Science.gov

Sample records for yacoraite formation northwestern

  1. Hydrogeology of formation waters, northwestern Alberta basin

    SciTech Connect

    Bachu, S.; Underschultz, J.R. )

    1993-10-01

    Generally, temperature seems to be the main controlling factor on salinity distributions. The salinity of formation waters increases in the vicinity of evaporitic beds, and decreases close to the surface because of mixing with fresh meteoric water introduced through local flow systems. The Lower and Middle Devonian pre-Prairie aquifer systems, beneath the regionally extensive Prairie aquiclude, are characterized by regional topographically-driven flow updip to the northeast. The flow of formation waters in the northeastern Alberta played an important role in the formation of the huge Athabasca oil sands deposits. Hydrocarbons that migrated into the area from the west were trapped into local reservoirs, and biodegraded and washed by fresh meteoric water introduced by local flow systems. Environmentally, the subsurface hydrogeology in the area imposes specific constraints on waste disposal in deep formations mostly because of the absence of a thick, continuous regional aquitard and because most aquifers subcrop at shallow depth or crop out and discharge along the valleys of the Athabasca River system and at the basin edge.

  2. Simplified stratigraphic cross sections of the Eocene Green River Formation in the Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Dietrich, John D.; Johnson, Ronald C.

    2013-01-01

    Thirteen stratigraphic cross sections of the Eocene Green River Formation in the Piceance Basin of northwestern Colorado are presented in this report. Originally published in a much larger and more detailed form by Self and others (2010), they are shown here in simplified, page-size versions that are easily accessed and used for presentation purposes. Modifications to the original versions include the elimination of the detailed lithologic columns and oil-yield histograms from Fischer assay data and the addition of ground-surface lines to give the depth of the various oil shale units shown on the cross section.

  3. Magnetostratigraphy of the Miocene Las Arcas Formation, Santa María Valley, northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Spagnuolo, Cecilia M.; Georgieff, Sergio M.; Rapalini, Augusto E.

    2015-11-01

    The first magnetostratigraphic study of the Las Arcas Formation (Late Miocene) was carried out in Las Totoritas creek (26º12‧S; 65º47‧W, NW Argentina), a key place in between of two geological provinces: Northwestern Pampean Ranges and Eastern Cordillera, in northwestern Argentina. This was accompanied by isotopic dating (9.01 ± 0.12 Ma, 40Ar-39Ar in amphibole) of the unit, obtained from a 3.4 m thick tuff intercalated at ˜45 m above the base. The Las Arcas Formation is 810 m thick at the sampling locality and it is mainly composed of tabular reddish conglomerates, sandstones and siltstones in both coarsening- and thickening-upward arrangements. The exposed section was sampled at 48 sites, 26 of which are interpreted as carrying primary magnetization. The new magnetostratigraphic column was correlated with the Geomagnetic Polarity Time Scale (GPTS), and suggests that deposition of the Las Arcas Formation strata started at around 9.1 Ma and ended around 6.8 Ma. The paleomagnetic pole obtained for this unit (Dec = 8.7° Inc = -43.9° dp = 14.9 dm 9.3) indicates that this area underwent non-significant rotation (11.0° ± 13.6°) since the Late Miocene.

  4. Undrilled Muddy formation (Lower Cretaceous) paleodrainage basin, southwestern Wyoming and northwestern Colorado

    SciTech Connect

    Dolson, J.; Leighton, V.

    1989-03-01

    The Muddy formation (Lower Cretaceous) of the central and northern Rocky Mountains has produced over 1.5 billion bbl of oil equivalent hydrocarbons. Traps are developed in buried hills, valley fills, and onlapping marine sands associated with subaerial unconformities formed during a sea level drop. At least 10 paleodrainage basins developed at maximum lowstand. Of these, production has been established in seven. One such paleodrainage, herein designated the Washakie/Sand Wash basin (WSW) drainage, is only drilled peripherally and remains essentially untested over nearly 20,000 km/sup 2/. The WSW paleodrainage is productive in Wyoming from local tributary sandstones at Sugar Creek field (Sierra Madre uplift) and Lost Soldier field (Sweetwater uplift). A major through-going trunk drainage network is productive at Brady field (Rock Springs uplift) and in numerous pools on the Axial and Douglas Creek arches of northwestern Colorado. A recent deep wildcat in northwestern Colorado has confirmed subsurface existence of additional valley networks. Ten to fourteen percent porosity at 5800 m and recent deep Muddy equivalent valley fill discoveries on the southern Moxa arch (Wyoming) demonstrate reservoir potential throughout this trend. Future drilling successes will require 3400 to 6000-m deep tests but should result in significant deep gas and condensate production.

  5. Formation of bottom water and its variability in the northwestern part of the Sea of Japan

    NASA Astrophysics Data System (ADS)

    Tanaka, Kiyoshi

    2014-03-01

    The downslope descent of dense shelf water in the northwestern part of the Sea of Japan is investigated from a dynamical point of view, paying attention to the formation of bottom water in the winter of 2001. It is supposed that before 1980, the shelf water in Peter the Great Bay sometimes descended far down the continental slope, at least partly reaching depths in excess of 3000 m (the foot of the continental slope). After 1980, however, the shelf water did not descend as far; it either descended only moderately or not at all. In Winter 2001, however, the dense shelf water again descended to depths greater than 3000 m, resulting in the formation of bottom water. Descents of more than 3000 m are due to low temperatures coupled with high salinities, whereas the moderate descents of the late 20th century were purely related to the low temperature of the shelf water. It is estimated that over the continental slope, the shelf water becomes mixed with the ambient water in a ratio of about 1:9 for deep descents, whereas the ratio is about 1:5 for moderate descents. The formation of bottom water is greatly influenced by interannual atmospheric variability; thus in Winter 2001 a combination of the strengthened Siberian High (especially in its northern part) and the Aleutian Low advected very cold air into northeast Asia, producing dense shelf water and resulting in the formation of bottom water.

  6. Stratigraphy, depositional environments, and diagenesis related to porosity development and destruction in Jefferson Formation, northwestern Montana

    SciTech Connect

    Blount, G.C.

    1986-08-01

    The Jefferson Formation in northwestern Montana consists of a lower member (< 155 m or 508 ft) and the Birdbear Member (< 72 m or 236 ft), which are correlative to the Duperow and Birdbear Formations of the Williston basin. The lower member consists of sucrosic and nonsucrosic dolomites, limestones, and evaporite solution breccias. The Birdbear Member consists of silty nonsucrosic dolomites and limestones, and sucrosic evaporite solution breccias. Paragenesis of diagenetic events based on petrographic cross-cutting relations, cathodoluminescence, microprobe analysis, conodont alteration indices, and field relations indicate that most porosity development and destruction occurred at relatively shallow depth prior to thrusting. Devonian events include early cementation of desiccation structures and intergranular spaces, localized vuggy and moldic porosity development, and dolomitization and formation of intercrystalline porosity. Mississippian to pre-Jurassic events include burial to oil window, kerogen maturation, and loading stylolitization. Later erosion of Mississippian strata and ground-water circulation resulted in brecciation, subvertical fracture development related to collapse, and dedolomitization followed by near-complete calcite cement infilling of available porosity. Paleocene to early Eocene thrusting events include stylolitization, folding of breccias, and nonfilled fracture formation. Post-early Eocene exposure-induced events results in vuggy porosity and precipitation of speletic cements.

  7. A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina

    PubMed Central

    Alcober, Oscar A.; Martinez, Ricardo N.

    2010-01-01

    Abstract Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper Triassic of Argentina and Brazil, which have yielded remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, respectively. Systematic opinion regarding the position of Herrerasauridae at the base of Dinosauria has varied. Here we describe a new herrerasaurid, Sanjuansaurus gordilloi gen. n., sp. n., based on a partial skeleton from Carnian-age strata of the the Upper Triassic Ischigualasto Formation of northwestern Argentina. The new taxon is diagnosed by numerous features, including long, band-shaped and posterolaterally oriented transverse process on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; scapula and coracoid with everted lateral margins of the glenoid; and short pubis (63% of the femoral length). Phylogenetic analysis placed Sanjuansaurus within a monophyletic Herrerasauridae, at the base of Theropoda and including Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of the Ischigualasto Formation, along with other dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus suggests that saurischian dinosaurs in southwestern Pangea were already widely diversified by the late Carnian rather than increasing in diversity across the Carnian-Norian boundary. PMID:21594020

  8. A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina.

    PubMed

    Alcober, Oscar A; Martinez, Ricardo N

    2010-01-01

    Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper Triassic of Argentina and Brazil, which have yielded remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, respectively. Systematic opinion regarding the position of Herrerasauridae at the base of Dinosauria has varied. Here we describe a new herrerasaurid, Sanjuansaurus gordilloi gen. n., sp. n., based on a partial skeleton from Carnian-age strata of the the Upper Triassic Ischigualasto Formation of northwestern Argentina. The new taxon is diagnosed by numerous features, including long, band-shaped and posterolaterally oriented transverse process on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; scapula and coracoid with everted lateral margins of the glenoid; and short pubis (63% of the femoral length). Phylogenetic analysis placed Sanjuansaurus within a monophyletic Herrerasauridae, at the base of Theropoda and including Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of the Ischigualasto Formation, along with other dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus suggests that saurischian dinosaurs in southwestern Pangea were already widely diversified by the late Carnian rather than increasing in diversity across the Carnian-Norian boundary. PMID:21594020

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  10. An uncertainty framework to estimate dense water formation rates : case study in the Northwestern Mediterranean.

    NASA Astrophysics Data System (ADS)

    Waldman, Robin; Somot, Samuel; Herrmann, Marine; Sevault, Florence; Estournel, Claude; Testor, Pierre

    2015-04-01

    The Northwestern Mediterranean (NWMed) sea is a key region for the Mediterranean thermohaline circulation as it includes the main deep water formation sites of the Western Mediterranean. The Mediterranean Ocean Observing System for the Environment (MOOSE) has been implemented since 2007 over that region to characterize the space and time variability of the main water masses up to interannual (yearly summer cruises) scale. However, despite a large covering of the NWMed region, the limited number of conductivity, temperature and depth (CTD) casts leads to subsampling errors and advocates for an uncertainty assessment of large-scale hydrology estimates. This study aims at estimating the error related to subsampling in time and space. For that purpose, an Observing System Simulation Experiment (OSSE) is performed with an eddy-permitting Mediterranean sea model (NEMOMED12) and an eddy-resolving NWMed sea model (SYMPHONIE). A subsampling of the full model fields in time and space allows for an error estimate in terms of large-scale hydrology. The methodology is applied to dense water volume estimates for the period july 2012 - july 2013. Secondly, an optimization framework is proposed to evaluate and improve MOOSE network's performances under a series of scientific constraints. The results will be discussed for an application in MOOSE observing network, as well as the main assumptions, the stakes and limitations of this framework.

  11. Detrital Zircon Provenance of Neoproterozoic and Cambrian Neruokpuk Formation of northwestern Canada: Implications for Phanerozoic Arctic Evolution

    NASA Astrophysics Data System (ADS)

    Lane, L.; Gehrels, G. E.; Layer, P. W.

    2012-12-01

    Neoproterozoic and Cambrian strata of northwestern Canada are characterized as being derived predominantly from one or more of three principal sources. The sources comprise cratonic rocks of Paleoproterozoic and Archean ages; early Neoproterozoic Mackenzie Mountains Supergroup clastic strata; and Mesoproterozoic Wernecke Supergroup clastic strata, which are widely preserved in the northern Canadian Cordillera. The Neruokpuk Formation is a Late Neoproterozoic and Early Cambrian turbiditic succession located adjacent to the Yukon Stable Block in northwestern Yukon and adjacent northeastern Alaska. The dominant lithology is quartz to quartz-lithic sandstone, locally containing altered detrital feldspar and muscovite indicating contributions from a metamorphic source. The unit forms part of a Neoproterozoic to Early Devonian slope and basin succession that can be correlated in detail to coeval strata in the Selwyn Basin of the northern Canadian Cordillera. However, the Devonian structural and magmatic record for the unit associates it more closely with the Arctic Alaska terrane to the west and to northern Ellesmere Island, some 2000 km to the northeast, than to its present position in northwestern Laurentia. To test whether the Neruokpuk Formation is autochthonous relative to northwestern Laurentia, samples of sandstone from both the Proterozoic lower part and the Cambrian upper part of the unit were processed for detrital zircon analyses. These results were compared to previously published results from the Cambrian of northwestern Canada, as well as to newly analysed Late Neoproterozoic and Cambrian control samples that are known to be autochthonous. Neruokpuk Formation zircons are dominated by 1800-2000 Ma grains with subsidiary populations of 1000-1600 Ma, 2300-2500 Ma and 2600-2900 Ma, consistent with a mixed provenance strongly dominated by a Laurentian cratonic source, with minor contributions from Mackenzie Mountains Supergroup (which is dominated by 1000-1700 Ma populations) and Wernecke Supergroup. In addition, detrital muscovite yielded disturbed Ar-Ar spectra of 1800-1900 Ma, consistent with the most dominant zircon population. Detrital zircon distributions dominated by north Laurentian cratonic populations are widespread along the Arctic margin as far afield as northeastern Greenland. After integrating stratigraphic, biostratigraphic, structural, petrographic and geochronologic data, we infer that the Neruokpuk Formation was most likely deposited more or less in its present location relative to the Laurentian craton. Thus the northeasternmost part of Arctic Alaska probably is not far-travelled. The same conclusion cannot be assumed for other parts of Arctic Alaska which may comprise several individual terranes, some of which may be far-travelled, that assembled prior to Late Devonian time.

  12. Sedimentology and depositional environments of Lower Permian Yeso Formation in northwestern New Mexico

    SciTech Connect

    Stanesco, J.D. )

    1989-09-01

    The northwesternmost exposures of the Lower Permian (Leonardian) Yeso Formation are in uplifts that bound the southern half of the San Juan basin in northwestern New Mexico. The Yeso comprises the Meseta Blanca member and overlying San Ysidro Member. The latter is called the Los Vallos Member in the southern part of the study area. The Meseta Blanca consists of cross-stratified and horizontal to wavy-bedded sandstones of eolian-dune, sand-sheet, and sabkha origin. These facies also occur in the San Ysidro (Los Vallos), which additionally includes mud-draped, ripple-laminated sandstones of supratidal mud-flat origin, gypsiferous sandstones and siltstones of sabkha origin, and evaporite-carbonate rocks of intertidal to marine-shelf origin. Paleocurrent analysis indicates that eolian dunes in the Meseta Blanca migrated southward in the northern part of the study area. These dunes may have been extensions of the DeChelly Sandstone erg to the northwest. Dunes in the southern part of the study area shifted under variable north-south winds. This variability may reflect a seasonal onshore/offshore wind regime. Lateral facies changes in the San Ysidro (Los Vallos) indicate a juxtaposition of eolian-dune and sand-dominated sabkha environments in the northern part of the study area, with coastal-sabkha, tidal, and shelf environments in the southern part. Eolian dunes prograded southward over coastal sabkhas at least 12 times during deposition of the Yeso. A northward shift of all facies during middle San Ysidro deposition suggests a marine transgression from the south.

  13. Nahcolite Resources in the Green River Formation, Piceance Basin, Northwestern Colorado

    USGS Publications Warehouse

    Brownfield, Michael E.; Johnson, Ronald C.; Self, Jesse G.; Mercier, Tracey J.

    2009-01-01

    The U.S. Geological Survey (USGS) recently completed an assessment of in-place nahcolite (NaHCO3) resources in the Piceance Basin, northwestern Colorado. Nahcolite is present in the oil shale deposits of the Parachute Creek Member of the Eocene Green River Formation. It occurs as disseminated aggregates, nodules, bedded units of disseminated brown crystals, and white crystalline beds associated with dawsonite (NaAl(OH)2CO3) and halite (NaCl). The nahcolite-bearing facies are divided into an unleached part containing the nahcolite and halite, which is estimated to be as much as 1,130 ft thick, and an upper leached part several hundred feet thick containing minor nahcolite aggregates and nodules. Locally, thick beds of halite and brown fine-grained nahcolite lie in the depocenter of the basin, but thin laterally away from the basin center and grade into beds of white, coarse-grained nahcolite. In the central part of the study area, the top of the nahcolite-bearing rocks range in depth from about 1,300 to 2,000 ft. Dissolution of water-soluble minerals, mostly nahcolite and halite, in the upper part of the nahcolite-bearing facies has created a collapsed leached zone as much as 580 ft thick that consists of laterally continuous units of solution breccia and fractured oil shale containing solution cavities. The top of the leached zone is not yet defined in the basin, but it probably extends into the A groove in the upper part of the Parachute Creek Member.

  14. Quartz latite rheoignimbrite flows of the Etendeka Formation, north-western Namibia

    NASA Astrophysics Data System (ADS)

    Milner, Sc; Duncan, Ar; Ewart, A.

    1992-02-01

    The Etendeka Formation of north-western Namibia consists of a sequence of interbedded quartz latites and tholeiitic basalts and forms part of the Karoo Igneous Province in southern Africa. The age of the Etendeka Formation is approximately 130 135 Ma. The quartz latites make up a significant proportion of the stratigraphic succession (<25% of the total stratigraphic thickness) and form as much as 60% of the outcrop area in the southern Etendeka. Apart from some systematic differences between pitchstones and devitrified quartz latite, largely explained by alteration processes, individual quartz latite units exhibit remarkably uniform compositions with no significant vertical or lateral variation. Geochemistry can be used as a primary criterion for the correlation of major quartz latite units over much of the southern Etendeka area enabling the reconstruction of the Etendeka Formation stratigraphy in this region. Individual quartz latite units occur as voluminous (400 2600 km3), widespread (up to 8800 km2), sheet-like deposits typically between 40 and 300 m thick. Each unit consists of basal, main and upper zones. The main zone generally constitutes over 70% of the thickness of the unit and typically consists of texturally featureless devitrified quartz latite. In contrast the basal and upper zones of the flow are characterised by flow banding, pitchstone lenses and breccia, with rare occurrences of pyroclastic textures. The quartz latites are sparsely porphyritic (<10% phenocrysts) with glassy or devitrified groundmass textures. The phenocrysts consist of plagioclase, pyroxene, titanomagnetite and rare ilmenite. Pyroxene geothermometry indicates high (1000 1100C) temperatures of crystallisation which, coupled with the absence or primary hydrous phases, indicates that the quartz latites were relatively hot, H2O-undersaturated magmas. The quartz latites display features common to both rhyolite lavas and ignimbrites and are clearly the products of an unusual eruption style. The local preservation of pyroclastic textures and the broad areal extent of these units lead to the conclusion that the quartz latites are high-temperature rheomorphic ignimbrites (i.e. rheoignimbrites). A combination of high eruption temperature and relatively low viscosity helps to explain the often completely welded and homogeneous textures observed in most quartz latite outcrops in the Etendeka area.

  15. Shelf-facies microbiotas from the Odjick and Rocknest Formations (Epworth Group; 1. 89 Ga), northwestern Canada

    SciTech Connect

    Hofmann, H.J.; Grotzinger, J.P.

    1985-01-01

    Moderately well preserved microfossils are reported from two formations of the Epworth Group, Wopmay Orogen, northwestern Canada. An assemblage in an open marine, hematitic stromatolitic unit in the uppermost part of the Odjick Formation contains Huroniospora spp., Gunflintia sp., and Frutexites sp. This assemblage, which is remarkable for its preservation in a carbonate matrix, is similar to one found in a stromatolitic chert facies in the approximately coeval Gunflint Iron Formation of Ontario. Taxa in four members of the overlying Rocknest Formation occur in cherty dolostones of inner-shelf shallowing-upward cycles capped by small digitate stromatolites. These assemblages are environmentally restricted and comprise the spheroidal taxa Huroniospora spp., Melasmatosphaera magna, Sphaerophycus sp., and Palaeoanacystis sp., the filamentous taxa Archaeotrichion sp., Eomycetopsis sp, Siphonophycus sp., Brevitrichoides sp., Biocatenoides incrustata, Gunflintia. sp., and Archaeonema sp., the spinose acritarch Eomicrhystridium sp., and rare specimens of 2 unidentified and problematic forms. These assemblages represent the northwestern most occurrences of Aphebian (early Proterozoic) microfossils now known in North America. The presence of Frutexites in a hematitic unit of the Odjick Formation conforms to previous reports of this taxon from iron-rich sedimentary rocks, ranging in age from Proterozoic to Mesozoic; one occurrence from the Upper Devonian in Australia reportedly has an iridium anomaly associated with it.

  16. Morphology and formation of spreading cracks on pillow lavas at Cape Grim, northwestern Tasmania, Australia

    NASA Astrophysics Data System (ADS)

    Goto, Yoshihiko; McPhie, Jocelyn

    2012-09-01

    Tertiary basaltic pillow lobes at Cape Grim, northwestern Tasmania, Australia display well-preserved spreading cracks in the glassy crust. The spreading cracks are lens-shaped or rectangular in plan view. In cross section, they consist of a graben-like depression with a broad floor bounded by steep scarps. The floor of spreading crack contains an axial crack and a number of ridges that are arranged symmetrically with respect to the axial crack. The ridges within spreading cracks are inferred to have formed by the regular, repeated production and splitting of new crust at the centre of the spreading crack. This new interpretation of ridges in spreading cracks differs from the previous interpretation in which they are regarded as elongate normal fault blocks. Our interpretation provides new insight into the propagation mechanisms of pillow lavas.

  17. High resolution modelling of dense water formation in the Northwestern Mediterranean: benefits from an improved initial stratification in summer

    NASA Astrophysics Data System (ADS)

    Estournel, Claude; Testor, Pierre; Damien, Pierre; Mortier, Laurent; Marsaleix, Patrick; Lellouche, Jean-Michel; Ulses, Caroline; Kessouri, Faycal; Raimbault, Patrick; Coppola, Laurent

    2014-05-01

    The period that extends from summer 2012 to summer 2013 was the subject of several field campaigns in the northwestern Mediterranean that allowed to characterize the stratification on a seasonal scale in this region of deep water formation. This period is therefore ideal for testing hydrodynamic models and assessing the accuracy required on initial conditions and meteorological forcing. A 1 km resolution simulation of the vertical stratification evolution of the northwestern Mediterranean between summer 2012 and spring 2013 was conducted. The representation of winter convection was shown to be highly dependent on initial conditions in summer. A method was developed to correct the initial state of the model using the observations of the annual summer cruise of the MOOSE monitoring program and data from ARGO profilers. In addition, an adjustment of the wind helped to better approach winter observations, the criterion being the profile of residual buoyancy, simple index of the potential of the water column to convect more or less deeply and rapidly. The simulation obtained after correction of the initial conditions and wind forcing allowed to accurately represent the characteristics of the water masses formed during the convective period, the area concerned by convection and its timing. We will first present the methodology used to correct the initial state of the simulation, and then the validation of the simulation based on the observations from the DEWEX cruise (MERMEX program) and from profilers deployed in the frame of the HyMeX program. Then the volume of dense water formed and its characteristics will be quantified as well as their sensitivity to initial conditions.

  18. Fluvial transitions and paleogeography in upper part of Maroon Formation (Pennsylvanian and Permian), northwestern Colorado

    SciTech Connect

    Johnson, S.Y.

    1986-08-01

    Six detailed lateral profiles (as much as 7 m thick and 50 m long) of fluvial channel sandstone bodies were measured at different locations in the northern part of the Eagle basin, northwestern Colorado. Contrasts in the grain size, internal geometry, and architecture of the sandstone bodies reveal significant facies changes across the basin. Proximal bodies that formed closest to the basin-margin ancestral Uncompahgre and Front Range uplifts consists of massive cross-bedded and flat-bedded coarse-grained to conglomeratic sandstone deposited mainly channel scour and fill and by vertical and lateral accretion on sand-gravel bars in low-sinuosity rivers. Medial sandstone bodies consist mostly of cross-bedded and flat-bedded fine to coarse-grained sandstone that was also deposited in low-sinuosity rivers on sand flats and in sandy bars. Bankfull discharge in proximal and medial channels was probably about 400 to 1000 m/sup 3//sec. The most distal sandstone body is composed of flat- and ripple-laminated, very fine to fine-grained sandstone that probably was deposited in a distributary area, in part by sheet floods. Overall facies changes indicate down-system decreases in competence and depth of flow. Paleocurrent data indicate that Maroon rivers draining the ancestral Uncompahgre uplift flowed northeastward across most of the basin before merging with rivers draining the ancestral Front Range uplift. The depositional axis of the basin was therefore probably strongly skewed to the northeast during late Maroon time.

  19. Reservoir Properties of the Zonguldak Formation, Located in the Western Black Sea Region, Northwestern Turkey

    NASA Astrophysics Data System (ADS)

    Küçükkuş, N.; Ayyıldız, T.

    2012-04-01

    The Zonguldak Formation (Westfalian-Stefanian), which is situated in the Western Black Sea basin, is considered to have hydrocarbon potential for coalbed methane (Yalcin and Inan 2001). Additionally, the shale levels of the delta environment of Alacaagzi Formation (Namurian), underline the Zonguldak Formation is considered to have a source rock potential (Derman and Iztan 1997; Sahinturk and Ozcelik 1983). The delta plain of the Zonguldak Formation consists of shales, coals and siliciclastic rocks which have deposited in the lake, marsh and river environment, having ranging from 1000 to 1400 m thickness. The coals and siliciclastics which belong to the formation have persistence in both onshore and offshore. Nevertheless, there have not been published data related to the reservoir rock potential of siliciclastic levels of the Zonguldak Formation which is recognized to have CBM potential. Three deep research wells (Gegendere-1, Amasra -1 and Cakraz-1) have been drilled by TPAO on research area of the Western Black Sea Region to determine the hydrocarbon potential of the Zonguldak Formation. The Yilanli, Alacaagzi, Zonguldak, Cakraz, and Yemislicay formations have been penetrated in the wells. Methane was detected during drilling; but there was no economic detection from DST. The lithology of the Zonguldak formation was characterized through the core and cutting samples taken from the three wells and also thin sections. The petrographic studies were conducted on 44 thin sections, taken from core and cutting samples, indicating that they are fine to medium grained, moderate sorted, litharenite, sublitarenite, feldspathic arenite, carbonaceous mudstone, and quartz arenite composition. Cement materials are mainly clay matrix, and slightly calcite and silica. The XRD and SEM analyze show that the clay types are kaolinite, illite, chlorite and smectite, and high API values from GR logs support that siliciclastics levels have high content clay matrix. Petrographic determinations show that porosity ratio is less than 1%. The core plug samples taken from the Amasra-1 were used to better understanding about the petrophysical properties. Porosity and permeability values are 1,7-2,4% and 0.01-0.03 md, respectively. The petrographic, petropysical, minerological and reservoir rocks analyses on the siliciclastic levels of the Zonguldak Formation indicate that the formation has a poor reservoir potential in the studied wells.

  20. Osteology of Pseudochampsa ischigualastensis gen. et comb. nov. (Archosauriformes: Proterochampsidae) from the early late triassic ischigualasto formation of Northwestern Argentina.

    PubMed

    Trotteyn, M Jimena; Ezcurra, Martín D

    2014-01-01

    Proterochampsids are crocodile-like, probably semi-aquatic, quadrupedal archosauriforms characterized by an elongated and dorsoventrally low skull. The group is endemic from the Middle-Late Triassic of South America. The most recently erected proterochampsid species is "Chanaresuchus ischigualastensis", based on a single, fairly complete skeleton from the early Late Triassic Ischigualasto Formation of northwestern Argentina. We describe here in detail the non-braincase cranial and postcranial anatomy of this species and revisit its taxonomy and phylogenetic relationships. The phylogenetic analysis recovered 'Chanaresuchus ischigualastensis' as part of a trichotomy together with Gualosuchus reigi and Chanaresuchus bonapartei. Accordingly, "Chanaresuchus ischigualastensis" can be potentially more closely related to Gualosuchus reigi, or even Rhadinosuchus gracilis, than to Chanaresuchus bonapartei. In addition, after discussing previously claimed synapomorphies of Chanaresuchus, we could not find unambiguous support for the monophyly of the genus. As a result, we propose here the erection of the new genus Pseudochampsa for 'Chanaresuchus ischigualastensis', which results in the new combination Pseudochampsa ischigualastensis. The information provided here about the anatomy and taxonomy of Pseudochampsa ischiguaslastensis will be useful for future quantitative analyses focused on the biogeography and macroevolutionary history of proterochampsids. PMID:25426846

  1. Osteology of Pseudochampsa ischigualastensis gen. et comb. nov. (Archosauriformes: Proterochampsidae) from the Early Late Triassic Ischigualasto Formation of Northwestern Argentina

    PubMed Central

    Trotteyn, M. Jimena; Ezcurra, Martín D.

    2014-01-01

    Proterochampsids are crocodile-like, probably semi-aquatic, quadrupedal archosauriforms characterized by an elongated and dorsoventrally low skull. The group is endemic from the Middle-Late Triassic of South America. The most recently erected proterochampsid species is “Chanaresuchus ischigualastensis”, based on a single, fairly complete skeleton from the early Late Triassic Ischigualasto Formation of northwestern Argentina. We describe here in detail the non-braincase cranial and postcranial anatomy of this species and revisit its taxonomy and phylogenetic relationships. The phylogenetic analysis recovered ‘Chanaresuchus ischigualastensis’ as part of a trichotomy together with Gualosuchus reigi and Chanaresuchus bonapartei. Accordingly, “Chanaresuchus ischigualastensis” can be potentially more closely related to Gualosuchus reigi, or even Rhadinosuchus gracilis, than to Chanaresuchus bonapartei. In addition, after discussing previously claimed synapomorphies of Chanaresuchus, we could not find unambiguous support for the monophyly of the genus. As a result, we propose here the erection of the new genus Pseudochampsa for ‘Chanaresuchus ischigualastensis’, which results in the new combination Pseudochampsa ischigualastensis. The information provided here about the anatomy and taxonomy of Pseudochampsa ischiguaslastensis will be useful for future quantitative analyses focused on the biogeography and macroevolutionary history of proterochampsids. PMID:25426846

  2. A New Basal Sauropodomorph (Dinosauria: Saurischia) from Quebrada del Barro Formation (Marayes-El Carrizal Basin), Northwestern Argentina

    PubMed Central

    Apaldetti, Cecilia; Martinez, Ricardo N.; Alcober, Oscar A.; Pol, Diego

    2011-01-01

    Background Argentinean basal sauropodomorphs are known by several specimens from different basins; Ischigualasto, El Tranquilo, and Mogna. The Argentinean record is diverse and includes some of the most primitive known sauropodomorphs such as Panphagia and Chromogisaurus, as well as more derived forms, including several massospondylids. Until now, the Massospondylidae were the group of basal sauropodomorphs most widely spread around Pangea with a record in almost all continents, mostly from the southern hemisphere, including the only record from Antarctica. Methodology/Principal Finding We describe here a new basal sauropodomorph, Leyesaurus marayensis gen. et sp. nov., from the Quebrada del Barro Formation, an Upper Triassic-Lower Jurassic unit that crops out in northwestern Argentina. The new taxon is represented by a partial articulated skeleton that includes the skull, vertebral column, scapular and pelvic girdles, and hindlimb. Leyesaurus is diagnosed by a set of unique features, such as a sharply acute angle (50 degrees) formed by the ascending process of the maxilla and the alveolar margin, a straight ascending process of the maxilla with a longitudinal ridge on its lateral surface, noticeably bulging labial side of the maxillary teeth, greatly elongated cervical vertebrae, and proximal articular surface of metatarsal III that is shelf-like and medially deflected. Phylogenetic analysis recovers Leyesaurus as a basal sauropodomorph, sister taxon of Adeopapposaurus within the Massospondylidae. Moreover, the results suggest that massospondylids achieved a higher diversity than previously thought. Conclusions/Significance Our phylogenetic results differ with respect to previous analyses by rejecting the massospondylid affinities of some taxa from the northern hemisphere (e.g., Seitaad, Sarahsaurus). As a result, the new taxon Leyesaurus, coupled with other recent discoveries, suggests that the diversity of massospondylids in the southern hemisphere was higher than in other regions of Pangea. Finally, the close affinities of Leyesaurus with the Lower Jurassic Massospondylus suggest a younger age for the Quebrada del Barro Formation than previously postulated. PMID:22096511

  3. Depositional facies of the Miocene-Pliocene Ogallala Formation, northwestern Texas and eastern New Mexico

    SciTech Connect

    Gustavson, T.C.; Winkler, D.A.

    1988-03-01

    Deposition of the basal fluvial sediments of the Miocene-Pliocene Ogallala Formation in western Texas and eastern New Mexico was controlled by topography on the underlying erosional surface. Paleovalley-fill facies consist of gravelly and sandy braided-stream deposits interbedded with and overlain by eolian sediments deposited as sand sheets and loess. Uplands on the pre-Ogallala erosional surface are overlain primarily by similar eolian sediments. Calcic paleosols, consisting mostly of glaebules and rhizoconcretions of CaCO/sub 3/, occur throughout the eolian facies. Massive to laminated and locally pisolitic, brecciated, and recemented pedogenic calcretes occur primarily near or at the top of the Ogallala Formation. Eolian facies preserve numerous superposed calcretes and calcic paleosols, reflecting slow episodic aggradation on a savannah or grassland under arid to subhumid climatic conditions. The change from fluvial to mostly eolian sedimentation probably resulted from diversion of streams that deposited fluvial sediments of the Ogallala Formation to form the Pecos and Canadian rivers. Source areas for eolian sediments may initially have been flood plains of Ogallala braided streams and later the flood plains of the newly formed Pecos and Canadian rivers. 38 references.

  4. Depositional facies of the Miocene-Pliocene Ogallala Formation, northwestern Texas and eastern New Mexico

    NASA Astrophysics Data System (ADS)

    Gustavson, Thomas C.; Winkler, Dale A.

    1988-03-01

    Deposition of the basal fluvial sediments of the Miocene-Pliocene Ogallala Formation in western Texas and eastern New Mexico was controlled by topography on the underlying erosional surface. Paleovalley-fill facies consist of gravelly and sandy braided-stream deposits interbedded with and overlain by eolian sediments deposited as sand sheets and loess. Uplands on the pre-Ogallala erosional surface are overlain primarily by similar eolian sediments. Calcic paleosols, consisting mostly of glaebules and rhizoconcretions of CaCO3, occur throughout the eolian facies. Massive to laminated and locally pisolitic, brecciated, and recemented pedogenic calcretes occur primarily near or at the top of the Ogallala Formation. Eolian facies preserve numerous superposed calcretes and calcic paleosols, reflecting slow episodic aggradation on a savanna or grassland under and to subhumid climatic conditions. The change from fluvial to mostly eolian sedimentation probably resulted from diversion of streams that deposited fluvial sediments of the Ogallala Formation to form the Pecos and Canadian rivers. Source areas for eolian sediments may initially have been floodplains of Ogallala braided streams and later the floodplains of the newly formed Pecos and Canadian rivers.

  5. Probable Ankylosaur Ossicles from the Middle Cenomanian Dunvegan Formation of Northwestern Alberta, Canada

    PubMed Central

    Burns, Michael E.; Vavrek, Matthew J.

    2014-01-01

    A sample of six probable fragmentary ankylosaur ossicles, collected from Cenomanian deposits of the Dunvegan Formation along the Peace River, represent one of the first dinosaurian skeletal fossils reported from pre-Santonian deposits in Alberta. Specimens were identified as ankylosaur by means of a palaeohistological analysis. The primary tissue is composed of zonal interwoven structural fibre bundles with irregularly-shaped lacunae, unlike the elongate lacunae of the secondary lamellar bone. The locality represents the most northerly Cenomanian occurrence of ankylosaur skeletal remains. Further fieldwork in under-examined areas of the province carries potential for additional finds. PMID:24816807

  6. Probable ankylosaur ossicles from the middle Cenomanian Dunvegan formation of northwestern Alberta, Canada.

    PubMed

    Burns, Michael E; Vavrek, Matthew J

    2014-01-01

    A sample of six probable fragmentary ankylosaur ossicles, collected from Cenomanian deposits of the Dunvegan Formation along the Peace River, represent one of the first dinosaurian skeletal fossils reported from pre-Santonian deposits in Alberta. Specimens were identified as ankylosaur by means of a palaeohistological analysis. The primary tissue is composed of zonal interwoven structural fibre bundles with irregularly-shaped lacunae, unlike the elongate lacunae of the secondary lamellar bone. The locality represents the most northerly Cenomanian occurrence of ankylosaur skeletal remains. Further fieldwork in under-examined areas of the province carries potential for additional finds. PMID:24816807

  7. Paleoenvironments and age of the Talampaya Formation: The Permo-Triassic boundary in northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Gulbranson, E. L.; Ciccioli, P. L.; Montañez, I. P.; Marenssi, S. A.; Limarino, C. O.; Schmitz, M. D.; Davydov, V.

    2015-11-01

    The Talampaya Formation is the basal unit of the Ischigualasto-Villa Unión rift system and has been traditionally assigned to the Triassic based on stratigraphic relationships. A median U-Pb age of 252.38 (+0.09/-0.22) Ma was obtained from volcanic zircons collected from a tuff bed close to the top of this unit at the Bordo Atravesado locality in the Cuesta de Miranda area (La Rioja, Argentina). This radiometric age is very close to the accepted Permian-Triassic boundary indicating that, at least in this locality, sedimentation occurred during the Late Permian but may have extended into the earliest Triassic. This new evidence indicates that the onset of the extensional event that gave rise to the rift basins in western Argentina started during the Permian. Detailed sedimentological studies of the 260 m thick Talampaya Formation allowed subdividing the succession into seven facies associations grouped into three evolutionary stages indicating that sedimentary environments initially evolved from alluvial fans to a braided river system. Subsequent intrabasinal volcanism associated with sediment deposition by low-to moderate-sinuosity rivers is recorded in the lower third of the column. The middle and upper part of the unit captures the evolution from ephemeral fluvial systems with an eolian interval to an ephemeral clastic lake with intermittent volcanic ash deposits. These changes indicate a progressive lowering of the landscape and a transition towards arid or semiarid conditions.

  8. Sedimentology of the Pliocene Upper Onzole Formation, an inner-trench slope succession in northwestern Ecuador

    NASA Astrophysics Data System (ADS)

    Aalto, K. R.; Miller, W.

    1999-01-01

    The Pliocene Upper Onzole Formation exposed in the vicinity of Punta Gorda, near Esmeraldas, Ecuador, is composed mainly of fine-grained mud turbidites, having regular vertical sequences of sedimentary structures associated with a positive grading, and bioturbation restricted mostly to the tops of beds. The remainder of beds measured consist of volcanic ash, mud pelagite, and glauconitic silt-sand turbidites. Vertical sequential analysis of stratigraphic sections for the most part show no pronounced trends in bed thickness or grain size. Volcanic ashes are crystal-vitric tuffs occurring in four bedding styles: (A) normally-graded ashes with burrowed gradational tops and sharp wavy bases; (B) ashes that form part of a complex microstratigraphy consisting of thinly-bedded mudstone, silt-sand turbidites, tuffaceous mudstone, and ash beds; (C) less conspicuous ash laminae and ash-filled burrows; and (D) a tuffaceous bed with ash and mud swirled together in convolute layers. Ash chemistry suggests an Andean high-K calc-alkaline provenance. Facies relations, paleontologic data and regional geologic setting suggest sediment accumulation on an inner trench slope in a basin situated oceanward of the Pliocene trench-slope break. Faulting is extensive and reflects two deformational episodes, the youngest involving Holocene marine and fluvial terraces. Faults group into an older, northerly trending, listric set, and a younger, west-northwest-trending high-angle set. Fault striations of both sets suggest dominantly dip-slip motion. The faults reflect an episode of latest Pliocene through Quaternary trench-normal extension in the forearc, followed by trench-parallel extension. Both sets of faults crosscut large northeast-trending regional folds. Post-Pliocene changes in stress regime, from generally northwest-southeast compression, to east-west tension, to north-northeast-south-southwest tension probably reflect change in stress vectors that resulted from the ongoing collision of the leading edge of the South America plate with the thick oceanic crust of the Carnegie Ridge.

  9. Depositional environment of the Cambro-Ordovician Rose Run Formation in northeastern Ohio, and equivalent, Gatesburg Formation in northwestern Pennsylvania

    SciTech Connect

    Enterline, D.S.; Foos, A.M. )

    1991-03-01

    An ideal sedimentary sequence from the Rose Run Formation consists of three facies in the following order: (1) algal laminated/stromatolite facies, (2) bioturbated dolomite facies, and (3) crossbedded sandstone facies. The algal laminated/stromatolite facies is composed of fine to very fine crystalline dolomite with laminations 2-4 cm thick. Also observed in this facies are mudcracks. The bioturbated dolomite facies is a fine to medium crystalline dolomite with an average of 10% clastic constituents such as quartz, orthoclase, microcline, and glauconite. Bioturbation in this facies ranges from slight to well with burrows 0.5-3 cm in diameter. Other structures observed include rip-up clasts, pelloids, and oncolites. The cross-bedded sandstone facies is characterized by low-angle crossbedded, fine- to coarse-grained sandstones. This sandstone has on the average 79% quartz, 12% orthoclase, 6% microcline, 1% detridal chert, and 1-2% glauconite. The heavy mineral fraction consists of tourmaline and zircon in {approximately}1% concentrations. The grains are subrounded to rounded with a size range of 0.15-0.30 mm. Sedimentary structures include rip-up clasts, current ripples, herringbone crossbedding, and herringbone imbricate rip-up clasts.

  10. The Inskip Formation, the Harmony Formation, and the Havallah Sequence of Northwestern Nevada - An Interrelated Paleozoic Assemblage in the Home of the Sonoma Orogeny

    USGS Publications Warehouse

    Ketner, Keith B.

    2008-01-01

    An area between the towns of Winnemucca and Battle Mountain in northwestern Nevada, termed the arkosic triangle, includes the type areas of the middle to upper Paleozoic Inskip Formation and Havallah sequence, the Upper Devonian to Mississippian Harmony Formation, the Sonoma orogeny, and the Golconda thrust. According to an extensive body of scientific literature, the Havallah sequence, a diverse assemblage of oceanic rocks, was obducted onto the continent during the latest Permian or earliest Triassic Sonoma orogeny by way of the Golconda thrust. This has been the most commonly accepted theory for half a century, often cited but rarely challenged. The tectonic roles of the Inskip and Harmony Formations have remained uncertain, and they have never been fully integrated into the accepted theory. New, and newly interpreted, data are incompatible with the accepted theory and force comprehensive stratigraphic and tectonic concepts that include the Inskip and Harmony Formations as follows: middle to upper Paleozoic strata, including the Inskip, Harmony, and Havallah, form an interrelated assemblage that was deposited in a single basin on an autochthonous sequence of Cambrian, Ordovician, and lowest Silurian strata of the outer miogeocline. Sediments composing the Upper Devonian to Permian sequence entered the basin from both sides, arkosic sands, gravel, limestone olistoliths, and other detrital components entered from the west, and quartz, quartzite, chert, and other clasts from the east. Tectonic activity was expressed as: (1) Devonian uplift and erosion of part of the outer miogeocline; (2) Late Devonian depression of the same area, forming a trough, probably fault-bounded, in which the Inskip, Harmony, and Havallah were deposited; (3) production of intraformational and extrabasinal conglomerates derived from the basinal rocks; and (4) folding or tilting of the east side of the depositional basin in the Pennsylvanian. These middle to upper Paleozoic deposits were compressed in the Jurassic, causing east-verging thrusts in the eastern part of the depositional basin (Golconda thrust) and west-verging thrusts and folds in the western part. Hypotheses involving a far-traveled allochthon that was obducted from an ocean or back-arc basin are incompatible with modern observations and concepts.

  11. Lithofacies, age, depositional setting, and geochemistry of the Otuk Formation in the Red Dog District, northwestern Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; Burruss, Robert A.; Blome, Charles D.

    2013-01-01

    Complete penetration of the Otuk Formation in a continuous drill core (diamond-drill hole, DDH 927) from the Red Dog District illuminates the facies, age, depositional environment, source rock potential, and isotope stratigraphy of this unit in northwestern Alaska. The section, in the Wolverine Creek plate of the Endicott Mountains Allochthon (EMA), is ~82 meters (m) thick and appears structurally uncomplicated. Bedding dips are generally low and thicknesses recorded are close to true thicknesses. Preliminary synthesis of sedimentologic, paleontologic, and isotopic data suggests that the Otuk succession in DDH 927 is a largely complete, albeit condensed, marine Triassic section in conformable contact with marine Permian and Jurassic strata. The Otuk Formation in DDH 927 gradationally overlies gray siliceous mudstone of the Siksikpuk Formation (Permian, based on regional correlations) and underlies black organic-rich mudstone of the Kingak(?) Shale (Jurassic?, based on regional correlations). The informal shale, chert, and limestone members of the Otuk are recognized in DDH 927, but the Jurassic Blankenship Member is absent. The lower (shale) member consists of 28 m of black to light gray, silty shale with as much as 6.9 weight percent total organic carbon (TOC). Thin limy layers near the base of this member contain bivalve fragments (Claraia sp.?) consistent with an Early Triassic (Griesbachian-early Smithian) age. Gray radiolarian chert dominates the middle member (25 m thick) and yields radiolarians of Middle Triassic (Anisian and Ladinian) and Late Triassic (Carnian-late middle Norian) ages. Black to light gray silty shale, like that in the lower member, forms interbeds that range from a few millimeters to 7 centimeters in thickness through much of the middle member. A distinctive, 2.4-m-thick interval of black shale and calcareous radiolarite ~17 m above the base of the member has as much as 9.8 weight percent TOC, and a 1.9-m-thick interval of limy to cherty mudstone immediately above this contains radiolarians, foraminifers, conodonts, and halobiid bivalve fragments. The upper (limestone) member (29 m thick) is lime mudstone with monotid bivalves and late Norian radiolarians, overlain by gray chert that contains Rhaetian (latest Triassic) radiolarians; Rhaetian strata have not previously been documented in the Otuk. Rare gray to black shale interbeds in the upper member have as much as 3.4 weight percent TOC. At least 35 m of black mudstone overlies the limestone member; these strata lack interbeds of oil shale and chert that are characteristic of the Blankenship, and instead they resemble the Kingak Shale. Vitrinite reflectance values (2.45 and 2.47 percent Ro) from two samples of black shale in the chert member indicate that these rocks reached a high level of thermal maturity within the dry gas window. Regional correlations indicate that lithofacies in the Otuk Formation vary with both structural and geographic position. For example, the shale member of the Otuk in the Wolverine Creek plate includes more limy layers and less barite (as blades, nodules, and lenses) than equivalent strata in the structurally higher Red Dog plate of the EMA, but it has fewer limy layers than the shale member in the EMA ~450 kilometers (km) to the east at Tiglukpuk Creek. The limestone member of the Otuk is thicker in the Wolverine Creek plate than in the Red Dog plate and differs from this member in EMA sections to the east in containing an upper cherty interval that lacks monotids; a similar interval is seen at the top of the Otuk Formation ~125 km to the west (Lisburne Peninsula). Our observations are consistent with the interpretations of previous researchers that Otuk facies become more distal in higher structural positions and that within a given structural level more distal facies occur to the west. Recent paleogeographic reconstructions indicate that the Otuk accumulated at a relatively high paleolatitude with a bivalve fauna typical of the Boreal realm. A suite of δ13Corg (carbon isotopic composition of carbon) data (n=38) from the upper Siksikpuk Formation through the Otuk Formation and into the Kingak(?) Shale in DDH 927 shows a pattern of positive and negative excursions similar to those reported elsewhere in Triassic strata. In particular, a distinct negative excursion at the base of the Otuk (from ‒23.8 to ‒31.3‰ (permil, or parts per thousand)) likely correlates with a pronounced excursion that marks the Permian-Triassic boundary at many localities worldwide. Another feature of the Otuk δ13Corg record that may correlate globally is a series of negative and positive excursions in the lower member. At the top of the Otuk in DDH 927, the δ13Corg values are extremely low and may correlate with a negative excursion that is widely observed at the Triassic-Jurassic boundary.

  12. Interannual variability (1979-2013) of the North-Western Mediterranean deep water mass formation: past observation reanalysis and coupled ocean-atmosphere high-resolution modelling

    NASA Astrophysics Data System (ADS)

    Somot, Samuel; Houpert, Loic; Sevault, Florence; Testor, Pierre; Bosse, Anthony; Durrieu de Madron, Xavier; Dubois, Clotilde; Herrmann, Marine; Waldman, Robin; Bouin, Marie-Nolle; Cassou, Christophe

    2015-04-01

    The North-Western Mediterranean Sea is known as one of the only place in the world where open-sea deep convection occurs (often up to more than 2000m) with the formation of the Western Mediterranean Deep Water (WMDW). This phenomena is mostly driven by local preconditioning of the water column and strong buoyancy losses during Winter. At the event scale, the WMDW formation is characterized by different phases (preconditioning, strong mixing, restratification and spreading), intense air-sea interaction and strong meso-scale activity but, on a longer time scale, it also shows a large interannual variability and may be strongly affected by climate change with impact on the regional biogeochemistry. Therefore observing, simulating and understanding the long-term temporal variability of the North-Western Mediterranean deep water formation is still today a very challenging task. We try here to tackle those issues thanks to (1) a thorough reanalysis of past in-situ observations (CTD, Argo, surface and deep moorings, gliders) and (2) an ERA-Interim driven simulation using a recently-developed fully coupled Regional Climate System Model (CNRM-RCSM4, Sevault et al. 2014). The multi-decadal simulation (1979-2013) is designed to be temporally and spatially homogeneous with a realistic chronology, a high resolution representation of both the regional ocean and atmosphere, specific initial conditions, a long-term spin-up and a full ocean-atmosphere coupling without constraint at the air-sea interface. The observation reanalysis allows to reconstruct interannual time series of deep water formation indicators (ocean surface variables, mixed layer depth, surface of the convective area, dense water volumes and characteristics of the deep water). Using the observation-based indicators and the model outputs, the 34 Winters of the period 1979-2013 are analysed in terms of weather regimes, related Winter air-sea fluxes, ocean preconditioning, mixed layer depth, surface of the convective area, deep water formation rate and long-term evolution of the deep water hydrology.

  13. Kizilcaören ore-bearing complex with carbonatites (northwestern Anatolia, Turkey): Formation time and mineralogy of rocks

    NASA Astrophysics Data System (ADS)

    Nikiforov, A. V.; Öztürk, H.; Altuncu, S.; Lebedev, V. A.

    2014-02-01

    The results of isotope-geochronological and mineralogical studies of the rocks making up the Kizilcaören fluorite-barite-REE deposit, northwestern Anatolia, Turkey are discussed in the paper. The ore is a constituent of the subvolcanic complex localized in a large fault zone. The complex combines (from earlier to later rocks): (1) phonolite and trachyte stocks, (2) carbonatite and carbonate-silicate dikelike bodies; and (3) fluorite-barite-bastnaesite ore in the form of thick homogeneous veins and cement in breccia. The K-Ar dating of silicate igneous rocks and carbonatites shows that they were formed in the Chattian Age of the Oligocene 25-24 Ma ago. Mineralogical observations show that the ore is the youngest constituent in the rock complex. Supergene alteration deeply transformed ore-bearing rocks, in particular, resulting in leaching of primary minerals, presumably Ca-Mn-Fe carbonates, and in cementation of the residual bastnaesitefluorite framework by Fe and Mn hydroxides. Most of the studied rocks contain pyrochlore, LREE fluorocarbonates, Nb-bearing rutile, Fe-Mg micas, and K-feldspar. The genetic features of the deposit have been considered. In general, the ore-bearing rock complex is compared in the set of rocks and their mineralogy and geochemistry with deposits of the Gallinas Mountains in the United States, the Arshan and Khalyuta deposits in the western Transbaikalia region, and Mushugai-Khuduk deposit in Mongolia. The Kizilcaören deposit represents a variant of postmagmatic mineralization closely related to carbonatite magmatism associated with alkaline and subalkaline intermediate rocks.

  14. Hydrogeology and quality of ground water in the Boone Formation and Cotter Dolomite in karst terrain of northwestern Boone County, Arkansas

    SciTech Connect

    Leidy, V.A.; Morris, E.E. )

    1991-01-01

    Shallow groundwater flow systems in karst terrain of northwestern Boone County, Arkansas, are particularly susceptible to contamination. The potential for groundwater contamination probably is greater in the northern one-half of the study area where there are more photolineaments and presumably subsurface fractures. Groundwater samples from 17 springs discharging from the Boone Formation and 17 wells completed in the Cotter Dolomite were analyzed to determine ambient groundwater quality and to document water quality variations. The chemical constituents in groundwater generally did not exceed US Environmental Protection Agency primary or secondary maximum contaminant levels. However, fecal coliform and fecal streptococcus bacteria were detected in most springs and in three wells. One spring, located near an abandoned wood-treatment plant (a designated Superfund site), had maximum iron, manganese, lead, and pentachlorophenol concentration that exceeded US Environmental Protection Agency's primary or secondary maximum contamination levels for drinking water. Water samples collected from selected springs emerging from the Boone Formation exhibited an overall decrease in specific conductance and total alkalinity, calcium, magnesium, sodium, and chloride concentrations and an overall increase in nitrate, fecal coliform, and fecal streptococcus bacteria concentrations 3 to 8 hours after a rainstorm.

  15. The Kharapeh orogenic gold deposit: Geological, structural, and geochemical controls on epizonal ore formation in West Azerbaijan Province, Northwestern Iran

    USGS Publications Warehouse

    Niroomand, Shojaeddin; Goldfarb, Richard J.; Moore, Farib; Mohajjel, Mohammad; Marsh, Erin E.

    2011-01-01

    The Kharapeh gold deposit is located along the northwestern margin of the Sanandaj–Sirjan Zone (SSZ) in the West Azerbaijan province, Iran. It is an epizonal orogenic gold deposit formed within the deformed zone between central Iran and the Arabian plate during the Cretaceous–Tertiary Zagros orogeny. The deposit area is underlain by Cretaceous schist and marble, as well as altered andesite and dacite dikes. Structural analysis indicates that the rocks underwent tight to isoclinal recumbent folding and were subsequently co-axially refolded to upright open folds during a second deformation. Late- to post-tectonic Cenozoic granites and granodiorites occur northeast of the deposit area. Mineralization mainly is recognized within NW-trending extensional structures as veins and breccia zones. Normal faults, intermediate dikes, and quartz veins, oriented subparallel to the axial surface of the Kharapeh antiform, indicate synchronous extension perpendicular to the fold axis during the second folding event. The gold-bearing quartz veins are >1 km in length and average about 6 m in width; breccia zones are 10–50 m in length and ≤1 m in width. Hydrothermal alteration mainly consists of silicification, sulfidation, chloritization, sericitization, and carbonatization. Paragenetic relationships indicate three distinct stages—replacement and silicification, brecciation and fracture filling, and cataclastic brecciation—with the latter two being gold-rich. Fluid inclusion data suggest mineral deposition at temperatures of at least 220–255°C and depths of at least 1.4–1.8 km, from a H2O–CO2±CH4 fluid of relatively high salinity (12–14 wt.% NaCl equiv.), which may reflect metamorphism of passive margin carbonate sequences. Ore fluid δ18O values between about 7‰ and 9‰ suggest no significant meteoric water input, despite gold deposition in a relatively shallow epizonal environment. Similarities to other deposits in the SSZ suggest that the deposit formed as part of a diachronous gold event during the middle to late Tertiary throughout the SSZ and during the final stages of the Zagros orogeny. The proximity of Kharapeh to the main tectonic suture of the orogen, well-developed regional fold systems with superimposed complex fracture geometries, and recognition of nearby volcanogenic massive sulfide systems that suggest a region characterized by sulfur- and metal-rich crustal rocks, collectively indicate an area of the SSZ with high favorability for undiscovered gold resources.

  16. Aeolian fluvial interaction: evidence for Late Quaternary channel change and wind-rift linear dune formation in the northwestern Simpson Desert, Australia

    NASA Astrophysics Data System (ADS)

    Hollands, Cameron B.; Nanson, Gerald C.; Jones, Brian G.; Bristow, Charlie S.; Price, David M.; Pietsch, Timothy J.

    2006-01-01

    In central Australia, the most easterly extent of the MacDonnell Ranges border the Simpson Desert dunefield where widely spaced strike ridges intercept and isolate pockets of broad-crested linear dunes that reflect regional changes in Late Quaternary climate, flow regime and channel avulsion. An energetic Todd River reworked the eastern part of Camel Flat basin from 75-65 ka until the Last Glacial Maximum (LGM) when it shifted eastwards, but with some flows persisting through the basin until about 10 ka. Resulting desert surfaces of different age facilitate temporal comparisons of linear dune formation. Fine-grained red dunes, 75-65 ka in age occur on the western floor of the basin and are ramped against the foot-slopes of the range. After the LGM, and especially during the Holocene, the river's departure enabled small, pale-coloured, closely spaced, coarser-textured linear dunes to form on the abandoned floodplain in the eastern basin, their orientation 20° farther west than the larger and older red dunes. This realignment indicates that the Australian wind-whorl shifted southwards some 160 km or 1.5° after the LGM. Linear dunes in the northwestern Simpson Desert were formed by wind rifting involving vertical accretion of sand from a proximal source, not by long-distance sand transport with linear extension. The blocking ranges have caused negligible downwind sediment accumulation over the past 75 ka.

  17. Quaternary basin formation along the Dien Bien Phu fault zone and its neotectonic implication of northwestern Vietnam

    NASA Astrophysics Data System (ADS)

    Lai, K.; Chen, Y.; Chung, L.; Li, P.; Lam, D.

    2006-12-01

    The Dien Bien Phu (DBP) fault zone is one of the most conspicuous fault systems in the Indochina, extending over a distance of 150 km from Yunnan, China through the NW Vietnam into Laos. Recent Global Positioning system (GPS) data in China yielded that the present clockwise rotation of the southeastern Tibet block geologically corresponds to a region of left-lateral strike-slip faults, such as the Xianshuihe-Xiaojang fault and Dien Bien Phu fault, which appear to have accommodated clockwise rotation; whereas other GPS data from the network of Southeast Asia proposed that Indochina constitutes a stable tectonic block moving approximately east with respect to Eurasia. Although above GPS data show insignificant differential motion along DBP fault, active sinistral slip can be identified by clear geomorphic features, focal solutions and seismicity distribution in a NNE-striking zone parallel to the fault zone. Mapping of surface fault traces along the DBP fault zone using field outcrops, geophysical data, and geomorphologic features recognized by the aerial photos, SRTM, ASTER imageries and derived digital elevation models shows that virtually all active faults are reactivated structures sub-parallel to chronostratigraphic boundary. Along the DBF fault, three larger basins have been developed by different kinematics from north to south. The northern one at Chan Nua is rhomboidal in shape with a dimension of 2.5 km?.5 km, which can be defined as a pull-apart basin resulted by the strike-slip motion of the DBP fault. The fault configuration associated with the central one changes to two parallel sinistral and sinistral-normal faults forming a narrow subsiding weak zone (10 km?.5 km) filled with Quaternary deposits. The southern one is, however, created by that the main DBP fault bends the strike from NNE to NE where branches out a sinistral- normal fault with N-striking controlling a half-graben basin (17 km? km) filled with Quaternary deposits about 200 m in depth above the late Neogene olivine basalt. The late Neogene basalt of age ca. 5 Ma seems being at least displaced 10 km by the branched sinistral-normal fault, giving a rate of ca. 2 mm/yr by left-lateral strike-slip since volcanic eruption. For the southern two basins, normal faulting has been confirmed occurring along their east margin, implying the NW-striking fault systems, i.e. Son La and Song Ma faults, in northwestern Vietnam are active. Although the proposed mechanisms of above-mentioned basins are still tentative, the DBP fault zone is undoubtedly undergoing extensional tectonic environment in rigid Indochina block. Further studies on basin depositional history and age determination are needed for the purpose of establishing the dynamic model of each basin and recognizing the neotectonic behavior of DBP fault.

  18. Spatial and stratigraphic distribution of water in oil shale of the Green River Formation using Fischer assay, Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Johnson, Ronald C.; Mercier, Tracey J.; Brownfield, Michael E.

    2014-01-01

    The spatial and stratigraphic distribution of water in oil shale of the Eocene Green River Formation in the Piceance Basin of northwestern Colorado was studied in detail using some 321,000 Fischer assay analyses in the U.S. Geological Survey oil-shale database. The oil-shale section was subdivided into 17 roughly time-stratigraphic intervals, and the distribution of water in each interval was assessed separately. This study was conducted in part to determine whether water produced during retorting of oil shale could provide a significant amount of the water needed for an oil-shale industry. Recent estimates of water requirements vary from 1 to 10 barrels of water per barrel of oil produced, depending on the type of retort process used. Sources of water in Green River oil shale include (1) free water within clay minerals; (2) water from the hydrated minerals nahcolite (NaHCO3), dawsonite (NaAl(OH)2CO3), and analcime (NaAlSi2O6.H20); and (3) minor water produced from the breakdown of organic matter in oil shale during retorting. The amounts represented by each of these sources vary both stratigraphically and areally within the basin. Clay is the most important source of water in the lower part of the oil-shale interval and in many basin-margin areas. Nahcolite and dawsonite are the dominant sources of water in the oil-shale and saline-mineral depocenter, and analcime is important in the upper part of the formation. Organic matter does not appear to be a major source of water. The ratio of water to oil generated with retorting is significantly less than 1:1 for most areas of the basin and for most stratigraphic intervals; thus water within oil shale can provide only a fraction of the water needed for an oil-shale industry.

  19. Spatial and stratigraphic distribution of water in oil shale of the Green River Formation using Fischer Assay, Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Johnson, Ronald C.; Mercier, Tracey J.; Brownfield, Michael E.

    2014-01-01

    The spatial and stratigraphic distribution of water in oil shale of the Eocene Green River Formation in the Piceance Basin of northwestern Colorado was studied in detail using some 321,000 Fischer assay analyses in the U.S. Geological Survey oil-shale database. The oil-shale section was subdivided into 17 roughly time-stratigraphic intervals, and the distribution of water in each interval was assessed separately. This study was conducted in part to determine whether water produced during retorting of oil shale could provide a significant amount of the water needed for an oil-shale industry. Recent estimates of water requirements vary from 1 to 10 barrels of water per barrel of oil produced, depending on the type of retort process used. Sources of water in Green River oil shale include (1) free water within clay minerals; (2) water from the hydrated minerals nahcolite (NaHCO3), dawsonite (NaAl(OH)2CO3), and analcime (NaAlSi2O6.H20); and (3) minor water produced from the breakdown of organic matter in oil shale during retorting. The amounts represented by each of these sources vary both stratigraphically and areally within the basin. Clay is the most important source of water in the lower part of the oil-shale interval and in many basin-margin areas. Nahcolite and dawsonite are the dominant sources of water in the oil-shale and saline-mineral depocenter, and analcime is important in the upper part of the formation. Organic matter does not appear to be a major source of water. The ratio of water to oil generated with retorting is significantly less than 1:1 for most areas of the basin and for most stratigraphic intervals; thus water within oil shale can provide only a fraction of the water needed for an oil-shale industry.

  20. Paleoenvironmental interpretation and palynology of outcrop and subsurface sections of the Tarija Formation (Upper Carboniferous), northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Papa, Cecilia del; Pasquo, Mercedes di

    2007-01-01

    The Tarija Formation of the Macharetí Group has been studied sedimentologically and palynologically at Zanja Honda Creek and the Zanja Honda x-1 well to assess the paleoenviromental and paleoclimatic evolution of the southern portion of the Tarija Basin. In addition, new palynological data and their implications are presented. The Tarija Formation consists mainly of thick diamictites interbedded with sandstone and mudstone layers; for the first time, a varves succession is described from the cores of the ZH x-1 well. Fifty-six spore species, 18 monosaccates, 1 praecolpate pollen grain, 4 paleophytoplankton species, and much phytodebris are recorded. The indigenous miospores are assigned to the middle portion of the Dictyotriletes bireticulatus-Cristatisporites chacoparanensis (BC) Biozone di Pasquo of early Late Carboniferous (Westphalian) age. Moreover, abundant reworked palynomorphs occur in both assemblages, recording erosion of Silurian-Early Carboniferous rocks. Some Late Carboniferous species such as Crassispora kosankei (Potonié and Kremp) Bhardwaj emend. Smith and Butterworth, Cristatisporites rollerii Ottone, and Cystoptychus azcuyi di Pasquo, exclusive of the KA Biozone, and Raistrickia radiosa Playford and Helby of the RS Biozone di Pasquo are interpreted as reworked from the lower Tupambi and Itacuamí formations. A fluviolacustrine setting is interpreted for the Tarija Formation on the basis of the presence of glacial varves, continental algae such as Botryococcus braunii Kützing, and overall facies associations. A hiatus between the fluviodeltaic interglacial Tupambi-Itacuamí depositional cycle ("Cycle I") and the fluviolacustrine, glacially influenced Itacuamí-Tarija depositional cycle ("Cycle II") is suggested by the sedimentary and palynologic data. This interpretation is confirmed by short-ranged species with biostratigraphic value, as well as the recognition of useful lithological and palynological differences helpful for characterizing both similar superposed sedimentary cycles.

  1. 3D slicing of radiogenic heat production in Bahariya Formation, Tut oil field, North-Western Desert, Egypt.

    PubMed

    Al-Alfy, I M; Nabih, M A

    2013-03-01

    A 3D block of radiogenic heat production was constructed from the subsurface total gamma ray logs of Bahariya Formation, Western Desert, Egypt. The studied rocks possess a range of radiogenic heat production varying from 0.21 μWm(-3) to 2.2 μWm(-3). Sandstone rocks of Bahariya Formation have higher radiogenic heat production than the average for crustal sedimentary rocks. The high values of density log of Bahariya Formation indicate the presence of iron oxides which contribute the uranium radioactive ores that increase the radiogenic heat production of these rocks. The average radiogenic heat production produced from the study area is calculated as 6.3 kW. The histogram and cumulative frequency analyses illustrate that the range from 0.8 to 1.2 μWm(-3) is about 45.3% of radiogenic heat production values. The 3D slicing of the reservoir shows that the southeastern and northeastern parts of the study area have higher radiogenic heat production than other parts. PMID:23291561

  2. Archean Age Fossils from Northwestern Australia (Approximately 3.3 to 3.5 GA, Warrawoona Group, Towers Formation)

    NASA Technical Reports Server (NTRS)

    Smith, Penny A. Morris

    1999-01-01

    Archean aged rocks from the Pilbara Block area of western Australia (Warrawoona Group, Towers Formation, -3.3-3.5 Ga) contain microfossils that are composed of various sizes of spheres and filaments. The first descriptions of these microfossils were published in the late 1970's (Dunlop, 1978; Dunlop, et. al., 1978). The authenticity of the microfossils is well established. The small size of the microfossils prevents isotope dating, at least with the present technology. Microbiologists, however, have established guidelines to determine the authenticity of the Archean aged organic remains (Schopf, Walter, 1992).

  3. Carbonate bodies within the basal swift formation (Jurassic) of northwestern North Dakota. Report of investigation No. 81

    SciTech Connect

    Langtry, T.M.

    1983-01-01

    The carbonate bodies of the basal Swift Formation (Upper Jurassic) occur as anomalous deflections on a relatively uniform mechanical well-log section. The areal distribution, stratigraphic relationships, and genesis of the carbonate bodies were determined using the gamma-ray log, the spontaneous-potential log, the resistivity log suite, and megascopic and microscopic core analysis. The carbonate bodies of the basal Swift Formation were found to be coarsening-upward sequences composed of predominantly sand-sized, recrystallized mollusk grains. These grains were transported by strong bottom currents across the irregular sea floor of the shallow epicontinental Jurassic sea, and were deposited under agitated water conditions in the offshore environment. These carbonate sand bodies are analogous to offshore-bar deposits of similar age that are recognized across the midcontinent region. The shape of the carbonate bodies, their high moldic porosity and good permeability of the grainstones, coupled with the seal provided by the overlying shale, makes these basal Swift carbonate bodies good reservoir rocks. The shallow depth of burial and the thermal immaturity of the surrounding shales makes it unlikely that thermally generated hydrocarbons will be found in the carbonate bodies. However,the possibility of the existence of biogenic gas, derived from the surrounding shales, makes these deposits potential sites for exploration. 66 references, 32 figures, 4 tables.

  4. The oleaginous Botryococcus from the Triassic Yanchang Formation in Ordos Basin, Northwestern China: Morphology and its paleoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Ji, Li-ming; Yan, Kui; Meng, Fan-wei; Zhao, Min

    2010-05-01

    High abundance but rather low diversity algal fossils were found in the hydrocarbon source rocks of the Ch 7-2-Ch 7-3 section, Triassic Yanchang Formation in the Xifeng area of southwest Ordos Basin, which are mainly composed of prolific Leiosphaeridia and Botryococcus. Botryococcus colonies are of various forms; the majority is nubbly, with some of cluster and cotton shape. The nubbly colonies appear globular, cordiform, ternate petal, obtuse triangle, chrysanthemum shape and so on. Most Botryococcus are saffron or brown and are frequently covered with clay under transmission microscope, and shows strong yellow and light brown under fluorescence microscope. Botryococcus could live in freshwater and brackish water. The Botryococcus colonies that lived in fresh water are small with small single cells arranged radially, with undulant or indented edges. The Botryococcus colonies that lived in brackish water are bigger, with larger single cells arranged irregularly, with slippery contours. The most of Botryococcus are discovered from the organic-rich argillaceous sediment with abundant pyrites in the semi- and deep-lake facies, and shows they were preserved in low-energy reducing environments. Taphonomic characteristics of various microfossils and the present of Pediastrum in the phytoplankton flora indicate that they are in situ or near burial. The lake area of the Ordos Basin was gradually expanding and reaching its most extensive flood surface in the Ch 7 of Yanchang Formation interval during the Middle and Late Triassic, with warm climate, plentiful rainfall, and luxuriant vegetation, as determined by the environmental analysis with Botryococcus in Xifeng area. The presence of two ecological types of Botryococcus indicates that the salinity of lake water was fluctuating in the Ch 7 interval. The occurrence of symbiotic acritarchs and geochemical salinity indices show that the Ordos Lake was a typical fresh-water lake, which was gradually desalted, and its salinity fluctuation was narrow during the Mid-Later Triassic. The ecological type of the palynological flora discovered from the Ch 7 to Ch 8 in Xifeng area is similar to that from the Fuxian Lake, with abundant Botryococcus in the Yungui Plateau of China. These findings imply that the Ordos Basin was in a lower-latitude area of temperate to subtropical climate during the Middle and Late Triassic.

  5. Regional distribution and chronostratigraphy of the Qusaiba member of the Qalibah formation in the Nafud Basin, Northwestern Saudia Arabia

    SciTech Connect

    Aoudeh, S.M.; Al-Hajri, S.A.

    1995-08-01

    The Qusaiba Member of the Qalibah Formation (Silurian age) is a thick sequence consisting of massive dark gray shales. Only the very basal shales are black and highly organic rich. The basal {open_quote}Hot Shale{close_quote} unit is a prolific source correlated to all the Paleozoic discoveries in Central and Eastern Saudi Arabia. In the Nafud Basin, Northwest Saudi Arabia, this same sequence acts as both source and seal to the underlying Ordovician reservoir, making the understanding of this sequence essential to the current exploration program underway in the region. Acquiring high resolution blostratigraphy and detailed source rock analysis substantially contributed to the better understanding of the regional depositional setting of the seal, source, and the reservoirs in the area. Graptolites and chitinozoans zonation were utilized to fine-tune the chronostratigraphy and to further subdivide this huge basin into more manageable subbasins. Regional chronostratigraphic analysis has indicated that the early Qusaiba transgression took place swiftly and covered all of the Arabian plate during early Rhuddanian time. Only high areas not covered by the Rhuddanian transgression and areas that experienced later uplift and erosion lack the Rhuddanian deposits.

  6. Monitoring of Intense Events of Deep Water Formations in the Northwestern Mediterranean over the last five years

    NASA Astrophysics Data System (ADS)

    Houpert, Loïc; Durrieu de Madron, Xavier; Testor, Pierre; Bosse, Anthony; Mortier, Laurent

    2014-05-01

    A multi-platforms and integrated monitoring system in the framework of the Mediterranean Ocean Observing System on Environment (MOOSE) enables to monitor the deep water formation processes. Since 2007, it provides high frequency in-situ temperature, salinity vertical profiles, derived from CTD measurements on moorings, ships, and gliders, as well as horizontal and vertical currents from moorings. The aim of this study is to investigate the temporal scales associated to the deep convection phases. We also studied the interannual variability of the deep convection and its implication in the evolution of deep water thermohaline characteristics. Recent measurements from the mooring lines reveal the temporal evolution of the physical processes interfering in the phases of deep convection. Horizontal currents were strongly equivalent barotropic during each deployment and strong currents were also recorded during the different events of deep ocean convection: high frequencies vertical velocities exceeded 10 cm.s-1 during the violent vertical mixing phase and strong mesoscale horizontal currents reached 40cm.s-1 during the spreading/restratification phase. Using a eddy-detection method based on a kinematic model, more than 34 eddies crossing the mooring line were detected between November 2009 and July 2012, 19 cyclones and 15 anticyclones. The radii (resp. velocities) ranging from 1.9 km to 20.0 km (resp. 2.5 cm.s-1 to 25.1 cm.s-1 ). The main mode of the distribution of eddies radii is centered at 4km for the cyclones and 5km for the anticyclones. The apparition of newly-formed deep waters was detected in winter 2009, 2010, 2011 and 2012. In winter 2010, two newly-formed deep waters were detected after the deep convection event, both present a different potential temperature but a similar salinity, suggesting that both might be formed in the cyclonic gyre, but in different locations. In 2012, two new deep waters were detected at the mooring location, one was identified as a result of open-ocean deep convection, while the other seems to be the result of a dense shelf water cascading event that occurred in winter 2012.

  7. Sequence stratigraphy, sedimentary systems and petroleum plays in a low-accommodation basin: Middle to upper members of the Lower Jurassic Sangonghe Formation, Central Junggar Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Feng, Youliang; Jiang, Shu; Wang, Chunfang

    2015-06-01

    The Lower Jurassic Junggar Basin is a low-accommodation basin in northwestern China. Because of low subsidence rates and a warm, wet climate, deposits of the Central subbasin of the Junggar Basin formed from fluvial, deltaic, shallow lake facies. Sequence stratigraphy and sedimentary systems of the Lower Jurassic members of the Sangonghe Formation (J1s) were evaluated by observing cores, interpreting wireline logs and examining seismic profiles. Two third-order sequences were recognized in the strata. The distribution of the sedimentary systems in the systems tracts shows that tectonic movement, paleorelief, paleoclimate and changes in lake level controlled the architecture of individual sequences. During the development of the lowstand systems tract (LST), the intense structural movement of the basin resulted in a significant fall in the water level in the lake, accompanied by rapid accommodation decrease. Braided rivers and their deltaic systems were also developed in the Central Junggar Basin. Sediments carried by braided rivers were deposited on upward slopes of the paleorelief, and braid-delta fronts were deposited on downward slopes. During the transgressive systems tract (TST), the tectonic movement of the basin was quiescent and the climate was warm and humid. Lake levels rose and accommodation increased quickly, shoal lines moved landward, and shore- to shallow-lake deposits, sublacustrine fans and deep-lake facies were deposited in shallow- to deep-lake environments. During the highstand systems tract (HST), the accommodation no longer increased but sediment supply continued, far exceeding accommodation. HST deposits slowly formed in shallow-lake to meandering river delta-front environments. Relatively low rates of structural subsidence and low accommodation resulted in coarse-grained successions that were fining upward. Deposits were controlled by structural movement and paleorelief within the LST to TST deposits in the Central subbasin. Fine- to medium-grained coarsening-upward successions developed during the HST. The sand bodies of braid-delta fronts on the downward slopes of the paleorelief in the LST and the sublacustrine fans in the TST became reservoirs for hydrocarbon accumulation. Petroleum plays have only been found in the Sangonghe Formation (J1s) located on structural ridges that consist of sand bodies comprising these sequences. Favorable conditions for petroleum plays in HST1-LST2 occur where the sand bodies have been fractured by faults and sealed by denudation and pinch-out lines, then overlain by deep lake mudstone in TST2. The favorable condition of the sand bodies within TST2 occurs where isolated sand bodies have been fractured by faults.

  8. Geohydrology of the aquifers that may be affected by the surface mining of coal in the Fruitland Formation in the San Juan Basin, northwestern New Mexico

    USGS Publications Warehouse

    Myers, R.G.; Villanueva, E.D.

    1986-01-01

    A monitoring network of 50 wells was installed from 1975 to 1979 in the surface-mineable coal area. The purpose of the network was to collect hydrologic data and to establish a data base. The hydrologic data consist of water level measurements, water chemistry, and selected aquifer characteristics. The four aquifers considered in this study are: (1) The Pictured Cliffs Sandstone; (2) coal seams and interbedded lithologic units of the Fruitland Formation; (3) overburden of the Kirtland Shale and Fruitland Formation; and (4) the alluvium along the Chaco River and its eastern and northeastern tributaries. Five sites were selected for study. Four of these sites, Western Coal Company 's lease near Fruitland, Bisti West, Kimbeto, and Ojo Encino, have surface-mineable coal. The Chaco River alluvium was selected because it is downstream from anticipated mining activity. The specific conductances of the representative water samples from selected wells in the 4 aquifers in the 5 study areas ranged from 800 to 23,000 microsiemens/cm at 25 C. The dominant cation in all samples was sodium. The water is brackish in the Pictured Cliffs Sandstone and in the coal seams and interbedded lithologic units of the Fruitland Formation. It is fresh to saline in the overburden of the Fruitland Shale and Fruitland Formation, and fresh to brackish in the Chaco River alluvium. (Author 's abstract)

  9. Petrologic and experimental evidence for the etching of garnets by organic acids in the upper Jurassic Morrision Formation, northwestern New Mexico.

    USGS Publications Warehouse

    Hansley, P.L.

