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Sample records for yacoraite formation northwestern

  1. Geological context, mineralization, and timing of the Juramento sediment-hosted stratiform copper-silver deposit, Salta district, northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Durieux, C. Gustavo; Brown, Alex C.

    2007-11-01

    The Juramento deposit in northwestern Argentina exhibits several readily visible general characteristics of sediment-hosted stratiform copper (SSC) mineralization. It consists of fine-grained disseminated base-metal sulfides within marine to lacustrine graybeds (the basal whitish Late Cretaceous Lecho Sandstone and shallow-water carbonates of the overlying Maastrichtian Yacoraite Formation) that overlie a thick sequence of redbeds (the Pirgua Subgroup). The property has been examined and drilled in three successive exploration programs as a possible analog of world-class mineralization in the copperbelts of central Africa and the Kupferschiefer. The present report provides specific field and laboratory results that confirm the classification as SSC-type mineralization. The host graybeds are the basal sandstone and overlying oolitic and stromatolitic units of the Yacoraite Formation, which are shown from textural studies to be carbonaceous and to have initially contained very fine-grained, disseminated, syndiagenetic pyrite. These sediments would have been sufficiently porous and permeable in early diagenetic time to allow an infiltration of metalliferous fluids from the underlying redbeds, resulting in the observed progressive replacement of in situ pyrite by common base-metal sulfides (sphalerite, galena, argentiferous tetrahedrite, and copper-rich sulfides: first chalcopyrite, then bornite, and finally chalcocite). Sulfur isotope analyses indicate that a portion of the sulfur of ore-stage sulfides is isotopically heavier than that of pyrite, possibly due to a contribution from associated gypsum. Ore-stage sulfides are zoned vertically and obliquely through the mineralized zones, from cupriferous sulfides at low stratigraphic levels to lead- and zinc-rich mineralization above, with unreplaced pyrite remaining within upper Yacoraite strata. The zoned sulfides and their replacement textures, the peneconformable configuration of the mineralized zones, and the position of ore-stage mineralization adjacent to a stratigraphically defined redox transition from redbeds upward into graybeds indicate an overprint of copper (and accompanying ore-stage metals) on originally pyritic graybeds. The influx of ore-stage metals, presumably in an oxidized low-temperature brine, terminated with a silicification event that effectively sealed the host carbonates. These observations and the overall genetic interpretation are consistent with the general deposit-scale genetic model for early diagenetic SSC mineralization. The regional geologic context is also consistent with its classification as a SSC deposit: It is hosted by post-oxyatmoversion sediments and was formed in association with evaporites at a low paleolatitude in a major intracontinental rift system.

  2. Airfall tuff in the Browns Park Formation, northwestern Colorado and northeastern Utah.

    USGS Publications Warehouse

    Luft, S.J.

    1985-01-01

    Bedded airfall tuffs, mainly rhyolitic in composition and locally very thick, occur throughout the Browns Park Formation (upper Oligocene to upper Miocene) in northwestern Colorado and northeasternmost Utah. They have received only cursory attention other than for the purpose of radiometric dating. The present writer began study of the tuffs in 1980, hoping to use them as time-stratigraphic marker beds within the formation. Several tuff-rich stratigraphic sections were measured and numerous samples were collected. The results of petrographic and petrochemical studies of these samples are presented. -from Author

  3. Paleogeothermal gradients and timing of oil generation in the Belden Formation, Eagle Basin, northwestern Colorado

    USGS Publications Warehouse

    Nuccio, V.F.; Johnson, S.Y.; Schenk, C.J.

    1989-01-01

    Paleogeothermal gradients and timing of oil generation for the Lower and Middle Pennsylvanian Belden Formation have been estimated for four locations in the Eagle Basin of northwestern Colorado, by comparing measured vitrinite reflectance with maturity modeling. Two thermal models were made for each location: one assumes a constant paleogeothermal gradient through time while the other is a two-stage model with changing paleogeothermal gradients. The two-stage paleogeothermal gradient scenario is considered more geologically realistic and is used to estimate the timing of oil generation throughout the Eagle basin. From the data and interpretations, one would expect Belden oil to be found in either upper Paleozoic or Mesozoic reservoir rocks. -Authors

  4. 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.

  5. 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.

  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. 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.

  8. 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

  9. 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

  10. 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.

  11. Depositional environment, sand provenance, and diagenesis of the Basal Salina Formation (lower Eocene), northwestern Peru

    NASA Astrophysics Data System (ADS)

    Marsaglia, K. M.; Carozzi, A. V.

    The Basal Salina Formation is a lower Eocene transgressive sequence consisting of interbedded shales, siltstones, and conglomeratic sandstones. This formation occurs in the Talara basin of northwestern Peru and is one of a series of complexly faulted hydrocarbon-producing formations within this extensional forearc basin. These sediments were probably deposited in a fan-delta complex that developed along the ancestral Amotape Mountains during the early Eocene. Most of the sediment was derived from the low-grade metamorphic and plutonic rocks that comprise the Amotape Mountains, and their sedimentary cover. Detrital modes of these sandstones reflect the complex tectonic history of the area, rather than the overall forearc setting. Unlike most forearc sediments, these are highly quartzose, with only minor percentages of volcanic detritus. This sand is variably indurated and cemented by chlorite, quartz, calcite, and kaolinite. Clay-mineral matrix assemblages show gradational changes with depth, from primarily detrital kaolinite to diagenetic chlorite and mixed-layered illite/smectite. Basal Salina sandstones exhibit a paragenetic sequence that may be tied to early meteoric influx or late-stage influx of thermally driven brines associated with hydrocarbon migration. Much of the porosity is secondary, resulting from a first-stage dissolution of silicic constituents (volcanic lithic fragments, feldspar, and fibrous quartz) and a later dissolution of surrounding carbonate cement. Types of pores include skeletal grains, grain molds, elongate pores, and fracture porosity. Measured porosity values range up to 24% and coarser samples tend to be more porous. Permeability is enhanced by fractures and deterred by clay-mineral cements and alteration residues.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Makah Formation; a deep-marginal-basin sequence of late Eocene and Oligocene age in the northwestern Olympic Peninsula, Washington

    USGS Publications Warehouse

    Snavely, P. D.; Niem, A.R.; MacLeod, N.S.; Pearl, J.E.; Rau, W.W.

    1980-01-01

    The Makah Formation of the Twin River Group crops out in a northwest-trending linear belt in the northwesternmost part of the Olympic Peninsula, Wash. This marine sequence consists of 2800 meters of predominantly thin-bedded siltstone and sandstone that encloses six distinctive newly named members--four thick-bedded amalgamated turbidite sandstone members, an olistostromal shallow-water marine sandstone and conglomerate member, and a thin-bedded water-laid tuff member. A local unconformity of submarine origin occurs within the lower part of the Makah Formation except in the central part of the study area, where it forms the contact between the older Hoko River Formation and the Makah. Foraminiferal faunas indicate that the Makah Formation ranges in age from late Eocene (late Narizian) to late Oligocene (Zemorrian) and was deposited in a predominantly lower to middle bathyal environment. The Makah Formation is part of a deep-marginalbasin facies that crops out in the western part of the Olympic Peninsula, in southwesternmost Washington and coastal embayments in northwestern Oregon, and along the central part of the coast of western Vancouver Island. On the basis of limited subsurface data from exploratory wells, correlative deep-marginal-basin deposits underlie the inner continental shelf of Oregon and the continental shelf (Tofino basin) along the southwestern side of Vancouver Island. Directional structures in the Makah Formation indicate that the predominantly lithic arkosic sandstone that forms the turbidite packets was derived from the northwest. A possible source of the clastic material is the dioritic, granitic, and volcanic terranes in the vicinity of the Hesquiat Peninsula and Barkley Sound on the west coast of Vancouver Island. Vertical and lateral variations of turbidite facies suggest that the four packets of sandstone were formed as depositional lobes on an outer submarine fan. The thin-bedded strata between the turbidite packets have characteristics of basin-plain and outer-fan fringe deposits.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. Heavy Rainfall Impacts on Trihalomethane Formation in Contrasting Northwestern European Potable Waters.

    PubMed

    Delpla, Ianis; Jones, Timothy G; Monteith, Don T; Hughes, David D; Baurs, Estelle; Jung, Aude-Valrie; Thomas, Olivier; Freeman, Chris

    2015-07-01

    There is emerging concern over the impact of extreme events such as heavy rainfall on the quality of water entering the drinking water supply from aboveground sources, as such events are expected to increase in magnitude and frequency in response to climate change. We compared the impact of rainfall events on streamwater quality in four contrasting upland (peatland and mineral soil) and lowland agricultural catchments used to supply drinking water in France (Brittany) and the United Kingdom (North Wales) by analyzing water samples collected before, during, and after specific events. At all four streams, heavy rainfall led to a considerable rise in organic matter concentration ranging from 48 to 158%. Dissolved organic carbon (DOC) quality, as determined using specific ultraviolet absorbance, changed consistently at all sites during rainfall events, with a greater proportion of aromatic and higher molecular weight compounds following the onset of rainfall. However, the change in DOC quality and quantity did not significantly alter the trihalomethane formation potential. We observed small increases in trihalomethane (THM) generation only at the Welsh peatland and agricultural sites and a small decrease at the Brittany agricultural site. The proportion of brominated THMs in chlorinated waters was positively correlated with bromide/DOC ratio in raw waters for all sites and hydrological conditions. These results provide a first indication of the potential implications for surface-based drinking water resources resulting from expected future increases in rainfall event intensity and extension of dry periods with climate changes. PMID:26437106

  2. Depositional systems of Fountain formation and its basinal equivalents, northwestern Denver Basin, Colorado

    SciTech Connect

    Napp, K.F.; Ethridge, F.G.

    1985-05-01

    The objective of this study is to provide a better understanding of the depositional systems of the Pennsylvanian Fountain Formation in north-central Colorado. The study area is bounded by T4N, T11N, R66W, and R70W, encompassing portions of the foothills outcrop belt and the Denver basin. The sedimentary sequence observed in surface exposures displays little vertical variation. It is composed of vertically stacked, fining-upward, gravel to siltstone and mudstone cycles containing trough and planar cross-beds, horizontal beds, root structures, and nodular limestone. This succession represents deposition in Donjek-type braided streams and abandoned channel-fill sequences, and the development of soil horizons on a subaerial alluvial fan or alluvial plain. In the subsurface, the vertical succession begins with a basal course-grained 140-ft (43-m) thick interval that is identical on the rocks found in surface outcrops to the west. This interval is overlain be 410 ft (125 m) of red shale, siltstone, sandstone, and fossilferous limestone that grades eastward into black organic shale and limestone. Capping the sequence is a 500-ft (152 m) interval of red shale, siltstone, sandstone, gypsum- and anhydrite-bearing dolomites and fossiliferous limestones that interfinger with typical Fountain coarse-grained terrigenous clastics. This vertical succession of Fountain rocks in the subsurface suggests the following sequence of depositional systems from base to top: alluvial fan and braided alluvial plain, fan deltas, and small interfan embayments that grade eastward into a normal-salinity marine shoreface and an offshore hypersaline carbonate shelf. Normal salinity marine conditions were probably maintained in the parallic zone by the influx of ancestral Front Range runoff.

  3. 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.

  4. 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.

  5. 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.

  6. Sedimentology and sequence stratigraphy of the Shanxi Formation (Lower Permian) in the northwestern Ordos Basin, China: an alternative sequence model for fluvial strata

    NASA Astrophysics Data System (ADS)

    Zhang, Zhouliang; Sun, Keqin; Yin, Jarun

    1997-08-01

    The Lower Permian Shanxi Formation in the northwestern Ordos Basin was deposited in fluvial environments under warm and humid climatic conditions. Braided, anastomosing and meandering fluvial facies associations can be recognized in the lower, middle and upper parts of the Shanxi Formation, respectively. They form a complete type-1 fluvial sequence. Based on this sequence as well as on the analysis of base level changes and their effect on fluvial deposition, an alternative sequence model for fluvial strata is proposed. The lowstand systems tract in the model comprises braided river deposits, the transgressive systems tract consists mainly of fine-grained anastomosing river deposits, and meandering river deposits dominate in the highstand systems tract. Braided sandstones in the lowstand systems tract seem to be widely distributed and have high lateral continuity. Anastomosing channel sand-bodies in the transgressive systems tract appear to be isolated and display relative low lateral continuity.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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).

