001

    International Nuclear Information System (INIS)

    The clinical north central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  6. Specialized consultant in radiological safety to the north central hospital of high speciality, PEMEX. I. - May-June of 2003

    International Nuclear Information System (INIS)

    The north central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  7. Specialized consultant in radiological safety to the north central hospital of high speciality, PEMEX. I. - July of 2001

    International Nuclear Information System (INIS)

    The north central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  8. An integrated ecosystem trophic model for the North and Central Gulf of California: An alternative view for endemic species conservation

    OpenAIRE

    Díaz-Uribe, J. Gabriel; Arreguín Sánchez, Francisco; Lercari-Bernier, Diego; Cruz Escalona, Víctor Hugo; Zetina Rejón, Manuel Jesús; Del Monte Luna, Pablo; Martínez-Aguilar, Susana

    2012-01-01

    Understanding of the intricate interactions of endemic species with anthropogenic impacts of diverse economic interests on ecosystems is of paramount importance to the implementation of effective con-servation programs. A trophic mass-balance model was used to analyze the structural properties of the North and Central Gulf of California (NC-GulfCal) ecosystem, the most important fishing area in Mexico and where conservation efforts for protecting the endangered endemic porpoise known as vaqui...

  9. Specialized consultant in radiological safety to the north central hospital of high speciality, PEMEX. III. - September of 2001

    International Nuclear Information System (INIS)

    The north central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  10. Specialized consultant in radiological safety to the north central hospital of high speciality, PEMEX. II. - August of 2001

    International Nuclear Information System (INIS)

    The north central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  11. Evaluation of surface water dynamics for water-food security in seasonal wetlands, north-central Namibia

    OpenAIRE

    T. Hiyama; Suzuki, T.; Hanamura, M.; Mizuochi, H.; Kambatuku, J. R.; Niipele, J. N.; Fujioka, Y.; Ohta, T.; Iijima, M

    2014-01-01

    Agricultural use of wetlands is important for food security in various regions. However, land-use changes in wetland areas could alter the water cycle and the ecosystem. To conserve the water environments of wetlands, care is needed when introducing new cropping systems. This study is the first attempt to evaluate the water dynamics in the case of the introduction of rice-millet mixed-cropping systems to the Cuvelai system seasonal wetlands (CSSWs) in north-central Namibia. We first investiga...

  12. Reassessing the Significance of Firearms in Central Africa: The Case of North-Western Zambia to the 1920s

    OpenAIRE

    Macola, Giacomo

    2010-01-01

    Based on a close examination of European travelogues and the evidence produced in the wake of the formulation of colonial gun policies, this article contends that the significance of firearms in Central Africa in the nineteenth and early twentieth centuries has been unduly played down in the existing literature. The first substantive section of the article charts the movement of the gun frontier in nineteenth-century north-western Zambia. It foregrounds the new technology’s economic and milit...

  13. Seasonal and spatial contrasts of sedimentary organic carbon in floodplain lakes of the central Amazon basin.

    Science.gov (United States)

    Sobrinho, Rodrigo; Kim, Jung-Hyun; Abril, Gwenaël; Zell, Claudia; Moreira-Turcq, Patricia; Mortillaro, Jean-Michel; Meziane, Tarik; Damsté, Jaap; Bernardes, Marcelo