    1987-01-01

    Etching of garnets and partial to complete dissolution of other aluminosilicate minerals were caused by high concentrations of organic acids generated during the maturation of epigenetic organic matter (predominantly type-III kerogen) in the Morrison Formation. The presence of authigenic phases that form near 100oC indicates that temperatures were high enough during diagenesis to cause the thermal degradation of kerogen.-from Author

  10. Blastomycosis in Northwestern Ontario

    PubMed Central

    McIntyre, Lynn

    1985-01-01

    Nine cases of blastomycosis were seen at the Sioux Lookout Zone Hospital in northwestern Ontario from 1970 to 1983. Although this region has been described as a focus of endemic infection, little published information is available. Seven male and two female Canadian Indians, aged 4-54 years, acquired the infection. Three children were infected; a mother and her son became ill one month apart. All cases presented as progressive pulmonary disease and no extrapulmonary involvement was found. Delay in diagnosis ranged from 11 days to eight weeks, with a mean of 31 days. Patients generally responded favorably to treatment with amphotericin B. Epidemiologic data suggest that environmental, geographic, occupational and recreational determinants are necessary factors in disease acquisition. PMID:21279155

  11. Biogenic Iron-Rich Filaments in the Quartz Veins in the Uppermost Ediacaran Qigebulake Formation, Aksu Area, Northwestern Tarim Basin, China: Implications for Iron Oxidizers in Subseafloor Hydrothermal Systems.

    PubMed

    Zhou, Xiqiang; Chen, Daizhao; Tang, Dongjie; Dong, Shaofeng; Guo, Chuan; Guo, Zenghui; Zhang, Yanqiu

    2015-07-01

    Fe-(oxyhydr)oxide-encrusted filamentous microstructures produced by microorganisms have been widely reported in various modern and ancient extreme environments; however, the iron-dependent microorganisms preserved in hydrothermal quartz veins have not been explored in detail because of limited materials available. In this study, abundant well-preserved filamentous microstructures were observed in the hydrothermal quartz veins of the uppermost dolostones of the terminal-Ediacaran Qigebulake Formation in the Aksu area, northwestern Tarim Basin, China. These filamentous microstructures were permineralized by goethite and hematite as revealed by Raman spectroscopy and completely entombed in chalcedony and quartz cements. Microscopically, they are characterized by biogenic filamentous morphologies (commonly 20-200 μm in length and 1-5 μm in diameter) and structures (curved, tubular sheath-like, segmented, and mat-like filaments), similar to the Fe-oxidizing bacteria (FeOB) living in modern and ancient hydrothermal vent fields. A previous study revealed that quartz-barite vein swarms were subseafloor channels of low-temperature, silica-rich, diffusive hydrothermal vents in the earliest Cambrian, which contributed silica to the deposition of the overlying bedded chert of the Yurtus Formation. In this context, this study suggests that the putative filamentous FeOB preserved in the quartz veins might have thrived in the low-temperature, silica- and Fe(II)-rich hydrothermal vent channels in subseafloor mixing zones and were rapidly fossilized by subsequent higher-temperature, silica-rich hydrothermal fluids in response to waning and waxing fluctuations of diffuse hydrothermal venting. In view of the occurrence in a relatively stable passive continental margin shelf environment in Tarim Block, the silica-rich submarine hydrothermal vent system may represent a new and important geological niche favorable for FeOB colonization, which is different from their traditional habitats reported in hydrothermal vent systems at oceanic spreading centers or volcanic seamounts. Thus, these newly recognized microfossils offer a new clue to explore the biological signatures and habitat diversity of microorganisms on Earth and beyond. PMID:26168395

  12. Structural geology of northwestern Ohio

    SciTech Connect

    Wickstrom, L.H.; Gray, J.D.

    1987-09-01

    Recently developed structure contour maps for the Cambrian and Ordovician strata show the northwestern Ohio area to be much more structurally complex than previously noted. These new maps illustrate several new faults and structural trends. Analysis of these faults indicates that northwestern Ohio is broken by a series of wrench faults, with associated folding. Vertical displacement is noted along some of these wrench faults. Fault-plane solutions from this area reveal a dominant compressive stress direction from the southeast. This stress orientation would be consistent with those generated during the Taconic orogeny. Timing indicators from seismic analysis reveal one episode of faulting occurred shortly after deposition of the Trenton Limestone. At least one episode of movement has occurred since that time, as evidenced by displacement within the Silurian bedrock. Furthermore, seismic, gravity, and magnetic surveys indicate that preexisting weaknesses within the Precambrian may have influenced the position of many of the structural features noted.

  13. Middle cretaceous carbonate reservoirs, Fahud Field and northwestern Oman: discussion

    SciTech Connect

    Brennan, P.

    1985-05-01

    A discussion is presented of the Cretaceous formations involved in Fahud field. Along the Trucial Coast, as in northwestern Oman, it is not difficult to date the time of formation of the foredeep. This article provides a stratigraphic correlation chart for the Cretaceous along the Arabian side of the Arabian Gulf. The terminology presented on this correlation chart reflects oil-industry usage in the area, including correlations published by Owen and Nasr, Loutfi and Jaber, Arabian American Oil Company, Beydoun and Dunnington, and Hassan et al.

  14. Scholarship, Policy, and Personal Development at Northwestern.

    ERIC Educational Resources Information Center

    Leviton, Laura C.

    2003-01-01

    Describes the author's experiences in the evaluation training program at Northwestern University (1978-1980) in a postdoctoral fellowship in methodology and evaluation research. Also discusses the value of the friendships and professional relationships formed at that time. (SLD)

  15. Northwestern Memorial Hospital v. Ashcroft.

    PubMed

    2004-01-01

    Court Decision: 362 Federal Reporter, 3d Series 923; 2004 Mar 26 (date of decision). The U.S. Court of Appeals for the Seventh Circuit affirmed a lower court decision that quashed a Department of Justice subpoena seeking late-term abortion patients' medical records because the subpoena unduly burdened the hospital and provided limited probative value compared to the consequent harm to patients and the hospital. The Department of Justice issued Northwestern Memorial Hospital a subpoena seeking records for use in a case challenging the constitutionality of the Partial-Birth Abortion Ban Act. Although the administrative hardship of compliance would be modest, the Seventh Circuit found that, as a result of compliance, the hospital could lose the confidence of its patients, people could be inclined to seek care at other hospitals, and there would be an invasion of patient privacy even if there is no possibility of learning the patient's identity. The burden of compliance would exceed the benefit of producing the requested medical records. The court declined to base its holding on Health Insurance Portability and Accountability Act (HIPAA) regulations or federal common law and found that neither privileged the information sought by the subpoena. PMID:16477725

  16. The age and tectonic setting of the Puncoviscana Formation in northwestern Argentina: An accretionary complex related to Early Cambrian closure of the Puncoviscana Ocean and accretion of the Arequipa-Antofalla block

    NASA Astrophysics Data System (ADS)

    Escayola, Mónica P.; van Staal, Cees R.; Davis, William J.

    2011-12-01

    TIMS and SHRIMP U-Pb zircon geochronology of selected parts of the Puncoviscana Formation suggest its deposition took place mainly during the Early Cambrian, coeval with 540-535 Ma calc-alkaline Pampean arc volcanism mainly preserved as tuff beds in the oldest identified parts of this unit. Syn- to post-tectonic plutons constrains the Tilcarian-Pampean orogeny to have occurred between ca. 530 Ma and deposition of the unconformably overlying Middle-Upper Cambrian Meson Group. Deposition of the Puncoviscana Formation continued after the onset of the Tilcarian-Pampean orogeny. We propose that the Puncoviscana Formation rocks older than 530 Ma were deposited in the arc-trench gap of the west-facing Pampean arc and/or the associated trench, whereas the rocks younger than 530 Ma were deposited in a syn-collision foreland basin. The Puncoviscana Formation rocks were progressively assembled into a west-younging accretionary complex, consistent with the style of deformation and low-grade metamorphism. The age of the syn-collision plutons (≤530 Ma) suggest the foredeep deposits record the transition from trench to foreland basin, due to arrival of the Arequipa-Antofalla block at the west-facing trench at ca. 530 Ma. Our geochronological and Pb-isotope investigations suggest that the Arequipa-Antofalla terrane was a coherent, ribbon-shaped crustal block that also included the western part of the Pampia terrane. A compilation of existing U-Pb zircon studies suggests that the Pampean arc extended along the length of the proto-Andean margin of West Gondwana, represented by the previously amalgamated Amazonia and Rio de La Plata cratons, and probably was initiated during the late Ediacaran after 600 Ma. Following earlier workers, we reaffirm that the Arequipa-Antofalla block was originally separating Laurentia and Amazonia in Rodinia. It probably rifted from Laurentia during the Ediacaran between 600 and 570 Ma, following an earlier departure of Amazonia (˜650 Ma?). The separation of Arequipa-Antofalla from Amazonia and Laurentia opened the Puncoviscana and Iapetus oceans respectively.

  17. Northwestern University School of Speech: A History.

    ERIC Educational Resources Information Center

    Rein, Lynn Miller

    This book presents a concise history of the first 100 years of development of the school of speech at Northwestern University (Illinois). Following an introduction that provides an overview of the school, the first chapter focuses on both the efforts of Robert McLean Cumnock to found a school of oratory on the principles of elocution and the…

  18. Geology of the lower Yellow Creek area, northwestern Colorado

    SciTech Connect

    Hail, W.J. Jr.

    1990-01-01

    The geology and resources of the lower Yellow Creek area, an area at the northwestern margin of the Piceance Creek basin comprising of four 7.5-minute quadrangles, are described. Subsurface face rocks penetrated by drill holes range in age from Pennsylvania to Cretaceous. Measured sections show the Mancos Shale and the Castlegate Sandstone, Iles Formation, and Williams Fork Formation of the Mesaverde Group of Late Cretaceous age and the Fort Union, Wasatch, Green River, and Uinta formations of Tertiary age. Surficial deposits of Quaternary age include terrace gravels, alluvium, and landslides. Fold axes and faults in the area trend northwesterly. The southern part of the area contains major oil-shale resources. Coal-bearing zones in the Williams Fork and Iles formations contain considerable coal. The coal-resources potential is limited, however, by nonpersistence of the thicker coal beds. Small amounts of gas have been produced from shallow, lenticular Tertiary sandstones. Large, but very lowgrade uranium resources are present in the Fort Union Formation.

  19. Uranium mine waste water: potential source of ground water in northwestern New Mexico

    USGS Publications Warehouse

    Hiss, W.L.

    1977-01-01

    Substantial quantities of water are being pumped from the Morrison Formation of Late Jurassic age in uranium mines in the Grants mineral belt in northwestern New Mexico. The water often contains unacceptable amounts of dissolved uranium, radium, iron, and selenium and suspended solids, but with treatment it can be made suitable for municipal and industrial purposes. Water salvaged from current and projected mining operations constitutes the most readily available water in this otherwise water-deficient area.

  20. Flood of September 2008 in Northwestern Indiana

    USGS Publications Warehouse

    Fowler, Kathleen K.; Kim, Moon H.; Menke, Chad D.; Arvin, Donald V.

    2010-01-01

    During September 12-15, 2008, rainfall ranging from 2 to more than 11 inches fell on northwestern Indiana. The rainfall resulted in extensive flooding on many streams within the Lake Michigan and Kankakee River Basins during September 12-18, causing two deaths, evacuation of hundreds of residents, and millions of dollars of damage to residences, businesses, and infrastructure. In all, six counties in northwestern Indiana were declared Federal disaster areas. U.S. Geological Survey (USGS) streamgages at four locations recorded new record peak streamflows as a result of the heavy rainfall. Peak-gage-height data, peak-streamflow data, annual exceedance probabilities, and recurrence intervals are tabulated in this report for 10 USGS streamgages in northwestern Indiana. Recurrence intervals of flood-peak streamflows were estimated to be greater than 100 years at six streamgages. Because flooding was particularly severe in the communities of Munster, Dyer, Hammond, Highland, Gary, Lake Station, Hobart, Schererville, Merrillville, Michiana Shores, and Portage, high-water-park data collected after the flood were tabulated for those communities. Flood peak inundation maps and water-surface profiles for selected streams were made in a geographic information system by combining high-water-mark data with the highest resolution digital elevation model data available.

  1. Basin development, petrology, and paleogeography - Early Permian carbonates, northwestern Bolivia

    SciTech Connect

    Canter, K.L.; Isaacson, P.E. )

    1990-05-01

    Early Permian carbonate rocks of the Yaurichambi Formation in northwestern Bolivia demonstrate in-situ, low-paleolatitude development within a complexly interbedded sequence punctuated by siliciclastics apparently derived from a western source. The Yaurichambi Formation (Copacabana Group) occurs above a regional caliche surface that caps Upper Carboniferous quartzarenites. Lower beds of the formation are characterized by interbedded carbonate and quartz-rich lithologies. This interval is gradationally overlain by a shallowing-upward, carbonate-dominated sequence. Mud-rich wackestones and packstones grade upward to bioclastic packstones and grainstones. Common allochems in bioclastic-rich lithologies include echinoderms, brachiopods, fenestrate bryozoans, intraclasts, and less common corals. Uppermost beds contain abundant siliciclastic interbeds. Where exposed, this carbonate sequence is terminated by the Tiquina Sandstone. Permian rocks were deposited in a northwest-southeast-oriented basin. Siliciclastic flooding from the western and southwestern margin of the basin dominated throughout the Carboniferous and occurred intermittently during the Permian, with apparent shallowing to the south. A low-latitude paleogeographic setting for these rocks is indicated by the carbonate lithologies dominating the Lower Permian sequence. Sedimentary and diagenetic features diagnostic of semi-arid warm-water deposition include penecontemporaneous dolomites, fenestral fabric, and calcretes. Furthermore, the faunas are similar to those found in equivalent strata of the Permian basin area of west Texas, indicating that deposition occurred at relatively low latitudes.

  2. Exploration strategy in Keg River carbonates of northwestern Alberta, Canada

    SciTech Connect

    Majid, A.H.

    1987-05-01

    The analysis of reservoir quality and seal capacity of the Middle Devonian Keg River carbonate reservoirs in northwestern Alberta requires facies studies of rock units of the Keg River Formation and of the overlying Muskeg and Sulphur Point formations. Using lithologic criteria, faunal type, and stratigraphic positions, the entire sequence is subdivided into ten major facies. The system used is that of standard facies belts with second-order modification to Wilson's terminology. These facies are (from basin to land): basin, open sea shelf, toe of slope, foreslope, organic buildup, shoal lime sand, open lagoon, restricted lagoon, tidal flats, and sabkha evaporites. The upper member of the Keg River Formation is the main hydrocarbon reservoir in the study area. It consists of floatstone, rudstone, and boundstone with wackestone, packstone, and grainstone matrix. The principal faunal constituents are crinoids, brachiopods, stromatoporoids, corals, and stachyodes. The reservoir porosity is of primary intergranular and intragranular and secondary vugular textures. The upper Keg River member is composed of two major facies: patch reefs and banks. Both facies are formed in an open lagoon environment fronted by Presqu'ile barrier to the west-northwest. Water depth was the main factor in controlling the distribution of the bank and patch reef facies. Patch reefs were developed in areas of deeper water, whereas banks were formed in shallower areas of the open lagoon. Recent analogs of the Keg River buildups are found on the Bermuda Platform and Belize Shelf. A direct relationship exists between the thickness of overlying anhydrites of the Muskeg Formation and hydrocarbon occurrences in the Keg River Formation. Generally in areas where patch reefs are developed, the thickness of the anhydrite is more than 30 ft. However, areas of bank are covered by less than 30 ft of anhydrite.

  3. Geology and petroleum resources of northwestern Africa

    SciTech Connect

    Peterson, J.A.; Klemme, H.D.

    1986-05-01

    The main onshore basins of northwestern Africa are (1) basins in the Atlas folded geosynclinal belt adjacent to the Mediterranean Sea, (2) the Tindouf, Bechar, and Reggane basins of western Algeria and southern Morocco, and (3) the Taoudeni basin of Mauritania and Mali. Coastal basins are (1) the Essaouria basin of southwestern Morocco, (2) the Tarfaya basin of Western Sahara, (3) the Senegal basin of Senegal and western Mauritania, (4) the Sierra Leone-Liberia basin, and (5) the Ivory Coast basin. The petroleum geology and resource potential of these basins is detailed.

  4. Biostratigraphic interpretation for the cyclic sedimentation in northwestern Libya

    SciTech Connect

    Tekbali, A.O.; Cornell, W.C. Dept. of Geological Sciences)

    1993-02-01

    Mesozoic sediments in western Libya are best exposed along the Jabal Nafusah escarpment. This northeast-southwest trending structure overlooks the Al Jifarah plain and extends more than 300 km westward to connect with a T-shaped anticlinorium in Algeria and Tunisia. The Al Aziziyan fault (normal, north side down) parallels the northern edge of the escarpment and marks its initial position. Alternate deposition of marine and continental sediments began in the Triassic before the formation of a major monocline in the Late Jurassic-Early Cretaceous time. Subsequent epiorogenic movements and isostatic adjustments initiated a westward sloping shelf along the southern edge of the Tethys. As a result, the eastern and central regions of western Libya were subjected to severe erosion and coalescing of unconformities towards the topographic highs, prior to the deposition of the overstepping Kiklah Formation. Geometrical and physical interpretation of the Mesozoic sediments in the region, combined with paleogeographic reconstruction indicate that the post-Hercynian epiorogenic adjustments and fluctuations of the Tethys resulted in local cyclic sedimentation. Accurate age assessment of the boundaries between the Jurassic-Early Cretaceous facies in northwestern Libya can be carried out on the basis of microfloral and faunal distribution and makes possible correlation of aquifers and probable oil-bearing sequences in western Libya.

  5. Vertebrate-bearing eolian unit from the Ogallala Group (Miocene) in northwestern Texas

    SciTech Connect

    Winkler, D.A.

    1987-08-01

    The upper Couch Formation is part of the lower of two formations composing the Ogallala Group in Blanco and Yellowhouse canyons in northwestern Texas. An eolian origin for the upper Couch Formation is indicated by its mean grain size, pedogenic carbonate nodules, massive bedding, and blanketlike morphology. The unit conforms poorly to the usual eolian depositional models; it resulted from a combination of the processes involved in loess and sand-sheet formation. Grassland or savanna vegetation probably existed over the area and aided in sediment trapping. Vertebrates are unusual in eolian units, but the adaptations and mode of preservation of those in the upper Couch Formation also support an eolian interpretation. This and other widespread silty sand sheets in the Ogallala indicate major fluctuations in depositional style, possibly climatically controlled. Lateral continuity and preservation of vertebrates give silty sand sheets great potential as correlation tools.

  6. Biogeochemistry of a treeline watershed, northwestern Alaska

    USGS Publications Warehouse

    Stottlemyer, R.

    2001-01-01

    Since 1950, mean annual temperatures in northwestern Alaska have increased. Change in forest floor and soil temperature or moisture could alter N mineralization rates, production of dissolved organic carbon (DOC) and organic nitrogen (DON), and their export to the aquatic ecosystem. In 1990, we began study of nutrient cycles in the 800-ha Asik watershed, located at treeline in the Noatak National Preserve, northwestern Alaska. This paper summarizes relationships between topographic aspect, soil temperature and moisture, inorganic and organic N pools, C pools, CO2 efflux, growing season net N mineralization rates, and stream water chemistry. Forest floor (O2) C/N ratios, C pools, temperature, and moisture were greater on south aspects. More rapid melt of the soil active layer (zone of annual freeze-thaw) and permafrost accounted for the higher moisture. The O2 C and N content were correlated with moisture, inorganic N pools, CO2 efflux, and inversely with temperature. Inorganic N pools were correlated with temperature and CO2 efflux. Net N mineralization rates were positive in early summer, and correlated with O2 moisture, temperature, and C and N pools. Net nitrification rates were inversely correlated with moisture, total C and N. The CO2 efflux increased with temperature and moisture, and was greater on south aspects. Stream ion concentrations declined and DOC increased with discharge. Stream inorganic nitrogen (DIN) output exceeded input by 70%. Alpine stream water nitrate (NO-3) and DOC concentrations indicated substantial contributions to the watershed DIN and DOC budgets.

  7. Exhumation history of the Northwestern Tibet

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Huan; Lee, Yuan-His; Xin, Wang

    2015-04-01

    In order to reveal the exhumation history in northwestern Tibet we use fission track, U-Th/He dating to revealtheexhumation history along the mountain front of eastern side of the Pamir plateau (western side of Kunglun Mountain). The structural style shows thrusting and strike-slip fault dominantly in the mountain front and it becomes normal fault dominantly in the internal of the mountain belt. We collect two 40 km length transects from deformation front to mountain belt. The preliminary results show the resetzircon fission track ages range from ca.25 to 7 Ma, the Zircon U-Th/He ages range fromca. 2-17Ma, apatite fission track ages range from ca. 3-6 Ma, and apatite U-Th/He range fromca. 2-10Ma. Some Zircon and apatite U-Th/He ages are similar ca. 2 and 5 Ma that indicates the developing timing of shear zone. The preliminary result shows the Cenozoic exhumation started from ca. 25 Ma and increases the exhumation rate since the ca. Pliocene in northwestern Tibet. The exhumation amount and rate progressively increases from southeast to northwest that is consistent with the topography variation. We suspect that increasing the exhumation rate and topography toward to the northwest result from the collision between the India plate and Eurasia plate.

  8. Seismicity and seismotectonics of northwestern Libya

    NASA Astrophysics Data System (ADS)

    Ben Suleman, Abdunnur; Elmeladi, Abdalla

    2014-05-01

    As a result of the relative motion of the African and European plates, Libya has experienced a considerable intraplate tectonism particularly at its northern regions. In this study we investigate the seismic activity and the seismotectonics of northwestern Libya. The northwestern part of Libya has experienced a number of earthquakes including earthquakes of magnitude greater than six. The seismic activity shows three major seismic trends. The first trend is a NW-SE trending cluster of seismicity coinciding with the eastern boarder of the Hun Graben. A second trend is also a NW-SE direction in the offshore area northern of the city of Misuratah. The third cluster was located in the western Gulf of Sirt. The rest of seismicity is diffuse either offshore or in land, with no good correlation with well-mapped faults. Fault plane solution was estimated for 17 earthquakes recorded by the Libyan National Seismograph Network. Fault plain solution for the first area suggests oblique reverse to strike slip faulting with dominant compressional P-axes trending NW-SE and NE-SW. The second area suggests strike-slip to reverse faulting with dominant compressional P-axes trending NW-SE and NE-SW. Fault plain solution for 3 earthquakes located southern Tripoli suggests an oblique normal faulting with dominant compressional P-axes trending E-W to NE-SW. Further west to the Tunisian boarder, fault plain solution suggests oblique normal faulting with dominant compressional P-axes trending NW-SE.

  9. Biogeochemistry of a treeline watershed, northwestern Alaska.

    PubMed

    Stottlemyer, R

    2001-01-01

    Since 1950, mean annual temperatures in northwestern Alaska have increased. Change in forest floor and soil temperature or moisture could alter N mineralization rates, production of dissolved organic carbon (DOC) and organic nitrogen (DON), and their export to the aquatic ecosystem. In 1990, we began study of nutrient cycles in the 800-ha Asik watershed, located at treeline in the Noatak National Preserve, northwestern Alaska. This paper summarizes relationships between topographic aspect, soil temperature and moisture, inorganic and organic N pools, C pools, CO2 efflux, growing season net N mineralization rates, and stream water chemistry. Forest floor (O2) C/N ratios, C pools, temperature, and moisture were greater on south aspects. More rapid melt of the soil active layer (zone of annual freeze-thaw) and permafrost accounted for the higher moisture. The O2 C and N content were correlated with moisture, inorganic N pools, CO2 efflux, and inversely with temperature. Inorganic N pools were correlated with temperature and CO2 efflux. Net N mineralization rates were positive in early summer, and correlated with O2 moisture, temperature, and C and N pools. Net nitrification rates were inversely correlated with moisture, total C and N. The CO2 efflux increased with temperature and moisture, and was greater on south aspects. Stream ion concentrations declined and DOC increased with discharge. Stream inorganic nitrogen (DIN) output exceeded input by 70%. Alpine stream water nitrate (NO3-) and DOC concentrations indicated substantial contributions to the watershed DIN and DOC budgets. PMID:11790005

  10. Digital surfaces and thicknesses of selected hydrogeologic units within the Ozark Plateaus aquifer system, northwestern Arkansas

    USGS Publications Warehouse

    Czarnecki, John B.; Bolyard, Susan E.; Hart, Rheannon M.; Clark, Jimmy M.

    2014-01-01

    Digital surfaces and thicknesses of nine hydrogeologic units of the Ozark Plateaus aquifer system from land surface to the top of the Gunter Sandstone in northwestern Arkansas were created using geophysical logs, drillers’ logs, geologist-interpreted formation tops, and previously published maps. The 6,040 square mile study area in the Ozark Plateaus Province includes Benton, Washington, Carroll, Madison, Boone, Newton, Marion, and Searcy Counties. The top of each hydrogeologic unit delineated on geophysical logs was based partly on previously published reports and maps and also from drillers’ logs. These logs were then used as a basis to contour digital surfaces showing the top and thickness of the Fayetteville Shale, the Boone Formation, the Chattanooga Shale, the Everton Formation, the Powell Dolomite, the Cotter Dolomite, the Roubidoux Formation, the Gasconade Dolomite, and the Gunter Sandstone.

  11. Solimoes megashear: Intraplate tectonics in northwestern Brazil

    SciTech Connect

    Caputo, M.V. )

    1991-03-01

    A belt of deformation in the Solimoes basin of northwestern Brazil extends east-northeast from near the Peruvian border for about 1300 km. The belt is characterized by the en echelon arrangement of folds and faults interpreted as the result of right-slip displacements in a transpressive regime. The structures were formed during Late Jurassic time, probably due to collision of South America with allochthonous terranes as the opening of the South Atlantic Ocean began. The Iquitos arch near the western end of the megashear separates the Solimoes basin from Subandean basins. The development of the Iquitos arch is interpreted to be related to orogenic loading along western South America by the Andean mountain belt. In Brazil, folds and faults associated with the Solimoes megashear hold hydrocarbons within Paleozoic strata, and 15 gas and oil fields have so far been discovered.

  12. The Northwestern University Neuroimaging Data Archive (NUNDA).

    PubMed

    Alpert, Kathryn; Kogan, Alexandr; Parrish, Todd; Marcus, Daniel; Wang, Lei

    2016-01-01

    The Northwestern University Neuroimaging Data Archive (NUNDA), an XNAT-powered data archiving system, aims to facilitate secure data storage; centralized data management; automated, standardized data processing; and simple, intuitive data sharing. NUNDA is a federated data archive, wherein individual project owners regulate access to their data. NUNDA supports multiple methods of data import, enabling data collection in a central repository. Data in NUNDA are available by project to any authorized user, allowing coordinated data management and review across sites. With NUNDA pipelines, users capitalize on existing procedures or standardize custom routines for consistent, automated data processing. NUNDA can be integrated with other research databases to simplify data exploration and discovery. And data on NUNDA can be confidently shared for secure collaboration. PMID:26032888

  13. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology

    NASA Astrophysics Data System (ADS)

    Li, Jiyan; Dong, Zhibao; Qian, Guangqiang; Zhang, Zhengcai; Luo, Wanyin; Lu, Junfeng; Wang, Meng

    2016-03-01

    The northwestern Qaidam Basin exposes one of the largest and highest elevation yardang fields on Earth. The aim of the present study was to describe the distribution and morphology of these yardangs, and analyze the factors responsible for the distribution pattern of these aeolian landforms. The yardang fields are bounded by piedmont alluvial-diluvial fans from the mountain ranges surrounding the basin, except in the south, where they are bounded by dune fields, dry salt flats, lakes, and rivers. This distribution pattern can be attributed to regional tectogenesis and its corresponding environmental impacts. The morphology of the yardangs varies considerably in response to the diverse factors that control their formation and evolution. Long-ridge yardangs are mainly located in the northernmost part of the yardang field, and the long ridges are gradually dissected into smaller ridges in the downwind direction. Further downwind, the convergence of northerly and northwesterly winds and the effects of temporary runoff cause the ridges to gradually transition into mesa yardangs. Saw-toothed crests, and conical and pyramidal yardangs, occur in groups on folded brachyanticlinal structures. Typical whaleback yardangs are found in the southeast, at the northern margin of Dabuxun Lake. Morphological parameters vary among the yardang types. The orientation of the yardangs in the northernmost area is nearly N-S, with a transition towards NW-SE in the southernmost area in response to a change in the dominant wind direction that results from the orientations and positions of the mountain ranges that surround the basin.

  14. A paleomagnetic test of the proposed Mojave-Sonora megashear in Northwestern Mexico

    NASA Astrophysics Data System (ADS)

    Cohen, Karen Kluger; Anderson, Thomas H.; Schmidt, Victor A.

    1986-11-01

    Three Upper Triassic-Lower Jurassic formations in southwestern United States and northwestern Mexico have been investigated paleomagnetically as a means of testing for displacement along the proposed Mojave-Sonora megashear. Luning Formation of west-central Nevada and Sil Nakya Formation of southern Arizona lie north of the megashear whereas, in northwestern Sonora, Antimonio Formation lies south of the megashear. Previously published results from the Nazas Formation of presumed Lower Jurassic age from north-central Mexico were incorporated into the interpretations. These four units compose two sets of correlative formations on opposite sides of the proposed megashear. Restoration of 800 km of left-lateral displacement along the megashear about the pole of rotation determined by Anderson and Schmidt (1983), improves the grouping of the two sets of paleomagnetic poles noticeably, with the improvement having statistical significance at the 95% confidence level. We feel that the data support, but do not prove, the postulated displacement along the megashear. All four poles are displaced from Irving's (1979) smoothed apparent polar wander path for cratonic North America in the intervals 190 and 200 Ma. The displacement needed to bring all of these poles into coincidence is a pure rotation of about 8° counterclockwise about the sampling area. Two probable Cretaceous poles were obtained from the Sand Wells Formation of southern Arizona and from unnamed volcanics in northwest Sonora. These poles are essentially identical and suggest that displacement along the megashear had ceased by the Cretaceous. Data from the Early Jurassic Mulberry Wash and Pitoikam formations in southern Arizona appear to have been remagnetized in a later Cretaceous event and were not used in this study.

  15. The Ostracoda assemblage of the Eocene-Oligocene transition in northwestern Thrace: Kırklareli-Edirne area (northwestern Turkey)

    NASA Astrophysics Data System (ADS)

    Şafak, Ümit; Güldürek, Manolya

    2016-05-01

    The aim of the study is to investigate the Eocene-Oligocene transition in detail in northwest Thrace (NW Turkey) with heavy reliance on ostracod fauna. The lithologies formed and the environmental changes during this time period were also studied. The study was carried out in northwest Thrace within the outcropping Koyunbaba, Soğucak, and Ceylan Formations; Mezardere, Osmancık, and Danişmen Formations of the Yenimuhacir Group; and the Taşlısekban and Pınarhisar members of the Danişmen Formation. Rich ostracod fauna indicating an Eocene and Oligocene age and environment are found within these units. The Ostracoda fauna identified were ostracods Triebelina punctata, Bairdia cymbula, Bairdia tenuis, Cyamocytheridea nova, Krithe bartonensis, Krithe angusta, Krithe rutoti, Krithe parvula, Echinocythereis isabenana, Leguminocythereis genappensis, Grinioneis triebeli, Xestoleberis subglobosa and Xestoleberis muelleriana from the Mid-Late Eocene epoch; Cytheromorpha zinndorfi, Hemicyprideis montosa, Neocyprideis williamsoniana, Cladarocythere apostolescui, Hammatocythere hebertiana, Haplocytheridea helvetica, Cytheridea pernota, Callistocythereis vitilis, Cushmanidea cf. scrobiculata, Pterygocythereis fimbriata, Pokornyella limbata, Grinioneis paijenborchiana, Cytheretta tracensis, Macrocypris wrightii and Paracypris bouldnorensis from the Late Eocene-Early Oligocene epoch; and Novocypris eocenana, Novocypris striata, Moenocypris forbesi, Candona (Pseudocandona) fertilis, Candona (Lineocypris) sp. and Cypridopsis soyeri from the Early-Late Oligocene epoch. The study was also correlated to previous research conducted on Eocene-Oligocene age ostracods around the area, in northwestern Europe, and in the Paris-Akiten Basin, in view of similar age-environment relationships determined by said studies. On the basis of evidence from the lithologic content of the beds and the micropaleontological investigation, the fossil community identified in this study indicates that the sea reached deeper levels in the Eocene epoch than during the Oligocene epoch.

  16. Geomorphological context of the basins of Northwestern Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Sautter, Benjamin; Pubellier, Manuel; Menier, David

    2014-05-01

    Geomorphological context of the basins of Northwestern Peninsular Malaysia Benjamin Sautter, Manuel Pubellier, David Menier Department of Petroleum Geosciences, Universiti Teknologi PETRONAS CNRS-UMR 8538, Ecole Normale Supérieure, 24, Rue Lhomond, 75231, Paris Cedex 05, France Petroleum basins of Western Malaysia are poorly known and their formation is controlled by the Tertiary stress variations applied on Mesozoic basement structures. Among these are the Paleozoic-Mesozoic Bentong Raub, Inthanon, and Nan suture zones. By the end of Mesozoic times, the arrival of Indian plate was accompanied by strike slip deformation, accommodated by several Major Faults (Sagaing, Three Pagodas, Mae Ping, Red River, Ranong and Klong Marui Faults). Due to changes in the boundary forces, these areas of weakness (faults) were reactivated during the Tertiary, leading to the opening of basins in most of Sundaland. Within this framework, while most of the Sundaland records stretching of the crust and opening of basins (SCS, Malay, Penyu, Natuna, Mergui) during the Cenozoics, Peninsular Malaysia and the Strait of Malacca are considered to be in tectonic quiescence by most of the authors. We present the geomorphology of the Northwestern Malaysia Peninsula with emphasis on the deformations onshore from the Bentong Raub Suture Zone to the Bok Bak Fault, via the Kinta Valley, and offshore from the Port Klang Graben to the North Penang Graben. By analyzing Digital Elevation Model from ASTER and SRTM data, two main directions of fractures in the granitic plutons are highlighted: NW-SE to W-E sigmoidal faults and N-S to NE-SW linear fractures which seem to cross-cut the others. In the field in the area of the Kinta Valley (Western Belt, NW Peninsular Malaysia), granitic bodies show intense fracturation reflecting several stages of deformation. The granites are generally syntectonic and do not cut fully across the Late Paleozoic platform limestone. Two sets of fractures (NW-SE and NE-SW) appear more penetrative in both granitic and limestone units. On most of the studied outcrops, exfoliation fractures are reactivated into normal faults. Deformation is particularly severe at the contact of the granites and the sediments which is underlined by cataclasic quartz dykes and hornfelds. Off-shore, in the Straits of Malacca, nine tertiary half-grabens are present, all oriented in N-S to NE-SW direction with N-S boundary faults on their western margin. We propose a tectonic scenario for the north-western Malaysia Peninsula according to which the northward motion of India induced first right-lateral transpressionnal tectonics at the End of the Mesozoics (Cretaceous early Tertiary). This system is illustrated in the NW-SE trending fractures of the Main Range Batholith and other Triassic plutons within a system bounded and controlled by the Bok Bak Fault, the KL fault zone and the Bentong Raub Suture Zone. Later, a second stage of transtension led to the opening of the en echelon onshore basins in a tear-faults system, and to the opening of half grabens offshore in the Straits of Malacca.

  17. Avian Community Structure Among Restored Riparian Habitats in Northwestern Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historically, expanding agriculture and stream channelization have degraded riparian zones that serve as vital habitat for avian communities within agroecosystems. Riparian zones and agricultural fields adjacent to incised streams in northwestern Mississippi are impacted by gully erosion initiated b...

  18. Northeastern Exterior, Northwestern Exterior, & Southwestern Exterior Elevations, Northeastern Interior, ...

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

    Northeastern Exterior, Northwestern Exterior, & Southwestern Exterior Elevations, Northeastern Interior, Southeastern Interior, & Southwestern Interior Elevations, Floor Plan, and Eastern Corner Detail - Manatoc Reservation, Vale Edge Adirondack, 1075 Truxell Road, Peninsula, Summit County, OH

  19. A Psychometric Evaluation of the Northwestern Syntax Screening Test

    ERIC Educational Resources Information Center

    Arndt, William B.

    1977-01-01

    In evaluating the Northwestern Syntax Screening Test (a test for assessing expressive and receptive grammar in preschool and primary age children), the author points out problems with the test norms, reliability, and validity. (SBH)

  20. 14. INTERIOR, NORTHWESTERN WING, SHOW ROOM, DETAIL OF FIREPLACE ...

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

    14. INTERIOR, NORTHWESTERN WING, SHOW ROOM, DETAIL OF FIREPLACE - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  1. 15. INTERIOR, NORTHWESTERN WING, SHOW ROOM, DETAIL OF BALCONY ...

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

    15. INTERIOR, NORTHWESTERN WING, SHOW ROOM, DETAIL OF BALCONY - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  2. Scaling Tendency of Geothermal Waters Armutlu Peninsula, Northwestern Turkey

    NASA Astrophysics Data System (ADS)

    Ertekin, Can

    2015-04-01

    Prediction of scaling tendencies from geothermal waters is important for taking necessary precautions to prevent or control the scale formation. This study contains scaling tendency of geothermal outlets occurring through Armutlu Peninsula in Northwestern Turkey. The E-W trending region stretches into the Marmara Sea (ca. 117 km E-W by 45 km N-S) and is bounded to the north and the south by North Anatolian Fault Zone (NAFZ). The two branches of NAFZ traversing the peninsula control not only active seismicity but also geothermal discharges of the region. Widespread basement rocks across the peninsula including metamorphic assemblage of granitic and volcanic rocks host geothermal fluids. The two distinctive geothermal discharges (Armutlu and Yalova) take place through lineaments appurtenant to the northern branch of NAFZ. Their discharge temperatures of 65 ° C (Yalova) and 70 ° C (Armutlu) are the highest of the region. According to their water chemical results, scaling tendency were computed by using WATCH for different temperature steps under the assumptions of single-stage adiabatic boiling and equilibrium degassing. To evaluate their scaling tendencies, mean geothermal reservoir temperatures were computed by using chemical geothermometers. Scaling tendencies were plotted for calcite, amorphous silica and quartz minerals for different temperature values including reservoir temperatures. Their scaling behavior reveals that oversaturation with calcite and quartz minerals are rapidly attained for the geothermal fluids (Yalova and Armutlu) at relatively lower temperatures. Regarding amorphous silica, they are completely undersaturated. Besides, Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI) were calculated. Their results depict scale formation due to being positive LSI and less than 6.0 of RSI values.

  3. The history of neurological surgery at Northwestern University.

    PubMed

    Engelhard, H H; Grant, J; Ciric, I S; Wetzel, N C; Batjer, H H

    1998-10-01

    The residency program in neurological surgery at Northwestern University was founded in 1924 by Loyal Davis and was formally accredited by the American Board of Neurological Surgery in 1946. Allen Kanavel, mentor to Davis, was one of the original members of the Society of Neurological Surgeons. Five individuals have served as chief of neurosurgery at Northwestern: Davis, Paul Bucy, Anthony Raimondi, Albert Butler, and H. Hunt Batjer. Davis was the first surgeon west of the Appalachians to limit his work to neurosurgery. Between 1954 and 1963, there were two independent neurosurgery residency programs at Northwestern, one headed by Davis and the other by Bucy. A master surgeon and superb teacher, Bucy trained more than 65 residents and became one of the greatest authors and leaders in the field of neurosurgery. Neurosurgical training at Northwestern has traditionally emphasized excellence of patient care, strong resident and student teaching, and basic science research. Through the years, a major strength of the program has been its clinical volume and diversity. Four hospitals have played major roles in the program: Northwestern Memorial Hospital (created by the merger of Chicago Wesley Memorial Hospital and Passavant Memorial Hospital), Children's Memorial Hospital, Evanston Hospital, and the Veterans Administration Lakeside Hospital. This article traces the development of neurological surgery at Northwestern, with an emphasis on its historical background and the contributions of Kanavel, Davis, and Bucy. The present philosophy and structure of the training program and the program's future under the direction of Batier are also described. PMID:9766320

  4. Facies analysis of the lower cycles of the Mesaverde Group (Upper Cretaceous) in northwestern Colorado

    USGS Publications Warehouse

    Kiteley, L.W.

    1983-01-01

    The uppermost 180 m of the Mancos Shale and overlying 390 m of the Iles Formation of the Mesaverde Group in northwestern Colorado were deposited at the west margin of an epicontinental seaway that spanned North America 66-98 million years ago from the circumboreal seaway on the north to the Gulf of Mexico on the south. Sedimentation in the seaway was controlled by uplift in source areas to the west, subsidence in the basin, and eustatic sea level changes. Sedimentation rates were relatively high, averaging about 220m/million years; marine cycles of deposition occurred in northwestern Colorado that correspond to the Claggett, Judith River, and Bearpaw regressions of Montana. The upper Mancos shale and lower Iles Formation can be subdivided into ten facies based on five criteria: (1) Lithology, texture, and thickness relations (geometry); (2) sedimentary structures and contacts; (3) trace and body fossils; (4) paleocurrent data; and (5) adjoining facies (underlying, overlying, and laterally). Each facies has distinct attributes which characterize a specific depositional environment. Environments represented by facies include (A) offshore shoreface transition (prodelta); (B) shallow marine sand bars; (C) destructional delta front; (D) constructional delta front (sheet sands and mouth bars); (E) beach foreshore-shoreface deposits; (F) interdistributary marsh and swamp deposits and fluvial floodplain; (G) distributary channels; (H) crevasse splays; (J) fluvial streams; and (K) tidally influenced distributary channel. Facies analysis of outcrop data shows that transgressions and regressions occurred, some of which are related to major (eustatic) sea level changes and others that reflect only local causes. These events in northwestern Colorado are summarized in following chapters, and an attempt is made to show their relationship to broad regional patterns of sedimentation.

  5. Holocene Paleolimnological Records from Thule, Northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Corbett, L.; Osterberg, E. C.; Kelly, M. A.; Axford, Y.

    2012-12-01

    Assessing Holocene climatic and environmental variability around the margin of the Greenland Ice Sheet provides important information against which to compare ice sheet margin fluctuations. Here, we report preliminary results from ongoing research in northwestern Greenland. We present records of physical properties of lake sediments and use these to make inferences about the evolution of the lake and its surroundings over the latter half of the Holocene. We collected two sediment cores, 90 and 72 cm in length, from a small (surface area ~0.3 km2), shallow (maximum depth ~4.5 m) lake at 76°33'40''N 68°26'31''W near Thule Air Base in July 2012. The length of the cores was limited by the length of the core barrel and does not reflect the total thickness of sediment in the lake. The lake is situated within the glacial limit and likely formed subsequent to deglaciation of the region during early Holocene time. No glaciers exist within the lake's catchment today; the primary modern source of sediment is a perennial inflow from the west. We developed a preliminary depth-age model using radiocarbon ages of terrestrial organic macrofossils. Thus far, we have analyzed the sediments for magnetic susceptibility and loss-on-ignition. A radiocarbon age of 6069 ± 90 cal yr BP at the base of the core indicates that the sediments preserve a continuous record of middle to late Holocene conditions. The top of both cores consists of a thick (~12 cm) layer of dark gray unlaminated sediments, while the rest of the material in both cores is lighter brown to olive, finely laminated sediment. The upper layer is characterized by low water content (<25%), low loss-on-ignition (<5%), and high magnetic susceptibility (~150-250 x10-6). Conversely, the laminated sediments beneath have higher water content (~40-50%), higher loss-on-ignition (~5-10%), and much lower magnetic susceptibility (<50 x10-6). We hypothesize that the upper, less organic unit may represent a single event in the lake's recent history. We are refining the depth-age model with more radiocarbon ages, measuring grain size and carbon to nitrogen ratios of the sediments, and evaluating possible linkages between the sediment physical properties and precipitation as recorded by annual accumulation in ice cores in northwestern Greenland and Arctic Canada. This project will provide a foundation for future work in Thule investigating Holocene fluctuations of local ice cap and ice sheet margin positions.

  6. Tracking slabs beneath northwestern Pacific subduction zones

    NASA Astrophysics Data System (ADS)

    Gu, Yu Jeffrey; Okeler, Ahmet; Schultz, Ryan

    2012-05-01

    This study uses the amplitudes of bottom-side reflected shear waves to constrain the morphology and dynamics of subducted oceanic lithosphere beneath northwestern Pacific subduction zones. Across Honshu arc, the 410- and 660-km seismic discontinuities are detected at the respective depths of 395 5 and 685 5 km within the Wadati-Benioff zone. Their topographies are negatively correlated along slab dip, showing the dominant effect of temperature on the olivine phase changes within the upper mantle transition zone. The base of the upper mantle shows broad depressions as well as localized zones of shallow/average depths beneath Korea and northeast China. The 15 + km peak-to-peak topography west of the Wadati-Benioff zones suggests that the stagnant part of the subducted Pacific plate is not as flat as previously suggested. Eastward slab 'pile-up' is also possible at the base of the upper mantle. Across southern Kuril arc, the shear wave reflection coefficients of major olivine phase boundaries fall below 5% within the Wadati-Benioff zone. The apparent reflection gaps and the spatial connection between a strong reflector at ~ 900 km depth may imply 1) possible compositional variations at the top and bottom of the transition zone and 2) substantial mass/heat flux across the 660-km seismic discontinuity. We also identify strong reflectors within the subducted oceanic lithosphere at mid transition zone depths. The depths and strengths of these reflectors are highly variable between Honshu and southern Kuril islands.

  7. Northwestern Tharsis Latent Outflow Activity Mars

    NASA Technical Reports Server (NTRS)

    Dohm, J. M.; Anderson, R. C.; Baker, V. R.; Ferris, J. C.; Hare, T. M.; Strom, R. G.; Rudd, L.; Rice, J. W., Jr.; Scott, D. H.

    2000-01-01

    Previously defined outflow channels, which are indicated by relict landforms similar to those observed on Earth, signify ancient catastrophic flood events on Mars. These conspicuous geomorphic features are some of the most remarkable yet profound discoveries made by geologists to date. These outflow channels, which debouched tremendous volumes of water into topographic lows such as Chryse, Utopia, Elysium, and Hellas Planitiae, may represent the beginning of warmer and wetter climatic periods unlike the present-day cold and dry Mars. In addition to the previously identified outflow channels, observations permitted by the newly acquired Mars Orbiter Laser Altimeter (MOLA) data have revealed a system of gigantic valleys, referred to as the northwestern slope valleys (NSV), that are located to the northwest of a huge shield volcano, Arsia Mons, western hemisphere of Mars. These features generally correspond spatially to gravity lows similar to the easternmost, circum-Chryse outflow channel systems. Geologic investigations of the Tharsis region suggest that the large valley system pre-dates the construction of Arsia Mons and its extensive associated lava flows of mainly Late Hesperian and Amazonian age and coincides stratigraphically with the early development of the circum-Chryse outflow channel systems that debouch into Chryse Planitia. This newly identified system, the NSV, potentially signifies the largest flood event(s) ever recorded for the solar system. Additional information is contained in original extended abstract.

  8. Phytoplankton in the northwestern Kara Sea

    NASA Astrophysics Data System (ADS)

    Sukhanova, I. N.; Flint, M. V.; Druzhkova, E. I.; Sazhin, A. F.; Sergeeva, V. M.

    2015-07-01

    Studies were conducted in the northwestern Kara Sea in late September of 2007 and 2011. The assessment of species, size, structure, abundance, and biomass of phytoplankton and the role of autotrophic and heterotrophic components in phytocenoses was conducted. The abundance of autotrophic micro-, nanoand picoplankton increased by more than an order of magnitude in each of the following smaller-sized groups of algae. Microphytoplankton dominated in the total biomass of autotrophic phytoplankton. The wet biomass of microphytoplankton was 2.5 times higher than the wet biomass of nanophytoplankton and 5 times higher than that of picoplankton. Nanophytoplankton dominated in abundance and biomass in the heterotrophic component of phytoplankton. The ratio of the total abundance of autotrophic and heterotrophic phytotoplankton was 7: 1, the ratio of the wet biomass of the both groups was 2.5: 1, and the proportion of the carbon biomass was 2: 1. Three biotopes were distinguished in the area of the outer shelf, the continental slope, and the deepwater area adjacent to the St. Anna Trough, which differed in composition and quantitative characteristics of phytocenoses. Frontal zones dividing the biotopes are characterized by high phytoplankton biomass and the dominance of diatoms in the community (more than 40% of the total biomass), which indicates the local availability of "new" nutrients for planktonic algae.

  9. Lineament analysis near French Creek, northwestern Pennsylvania

    SciTech Connect

    O'Neil, C.; Anderson, T.

    1984-12-01

    The authors are attempting to characterize the nature of linear topographic features in the vicinity of French Creek, northwestern Pennsylvania. Straight valleys that trend north to northwest and that are partially filled with glaciofluvial deposits distinguish prominent lineaments in Crawford, Venango, and Mercer Counties. The traces of these linear valleys are 1-15 mi (1.6-24 km) long and 10-4000 ft (3-1220 m) wide. The vertical extents of the lineaments are assumed to be proportional to their lengths. They assume that the topographic lineaments mark easily eroded zones coincident with fractures. The French Creek lineaments have been plotted on a Landsat photo, glacial map, regional map, and topographic maps. Subsurface structural and isopach maps may show facies changes or anomalous thickness across the lineaments. Geochemical surveys determine if there is any enhanced vertical migration of hydrocarbons along a lineament, and very low-frequency magnetic surveys would indicate any increase in groundwater concentration associated with the fracture zones. Well log data on initial production and breakdown pressures have been compared to lineament positions for possible correlations.

  10. MISR Images Wildfires in Northwestern US

    NASA Technical Reports Server (NTRS)

    2000-01-01

    MISR image of smoke plumes from devastating wildfires in the northwestern US. This view of the Clearwater and Salmon River Mountains in Idaho was acquired on August 5, 2000 (Terra orbit 3370). The body of water to the left of image center is the Cascade Reservoir, located about 100 km north of Boise and 80 km east of the Snake River. North is at the top, and the image is approximately 380 km across.

    In addition to the huge plumes traversing the mountains in the northern part of the image, smoke accumulating in the lower elevation canyons and plains is visible. This image was generated using data from the MISR camera that looks forward at a steep angle (70.5 degrees). The smoke is far more visible when viewed at this highly oblique angle than it would be in a conventional, straight-downward view. In creating this color composite, data from the blue and green MISR bands, acquired at 1.1-km spatial resolution, were digitally 'sharpened' using 275-m resolution data acquired in the red band.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

    For more information: http://www-misr.jpl.nasa.gov

  11. Jurassic platform development, northwestern Gulf of Mexico

    SciTech Connect

    Moore, C.H. Jr.

    1987-05-01

    Triassic and Early Jurassic rifting set the stage for the subsequent development of carbonate platforms in the Late Jurassic. These platforms formed along the interior margins of salt basins separated from the main ancestral Gulf of Mexico by a series of positive features. A major sea level rise, after deposition of the Louann Salt (late Callovian), drowned the interior salt basins around the margins of the Gulf of Mexico, leading to an anoxic event. Organic-rich sediments of the lower Smackover were deposited as a basin-fill sequence, forming one of the major hydrocarbon source rocks of the region. As sea level rise slowed in the late Oxfordian, carbonate production began to catch up with sea level rise along the basin margins, leading to the initial development of a rimmed carbonate platform. The platform margin was marked by high-energy ooid grainstones, while crustacean pellet muds were deposited in the platform interior. A high-energy ooid-dominated platform (upper Smackover) developed in the late Oxfordian when sea level reached a standstill. During the subsequent Kimmeridgian sea level rise, a second rimmed carbonate platform, the Haynesville, was developed. During the initial rise, grainstones were deposited on the platform margin, while the interior was dominated by evaporites (Buckner) and siliciclastics. As sea level slowed and reached a standstill, the platform margin facies extended shoreward (Gilmer) and a high-energy platform, analogous to the upper Smackover, was formed. The Smackover and Haynesville platforms of the northwestern gulf show a parallel evolution in response to cyclic changes in Upper Jurassic sea level.

  12. The influence of impaction to the third molar mineralization in northwestern Chinese population.

    PubMed

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhang, Wen-tao; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-07-01

    Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C-H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C-H were 0.02-1.42 years higher in males and 0.04-1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation. PMID:24532176

  13. Structural development and oil occurrence on northeast flank of Uinta Mountains near Irish Canyon, northwestern Colorado

    SciTech Connect

    Roehler, H.W.

    1985-05-01

    The study area is located along Vermillion Creek, 1-3 mi (1.6-5 km) east of Irish Canyon, in northwestern Colorado. The exposed stratigraphic section consists of steeply dipping to vertical Upper Cretaceous Almond Formation, Ericson, Sandstone, and Mancos Shale along the toe of the Sparks Ranch thrust fault, and of lesser dipping older Mesozoic and Paleozoic formations in distant parts of the thrust plate. In most places, the Almond Formation is in contact across the thrust fault with the Eocene Wasatch and Green River Formations, and all of these formations are unconformably overlain by the Oligocene Bishop Conglomerate and the Miocene Browns Park Formation. The structural development of the area has involved three major events: (1) Late Cretaceous uplift of the Uinta Mountains; (2) Paleocene and Eocene thrust movements of the sparks Ranch fault; and (3) late Tertiary normal faulting associated with a collapse of the eastern Uinta Mountains. Oil-saturated sandstones are present in outcrops of 10 Paleozoic, Mesozoic, and Tertiary formations adjacent to several of the late Tertiary normal faults. Oil is escaping to the surface along these faults, probably from a large, deep-seated reservoir located below the Sparks Ranch thrust fault.

  14. Guillain-Barré syndrome in northwestern China.

    PubMed

    Jiang, W; Wang, H D; Huang, Y G; Wan, Q; Xu, Y; Wu, B R

    2001-01-01

    We reviewed 100 patients with Guillan-Barré syndrome (GBS) from 1994 to 2000 from northwestern China. We examined clinical and electro-diagnostics features and compared them to patients from Europe, North America and northern China. Results indicated that among 100 patients with GBS, the demyelinating pattern was present in 51 patients, the axonal pattern in 25 patients, and 8 patients were inexcitable, 12 patients equivocal and 4 patients normal. The electrophysiological and clinical features of various subtypes of GBS in northwestern China seemed to be different in some ways from those in western countries and in northern China. However, in northwestern China, the demyelinating pattern is the major electrophysiological subtype. PMID:11721293

  15. Incidence of narcotic abuse during pregnancy in northwestern Ontario

    PubMed Central

    Kelly, Len; Guilfoyle, John; Dooley, Joe; Antone, Irwin; Gerber-Finn, Lianne; Dooley, Roisin; Brunton, Nicole; Kakegamuck, Kara; Muileboom, Jill; Hopman, Wilma; Cromarty, Helen; Linkewich, Barb; Maki, Jennifer

    2014-01-01

    Abstract Objective To document the incidence and outcomes of narcotic use during pregnancy in northwestern Ontario. Design Three-year prospective cohort study. Setting Sioux Lookout and surrounding communities in northwestern Ontario. Participants A total of 1206 consecutive births in a catchment area of 28 000 First Nations patients. Main outcome measures Incidence of narcotic use, and maternal and neonatal outcomes. Results Incidence of narcotic use in pregnancy has risen to 28.6% (P < .001) and incidence of neonatal abstinence syndrome has fallen to 18.0% of narcotic-exposed births (P = .003). Daily intravenous drug use is now a common pattern of abuse. Conclusion Narcotic abuse in pregnancy has dramatically increased in northwestern Ontario. Neonatal outcomes have improved as a result of a family medicine–based prenatal and obstetric program that includes a narcotic replacement and tapering program. PMID:25316764

  16. Middle and upper Cambrian platform evolution and paleogeography, northwestern Montana, northern Idaho, and northeastern Washington

    SciTech Connect

    Bush, J.H.; Hayden, L.L.

    1987-08-01

    In western Montana, three Middle and Late Cambrian correlative Grand Cycles commence with inner detrital basal half cycles overlain by middle carbonate half cycles. Each half cycle represents up to one formation with the Park to Pilgrim, shale to carbonate transition, an example of one complete cycle. As with other regions of the Cambrian Cordilleran shelf, cycle components are closely related to paleogeographic position, producing differences that make correlation across depositional belts difficult. However, combined lithologic paleontologic, and cyclic correlations from southwestern Montana to isolated outcrops in northwestern Montana, northern Idaho, and northeastern Washington outline platform evolution and paleogeography. Early Middle Cambrian ramp deposition occurred with non-tectonic highs (Montania) in northwestern Montana and possible distally steepened ramps in northern Idaho. After eastward transgression, upward-shallowing Middle Cambrian carbonates formed algal-peritidal complexes that extended from central Montana to northeastern Washington. These complexes were influenced by clastic influx from central Idaho (Lemhi arch .), but they completely covered Montania and separated an eastern intrashale basin from the outer ramp. During the Late Cambrian, below wave base distal ramp carbonate deposition returned to northern Idaho and northeastern Washington. However, the distal ramp was separated from the intrashelf basin until Early Ordovician by the still existent but less extensive peritidal complexes. The ramp that developed over portions of the three states differed considerably from the cratonic margin in southern British Columbia, described by Aitken in 1966 and 1978, as a stationary accretionary rim on its seaward side persisting from Middle Cambrian to Middle Ordovician time.

  17. Development of the Permian-Triassic unconformity in southwestern Utah, southeastern Nevada and northwestern Arizona

    SciTech Connect

    Nielson, R.L. . Dept. of Geology)

    1993-04-01

    Development of positive areas, that are oriented northwest-southeast in south-western Utah, southeastern Nevada, and northwestern Arizona, are indicated by the depositional patterns of the Rock Canyon Conglomerate and facies changes produced by on-lapping during the deposition of the Timpoweap, Lower Red, and Virgin Limestone Members of the Moenkopi Formation. The lack of facies change in the Kaibab Formation indicates that uplift of the positive areas did not start during the early Permian. The Fossil Mountain Member of the Kaibab Formation, is a marker of continuous shallow marine sedimentation across the area. The Harrisburg Member contains three limestone units, separated by gypsum and shale units, that represent regressions and transgressions. Where the gypsum in the Kaibab Formation thins, collapse breccia and deformed shale units are present indicating that the gypsum was deposited and then removed by dissolution. Channels cut during the late Permian and early Triassic Periods do not cut through the Harrisburg Member of the Kaibab Formation. West of St. George, Utah, where the gypsum deposits are thickest, is the location where Timpoweap, Lower Red, and Virgin Limestone members thin and are absent. Late Permian and early Triassic topography may have in part been controlled by dissolution of the gypsum deposits in the Kaibab Formation. The low angle of discordance between Permian and Triassic units indicated that the area was not subjected to major deformation during the late Permian and early Triassic, but was gently tilted and uplifted.

  18. Northwestern Argentina as seen from the Apollo 7 spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Puna de Atacama area of northwestern Argentina, Provinces of Salta and Catamarca, as seen from the Apollo 7 spacecraft during its 154th revolution of the earth. Photographed from an altitude of 175 nautical miles, at ground elapsed time of 243 hours and 58 minutes.

  19. Emergence of African Swine Fever Virus, Northwestern Iran

    PubMed Central

    Rahimi, Pooneh; Sohrabi, Amir; Ashrafihelan, Javad; Edalat, Rosita; Alamdari, Mehran; Masoudi, Mohammadhossein; Mostofi, Saied

    2010-01-01

    In 2008, African swine fever was introduced into Georgia, after which it spread to neighboring Armenia, Azerbaijan, and the Russian Federation. That same year, PCR and sequence analysis identified African swine fever virus in samples from 3 dead female wild boars in northwestern Iran. Wild boars may serve as a reservoir. PMID:21122227

  20. 8. BUILDING 332, INTERIOR, HALLWAY NEAR MAIN ENTRANCE IN NORTHWESTERN ...

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

    8. BUILDING 332, INTERIOR, HALLWAY NEAR MAIN ENTRANCE IN NORTHWESTERN PORTION OF BUILDING, LOOKING NORTH, WITH LOBBY TO LEFT AND CONFERENCE ROOM TO RIGHT. - Oakland Naval Supply Center, Dry Provisions Storehouses, Between Third & Fourth Streets, Between G & L Street, Oakland, Alameda County, CA

  1. Beak deformities in Northwestern Crows: evidence of a multispecies epizootic

    USGS Publications Warehouse

    Van Hemert, Caroline; Handel, Colleen M.

    2010-01-01

    Beak abnormalities are rare among adult birds and, typically, are not widespread in a given population, within a region, or across multiple species. A high concentration of beak deformities was recently documented in Black-capped Chickadees (Poecile atricapillus) and other resident avian species in Alaska. We describe a parallel condition in Northwestern Crows (Corvus caurinus) that signals the emergence of a multispecies epizootic. On the basis of 186 Northwestern Crows captured at six sites in Alaska during 2007 and 2008, we estimated the prevalence of beak deformities in adults to be 16.9 ± 5.3%, the highest rate of gross deformities ever recorded in a wild bird population. Prevalence varied among sites and was as high as 36% on the Kenai Peninsula, which suggests possible epizootic clusters. We also documented beak abnormalities in an additional 148 Northwestern Crows in south-central and southeastern Alaska and in 64 crows near Vancouver, British Columbia, and Puget Sound, Washington, a region where both Northwestern Crows and American Crows (C. brachyrhynchos) occur. The increase in frequency and distribution of crows observed with abnormal beaks throughout the Pacific Northwest since the late 1990s indicates a geographic expansion of this problem. Affected crows exhibited elongated and often crossed beaks that were morphologically similar to deformities documented in Black-capped Chickadees and other species in Alaska over approximately the same period. Additional research is needed to determine the etiology and potential adverse effects on bird populations affected by this disorder.

  2. African Oral Traditions: Riddles Among the Haya of Northwestern Tanzania

    ERIC Educational Resources Information Center

    Ishengoma, Johnson M.

    2005-01-01

    This study argues for the integration of African oral traditions and other elements of traditional learning into the modern school curriculum. It thus contributes to supporting the increased relevance of education to local communities. In particular, using the example of riddles collected from one of the main ethnic groups in Northwestern

  3. Capturing Qualitative Data: Northwestern University Special Libraries' Acknowledgments Database

    ERIC Educational Resources Information Center

    Stigberg, Sara; Guittar, Michelle; Morse, Geoffrey

    2015-01-01

    Assessment and supporting data have become of increasing interest in librarianship. In this paper, we describe the development and implementation of the Northwestern University Library Acknowledgments Database tool, which gathers and documents qualitative data, as well as its component reporting function. This collaborative project and resulting…

  4. Capturing Qualitative Data: Northwestern University Special Libraries' Acknowledgments Database

    ERIC Educational Resources Information Center

    Stigberg, Sara; Guittar, Michelle; Morse, Geoffrey

    2015-01-01

    Assessment and supporting data have become of increasing interest in librarianship. In this paper, we describe the development and implementation of the Northwestern University Library Acknowledgments Database tool, which gathers and documents qualitative data, as well as its component reporting function. This collaborative project and resulting

  5. Identification of potential artificial groundwater recharge zones in Northwestern Saudi Arabia using GIS and Boolean logic

    NASA Astrophysics Data System (ADS)

    Zaidi, Faisal K.; Nazzal, Yousef; Ahmed, Izrar; Naeem, Muhammad; Jafri, Muhammad Kamran

    2015-11-01

    Identifying potential groundwater recharge zones is a pre-requisite for any artificial recharge project. The present study focuses on identifying the potential zones of Artificial Groundwater Recharge (AGR) in Northwestern Saudi Arabia. Parameters including slope, soil texture, vadose zone thickness, groundwater quality (TDS) and type of water bearing formation were integrated in a GIS environment using Boolean logic. The results showed that 17.90% of the total studied area is suitable for AGR. The identified zones were integrated with the land use/land cover map to avoid agricultural and inhabited lands which reduced the total potential area to 14.24%. Geomorphologically the wadi beds are the most suitable sites for recharge. On the basis of the potential AGR zones closeness to the available recharge water supply (rain water, desalinated sea water and treated waste water) the potential zones were classified as Category A (high priority) and Category B (low priority).

  6. Effect of the Spanish Conquest on coastal change in Northwestern Peru.

    PubMed

    Belknap, Daniel F; Sandweiss, Daniel H

    2014-06-01

    When Francisco Pizarro and his small band of Spanish conquistadores landed in northern Peru in A.D. 1532 to begin their conquest of the vast Inca Empire, they initiated profound changes in the culture, language, technology, economics, and demography of western South America. They also altered anthropogenically modulated processes of shoreline change that had functioned for millennia. Beginning with the extirpation of local cultures as a result of the Spanish Conquest, and continuing through today, the intersection of demography, economy, and El Niño-driven beach-ridge formation on the Chira beach-ridge plain of Northwestern Peru has changed the nature of coastal evolution in this region. A similar event may have occurred at about 2800 calibrated y B.P. in association with increased El Niño frequency. PMID:24843118

  7. Geochemistry and petrogenesis of late proterozoic volcanic rocks from north-western Africa

    NASA Astrophysics Data System (ADS)

    Chikhaoui, M.; Dupuy, C.; Dostal, J.

    1980-09-01

    The Upper Proterozoic volcanism of northwestern Africa is characterized by the predominance of calc-alkaline rocks. Volcanics with tholeiitic affinities and alkali basalts are rare. The geochemistry and the relative proportions of calc-alkaline rocktypes in the Silet zone (Algeria) and the Ouarzazate formation (Morocco) are similar to those of recent island arc suites where basalts are most abundant while in the Tassendjanet and Gara Akofo zones (Algeria) they resemble contintal margin volcanic suites with a predominance of andesites. The volcanic rocks have undergone low-grade metamorphism which strongly affected alkali and alkali-earth elements and also to a smaller degree, the less mobile elements such as REE, Zr, Hf, Nb, and P. The geochemistry of the calc-alkaline rocks point to a complex origin involving low-pressure fractional crystallization, crustal contamination and derivation from a source already enriched in LILE.

  8. Neogene coupling between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China.

    PubMed

    He, Guang-Yu; Chen, Han-Lin

    2004-08-01

    Based on the sedimentary and subsiding features of Kuqa foreland basin, this paper presents the following characteristics of Neogene coupling relationship between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China: (1) The Southern Tien Shan Orogen underwent Neogene uplifting of 4 km in height and the Kuqa Basin underwent Neogene subsidence of 4-6 km in depth accordingly beginning in 25 Ma; (2) The Southern Tien Shan Orogen moved continuously toward the Kuqa Basin, with largest structural shortening rate of greater than 53.7%, and the north boundary of the Kuqa Basin retreated continuously southward accordingly since the Miocene; (3) There are two subsidence centers with high subsiding rates and large subsiding extent, located in the eastern and western Kuqa Basin respectively, with the subsiding maximizing in the deposition period of Kuqa Formation. PMID:15236483

  9. Effect of the Spanish Conquest on coastal change in Northwestern Peru

    PubMed Central

    Belknap, Daniel F.; Sandweiss, Daniel H.

    2014-01-01

    When Francisco Pizarro and his small band of Spanish conquistadores landed in northern Peru in A.D. 1532 to begin their conquest of the vast Inca Empire, they initiated profound changes in the culture, language, technology, economics, and demography of western South America. They also altered anthropogenically modulated processes of shoreline change that had functioned for millennia. Beginning with the extirpation of local cultures as a result of the Spanish Conquest, and continuing through today, the intersection of demography, economy, and El Niño-driven beach-ridge formation on the Chira beach-ridge plain of Northwestern Peru has changed the nature of coastal evolution in this region. A similar event may have occurred at about 2800 calibrated y B.P. in association with increased El Niño frequency. PMID:24843118

  10. Paleogeographic reconstruction of northwestern Oregon based on Eocene freshwater deposition in accreted terrane

    SciTech Connect

    Ries, J.E.

    1989-03-01

    Freshwater deposits exposed in the Coast Range of Oregon have been identified by the absence of marine organisms, significant floral remains, and the identification of a freshwater fish assemblage. These facies have been correlated with foraminiferal and lithologic horizons from test wells from the Mist Gas field of northwestern Oregon. Consistent records of inner neritic and marginal marine deposition in the Narizian stage, upper Cowlitz Formation, suggest the existence of an Eocene volcanic archipelago. Foraminiferal correlation through this stage is complicated by the absence of stratigraphically significant species in several of the wells. Floral remains from exposed sections have provided diverse elements, allowing paleogeographic reconstruction. A sea level coastal swamp was dominated by a subtropical flora consisting of Sabalites, Platanophyllum, and Equisetum. The swamp was apparently backed by higher altitude volcanic uplands dominated by a more temperate flora including Cornus, Chamaecyparis, Ailanthus, Pinus, and Picea.

  11. Paleogeographic interpretation of several Eocene floral assemblages from Coast Range of northwestern Oregon

    SciTech Connect

    Ries, J.E.

    1989-04-01

    Several freshwater and brackish water deposits are exposed throughout the Coast Range of northwestern Oregon. Occurring as interbeds in the Tillamook Volcanic Sequence and the Cowlitz Formation, these strata are stratigraphically equivalent to hydrocarbon bearing strata in the Mist gas field to the north. From analysis of macrofossils, species appear to be present from two different paleoaltitude zones. A coastal swamp stream deposit has produced specimens of Sabalites, Platanophyllum, Alnus, Lastera, and rooted Equisetum. Both floristic and physiognomic analysis of the flora indicates a moist subtropical climate. Deposits exposed in the Tillamook uplands are apparently lacustrine shales. The flora preserved is not as diverse, represented by specimens of Cornus, Chamaecyparis, Ailanthus, Pinus, and Picea. The climate here appears significantly more temperate than the assemblage preserved to the northeast, although deposited at approximately the same time. This difference can be explained by the existence of volcanic uplands backing the coastal swamp.

  12. Circulation on the Northwestern Iberian Margin: Swoddies

    NASA Astrophysics Data System (ADS)

    Teles-Machado, Ana; Peliz, Álvaro; McWilliams, James C.; Dubert, Jesus; Cann, Bernard Le

    2016-01-01

    We study the eddies that form by destabilization of the Iberian Poleward Current. Some anticyclones have been identified in satellite Sea Surface Temperature, as they are persistent and remarkably warm, and they contain IPC waters in their core. The number of observed eddies is small, and little is known about their statistics, places of formation, separation processes, and behavior away from the slope. In this study, the output of a 20-year high-resolution numerical simulation is analyzed to study the formation of anticyclonic and cyclonic eddies by destabilization of the Iberian Poleward Current, using an automatic eddy detection algorithm. The model reproduces the formation of some of the eddies at the same time and place, and with similar sizes as observed in satellite SST, although it fails to reproduce their observed trajectories as they propagate away from the slope. We found distinct layers with different relative vorticity distribution. The top 200 m of the water column has an anticyclonic dominance, with stronger anticyclones; in the layer between 200 and 600 m there are more and stronger cyclones; and from 600 to 1000 m there is again an anticyclonic dominance, with more and stronger anticyclones than cyclones. The results show that the cyclones form mainly where topographic contours veer cyclonically in the poleward direction, while the anticyclones tend to form in places where topographic contours veer anticyclonically. We found that there is a relationship between the formation of eddies and the wind variability. A sudden decrease in southerly winds results in the development of instabilities in the IPC and formation of eddies. The shedding of the surface intensified anticyclones is accompanied by the shedding of deeper layer cyclones. In general, the deep cyclones spin down faster than the surface anticyclones; anticyclones are tracked, and conserve their maximum relative vorticity for longer periods. The vertical structure of these surface intensified anticyclones, at the moment of formation, extends to deeper than 1200 m, and this vertical extent decreases with time. They can survive winter deep convection that homogenizes their core.

  13. Generalized Geologic evaluation of side looking radar imagery of the Teton Range and Jackson Hole, northwestern Wyoming

    NASA Technical Reports Server (NTRS)

    Love, J. D.

    1970-01-01

    A generalized geologic evaluation of lines, localities, and features of various types that are visible on a series of radar image strips covering the Teton Range and Jackson Hole in northwestern Wyoming, is given. No attempt was made to collate a complete geologic map with the radar image at each locality. Formation names, problems of geologic interpretation, and details of stratigraphy and structure that are not directly pertinent to a study of the imagery are omitted, but reference is made to publications that contain this type of supplementary information.

  14. Geology and timing of mineralization at the Cangshang gold deposit, north-western Jiaodong Peninsula, China

    USGS Publications Warehouse

    Zhang, X.; Cawood, Peter A.; Wilde, S.A.; Liu, R.; Song, H.; Li, W.; Snee, L.W.

    2003-01-01

    The Cangshang gold deposit of the northwestern Jiaodong Peninsula contains reserves of greater than 50 tonnes (t) and is developed by the largest open pit gold mine in China. This deposit is a Jiaojia-style (i.e. disseminated-and-veinlet) deposit. It is controlled by the San-Cang fault zone, which trends ???040?? and dips 40-75??SE at the mine site. The main (no. 1) orebody lies between a hanging wall of Precambrian metamorphic rocks (mainly amphibolite) of the Fenzishan Group and a footwall composed of the Mesozoic Linglong granitoid. The ore zone is mainly composed of pyritized, sericitized and silicified granitoid, which has undergone variable degrees of cataclasis. SHRIMP U-Pb dating of zircon indicates that the protolith of the hanging wall amphibolite was formed at 2530 ?? 17 Ma and underwent metamorphism at 1852 ?? 37 Ma. The footwall granodiorite has been dated at 166 ?? 4 Ma, whereas zircons from the ore zone yield a younger age of 154 ?? 5 Ma. Cathodoluminescence images of zircons from the granodiorite and ore zone show oscillatory zonation indicative of an igneous origin for both and the ages of these zircons, therefore, are all interpreted to be representative of magmatic crystallization. Dating of sericite by 40Ar-39Ar has been used to directly determine the timing of formation of the Cangshang deposit, providing the first time absolute age on formation of the Jiaojia-style gold deposits. The well-defined age of 121.3 ?? 0.2 Ma provides the precise timing of gold mineralization at the Cangshang deposit. This age is consistent with those of Linglong-style (vein type) gold mineralization, also from the north-western Jiaodong Peninsula, at between 126 and 120 Ma. Therefore, our work indicates that both styles of gold deposits in the Jiaodong Peninsula were formed during the same mineralization event.

  15. Eocene exhumation and basin development in the Puna of northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Carrapa, B.; Decelles, P. G.

    2008-02-01

    The Puna is part of the larger Puna-Altiplano Plateau (also known as the Central Andean Plateau), characterized by high elevation, low relief, and aridity, located in the central Andes of Bolivia and Argentina. Tertiary sedimentary rocks preserved within the Puna contain a unique archive of information regarding the paleogeography, depositional environments, and timing of sediment source exhumation during the early stages of Andean mountain building. The Eocene Geste Formation in the Salar de Pastos Grandes area (within the central Puna of northwestern Argentina) consists of deposits that are the result of confined to unconfined flows in a sandy to gravelly, braided fluvial system and alluvial fans proximal to the source terrane. Paleocurrent data document an overall eastward flow direction. Up-section coarsening of the Geste Formation suggests that topographic relief in the source area increased through time, possibly owing to enhanced tectonic activity and source terrane unroofing. Sandstone petrography and conglomerate clast-count data document quartzose and phyllitic compositions typical of Ordovician rocks preserved just west of the Salar de Pastos Grandes area. Paleocene-Eocene detrital apatite fission track age populations (P1: ˜35-52 Ma; P2: ˜52-65 Ma) of the Geste Formation and their consistent trends up-section suggest moderate to rapid (˜0.4 mm/a to >1 mm/a) exhumation of western sediment sources during the early to mid-Tertiary stages of Andean mountain building. Sedimentation rates increase up-section from ˜0.1 mm/a to 1 mm/a. Our data, when combined with other structural, stratigraphic and seismic evidence from surrounding regions, suggest that the Geste Formation was deposited in response to crustal shortening and resulting erosion and sedimentation, which started as early as Cretaceous in the Chilean Cordillera de Domeyko and in the Salar de Pastos Grandes area by Eocene time. The Geste Formation could be interpreted either as a local wedge-top accumulation on the eastward propagating central Andean orogenic wedge, or as a local intermontane basin. The similarities between wedge-top deposits preserved in Bolivia and Eocene deposits in northwestern Argentina, south of ˜25°S, lead us to favor the wedge-top scenario for the Geste Formation. If correct, this implies that the deformation front of the Andean orogenic wedge incorporated both thin- and thick-skinned structures as it migrated, possibly unsteadily, from the Cordillera de Domeyko during the Cretaceous-Paleocene to areas within the Puna and Eastern Cordillera by mid-late Eocene time. Contemporaneously, a regional-scale foreland basin system developed over an along-strike distance of at least 650 km.

  16. Heat flow from eastern Panama and northwestern Colombia

    USGS Publications Warehouse

    Sass, J.H.; Munroe, R.J.; Moses, T.H., Jr.

    1974-01-01

    Heat flows were determined at 12 sites in four distinct areas between longitude 77?? and 80??W in eastern Panama and northwestern Colombia. Evidently, most of the region is underlain by mafic oceanic crust so that the crustal radiogenic component of heat flow is very small (??? 0.1 ??cal cm-2 sec-1). Low heat-flow values (??? 0.7 ??cal cm-2 sec-1) in northwestern Colombia may reflect thermal transients associated with shallow subduction. The normal values (??? 1) at about 78??W are consistent with the mean heat flow from the western Caribbean and the Gulf of Mexico. At 80??W, a fairly high value of 1.8 may define the easterly limit of thermal transients due to Cenozoic volcanic activity in Central America. ?? 1974.

  17. Geological mapping in northwestern Saudi Arabia using LANDSAT multispectral techniques

    NASA Technical Reports Server (NTRS)

    Blodget, H. W.; Brown, G. F.; Moik, J. G.

    1975-01-01

    Various computer enhancement and data extraction systems using LANDSAT data were assessed and used to complement a continuing geologic mapping program. Interactive digital classification techniques using both the parallel-piped and maximum-likelihood statistical approaches achieve very limited success in areas of highly dissected terrain. Computer enhanced imagery developed by color compositing stretched MSS ratio data was constructed for a test site in northwestern Saudi Arabia. Initial results indicate that several igneous and sedimentary rock types can be discriminated.