  16. High resolution sequence stratigraphic architecture and reservoir characterization of the Mississippian Burlington/Keokuk Formation, northwestern Arkansas

    NASA Astrophysics Data System (ADS)

    Price, Buddy James

    The Upper Osagean Burlington-Keokuk Formation is a limestone and chert interval within the Mid-continent containing reservoir quality rock. Outcrop analogs in northwest Arkansas were studied in order to accurately characterize potential reservoir intervals in the subsurface of Kansas and Oklahoma. Using an integrated sequence stratigraphic approach combining thin-section analysis, high-resolution photography, and spectral gamma-ray logs, packages of coarsening and thickening upward successions of skeletal packstones and grainstones were identified. Accurate identification of cyclic stacking patterns allowed for the recognition and correlation of high frequency sequences across the outcrop, which enhance the predictability of potential reservoir and seal units. Within each sequence regressive skeletal grainstones exhibit abundant early syntaxial cement, occluding all effective pore space. Transgressive packstones contain little to no void-filling cement and exhibit varying degrees of silicification and dissolution, creating adequate reservoir rock in many cases. Facies associations suggest deposition occurred within a high energy skeletal shoal complex. Analysis of depositional analogs was utilized to provide first approximations of the scale of facies geometries and distributions in plan-view not provided by outcrop. Stochastic modeling allowed for integration of variables from analogs with the sequence framework and facies successions interpreted from outcrop in order to visually represent facies variability and potential reservoir distribution in the formation. Comparison of geostatistical models with two-dimensional rock data from outcrop allowed for the creation of multiple model iterations and identification of modeling parameters necessary for accurate subsurface representation and visualization.

  17. 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.

  18. Lithospheric modeling of the Ordovician foreland basin in the Puna of northwestern Argentina: on the influence of arc loading on foreland basin formation

    NASA Astrophysics Data System (ADS)

    Bahlburg, Heinrich; Furlong, Kevin P.

    1996-06-01

    In a qualitative sedimentological model of the Ordovician basin in the Puna of northwestern Argentina, the temporal and spatial distribution of predominantly marine volcanoclastic facies was interpreted to indicate a basin evolution from extensionally related subsidence to that driven by crustal down flexure. Sedimentological data were taken to reflect a Middle Ordovician eastward thrusting of an extinct Early Ordovician arc over part of its back-arc basin in the course of the collision of the allochthonous Arequipa Massif terrane with the South American margin. To test the original qualitative sedimentological interpretation of the Puna basin, an infinite beam elastic plate loading model was applied using the constraints of the field data. Contrary to the original interpretation, results show that the Puna basin can be modeled as resulting entirely from the effects of lithospheric loading caused by the progressive contruction of a static load, i.e., a volcanic arc. Two loading events, one in the Early Ordovician, and one in the Llanvirnian, with tectonic load thicknesses of 6000 and 2000 m, respectively, best explain the observed basin geometry. The onlap patterns on the distal margin on the peripheral bulge are reproduced well using a flexural rigidity of 10 22 N m representing an equivalent elastic thickness of 14 km of the loaded plate. Higher values for the flexural rigidity are considered unlikely, as they result in an enhanced peripheral bulge which uplifts marine near-shore deposits on the distal margin to unrealistic subaereal positions. The model results fit a foreland basin development where crustal thickening was caused by the construction of a static volcanic arc on a previously passive margin. Modeling the movement of thrust loads over parts of the basin according to traditional models of foreland basin formation in this case leads to model results which are inconsistent with field data, even when moderate thrust rates are considered.

  19. 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.

  20. 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.

  1. 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.

  2. Internanual variability of the biogeochemical fluxes in the deep water formation area in the northwestern Mediterranean Sea from a 3D coupled physical-biogeochemical model

    NASA Astrophysics Data System (ADS)

    Ulses, Caroline; Auger, Pierre-Amal; Soetaert, Karline; Diaz, Fredric; Marsaleix, Patrick; Kessouri, Fayal; Herrmann, Marine; Estournel, Claude

    2014-05-01

    A biogeochemical model was coupled to a regional circulation model to investigate the interannual variability of the biogeochemical fluxes in the northwestern Mediterranean Sea. The physical model is the primitive equation ocean circulation S model [Marsaleix et al., 2011]. The biogeochemical model Eco3M-S [Auger et al., 2011] was used to describe the cycles of carbon, nitrogen, phosphorus and silica. The model results were compared with a set of in-situ and satellite observations available over the 5-year period study, 2004-2008. The comparisons provided a reasonable validation of the model reproducing the recorded spatial and temporal variations and suggested that it can be used to estimate a budget of biogenic elements. A strong variability of the intensity of the deep convection was observed over the study period. We investigated the impact of this variability on (1) the import of nutrients upwelled in the surface layer, (2) the primary production, (3) the export of organic carbon towards the bottom and on (4) the lateral exchanges.

  3. 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

  4. 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

  5. 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.

  6. 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)

  7. 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

  8. Profiles in College Teaching: Models at Northwestern.

    ERIC Educational Resources Information Center

    Mathis, B. Claude, Ed.; McGaghie, William C., Ed.

    This book presents a series of readings prepared for college teachers. Its chapters provide first-person accounts of teaching strategies that have been successfully employed at Northwestern University. Each chapter offers a unique perspective on teaching by an individual credited with exceptional skill in his craft. Contributors were selected

  9. Spontaneously Settled Refugees in Northwestern Province, Zambia.

    ERIC Educational Resources Information Center

    Freund, Paul J.; Kalumba, Katele

    1986-01-01

    Presents results of a socioeconomic survey and census of "spontaneously settled" Zairean and Angolan refugees in the Northwestern Province of Zambia. Finds refugees' difficulties to be caused by lack of a clear national policy and negative attitudes toward them, as well as Zambia's own deteriorating economic situation. (GC)

  10. 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.

  11. Interannual variability of sea fog frequency in the Northwestern Pacific in July

    NASA Astrophysics Data System (ADS)

    Zhang, Suping; Chen, Yang; Long, Jingchao; Han, Geng

    2015-01-01

    The interannual variability in the sea fog frequency (SFF) in July in the midlatitude Northwestern Pacific (40N-50N, 140E-170W) from 1979 to 2009 is investigated with observations and reanalysis datasets. Composite analysis shows that in high-SSF years the center of the Northwestern Pacific subtropical high (SH) shifts eastward and a strengthened ridge exists in the midlatitude Northwestern Pacific. Under such conditions, large amount of moisture from the subtropics are transported northwardly by the southerlies over the west flank of the SH. The ridge is helpful for stable stratification and conductive to fog formation. In contrast, in low-SFF years the center of the SH expands westward and drifts further south; thus moisture can hardly reach the midlatitudes. Meanwhile an anomalous trough in the midlatitudes and the associated anomalous northerlies both weaken the southerlies and reduce the stability, unfavorable for fog occurrence. The case studies confirmed that the air parcels moving from the subtropical zone to the midlatitudes controlled by the SH, kept the higher temperature and humidity when flowing across the Kuroshio Extension, and then cooled down over the cold oceanic surface in fog case. The SFF in the Northwestern Pacific would decline under the conditions of global warming.

  12. 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.

  13. Northwestern University | Physical Sciences in Oncology

    Cancer.gov

    Northwestern University Physical Sciences-Oncology Center's (NU PS-OC) main focus is to probe the molecular basis of information flow within malignant cells. This centers studies will highlight diverse characteristics of gene expression and storage. Moreover, these investigators postulate that in the cancerous state, the epigenome is significantly mutated. By merging experimental molecular and cellular biology with the physical sciences, these investigators will examine the regulation and expression of genes.

  14. 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.

  15. 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.

  16. 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.

  17. Male adolescent concubinage in Peshawar, Northwestern Pakistan.

    PubMed

    de Lind van Wijngaarden, Jan Willem; Rani, Bushra

    2011-10-01

    This paper reports on findings from four interviews held with young men who have experienced male adolescent concubinage relationships with adult men in Peshawar, Northwestern Pakistan. These relationships are referred to by the Pashtun people involved as bacha baazi. Similar relationships (called bacabozlik) were described by Ingeborg Baldauf among the Uzbeks and Pashtun of Afghanistan, based on observations made in the late-1970s. This paper compares Baldauf's observations with our own, indicating significant differences and similarities. Implications for future research and for social protection programmes are discussed. PMID:21815728

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Petroleum in the Junggar basin, northwestern China

    NASA Astrophysics Data System (ADS)

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

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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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)

  12. FACING SOUTH OF LANDSCAPING IN NORTHWESTERN PORTION OF PARK ...

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

    FACING SOUTH OF LANDSCAPING IN NORTHWESTERN PORTION OF PARK - Candler Park Historic District, Roughly bounded by Moreland, Dekalb, McLendon & Harold Avenues, Matthews Street & Clifton Terrace, Atlanta, Fulton County, GA

  13. 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...

  14. 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

  15. 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.

  16. Oil and gas developments in eastern and northwestern Colorado in 1984

    SciTech Connect

    Ligrani, L.D.; Adams, C.W.; Nibbelink, K.A.

    1985-10-01

    Drilling activity in eastern and northwestern Colorado was up approximately 10% from 1430 wells in 1983 to 1589 wells in 1984. This increase in total wells drilled resulted mainly from development activity. The success rate for the 488 exploratory wells drilled in 1984 was 24%, down about 7% from the 1983 level of 31%. Activity in eastern Colorado focused on Pennsylvanian and Mississippian rocks along the Las Animas arch and northern Hugoton embayment. Drilling for Cretaceous formations in the Denver basin increased with much of the new activity centered around the Codell sandstone and Niobrara Formation near Greeley. Significant new Niobrara production was established in northern Weld County. In the San Luis Valley of south-central Colorado, oil shows were reported for the first time in the Cretaceous Dakota Formation beneath volcanic rocks. 1 figure, 2 tables.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Northwestern Tharsis Latent Outflow Activity Mars

    NASA Astrophysics Data System (ADS)

    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.

    2000-08-01

    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.

  2. 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.

  3. Diatom evidence for paleoclimate changes in the northwestern Pacific during the last 20000 years

    NASA Astrophysics Data System (ADS)

    Smirnova, M. A.; Kazarina, G. Kh.; Matul, A. G.; Max, L.

    2015-05-01

    The micropaleontological study of two sediment cores taken from the continental slope of the Eastern Kamchatka Peninsula and from the northern Shirshov Ridge in the Bering Sea in the scope of the international KALMAR project reveals regional environmental changes over the last 20 kyr: the end of the last glaciation 20-15 ka, Blling-Allerd warming 15.0-13.3 ka, the Younger Dryas cooling 13.3-11.9 ka, and the Early Holocene 11.9-5.0 ka. The most drastic paleoclimatic changes occurred at the transition from the last glacial period to the Holocene, which had different consequences in these two neighboring areas of the northwestern Pacific. The Blling-Allerd warming episode resulted in the formation of a high- productivity marginal ice zone over the Shirshov Ridge and open-ocean conditions near eastern Kamchatka with the dominant influence of Alaskan water masses. The Younger Dryas cooling event in the continental slope area of Kamchatka was likely the most significant over the last 20 kyr: the neritic environments with a winter ice cover were dominant in this area at that time. The onset of the Holocene was probably marked by the formation of seasonally contrasting surface conditions in the northwestern corner of the open subarctic Pacific, which is evident from features indicating winter sea ice development and penetration of south-boreal water masses.

  4. 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.

  5. 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 lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2013 at zero lobsters....

  6. 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

  7. 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.

  8. 78 FR 53175 - The Northwestern Mutual Life Insurance Company, et al.;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... COMMISSION The Northwestern Mutual Life Insurance Company, et al.; Notice of Application Agency: Securities... Section 17(b) of the Act from Section 17(a) of the Act. Applicants: The Northwestern Mutual Life Insurance... Account A and VA Account B, the ``Annuity Accounts'') and Northwestern Mutual Variable Life Account...

  9. 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.

  10. 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.

  11. How does the Amur River discharge flow over the northwestern continental shelf in the Sea of Okhotsk?

    NASA Astrophysics Data System (ADS)

    Fujisaki, Ayumi; Mitsudera, Humio; Wang, Jia; Wakatsuchi, Masaaki

    2014-08-01

    The paths of the Amur River discharge on the continental shelf in the Sea of Okhotsk are still unknown despite their significance in transporting dissolved and particulate iron. In this study, we conduct a coupled ice-ocean simulation for the northern Sea of Okhotsk from June 1998 to September 2000 to answer the question: Does the Amur River discharge deposit materials to the pathway of the dense shelf water? In a series of numerical experiments, we identified two routes (the western and eastern routes) that could transport the river water more than 100 km offshore over the northwestern continental shelf. The two routes share the clockwise gyre in the Sakhalin Gulf and the northeastward flow on the northwestern continental shelf. These features are connected through the westward jet along the slope from the Sakhalin Gulf (the western route) and the northward transport over the shelf break canyon (the eastern route). The river water, the dense shelf water, and the easterly wind are in a fine geophysical balance for those features, and all are required for the formation of the two routes. The model results show that these unique joint effects in the Sea of Okhotsk allow the Amur River discharge to be effectively transported over the northwestern continental shelf, unlike a general river discharge that flows along the coast, and deposit materials into the pathway of the dense shelf water.