    2014-05-01

    Three-quarters of the area of flooded land in the world are temporary wetlands (Downing, 2009), which play a significant role in the global carbon cycle(Einsele et al., 2001; Cole et al., 2007; Battin et al., 2009; Abril et al., 2013). Previous studies of the Amazonian floodplain lakes (várzeas), one important compartment of wetlands, showed that the sedimentation of organic carbon (OC) in the floodplain lakes is strongly linked to the periodical floods and to the biogeography from upstream to downstream(Victoria et al., 1992; Martinelli et al., 2003). However, the main sources of sedimentary OC remain uncertain. Hence, the study of the sources of OC buried in floodplain lake sediments can enhance our understanding of the carbon balance of the Amazon ecosystems. In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Miratuba, and Curuai) which have different morphologies, hydrodynamics and vegetation coverage. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as C:N ratio and stable isotopic composition of organic carbon (δ13COC). These results were compared with lignin-phenol parameters as an indicator of vascular plant detritus (Hedges and Ertel, 1982) and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the soil OC from land to the aquatic settings (Hopmans et al., 2004). Our data showed that during the RW and FW seasons, the concentration of lignin and brGDGTs were higher in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of a mixture of C3 plant detritus and soil OC. However, a downstream increase in C4 plant-derived OC contribution was observed along the gradient of increasingly open waters, i

  14. Climate change impact on soil erosion in the Mandakini River Basin, North India

    Science.gov (United States)

    Khare, Deepak; Mondal, Arun; Kundu, Sananda; Mishra, Prabhash Kumar

    2016-05-01

    Correct estimation of soil loss at catchment level helps the land and water resources planners to identify priority areas for soil conservation measures. Soil erosion is one of the major hazards affected by the climate change, particularly the increasing intensity of rainfall resulted in increasing erosion, apart from other factors like landuse change. Changes in climate have an adverse effect with increasing rainfall. It has caused increasing concern for modeling the future rainfall and projecting future soil erosion. In the present study, future rainfall has been generated with the downscaling of GCM (Global Circulation Model) data of Mandakini river basin, a hilly catchment in the state of Uttarakhand, India, to obtain future impact on soil erosion within the basin. The USLE is an erosion prediction model designed to predict the long-term average annual soil loss from specific field slopes in specified landuse and management systems (i.e., crops, rangeland, and recreational areas) using remote sensing and GIS technologies. Future soil erosion has shown increasing trend due to increasing rainfall which has been generated from the statistical-based downscaling method.

  15. Chemosynthetic activity prevails in deep-sea sediments of the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Das, A.; Sujith, P.P.; Mourya, B.S.; Biche, S.U.; LokaBharathi, P.A.

    with volcanic signatures fixed 230-9,401 nmol C g sup(-1) dry wt day sup(-1) while siliceous radiolarian oozes of the basin fixed only 5-45 nmol C g sup(-1) dry wt day sup(-1). These rates are comparable to those of white smoker waters and are 1-4 orders...

  16. GEOMORPHIC AND HYDROGEOLOGICAL CONTROLS ON THE DISTRIBUTION OF WET MEADOWS IN THE CENTRAL GREAT BASIN

    Science.gov (United States)

    The Great Basin is an arid landscape dominated by dryland vegetation such as big sage and xeric grasses. Meadow complexes occur in mountain drainages and consist of discrete parcels of land up to several hectares in area that are characterized by high water tables and that primar...

  17. Testing models of drainage stability in East Asia: a source-to-sink study of the Neogene-recent Amur River and its delta in the North Sakhalin Basin

    Science.gov (United States)

    Nicholson, Uisdean; Poynter, Sarah; Clift, Peter; Macdonald, David

    2013-04-01

    Throughout the Neogene the North Sakhalin Basin in the Russian Far East was supplied with clastic sediment by the Amur River, one of the ten largest rivers on Earth, with a catchment area of more than 1.8M km2, and a trunk stream more than 4,500 km long. This river drains a complex collage of tectonic terranes which make up the eastern part of the Central Asian Orogenic Belt, as well as adjacent cratons. We use an extensive dataset from more than 200 sandstone samples, together with seismically-derived sediment budget calculations, to provide a comprehensive source-to-sink analysis for the Amur River and to test models of Neogene drainage capture. The majority of sand-sized sediment in the Amur River and its delta comes from upstream of the Lesser Khingan Ridge, shown by the composition of the deltaic sediments the lower 1700 km of the river. Stable mineral ratios, U-Pb age spectra and garnet geochemistry show little stratigraphic provenance-specific variation in the Neogene delta, and the grain assemblages indicate that much of the sediment was derived from the upper catchment of the Amur throughout the Neogene. This renders Miocene-Pliocene drainage capture models unlikely. Sediment budget calculations show significant temporal variations in Neogene sediment flux, which we attribute to climatic processes and uplift and recycling of deltaic sediment in the North Sakhalin Basin.