  18. Dynamics, Patterns and Causes of Fires in Northwestern Amazonia

    PubMed Central

    Armenteras, Dolors; Retana, Javier

    2012-01-01

    According to recent studies, two widespread droughts occurred in the Amazon basin, one during 2005 and one during 2010. The drought increased the prevalence of climate-driven fires over most of the basin. Given the importance of human-atmosphere-vegetation interactions in tropical rainforests, these events have generated concerns over the vulnerability of this area to climate change. This paper focuses on one of the wettest areas of the basin, Northwestern Amazonia, where the interactions between the climate and fires are much weaker and where little is known about the anthropogenic drivers of fires. We have assessed the response of fires to climate over a ten-year period, and analysed the socio-economic and demographic determinants of fire occurrence. The patterns of fires and climate and their linkages in Northwestern Amazonia differ from the enhanced fire response to climate variation observed in the rest of Amazonia. The highest number of recorded fires in Northwestern Amazonia occurred in 2004 and 2007, and this did not coincide with the periods of extreme drought experienced in Amazonia in 2005 and 2010. Rather, during those years, Northwestern Amazonia experienced a relatively small numbers of fire hotspots. We have shown that fire occurrence correlated well with deforestation and was determined by anthropogenic drivers, mainly small-scale agriculture, cattle ranching (i.e., pastures) and active agricultural frontiers (including illegal crops). Thus, the particular climatic conditions for air convergence and rainfall created by proximity to the Andes, coupled with the presence of one of the most active colonisation fronts in the region, make this region differently affected by the general drought-induced fire patterns experienced by the rest of the Amazon. Moreover, the results suggest that, even in this wet region, humans are able to modify the frequency of fires and impact these historically well preserved forests. PMID:22523580

  19. 41. SOUTHEAST ACROSS WOODWORKING SHOP AREA IN NORTHWESTERN QUADRANT OF ...

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

    41. SOUTHEAST ACROSS WOODWORKING SHOP AREA IN NORTHWESTERN QUADRANT OF FACTORY SHOWING ON LEFT CIRCA 1900 CROSS-CUTOFF CIRCULAR SAW AND ON RIGHT CIRCA 1900 TABLE SAW. BEHIND THE CROSS-CUTOFF SAW IS A CIRCA 1900 SNAG GRINDER. IN THE CENTER BACKGROUND IS THE CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  20. Northwestern University Facility for Clean Catalytic Process Research

    SciTech Connect

    Marks, Tobin Jay

    2013-05-08

    Northwestern University with DOE support created a Facility for Clean Catalytic Process Research. This facility is designed to further strengthen our already strong catalysis research capabilities and thus to address these National challenges. Thus, state-of-the art instrumentation and experimentation facility was commissioned to add far greater breadth, depth, and throughput to our ability to invent, test, and understand catalysts and catalytic processes, hence to improve them via knowledge-based design and evaluation approaches.

  1. A southwest monsoon hydrographic climatology for the northwestern Arabian Sea

    NASA Astrophysics Data System (ADS)

    Brock, John C.; McClain, Charles R.; Hay, W. W.

    1992-06-01

    This paper provides a detailed hydrographic climatology for the shallow northwestern Arabian Sea prior to and during the southwest monsoon, presented as multiple-year composite vertical hydrographic sections based on National Oceanographic Data Center historical ocean station data. Temperature and salinity measurements are used to infer the water masses present in the upper 500 m. The hydrographic evolution depicted on bimonthly sections is inferred to result from wind-driven physical processes. In the northwestern Arabian Sea the water mass in the upper 50 m is the Arabian Sea Surface Water. Waters from 50 to 500 m are formed by mixing of Arabian Sea Surface Water with Antarctic and Indonesian intermediate waters. The inflow of Persian Gulf Water does not significantly influence the hydrography of the northwestern Arabian Sea along the Omani coast. Nitrate has a high inverse correlation with temperature and oxygen in the premonsoon thermocline in the depth interval 50-150 m. During the southwest monsoon, coastal upwelling off Oman and adjacent offshore upward Ekman pumping alter the shallow hydrography.

  2. Undercurrent-driven upwelling in the northwestern Arafura Sea

    NASA Astrophysics Data System (ADS)

    Kämpf, Jochen

    2015-11-01

    A three-dimensional process-oriented model is applied to explore the circulation in the Arafura Sea during the southeasterly monsoon. During this period, widespread phytoplankton blooms develop in a large area (300 km × 300 km) in the northwestern Arafura Sea. The model findings indicate that undercurrents are the principal source of nutrient-rich Banda Sea slope water for the region. It is demonstrated that these undercurrents operate to flush the northwestern Arafura Sea with Banda Sea slope water on a time scale of 1-3 months, which is consistent with observational evidence. The simulated undercurrents are the signature of the classical lee effect, frequently observed in lakes, that comes into play in the Arafura Sea given its bay-like geometry, shallow-water depth (40-50 m), and close vicinity to the equator. It is also shown that density stratification and rotational effects have important influences on the pathway and intensity of the overturning circulation in the northwestern Arafura Sea, which needs to be further explored in the future.

  3. Food habits of pumas in northwestern Sonora, Mexico

    USGS Publications Warehouse

    Rosas-Rosas, O. C.; Valdez, R.; Bender, L.C.; Daniel, D.

    2003-01-01

    It is questionable whether food-habits studies of pumas conducted in the southwestern United States can be extrapolated to northwestern Mexico, because of differences in management, distribution, and abundance of wildlife. We determined food habits of pumas (Puma concolor) in the Sonoran Desert of northwestern Sonora, Mexico. Based on studies in the western United States, we hypothesized that desert mule deer (Odocoileus hemionus) were the major food source of pumas in Sonoran Desert habitats of Mexico. The study area supports populations of desert mule deer, white-tailed deer (Odocoileus virginianus), lagomorphs (Lepus spp. and Sylvilagus audubonii), collared peccary (Pecari tajacu), and the largest population (???300 individuals) of desert bighorn sheep (Ovis canadensis) in Sonora. Based on pugmark characteristics, we recorded 3 different adult resident pumas in approximately 90 km2. We analyzed 60 puma fecal samples collected September 1996-November 1998. Primary prey items based on frequency of occurrence and estimated biomass consumed were desert bighorn sheep (40% and 45%, respectively), lagomorphs (33%, 19%), deer (17%, 17%), and collared peccary (15%, 11%). The high percentage of desert bighorn sheep in puma diets may be due to high abundance relative to mule deer, which declined in number during our study. No differences were found in puma diets between seasons (??22=2.4526, P=0.2934). Fluctuations in mule deer populations in northwestern Sonora may influence prey selection by pumas.

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

    SciTech Connect

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

    1995-05-01

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

  5. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma

    USGS Publications Warehouse

    Becker, C.J.; Runkle, D.L.; Rea, Alan

    1997-01-01

    ARC/INFO export and nonproprietary format files The data sets in this report include digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers approximately 82 square miles and supplies water for irrigation, domestic, municipal, and industrial use for the City of Enid and western Garfield County. The Quaternary-age Enid isolated terrace aquifer is composed of terrace deposits that consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer is unconfined and is bounded by the underlying Permian-age Hennessey Group on the east and the Cedar Hills Sandstone Formation of the Permian-age El Reno Group on the west. The Cedar Hills Sandstone Formation fills a channel beneath the thickest section of the Enid isolated terrace aquifer in the midwestern part of the aquifer. All of the data sets were digitized and created from information and maps in a ground-water modeling thesis and report of the Enid isolated terrace aquifer. The maps digitized were published at a scale of 1:62,500. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  6. Potential particulate impacts at the Grand Canyon from northwestern Mexico.

    PubMed

    Eatough, D J; Green, M; Moran, W; Farber, R

    2001-08-10

    Project MOHAVE was a major air quality and visibility research program conducted from 1990 to 1999 to investigate the causes of visibility impairment in the Grand Canyon National Park region. At Meadview, a remote monitoring site just west of the Grand Canyon National Park, on September 1 and 2, 1992, the concentrations of sulfate (3.1 and 4.3 microg sulfate/m3) were the highest seen in 6 years of monitoring at this site. During this period, the concentrations of SO2 at Meadview were also abnormally high and approximately three times the sulfate concentrations, on a nmol/m3 basis. High concentrations of sulfate and SO2 extended south into southern Arizona and northwestern Mexico. Based on ambient atmospheric conditions, emissions from the Mohave Power Project (MPP) 110 km upwind of Meadview could not have been responsible for the majority of the regionally observed sulfur oxides. The geographical distribution of SO2 and sulfate, and available source information suggest that northwestern Mexico was a significant source of the unusually high observed sulfur oxides. A CMB model developed during Project MOHAVE was used to apportion sulfur oxides at Meadview and other sampling sites throughout the study region for August 31-September 2, 1992. The results indicate that the contribution of MPP to sulfate at Meadview was typical. However, the transport of SOx from northwestern Mexico was elevated throughout much of the region during this time period. This led to the large increase in sulfate concentrations at Meadview on September 1 and 2. These results indicate that emissions from Mexico can be a significant source of particulate material in the Grand Canyon. PMID:11516140

  7. African Oral Traditions: Riddles Among The Haya of Northwestern Tanzania

    NASA Astrophysics Data System (ADS)

    Ishengoma, Johnson M.

    2005-05-01

    This study argues for the integration of African oral traditions and other elements of traditional learning into the modern school curriculum. It thus contributes to supporting the increased relevance of education to local communities. In particular, using the example of riddles collected from one of the main ethnic groups in Northwestern Tanzania, the Haya people, the present study challenges the views of those social and cultural anthropologists who hold that African riddles have no substantially meaningful educational value. Instead, it is maintained that riddles make an important contribution to children's full participation in the social, cultural, political, and economic life of African communities, especially by fostering critical thinking and transmitting indigenous knowledge.

  8. Climate Change and Neotectonic History of Northwestern China

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Chadwick, Oliver; Evans, Diane; Gillespie, Alan; Peltzer, Gilles; Tapponnier, Paul

    1996-01-01

    The progress, results and future plans for the following objectives are presented: (1) To compare the types, rates, and magnitudes of surficial modification processes that have operated in Northwest China and the Southwestern U.S.; (2) To quantify and understand the basis of the remote sensing signatures of these processes to allow extrapolation from field sites to regional maps and to allow comparisons between widely separated arid regions; (3) To use the resulting chronologies to help define the temporal and spatial distribution of continental climate changes; and (4) Determine the ages of movements on some of the active faults in Northwestern China.

  9. Finite frequency tomography fort the northwestern Pacific region

    NASA Astrophysics Data System (ADS)

    Obayashi, M.; Yoshimitsu, J.; Nolet, G.; Fukao, Y.; Shiobara, H.; Sugioka, H.; Kasahara, M.; Gao, Y.

    2012-12-01

    We constructed a new P-wave tomographic model of the whole mantle with a focus on the northwestern Pacific region using more than ten millions of travel time data. The subducted slabs in the northwestern Pacific region show a complicated morphology; the slabs subducted from the south Kurile, Japan, Izu-Bonin arcs tend to be trapped in the mantle transition region, while to the north beneath the north Kurile and to the south beneath Mariana the slabs tend to penetrate the 660-km seismic discontinuity. To understand the relationship between such different behaviors of the subducted slabs, broadband seismic networks in the western Pacific Ocean and in the Russian Far East were deployed along with the Stagnant Slab Project (Japan) from 2005 to 2007. We collected other broadband seismograms in the northwestern Pacific region including Japan, China and the islands in the region. We picked the onsets of the first arrivals on the unfiltered seismograms if possible. The background noise level of the broadband ocean bottom seismogram is, in general, high in the periods less than 5 second due to the microseisms (pressure variations on the ocean floor induced by ocean waves) and in the periods around 100sec due to the infragravity waves. However the noise level takes a minimum and is comparable to that of the land stations in the periods in between. Therefore we measured P-wave differential times between two stations by applying the band-pass filter at the corners 0.03 and 0.08 Hz. We also measured PP-P differential times on the broadband seismograms of the global stations in around 0.1Hz frequency band. Finite frequency kernels were calculated at the corresponding frequency band for these differential travel time data. The finite frequency effect was also taken into account for the handpicked and the ISC data by calculating finite frequency kernels at 2 Hz instead of the ray theory. Such treatment for the handpicked data helps to reduce the artificial structures in the less resolved regions when the tomographic model constructed from the high frequency handpicked data and the lower frequency differential traveltime data simultaneously. The resolution of the obtained model become much better along the northwestern Pacific trenches than our previous model. The transition between the slab stagnation and penetration along the Izu-Bonin to Mariana trenches are well resolved.

  10. Revision of the Upper Cretaceous rudists from northwestern Peru

    NASA Astrophysics Data System (ADS)

    Philip, Jean; Jaillard, Etienne

    2004-09-01

    Revision of the Upper Cretaceous rudists of northwestern Peru has led to new discoveries and enabled the specification of their taxonomy and stratigraphic locations. Different species have been identified: Biradiolites cf. jamaicensis Trechmann 1924, Radiolites cf. macroplicatus Whitfield 1897, Praebarrettia sparcilirata (Whitfield, 1897) of Late Campanian age, and Macgillavryia nicholasi (Whitfield, 1897) of Middle-Late Maastrichtian age. During the Campanian and Maastrichtian, rudists of Peru show paleobiogeographic affinities with those of the Mexican and Caribbean domains. A paleogeographic route for rudist migrations may have existed at that time along the Caribbean arc and the Curaçao-Ecuador coastline.

  11. Climatic Limits on Landscape Development in the Northwestern Himalaya

    PubMed

    Brozović; Burbank; Meigs

    1997-04-25

    The interaction between tectonism and erosion produces rugged landscapes in actively deforming regions. In the northwestern Himalaya, the form of the landscape was found to be largely independent of exhumation rates, but regional trends in mean and modal elevations, hypsometry (frequency distribution of altitude), and slope distributions were correlated with the extent of glaciation. These observations imply that in mountain belts that intersect the snowline, glacial and periglacial processes place an upper limit on altitude, relief, and the development of topography irrespective of the rate of tectonic processes operating. PMID:9110972

  12. 40. NORTH ACROSS WOODWORKING AREA IN NORTHWESTERN QUADRANT OF FACTORY ...

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

    40. NORTH ACROSS WOODWORKING AREA IN NORTHWESTERN QUADRANT OF FACTORY ACROSS STACKED LUMBER ON SAWHORSES TOWARD CIRCA 1900 THICKNESS PLANER, SHOP-MADE BELT GUARD, AND BELOW THE SKYLIGHT OVERHEAD LINE SHAFT, BELTS, AND PULLEYS. BEYOND THE LUMBER ON A WHEELED WORK STATION ARE CIRCA 1900 ROLLS FOR BENDING PROPER CURVATURE IN STEEL WINDMILL BLADES AND CIRCA 1900 BEADING MACHINE FOR FORMING CREASES IN THE EDGES OF SHEET METAL PARTS SUCH AS WHEEL BLADES. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. 77 FR 5585 - Northwestern Mutual Series Fund, Inc. and Mason Street Advisors, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... COMMISSION Northwestern Mutual Series Fund, Inc. and Mason Street Advisors, LLC; Notice of Application... financial instruments. Applicants: Northwestern Mutual Series Fund, Inc. (``Company'') and Mason Street.... FOR FURTHER INFORMATION CONTACT: Barbara T. Heussler, Senior Counsel, at (202) 551-6990, or Jennifer...

  14. The Center for Talent Development at Northwestern University: An Example of Replication and Reformation

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula

    2005-01-01

    This article describes implementation of the talent search model developed by Julian Stanley at the Center for Talent Development of Northwestern University. While remaining true to the basic components of the talent search, the talent center at Northwestern has emphasized using talent search as a means to influence programming in local schools…

  15. The Northwestern Africana Project: An Experiment in Decentralized Bibliographic and Authority Control.

    ERIC Educational Resources Information Center

    Hill, Janet Swan

    1981-01-01

    An investigation of the feasibility of using a computer-assisted decentralized bibliographic control system to build a comprehensive, consistent national database for use in a national library network used the Northwestern On-line Total Integrated System to establish a center for African materials at Northwestern University. Eleven references are…

  16. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the... Quality Control Region. 81.126 Section 81.126 Protection of Environment ENVIRONMENTAL PROTECTION......

  17. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the... Quality Control Region. 81.126 Section 81.126 Protection of Environment ENVIRONMENTAL PROTECTION......

  18. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the... Quality Control Region. 81.126 Section 81.126 Protection of Environment ENVIRONMENTAL PROTECTION......

  19. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the... Quality Control Region. 81.126 Section 81.126 Protection of Environment ENVIRONMENTAL PROTECTION......

  20. Descriptions and illustrations of fossils from Vancouver's and Sucia Islands, and other northwestern localities

    USGS Publications Warehouse

    Meek, F.B.

    1876-01-01

    The fossils described and illustrated in this paper were in part collected by Mr. George Gibbs, geologist of the Northwestern Boundary Survey, under the direction of Archibald Campbell, esq., the commissioner appointed in behalf of the United States Government on the joint commission for the survey of the Northwestern Boundary-line.

  1. Map of water table in Graham County, northwestern Kansas, March 1979

    USGS Publications Warehouse

    Spinazola, Joseph M.

    1981-01-01

    A map of the water table in Graham County provides current (1980) information on water levels in the unconsolidated deposits. Graham County has an area of 900 square miles in northwestern Kansas. The principal source of water for domestic, stock, municipal, and irrigation use if from wells in the shallow unconsolidated deposits. The aquifers occur chiefly in the Ogallala Formation of Miocene age and in deposits of Quaternary age. Water in the aquifers generally downgradient from west to east. In the Ogallala Formation, water also moves toward the stream valleys that drain the uplands. The altitude of the water table varies seasonally in response to changes in recharge and discharge. Major sources of recharge are subsurface flow from the west, leakage from streams, and infiltration of moisture from precipitation. Discharge includes subsurface flow to the east, transpiration by plants, evaporation from the aquifer where the water table is near the land surface, flow from seeps, and pumpage from wells. The altitude of the water table is based on water-level measurements made during March 1979. (USGS)

  2. Regional correlation of deposition sequences in the southern Mesozoic marine province, northwestern Nevada

    SciTech Connect

    Satterfield, J.I.; Oldow, J.S. . Dept. of Geology and Geophysics)

    1993-04-01

    Strata of the Mesozoic marine province of a northwestern Nevada, deposited in subaerial to deep marine environment in a backarc basin, underwent severe deformation during the late Mesozoic. Restoration of stratigraphic relations among constituent volcanic, volcanogenic, carbonate, and continentally-derived siliciclastic rocks has been hampered by sparse biostratigraphic age control. Regional correlation of coeval facies is made possible by coupling depositional sequences with biostratigraphic control in the southwestern Gabbs Valley Range, the southern Shoshone Mountains, and the southern Clan Alpine Mountains, which serve as reference sections for Late Triassic and Early Jurassic ammonite zonation of western North America. Differentiation between regionally significant sequence boundaries and those of limited areal extent is possible only by linking the biostratigraphy and physical stratigraphic relations, such as abrupt vertical transitions in lithology corresponding to large facies changes. Physical stratigraphic relations alone are not adequate for correlation ad indicated by the diachronous initiation of Early to Middle( ) Jurassic deposition in half-graben basins (Dunlap Formation) which locally cloaks eustatically( ) controlled depositional sequences. Within these limitations, three regionally extensive sequences are recognized in the reference sections and have lower boundaries at the base of Upper Triassic shallow marine to deltaic carbonate-clastic rocks (Luning Formation) and at the base and within subtidal to offshore-marine carbonate and clastic rocks (Triassic and Jurassic Volcano Peak Group).

  3. Lithofacies Associations and Depositional Environments of the Neogene Molasse succession, Pishin Belt, northwestern Pakistan

    NASA Astrophysics Data System (ADS)

    Kasi, A.; Kassi, A.; Friis, H.; Umar, M.

    2013-12-01

    The Pishin Belt is a NE-SW trending mixed flysch and molasse basin, situated at the northwestern part of Pakistan, bordered by Afghan Block of the Eurasian Plate in the west and Indian Plate in the east. Western boundary of the belt is marked by the well-known Chaman Transform Fault, whereas the Zhob Valley Thrust and Muslim Bagh-Zhob Ophiolite mark the eastern boundary. The Belt is divisible into six tectono-stratigraphic zones bounded by major thrusts. Muslim Bagh-Zhob Ophiolite is the base and Zone-I of this belt. Zone-II comprises shallow marine and flysch successions of the Eocene Nisai Formation and Oligocene Khojak Formation. The Early to Middle Miocene Dasht Murgha group comprises Zone-III, the Late Miocene-Pliocene Malthanai formation comprises Zone-IV, the Pleistocene Bostan Formation makes Zone-V, and the flat-laying Holocene deposits of the Zhob Valley comprise Zone-VI. The Neogene molasse successions of the Pishin Belt include the Dasht Murgha group, Malthanai formation and Bostan Formation; these are mostly composed of sandstone, claystone and conglomerate lithologies. Sandstones have been classified as lithic arenites and their QFL values suggest quartzolithic composition. Twelve distinct lithofacies have been recognized in the succession and thus grouped into four types of facies associations. Lithofacies include clast-supported massive gravel (Gcm), clast-supported crudely bedded gravel (Gh), cross-stratified conglomerate (Gt and Gp), trough cross-stratified sandstone (St), planar cross-stratified sandstone (Sp), ripple cross-laminated sandstone (Sr), horizontally stratified sandstone (Sh), low-angle cross-stratified sandstone (Sl), massive sandstones (Sm), massive mudstone and siltstone (Fm) and paleosol carbonate (P). The lithofacies associations include channel facies association (CHA), crevasse-splay facies association (CSA), natural-levee facies association (LVA) and floodplain facies association (FPA). The lithofacies associations suggest that the Dasht Murgha group was deposited by a sandy braided to mixed-load high-sinuosity fluvial system, the Malthanai formation by a mixed-load high-sinuosity fluvial system and Bostan Formation by gravelly braided channels of a coalescing alluvial fan system. We propose that prolonged and continued collision of the Indian Plate with the Afghan Block of the Eurasian Plate resulted in the closure of the Katawaz Remnant Ocean (the southwestern extension of the Neo-Tethys) in the Early Miocene. Uplifted orogens of the Muslim Bagh-Zhob Ophiolite and marine successions of the Nisai and Khojak formations served as the major source terrains for the Miocene through Holocene molasse succession in the south and southeast verging successive thrust-bound foreland basins at the outer most extremity of the Pishin Belt.

  4. Acute rheumatic fever in First Nations communities in northwestern Ontario

    PubMed Central

    Gordon, Janet; Kirlew, Mike; Schreiber, Yoko; Saginur, Raphael; Bocking, Natalie; Blakelock, Brittany; Haavaldsrud, Michelle; Kennedy, Christine; Farrell, Terri; Douglas, Lloyd; Kelly, Len

    2015-01-01

    Abstract Objective To document a case series of 8 young First Nations patients diagnosed with acute rheumatic fever (ARF), a preventable disease that resulted in the death of 2 patients, in northwestern Ontario in the context of late diagnosis, overcrowded housing, and inadequate public health response. Design Retrospective case series over an 18-month period. Setting Remote First Nations communities in northwestern Ontario. Participants Eight patients with ARF. Main outcome measures Incidence, mortality, residual rheumatic heart disease, time to diagnosis, barriers to diagnosis and treatment, housing situation of patients, patient demographic characteristics (age, sex), and investigation results. Results The incidence of ARF in this population was 21.3 per 100 000, which is 75 times greater than the overall Canadian estimated incidence. The average patient age was 9.4 years. Most cases developed joint findings, and 5 of the surviving patients had rheumatic heart disease when they received echocardiography. The average time to diagnosis was 88 days. Two 4-year-old children died from ARF. Most patients lived in inadequate and crowded housing. Conclusion This rare disease still exists in remote First Nations communities. These communities demonstrate an incidence equal to that in aboriginal communities in Australia and New Zealand, which have among the highest international incidence of ARF. Primordial prevention, including improved on-reserve housing, is urgently needed. Case detection and ongoing surveillance for primary and secondary prophylaxis requires a well resourced regional strategy. PMID:26759842

  5. Lay theory of healing in northwestern New Spain.

    PubMed

    Kay, M

    1987-01-01

    Northwestern New Spain experienced not only a territorial and a spiritual conquest, but a medical conquest. This medical conquest came from a tradition, established after the conquest of central New Spain, that had fused classical medicine of the Old World with medicine of indigenous groups, in the writings of European doctors and scientists as well as graduates of Mexican colleges. The medical conquest of Sonora was accomplished by laymen, explorers and missionaries who carried the theory of healing resulting from these syncretic processes into the northern lands, adding new materials that they learned from indigenous peoples there. When the Indians were ill with epidemic disease or injuries, they were cared for by missionaries brought up on European domestic medicine. The theory of illness and its cure held by the lay healers became predominantly that of the conquest culture. The conquerers', missionaries' and colonists' interpretations of native plant, animal and mineral remedies that they learned from northwestern native medicine were colored by their own concepts of disease and healing, resulting in an epistemology which continues to guide lay or domestic medicine not only in Sonora but also in the rest of the American Mexican west today. PMID:3306941

  6. Geomagnetic variation anomalies in north-western Italy

    NASA Astrophysics Data System (ADS)

    Bozzo, Emanuele; Meloni, Antonio

    1989-03-01

    A preliminary geomagnetic variation data analysis has been made in the Piedmont-Ligurian area in north-western Italy. Data were collected by means of two instruments: an Askania portable variograph and a LaCour fixed station operated in the Roburent geomagnetic observatory. The portable variograph has been moved to several locations in north-western Italy. Parkinson vectors were drawn for 8, 20 and 60 min respectively, considering bay-like events recorded at single stations. Fourier parameters and anomaly maps for 32 and 64 min have been obtained after selecting similar events in order to simulate a magnetometric array. Results show trends that suggest possible correlations with three main geological features of the investigated area: (1) a coast effect probably also related to the lithospheric thickness of the Ligurian Sea; (2) a possible highly conductive channel connected to the Alpine system that could be analogous to anomalous structures found in Europe; and (3) an effect of the lower crust being obducted in the Ivrea body and subducted in the Southern Alps.

  7. Great Earthquakes and Tsunamis of the Northwestern Aceh Coast, Sumatra

    NASA Astrophysics Data System (ADS)

    Kelsey, H. M.; Horton, B. P.; Rubin, C. M.; Daly, P.; Grand Pre, C.; Hawkes, A.; Daryono, M.; Ismail, N.

    2011-12-01

    The 2004 Andaman Aceh earthquake occasioned coseismic coastal subsidence in the range of 0.5 to 2.0 m on the northwestern Aceh coast. This coastal lowland contains stratigraphic evidence of previous great earthquakes and tsunamis on the Sunda megathrust that affected the coastline for hundreds of kilometers. We focused our research at three coastal sites in northwestern Aceh province. We conclude that three subduction zone earthquakes occurred in the early to mid Holocene (4500-7000 years ago) with an average recurrence of approximately 1000 years during conditions of relative sea level rise. Detailed investigations of lithology and micro- and macrofossil assemblages reveal regionally extensive buried mangrove soils that were coseismically subsided during the earthquakes and abruptly overlain by thin sand deposits of tsunami origin. The sands are covered by a sequence of intertidal muds. Tsunami deposits are inconsistently preserved, whereas the coseismic signal from buried soils is ubiquitously preserved. There is no stratigraphic record of subsidence in the late Holocene (4500 years to present) along the same coastal reach. In this time interval, far field locations such as Sumatra record stable or falling relative sea levels, which precludes coastal weltand progradation that leads to preservation of buried soils. In this younger, late Holocene time interval, the search for unique depocenters that preserve tsunami deposits provides a promising, alternative approach to constructing a paleoseimic record for the Aceh portion of the Sunda subduction zone.

  8. Spatial variability of snow physical properties across northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Courville, Z.; Polashenski, C.; Dibb, J. E.; Domine, F.

    2013-12-01

    In the late spring and early summer of 2013, researchers on the SAGE (Sunlight Absorption on the Greenland ice sheet Experiment) Traverse, embarked on a 4000 km ground traverse across northwestern Greenland in an attempt to quantify spatial variability of snow chemistry, snow physical properties, and snow reflectance. The field team targeted sites first visited by Carl Benson during his series of traverses from 1952 to 1955 as part of his pioneering work to characterize the Greenland Ice Sheet. This route now represents a rapidly changing and variable area of Greenland, as the route passes through several of the ice sheet facies first delimited by Benson. Along the traverse, the SAGE field team made ground-based albedo measurements using a hand-held spectroradiometer and collected snow physical property samples to determine snow specific surface area (SSA) from shallow, 2m pits. In addition, snow density and stratigraphy were measured. Snow layers in the near-surface and at the previous season's melt layer were targeted for sampling. Here we present preliminary snow physical property results from the upper portion of the snow pits and relate these to surface albedo data collected over the route. Further measurements of snow properties in the 2012 melt layer will be analyzed to assess the potential role of snow chemical (see Dibb et al. for a discussion of chemical analysis) and physical property driven albedo feedbacks could have played in contributing to that event. Route of 2013 SAGE Traverse in northwestern Greenland.

  9. Prevalence of anemia in First Nations children of northwestern Ontario.

    PubMed Central

    Whalen, E. A.; Caulfield, L. E.; Harris, S. B.

    1997-01-01

    OBJECTIVE: To estimate the prevalence of anemia among First Nations children of northwestern Ontario. DESIGN: Retrospective review of all hemoglobin determinations between 1990 and 1992 in the Sioux Lookout Zone. SETTING: The Sioux Lookout Zone Hospital, a secondary care referral hospital for 28 remote First Nations communities in northwestern Ontario, affiliated with the University of Toronto's Sioux Lookout Program. PARTICIPANTS: All First Nations children age 3 to 60 months who had produced venipuncture or fingerprick blood samples between 1990 and 1992 (614 children had a total of 1223 hemoglobin determinations). MAIN OUTCOME MEASURES: Prevalence of anemia by age, sex, geographical location, and diagnosis. Anemia was defined as a hemoglobin value less than 110g/L. RESULTS: Prevalence of anemia peaked in the age range of 6 to 24 months with prevalence rates of 51.7% to 79.3%. Conditions most commonly associated with anemia were respiratory tract infections. Children living in communities in the western part of the Sioux Lookout Zone were 1.64 times more likely to have anemia (95% confidence interval 1.15, 2.35) than children in the other communities. CONCLUSIONS: Anemia appears to be a serious public health problem among preschool children in the Sioux Lookout Zone. PMID:9111982

  10. Hydro-geophysical characterization for groundwater resources potential of fractured limestone reservoirs in Amdoun Monts (North-western Tunisia)

    NASA Astrophysics Data System (ADS)

    Redhaounia, Belgacem; Bédir, Mourad; Gabtni, Hakim; Batobo, Ountsche Ilondo; Dhaoui, Mohamed; Chabaane, Achref; Khomsi, Sami

    2016-05-01

    This study has led to the identification of the Upper Cretaceous and Lower Eocene (Abiod, Boudabbous/El Gueria Formations) fractured and karstic aquifers in the Amdoun region (Northwestern Tunisia). Geological information (litho-stratigraphy and fractures network study) and geophysical (gravity, wells analysis, seismic reflection, Electrical Resistivity Tomography (ERT)) investigations performed in the area have highlighted, with some detail, images of structures of carbonate aquifers near anticline flanks and along perched synclines. Some factors such as fracture intensity, karsts evolution and structural position have an important influence on the hydrologic productivity of Abiod and Boudabbous/El Gueria reservoirs. Different methodologies were used to characterize the geological and hydro-geological perched aquifers and produce the 3D geo-electrical model of near surface karstic features and cavities of the carbonate limestone in the Aïn Sallem site. This study integrates the geological and geophysical information available and can serve as a representative example in the description of the most important hydraulic reserves in the North-western Tunisia.

  11. Spreading of Levantine Intermediate Waters by submesoscale coherent vortices in the northwestern Mediterranean Sea as observed with gliders

    NASA Astrophysics Data System (ADS)

    Bosse, Anthony; Testor, Pierre; Mortier, Laurent; Prieur, Louis; Taillandier, Vincent; d'Ortenzio, Fabrizio; Coppola, Laurent

    2015-03-01

    Since 2007, gliders have been regularly deployed in the northwestern Mediterranean Sea, a crucial region regarding the thermohaline circulation of the Mediterranean Sea. It revealed for the first time very warm (+0.4∘C) and saline (+0.1) submesoscale anticyclones at intermediate depth characterized by a small radius (˜5 km), high Rossby (˜0.3), and Burger (˜0.7) numbers. They are likely order of 10 to be formed each year, have a life time order a year and certainly contribute significantly to the spreading of the Levantine Intermediate Waters (LIW) toward the whole subbasin, thus potentially impacting wintertime vertical mixing through hydrographical and dynamical preconditioning. They could be mainly formed by the combined action of turbulent mixing and flow detachment of the northward flow of LIW at the northwestern headland of Sardinia. Upwelling conditions along the western coast of Sardinia associated with a southward geostrophic flow within the upper layers seem to play a key role in their formation process.

  12. Geogenic sources of local arsenic enrichment in groundwater from northwestern Thuringia, Germany

    NASA Astrophysics Data System (ADS)

    Abratis, Michael; Viereck, Lothar

    2014-05-01

    Aqueous fluids migrating in the Earth's crust interact with the host rocks and partially take up their geochemical signatures. Mineralization and sometimes geogenic contamination of the groundwater may be the consequence: The aquifer systems of the Lower Triassic Buntsandstein Formation, an important source of drinking water in north-western Thuringia, and the Rotliegend Formation are locally affected by elevated arsenic concentrations. Data from water wells locally show arsenic concentrations above the limit value for drinking water (10 μg/L). The regional distribution as well as lack of secondary vein mineralizations or anthropogenic sources within this area point to a geogenic stratibound source of arsenic. The average concentration of the toxic, carcinogenic trace element arsenic in rocks of Phanerozoic rocks in Germany range from 5 to 12 μg/g for different lithologies, being generally higher in Variscan rocks. However, it can be several times enriched in certain sedimentary lithologies such as pelites and even more so in coal beds. In our present study we investigate all sequences of the Buntsandstein and Rotliegend Formation with their different lithologies in order to identify the relevant carriers of arsenic. Geochemical analyses on samples from selected drill cores and outcrops show arsenic of >50 μg/g especially in carbonaceous sediment sections as well as in primarily gray-green lacustrine clay stones. Elevated arsenic concentrations seem to be related to lithofacies of lacustrine origin in the Buntsandstein and carbonaceous sediment sections in the Rotliegend. Aim of the current study is now to identify the appropriate synsedimentary mineral phases that incorporate arsenic and to identify the processes and conditions under which arsenic is mobilized from these phases and transferred into the groundwater.

  13. Ankylosaur Remains from the Early Cretaceous (Valanginian) of Northwestern Germany

    PubMed Central

    Sachs, Sven; Hornung, Jahn J.

    2013-01-01

    A fragmentary cervico-pectoral lateral spine and partial humerus of an ankylosaur from the Early Cretaceous (early Valanginian) of Gronau in Westfalen, northwestern Germany, are described. The spine shows closest morphological similarities to the characteristic cervical and pectoral spines of Hylaeosaurus armatus from the late Valanginian of England. An extensive comparison of distal humeri among thyreophoran dinosaurs supports systematic differences in the morphology of the distal condyli between Ankylosauria and Stegosauria and a referral of the Gronau specimen to the former. The humerus fragment indicates a rather small individual, probably in the size range of H. armatus, and both specimens are determined herein as ?Hylaeosaurus sp.. A short overview of other purported ankylosaur material from the Berriasian-Valanginian of northwest Germany shows that, aside from the material described herein, only tracks can be attributed to this clade with confidence at present. PMID:23560099

  14. Origin of arches in the northwestern Gulf of Mexico basin

    SciTech Connect

    Laubach, S.E.; Jackson, M.L.W. )

    1990-07-01

    The San Marcos and Sabine arches are prominent north- to northwest-trending basement uplifts in the northwestern Gulf of Mexico basin that may be late Mesozoic to Cenozoic foreland or intraplate folds rather than domes over plutons or buoyant basement blocks. These arches are subparallel to and contemporaneous with orogenic episodes in the northwest-trending fold-thrust belt of Mexico. Arch movement was also contemporaneous with rapid convergence between the North American and Pacific plates. Arch development in the gulf as a result of tectonic compression is plausible in view of increasing recognition of wide zones of foreland and intraplate deformation in continents. Current tectonic models of the development of the gulf inaccurately predict gradual, decelerating subsidence when these arches were most active.

  15. Seismic and chronostratigraphic results from SHALDRIL II, northwestern Weddell Sea

    USGS Publications Warehouse

    Anderson, J.B.; Wellner, J.; Wise, S.; Bohaty, S.; Manley, P.; Smith, T.; Weaver, F.; Kulhanek, D.

    2007-01-01

    The 2006 SHALDRIL II cruise was conducted in the northwestern Weddell Sea, with primary drilling targets in the James Ross Basin. A site drilled along the northern edge of the James Ross Basin sampled either latest Eocene or earliest Oligocene deposits, providing a lower chronostratigraphic benchmark for our seismic stratigraphic age model. Severe sea ice conditions forced abandonment of several of the James Ross Basin sites. Three alternate sites were drilled along the southern flank of the Joinville Plateau. Seismic data from the area show a thick, southward dipping stratigraphic succession with no conspicuous gaps. Three drill sites sampled this succession and recovered Oligocene, middle Miocene, and early Pliocene strata overlain by a thin drape of Pleistocene deposits. The Pliocene-Miocene boundary appears to be represented by a disconformity within the cored interval. Otherwise, this is one of the most complete post-Eocene successions anywhere on Antarctica and its adjacent margins

  16. Occurrence of Trichinella spp. in wild animals in northwestern Libya.

    PubMed

    Hosni, M M; Maghrbi, A A El; Ganghish, K S

    2013-01-01

    The present study determined the occurrence of Trichinella spp. in captured and some perished wildlife animals which included 70 hedgehogs, 19 red foxes, 13 common jackals and 8 crested porcupines in northwestern Libya. Muscle samples of these animals were examined by trichinoscopy. Trichinella larvae were detected only in 4 (5.7%) of the hedgehogs (Erinaceus algirus) and 2 (10.5%) of the red foxes (Vulpes vulpes). Larvae were found in the muscles of the diaphragm, abdomen, tongue, forelimb, hindlimb and intercostal muscles. Examination of tissue sections revealed the presence of numerous cysts within the muscle fibers containing one or more coiled or elongated larvae. Inflammatory cell infiltration was observed around the cysts especially at their poles. Results indicated the importance of wild animals as reservoirs of Trichinella larvae and their role in the transmission of the disease to other wild and domestic animals as well as humans. PMID:26623318

  17. Ankylosaur remains from the early cretaceous (valanginian) of northwestern Germany.

    PubMed

    Sachs, Sven; Hornung, Jahn J

    2013-01-01

    A fragmentary cervico-pectoral lateral spine and partial humerus of an ankylosaur from the Early Cretaceous (early Valanginian) of Gronau in Westfalen, northwestern Germany, are described. The spine shows closest morphological similarities to the characteristic cervical and pectoral spines of Hylaeosaurus armatus from the late Valanginian of England. An extensive comparison of distal humeri among thyreophoran dinosaurs supports systematic differences in the morphology of the distal condyli between Ankylosauria and Stegosauria and a referral of the Gronau specimen to the former. The humerus fragment indicates a rather small individual, probably in the size range of H. armatus, and both specimens are determined herein as ?Hylaeosaurus sp.. A short overview of other purported ankylosaur material from the Berriasian-Valanginian of northwest Germany shows that, aside from the material described herein, only tracks can be attributed to this clade with confidence at present. PMID:23560099

  18. Northwestern Pacific typhoon intensity controlled by changes in ocean temperatures.

    PubMed

    Mei, Wei; Xie, Shang-Ping; Primeau, François; McWilliams, James C; Pasquero, Claudia

    2015-05-01

    Dominant climatic factors controlling the lifetime peak intensity of typhoons are determined from six decades of Pacific typhoon data. We find that upper ocean temperatures in the low-latitude northwestern Pacific (LLNWP) and sea surface temperatures in the central equatorial Pacific control the seasonal average lifetime peak intensity by setting the rate and duration of typhoon intensification, respectively. An anomalously strong LLNWP upper ocean warming has favored increased intensification rates and led to unprecedentedly high average typhoon intensity during the recent global warming hiatus period, despite a reduction in intensification duration tied to the central equatorial Pacific surface cooling. Continued LLNWP upper ocean warming as predicted under a moderate [that is, Representative Concentration Pathway (RCP) 4.5] climate change scenario is expected to further increase the average typhoon intensity by an additional 14% by 2100. PMID:26601179

  19. Hantavirus Infection in Humans and Rodents, Northwestern Argentina

    PubMed Central

    Levis, Silvana; Calderón, Gladys; Ramirez, Josefina; Bravo, Daniel; Lozano, Elena; Ripoll, Carlos; St. Jeor, Stephen; Ksiazek, Thomas G.; Barquez, Ruben M.; Enria, Delia

    2003-01-01

    We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)–endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high prevalence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats. PMID:14519242

  20. Northwestern Pacific typhoon intensity controlled by changes in ocean temperatures

    PubMed Central

    Mei, Wei; Xie, Shang-Ping; Primeau, François; McWilliams, James C.; Pasquero, Claudia

    2015-01-01

    Dominant climatic factors controlling the lifetime peak intensity of typhoons are determined from six decades of Pacific typhoon data. We find that upper ocean temperatures in the low-latitude northwestern Pacific (LLNWP) and sea surface temperatures in the central equatorial Pacific control the seasonal average lifetime peak intensity by setting the rate and duration of typhoon intensification, respectively. An anomalously strong LLNWP upper ocean warming has favored increased intensification rates and led to unprecedentedly high average typhoon intensity during the recent global warming hiatus period, despite a reduction in intensification duration tied to the central equatorial Pacific surface cooling. Continued LLNWP upper ocean warming as predicted under a moderate [that is, Representative Concentration Pathway (RCP) 4.5] climate change scenario is expected to further increase the average typhoon intensity by an additional 14% by 2100. PMID:26601179

  1. The use of photovoltaics for rural electrification in northwestern China

    SciTech Connect

    Wallace, W.L.; Li Jingming; Gao Shangbin

    1998-09-01

    The use of renewable energy technologies in China is becoming increasingly important to meet the needs of a large rural population. Solar and wind renewable resources in particular are available in regions of China that at present have no access to conventional grid power. Two regions in China that have an acute lack of electricity are a large region in northern and western China and the coastal island region of China. These regions have attracted the attention of the Chinese government in terms of increasing the quality of life and standard of living conditions of the rural population. These regions have also attracted the attention of domestic Chinese companies and of international companies, governments, and multilateral development organizations as a potential market for renewable energy rural electrification systems. This paper focuses on the bilateral cooperation between the US Department of Energy and China in providing assistance for the use of renewable technologies for rural electrification in northwestern China.

  2. Geothermal gradients in the steen river area of Northwestern Alberta

    NASA Astrophysics Data System (ADS)

    Jones, F. W.; Lam, H. L.

    1984-03-01

    A total of 6540 bottom-hole temperature values from 1879 petroleum exploration wells in northwestern Alberta in the region 57°N-60°N and 114°W-120°W have been used to estimate temperature gradients there. A thermal gradient contour map constructed for the region shows a number of local high geothermal gradient areas. Comparison with available aeromagnetic and gravity maps indicates that a high geothermal gradient near Steen River is probably associated with an igneous intrusion and that nearby high geothermal gradient areas may be due to the transport of heat away from the basement by upward and lateral water motion. Also, it is noted that, in this region of Alberta, oil field locations appear to coincide with areas of low geothermal gradient, whereas gas fields appear to coincide with high geothermal gradients.

  3. A Santonian - Campanian boundary locality from North-western Turkey

    NASA Astrophysics Data System (ADS)

    Wolfgring, Erik; Wagreich, Michael; Dinarès-Turell, Jaume; Omer Yilmaz, Ismail; Boehm, Katharina

    2015-04-01

    A Santonian - Campanian boundary section, close to the village of Göynük in North-western Turkey (Bolu province), was recorded and examined in respect to nannofossil and foraminiferal biostratigraphy, magnetic susceptibility, as well as magnetic polarity. During the Late Cretaceous, the Mudurnu-Göynük basin was located in the northern Tethyan Ocean, on the Sakarya continent (between the Intra-Pontide Ocean and northern branch of the Tethys). The section yields reddish hemipelagic to pelagic deposits. The stratigraphically older part is characterised by uniform limestone. Towards the top, the section displays marls and marly limestones with frequent tuff intercalations. The section represents a hemipelagic to pelagic environment. Planktonic foraminifera prevail in numbers and represent a typical Santonian to Campanian foraminifera community. Benthic foraminifera are sparse. Biostratigraphic data suggest an age from the late Santonian Dicarinella asymetrica to the early Campanian Globotruncanita elevata planktonic foraminifera zone (nannofossil zones CC16-CC18). By investigation of magnetic polarity, the older part of the section can be assigned to the Santonian C34 normal, while the base-Campanian reversal C33r is evident in the upper part of the section. Results from the assessment of magnetic susceptibility give evidence for Milankovitch cycles. We witness a strong signal for what would presumably be the 400 kyr eccentricity cycle. The Campanian interval measured at this section gives results of unusually high values for magnetic susceptibility. Compared to the older part of the section, we find values twice as high in the younger interval. As evidence for volcanic activity is frequent in the Campanian part of the section, the abrupt shift in the magnitude of magnetic susceptibility values may be explained by volcanic admixture. Apart from implications for biostratigraphy and palaeoenvironments, the record of frequent volcanic activities in this Santonian - Campanian boundary section might also provide insights in the history of volcanic events in the North-western Tethyan realm.

  4. Regional-scale drivers of forest structure and function in northwestern Amazonia.

    PubMed

    Higgins, Mark A; Asner, Gregory P; Anderson, Christopher B; Martin, Roberta E; Knapp, David E; Tupayachi, Raul; Perez, Eneas; Elespuru, Nydia; Alonso, Alfonso

    2015-01-01

    Field studies in Amazonia have found a relationship at continental scales between soil fertility and broad trends in forest structure and function. Little is known at regional scales, however, about how discrete patterns in forest structure or functional attributes map onto underlying edaphic or geological patterns. We collected airborne LiDAR (Light Detection and Ranging) data and VSWIR (Visible to Shortwave Infrared) imaging spectroscopy measurements over 600 km2 of northwestern Amazonian lowland forests. We also established 83 inventories of plant species composition and soil properties, distributed between two widespread geological formations. Using these data, we mapped forest structure and canopy reflectance, and compared them to patterns in plant species composition, soils, and underlying geology. We found that variations in soils and species composition explained up to 70% of variation in canopy height, and corresponded to profound changes in forest vertical profiles. We further found that soils and plant species composition explained more than 90% of the variation in canopy reflectance as measured by imaging spectroscopy, indicating edaphic and compositional control of canopy chemical properties. We last found that soils explained between 30% and 70% of the variation in gap frequency in these forests, depending on the height threshold used to define gaps. Our findings indicate that a relatively small number of edaphic and compositional variables, corresponding to underlying geology, may be responsible for variations in canopy structure and chemistry over large expanses of Amazonian forest. PMID:25793602

  5. Fluvial response to late Quaternary climatic fluctuations, central Kobuk Valley, northwestern Alaska

    SciTech Connect

    Ashley, G.M. . Dept. of Geological Sciences); Hamilton, T.D. )

    1993-09-01

    Much of northwestern Alaska remained unglaciated during the Pleistocene and thus offers a favorable setting for examining long-term records of high-latitude geological and biological change. Epiguruk, a large cut bank 3.5 km long and up to 36 m high on the Kobuk River south of the Brooks Range in eastern Beringia, exposes complex sedimentary successions representing cycles of upper quaternary alluviation and eolian sedimentation, downcutting, and soil formation. A rich record of plants and mammals is also preserved in the section. Deposits of fluvial channels and flood plains, eolian dunes, sand sheets, loess, and ponds, as well as organic soils (Histosols) are represented. Parallel-bedded fine sand and coarse silt couplets that commonly contain root structures, ripple cross-lamination, silt drapes are flood-plain sediments apparently deposited at the interface of fluvial and eolian environments. Multiple fluvial-to-eolian depositional sequences were caused by influx of eolian sediment to the river from intermittently active dune fields south of the Kobuk River. Alluviation in the Kobuk Valley was coeval with glaciation in the Brooks Range, whereas downcutting occurred during interstadials when dune stabilization limited sediment supply. The depositional model developed at Epiguruk may be useful in interpreting some of the widespread subhorizontally stratified late-glacial deposits of Europe and North America.

  6. Geology of northwestern Mindoro and its offshore islands: Implications for terrane accretion in west Central Philippines

    NASA Astrophysics Data System (ADS)

    Canto, A. P. B.; Padrones, J. T.; Concepcion, R. A. B.; Perez, A. D. C.; Tamayo, R. A.; Dimalanta, C. B.; Faustino-Eslava, D. V.; Queaño, K. L.; Yumul, G. P.

    2012-11-01

    In over four decades, terrane studies of Mindoro Island have evolved from one terrane- to three terrane-models. Recent mapping of northwestern Mindoro and the islands of Lubang and Ambil roughly agrees with a 1990 suggestion that the island is composed of two terranes: the Central Range and the San Jose Platform. However, in contrast to this older model, our study, which takes into consideration the petrochemical and paleontological characteristics of the units, subdivides Northwest Mindoro into the Amnay Ophiolite and the Halcon Metamorphic terranes. Southwest-verging thrust faults parallel to the currently active Manila Trench demarcate the younger Amnay Ophiolite from the latter. Components of the older Mangyan Ophiolitic Complex, formerly thought to represent a terrane distinct from the metamorphic body, are now suggested to occur as disrupted bodies enclosed within the schists of the Halcon Metamorphics. The timing of incorporation of these megaclast materials and the regional metamorphism that occurred is constrained by the deposition of the sedimentary sequences of the Late Eocene Lasala Formation. Petrochemical studies of these younger sedimentary units reveal their continent-derived character. Therefore, accretion of the Cretaceous Mangyan Ophiolitic Complex marks the collision between the Cretaceous oceanic lithosphere and mainland Asia that is considered to be the protolith of the Halcon Metamorphics. A subsequent collision occurred which led to the amalgamation of the Amnay Ophiolite suite to the metamorphosed terrane.

  7. Biostratigraphy of a Middle Miocene-Pliocene sequence from Cumarebo area, Falcon State, northwestern Venezuela

    SciTech Connect

    Giffuni, G. )

    1991-03-01

    The southern Caribbean region offers little in the way of continuous sequences for the late Neogene. An upward facies shallowing trend unfavorable for planktonic foraminifers and erosional truncation seems to be almost a rule for such sediments. A fairly complete sedimentary sequence mainly represented by clays, silts, and carbonate rocks from the Cumarebo region, Falcon State, northwestern Venezuela, was chosen to study the biostratigraphy of the late Neogene using foraminifers. More than one hundred surface samples were analyzed throughout. The study of foraminiferal fossil assemblages and other microfossils was also used to define paleoenvironments of deposition. Four formations are involved in this work. From base to top they are the Socorro, Caujarao, El Veral, and Tucupido. From the study of planktonic foraminifers, six biostratigraphic zones were recognized: Globorotalia mayeri Zone, Globorotalia menardii Zone, Globorotalia acostaensis Zone, Globorotalia humerosa Zone, Globorotalia margaritae Zone, and Globorotalia miocenica Zone. These zones indicate that the age of the sequence ranks from late middle Miocene to middle Pliocene. Generally speaking, with some variations, the paleoenvironments of the sequence show a shallowing trend from marine upper-middle bathyal to middle neritic. These results make an important contribution to the stratigraphy and geologic history of the Cumarebo area, which is related to the Agua Salada basin, and may help clarify the paleogeography and paleotectonic evolution of this region for petroleum exploration.

  8. Retardation of vitrinite reflectance in Green River oil shales, Piceance Creek basin, northwestern Colorado

    SciTech Connect

    Nuccio, V.F.; Johnson, R.C.

    1984-04-01

    Vitrinite reflectance (R/sub o/) of coaly inclusions in the otherwise alginitic rocks of the Green River Formation, northwestern Colorado, is greater in sandstones, marlstones, and organic-lean oil shales than in adjacent organic-rich oil shales. The R/sub o/ of the coaly inclusions in these organic-lean rocks increases from about 0.30% for samples with a maximum burial depth of less than 1000 m (3300 ft) to 0.55% for samples with a maximum burial depth of more than 1500 m (5000 ft). The higher R/sub o/ in the organic-lean rocks (oil yield < 10 gal/ton with the modified Fischer assay method) thus appears to record the thermal history of the area more precisely. In contrast, coaly inclusions from oil shales (yields > 10-15 gal/ton) all have lower R/sub o/ values, typically in the range of 0.20-0.27, regardless of depth of burial. This retardation effect appears to be very localized and has not altered the vitrinite in coaly material as close stratigraphically as 30 cm (12 in.) to rich oil-shale beds.

  9. Study of thunderstorm activity connection with weather system structures over the North-Western Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Permyakov, M. S.; Cherneva, N. V.; Shevtsov, B. M.; Potalova, E. Yu.; Holzworth, Robert

    2014-11-01

    Applying the data of VLF direction finder receiving station of IKIR FEB RAS, included into the World Wide Lightning Location Network (WWLLN), the paper investigates the relations of field characteristics of recorded lightning discharges in the north-western part of the Pacific ocean with field characteristics of weather formation meteorological elements, evaluated according to the data of Earth remote sounding from satellites. On the example of separate tropical cyclones (TC) for 2012-2013, the relation of lightning discharge frequency and density with spatial distribution of driving wind whirl is shown. TC structure evolution is traced in cloudiness fields, driving wind whirl, and lightning discharge distribution. This publication is based on work supported by a grant from the U.S. Civilian Research and Development Foundation (RUG1-7084-PA-13) with funding from the United States Department of State. The opinions, findings and conclusions stated herein are those of the authors and do not necessarily reflect those of CRDF Global or the United States Department of State.

  10. Thermal maturity and source-rock potential in Northwestern Melville Island, Arctic Canada

    SciTech Connect

    Gentzis, T. ); Goodarzi, F. )

    1992-10-01

    This paper reports that approximately 130 core and drillhole cuttings samples taken from the Palaeozoic and Mesozoic of northwestern Melville Island were examined using reflected-light microscopy and Rock-Eval pyrolysis. The Palaeozoic section is dominated by bitumen, and often numerous bitumen populations are identified based on morphology, texture, and optical properties. Bitumen reflectance increases with depth, following a trend almost parallel to vitrinite, an indication that it is primary and has been subjected to similar thermal stress. The upper Palaeozoic sediments are within the hydrocarbon generation zone but have limited potential, except for an algal-rich interval in the Permian Trold Fiord Formation. Overall, the study is important because it attempts to identify the source rocks in an area of Melville Island where no previous work has been reported on the hydrocarbon-generating potential of the sedimentary succession. In addition, the use of bitumen reflectance in lower Palaeozoic strata devoid of vitrinite is evaluated and the amount of eroded section is calculated based on the thermal maturity pattern of bitumen.

  11. Lower Cambrian sedimentary Grand Cycle A in northwestern Canada and southern Nevada-southeastern California

    SciTech Connect

    Fritz, W.H. )

    1993-04-01

    Grand Cycle A is herein restricted by raising the base to a level just above the base of the Sekwi Formation. In ascending order, Grand Cycle A shares the following features in northwestern Canada and southern Nevada-southeastern California: (1) an initial transgression with reduced clastic size, lack of appreciable limestone, and an abrupt faunal change at the Fallotaspis-Nevadella Zone boundary, (2) gradual increase of limestone that is platy and deposited below wave base, (3) biotherms with archaeocyathids or algal buildups, (4) thick succession of shallow water limestone, (5) an abrupt termination of Grand Cycle A at the top of the thick limestone succession. The boundary between the Nevadella Zone and the Bonnia-Olenellus Zone may be at the top of Grand Cycle A or a short distance above in the basal clastics of Grand Cycle B. Grand Cycle A is not considered to be a typical grand cycle, but rather a hybrid that straddles a thermal change. Below are the large, cold water cycles of the Windermere Supergroup. There the clastic half-cycles represent transgression and the carbonate half-cycles regression. Above Grand Cycle A, are warm water, true grand cycles where clastic half-cycles represent regression and the carbonate half-cycles transgression. In Grand Cycle A, both halves represent transgression, with the upper half being a typical warm water limestone.

  12. Upper Almond and Lewis reservoir geometries, southwestern Wyoming and northwestern Colorado

    SciTech Connect

    Hendricks, M.L.

    1996-06-01

    Upper Almond marine sandstones are major petroleum reservoirs in southwestern Wyoming. These sandstones were deposited as part of a transgressive systems tract which capped fluvial and coastal plain sediments of the upper Ericson and lower Almond formations. Marine sandstone reservoirs were deposited in shoreface and tidal channel environments. Shoreface environments in the Echo Springs-Standard Draw trend are extensive and constitute major gas reserves in Carbon County. Shoreface and tidal channel deposits are major oil and gas reservoirs at Patrick Draw Field, Sweetwater County. Major gas resources in upper Almond marine sandstones are yet to be exploited in the deeper portions of the Great Divide, Washakie, and Sand Wash basins. Tapping this basin centered gas resource will require careful reservoir modeling and fracture treatments that significantly increase permeability and reservoir flow. Lewis sandstones are also petroleum reservoirs in the Great Divide, Washakie, and Sand Wash basins. The sandstones are part of the final Cretaceous regressive systems tract in southwestern Wyoming and northwestern Colorado. Well developed clinoforms accompany Lewis and Fox Hills progradation and basin fill. Associated with these progradational systems are correlative density flow and turbidite deposits that locally form reservoirs. These reservoirs commonly occur near the toe of prograding clinoforms and are trapped by rapid facies changes to impermeable siltstones and basinal shales.

  13. Perched groundwater at the northwestern coast of Egypt: a case study of the Fuka Basin

    NASA Astrophysics Data System (ADS)

    Yousif, Mohamed; Bubenzer, Olaf

    2012-03-01

    Perched groundwater resources on the northwestern coast of Egypt have thus far been little studied. However, if replenished by rainwater, they can provide a considerable amount of renewable water, i.e., for sustainable irrigation. These resources are limited, show different salinity contents and are endangered by overuse, pollution and by the sea level rising in the context of global warming. This paper presents new climatic data, geomorphologic, geologic, geochemical and hydrological researches in combination with remote sensing and GIS applications from Fuka Basin. Fuka constitutes a special synclinal basin where the interbedded limestone and clays have been folded into gentle synclinal structures. Fractured Middle Miocene limestone represents the bearing formation for the perched groundwater. According to the hydrogeochemical analysis and the PHREEQC model, the aquifer is recharged during the winter season by rainwater from the surrounding tableland and the chemical evolution of the perched water is attributed to water-rock interaction and mixing of fresh water with sea water. The salinity of the perched water ranges from 2,126 to 2,644 mg/L whereas for the deep groundwater it reaches 9,800 mg/L. The study explores origin and potential of the perched groundwater of Fuka Basin and gives recommendations for a future sustainable use and further investigations.

  14. Regional-Scale Drivers of Forest Structure and Function in Northwestern Amazonia

    PubMed Central

    Higgins, Mark A.; Asner, Gregory P.; Anderson, Christopher B.; Martin, Roberta E.; Knapp, David E.; Tupayachi, Raul; Perez, Eneas; Elespuru, Nydia; Alonso, Alfonso

    2015-01-01

    Field studies in Amazonia have found a relationship at continental scales between soil fertility and broad trends in forest structure and function. Little is known at regional scales, however, about how discrete patterns in forest structure or functional attributes map onto underlying edaphic or geological patterns. We collected airborne LiDAR (Light Detection and Ranging) data and VSWIR (Visible to Shortwave Infrared) imaging spectroscopy measurements over 600 km2 of northwestern Amazonian lowland forests. We also established 83 inventories of plant species composition and soil properties, distributed between two widespread geological formations. Using these data, we mapped forest structure and canopy reflectance, and compared them to patterns in plant species composition, soils, and underlying geology. We found that variations in soils and species composition explained up to 70% of variation in canopy height, and corresponded to profound changes in forest vertical profiles. We further found that soils and plant species composition explained more than 90% of the variation in canopy reflectance as measured by imaging spectroscopy, indicating edaphic and compositional control of canopy chemical properties. We last found that soils explained between 30% and 70% of the variation in gap frequency in these forests, depending on the height threshold used to define gaps. Our findings indicate that a relatively small number of edaphic and compositional variables, corresponding to underlying geology, may be responsible for variations in canopy structure and chemistry over large expanses of Amazonian forest. PMID:25793602

  15. New Circulation Features in the Northwestern Tropical Pacific Ocean from Profiling Float Measurements

    NASA Astrophysics Data System (ADS)

    Qiu, B.; Rudnick, D. L.; Chen, S.

    2012-12-01

    Ten SOLO-II profiling floats have were deployed in the northwestern tropical Pacific Ocean in August 2011 as part of the ONR's Origin of the Kuroshio and Mindanao Currents (OKMC) project. These floats have a 5-day repeat cycle and measure T/S profiles at a vertical resolution of 2-dbars. By combining the OKMC and Argo data, we observed two well-defined branches of the eastward-flowing subtropical countercurrent (STCC). These two branches, located respectively along 19.0N and 21.5N, are embedded within the westward-flowing North Equatorial Current (NEC) between 7N and 25N and above the 26.5 isopycnal surface. Below the unventilated 26.5 isopycnal layer, the circulation is dominated by three, eastward-flowing, zonal jets. Dubbed the North Equatorial Undercurrent Jets (NEUJ), these three subthermocline jets are quasi-stationary and persist approximately along 10N, 13N and 18N, respectively. In the presentation, we will discuss in detail the mean structure and formation mechanism of these newly-observed NEUJs.

  16. Paleocene-Early Eocene uplift of the Altyn Tagh Mountain: Evidence from detrital zircon fission track analysis and seismic sections in the northwestern Qaidam basin

    NASA Astrophysics Data System (ADS)

    Wang, Yadong; Zheng, Jianjing; Zheng, Youwei; Liu, Xingwang; Sun, Guoqiang

    2015-12-01

    Most existing tectonic models suggest that the deformation and uplift of the northern Tibetan Plateau is the latest crustal response to the collision of the India Plate and Eurasian Plate. The tectonic evolution of Altyn Tagh Mountain (hereafter called simply the "Altyn Tagh"), on the northern margin of the Tibetan Plateau, has attracted considerable scientific attention. In this study, we use fission track age dates of detrital zircons from the northwestern Qaidam basin together with sedimentary observations to understand more fully the Cenozoic tectonic uplift of the Altyn Tagh. Detrital zircons from five borehole samples distributed in different folds in the northwestern Qaidam basin yielded ages mainly ranging from 88.5 to 49.2 Ma, older than their sedimentary deposition ages (43.8-22 Ma). The binomial distribution in grain age fitted peaks was generally dominated by one young peak, P1, which varied from 73.6 to 47.2 Ma. A thinning of the Cenozoic Lulehe Formation (53.5-43.8 Ma) stretched from the inner Qaidam basin to the slopes of the Altyn Tagh in the seismic sections of the northwestern Qaidam basin. Based on magnetostratigraphic dating, there was a hiatus in sedimentation in the Qaidam basin between 65 Ma and 54 Ma; this was confirmed by seismic profiles and borehole data, which show an unconformity between the Mesozoic Quanyagou Formation and the Lulehe Formation. Combined with an analysis of provenance, the detrital zircon young peak age and the sedimentary record revealed that the most significant regional uplift of the Altyn Tagh occurred during the Paleogene-Early Eocene, almost coinciding with the collision of the Indian and Eurasian plates between 65 Ma and 44 Ma.

  17. Correlation of Glaciations: a Comparison of Northwestern North America and the South American Cordillera

    NASA Astrophysics Data System (ADS)

    Barendregt, R. W.; Duk-Rodkin, A.

    2008-12-01

    Northwest Canada is one of the relatively few regions of the world where ice sheets from mountains (valley glaciers) and plains (Laurentide Ice Sheet) coalesced. This also occurred to a minor degree in N.W. Siberia (Arctic Ice Sheet and northern Ural Mountain valley glaciers) while in southern Argentina and Chile large coalescing Piedmont glaciers (Patagonian Ice Sheet) radiated out to the east and west, reaching both the Atlantic and Pacific Oceans. For the most part, build up of continental and Cordilleran ice was coincident in northwestern North America, clearly reflecting the 100 ka Milankovitch cycles. The notable absence of ice from MIS 56 to 38 in both N.A. and S.A. coincides with the low amplitude del 18O values, and bridges the time span during which the transition from 40 ka to 100 ka cycles is seen in the marine isotope record. The Argentinean record, which is the most complete thus far, appears to indicate a record of glaciation which considerably precedes that of N.A. Records from 5-6 Ma in N.A. and S.A have some similarities but the Argentinean record indicates a much earlier initiation of glaciation, dating back as far as 7.5 Ma. Small local glacier occurrences are rare in the earlier N.A. record (e.g. Yakataga Formation, Alaska) but much more common in the Argentinean record, suggesting that Argentinean valley glaciers may have developed earlier in response to cooling associated with the presence of the Antarctic Ice Sheet and the associated northward outflow of cold water along S.A. coasts. In N.A. the major Cordilleran/Montane glacial events commenced immediately preceding the Gauss/Matuyama boundary (2.8-2.6 Ma) and increased in frequency and magnitude with the advance of time. At the time of the Gauss-Matuyama boundary the N.A. and S.A. records are nearly synchronous. Proceeding back in time from the mid-Pleistocene transition (MIS 38), periods of ice free conditions appear to have been more extensive. In southern Argentina the Cordilleran glacial record appears to be somewhat independent from the global ice volume record. The extensive nonglacial periods that are noted in both continents correspond to major periods of tectonic stability and regional denudation. In northwestern North America there are at least 5 and possibly as many as 7 levels of pedimentation documented. In S.A. this record of pedimentation is considerably more extensive.

  18. Detrital cave sediments record Late Quaternary hydrologic and climatic variability in northwestern Florida, USA

    NASA Astrophysics Data System (ADS)

    Winkler, Tyler S.; van Hengstum, Peter J.; Horgan, Meghan C.; Donnelly, Jeffrey P.; Reibenspies, Joseph H.

    2016-04-01

    Detrital sediment in Florida's (USA) submerged cave systems may preserve records of regional climate and hydrologic variability. However, the basic sedimentology, mineralogy, stratigraphic variability, and emplacement history of the successions in Florida's submerged caves remains poorly understood. Here we present stratigraphic, mineralogical, and elemental data on sediment cores from two phreatic cave systems in northwestern Florida (USA), on the Dougherty Karst Plain: Hole in the Wall Cave (HITW) and Twin Cave. Water flowing through these caves is subsurface flow in the Apalachicola River drainage basin, and the caves are located just downstream from Jackson Blue (1st magnitude spring, > 2.8 m3 s- 1 discharge). Sedimentation in these caves is dominated by three primary sedimentary styles: (i) ferromanganese deposits dominate the basal recovered stratigraphy, which pass upsection into (ii) poorly sorted carbonate sediment, and finally into (iii) fine-grained organic matter (gyttja) deposits. Resolving the emplacement history of the lower stratigraphic units was hampered by a lack of suitable material for radiocarbon dating, but the upper organic-rich deposits have a punctuated depositional history beginning in the earliest Holocene. For example, gyttja primarily accumulated in HITW and Twin Caves from ~ 5500 to 3500 cal yr. BP, which coincides with regional evidence for water-table rise of the Upper Floridian Aquifer associated with relative sea-level rise in the Gulf of Mexico, and evidence for invigorated drainage through the Apalachicola River drainage basin. Gyttja sediments were also deposited in one of the caves during the Bølling/Allerød climate oscillation. Biologically, these results indicate that some Floridian aquatic cave (stygobitic) ecosystems presently receive minimal organic matter supply in comparison to prehistoric intervals. The pre-Holocene poorly sorted carbonate sediment contains abundant invertebrate fossils, and likely documents a period of enhanced limestone dissolution and cave formation (speleogenesis) during lower paleo water levels. Further work is still required to (a) determine whether precipitation of the ferromanganese deposits is inorganically or biologically mediated, (b) temporally constrain the emplacement history of the primary sedimentary styles, and (c) determine the full geographic extent of these sedimentary signals. However, these preliminary observations suggest that sedimentation in the inland underwater caves of northwestern Florida is related to Quaternary-scale hydrographic variability in the Apalachicola River drainage basin in response to broader ocean and atmospheric forcing.

  19. Structure and chemistry in the northwestern condensation of the Serpens molecular cloud core

    NASA Technical Reports Server (NTRS)

    Mcmullin, Joseph P.; Mundy, Lee G.; Wilking, Bruce A.; Hezel, T.; Blake, Geoff A.

    1994-01-01

    We present single-dish and interferometric observations of gas and dust in the core of the Serpens molecular cloud, focusing on the northwestern condensation. Single-dish molecular line observations are used to probe the structure and chemistry of the condensation while high-resolution images of CS and CH30H are combined with continuum observations from lambda = 1.3 mm to lambda = 3.5 cm to study the subcondensations and overall distribution of dust. For the northwestern condensation, we derive a characteristic density of 3 x 10(exp 5)/ cu cm and an estimated total mass of approximately 70 solar mass. We find compact molecular emission associated with the far-infrared source S68 FIRS 1, and with a newly detected subcondensation named S68 N. Comparison of the large-and small-scale emission reveals that most of the material in the northwest condensation is not directly associated with these compact sources, suggesting a youthful age for this region. CO J = 1 approaches 0 observations indicate widespread outflow activity. However, no unique association of embedded objects with outflows is possible with our observations. The SiO emission is found to be extended with the overall emission centered about S68 FIRS 1; the offset of the peak emission from all of the known continuum sources and the coincidence between the blueshifted SiO emission and blueshifted high-velocity gas traced by CO and CS is consistent with formation of SiO in shocks. Derived abundances of CO and HCO(+) are consistent with quiescent and other star-forming regions while CS, HCN, and H2CO abundances indicate mild depletions within the condensation. Spectral energy distribution fits to S68 FIRS 1 indicate a modest luminosity (50-60 solar luminosity), implying that it is a low-mass (0.5-3 solar mass) young stellar object. Radio continuum observations of the triple source toward S68 FIRS 1 indicate that the lobe emission is varying on timescales less than or equal to 1 yr while the central component is relatively constant over approximately 14 yr. The nature of a newly detected compact emission region, S68 N, is less certain due to the absence of firm continuum detections; based on its low luminosity (less than 5 solar luminosity) and strong molecular emission, S68 N may be prestellar subcondensation of gas and dust.

  20. Use of Anticlines for Geologic Sequestration of Carbon Dioxide in a Saline Aquifer in Northwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Shin-Hsun; Liou, Tai-Sheng

    2013-04-01

    In this study, migration of CO2 in a deep saline aquifer with anticlines under various injection schemes was numerically simulated using the ECO2N simulator. The hypothetical study site was selected at the Taoyuan Plateau near the second largest coal-fired power plant, Datan power plant (annual CO2 emission of 1.5 Mt/yr), in Northwestern Taiwan. A 15x15 km2 simulation domain, containing two sub-parallel east-northeast Hukou and Pingzhen anticlines, was discretized into unstructured grid with spatial refinement at the injection borehole. Kueichulin sandstone and Chinshui shale in the simulation domain were considered as the storage formation and the cap rock, respectively. It was assumed that no CO2 exists in the aquifer prior to injection, and that the aquifer has a hydrostatic pressure distribution and a constant salinity of 3%. All boundaries were assumed to be "open". Isothermal simulations with 1 Mt/yr injection rate and 20 years of injection period were considered. van Genuchten capillary pressure and Corey relative permeability were assumed for all rock formations. Simulation results indicated that pressure buildup characterized the CO2 migration into three different phases: drainage of brine, formation dry-out, and dissolution and gravity take-over . It was found that the worst leakage scenario occurs if a single injection borehole is placed along the anticline axis. In this case, rock formations near the anticline axis provide a leakage path such that CO2 ultimately leaks out of the upper boundary. On the other hand, CO2 can be safely sequestrated in the storage formation if the injection borehole was placed away from the anticline axis. This is because gas phase CO2 migrates along the counter dipping direction of the anticline as a result of buoyancy. More favorable scenarios were found if a multiple-borehole injection scheme was used. In such cases, not only pressure buildup was significantly mitigated but the amount of precipitated salt was reduced. If a five-borehole scheme was used, for example, pressure buildup and the amount of precipitated salt can be reduced by 20% and 90%, respectively. More interestingly, if injection borehole was placed midway between the two anticlines, buoyancy dominates the migration of CO2 such that most CO2 is accumulated under the apex of anticline. Therefore, it is suggested that a multiple-borehole injection scheme would be a preferable scenario because of the reduced risks of pressure buildup and salt precipitation. Moreover, it would be better to place the injection boreholes away from the anticline axis in order to make good use of all possible trapping mechanisms to permanently sequestrate CO2 in deep rock formations.

  1. Hydrologic investigations and data-collection network in strippable coal-resource areas in northwestern New Mexico

    USGS Publications Warehouse

    Hejl, H.R.

    1982-01-01

    This report presents hydrologic investigations and data collections conducted by the U.S. Geological Survey in the strippable coal areas of northwestern New Mexico. Streamflow, ground-water, and quality-of-water data were collected to provide information about baseline or prevailing hydrologic conditions. A network of hydrologic data-collection sites in the strippable coal areas of the Fruitland Formation was designed to meet the need of detailed investigations, including site-specific studies, and to provide hydrologic data in support of the expanding mining activity. The network consists of 34 continuous-record streamflow-gaging stations (32 included water-quality sampling), 20 miscellaneous water quality of streamflow stations, 12 annual maximum discharge stations, 27 observation wells completed in strata associated with the strippable coal seams, and 24 observation wells completed in channel alluvium downstream from strippable coal areas. (USGS)

  2. Identification of new cytotypes of Valeriana jatamansi Jones, 1970 (Valerianaceae) from North-Western Himalayan region of India

    PubMed Central

    Rani, Savita; Sharma, Tilak Raj; Kapila, Rakesh; Chahota, Rakesh Kumar

    2015-01-01

    Abstract Valeriana jatamansi, a medicinally important species of the family Valerianaceae, has been cytologically studied in different geographical areas of North-Western Himalayan region of India. The tetraploid cytotype with chromosome numbers 2n=32 is in conformity with the earlier reports of the species from different parts of the world. An octoploid cytotype (2n=64) makes a new addition for the species on a worldwide basis, whereas the diploid cytotype (2n=16) is new to India have been reported for the first time in India. These cytotypes (2n=16, 32, 64) show significant variations with respect to morphology as well as geographical distribution in the Western Indian Himalayas. Further, anomalous populations have been marked with meiotic abnormalities in the form of cytomixis, chromosomal stickiness, unoriented bivalents, formation of laggards and bridges resulting in abnormal microsporogenesis, and production of heterogeneous-sized fertile pollen grains along with reduced pollen fertility. PMID:26753070

  3. Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment

    USGS Publications Warehouse

    Currens, C.R.; Liss, W.J.; Hoffman, R.L.

    2007-01-01

    The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the effects of gape-limited Brook Trout (Salvelinus fontinalis) on larval Northwestern Salamander (Ambystoma gracile) growth. We specifically tested whether the presence of fish too small to consume larvae had a negative effect on larval growth. The results of this study indicate that the presence of a gape-limited S. fontinalis can have a negative effect on growth of larval A. gracile salamanders. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  4. 75 FR 6790 - Nebraska Northwestern Railroad, Inc.-Acquisition and Operation Exemption-Dakota, Minnesota...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ...--Dakota, Minnesota & Eastern Railroad Corporation Nebraska Northwestern Railroad, Inc. (NNW), a noncarrier... Dakota, Minnesota & Eastern Railroad Corporation (DM&E) and to operate approximately 28.1 miles of...

  5. 75 FR 1597 - Western Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-12

    ... Monument (74 FR 47119, September 15, 2009). During December 2009 and January 2010, eligible NWHI lobster... Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notification of lobster...

  6. 78 FR 9327 - Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ...; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service... lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial... harvest guideline for lobster Permit Area 1, comprised of Federal waters around the (NWHI)....

  7. 76 FR 77214 - Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial lobster fishery in...

  8. The Northwestern Archeological Program: Direct Student Involvement in the Archeoogica Archeological Process

    ERIC Educational Resources Information Center

    Gilmour, Peter; Struever, Stuart

    1975-01-01

    Northwestern University's Archeological Program has developed a wide range of educational programs which feature direct student (junior high through Ph.D. candidates and out of school adults) involvement in the field. (JC)

  9. Morphologic Map of Glacial and Periglacial Features in the Northwestern Argyre Basin, Mars

    NASA Astrophysics Data System (ADS)

    Raack, J.; Hiesinger, H.; Reiss, D.

    2010-03-01

    We produced a morphological map of the northwestern rim of the Argyre Basin with focus on glacial and periglacial features. We report on features such as gullies, pingo-like forms and glacial remnants which are observed.

  10. [High energy physics research]: Annual performance report, December 1, 1991--November 30, 1992. [Northwestern Univ

    SciTech Connect

    Rosen, J; Block, M; Buchholz, D; Gobbi, B; Schellman, H; Buchholz, D; Rosen, J; Miller, D; Braaten, E; Chang, D; Oakes, R; Schellman, H

    1992-01-01

    The various segments of the Northwestern University high energy physics research program are reviewed. Work is centered around experimental studies done primarily at FNAL; associated theoretical efforts are included.

  11. The Idaho cobalt belt, northwestern United States — A metamorphosed Proterozoic exhalative ore district

    NASA Astrophysics Data System (ADS)

    Nold, J. L.

    1990-07-01

    In the Idaho cobalt belt, originally exhalative, stratiform mineralization within the Proterozoic Yellow-jacket Formation has become increasingly coarse-grained and remobilized toward the northwest in the direction of increasing regional metamorphic grade. The Idaho cobalt belt is located about 40 km west of Salmon, Idaho in the northwestern United States. The most important deposit in the district is the Blackbird mine which produced copper-cobalt ore sporadically from the early 1900's until about 1960. The Iron Creek deposit at the southeast end of the belt has undergone greenschist fades, biotite zone metamorphism; zones of disseminated, veinlet and massive sulfides lie more or less parallel to bedding of quartzites and phyllites. The main ore minerals are chalcopyrite and cobaltiferous pyrite. Toward the northwest at the Blackpine mine, remobilization has concentrated most of the mineralization into relatively thin concordant and discordant veins containing chalcopyrite, pyrite and arsenopyrite. The cobalt is reported to occur within arsenopyrite. Further northwest at the Blackbird mine where the Yellowjacket formation has been metamorphosed to the lower amphibolite facies, zones of disseminated and coarse-grained vein ores lie approximately along the same stratigraphic zone. Chalcopyrite, cobaltite, arsenopyrite, pyrite and pyrrhotite are the dominant ore minerals. Up to 0.22 oz. Au/ton was present in some of the ore. In addition, tourmaline-bearing sedimentary rocks (tourmalinites) are associated with some of the Blackbird ores. The Salmon Canyon deposit at the northwest end of the belt has undergone upper amphibolite facies, sillimanite zone metamorphism. In these garnet-sillimanite gneisses, chalcopyrite is found as coarse blebs and cobaltite as large porphyroblastic crystals. Gold occurs in amounts up to 0.02 oz. Au/ton. Elsewhere in the world the two most similar districts are the cobalt-bearing portion of the Zambian-Zairian Copperbelt of central Africa where Proterozoic Roan sedimentary rocks contain stratiform copper-cobalt ore-bodies over a distance of more than 500 kilometers, and the Sheep Creek district of Meagher County, Montana, which contains strata-bound copper-cobalt mineralization. The Idaho cobalt belt is a strata-bound copper-cobalt district hosted by the Proterozoic Yellowjacket Formation and located in east-central Idaho within Lemhi County, approximately 40 kilometers west of Salmon, Idaho, northwestern United States (Fig. 1). Of the four main deposits described here (from southeast to northwest, the Iron Creek, Blackpine, Blackbird, and the Salmon Canyon deposits), the Blackbird mine is the most important in the district. It was discovered in 1893 and sporadically produced copper and cobalt until about 1960. The Yellowjacket Formation has undergone an increasing degree of metamorphism toward the northwest. The deposits are largely strata-bound in a belt over 50 km in length, strongly suggesting a syngenetic mode of origin. However, the proximity of the district to satellitic granitic plutons of the Idaho batholith has prompted many investigators to suggest an epigenetic hydrothermal origin (Anderson 1947 and Purdue 1975). Remobilization of some of the mineralization into veins at the Blackbird mine, where most of the previous work has been concentrated, has also suggested an epigenetic origin. A more district-wide view of the mineralization points to a strong degree of stratigraphic control.