  12. 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.

  13. Novel Poxvirus in Big Brown Bats, Northwestern United States

    PubMed Central

    Nordhausen, Robert; Garner, Michael M.; Huckabee, John R.; Johnson, Steven; Wohrle, Ron D.; Davidson, Whitni B.; Wilkins, Kimberly; Li, Yu; Doty, Jeffrey B.; Gallardo-Romero, Nadia F.; Metcalfe, Maureen G.; Karem, Kevin L.; Damon, Inger K.; Carroll, Darin S.

    2013-01-01

    A wildlife hospital and rehabilitation center in northwestern United States received several big brown bats with necrosuppurative osteomyelitis in multiple joints. Wing and joint tissues were positive by PCR for poxvirus. Thin-section electron microscopy showed poxvirus particles within A-type inclusions. Phylogenetic comparison supports establishment of a new genus of Poxviridae. PMID:23735421

  14. Northwestern Mexico as seen from the Gemini 9-A spacecraft

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Northwestern Mexico as seen from the Gemini 9-A spacecraft during its 32nd revolution of the earth. Large peninsula is Baja California. Body of water at lower right is Pacific Ocean. Land mass at upper left is State of Sonora. Gulf of California separates Sonora from peninsula. Nose of spacecraft is at left and at right is open hatch of spacecraft.

  15. New provincial records of skinks (Squamata: Scincidae) from northwestern Vietnam.

    PubMed

    Pham, Anh Van; Le, Dzung Trung; Nguyen, Son Lan Hung; Ziegler, Thomas; Nguyen, Truong Quang

    2015-01-01

    We report six new records of skinks from northwestern Vietnam: Eutropis macularius, Scincelladevorator , S.monticola, S.ochracea, Sphenomorphuscryptotis and S.indicus. Our new findings increase the species number of skinks (Scincidae) to nine in Dien Bien Province and to 14 in Son La Province. We also provide additional natural history data of aforementioned species. PMID:25698899

  16. New provincial records of skinks (Squamata: Scincidae) from northwestern Vietnam

    PubMed Central

    Pham, Anh Van; Le, Dzung Trung; Nguyen, Son Lan Hung; Ziegler, Thomas

    2015-01-01

    Abstract We report six new records of skinks from northwestern Vietnam: Eutropis macularius, Scincella devorator, S. monticola, S. ochracea, Sphenomorphus cryptotis and S. indicus. Our new findings increase the species number of skinks (Scincidae) to nine in Dien Bien Province and to 14 in Son La Province. We also provide additional natural history data of aforementioned species. PMID:25698899

  17. 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.

  18. 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…

  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. 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

  1. 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

  2. The Center for Talent Development at Northwestern University

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula

    2004-01-01

    During the summer and on weekends, it is not unusual to see many children, the youngest holding their parents' hands, walking to classes amongst the beautiful landscaping and old buildings of Northwestern University on Lake Michigan's shores in Evanston, Illinois. The Center for Talent Development (CTD) has been offering services and programs to

  3. Oil and gas developments in eastern and northwestern Colorado in 1985

    SciTech Connect

    Glenister, L.M.; Ligrani, L.D.

    1986-10-01

    Drilling activity in eastern and northwestern Colorado was at record levels in 1985, with 1918 wells drilled in the area. This represents a 21% increase in drilling from 1984's 1589 wells. One-third of the total, or 644 wells, were exploration tests with a success rate of 29%, up from the 24% success rate in 1984. Activity in eastern Colorado focused on Pennsylvanian rocks along the Las Animas arch and Cretaceous formations in the Denver basin, especially in the Greeley area. Limited activity was also seen in the deeper zones in the Denver basin, in Tertiary and Cretaceous sediments of the Raton basin, and in subvolcanic rocks in the San Luis basin area. 1 figure, 2 tables.

  4. 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.

  5. 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.

  6. 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 Nio-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 Nio 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

    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 Nio-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 Nio frequency. PMID:24843118

  10. 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).

  11. 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.

  12. 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.

  13. An accreted continental terrane in northwestern Peru

    NASA Astrophysics Data System (ADS)

    Mourier, T.; Laj, C.; Mgard, F.; Roperch, P.; Mitouard, P.; Farfan Medrano, A.

    1988-04-01

    A paleomagnetic study of over 250 cores from 26 sites sampled in Early to Late Cretaceous and Paleogene volcanic, plutonic and sedimentary formations of the Lancones basin in the Piura province of northern Peru, indicates that most of these lithologies carry a stable primary remanent magnetization whose direction is significantly different from that of coeval formations of stable South America. A clockwise rotation ranging from 90 for the lowermost units to 35 for the uppermost ones has been documented, although the lack of precise chronology has not allowed a detailed temporal description. Four sites from Late Carboniferous (Pennsylvanian) formations in the Amotape-Tahuin Range also show a 110 clockwise rotation and yield evidence for a northward displacement. When considered together with previous geological studies, these data are consistent with the hypothesis of the accretion of an Amotape-Tahuin continental terrane to the Peruvian margin in Neocomian times. The accretion was followed by in situ rotation, suggesting a dextral shear regime. These results indicate that the geodynamical evolution of northern Peru is more closely related to the processes observed in Ecuador than to those classically assumed for the Central Andes of Peru.

  14. 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.

  15. 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.

  16. Geology of the lower Yellow Creek Area, Northwestern Colorado

    SciTech Connect

    Hail, W.J.

    1990-01-01

    The lower Yellow Creek area is located in Rio Blanco and Moffat Counties of northwestern Colorado, about midway between the towns of Rangely and Meeker. The study area is in the northwestern part of the Piceance Creek basin, a very deep structural and sedimentary basin that formed during the Laramide orogeny. Potentially important resources in the area are oil shale and related minerals, oil and gas, coal, and uranium. Topics discussed in the report include: Stratigraphy (Subsurface rocks, Cretaceous rocks, Tertiary rocks, and Quaternary deposits); Structure (Midland anticline, graben at Pinyon Ridge, and Crooked Wash syncline, Folds and faults in the vicinity of the White River, Red Wash syncline and central graben zone, Yellow Creek anticlinal nose); Economic geology (Oil shale and associated minerals, Coal, Oil and gas, Uranium, Gravel).

  17. Northwestern Mexico as seen from the Gemini 12 spacecraft

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Area of northwestern Mexico as seen from the Gemini 12 spacecraft during its 16th revolution of the earth. View is looking northwest. Body of water in foreground is Gulf of California. Pacific Ocean is in background. Peninsula in center of picture is Baja California. States of Sonora (upper right) and Sinaloa (lower center) of Mexican mainland is in right foreground. City of Guaymas, Sonora, is near center of picture.

  18. 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

  19. Dynamics, patterns and causes of fires in Northwestern Amazonia.

    PubMed

    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

  20. 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.

  1. 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.

  2. 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

  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. 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

  8. 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.

  9. 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

  10. 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.

  11. 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 Curaao-Ecuador coastline.

  12. 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......

  13. 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......

  14. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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......

  15. 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......

  16. 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......

  17. 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

  18. 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.

  19. 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 lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2011 is established at...

  20. 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…

  1. 75 FR 6790 - Nebraska Northwestern Railroad, Inc.-Acquisition and Operation Exemption-Dakota, Minnesota...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... Surface Transportation Board Nebraska Northwestern Railroad, Inc.--Acquisition and Operation Exemption--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...

  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. Contemporary radioecological state of the North-western Black Sea and the problems of environment conservation.

    PubMed

    Tereshchenko, N N; Mirzoyeva, N Yu; Gulin, S B; Milchakova, N A

    2014-04-15

    Review is devoted to the analysis of a radioecological situation in the North-western Black Sea and concerns the levels of contamination of the components of an ecosystem by the main artificial radioactive isotopes ((90)Sr, (137)Cs, (239,240)Pu). The long-term accumulation trends of these radionuclides were analyzed in components of the Black Sea ecosystem after the Chernobyl nuclear power plant accident. Zones that have an increased ability to accumulate these radioisotopes were revealed. The assessment of irradiation dose rates formed by (90)Sr, (137)Cs and (239,240)Pu in Black Sea hydrobionts was obtained. The strategy for biodiversity conservation and sustainable management of natural resources should include monitoring of the radioecological state of the marine ecosystems, and the formation of a complex of biogeochemical criteria for assessment of an ecological situation in the sea. This approach is important for marine protected areas, since it allows the formation of a basis for scientific and practical function. PMID:24461697

  4. 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.

  5. 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.

  6. 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.

  7. Early Mesozoic structure and stratigraphy of the northwestern Florida shelf

    SciTech Connect

    Reitz, B.K. )

    1991-03-01

    The pre-Mesozoic basement of the northwestern Florida shelf is composed of attenuated continental crust deformed during the late Triassic and Early Jurassic rifting of the Gulf of Mexico. Two distinct areas with different rift basin orientations are defined on the northwestern Florida shelf. The northeastern set of rifts has axes parallel to the rift basins of the Atlantic margin. The southwestern rift axes are orthogonal to the first set. These two areas are separated by an undisturbed northwest-southwest linear zone previously termed the Bahama fault zone. Margins of a major asymmetric rift basin, north of the Middle Ground arch, parallel the Bahamas fault zone. The asymmetric plan view and degree of crustal extension calculated for this basin suggests the Middle Ground arch formed by a counterclockwise rotation of 16{degree}. The geometries of the Upper Jurassic postrift sediments are related to rift morphology. Louann Salt updip limits are parallel to or coincident with the margins of the rift basins and the salt is thickest over the deepest portions of the rift basins. The distribution of Smackover-Haynesville and Cotton Valley Group sediments is strongly influenced by the underlying rift basins.

  8. 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

  9. 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

  10. Impact of Irrigation on Local Climate over Northwestern China

    NASA Astrophysics Data System (ADS)

    Wen, L.; Jin, J.

    2009-12-01

    Three dominant land use types in northwestern China are irrigated cropland, grassland and desert. Observational analysis indicates that irrigated cropland has both the coolest surface and the slowest warming trend of the three land use types for the period of 1979-2005. The single column atmospheric model (SCAM) developed by the National Center for Atmospheric Research was used to investigate and better understand the differences in long-term climate conditions and change over these three land use types. The results indicate that the SCAM can reasonably reproduce the observed climate conditions in this region. The irrigated cropland of the region generates strong evaporation that cools the surface, slows the warming trend, and produces stronger precipitation when compared to the natural grassland and desert. The irrigated cropland region receives its irrigated water primarily from melting snowpack from the nearby mountains, and a series of sensitivity SCAM simulations indicate that a drier and warmer climate occurs with the shrinking of this irrigated cropland region. Thus, the irrigation process has a profound impact on the local climate in northwestern China.

  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. Stratigraphic Analysis of Upper Cretaceous Rocks in the Mahajanga Basin, Northwestern Madagascar: Implications for Ancient and Modern Faunas.

    PubMed

    Rogers; Hartman; Krause

    2000-05-01

    Upper Cretaceous strata of the Mahajanga Basin, northwestern Madagascar, yield some of the most significant and exquisitely preserved vertebrate fossils known from Gondwana. The sedimentology of these strata and their stratigraphic relations have been the focus of renewed geological investigations during the course of five expeditions since 1993. We here designate stratotypes and formalize the terrestrial Maevarano Formation, with three new members (Masorobe, Anembalemba, Miadana), and the overlying marine Berivotra Formation. The Maevarano Formation accumulated on a broad, semiarid alluvial plain bounded to the southeast by crystalline highlands and to the northwest by the Mozambique Channel. The Berivotra Formation was deposited in an open marine setting that evolved from a clastic- to a carbonate-dominated shelf, resulting in deposition of the overlying Betsiboka limestone of Danian age. New stratigraphic data clearly indicate that the Maevarano Formation correlates, at least in part, with the Maastrichtian Berivotra Formation, and this in turn indicates that the most fossiliferous portions of the Maevarano Formation are Maastrichtian in age, rather than Campanian as previously reported. This revised age for the Maevarano vertebrate assemblage indicates that it is approximately contemporaneous with the vertebrate fauna recovered from the Deccan basalt volcano-sedimentary sequence of India. The comparable age of these two faunas is significant because the faunas appear to be more similar to one another than either is to those from any other major Gondwanan landmass. The revised age of the Maevarano Formation, when considered in the light of our recent fossil discoveries, further indicates that the ancestral stocks of Madagascar's overwhelmingly endemic modern vertebrate fauna arrived on the island in post-Mesozoic times. The basal stocks of the modern vertebrate fauna are conspicuously absent in the Maevarano Formation. Finally, the revised age of the Maevarano Formation serves to expand our global perspective on the K/T event by clarifying the age of a diverse, and arguably the best preserved, sample of Gondwanan vertebrates from the terminal Cretaceous. PMID:10769157

  13. 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 ?g/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 ?g/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 ?g/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.