  18. Quantifying present and future glacier melt-water contribution to runoff in a central Himalayan river basin

    Directory of Open Access Journals (Sweden)

    M. Prasch

    2013-05-01

    Full Text Available Water supply of most lowland cultures heavily depends on rain and melt water from the upstream mountains. Especially melt-water release of alpine mountain ranges is usually attributed a pivotal role for the water supply of large downstream regions. Water scarcity is assumed as consequence of glacier shrinkage and possible disappearance due to global climate change (GCC, in particular for large parts of Central and Southeast Asia. In this paper, the application and validation of a coupled modeling approach with regional climate model (RCM outputs and a process-oriented glacier and hydrological model is presented for the central Himalayan Lhasa River basin despite scarce data availability. Current and possible future contributions of ice melt to runoff along the river network are spatially explicitly shown. Its role among the other water balance components is presented. Although glaciers have retreated and will continue to retreat according to the chosen climate scenarios, water availability is and will be primarily determined by monsoon precipitation and snowmelt. Ice melt from glaciers is and will be a minor runoff component in summer monsoon-dominated Himalayan river basins.

  19. Quantifying present and future glacier melt-water contribution to runoff in a Central Himalayan river basin

    Directory of Open Access Journals (Sweden)

    M. Prasch

    2012-10-01

    Full Text Available Water supply of most lowland cultures heavily depends on rain and melt-water from the upstream mountains. Especially melt-water release of alpine mountain ranges is usually attributed a pivotal role for the water supply of large downstream regions. Water scarcity is assumed as consequence of glacier shrinkage and possible disappearance due to Global Climate Change, particular for large parts of Central and South East Asia. In this paper, the application and validation of a coupled modeling approach with Regional Climate Model outputs and a process-oriented glacier and hydrological model is presented for a Central Himalayan river basin despite scarce data availability. Current and possible future contributions of ice-melt to runoff along the river network are spatially explicitly shown. Its role among the other water balance components is presented. Although glaciers have retreated and will continue to retreat according to the chosen climate scenarios, water availability is and will be primarily determined by monsoon precipitation and snow-melt. Ice-melt from glaciers is and will be a minor runoff component in summer monsoon-dominated Himalayan river basins.

  20. New Data on Land Subsidence Phenomena Due to Excessive Ground Water Withdrawal in the Western Thessaly Basin, Central Greece

    Science.gov (United States)

    Sideri, D.; Rozos, D.; Loupasakis, C.; Kotsanis, D.

    2012-04-01

    The Western Thessaly basin is a major plain which is located in Central Greece. During the last decades this area exhibits an intensive development, mainly based on the agricultural economy. Due to that agricultural development, several thousand boreholes have been drilled for irrigation purposes. The overexploitation of the ground water, in the wider area, has triggered the manifestation of land subsidence phenomena. These phenomena were firstly observed in 2002 in the Stavros and Farsala sites (southeast part of the Western Thessaly basin), in the form of various surface ruptures. In 2009 similar phenomena appeared in Agios Georgios village and in 2011 in Anohori and Katohori villages, which are located between Farsala and Stavros towns. The geological environment of the research area consists of terrestrial sands and gravels horizons Pleistocene in age, with brown and grey clayey silt to silty clay intercalations. These alternations of permeable coarse-grained deposits (aquifers) with impermeable to low permeability strata (aquitards) create a number of successive semi-confined to confined aquifers, sometimes artesians. Land subsidence