  12. Brittle tectonics within the Jurassic formations of the Ouarsenis culminating area, northwestern Algeria

    NASA Astrophysics Data System (ADS)

    Aïfa, Tahar; Zaagane, Mansour

    2014-08-01

    Brittle structures within the Ouarsenis culminating zone were studied in order to characterize the polyphased tectonics. Field observations revealed that the dominant structures are highly tilted. They are represented by faults and joints, shears, reverse or curvilinear, locally associated with gypsum intrusions. Field data analysis shows that large scale shear faults are localized within the limits of the structural entities. Two main tectonic phases, having affected the Ouarsenis culminating zone were identified: (i) A NW-SE oriented compressive phase, represented by the contacts marked out by in-depth reverse faults and folding, mainly located in the westernmost part of Sra Abdelkader, Rokba Atba and in the western part of Batha, Fartas and Belkeiret (thrusts), respectively. This phase was also identified in reverse and sinistral faulting within Sidi Djber at the easternmost part of Sra Abdelkader, and the Grand Pic and the southern massif of Belkheiret respectively. (ii) A NNE-SSW oriented compressive phase, characterized by dextral strike-slips, is located in the easternmost part of Sra Abdelkader and Rokba Atba. North of the Grand Pic, a sinistral ∼N120° oriented shearing occurred, with a lateral slip reaching ∼2 km. The examination and the data analysis show a major N110-120° oriented fault with a sinistral signature. This movement would be responsible for block rotations and tilts. Counterclockwise rotations of the paleostress of ∼38° and ∼43° from west to east of the Sra Abdelkader massif and from Belkeiret to Batha, Fartas blocks were recorded, respectively. This local change of the stress field is mainly due to a deformation controlled by the regional post-Miocene geodynamic system, possibly explained by the proposed model.

  13. A quantitative look on northwestern Tethyan foraminiferal assemblages, Campanian Nierental Formation, Austria

    PubMed Central

    Wagreich, Michael

    2016-01-01

    Deposits spanning the Radotruncana calcarata Taxon Range Zone at the Postalm section, Northern Calcareous Alps (Austria) are examined quantitatively for foraminiferal assemblages, especially the planktonic group. This study focuses on establishing a high resolution record spanning an 800 ka long stratigraphic interval from the active continental margin of the Penninic Ocean. The Postalm section displays reddish limestone- marl alternations representing precession cycles. For this study, 26 samples were taken bed by bed to allow a “per-precession-cycle” resolution (i.e., a minimum sample distance of ∼20 ka). Samples from limestones as well as from marls were examined for foraminiferal assemblages. Data suggest a typical, open marine Campanian foraminiferal community. The >63 µm fraction is dominated by opportunist taxa, i.e., members of Muricohedbergella and biserial planktic foraminifera. Archaeoglobigerina and “Globigerinelloides” appear frequently and benthic foraminifera are very sparsely found. The share of globotruncanids, representing more complex morphotypes amongst planktonic foraminifera, is recorded with 5–10%. The state of preservation of foraminifera from the Postalm section is moderate to poor. Differences between samples from marls and samples from limestone are evident, but do not reveal evidence that there was an influence on the postdepositional microfossil communities. However, data from microfossils showing moderate to bad preservation can still offer valuable insight into the palaeoenvironment and biostratigraphy. Information gathered on the composition of the planktonic foraminiferal assemblage confirms a low-to-mid-latitude setting for the Postalm section. As well resolved records of Late Cretaceous foraminifera assemblages are rare, the examination of the Radotruncana calcarata Taxon Range Zone provides some insights into variations and short term changes during the very short period of 800 ka. PMID:26989610

  14. A quantitative look on northwestern Tethyan foraminiferal assemblages, Campanian Nierental Formation, Austria.

    PubMed

    Wolfgring, Erik; Wagreich, Michael

    2016-01-01

    Deposits spanning the Radotruncana calcarata Taxon Range Zone at the Postalm section, Northern Calcareous Alps (Austria) are examined quantitatively for foraminiferal assemblages, especially the planktonic group. This study focuses on establishing a high resolution record spanning an 800 ka long stratigraphic interval from the active continental margin of the Penninic Ocean. The Postalm section displays reddish limestone- marl alternations representing precession cycles. For this study, 26 samples were taken bed by bed to allow a "per-precession-cycle" resolution (i.e., a minimum sample distance of ∼20 ka). Samples from limestones as well as from marls were examined for foraminiferal assemblages. Data suggest a typical, open marine Campanian foraminiferal community. The >63 µm fraction is dominated by opportunist taxa, i.e., members of Muricohedbergella and biserial planktic foraminifera. Archaeoglobigerina and "Globigerinelloides" appear frequently and benthic foraminifera are very sparsely found. The share of globotruncanids, representing more complex morphotypes amongst planktonic foraminifera, is recorded with 5-10%. The state of preservation of foraminifera from the Postalm section is moderate to poor. Differences between samples from marls and samples from limestone are evident, but do not reveal evidence that there was an influence on the postdepositional microfossil communities. However, data from microfossils showing moderate to bad preservation can still offer valuable insight into the palaeoenvironment and biostratigraphy. Information gathered on the composition of the planktonic foraminiferal assemblage confirms a low-to-mid-latitude setting for the Postalm section. As well resolved records of Late Cretaceous foraminifera assemblages are rare, the examination of the Radotruncana calcarata Taxon Range Zone provides some insights into variations and short term changes during the very short period of 800 ka. PMID:26989610

  15. Geomorphic surfaces in the northwestern Klamath Mountains, California and Oregon

    SciTech Connect

    Baldwin, K.S. ); Ricks, C.L. )

    1993-04-01

    Thick, residual, colluvial and alluvial soils derived from ophiolitic rocks mantle at least four geomorphic surfaces in the Siskiyou and marble mountains, in northwestern California and Illinois Valley, in southwestern Oregon. Analysis of digital elevation data provides constraints on the distribution and origin of these surfaces. Because of the geomorphic expression and soil mechanical properties of the surfaces, a map of slope gradients less than 22 degrees closely approximates the distribution of geomorphic surfaces as they are known from field observations. Preliminary definition of individual surfaces is based upon classification of the slop-map by elevation ranges. The Klamath Peneplain'' of Diller (1902) and associated soils, recently referred to as Klamath Saprolite'', are recognized near summit elevation (1,500 meters) across the area. Regional uplift and erosion has resulted in extensive, large earthflow landslides derived from these soils. Alluvial and residual deposits on the floor of the Illinois Valley occur at the same elevation (300 meters) as incised alluvial and colluvial terrace deposits along the Klamath River and tributary streams. At least two additional surfaces have been identified in the Siskiyou and Marble Mountains at approximately elevation 750 and 1,000 meters. Analysis of digital elevation data, combined with the map of earthflow landslides, allows rapid preliminary mapping of geomorphic surfaces in this terrain.

  16. Precambrian basement control on joint domains in northwestern Ohio

    SciTech Connect

    Dean, S.L.; Armstrong, W.B.; Kulander, B.R.

    1986-08-01

    Joint attitudes in Upper Silurian and Lower Devonian carbonates in northwestern Ohio reveal a marked north-south-trending joint domain boundary in Lucas and Wood Counties. East of the domain boundary, first-formed systematic joints trend N45/sup 0/W; west of this boundary, first-formed systematics trend N40/sup 0/E. The line of change in joint trends follows the Lucas County monocline-Bowling Green fault complex and the projected position of the Grenville front from the Canadian shield. Basement well information and gravity and magnetic data indicate a major change in Precambrian rock types across the domain boundary that is coincident with the projected position of the Grenville front. Observed joint patterns are interpreted to result from extensional tectonics associated with the evolution of the Findlay arch and Michigan basin. Recurrent movements on the Bowling Green fault during the early and middle Paleozoic may have been caused by reactivation of Grenville-age faults, which ultimately localized the joint domain boundary along the Lucas County monocline-Bowling Green fault trend.

  17. Northwestern University Schizophrenia Data and Software Tool (NUSDAST)

    PubMed Central

    Wang, Lei; Kogan, Alex; Cobia, Derin; Alpert, Kathryn; Kolasny, Anthony; Miller, Michael I.; Marcus, Daniel

    2013-01-01

    The schizophrenia research community has invested substantial resources on collecting, managing and sharing large neuroimaging datasets. As part of this effort, our group has collected high resolution magnetic resonance (MR) datasets from individuals with schizophrenia, their non-psychotic siblings, healthy controls and their siblings. This effort has resulted in a growing resource, the Northwestern University Schizophrenia Data and Software Tool (NUSDAST), an NIH-funded data sharing project to stimulate new research. This resource resides on XNAT Central, and it contains neuroimaging (MR scans, landmarks and surface maps for deep subcortical structures, and FreeSurfer cortical parcellation and measurement data), cognitive (cognitive domain scores for crystallized intelligence, working memory, episodic memory, and executive function), clinical (demographic, sibling relationship, SAPS and SANS psychopathology), and genetic (20 polymorphisms) data, collected from more than 450 subjects, most with 2-year longitudinal follow-up. A neuroimaging mapping, analysis and visualization software tool, CAWorks, is also part of this resource. Moreover, in making our existing neuroimaging data along with the associated meta-data and computational tools publically accessible, we have established a web-based information retrieval portal that allows the user to efficiently search the collection. This research-ready dataset meaningfully combines neuroimaging data with other relevant information, and it can be used to help facilitate advancing neuroimaging research. It is our hope that this effort will help to overcome some of the commonly recognized technical barriers in advancing neuroimaging research such as lack of local organization and standard descriptions. PMID:24223551

  18. Microbial growth and macromolecular synthesis in the northwestern Atlantic Ocean

    SciTech Connect

    Cuhel, R.L.; Jannasch, H.W.; Taylor, C.D.

    1983-01-01

    Simultaneous time-course measurements of /sup 35/SO/sub 4//sup 2 -/, /sup 32/PO/sup 43 -/, /sup 15/NH/sub 4//sup +/, and (/sup 14/C)acetate, glucose, and glutamate uptake were made at three stations in the northwestern Atlantic Ocean, using water samples taken from well below the euphotic zone. Marked deviations from linearity were observed in 14 of the 15 cases. At the two most inshore stations uptake of /sup 15/NH/sub 4//sup +/ or incorporation of /sup 35/SO/sub 4//sup 2 -/ into protein was undetectable for 16-30 h, followed by very rapid increases in the rates of activity. The sudden burst of SO/sub 4//sup 2 -/and NH/sub 4//sup +/ uptake was accompanied by a major increase in the incorporation of /sup 32/P into RNA and lipid fractions of the microbial population at a continental slope station. At a station in Sargasso Sea, all substrates were taken up without lag. Extended incubations led to a growth plateau which may be a measure of the total biologically labile organic nutrient supply. In all cases tested, chloramphenicol severely restricted uptake. One of the inshore stations was revisited a year later with similar results. The combined data demonstrate the utility of using inorganic nutrient uptake and subcellular incorporation patterns to measure microbial growth and metabolism and stress the necessity of time-course rather than end-point incubations.

  19. Geosites inventory of the northwestern Tabular Middle Atlas of Morocco

    NASA Astrophysics Data System (ADS)

    El Wartiti, Mohamed; Malaki, Amina; Zahraoui, Mohamed; El Ghannouchi, Abdelilah; di Gregorio, Felice

    2008-07-01

    Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils that provide key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating methods of site conservation as well as remembering that rocks, minerals, fossils, soils, landforms form an integral part of the natural world. The significance of certain sites for aesthetic or tourism reasons is obvious. There are numerous geosites, which could contribute to effective exploitation of geotourism, often in conjunction with ecotourism. The strategy employed to such sites involves close consultation with all communities in the vicinity of the respective geosite and is not only aimed at tourism and education, but also at sustainable improvement of the infrastructure of the people of this area. Geological heritage sites, properly managed, can generate employment and new economic activities, especially in regions in need of new or additional sources of income.

  20. Mountain goat response to hydroelectric exploration in northwestern British Columbia

    SciTech Connect

    Foster, B.R.; Rahs, E.Y.

    1983-03-01

    The behavioral responses of more than 800 mountain goats, comprised of 195 social groups, were recorded during hydroelectric exploration activities (primarily aircraft) in northwestern British Columbia. Four categories of overt response were recorded during case tests, ranging from maintenance activity to severe flight. More than 80 percent (n=667) of the observed goats elicited some form of behavioral stress-response, with 33 percent (n=265) displaying a severe flight response to local rock or plant cover. Multiple regression analysis inferred goat responses to be statistically independent of the time of year, type, and vertical orientation of disturbance and group size. As expected, significant correlations (p less than or equal to 0.05) existed between distance of disturbance, geographic area, cover availability, and degree of awareness. Responses were stimulated primarily by auditory and secondarily by visual cues. Repeated aerial and ground follow-up surveys documented temporary range abandonment and changing observability indices (habitat use and activity patterns) associated with areas of intense exploration activity. The assessed data offer mitigation possibilities and enable formulation of management guidelines to lessen project impacts during future exploration, construction, and operation phases.

  1. Antimicrobial activity of Northwestern Mexican plants against Helicobacter pylori.

    PubMed

    Robles-Zepeda, Ramón E; Velázquez-Contreras, Carlos A; Garibay-Escobar, Adriana; Gálvez-Ruiz, Juan C; Ruiz-Bustos, Eduardo

    2011-10-01

    Helicobacter pylori is the major etiologic agent of such gastric disorders as chronic active gastritis and gastric carcinoma. Over the past few years, the appearance of antibiotic-resistant bacteria has led to the development of better treatments, such as the use of natural products. This study evaluated the anti-H. pylori activity of 17 Mexican plants used mainly in the northwestern part of Mexico (Sonora) for the empirical treatment of gastrointestinal disorders. The anti-H. pylori activity of methanolic extracts of the plants was determined by using the broth microdilution method. The 50% minimum inhibitory concentrations ranged from less than 200 to 400 μg/mL for Castella tortuosa, Amphipterygium adstringens, Ibervillea sonorae, Pscalium decompositum, Krameria erecta, Selaginella lepidophylla, Pimpinella anisum, Marrubium vulgare, Ambrosia confertiflora, and Couterea latiflora and were greater than 800 μg/mL for Byophyllum pinnatum, Tecoma stans linnaeus, Kohleria deppena, Jatropha cuneata, Chenopodium ambrosoides, and Taxodium macronatum. Only Equisetum gigantum showed no activity against H. pylori. This study suggests the important role that these plants may have in the treatment of gastrointestinal disorders caused by H. pylori. The findings set the groundwork for further characterization and elucidation of the active compounds responsible for such activity. PMID:21663492

  2. Northwestern University Schizophrenia Data and Software Tool (NUSDAST).

    PubMed

    Wang, Lei; Kogan, Alex; Cobia, Derin; Alpert, Kathryn; Kolasny, Anthony; Miller, Michael I; Marcus, Daniel

    2013-01-01

    The schizophrenia research community has invested substantial resources on collecting, managing and sharing large neuroimaging datasets. As part of this effort, our group has collected high resolution magnetic resonance (MR) datasets from individuals with schizophrenia, their non-psychotic siblings, healthy controls and their siblings. This effort has resulted in a growing resource, the Northwestern University Schizophrenia Data and Software Tool (NUSDAST), an NIH-funded data sharing project to stimulate new research. This resource resides on XNAT Central, and it contains neuroimaging (MR scans, landmarks and surface maps for deep subcortical structures, and FreeSurfer cortical parcellation and measurement data), cognitive (cognitive domain scores for crystallized intelligence, working memory, episodic memory, and executive function), clinical (demographic, sibling relationship, SAPS and SANS psychopathology), and genetic (20 polymorphisms) data, collected from more than 450 subjects, most with 2-year longitudinal follow-up. A neuroimaging mapping, analysis and visualization software tool, CAWorks, is also part of this resource. Moreover, in making our existing neuroimaging data along with the associated meta-data and computational tools publically accessible, we have established a web-based information retrieval portal that allows the user to efficiently search the collection. This research-ready dataset meaningfully combines neuroimaging data with other relevant information, and it can be used to help facilitate advancing neuroimaging research. It is our hope that this effort will help to overcome some of the commonly recognized technical barriers in advancing neuroimaging research such as lack of local organization and standard descriptions. PMID:24223551

  3. Estimate of ozone production and destruction over northwestern Europe

    NASA Astrophysics Data System (ADS)

    Beck, Jeannette P.; Grennfelt, Peringe

    Ozone data from more than 70 monitoring sites in the European TOR and EMEP networks from 1989 were evaluated. In summer the general spatial pattern showed a gradient in the average diurnal maximum ozone concentration with lower values (30-40 ppb) in the northwestern part and higher concentrations (60-70 ppb) towards the southeastern part of the networks. In winter a decreasing gradient was exhibited from the northwest to the southeast. The current UN-ECE 1-h guide value (75 ppb) for the prevention of vegetation damage was exceeded regularly at nearly all sites; the provisional O 3 exposure limit of 300 ppb.h (product of the residual ozone concentration above a threshold (40 ppb) value and exposure duration) was exceeded at all monitoring sites. An estimate of the European internal production and destruction of ozone was made by analyzing the diurnal variation in ozone at European boundary layer background "reference" sites and "polluted" sites. The assessment led to a summer mean internal production of 10-15 ppb in some areas in central Europe, while during winter an ozone sink was found. A complicating factor in this work proved to be the degree of influence of local factors, e.g. emission of oxides of nitrogen and dry deposition. This study therefore emphasizes the importance of spatial characterization of the monitoring sites.

  4. Regional frontier exploration in Sinu basin, northwestern Colombia

    SciTech Connect

    Lindberg, F.A.; Ellis, J.M.; Dekker, L.L.

    1989-03-01

    In 1983, Gulf and Ecopetrol undertook a regional hydrocarbon evaluation of northwestern Colombia, during the course of which much of the Sinu basin was mapped by field geologists aided by low-altitude aerial photographs. Additional seismic and airborne radar data were acquired to assist in developing a regional structural model. The dominant structures of the Sinu basin were produced by westward-vergent thrust faults, which are offset on the order of 10 to 20 km by northwest-southeast-trending compartmental faults. Numerous mud volcanos are surface expressions of overpressured shales, which migrate upward along both thrust and strike-slip faults. Thrust faults are expressed, on the surface, by steep-sided, asymmetrical anticlines, which are separated by broad synclines filled with clastics shed during Tertiary thrusting. The extremely thick section of Tertiary sediments is dominated by shale but contains some potential reservoir sandstones. These resistive sandstones could be accurately mapped on the radar imagery and projected into the subsurface allowing traps to be better defined. Combining field geology with geologic interpretation of aerial photographs and radar images was very effective in developing a regional structural framework of the Sinu basin.

  5. Cancer surveillance in a remote Indian population in northwestern Ontario.

    PubMed Central

    Young, T K; Frank, J W

    1983-01-01

    The incidence and mortality rates of malignant neoplasms in an isolated Indian population in northwestern Ontario, Canada during the period 1972-81 were determined and age-adjusted comparisons with the Canadian national population computed. Indian men were at half the risk of developing and dying from cancer compared to Canadian men, while among women the risks were similar. The most outstanding feature was the high mortality and incidence rates of kidney cancer in both sexes (relative risks for mortality and incidence 7 to 13 times that for Canadians). Gallbladder cancer was of importance in females, similar to observations in other Amerindian groups. Low-risk sites among Indians included: lung in men, breast in women, and skin in both sexes. Other sites such as colon and prostate were common in both populations. Establishing baseline incidence and mortality data and continuing surveillance over a period of time in a well-defined, geographically isolated Native population undergoing rapid social change is of interest both epidemiologically and from the health service perspective. Further studies may elucidate risk factors, of which diet appears most responsible for the peculiar pattern observed. PMID:6837814

  6. Improved ice loss estimate of the northwestern Greenland ice sheet

    NASA Astrophysics Data System (ADS)

    Kjeldsen, Kristian K.; Khan, Shfaqat Abbas; Wahr, John; Korsgaard, Niels J.; KjæR, Kurt H.; BjøRk, Anders A.; Hurkmans, Ruud; Broeke, Michiel R.; Bamber, Jonathan L.; Angelen, Jan H.

    2013-02-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003-2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change estimate, we supplement the ICESat data with altimeter surveys from NASA's Airborne Topographic Mapper from 2002 to 2010 and NASA's Land, Vegetation and Ice Sensor from 2010. The Airborne data are mainly concentrated along the ice margin and thus have a significant impact on the estimate of the volume change. Our results show that adding Airborne Topographic Mapper and Land, Vegetation and Ice Sensor data to the ICESat data increases the catchment-wide estimate of ice volume loss by 11%, mainly due to an improved volume loss estimate along the ice sheet margin. Furthermore, our results show a significant acceleration in mass loss at elevations above 1200 m. Both the improved mass loss estimate along the ice sheet margin and the acceleration at higher elevations have implications for predictions of the elastic adjustment of the lithosphere caused by present-day ice mass changes. Our study shows that the use of ICESat data alone to predict elastic uplift rates biases the predicted rates by several millimeters per year at GPS locations along the northwestern coast.

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

    SciTech Connect

    Lugo, J. )

    1991-03-01

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

  8. Quaternary shoreline development: the northwestern coast of Egypt

    NASA Astrophysics Data System (ADS)

    El-Asmar, Hesham M.; Wood, Philip

    2000-07-01

    New age estimates for samples representing different sedimentary units of the coastal ridges along El-Omayid-Burg El-Arab, northwestern coast of Egypt reveal that the Coastal (first) ridge is related to Holocene high sea level, aminozone "A", with evidence of recent (0.6±0.1 ka) ooid contributions. The El-Max-Abu Sir (second) ridge appears to be associated with the Last Interglacial and related to Oxygen Isotope Substages (OIS) 5c/5a. Beach boulders at the bottom of the Gebel Maryut (third) ridge are related to the Last Interglacial high-stand (OIS 5e), while the molluscan and Cardium limestones are related to a Cardium beach of lagoonal to shallow marine environment. This beach represents a coastal barrier, which existed between 208±59 to 292±48 ka, and is related to aminozones F-G and OIS 7-9. Complex paleosols are developed on the northern flanks of both the second and the third ridges with an estimate age of 67±31 ka and aminozone "C". These appear related to interstadial conditions at the early Last Glacial Stage. The paleosols (Pink limestone) at the top of the Khashm El-Ish (fourth) ridge show a wide range of ages, giving age estimates between 360±140 and 584±317 ka indicating a Middle Pleistocene age.

  9. An assessment of wind energy resource for northwestern California

    NASA Astrophysics Data System (ADS)

    Ruff, R. E.; Endlich, R. M.

    The methodology employed to choose prospective wind farm sites, develop a mesoscale numerical model of the wind regime, and select sites for anemometer emplacement in northwestern California is described. The study began with elimination of prospects governed by legal, aesthetic, and accessibility impediments. Twenty candidate sites, each with 300-1000 acres of land, were found and five were eliminated for environmental reasons. NWS data and other short-term wind data were used, together with topographic maps and U-2 aerial photography to develop a list of ranked sites. A computer simulation was employed with a parameter which accounted for large terrain height variations. A 5-10 km mesh was used in the horizontal and 100 m in the vertical, and a boundary layer of thickness of 800 m was assumed. Contact anemometers and wind vanes, microprocessor controlled and battery powered for a month, were chosen for instrumentation. One year monitoring at 10 m at 15 candidate sites was scheduled to begin in Sept. 1981.

  10. Radioactive Contamination of the North-western Black Sea Sediments

    NASA Astrophysics Data System (ADS)

    Gulin, S. B.; Polikarpov, G. G.; Egorov, V. N.; Martin, J. M.; Korotkov, A. A.; Stokozov, N. A.

    2002-03-01

    The paper deals with the input and deposition of the man-made radionuclides 137Cs, 238 Pu, 239+240Pu and 241Am introduced to the north-western Black Sea, over the last few decades, as the result of atmospheric nuclear weapons testing and the Chernobyl nuclear accident. One approach taken was to retrieve the deposition records of these radionuclides in the sediments. The deposition chronology was compared with monitoring data of the post-Chernobyl input of 137Cs to the NW Black Sea sediments from the Danube River. The partitioning of 137 Cs between suspended matter and water was traced along the salinity gradient in the Danube mixing zone. In sediments deposited in the vicinity of the Danube delta and the Dniepr estuary, the activity of Chernobyl 137Cs had reached its maximum 5 and 10 years after the accident, respectively. The activity ratio of 137Cs to 239+240Pu and 241 Am revealed a higher mobility of 137Cs in the Danube River basin compared to plutonium and americium. The percentage of particulate 137Cs and its distribution coefficient vs salinity have allowed the estimation of sedimentary scavenging and desorption of caesium in the Danube mixing zone. Comparison of the post-Chernobyl 137Cs input from the Danube to the 137Cs inventory in the adjacent Black Sea sediments showed that more than 70% of this radionuclide was deposited in the Danube-Black Sea mixing zone.

  11. Late Devonian conodonts and event stratigraphy in northwestern Algerian Sahara

    NASA Astrophysics Data System (ADS)

    Mahboubi, Abdessamed; Gatovsky, Yury

    2015-01-01

    Conodonts recovered from the Late Devonian South Marhouma section comprise 5 genera with 31 species (3 undetermined). The fauna establishes the presence of MN Zones 5, undifferentiated 6/7, 8/10 for the Middle Frasnian, the MN Zones 11, 12, 13 for the Upper Frasnian as well as the Early through Late triangularis Zones in the basal Famennian. The outcropping lithological succession is one of mostly nodular calcilutites alternating with numerous marly and shaly deposits, which, in the lower and upper part, comprise several dysoxic dark shale intervals. Among these the Upper Kellwasser horizon can be precisely dated and as such the presence of the terminal Frasnian Kellwasser Event is recognized for the first time in Algeria. Both the Middlesex and Rhinestreet Events cannot yet be precisely located, but supposedly occur among the dark shale horizons in the lower part of the section. However, their assignment to a precise level has so far not been established. Though poor in conodont abundance the South Marhouma section provides first evidence of the presence of several Montagne Noire conodont zones within the so far widely unstudied Frasnian of the Ougarta Chain. As such it is considered representative for the northwestern Algerian Saoura region.

  12. Water resources of the Bighorn basin, northwestern Wyoming

    USGS Publications Warehouse

    Lowry, Marlin E.; Lowham, H.W.; Lines, Gregory C.

    1976-01-01

    This 2-sheet map report includes the part of the Bighorn Basin and adjacent mountains in northwestern Wyoming. Water-bearing properties of the geologic units are summarized. The hydrogeologic map illustrates the distribution of wells in the different units and gives basic data on the yields of wells, depth of wells, depth to water, and dissolved solids and conductance of the water. Aquifers capable of yielding more than 1,000 gpm (gallons per minute) underlie the area everywhere, except in the mountains on the periphery of the basin. In 1970, approximately 29,500 of the 40,475 people living in the Bighorn Basin were served by municipal water supplies. The municipal supply for about 6,300 of these people was from ground water. The natural flows of streams in the Bighorn Basin differ greatly due to a wide range in the meteorologic, topographic, and geologic conditions of the basin. The station locations and the average discharge per square mile are shown on the map and give an indication of the geographic variation of basin yields. The maximum instantaneous discharge that has occurred at each station during its period of record is shown. Most of the runoff in the basin is from snowmelt in the mountains. (Woodard-USGS)

  13. Evaluation of seismic hazard at the northwestern part of Egypt

    NASA Astrophysics Data System (ADS)

    Ezzelarab, M.; Shokry, M. M. F.; Mohamed, A. M. E.; Helal, A. M. A.; Mohamed, Abuoelela A.; El-Hadidy, M. S.

    2016-01-01

    The objective of this study is to evaluate the seismic hazard at the northwestern Egypt using the probabilistic seismic hazard assessment approach. The Probabilistic approach was carried out based on a recent data set to take into account the historic seismicity and updated instrumental seismicity. A homogenous earthquake catalogue was compiled and a proposed seismic sources model was presented. The doubly-truncated exponential model was adopted for calculations of the recurrence parameters. Ground-motion prediction equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of seismic hazard in the frame of logic tree approach. Considering a grid of 0.2° × 0.2° covering the study area, seismic hazard curves for every node were calculated. Hazard maps at bedrock conditions were produced for peak ground acceleration, in addition to six spectral periods (0.1, 0.2, 0.3, 1.0, 2.0 and 3.0 s) for return periods of 72, 475 and 2475 years. The unified hazard spectra of two selected rock sites at Alexandria and Mersa Matruh Cities were provided. Finally, the hazard curves were de-aggregated to determine the sources that contribute most of hazard level of 10% probability of exceedance in 50 years for the mentioned selected sites.

  14. Hydrogeologic framework of the Maku area basalts, northwestern Iran

    NASA Astrophysics Data System (ADS)

    Asghari Moghaddam, Asghar; Fijani, Elham

    2009-06-01

    The Maku area in northwestern Iran is characterized by young lava flows which erupted from Mount Ararat in Turkey. These fractured volcanic rocks overlie alluvium associated with pre-existing rivers and form a good basalt-alluvium aquifer over an area of 650 km2. Groundwater discharge occurs from 12 large springs, ranging from 20 to 4,000 L s-1, and from some extraction wells. Permian and Oligo-Miocene age limestones along the northern boundary of the Bazargan and Poldasht Plains basalts are intensively karstified and groundwater from these high lands easily enters the basalt-alluvium aquifers. The transmissivity of the basalt-alluvium aquifer ranges from 24 to 870 m2 d-1, indicating heterogeneity. Groundwater of the aquifer is a sodium-bicarbonate and mixed cation-bicarbonate type and the concentration of fluoride is higher than the universal maximum admissible concentrations for drinking. In order to determine the chemical composition and identify the source of the high fluoride concentrations in the groundwater of the basaltic area, water samples from the springs, wells and rivers were analyzed. The results indicate that the high fluoride water enters the study area from the Sari Su River.

  15. Deglaciation of the northwestern White Mountains, New Hampshire

    USGS Publications Warehouse

    Thompson, W.B.; Fowler, B.K.; Dorion, C.C.

    1999-01-01

    The mode of deglaciation in the northwestern White Mountains of New Hampshire has been controversial since the mid 1800's. Early workers believed that active ice deposited the Bethlehem Moraine complex in the Ammonoosuc River basin during recession of the last ice sheet. In the 1930's this deglaciation model was replaced by the concept of widespread simultaneous stagnation and downwastage of Late Wisconsinan ice. The present authors reexamined the Bethlehem Moraine complex and support the original interpretation of a series of moraines deposited by active ice. We found other moraine clusters of similar age to the northeast in the Johns River and Israel River basins. Ice-marginal deposits that probably correlate with the Bethlehem Moraine also occur west of Littleton. The Bethlehem Moraine complex and equivalent deposits in adjacent areas were formed by readvance and oscillatory retreat of the Connecticut Valley lobe of the Laurentide Ice Sheet. This event is called the Littleton-Bethlehem Readvance. Throughout the study area, sequences of glaciolacustrine deposits and meltwater drainage channels indicate progressive northward recession of the glacier margin. Radiocarbon dates from nearby New England and Quebec suggest that the ice sheet withdrew from this part of the White Mountains between about 12,500 and 12,000 14C yr BP. We attribute the Littleton-Bethlehem Readvance to a brief climatic cooling during Older Dyas time, close to 12,000 BP.

  16. Drought induces spruce beetle (Dendroctonus rufipennis) outbreaks across northwestern Colorado.

    PubMed

    Hart, Sarah J; Veblen, Thomas T; Eisenhart, Karen S; Jarvis, Daniel; Kulakowski, Dominik

    2014-04-01

    This study examines influences of climate variability on spruce beetle (Dendroctonus rufipennis) outbreak across northwestern Colorado during the period 1650 2011 CE. Periods of broad-scale outbreak reconstructed using documentary records and tree rings were dated to 1843-1860, 1882-1889, 1931-1957, and 2004-2010. Periods of outbreak were compared with seasonal temperature, precipitation, vapor pressure deficit (VPD), the Palmer Drought Severity Index (PDSI), and indices of ocean-atmosphere oscillation that include the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). Classification trees showed that outbreaks can be predicted most successfully from above average annual AMO values and above average summer VPD values, indicators of drought across Colorado. Notably, we find that spruce beetle outbreaks appear to be predicted best by interannual to multidecadal variability in drought, not by temperature alone. This finding may imply that spruce beetle outbreaks are triggered by decreases in host tree defenses, which are hypothesized to occur with drought stress. Given the persistence of the AMO, the shift to a positive AMO phase in the late 1990s is likely to promote continued spruce beetle disturbance. PMID:24933812

  17. Geophysical evidence of an impact crater in northwestern South America

    NASA Astrophysics Data System (ADS)

    Hernandez, O.; von Frese, R. R.; Khurama, S.

    2007-05-01

    A prominent positive terrain correlated free-air gravity anomaly over regionally depressed topography may identify a mascon centered on (4.15 N, 69.5W) in the Vichada plain, Guiana Shield in Northwestern South America. The topographic depression was recognized by LANDSAT images, showing a complex crater with two rings of 30 km and 50 km of diameter. Being one third of the size of the Chibxulub's impact crater, the 50 km-wide impact crater is the first meteor impact found in Colombia and the biggest impact crater of South America. This structure has been partially eroded by the Vichada River and its topographic expression is obscured by dense vegetation and erosion. Free air gravity anomalies at 20 km altitude from EGM-96 do not show any significant signature. However, concentric positive terrain-correlated free-air gravity anomalies are superposed to the impact crater. Also negative Terrain decorrelated free air gravity anomalies are located at the impact crater structure. MOHO estimates from inverse modeled compensated terrain gravity effects show a shallower MOHO below the impact crater, with a thinning of the continental crust, that could be created as a result of the mantle rebound after the shock waves generated by the impact, creating a mascon, typical of an impact crater structure, with a 40 km-wide, 3 km-high plug of mantle material that had risen up into the Earth's crust. Concentric negative total field magnetic anomalies superposed to the gravity anomalies also support the impact crater model.

  18. Reconstruction of the pre-Merida glaciation, northwestern Venezuelan Andes

    NASA Astrophysics Data System (ADS)

    Mahaney, William C.; Kalm, Volli; Menzies, John; Hancock, Ronald G. V.; Milner, Michael W.

    2010-10-01

    Valley glaciers have been well studied in the northwestern Venezuelan Andes over the last 20-year period but most reconstructions have been limited to the Last Glacial Maximum (LGM). Analyses have been confined to the mapping of moraine positions and the detailed analysis of pedostratigraphic sequences reaching back through the Middle to the Early Wisconsinan (Weichselian) Glaciation. Using bedding macrofeatures, fabric analysis (magnetic azimuths) with mirror images, clast inclination and microtextural evidence much has been learned about the lithology, source of ice, growth of an ice cap in the eastern cordillera and weathered state of surface paleosols. Analysis of two sections of pre-Mérida age, the only two such sections known in the Sierra de Santa Domingo (eastern cordillera), provides new information on lithology, source of the ice and weathered state of sediment of pre-Mérida age. The fabric in these sections is used to deduce the build-up of valley ice in the lower El Caballo Valley from an ice cap similar to one that developed later in Early Mérida time (~ 90 ka to ~ 65 ka). The presence of weathered tills in both sections suggests two glaciations perhaps correlative with the Illinoian and Kansan glaciations of North America. The weathered state of tills and outwash in both sections is assessed on the basis of geochemical (INAA) and mineral composition (XRD) and microtextural evidence determined by SEM/EDS.

  19. Miocene reef platforms from northwestern Tuamotu Islands, central Pacific

    SciTech Connect

    Montaggioni, L.F.; Mnhn-Ephe, A.

    1988-02-01

    Reef deposits of Miocene age occur on several northwestern Tuamotu atolls as either pointed residual and scattered reliefs through the Holocene reef sequence (Mataiva, Rangiroa, Tikehau, Kaukura) or elevated atoll-shaped platforms (Makatea). Throughout the region considered, the depositional/diagenetic history of Miocene reefs can be reconstructed as follows. During early Miocene times (e-f range-biozones), reef platforms developed on top of older carbonate banks, capping a midplate volcanic ridge of early Tertiary age. More than 100 m thick, these platforms displayed concentrically zoned environments of deposition: a peripheral subemergent rim composed of coralgalforaminiferal boundstones, and a very shallow central area in which foraminiferal and molluscan fine sands and muds were subhorizontally deposited. Local evidence of internal unconformity surfaces and subaerially produced features indicates that periods of relative emergency occurred as the reef piles grew upward. The ultimate stage of platform development is believed to have been a complete upfilling of the back-reef areas and subsequent emergence. Correlatively, a freshwater lens would have been formed close to the surface level of each of the so-formed islands. Dolomitization may have been initiated in the marine water/freshwater phreatic mixing zone. During lowstands, severe meteoric alteration affected emergent carbonate deposits, forming incipient cavity systems; the usual atoll morphology is considered to have been initiated at this time (presumably middle Micoene).

  20. Community Problems in Eight Northwestern Counties. Report No. 1 of a Series on Quality of Life and Development in Northwestern Wisconsin, January 1976.

    ERIC Educational Resources Information Center

    Lambert, Virginia

    As part of a study of the quality of life in northwestern Wisconsin, questions re: important problems, public services, and environmental concerns were asked of a sample of 150 people in each of 5 counties (Bayfield, Douglas, Price, Taylor, and Washburn) in 1974. Responses to similar questions asked in a 1973 study of Ashland, Burnett, and Rusk…

  1. The carbon-isotopic composition of Proterozoic carbonates: Riphean successions from northwestern Siberia (Anabar Massif, Turukhansk Uplift)

    NASA Technical Reports Server (NTRS)

    Knoll, A. H.; Kaufman, A. J.; Semikhatov, M. A.

    1995-01-01

    Thick carbonate-dominated successions in northwestern Siberia document secular variations in the C-isotopic composition of seawater through Mesoproterozoic and early Neoproterozoic (Early to early Late Riphean) time. Mesoproterozoic dolomites of the Billyakh Group, Anabar Massif, have delta 13C values that fall between 0 and -1.9 permil versus PDB, with values in the upper part of the succession (Yusmastakh Formation) consistently higher than those of the lower (Ust'-Il'ya and Kotuikan formations). Consistent with available biostratigraphic and radiometric data, delta 13C values for Billyakh carbonates compare closely with those characterizing early Mesoproterozoic carbonates (about 1600-1200 Ma) worldwide. In contrast, late Mesoproterozoic to early Neoproterozoic limestones and dolomites in the Turukhansk Uplift exhibit moderate levels of secular variation. Only the lowermost carbonates in the Turukhansk succession (Linok Formation) have delta 13C values that approximate Billyakh values. Higher in the Turukhansk succession, delta 13C values vary from -2.7 to +4.6 permil (with outliers as low as -5.0 permil interpreted as diagentically altered). Again, consistent with paleontological and radiometric data, these values compare well with isotopic values from 1200 to 850 Ma successions elsewhere. Five sections measured in different parts of the Turukhansk basin show nearly identical patterns of variation, confirming that carbonate delta 13C correlates primarily with time and not facies. The Siberian sections illustrate the potential of integrated biostratigraphic and chemostratigraphic data in the intra- and interbasinal correlation of Mesoproterozoic and early Neoproterozoic rocks.

  2. Mafic alkalic magmatism in central Kachchh, India: a monogenetic volcanic field in the northwestern Deccan Traps

    NASA Astrophysics Data System (ADS)

    Kshirsagar, Pooja V.; Sheth, Hetu C.; Shaikh, Badrealam

    2011-07-01

    Magmatism in Kachchh, in the northwestern Deccan continental flood basalt province, is represented not only by typical tholeiitic flows and dikes, but also plug-like bodies, in Mesozoic sandstone, of alkali basalt, basanite, melanephelinite and nephelinite, containing mantle nodules. They form the base of the local Deccan stratigraphy and their volcanological context was poorly understood. Based on new and published field, petrographic and geochemical data, we identify this suite as an eroded monogenetic volcanic field. The plugs are shallow-level intrusions (necks, sills, dikes, sheets, laccoliths); one of them is known to have fed a lava flow. We have found local peperites reflecting mingling between magmas and soft sediment, and the remains of a pyroclastic vent composed of non-bedded lapilli tuff breccia, injected by mafic alkalic dikes. The lapilli tuff matrix contains basaltic fragments, glass shards, and detrital quartz and microcline, with secondary zeolites, and there are abundant lithic blocks of mafic alkalic rocks. We interpret this deposit as a maar-diatreme, formed due to phreatomagmatic explosions and associated wall rock fragmentation and collapse. This is one of few known hydrovolcanic vents in the Deccan Traps. The central Kachchh monogenetic volcanic field has >30 individual structures exposed over an area of 1,800 km2 and possibly many more if compositionally identical igneous intrusions in northern Kachchh are proven by future dating work to be contemporaneous. The central Kachchh monogenetic volcanic field implies low-degree mantle melting and limited, periodic magma supply. Regional directed extension was absent or at best insignificant during its formation, in contrast to the contemporaneous significant directed extension and vigorous mantle melting under the main area of the Deccan flood basalts. The central Kachchh field demonstrates regional-scale volcanological, compositional, and tectonic variability within flood basalt provinces, and adds the Deccan Traps to the list of such provinces containing monogenetic- and/or hydrovolcanism, namely the Karoo-Ferrar and Emeishan flood basalts, and plateau basalts in Saudi Arabia, Libya, and Patagonia.

  3. Can the Metamorphic Basement of Northwestern Guatemala be Correlated with the Chuacús Complex?

    NASA Astrophysics Data System (ADS)

    Cacao, N.; Martens, U.

    2007-05-01

    The Chuacús complex constitutes a northward concave metamorphic belt that stretches ca. 150 km south of the Cuilco-Chixoy-Polochic (CCP) fault system in central and central-eastern Guatemala. It represents the basement of the southern edge of the Maya block, being well exposed in the sierra de Chuacús and the sierra de Las Minas. It is composed of high-Al metapelites, amphibolites, quartzofeldspathic gneisses, and migmatites. In central Guatemala the Chuacús complex contains ubiquitous epidote-amphibolite mineral associations, and local relics of eclogite reveal a previous high-pressure metamorphic event. North of the CCP, in the Sierra de Los Cuchumatanes area of western Guatemala, metamorphic rocks have been considered the equivalent of the Chuacús complex and hence been given the name Western Chuacús group, These rocks, which were intruded by granitic rocks and later mylonitized, include chloritic schist and gneiss, biotite-garnet schist, migmatites, and amphibolites. No eclogitic relics have been found within metamorphic rocks in northwestern Guatemala. Petrographic analyses of garnet-biotite schist reveal abundant retrogression and the formation of abundant zeolite-bearing veins associated with intrusion. Although metamorphic conditions in the greenschist and amphibolite facies are similar to those in the sierra de Chuacús, the association with deformed intrusive granites is unique for western Guatemala. Hence a correlation with metasediments intruded by the Rabinal granite in the San Gabriel area of Baja Verapaz seems more feasible than a correlation with the Chuacús complex. This idea is supported by reintegration of the Cenozoic left-lateral displacement along the CCP, which would place the metamorphic basement of western Guatemala north of Baja Verapaz, adjacent to metasediments intruded by granites in the San Gabriel-Rabinal area.

  4. Dose estimation, kinetics and dating of fossil marine mollusc shells from northwestern part of Turkey.

    PubMed

    Aydaş, Canan; Engin, Birol; Kapan, Sevinç; Komut, Tolga; Aydın, Talat; Paksu, Ufuk

    2015-11-01

    Electron spin resonance (ESR) spectroscopy was used to determine the geological formation age of fossil mollusc shells taken from marine terrace deposits (İkizlerçeşme-Çanakkale) in northwestern part of Turkey. This work reports the first results obtained by the ESR technique on shells collected from this region. In the ESR spectra of the natural and γ-irradiated shell samples, two different signals attributed to orthorombic (gxx=2.0030, gzz=2.0015, gyy=1.9980) and isotropic (g=2.0006) CO2(-) ion radicals were overlaped (Signal C). Annealing and kinetic experiments suggest the possibility of using the ESR signal at g=2.0015 (C signal) for the estimation of accumulated geological doses. The ESR signal growth curve on additional gamma irradiation has been best fitted by a combination of two single exponential saturation functions. This may support the existence of at least two components of the g=2.0015 ESR dating signal. Based on this model, the accumulated dose of the samples was determined as 110±11Gy. Also the isothermal decay curves of the ESR dating signal could be best described by the combination of two first order decay functions. Activation energy and meanlifetime values at 15°C of the two components were calculated as E1=1.4±0.1eV, E2=1.1±0.1eV, τ1=7.2×10(6) years and τ2=3.3×10(3) years, respectively. Uranium content of the studied shells was found to be high according to their chemical analysis. This may point out that the marine shell has received uranium from outside particularly in carbonate sediment. Therefore, the ESR age of the samples was also calculated using Early Uptake (EU), Linear Uptake (LU) and Combined Uptake (CU) models and results were discussed. PMID:26254035

  5. Organic matter diagenesis and hydrocarbon generation on outer Continental Margin of northwestern Australia

    SciTech Connect

    Meyers, P.A.; Snowdon, L.R.; Heggie, D.; Bent, A.

    1989-03-01

    Organic geochemical analyses of sediments and rocks obtained from drill sites on the Exmouth and Wombat Plateaus and the Argo Abyssal Plain on the northwestern margin of Australia were done onboard the JOIDES Resolution during Ocean Drilling Program Legs 122 and 123. These analyses provide information about the sources of organic matter to these offshore locations from Triassic to Holocene times and also indicate the degree of postdepositional diagenesis and maturation the organic matter has experienced. Because this margin has interest to petroleum explorationists, these data have practical as well as fundamental significance. Triassic claystones (equivalent to the onshore Mungeroo Formation) from the Wombat Plateau contain up to several percent of land-derived organic carbon. Neocomian siltstones and claystones (equivalent to the Barrow Group and Muderong Shale) from the Exmouth Plateau hold similar organic matter but at lower concentrations. Younger sediments are generally very lean in organic matter. Gas chromatographic analysis of extractable hydrocarbons shows a large and often dominant contribution of continental components, notably n-alkanes with a strong odd/even ratio and tricyclic diterpanes. Both Rock-Eval and hydrocarbon results agree in indicating low to moderate levels of thermal maturity. Locations on the Exmouth Plateau typically contain large amounts of thermogenic gaseous hydrocarbons dominated by methane. Concentrations peak in Senonian chalk sequences. In Neocomian siltstones and claystones, methane-ethane ratios diminish as concentrations decrease. The source of these hydrocarbons is likely to be the Triassic coals and coaly material below the Dingo claystone, which was not drilled during these legs but has been characterized from industry wells on this passive margin.

  6. High resolution modelling of the oceanic circulation and winter vertical mixing in the northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Damien, Pierre; Estournel, Claude; Marsaleix, Patrick

    2013-04-01

    The North Western Mediterranean Sea is one of the few regions in the world where open-ocean deep convection occurs. The local cyclonic circulation brings weakly stratified waters close to the surface. In winter, atmospheric conditions (strong cold winds and high heat losses) trigger the deep convection. When the strong forcing stops, restratification of the mixed patch occurs by lateral advection of surrounding lighter water. Mesoscale and submesoscale structures play an important role during these events both in the sinking and spreading of the new dense water formed and in the advection of light surrounding water. The objective is first to check the capabilities of a high resolution model to reproduce the oceanic response to strong wind and, second, to identify processes involved in the water column restratification in terms of spacial and temporal scales. The SYMPHONIE model was implemented at 1 km resolution over the north-western Mediterranean. Simulations were initialized and forced at the open boundaries by the recent MERCATOR release PSY2V4R3. Two atmospheric forcings were use at the surface, ECMWF through bulk formulae and ARPERA. The recent years were simulated and comparisons were performed with the available data set particularly Argo and glider floats and the data of the CASCADE experiment in March 2011. A special attention was paid to the representation of the vertical stratification, of the mixed layer depth and of the properties of the water masses. The characteristics of the deep convection event and of its restratification are examined in terms of water mass formation and budgets. The role played by small scale structures is quantified.

  7. Trace elements in moose (Alices alces) found dead in Northwestern Minnesota, USA

    USGS Publications Warehouse

    Custer, T.W.; Cox, E.; Gray, B.

    2004-01-01

    The moose (Alces alces) population in bog and forest areas of Northwestern Minnesota has declined for more than 25 years, and more recently the decline is throughout Northwestern Minnesota. Both deficiencies and elevations in trace elements have been linked to the health of moose worldwide. The objective of this study was to evaluate whether trace element toxicity or deficiency may have contributed to the decline of moose in Northwestern Minnesota. Livers of 81 moose found dead in Northwestern Minnesota in 1998 and 1999 were analyzed for trace elements. With the exception of selenium (Se) and copper (Cu), trace elements were not at toxic or deficient levels based on criteria set for cattle. Selenium concentrations in moose livers based on criteria set for cattle were deficient in 3.7% of livers and at a chronic toxicity level in 16% of livers. Copper concentrations based on criteria set for cattle were deficient in 39.5% of livers, marginally deficient in 29.5% of livers and adequate in 31% of livers. Moose from agricultural areas had higher concentrations, on average, of Cd, Cu, Mo and Se in their livers than moose from bog and forest areas. Older moose had higher concentrations of Cd and Zn, and lower concentrations of Cu than younger moose. Copper deficiency, which has been associated with population declines of moose in Alaska and Sweden, may be a factor contributing to the decline of moose in Northwestern Minnesota. (C) 2004 Elsevier B.V. All rights reserved.

  8. Petroleum exploration in Absaroka basin of northwestern Wyoming

    SciTech Connect

    Sundell, K.A.

    1986-08-01

    A new, virtually unexplored petroleum province with large potential resources can be defined in northwestern Wyoming. Structurally, the Absaroka basin is bounded on the north by the Beartooth uplift, to the west by the Gallatin and Washakie uplifts, to the south by the Washakie and Owl Creek uplifts, and to the east by the Cody arch. The Cody arch connects the southern Beartooth uplift with the northwesternmost Owl Creek uplift and separates the Bighorn basin to the east from the Absaroka basin to the west. The eastern flank of the cody arch is bounded by a major west-dipping thrust fault. The western flank is locally a subhorizontal shelf but overall gently dips to the west-southwest into deeper parts of the Absaroka basin. In contrast to most petroleum basins, the Absaroka basin is topographically a rugged mountain range, created by erosion of a thick sequence of Eocene volcanic rocks that fill the center of the basin and lap onto the adjacent uplifts. Mesozoic and Paleozoic rocks that have produced several billion barrels of oil from the adjacent Bighorn and Wind River basins are probably present within the Absaroka basin and should have similar production capabilities. The Absaroka basin may have greater potential than adjacent basins because the volcanics provide additional traps and reservoirs. Domes in Mesozoic and Paleozoic rocks beneath the volcanics and stratigraphic traps at the angular unconformity between the volcanics and underlying reservoirs are primary exploration targets. Unique geologic, geophysical, permitting, access, and drilling problems are encountered in all aspects of exploration.

  9. Reclamation studies on oil shale lands in northwestern Colorado

    SciTech Connect

    Cook, C.W.; Redente, E.F.

    1980-02-01

    The overall objective of this project is to study the effects of various reclamation practices on above- and belowground ecosystem development associated with disturbed oil shale lands in northwestern Colorado. Plant growth media that are being used in field test plots include retorted shale, soil over retorted shale, subsoil materials, and surface disturbed topsoils. Some of the more significant results are: (1) a soil cover of at least 61 cm in conjunction with a capiallary barrier provided the best combination of treatments for the establishment of vegetation and a functional microbial community, (2) aboveground production values for native and introduced species mixtures are comparable after three growing seasons, (3) cover values for native species mixtures are generally greater than for introduced species, (4) native seed mixtures, in general, allow greater invasion to occur, (5) sewage sludge at relatively low rates appears to provide the most beneficial overall effect on plant growth, (6) cultural practices, such as irrigated and mulching have significant effects on both above- and belowground ecosystem development, (7) topsoil storage after 1.5 years does not appear to significantly affect general microbial activities but does reduce the mycorrhizal infection potential of the soil at shallow depths, (8) populations of mycorrhizal fungi are decreased on severely disturbed soils if a cover of vegetation is not established, (9) significant biological differences among ecotypes of important shrub species have been identified, (10) a vegetation model is outlined which upon completion will enable the reclamation specialist to predict the plant species combinations best adapted to specific reclamation sites, and (11) synthetic strains of two important grass species are close to development which will provide superior plant materials for reclamation in the West.

  10. Seasonal thermocline in the China Seas and northwestern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Hao, Jiajia; Chen, Yongli; Wang, Fan; Lin, Pengfei

    2012-02-01

    Climatological seasonal variations of the thermocline in the China Seas and northwestern Pacific Ocean were studied using historical data from 1930 through 2001 (707,624 profiles). The quantitative roles of surface thermal buoyancy (Bq), haline buoyancy flux (Bp), and total buoyancy flux (B) against the wind-induced mixing (τ) in different seasons and regions were also explored using the buoyancy ratio (R = ∣Bq/Bp∣) and the Monin-Obukhov depth ratio (δ), respectively. The thermocline has obvious seasonal variations in the study area north of 20°N. There is no thermocline along the west coast of the Bohai Sea (BS), Yellow Sea (YS), and northern East China Sea from December to March resulting from surface cooling and wind mixing. The significantly different variation of the thermocline strength on and off the Chinese shelf is mainly caused by the fact that the thermal stratification is enhanced by bottom tidal mixing on the shelf. The δ indicates that the thermocline depth on the Chinese shelf is mainly dominated by B in summer, while it is dominated by τ in winter. It reveals an opposite feature in the Kuroshio region; the dominating factor is B in winter, associated with the large heat buoyancy loss there. South of 20°N, the dominating factor is similar to that on the shelf, with the more obvious B dominant characteristic during the monsoon transition periods. The R demonstrates that B is mainly controlled by Bq all year round, with some sporadically Bp-dominated regions in the tropical area in winter and in the BS and eastern YS in September.

  11. Geoid modeling over Alaska, USA and northwestern Canada

    NASA Astrophysics Data System (ADS)

    Li, X.; Huang, J.; Roman, D. R.; Wang, Y.; Smith, D. A.; Véronneau, M.

    2013-05-01

    Geoid modeling over Alaska, USA and northwestern Canada is not only a transboudary issue, but also technically challenging. The region features (1) a complex terrain that includes the two highest mountains in North America, Mount McKinely (20,320ft) in Alaska and Mount Logan (19,541ft) in the Yukon Territory and six major mountain chains; (2) a dynamic geology characterized with strong tectonic movement, significant post glacial rebound and ice melting; (3) inhomogeneous and sparse surface gravity data collected over a span of a century; and (4) a lack of high-quality independent validation data limited to a few leveling lines that are subject to large systematic errors. The previous joint studies (EGU 2012 and AGU 2012) between the US National Geodetic Survey and Geodetic Survey Division of Natural Resources Canada showed that GRACE and GOCE have improved the knowledge of the Earth's gravity field, correspondingly the geoid model over this region. However, several key aspects are still open to further improvement including data interpolation, downward continuation, optimal satellite and terrestrial data combination, and geoid validation. This continuous study deals with these aspects in order to improve the determination of, and better understand the accuracy of the resulting geoid model in this region. First, the low to middle degree components of satellite-only global gravity models are used to reflect the long wavelength geology signals of the geoid. Second the tailored spherical harmonic approach is applied to improve the global geopotential model such as EGM2008 in the middle to high frequency band. Third, a rigorous downward continuation in the mountainous regions is employed to account for the topographic effect. Finally the existing GPS-Leveling data are analyzed to detect and reduce the crustal motion effect and systematic errors. They are used to infer the accuracy of the geoid model. The validation also includes comparisons to EGM2008 and CGG2010.

  12. Comparative phylogeography in marginal seas of the northwestern Pacific.

    PubMed

    Ni, Gang; Li, Qi; Kong, Lingfeng; Yu, Hong

    2014-02-01

    The maturation of marine phylogeography depends on integration of comparative information across different regions globally. The northwestern Pacific, characterized by unique tectonic setting, however, is still underrepresented. This study seeks to highlight its phylogeographical history based on the available population data, focusing on three seas: the East China Sea (ECS), the South China Sea (SCS) and the Sea of Japan (SOJ). We first conducted a literature survey to evaluate current research efforts and then reanalysed the population structure, historical demography and genealogy for two selections of studies (namely ‘the ECS category’ and ‘the multiple-sea category’) to elucidate the evolutionary processes within and across the seas, respectively. For the ECS category, the meta-analyses revealed most studies displayed a shallow phylogeny, indicating a single origin from the sea. Significant population structure was commonplace, particularly in molluck and crustacean studies, with proportions of 89% and 80%, respectively. Nearly all studies selected showed signals of population expansion: the times estimated were closely linked to a period of ~120-140 Kya rather than the last glacial maximum. For the latter category, divergent intraspecific lineages appeared among seas and overlapped in the adjacent regions, a pattern implying each sea had served as an independent refugium during glaciations. The genetic splits, however, were estimated to arise from separate events dating from late Miocene to middle Pleistocene. As phylogeography is still in its infancy in the region, more effort is needed to test and complement the general rules abstracted here. Finally, challenges and prospects were discussed to accelerate further research. PMID:24600706

  13. A soil catena on schist in northwestern California

    USGS Publications Warehouse

    Marron, D.C.; Popenoe, J.H.

    1986-01-01

    Soil characteristics in a small steepland watershed underlain by schist in a rainy, tectonically active area in northwestern California show close associations with drainage-basin position and slope characteristics. Five soil-topography units based on these associations are defined in the study watershed. Spatial relationships of soil series, and patterns of soil development as indicated by B-horizon clay content and redness, reflect interactions between pedogenesis and erosion. General soil-topography patterns include: (1) decreases in soil-development moving from low-order to higher-order stream vallyes; and (2) more developed soils on north-facing as opposed to south-facing slopes. Decreases in soil-profile development moving from slopes near low-order streams to slopes near higher-order streams approximately correlate with increases in gradient, vertical relief, and drainage density, and reflect a more vigorous stripping of regolith by erosion on the slopes near the higher-order streams. The larger percentage of area covered by the more developed soils on north-facing as opposed to south-facing slopes appears to reflect a contrast in the way dominant erosional processes interact with pedogenic processes. Roadcuts on middle and upper slopes show soil discontinuities indicative of disturbance by block slides or slumps or both. Roadcuts on lower slopes show disrupted soils in small bedrock hollows that could have been created by rapid, shallow landslides or by the pulled-up root wads of toppled trees. Soil-profile characteristics and soil-topography patterns in the study area demonstrate that both erosional and pedogenic processes need to be considered when interpreting characteristics of hillslope soils. ?? 1986.

  14. Sedimentary and crustal structure of the northwestern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Ebeniro, Joseph O.; Nakamura, Yosio; Sawyer, Dale S.; O'Brien, William P., Jr.

    1988-08-01

    We conducted a large-offset seismic experiment in the northwestern Gulf of Mexico using largecapacity air guns and digital ocean-bottom seismographs to determine the velocity structure of the sediments, crust, and upper mantle. Five multiple-detector split-profile lines were shot over an area extending from the shallow midshelf south of Galveston to the continental rise just south of the Sigsbee escarpment. The data were of adequate spatial density and quality to allow combined use of near-vertical reflections, wide-angle reflections, and refractions for interpretation. Several techniques were used to obtain velocity-depth functions: (1) conventional constant-velocity-layer analysis, (2) interval velocities from moveouts of the precritical reflections, (3) analysis in the tau-p domain to determine extremal depth bounds, (4) estimation of the thickness of the allochthonous salt from the limiting distance of salt refractions, and (5) forward modeling using two-dimensional (2-D) ray tracing. A sedimentary sequence of nearly constant thickness (13 to 15 km) covers the study area. Various mobilized salt features exist within the sediments in the slope area, ranging from deeply buried layers and diapirs under the inner slope to shallow, thin, allochthonous bodies under the outer slope. In contrast to the sediments, the crust shows considerable variation in thickness, from normal oceanic crustal thickness beneath the continental rise to nearly normal continental thickness beneath the shelf. The transition under the slope, however, is not monotonie but includes thinning to nearly oceanic thickness under the midslope, possibly suggesting an incipient rift that failed to materialize during the opening of the gulf.

  15. Clastic dikes of Heart Mountain fault breccia, northwestern Wyoming, and their significance

    USGS Publications Warehouse

    Pierce, W.G.

    1979-01-01

    Structural features in northwestern Wyoming indicate that the Heart Mountain fault movement was an extremely rapid, cataclysmic event that created a large volume of carbonate fault breccia derived entirely from the lower part of the upper plate. After fault movement had ceased, much of the carbonate fault breccia, here called calcibreccia, lay loose on the resulting surface of tectonic denudation. Before this unconsolidated calcibreccia could be removed by erosion, it was buried beneath a cover of Tertiary volcanic rocks: the Wapiti Formation, composed of volcanic breccia, poorly sorted volcanic breccia mudflows, and lava flows, and clearly shown in many places by inter lensing and intermixing of the calcibreccia with basal volcanic rocks. As the weight of volcanic overburden increased, the unstable water-saturated calcibreccia became mobile and semifluid and was injected upward as dikes into the overlying volcanic rocks and to a lesser extent into rocks of the upper plate. In some places the lowermost part of the volcanic overburden appears to have flowed with the calcibreccia to form dike like bodies of mixed volcanic rock and calcibreccia. One calcibreccia dike even contains carbonized wood, presumably incorporated into unconsolidated calcibreccia on the surface of tectonic denudation and covered by volcanic rocks before moving upward with the dike. Angular xenoliths of Precambrian rocks, enclosed in another calcibreccia dike and in an adjoining dikelike mass of volcanic rock as well, are believed to have been torn from the walls of a vent and incorporated into the basal part of the Wapiti Formation overlying the clastic carbonate rock on the fault surface. Subsequently, some of these xenoliths were incorporated into the calcibreccia during the process of dike intrusion. Throughout the Heart Mountain fault area, the basal part of the upper-plate blocks or masses are brecciated, irrespective of the size of the blocks, more intensely at the base and in places extending upward for several tens of meters. North of Republic Mountain a small 25-m-high upper-plate mass, brecciated to some degree throughout, apparently moved some distance along the Heart Mountain fault as brecciated rock. Calcibreccia dikes intrude upward from the underlying 2 m of fault breccia into the lower part of the mass and also from its top into the overlying volcanic rocks; an earthquake-related mechanism most likely accounts for the observed features of this deformed body. Calcibreccia dikes are more common within the bedding-plane phase of the Heart Mountain fault but also occur in its transgressive and former land-surface phases. Evidence that the Wapiti Formation almost immediately buried loose, unconsolidated fault breccia that was the source of the dike rock strongly suggests a rapid volcanic deposition over the area in which clastic dikes occur, which is at least 75 km long. Clastic dikes were injected into both the upper-plate and the volcanic rocks at about the same time, after movement on the Heart Mouuntain fault had ceased, and therefore do not indicate a fluid-flotation mechanism for the Heart Mountain fault. The difference between contacts of the clastic dikes with both indurated and unconsolidated country rock is useful in field mapping at localities where it is difficult to distinguish between volcanic rocks of the Cathedral Cliffs and Lamar River Formations, and the Wapiti Formation. Thus, calcibreccia dikes in the Cathedral Cliffs and Lamar River Formations show a sharp contact because the country rock solidified prior to fault movement, whereas calcibreccia dikes in the Wapiti Formation in many instances show a transitional or semifluid contact because the country rock was still unconsolidated or semifluid at the time of dike injection.

  16. Borrelia crocidurae in Ornithodoros ticks from northwestern Morocco: a range extension in relation to climatic change?

    PubMed

    Souidi, Yassine; Boudebouch, Najma; Ezikouri, Sayeh; Belghyti, Driss; Trape, Jean-Franois; Sarih, M'hammed

    2014-12-01

    Tick-borne relapsing fever (TBRF) is caused by Borrelia spirochetes transmitted to humans by Argasid soft ticks of the genus Ornithodoros. We investigated the presence of Ornithodoros ticks in rodent burrows in nine sites of the Gharb region of northwestern Morocco where we recently documented a high incidence of TBRF in humans. We assessed the Borrelia infection rate by nested PCR and sequencing. All sites investigated were colonized by ticks of the Ornithodoros marocanus complex and a high proportion of burrows (38.4%) were found to be infested. Borrelia infections were observed in 6.8% of the ticks tested. Two Borrelia species were identified by sequencing: B. hispanica and B. crocidurae. The discovery in northwestern Morocco of Ornithodoros ticks infected by B. crocidurae represents a 350 km range extension of this Sahelo-Saharan spirochete in North Africa. The spread of B. crocidurae may be related to the increasing aridity of northwestern Morocco in relation to climate change. PMID:25424260

  17. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  18. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  19. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  20. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  1. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  2. Assessing impacts of unconventional natural gas extraction on microbial communities in headwater stream ecosystems in Northwestern Pennsylvania

    PubMed Central

    Trexler, Ryan; Solomon, Caroline; Brislawn, Colin J.; Wright, Justin R.; Rosenberger, Abigail; McClure, Erin E.; Grube, Alyssa M.; Peterson, Mark P.; Keddache, Mehdi; Mason, Olivia U.; Hazen, Terry C.; Grant, Christopher J.; Lamendella, Regina

    2014-01-01

    Hydraulic fracturing and horizontal drilling have increased dramatically in Pennsylvania Marcellus shale formations, however the potential for major environmental impacts are still incompletely understood. High-throughput sequencing of the 16S rRNA gene was performed to characterize the microbial community structure of water, sediment, bryophyte, and biofilm samples from 26 headwater stream sites in northwestern Pennsylvania with different histories of fracking activity within Marcellus shale formations. Further, we describe the relationship between microbial community structure and environmental parameters measured. Approximately 3.2 million 16S rRNA gene sequences were retrieved from a total of 58 samples. Microbial community analyses showed significant reductions in species richness as well as evenness in sites with Marcellus shale activity. Beta diversity analyses revealed distinct microbial community structure between sites with and without Marcellus shale activity. For example, operational taxonomic units (OTUs) within the Acetobacteracea, Methylocystaceae, Acidobacteriaceae, and Phenylobacterium were greater than three log-fold more abundant in MSA+ sites as compared to MSA− sites. Further, several of these OTUs were strongly negatively correlated with pH and positively correlated with the number of wellpads in a watershed. It should be noted that many of the OTUs enriched in MSA+ sites are putative acidophilic and/or methanotrophic populations. This study revealed apparent shifts in the autochthonous microbial communities and highlighted potential members that could be responding to changing stream conditions as a result of nascent industrial activity in these aquatic ecosystems. PMID:25408683

  3. Assessing impacts of unconventional natural gas extraction on microbial communities in headwater stream ecosystems in Northwestern Pennsylvania.

    PubMed

    Trexler, Ryan; Solomon, Caroline; Brislawn, Colin J; Wright, Justin R; Rosenberger, Abigail; McClure, Erin E; Grube, Alyssa M; Peterson, Mark P; Keddache, Mehdi; Mason, Olivia U; Hazen, Terry C; Grant, Christopher J; Lamendella, Regina

    2014-01-01

    Hydraulic fracturing and horizontal drilling have increased dramatically in Pennsylvania Marcellus shale formations, however the potential for major environmental impacts are still incompletely understood. High-throughput sequencing of the 16S rRNA gene was performed to characterize the microbial community structure of water, sediment, bryophyte, and biofilm samples from 26 headwater stream sites in northwestern Pennsylvania with different histories of fracking activity within Marcellus shale formations. Further, we describe the relationship between microbial community structure and environmental parameters measured. Approximately 3.2 million 16S rRNA gene sequences were retrieved from a total of 58 samples. Microbial community analyses showed significant reductions in species richness as well as evenness in sites with Marcellus shale activity. Beta diversity analyses revealed distinct microbial community structure between sites with and without Marcellus shale activity. For example, operational taxonomic units (OTUs) within the Acetobacteracea, Methylocystaceae, Acidobacteriaceae, and Phenylobacterium were greater than three log-fold more abundant in MSA+ sites as compared to MSA- sites. Further, several of these OTUs were strongly negatively correlated with pH and positively correlated with the number of wellpads in a watershed. It should be noted that many of the OTUs enriched in MSA+ sites are putative acidophilic and/or methanotrophic populations. This study revealed apparent shifts in the autochthonous microbial communities and highlighted potential members that could be responding to changing stream conditions as a result of nascent industrial activity in these aquatic ecosystems. PMID:25408683

  4. Pedogenesis and Permafrost Carbon Over the Eboling Ridge in Heihe River Basin, Northwestern China

    NASA Astrophysics Data System (ADS)

    Mu, C.; Zhang, T.; Cao, B.; Wang, Q.; Peng, X.; Cheng, G.

    2013-12-01

    Based on field permafrost sampling and laboratory analysis, we found that the average storages of soil organic carbon (SOC), total nitrogen (TN) and soil inorganic carbon (SIC) in permafrost soils were much more than that in the active layer on the Eboling Mountain in the upper reach of Heihe River basin, northwestern China. The objective of this study is to better understand the main soil physicochemical parameters influencing C and N dynamics in permafrost regions of northwestern China. Specifically, we investigated the effect of pedogenesis, cryogenic structure and SIC on SOC, TN and water-soluble organic carbon (WSOC) in the permafrost regions. The preliminary results show that SIC is a significant factor influencing carbon flux between atmosphere and terrestrial ecosystem and the distribution patterns of SOC and N. There are high correlation between SIC, SOC and N in permafrost. SOC and SIC can interact with each other, their small change may radically alter the carbon balance. SIC as a major factor will be crucial for developing large scale models evaluating C and N dynamics. High contents of C and N combined with a low vertical variability in each horizon on the Eboling Mountain can be explained by longer duration of pedogenesis and the influence of permafrost. In permafrost regions, the vertical distribution of soil C and N is also influenced by soil cryogenic structure. The high content of WSOC in deep permafrost soils can be explained by the formation of the ground ice causes the WSOC enrichment followed moisture migration. The average WSOC content in permafrost soils was larger than that in the active layer, suggesting that the labile carbon in permafrost soils has higher quality. SIC can reflect the microbial activity indirectly, due to the good negative relationship between SIC, soil pH and C/N ratios in permafrost. Soil pH values were the important factor influencing the distribution of SIC in deep permafrost soils. SIC in permafrost soils was controlled by acidification and other processes depending on soil pH. Microbial activity may be lower in soils with more acidic pH than in soils at circumneutral and alkaline pH, due to less soluble dissolved organic matter. The effect of geochemical variation in permafrost soils on microbial activity and SOM decomposition rates needs more research. The degradation of permafrost and ground ice melting with permafrost temperature increase on the Eboling Mountain would have severe impact on soil C and available N, which may alter the ecosystems function in arid and semiarid regions. However, in the long term, the growth of vegetation can enhance due to growing season extending, precipitation increasing and temperature increase, which may cause more atmospheric carbon into plants and soils through the photosynthesis. Therefore, the response of permafrost degradation in arid and semi-arid regions to future climate, ecology and landscapes needs more experimental and modeling studies.

  5. A faunistic study on the leafhoppers of northwestern Iran (Hemiptera, Cicadellidae)

    PubMed Central

    Abdollahi, Tandis; Jalalizand, Ali Reza; Mozaffarian, Fariba; Wilson, Michael

    2015-01-01

    Abstract The leafhopper fauna of northwestern Iran: Azarbaijan-e-Sharghi, Azarbaijan-e-Gharbi and Ardabil provinces is listed from previously published records and from our current work. Sixty-nine species are included with four species (Mogangella straminea Dlabola, 1957, Doratura stylata (Boheman, 1847), Macrosteles sordidipennis (Stål, 1858) and Psammotettix seriphidii Emeljanov, 1962) listed as new for Iran and Balclutha punctata (Fabricius, 1775), as a new record for the region. A distribution map of the species in northwestern Iran is given. PMID:25931954

  6. The Talara Basin province of northwestern Peru: cretaceous-tertiary total petroleum system

    USGS Publications Warehouse

    Higley, Debra K.

    2004-01-01

    More than 1.68 billion barrels of oil (BBO) and 340 billion cubic feet of gas (BCFG) have been produced from the Cretaceous-Tertiary Total Petroleum System in the Talara Basin province, northwestern Peru. Oil and minor gas fields are concentrated in the onshore northern third of the province. Current production is primarily oil, but there is excellent potential for offshore gas resources, which is a mostly untapped resource because of the limited local market for gas and because there are few pipelines. Estimated mean recoverable resources from undiscovered fields in the basin are 1.71 billion barrels of oil (BBO), 4.79 trillion cubic feet of gas (TCFG), and 255 million barrels of natural gas liquids (NGL). Of this total resource, 15 percent has been allocated to onshore and 85 percent to offshore; volumes are 0.26 BBO and 0.72 TCFG onshore, and 1.45 BBO and 4.08 TCFG offshore. The mean estimate of numbers of undiscovered oil and gas fields is 83 and 27, respectively. Minimum size of fields that were used in this analysis is 1 million barrels of oil equivalent and (or) 6 BCFG. The Paleocene Talara forearc basin is superimposed on a larger, Mesozoic and pre-Mesozoic basin. Producing formations, ranging in age from Pennsylvanian to Oligocene, are mainly Upper Cretaceous through Oligocene sandstones of fluvial, deltaic, and nearshore to deep-marine depositional origins. The primary reservoirs and greatest potential for future development are Eocene sandstones that include turbidites of the Talara and Salinas Groups. Additional production and undiscovered resources exist within Upper Cretaceous, Paleocene, and Oligocene formations. Pennsylvanian Amotape quartzites may be productive where fractured. Trap types in this block-faulted basin are mainly structural or a combination of structure and stratigraphy. Primary reservoir seals are interbedded and overlying marine shales. Most fields produce from multiple reservoirs, and production is reported commingled. For this reason, and also because geochemical data on oils and source rocks is very limited, Tertiary and Cretaceous production is grouped into one total petroleum system. The most likely source rocks are Tertiary marine shales, but some of the Cretaceous marine shales are also probable source rocks, and these would represent separate total petroleum systems. Geochemical data on one oil sample from Pennsylvanian rock indicates that it was probably also sourced from Tertiary shales.

  7. Neotectonic and paleoseismicity studies on the Urumaco Fault, northern Falcón Basin, northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard, Franck A.; Bousquet, Jean-Claude; Rodríguez, José A.

    1999-07-01

    The northern Falcón Basin in northwestern Venezuela is affected by several small active faults, subordinated to the major right-lateral east-west-trending Oca-Ancón Fault System. A set of prominent NW-SE right-lateral faults — synthetic shears — such as the Urumaco, Rı´o Seco, Lagarto and La Soledad faults, stands out among those. The Urumaco Fault, located between the Lagarto and Mitare rivers (in the Urumaco Trough, west of Coro), presents a rather complex active fault trace that comprises two NW-SE fault segments linked by an ENE-WSW reverse echelon, all showing a restraining stepover geometry. Its western segment seems to continue to the north at sea. Conversely, the eastern one dies out on land and its northern tip ends in a transtensive horse-tail structure, that disrupts an Early Pleistocene conglomerate. This same unit is flexed and upheaved some 30 m at the restraining overlap. The kinematics and present stress tensor, the latest activity and the seismogenic potential of the eastern segment of the Urumaco Fault, have been assessed at a set of three river cuts of an ephemeral tributary stream of the Urumaco River, 3 km north of the Urumaco village, where the Urumaco Formation is truncated by a Late Pleistocene terrace ( 14C date of 20,700±950 yr BP at the base) of the Urumaco River. On the one hand, one of these outcrops features the Urumaco Fault affecting the Late Miocene Urumaco Formation, which comprises two prominent fault planes disposed as a wedge. The southwestern bounding plane juxtaposes two different sequences whereas the northeastern one does not, implying different slip behavior. In fact, the northeastern plane shows oblique-slip striations (29°N, normal-dextral), whereas the other one shows perfectly horizontal striations (right-lateral). On the other hand, both updip plane prolongations in the overlying alluvial unit are not so sharp, if the 17-cm throw of the erosive bottom of such terrace measured at the lowermost part of the southwestern plane is regarded as an artifact. However, a mudflat deposit within this unit is bent with a 14-cm throw right above the northeastern fault plane clearly affecting the underlying Miocene unit. The estimated total offset per event allows to infer the occurrence of two individual events of magnitude ranging between Ms 5.8 and 6.4 on this strand of the eastern segment of the Urumaco Fault in the last 20,000 yr.

  8. Geology of the central Roan Plateau area, northwestern Colorado

    SciTech Connect

    Hail, W.J. Jr.

    1992-01-01

    The geology of the central Roam Plateau area in the south-central part of the Piceance Creek basin, comprising four 7.5-minute quadrangles, is described. Subsurface rocks penetrated by drill holes include the Mancos Shale and Mesaverde Formation of Later Cretaceous age, and parts of the Wasatch Formation of Paleocene and Eocene age, and Green River Formation of Eocene age. Exposed rocks, aggregating as much as 4,550 feet in thickness, are all Eocene in age and include the upper part of the Wasatch Formation , and the Green River and Uinta formations. The Green River and Uinta formations are extensively intertongued. Surficial deposits of Quaternary age include alluvium, talus, slopewash, and landslides. Two northwesterly trending folds, the Clear Creek Syncline and the Crystal Creek anticlinal nose, are present in the northern part of the area. There are no major faults. The area contains large potentially important oil-shale resources, mostly in the Parachute Creek member of the Green River Formation.