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

    PubMed Central

    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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. Sinking velocity of particulate radiocesium in the northwestern North Pacific

    NASA Astrophysics Data System (ADS)

    Honda, Makio C.; Kawakami, Hajime

    2014-06-01

    Sinking particles (SP) were collected by time series sediment traps at two depths in the northwestern Pacific before and after the Fukushima Daiichi Nuclear Power Plant accident, and accident-derived particulate radiocesium was measured. Radiocesium (137Cs) was first detected at 500 m (4810 m) about 2 weeks (1 month) after the accident. 137Cs of SP collected over 1 year revealed that the time lag between two depths was larger than that for the first 137Cs detection (about 2 weeks). We estimated the transient sinking velocity (SV) from the cumulative temporal 137Cs flux and the time lags at the two depths. Although the SV of SP collected in very early period was large, the estimated SV of most particulate 137Cs (about 80%) was about 50 m d-1. Based on comparison of 137Cs concentration in total SP with that in SP without organic materials, we suspect that most of the 137Cs was likely incorporated into aluminosilicates.

  1. Intoxication of nontarget wildlife with rodenticides in northwestern Kansas.

    PubMed

    Ruder, Mark G; Poppenga, Robert H; Bryan, John A; Bain, Matt; Pitman, Jim; Keel, M Kevin

    2011-01-01

    The perception of prairie dogs (Cynomys spp.) both as a nuisance species and a keystone species presents a significant challenge to land, livestock, and wildlife managers. Anticoagulant and nonanticoagulant rodenticides are commonly employed to control prairie dog populations throughout their range. Chlorophacinone, and to a lesser extent zinc phosphide, are widely used in northwestern Kansas for controlling black-tailed prairie dog (Cynomys ludovicianus) populations. Although zinc phosphide poisoning of gallinaceous birds is not uncommon, there are few published accounts of nontarget chlorophacinone poisoning of wildlife. We report three mortality events involving nontarget rodenticide poisoning in several species, including wild turkeys (Meleagris gallopavo), a raccoon (Procyon lotor), and an American badger (Taxidea taxus). This includes the first documentation of chlorophacinone intoxication in wild turkeys and an American badger in the literature. The extent of nontarget poisoning in this area is currently unknown and warrants further investigation. PMID:21270011

  2. 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

  3. The Northwestern (Maghreb) boundary of the Nubia (Africa) Plate

    NASA Astrophysics Data System (ADS)

    Mauffret, Alain

    2007-01-01

    A study of the present compressional deformation of the Northwestern (Maghreb) Nubia (Africa) margin is derived from the analysis of more than 20,000 km of seismic profiles. In the western part the compression is distributed in a large zone with on-land compression in Algeria, mainly strike-slip deformation on the Algerian margin and folds and strike-slip faulting in Eastern Spain. In the middle of the Algerian margin, around Algiers, the evidences of compression become more obvious. In this area a ridge trending N-S that is interpreted as a middle to late Miocene spreading center interacted with the transpressional margin that trends E-W. North of the location of the Boumerdes-Zemmouri earthquake the oceanic crust is deformed by blind thrusts up to 60 km from the coast. These thrusts are south dipping and with the northward dipping thrusts located onshore form a wedge that maybe a positive flower structure at a crustal scale related to the right-lateral transpression of the margin. In the eastern part of the Northwestern (Maghreb) Nubia (Africa) Deformed Belt, off eastern Algeria and Tunisia, the deformation is more intense but limited to the north by the continental slope. Large late Miocene Tortonian folds are cut by the Messinian erosional surface but the present deformation is also evident. It is suggested that the deformation with a double vergence may be followed up to the north of Sicily. After the docking (18 Ma) of the Kabylies to the Africa Plate, the crust has been thinned and the Algerian Basin opened during the middle-late Miocene with an E-W direction. From the late Miocene to the Present the margin has been rethickened by transpression and uplifted.

  4. 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.

  5. 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.

  6. 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.

  7. A trace of Au-rich coal in Tuha Basin on northwestern China

    SciTech Connect

    Liang, H.

    1997-12-31

    A series of samples, collected from Jurassic coal in Tuha Basin of northwestern China, is analyzed qualitatively by secondary ion mass spectrometry (SIMS) and quantitatively by inductively coupled plasma mass spectrometry (ICP/MS). Gold (Au), silver (Ag) and the rare earth elements (REE) are detected with unusually high content (positive difference) in the original coals in some seams, such as Au about 43{plus_minus}0.32 ppm, Ag 542{plus_minus}4.8ppm, Lu 31{plus_minus}0.33 ppm, Tl 7.1{plus_minus}0.74ppm and Cu 40{plus_minus}3.7 ppm. The data also show that gold absorbs more in the organic phase than in pyrite in the coal and a with very low content (negative difference) both in bed roofs (clay rock) and in bed plates (seat earth) such as Au 0.57 ppb for the later. It is evident that the weathering mechanism probably corresponds to formation of the Au-rich coal.

  8. Two distinct shear wave splitting directions in the northwestern Deccan Volcanic Province

    NASA Astrophysics Data System (ADS)

    Madhusudhan Rao, K.; Ravi Kumar, M.; Singh, Arun; Rastogi, B. K.

    2013-10-01

    The northwestern Deccan Volcanic Province in India has witnessed several tectonic episodes resulting in the formation of rift zones, wide spread magmatism, and deep-seated faults that are host to some deadly intraplate earthquakes. In this study, we attempt to decipher the mantle deformation beneath the region using the SKS splitting technique applied to high-quality data from a regional network comprising 44 broadband seismic stations sited on diverse tectonic environments. The first measurements of 461 (312 SKS and 149 SKKS) splitting parameters from 117 earthquake sources reveal two major trends, one coinciding with the absolute plate motion (APM) of the Indian plate and the other roughly oriented in the E-W direction. Forward modeling of the dependence of the splitting parameters on incoming polarization assuming horizontal axis of symmetry brings out two layers of anisotropy beneath the study region with the fast axis azimuths oriented N22E in the bottom layer and N77E in the top layer. While stronger anisotropy (?t1.2 s) in the bottom layer is related to asthenospheric flow, a weaker anisotropy (?t 0.5 s) in the upper layer could represent anisotropy frozen in the lithosphere due to deformation related to widespread magmatism in this plume affected region.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  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

    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. 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.

  16. 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.

  17. Previously unrecognized ornithuromorph bird diversity in the Early Cretaceous Changma Basin, Gansu Province, northwestern China.

    PubMed

    Wang, Ya-Ming; O'Connor, Jingmai K; Li, Da-Qing; You, Hai-Lu

    2013-01-01

    Here we report on three new species of ornithuromorph birds from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province, northwestern China: Yumenornis huangi gen. et sp. nov., Changmaornis houi gen. et sp. nov., and Jiuquanornis niui gen. et sp. nov.. The last of these is based on a previously published but unnamed specimen: GSGM-05-CM-021. Although incomplete, the specimens can be clearly distinguished from each other and from Gansus yumenensis Hou and Liu, 1984. Phylogenetic analysis resolves the three new taxa as basal ornithuromorphs. This study reveals previously unrecognized ornithuromorph diversity in the Changma avifauna, which is largely dominated by Gansus but with at least three other ornithuromorphs. Body mass estimates demonstrate that enantiornithines were much smaller than ornithuromorphs in the Changma avifauna. In addition, Changma enantiornithines preserve long and recurved pedal unguals, suggesting an arboreal lifestyle; in contrast, Changma ornithuromorphs tend to show terrestrial or even aquatic adaptions. Similar differences in body mass and ecology are also observed in the Jehol avifauna in northeastern China, suggesting niche partitioning between these two clades developed early in their evolutionary history. PMID:24147058

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. 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

  5. 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.

  6. NOTIS-3 (Northwestern On-Line Total Integrated System): Technical Services Applications.

    ERIC Educational Resources Information Center

    Horny, Karen L.

    1978-01-01

    Northwestern University Library's locally developed automated support system, NOTIS, operational since 1970-71, is described in terms of its technical services aspects. Internal applications and relevance to projected national networking developments are considered. (Author)

  7. [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.

  8. ATMOSPHERIC VOLATILE HYDROCARBON COMPOSITION AT FIVE REMOTE SITES IN NORTHWESTERN NORTH CAROLINA

    EPA Science Inventory

    The results of a study to measure the volatile hydrocarbon composition of the atmosphere at several sites in the southern Appalachian Mountains of northwestern North Carolina are presented. Ambient air was sampled repeatedly at five geographically and botanically different remote...

  9. 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...

  10. 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...

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

    PubMed

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

    2015-01-01

    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 (Mogangellastraminea Dlabola, 1957, Doraturastylata (Boheman, 1847), Macrostelessordidipennis (Stl, 1858) and Psammotettixseriphidii Emeljanov, 1962) listed as new for Iran and Balcluthapunctata (Fabricius, 1775), as a new record for the region. A distribution map of the species in northwestern Iran is given. PMID:25931954

  12. Sulfur geochemical constraints on mesoproterozoic restricted marine deposition: lower Belt Supergroup, northwestern United States

    NASA Astrophysics Data System (ADS)

    Lyons, Timothy W.; Luepke, James J.; Schreiber, Madeline E.; Zieg, Gerald A.

    2000-02-01

    Despite nearly a century of study by a diverse group of Precambrian workers, competing interpretations have persisted that favor both marine and nonmarine depositional settings for the Mesoproterozoic Belt Supergroup of the northwestern United States. Our data for sedimentary pyrite formation in unmetamorphosed organic-rich shales of the Newland Formation of the lower Belt Supergroup, western Montana, argue that at least a portion of the Belt basin, during its early history, was characterized by restricted marine conditions with only episodic incursions of seawater. This model is supported by ratios of organic carbon (C org) to pyrite sulfur that, once corrected for selective diagenetic and thermal loss of C org and the inferred high reactivity of the C org reservoir in the absence of vascular land-plant remains, suggest degrees of sulfate limitation consistent with a restricted marine setting. The isotopically heavy disseminated pyrite that dominates the black shales shows a broad range of ? 34S values of bacterial origin (? 34S ranges from -8.7 to +36.3; mean = +7.6, n = 41). The pyrite data overlap with the ? 34S range of coeval (barite) sulfate within the basin and are similar to independent estimates for the sulfate of Mesoproterozoic seawater. These relationships have allowed us to delineate a record of bacteriogenic pyrite that formed in a modified marine reservoir where the supply of sulfate was limited. A bacterial mechanism is further suggested by the morphological character of this early-formed pyrite, including the ubiquitous framboids. After comparing our results with those from present-day localities, such as the Black Sea and sites of lacustrine deposition, we conclude that the abundant 34S-enriched bacteriogenic disseminated pyrite observed in black shales of the Newland Formation must record a style of sulfate limitation possible only within an isolated marine basin receiving an intermittent flux of seawater. Although the entire Belt basin likely remained a restricted marine setting throughout deposition of the lower Belt Supergroup, sulfur isotope data from the Newland Formation at two localities separated by more than 150 km in the eastern Belt basin reveal stratigraphic trends in the strength of the marine connection. Specifically, the connection evolved such that inputs of seawater sulfate increased progressively in frequency and possibly strength during deposition of the Newland Formation. Overall, the hypothesized restricted marine setting, when viewed in light of independent tectonic, sedimentologic and geochronologic evidence, suggests syndepositional and likely episodic continental rifting, which helps constrain the Proterozoic paleotectonic history of western Laurentia.

  13. 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

  14. 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

  15. 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.

  16. Intense phenomena during the winter of 1998/1999 in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Hong, X.; Hodur, R. M.; Pascual, A.; Cummings, J. A.; Martin, P. J.