  9. Malaria transmission in two localities in north-western Argentina

    PubMed Central

    Dantur Juri, María J; Zaidenberg, Mario; Claps, Guillermo L; Santana, Mirta; Almirón, Walter R

    2009-01-01

    Background Malaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution of malaria vectors and the disease has been studied in different countries. In the present study, ecological aspects of the malaria vector Anopheles (Anopheles) pseudopunctipennis and their relationship with climatic variables, as well as the seasonality of malaria cases, were studied in two localities, El Oculto and Aguas Blancas, in north-western Argentina. Methods The fluctuation of An. pseudopunctipennis and the malaria cases distribution was analysed with Random Effect Poisson Regression. This analysis takes into account the effect of each climatic variable on the abundance of both vector and malaria cases, giving as results predicted values named Incidence Rate Radio. Results The number of specimens collected in El Oculto and Aguas Blancas was 4224 (88.07%) and 572 (11.93%), respectively. In El Oculto no marked seasonality was found, different from Aguas Blancas, where high abundance was detected at the end of spring and the beginning of summer. The maximum mean temperature affected the An. pseudopunctipennis fluctuation in El Oculto and Aguas Blancas. When considering the relationship between the number of malaria cases and the climatic variables in El Oculto, maximum mean temperature and accumulated rainfall were significant, in contrast with Aguas Blancas, where mean temperature and humidity showed a closer relationship to the fluctuation in the disease. Conclusion The temporal distribution patterns of An. pseudopunctipennis vary in both localities, but spring appears as the season with better conditions for mosquito development. Maximum mean temperature was the most important variable in both localities. Malaria cases were influenced by the maximum mean temperature in El Oculto, while the mean temperature and humidity were significant in Aguas Blancas. In Aguas Blancas peaks of mosquito abundance and three months later, peaks of malaria cases were observed. The study reported here will help to increase knowledge about not only vectors and malaria seasonality but also their relationships with the climatic variables that influence their appearances and abundances. PMID:19152707

  10. Molecular identification of Theileria parasites of northwestern Chinese Cervidae

    PubMed Central

    2014-01-01

    Background Theileria and Babesia protozoan parasites are transmitted mainly by tick vectors. These parasites cause heavy economic losses to the live-stock industry, as well as affecting the health of wild animals in parasite-endemic areas. Identification of infectious agents in wild animals is not only crucial for species preservation, but also provides valuable information on parasite epidemiology. Here, we conducted a molecular surveillance study in Northwestern China to assess the prevalence of blood pathogens in cervids. Methods PCR analysis and microscopic evaluation of blood smears to detect Theileria- and Babesia-related diseases in Cervidae were conducted, in which 22 blood samples from red deer (n = 22) in Qilian Mountain and 20 from sika deer (n = 20) in Long Mountain were collected and tested for the presence of Theileria and Babesia. The 18S rRNA gene was amplified, and selected polymerase chain reaction (PCR)-positive samples were sequenced for species identification. Results PCR revealed that 9.1% of the Qilian Mountain samples and 20% of the Long Mountain samples were positive for Theileria uilenbergi; 90.09% of the Qilian Mountain samples (n = 22) were positive for T. capreoli, but all of the Long Mountain samples (n = 20) were negative for T. capreoli; no other Theileria or Babesia species were found. PCR showed that T. uilenbergi and T. capreoli were present in red deer in Qilian Mountain, while only T. uilenbergi was found in sika Deer in Long Mountain. The 18S rRNA gene sequences were aligned against the corresponding GenBank sequences of known isolates of Theileria and Babesia and subjected to phylogenetic analysis. The phylogenetic tree showed that the newly isolated Theileria spp. could be classified as belonging to two clades: one group belonged to the same clade as T. uilenbergi, the other to a clade containing T. capreoli. Conclusions Our results provide important data to increase understanding of the epidemiology of Cervidae theileriosis, and will assist with the implementation of measures to control theileriosis transmission to Cervidae and small ruminants in central China. PMID:24885179

  11. Pulsed remineralisation in the northwestern Mediterranean Sea: a hypothesis

    NASA Astrophysics Data System (ADS)

    Denis, Michel; Martin, Valrie; Momzikoff, Andr; Gondry, Genevive; Stemmann, Lars; Demers, Serge; Gorsky, Gaby; Andersen, Valrie

    2003-02-01

    A general study of biogeochemical processes (DYNAPROC cruise) was conducted in May 1995 at a time-series station in the open northwestern Mediterranean Sea where horizontal advection was weak. Short-term variations of the vertical distributions of pico- and nanophytoplankton were investigated over four 36-h cycles, along with parallel determinations of metabolic CO 2 production rates and amino acid-containing colloid (AACC) concentrations at the chlorophyll maximum depth. The vertical (0-1000-m depth) distributions of (i) AACC, (ii) suspended particles and (iii) metabolic CO 2 production rate were documented during the initial and final stages of these 36-h cycles. This study was concerned with diel vertical migration (DVM) of zooplankton, which provided periodic perturbations. Accordingly, the time scale of the experimental work varied from a few hours to a few days. Although all distributions exhibited a periodic behaviour, AACC distributions were generally not linked to diel vertical migrations. In the subsurface layer, Synechococcus made the most abundant population and large variations in concentration were observed both at day and at night. The corresponding integrated (over the upper 90 m) losses of Synechococcus during one night pointed to a potential source of exported organic matter amounting to 534 mg C m -2. This study stresses the potential importance of organic matter export from the euphotic zone through the daily grazing activity of vertically migrating organisms, which would not be accounted for by measurements at longer time scales. The metabolic CO 2 production exhibited a peak of activity below 500 m that was shifted downward, apparently in a recurrent way and independently of the vertical distributions of AACC or of suspended particulate material. To account for this phenomenon, a sustained wave train hypothesis is proposed that combines the effect of the diel superficial faecal pellet production by swarming migrators and the repackaging activity of the nonmigrating midwater populations. Our results confirm the recent finding that the particulate compartment is not the major source of the observed instantaneous remineralisation rate and shed a new light on the fate of organic matter in the aphotic zone.

  12. Use of timesat to estimate phenological parameters in Northwestern Patagonia

    NASA Astrophysics Data System (ADS)

    Oddi, Facundo; Minotti, Priscilla; Ghermandi, Luciana; Lasaponara, Rosa

    2015-04-01

    Under a global change context, ecosystems are receiving high pressure and the ecology science play a key role for monitoring and assessment of natural resources. To achieve an effective resources management to develop an ecosystem functioning knowledge based on spatio-temporal perspective is useful. Satellite imagery periodically capture the spectral response of the earth and remote sensing have been widely utilized as classification and change detection tool making possible evaluate the intra and inter-annual plant dynamics. Vegetation spectral indices (e.g., NDVI) are particularly suitable to study spatio-temporal processes related to plant phenology and remote sensing specific software, such as TIMESAT, has been developed to carry out time series analysis of spectral indexes. We used TIMESAT software applied to series of 25 years of NDVI bi-monthly composites (240 images covering the period 1982-2006) from the NOAA-AVHRR sensor (8 x 8 km) to assessment plant pheonology over 900000 ha of shrubby-grasslands in the Northwestern of Patagonia, Argentina. The study area corresponds to a Mediterranean environment and is part of a gradient defined by a sharp drop west-east in the precipitation regime (600 mm to 280 mm). We fitted the temporal series of NDVI data to double logistic functions by least-squares methods evaluating three seasonality parameters: a) start of growing season, b) growing season length, c) NDVI seasonal integral. According to fitted models by TIMESAT, start average of growing season was the second half of September (± 10 days) with beginnings latest in the east (dryer areas). The average growing season length was 180 days (± 15 days) without a clear spatial trend. The NDVI seasonal integral showed a clear trend of decrease in west-east direction following the precipitation gradient. The temporal and spatial information allows revealing important patterns of ecological interest, which can be of great importance to environmental monitoring. In this work we also show as utilizing TIMESAT to characterize the plant phenology at regional scale.

  13. Changing Coastal oceanography of the Black Sea. I: Northwestern Shelf

    NASA Astrophysics Data System (ADS)

    Tolmazin, D.

    This article describes the hydrography of the Northwestern Shelf (NWS), of the Black Sea emphasizing the changes induced by water management in the Dniejer and Dniester river basins. The existing literature and previously unpublished data have been reviewed and synthesized to describe water property fields and transport mechanisms of the NWS and the Dnieper and Dniester estuaries before the early 1960s, or the so-called precontrol period, when the effect of artificial river flow control upon the coastal waters was insignificant. After the hydroenergy complexes and water withdrawal and disposal systems on rivers became fully operational in the early 1970s (the so-called postcontrol period), the annual river discharge from the Dnieper and Dniester had noticeably decreased and seasonal river flow patterns had been artificially modified. Instead of a powerful and short early spring flood, typical for the natural conditions in the Dnieper river, the hydrographs in the postcontrol period exhibit two smaller peaks of river discharge of much longer period. One of them (winter-early spring) is caused by intense hydroenergy generation and weir discharges through the cascade of storage reservoirs. Another is associated with spring flood, modified by intense water consumption and storage in this period. High average river discharge in late May-early June strengthened the summer pycnocline which inhibits vertical mixing in the estuaries and coastal waters. Owing to a slow summer circulation, the rate of natural purification of the entire coastal system has been reduced. This coupled with the increased nutrient, organic and pollutant transport, decreased the dissolved-oxygen concentration and led to anoxic events and mass mortalities of marine organisms in the previously productive regions. These effects have primarily plagued the benthic communities along the entire western coast of the NWS since 1973. Winter convective overturn in the Black Sea reaches its maximum depth at the southern boundary of the NWS. Thus, the NWS waters descend beneath the seasonal and main thermoclines in the open sea and are spread by the prevailing currents across the entire sea in the cold intermediate layer (CIL). By this dynamic mechanism the projected man-made modifications in the riverine-estuarine systems of the NWS will affect and change the large-scale thermohaline structure and marine life of the Black Sea.

  14. Deformation of Northwestern South America from GPS Geodesy

    NASA Astrophysics Data System (ADS)

    Mora-Paez, H.; La Femina, P. C.; Mothes, P. A.; Ruiz, A. G.; Fernandes, R. M.

    2013-12-01

    The North Andes block (NAB) is a hypothesized tectonic block that migrates (escapes) north-northeast relative to a stable South American reference frame. The motion of this block is thought-to-be derived by the collision of the Carnegie Ridge in southern Ecuador and/or by oblique convergence and high degrees of interplate coupling north of the ridge (i.e., strain partitioning). At the latitude of Ecuador, the NAB is defined by transpressional deformation accommodating east-northeastward motion along its boundary with South America. In southern to central Colombia, the NAB is dissected by several mapped and prominent regional shear zones. At these latitudes the NAB may be bound to the west by the Choco block and the transpressional Atrato-Uraba fault system and to the east by the Guayaquil-Algeciras fault system. And in northern Colombia the Caribbean - South America plate boundary is defined by the NAB and proposed Maracaibo and Guajira blocks. We investigate the deformation of northwestern South America, including the kinematics of NAB utilizing a new velocity field based on continuous GPS and existing episodic GPS data in Ecuador, Colombia, Venezuela and Panama. We reference these new velocities to a newly estimated Euler vector for the South America plate based on inversion of cGPS data from stations east of the Andes. The new velocity field and published earthquake slip vectors are inverted to solve for the Euler vectors of the NAB, Choco, Panama, Maracaibo and Guajira blocks and interseismic elastic strain accumulation (interseismic coupling) on block-bounding faults using a block modeling approach. We test a suite of block models to investigate the tectonic nature of the NAB along strike and the style of faulting in the upper plate accommodating block motion. Through the estimation of elastic strain accumulation on all block-bounding faults, we improve the understanding of interseismic coupling along a convergent margin capable of producing M>8 earthquakes and faults in the upper plate capable of generating M>6 earthquakes.

  15. Little known mid-Paleozoic salts of northwestern North Dakota

    SciTech Connect

    Fischer, D.W.; Anderson, S.B.

    1984-07-01

    Four Paleozoic formations that contain bedded salts previously undescribed in North Dakota have been identified and mapped. They are the Silurian Interlake, and Devonian Ashern, Souris River, and Duperow Formations. A series of stratigraphically and areally discontinuous, thin, bedded salts has been identified in the Silurian Interlake Formation. As many as five, thin, bedded salts are present in the upper gray member of the Devonian Ashern Formation. Where found, these salts are stratigraphically correlatable but laterally discontinuous. A thin, bedded salt is present in both the Souris River and Duperow. These salts are laterally continuous with salts previously described in Saskatchewan. Although the occurrences of the salts discussed commonly are discontinuous, knowledge of their presence can be helpful in designing a drilling and testing program for wells in areas where they occur. Furthermore, a knowledge of the presence of these salts is helpful in understanding the overall tectonic and depositional history of the Williston basin.

  16. 40 CFR 81.184 - Northwestern Connecticut Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northwestern Connecticut Intrastate Air Quality Control Region. 81.184 Section 81.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING...

  17. 40 CFR 81.184 - Northwestern Connecticut Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Northwestern Connecticut Intrastate Air Quality Control Region. 81.184 Section 81.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING...

  18. 40 CFR 81.184 - Northwestern Connecticut Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Northwestern Connecticut Intrastate Air Quality Control Region. 81.184 Section 81.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING...

  19. 40 CFR 81.184 - Northwestern Connecticut Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Northwestern Connecticut Intrastate Air Quality Control Region. 81.184 Section 81.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING...

  20. 40 CFR 81.184 - Northwestern Connecticut Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Northwestern Connecticut Intrastate Air Quality Control Region. 81.184 Section 81.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING...

  1. A STUDY OF THE GOALS AND CHARACTERISTICS OF EXTENSION CREDIT STUDENTS IN NORTHWESTERN MICHIGAN.

    ERIC Educational Resources Information Center

    HAGELBERG, MILTON JOHN

    AN ANALYSIS WAS MADE OF THE GOALS AND CHARACTERISTICS OF STUDENTS ENROLLED IN EXTENSION CREDIT COURSES OFFERED BY MICHIGAN STATE UNIVERSITY IN NORTHWESTERN MICHIGAN DURING THE FALL OF 1959. ALSO CONSIDERED WERE DATA ON STUDENT PROBLEMS AND ON CONTACTS AND RELATIONSHIPS WITH THE UNIVERSITY. GROUP ADMINISTERED QUESTIONNAIRES WERE USED TO COLLECT…

  2. A possible bedrock source for obsidian found in archeological sites in northwestern alaska.

    PubMed

    Patton, W W; Miller, T P

    1970-08-21

    Recently discovered deposits of obsidian in the Koyukuk valley may be the long-sought-for source of obsidian found in archeological sites in northwestern Alaska. Obsidian from these deposits compares favorably in physical characteristics and sodium-manganese ratio with the archeological obsidian, and there is evidence that the deposits have been "mined" in the past. PMID:17820304

  3. Education, Employment and Empowerment: The Case of a Young Woman in Northwestern China

    ERIC Educational Resources Information Center

    Maslak, Mary Ann

    2011-01-01

    As a marginalized region of the world, the rural Gansu Province of northwestern China provides an informative canvas on which to examine and understand the ways in which education contributes to the lives of local Muslim women and supports their goals for work. Specifically, this article highlights the role education plays in the life of one young…

  4. 78 FR 53175 - The Northwestern Mutual Life Insurance Company, et al.;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... instead is available to the variable separate accounts of multiple insurance companies, pension plans and... companies, to certain tax-qualified pension and retirement plans and other investment companies. 10. The... COMMISSION The Northwestern Mutual Life Insurance Company, et al.; Notice of Application Agency:...

  5. A Collaborative Model for Teaching E-Resources: Northwestern University's Graduate Training Day

    ERIC Educational Resources Information Center

    Lightman, Harriet; Reingold, Ruth N.

    2005-01-01

    The authors report on the planning, execution, and future of Northwestern University's Introduction to Electronic Resources/Humanities Computing Training Day, a mandatory one-day set of classes for first-year doctoral students in humanities disciplines. The project is a collaborative effort among the Office of the Dean of the Weinberg College of…

  6. "Dual Compensation" and "Separate Compensation" Arrangements in the Wake of the Northwestern University Settlement

    ERIC Educational Resources Information Center

    Kenney, Robert J., Jr.

    2004-01-01

    This commentary makes the case for a re-examination of certain existing guidelines of the Department of Health and Human Services (DHHS) and the National Institutes of Health (NIH) regarding reimbursement of salary costs under NIH grants. The settlement earlier this year involving salary costs and effort reporting at Northwestern University has…

  7. Linking Research and Policy Concerns: Northwestern University's Institute for Policy Research.

    ERIC Educational Resources Information Center

    Cook, Fay Lomax; Chambers, Audrey

    2000-01-01

    Describes the founding, organization and structure, and relationship between social issues and funders of the Institute for Policy Research at Northwestern University. The institute's history and research have been marked by a commitment to societal concerns such as poverty, crime, race and inequality, social welfare policy, and community

  8. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of... Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by the boundaries of the following jurisdictions or described area (including the territorial area of...

  9. 76 FR 4551 - Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ...; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service... lobster harvest guideline. SUMMARY: NMFS announces that the annual harvest guideline for the commercial... at 50 CFR 665.252(b) require NMFS to publish an annual harvest guideline for lobster Permit Area...

  10. A possible bedrock source for obsidian found in archeological sites in northwestern Alaska

    USGS Publications Warehouse

    Patton, W.W., Jr.; Miller, T.P.

    1970-01-01

    Recently discovered deposits of obsidian in the Koyukuk valley may be the long-sought-for source of obsidian found in archeological sites in northwestern Alaska. Obsidian from these deposits compares favorably in physical characteristics and sodium-manganese ratio with the archeological obsidian, and there is evidence that the deposits have been "mined" in the past.

  11. 76 FR 27171 - Northwestern Pacific Railroad Co.; Notice of Partial Relief from Emergency Order No. 21

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... signals. 63 FR 67976 (Dec. 9, 1998). The only exception to the prohibition on train operations over that... on the railroad.'' 63 FR 67978. On May 28, 1999, FRA granted the petition of the Northwestern Pacific... 20, 24, 25, 26, 27, 709, and 711 in Willits Yard. Emergency Order No. 21, Notice No. 2, 64 FR...

  12. Aerodynamic properties of agricultural and natural surfaces in northwestern Tarim Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Friction velocity (u*) and aerodynamic roughness (z0) are important parameters that influence soil erosion, but no attempts have been made to quantify these parameters as affected by different land use types in the northwestern Tarim Basin. Wind velocity profiles were measured and used to determine ...

  13. "A Child has Many Mothers": Views of Child Fostering in Northwestern Cameroon

    ERIC Educational Resources Information Center

    Verhoef, Heidi

    2005-01-01

    This article examines 20 fostering arrangements in a growing urban community in northwestern Cameroon from the perspectives of those involved. Analysis of interviews with caregivers and birth mothers suggests that the nature of adult relationships is central to children's living arrangements. Three caregiver-mother relationship profiles are

  14. Spawning migration and intraspecies differentiation of pink salmon from northwestern Sakhalin waters

    NASA Astrophysics Data System (ADS)

    Ivanov, Alexander N.; Shershnev, Alexej; Kaplanova, Nina P.; Pusankov, Konstantin L.; Ivanova, Lubov V.; Pusankova, Ekaterina N.

    2002-03-01

    Pacific salmon fishery near the northwestern Sakhalin coast is based on fish spawning both in the island and continental rivers. Salmon fishery near the Sakhalin coast of Amur Estuary has significantly lost contact with the main salmon rivers of the region. Pink salmon is the most abundant salmon species of the region rivers. Biology of the northwestern Sakhalin pink salmon is less studied of all the fishery regions on the island. So far, their migratory ways from feeding and wintering areas to the spawning rivers have not been ascertained. The results of monitoring for pink salmon have shown that by some biological indices, commercial-statistic data, and also by the data of satellites NOAA-10, NOAA-12, NOAA-14, their commercial catches near the northwestern Sakhalin are formed by fish groups migrating both through the Amur Estuary from the south, and through the Sakhalin Bay from the north. The base of spawning fish in rivers of northwestern Sakhalin is formed by the summer pink salmon migrating from the north. A preliminary computation of distinguished pink salmon groups (summer southern and northern autumn) shows a ratio 0.1:5.7:1 in odd years and 1:2:1 in even years.

  15. Late quaternary vegetational change in the Kotzebue sound area, northwestern Alaska

    SciTech Connect

    Anderson, P.M.

    1985-01-01

    Two sediment cores from Kaiyak and Squirrel lakes in northwestern Alaska yielded pollen records that date to ca. 39,000 and 27,000 yr B.P., respectively. Between 39,000 and 14,000 yr B.P., the vegetation around these lakes was dominated by Gramineae and Cyperaceae with some Salix and possibly Betula nana/glandulosa forming a local, shrub component of the vegetation. Betula pollen percentages increased about 14,000 yr B.P., indicating the presence of a birch-dominated shrub tundra. Alnus pollen appeared at both sites between 9000 and 8000 yr B.P., and Picea pollen (mostly P. mariana) arrived at Squirrel Lake about 5000 yr B.P. The current forest-tundra mosaic around Squirrel Lake was established at this time, whereas shrub tundra existed near Kaiyak Lake throughout the Holocene. When compared to other pollen records from northwestern North America, these cores (1) represent a meadow component of lowland, Beringian tundra between 39,000 and 14,000 yr B.P., (2) demonstrate an early Holocene arrival of Alnus in northwestern Alaska that predates most other Alnus horizons in northern Alaska or northwestern Canada, and (3) show an east-to-west migration of Picea across northern Alaska from 9000 to 5000 yr B.P.

  16. INCIDENCE OF INTROGRESSION BETWEEN CULTIVATED ALFALFA AND WILD RELATIVES IN NORTHWESTERN KAZAKHSTAN.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Central Asia is considered the primary center of origin for alfalfa and has a rich diversity of taxa in the Medicago sativa Complex. An exploration was carried out in 2000 to collect germplasm of wild relatives of alfalfa in Northwestern Kazakhstan. Russian scientists had previously proposed areas w...

  17. 75 FR 39705 - Notice of Temporary Closures on Public Lands in Northwestern Elko County, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ...Notice is hereby given that temporary closures to public access, use, and occupancy will be in effect for the dates and times specified in this Notice on public lands administered by the Bureau of Land Management (BLM), Tuscarora Field Office, Elko, Nevada within the Owyhee, Rock Creek, and Little Humboldt Wild Horse Herd Management Areas (HMAs) in the northwestern portion of Elko County,......

  18. 76 FR 77779 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... Coral Reef Ecosystem Reserve Advisory Council AGENCY: Office of National Marine Sanctuaries (ONMS... the following vacant seats on the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory....byers@noaa.gov . SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a ]...

  19. 77 FR 16211 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... Coral Reef Ecosystem Reserve Advisory Council AGENCY: Office of National Marine Sanctuaries (ONMS... the following vacant seats on the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory... . SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a marine protected area designed to...

  20. "A Child has Many Mothers": Views of Child Fostering in Northwestern Cameroon

    ERIC Educational Resources Information Center

    Verhoef, Heidi

    2005-01-01

    This article examines 20 fostering arrangements in a growing urban community in northwestern Cameroon from the perspectives of those involved. Analysis of interviews with caregivers and birth mothers suggests that the nature of adult relationships is central to children's living arrangements. Three caregiver-mother relationship profiles are…

  1. West Nile Virus Isolated from a Virginia Opossum (Didelphis virginiana) in Northwestern Missouri, USA, 2012

    PubMed Central

    Bosco-Lauth, Angela; Harmon, Jessica R.; Lash, R. Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry M.; Godsey, Marvin S.; Burkhalter, Kristen; Root, J. Jeffrey; Gidlewski, Thomas; Nicholson, William L.; Brault, Aaron C.; Komar, Nicholas

    2016-01-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, Flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology. PMID:25098303

  2. Transition in the cause of fever from malaria to dengue, Northwestern Ecuador, 1990-2011.

    PubMed

    Cifuentes, Sara G; Trostle, James; Trueba, Gabriel; Milbrath, Meghan; Baldeón, Manuel E; Coloma, Josefina; Eisenberg, Joseph N S

    2013-10-01

    In tropical areas, the predominant cause of fever has historically been malaria. However by 2011, among febrile patients in northwestern Ecuador, dengue was identified in 42% and malaria in none. This finding suggests a transition in the cause of fever from malaria to other illnesses, such as dengue. PMID:24047566

  3. Stable Isotopic Constraints of the Turpan Basin in Northwestern China

    NASA Astrophysics Data System (ADS)

    Schaen, A. J.

    2010-12-01

    Stable isotopic analysis of sedimentary rocks can be used to reconstruct past geologic changes in the elevation and climate of topographic features such as mountain ranges and plateaus. The Tibetan Plateau is an ideal field laboratory for conducting this type of study because of the Plateau’s extreme topographic relief and relatively recent geologic growth. Here we present oxygen and carbon isotope compositions from a suite of sedimentary rock samples taken from the western Turpan Basin in northwestern China. This area of the basin collects sediment from weathering and erosion of the Bogda Shan located to the north. The goal of this study is to analyze changes in the stable isotope composition as a function of stratigraphic position to reconstruct paleoelevations and paleoclimates in this part of the Tibetan Plateau. The sedimentary rock samples analyzed in this study are Late Jurassic to Neogene age and are primarily mudstone, siltstone, fine sandstone along with lesser limestone. Samples were powered and then dissolved with phosphoric acid at 72οC. The liberated CO2 gas was then analyzed using a Finnigan Delta Plus XL mass spectrometer with a gasbench inlet system. Oxygen isotope values range from -13.72 to -1.62‰ (PDB) and exhibit a large scale trend to more negative values toward the top of the stratigraphic sequence. Superimposed on this large scale trend are systematic variations in isotopic composition as a function of age. The most positive δ18O values occur at approximately 160, 115, 60, and 5 ma. Conversely, δ18O minima are observed at 150, 90, and 40 ma. δ13C values range from -10.69‰ to 1.40‰ (PDB). The most positive δ13C values (-4.3 to 1.4) occur from 120-160 ma. Younger samples display small scale variations with age with notable δ13C minima of -10.7, -14.7, and -7.6‰ at 108, 80, and 17 ma, respectively. The variable δ18O and positive δ13C values from the Jurassic (145-160 ma) are consistent with an arid climate and high atmospheric PCO2 levels during the warm Mesozoic Era. The overall decrease in δ18O values observed during the Cretaceous (145-65 ma) can be explained by the global climatic transition from a warm Mesozoic to a relatively cool Cenozoic Era. We take into account other possible influences on the isotopic record including detrital effects, diagensis, and evaporation, but infer the primary control on the isotopic records to be changes in climate during these time periods. Because the magnitude of oxygen isotope changes is consistent with that expected due to global climate change, we infer that there were not significant changes in the elevation of the Bogda Shan during this time period. This conclusion is also supported by the similar grain size/lithology (siltstone-finer grained sandstones) from bottom to top through the stratigraphic sequence, consistent with dormant topography prior to the Tertiary Period.

  4. Canopy storage capacity of xerophytic shrubs in Northwestern China

    NASA Astrophysics Data System (ADS)

    Wang, Xin-ping; Zhang, Ya-feng; Hu, Rui; Pan, Yan-xia; Berndtsson, Ronny

    2012-08-01

    SummaryThe capacity of shrub canopy water storage is a key factor in controlling the rainfall interception. Thus, it affects a variety of hydrological processes in water-limited arid desert ecosystems. Vast areas of revegetated desert ecosystems in Northwestern China are occupied by shrub and dwarf shrub communities. Yet, data are still scarce regarding their rainwater storage capacity. In this study, simulated rainfall tests were conducted in controlled conditions for three dominant xerophytic shrub types in the arid Tengger Desert. Eight rainfall intensities varying from 1.15 to 11.53 mm h-1 were used to determine the canopy water storage capacity. The simulated rainfall intensities were selected according to the long-term rainfall records in the study area. The results indicate that canopy storage capacity (expressed in water storage per leaf area, canopy projection area, biomass, and volume of shrub respectively) increased exponentially with increase in rainfall intensity for the selected shrubs. Linear relationships were found between canopy storage capacity and leaf area (LA) or leaf area index (LAI), although there was a striking difference in correlation between storage capacity and LA or LAI of Artemisia ordosica compared to Caragana korshinskii and Hedysarum scoparium. This is a result of differences in biometric characteristics, especially canopy morphology between the shrub species. Pearson correlation coefficient indicated that LA and dry biomass are better predictors as compared to canopy projection area and volume of samples for precise estimation of canopy water storage capacity. In terms of unit leaf area, mean storage capacity was 0.39 mm (range of 0.24-0.53 mm), 0.43 mm (range of 0.28-0.60 mm), and 0.61 mm (range of 0.29-0.89 mm) for C. korshinskii, H. scoparium, and A. ordosica, respectively. Correspondingly, divided per unit dry biomass, mean storage capacity was 0.51 g g-1 (range of 0.30-0.70 g g-1), 0.41 g g-1 (range of 0.26-0.57 g g-1), and 0.73 g g-1 (range of 0.38-1.05 g g-1) for C. korshinskii, H. scoparium, and A. ordosica, respectively, when the rainfall intensities ranged from 1.15, 2.31, 3.46, 4.61, 6.92, 9.23 to 11.53 mm h-1. The needle-leaved species A. ordosica had a higher canopy water storage capacity than the ovate-leaved species C. korshinskii and H. scoparium at the same magnitude of rainfall intensity, except for C. korshinskii when it was expressed in unit of canopy projection area. Consequently, A. ordosica will generate higher interception losses as compared to C. korshinskii and H. scoparium. This is especially the case as it often forms dense dwarf shrub communities despite its small size.

  5. High-frequency fluxes of labile compounds in the central Ligurian Sea, northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Goutx, M.; Momzikoff, A.; Striby, L.; Andersen, V.; Marty, J. C.; Vescovali, I.

    2000-03-01

    Sinking particles were collected every 4 h with drifting sediment traps deployed at 200 m depth in May 1995 in a 1-D vertical system during the DYNAPROC observations in the northwestern Mediterranean sea. POC, proteins, glucosamine and lipid classes were used as indicators of the intensity and quality of the particle flux. The roles of day/night cycle and wind on the particle flux were examined. The transient regime of production from late spring bloom to pre-oligotrophy determined the flux intensity and quality. POC fluxes decreased from, on average, 34 to 11 mg m -2 d -1, representing 6-14% of the primary production under late spring bloom conditions to 1-2% under pre-oligotrophic conditions. Total protein and chloroplast lipid fluxes correlated with POC and reflected the input of algal biomass into the traps. As the season proceeded, changes in the biochemical composition of the exported material were observed. The C/N ratio rose from 7.8 to 12. Increases of serine (10-28% of total proteins), total lipids (7-9 to 14-28% of POC) and reserve lipids (1-5 to 5-22% of total lipids) were noticeable, whereas total protein content in POC decreased (20-27 to 18-7%). N-acetyl glucosamine, a tracer of fecal pellet flux, showed that zooplankton grazing was a major vector of downward export during the decaying bloom. Against this background pattern, episodic events specifically increased the flux, modifying the quality and the settling velocity of particles. Day/night signals in biotracers (POC, N-acetyl glucosamine, protein and chloroplast lipids) showed that zooplankton migrations were responsible for sedimentation of fresh material through fast sinking particles ( V=170-180 m d -1) at night. Periodic signatures of re-processed material (high lipolysis and bacterial biomass indices) suggested that other zooplankton fecal pellets or small aggregates, probably of lower settling velocities ( V<170 m d -1), contributed to the flux during calm periods. At the beginning of the experiment, during the development of a prymnesiophyte bloom in the upper layers, the sterol signal with no periodicity enabled us to estimate high particle settling velocities (⩾600 m d -1) likely related to large aggregate formation. A wind event increased biotracer fluxes (POC, protein, chloroplast lipids). The rapid transmission of surface signals through extremely fast sinking particles could be a general feature of particle fluxes in marine areas unaffected by horizontal advection.

  6. Evolution of Middle to Late Pleistocene Sandy Calcareous Palaeosols Underlying the Northwestern Negev Desert Dunefield (Israel)

    NASA Astrophysics Data System (ADS)

    Roskin, Joel; Katra, Itzhak; Porat, Naomi; Zilberman, Ezra

    2014-05-01

    Calcareous palaeosols in the northwestern (NW) Negev Desert dunefield, Israel, at the eastern end of the Sinai-Negev erg were studied in relation to their overlying stabilized dunes and downwind loess deposits, using sedimentological analyses, spectroscopy, and optically stimulated luminescence (OSL) dating. During the Middle to Late Pleistocene, between around MIS 7 and through MIS 3, several cycles of sand veneer (sheet) deposition, stabilization, pedogenesis, and erosion formed a spatially variable sequence of sandy calcareous palaeosols in the NW Negev. Periods of stability on the order of several thousand years to over ten thousand years, characterized by post-depositional illuviation of aeolian silts, clays, and salts, enabled the formation of diagnostic, often-indurated, calcareous, Bk horizons (stages I-III), with orthic carbonate nodules. The primary particle-size mode of the palaeosol (127 µm) is intermediate between the modes of the overlying (MIS 2) dune sand and the mode of primary northern Negev (~MIS 6 through MIS 2) loess deposits in the dunefield periphery. The sand fraction of the palaeosols is slightly finer than the dune sand, and its spatial sedimentation pattern correlates with the pattern of the subsequent dune incursions. These observations suggest that (1) Bk palaeosol horizons were resistant to (MIS 6 - MIS 3) sand veneer aeolian erosion and formed chronologically differentiated and durable surfaces; (2) these surfaces remained in equilibrium for extensive periods, being intermittently covered and preserved by shifting sand veneers; (3) the MIS 2 dune incursion episodes followed the same transport routes of the underlying palaeosol sand substrate while producing a limited amount of aeolian erosion on the Bk horizons, and; (4) the similar sedimentological and chronological framework of the palaeosols and loess deposits suggests a partial genetic connection. As for the overlying dunes, aeolian sand supply to the parent material of the palaeosols was initially controlled by sediment availability originating in the Nile Delta and probably linked to glacial-interglacial eustatic cycles and glacial and cold-event windiness. The NW Negev sand deposition episodes that markedly differ from the ages of a nearby sandy palaeosol sequence of coastal origin exemplify the role of sand supply on the development of palaeosol sequences in a similar palaeoclimate.

  7. Flooding of property by runoff from agricultural land in northwestern Europe

    NASA Astrophysics Data System (ADS)

    Boardman, John; Ligneau, Laurence; de Roo, Ad; Vandaele, Karel

    1994-08-01

    In the last twenty years there has been an increase in the incidence of flooding of property by runoff from agricultural land in many areas of northwestern Europe. These events take the form of inundations by soil-laden water associated with erision and the formation of ephemeral or talweg gullies developed in normally dry valley bottoms. Costs of such events may be considerable e.g. almost US$2M at Rottingdean, southern England, in 1987. These costs are largely borne by individual house occupants, insurance companies and local councils. The distribution of flooding is widespread but areas of high risk can be identified: the hilly area of central Belgium, parts of northern France, the South Downs in southern England and South-Limburg (the Netherlands). All these areas have silty, more or less loessial soils. Two types of flooding may be distinguished: winter flooding associated with wet soils and the cultivation of winter cereals, and summer flooding due to thunderstorm activity and runoff particularly from sugar beet, maize and potato crops. The distribution of these types of erosion varies in relation to the interaction between physical characteristics (soils and topography), climatic conditions and land use across the region. The reason for the recent increase in flooding events appears to be changes in land use, in the area of arable cropping, and the continued intensification of farming such as the use of chemical fertilizers, the decline in aggregate stability, the increase in the size of fields and compaction by farm vehicles. In some regions the risk of flooding has also increased because of expansion of urban areas in valley bottom locations. Communities have responded to the flooding hazard with emergency or protective measures usually involving engineered structures rather than land use change. The policy response to the increased risk of flooding has been very limited especially at the national and provincial level, the exception being plans developed with farming organisations in South-Limburg and the Pays de Caux. In southern England initiatives have been few and largely consist of protective measures undertaken by urban municipalities.

  8. Observations of anticyclonic and cyclonic Subthermocline Submesoscale Coherent Vortices: a case study in the Northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Bosse, Anthony; Testor, Pierre; Mortier, Laurent; Houpert, Loc

    2014-05-01

    The surface geostrophic turbulence is mainly constituted by strong surface intensified eddies formed by boundary current instability, whereas within the interior of the ocean smaller vortical structures appear to be prominent. They are called Submesoscale Coherent Vortices (SCVs) and are known to be long-lived features. They are particularly efficient in transporting tracers (like temperature, salinity, dissolved oxygen for instance) over long distances. Anticylonic SCVs have been commonly observed in several oceans since the late 70s and the discovery of the Meddies, but less is known about cyclonic SCVs, which were hypothesized to be less stable and therefore harder to observe. Mooring data, cruises and in particular, regular deployments of gliders in the Northwestern Mediterranean Sea since 2007 revealed the presence of several anticyclonic and cyclonic SCVs. They are both characterized by small radius (~5-10km, about the internal radius of deformation of the area), velocity maxima at intermediate depth of ~5-15cm/s, high Rossby numbers of 0.1-0.5 and local Potential Vorticity anomalies. In this study, we present a census and a dynamical description of the encountered SCVs, as well as a discussion on their formation process and role in the ocean circulation.

  9. Anomalous arsenic contents in Lower Pennsylvanian Coals, Warrior field, northwestern Alabama, USA: Evidence for fluid flow during Alleghanian thrusting

    SciTech Connect

    Hatch, J.R.; Goldhaber, M.B.; Pashin, J.C.; Offield, T.W.; Finkelman, R.B.

    1998-12-31

    This paper summarizes initial results from a study of the geology and geochemistry of anomalous arsenic (As) contents in bituminous coals from the Lower Pennsylvanian Pottsville Formation, Warrior field, northwestern Alabama. Since 1977, the US Geological Survey has chemically analyzed 913 core and mine samples of coal and shaley coal from the Warrior field. These analyses document arsenic contents in coal of up to 1500 ppm (whole-coal, remnant-moisture basis) which are some of the highest contents reported for all United States coals. Warrior field coals also have elevated contents of copper (Cu), molybdenum (Mo), and antimony (Sb). For the approximately 13,000 samples of United States coals analyzed by the US Geological Survey, mean arsenic content is about 24 ppm. Nearly 80% of the 103 arsenic analyses greater than three standard deviations above this mean are from Alabama. A figure illustrates the distribution of arsenic contents in Warrior field coals and compares this distribution with the substantially lower arsenic contents in Paleocene coals from the Powder River basin, Wyoming and Montana, and Middle Pennsylvanian coals from the Illinois basin, Illinois, Indiana and western Kentucky.

  10. Hiatus-related processes: Paleokarst, paleosol, and a transgressive rocky shore from the Mississippian-Pennsylvanian unconformity in northwestern Arkansas

    SciTech Connect

    Webb, G.E. . Dept. of Geology)

    1992-01-01

    Unconformities are often considered only as stratigraphic gaps or sequence boundaries despite the evidence of climate- and paleogeography-linked hiatus processes that they may preserve. In northwestern Arkansas, progressively older Paleozoic strata are truncated to the north and west by the Mississippian-Pennsylvanian unconformity. In southern Washington County, Arkansas, the partly truncated Chesterian Pitkin Limestone is unconformably overlain by the Cane Hill Member of the Morrowan Hale Formation. The top of the Pitkin Limestone locally consists of cryptokarst with abundant solution pipes and lithoclasts formed by dissolution fragmentation. These lithoclasts, and surrounding clay dissolution residue, form regolith that is increasingly altered by pedogenic calcretization towards the top. The basal conglomerate of the overlying Cane Hill Member is interpreted as a transgressive boulder shore deposit. Conglomerate clasts consist of Pitkin cobbles and boulders that were derived from the erosion of local Pitkin highs.'' Most clasts are heavily bored on all sides by a variety of Trypanites and acrothoracian barnacle borings. Encrusting bryozoans and the encrusting tabulate coral, Michelinia, complete the rocky shore fauna. Preservation of paleokarst and poorly-indurated paleosol in low-lying areas around the eroded Pitkin highs,'' suggests that: (1) the vast majority of missing Pitkin was removed from the section by karstification during the hiatus, and not by erosion during the subsequent transgression; (2) transgression was too rapid to effectively scour the transgressed surface to bed rock; and (3) the net nearshore sediment transport direction was shoreward as the sea transgressed.

  11. Gas reserves in medina group of northwestern Pennsylvania as related to fracture-porosity and stratigraphic control

    SciTech Connect

    Star, I.; Gold, D.P.; Canich, M.R.

    1984-12-01

    Gas reserves in the Medina Group of northwestern Pennsylvania were investigated for fracture-porosity and stratigraphic control with remote sensing and geophysical tools. Lineaments were mapped on Landsat MSS band 7 (scale 1:250,000), and RBV (scales 1:125,000 and 1:500,000) images, and low-altitude photographs (scale 1:20,000). Zones of high estimated-net gas reserves were noted along French Creek, between Meadville and Franklin, Pennsylvania. A lineament, which bisects the French Creek Lineament and is oriented N55/sup 0/E, also parallels and overlaps gas-pool trends. The largest gas pool underlies an area devoid of lineaments mapped on Landsat imagery. The ..gamma..-ray log was used to establish stratigraphic parameters and to approximate lithologies. Sandstones were subdivided into qualities representing degrees of shaliness. Other variables derived from this log with respect to the Medina Group include: depth below sea level, formation thickness, net-sandstone thickness, and Cabot Head Shale thickness. The Whirlpool Sandstone Member was not included in this analysis. No statistical correlation was found between the above variables and estimated-net gas reserves. Visual inspection reveals trends common to the isopach maps and estimated-net gas reserves. Thus, stratigraphic control probably is important to hydrocarbon-pool location and geometry, with the proper combination of variables yet to be identified.

  12. Comparative Phylogeography Reveals Cryptic Diversity and Repeated Patterns of Cladogenesis for Amphibians and Reptiles in Northwestern Ecuador

    PubMed Central

    Pyron, R. Alexander; Peñafiel, Nicolás; Romero-Barreto, Paulina; Culebras, Jaime; Bustamante, Lucas; Yánez-Muñoz, Mario H.; Guayasamin, Juan M.

    2016-01-01

    Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history. PMID:27120100

  13. The Corossol structure: A possible impact crater on the seafloor of the northwestern Gulf of St. Lawrence, Eastern Canada

    NASA Astrophysics Data System (ADS)

    Lajeunesse, Patrick; St-Onge, Guillaume; Locat, Jacques; Duchesne, Mathieu J.; Higgins, Michael D.; Sanfaçon, Richard; Ortiz, Joseph

    2013-12-01

    We report on a 4.1 (±0.2) km diameter and 185 m deep circular submarine structure exposed on the seabed in >40 m water depths in the northwestern Gulf of St. Lawrence (Eastern Canada) from the analysis of high-resolution multibeam bathymetric and seismic data. The presence of a circular form characterized by a central uplift and concentric rings resembles the morphology and geometry of complex meteorite impact structures. Also, other origins, such as kimberlites, intrusions, karsts, or diapirs, can be eliminated on geological criteria. A single 4 cm long breccia fragment recovered from the central uplift has numerous glassy droplets of fluorapatite composition, assumed to be impact melts, and a single quartz grain with planar intersection features thought to be shock-induced planar deformation features (PDFs). The absolute age of this possible impact structure is unknown, but its geological setting indicates that it was formed long after the Mid-Ordovician and before regional pre-Quaternary sea-level lowstands. Present results outline the need for further examination to confirm an impact origin and to precisely date the formation of the structure.

  14. Comparative Phylogeography Reveals Cryptic Diversity and Repeated Patterns of Cladogenesis for Amphibians and Reptiles in Northwestern Ecuador.

    PubMed

    Arteaga, Alejandro; Pyron, R Alexander; Peñafiel, Nicolás; Romero-Barreto, Paulina; Culebras, Jaime; Bustamante, Lucas; Yánez-Muñoz, Mario H; Guayasamin, Juan M

    2016-01-01

    Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history. PMID:27120100

  15. Tectonic and climate driven fluctuations in the stratigraphic base level of a Cenozoic continental coal basin, northwestern Andes

    NASA Astrophysics Data System (ADS)

    Silva Tamayo, J. C.; Sierra, G. M.; Correa, L. G.

    2008-12-01

    Changes in the sedimentologic and stratigraphic characteristics of the coal-bearing middle Oligocene-late Miocene siliciclastic Amagá Formation, northwestern Colombia, reflect major fluctuations in the stratigraphic base level within the Amagá Basin, which paralleled three major stages of evolution of the middle Cenozoic Andean Orogeny. These stages, which are also traceable by the changes in the compositional modes of sandstones, controlled the occurrence of important coal deposits. The initial stage of evolution of the Amagá Basin was related to the initial uplift of the Central Cordillera of Colombia around 25 Ma, which promoted moderate subsidence rates and high rates of sediment supply into the basin. This allowed the development of aggradational braided rivers and widespread channel amalgamation resulting in poor preservation of both, low energy facies and geomorphic elements. The presence of poorly preserved Alfisols within the scarce flood plains and the absence of swamp deposits suggest arid climate during this stage. The compositional modes of sandstones suggest sediment supply from uplifted basement-cored blocks. The second stage of evolution was related to the late Oligocene eastward migration of the Pre-Andean tholeitic magmatic arc from the Western Cordillera towards the Cauca depression. This generated extensional movements along the Amagá Basin, enhancing the subsidence and increasing the accommodation space along the basin. As a result of the enhanced subsidence rates, meandering rivers developed, allowing the formation of extensive swamps deposits (currently coal beds). The excellent preservation of Entisols and Alfisols within the flood plain deposits suggests rapid channels migration and a humid climate during deposition. Moderate to highly mature channel sandstones support this contention, and point out the Central Cordillera of Colombia as the main source of sediment. Enhanced subsidence during this stage also prevented channels amalgamation and promoted both, high preservation of geomorphic elements and high diversity of sedimentary facies. This resulted in the most symmetric stratigraphic cycles of the entire Amagá Formation. The final stage of evolution of the Amagá Basin was related to the early stage of development of the late Miocene northwestern Andes tholeitic volcanism (from ˜10 to ˜8 Ma). The extensive thrusting and folding associated to this volcanism reduced the subsidence rates along the basin and thus the accommodation space. This permitted the development of highly aggradational braided rivers and promoted channels amalgamation. Little preservation of low energy facies, poor preservation of the geomorphic elements and a complete obliteration of important swamp deposits (coal beds) within the basin are reflected by the most asymmetric stratigraphic cycles of the whole formation. The presence of greenish/reddish flood plain deposits and Alfisols suggests a dry climate during this depositional stage. The presence of channel sandstones with high contents of volcanic rock fragments supports a dry climate, and suggests an incipient phase of the Combia tholeiitic magmatism present during deposition of the Amagá Formation. The subsequent eastward migration of the NW Andes magmatic arc (after ˜8 Ma) may have produced basin inversion and suppressed deposition along the Amagá Basin.

  16. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

    USGS Publications Warehouse

    Adams, G.P.; Runkle, Donna; Rea, Alan; Cederstrand, J.R.

    1997-01-01

    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries, maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma. Ground water in 1,305 square miles of Quaternary-age alluvial and terrace deposits along the the Cimarron River from Freedom to Guthrie is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. Alluvial and terrace deposits are composed of interfingering lenses of clay, sandy clay, and cross-bedded poorly sorted sand and gravel. The aquifer is composed of hydraulically connected alluvial and terrace deposits that unconformably overlie the Permian-age Formations. The aquifer boundaries are from a ground-water modeling report on the alluvial and terrace aquifer along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma and published digital surficial geology data sets. The aquifer boundary data set was created from digital geologic data sets from maps published at a scale of 1:250,000. The hydraulic conductivity values, recharge rates, and ground-water level elevation contours are from the ground-water modeling report. Water-level elevation contours were digitized from a map at a scale of 1:250,000. The maps were published at a scale of 1:900,000. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  17. A deep water turbidity origin for the Altuda Formation (Capitanian, Permian), Northwest Glass Mountains, Texas

    USGS Publications Warehouse

    Haneef, Mohammad; Rohr, D.M.; Wardlaw, B.R.

    2000-01-01

    The Altuda Formation (Capitanian) in the northwestern Glass Mountains is comprised of thin, even bedded limestones, dolostones, mixed clastic-carbonates, and silt/sandstones interbedded with basin-ward dipping wedge-shaped clinoforms of the Captian Limestone. The formation is characterized by graded bedding, planar laminations, flame structures, contorted/convolute bedding, horizontal branching burrows, and shelf-derived normal marine fauna. A detailed study of the Altuda Formation north of Old Blue Mountain, Glass Mountains, reveals that the formation in this area was deposited by turbidity currents in slope to basinal settings.

  18. Abundances of northwestern salamander larvae in montane lakes with and without fish, Mount Rainier National Park, Washington

    USGS Publications Warehouse

    Larson, Gary L.; Hoffman, Robert L.

    2002-01-01

    In Mount Rainier National Park, the northwestern salamander usually inhabits relatively large and deep lakes and ponds (average size = 0.3 ha; average depth > 2 m) that contain flocculent, organic bottom sediments and abundant coarse wood. Prior to 1970, salmonids were introduced into many of the park's lakes and ponds that were typical habitat of the northwestern salamander. The objective of this study was to compare, in lakes and ponds with suitable habitat characteristics for northwestern salamanders, the observed abundances of larvae in takes and ponds with and without these introduced salmonids. Day surveys of 61 lakes were conducted between 1993 and 1999. Fish were limited to takes and ponds deeper than 2 in. For the 48 lakes and ponds deeper than 2 in (i.e., 25 fishless lakes and 23 fish lakes), the mean and median observed abundances of northwestern salamander larvae in fishless lakes and ponds was significantly greater than the mean and median observed abundances of larvae in lakes and ponds with fish. Northwestern salamander larvae were not observed in 11 fish lakes. These lakes were similar in median elevation, surface area, and maximum depth to the fishless lakes. The 12 fish lakes with observed larvae were significantly lower in median elevation, larger in median surface area, and deeper in median maximum depth than the fishless lakes. Low to null observed abundances of northwestern salamander larvae in lakes and ponds with fish were attributed to a combination of fish predation of larvae and changes in larval behavior.

  19. New data on Upper Devonian stratigraphy of the northwestern Kuznetsk basin: Evidence from foraminifera and chondrichthyes

    NASA Astrophysics Data System (ADS)

    Timokhina, I. G.; Rodina, O. A.

    2015-09-01

    The thorough investigation of four Frasnian-Famennian (Upper Devonian) boundary sections along the right side of the Tom River northwest of Kemerovo yielded new data on the composition of their foraminiferal and ichthyofaunal assemblages. These data were used for development of the zonal foraminiferal scale for Upper Devonian deposits of the northwestern Kuznetsk coal basin and the first zonal scale for their subdivision on the basis of Elasmobranchii remains and for correlation of the examined sections between each other and with Upper Devonian sequences in other regions. The analysis of foraminiferal and ichthyofaunal assemblages, which are the most widespread in upper Frasnian sections of the northwestern Kuznetsk coal basin, made it possible to specify the regional stratigraphic model.

  20. Summary of reported agriculture and irrigation water use in northwestern Arkansas counties, 1991

    USGS Publications Warehouse

    Holland, T.W.; Manning, C.A.; Stafford, K.L.

    1993-01-01

    This report summarizes the 1991 water-use reporting through the Conservation District Offices in the following northwestern Arkansas counties: Baxter, Benton, Boone, Carroll, Cleburne, Fulton, Izard, Madison, Marion, Newton, Searcy, Sharp, Stone, Van Buren, and Washington. The number of withdrawal registrations for northwestern Arkansas counties was 106 (16 groundwater and 90 surface water). Water withdrawals reported during the registration process total 41.72 Mgal/d (0.74 Mgal/d groundwater and 40.98 Mgal/d surface water) for agriculture and 3.33 Mgal/d (0.27 Mgal/d groundwater and 3.06 Mgal/d surface water) for irrigation. The registration reports for 1991 indicate that this water was applied to 3,588 acres of land to irrigate rice, soybeans, cash grains, hay, oats, vegetables, sod, berries, fruit trees, and timber as well as for the agricultural use of animal aquaculture.

  1. Flooding in northwestern Hillsborough and southern Pasco counties, Florida, in 1979

    USGS Publications Warehouse

    Murphy, W.R., Jr.; Evans, R.P.; Whalen, James K.

    1984-01-01

    Heavy rainfall in the late spring and summer of 1979 caused severe flooding in northwestern Hillsborough and southern Pasco counties, including north Tampa. May 7-9 rainfall for some stations had a recurrence interval in excess of 100 years; the August and September rainfall total had a recurrence interval in excess of 50 years. The frequency of flooding of streams and lakes in the study area for the May 7-9 storm ranged from less than 2 to 25 years; for the period August to October, recurrence intervals ranged from 3 to 25 years. Areas of maximum flooding for a 48-square-mile area of northwestern Hillsborough and southern Pasco Counties are indicated on 12 sheets of aerial photography. Drainage patterns, control structures, drainage basins, and existing and proposed urban developments are shown and related to flooding. Stage and streamflow hydrographs are shown for 12 lakes and 2 streams. (USGS)

  2. Seasonal variation of turbulent diapycnal mixing in the northwestern Pacific stirred by wind stress

    NASA Astrophysics Data System (ADS)

    Jing, Zhao; Wu, Lixin

    2010-12-01

    Profiles of potential density obtained from CTD measurements along the northwestern Pacific section at 137°E are used to estimate both mean and seasonal variations of turbulent diapycnal mixing based on both a Thorpe-scale method and a finescale parameterization method. In general, away from the bottom, the estimated mean value along this section is about O(10-4 m2/s), indicating much stronger mixing in the Northwestern Pacific than in the stratified mid-latitude interior ocean. It is further found that the diffusivity can even exceed 10-4 m2/s around the rough topography. The turbulent diapycnal mixing in the upper ocean also displays a distinct seasonal variation with the amplitude decreasing with depth, bearing a statistically significant correlation with surface wind stress forcing. Our study here provides evidence for the important role of energy input from wind stress in sustaining the deep ocean mixing.

  3. Tularemia Outbreaks and Common Vole (Microtus arvalis) Irruptive Population Dynamics in Northwestern Spain, 1997-2014.

    PubMed

    Luque-Larena, Juan José; Mougeot, François; Roig, Dolors Vidal; Lambin, Xavier; Rodríguez-Pastor, Ruth; Rodríguez-Valín, Elena; Anda, Pedro; Escudero, Raquel

    2015-09-01

    During the last decades, large tularemia outbreaks in humans have coincided in time and space with population outbreaks of common voles in northwestern Spain, leading us to hypothesize that this rodent species acts as a key spillover agent of Francisella tularensis in the region. Here, we evaluate for the first time a potential link between irruptive vole numbers and human tularemia outbreaks in Spain. We compiled vole abundance estimates obtained through live-trapping monitoring studies and official reports of human tularemia cases during the period 1997-2014. We confirm a significant positive association between yearly cases of tularemia infection in humans and vole abundance. High vole densities during outbreaks (up to 1000 voles/hectare) may therefore enhance disease transmission and spillover contamination in the environment. If this ecological link is further confirmed, the apparent multiannual cyclicity of common vole outbreaks might provide a basis for forecasting the risk of tularemia outbreaks in northwestern Spain. PMID:26333034

  4. Geochemical soil sampling for deeply-buried mineralized breccia pipes, northwestern Arizona

    USGS Publications Warehouse

    Wenrich, K.J.; Aumente-Modreski, R. M.

    1994-01-01

    Thousands of solution-collapse breccia pipes crop out in the canyons and on the plateaus of northwestern Arizona; some host high-grade uranium deposits. The mineralized pipes are enriched in Ag, As, Ba, Co, Cu, Mo, Ni, Pb, Sb, Se, V and Zn. These breccia pipes formed as sedimentary strata collapsed into solution caverns within the underlying Mississippian Redwall Limestone. A typical pipe is approximately 100 m (300 ft) in diameter and extends upward from the Redwall Limestone as much as 1000 m (3000 ft). Unmineralized gypsum and limestone collapses rooted in the Lower Permian Kaibab Limestone or Toroweap Formation also occur throughout this area. Hence, development of geochemical tools that can distinguish these unmineralized collapse structures, as well as unmineralized breccia pipes, from mineralized breccia pipes could significantly reduce drilling costs for these orebodies commonly buried 300-360 m (1000-1200 ft) below the plateau surface. Design and interpretation of soil sampling surveys over breccia pipes are plagued with several complications. (1) The plateau-capping Kaibab Limestone and Moenkopi Formation are made up of diverse lithologies. Thus, because different breccia pipes are capped by different lithologies, each pipe needs to be treated as a separate geochemical survey with its own background samples. (2) Ascertaining true background is difficult because of uncertainties in locations of poorly-exposed collapse cones and ring fracture zones that surround the pipes. Soil geochemical surveys were completed on 50 collapse structures, three of which are known mineralized breccia pipes. Each collapse structure was treated as an independent geochemical survey. Geochemical data from each collapse feature were plotted on single-element geochemical maps and processed by multivariate factor analysis. To contrast the results between geochemical surveys (collapse structures), a means of quantifying the anomalousness of elements at each site was developed. This degree of anomalousness, named the "correlation value", was used to rank collapse features by their potential to overlie a deeply-buried mineralized breccia pipe. Soil geochemical results from the three mineralized breccia pipes (the only three of the 50 that had previously been drilled) show that: (1) Soils above the SBF pipe contain significant enrichment of Ag, Al, As, Ba, Ga, K, La, Mo, Nd, Ni, Pb, Sc, Th, U and Zn, and depletion in Ca, Mg and Sr, in contrast to soils outside the topographic and structural rim; (2) Soils over the inner treeless zone of the Canyon pipe show Mo and Pb enrichment anf As and Ga depletion, in contrast to soils from the surrounding forest; and (3) The soil survey of the Mohawk Canyon pipe was a failure because of the rocky terrane and lack of a B soil horizon, or because the pipe plunges. At least 11 of the 47 other collapse structures studied contain anomalous soil enrichments similar to the SBF uranium ore-bearing pipe, and thus have good potential as exploration targets for uranium. One of these 11, #1102, does contain surface mineralized rock. These surveys suggest that soil geochemical sampling is a useful tool for the recognition of many collapse structures with underlying ore-bearing breccia pipes. ?? 1994.

  5. Structural influence on hydrocarbon entrapment in the northwestern Red Sea, Egypt

    SciTech Connect

    Salah, M.G.; Alsharhan, A.S.

    1996-01-01

    The northwestern part of the Egyptian Red Sea has attracted the attention of many geologists because it lies at the triple junction of the main rifts between the Red Sea, the Gulf of Aqaba, and Gulf of Suez. The geometry of the fault system in this area of the basin clearly indicates an extensional setting. The area has a southwestward regional dip, and it has experienced more extension than the rest of the Gulf of Suez. Six tectonic stages, different in their stress history, sedimentary fill, and depositional setting, are recognized for the northwestern Red Sea: (1) Cambrian to early Cretaceous stage; (2) late Cretaceous to Oligocene stage; (3) early Miocene stage; (4) early to middle Miocene stage; (5) middle to late Miocene stage; and (6) post-Miocene stage. Magnetic, gravity, seismic, surface, and subsurface data from the northwestern Red Sea delineate several elongate structural highs separated by elongate troughs. Both highs and troughs have the same northwest-southeast direction as the clysmic trend. Some of the highs are dissected by cross elements that trend northeast-southwest and east-north-east-west-southwest and laterally offset these highs. The tectonic framework of the northwestern sector of the Red Sea had a significant influence on hydrocarbon generation, migration, and accumulation. The evidence for this influence includes the following: (1) the troughs form the main source kitchens where the Precambrian basement rocks are present at depths exceeding 4877 in (e.g., Gemsa Trough); (2) the magnitude of throw on the clysmic fault is critical in the entrapment mechanisms; (3) the cross elements play a major role in the hydrocarbon migration and accumulation because they truncate the extension of most of the oil fields and form their bounding faults; and (4) all the discovered oil fields in the study area are structural and/or combination traps and show good matches to the magnetic anomalies.

  6. Draft Genome Sequence of Pseudomonas fluorescens Strain ET76, Isolated from Rice Rhizosphere in Northwestern Morocco.

    PubMed

    Aarab, Saida; Arakrak, Abdelhay; Ollero, Francisco Javier; Megías, Manuel; Gomes, Douglas Fabiano; Ribeiro, Renan Augusto; Hungria, Mariangela

    2016-01-01

    Pseudomonas fluorescens ET76 was isolated from rice rhizosphere in northwestern Morocco. Its draft genome was estimated to be 6,681,652 bp with 5,789 coding sequences (CDSs). Genes encoding for type I to VI secretion systems, PvdQ, proteases, siderophores, hydrogen cyanide synthase, ACC-deaminase, among others, highlight its potential use in biological control of plant pathogens. PMID:27198014

  7. The oceanic crustal structure of the Northwestern Subbasin in the South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Z.; Li, J.; Ruan, A.; Ding, W.; Zhang, T.; Niu, X.

    2011-12-01

    The oceanic crustal structure of the Northwestern Sub-basin (NWSB) area in the South China Sea (SCS) was inverted using wide-angle seismic survey line data across the entire region and on both sides of its bounding continental margin. The survey line extended 484 km in length. A total of 14 Ocean Bottom Seismometers (OBS) were deployed at intervals of 30 km, with a volume of the combined gun array of 5160 in3. The crustal velocity structure of the northwestern sub-basin area was acquired through integration of multi-channel seismic data. OBS data were processed and modeled initially using ray tracing inversion techniques. Results indicate that crustal thickness under the continental slope decreases from 21 km to 11 km, crustal thickness of NWSB is 7.7 km, and the depth to the Moho ascends from 21 km under the upper continental slope to 11 km under the middle basin. The oceanic crustal structure of NWSB is similar to that the Eastern Sub-basin (ESB). This oceanic structure has a thicker layer 1 (sedimentary layer) and thinner layer 2. These characteristics are especially clear in ESB, which differs somewhat from typical oceanic crustal structure. Because the seafloor spreading period of the northwestern sub-basin was short, layer 2 might have experienced asymmetrical basalt magma flows, which may have blurred the magnetic anomaly lineations of the northwestern sub-basin. By comparing with the oceanic crustal structure of the OBS survey line near Liyue Bank, we suggest that these two lines could be conjugate pair. Acknowledgements This study was supported by the National Key Basic Research Project of China (Grant No. 2007CB411701), Scientific Research Fund of the Second Institute of Oceanography, SOA(Grant No. JT1101), Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (Grant No.MSGL09-07).

  8. Was the Coppermine Homocline of northwestern Canada uplifted as part of a Middle Proterozoic forebulge

    SciTech Connect

    Cook, F.A. )

    1991-01-01

    Application of the principles of elastic plate bending to subsurface geometric information and outcrop in northwestern Canada suggests that Proterozoic crust was loaded and deflected during orogenic activity between about 1.6 and 1.1 Ga. Exposed Hudsonian (ca. 1.8-2.0 Ga) basement separating younger but coeval stratigraphic sequences in the Coppermine Homocline on the west and Bathurst Inlet on the east can be explained as a forebulge associated with the loading.

  9. Oil and gas seeps within Absaroka volcanics of northwestern Wyoming

    SciTech Connect

    Sundell, K.A.; Love, J.D.

    1986-08-01

    Three new occurrences of asphaltic, liquid, and gaseous hydrocarbons have been discovered in the southeastern Absaroka Range. These petroleum seeps are 40 to 110 mi southeast of previously known seeps within Eocene volcaniclastic rocks at Calcite Springs, Tower Junction, and Sweetwater Mineral Springs, Wyoming. The Middle Fork seep and Castle Rocks seep are near the headwaters of the Middle and North Forks of Owl Creek, respectively. The Chimney Rock asphalt locality is along the South Fork of the Wood River. Water samples from the Middle Fork seep fluoresce greenish-orange and contain 6 to 8 mg/L of extractable bituminous hydrocarbons. An iridescent oily film forms on the water surface and on abundant gas bubbles trapped within moss. The Castle Rocks seep, in Quaternary gravels along the bed of the North Fork of Owl Creek, shows iridescent oily bubbles in emerging spring water and black, sooty lenses of carbon-coated gravels in overlying dry deposits. The Middle Fork and Castle Rocks seeps rise through thin Quaternary deposits overlying the Aycross Formation (Eocene). The Chimney Rock asphalt locality is in a northwest-trending paleovalley fill consisting of highly deformed masses of volcanic strata in the Tepee Trail and Wiggins Formations. Thin (< 1 in. thick), discontinuous, subvertical veins of asphaltum cut through these rocks. These petroleum seeps demonstrate migration of hydrocarbons after the volcaniclastic strata were emplaced and suggest that significant petroleum resources may occur elsewhere within Eocene volcaniclastic rocks and/or within Mesozoic and Paleozoic reservoirs beneath the volcanics.

  10. Time variable bottom water outflow in the Northwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Kanzow, Torsten; Rohardt, Gerd

    2015-04-01

    The Antarctic Bottom Water (AABW) has shown widespread warming in recent decades, with implications for sea level rise and global heat uptake. Anomalously warm AABW has recently been reported to have reached the Brazil basin in the South Atlantic, while the warming further south partly seems to have come to a halt. The Weddell Sea represents the primary source of Antarctic Bottom Water (AABW) formation in the Southern Ocean. More than 60% of the AABW are supplied by Weddell Sea Deep Water, of which Weddell Sea Bottom Water (WSBW) is the main source. WSBW descends down the continental slope along the western margin of the Weddell Sea as a northward flowing plume, thereby entraining warmer ambient waters. The plume has been observed using moored current meters and temperature sensors between 1989 and 1998 and between 2005 and 2012 near the tip of the Antarctic Peninsula, complemented by repeated cross-slope CTD sections along the mooring array. In this study we extend the WSBW volume transport and temperature time series of Fahrbach et al. (2001) originally covering the 1989-1998 interval by the more recent period. We will report on both seasonal to inter-annual variability and possible longer-term trends in both volume transport and temperature of WSBW. The results will be discussed in the context of changes in the source areas of WSBW, such as the breakup of parts of the Larsen Ice Shelf on the eastern Arctic Peninsula, possibly fueling the formation dense water on the shelf.

  11. Newly found submerged reefs on the Miyako-Sone platform, Ryukyu Arc, northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Arai, K.; Matsuda, H.; Sasaki, K.; Machiyama, H.; Inoue, T.; Iryu, Y.

    2013-12-01

    Bathymetric mapping and observations of the seafloor using a remotely operated vehicle were carried out on the top of the Miyako-Sone submarine platform, northeast of Miyako-jima, Ryukyu Islands, northwestern Pacific. The high-resolution bathymetric map provides a detailed geomorphology and spatial distribution of submerged reefs and terraces on the platform. Our observations show that a submerged reef occurs at a water depth of ca. 55 m as a barrier reef that are up to 500 m across (from east to west) and 1,000 m lonng (from north to south) with a prominent ridge structure (reef crest). The submerged reef deepens westward from the crest along which spurs and grooves are well developed. A shallow lagoon extends on the east of the crest. Submersible observations confirm that the submerged reef now serves a hard substrate on which soft corals and algae grow. Terraces form at a water depth of ca. 110 m around a submerged reef on the northwestern Miyako-Sone platform. Submersible observations show the terrace surface is extensivbely covered with modern rhodoliths and living larger benthic foraminifers. Well-preserved coral-reef topography likely indicates limited sediment transportion from Miyako-jima and Okinwa-jima islands to the Miyako-Sone submarine platform. We plan to provide chronological constraint by direct sampling from the submerged reef and terraces, which enable to delineate a global deglacial sea-level history especially during early deglacial times in the northwestern Pacific.

  12. Is There any Relationship Between the Santa Elena Depression and Chicxulub Impact Crater, Northwestern Yucatan Peninsula, Mexico?

    NASA Astrophysics Data System (ADS)

    Lefticariu, L.

    2005-05-01

    The Terminal Cretaceous Chicxulub Impact Crater had a strong control on the depositional and diagenetic history of the northern Yucatan Platform during most of the Cenozoic Era. The Chicxulub Sedimentary Basin (henceforth Basin), which approximately coincides with the impact crater, is circumscribed by a concentration of karstic sinkholes known as the Ring of Cenotes. Santa Elena Depression (henceforth Depression) is the name proposed for the bowl-shaped buried feature, first contoured by geophysical studies, immediately south of the Basin, in the area where the Ticul 1 and UNAM 5 wells were drilled. Lithologic, petrographic, and biostratigraphic data on PEMEX, UNAM, and ICDP cores show that: 1) Cenozoic deposits are much thicker inside the Basin than inside the Depression, 2) in general, the Cenozoic formations from inside the Depression are the thickest among those outside the Basin, 3) variably dolomitized pelagic or outer-platform wackestone or mudstone occur both inside the Basin and Depression, 4) the age of the deeper-water sedimentary carbonate rocks is Paleocene-Eocene inside the Basin and Paleocene?-Early Eocene inside the Depression, 5) the oldest formations that crop out are of Middle Eocene age at the edge of the Basin and Early-Middle Eocene age inside the Depression, 6) saline lake deposits, that consist chiefly of anhydrite, gypsum, and fine carbonate, and also contain quartz, chert, clay, zeolite, potassium feldspar, pyrite, and fragments of wood, are present in the Cenozoic section of the UNAM 5 core between 282 and 198 m below the present land surface, 7) the dolomite, subaerial exposure features (subaerial crusts, vugs, karst, dedolomite), and vug-filling cement from the Eocene formations are more abundant inside the Depression than inside the Basin. The depositional environments that are proposed for explaining the Cenozoic facies succession within the Santa Elena Depression are: 1) deeper marine water (Paleocene?-Early Eocene), 2) relatively isolated saline lake (Middle Eocene), and 3) shallow marine water (Middle-Late Eocene?). In places, the deeper-water facies are similar to those within the Chicxulub Sedimentary Basin. The shallow-water facies is similar to those occurring outside the Basin. In general, quartz and silicates are rare in the Cenozoic sedimentary carbonate of the northwestern Yucatan Peninsula. Therefore, their presence in the UNAM 5 core could be attributed to either impact breccia reworking or silicic volcanic processes. Quartz, chert, zeolite, and clay also are common in the suevite breccia of both Yax-1 and UNAM 5 cores. The fact that the Santa Elena Depression was a distinct sedimentary basin during much of the Paleogene could be explained by any or a combination of the following hypotheses: 1) In spite of being located outside the cenote ring, the Depression is a sub-basin of the larger and deeper Chicxulub Sedimentary Basin and is therefore located within the Chicxulub Impact Crater, 2) the Depression coincides with an impact crater distinct from the Chicxulub Impact Crater, 3) the Depression formed after the Chicxulub bolide impact due to slumping, crater wall failure, or larger-scale tectonic processes. The lack of conclusive evidence for multiple impact breccia layers in the northwestern Yucatan Peninsula, corroborated with the presence on top of the impact breccia from UNAM 5 core of deeper-water limestone similar to that of Late Paleocene-Early Eocene age from Yax-1 core, would be more consistent with either the first or third hypothesis.

  13. A late Jurassic pterosaur (Reptilia, Pterodactyloidea) from northwestern Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Codorniú, Laura; Gasparini, Zulma; Paulina-Carabajal, Ariana

    2006-03-01

    A small to medium-sized pterodactyloid pterosaur (wingspan approximately 1.10 m) from the Upper Jurassic (middle-late Tithonian) marine deposits of the Vaca Muerta Formation of Patagonia (Los Catutos area, central Neuquén Province, Argentina) is reported. The specimen lacks the skull but constitutes a nearly complete postcranial skeleton, which includes cervical and dorsal vertebrae; a few thoracic ribs; both pectoral girdles; the left pelvic girdle; a proximal right wing (humerus, ulna, and radius) and metacarpal IV; a left wing that lacks only wing phalanx four; and both hindlimbs, the right one without the foot. Ontogenetic features suggest that the new fossil corresponds to a relatively mature individual, probably a subadult. Observed characters support its assignment to the Archaeopteroactyloidea, a basal clade within the Pterodactyloidea. This specimen is the second pterosaur from Los Catutos and the most complete Jurassic pterosaur so far known from South America.

  14. The Cocos Ridge drives collision of Panama with northwestern South America

    NASA Astrophysics Data System (ADS)

    LaFemina, Peter; Govers, Rob; Mora-Paez, Hector; Geirsson, Halldor; Cmacho, Eduardo

    2015-04-01

    The collision of the Panamanian isthmus with northwestern South America is thought to have initiated as early as Oligocene - Miocene time (23-25 Ma) based on geologic and geophysical data and paleogeographic reconstructions. This collision was driven by eastward-directed subduction beneath northwestern South America. Cocos - Caribbean convergence along the Middle America Trench, and Nazca - Caribbean oblique convergence along the South Panama Deformed Belt have resulted in complex deformation of the southwestern Caribbean since Miocene - Pliocene time. Subduction and collision of the aseismic Cocos Ridge is thought to have initiated <3.5 Ma and has been linked to: 1) late Miocene-Pliocene cessation of volcanism and uplift of the Cordillera de Talamanca; 2) Quaternary migration of the volcanic arc toward the back-arc; 3) Quaternary to present deformation within the Central Costa Rica Deformed Belt; 4) Quaternary to present shortening across the fore-arc Fila Costeña fold and thrust belt and back-arc North Panama Deformed Belt (NPDB); 5) Quaternary to present outer fore-arc uplift of Nicoya Peninsula above the seamount domain, and the Osa and Burica peninsulas above the ridge; and 6) Pleistocene to present northwestward motion of the Central American Fore Arc (CAFA) and northeastward motion of the Panama Region. We investigate the geodynamic effects of Cocos Ridge collision on motion of the Panama Region with a new geodynamic model. The model is compared to a new 1993-2015 GPS-derived three-dimensional velocity field for the western Caribbean and northwestern South America. Specifically, we test the hypotheses that the Cocos Ridge is the main driver for upper plate deformation in the western Caribbean. Our models indicate that Cocos Ridge collision drives northwest-directed motion of the CAFA and the northeast-directed motion of the Panama Region. The Panama Region is driven into the Caribbean across the NPDB and into northwestern South America, which is also converging with the Panama Region, pushing it toward the west-northwest. Therefore, modern collision of Panama with northwestern South America is driven by collision of the Cocos Ridge.

  15. Cenozoic tectonic evolution of the basin and range province in northwestern Nevada

    USGS Publications Warehouse

    Colgan, J.P.; Dumitru, T.A.; Reiners, P.W.; Wooden, J.L.; Miller, E.L.

    2006-01-01

    A regional synthesis of new and existing geologic and thermochronologic data document late Cretaceous - early Cenozoic regional erosion, Oligocene - Miocene volcanism, and subsequent late Miocene extension of the Basin and Range Province in northwestern Nevada and northeastern California. Across an ???220-km-wide region between the Santa Rosa and Warner Ranges, conformable sequences of 35 to 15 Ma volcanic rocks are cut by only a single generation of high-angle normal faults that accommodated ???23 km of total east-west extension (???12%). Fission-track, (U-Th)/He, geologic, and structural data from the Pine Forest Range show that faulting there began at 11 to 12 Ma, progressed at a relatively constant rate until at least 3 Ma, and has continued until near the present time. Extension in the Santa Rosa Range to the east took place during the same interval, although the post-6 Ma part of this history is less well constrained. Less complete constraints from adjacent ranges permit a similar timing for faulting, and we infer that extensional faulting in northwestern Nevada began everywhere at 12 Ma and has continued up to the present. Faulting in the Warner Range in northeastern California can only be constrained to have begun between 14 and 3 Ma, but may represent westward migration of Basin and Range extension during the Pliocene. Compared to the many parts of the Basin and Range in central and southern Nevada, extension in northwestern Nevada began more recently, is of lesser total magnitude, and was accommodated entirely by high-angle normal faults. Fission-track data document Late Cretaceous unroofing of Cretaceous (115 - 100 Ma) granitic basement rocks in northwestern Nevada, followed by a long period of relative tectonic quiescence that persisted through Oligocene and Miocene volcanism until the onset of Basin and Range extension at ???12 Ma. The low magnitude of extension (12%) and early Tertiary stability suggest that the modern ???31 km thick crust in northwestern Nevada was only slightly thicker (???35 km) prior to extension at 12 Ma, and was no thicker than ???38 km in the Late Cretaceous. This stands in contrast to other parts of the Basin and Range, where the crust was thickened to at least 45 to 50 km by Cretaceous thrusting and subsequently thinned to ???30 km by large magnitude (>50%) extension.

  16. Early Evidence of Acheulean Settlement in Northwestern Europe - La Noira Site, a 700 000 Year-Old Occupation in the Center of France

    PubMed Central

    Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe

    2013-01-01

    The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45th parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage from la Noira thus provides behavioral and technological data on early Acheulean occupation in Europe and contributes to our understanding of the diffusion of this tradition. PMID:24278105

  17. Early evidence of Acheulean settlement in northwestern Europe--la Noira site, a 700,000 year-old occupation in the center of France.

    PubMed

    Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe

    2013-01-01

    The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45(th) parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage from la Noira thus provides behavioral and technological data on early Acheulean occupation in Europe and contributes to our understanding of the diffusion of this tradition. PMID:24278105

  18. Numerical simulation of the High Plains regional aquifer, northwestern Oklahoma

    USGS Publications Warehouse

    Havens, J.S.; Christenson, S.C.

    1984-01-01

    The High Plains aquifer consists of the Tertiary Ogallala Formation and overlying Quaternary alluvium and terrace deposits together with parts of underlying rocks. Before extensive irrigation in the 1960's, recharge from precipitation was balanced by natural discharge. Baseflow was estimated as approximately 118 cubic feet per second in 1980. A finite-difference digital model simulated flow in the aquifer. Recharge was adjusted so that 1980 baseflow was 118 cubic feet per second. Recharge in the eastern half of the modeled area was 0.45 inch per year and one-half this value in the western half. Three hydraulic conductivity zones were used: 19.3 feet per day in the east; 16.2 feet per day in the center; and 8.28 feet per day in the west. A specific yield of 14.7 percent was used. The calibrated model gave a mean difference between predevelopment modeled and measured heads of -0.044 foot. Using 1980 pumping rates, the model was used to predict 1993 and 2020 water in storage and saturated thickness. The calculated water in storage , in million acre-feet, in 1941 (predevelopment) was 135.2; in 1980, 121.9; in 1993, 112.7; and in 2020, 96.2. (USGS)

  19. Late Pleistocene Vertebrates and Other Fossils from Epiguruk, Northwestern Alaska

    NASA Astrophysics Data System (ADS)

    Hamilton, Thomas D.; Ashley, Gall M.; Reed, Katherine M.; Schweger, Charles E.

    1993-05-01

    Sediments exposed at Epiguruk, a large cutbank on the Kobuk River about 170 km inland from Kotzebue Sound, record multiple episodes of glacial-age alluviation followed by interstadial downcutting and formation of paleosols. Vertebrate remains from Epiguruk include mammoth, bison, caribou, an equid, a canid, arctic ground squirrel, lemmings, and voles. Radiocarbon ages of bone validated by concordant ages of peat and wood span the interval between about 37,000 and 14,000 yr B.P. The late Pleistocene pollen record is dominated by Cyperaceae, with Artemisia, Salix, Betula, and Gramineae also generally abundant. The fossil record from Epiguruk indicates that the Kobuk River valley supported tundra vegetation with abundant riparian willows during middle and late Wisconsin time. Large herbivores were present during the height of late Wisconsin glaciation as well as during its waning stage and the preceding interstadial interval. The Kobuk River valley would have been a favorable refugium for plants, animals, and possibly humans throughout the last glaciation.

  20. Costs of Nutrient Losses in Priceless Soils Eroded From the Highlands of Northwestern Ethiopia

    NASA Astrophysics Data System (ADS)

    Gebreselassie, Yihenew; Belay, Yihenew

    2014-05-01

    Soils formation is a geomorphic process that takes place through the interaction of soil forming factors in several hundreds and thousands of years. However, land degradation and soil erosion is consistently taking place in the horn of Africa washing away this priceless product in short period of time. The scale of the problem dramatically increased due to the increase in deforestation, overgrazing, over-cultivation, inappropriate farming practices, and increasing human population. Several research results were published in the region showing the extent of land degradation and soil loss. However, little attempt has been done to estimate the nutrient loss in monitory terms which made it difficult for policy makers to properly understand the extent of the problem. A study was, therefore, conducted in 2011 to estimate soil and nutrient losses caused by water erosion and predict nutrient replacement costs on different land use types and slope classes at Harfetay watershed, Northwestern Ethiopia. The revised soil loss equation (RUSLE) was used to estimate the soil loss from the different land uses and slope classes in watershed. Moreover, nutrient loss from similar units was calculated by multiplying the in situ nutrient concentration of soil samples by the estimated soil loss using RUSLE. The replacement costs of nutrient losses were calculated by multiplying the nutrient loss with the price of available nutrients in urea and diammonium phosphate. The estimate of the RUSLE indicated that the average soil losses in the study watershed were 119 tons ha-1 year-1 for non-conserved crop land, 23 tons for conserved farmlands, 23 tons for forest and shrub lands, 19 tons for grazing lands, and 6 tons for plantation forest. The mean soil loss for lower slope classes (<15%), middle slope classes (15-30%) and upper slope classes (>30%) were 30.11, 48.09 and 57.22 tons ha-1 year-1, respectively. The highest losses of total nitrogen (154.7 kg ha-1 year-1), available phosphorus (1.84 kg ha-1 year-1), and organic matter (1677.9 kg ha-1 year-1) were obtained from non-conserved cropland. Conversely, the lowest values of the same parameters were registered from the land covered with plantation forest. Comparing slope classes for non conserved cropland, organic matter and nutrient losses were higher in upper slope classes followed by middle and lower ones. The replacement cost of available N and available P for non-conserved cropland, conserved cropland, forest/shrub lands, grazing lands and plantations were 121, 36, 27, 32 and 13 Birr ha-1 year-1, respectively (1USD = 19 Birr); and the weighted mean replacement cost in the watershed was estimated to be 98 Birr ha-1 year-1 which is about 20% of the cost of fertilizer applied per individual farmers in the watershed. From the study it was possible to conclude that conversion of forest lands and plantation forests to cropland causes serious soil and nutrient losses. Construction of conservation structures on cropland, however, will reduce soil and nutrient losses. To halt soil and nutrient loss and ensure sustainable land management and agricultural development in the Harfetay watershed and similar watersheds, policy and development interventions including increasing awareness of farmers on of soil and nutrient losses, enforcing land use policies and expanding bio-physical soil conservation practices are required.

  1. Paleozoic-early Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China

    USGS Publications Warehouse

    Rui, Z.; Goldfarb, R.J.; Qiu, Y.; Zhou, T.; Chen, R.; Pirajno, F.; Yun, G.

    2002-01-01

    The late Paleozoic-early Mesozoic tectonic evolution of Xinjiang Autonomous Region, northwestern China provided a favorable geological setting for the formation of lode gold deposits along the sutures between a number of the major Eastern Asia cratonic blocks. These sutures are now represented by the Altay Shan, Tian Shan, and Kunlun Shan ranges, with the former two separated by the Junggar basin and the latter two by the immense Tarim basin. In northernmost Xinjiang, final growth of the Altaid orogen, southward from the Angara craton, is now recorded in the remote mid- to late Paleozoic Altay Shan. Accreted Early to Middle Devonian oceanic rock sequences contain typically small, precious-metal bearing Fe-Cu-Zn VMS deposits (e.g. Ashele). Orogenic gold deposits are widespread along the major Irtysh (e.g. Duyolanasayi, Saidi, Taerde, Kabenbulake, Akexike, Shaerbulake) and Tuergen-Hongshanzui (e.g. Hongshanzui) fault systems, as well as in structurally displaced terrane slivers of the western Junggar (e.g. Hatu) and eastern Junggar areas. Geological and geochronological constraints indicate a generally Late Carboniferous to Early Permian episode of gold deposition, which was coeval with the final stages of Altaid magmatism and large-scale, right-lateral translation along older terrane-bounding faults. The Tian Shan, an exceptionally gold-rich mountain range to the west in the Central Asian republics, is only beginning to be recognized for its gold potential in Xinjiang. In this easternmost part to the range, northerly- and southerly-directed subduction/accretion of early to mid-Paleozoic and mid- to late Paleozoic oceanic terranes, respectively, to the Precambrian Yili block (central Tian Shan) was associated with 400 to 250 Ma arc magmatism and Carboniferous through Early Permian gold-forming hydrothermal events. The more significant resulting deposits in the terranes of the southern Tian Shan include the Sawayaerdun orogenic deposit along the Kyrgyzstan border and the epithermal and replacement deposits of the Kanggurtag belt to the east in the Chol Tagh range. Gold deposits of approximately the same age in the Yili block include the Axi hot springs/epithermal deposit near the Kazakhstan border and a series of small orogenic gold deposits south of Urumqi (e.g. Wangfeng). Gold-rich porphyry copper deposits (e.g. Tuwu) define important new exploration targets in the northern Tian Shan of Xinjiang. The northern foothills of the Kunlun Shan of southern Xinjiang host scattered, small placer gold deposits. Sources for the gold have not been identified, but are hypothesized to be orogenic gold veins beneath the icefields to the south. They are predicted to have formed in the Tianshuihai terrane during its early Mesozoic accretion to the amalgamated Tarim-Qaidam-Kunlun cratonic block.

  2. Lateglacial and early Holocene vegetation development in the Gutaiului Mountains, northwestern Romania

    NASA Astrophysics Data System (ADS)

    Björkman, Leif; Feurdean, Angelica; Cinthio, Kajsa; Wohlfarth, Barbara; Possnert, Göran

    2002-04-01

    Pollen analyses and AMS 14C measurements were performed on lacustrine sediments and peat sequences from two former crater lakes (Preluca Tiganului, Steregoiu) situated in the Gutaiului Mountains in northwestern Romania, in order to reconstruct the vegetation development during the Lateglacial and Early Holocene. Before c. 14,700 cal. years BP (GS-2) open vegetation with shrubs ( Salix, Juniperus), grasses and herbs (e.g. Artemisia and Chenopodiaceae) prevailed in the area. Around c. 14,700 cal. years BP and coinciding with the beginning of GI-1e, Pinus expanded, and patchy vegetation with scattered Pinus stands developed. The last 100 years of GI-1e (14,150-14,050 cal. years BP) were characterised by an increase in Pinus and Betula and an expansion of open forest communities. This development was shortly interrupted between 14,050 and 13,800 cal. years BP (likely corresponding to the cold phase GI-1d), when the tree cover became reduced and open vegetation with scattered Pinus individuals became frequent. The period with a significant expansion of Betula and Picea and the formation of an open forest (including Pinus and Ulmus), which took place between 13,800 and c. 12,950 cal. years BP, is tentatively correlated with GI-1c-a. A renewed reduction in tree cover (decrease of Picea and Betula, disappearance of Ulmus) started at ˜12,950 cal. years BP and at 12,600 cal. years BP forest stands were rapidly replaced by open vegetation communities with low shrubs ( Salix, Juniperus), grasses and herbs (e.g. Artemisia and Chenopodiaceae). The period between 12,900 and 11,500 is correlated with the cold phase GS-1. At 11,500 cal. years BP, most likely as a response to the warmer climatic conditions at the beginning of the Holocene, an expansion of Betula and Alnus and, slightly later, also of Ulmus can be observed. Between 11,500 and 11,250 cal. years BP, open forests with Betula, Pinus and Ulmus were widespread in the area. At 11,250 cal. years BP dense forests dominated by Ulmus replaced the open forest type. Around 10,700 cal. years BP Quercus, Tilia and Fraxinus expanded strongly, and Acer and Corylus became established. Mixed deciduous forest with Picea dominated the upland vegetation between 10,700 and 10,150 cal. years BP. At 10,150 cal. years BP Corylus increased significantly and between 10,150 and 8500 cal. years BP, dense mixed deciduous forests with Picea and Corylus were abundant in the area. Climatic fluctuations seem to have been the driving force behind vegetation changes during the Lateglacial period, while the forest development during the Early Holocene was mainly driven by migrational and successional processes.

  3. Bedout basement rise, offshore northwestern Australia: evidence of an unshocked mafic volcanic hyaloclastite volcanic breccia

    NASA Astrophysics Data System (ADS)

    Glikson, A.

    2004-12-01

    Core samples from Bedout-1 (3035.8-3044.95 m.), Bedout basement rise, offshore northwestern Australia, were examined by optical microscopy, SEM, EDS and WDS spectrometry. At this stratigraphic depth level Becker et al. (2004) interpret cryptocrystalline alteration zones around and within plagioclase in terms of shock-induced transformation of feldspar into diaplectic maskelynite glass _u postulating a ~200 km-large impact structure and thereby an impact connection of the Permian-Triassic boundary mass extinction. However, the breccia is dominated by fragments of microlitic basalt and ophitic-textured dolerite with well preserved igneous textures, showing no evidence of shock metamorphism. Euhedral pseudomorphs of chlorite and amphibole, probably after pyroxene, protrude into or are enveloped by euhedral albite-twinned calcic plagioclase (andesine to bytownite). Minor phases include euhedral ilmenite needles and subhedral magnetite grains. Plagioclase is altered by cryptocrystalline albite and microcrystalline albite-chlorite matrix along crystal boundaries, along twin lamella and within internal oscillatory crystal zones, consistent with burial metamorphosed hydrovolcanic basalts and spilites (e.g. Amstutz, 1974). The volcanic fragments are set within, and injected by, microcrystalline intergranular mesostasis of mixed mineral fragments and volcanic meta-glass. Becker et al. (2004) refer to the breccia in part as product of Mg-rich sediments (e.g. dolomites). However, apart from the pristine igneous textures of the breccia, the transition element levels (chlorite in dolerite fragment "C Ni 97-160 ppm; Co 75-152 ppm; Cu 69-204 ppm; mesostasis "C Ni 29-45 ppm; Co 18-52 ppm; Cu 26-110 ppm) are consistent with Fe-rich basalts but exceed common abundances in carbonates and marls (BVTP, 1981; Wedepohl, 1978). No shock metamorphic features, such as planar deformation features (PDF), are observed in the feldspar or in any other phases. No criteria for discriminating maskelynite and volcanic meta-glass are indicated by Becker et al. (2004). As PDF formation (10-35 GPa) necessarily precedes diaplectic transformation into maskelynite (35-45 GPa) (French, 1998), a presence of maskelynite is inconsistent with the absence of PDF in the plagioclase _u a phase prone to the development of shock effects (e.g. Mory, 2000). Little evidence exists for the hydrothermal activity which typically follows impact events. However, thanks to a partial development of a rim syncline-like structure in Triassic sediments around the Bedout rise, further testing of the origin of this remarkable structure is warranted. Amstutz, G.C., 1974, Spilites and Spilitic Rocks, Springer-Verlag, Berlin; Becker, L. et al., 2004, Science Express, 13.5.04; BVSP - Basaltic Volcanism Study Project, 1981, Pergamon; French, B.M., 1998, Traces of Catastrophe, Lunar and Planetary Contributions 954; Mory et al., 2000, Earth and Planetary Science, 177, 119-128; Wedepohl, K.H., Handbook of Geochemistry, Springer-Verlag, 1978.

  4. Geologic Map of the Mount Trumbull 30' X 60' Quadrangle, Mohave and Coconino Counties, Northwestern Arizona

    USGS Publications Warehouse

    Billingsley, George H.; Wellmeyer, Jessica L.

    2003-01-01

    The geologic map of the Mount Trumbull 30' x 60' quadrangle is a cooperative product of the U.S. Geological Survey, the National Park Service, and the Bureau of Land Management that provides geologic map coverage and regional geologic information for visitor services and resource management of Grand Canyon National Park, Lake Mead Recreational Area, and Grand Canyon Parashant National Monument, Arizona. This map is a compilation of previous and new geologic mapping that encompasses the Mount Trumbull 30' x 60' quadrangle of Arizona. This digital database, a compilation of previous and new geologic mapping, contains geologic data used to produce the 100,000-scale Geologic Map of the Mount Trumbull 30' x 60' Quadrangle, Mohave and Coconino Counties, Northwestern Arizona. The geologic features that were mapped as part of this project include: geologic contacts and faults, bedrock and surficial geologic units, structural data, fold axes, karst features, mines, and volcanic features. This map was produced using 1:24,000-scale 1976 infrared aerial photographs followed by extensive field checking. Volcanic rocks were mapped as separate units when identified on aerial photographs as mappable and distinctly separate units associated with one or more pyroclastic cones and flows. Many of the Quaternary alluvial deposits that have similar lithology but different geomorphic characteristics were mapped almost entirely by photogeologic methods. Stratigraphic position and amount of erosional degradation were used to determine relative ages of alluvial deposits having similar lithologies. Each map unit and structure was investigated in detail in the field to ensure accuracy of description. Punch-registered mylar sheets were scanned at the Flagstaff Field Center using an Optronics 5040 raster scanner at a resolution of 50 microns (508 dpi). The scans were output in .rle format, converted to .rlc, and then converted to ARC/INFO grids. A tic file was created in geographic coordinates and projected into the base map projection (Polyconic) using a central meridian of -113.500. The tic file was used to transform the grid into Universal Transverse Mercator projection. The linework was vectorized using gridline. Scanned lines were edited interactively in ArcEdit. Polygons were attributed in ArcEdit and all artifacts and scanning errors visible at 1:100,000 were removed. Point data were digitized onscreen. Due to the discovery of digital and geologic errors on the original files, the ARC/INFO coverages were converted to a personal geodatabase and corrected in ArcMap. The feature classes which define the geologic units, lines and polygons, are topologically related and maintained in the geodatabase by a set of validation rules. The internal database structure and feature attributes were then modified to match other geologic map databases being created for the Grand Canyon region. Faults were edited with the downthrown block, if known, on the 'right side' of the line. The 'right' and 'left' sides of a line are determined from 'starting' at the line's 'from node' and moving to the line's end or 'to node'.

  5. Morphologic Map of Glacial and Periglacial Features in the Northwestern Argyre Basin, Mars

    NASA Astrophysics Data System (ADS)

    Raack, Jan; Hiesinger, Harald; Reiss, Dennis

    2010-05-01

    Previous studies of morphologic features in the Argyre Basin suggested that they could have been formed by glacial processes [1,2,3]. Possible evidence for a past glaciation of the Argyre basin include landforms interpreted as e.g., eskers, drumlins, moraines and kettles [1]. Glacial features like lineated grooves, streamlined hills, U-shaped valleys and semicircular embayments (possible cirques) are consistent with extensive glacial modifications in the Argyre Basin [3]. For our study we chose a mountainous terrain in the northwestern part of Argyre basin (44°S - 48.5°S and 323.5°E - 329°E) to reinvestigate the glacial inventory and the history and evolution of glacial landforms and processes in this region with new, higher resolution image data. We produced a detailed morphologic map with 13 morphologic units based on High Resolution Stereo Camera (HRSC), Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE) imagery. Large areas of the study region are covered with dissected and intact mantle material units. The smooth and flat mantle interpreted to be a dust/ice mantle [4] occurs in protected depressions or on southern, pole-facing slopes, which receive less insolation. Glacial/periglacial features (glaciers and viscous flow features) and fluvial features (gullies) are directly related to the dust/ice layer. Gullies are the most common fluvial features in the mapped area. They occur in areas where the mantle appears to be thick. The most obvious characteristics of the gullies are that they only erode into the dust/ice mantle and not the underlying bedrock, indicating a formation by melting of the water-ice-rich mantle [5]. The preferred orientation of the gullies is on poleward-facing slopes, where the dust/ice mantle is thickest. Often the gullies occur in conjunction with viscous flow features. Stratigraphically the gullies are one of the youngest landforms in the study region. Viscous flow features mostly occur between gullies and on dissected mantle material [6]. Often gully debris fans are superposed on this material. Other locations covered with viscous flow features include dust/ice mantle filled craters, where sediments in inclined craters have been deformed. A well-preserved glacier-like flow feature is located in the northernmost part of the mapping region. It shows well developed flow features (striae), which indicate an east to west flow direction with an average gradient of ~1,9°. The glacier is located in a protected area, almost completely surrounded by high mountains. Other possible glacial landforms such as pingo-like forms and polygonal terrains also occur on the dissected mantle material. Recent studies with HiRISE-data indicate a sequence from glaciation to ablation and perhaps subsequent periglacial processes [3]. We have investigated the relative stratigraphy of the morphologic units in our study region: (1) Glacial morphologies (viscous and glacier-like flow features) are superposed on mantle materials; (2) Morphologies formed by fluvial and periglacial processes (gullies, polygonal terrains, pingo-like forms), superpose or originate from glacial morphologies or mantle materials (dust/ice mantle); (3) Aeolian morphologies (various kinds of dunes, ripples) have a wide range of ages and overlie or were superposed by some periglacial morphologies. [1] Kargel, J. S. and Strom, R. G. (1992) Geology, 20, 3-7. [2] Hiesinger, H. and Head, J. W. (2002) PSS, 50, 939-981. [3] Banks, M. E. et al. (2008) JGR, 113, E12015, doi:10.1029/2007JE002994. [4] Mustard et al., (2001) Nature, 412, 411-414. [5] Christensen, P. R. (2003) Nature, 422, 45-47. [6] Milliken, R. E. et al. (2003) JGR, 108, doi:10.1029/ 2002JE002005.

  6. Do Neogene foreland basin sediments of the Orn Group, northwestern Argentina record changing conditions in the Eastern Cordillera?

    NASA Astrophysics Data System (ADS)

    Staffo, K.; Rahl, J. M.; Harbor, D. J.; Galli, C.; Bovay, C.

    2010-12-01

    Examination of foreland basin sediments in northwestern Argentina provides insight into the erosional history of the Eastern Cordillera of the Andes, including transient geomorphic responses to tectonics, climate, and drainage integration. The Neogene to Quaternary deposits of the Orn Group are well-exposed along the Ro Iruya near the town of Isla de Caas, where the total section is > 7 km thick. The package of muds, sands, and gravels has been interpreted to have formed in a variety of environments, including both proximal and distal fans, braided streams, and mud flats. Pliocene to Recent sediments exhibit a distinct coarsening upwards sequence. Lower parts of the section are dominated by muds, silts, and sands, typically deposited in tabular and often discontinuous beds interrupted by small sand bars and channels. Upsection, the abundance of silts and sands decrease and are replaced by gravelly beds that dominate the upper part of the section. Clast size data indicate an increase in cobble size in gravel horizons moving upsection, suggesting a transition from a distal to more proximal source. We have analyzed clast compositions from conglomerates within the section to identify potential changes in sedimentary provenance. Bedrock lithology in the adjacent Eastern Cordillera is varied and distinctive, facilitating clast identification. Beds throughout the studied section contain three major components: 1) grey-green shale, greywacke, quartzite, and phyllite of the Precambrian Puncoviscana Formation; 2) generally rose-colored conglomerate, quartz arenite, and mudstone of Cambrian age; and 3) olive-beige sand and mudstone of Ordovician age. Highly weathered sandstone and mudstone of Silurian age are locally abundant, having been eroded from upstream, previously active foreland folds. Although clast composition varies between beds, we find no systematic lithologic changes upsection. This result suggests that the coarsening upward sequence observed in the upper part of the Orn Group stems from tectonic or climatic processes rather than changes in the upstream drainage basin network.

  7. Structural style in a young flexure-induced oblique extensional system, north-western Bonaparte Basin, Australia

    NASA Astrophysics Data System (ADS)

    Saqab, Muhammad Mudasar; Bourget, Julien

    2015-08-01

    In the north-western Bonaparte Basin (North West Shelf of Australia) Neogene to Recent flexure-induced extension superimposed obliquely over the Mesozoic rift structures. Thus, the area offers a good opportunity to investigate the dynamics and architecture of oblique extension fault systems. Analysis of basin-scale 2D and 3D seismic data along the Vulcan sub-basin shows that Neogene deformation produced a new set of extensional, en échelon faults, at places accompanied by the reactivation of the Mesozoic faults. The pre-existing Mesozoic structures strongly control the distribution of the Neogene-Recent deformation, both at regional and local scales. Main controls on the Neogene-Recent fault style, density and segmentation/linkage include: (1) the orientation of the underlying Mesozoic structures, (2) the obliqueness of the younger extension relative to the rift-inherited faults, and (3) the proximity to the Timor Trough. Three types of vertical relationships have been observed between Mesozoic and Neogene-Recent faults. Hard linkages seems to develop when both fault systems trend parallel, therefore increasing risks for trap integrity. It is suggested that the orientation of maximum horizontal stress (SHmax) relative to the Mesozoic faults, forming hydrocarbon traps, is critical for their potential seal/leak behaviour. Stratigraphic growth across the faults indicates that main fault activity occurred during the Plio-Pleistocene, which corresponds to the timing of tectonic loading on Timor Island and the development of lithospheric flexure. Synchronism of normal faulting with flexural bending suggests that extensional deformation on the descending Australian margin accompanied the formation of the Timor Trough.

  8. Characterization of Most Promising Sequestration Formations in the Rocky Mountain Region (RMCCS)

    SciTech Connect

    McPherson, Brian; Matthews, Vince

    2013-09-30

    The primary objective of the “Characterization of Most Promising Carbon Capture and Sequestration Formations in the Central Rocky Mountain Region” project, or RMCCS project, is to characterize the storage potential of the most promising geologic sequestration formations within the southwestern U.S. and the Central Rocky Mountain region in particular. The approach included an analysis of geologic sequestration formations under the Craig Power Station in northwestern Colorado, and application or extrapolation of those local-scale results to the broader region. A ten-step protocol for geologic carbon storage site characterization was a primary outcome of this project.

  9. Narcotic-exposed neonates in a First Nations population in northwestern Ontario

    PubMed Central

    Kelly, Len; Dooley, Joe; Cromarty, Helen; Minty, Bryanne; Morgan, Alanna; Madden, Sharen; Hopman, Wilma

    2011-01-01

    Abstract Objective To document the incidence of neonatal abstinence syndrome (NAS) and the rate of narcotic use during pregnancy in northwestern Ontario, where narcotic abuse is a growing social and medical problem. Design Retrospective chart review. Setting The Sioux Lookout Meno Ya Win Health Centre catchment area in northwestern Ontario. Participants Mothers and neonates for the 482 live births that took place in the 18-month study period (January 2009 to June 2010). Main outcome measures Maternal drug use and neonatal outcomes were documented. Results The incidence of narcotic (oxycodone) abuse during pregnancy increased from a low of 8.4% at the beginning of the study period to a high of 17.2% by mid-2010. Narcotic-using mothers were more likely to also use nicotine and alcohol, to have premature deliveries, and to be episodic users. Narcotic-exposed neonates experienced NAS 29.5% of the time; daily maternal use was associated with a higher rate of NAS (66.0%). While all infants roomed in with their mothers, exposed infants were more likely to require transfer to a tertiary care nursery. Infants with severe NAS were treated with oral morphine and had significantly longer hospital stays compared with the entire cohort (4.5 vs 1.5 days, P = .004). Narcotic abuse during pregnancy in our region is not currently associated with increased rates of HIV or hepatitis C infection, as intravenous route of administration is less common at present than intranasal and oral ingestion. Conclusion Narcotic abuse during pregnancy is a considerable problem in First Nations communities in northwestern Ontario. Community-based initiatives need to be developed to address this issue, and medical and nursing staff need to develop surveillance, assessment, and therapeutic responses. Passive neonatal addiction and withdrawal result from maternal narcotic use during pregnancy. Rates of opioid use among pregnant Canadian women are unknown. PMID:22084474

  10. Paleoseismic evidence of a surface rupture along the northwestern Himalayan Frontal Thrust (HFT)

    NASA Astrophysics Data System (ADS)

    Kumahara, Yasuhiro; Jayangondaperumal, R.

    2013-01-01

    New paleoseismic evidence is presented from the Bhatpur (N 31°18'16.28″, E 76°9'50.00″) Trench site along the Himalayan Frontal Thrust (HFT) on western margin of the Janauri Anticline in NW Himachal Himalaya, India. The latest surface rupture at this site demonstrates coseismic displacement of at least 9.3 m. Radiocarbon dating of trench samples indicates that the surface ruptures occurred at A.D. 1400-1460. After comparison with other trench results along the Himalayan Front, two scenarios are presented of the latest surface rupturing earthquake event in the northwestern Indian Himalaya: (1) a single-event surface rupturing for a minimum fault length of 450 km, or (2) two-events of different lateral extent. According to the former scenario, the latest surface rupture occurred between A.D. 1404 and 1422. The latter scenario suggests the latest surface rupture occurred between A.D. 1404 and A.D. 1460 in the northwestern extent from Kala Amb to Hajipur with ~ 9.0 m of coseismic displacement over a minimum fault length of 200 km. Yet another surface rupture event in the southeastern extent from Kala Amb to Ramnagar has occurred between A.D. 1282 and A.D. 1422, with displacement ranging from 16.0 m to 26.0 m, and a minimum surface rupture length of 230 km. On the basis of these observations and historical earthquakes, it is suggested that the potential for earthquakes larger than those in the historical records are capable of producing surface-rupture lengths greater than the ~ 200 to ~ 230 km or ~ 450 km in the northwestern Indian Himalayan Front.

  11. Co-location opportunities for renewable energy and agriculture in Northwestern India: Tradeoffs and Synergies

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Macknick, J.; Lobell, D. B.; Field, C. B.; Ganesan, K.; Jain, R.; Elchinger, M.; Stoltenberg, B.

    2014-12-01

    Solar energy installations in arid and semi-arid regions of India are rapidly increasing, due to technological advances and policy support. Even though solar energy provides several benefits such as reduction of greenhouse gases, reclamation of degraded land, and improving the quality of life, the deployment of large-scale solar energy infrastructure can adversely impact land and water resources. A major challenge is how to meet the ever-expanding energy demand with limited land and water resources, in the context of increasing competition from agricultural and domestic consumption. We investigated whether water consumption for solar energy development in northwestern India could impact other water and land uses, and explored opportunities to co-locate solar infrastructures and agricultural crops to maximize the efficiency of land and water use. We considered energy inputs/outputs, water use, greenhouse gas emissions and economics of solar installations in northwestern India in comparison to Aloe vera cultivation, a widely promoted land use in the region. The life cycle analyses show that co-located systems are economically viable in some rural areas and may provide opportunities for rural electrification and stimulate economic growth. The water inputs for cleaning solar panels and dust suppression are similar to amounts required for aloe, suggesting the possibility of integrating the two systems to maximize water and land use efficiency. A life-cycle analysis of a hypothetical co-location indicated higher returns per m3 of water used than either system alone. The northwestern region of India is experiencing high population growth, creating additional demand for land and water resources. In these water limited areas, coupled solar infrastructure and agriculture could be established on marginal lands, thus minimizing the socioeconomic and environmental issues resulting from cultivation of non-food crops (e.g. Aloe) in prime agricultural lands.

  12. Volcanic Features in the Northwestern Hawaiian Islands Revealed by SWATH Mapping

    NASA Astrophysics Data System (ADS)

    Smith, J. R.; Miller, J.; Evans, B. K.; Johnson, P.; Weirich, J. B.

    2003-12-01

    The Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve (NWHICRER) has only recently been established, and has already caused an infusion of interest and funds for studies to assess what is there to preserve and how best to do it. The Northwestern chain stretches over 2200 km to the northwest of the 775 km-long Main Hawaiian Islands (MHI). The MHI have only in recent years been systematically mapped with modern multibeam swath sonar systems and the work is not yet complete. With these southeastern islands being the population center, it is easy to imagine the lack of coverage along the Northwestern chain where no one lives except those stationed at remote outposts for scientific study. Manned and robotic submersible studies and limited multibeam mapping have been carried out by the Hawaii Undersea Research Lab every year in the NWHICRER for the past several years though focused on relatively shallow water biological sites. In late 2002, the first dedicated exploratory multibeam mapping expedition took place aboard the new University of Hawaii SWATH ship R/V Kilo Moana. While the primary mission was shallow mapping on carbonate platforms in support of the NWHICRER boundaries, a large amount of data were collected over the deeper volcanic foundations of the atolls. These surveys revealed dramatic rift zones on the same scale as those in the MHI, sea level terraces, submarine canyons cutting through the platforms with debris chutes continuing down to base of the islands, additional submarine landslide scars and debris fields in more detail than the USGS GLORIA sidescan program of the previous decade, and previously unmapped seamounts with some likely resulting from Hawaiian hot spot activity while others formed during creation of the Pacific Plate. A diving program is planned on many of these features in late 2003 and preliminary results will be presented.

  13. Water-level map of the Mississippi delta alluvium in northwestern Mississippi, April 1981

    USGS Publications Warehouse

    Darden, Daphne

    1981-01-01

    Water levels were measured in 454 wells in the alluvial sediments in northwestern Mississippi during the period April 13-24, 1981. Ground-water levels are higher after winter and spring rains and lower after heavy agricultural and industrial pumping. Locally, water levels fluctuate as rivers and streams fluctuate. Because of the drought conditions in April 1981, most water wells had risen several feet. In some areas, however, water levels had not recovered from the relatively low levels measured in September 1980. (USGS)

  14. Late Proterozoic crustal evolution of the Midyan region, northwestern Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Clark, Malcolm D.

    1985-09-01

    Three volcano-sedimentary sequences and related intrusive suites, ranging in age from pre-700 Ma to about 570 Ma, are recorded in the Midyan region of northwestern Saudi Arabia. Crustal history involved island-arc accretion and compressional tectonics up to about 625 Ma and extensional tectonics and rifting after that date. Possible correlatives of the Midyan stratigraphy, as well as ophiolitic rocks of a probable suture zone, may exist in southeastern Sinai, although doubt exists because of the conflicting views of workers in that area.

  15. Spauligodon loboi n. sp. (Nematoda: Pharyngodonidae) parasite of Liolaemus spp. (Iguania: Liolaemidae) from northwestern Argentina.

    PubMed

    Ramallo, Geraldine; Bursey, Charles R; Goldberg, Stephen R

    2002-04-01

    Three-hundred and forty-nine specimens of Spauligodon loboi n. sp. (Nematoda, Pharyngodonidae) were found in the large intestines of 55 of 225 adult specimens representing 5 species of Liolaemus collected in 11 localities of northwestern Argentina. Prevalence of infection was 24% (mean intensity = 6.3 +/- 3.4, range = 2-28). Spauligodon loboi n. sp. differs from other neotropical species in that the filamentous portion of the tail of males is spiny, whereas that of females is smooth. A key to the species of Spauligodon in the Neotropical Realm is provided. PMID:12054014

  16. [Physaloptera lutzi (Nematoda, Physalopteridae) parasite of Liolaemus (Iguania, Tropiduridae) from north-western Argentina].

    PubMed

    Ramallo, G; Díaz, F

    1998-01-01

    Specimens collected in several localities from Salta and Tucumán provinces (north-western Argentina) Liolaemus quilmes and L. ornatus (oviparous population), and L. alticolor (viviparous population) were dissected. The specimens of lizards examinated have nematodes, in stomach, fore-gut and cloaca, identified as Physaloptera lutzi Guimaraes, Cristófaro and Rodrigues, 1976. This represents the first record for this parasite from Liolaemus species in Argentina. Morphologic and morphometric parasitological studies were done. The specimens were drawn and photographed. Also, the following parasitic infection indexes were calculated: prevalence, mean and maximum intensity. PMID:9830719

  17. The choco block in the northwestern corner of South America: Structural, tectonostratigraphic, and paleogeographic implications

    NASA Astrophysics Data System (ADS)

    Duque-Caro, H.

    The Choco Block, located in the northwestern corner of South America, comprises the isthmus of Panama east of the Canal Zone and northwestern Colombia, including the westernmost flanks of the Cordillera Occidental above latitude 4°N. Three major structural and lithogenetic elements compose this terrain: the Dabeiba and Baudo Arches, the Atrato-Chucunaque Basins, and the Istmina Deformed Zone. The Dabeiba and Baudo Arches outline the external boundaries of the Choco Block and display similar characteristics: (a) mostly positive gravity anomalies and association of igneous bodies of oceanic origin with sedimentary suites, and (b) occurence of Upper Cretaceous to Miocene pelagic and hemipelagic and terrigenous strata in blocks of different ages and environments associated with mafic igneous rocks. The Dabeiba Arch exhibits a melange fabric, particularly at its eastern margin, in which disrupted strata and inclusions of Upper Cretaceous-Paleocene, Eocene-Oligocene, and Miocene exotic blocks are dispersed in a sheared pelitic matrix of middle Miocene age. The Atrato-Chucunaque Basins contain sedimentary fill exceeding 10 km in thickness. Two distinctive stratigraphic sequences comprise: (1) an outcropping and apparently continuous Oligocene to middle Miocene sequence composed mostly of pelagic and hemipelagic strata, overlain by hemipelagic and terrigenous strata of latest Middle Miocene to Pliocene age, and (2) an underlying middle Miocene and older sequence, composed mostly of turbidities, which has been recognized only in subsurface sections. An evaluation and synthesis of the structural and lithogenetic information of the Choco Block indicate the following conclusions. The Choco Block is an exotic terrane with no lithogenetic affinity with South America, accreted onto the northwestern flanks of the Cordillera Occidental during the middle Miocene. The occurence of exotic upper Paleocene planktic foraminiferal assemblages in the Dabeiba Arch suggests an origin for the Choco Block as distant as the northern latitudes of Guatemala and Mexico. The Uramita Fault Zone is the suture between the Choco Block and the Cordillera Occidental in NW South America. The young intermontane Atrato and Chucunaque Basins and the Istmina Deformed Zone were formed as a result of the accretion of the Choco Block to the northwestern flanks of the Cordillera Occidental during middle Miocene time.

  18. The correct name of the endemic Dasypus (Cingulata: Dasypodidae) from northwestern Argentina.

    PubMed

    Feijó, Anderson; Cordeiro-Estrela, Pedro

    2014-01-01

    We show that Dasypus mazzai Yepes 1933 is a senior synonym of Dasypus yepesi Vizcaíno 1995. We present morphological evidence that the holotype of D. mazzai is not a juvenile of Dasypus novemcinctus or any other species of this genus, but a distinct endemic species from northwestern Argentina undistinguishable from D. yepesi. Therefore, the correct name for the long-nosed armadillo of intermediate size occurring in the Argentinean provinces of Jujuy and Salta is Dasypus mazzai Yepes 1933. PMID:25543926

  19. Carbon isotopic composition of deep carbon gases in an ombrogenous peatland, northwestern Ontario, Canada

    SciTech Connect

    Aravena, R. . Center for Groundwater Research and Wetlands Research Center); Warner, B.G. . Wetlands Research Center and Dept. of Geography); Charman, D.J. . Dept. of Geographical Sciences); Belyea, L.R. . School of Biological Sciences); Mathur, S.P. ); Dinel, H. )

    1993-01-01

    Radiocarbon dating and carbon isotope analyses of deep peat and gases in a small ombrogenous peatland in northwestern Ontario reveals the presence of old gases at depth that are 1000-2000 yr younger than the enclosing peat. The authors suggest that the most likely explanation to account for this age discrepancy is the downward movement by advection of younger dissolved organic carbon for use by fermentation and methanogens bacteria. This study identifies a potentially large supply of old carbon gases in peatlands that should be considered in global carbon models of the terrestrial biosphere.

  20. Suillus indicus sp. nov. (Boletales, Basidiomycota), a new boletoid fungus from northwestern Himalayas, India

    PubMed Central

    Verma, Balwant; Reddy, M. Sudhakara

    2015-01-01

    The new species Suillus indicus is described based on the morpho-anatomical description and molecular analysis of basidiomes found in conifer forests of the northwestern Himalayas, India. Morphologically, the key diagnostic characteristics of the new taxon are brownish-orange to reddish-brown pileus with low obtuse umbo, brownish-red to reddish-brown fibrillose squamules over the pileal surface, and absence of fibrillose squamules and glandular dots on the stipe surface. Sequences derived from the internal transcribed spacer region of basidiomes and culture demonstrated that the species is clearly distinct from other known taxa of Suillus and new to science. PMID:26000197

  1. Crustaceans from antipatharians on banks of the northwestern Gulf of Mexico

    PubMed Central

    Wicksten, Mary K.; Nuttall, Marissa F.; Hickerson, Emma L.

    2014-01-01

    Abstract The stalked barnacle Oxynaspis gracilis, the chirostylid squat lobster Uroptychus sp., and the caridean shrimps Periclimenes cf. antipathophilus and Pseudopontonides principis have been collected at 68–124 m by a remotely operated vehicle (ROV) on banks in the northern Gulf of Mexico. These species inhabited six species of antipatharian hosts. Pseudopontonides principis, Oxynaspis gracilis, and Uroptychus sp. were not confined to a single host species. Except for Oxynaspis gracilis, collected by ROV in 2004–2005, these species have not been reported previously in the northwestern Gulf of Mexico. PMID:25561830

  2. Implementation of a siting methodology for utility size WECS in western Massachusetts and northwestern Connecticut

    NASA Astrophysics Data System (ADS)

    Kirchhoff, R. H.; Kaminsky, F. C.

    1981-12-01

    This paper describes a long term research project by Northeast Utilities and the University of Massachusetts to identify candidate sites for utility size wind energy systems in Western Massachusetts and Northwestern Connecticut. A generalized methodology is described for identifying the candidate sites. This methodology includes the use of biological wind prospecting, data collection with TALA kites, computerized wind mapping with MATHEW, and the installation of long run data collection stations. This paper also describes the use of a mass consistent flow model known as MATHEW in developing computerized wind maps for selected regions of the area under study.

  3. Hydrologic data from Naval Oil Shale Reserves, Parachute Creek basin, northwestern Colorado, 1980-81

    USGS Publications Warehouse

    Galyean, K.C.; Adams, D.B.; Collins, D.L.

    1985-01-01

    Two years (water yr 1980 and 1981) of data collected by the U.S. Geological Survey for the U.S. Department of Energy, Naval Petroleum and Oil Shale Reserves, in the Parachute Creek drainage basin of northwestern Colorado are tabulated. Data were obtained from five surface water gages, two automatic sediment samplers, and two water quality monitors. Climate data include maximum, minimum, and average temperature and relative humidity, average wind speed and wind direction, and total daily solar radiation. Daily total precipitation is reported for three stations, and snow-course data reported for one site. (Author 's abstract)

  4. Florida coastal ecological characterization: a socioeconomic study of the northwestern region. Volume I. Text

    SciTech Connect

    French, C.O.; Parsons, J.W.

    1983-08-01

    Data are compiled from existing sources on the social and economic characteristics of the Northwestern coastal region of Florida, which is made up of Escambia, Santa Rosa, Okaloosa, Walton, Bay, Gulf, and Franklin Counties. Described are the components and interrelationships among complex processes that include population and demographics characteristics, mineral production, multiple-use conflicts, recreation and tourism, agricultural production, sport and commercial fishing, transportation, industrial and residential development, and environmental issues and regulations. Energetics models of socioeconomic systems are also presented. 40 figures, 108 tables.

  5. Logging Effects on Streamflow: Water Yield and Summer Low Flows at Caspar Creek in Northwestern California

    NASA Astrophysics Data System (ADS)

    Keppeler, Elizabeth T.; Ziemer, Robert R.

    1990-07-01

    Streamflow data for a 21-year period were analyzed to determine the effects of selective tractor harvesting of second-growth Douglas fir and redwood forest on the volume, timing, and duration of low flows and annual water yield in northwestern California. The flow response to logging was highly variable. Some of this variability was correlated with antecedent precipitation conditions. Statistically significant increases in streamflow were detected for both the annual period and the low-flow season. Relative increases in water yield were greater for the summer low-flow period than for annual flows, but these summer flow increases generally disappeared within 5 years.

  6. Malaria in south-western and north-western Nigerian communities

    PubMed Central

    Archibald, H. Munro

    1956-01-01

    An attempt is made to describe the comparative epidemiology of malaria in representative communities of south-western and north-western Nigeria. The climates of the two areas are contrasted and their influence on the seasonal densities and infectivities of the local vectors, Anopheles gambiae and A. funestus, is shown. Malaria occurs in holoendemic proportions in both areas and its effect on local mortality and morbidity is examined, with special reference to children in the pre-school age-groups. PMID:13404444

  7. Characteristics of extreme rainfall events in northwestern Peru during the 1982-1983 El Nino period

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Tisnado, G. M.; Scofield, R. A.

    1987-01-01

    Histograms and contour maps describing the daily rainfall characteristics of a northwestern Peru area most severely affected by the 1982-1983 El Nino event were prepared from daily rainfall data obtained from 66 stations in this area during the El Nino event, and during the same 8-month intervals for the two years preceding and following the event. These data were analyzed, in conjunction with the anlysis of visible and IR satellite images, for cloud characteristics and structure. The results present a comparison of the rainfall characteristics as a function of elevation, geographic location, and the time of year for the El Nino and non-El Nino periods.

  8. Interim Summary: Nesting Counts of Ospreys and Brown Pelicans in Northwestern Mexico, 2006

    USGS Publications Warehouse

    Henny, Charles J.; Anderson, Daniel W.

    2007-01-01

    The distribution and abundance of nesting populations of California brown pelicans (Pelecanus occidentalis californicus) and ospreys (Pandion haliaetus) were documented in 2006 in northwestern Mexico. For ospreys only, the 2006 data were compared to population estimates from two previous surveys (one conducted in 1977 and another conducted in the period 1992-1993). Overall, the total osprey nesting population increased from 1977 to 1992-1993 and then only changed slightly by 2006, but included regions with localized declines, increases, and stable populations. Preliminary population estimates for California brown pelicans suggest a large and apparently healthy breeding population.

  9. Caribou antlers as nest materials for golden eagles in northwestern Alaska

    USGS Publications Warehouse

    Ellis, D.H.; Bunn, R.L.

    1998-01-01

    There are few published records of antlers in golden eagle (Aquila chrysaetos) nests. This note reports extensive use of caribou (Rangifer tarandus) antlers in three golden eagle nests in the Cape Kruzenstern region of northwestern Alaska. The importance of antlers to this population of eagles can be explained at least in part by (1) the lack of suitable woody vegetation on the open tundra, (2) the similarity of antlers to sticks, and (3) the abundance of antlers, especially cow caribou antlers, in the region.

  10. Public awareness of Lyme disease in obstetric, pediatric, and student settings in northwestern Connecticut.

    PubMed

    Curi, M B

    1993-10-01

    The purpose of this study has been to survey the attitudes and understandings of Lyme disease by pregnant women, mothers, and ninth-grade students in Northwestern Connecticut. A sample of 100 obstetrical patients from two private obstetric offices, 100 mothers from four private pediatric offices, and 200 students from four secondary schools was asked to complete a 15 question survey about Lyme disease. In all groups, the responses indicated some misconceptions or a lack of knowledge about the manifestations, diagnosis, and treatment of Lyme disease, as well as about the transmission of Borrelia burgdorferi. This information indicates that better public education about Lyme disease is important. PMID:8275686

  11. First record of a digenean from invasive lionfish, Pterois cf. volitans, (Scorpaeniformes: Scorpaenidae) in the northwestern Atlantic Ocean.

    PubMed

    Bullard, S A; Barse, A M; Curran, S S; Morris, J A

    2011-10-01

    Adults of Lecithochirium floridense (Digenea: Hemiuridae) parasitized the stomach in each of 22 necropsied lionfish, Pterois cf. volitans (Scorpaeniformes: Scorpaenidae) (prevalence  =  100%, mean intensity  =  11), captured in the northwestern Atlantic Ocean off Beaufort, North Carolina (34°14.83'N, 76°35.25'W). This is the first report of a digenean from the invasive lionfish and that of L. floridense from a species of Pterois. The leech specimen previously identified as Myzobdella lugubris from P. volitans in the northwestern Atlantic Ocean is re-identified as Trachelobdella lubrica based on a study of the original voucher specimen. PMID:21506808

  12. Geohydrology of the lower Apalachicola-Chattahoochee-Flint River basin, southwestern Georgia, northwestern Florida, and southeastern Alabama

    USGS Publications Warehouse

    Torak, Lynn J.; Painter, Jaime A.

    2006-01-01

    The lower Apalachicola-Chattahoochee-Flint (ACF) River Basin contains about 4,600 square miles of karstic and fluvial plains and nearly 100,000 cubic miles of predominantly karst limestone connected hydraulically to the principal rivers and lakes in the Coastal Plain of southwestern Georgia, northwestern Florida, and southwestern Alabama. Sediments of late-middle Eocene to Holocene in hydraulic connection with lakes, streams, and land surface comprise the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower semiconfining unit and contribute to the exchange of ground water and surface water in the stream-lake-aquifer flow system. Karst processes, hydraulic properties, and stratigraphic relations limit ground-water and surface-water interaction to the following hydrologic units of the stream-lake-aquifer flow system: the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower confining unit. Geologic units corresponding to these hydrologic units are, in ascending order: Lisbon Formation; Clinchfield Sand; Ocala, Marianna, Suwannee, and Tampa Limestones; Hawthorn Group; undifferentiated overburden (residuum); and terrace and undifferentiated (surficial) deposits. Similarities in hydraulic properties and direct or indirect interaction with surface water allow grouping sediments within these geologic units into the aforementioned hydrologic units, which transcend time-stratigraphic classifications and define the geohydrologic framework for the lower ACF River Basin. The low water-transmitting properties of the lower confining unit, principally the Lisbon Formation, allow it to act as a nearly impermeable base to the stream-lake-aquifer flow system. Hydraulic connection of the surficial aquifer system with surface water and the Upper Floridan aquifer is direct where sandy deposits overlie the limestone, or indirect where fluvial deposits overlie clayey limestone residuum. The water level in perched zones within the surficial aquifer system fluctuates independently of water-level changes in the underlying aquifer, adjacent streams, or lakes. Where the surficial aquifer system is connected with surface water and the Upper Floridan aquifer, water-table fluctuations parallel those in adjacent streams or the underlying aquifer. More...

  13. Aquifers in the Sokoto basin, northwestern Nigeria, with a description of the general hydrogeology of the region

    USGS Publications Warehouse

    Anderson, H.R.; Ogilbee, William

    1973-01-01

    The Sokoto Basin of northwestern Nigeria lies in the sub-Saharan Sudan belt of west Africa in a zone of savannah-type vegetation. Rainfall, averaging about 30 inches annually in much of the basin, occurs chiefly in a wet season which lasts from May to October. A prolonged dry season extending from October to April is dominated by dusty harmattan winds from the northeast. April and May are the hottest months, when temperatures occasionally reach 105?F. Flow in streams of the Sokoto Basin is mostly overland runoff. Only in a few reaches, fed by ground-water discharge from the sedimentary rocks, are streams perennial. In the River Zamfara basin, ground-water discharge contributes almost 1 inch of the average 3.33 inches of total annual runoff. In the vicinity of Sokoto, the River Rima flows throughout the year sustained by spring discharge from perched ground water in limestone of the Kalambaina Formation. On the crystalline terrane where most of the streams rise, total annual runoff may exceed 5 inches, very little of which is ground-water discharge. The sedimentary rocks of the basin range in age from Cretaceous to Tertiary and are composed mostly of interbedded sand, clay, and some limestone; the beds dip gently toward the northwest. Alluvium of Quaternary age underlies the lowlands of the River Sokoto (now Sokoto) and its principal tributaries. These rocks contain three important artesian aquifers, in addition to regional unconfined ground-water bodies in all the principal outcron areas, and a perched water body in the outcrop of the Kalambaina Formation. Artesian aquifers occur at depth in the Gundumi Formation, the Rima Group, and the Gwandu Formation and are separated from one another by clay beds in the lower part of the Rima Group and the Dange Formation. In outcrop, clay in the Dange Formation also supports the perched water of the Kalambaina Formation. The Gundumi Formation, resting on the basement complex, is composed of varicolored clay, sand, and gravel and attains a thickness of 800 to 1,000 feet in its downdip extensions. Most of the formation is thin bedded and clayey and therefore does not yield large quantities of water to boreholes; the average yield is 2,700 gph (gallons per hour). (All gallons are imperial gallons.) Nevertheless, the upper part of the formation is sandy and more permeable and forms a regional artesian aquifer from which yields of as much as 6,600 gph are obtained from single boreholes. Clay in the lower part of the Rima Group confines the Gundumi aquifer downdip, so that at Rabah and Sokoto, for example, in the River Sokoto fadama (valley floor), artesian flow is found in boreholes screened in the Gundumi. Aquifer tests indicate low transmissivities, ranging from 300 to 5,000 gpd per ft (gallons per day per foot) in the lower part of the Gundumi Formation; but in the upper sandy zone the transmissivities are much higher, reaching 66,000 gpd per ft. In the western part of the Sokoto Basin, more productive aquifers with higher heads usually lie above the Gundumi aquifer so that it is not attractive for development, except in the River Sokoto fadama where artesian flow is possible. The Illo Group, which is in part contemporaneous with the Gundumi Formation, includes interbedded varicolored clay and grit in the southern part of the Sokoto Basin. The upper part of the Illo is known to be water-bearing; however, except for the test borehole at Mungadi, little is known of its subsurface extent and water-yielding potential. Overlying the Gundumi Formation in the central and northern part of the Sokoto Basin are interbedded fine gray sand and dark gray clay of the Wurno and Taloka Formations, separated in the extreme north by clay shale of the Dukamaje Formation. Collectively known as the Rima Group, these sediments attain a thickness of more than 1,000 feet near the Niger border. At depth and downdip the clayey beds practically disappear; the sandy beds become thicker and coar

  14. Impacts of Surface Water Diversions for Marijuana Cultivation on Aquatic Habitat in Four Northwestern California Watersheds

    PubMed Central

    Cockrill, Adam; van Hattem, Michael; Miller, Linda; Tauzer, Margaret; Leppig, Gordon

    2015-01-01

    Marijuana (Cannabis sativa L.) cultivation has proliferated in northwestern California since at least the mid-1990s. The environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property. To evaluate the impacts of water diversions at a watershed scale, we interpreted high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California, USA. Low-altitude aircraft flights and search warrants executed with law enforcement at cultivation sites in the region helped to validate assumptions used in aerial imagery interpretation. We estimated the water demand of marijuana irrigation and the potential effects water diversions could have on stream flow in the study watersheds. Our results indicate that water demand for marijuana cultivation has the potential to divert substantial portions of streamflow in the study watersheds, with an estimated flow reduction of up to 23% of the annual seven-day low flow in the least impacted of the study watersheds. Estimates from the other study watersheds indicate that water demand for marijuana cultivation exceeds streamflow during the low-flow period. In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state-and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species. PMID:25785849

  15. The rural carbonaceous aerosols in coarse, fine, and ultrafine particles during haze pollution in northwestern China.

    PubMed

    Zhu, Chong-Shu; Cao, Jun-Ji; Tsai, Chuen-Jinn; Shen, Zhen-Xing; Liu, Sui-Xin; Huang, Ru-Jin; Zhang, Ning-Ning; Wang, Ping

    2016-03-01

    The carbonaceous aerosol concentrations in coarse particle (PM10: Dp ≤ 10 μm, particulate matter with an aerodynamic diameter less than 10 μm), fine particle (PM2.5: Dp ≤ 2.5 μm), and ultrafine particle (PM0.133: Dp ≤ 0.133 μm) carbon fractions in a rural area were investigated during haze events in northwestern China. The results indicated that PM2.5 contributed a large fraction in PM10. OC (organic carbon) accounted for 33, 41, and 62 % of PM10, PM2.5, and PM0.133, and those were 2, 2.4, and 0.4 % for EC (elemental carbon) in a rural area, respectively. OC3 was more abundant than other organic carbon fractions in three PMs, and char dominated EC in PM10 and PM2.5 while soot dominated EC in PM0.133. The present study inferred that K(+), OP, and OC3 are good biomass burning tracers for rural PM10 and PM2.5, but not for PM0.133 during haze pollution. Our results suggest that biomass burning is likely to be an important contributor to rural PMs in northwestern China. It is necessary to establish biomass burning control policies for the mitigation of severe haze pollution in a rural area. PMID:26518000

  16. The effect of local circulations on the variation of atmospheric pollutants in the northwestern Taiwan

    SciTech Connect

    Pay-Liam Lin; Hsin-Chih Lai

    1996-12-31

    A field experiment was held in the northwestern Taiwan as a part of a long-term research program for studying Taiwan`s local circulation. The program has been named as Taiwan Regional-circulation Experiment (TREX). The particular goal of this research is to investigate characteristics of boundary layer and local Circulation and their impact on the distribution and Variation of pollutants in the northwestern Taiwan during Mei-Yu season. It has been known for quite sometime that land-sea breeze is very pronounced under hot and humid conditions. Extensive network includes 11 pilot ballon stations, 3 acoustic sounding sites, and 14 surface stations in about 20 km by 20 km area centered at National Central University, Chung-Li. In addition, there are ground temperature measurements at 3 sites, Integrated Sounding System (ISS) at NCU, air plane observation, tracer experiment with 10 collecting stations, 3 background upper-air sounding stations, 2 towers etc. NOAA and GMS satellite data, sea surface temperature radar, and precipitation data are collected. The local circulations such as land/sea breezes and mountain/valley winds, induced by thermal and topographical effects often play an important role in transporting, redistributing and transforming atmospheric pollutants. This study documents the effects of the development of local circulations and the accompanying evolution of boundary layer on the distribution and the variation of the atmospheric pollutants in the north western Taiwan during Mei-Yu season.

  17. Genetic structuring of remnant forest patches in an endangered medicinal tree in North-western Ethiopia

    PubMed Central

    2014-01-01

    Background Habitat loss and fragmentation may have detrimental impacts on genetic diversity, population structure and overall viability of tropical trees. The response of tropical trees to fragmentation processes may, however, be species, cohort or region-specific. Here we test the hypothesis that forest fragmentation is associated with lower genetic variability and higher genetic differentiation in adult and seedling populations of Prunus africana in North-western Ethiopia. This is a floristically impoverished region where all but a few remnant forest patches have been destroyed, mostly by anthropogenic means. Results Genetic diversity (based on allelic richness) was significantly greater in large and less-isolated forest patches as well as in adults than seedlings. Nearly all pairwise FST comparisons showed evidence for significant population genetic differentiation. Mean FST values were significantly greater in seedlings than adults, even after correction for within population diversity, but varied little with patch size or isolation. Conclusions Analysis of long-lived adult trees suggests the formerly contiguous forest in North-western Ethiopia probably exhibited strong spatial patterns of genetic structure. This means that protecting a range of patches including small and isolated ones is needed to conserve the extant genetic resources of the valuable forests in this region. However, given the high livelihood dependence of the local community and the high impact of foreign investors on forest resources of this region, in situ conservation efforts alone may not be helpful. Therefore, these efforts should be supported with ex situ gene conservation actions. PMID:24602239

  18. Northwestern Argentina: a center of genetic diversity of lemon verbena (Aloysia citriodora PALÁU, Verbenaceae).

    PubMed

    Di Leo Lira, Paola; van Baren, Catalina M; López, Simon; Molina, Ana; Heit, Cecilia; Viturro, Carmen; de Lampasona, Marina P; Catalán, Cesar A; Bandoni, Arnaldo

    2013-02-01

    The aerial parts of lemon verbena (Aloysia citriodora PALÁU) are worldwide used due to their medicinal and aromatic properties. The essential-oil and acteoside contents have been proposed as the main quality markers for their pharmacological and organoleptic features. The northwestern region of Argentina has been repeatedly proposed as the place of origin for this species. For this reason, the essential-oil yields and chemical compositions of leaves of 25 populations of lemon verbena from both wild collections and experimental crops from this region were studied. Plants from six different collections were subsequently grown on the same experimental parcel located at Cerrillos, Salta province, during more than seven years. In addition, the acteoside contents determined in all the samples collected in 2010 showed significant variations (from 0.5 to 4.0%). Large differences were observed in the essential-oil composition and yields, which ranged from 0.4 to 2.1% (v/w). Nevertheless, most of the samples complied with the European Pharmacopoeia specifications. A remarkable chemical diversity with at least four clearly defined chemotypes was detected in this region. Therefore, it would be urgent to encourage actions to protect these genotypes of lemon verbena in the northwestern Argentina. PMID:23418172

  19. Characterization of ambient fine particles in the northwestern area and Anchorage, Alaska.

    PubMed

    Kim, Eugene; Hopke, Philip K

    2008-10-01

    Ambient PM2.5 (particulate matter less than 2.5 microm in aerodynamic diameter) in the northwestern United States and Alaska is dominated by carbonaceous compounds associated with wood burning and transportation sources. PM2.5 source characterization studies analyzing recent PM2.5 speciation data have not been previously reported for these areas. In this study, ambient PM2.5 speciation samples collected at two monitoring sites located in the northwestern area, Olympic Peninsula, WA, and Portland, OR, and one monitoring site located in Anchorage, AK, were characterized through source apportionments. Gasoline vehicle, secondary sulfate, and wood smoke were the largest sources of PM2.5 collected at the Anchorage, Olympic, and Portland monitoring sites, respectively. Secondary sulfates showed an April peak at Anchorage and a November peak at Portland that are likely related to the increased photochemical reaction and long-range transport in Anchorage and meteorological stagnation in Portland. Secondary nitrate at the Olympic site showed a weak summer high peak that could be caused by seasonal tourism in the national park. Backward trajectories suggested that the elevated aged sea salt concentrations at the Portland monitoring site could be regional transport of sea salt that passed through other contaminated air sheds along the coast. Oil combustion emissions that might originate from ships and ferries were observed at the Olympic monitoring site. PMID:18939780

  20. Fire cue effects on seed germination of six species of northwestern Patagonian grasslands

    NASA Astrophysics Data System (ADS)

    Gonzalez, S. L.; Ghermandi, L.

    2012-09-01

    Postfire recruitment of seedlings has been attributed to a stimulation of germination by fire-related cues. The germination response to heat shock (80 °C - 5 min), smoke (60 min), the combination of both factors and no heat no smoke (control) was studied in six native species (two dominant grasses, two dominant shrubs and two annual fugitive herbs) of northwestern Patagonian grasslands. Seeds of the grasses Festuca pallescens and Stipa speciosa and the shrub Senecio bracteolatus (Asteraceae) germinated when they were exposed to heat shock, whereas seeds of the other shrub, Mulinum spinosum (Apiaceae), were killed by this fire cue. In grasses, probably the glume of caryopsis protected embryos from heat. Possibly, the seed size could explain the different responses of the two shrubs. Heat combined with smoke reduced seed germination for S. speciosa and S. bracteolatus. The heat could have scarified seeds and the longer exposure to smoke could have been toxic for embryos. The same treatment increased germination of the annual fugitive herb Boopis gracilis (Calyceraceae). We concluded that fire differentially affects the seedling recruitment of the studied species in the northwestern Patagonian grasslands.

  1. Seroprevalence of Toxoplasma gondii infection in dairy goats in Shaanxi Province, Northwestern China

    PubMed Central

    2011-01-01

    Background Toxoplasma gondii is an important zoonotic pathogen causing significant human and animal health problems. Infection in dairy goats not only results in significant reproductive losses, but also represents an important source of human infection due to consumption of infected meat and milk. In the present study we report for the first time seroprevalence of T. gondii infection in Guanzhong and Saanen dairy goats in Shaanxi province, Northwestern China. Results Sera from 751 dairy goats from 9 farms in 6 counties were examined for T. gondii antibodies with an indirect haemagglutination (IHA) test. Antibodies to T. gondii were detected in 106 (14.1%) serum samples, with antibody titres ranging from 1:64 to 1:1024. Seropositive goats were found in all 9 farms and seroprevalences in Guanzhong (16.3%, 75/461) and Saanen (10.7%, 31/290) dairy goats were not statistically significantly different. All the factors (sex, age and location) reported in the present study affected prevalence of infection, and seroprevalence increased with age, suggesting postnatal acquisition of T. gondii infection. Conclusions The results of the present survey indicate that infection by T. gondii is widely prevalent in dairy goats in Shaanxi province, Northwestern China, and this has implications for prevention and control of toxoplasmosis in this province. PMID:21457538

  2. Lyme Disease Borrelia spp. in Ticks and Rodents from Northwestern China

    PubMed Central

    Takada, Nobuhiro; Masuzawa, Toshiyuki; Ishiguro, Fubito; Fujita, Hiromi; Kudeken, Midori; Mitani, Harumi; Fukunaga, Masahito; Tsuchiya, Kimiyuki; Yano, Yasuhiro; Ma, Xiao-Hang

    2001-01-01

    In May 1999, field surveys of Lyme disease spirochetes were conducted around the Tianshan Mountains in Xinjiang Uygur Autonomous Region in northwestern People's Republic of China. Ixodes persulcatus ticks were obtained in a Tianchi Lake valley with primary forest, while the tick fauna was poor in the semidesert or at higher altitudes in this region. Species identities were confirmed by molecular analysis in which an internal transcribed spacer sequence was used. Of 55 adult ticks, 22 (40%) were positive for spirochetes as determined by Barbour-Stoenner-Kelly culture passages. In addition, some rodents, including Apodemus uralensis (5 of 14 animals) and Cricetulus longicaudatus (the only animal examined), and some immature stages of I. persulcatus (4 of 11 ticks) that had fed on A. uralensis were positive for spirochetes. Based on 5S-23S rRNA intergenic spacer restriction fragment length polymorphism analysis and reactivity with monoclonal antibodies, 35 cultures (including double isolation cultures) were identified as Borrelia garinii (20 isolates, including 9 Eurasian pattern B isolates and 11 Asian pattern C isolates), Borrelia afzelii (10 pattern D isolates), and mixed cultures (5 cultures, including isolates that produced B. garinii patterns B and C plus B. afzelii pattern D). These findings revealed that Lyme disease pathogens are distributed in the mountainous areas in northwestern China even though it is an arid region, and they also confirmed the specific relationship between I. persulcatus and genetic patterns of Borrelia spp. on the Asian continent. PMID:11679340

  3. Aeolianite sedimentation along the northwestern coast of Egypt: Evidence for middle to late quaternary aridity

    NASA Astrophysics Data System (ADS)

    El-Asmar, Hesham M.

    Aeolian sediments along the northwestern coast of Egypt are described, analyzed for oxygen and carbon isotopes and dated using radiocarbon, U-Series and amino-acid geochronology. Although deposition of the aeolianites along the northwestern Mediterranean coast of Egypt does not necessarily indicate regressive sea-level events, their development is often associated with arid climatic conditions. The study of the aeolian sediments which constitute part of the coastal calcarenite ridges that are distributed parallel to the presen shoreline, reveals the presence of at least four arid climatic phases following four major humid phases associated with high marine levels. The aeolian phases are characterized by high positive δ18O and δ13C values and are related to aminozones A (Holocene), C (Oxygen Isotope Substage 5a/5c), E (Oxygen Isotope Substage 5e) and G (Oxygen Isotope Stage 9), which are represented by the Coastal ridge, El-Max-Abu Sir ridge and the complex cycles of Gebel Maryut ridge respectively. A positive increasing trend of both δ18O and δ13C values is observed from Gebel Maryut ridge to the Coastal ridge. This indicates a general increasing of aridity with short intermittent moist conditions during which the reddish brown palaeosols were developed with their characteristic low δ18O and δ13C values.

  4. Impacts of surface water diversions for marijuana cultivation on aquatic habitat in four northwestern California watersheds.

    PubMed

    Bauer, Scott; Olson, Jennifer; Cockrill, Adam; van Hattem, Michael; Miller, Linda; Tauzer, Margaret; Leppig, Gordon

    2015-01-01

    Marijuana (Cannabis sativa L.) cultivation has proliferated in northwestern California since at least the mid-1990s. The environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property. To evaluate the impacts of water diversions at a watershed scale, we interpreted high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California, USA. Low-altitude aircraft flights and search warrants executed with law enforcement at cultivation sites in the region helped to validate assumptions used in aerial imagery interpretation. We estimated the water demand of marijuana irrigation and the potential effects water diversions could have on stream flow in the study watersheds. Our results indicate that water demand for marijuana cultivation has the potential to divert substantial portions of streamflow in the study watersheds, with an estimated flow reduction of up to 23% of the annual seven-day low flow in the least impacted of the study watersheds. Estimates from the other study watersheds indicate that water demand for marijuana cultivation exceeds streamflow during the low-flow period. In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state- and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species. PMID:25785849

  5. Forest site-quality estimation using Forest Ecosystem Classification in Northwestern Ontario.

    PubMed

    Carmean, W H

    1996-01-01

    Site index for jack pine, black spruce and trembling aspen was found to be poorly related to soil types described in the Northwestern Ontario Forest Ecosystem Classification (NWO FEC). Statistical analyses showed that average site indices for most soil types and groupings of soil types were not significantly different from each other.Site index varies greatly within presently defined NWO FEC soil types because certain soil and topographic features that are closely related to site index vary greatly within soil types or are not well described by the NWO FEC soil types. These critical soil features have been identified by soil-site studies that show features most closely related to site index usually are surface soil features found within the effective rooting zone of forest trees. These critical features include depth to bedrock, depth to root restricting soil layers, and coarse fragment content and texture of surface soil horizons.Site-quality research in Northwestern Ontario is closely integrated with the NWO FEC program, thus future NWO FEC soil classifications probably will use results from our soil-site research as a basis for soil type revisions. The result will be future soil types that are more closely related to forest site quality and thus to the capability of forest land to produce tree growth. PMID:24198025

  6. Profundulus kreiseri, a new species of Profundulidae (Teleostei, Cyprinodontiformes) from northwestern Honduras

    PubMed Central

    Matamoros, Wilfredo A.; Schaefer, Jacob F.; Hernández, Carmen L.; Prosanta Chakrabarty

    2012-01-01

    Abstract A new species of Profundulus, Profundulus kreiseri (Cyprinodontiformes: Profundulidae), is described from the Chamelecón and Ulúa Rivers in the northwestern Honduran highlands. Based on a phylogenetic analysis using cytochrome b and the presence of synapomorphic characters (dark humeral spot, a scaled preorbital region and between 32-34 vertebrae), this new species is placed in the subgenus Profundulus, which also includes Profundulus (Profundulus) oaxacae, Profundulus (Profundulus) punctatus and Profundulus (Profundulus) guatemalensis. Profundulus kreiseri can be distinguished from other members of the subgenus Profundulus by having less than half of its caudal fin densely scaled. Profundulus kreiseri can further be differentiated from Profundulus (Profundulus) oaxacae and Profundulus (Profundulus) punctatus by the absence of rows of dark spots on its flanks. The new species can further be differentiated from Profundulus (Profundulus) guatemalensis by the presence of fewer caudal- and pectoral-fin rays. The new species is distinguished from congeners of the profundulid subgenus Tlaloc (viz., Profundulus (Tlaloc) hildebrandi, Profundulus (Tlaloc) labialis, Profundulus (Tlaloc) candalarius and Profundulus (Tlaloc) portillorum) by having a scaled preorbital region and a dark humeral spot. Profundulus kreiseri and Profundulus portillorum are the only two species of Profundulus that are endemic to the region south of the Motagua River drainage in southern Guatemala and northwestern Honduras. PMID:23166464

  7. A case study of particulate impacts on the Grand Canyon from northwestern Mexico

    SciTech Connect

    Eatough, D.J.; Green, M.; Moran, W.; Farber, R.

    1999-07-01

    The concentrations of sulfate measured at Meadview, a remote monitoring site just west of the Grand Canyon National Park, on September 1 and 2, 1992 were the highest concentrations reported at this site in six years of monitoring. During this period, the concentrations of SO{sub 2} at Meadview were also high and about three times the sulfate concentrations. In addition, the concentrations of sulfate and SO{sub 2} were also comparably high between Meadview and the southernmost sampling sites near the Mexican border. Based on ambient atmospheric conditions, emissions from the Mohave Power Project (MPP) 110 km upwind of Meadview could not have been responsible for the majority of the regionally observed sulfur oxides. The geographical distribution of SO{sub 2} and sulfate suggest that northwestern Mexico was a significant source of the unusually high observed sulfur oxides. A CMB model developed during Project MOHAVE was used to apportion sulfur oxides at Meadview and other sampling sites throughout the study region for August 31--September 2, 1992. The results indicate that the contribution of MPP to sulfate at Meadview was typical. However, transport of SO{sub x} from northwestern Mexico was elevated throughout much of the region during this time period. This lead to the large increase in sulfate concentrations at Meadview on September 1 and 2. These results indicate that emissions from Mexico can be a significant source of sulfate in the Grand Canyon.

  8. First report on natural infection of the Phlebotomus tobbi by Leishmania infantum in northwestern Iran.

    PubMed

    Rassi, Yavar; Sanei Dehkordi, Alireza; Oshaghi, Mohammad A; Abai, Mohammad R; Mohtarami, Fatemeh; Enayati, Ahmadali; Zarei, Zabiholah; Javadian, Ezatoldin

    2012-07-01

    Visceral leishmaniasis (VL) is an important health problem in Ardebil, where it borders Azerbaijan in the northwestern Iran. In spite of the presence of both cutaneous and visceral leishmaniasis (CL and VL) in northwestern Iran, previous researches have consistently revealed the etiologic agent of VL in the region to be Leishmania infantum. This is the first report of natural infection of Phlebotomus tobbi with L. infantum in Bilesavar district in the northern part of Ardebil province bordering Azerbaijan. Polymerase chain reaction (PCR) of kDNA, ITS1-rDNA, and CPB genes of the parasite followed by restriction fragment length polymorphism (RFLP) and gene sequencing analyses revealed presence of L. infantum in six out of 433 tested female sand fly specimens. Although sand flies of P. tobbi were infrequent, two out of 32 (6.25%) females captured in the area were found infected with the parasite. Phlebotomus perfiliewi transcaucasicus, the known vector of VL in the area, were the most dominant species but only four out of 273 (1.47%) tested were infected with L. infantum. This study showed that P. tobbi similar to P. perfiliewi transcaucasicus could play a significant role in the transmission of the L. infantum. However more investigations are needed to demonstrate that L. infantum is the only species circulating in the focus. PMID:22609304

  9. Soil, environmental, and watershed measurements in support of carbon cycling studies in northwestern Mississippi

    USGS Publications Warehouse

    Huntington, T.G.; Harden, J.W.; Dabney, S.M.; Marion, D.A.; Alonso, C.; Sharpe, J.M.; Fries, T.L.

    1998-01-01

    Measurements including soil respiration, soil moisture, soil temperature, and carbon export in suspended sediments from small watersheds were recorded at several field sites in northwestern Mississippi in support of hillslope process studies associated with the U.S. Geological Survey's Mississippi Basin Carbon Project (MBCP). These measurements were made to provide information about carbon cycling in agricultural and forest ecosystems to understand the potential role of erosion and deposition in the sequestration of soil organic carbon in upland soils. The question of whether soil erosion and burial constitutes an important net sink of atmospheric carbon dioxide is one hypothesis that the MBCP is evaluating to better understand carbon cycling and climate change. This report contains discussion of methods used and presents data for the period December 1996 through March 1998. Included in the report are ancillary data provided by the U.S. Department of Agriculture (USDA) ARS National Sedimentation Laboratory and U.S. Forest Service (USFS) Center for Bottomland Hardwoods Research on rainfall, runoff, sediment yield, forest biomass and grain yield. Together with the data collected by the USGS these data permit the construction of carbon budgets and the calibration of models of soil organic matter dynamics and sediment transport and deposition. The U.S. Geological Survey (USGS) has established cooperative agreements with the USDA and USFS to facilitate collaborative research at research sites in northwestern Mississippi.

  10. Mineral precipitation and dissolution at two slag-disposal sites in northwestern Indiana, USA

    USGS Publications Warehouse

    Bayless, E.R.; Schulz, M.S.

    2003-01-01

    Slag is a ubiquitous byproduct of the iron- and steel-refining industries. In northwestern Indiana and northeastern Illinois, slag has been deposited over more than 52 km2 of land surface. Despite the widespread use of slag for fill and construction purposes, little is known about its chemical effects on the environment. Two slagdisposal sites were examined in northwestern Indiana where slag was deposited over the native glacial deposits. At a third site, where slag was not present, background conditions were defined. Samples were collected from cores and drill cuttings and described with scanning electron microscopy and electron microprobe analysis. Ground-water samples were collected and used to assess thermodynamic equilibria between authigenic minerals and existing conditions. Differences in the mineralogy at background and slag-affected sites were apparent. Calcite, dolomite, gypsum, iron oxides, and clay minerals were abundant in native sediments immediately beneath the slag. Mineral features indicated that these minerals precipitated rapidly from slag drainage and co-precipitated minor amounts of non-calcium metals and trace elements. Quartz fragments immediately beneath the slag showed extensive pitting that was not apparent in sediments from the background site, indicating chemical weathering by the hyperalkaline slag drainage. The environmental impacts of slag-related mineral precipitation include disruption of natural ground-water flow patterns and bed-sediment armoring in adjacent surface-water systems. Dissolution of native quartz by the hyperalkaline drainage may cause instability in structures situated over slag fill or in roadways comprised of slag aggregates.

  11. Holocene tephra stratigraphy in four lakes in southeastern Oregon and northwestern Nevada, USA

    NASA Astrophysics Data System (ADS)

    Foit, Franklin F.; Mehringer, Peter J.

    2016-03-01

    To better understand the regional tephra stratigraphy and chronology of northern Nevada and southern Oregon, tephras in archived cores, taken as part of the Steens Mountain Prehistory Project from four lakes, Diamond Pond, Fish and Wildhorse lakes in southeastern Oregon and Blue Lake in northwestern Nevada, were reexamined using more advanced electron microprobe analytical technology. The best preserved and most complete core from Fish Lake along with Wildhorse Lake hosted two tephras from Mt. Mazama (Llao Rock and the Climactic Mazama), a mid-Holocene basaltic tephra from Diamond Craters, Oregon, two Medicine Lake tephras and an unexpected late Holocene Chaos Crags (Mt. Lassen volcanic center) tephra which was also found in the other lakes. Blue Lake was the only lake that hosted a Devils Hill tephra from the Three Sisters volcano in west central Oregon. Another tephra from the Three Sisters Volcano previously reported in sediments of Twin Lakes in NE Oregon, has now been confirmed as Rock Mesa tephra. The Chaos Crags, Devils Hill and Rock Mesa tephras are important late Holocene stratigraphic markers for central and eastern Oregon and northwestern Nevada.

  12. New high-precision 40Ar/39Ar ages on Oligocene volcanic rocks of northwestern Kenya

    NASA Astrophysics Data System (ADS)

    Brown, Francis H.; Jicha, Brian R.

    2016-02-01

    New, high-precision 40Ar/39Ar ages from volcanic rocks in northwestern Kenya are provided for some areas of exposure in this remote area. We report seven 40Ar/39Ar ages generated from single crystal total fusion experiments on alkali feldspar separated from volcanic rocks in the Mogila, Songot, and Lokwanamur Ranges and the Gatome valley. A rhyolite from the lower part of the sequence in the Mogila Range yielded ages of 32.31 ± 0.06 Ma and 32.33 ± 0.07 Ma, and a rhyolite near the top of that sequence yielded 31.67 ± 0.04 Ma. A single sample from the Songot Range yielded an age of 32.49 ± 0.07 Ma, slightly older than the rocks collected from Mogila. In both ranges the early Oligocene rhyolites are underlain by basalts, as is also the case in the Labur Range. Ages of 25.95 ± 0.03 Ma, 25.91 ± 0.04 Ma, and 27.15 ± 0.03 Ma were measured on alkali feldspar from rhyolites from the Lokwanamur Range, and the nearby Gatome valley. All of these rocks are part of an episode of widespread volcanism in northwestern Kenya in the mid-to late Oligocene that is not currently known from the Ethiopian Rift Valley.

  13. Ecology of petroleum platforms in the northwestern Gulf of Mexico: a community profile

    SciTech Connect

    Gallaway, B.J.; Lewbel, G.S.

    1982-07-01

    This community profile of petroleum platforms describes the structure and ecological function of petroleum platforms in the northwestern Gulf of Mexico. The profile proceeds from an introductory section describing the history of platform installation, structural properties, and their distribution in the northwestern Gulf of Mexico, to characterizations of the composition and biology of some of the major faunal groups on or around the platforms, to descriptions of structural attributes of petroleum platform communities, to observations of successional patterns and growth of the communities, to discussions of the ecosystem dynamics of the communities in terms of trophic linkage and biomass and carbon flows. In each of these sections, the effects of discharges from the active structures on the communities are described. The effects of the petroleum platform community on the surrounding soft-bottom communities are implicitly described throughout the profile, and explicitly addressed under the section describing the ecosystem dynamics. We then briefly summarize some of the values of production platform communities to man, and, in the final section of the text make an appeal that specific steps be taken to preserve an endangered biological resource: production platform communities.