    2003-04-01

    The Northwestern Mediterranean Sea was characterized by intense weather and ocean phenomena during the winter of 1998/1999. This winter season exhibited very strong and prolonged periods of northwesterly winds (Mistral) with associated large losses of heat from the ocean due to enhanced surface buoyancy fluxes. Dense water formation occurred in the Gulf of Lion as the surface layer temperature dropped to 12 oC and the salinity increased to 38.2 psu. Hydrological and current data collected in 1999 revealed the spreading of newly formed deep water with unusual characteristics over the whole Algero-Provencal basin (Bethoux et al. 2002) and provided evidence of deep-water formation during the intense weather phenomenon. Sea surface topography from the TOPEX/Poseidon and ERS satellites, SST images derived from advanced very high resolution radiometer (AVHRR) sensors, and conductivity-temperature-depth (CTD) data collected during an oceanographic survey showed the presence of an intense anticyclonic eddy in the Balearic Sea from September 1998 to March 1999. The formation of this eddy is believed to be related to the transmission of anticyclonic vorticity from the shear of the strong Mistral (Pascual et al. 2002). To investigate these intense phenomena during the winter of 1998/1999, high-resolution (6-km) numerical simulations are conducted for the Mediterranean Sea using the US Navy Coastal Ocean Model (NCOM). The surface atmospheric forcing fields used in NCOM are from atmospheric reanalyses of the Mediterranean Sea area produced by the US Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPSTM). The reanalyzed fields include 10-m surface wind, surface wind stress, surface sensible and latent heat fluxes, solar and long-wave radiation at the surface, and accumulated precipitation. The temporal resolution of the atmospheric forcing fields is 1 hr and the horizontal resolution is 27 km. The simulations of these events are compared against all available observations. The mechanisms for the formation and development of the intense ocean phenomena during the winter of 1998/1999 are also investigated and discussed with sensitivity experiments under different atmospheric forcing.

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

    NASA Astrophysics Data System (ADS)

    Foster, Bryan R.; Rahs, Engel 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?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.

  18. 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

  19. 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.

  20. Nutrients and phytoplankton in the Gulf of Lions, northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Cruzado, Antonio; Velasquez, Zoila R.

    1990-09-01

    The mostly oligotrophic character of the Mediterranean Sea is altered drastically in areas receiving the outflow from large rivers. The Gulf of Lions, receiving discharges from the Rhone River, has nutrient and phytoplankton concentration much higher than the adjacent open northwestern Mediterranean Sea. A surface layer of freshwater, with thickness that varies with the meteorological conditions between 2 and 40 m, overlies the deeper open seawater; this is advected onto the shelf and influences an area that covers the eastern half of the Gulf of Lions. Most of the waters affected by the river discharges show property relationships indicating conservative behaviour, with very little or no loss of nutrients through phytoplankton uptake, particularly in winter. Phytoplankton populations in winter are sparse, with maximum densities just above and below the boundary between the fresh- and seawater. Diatoms are the main group of organisms, although dinoflagellates, coceolithophorids and cyanobacteria are abundant. Small heterotrophs (cilliates, tintinnids, etc.) are also abundant and are positively correlated with the diatoms. A water balance model, linking the river discharge to the advective fluxes of water and nutrients, is proposed. The primary productivity supported by such fluxes is estimated.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Strain rates in northwestern Italy from spatially smoothed seismicity

    NASA Astrophysics Data System (ADS)

    Barani, Simone; Scafidi, Davide; Eva, Claudio

    2010-07-01

    This work presents seismic strain rate maps for the Western Alps and Northern Apennines (northern Italy) as derived from an earthquake catalog collecting both historical and instrumental data. Strain rates are calculated on the basis of the rate of seismic moment release using the Anderson method. Unlike previous applications, which determined the total strain rate associated with specific seismogenic sources, we have employed an innovative zoneless approach based on a spatially smoothed seismicity method. In addition, a Monte Carlo simulation procedure is applied to allow for uncertainty in the input data (e.g., magnitude to moment conversion, seismogenic thickness, maximum earthquake magnitude). Strain rate maps are developed by summing the moments of the earthquakes reported in the catalog and by using two different earthquake recurrence relations. Our results indicate that deformation rates are quite high, ranging from about 2 to 12 10-9 yr-1 in the Northern Apennines and from 0.5 to 6 10-9 yr-1 in the Western Alps. These values, however, are 1 order less than those derived from Global Positioning System measurements, suggesting that a portion of the recent deformation in northwestern Italy is related to aseismic processes. The discrepancies between seismic and geodetic strain rates may also indicate that the record of seismicity may not provide a sufficient time window for assessment of secular rates of moment release (or secular deformation rates) and rates of recurrence of large magnitude earthquakes in the study area.

  7. 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 Nio 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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).

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. Reservoir Model of the Jacksonburg-Stringtown Oil Field; Northwestern West Virginia: Potential for Miscible Carbon Dioxide Enhanced Oil Recovery

    NASA Astrophysics Data System (ADS)

    Bergerud, Blake

    Located in northwestern West Virginia, the Jacksonburg-Stringtown field has produced over 22 million barrels of oil (MMBO) since its discovery in 1895. The primary producing interval within the field is the Late Devonian Gordon Stray. Log analysis shows this formation to represent an estuarine depositional system. Four subunits within the formation are defined based on depositional framework: barrier sand, central bay shale, estuarine channels, and fluvial channel subunits. RHOmaa/Umaa lithological composition plots support the conclusion of a marine-influenced estuarine depositional framework. Structural and isopach maps generated with data from 73 local wells reveal a northeast-southwest trending sand deposit of 15-35 foot thickness, which is interpreted as the depocenter for the incised valley of the Gordon Stray. Analysis of formation horizon maps shows that the reservoir is synclinal and, as a result, contains a stratigraphic trap as opposed to the more common structural traps found in the immediate area. Porosity and pore-feet distribution maps indicate high porosity regions in southern regions of the field and high pore volume in northern areas. A miscible CO2 flood model estimates that an additional 7.3 MMBO could be recovered from the high porosity regions in the southern half of the field. The Jacksonburg-Stringtown field is well-suited for enhanced oil recovery and/or geologic CO2 sequestration.

  3. Paleostress pattern and salt tectonics within a developing foreland basin (north-western Subhercynian Basin, northern Germany)

    NASA Astrophysics Data System (ADS)

    Brandes, Christian; Schmidt, Carolin; Tanner, David Colin; Winsemann, Jutta

    2013-11-01

    Analysing the paleostress field in sedimentary basins is important for understanding tectonic processes and the planning of drilling campaigns. The Subhercynian Basin of northern Germany is a perfect natural laboratory to study the paleostress field in a developing foreland basin. The simple layer-cake geometry of the basin-fill is dominated by several piercing and non-piercing salt structures. We derived the paleostress field from the orientation of fracture sets, faults, slickensides and stylolites. On a regional scale, the basin-fill is characterized by a horizontal compressional paleostress vector that is mainly NNE-SSW-oriented, which reflects the Late Cretaceous inversion phase in Central Europe. We show that the local paleostress field is distinctly perturbated due to the salt structures. Along the edge of the salt pillows, the maximum horizontal paleostress vector is deflected by up to 90 from the regional trend. In the case of the Elm salt pillow, it forms a radial pattern. Restoration of balanced cross-sections demonstrates at least 9 % of the shortening of the north-western part of the Subhercynian Basin was achieved by folding. The salt structures in the north-western Subhercynian Basin are the result of varying stress conditions. Initial extension in the Triassic caused first salt movements that prevailed during the Jurassic and Early Cretaceous. Most important is the Late Cretaceous contractional phase that shortened the diapirs and led to the formation of the salt pillows between diapirs due to detachment folding. We derive four main controlling factors for such salt-dominated contractional basins: (1) the wedge-shape basin-fill is the product of the dynamic load at the southern margin of the basin, (2) a basal salt layer fed the diapirs and acted as a detachment horizon during the later shortening, (3) detachment folding was the dominating deformation mechanism during contraction, and (4) the pre-existing diapirs controlled the position of the detachment folds.

  4. Subduction of the Eastern Panama Basin and seismotectonics of northwestern South America

    NASA Astrophysics Data System (ADS)

    Pennington, Wayne D.

    1981-11-01

    Spreading along the Cocos-Nazca plate boundary since the breakup of the Farallon plate in the Miocene has resulted in the formation of the Panama basin and a complex interaction of plates in and near northwestern South America. Current plate boundaries have been defined, and segments of subducted lithosphere identified through selection of hypocentral locations of earthquakes, considering only well-located events, and through focal mechanism determinations. The existence of relict plate boundaries, bathymetric features, and the Panamanian isthmus has affected the subduction process of the Nazca plate beneath South America and determined the present-day configuration of the subducting lithospheric plate. There is no single triple junction separating the Caribbean, South American, and Nazca plates. Instead, the Panamanian isthmus and surrounding areas are accommodating east-west compression (and a lesser degree of north-south compression) along a series of thrust faults striking NW to NE, and the Andean ranges of Ecuador, Colombia, and Venezeula are moving as a block NNE relative to the rest of the South American plates, along a system of faults following the front of the Eastern Cordillera. The subducted portions of the Panama basin and old Farallon plate have become segmented into three pieces recognized in this study. From north to south, they are (1) a `Bucaramanga' segment continuous with the Caribbean seafloor northwest of Colombia, (2) a `Cauca' segment continuous with oceanic crust (Nazca plate) currently being subducted beneath South America at the Colombia-Ecuador trench, and (3) an `Ecuador' segment at the northern end of the subducted lithospheric plate which is dipping at a small angle to the east beneath northern Peru. The segmentation of the subducted plate can be explained by the buoyancy of bathymetric features which have been partially subducted.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Evaluating Channel Head Conditions for Environmental Impact Assessment in Northwestern Sonoma County, California

    NASA Astrophysics Data System (ADS)

    Sherwood, M. N.; O'Connor, M.; Pennington, R.

    2007-12-01

    Erosion and sedimentation have been identified as processes significantly affecting water quality in northern California Coast Range watersheds. These watersheds, including the Gualala River watershed in northwestern Sonoma County, have been designated as having water quality impaired by sediment under provisions of the Clean Water Act Section 303(d). A study was performed to estimate potential increases in erosion rates resulting from proposed vineyard development of ridge top forestland in the Gualala River watershed. The study area has an extensive history of logging, with substantial ground disturbance from tractors. The study area is characterized by flat ridge tops with steeply incised drainages shaped by debris slides, rock slides and earth flows. Jurassic age sedimentary and meta-sedimentary rocks of the coastal and central belt Franciscan formation comprise the underlying bedrock. Channel head development and advancement has long been understood to play a key role in sediment delivery and is possibly the most sensitive to changes in the external factors such as changes in climate or land use (Dietrich and Dunne 1993). Quantifying the amount of sediment contributed by potential channel head incision and/or initiation is an objective of environmental analysis for the project. Field surveys were performed during the field seasons of 2005 and 2006 to acquire measurements of channel head locations and slope, channel dimensions and substrate associated with the proposed development sites. Analysis of this field data, including the use of ArcGIS, allowed us to examine the local relationships between variables that influence channel initiation. Variables considered include drainage area, slope, soil type, geology and vegetation. An initial analysis of a selection of area-slope data failed to produce an inverse area-slope relationship as has been found in previous studies by Montgomery and Dietrich (1988). A more complete evaluation of the entire data set is presented here.

  11. The AAS ``Semi-centennial" Meeting: Northwestern University and Yerkes Observatory, September 1947

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1999-05-01

    The AAS celebrated its "semi-centennial" fifty-two years ago! It was actually the fiftieth anniversary of the "First Conference" of astronomers and astrophysicists held at the dedication of Yerkes Observatory in 1897, which led to the actual formation of the Society two years later. Otto Struve, president of the AAS, was publicizing the fiftieth anniversary of his Yerkes Observatory in 1947, and he simply announced it was also the semi-centennial of the Society. Joel Stebbins, the grand old man of the AAS who had joined it as a graduate student in 1900, and held nearly every office in the Society from councilor to president, supported Struve's early celebration of the anniversary, probably largely because he was to retire himself in 1948. The meeting was held at Northwestern University and at Yerkes. There were then 625 AAS members. About 140 of them attended the meeting, and presented some 50 papers, all oral, with no parallel sessions. Struve organized a symposium on stellar atmospheres, with 5 invited speakers, and the great majority of the contributed papers were also on stars, a few on nebulae and interstellar matter, one on galaxies, and none on cosmology. Not to be outdone, Gerard P. Kuiper, who had recently succeeded Struve as director of Yerkes Observatory, organized a second symposium on the atmospheres of the planets, held at Yerkes immediately after the AAS meeting. After two days of sessions at Evanston, the members had driven to Williams Bay for the closing session Saturday, at which Struve and Stebbins gave their versions of the history of the observatory and of the Society. The two symposia formed the bases for two important books, Astrophysics: A Topical Symposium, and The Atmospheres of the Earth and the Planets, edited by J. Allen Hynek and Kuiper respectively.

  12. 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.

  13. Hydrogeochemistry and simulated solute transport, Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Robson, Stanley G.; Saulnier, George J.

    1980-01-01

    Oil-shale mining activities in Piceance basin in northwestern Colorado could adversely affect the ground- and surface-water quality in the basin. This study of the hydrology and geochemistry of the area used groundwater solute-transport-modeling techniques to investigate the possible impact of the mines on water quality. Maps of the extent and structure of the aquifer were prepared and show that a saturated thickness of 2,000 feet occurs in the northeast part of the basin. Ground-water recharge in the upland areas in the east, south, and west parts of the basin moves down into deeper zones in the aquifer and laterally to the discharge areas along Piceance and Yellow Creeks. The saline zone and the unsaturated zone provide the majority of the dissolved solids found in the ground water. Precipitation, ion-exchange, and oxidation-reduction reactions are also occurring in the aquifer. Model simulations of groundwater pumpage in tracts C-a and C-b indicate that the altered direction of groundwater movement near the pumped mines will cause an improvement in groundwater quality near the mines and a degradation of water quality downgradient from the tracts. Model simulations of mine leaching in tract C-a and C-b indicate that equal rates of mine leaching in the tracts will produce much different effects on the water quality in the basin. Tract C-a, by virtue of its remote location from perennial streams, will primarily degrade the groundwater quality over a large area to the northeast of the tract. Tract C-b, by contrast, will primarily degrade the surface-water quality in Piceance Creek, with only localized effects on the groundwater quality. (USGS)

  14. Hydrogeochemistry and simulated solute transport, Piceance Basin, northwestern Colorado

    USGS Publications Warehouse

    Robson, S.G.; Saulnier, G.J., Jr.

    1981-01-01

    Oil-shale mining activities in Piceance basin in northwestern Colorado could adversely affect the ground- and surface-water quality in the basin. This study of the hydrology and geochemistry of the area used ground-water solute-transport-modeling techniques to investigate the possible impact of the mines on water quality. Maps of the extent and structure of the aquifer were prepared and show that a saturated thickness of 2,000 feet occurs in the northeast part of the basin. Ground-water recharge in the upland areas in the east, south, and west parts of the basin moves down into deeper zones in the aquifer and laterally to the discharge areas along Piceance and Yellow Creeks. The saline zone and the unsaturated zone provide the majority of the dissolved solids found in the ground water. Precipitation, ion-exchange, and oxidation-reduction reactions are also occuring in the aquifer. Model simulations of ground-water pumpage in tracts C-a and C-b indicate that the altered direction of ground-water movement near the pumped mines will cause an improvement in ground-water quality near the mines and a degradation of water quality downgradient from the tracts. Model simulations of mine leaching in tract C-a and C-b indicate that equal rates of mine leaching in the tracts will produce much different effects on the water quality in the basin. Tract C-a, by virtue of its remote location from perennial streams, will primarily degrade the ground-water quality over a large area to the northeast of the tract. Tract C-b, by contrast, will primarily degrade the surface-water quality in Piceance Creek, with only localized effects on the ground-water quality. (USGS)

  15. Upper Cretaceous source rocks of northern and northwestern South America

    SciTech Connect

    Talukdar, S.; Gallango, O.; Cassani, F.; Vallejos, C.

    1989-03-01

    Organic carbon-rich, laminated, calcareous shales and limestones of Cenomanian to Campanian age are widespread in the polyhistory basins of Venezuela, Colombia, and Trinidad and are identified as the most important oil-generating source rocks in these basins. Available data on sedimentological, geochemical, and organic petrographic characteristics demonstrate that these source rocks are characterized by predominantly marine organic matter deposited in anoxic to near-anoxic marine environments. Marine transgressions due to eustatic sea level rise, with consequent flooding of available shelves of the northern and northwestern passive margin of the Cretaceous South American continent and resulting upwelling conditions, appears to be the key geologic control for the deposition of these laterally extensive source rocks. Significant vertical variations in geochemical properties are observed. These variations were caused by temporal changes in the influx of terrestrial organic matter and/or alternations of relatively oxic and anoxic conditions. Regional variations in organic carbon content, organic matter type, and oil potential broadly reflect the paleogeographic setting of the Cretaceous continental margin. The regionally extensive oil-prone source rocks became largely mature for hydrocarbon generation during the Tertiary, consequent to the development of the individual polyhistory basins. Rock-Eval pyrolysis data from several samples and results from hydrous pyrolysis experiments on some selected immature samples from the Venezuelan basins are used to define the oil-generating capacity, and kinetic parameters obtained from Rock-Eval experiments on the same samples are considered to outline the oil generation under the geological heating rates encountered in the sedimentary basins.

  16. Determinants of fish assemblage structure in Northwestern Great Plains streams

    USGS Publications Warehouse

    Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W.

    2011-01-01

    Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American Fisheries Society 2011.

  17. Development and mapping of seleniferous soils in northwestern India.

    PubMed

    Dhillon, Karaj S; Dhillon, Surjit K

    2014-03-01

    Periodic surveys were undertaken to identify and characterize Se-contaminated soils in northwestern India. Total Se content varied from 0.023 to 4.91mgkg(-1) in 0-15cm surface soil and 0.64-515.0mgkg(-1) in samples of vegetation. Selenium-contaminated land occupying an area of 865ha was classified into different categories based on total Se content of soils as moderately contaminated (0.5-2.0mg Sekg(-1)) and highly contaminated (>2.0mg Sekg(-1)). The normal soils contained <0.5mg Sekg(-1). The soil map was prepared using village level cadastral maps. Se-contaminated soils were silty loam to silty clay loam in texture and tested pH 7.9-8.8, electrical conductivity 0.3-0.7dSm(-1), calcium carbonate 0.1-4.1% and organic carbon 0.4-1.0%. Selenium was present throughout the soil profile up to 2m depth; 0-15cm surface soil layer contained 1.5 to 6.0 times more Se than in subsurface layers. Selenium content in rock samples collected from lower and upper Shiwalik sub-Himalayan ranges varied from 1864 to 2754 and 11 to 847?gkg(-1), respectively. The sediments transported through seasonal rivulets linking the Shiwalik ranges to affected sites contained 0.57-2.89mg Sekg(-1). The underground water containing 2.5-69.5?g SeL(-1) used for irrigating transplanted rice grown in Se-contaminated area resulted in a net Se addition in soil up to 881gha(-1)y(-1); possibly further aggravating the Se-toxicity problem. Presence of substantial amount of Se in rock samples and sediments of seasonal rivulets suggests that Se-rich materials are being transported from Shiwalik hills and deposited in regions where seasonal rivulets end up. PMID:24210553

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.; Vronneau, 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.

  3. Rabies surveillance in bats in Northwestern State of So Paulo.

    PubMed

    Casagrande, Daiene Karina Azevedo; Favaro, Ana Beatriz Botto de Barros da Cruz; Carvalho, Cristiano de; Picolo, Mileia Ricci; Hernandez, Janana Camila Borges; Lot, Monique Serra; Albas, Avelino; Arajo, Danielle Bastos; Andr Pedro, Wagner; Queiroz, Luzia Helena

    2014-01-01

    Introduction Rabies is an important zoonosis that occurs in mammals, with bats acting as Lyssavirus reservoirs in urban, rural and natural areas. Rabies cases in bats have been recorded primarily in urban areas in Northwestern State of So Paulo since 1998. This study investigated the circulation of rabies virus by seeking to identify the virus in the brain in several species of bats in this region and by measuring rabies-virus neutralizing antibody levels in the hematophagous bat Desmodus rotundus. Methods From 2008 to 2012, 1,490 bat brain samples were sent to the Universidade Estadual Paulista (UNESP) Rabies Laboratory in Araatuba, and 125 serum samples from vampire bats that were captured in this geographical region were analyzed. Results Rabies virus was detected in the brains of 26 (2%) of 1,314 non-hematophagous bats using the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). None of the 176 hematophagous bat samples were positive for rabies virus when a virus detection test was utilized. Out of 125 vampire bat serum samples, 9 (7%) had levels of rabies virus neutralization antibodies (RVNAs) that were higher than 0.5IU/mL; 65% (81/125) had titers between 0.10IU/mL and 0.5IU/mL; and 28% (35/125) were negative for RVNAs using the simplified fluorescent inhibition microtest (SFIMT) in BHK21 cells. The observed positivity rate (1.7%) was higher than the average positivity rate of 1.3% that was previously found in this region. Conclusions The high percentage of vampire bats with neutralizing antibodies suggests that recent rabies virus exposure has occurred, indicating the necessity of surveillance measures in nearby regions that are at risk to avoid diffusion of the rabies virus and possible rabies occurrences. PMID:25626649

  4. 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.

  5. 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.

  6. Eolian and fluvial facies in sandstones of Queen Formation, Permian basin, Texas

    SciTech Connect

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

    1988-02-01

    The Queen Formation (Guadalupian) is a sequence of carbonates, evaporites, and sandstones that is found across the Northwestern shelf and Central Basin platform of the Permian basin. Cores, logs, and thin sections of the Queen sandstones, which are commonly stratigraphic traps for oil, were examined in five fields in order to determine their sedimentation history.

  7. 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

  8. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in Northwestern Washington-Regulated Navigation Area. 165.1301 Section 165.1301 Navigation and... WashingtonRegulated Navigation Area. The following is a regulated navigation areaAll of the following northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  9. 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...

  10. 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...

  11. 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

  12. 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

  13. 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.

  14. 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

  15. The Evolution of the Perdido Fold Belt, Northwestern Gulf of Mexico - Insights from Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Gradmann, S.; Beaumont, C.

    2007-12-01

    The Perdido Fold Belt (PFB) in the northwestern Gulf of Mexico is a large deep-water salt-tectonic structure. It is located above the seaward limit of the Jurassic Louann salt and lies within the compressional domain of a salt tectonic continental margin system. The PFB is well documented in several geophysical surveys and deep-water hydrocarbon discoveries associated with this structure have recently been made. The region consists of up to 8 symmetric, ~15 km wide and 60 km long folds in exceptionally thick (4.6 km) overburden sediments. Folding is estimated to have occurred synchronously within only ~6 Ma and the entire fold belt is tilted seawards. The conditions that led to the given geometry, timing and extent of the fold belt including the role of the landward located Sigsbee salt canopy are poorly understood. This work investigates the formation of the PFB using 2D finite-element models in which frictional-plastic sediments overly a viscous salt layer. The models comprise the sediments of a passive margin from shelf to deep water to account for the dynamical interaction of gravity gliding and spreading caused by shelf progradation. The model experiments also include flexural isostasy, loading by the overlying water column and sediment compaction. Effects of pore fluid pressures are included by parametric calculations of an effective internal angle of friction. An analytical stability analysis and numerical experiments reveal that gravity spreading alone can fold a 4.6 km thick layer of frictional-plastic sediments in a setting like the western Gulf of Mexico. To obtain failure along the margin, the overburden is required to have a strength of only moderately overpressured, wet sand. Sediment compaction, which increases density, increases the translational velocity of the unstable overburden and results in earlier and faster formation of the fold belt. It also enhances the evolution of buoyancy driven structures. Additional numerical model results show the role of an adjacent salt nappe on the evolution of the PFB and the inflation of the detachment layer. Furthermore, the influence of salt taper and basement steps on the timing and extent of the fold belt is shown which helps constrain the initial salt thickness.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

    PubMed Central

    Dantur Juri, Mara J; Zaidenberg, Mario; Claps, Guillermo L; Santana, Mirta; Almirn, 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

  2. Upper Ocean Responses to typhoons in the Northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Hong, C.; Masuda, A.; Yoon, J.