  14. Uplift and Subsidence in the Northwestern German North Sea and their Impact on Sedimentation and Erosion of Mesozoic to Cenozoic sediments

    NASA Astrophysics Data System (ADS)

    Jaehne, Fabian; Arfai, Jashar; Lutz, Rdiger

    2013-04-01

    Within the framework of the GPDN project (www.geopotenzial-nordsee.de) a detailed seismic mapping project focuses on the northwestern offshore part of the German North Sea sector, the so called 'Entenschnabel' area, which was not considered in former studies (Baldschuhn et al., 2001) of the German North Sea sector. The Northwestern German North Sea is characterized by a complex rift dominated structural pattern in the Mesozoic, with the Central Graben as the main structure, resulting from a multiphase tectonic evolution. Several phases of uplift and subsidence were driven by extensional and compressional tectonic events, as well as by volcanic activity at the North Sea Dome and by extensive mobilization of Zechstein salt. These different influences on the sedimentary and structural evolution and their changes over time are distinguishable by detailed mapping of several formations. Spatial distribution of these formations and their thickness variations reveal changes of depocenters and changes of internal geometry. In the Entenschnabel area, the Central Graben is the dominating structural element. First extensional pulses took place in the Lower Triassic followed by several phases of rifting from the Middle to Late Triassic. The age of rifting phases can be defined by thickening of syn-tectonic Triassic to Jurassic strata towards the major fault zones. During the Jurassic the main extensional phase took place in combination with extensive diapirism. Analyses of the distribution and the thicknesses of sediments in rim-synclines reveal that most of the salt structures inside the Central Graben had a main phase of growth during the Late Jurassic. The Jurassic to Cenozoic evolution of the Central Graben and surrounding areas is closely related to the evolution of the volcanic activity at the North Sea Rift Dome (Graversen, 2006). In most of the German North Sea a supra-regional uplift driven by this volcanic activity led to a major erosional event, which is defined by a major unconformity at the base of the Lower Cretaceous. In contrast the German part of the Central Graben is characterized by continuous sedimentation during this time. Another difference of the German Central Graben compared to the rest of the German North Sea is a structural inversion of parts of the graben during the Late Cretaceous. Greatest thicknesses of the Upper Cretaceous are reached on the eastern graben shoulder of the Central Graben along the Nordschillgrund High. The reason for subsidence along this long-living Triassic to Jurassic structural high has to be investigated. Baldschuhn, R., et al. (2001). Geotektonischer Atlas von Nordwestdeutschland und dem deutschen Nordsee-Sektor - Strukturen, Strukturentwicklung, Palogeographie. Geologisches Jahrbuch, A 153: 3-95. Graversen, O. (2006). The Jurassic-Cretaceous North Sea Rift Dome and Associated Basin Evolution. Search and Discovery.

  15. Northwestern University Initiative for Teaching NanoSciences (NUITNS): An Approach for Teaching Computational Chemistry to Engineering Undergraduate Students

    ERIC Educational Resources Information Center

    Simeon, Tomekia; Aikens, Christine M.; Tejerina, Baudilio; Schatz, George C.

    2011-01-01

    The Northwestern University Initiative for Teaching Nanosciences (NUITNS) at nanohub.org Web site combines several tools for doing electronic structure calculations and analyzing and displaying the results into a coordinated package. In this article, we describe this package and show how it can be used as part of an upper-level quantum chemistry

  16. FIRST REPORT OF THE NECROTIC STRAIN OF POTATO VIRUS Y (PVYN) POTYVIRUS ON POTATOES IN THE NORTHWESTERN UNITED STATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 50 isolates of Potato virus Y (PVY) with the characteristics of strains which cause tobacco veinal necrosis (PVYN) were obtained from potatoes (Solanum tuberosum L.) grown in the northwestern U.S. These isolates are being characterized at the biological and molecular levels. Isolate RR1 w...

  17. Impact and occurrence of Phytophthora rubi and Pratylenchus penetrans in commercial red raspberry (Rubus idaeus) fields in northwestern Washington

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red raspberry (Rubus idaeus) production is a vital component of northwestern Washingtons agriculture. The main objectives of this study were to document the occurrence of soilborne pathogens Phytophthora rubi and Pratylenchus penetrans in early stage production fields, relate this information to so...

  18. 75 FR 26786 - Notice of Public Meeting: Sierra Front-Northwestern Great Basin Resource Advisory Council, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNV912000 L16400000.PH0000 LXSS006F0000 261A; 10-08807; MO 4500012081; TAS: 14X1109] Notice of Public Meeting: Sierra Front-Northwestern Great Basin Resource Advisory Council,...

  19. 78 FR 13374 - Notice of Public Meetings: Sierra Front-Northwestern Great Basin Resource Advisory Council, Nevada

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNVS00000 L12200000.PM0000 LXSS006F0000 261A; 12-08807; MO 4500034358; TAS: 14X1109] Notice of Public Meetings: Sierra Front-Northwestern Great Basin Resource Advisory...

  20. An Integrated Multi-Institutional Diabetes Prevention Program Improves Knowledge and Healthy Food Acquisition in Northwestern Ontario First Nations

    ERIC Educational Resources Information Center

    Ho, Lara S.; Gittelsohn, Joel; Rimal, Rajiv; Treuth, Margarita S.; Sharma, Sangita; Rosecrans, Amanda; Harris, Stewart B.

    2008-01-01

    This article presents the impact results of a feasibility study in Canada for prevention of risk factors for diabetes in seven northwestern Ontario First Nations. Baseline and follow-up data were collected before and after the 9-month intervention program in schools, stores, and communities that aimed to improve diet and increase physical activity…

  1. Analogous Study of the Linguistic Knowledge between Monolingual and Bilingual Students in the Minority Region of Northwestern China

    ERIC Educational Resources Information Center

    He, Hao

    2008-01-01

    Minority students' English learning is a special and an indispensable component of English education system in China. This article studies students' linguistic knowledge that live in Northwestern China--Gan Nan Autonomy State of Gan Su Province with majority population of Tibetan, mixed with Chinese and some Muslim. An analogous analysis is…

  2. Petrology of Cretaceous coals from northwestern Alaska. Semi-annual progress report, September 1, 1980-August 31, 1981

    SciTech Connect

    Rao, P.D.

    1981-03-01

    Coal of the Cretaceous age from northwestern Alaska has been sampled, crushed and pelletized for reflectivity measurement and petrographic examination. Reflectance measurements have been completed on 21 samples. The samples (300) were obtained from seismic shotholes, Auger holes, test wells and by channel sampling. (LTN)

  3. Northwestern University Initiative for Teaching NanoSciences (NUITNS): An Approach for Teaching Computational Chemistry to Engineering Undergraduate Students

    ERIC Educational Resources Information Center

    Simeon, Tomekia; Aikens, Christine M.; Tejerina, Baudilio; Schatz, George C.

    2011-01-01

    The Northwestern University Initiative for Teaching Nanosciences (NUITNS) at nanohub.org Web site combines several tools for doing electronic structure calculations and analyzing and displaying the results into a coordinated package. In this article, we describe this package and show how it can be used as part of an upper-level quantum chemistry…

  4. Influenza-A viruses in ducks in northwestern Minnesota: fine scale spatial and temporal variation in prevalence and subtype diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July – October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. Prevalence of AIV peaked in late summer. We detected 27 A...

  5. Potential impacts of northeastern Eurasian snow cover on generation of dust storms in northwestern China during spring

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Ho, Chang-Hoi; Kim, Jhoon; Kim, Jinwon

    2013-08-01

    The effects of the northeastern Eurasian snow cover on the frequency of spring dust storms in northwestern China have been examined for the period 1979-2007. Averaged over all 43 stations in northwestern China, a statistically significant relationship has been found between dust-storm frequency (DSF) and Eurasian snow-water equivalent (SWE) during spring: mean DSF of 7.4 and 3.3 days for years of high- and low SWE, respectively. Further analyses reveal that positive SWE anomalies enhance the meridional gradients of the lower tropospheric temperatures and geopotential heights, thereby strengthening westerly jets and zonal wind shear over northwestern China and western Inner Mongolia of China, the regions of major dust sources. The anomalous atmospheric circulation corresponding to the Eurasian SWE anomalies either reinforces or weakens atmospheric baroclinicity and cyclogenesis, according to the sign of the anomaly, to affect the spring DSF. This study suggests that Eurasian SWE anomalies can be an influential factor of spring DSF in northwestern China and western Inner Mongolia of China.

  6. Galaxy formation

    SciTech Connect

    Silk, J.

    1984-11-01

    Implications of the isotropy of the cosmic microwave background on large and small angular scales for galaxy formation are reviewed. In primeval adiabatic fluctuations, a universe dominated by cold, weakly interacting nonbaryonic matter, e.g., the massive photino is postulated. A possible signature of photino annihilation in our galactic halo involves production of cosmic ray antiprotons. If the density is near its closure value, it is necessary to invoke a biasing mechanism for suppressing galaxy formation throughout most of the universe in order to reconcile the dark matter density with the lower astronomical determinations of the mean cosmological density. A mechanism utilizing the onset of primordial massive star formation to strip gaseous protogalaxies is described. Only the densest, early collapsing systems form luminous galaxies. (ESA)

  7. Galaxy formation

    NASA Technical Reports Server (NTRS)

    Silk, J.

    1984-01-01

    Implications of the isotropy of the cosmic microwave background on large and small angular scales for galaxy formation are reviewed. In primeval adiabatic fluctuations, a universe dominated by cold, weakly interacting nonbaryonic matter, e.g., the massive photino is postulated. A possible signature of photino annihilation in our galactic halo involves production of cosmic ray antiprotons. If the density is near its closure value, it is necessary to invoke a biasing mechanism for suppressing galaxy formation throughout most of the universe in order to reconcile the dark matter density with the lower astronomical determinations of the mean cosmological density. A mechanism utilizing the onset of primordial massive star formation to strip gaseous protogalaxies is described. Only the densest, early collapsing systems form luminous galaxies.

  8. Comet formation

    NASA Astrophysics Data System (ADS)

    Blum, J.

    2014-07-01

    There has been vast progress in our understanding of planetesimal formation over the past decades, owing to a number of laboratory experiments as well as to refined models of dust and ice agglomeration in protoplanetary disks. Coagulation rapidly forms cm-sized ''pebbles'' by direct sticking in collisions at low velocities (Güttler et al. 2010; Zsom et al. 2010). For the further growth, two model approaches are currently being discussed: (1) Local concentration of pebbles in nebular instabilities until gravitational instability occurs (Johansen et al. 2007). (2) A competition between fragmentation and mass transfer in collisions among the dusty bodies, in which a few ''lucky winners'' make it to planetesimal sizes (Windmark et al. 2012a,b; Garaud et al. 2013). Predictions of the physical properties of the resulting bodies in both models allow a distinction of the two formation scenarios of planetesimals. In particular, the tensile strength (i.e, the inner cohesion) of the planetesimals differ widely between the two models (Skorov & Blum 2012; Blum et al. 2014). While model (1) predicts tensile strengths on the order of ˜ 1 Pa, model (2) results in rather compactified dusty bodies with tensile strengths in the kPa regime. If comets are km-sized survivors of the planetesimal-formation era, they should in principle hold the secret of their formation process. Water ice is the prime volatile responsible for the activity of comets. Thermophysical models of the heat and mass transport close to the comet-nucleus surface predict water-ice sublimation temperatures that relate to maximum sublimation pressures well below the kPa regime predicted for formation scenario (2). Model (1), however, is in agreement with the observed dust and gas activity of comets. Thus, a formation scenario for cometesimals involving gravitational instability is favored (Blum et al. 2014).

  9. Atmospheric nitrogen deposition to the northwestern Pacific: seasonal variation and source attribution

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Zhang, L.; Pan, Y.; Wang, Y.; Paulot, F.; Henze, D. K.

    2015-09-01

    Rapid Asian industrialization has led to increased downwind atmospheric nitrogen deposition threatening the marine environment. We present an analysis of the sources and processes controlling atmospheric nitrogen deposition to the northwestern Pacific, using the GEOS-Chem global chemistry model and its adjoint model at 1/2° × 2/3° horizontal resolution over East Asia and its adjacent oceans. We focus our analyses on the marginal seas: the Yellow Sea and the South China Sea. Asian nitrogen emissions in the model are 28.6 Tg N a-1 as NH3 and 15.7 Tg N a-1 as NOx. China has the largest sources with 12.8 Tg N a-1 as NH3 and 7.9 Tg N a-1 as NOx; the high-NH3 emissions reflect its intensive agricultural activities. We find Asian NH3 emissions are a factor of 3 higher in summer than winter. The model simulation for 2008-2010 is evaluated with NH3 and NO2 column observations from satellite instruments, and wet deposition flux measurements from surface monitoring sites. Simulated atmospheric nitrogen deposition to the northwestern Pacific ranges 0.8-20 kg N ha-1 a-1, decreasing rapidly downwind of the Asian continent. Deposition fluxes average 11.9 kg N ha-1 a-1 (5.0 as reduced nitrogen NHx and 6.9 as oxidized nitrogen NOy) to the Yellow Sea, and 5.6 kg N ha-1 a-1 (2.5 as NHx and 3.1 as NOy) to the South China Sea. Nitrogen sources over the ocean (ship NOx and oceanic NH3) have little contribution to deposition over the Yellow Sea, about 7 % over the South China Sea, and become important (greater than 30 %) further downwind. We find that the seasonality of nitrogen deposition to the northwestern Pacific is determined by variations in meteorology largely controlled by the East Asian monsoon and in nitrogen emissions. The model adjoint further estimates that nitrogen deposition to the Yellow Sea originates from sources over China (92 % contribution) and the Korean peninsula (7 %), and by sectors from fertilizer use (24 %), power plants (22 %), and transportation (18 %). Deposition to the South China Sea shows source contribution from mainland China (66 %), Taiwan (20 %), and the rest (14 %) from the southeast Asian countries and oceanic NH3 emissions. The adjoint analyses also indicate that reducing Asian NH3 emissions would increase NOy dry deposition to the Yellow Sea (28 % offset annually), limiting the effectiveness of NH3 emission controls on reducing nitrogen deposition to the Yellow Sea.

  10. Three-dimensional inversion of EarthScope MT data collected over the northwestern United States

    NASA Astrophysics Data System (ADS)

    Cuma, M.; Zhdanov, M. S.; Gribenko, A.; Marie, G.

    2012-12-01

    We have inverted magnetotelluric (MT) data collected in nine states of the northwestern United States as a part of the EarthScope project for 3D imaging of electrical resistivity to a depth of 500 km using recent advances in extremely large-scale electromagnetic modeling and inversion. 3D inversion was applied to the EarthScope MT data collected at 260 stations over an area extending from ˜123° W to ˜105° W and from ˜38° N to ˜49° N. We used cells with a horizontal discretization of 10 km by 10 km, and a vertical discretization starting from 1 km at the surface and logarithmically increasing with depth. The inversion domain contained 2,138,400 cells, and had an initial model of a 100 ohm-m half space. In our inversion we fit both the amplitude and phase of all four components of the impedance tensors for 16 periods logarithmically spaced between 10 s and 10,000 s. The results of our mega-cell 3D inversion reveal multi-scale geoelectrical inhomogeneities in the upper mantle closely related to major known tectonic features. Our geoelectrical model clearly shows a resistive structure associated with the Juan de Fuca slab subducting beneath the northwestern United States, and the conductive zone of partially melted material above the subducting slab due to the release of fluids from the downgoing slab. We observe extensive areas of moderate-to-high conductive asthenosphere below 100 to 200 km. The geoelectrical model also shows a prominent conductive feature associated with the partially melted mantle plume-like layer of the Yellowstone hotspot. These results correlate reasonably well with P-wave and S-wave velocity models independently obtained from seismic tomography. We acknowledge that our geoelectrical model of the northwestern United States represents just one of the first models obtained from 3D inversion of EarthScope MT data. Such large-scale MT inversions are extremely complex, and require significant additional efforts to fully model, understand, and interpret the EarthScope MT data.

  11. Precipitation reconstruction for the northwestern Chinese Altay since 1760 indicates the drought signals of the northern part of inner Asia.

    PubMed

    Chen, Feng; Yuan, Yujiang; Zhang, Tongwen; Shang, Huaming

    2016-03-01

    Based on the significant positive correlations between the regional tree-ring width chronology and local climate data, the total precipitation of the previous July to the current June was reconstructed since AD 1760 for the northwestern Chinese Altay. The reconstruction model accounts for 40.7 % of the actual precipitation variance during the calibration period from 1959 to 2013. Wet conditions prevailed during the periods 1764-1777, 1784-1791, 1795-1805, 1829-1835, 1838-1846, 1850-1862, 1867-1872, 1907-1916, 1926-1931, 1935-1943, 1956-1961, 1968-1973, 1984-1997, and 2002-2006. Dry episodes occurred during 1760-1763, 1778-1783, 1792-1794, 1806-1828, 1836-1837, 1847-1849, 1863-1866, 1873-1906, 1917-1925, 1932-1934, 1944-1955, 1962-1967, 1974-1983, 1998-2001, and 2007-2012. The spectral analysis of the precipitation reconstruction shows the existence of some cycles (15.3, 4.5, 3.1, 2.7, and 2.1 years). The significant correlations with the gridded precipitation dataset revealed that the precipitation reconstruction represents the precipitation variation for a large area of the northern part of inner Asia. A comparison with the precipitation reconstruction from the southern Chinese Altay shows the high level of confidence for the precipitation reconstruction for the northwestern Chinese Altay. Precipitation variation of the northwestern Chinese Altay is positively correlated with sea surface temperatures in tropical oceans, suggesting a possible linkage of the precipitation variation of the northwestern Chinese Altay to the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). The synoptic climatology analysis reveals that there is the relationship between anomalous atmospheric circulation and extreme climate events in the northwestern Chinese Altay. PMID:26232944

  12. Precipitation reconstruction for the northwestern Chinese Altay since 1760 indicates the drought signals of the northern part of inner Asia

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Yuan, Yujiang; Zhang, Tongwen; Shang, Huaming

    2016-03-01

    Based on the significant positive correlations between the regional tree-ring width chronology and local climate data, the total precipitation of the previous July to the current June was reconstructed since AD 1760 for the northwestern Chinese Altay. The reconstruction model accounts for 40.7 % of the actual precipitation variance during the calibration period from 1959 to 2013. Wet conditions prevailed during the periods 1764-1777, 1784-1791, 1795-1805, 1829-1835, 1838-1846, 1850-1862, 1867-1872, 1907-1916, 1926-1931, 1935-1943, 1956-1961, 1968-1973, 1984-1997, and 2002-2006. Dry episodes occurred during 1760-1763, 1778-1783, 1792-1794, 1806-1828, 1836-1837, 1847-1849, 1863-1866, 1873-1906, 1917-1925, 1932-1934, 1944-1955, 1962-1967, 1974-1983, 1998-2001, and 2007-2012. The spectral analysis of the precipitation reconstruction shows the existence of some cycles (15.3, 4.5, 3.1, 2.7, and 2.1 years). The significant correlations with the gridded precipitation dataset revealed that the precipitation reconstruction represents the precipitation variation for a large area of the northern part of inner Asia. A comparison with the precipitation reconstruction from the southern Chinese Altay shows the high level of confidence for the precipitation reconstruction for the northwestern Chinese Altay. Precipitation variation of the northwestern Chinese Altay is positively correlated with sea surface temperatures in tropical oceans, suggesting a possible linkage of the precipitation variation of the northwestern Chinese Altay to the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). The synoptic climatology analysis reveals that there is the relationship between anomalous atmospheric circulation and extreme climate events in the northwestern Chinese Altay.

  13. Copper-silver deposits of the Revett Formation, Montana and Idaho: origin and resource potential

    USGS Publications Warehouse

    Frost, Thomas P.; Zientek, Michael L.

    2006-01-01

    The Revett Formation of northern Idaho and western Montana contains major stratabound copper-silver deposits near Troy, Rock Creek, and Rock Lake, Montana. To help the U.S. Forest Service (USFS) meet its goal of integrating geoscience information into the land-planning process, U.S. Geological Survey (USGS) scientists recently completed a compilation of regional stratigraphy and mineralogy of the Revett Formation and a mineral resource assessment of Revett-type copper-silver deposits. The USGS assessment indicates that a large area of USFS-administered land in northwestern Montana and northern Idaho may contain significant undiscovered Revett-type copper-silver deposits.

  14. An association between urinary cadmium and urinary stone disease in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    SciTech Connect

    Swaddiwudhipong, Witaya; Mahasakpan, Pranee; Limpatanachote, Pisit; Krintratun, Somyot

    2011-05-15

    Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: {yields} Excessive calciuria is the major risk of urinary stone formation. {yields} We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. {yields} The rate of urinary stones increases with increasing urinary cadmium. {yields} Urinary calcium excretion increases with increasing urinary cadmium. {yields} Elevated calciuria induced by cadmium may increase the risk of urinary stones.

  15. Planet Formation

    NASA Astrophysics Data System (ADS)

    Klahr, Hubert; Brandner, Wolfgang

    2011-02-01

    1. Historical notes on planet formation Bodenheimer; 2. The formation and evolution of planetary systems Bouwman et al.; 3. Destruction of protoplanetary disks by photoevaporation Richling, Hollenbach and Yorke; 4. Turbulence in protoplanetary accretion disks Klahr, Rozyczka, Dziourkevitch, Wunsch and Johansen; 5. The origin of solids in the early solar system Trieloff and Palme; 6. Experiments on planetesimal formation Wurm and Blum; 7. Dust coagulation in protoplanetary disks Henning, Dullemond, Wolf and Dominik; 8. The accretion of giant planet cores Thommes and Duncan; 9. Planetary transits: direct vision of extrasolar planets Lecavelier des Etangs and Vidal-Madjar; 10. The core accretion - gas capture model Hubickyj; 11. Properties of exoplanets Marcy, Fischer, Butler and Vogt; 12. Giant planet formation: theories meet observations Boss; 13. From hot Jupiters to hot Neptures … and below Lovis, Mayor and Udry; 14. Disk-planet interaction and migration Masset and Kley; 15. The Brown Dwarf - planet relation Bate; 16. From astronomy to astrobiology Brandner; 17. Overview and prospective Lin.

  16. Geothermal and compositional variety of old oceanic upper mantle in northwestern Pacific: Insights from seafloor magnetotelluric experiments

    NASA Astrophysics Data System (ADS)

    Utada, H.; Baba, K.; Tada, N.; Shimizu, H.; Zhang, L.; Liang, P.

    2014-12-01

    Oceanic upper mantle beneath the northwestern Pacific has large-scale lateral heterogeneity that is impossible to attribute to just an age-dependency of the thermal structure based on a cooling of homogeneous mantle with age. This surprising fact was revealed from seafloor magnetotelluric (MT) data collected in three areas, northwest (Area A) and southeast (Area B) of the Shatsky Rise, and off the Bonin Trench (Area C), through the Normal Oceanic Mantle Project and the Stagnant Slab Project. One-dimensional structures of electrical conductivity representing each area show significant difference in the thickness of the upper resistive layer that may be interpreted as cool lithosphere. The thickness of the layer that is more resistive than 0.01 S m-1 is ~80 km for Area A, ~110 km for Area B, and ~180 km for Area C. The conductivity below the resistive layer is similar to ~0.03 S m-1 for Areas A and C but a slightly higher than it for Area B. The thermal structures for the lithospheric age representing the areas (130, 140, and 147 Ma for Areas A, B, and C, respectively) predicted from a simple plate cooling model are almost identical and thus cannot reproduce such variations in electrical conductivity. Then, in this study, thermal and compositional states of the mantle beneath the three areas were investigated to discuss the cause of the variations. Combination of five model parameters, electrical conductivity of crust, mantle potential temperature, thickness of thermally conductive plate, and H2O and CO2 contents in the asthenospheric mantle were searched by forward modeling and the χ2 misfit between the MT responses observed and predicted were assessed with 95% acceptable level. The possibility of partial melting was taken into account by comparing to the solidus of peridotite that is reduced by H2O and CO2. We assumed that the mantle conductivity may be represented by the mixture of hydrous olivine and hydrous carbonated melt. The results suggest a possible influence of a mantle up-welling associated with the formation of the Shatsky Rise to the mantle beneath Areas A and B although these areas are away from the bathymetric anomaly.

  17. GIS-based geospatial infrastructure of water resource assessment for supporting oil shale development in Piceance Basin of Northwestern Colorado

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Minnick, Matthew D.; Mattson, Earl D.; Geza, Mengistu; Murray, Kyle E.

    2015-04-01

    Oil shale deposits of the Green River Formation (GRF) in Northwestern Colorado, Southwestern Wyoming, and Northeastern Utah may become one of the first oil shale deposits to be developed in the U.S. because of their richness, accessibility, and extensive prior characterization. Oil shale is an organic-rich fine-grained sedimentary rock that contains significant amounts of kerogen from which liquid hydrocarbons can be produced. Water is needed to retort or extract oil shale at an approximate rate of three volumes of water for every volume of oil produced. Concerns have been raised over the demand and availability of water to produce oil shale, particularly in semiarid regions where water consumption must be limited and optimized to meet demands from other sectors. The economic benefit of oil shale development in this region may have tradeoffs within the local and regional environment. Due to these potential environmental impacts of oil shale development, water usage issues need to be further studied. A basin-wide baseline for oil shale and water resource data is the foundation of the study. This paper focuses on the design and construction of a centralized geospatial infrastructure for managing a large amount of oil shale and water resource related baseline data, and for setting up the frameworks for analytical and numerical models including but not limited to three-dimensional (3D) geologic, energy resource development systems, and surface water models. Such a centralized geospatial infrastructure made it possible to directly generate model inputs from the same database and to indirectly couple the different models through inputs/outputs. Thus ensures consistency of analyses conducted by researchers from different institutions, and help decision makers to balance water budget based on the spatial distribution of the oil shale and water resources, and the spatial variations of geologic, topographic, and hydrogeological characterization of the basin. This endeavor encountered many technical challenging and has not been done in the past for any oil shale basin. The database built during this study remains valuable for any other future studies involving oil shale and water resource management in the Piceance Basin. The methodology applied in the development of the GIS based geospatial infrastructure can be readily adapted for other professionals to develop database structure for other similar basins.

  18. Geochemical and geomorphological evidence for the provenance of aeolian deposits in the Badain Jaran Desert, northwestern China

    NASA Astrophysics Data System (ADS)

    Hu, Fangen; Yang, Xiaoping

    2016-01-01

    Identifying provenance of aeolian deposits in the mid-latitude deserts of Asia is essential for understanding formation and changes of Earth surface processes due to palaeoclimatic fluctuations. While some earlier studies focused on the interpretation of palaeoenvironments on the basis of aeolian deposits mainly in the desert margins and inter-dune lacustrine sediments, research on provenance of desert sands in the vast Asian mid-latitude deserts is still rare. In this paper, we present new geochemical data which provide insight to the provenance of dune sands in the Badain Jaran Desert, northwestern China, an important part of this desert belt. We sampled aeolian and lacustrine sediments in various parts of the Badain Jaran Desert, and examined their major, trace and rare earth elements (REE) in bulk samples, coarse and fine fractions, respectively. In addition, we took and analyzed samples from a rarely known dune field with red sands, northeast of the Badain Jaran. Our results show that the sands from the Badain Jaran Desert are generally different from those in the red sand dune field in terms of REE pattern and geochemical characteristics, suggesting different sediment origins. Geochemical composition of the aeolian sand samples indicates these sediments should be mainly derived from mixed source rocks of granite, granitoids and granodiorite. Comparing the immobile trace elements and REE ratios of the samples from the Badain Jaran Desert, red sand dune field with rocks of granite, granitoids in their potential source areas, we conclude that: (1) The aeolian deposits in the Badain Jaran Desert are predominantly derived from the Qilian Mountains, northeastern Tibetan Plateau initially via fluvial processes; (2) The Altay Mountains and Mongolian Gobi are the ultimate source areas for the red sand dune field; (3) The Altai Mountains and Mongolian Gobi in the northwest, that could produce massive amounts of materials via intensive deflation and alluvial process, are additional sand sources of the Badain Jaran Desert although their contribution is of secondary significance. As the Badain Jaran Desert acts as sediment sinks of sediments from the Qilian Mountains of northeastern Tibetan Plateau via fluvial processes, it is likely that zircon grains of loess on the Chinese Loess Plateau with age distributions similar to those of the northern Tibetan Plateau could be derived from the Badain Jaran Desert, as the wind data suggest.

  19. Origin of the Early Permian zircons in Keping basalts and magma evolution of the Tarim Large Igneous Province (northwestern China)

    NASA Astrophysics Data System (ADS)

    Li, Yin-Qi; Li, Zi-Long; Yu, Xing; Langmuir, Charles H.; Santosh, M.; Yang, Shu-Feng; Chen, Han-Lin; Tang, Zhong-Li; Song, Biao; Zou, Si-Yuan

    2014-09-01

    The Tarim continental flood basalts (CFBs) provide important clues about the genesis and magmatic evolution of the Early Permian Tarim Large Igneous Province (Tarim LIP) in northwestern China. Here we present results of LA-MC-ICPMS Lu-Hf isotope analysis on Early Permian (ca. 290 Ma) zircons extracted from the Tarim CFBs in the Keping area, northwest of the Tarim Basin. Zircons from two sub-groups of Keping basalts (Groups 1a and 1b) have similar Lu-Hf isotopic compositions and exhibit a relatively large range of 176Hf/177Hf ratios between 0.282422 and 0.282568. Their negative εHf(t) values (- 6.8-- 1.4) are generally lower than the whole-rock εHf(t) values of their host basalts (- 2.8-2.1), and are distinct from other known intrusive rocks (- 0.3-7.1) in the Tarim LIP and their hosted zircons (4.9-8.8). Systematic studies of Hf isotopic data from Tarim and its adjacent regions reveal that these zircons are probably xenocrysts, sourced from coeval igneous rocks in the South Tianshan Orogen (e.g., the Lower Permian Xiaotikanlike Formation volcanic and pyroclastic rock suite). This, together with the presence of Precambrian zircons in Keping basalts, clearly indicates crustal contamination during their eruptions and provides hints about the potential contaminant sources. Geochemical modeling further suggests that the earlier erupted Group 1b basalts experienced more contamination, predominantly by some high Th-U-Pb rock components, most likely from the South Tianshan Orogen. The later erupted Group 1a basalts in the Keping area have been less contaminated with mainly the Tarim Precambrian rocks. Another group of the Tarim CFBs in the Northern Tarim Uplift (Group 2) appears to have undergone negligible crustal contamination but possesses evidence for variable source compositions. The modeling also indicates that the uncontaminated parental magmas of various Tarim LIP rocks (from the picrites and basalts to ultramafic-mafic and syenitic intrusive rocks) exhibit a wide range of εNd(t) values (ca. - 5-5), reflecting source isotopic heterogeneity, which may be a consequence of plume-lithosphere interaction during the generation of the Tarim LIP.

  20. GIS-based Geospatial Infrastructure of Water Resource Assessment for Supporting Oil Shale Development in Piceance Basin of Northwestern Colorado

    SciTech Connect

    Zhou, Wei; Minnick, Matthew D; Mattson, Earl D; Geza, Mengistu; Murray, Kyle E.

    2015-04-01

    Oil shale deposits of the Green River Formation (GRF) in Northwestern Colorado, Southwestern Wyoming, and Northeastern Utah may become one of the first oil shale deposits to be developed in the U.S. because of their richness, accessibility, and extensive prior characterization. Oil shale is an organic-rich fine-grained sedimentary rock that contains significant amounts of kerogen from which liquid hydrocarbons can be produced. Water is needed to retort or extract oil shale at an approximate rate of three volumes of water for every volume of oil produced. Concerns have been raised over the demand and availability of water to produce oil shale, particularly in semiarid regions where water consumption must be limited and optimized to meet demands from other sectors. The economic benefit of oil shale development in this region may have tradeoffs within the local and regional environment. Due to these potential environmental impacts of oil shale development, water usage issues need to be further studied. A basin-wide baseline for oil shale and water resource data is the foundation of the study. This paper focuses on the design and construction of a centralized geospatial infrastructure for managing a large amount of oil shale and water resource related baseline data, and for setting up the frameworks for analytical and numerical models including but not limited to three-dimensional (3D) geologic, energy resource development systems, and surface water models. Such a centralized geospatial infrastructure made it possible to directly generate model inputs from the same database and to indirectly couple the different models through inputs/outputs. Thus ensures consistency of analyses conducted by researchers from different institutions, and help decision makers to balance water budget based on the spatial distribution of the oil shale and water resources, and the spatial variations of geologic, topographic, and hydrogeological Characterization of the basin. This endeavor encountered many technical challenging and hasn't been done in the past for any oil shale basin. The database built during this study remains valuable for any other future studies involving oil shale and water resource management in the Piceance Basin. The methodology applied in the development of the GIS based Geospatial Infrastructure can be readily adapted for other professionals to develop database structure for other similar basins.

  1. Hydrogeochemical and vertical electrical soundings for groundwater investigations, Burg El-Arab area, Northwestern Coast of Egypt

    NASA Astrophysics Data System (ADS)

    Atwia, Mohamed G.; Abu-Heleika, Mohamed M.; El-Horiny, Mohamed M.

    2013-04-01

    An integrated geological, hydrochemical, and geoelectrical investigation of shallow groundwater occurrence in Burg El-Arab area, northwestern coastal zone of Egypt is carried out. Groundwater of oolitic limestone and clastic aquifers is the principal source of water supply for agriculture in the area. The purpose of this study is to describe the hydrogeologic characteristics of aquifers and to provide a general evaluation of the chemical quality of water in aquifers. Chemical analysis was used to evaluate the chemical characteristics of groundwater and assessment of water quality. Electrical soundings were employed to delineate different water bearing formations and the configuration of the interface between them. Thirty-four water samples were collected and chemically analyzed from the two main aquifers in the area. Groundwaters of oolitic limestone aquifer are dominated by NaCl and have average TDS of approximately 2830 mg/l. Groundwater samples from clastic aquifer are slightly weakly mineralized (TDS approximately 2700 mg/l) and dominated by CaSO4. The hydrochemical data indicate that the groundwater is of meteoric origin. The variation in the chemistry of water is thought to be related to the weathering of minerals of the water-bearing sediments, mixing with marine water, and leaching of fertilizers in the newly reclaimed areas. Groundwater of the area can be used for irrigation under special circumstances management as the sodium hazard is medium while the salinity hazard ranges from high to very high. Thirty-four profiles of vertical electrical soundings (VESs) were obtained in Burg El-Arab area to examine the variations of subsurface geology and associated groundwater chemistry. Resistivity and thickness of aquifers, resistivity of the unsaturated zone and depth to the confining bed have been delineated from the interpretation of electrical sounding data. The range of electrical resistivity values have been assigned to different layers by calibrating electrical resistivity with the borehole data. Results of the vertical electrical soundings and the hydrochemistry of the groundwater samples show that the brackish groundwater is dominated in the study area whereas the fresh groundwater is found as isolated patches in oolitic limestone aquifer.

  2. On the wet and dry deposition of ionic species in the vicinity of coal-fired power plants, northwestern Greece

    NASA Astrophysics Data System (ADS)

    Tsitouridou, R.; Anatolaki, Ch.

    2007-01-01

    Rainwater and deposited particle samples were collected for 1 year (October 2000-October 2001), at two sites in the area of "Eordaia Basin", northwestern Greece, where four lignite-burning power units (total capacity 4000 MW) are operated. The samples were collected on a monthly basis and analyzed for Cl -, NO 3-, SO 42-, Na +, K +, NH 4+, Ca 2+ and Mg 2+. pH and conductivity measurements were conducted only for rain samples. The lowest rain pH values measured at the two sites (S1 and S2) were 4.15 and 5.20 respectively. 40-50% of rain samples at both sites showed pH values in the acidic area (mean values: 5.13 and 5.99 respectively). The quantification of the neutralization effect of the alkaline ions showed the prevalence role of Ca, followed by NH 4, Na and Mg. Wet and dry ionic concentrations and deposition fluxes showed considerable variability between the sites with higher values for Ca and SO 4 for both sites. This could be partly attributed to the strong influence of the local emissions. Fly ash, produced in huge amounts, is the major source for Ca and SO 4 in the area even at the site of Vegoritida (S2), which is a pure remote site located out of the main wind flow of the basin. The relative contribution of wet and dry to the total annual deposition for the site of Petrana (S1) is 45% and 55% respectively for SO 4, 41% and 59% for NO 3 and 41% and 59% for Ca. Contrary, for Vegoritida site (S2) the wet deposition is the main contributor to the total, by 60-80%, for the majority of the species. The difference between the two site environments could be explained by the different local source effect, which is more obvious to dry deposition of the nearest to power plants site of Petrana. Additionally, the application of principal component analysis confirmed the different formation patterns for rain and dust and considerable difference in source emission impact between the sites.

  3. Land-sea correlations in the Australian region: post-glacial onset of the monsoon in northwestern Western Australia

    NASA Astrophysics Data System (ADS)

    De Deckker, Patrick; Barrows, Timothy T.; Rogers, John

    2014-12-01

    Deep-sea core Fr10/95-GC17, collected offshore North West Cape at the western tip of Western Australia, is located beneath the path of the Leeuwin Current. This shallow, warm and low salinity current is an offshoot of the Indonesian Throughflow that transfers water and heat from the West Pacific Ocean into the Indian Ocean. The location is at the edge of the Indo Pacific Warm Pool, the source of large-scale transfer of moisture and heat from the ocean to the atmosphere. For this core, we combine previously published data with new research and use a revised chronology to re-examine the timing of climate change during the last 34,000 years in the tropics of northern Australia. The age model for the core is based on 15 radiocarbon dates complemented by luminescence ages and an oxygen isotope record. This study draws on an extensive range of analyses that have been performed on the core, including micropalaeontology of planktic and benthic foraminifera and coccoliths, stable isotopes analysis of foraminifera and their faunal composition, clay content, sediment composition and pollen analyses. Sea-surface and land temperatures are estimated from the foraminifer faunal analyses and from pollen spectra, respectively. The clay fraction and sediment composition and radiogenic isotopes of that fraction helped identify changes both on land and at sea: changes such as rainfall as shown by river discharge, and oceanic current tracing by neodymium, strontium and lead isotopes obtained from sediments. The most significant finding is that a major threshold was crossed at 13 ka BP. Prior to that time, rainfall over NW Western Australia was low as was sea-surface temperature (SST); river discharge to the ocean was also low as a result of the lack of monsoonal activity and finally, ocean alkalinity would have been lower than at present due to the uptake of atmospheric CO2. By 13 ka BP, the entire system moved away from glacial period conditions. The Indo-Australian monsoon commenced in and offshore northwestern Western Australia. SST and land temperature increased dramatically and ocean alkalinity changed due to the formation of a "barrier layer" (a low salinity cap), over the Indo Pacific Warm Pool. During the Holocene, river discharge and the land and ocean temperatures did not covary, for example, the highest rainfall did not coincide with the highest SST. Finally, the last 5 ka saw a strengthening of ENSO in the region.

  4. Historical pattern and mass balance of trace metals in sediments of the northwestern Adriatic Sea Shelf.

    PubMed

    Romano, Stefania; Langone, Leonardo; Frignani, Mauro; Albertazzi, Sonia; Focaccia, Paola; Bellucci, Luca Giorgio; Ravaioli, Mariangela

    2013-11-15

    In view of the recent action in Marine Strategy Framework Directive, reconstructing the history of anthropogenic metal inputs and calculating the budgets for the northwestern part of the Italian Adriatic basin can provide a benchmark for comparison with new evidences and enlighten recent environmental changes. Among the metals, the attention was focused on Pb and Zn, as they provide the most significant anthropogenic signals. In 1988, areal distributions clearly identified the Po, Adige and Brenta rivers as the main sources of contaminants. The study area was divided in three compartments. The area in front of the Po delta represented a sink for metals but the accumulation of Zn and Pb integrated over the entire study area suggests an effective export throughout southern boundary. Most concentration-depth/year profiles in cores showed an upward increase from the Italian Unification (1861), with a still significant anthropogenic supply at the time of sampling. PMID:24119313

  5. Factors associated with self-reported symptoms of acute pesticide poisoning among farmers in northwestern Jamaica

    PubMed Central

    Ncube, Ngqabutho M.; Fogo, Christopher; Bessler, Patricia; Jolly, Curtis M.; Jolly, Pauline E.

    2011-01-01

    Pesticide poisoning is a major public health concern in developing countries. We conducted a population survey among farmers in three parishes of northwestern Jamaica to determine the occurrence of acute pesticide poisoning and to identify factors associated with pesticide poisoning. Approximately 16% of 359 farmers who participated in the study reported one or more incidents of acute pesticide poisoning within the last two years. Only 25% of the farmers reported ever receiving training in pesticide handling or safety. The majority (68%) of farmers who reported pesticide poisoning never sought medical attention for poisoning. The factors found to be associated with pesticide poisoning in this study indicate that implementation of specific intervention strategies and education of farmers is needed in order to improve safe handling, use and disposal of pesticides and reduce incidents of acute pesticide poisoning. PMID:24484363

  6. Tectonic, volcanic, and climatic geomorphology study of the Sierras Pampeanas Andes, northwestern Argentina

    NASA Technical Reports Server (NTRS)

    Bloom, A. L.; Strecker, M. R.; Fielding, E. J.

    1984-01-01

    A proposed analysis of Shuttle Imaging Radar-B (SIR-B) data extends current research in the Sierras Pampeanas and the Puna of northwestern Argentina to the determination - by the digital analysis of mountain-front sinuousity - of the relative age and amount of fault movement along mountain fronts of the late-Cenozoic Sierras Pampeanas basement blocks; the determination of the age and history of the boundary across the Andes at about 27 S latitude between continuing volcanism to the north and inactive volcanism to the south; and the determination of the age and extent of Pleistocene glaciation in the High Sierras, as well as the comparative importance of climatic change and tectonic movements in shaping the landscape. The integration of these studies into other ongoing geology projects contributes to the understanding of landform development in this active tectonic environment and helps distinguish between climatic and tectonic effects on landforms.

  7. Impact of fire on long-term vegetation dynamics of ombrotrophic peatlands in northwestern Qubec, Canada

    NASA Astrophysics Data System (ADS)

    Magnan, Gabriel; Lavoie, Martin; Payette, Serge

    2012-01-01

    A 7000-year record of local fire history was reconstructed from three ombrotrophic peatlands in the James Bay lowlands (northwestern Qubec, Canada) using a high-resolution analysis of macroscopic charcoal (long axis ? 0.5 mm). The impact of fire on vegetation changes was evaluated using detailed analysis of plant macrofossils. Compared to upland boreal forest, fire incidence in these Sphagnum-dominated bogs is rather low. Past fire occurrence seems to have been controlled primarily by internal processes associated with local hydroseral succession. Size of the peatland basin and distance from the well-drained forest soils also appear to be factors controlling fire occurrence. The impact of peatland fires on long-term vegetation succession appears negligible except in a forested bog, where it initiated the replacement of Sphagnum by mosses. In some circumstances, fire caused marked changes in the bryophyte assemblages over many decades. However, ombrotrophic peatland vegetation is generally resilient to surface fire.

  8. New blueberry and mortiño relatives (Ericaceae) from northwestern Colombia

    PubMed Central

    Pedraza-Peñalosa, Paola

    2015-01-01

    Abstract The inventory of the vascular plants of one of the richest and least studied floras, the Andean and Chocó regions of northwestern Colombia, targets Las Orquídeas National Park. As a result of field trips to areas never before collected, several epiphytic and small terrestrial shrubs in the family Ericaceae have been discovered in the Park’s humid forests. Five new, morphologically remarkable species of Ericaceae (tribe Vaccinieae), are here described and illustrated. In a separate phylogenetic analysis, Psammisia pinnata Pedraza, Psammisia pseudoverticillata Pedraza, Satyria orquidiensis Pedraza, and Satyria pterocalyx Pedraza, were placed by molecular sequence data within clades of the non-monophyletic genera Psammisia and Satyria; phylogenetic evidence for the placement of Psammisia sophiae Pedraza is still lacking. Their affinities are here discussed, along with their preliminary conservation status. PMID:25987884

  9. Ecological niches of three teuthophageous odontocetes in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Praca, E.; Gannier, A.

    2008-02-01

    In the northwestern Mediterranean Sea, sperm whales, pilot whales and Risso's dolphins prey exclusively or preferentially on cephalopods. In order to evaluate their competition, we modelled their habitat suitability with the Ecological Niche Factor Analysis (ENFA) and compared their ecological niches using a discriminant analysis. We used a long term (1995-2005) small boat data set, with visual and acoustic (sperm whale) detections. Risso's dolphin had the shallowest and the more spatially restricted principal habitat, mainly located on the upper part of the continental slope (640 m mean depth). With a wider principal habitat, at 1750 m depth in average, the sperm whale used a deeper part of the slope as well as the closest offshore waters. Finally, the pilot whale has the most oceanic habitat (2500 m mean depth) mainly located in the central Ligurian Sea and Provençal basin. Therefore, potential competition for food between these species may be reduced by the differentiation of their habitats.

  10. Ecological niche of three teuthophageous odontocetes in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Praca, E.; Gannier, A.

    2007-10-01

    In the northwestern Mediterranean Sea, sperm whales, pilot whales and Risso's dolphins prey on cephalopods exclusively or preferentially. In order to evaluate their competition, we modelled their habitat suitability with the Ecological Niche Factor Analysis (ENFA) and compared their ecological niche using a discriminant analysis. We used a long term (1995-2005) small boat data set, with visual and acoustic (sperm whale) detections. Risso's dolphin had the shallowest and the more spatially restricted principal habitat, mainly located on the upper part of the continental slope (640 m mean depth). With a wider principal habitat, at 1750 m depth in average, the sperm whale used a deeper part of the slope as well as close offshore waters. Finally, the pilot whale has the most oceanic habitat (2500 m mean depth) mainly located in the central Ligurian Sea and Provençal basin. Therefore, potential competition for food between these species may be reduced by the differentiation of their ecological niches.

  11. Late Devonian sedimentary record of the Paleotethys Ocean - The Mae Sariang section, northwestern Thailand

    NASA Astrophysics Data System (ADS)

    Königshof, P.; Savage, N. M.; Lutat, P.; Sardsud, A.; Dopieralska, J.; Belka, Z.; Racki, G.

    2012-06-01

    An 11 m thick condensed sequence of Late Devonian limestones in northwestern Thailand exhibits faunal associations and sedimentological-/microfacies data which are indicative of a pelagic facies setting. The entire long-ranging section is completely free from clastic input. Similar successions are known worldwide in a few sections only. The Mae Sariang section is characterised by low sedimentation rates as recognised by a number of hardgrounds, neptunian dikes and Fe/Mn crusts. The succession comprises a number of pelagic faunal elements e.g. conodonts, cephalopods and pelagic ostracodes. The fauna records rare macrofossils and the faunal diversity is low. The very condensed section ranges from the Late rhenana to praesulcata conodont biozones, but contains some global events as undoubtedly shown by biostratigraphical and carbon-isotope results (including major Kellwasser and Hangenberg biotic crises). In terms of plate tectonics this important succession most probably belongs to the Inthanon Zone comprising remnants of the Paleotethys Ocean.

  12. SALINITY AND SODICITY INTERACTIONS OF WEATHERED MINESOILS IN NORTHWESTERN NEW MEXICO AND NORTH EASTERN ARIZONA

    SciTech Connect

    Brent Musslewhite; Song Jin

    2006-05-01

    Weathering characteristics of minesoils and rooting patterns of key shrub and grass species were evaluated at sites reclaimed for 6 to 14 years from three surface coal mine operations in northwestern New Mexico and northeastern Arizona. Non-weathered minesoils were grouped into 11 classifications based on electrical conductivity (EC) and sodium adsorption ratio (SAR). Comparisons of saturated paste extracts, from non-weathered and weathered minesoils show significant (p < 0.05) reductions in SAR levels and increased EC. Weathering increased the apparent stability of saline and sodic minesoils thereby reducing concerns of aggregate slaking and clay particle dispersion. Root density of four-wing saltbush (Atriplex canascens), alkali sacaton (Sporobolus airoides), and Russian wildrye (Psathyrostachys junceus) were nominally affected by increasing EC and SAR levels in minesoil. Results suggest that saline and sodic minesoils can be successfully reclaimed when covered with topsoil and seeded with salt tolerant plant species.

  13. New blueberry and mortiño relatives (Ericaceae) from northwestern Colombia.

    PubMed

    Pedraza-Peñalosa, Paola

    2015-01-01

    The inventory of the vascular plants of one of the richest and least studied floras, the Andean and Chocó regions of northwestern Colombia, targets Las Orquídeas National Park. As a result of field trips to areas never before collected, several epiphytic and small terrestrial shrubs in the family Ericaceae have been discovered in the Park's humid forests. Five new, morphologically remarkable species of Ericaceae (tribe Vaccinieae), are here described and illustrated. In a separate phylogenetic analysis, Psammisiapinnata Pedraza, Psammisiapseudoverticillata Pedraza, Satyriaorquidiensis Pedraza, and Satyriapterocalyx Pedraza, were placed by molecular sequence data within clades of the non-monophyletic genera Psammisia and Satyria; phylogenetic evidence for the placement of Psammisiasophiae Pedraza is still lacking. Their affinities are here discussed, along with their preliminary conservation status. PMID:25987884

  14. [Spatial structure of natural foci of hantavirus on the territory of Northwestern Caucasus].

    PubMed

    Okulova, N M; Khliap, L A; Varshavskiĭ, A A; Dzagurova, T K; Iunicheva, Iu V; Riabova, T E; Baskevich, M I; Vasilenko, L E; Tkachenko, E A

    2013-01-01

    For the period from 2001 to 2011 zoological and epizootological studies in more than 100 points of Northwestern Caucasus including territories of Krasnodar Region and Republic of Adygea were carried out. 8723 specimens of small mammals represented by 20 rodent species and 7 insectivorous species were captured and examined. Organs and blood from 5057 specimens of creatures were studied for hantavirus infection. The presence of natural foci of circulation of 2 species of hantavirus--Dobrava/Belgrade and Tula--was established. Sochi viruses and presumably Kurkin with main natural hosts--Caucasian wood and field mice belong to the first species. Tula and Adler viruses with the main host--Microtus genus vole belong to the second species. Quantitative characteristics of infection of small mammals of various species during different seasons and years on the examined territories were obtained, that allowed to create a map of allocation of foci of hantavirus circulation that differ by structure. PMID:24605654

  15. Acadian remobilization of a Taconian ophiolite, Hare Bay allochthon, northwestern Newfoundland

    SciTech Connect

    Cadwood, P.A. )

    1989-03-01

    The Hare Bay fault is a major subhorizontal detachment at the base of the ophiolitic St. Anthony Complex in the Hare Bay allochthon, northwestern Newfounland. The fault is a postmetamorphic brittle detachment that truncates footwall structures related to both initial Ordovician (Taconian) assembly of the allochthon and subsequent Silurian-Devonian (Acadian) deformation. Although previously mapped as a thrust, the fault has an extensional rather than a contractional geometry; it cuts downsection to the west in the direction of transport, and it juxtaposes a hanging-wall sequence that contains little or no Acadian deformation against a footwall sequence that was pervasively deformed during the Acadian orogeny. The St. Anthony Complex lies on the western margin of the Acadian deformed zone. Its final emplacement, through movement on the Hare Bay fault, probably occurred through extensional faulting during gravitational collapse of the Acadian mountain front.

  16. Factors affecting bird communities in fragments ofsecondary pine forests in the north-western Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Brotons, Lluís; Herrando, Sergi

    2001-02-01

    We assessed the influence of size, extent of isolation and vegetation structure of secondary forest fragments on the richness and species composition of breeding bird communities in a sample of pine forest fragments surrounded by an agricultural matrix in the north-western Mediterranean basin. Fragment size was the main predictor of bird's occurrence, since it accounted for 70 % of the model variation. Isolation was also a valuable predictor of species occurrence, especially for forest specialists. Finally, subarboreal vegetation such as holm oak and a well-developed tree layer of large pines favoured forest species occurrence. Therefore, in spite of the long history of human impact, forest birds in Mediterranean mosaics are sensitive to both habitat loss and isolation of remnant patches in a similar manner to the patterns found in other temperate fragmented landscapes where human impact is more recent.

  17. Temporal variability of marine debris deposition at Tern Island in the Northwestern Hawaiian Islands.

    PubMed

    Agustin, Alyssa E; Merrifield, Mark A; Potemra, James T; Morishige, Carey

    2015-12-15

    A twenty-two year record of marine debris collected on Tern Island is used to characterize the temporal variability of debris deposition at a coral atoll in the Northwestern Hawaiian Islands. Debris deposition tends to be episodic, without a significant relationship to local forcing processes associated with winds, sea level, waves, and proximity to the Subtropical Convergence Zone. The General NOAA Operational Modeling Environment is used to estimate likely debris pathways for Tern Island. The majority of modeled arrivals come from the northeast following prevailing trade winds and surface currents, with trajectories indicating the importance of the convergence zone, or garbage patch, in the North Pacific High region. Although debris deposition does not generally exhibit a significant seasonal cycle, some debris types contain considerable 3 cycle/yr variability that is coherent with wind and surface pressure over a broad region north of Tern. PMID:26578295

  18. Phylogeography of the finless porpoise (genus Neophocaena): testing the stepwise divergence hypothesis in the northwestern Pacific

    PubMed Central

    Lin, Wenzhi; Frère, Céline H.; Karczmarski, Leszek; Xia, Jia; Gui, Duan; Wu, Yuping

    2014-01-01

    We used 344 mitochondrial control region (717 bp) sequences from the finless porpoise (genus Neophocaena) from the northwestern Pacific to investigate the extent and manner in which past climatic oscillations may have shaped patterns of genetic diversity for this marine mammal. Both SplitsTree and Analysis of Molecular Variance (AMOVA) revealed the presence of a deep divergence among N. phocaenoides in subtropical waters compared with N. asiaeorientalis in temperate waters. Results from Migrate-n indicated that migration increased along the continent during the early Pleistocene period. Migration increased, although to a lesser extent than that during the Pleistocene, along the marginal shelf in the Yellow/Bohai Sea during the Last Glacial Maximum (LGM) due to a shortening coastline. Our results suggest that the current patterns of genetic diversity of Neophocaena vary at a hierarchy on a temporal and spatial scale, and phylogeographic history should be taken into account when examining species population structure and taxonomy. PMID:25303422

  19. The role of the sea on the flash floods events over Liguria (northwestern Italy)

    NASA Astrophysics Data System (ADS)

    Cassola, F.; Ferrari, F.; Mazzino, A.; Miglietta, M. M.

    2016-04-01

    The sensitivity to sea surface temperature (SST) of small-scale, flood-causing convective systems in Mediterranean coastal areas is analyzed by means of mesoscale numerical simulations. Two different SST initializations are considered: a coarse field provided by a global atmospheric model and a high-resolution multisatellite analysis. Quantitative precipitation forecasts are evaluated for a number of recent severe rainfall episodes in Liguria (northwestern Italy). In several cases, using a higher-resolution SST leads to more realistic precipitation estimates in the forecasting range 36-48 h. In the shorter range, the satellite SST has a limited, or even negative, impact, due to the relatively slow adjustment of initial atmospheric fields. In one case, the satellite SST is beneficial for the only run forced with accurate large-scale initial conditions. The results of this work suggest that a potentially significant improvement in severe precipitation forecasting in the Mediterranean could be achieved using realistic small-scale SST fields.

  20. Aerial photographs reveal late-20th-century dynamic ice loss in northwestern Greenland.

    PubMed

    Kjær, Kurt H; Khan, Shfaqat A; Korsgaard, Niels J; Wahr, John; Bamber, Jonathan L; Hurkmans, Ruud; van den Broeke, Michiel; Timm, Lars H; Kjeldsen, Kristian K; Bjørk, Anders A; Larsen, Nicolaj K; Jørgensen, Lars Tyge; Færch-Jensen, Anders; Willerslev, Eske

    2012-08-01

    Global warming is predicted to have a profound impact on the Greenland Ice Sheet and its contribution to global sea-level rise. Recent mass loss in the northwest of Greenland has been substantial. Using aerial photographs, we produced digital elevation models and extended the time record of recent observed marginal dynamic thinning back to the mid-1980s. We reveal two independent dynamic ice loss events on the northwestern Greenland Ice Sheet margin: from 1985 to 1993 and 2005 to 2010, which were separated by limited mass changes. Our results suggest that the ice mass changes in this sector were primarily caused by short-lived dynamic ice loss events rather than changes in the surface mass balance. This finding challenges predictions about the future response of the Greenland Ice Sheet to increasing global temperatures. PMID:22859486

  1. The first radiocarbon data of bone remains of mammoth faunal forms in northwestern Russia

    NASA Astrophysics Data System (ADS)

    Nikonov, A. A.; van der Plicht, J.

    2010-05-01

    Unlike in the neighboring territories, the distribution and the period of habitation of late Pleistocene mammoth complex animals in the northwestern area of Russia had not been studied until recently. This article fills in this gap using the bone material from the Zoological Institute of the Russian Academy of Sciences and the collections of one of the authors. The samples of 14 bones and teeth of big mammals uncovered in different places of the region were dated. The data obtained by conventional 14C method and AMS method agree with each other and make it possible to determine two periods of habitation of mammoth complex animals in the region: 39 000-23 000 years ago and 13 000-9800 years ago, which confirms that ice-free landscapes existed here at these time intervals.

  2. Maternal Clinical Findings in Malaria in Pregnancy in a Region of Northwestern Colombia

    PubMed Central

    Gabriel Piñeros, Juan; Tobon-Castaño, Alberto; Álvarez, Gonzalo; Portilla, Carmencita; Blair, Silvia

    2013-01-01

    In malaria-endemic regions of Latin America, little is known about malaria in pregnancy. To characterize the clinical and laboratory findings of maternal infection, we evaluated 166 cases of pregnant women infected with Plasmodium spp. in a prospective study conducted in northwestern Colombia during 2005–2006. A total of 89.8% (149 of 166) had fever or a history of fever in the past 48 hours, 9.0% (15 of 166) had severe malaria, of which 66.7% was caused by Plasmodium vivax and 33.3% by P. falciparum. Hepatic dysfunction was the main complication (9 of 15) observed. The proportion of severe cases was similar for both species (P = 0.41). In malaria-endemic areas of Colombia, malaria in pregnancy has a broad clinical spectrum. In pregnant women, P. vivax infection frequently leads to organ-specific complications. PMID:23897991

  3. Reproductive ecology of the green treefrog (Hyla cinerea) in Northwestern Florida

    USGS Publications Warehouse

    Gunzburger, M.S.

    2006-01-01

    Information on life-history traits is critical to understanding population dynamics of anurans. The objective of this study was to examine aspects of the reproductive ecology of Hyla cinerea in northwestern Florida. Four breeding localities in Leon County, Florida, were sampled over three seasons (2001-2003), amplexed pairs were found as early as 12 April and as late as 12 August. Egg clutches were counted from 51 amplexed pairs and adult size was measured in 43 pairs. Average clutch size was 1214 ?? 528 eggs (x- ?? SE, range = 359-2658). Female H. cinerea were slightly larger than males (x- ?? SE tibiofibula length = 24.9 ?? 2.2 and 24 ?? 1.7 mm, respectively). Female size was significantly positively correlated with clutch size and weakly correlated with size of the paired male. Comparison of the results of this study with previous research indicates that the reproductive ecology of H. cinerea varies across its geographic range.

  4. Ocean glider observations of iceberg-enhanced biological production in the northwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Biddle, Louise C.; Kaiser, Jan; Heywood, Karen J.; Thompson, Andrew F.; Jenkins, Adrian

    2015-01-01

    Icebergs affect local biological production around Antarctica. We used an ocean glider to observe the effects of a large iceberg that was advected by the Antarctic Slope Current along the continental slope in the northwestern Weddell Sea in early 2012. The high-resolution glider data reveal a pronounced effect of the iceberg on ocean properties, with oxygen concentrations of (13 4) ?mol kg-1 higher than levels in surrounding waters, which are most likely due to positive net community production. This response was confined to three areas of water in the direct vicinity of the iceberg track, each no larger than 2 km2. Our findings suggest that icebergs have an impact on Antarctic production presumably through local micronutrient injections, on a scale smaller than typical satellite observations of biological production in the Southern Ocean.

  5. Infection of Myxobolus galaxii (Myxozoa) in Galaxias maculatus (Osmeriformes: Galaxiidae) from northwestern Patagonian Andean lakes (Argentina).

    PubMed

    Flores, Verónica; Viozzi, Gustavo

    2007-04-01

    The infection of Myxobolus galaxii Szidat, 1953, from the musculature and abdominal organs of northwestern Patagonian Galaxias maculatus is described. Plasmodia are histozoic and intercellular. Spores are pyriform in valvar view and biconvex in sutural view, with 4-9 edge notches in the sutural line, varying in shape within the same plasmodium. Myxobolus galaxii was detected in fish from 7 of 17 Andean Patagonian lakes, with prevalences ranging between 2 and 17%. A repeating pattern of summer increment in prevalence was observed, which could be explained by the ontogenetic migratory movements of the fish in Lake Gutiérrez. Also, accumulation of plasmodia through the life span of fish was detected. PMID:17539428

  6. Mercury levels in raccoons (Procyon lotor) from the Warta Mouth National Park, northwestern Poland.

    PubMed

    Lanocha, Natalia; Kalisinska, Elzbieta; Kosik-Bogacka, Danuta I; Budis, Halina; Podlasinska, Joanna; Jedrzejewska, Ewa

    2014-06-01

    This is the first report on mercury (Hg) levels in the liver, kidney, skeletal muscle, and brain of raccoon in Europe. It studied Hg concentration in 24 raccoons from the Warta Mouth National Park, northwestern Poland by atomic absorption spectroscopy (AAS). The highest total Hg concentrations in the raccoon were found in the liver (maximum, 18.45 mg/kg dry weight), while the lowest in the brain (maximum, 0.49 mg/kg dw). In adult raccoons, Hg concentrations in the liver, kidney, and brain were higher than in immature individuals (p<0.001), while similar in skeletal muscle in both age groups. Our results are consistent with studies by other authors conducted in North America in areas with similar environmental conditions. PMID:24736978

  7. Depositional history of polychlorinated biphenyls in a dated sediment core from the northwestern Arabian Gulf.

    PubMed

    Gevao, Bondi; Aba, Abdul Aziz; Al-Ghadban, Abdul Nabi; Uddin, Saif

    2012-05-01

    The vertical distribution of polychlorinated biphenyls (PCBs) was measured in a dated sediment core from the northwestern Arabian Gulf to reconstruct their depositional history. The downcore profile showed an increase in concentrations from depth to a subsurface maximum of approximately 1,500 pg g(-1) in approximately 1991, followed by an exponential decrease to the sediment-water interface. Current concentrations of ΣPCBs are similar to levels predating the episodic input of PCBs in sediments dated coincident with the 1991 Arabian Gulf war. The spike in ΣPCB concentrations during the war may be related to the destruction of PCB-laden transformers during the conflict. The 15-fold decrease in ΣPCB concentrations from the period of maximum flux to prewar levels suggests that the factors delivering PCBs to sediments at present are similar to those that that existed before the war-related inputs. PMID:22218707

  8. The phytoplankton bloom in the northwestern Arabian Sea during the southwest monsoon of 1979

    NASA Technical Reports Server (NTRS)

    Brock, John C.; Mcclain, Charles R.; Luther, Mark E.; Hay, William W.

    1991-01-01

    The present study investigates the biological variability of the northwestern Arabian Sea during the 1979 southwest monsoon by the synthesis of satellite ocean color remote sensing with an analysis of in situ hydrographic and meteorological data sets and the results of wind-driven modeling of upper-ocean circulation. The phytoplankton bloom peaked during August-September, extended from the Oman coast to about 65 deg E, and lagged behind the development of open-sea upwelling by at least 1 mo. The pigment distributions, hydrographic data, and model results all suggest that the boom was driven by spatially distinct upward nutrient fluxes to the euphotic zone forced by the physical processes of coastal upwelling and offshore Ekman pumping. Coastal upwelling was evident from May through September, yielded the most extreme concentrations of phytoplankton biomass, and, along the Arabian coast, was limited to the continental shelf in the promotion of high concentrations of phytoplankton.

  9. Evolution and petroleum potential of mesozoic marine province of northwestern Great Basin

    SciTech Connect

    Oldow, J.S.; Tipnis, R.S.

    1984-07-01

    The Mesozoic marine province of the northwestern Great Basin consists of late Early Triassic through Early Cretaceous volcanic, terrigenous clastic, and carbonate rocks. The rocks were deposited in a basin that was probably open to the north and bound on the west by the Sierran arc and on the east and south by continental uplands. Basin configuration was controlled by an enclave of noncontinental crust whose areal distribution and mechanical properties localized development of marine conditions in the region. Source-rock evaluation of thick, regionally extensive Upper Triassic carbonates has yielded TOC values ranging from 0.20 to 0.48 and conodont color indices (CAI 3.5-4.5) indicating paleotemperatures of about 180/sup 0/ to 250/sup 0/C. Kerogen analysis indicated that the dominant organic matter is sapropelic to amorphous and in one area suggests the presence of the oil window. Hydrocarbon generation within the carbonate is a distinct possibility.

  10. Variation in macrofaunal communities of sea grass beds along a pollution gradient in Bolinao, northwestern Philippines.

    PubMed

    Leopardas, Venus; Honda, Kentaro; Go, Gay Amabelle; Bolisay, Klenthon; Pantallano, Allyn Duvin; Uy, Wilfredo; Fortes, Miguel; Nakaoka, Masahiro

    2016-04-15

    This study examined the variation of macrofaunal communities in sea grass beds along a pollution gradient in Bolinao, northwestern Philippines. We established four stations and compared the diversity and abundance of macrofauna between them. The Shannon diversity index in the least polluted station was more than twice higher than that in the most polluted one. Abundance was more than thrice higher in the most polluted station. The species composition generally varied, with community difference explained largely by the predominance of the filter-feeding bivalve Gafrarium pectinatum and polychaete Capitella capitata. Species heterogeneity was reduced along the pollution gradient by approximately 19% from the least polluted to the most polluted station. This reduction indicates biodiversity alteration, which has a significant impact on ecosystem functioning. Aspects of species heterogeneity should be considered in environmental impact assessments and the management of coastal areas encountered with anthropogenic disturbances. PMID:26892202

  11. New records of Cantharellus species from the northwestern Himalayas of India

    PubMed Central

    Deepika, Kumari; Reddy, M. Sudhakara; Upadhyay, Ramesh C.

    2014-01-01

    This study investigated several collections of the genus Cantharellus (Cantharellaceae) from the northwestern Himalayas, India, on the basis of morphology and molecular data. Phylogenetic relationships and species limits were investigated by using nuclear ribosomal large subunit sequences (LSU). We recognized 13 species: Cantharellus appalachiensis Petersen, C. cibarius Fries, C. lateritius (Berk) Singer, C. miniatescens Heinem, C. minor Peck, C. pseudoformosus and seven species, C. applanatus sp. nov., C. elongatipes sp. nov., C. fibrillosus sp. nov., C. himalayensis sp. nov., C. indicus sp. nov., C. natarajanii sp. nov., and C. umbonatus sp. nov., as new to science. All these species are described and their taxonomy and ecology are discussed. In addition, a key is provided to all the recognized species. The phylogenetic analysis recovered 10 major supported clades of Cantharellus species. PMID:24587961

  12. Heavy metals in coastal water systems. A case study from the northwestern Gulf of Thailand.

    PubMed

    Censi, P; Spoto, S E; Saiano, F; Sprovieri, M; Mazzola, S; Nardone, G; Di Geronimo, S I; Punturo, R; Ottonello, D

    2006-08-01

    A geochemical survey of the northwestern part of the Thailand Gulf (Inner Gulf) was carried out in order to define concentrations and distribution patterns of selected heavy metals (V, Cr, Co, Ni, Cu, Zn, and U) in the coastal system and estuarine area of the Mae Klong river. The results indicate the presence of two different sources of heavy metals in the studied environment and allowed us to identify a lithogenic component that significantly influences the composition of coastal waters and suspended particulate matter (SPM). Comparison of the normalized heavy metals concentrations both in the studied samples and in those reported for the Sn-W ores present in the surrounding areas suggests an important anthropogenic contribution to the chemistry of the seafloor sediments. Vanadium and nickel enrichment factors (EF) calculated for coastal waters indicate that contamination by hydrocarbons discharge took place in the investigated area. PMID:16403556

  13. Geology of Norton Basin and continental shelf beneath northwestern Bering Sea, Alaska

    SciTech Connect

    Fisher, M.A.; Patton, W.W. Jr.; Holmes, M.L.

    1982-03-01

    The rocks that floor the Norton basin and the northwestern Bering Sea are most likely of Precambrian and Paleozoic age, like those rocks that crop out around the basin. A maximum of 6.5 km of mainly Cenozoic strata lie over basement in the basin. On the basis of the geometry of reflections in seismic data, it is believed alluvial fans to be present deep in the basin and to border major basement fault blocks. These fans are the lowest units of the basin fill in many areas and consist of uppermost Cretaceous or lower Paleogene, possibly coal- and volcanic-rich rocks. Mainly clastic nonmarine sedimentary rocks overlie the fan deposits. The Neogene and Quaternary basin rocks apparently were deposited in a marine environment.

  14. Jurassic normal and strike-slip faults at Crater Island, northwestern Utah

    USGS Publications Warehouse

    Miller, D.M.; Allmendinger, R.W.

    1991-01-01

    At Crater Island, northern Silver Island Mountains, northwestern Utah, an unbroken Tertiary fault block within the Basin and Range province exhibits Jurassic or older structures that are virtually unmodified by subsequent tectonism. Widespread high-angle faults, mainly striking north and north-east, offset the moderately west-dipping strata down to the west, thereby extending the strata parallel to bedding by 10% to 20%. The normal faults merge with a north northwest dextral strike-slip fault system. The two fault systems are kinematically compatible, suggesting that they may have been contemporaneous. The data indicate that minor thrusting, probably during the Jurassic, was followed by extensional faulting within a strike-slip fault system, probably close in time to intrusion. -from Authors

  15. Reef and nonreef aquifers - A comparison of hydrogeology and geochemistry, northwestern Indiana

    USGS Publications Warehouse

    Schnoebelen, D.J.; Krothe, N.C.

    1999-01-01

    The principal bedrock aquifer system across much of Indiana consists of carbonate rocks of Silurian and Devonian age. The Silurian-Devonian aquifer system is used extensively for irrigation in northwestern Indiana and is approximately 170 m thick. Reef and nonreef carbonate aquifers in northwestern Indiana were assessed using hydrogeology (lithology, geophysical logs, aquifer tests) and geochemistry (major ions and stable isotopes). The study showed differences in water quantity and quality between the reef and nonreef aquifers. The reef aquifer had few shales, abundant fossiliferous material (up to 100 m thick), and high porosities (10 to 15%). The nonreef aquifer had abundant shales, less fossiliferous material (a few meters thick), and low porosities. Total transmissivities at the reef sites were 697 m2/d, (meters squared per day) and 4831 m2/d, compared to 46 m2/d at the nonreef site. Flowpaths in the nonreef aquifer were associated with fractures and poorly connected moldic porosity with larger fractures and better connected vuggy porosity in the reef aquifer. Water chemistry data for the nonreef aquifer showed mean concentrations of sodium (235 mg/L [milligrams per liter]), sulfate (160 mg/L), sulfide (13 mg/L), fluoride (2.7 mg/L), and dissolved solids (635 mg/L) approximately two to five times larger when compared to mean concentrations in the reef aquifer. Ground water at the nonreef site was classified as a sodium-bicarbonate type while that at the reef sites was calcium-magnesium bicarbonate. The oxygen/deuterium isotope data indicates recharge from modern precipitation and not Pleistocene-age recharge.The principal bedrock aquifer system across much of Indiana consists of carbonate rocks of Silurian and Devonian age. The Silurian-Devonian aquifer system is used extensively for irrigation in northwestern Indiana and is approximately 170 m thick. Reef and nonreef carbonate aquifers in northwestern Indiana were assessed using hydrogeology (lithology, geophysical logs, aquifer tests) and geochemistry (major ions and stable isotopes). The study showed differences in water quantity and quality between the reef and nonreef aquifers. The reef aquifer had few shales, abundant fossiliferous material (up to 100 m thick), and high porosities (10 to 15%). The nonreef aquifer had abundant shales, less fossiliferous material (a few meters thick), and low porosities. Total transmissivities at the reef sites were 697 m2/d, (meters squared per day) and 4831 m2/d, compared to 46 m2/d at the nonreef site. Flowpaths in the nonreef aquifer were associated with fractures and poorly connected moldic porosity with larger fractures and better connected vuggy porosity in the reef aquifer. Water chemistry data for the nonreef aquifer showed mean concentrations of sodium (235 mg/L [milligrams per liter]), sulfate (160 mg/L), sulfide (13 mg/L), fluoride (2.7 mg/L), and dissolved solids (635 mg/L) approximately two to five times larger when compared to mean concentrations in the reef aquifer. Ground water at the nonreef site was classified as a sodium-bicarbonate type while that at the reef sites was calcium-magnesium bicarbonate. The oxygen/deuterium isotope data indicates recharge from modern precipitation and not Pleistocene-age recharge.

  16. Radioiodine retention in ovine thyroids in northwestern Greece following the reactor accident at Chernobyl

    SciTech Connect

    Ioannides, K.G.; Pakou, A.A.; Papadopoulou, C.V. )

    1991-04-01

    Iodine-131 concentrations were measured throughout the summer of 1986 in thyroids of lambs slaughtered at Ioannina (Northwestern Greece) following the accident at the Chernobyl nuclear reactor. During the survey, 40 thyroids were collected. The highest level of 131I detected was 2471 +/- 339 Bq per thyroid. The thyroids of 20 lambs did not contain detectable 131I concentrations, while the contamination content of the others was greatly variable. The transport of 131I from pasture to thyroids of lambs has been described through a simple model for the retention of 131I in the glands. The transfer coefficient fT, expressing the steady-state equilibrium, was estimated to be 564 +/- 270 kg-1 d. This result reflects the sensitivity of animal thyroids as biological radioiodine monitors.

  17. Distribution of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwestern USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Bull, E.L.; Green, D.E.; Bowerman, Jay; Adams, Michael J.; Hyatt, A.; Wente, W.

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and we found a?Y 1 detection of B. dendrobatidis from 43% of sites. Four of seven species tested positive for B. dendrobatidis, including the Northern Red-Legged Frog (Rana aurora), Columbia Spotted Frog (Rana luteiventris), and Oregon Spotted Frog (Rana pretiosa). We also detected B. dendrobatidis in nonnative American Bullfrogs (Rana catesbeiana) from six sites in western and central Oregon. Our study and other recently published findings suggest that B. dendrobatidis has few geographic and host taxa limitations among North American anurans. Further research on virulence, transmissibility, persistence, and interactions with other stressors is needed to assess the potential impact of B. dendrobatidis on Pacific Northwestern amphibians.

  18. The collection of the Herpetological Museum of the University of Antioquia (northwestern Colombia)

    PubMed Central

    Ortiz-Yusty, Carlos E.; Paez, Vivian P.; Bock, Brian C

    2015-01-01

    Abstract Northwestern South America harbors one of the richest herpetofauna in the world. The connection among several biogeographic provinces along with climatic and orographic complexity makes this region an important contributor to the Neotropical biodiversity. Despite of this importance, the amphibian and reptile fauna in this area remains largely unknown as few herpetological collections has been made in recent decades. Motivated by this, the Herpetological Museum at the Universidad de Antioquia (Medellín, Colombia) has been increasing the collection in the last 16 years to better understand the herpetofaunal diversity and thus contribute to ecological, systematic, biogeographic and conservation research in the Neotropics. Here, we present the results of this effort and highlight how future collection will impact our understanding of the Neotropical herpetofauna. PMID:25733961

  19. The collection of the Herpetological Museum of the University of Antioquia (northwestern Colombia).

    PubMed

    Ortiz-Yusty, Carlos E; Daza, Juan M; Paez, Vivian P; Bock, Brian C

    2015-01-01

    Northwestern South America harbors one of the richest herpetofauna in the world. The connection among several biogeographic provinces along with climatic and orographic complexity makes this region an important contributor to the Neotropical biodiversity. Despite of this importance, the amphibian and reptile fauna in this area remains largely unknown as few herpetological collections has been made in recent decades. Motivated by this, the Herpetological Museum at the Universidad de Antioquia (Medellín, Colombia) has been increasing the collection in the last 16 years to better understand the herpetofaunal diversity and thus contribute to ecological, systematic, biogeographic and conservation research in the Neotropics. Here, we present the results of this effort and highlight how future collection will impact our understanding of the Neotropical herpetofauna. PMID:25733961

  20. [Women, addiction and rehabilitation: Reflections from the northwestern border of Mexico].

    PubMed

    Galaviz Granados, Gloria

    2015-09-01

    Since the recognition of addiction as a mental illness, studies concerning treatment and therapeutic models have tended to focus on its psychiatric and psychological dimensions. The aim of this article is to highlight the centrality of the social dimension, not only as potential trigger of addictive behaviors and of stigma regarding these behaviors, but also as a variable that permeates diagnosis and treatment. The reflections are based on fieldwork carried out in rehabilitation centers for drug-consuming women in the border city of Tijuana, northwestern Mexico. The results show that the predominant therapeutic models in the city are based in and reproduce the traditional role of women. The social implications of this finding are analyzed, and it is suggested that these centers could be better utilized in the process of building a society with greater gender equality. PMID:26418093

  1. Late Quaternary paleoenvironments of Northwestern North America: implications for inland versus coastal migration routes

    NASA Astrophysics Data System (ADS)

    Mandryk, Carole A. S.; Josenhans, Heiner; Fedje, Daryl W.; Mathewes, Rolf W.

    2001-01-01

    Although the long held normative view of New World colonization relies on entrance through an interior ice-free corridor by terrestrially adapted big-game hunters, a recently demonstrated human presence in southern Chile dating prior to the existence of the corridor route implies different colonization scenarios which must be seriously considered. A renewed focus of archaeological and paleoecological research on early post-glacial landscapes in Northwestern North America has revitalized the "ice-free" vs. coastal corridor controversy. Geological findings from glacial geology and paleo-sea levels support the possibility of coastal migration from Beringia to the Pacific Northwest between about 14,000 and 10,000 BP, and preliminary paleoecological data suggest that the coastal landscape was in part vegetated and probably able to support a terrestrial fauna, including humans. The same cannot be said about the "ice-free corridor".

  2. Nutritional composition and antioxidant activities of 18 different wild Cantharellus mushrooms of northwestern Himalayas.