    2012-12-01

    Responses of upper ocean to typhoons in the Northwestern Pacific are studied using historical temperature data obtained at a buoy station (St. 21004; 29N,135E) of the Japan Meteorological Agency during 1982-2000 and a three-dimensional primitive equation model (the Princeton Ocean Model; POM). In the data period, 25 typhoons passed through within ~200km from the buoy, and cooled overall the sea surface by 1.6-4.3C. In particular, several intense, slowly moving typhoons (?4ms-1) showed common features of temperature variations; they very much cooled the sea surface water by 3-4C, and the cooled states kept longer than two weeks even after the passage of typhoons, and the SST minima occurred 1-2days after the typhoon passage. On the other hand, the subsurface temperatures at the depths of 50m and 100m increased 2-3days before the passage of typhoons, and showed near-inertial oscillations. The model is implemented for simulating the temperature variations with an intense, slowly moving Typhoon Abby (1983), and well reproduces these observed features before, during, and after the passage of the typhoon. The deepening of the surface mixed layer was simulated as well, though the corresponding observation was not available. The model also revealed that the subsurface temperature temporal-variation is roughly governed by a linearized thermal equation, showing that the temperature variation is mostly caused by the vertical displacement of the stratified water columns. An unexpected result in the numerical model is the appearance of a surface cyclonic flow in the rear of the typhoon, which was accompanied by the depression of the sea surface. Obviously such features could not have been detected from the analysis of temperature data only. In other presentation (Masuda and Hong, 2012), a theoretical explanation is given to both the surface cyclonic current and temperature variation of the upper ocean based on our conceptual model.; Fig.1. Time series of the observed temperatures with the passage of four typhoons (Fig.1a) and plan views of the simulated sea water variation (Fig. 1b), depicting the typhoon center (x) and the buoy station by a black triangle.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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...

  10. Attracting a New Market to Northwestern's Undergraduate Programs: Older Women Living on the North Shore.

    ERIC Educational Resources Information Center

    Fox, Karen F. A.

    Women over age 25 represent a substantial age group that may be recruited to bolster undergraduate student recruitment efforts at Northwestern University and similar institutions of higher education. By 1990, the number of recruitable 18-year-olds will fall by 20 percent nationwide, causing financial hardship for many private colleges and

  11. 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 ...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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 PURPOSES Designation of Air Quality Control Regions §...

  17. Recent Suicide Rates among Ten Ojibwa Indian Bands in Northwestern Ontario.

    ERIC Educational Resources Information Center

    Spaulding, John M.

    1986-01-01

    Investigated the rate of completed suicides for 10 Ojibwa Indian bands in northwestern Ontario between 1975 and 1982. Results indicated 61.7 suicides per 100,000 population. Suicide victims tended to be young males who used firearms. Alcohol or drug use was directly involved in over half of the suicides. (Author/BL)

  18. 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.

  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. 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 ]...

  1. WATER TABLE EFFECTS ON PHOSPHORUS RELEASE AND TRACE GAS FLUX IN A NORTHWESTERN MINNESOTA SHALLOW MARSH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A freshwater marsh, created by artificially draining a 105-ha shallow lake (Rice Lake), is a suspected source of phosphorus (P) to the Detroit Lake watershed, a major recreational destination for northwestern Minnesota. P loadings to the main drainage canal increase during the summer months, when th...

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

    NASA Astrophysics Data System (ADS)

    Anderson, Patricia M.

    1985-11-01

    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 birchdominated shrub tundra. Alnus pollen appeared at both sites between 9000 and 8000yr B.P., and Picea pollen (mostly P. mariana) arrived at Squirrel Lake about 5000 yr B.P. The current foresttundra 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 north-western 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.

  3. A Study of Instructional Needs of Part-Time Faculty at Northwestern Michigan College.

    ERIC Educational Resources Information Center

    Rhodes, Jean

    In 1991, an instructional development needs assessment was conducted of the part-time faculty at Northwestern Michigan College (NMC). A survey instrument, requesting participants to rank-order a variety of skills and competencies were mailed to two groups: part-time faculty who had taught at least one quarter at NMC in the 1989-90 school year; and

  4. Transition in the Cause of Fever from Malaria to Dengue, Northwestern Ecuador, 19902011

    PubMed Central

    Cifuentes, Sara G.; Trostle, James; Trueba, Gabriel; Milbrath, Meghan; Balden, Manuel E.; Coloma, Josefina

    2013-01-01

    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

  5. 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

  6. Nitrate distributions and source identification in the Abbotsford-Sumas Aquifer, northwestern Washington State.

    PubMed

    Mitchell, Robert J; Babcock, R Scott; Gelinas, Sharon; Nanus, Leora; Stasney, David E

    2003-01-01

    The Abbotsford-Sumas Aquifer is a shallow, predominantly unconfined aquifer that spans regions in southwestern British Columbia, Canada and northwestern Washington, USA. The aquifer is prone to nitrate contamination because of extensive regional agricultural practices. A 22-month ground water nitrate assessment was performed in a 10-km2 study area adjacent to the international boundary in northwestern Washington to examine nitrate concentrations and nitrogen isotope ratios to characterize local source contributions from up-gradient sources in Canada. Nitrate concentrations in excess of 10 mg nitrate as nitrogen per liter (mg N L(-1)) were observed in ground water from most of the 26 domestic wells sampled in the study area, and in a creek that dissects the study area. The nitrate distribution was characteristic of nonpoint agricultural sources and consistent with the historical documentation of agriculturally related nitrate contamination in many parts of the aquifer. Hydrogeologic information, nitrogen isotope values, and statistical analyses indicated a nitrate concentration stratification in the study area. The highest concentrations (> 20 mg N L(-1)) occurred in shallow regions of the aquifer and were linked to local agricultural practices in northwestern Washington. Nitrate concentrations in excess of 10 mg N L(-1) deeper in the aquifer (> 10 m) were related to agricultural sources in Canada. The identification of two possible sources of ground water nitrate in northwestern Washington adds to the difficulty in assessing and implementing local nutrient management plans for protecting drinking water in the region. PMID:12809280

  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. "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

  9. 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

  10. West Nile virus isolated from a Virginia opossum (Didelphis virginiana) in northwestern Missouri, USA, 2012.

    PubMed

    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

    2014-10-01

    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

  11. 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.

  12. 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.

  13. El Nio forcing on 10Be-based surface denudation rates in the northwestern Peruvian Andes?

    NASA Astrophysics Data System (ADS)

    Abbhl, Luca M.; Norton, Kevin P.; Schlunegger, Fritz; Kracht, Oliver; Aldahan, Ala; Possnert, Gran

    2010-11-01

    High magnitude precipitation events provide large contributions to landscape formation and surface denudation in arid environments. Here, we quantify the precipitation-dependent geomorphic processes within the Rio Piura drainage basin located on the Western Escarpment of the northern Peruvian Andes at 5S latitude. In this region, monsoonal easterly winds bring precipitation to the > 3000 m asl high headwaters, from where the annual amount of precipitation decreases downstream toward the Pacific coast. Denudation rates are highest in the knickzones near the headwaters, ~ 200-300 mm ky - 1 , and sediment discharge is limited by the transport capacity of the channel network. Every few years, this situation is perturbed by westerly, wind-driven heavy precipitation during El Nio events and results in supply-limited sediment discharge as indicated by bedrock channels. The detailed analysis of the stream-long profiles of two river basins within the Rio Piura catchment reveals a distinct knickzone in the transition zone between the easterly and westerly climatic influences, suggesting an En Nio forcing on the longitudinal channel profiles over at least Holocene timescales. Measured trunk stream catchment-wide denudation rates are up to ca. 300 mm ky - 1 and decrease successively downstream along the river profiles. Denudation rates of tributary rivers are ca. 200 mm ky - 1 near the plateau and show a stronger downstream decreasing trend than trunk stream rates. This suggests that the landscape is in a transient stage of local relief growth, which is driven by fluvial incision. This corroborates the results of paleoclimate studies that point towards higher El Nino frequencies during the past ca. 3000 years, leading to higher runoff and more erosion in the trunk channel compared to the hillslopes and thus growth of local relief. Downstream increases in channel gradient spatially coincide with the reaches of highest precipitation rates during El Nio events, we therefore interpret that Holocene landscape evolution has largely been controlled by climate. The ky-timescale of the 10Be data together with the transience of the landscape implies that El Nio events in northwestern Peru have occurred since at least the Holocene, and that adjustment to channel incision is still taking place.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 Amag Formation, northwestern Colombia, reflect major fluctuations in the stratigraphic base level within the Amag 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 Amag 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 Amag 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 Amag Formation. The final stage of evolution of the Amag 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 Amag Formation. The subsequent eastward migration of the NW Andes magmatic arc (after 8 Ma) may have produced basin inversion and suppressed deposition along the Amag Basin.

  19. Aeolian transport pathways along the transition from Tibetan highlands towards northwestern Chinese deserts

    NASA Astrophysics Data System (ADS)

    Nottebaum, Veit; Lehmkuhl, Frank; Stauch, Georg

    2014-05-01

    The identification and semi-quantification of aeolian transport pathways enhances the understanding of aeolian sediment archive formation and thus supports reliability and explanatory power concerning palaeoenvironmental reconstructions. Grain size analysis of 279 surface sediment samples from the transition of Tibetan highlands (Qilian Shan) towards northwestern Chinese deserts allows the differentiation of contributing pathways among three types of aeolian sediments: silty loess, sandy loess, and aeolian sands. The study area exhibits a high diversity of geomorphological surfaces due to varieties in relief, elevation and climatic conditions. Therefore, it provides the opportunity to investigate the characteristics of sediments in different geomorphological settings. Using the peaks of grain size frequency's standard deviation of primary loess allows identification of the most sensitive fractions to varying accumulation conditions. mU/fS-ratio (7 - 13 ?m / 58 - 84 ?m) of primary silty loess relates the far-travelled dust proportion to the locally transported fine sand component. In vicinity to fluvial channels in the foreland mU/fS-values are significantly decreased, whereas mU/fS-values increase with altitude (r2 = 0.74). This indicates higher contribution of long distance transport compared to lower regions. A prominent increase of mU/fS-values above 3000 m asl likely indicates an increasing contribution of fine and medium silt particles transported by Westerlies in higher altitudes. In contrast, lower areas seem to be more strongly influenced by low altitude monsoon currents (NW-Winter- / SE-summer monsoon). The difference in grain size properties is additionally enhanced by the contrasting geomorphologic settings along the mountain declivity: Plain foreland alluvial fans support fine sand supply and availability whereas steep high mountain topography provides only limited potential for fine sand deflation. Similarly, the relatively low relief in intramontane basins leads to fluvial sediment aggradation and allows comparably high fine sand deflation. This supports the formation of sandy loess in these regions and on foreland alluvial fans, whereas in contrast, sandy loess is absent in the high mountain geomorphologic setting. Aeolian sand distribution in the study area indicates a high dependence on sand supply. In eastern forelands perennial Hei River and northerly bordering Badain Jaran desert are important sand sources and hence support dune field formation in the northern Qilian Shan foreland (Hexi Corridor). In contrast, western forelands, dominated by gravel gobi surfaces, exhibit very few aeolian sand accumulations on the surface. The latter area shows only ephemeral discharge and is lacking large sand source areas. Therefore, although sufficient wind speeds occur, aeolian sand transport is limited due to restricted sand supply. Concluding, the medium scale geomorphological setting (103 m) exerts a rather underestimated influence when reconstructing aeolian transport processes. However, considering the spatial distribution of aeolian sediments in combination with their grain size distribution allows the reconstruction of dominant transport pathways.

  20. 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.

  1. Diagenetic history of the Korallenoolith (Malm) of northwestern Germany: Implications from in-situ trace element and isotopic studies

    NASA Astrophysics Data System (ADS)

    Bruhn, Frank; Veizer, Jn; Buhl, Dieter; Meijer, Jan

    2005-04-01

    We have collected rock samples from the abandoned Konrad iron ore mine near Salzgitter/Germany, to elucidate the diagenetic history of the Korallenoolith formation in northwestern Germany. Petrographic and cathodoluminescence investigations showed that the rocks contain a wide range of particles, from primary biogenic material to various generations of interparticle cements and cements in fissures and fractures. The diagenetic environment of cement precipitation was reconstructed using in-situ trace element microanalyses with PIXE, using the Bochum proton microprobe. Furthermore, the different components were analysed for their radiogenic (87Sr/86Sr) isotope signatures. 'Rim cements' around echinoid fragments display several stages of cement precipitation. Early cement generations show high Sr concentrations and low 87Sr/86Sr values. In contrast, later generations have relatively low Sr values, around 300 ppm, and iron concentrations of up to 3%. Fissure cements represent an even later stage of diagenetic history. They consist of calcite, anhydrite and celestite and are characterised by significantly higher 87Sr/86Sr values. The results of combined trace element and isotopic measurements indicate that the biogenic material was deposited in a shallow marine environment with normal salinity and a relatively high primary availability of iron. The early generations of diagenetic cements have similar, marine, signatures and were therefore precipitated in a closed system, where the trace element and isotopic properties were inherited from the dissolved precursor phases. In contrast, the later generations of rim cements and particularly the fissure cements show completely different and variable chemical signatures. They were precipitated in an open system from formation waters.