    PubMed

    Kumari, D; Reddy, M S; Upadhyay, R C

    2011-12-01

    A total of 18 wild edible mushrooms of Cantharellus species were collected from northwestern Himalayan region of India. The basic composition (moisture, total carbohydrates, dietary fiber, crude fat, ash, nitrogen and protein) and amino acid contents (by high-performance liquid chromatography) of these wild edible mushrooms were determined. The macronutrient profile in general revealed that the wild mushrooms were rich sources of protein and carbohydrates, and had low amounts of fat. Total phenolics and antioxidant activity from water and methanolic extracts of these mushrooms were also determined. These wild mushrooms also had significant amount of phenol content and antioxidant capacity. Studies also provide the precise antioxidant status of 18 indigenous species of mushrooms, which can serve as a useful database for the selection of mushrooms for the function of preparation of mushroom-based nutraceutics. PMID:22049158

  3. Graphically characterizing the movement of a rabid striped skunk epizootic across the landscape in northwestern Wyoming.

    PubMed

    Ramey, Craig A; Mills, Kenneth W; Fischer, Justin W; McLean, Robert G; Fagerstone, Kathleen A; Engeman, Richard M

    2013-09-01

    A striped skunk (Mephitis mephitis) rabies epizootic in northwestern Wyoming was studied from the Index Case in 1988 to the last case in 1993, and possibly is the first rabies epizootic in a previously rabies-free zone monitored from beginning to end. The 843 km(2) study area comprised skunk habitat along 90 km of Shoshone River's floodplain from Bighorn Lake upstream to Cody. Of 1,015 skunks tested, 215 were rabies-positive. Integrating spatial and temporal data from positive cases, we analyzed the epizootic's movements and dynamics at 6-month intervals using multivariate movement maps, a new multivariate descriptive methodology presented here to demonstrate the epizootic's directional flow, while illustrating areas with higher case densities (i.e., wave crests). This approach should help epidemiologists and public health officials to better understand future rabies epizootics. PMID:23812724

  4. Ethnic and geographic variations in HPV prevalence and genotype distribution in north-western Yunnan, China.

    PubMed

    Baloch, Zulqarnain; Yuan, Tao; Wang, Binghui; Tai, Wenlin; Feng, Yue; Liu, Yanqing; Li, Xiao; Feng, Yue; Liu, Li; Zhang, A-Mei; Wu, Xiaomei; Xia, Xueshan

    2016-03-01

    The prevalence and genotype distribution of human papillomavirus (HPV) vary throughout the world. To assess the prevalence and genotype distribution of HPV among three ethnic groups in two geographic locations in north-western Yunnan, we recruited 522 women in Shangri-le (n?=?255) and Lijiang (n?=?267). PCR amplification of HPV DNA was performed on cervical cells from these women using two consensus primer systems (MY09/11 and GP5/6). Amplified-HPV DNA was genotyped using the HPV GenoArray test. Geographically, the HPV prevalence was significantly higher (P?=?0.002) among Shangri-le women than among Lijiang women. Infections with high-risk (HR)-HPV and with multiple HPV genotypes were also significantly more common (P?=?0.001) among women in Shangri-le than women in Lijiang. Additionally, the prevalence of overall, HR-HPV, and single genotype HPV infections was significantly higher (P?=?0.001) among Tibetan women than among Naxi and Han women. HPV-16 and HPV-33 were significantly more frequent in Shangri-le women compared with Lijiang (P?=?0.006) women. In addition, HPV-16 (9.81%) and HPV-33 (5.88%) were significantly more prevalent in Tibetan women than in Naxi and Han women. Here, for the first time, we highlight the significant variation in the prevalence and genotype distribution of HPV in various populations in the north-western region of Yunnan Province. J. Med. Virol. 88:532-540, 2016. 2015 Wiley Periodicals, Inc. PMID:26266484

  5. Bacterial communities from shoreline environments (costa da morte, northwestern Spain) affected by the prestige oil spill.

    PubMed

    Alonso-Gutiérrez, Jorge; Figueras, Antonio; Albaigés, Joan; Jiménez, Núria; Viñas, Marc; Solanas, Anna M; Novoa, Beatriz

    2009-06-01

    The bacterial communities in two different shoreline matrices, rocks and sand, from the Costa da Morte, northwestern Spain, were investigated 12 months after being affected by the Prestige oil spill. Culture-based and culture-independent approaches were used to compare the bacterial diversity present in these environments with that at a nonoiled site. A long-term effect of fuel on the microbial communities in the oiled sand and rock was suggested by the higher proportion of alkane and polyaromatic hydrocarbon (PAH) degraders and the differences in denaturing gradient gel electrophoresis patterns compared with those of the reference site. Members of the classes Alphaproteobacteria and Actinobacteria were the prevailing groups of bacteria detected in both matrices, although the sand bacterial community exhibited higher species richness than the rock bacterial community did. Culture-dependent and -independent approaches suggested that the genus Rhodococcus could play a key role in the in situ degradation of the alkane fraction of the Prestige fuel together with other members of the suborder Corynebacterineae. Moreover, other members of this suborder, such as Mycobacterium spp., together with Sphingomonadaceae bacteria (mainly Lutibacterium anuloederans), were related as well to the degradation of the aromatic fraction of the Prestige fuel. The multiapproach methodology applied in the present study allowed us to assess the complexity of autochthonous microbial communities related to the degradation of heavy fuel from the Prestige and to isolate some of their components for a further physiological study. Since several Corynebacterineae members related to the degradation of alkanes and PAHs were frequently detected in this and other supralittoral environments affected by the Prestige oil spill along the northwestern Spanish coast, the addition of mycolic acids to bioremediation amendments is proposed to favor the presence of these degraders in long-term fuel pollution-affected areas with similar characteristics. PMID:19376924

  6. Vertical distribution of triple oxygen isotopic composition of dissolved oxygen in the northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Abe, Osamu; Honda, Makio; Saino, Toshiro

    2013-04-01

    Oxygen-17 excess of dissolved oxygen calculated from δ18O and δ17O is not affected by oxygen consumption process but controlled only by processes of primary production and air-water gas transfer. Evaluating gross primary productivity using the 17O-excess in ocean surface water are one of the most advanced geochemical researches for last 10 years. Oxygen-17 excess below ocean mixed/photic layer has not been much investigated because it might be out of focus for estimating present primary productivity, except for the purpose to correct diapycnal mixing effect on surface water. In principle, water mass which has not been affected both by photosynthesis and gas transfer after its separation from ocean surface could preserve 17O-excess value where the water mass was at the surface. The purpose of this study is to determine the vertical distribution of 17O-excess from the surface to the bottom of northwestern Pacific to know whether 17O-excess could really preserve its "original" value after the long and dark travel. Near stations K2 and KNOT, water mass which has a density of 26.8 ?? is observed at depth between 100 and 300 m. This water mass is mainly originated from bottom water in the Okhotsk Sea and spreading widely to entire northwestern Pacific, which is called North Pacific Intermediate Water (NPIW). NPIW is found at depth of 700 m at station S1. Samplings were conducted by two R/V Mirai cruises (MR10-06, Oct-Nov 2010; MR11-02, Feb-Mar 2011). Dissolved oxygen gas was purified by the method of Sarma et al. (2003) and its isotopic composition was determined by dual-inlet isotope ratio mass spectrometer (Thermo Scientific Delta Plus). Gross primary productivities at mixed layer estimated by 17O-excess were well consistent with those by conventional light and dark bottle incubations for stations K2 and S1.

  7. Feeding ecology of two demersal opportunistic predators coexisting in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    López, Nieves; Navarro, Joan; Barría, Claudio; Albo-Puigserver, Marta; Coll, Marta; Palomera, Isabel

    2016-06-01

    The study of the feeding ecology of marine organisms is crucial to understanding their ecological roles and advancing our knowledge of marine ecosystem functioning. The aim of this study was to analyse the trophic ecology of two demersal predator species, black anglerfish (Lophius budegassa) and white anglerfish (L. piscatorius), in the northwestern Mediterranean Sea. Both species are important in the study area due to their high abundance and economic value, but information about their feeding behaviour is scarce. Here, we described the diet composition and ecological role of these two species, investigating whether trophic segregation exists between them and amongst fish of different sizes. In addition, by using experimental survey data we described the spatial distribution of both species to help us interpret trophic behaviour patterns. We gathered samples of two different sizes (small individuals of a total length <30 cm and large individuals ≥30 cm) of both species and combined stomach content analyses (SCA) and stable isotope analyses (SIA) of nitrogen and carbon with isotopic mixing models. Our results revealed that both anglerfish species are opportunistic predators, showing a diet composed mainly of fishes and, to a lesser extent, of crustaceans, with a small proportion of cephalopods, gastropods, bivalves and echinoderms. We found trophic segregation between the two species and the two sizes, indicating that they feed on different prey, in line with differences in their spatial distribution within the study area. This partial partition of food resources could also be explained by the differences in rhythms of activity that were reported in previous studies. In addition, although both species occupied a high position within the food web, our results showed that white anglerfish individuals and the large-sized fish of both species held higher trophic positions. This study demonstrates the usefulness of complementary approaches for trophic studies and confirms that both anglerfish species play an important role as predators in the northwestern Mediterranean Sea food web.

  8. 3-D Imaging of the Precambrian Winagami Sill Complex in Northwestern Alberta, Canada: Continental Rebar Revealed?

    NASA Astrophysics Data System (ADS)

    Welford, J.; Clowes, R. M.

    2004-05-01

    The Winagami sill complex, discovered by Lithoprobe's CAT'94 and PRAISE'95 multichannel seismic reflection experiments, was intruded during the Paleoproterozoic into the crystalline basement underlying the Western Canada Sedimentary Basin of northwestern Alberta, Canada. Spanning an area of at least 120,000 km2, the extent of this upper crustal feature is comparable to large Phanerozoic igneous provinces. The intrusion of such sill complexes has been interpreted as a fundamental stage in the process of cratonization and a key to the strength of cratonic blocks. The very presence of such structures in northwestern, and also southwestern, Alberta may have contributed to the development of cratonic arches along the ancient rifted margin of North America which significantly impacted regional depositional environments. Using a 3-D seismic reflection dataset collected for exploration purposes by the Canadian petroleum industry that probed to depths of approximately 15 km, we have undertaken a 3-D investigation of the Winagami reflectors. To date, we have imaged the top of the Winagami sequence in 3-D over an area of 400 km2, producing the first areal seismic image of a Precambrian sill complex at depth. Secondly, we have obtained polarity constraints from known shallower reflections for comparison with the Winagami reflections to characterize the impedance contrast. Lastly, we have extracted areal characteristics using amplitude analyses and attributes on both pre-stack and post-stack data to better map local variations in reflectivity. These may be revealing thickness or lithological variations. Our results represent the first attempt to gain a better understanding of the nature of these important structures using industry 3-D seismic reflection techniques.

  9. Risk Assessment for Yellow Fever in Western and North-Western Provinces of Zambia

    PubMed Central

    Babaniyi, Olusegun A.; Mwaba, Peter; Mulenga, David; Monze, Mwaka; Songolo, Peter; Mazaba-Liwewe, Mazyanga L.; Mweene-Ndumba, Idah; Masaninga, Freddie; Chizema, Elizabeth; Eshetu-Shibeshi, Messeret; Malama, Costantine; Rudatsikira, Emmanuel; Siziya, Seter

    2015-01-01

    Background: North-Western and Western provinces of Zambia were reclassified as low-risk areas for yellow fever (YF). However, the current potential for YF transmission in these areas is unclear. Aims: To determine the current potential risk of YF infection. Setting and Design: A cross sectional study was conducted in North-Western and Western provinces of Zambia. Materials and Methods: Samples were tested for both YF virus-specific IgG and IgM antibodies by the ELISA and YF virus confirmation was done using Plaque Reduction Neutralization Test. The samples were also tested for IgG and IgM antibodies against other flaviviruses. Results: Out of the 3625 respondents who participated in the survey, 46.7% were males and 9.4% were aged less than 5 years. Overall, 58.1% of the participants slept under an impregnated insecticide-treated net and 20.6% reported indoor residual spraying of insecticides. A total of 616 (17.0%) samples were presumptive YF positive. The prevalence for YF was 0.3% for long-term infection and 0.2% for recent YF infection. None of the YF confirmed cases had received YF vaccine. Prevalence rates for other flaviviruses were 149 (4.1%) for Dengue, 370 (10.2%) for West Nile and 217 (6.0%) for Zika. Conclusion: There is evidence of past and recent infection of YF in both provinces. Hence, they are at a low risk for YF infection. Yellow fever vaccination should be included in the EPI program in the two provinces and strengthen surveillance with laboratory confirmation. PMID:25722614

  10. Geographical distribution of shear wave anisotropy within marine sediments in the northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Tonegawa, Takashi; Fukao, Yoshio; Fujie, Gou; Takemura, Shunsuke; Takahashi, Tsutomu; Kodaira, Shuichi

    2015-12-01

    In the northwestern Pacific, the elastic properties of marine sediments, including P-wave velocities ( Vp) and S wave velocities ( Vs), have recently been constrained by active seismic surveys. However, information on S anisotropy associated with the alignments of fractures and fabric remains elusive. To obtain such information, we used ambient noise records observed by ocean-bottom seismometers at 254 sites in the northwestern Pacific to calculate the auto-correlation functions for the S reflection retrieval from the top of the basement. For these S reflections, we measured differential travel times and polarized directions to reveal the potential geographical systematic distribution of S anisotropy. As a result, the observed differential times between fast and slow axes were at most 0.05 s. The fast polarization axes tend to align in the trench-parallel direction in the outer rise region. In particular, their directions changed systematically in accordance with the direction of the trench axis, which changes sharply across the junction of the Kuril and Japan trenches. We consider that a contributing factor for the obtained S anisotropy within marine sediments in the outer rise region is primarily aligned fractures due to the tensional stresses associated with the bending of the Pacific Plate. Moreover, numerical simulations conducted by using the three-dimensional (3D) finite difference method for isotropic and anisotropic media indicates that the successful extraction of S anisotropic information from the S reflection observed in this study is obtained from near-vertically propagating S waves due to extremely low Vs within marine sediments. In addition, we conducted an additional numerical simulation with a realistic velocity model to confirm whether S reflections below the basement can be extracted or not. The resultant auto-correlation function shows only S reflections from the top of the basement. It appears that such near-vertically propagating S waves obscure S reflections from interfaces below the basement.

  11. Shallow structure of part of northwestern Iberia from short-period Rayleigh-wave observations

    NASA Astrophysics Data System (ADS)

    Sarrate, J.; Canas, J. A.; Pujades, L.; Badal, J.; Corchete, V.; Payo, G.

    1993-04-01

    Propagation of 0.2-2.5 s short-period Rayleigh-waves across a part of northwestern Iberia is investigated. Analysis of a seismic profile line with recorded seismograms up to distances of 70 km from the shot-point, provides group-velocities and attenuation coefficients of the fundamental mode. First higher-mode group-velocity has been obtained for only one of the studied cases. The studied region has been divided into two subrogions, the northwestern and the southeastern side from the shot-point. Inversion procedures applied to the velocity and attenuation data yield the shear velocity and the Q-1β models up to a depth of about 1.5 km for the NW, and 2.4 for the SE side. From the shear-wave obtained models corresponding to the NW and to the SE sides, it is possible to infer the existence of some degree of lateral variation of S velocity. The NW side presents velocities varying between 1.8 km · s -1 (at the surface) and 3.3 km · s -1 (at 1.2 km depth). The velocities in the SE model, for the same depths, are 2.2 and 3.4 km · s -1, respectively. Using only the fist six traces of the SE side, it is possible to infer a low-velocity region located between 0.4 km and 0.7 km depth. It seems that the velocities are higher in the complex geological region of the SE side than in the NW one, which is in agreement with P velocity models found by others. From the tentative anelastic attenuation coefficients, Q-1β models have been inferred for both sides of the seismic refraction profile. Although the obtained Q-1β models are somehow different in shape, the maximum Q-1β value is about 0.05 in both cases.

  12. Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

    NASA Astrophysics Data System (ADS)

    Xin, Jinyuan; Gong, Chongshui; Wang, Shigong; Wang, Yuesi

    2016-05-01

    The optical properties of dust aerosols were measured using narrow-band data from a portable sun photometer at four desert and semi-desert stations in northwestern China from 2004 to 2007. Ground-based and satellite observations indicated absorbing dust aerosol loading over the region surrounded by eight large-scale deserts. Radiation forcing was identified by using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The ranges of annual mean aerosol optical depth (AOD), Angström exponents, and single-scattering albedo (SSA) were from 0.25 to 0.35, from - 0.73 to 1.18, and from 0.77 to 0.86, respectively. The ranges of annual mean aerosol direct radiative forcing values at the top of the atmosphere (TOA), mid-atmosphere, and on the surface were from 3.9 to 12.0, from 50.0 to 53.1, and from - 39.1 to - 48.1 W/m2, respectively. The aerosols' optical properties and radiative characteristics showed strong seasonal variations in both the desert and semi-desert regions. Strong winds and relatively low humidity will lead dust aerosols in the atmosphere to an increase, which played greatly affected these optical properties during spring and winter in northwestern China. Based on long-term observations and retrieved data, aerosol direct radiative forcing was confirmed to heat the atmosphere (50-53 W/m2) and cool the surface (- 39 to - 48 W/m2) above the analyzed desert. Radiative forcing in the atmosphere in spring and winter was 18 to 21 W/m2 higher than other two seasons. Based on the dust sources around the sites, the greater the AOD, the more negative the forcing. The annual averaged heating rates for aerosols close to the ground (1 km) were approximately 0.80-0.85 K/day.

  13. DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Du, Guoying; Wu, Feifei; Guo, Hao; Xue, Hongfan; Mao, Yunxiang

    2015-05-01

    A total of 142 specimens of Ceramiales (Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers, namely, partial large subunit rRNA gene (LSU), universal plastid amplicon (UPA), and partial mitochondrial cytochrome c oxidase subunit I gene (COI). No intraspecific divergence was found in our collection for these markers, except for a 1-3 bp divergence in the COI of Ceramium kondoi, Symphyocladia latiuscula, and Neosiphonia japonica. Because short DNA markers were used, the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in GenBank or BOLD (Barcode of Life Data) Systems. Three specimens were presumed as Heterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification, which was the first record in the investigated area, implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers, Heterosiphonia japonica converged with Dasya spp. and was distant from the other Heterosiphonia spp., implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species, but the COI had a higher ability to discriminate between species.

  14. Radiocarbon chronology of the last glacial maximum and its termination in northwestern Patagonia

    NASA Astrophysics Data System (ADS)

    Moreno, Patricio I.; Denton, George H.; Moreno, Hugo; Lowell, Thomas V.; Putnam, Aaron E.; Kaplan, Michael R.

    2015-08-01

    We examine the timing and magnitude of the last glacial maximum (LGM) and the last glacial termination (LGT) in northwestern Patagonia, situated in the middle latitudes of South America. Our data indicate that the main phase of the LGT began with abrupt warm pulses at 17,800 and 17,100 cal yrs BP, accompanied by rapid establishment of evergreen temperate rainforests and extensive deglaciation of the Andes within 1000 years. This response shows that South American middle-latitude temperatures had approached average interglacial values by 16,800 cal yrs BP. The temperature rise in northwestern Patagonia coincides with the beginning of major warming and glacier recession in the Southern Alps of New Zealand at southern mid-latitudes on the opposite side of the Pacific Ocean. From this correspondence, the warming that began at 17,800 cal yrs BP appears to have been widespread in middle latitudes of the Southern Hemisphere, accounting for at least 75% of the total temperature recovery from the LGM to the Holocene. Moreover, this warming pulse is coeval with the first half of the Heinrich Stadial 1 (HS1) in the North Atlantic region. HS1 featured a decline of North Atlantic meridional overturning circulation, a southward shift of the westerly wind belt in both hemispheres and of the Intertropical Convergence Zone, as well as a weakening of the Asian monsoon. Along with the initiating trigger, identifying the mechanisms whereby these opposing climate signals in the two polar hemispheres interacted -whether through an oceanic or an atmospheric bipolar seesaw, or both- lies at the heart of understanding the LGT.

  15. Phlebotomus perfiliewi transcaucasicus, a vector of Leishmania infantum in northwestern Iran.

    PubMed

    Rassi, Y; Javadian, E; Nadim, A; Rafizadeh, S; Zahraii, A; Azizi, K; Mohebali, M

    2009-09-01

    Visceral leishmaniasis is caused by Leishmania infantum, which is transmitted to humans by bites of phlebotomine sand flies and is one of the most important public health problems in Iran. To identify the vector(s), an investigation was carried out in Germi district, an important focus of the disease in Ardebil province in northwestern Iran, during July-September 2004 and 2005. Using sticky papers, CDC light traps and aspirators, 3,560 sand flies were collected and identified to species. Host bloodmeal preference and Leishmania infections in female specimens were evaluated using enzyme-linked immunosorbent assay (ELISA) for the former and microscopic examination followed by polymerase chain reaction (PCR) assay using species-specific kinetoplast minicircle primers for the latter. Nine sand fly species are present in the district, including Phlebotomus kandelakii Shchurenkova, Phlebotomus perfiliewi transcaucasicus Perfil'ev, Phlebotomus major Annandale, Phlebotomus balcanicus Theodor, Phlebotomus halepensis Theodor, Phlebotomus brevis Theodor & Meshghali, Phlebotomus papatasi Scopoli, Sergentomyia dentata Sinton, and Sergentomyia sintoni Pringle, with P. p. transcaucasicus being the most prevalent representative of the genus Phlebotomus at 45%. The anthropophilic index for P. p. transcaucasicus was 36.3%, indicating a strong preference for humans. Of 905 female P. p. transcuacasicus dissected, 10 (1.1%) were found naturally infected with promastigotes. Species-specific amplification of promastigotes eluted from Giemsa-stained slides revealed specific PCR products of L. infantum DNA. Based on its high anthropophily and natural infections with L. infantum, and the fact that it was the only species found infected with L. infantum, we conclude that P. p. transcaucasicus is the principal vector of L. infantum in northwestern Iran. PMID:19769040

  16. Interannual variability in phytoplankton blooms observed in the northwestern Arabian Sea during the southwest monsoon

    NASA Technical Reports Server (NTRS)

    Brock, John C.; Mcclain, Charles R.

    1992-01-01

    Interannual changes in the strength and seasonal evolution of the 1979 through 1982 surface-level southwest monsoon winds are related to variations in the summer phytoplankton bloom of the northwestern Arabian Sea by synthesis of satellite ocean-color remote sensing with analysis of in-situ hydrographic and meteorological data sets. The 1979-1981 southwest monsoon phytoplankton blooms in the northwest Arabian Sea peaked during August-September, extended from the Omani coast to about 6 E, and appeared to lag the development of open-sea upwelling by at least 1 month. In all 3 years the bloom was driven by spatially distinct upward nutrient fluxes to the euphotic zone forced by the physical processes of coastal upwelling and offshore Ekman pumping. Coastal upwelling was evident from May through September, yielded the most extreme concentrations of phytoplankton biomass, and along the Omani coast was limited in its impact on upper ocean biological variability to the continental shelf. Ekman pumping stimulated the development of a broad open-ocean component of the southwest monsoon phytoplankton bloom oceanward of the Omani shelf. Phytoplankton biomass on the Omani continental shelf was increased during both the early and late phases of the 1980 southwest monsoon due to stronger coastal upwelling under the most intense southwesterly winds of the four summers investigated. Diminished coastal upwelling during the early phase of the weak 1982 southwest monsoon resulted in a coastal bloom that reached a mean phytoplankton-pigment concentration that was 28 percent of that seen in 1980. The lack of a strong regional northwestern Arabian Sea bloom in late summer 1982 is attributed to the development of persistent, shallow temperature stratification that rendered Ekman pumping less effective in driving upward nutrient fluxes.

  17. Transmission cycles of Borrelia burgdorferi and B. bissettii in relation to habitat type in northwestern California.

    PubMed

    Eisen, Lars; Eisen, Rebecca J; Mun, Jeomhee; Salkeld, Daniel J; Lane, Robert S

    2009-06-01

    This study was undertaken to determine which rodent species serve as primary reservoirs for the Lyme disease spirochete Borrelia burgdorferi in commonly occurring woodland types in inland areas of northwestern California, and to examine whether chaparral or grassland serve as source habitats for dispersal of B. burgdorferi- or B. bissettii-infected rodents into adjacent woodlands. The western gray squirrel (Sciurus griseus) was commonly infected with B. burgdorferi in oak woodlands, whereas examination of 30 dusky-footed woodrats (Neotoma fuscipes) and 280 Peromyscus spp. mice from 13 widely spaced Mendocino County woodlands during 2002 and 2003 yielded only one infected woodrat and one infected deer mouse (P. maniculatus). These data suggest that western gray squirrels account for the majority of production by rodents of fed Ixodes pacificus larvae infected with B. burgdorferi in the woodlands sampled. Infections with B. burgdorferi also were rare in woodrats (0/47, 0/3) and mice (3/66, 1/6) captured in chaparral and grassland, respectively, and therefore these habitats are unlikely sources for dispersal of this spirochete into adjacent woodlands. On the other hand, B. bissettii was commonly detected in both woodrats (22/47) and mice (15/66) in chaparral. We conclude that the data from this and previous studies in northwestern California are suggestive of a pattern where inland oak-woodland habitats harbor a B. burgdorferi transmission cycle driven primarily by I. pacificus and western gray squirrels, whereas chaparral habitats contain a B. bissettii transmission cycle perpetuated largely by I. spinipalpis, woodrats and Peromyscus mice. The dominant role of western gray squirrels as reservoirs of B. burgdorferi in certain woodlands offers intriguing opportunities for preventing Lyme disease by targeting these animals by means of either host-targeted acaricides or oral vaccination against B. burgdorferi. PMID:20514140

  18. Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99

    USGS Publications Warehouse

    Brigham, M.E.; Krabbenhoft, D.P.; Olson, M.L.; DeWild, J.F.

    2002-01-01

    We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early 1999. MeHg levels in the outflow reached seasonal maxima in mid-summer (maximum of 1.0 ng L−1 in July 1997) and late-winter (maximum of 6.6 ng L−1 in February 1999), and are comparable to high levels observed in new hydroelectric reservoirs in Canada. Spring and autumn MeHg levels were typically about 0.1–0.2 ng L−1. Overall, MeHg levels in both the inflow (a ditch that drains peatlands) and outflow were significantly higher than in three nearby reference natural lakes. Eleven older permanent-pool impoundments and six natural lakes in northwestern Minnesota were sampled five times. The impoundments typically had higher MeHg levels (0.071–8.36 ng L−1) than natural lakes. Five of six lakes MeHg levels typical of uncontaminated lakes (0.014–1.04 ng L−1) with highest levels in late winter, whereas a hypereutrophic lake had high levels (0.37–3.67 ng L−1) with highest levels in mid-summer. Seven temporary-pool impoundments were sampled during summer high-flow events. Temporary-pool impoundments that retained water for about 10–15 days after innundation yielded pronounced increases in MeHg from inflow to outflow, in one case reaching 4.6 ng L−1, which was about 2 ng L−1 greater than the mean inflow concentration during the runoff event.

  19. Evidence for a Younger Dryas glacial advance in the Andes of northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Mahaney, William C.; Milner, M. W.; Kalm, Volli; Dirszowsky, Randy W.; Hancock, R. G. V.; Beukens, Roelf P.

    2008-04-01

    Deposits of push moraine, outwash and glaciolacustrine sediments, recovered from two areas in the northwestern Venezuelan Andes document the latest Pleistocene advance of Mérida ice. Underlying peats provide maximum ages on till and outwash evidently emplaced during the Younger Dryas (YD) climatic event. One example recovered from the Humboldt Massif, where the farthest extent of YD ice buried peat in the surface of Late Glacial till, provides a within-glacier advance age of 12.4 ka cal BP. The peat lies on moraine deposited during a stillstand event when the Humboldt Glacier retreated to the area of Lago Verde at ˜ 4000 m a.s.l. Approximately 0.5 km upvalley, toward Lago Suero, YD till buries peat deposited in glaciolacustrine sediments of presumed Late Glacial age. Farther north, in the Mucuñuque-Mucubají Catchment of the eastern cordillera, a push moraine of possible YD age buries older till of Late Glacial age; ˜ 0.2 km upvalley, outwash of YD age buries glaciolacustrine peat and organic-rich alluvial sediment dated to 13.7 and 13.3 ka cal BP. The latest Mérida advance documented here is approximately synchronous with the YD cold event of Europe and the North Atlantic Region (ca. 11.6-12.7 ka cal BP). The YD event in both areas of the northwestern Venezuelan Andes nearly reestablished earlier Late Glacial ice positions, and termination appears to have been abrupt; the valleys in both areas were evacuated of YD ice without emplacement of recessional moraines as during the main deglaciation. At the Humboldt site, equilibrium line altitudes (ELA's) for the Late Glacial were about 50 m lower than during the inferred YD; in the Mucuñuque-Mucubají catchment, ELA's for the Late Glacial (~ 3900 m a.s.l.) are difficult to establish given the absence of lateral moraines.

  20. Sensitivity analysis of seismic hazard for the northwestern portion of the state of Gujarat, India

    USGS Publications Warehouse

    Petersen, M.D.; Rastogi, B.K.; Schweig, E.S.; Harmsen, S.C.; Gomberg, J.S.

    2004-01-01

    We test the sensitivity of seismic hazard to three fault source models for the northwestern portion of Gujarat, India. The models incorporate different characteristic earthquake magnitudes on three faults with individual recurrence intervals of either 800 or 1600 years. These recurrence intervals imply that large earthquakes occur on one of these faults every 266-533 years, similar to the rate of historic large earthquakes in this region during the past two centuries and for earthquakes in intraplate environments like the New Madrid region in the central United States. If one assumes a recurrence interval of 800 years for large earthquakes on each of three local faults, the peak ground accelerations (PGA; horizontal) and 1-Hz spectral acceleration ground motions (5% damping) are greater than 1 g over a broad region for a 2% probability of exceedance in 50 years' hazard level. These probabilistic PGAs at this hazard level are similar to median deterministic ground motions. The PGAs for 10% in 50 years' hazard level are considerably lower, generally ranging between 0.2 g and 0.7 g across northwestern Gujarat. Ground motions calculated from our models that consider fault interevent times of 800 years are considerably higher than other published models even though they imply similar recurrence intervals. These higher ground motions are mainly caused by the application of intraplate attenuation relations, which account for less severe attenuation of seismic waves when compared to the crustal interplate relations used in these previous studies. For sites in Bhuj and Ahmedabad, magnitude (M) 7 3/4 earthquakes contribute most to the PGA and the 0.2- and 1-s spectral acceleration ground motion maps at the two considered hazard levels. ?? 2004 Elsevier B.V. All rights reserved.

  1. Deformation of the Western Caribbean and Northwestern South America From GPS Geodesy

    NASA Astrophysics Data System (ADS)

    LaFemina, Peter; Mora-Paez, Hector; Kobayashi, Daisuke; Fernandes, Rui; Mothes, Patricia

    2014-05-01

    We investigate the current kinematics of the western Caribbean and northwestern South America, two regions that are affected by ongoing collision of aseismic ridges and the motion of forearc slivers. We investigate these regions using a new PS derived surface velocity field spanning from Guatemala to Ecuador. The new velocity field and published earthquake slip vectors are inverted to solve for the Euler vectors of forearc blocks and interseismic elastic strain accumulation on block bounding faults using a block modeling approach. Along the western Caribbean margin, it has been demonstrated that the Cocos Ridge collision drives the Central American forearc block to the northwest. GPS network expansion in Panama and Colombia allows us to investigate the effect of ridge collision on the Panama region. In northwestern South America, the North Andes block (NAB) is a hypothesized tectonic block that migrates north-northeast relative to a stable South American reference frame. The motion of this block is thought to be derived by the collision of the Carnegie Ridge in southern Ecuador or by oblique convergence and high degrees of interplate coupling north of the ridge (i.e., strain partitioning). We test a suite of block models to investigate the tectonic nature of the Panama Region and North Andes block and the style of faulting in the upper plate accommodating block motion. Through the estimation of elastic strain accumulation on all block bounding faults, we improve the understanding of interseismic coupling along a convergent margin capable of producing M>8 earthquake and upper plate faults capable of M>6 earthquake.

  2. A comparison of hydrocarbon gases from natural sources in the northwestern United States

    SciTech Connect

    Lorenson, T.D.; Kvenvolden, K.A. )

    1993-01-01

    The northwestern United States hosts a remarkable quantity and variety of thermal springs, seeps, and other natural-gas sources. Although many studies have dealt with the liquids and nonhydrocarbon gases emanating from these sources, few have focused on hydrocarbon gases. Of these gases, methane in particular is now recognized as an important reactive trace gas in the Earth's atmosphere that plays a significant role in global warming because of its greenhouse properties. To understand better the magnitude and occurrence of emissions of hydrocarbons from natural sources to the atmosphere, we have begun a survey of these gases throughout the northwestern United States. This area encompasses a number of different tectonic provinces: The Yellowstone hot spot, the northern Basin and Range Province, the Cascade volcanic arc, and the Cascadia subduction complex. Each province hosts springs and seeps with some unique compositions owing to the geological processes operating there. Methane is present in each area at concentration levels ranging from about 2 parts per million by volume (ppm-v) to 95.6 percent (by volume). Hydrothermal activity in the Yellowstone area produces spring gases containing less than 4 percent methane, with carbon dioxide as the balance gas. The Grand Teton National Park area, immediately to the south, has a wide variety of gas compositions with either methane, carbon dioxide, or nitrogen as the primary gas component. Where methane is abundant, higher molecular weight hydrocarbon gases (ethane, ethene, propane, propene, isobutane, and n-butane) are also found in ppm-v concentrations. In the northern Great Basin, thermal springs and seeps typically occur along fault zones at the base of mountain ranges. Methane concentrations range from 0.2 to 47 percent, with higher molecular weight hydrocarbon concentrations from 0 to 3,100 ppm-v. 47 refs., 8 figs., 4 tabs.

  3. Cultural Transmission of Traditional Knowledge in two populations of North-western Patagonia

    PubMed Central

    Eyssartier, Cecilia; Ladio, Ana H; Lozada, Mariana

    2008-01-01

    Background In the present study we have investigated the cultural transmission of two types of traditional plant knowledge in two communities of North-western Patagonia, Argentina. In the Pilcaniyeu community, we studied the transmission of traditional knowledge related to horticultural practices in home-gardens, greenhouses and gardens; while in the community of Cuyin Manzano, we studied wild plant gathering customs. Methods Ethnobotanical fieldwork was conducted by means of semi-structured interviews, in which we investigated which plants are used, at what life history phase was learned, modes of transmission and who the principal transmitters were in childhood and adulthood. In both communities, each of this three aspects related to cultural transmission were categorized and the frequencies of each category were obtained. The total number of species recorded in each community was also calculated. Frequencies were analyzed with the Chi-square test of independence. Results and discussion In both communities, transmission of traditional plant knowledge begins at an early age, as a family custom, in which women play a predominant role. Wild plant use and horticultural knowledge continue to be learned during adulthood. This was particularly registered associated with horticultural learning, which receives greater influence from extension agents who are introducing new practices and technology. This outside influence, which implies novelty, could imply syncretism but also traditional knowledge loss. Conclusion Given the remarkable acculturation processes occurring at present in rural communities of Northwestern Patagonia, it might be of vital importance to document traditional knowledge of ancient practices. Moreover, it could be interesting to share our results with both populations in order to encourage participatory activities within the communities which could enhance traditional knowledge horizontal transmission, particularly among elder adults and youngsters. PMID:19077315

  4. [Soil carbon and nitrogen storage of different land use types in northwestern Shanxi Loess Plateau].

    PubMed

    Dong, Yun-Zhong; Wang, Yong-Liang; Zhang, Jian-Jie; Zhang, Qiang; Yang, Zhi-Ping

    2014-04-01

    The soil organic carbon (SOC) and total nitrogen (TN) storage under five different land use patterns, i. e. , poplar and Caragana microphylla plantation, C. microphylla artificial shrubland, poplar plantation, bare land and cropland were studied in the hilly [ness Plateau of northwestern Shanxi. The results showed that the contents, densities and storage of SOC and TN varied remarkably under the different land-use patterns. Soil carbon and nitrogen contents and storage in the 0-20 cm soil layer were significantly higher in the 20-40 cm and 40-60 cm soil layers under each of the five land use patterns. In the same soil layer, the contents and densities of SOC and TN under the five land use patterns were in the order of poplar and C. microphylla plantation > C. microphylla artificial shrubland > poplar plantation > bare land > cropland. The SOC storage in the 0-60 cm soil layer was in the order of poplar and C. microphylla plantation (30.09 t x hm(-2)) > C. microphylla artificial shrubland (24.78 t x hm(-2)) > poplar plantation (24.14 t x hm(-2)) > bare land (22.06 t x hm(-2)) > cropland (17.59 t x hm(-2)). Soil TN storage had the same trend as SOC storage, and TN storage in the 0-60 cm soil layer was the highest (4.94 t x hm(-2)) in poplar and Caragana microphylla plantation, followed by C. microphylla artificial shrubland (3.53 t x hm(-2)), poplar plantation (3.51 t x hm(-2)), bare land (3.40 t x hm(-2)), and cropland (2.71 t x hm(-2)). Poplar and C. microphylla plantation and C. microphylla artificial shrubland were the good land use patterns in the process of vegetation construction and ecological restoration in the hilly Loess Plateau of northwestern Shanxi. PMID:25011285

  5. The NCAR Ensemble-RTFDDA System for Wind Power Prediction in Northwestern China

    NASA Astrophysics Data System (ADS)

    Cheng, W. Y.; Liu, Y.; Pan, L.; Liu, Y.; Roux, G.; Hu, J.; Feng, S.; Liu, C.

    2012-12-01

    By the end of 2011, China had a cumulative wind energy capacity of more than 62 GW, making China the largest wind power provider in the world. China plans to increase its wind energy capacity to 100 GW by 2015. This is part of China's state policy to meet 11.4% of its energy needs from non-fossil fuel sources. In order to effectively integrate wind power into the electric grid system, accurate prediction of wind power is essential. Numerical weather prediction (NWP) models are able to simulate the evolution of weather systems that generate wind, making them an indispensable tool for wind power prediction. Many of the wind farms in China are located in northwestern areas with sparse observations and complex terrain. In such a situation, forecast from a single NWP model realization contains much uncertainty and can be very inaccurate. An ensemble of NWP forecasts that samples and propagates the uncertainties in the model and data presents exceptional benefit to providing a more reliable forecast, along with highly needed probabilistic forecasts and estimate of forecast uncertainties. To this end, in collaboration with the China Electric Power Research Institute (CEPRI), the Research Applications Laboratory (RAL) at NCAR has developed a multi-model, multi-physics, and multi- perturbations rapid-cycling real-time ensemble weather forecast system with data assimilation capability. The system is expected to provide realtime weather forecast in support of wind energy forecast for two major wind farm clusters in Northwestern China. The ensemble system covers China and a large portion of the Asian landmass with a nested grid configuration down to a horizontal grid spacing of 2.7 km. Perturbations from physics schemes include different cumulus parameterizations, microphysics, planetary boundary layer schemes. Perturbations from different initial/boundary conditions include GFS, GEM, and Japanese GSM. We will show results from model error statistics as well as case studies.

  6. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that most single stars should have rocky planets in orbit about them; the frequency of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models for the formation of the giant planets found in recent radial velocity searches are discussed.

  7. Planet formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1993-01-01

    Models of planetary formation are developed using the present single example of a planetary system, supplemented by limited astrophysical observations of star-forming regions and circumstellar disks. The solar nebula theory and the planetesimal hypothesis are discussed. The latter is found to provide a viable theory of the growth of the terrestrial planets, the cores of the giant planets, and the smaller bodies present in the solar system. The formation of solid bodies of planetary size should be a common event, at least around young stars which do not have binary companions orbiting at planetary distances. Stochastic impacts of large bodies provide sufficient angular momentum to produce the obliquities of the planets. The masses and bulk compositions of the planets can be understood in a gross sense as resulting from planetary growth within a disk whose temperature and surface density decreased with distance from the growing sun.

  8. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  9. Galaxy formation.

    PubMed

    Peebles, P J

    1998-01-01

    It is argued that within the standard Big Bang cosmological model the bulk of the mass of the luminous parts of the large galaxies likely had been assembled by redshift z approximately 10. Galaxy assembly this early would be difficult to fit in the widely discussed adiabatic cold dark matter model for structure formation, but it could agree with an isocurvature version in which the cold dark matter is the remnant of a massive scalar field frozen (or squeezed) from quantum fluctuations during inflation. The squeezed field fluctuations would be Gaussian with zero mean, and the distribution of the field mass therefore would be the square of a random Gaussian process. This offers a possibly interesting new direction for the numerical exploration of models for cosmic structure formation. PMID:9419326

  10. Galaxy formation

    PubMed Central

    Peebles, P. J. E.

    1998-01-01

    It is argued that within the standard Big Bang cosmological model the bulk of the mass of the luminous parts of the large galaxies likely had been assembled by redshift z ∼ 10. Galaxy assembly this early would be difficult to fit in the widely discussed adiabatic cold dark matter model for structure formation, but it could agree with an isocurvature version in which the cold dark matter is the remnant of a massive scalar field frozen (or squeezed) from quantum fluctuations during inflation. The squeezed field fluctuations would be Gaussian with zero mean, and the distribution of the field mass therefore would be the square of a random Gaussian process. This offers a possibly interesting new direction for the numerical exploration of models for cosmic structure formation. PMID:9419326

  11. Histograms showing variations in oil yield, water yield, and specific gravity of oil from Fischer assay analyses of oil-shale drill cores and cuttings from the Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Dietrich, John D.; Brownfield, Michael E.; Johnson, Ronald C.; Mercier, Tracey J.

    2014-01-01

    Recent studies indicate that the Piceance Basin in northwestern Colorado contains over 1.5 trillion barrels of oil in place, making the basin the largest known oil-shale deposit in the world. Previously published histograms display oil-yield variations with depth and widely correlate rich and lean oil-shale beds and zones throughout the basin. Histograms in this report display oil-yield data plotted alongside either water-yield or oil specific-gravity data. Fischer assay analyses of core and cutting samples collected from exploration drill holes penetrating the Eocene Green River Formation in the Piceance Basin can aid in determining the origins of those deposits, as well as estimating the amount of organic matter, halite, nahcolite, and water-bearing minerals. This report focuses only on the oil yield plotted against water yield and oil specific gravity.

  12. Mineralogy and diagenesis of low-permeability sandstones of Late Cretaceous age, Piceance Creek Basin, northwestern Colorado

    USGS Publications Warehouse

    Hansley, Paula L.; Johnson, Ronald C.

    1980-01-01

    This report presents preliminary results of a mineralogic and diagenetic study of some low-permeability sandstones from measured surface sections and cores obtained from drill holes in the Piceance Creek Basin of northwestern Colorado. A documentation of the mineralogy and diagenetic history will aid in the exploration for natural gas and in the development of recovery technology in these low-permability sandstones. These sandstones are in the nonmarine upper part of the Mesaverde Formation (or Group) of Late Cretaceous age and are separated from overlying lower Tertiary rocks by a major regional unconformity. Attention is focused on the sandstone units of the Ohio Creek Member, which directly underlies the unconformity; however, comparisons between the mineralogy of the Ohio Creek strata and that of the underlying sandstone units are made whenever possible. The Ohio Creek is a member of the Hunter Canyon Formation (Mesaverde Group) in the southwestern part of the basin, and the Mesaverde Formation in the southern and central parts of the basin. The detrital mineralogy is fairly constant throughout all of these nonrnarine Cretaceous sandstone units; however, in the southeastern part of the basin, there is an increase in percentage of feldspar, quartzite, and igneous rock fragments in sandstones of the Ohio Creek Member directly underlying the unconformity. In the southwestern part of the basin, sandstones of the Ohio Creek Member are very weathered and are almost-entirely comprised of quartz, chert, and kaolinite. A complex diagenetic history, partly related to the overlying unconformity, appears to be responsible for transforming these sandstones into potential gas reservoirs. The general diagenetic sequence for the entire Upper Cretaceous interval studied is interpreted to be (early to late): early(?) calcite cement, chlorite, quartz overgrowths, calcite cement, secondary porosity, analcime (surface only), kaolinite and illite, and late carbonate cements. Authigenic high-iron chlorite, which occurs on grain rims and in pore throats, is primarily responsible for the low-permeability of the subsurface sandstones of the Ohio Creek Member in the center of the basin. Kaolinite is the most abundant pore-filling authigenic clay in these sandstones, from the southwestern part of the basin and is responsible for their distinctive white-weathering color in outcrop. In the sandstones below the Ohio Creek Member, however, chlorite and kaolinite occur locally, and authigenic calcite and illite are more abundant. The occurrence and distribution of secondary porosity is one of the most important aspects of the diagenetic history of these sandstones. It is present as moldic intra- and intergranular porosity, as well as microporosity among authigenic clay pariicles. Although present locally in most sandstone units, secondary porosity is particularly common in the uppermost sandstone units and is interpreted to have formed primarily asa result ofweathering during the time represented by the Cretaceous-Tertiary unconformity.

  13. Pseudacteon calderensis, a new fly species (Diptera:Phoridae) attacking the fire ant Solenopsis interrupta (Hymenoptera:Formicidae) in northwestern Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of Pseudacteon phorid fly Pseudacteon calderis (Diptera: Phoridae) is described from females attacking worker ants of Solenopsis interrupta Santschi in Salta and Jujuy provinces, northwestern Argentina. Pseudacteon calderis differs from almost all other South American Pseudacteon speci...

  14. An Identification Key to Rodent Prey in Owl Pellets from the Northwestern and Southeastern United States: Employing Incisor Size to Distinguish among Genera

    ERIC Educational Resources Information Center

    Hager, Stephen B.; Cosentino, Bradley J.

    2006-01-01

    We present an identification key to the common rodent prey found in owl pellets from the Northwestern (NW) and Southeastern (SE) United States that is based on differences in incisor size (arc diameter) among genera.

  15. Amphiplex Formation

    NASA Astrophysics Data System (ADS)

    Petersen, Shannon; Laaser, Jennifer; Lodge, Timothy

    2015-03-01

    Polymer-micelle complexes are currently under heavy investigation due to their potential applications in targeted drug delivery and gene therapy, yet the dynamics of the complex formation is still relatively unstudied. By varying the ratios of poly(styrene sulfonate) chains and cationic poly(dimethylaminoethyl methacrylate)-b-poly(styrene) micelles and the ionic strength of the system, we created a variety of complex configurations of different sizes and charges. The complexes were characterized dynamic light scattering and zeta potential measurements which provided information regarding the hydrodynamic radius, distribution of sizes, and effective charge.

  16. Impact of the Pacific-Japan teleconnection pattern on July sea fog over the northwestern Pacific: Interannual variations and global warming effect

    NASA Astrophysics Data System (ADS)

    Long, Jingchao; Zhang, Suping; Chen, Yang; Liu, Jingwu; Han, Geng

    2016-04-01

    The northwestern Pacific (NWP) is a fog-prone area, especially the ocean east of the Kuril Islands. The present study analyzes how the Pacific-Japan (PJ) teleconnection pattern influences July sea fog in the fog-prone area using independent datasets. The covariation between the PJ index and sea fog frequency (SFF) index in July indicates a close correlation, with a coefficient of 0.62 exceeding the 99% confidence level. Composite analysis based on the PJ index, a case study, and model analysis based on GFDL-ESM2M, show that in high PJ index years the convection over the east of the Philippines strengthens and then triggers a Rossby wave, which propagates northward to maintain an anticyclonic anomaly in the midlatitudes, indicating a northeastward shift of the NWP subtropical high. The anticyclonic anomaly facilitates the formation of relatively stable atmospheric stratification or even an inversion layer in the lower level of the troposphere, and strengthens the horizontal southerly moisture transportation from the tropical-subtropical oceans to the fog-prone area. On the other hand, a greater meridional SST gradient over the cold flank of the Kuroshio Extension, due to ocean downwelling, is produced by the anticyclonic wind stress anomaly. Both of these two aspects are favorable for the warm and humid air to cool, condense, and form fog droplets, when air masses cross the SST front. The opposite circumstances occur in low PJ index years, which are not conducive to the formation of sea fog. Finally, a multi-model ensemble mean projection reveals a prominent downward trend of the PJ index after the 2030s, implying a possible decline of the SFF in this period.

  17. Post-rift tectonic reactivation and its effect on deep-water deposits in the Qiongdongnan Basin, northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Mao, Kainan; Xie, Xinong; Xie, Yuhong; Ren, Jianye; Chen, Hui

    2015-09-01

    The post-rift evolution of extensional basins is traditionally thought to be dominated by thermal subsidence due to cessation of the major fault activity during the post-rift stage. The Qiongdongnan Basin, which is located in the northwestern continental margins of the South China Sea, has exhibited significant deviations from typical post-rift characteristics. In the basin, a distinct tectonic reactivation occurred since the Late Miocene (11.6 Ma). Three notable aspects of the observed tectonic reactivation during the post-rift stage include, (1) pre-existing fault reactivation, (2) multiple large-scale magmatic intrusions, and (3) rapid post-rift subsidence. During this period the basin infill significantly changed in depositional environments shifting rapidly from littoral-neritic to bathyal-abyssal environments since Late Miocene. The pre-existing fault activity along the No. 2 fault of the basin resulted in the formation of initial shelf breaks and led to the development of continental slope. In addition, the pre-existing faults along the Central Depression zone created a small sub-basin with distinctive axial negative topography characteristics formed between structural highs. These geomorphological changes led to the formation of the Central Canyon. Large-scale magmatic intrusions occurred along the fault zone in the Central Depression of the basin during the post-rift stage. Those deviations, as evidenced from pre-existing fault reactivation, magmatic intrusions, and rapid post-rift subsidence in the Qiongdongnan Basin is believed to be related to the Hainan Plume event.

  18. 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

    NASA Astrophysics Data System (ADS)

    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 Upper Cretaceous.

  19. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Modern theories of star and planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. The most detailed models of planetary growth are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed, and the methods that are being used and planned for detecting and characterizing extrasolar planets are reviewed.

  20. Geochemical Constraints on Collision-related Intrusive Rocks in Central, Northwestern and Western Anatolia (Turkey)

    NASA Astrophysics Data System (ADS)

    Ilbeyli, Nurdane

    2010-05-01

    The intrusive rocks in Anatolia occupy a broad petrological range from I- to A- type granitoids. Thus, Turkey is a natural laboratory to study collision-related magmatism, its geochemical characteristic, source region and also tectono-magmatic evolution. The central, northwestern and western Anatolian magmatic provinces are defined by a large number of Late Mesozoic to Late Cenozoic collision-related granitoids (Ilbeyli and Kibici 2009). Calc-alkaline, subalkaline and alkaline intrusive rocks in central Anatolia are mainly metaluminous, high-K and I- to A-types. They cover a petrological range from monzodiorite through quartz monzonite to granite/syenite. All these intrusive rocks are enriched in LILE and are also radiogenic in terms of Sr, and unradiogenic in terms of Nd, isotope ratios. Their geochemical characteristics show that the intrusive rocks originated from a mantle source containing large subduction components, and have experienced crustal assimilation and fractional crystallization. Delamination of a thermal boundary layer, and/or slab breakoff is the likely mechanisms for the initiation of the diverse magmatism in the complex (Ilbeyli et al. 2009). Calc-alkaline plutonic rocks in northwestern Anatolia are mainly metaluminous, medium- to high-K and I-types. They are monzonite to granite, and all are enriched in LILE and depleted in HFSE, showing features of arc-related intrusive rocks. Geochemical data reveal that these plutons were derived from partial melting of mafic lower crustal sources. These rocks are related to subduction of the northern branch of the Neo-Tethyan ocean beneath the Sakarya microcontinent during Cretaceous-Paleocene times (Kibici et al. 2008). Calc-alkaline intrusive rocks in western Anatolia are metaluminous, high-K and I-types. They have a compositional range from granodiorite to granite, and are enriched in LILE and depleted in HFSE. Geochemical characteristics of these intrusive rocks indicate that they could have originated by the partial melting of mafic lower crustal source rocks. In western Anatolia, the melt generation mechanism for the intrusive rocks could be crustal extension and uplift following collision (Ozgenc and Ilbeyli 2008). References Kibici, Y., Ilbeyli, N., Yildiz, A. and Bagci, M. 2008. Geochemical constraints on the genesis of the Günyüzü pluton, Northwest Anatolia, Turkey. International Geology Review, 50, 931-947. Ozgenc I. and Ilbeyli, N. 2008. Petrogenesis of the Late Cenozoic Egrigöz pluton in western Anatolia (Turkey): implications for magma genesis and crustal processes. International Geology Review, 50, 375-391. Ilbeyli, N. and Kibici, Y. 2009. Collision-related granite magma genesis, potential sources and tectono-magmatic evolution: comparison between central, northwestern and western Anatolia (Turkey). International Geology Review, 51, 252-278. Ilbeyli, N., Pearce, J.A., Meighan, I.G. and Fallick, A.E. 2009. Contemporaneous Late Cretaceous calc-alkaline and alkaline magmatism in central Anatolia, Turkey: O isotope constraints on petrogenesis. Turkish Journal of Earth Sciences, 18, 529-549.

  1. Geologic map of the western part of the Cut Bank 1 degree by 2 degrees Quadrangle, northwestern Montana

    USGS Publications Warehouse

    Harrison, J. E., (compiler); Whipple, J.W.; Lidke, D.J.; digital database by Kayser, Helen Z.; Miller, Robert J.

    1998-01-01

    The paper geologic map of the western part of the Cut Bank 1 degrees x 2 degrees quadrangle, northwestern Montana (Harrison and others, 1998) was digitized and initially attributed by the Montana Bureau of Mines and Geology (MBMG) and remitted to the U.S. Geological Survey for further attribution and publication of the geospatial digital files. The resulting digital geologic map GIS can be queried in many ways to produce a variety of geological maps.

  2. [On the history of the spread of the black rat (Rattus rattus L., 1758) in northwestern Russia].

    PubMed

    Savinetskiĭ, A B; Krylovich, O A

    2011-01-01

    Data on the first reliable findings of subfossil remains of the black rat in north-western Russia (Vologda and Vladimir oblasts) are given. The burying of the remains dates to the twelfth to thirteenth centuries. It is assumed that the spread of the black rat in the European part of Russia in the Middle Ages was associated first of all with the development of trade. PMID:21509989

  3. [Variation of bacterioplankton number in the north-western part of the Black Sea depending on hydrological and hydrochemical factors].

    PubMed

    Kovaleva, N V

    2003-01-01

    Quantitative analysis of total bacteria numbers variations under influence of river outflow and development of anaerobic conditions has been carried out on the basis of long-term field research in the north-western part of the Black Sea. The regressive equations describing dependence of the total bacteria number on temperature, salinity and water saturation with oxygen have been calculated. These results allow to characterize more completely the regularities of eutrophication processes on the Black Sea shelf. PMID:14723155

  4. High-resolution multibeam mapping and submersible surveys of topographic features in the northwestern Gulf of Mexico

    USGS Publications Warehouse

    Hickerson, E.L.; Schmahl, G.P.; Weaver, D.C.; Gardner, J.V.

    2003-01-01

    The Flower Garden Banks National Marine Sanctuary (FGBNMS) and the USGS Pacific Seafloor Mapping Project mapped about 2000 km2 of the northwestern Gulf of Mexico continental shelf during June 2002, using a Kongsberg Simrad EM1000 multibeam echosounder. Mapping focused on select topographic highs thave hae been idetnnfied as biological features warranting protection from oil and gas activities by the Minerals Management Service (MMS). The base maps will be used for all future ROV and submersible missions.

  5. Repeat temperature measurements in borehole GC-1, northwestern Utah - Towards isolating a climate-change signal in borehole temperature profiles

    SciTech Connect

    Chapman, D.S.; Harris, R.N. )

    1993-09-01

    Temperature-depth profiles in borehole GC-1, northwestern Utah, were measured in 1978, 1990, and 1992. Borehole temperatures below 80 m depth are highly reproducible over the 14 year period indicating long term thermal stability. A slowly changing temperature field above 80 m depth has similiar characteristics to synthetic temperature profiles computed from a 100 year record of air temperature changes at Park Valley weather station 50 km northeast of the borehole site. 6 refs.

  6. Habit formation

    PubMed Central

    Smith, Kyle S.; Graybiel, Ann M.

    2016-01-01

    Habits, both good ones and bad ones, are pervasive in animal behavior. Important frameworks have been developed to understand habits through psychological and neurobiological studies. This work has given us a rich understanding of brain networks that promote habits, and has also helped us to understand what constitutes a habitual behavior as opposed to a behavior that is more flexible and prospective. Mounting evidence from studies using neural recording methods suggests that habit formation is not a simple process. We review this evidence and take the position that habits could be sculpted from multiple dissociable changes in neural activity. These changes occur across multiple brain regions and even within single brain regions. This strategy of classifying components of a habit based on different brain signals provides a potentially useful new way to conceive of disorders that involve overly fixed behaviors as arising from different potential dysfunctions within the brain's habit network. PMID:27069378

  7. Intermittent Outflow of Continental Aerosols over the Northwestern Rim of the North Pacific in the Springtime of 2001

    NASA Astrophysics Data System (ADS)

    Matsumoto, K.; Uematsu, M.

    2001-12-01

    As part of the Asia-Pacific Regional Aerosol Characterization Experiment (ACE-Asia), we conducted continuous measurements of atmospheric aerosols and their associated species on four islands, Rishiri, Sado, Hachijo and Chichi-jima, over the northwestern rim of the North Pacific from March to May 2001. In order to clarify the outflow patterns of continental anthropogenic aerosols over the North Pacific, we carried out higher time-resolved measurements of particulate carbonaceous materials, which are mainly derived from anthropogenic activities, together with the associated species. Here we present the spatial and temporal distributions of particulate carbonaceous materials over the northwestern rim of the North Pacific during the spring period and discuss about the outflow patterns of anthropogenic aerosols over the North Pacific. Mean concentrations of particulate elemental carbon in Rishiri, Sado, Hachijo and Chichi-jima are 0.32, 0.56, 0.31 and 0.22 μ g m-3, respectively. These values lie within the range reported in the previous studies over the western North Pacific in the winter and spring. It is found that the outflow of continental air masses over the northwestern rim of the North Pacific is accelerated by certain synoptic-scale weather systems associated with the occurrence of traveling anticyclone and/or low-pressure system.

  8. Of glaciers and refugia: a decade of study sheds new light on the phylogeography of northwestern North America.

    PubMed

    Shafer, Aaron B A; Cullingham, Catherine I; Côté, Steeve D; Coltman, David W

    2010-11-01

    Glacial cycles have played a dominant role in shaping the genetic structure and distribution of biota in northwestern North America. The two major ice age refugia of Beringia and the Pacific Northwest were connected by major mountain chains and bordered by the Pacific Ocean. As a result, numerous refugial options were available for the regions taxa during glacial advances. We reviewed the importance of glaciations and refugia in shaping northwestern North America's phylogeographic history. We also tested whether ecological variables were associated with refugial history. The recurrent phylogeographic patterns that emerged were the following: (i) additional complexity, i.e. refugia within refugia, in both Beringia and the Pacific Northwest; and (ii) strong evidence for cryptic refugia in the Alexander Archipelago and Haida Gwaii, the Canadian Arctic and within the ice-sheets. Species with contemporary ranges that covered multiple refugia, or those with high dispersal ability, were significantly more likely to have resided in multiple refugia. Most of the shared phylogeographic patterns can be attributed to multiple refugial locales during the last glacial maximum or major physiographic barriers like rivers and glaciers. However, some of the observed patterns are much older and appear connected to the orogeny of the Cascade-Sierra chain or allopatric differentiation during historic glacial advances. The emergent patterns from this review suggest we should refine the classic Beringian-southern refugial paradigm for northwestern North American biota and highlight the ecological and evolutionary consequences of colonization from multiple refugia. PMID:20849561

  9. Clinical and epidemiological features of leishmaniasis in northwestern-Argentina through a retrospective analysis of recent cases.

    PubMed

    García Bustos, María F; González-Prieto, Gabriela; Ramos, Federico; Mora, María C; Hashiguchi, Yoshihisa; Parodi, Cecilia; Basombrío, Miguel A; Moreno, Sonia; Monroig, Sibila; Beckar, Josefina; Jaime, Daniela; Sajama, Jesús; Yeo, Matthew; Marco, Jorge D; Locatelli, Fabricio M; Barrio, Alejandra

    2016-02-01

    Leishmaniasis is a parasitic disease caused by hemoflagellates of the genus Leishmania and is transmitted to humans by the bite of infected phlebotomine sandflies. Depending on the Leishmania species, the disease has different clinical forms including cutaneous, mucocutaneous, and visceral manifestations. Previous studies performed in endemic zones of northwestern-Argentina, during epidemic outbreaks, have been important for detecting patients suffering from the acute phase of the disease, but have not given a complete representation of the clinical and epidemiological features in the region. Furthermore, due to the resurgence of leishmaniasis worldwide and in particular the large increase of international tourism to the region, it seems pertinent to update the current epidemiological and clinical profile of leishmaniasis in northwestern-Argentina. Here we present a retrospective analysis of 95 Leishmania positive cases, presenting between 2000 and 2014. Patients were derived from hospitals and diagnosed in our lab at the University of Salta, located in a non-endemic area in Salta, Argentina. We detected numerous extensive mucocutaneous cases (34/95, 35.8%) distinct from mucosal affected patients, some instances originating in locations with no previously reported human cases. Additionally patients suffering from concomitant diseases, besides leishmaniasis, were assessed. These included Chagas disease, syphilis, deep mycoses, tuberculosis, toxoplasmosis and intestinal parasitosis. This study updates the clinical and epidemiological features of leishmaniasis in northwestern-Argentina, and discusses the implications and management strategy for patients who acquire the disease in this region. PMID:26611809

  10. Geographic structure and host specificity shape the community composition of symbiotic dinoflagellates in corals from the Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Stat, Michael; Yost, Denise M.; Gates, Ruth D.

    2015-12-01

    How host-symbiont assemblages vary over space and time is fundamental to understanding the evolution and persistence of mutualistic symbioses. In this study, the diversity and geographic structure of coral-algal partnerships across the remote Northwestern Hawaiian Islands archipelago was investigated. The diversity of symbionts in the dinoflagellate genus Symbiodinium was characterised using the ribosomal internal transcribed spacer 2 (ITS2) gene in corals sampled at ten reef locations across the Northwestern Hawaiian Islands. Symbiodinium diversity was reported using operational taxonomic units and the distribution of Symbiodinium across the island archipelago investigated for evidence of geographic structure using permutational MANOVA. A 97 % sequence similarity of the ITS2 gene for characterising Symbiodinium diversity was supported by phylogenetic and ecological data. Four of the nine Symbiodinium evolutionary lineages (clades A, C, D, and G) were identified from 16 coral species at French Frigate Shoals, and host specificity was a dominant feature in the symbiotic assemblages at this location. Significant structure in the diversity of Symbiodinium was also found across the archipelago in the three coral species investigated. The latitudinal gradient and subsequent variation in abiotic conditions (particularly sea surface temperature dynamics) across the Northwestern Hawaiian Islands encompasses an environmental range that decouples the stability of host-symbiont assemblages across the archipelago. This suggests that local adaptation to prevailing environmental conditions by at least one partner in coral-algal mutualism occurs prior to the selection pressures associated with the maintenance of a symbiotic state.

  11. Lower Cretaceous Fossil Record of The Lavrasian Continental Shelf in Northwestern Turkey and Its Correlation with Surrounding Areas

    NASA Astrophysics Data System (ADS)

    Menteş, Merve; Özkar Öngen, İzver

    2015-04-01

    This study contains Zonguldak, Amasra and Kırkalerli (İğneada) area in the Northwestern Turkey. In this region, The Istanbul-Zonguldak Composite Terrane consists of two Paleozoic terranes and their Mesozoic overstep sequences around Zonguldak and Amasra. However The Istranca Terrane is characterized by a complex nappe-pile that includes metamorphic assemblages unconformably overlain by Tertiary sediments of the Thrace basin around İğneada. The original purpose of this study to analyze fossil records of Kozlu-Zonguldak, Amasra and Kırklareli (İğneada) in which Lower Cretaceous of shallow nautical sedimentary stacking which is regarding to The Lavrasian continental shelf in Northwestern Turkey. After analysing about 90 thin section and 30 samples we followed and associated lito-biostratigraphical similarities and contrasts, horizontal and vertical variation in facies which includes Orbitolina, Neotrocholina, megalospheric Rudists and various benthic foraminifera fossil records. Correlation between sections with detailed paleontological analyse wasn't presented until today, however there are several geological examination in these areas. In accordance with this purpose, this study tries to determine possible paleogeographic borders, which are in Northwestern Anatolian of The Lavrasian continental shelf, with benthic foraminiferal assemblages . In this examination, the other aim is to correlate with researches of Lower Cretaceous continental shelf of Iranian in East, Bulgaria, Romania, Italy and Spain in West, to present comparisons and contrasts in Western Pontids. Keywords: Lower Cretaceous, Benthic Foraminifera, Correlation.

  12. An adjusted one year sea surface heat and water budget for the Northwestern Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Caniaux, Guy; Prieur, Louis; Giordani, Hervé

    2015-04-01

    The problem of heat and salt budget closure is an important subject in operational and research oceanography. The closure depends crucially on surface fluxes, as they are one of the most important processes in terms of the evolution of the heat and salt content in the oceanic top layers. However, in this problem, two points have to be considered. First, surface fluxes are affected by a variety of errors: those associated with the algorithms used for computing the turbulent fluxes, those due to the data used as input of bulk algorithms and the errors associated with the time and space resolution of the fluxes themselves. The second problem is that no surface flux dataset exists, that can be used as the truth, or as a reference, i.e. that can be used for closing observed heat and water budgets at various time and space scales. Here we address the question of adjusting surface heat and water fluxes so that they are in agreement with the evolution of the thermal and salt contents deduced from the extended dataset collected during the HyMex campaigns. These experiments were conducted in the North-western Mediterranean basin in 2012 and 2013. The method is based: (1) on the one-dimensional column modelling of the experimental area, by solving specific temperature and salinity equations and (2) on the optimization of adjustable coefficients with a genetic algorithm. The surface forcings, calculated from a mix of satellite retrievals, in-situ data, numerical weather prediction model observables and a bulk algorithm are also adjusted with the genetic algorithm. Finally, the adjusted fluxes allows to simulate the domain average sea surface temperature and salinity with errors less than 0.2 percent (or 0.03°C) and 0.08 percent (or 0.03 psu) respectively over one year. The adjusted fluxes are finally compared with various NWP models over the North-western Mediterranean basin and also locally with fluxes estimated at a mooring site (LION buoy).

  13. Frequency dependent attenuation characteristics of coda waves in the Northwestern Himalayan (India) region

    NASA Astrophysics Data System (ADS)

    Kumar, Sushil; Singh, Priyamvada; Singh, Pitam; Biswal, Shubhasmita; Parija, Mahesh Prasad

    2016-03-01

    Digital seismogram data of 82 earthquakes from the Northwestern Himalayan (India) region recorded at different stations during 2004-2006 were analyzed to study the seismic coda wave attenuation characteristics in this region. We used 132 seismic observations from local earthquakes with a hypocentral distance <240 km and a magnitude range of 1.2-4.9 to study the coda QC using the single isotropic scattering model. These earthquakes were recorded at 20 temporary seismic stations installed in the Northwestern Himalayas (India) by the Wadia institute of Himalayan Geology, Dehradun. The QC values were estimated at 10 central frequencies: 1.5, 3, 5, 7, 9, 12, 16, 20, 24, and 28 Hz using starting lapse-times of 10, 20, 30, 40, 50, and 60 s and coda window-lengths of 10, 20, 30, 40, and 50 s. The QC fits the frequency dependent power-law, QC =Q0fn . For a 10 s lapse time with a 10-s coda window length QC = 47.42f1.012 and for a 50 s lapse time with a 50 s coda window length, QC = 204.1f0.934 . Q0 (QC at 1 Hz) varied from ∼47 for a 10 s lapse time and a 10 s window length, to ∼204 for a 50 s lapse time and a 50 s window length. An average frequency dependent power law fit for the study region may be given as QC = 116.716f0.9943 . The exponent of the frequency dependence law n ranged from 1.08 to 0.9, which correlates well with values obtained in other seismically and tectonically active and heterogeneous regions of the world. In our study region, QC increases both with respect to lapse time and frequency, i.e., the attenuation decreases as the quality factor is inversely proportional to attenuation. The low QC values or high attenuation at lower frequencies and high QC values or low attenuation at higher frequencies suggest that the heterogeneity decreases with increasing depth in our study region.

  14. A study on the climate change in Northwestern Hebei Mountains area over the past 46 years

    NASA Astrophysics Data System (ADS)

    Liu, Yuming; Feng, Zhongjiang; Ge, Jingfeng; Xia, Zhengrong

    2008-10-01

    The northwestern Hebei mountains area is located in the transitional area from the subhumid and temperate zone to the semiarid zone, pertaining to the ecologically fragile area. Closing to Beijing and Tianjin, the area is in the windward and upriver area of the two cities. It is of great significance to study the climate change in this area for the purpose of understanding the law of local ecological development and constructing the Beijing-Tianjin ecological protective barrier. Based on the average monthly temperatures and precipitation data collected by three weather stations in the northwestern mountains area between 1956 and 2001, this paper studied the climate changes in this area over the past 46 years, by analyzing the average temperature anomaly and precipitation anomaly of yearly and quarterly, calculating the five years sliding average value of them, and applying the way of univariate linear regression to get linear regression equation of the five years sliding average value. Preliminary research was conducted on the average temperature anomaly and precipitation anomaly values and their development trends with the adoption of correlation analysis. Discussion on factors causing the climate change was carried out. The result shows that the average temperature was on an upward trend in the period 1956-2001 at a rate of 0.41 deg. Celcius /10a, with the highest growth rate seen in winter. In contrast, the annual precipitation was on decrease during the same period at a rate of 7.765mm/10a, with the highest rate seen in summer. The area under research is turning warmer and drier. The correlation analysis indicates no apparent correlation between the upward annual average temperature and the downward precipitation, which should be regarded as a process of independent change. This paper also explores the possible causes that have affected the climate in this area, including the global warming, the climate change in a larger area such as the circulation of water vapor in East Asia as well as the changes to local ecological environment such as pollution, greenhouse gas emissions, increased particulate matters in the atmosphere, ecological damages, etc.

  15. Quantitative risk assessment of entry of contagious bovine pleuropneumonia through live cattle imported from northwestern Ethiopia.

    PubMed

    Woube, Yilkal Asfaw; Dibaba, Asseged Bogale; Tameru, Berhanu; Fite, Richard; Nganwa, David; Robnett, Vinaida; Demisse, Amsalu; Habtemariam, Tsegaye

    2015-11-01

    Contagious bovine pleuropneumonia (CBPP) is a highly contagious bacterial disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony (SC) bovine biotype (MmmSC). It has been eradicated from many countries; however, the disease persists in many parts of Africa and Asia. CBPP is one of the major trade-restricting diseases of cattle in Ethiopia. In this quantitative risk assessment the OIE concept of zoning was adopted to assess the entry of CBPP into an importing country when up to 280,000 live cattle are exported every year from the northwestern proposed disease free zone (DFZ) of Ethiopia. To estimate the level of risk, a six-tiered risk pathway (scenario tree) was developed, evidences collected and equations generated. The probability of occurrence of the hazard at each node was modelled as a probability distribution using Monte Carlo simulation (@RISK software) at 10,000 iterations to account for uncertainty and variability. The uncertainty and variability of data points surrounding the risk estimate were further quantified by sensitivity analysis. In this study a single animal destined for export from the northwestern DFZ of Ethiopia has a CBPP infection probability of 4.76×10(-6) (95% CI=7.25×10(-8) 1.92×10(-5)). The probability that at least one infected animal enters an importing country in one year is 0.53 (90% CI=0.042-0.97). The expected number of CBPP infected animals exported any given year is 1.28 (95% CI=0.021-5.42). According to the risk estimate, an average of 2.73×10(6) animals (90% CI=10,674-5.9×10(6)) must be exported to get the first infected case. By this account it would, on average, take 10.15 years (90% CI=0.24-23.18) for the first infected animal to be included in the consignment. Sensitivity analysis revealed that prevalence and vaccination had the highest impact on the uncertainty and variability of the overall risk. PMID:26427634

  16. A boundary of stress-field orientation in northwestern area of the Kanto plain

    NASA Astrophysics Data System (ADS)

    Yano, T. E.; Takeda, T.; Shiomi, K.

    2014-12-01

    There is a boundary where pressure and tension axes dramatically change by almost at the right angles around northwestern area of the Kanto plain (north of Tokyo), reported by Suzuki (1989). Since 2013, we have launched Japan Unified High-resolution Relocated Catalog for Earthquakes (JUICE) project. The relocation method using the Double-Difference method (Waldhauser and Ellsworth, 2000) provided the high-resolution earthquake catalog, which enabled to further evaluate active faults (e.g. seismogenic layer thickness, or slip tendency direction etc.) In this presentation, we revisit the previous mystery regarding to the stress-field orientation boundary in northwestern Kanto plain by looking at much more and high-resolution data available than before. The stress axis boundary runs at particularly close (about 5 km north and parallel direction) to the Fukaya fault, which caused the M6.9 Western Saitama earthquake in 1931 occurred at very shallow depth, involving severe damages and many casualties in Kanto region. The high-resolution catalog clearly showed the majority of pressure (P-axis) and tension stress axis (T-axis) lie about 150˚ and 60˚ in the north of the stress axis boundary, while both the axes change into about 45˚ and 150˚ in the south of this boundary, respectively. In fact, both P- and T- axis, by crossing the boundary, suddenly changes about 90˚. The focal mechanism around this area dominated by the strike and thrust and both mechanisms seem to be randomly co-existing. Yet, depth distribution pattern changes abruptly across the boundary. The depth distribution pattern of north part of the boundary seems more confined than the southern part. We discuss the sharp stress discontinuity by two main perspectives. The first focuses on the effect due to local structure, such as possibly the buried Median tectonic line and/or ancient failed rift formed while the Sea of Japan had opened. The second focuses on the tectonic force due to complicated subduction of two oceanic plates, the Philippine Sea plate and Pacific plate, beneath the North American plate in this Kanto region.

  17. Control of pre-Cenozoic extensional heterogeneities on the kinematics of Cenozoic shortening: Northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Pearson, D. M.; Kapp, P. A.; Reiners, P. W.; Gehrels, G. E.

    2012-12-01

    Results from regional-scale mapping and structural analysis, (U-Th)/He and U-Pb age dating of apatite and zircon, and a regional balanced cross section allow us to build upon the pre-existing geological framework for the retroarc of northwestern Argentina. Coupled with previous work in the region, our results suggest that the style, distribution, and kinematics of shortening in the Eastern Cordillera and Santa Bárbara tectonomorphic provinces of the thrust belt at this latitude (24-25°S) were strongly influenced by the architecture of a Mesozoic rift system. In contrast to the thin-skinned Subandean fold-thrust belt of southern Bolivia where structures are primarily W-dipping and propagated progressively eastward through time, reverse faults in northwestern Argentina are more variably oriented, steeply E-dipping, locally inverted structures that propagated in an overall eastward direction in a much more sporadic manner. The first major eastward propagation event at this latitude occurred at ~40 Ma and is expressed as Eocene (U-Th)/He apatite and zircon ages coincident with the western arm of the Cretaceous Salta rift system. Other workers also documented angular unconformities of this age in the western and eastern arms of the rift system. Up until ~10 Ma, deformation and exhumation were restricted to the western margin of the Cretaceous rift in the western Eastern Cordillera and eastern margin of the Puna plateau. This was followed by an ~75 km jump in the location of the thrust front toward the east to bypass the central portion of a horst block of the Cretaceous rift system, followed by subsequent initiation of new E-dipping reverse faults in a subsystem that propagated toward the west into this pre-existing structural high. During Pliocene time, deformation again migrated >100 km eastward to a Cretaceous syn-rift depocenter in the Santa Bárbara Ranges and was likely followed by additional westward propagation to the current location of deformation with the Lavayén Valley. The observed sporadic foreland-ward propagation may be common in basement-involved thrust systems where the reactivation of pre-existing heterogeneities is important. A major implication is that variations in the pre-orogenic upper crustal architecture can strongly influence the behavior of the continental lithosphere during later orogenesis.

  18. Coral isotopic records during the medieval period from Ishigaki Island, northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Morimoto, Maki; Abe, Osamu

    2013-04-01

    Proxy-based paleoclimate reconstructions in high time-resolution and modeling studies have been greatly advanced in recent years to understand global temperature history over the past 1000 years. However, most proxy data for these reconstructions are from terrestrial sources such as tree-rings, speleothems, etc., and very few marine records in annual resolution have been obtained over 500 years. This is considered to be one of reasons for large uncertainties of global scale climatic reconstructions. Marine sediments can provide long consecutive records from several thousands of years to several million years. However, their time-resolutions of several tens to several thousands of years are insufficient for reconstructing decadal to centennial climate variabilities. Coral skeletal proxies, such as oxygen isotope ratios (δ18O) and Sr/Ca, have been used to reconstruct tropical and subtropical sea surface paleoenvironment in much higher time-resolution of weeks to months, which could provide comparable results with tree-ring records. The Northwestern Pacific is one of regions with sparse long paleoclimate records in high time-resolution for the last 1000 years. We collected a medieval fossil coral (Porites sp.) with a height of more than 5 m from a fringing reef of the southern coast of the Ishigaki Island, southern Japan, where the East Asian monsoon is predominant. Using combined annual age determination by annual band analysis and high resolution isotope measurements, yearly δ18O was obtained spanning 300 years of about 1000 years ago (1535+-35 ~ 1260+-80 14C age (ca. cal AD 850 ~ 1150)). This period corresponds to the beginning of the Medieval Warm Period, recently more commonly referred to as the Medieval Climate Anomaly (Stine, 1994), and it also is marked by a tendency for La Niña-like conditions in the tropical Pacific (Mann et al., 2009). Here we discuss about the transition to the warm period of the northwestern Pacific and its degree by comparing with other regions' and large-scale reconstructed temperature variations.

  19. Stable isotopic compositions of carbonates from the Mesoproterozoic Bangemall Group, northwestern Australia.

    PubMed

    Buick, R; Des Marais, D J; Knoll, A H

    1995-06-20

    Marine carbonate rocks from the Mesoproterozoic Bangemall Group of northwestern Australia show little deviation (+/-1.3%) in whole-rock delta 13C(carb)-values about a mean of -0.5%. This narrow range persists despite close sampling (every 10-20 m) through long sections (up to 2500 m) that are geographically widespread (up to 250 km apart), over many depositional environments (supralittoral to outer shelf), sediment sources (stromatolitic bioherms to detrital calcilutites) and rock types (pure limeston