  2. Sandstone petrography and evidences for provenance changes in Miaoli area from late Pliocene to early Pleistocene, northwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Fu, Cheng-Wei; Yang, Kenn-Ming; Ting, Hsih-Hsiu; Yang, Chih-Cheng; Zhong, Kun-Wei

    2015-04-01

    The Miaoli area is located in the outer Western Foothills in the northwestern Taiwan, and between the Peikang Basement High and the Taihsi Basin. Based on the wellbore data, outcrop investigation, and petrofacies analysis of the sediments within the proximal to distal parts of the foreland basin in the Miaoli area, we revealed the evolutionary relationship between orogen and basin and the inference to the results from foreland basin on orogenic development of Taiwan. This work mainly composed of sedimentary facies analysis, sedimentary environments interpretations, and petrofacies analysis of sandstones. Upon aforementioned results, we discussed tectonic evolution of the orogenic belt and petrofacies variation of the sedimentary basin. The results contains two parts: 1) investigation of outcropped profiles from the outer Western Foothills to the Coastal Plain for reconstructing evolution of ancient sedimentary environments, and 2) petrofacies analysis of lithic debris of wellbores and sandstone samples in the field for revealing the variation of sediment sources between the proximal and distal parts of the foreland basin. Our research represented that 1) the foreland basin was in deeper sedimentary environment and the sediments derived from both the continental block and recycled orogen during depositing of the Chinshui Shale; 2) percentage of metamorphosed lithics increased in the proximal part of the basin during depositing of the Cholan Formation, indicating that sediments derived mainly from the orogenic belts, and the underfilled basin became to be overfilled; and 3) large amount of coarse sediments entered the basin during depositing of the Toukoshan Formation, sedimentary environments were from shore semi-closed shallow sea to terrestrial braided river, indicating that the Taiwan Orogen had been completely exposed.

  3. 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.

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

    PubMed

    Luque-Larena, Juan Jos; Mougeot, Franois; Roig, Dolors Vidal; Lambin, Xavier; Rodrguez-Pastor, Ruth; Rodrguez-Valn, 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

  5. 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.

  6. 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)

  7. 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.

  8. 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.

  9. The Hei River Basin in northwestern China - tectonics, sedimentary processes and pathways

    NASA Astrophysics Data System (ADS)

    Rudersdorf, Andreas; Nottebaum, Veit; Schimpf, Stefan; Yu, Kaifeng; Hartmann, Kai; Stauch, Georg; Wnnemann, Bernd; Reicherter, Klaus; Diekmann, Bernhard; Lehmkuhl, Frank

    2014-05-01

    The Hei River Basin (catchment area of c. 130,000 km) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper catchment is represented by the Qilian Shan mountain range and its immediate foreland. Here, a tripartite altitudinal distribution of terrestrial sediment archives is evident, which is representative of catchment-wide sedimentological processes. Insights into their formation mechanisms, therefore, add valuable perspective regarding the reconstruction of sedimentological and paleoenvironmental conditions in the depositional area of the Hei River Basin. For the characterization of provenance and dispersal of Quaternary sediments in relation to the modern depositional environment, over 200 surface samples from the whole catchment were analyzed using XRD and XRF measurements on the clay fractions, heavy minerals and bulk sediments. The clay mineral results in-particular show that it is possible to discriminate between the chlorite rich metamorphic sediments originating from greenschist bearing rocks in the Qilian Shan Mountain Range in the south, and the more intrusive rocks from the Bei Shan Mountain Range west of the Hei River Basin. Additionally, these two main sources reflect different transportation processes; the Qilian Shan sediments are mainly transported by the rivers Heihe and Beida He, and the deposition of the Bei Shan sediments is mainly driven by wind or local runoff. Grain size results of primary loess deposits indicate different eolian transport pathways, i.e., far-travelled dust input (medium silty) vs. local deflation from active fluvial channels (fine sandy). Along the altitudinal transect, the varying geomorphological settings exert a significant influence on the grain size composition showing an increased contribution of far-travelled dust at higher altitudes.

  10. 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.

  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

    ...In response to a November 11, 2010, petition, this notice provides partial relief for the Northwestern Pacific Railroad Co. (NWP Co.) from the limitations of FRA Emergency Order No. 21. The relief allows the NWP Co. to re-open to rail traffic approximately 61.1 miles of trackage owned by Sonoma Marin Area Rail Transit (SMART) \\1\\ extending between (1) a point designated as Brazos Junction,......

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Concept Formation.

    ERIC Educational Resources Information Center

    Vaidya, Narendera

    This document, published in India by the Regional College of Education, deals with 13 subjects: the tough context (thinking), definitions of concept, functions of concept, the process of concept formation, discriminant learning, mediation process, second signalling system, factors affecting concept formation, studies in concept formation, the

  1. Miocene tectono-stratigraphic history of La Mision basin, northwestern Baja California: implications for early tectonic development of southern California continental borderland

    SciTech Connect

    Ashby, J.R.; Minch, J.

    1988-03-01

    The middle Miocene La Mision basin in northwestern Baja California, Mexico, provides a rare opportunity to study an onshore portion of the southern California continental borderland. Stratigraphy, geometry of dispersal, and a variety of lithotypes within the volcanic and volcaniclastic sediments of the Rosarito Beach Formation provide clues to the nature of early tectonic evolution of this area during the Miocene. The elongated, trough-shaped La Mision basin formed in response to peninsular basement uplifts and the formation of volcanic highlands west of the present coastline. Lithologies and depositional environments represented within the basin sediments include: subaerial basalt flows and airfall tuffs, submarine muddy- and sandy-matrix mudflow breccias, lapilli tuffs, crystal tuffs, tuffaceous sandstones,d diatomites, and conglomerates. The environments of deposition range from fluvatile to intertidal to shallow marine. Early basin infilling is characterized by sediments and basalts, with a western source terrane, that were deposited against the faulted seacliffs. progressive infilling against the seacliff resulted in the formation of an extensive eastward-sloping basaltic platform extending eastward to the foothill coastal belt of the Peninsular Ranges. Marine transgression and subsequent regression are recorded by diverse marine volcaniclastic lithologies. Abundant fossils, K-Ar dates, and paleomagnetic data obtained from the La Mision basin allow precise correlation with other areas in the continental borderland and provide conclusive evidence that this block of the borderland was formed and in its present position by 16-14 Ma.

  2. 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

  3. Microearthquake seismicity and active tectonics of northwestern Greece

    NASA Astrophysics Data System (ADS)

    King, G. C. P.; Tselentis, A.; Gomberg, J.; Molnar, P.; Roecker, S. W.; Sinvhal, H.; Soufleris, C.; Stock, J. M.

    1983-12-01

    We carried out a microearthquake survey lasting for six weeks in northwest Greece using 18 portable seismograph stations to examine a region in which normal and thrust faulting have been reported in close proximity to one another. With this array we located 148 events and determined fault plane solutions for eight events using only rays radiated upwards. The seismicity of the region is diffuse with events extending to depths of nearly 30 km, and there is a minimum in activity near a depth of 15 km. The fault plane solutions exhibit a wide spectrum of fault types and orientations and are not consistent with simple zones of shortening or extension. Neither tractions applied to the edges or bottom of the region nor deviatoric stresses that compensate for lateral variations in crustal thickness can account for the variety of fault plane solutions. We think that the complicated behavior is a manifestation of inhomogeneous deformation due, at least in part, to a pre-existing complicated juxtaposition of structures and formations.

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

    USGS Publications Warehouse

    Hamilton, T.D.; Ashley, G.M.; Reed, K.M.; Schweger, C.E.

    1993-01-01

    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.

  5. Integrated exploration study of Norwegian-Danish basin, northwestern Europe

    SciTech Connect

    Joergensen, N.B.; Haselton, T.M.

    1987-05-01

    The Norwegian-Danish basin (NDB) extends from offshore Norway southeast through Denmark. This study, initiated by the Danish Energy Agency to evaluate hydrocarbon potential, consists of geophysical structural and stratigraphic mapping combined with geologic source rock and reservoir analysis. Approximately 25 wells and 15,000 km of seismic data were included. Formation of the NDB resulted from uplift of the Variscan foldbelt followed by subsidence of the foreland, i.e., the NDB and the North German basin. The Ringkoebing-Fyn High, a positive feature probably established in the late Precambrian and persisting to present, separates the basins, thus constituting the southern boundary of the NDB. Northeast the basin is bounded by the Fennoscandian shield and to the west by the North Sea graben system. Following deposition of Rotliegendes eolian and fluviatile sandstones, a major Late Permian marine transgression deposited up to 2000 m of evaporites and carbonates. Early Triassic regression resulted in thick red-bed deposits. Halokinesis commencing in the Upper Triassic dominated subsequent structural development. Continued subsidence led to deposition of Early Jurassic shelf mudstones overlain by deltaic sandstones. Rising seas during Late Cretaceous allowed widespread deposition of oceanic pelagic chalk. Early Paleocene wrench movements produced inversion. Basinal downwarping during the Tertiary was accompanied by progradation from the northeast. The complex tectonic history provides numerous different structural styles and a variety of depositional environments. To date only obvious structural features have been tested. This integrated basin study demonstrates that a number of other hydrocarbon plays remain to be explored.

  6. 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.

  7. Hydrogeology, water use, and simulation of flow in the High Plains aquifer in northwestern Oklahoma, southeastern Colorado, southwestern Kansas, northeastern New Mexico, and northwestern Texas

    USGS Publications Warehouse

    Luckey, Richard L.; Becker, Mark F.

    1999-01-01

    The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, began a three-year study of the High Plains aquifer in northwestern Oklahoma in 1996. The primary purpose of this study was to develop a ground-water flow model to provide the Water Board with the information it needs to manage the quantity of water withdrawn from the aquifer. The study area consists of about 7,100 square miles in Oklahoma and about 20,800 square miles in adjacent states to provide appropriate hydrologic boundaries for the flow model. The High Plains aquifer includes all sediments from the base of the Ogallala Formation to the potentiometric surface. The saturated thickness in Oklahoma ranges from more than 400 feet to less than 50 feet. Natural recharge to the aquifer from precipitation occurs throughout the area but is extremely variable. Dryland agricultural practices appear to enhance recharge from precipitation, and part of the water pumped for irrigation also recharges the aquifer. Natural discharge occurs as discharge to streams, evapotranspiration where the depth to water is shallow, and diffuse ground-water flow across the eastern boundary. Artificial discharge occurs as discharge to wells. Irrigation accounted for 96 percent of all use of water from the High Plains aquifer in the Oklahoma portion of the study area in 1992 and 93 percent in 1997. Total estimated water use in 1992 for the Oklahoma portion of the study area was 396,000 acre-feet and was about 3.2 million acre-feet for the entire study area. Since development of the aquifer, water levels have declined more than 100 feet in small areas of Texas County, Oklahoma, and more than 50 feet in areas of Cimarron County. Only a small area of Beaver County had declines of more than 10 feet, and Ellis County had rises of more than 10 feet. A flow model constructed using the MODFLOW computer code had 21,073 active cells in one layer and had a 6,000- foot grid in both the north-south and east-west directions. The model was used to simulate the period before major development of the aquifer and the period of development. The model was calibrated using observed conditions available as of 1998. The predevelopment-period model integrated data or estimates on the base of aquifer, hydraulic conductivity, streambed and drain conductances, and recharge from precipitation to calculate the predevelopment altitude of the water table, discharge to the rivers and streams, and other discharges. Hydraulic conductivity, recharge, and streambed conductance were varied during calibration so that the model produced a reasonable representation of the observed water table altitude and the estimated discharge to streams. Hydraulic conductivity was reduced in the area of salt dissolution in underlying Permianage rocks. Recharge from precipitation was estimated to be 4.0 percent of precipitation in greater recharge zones and 0.37 percent in lesser recharge zones. Within Oklahoma, the mean difference between water levels simulated by the model and measured water levels at 86 observation points is -2.8 feet, the mean absolute difference is 44.1 feet, and the root mean square difference is 52.0 feet. The simulated discharge is much larger than the estimated discharge for the Beaver River, is somewhat larger for Cimarron River and Wolf Creek, and is about the same for Crooked Creek. The development-period model added specific yield, pumpage, and recharge due to irrigation and dryland cultivation to simulate the period 1946 through 1997. During calibration, estimated specific yield was reduced by 15 percent in Oklahoma east of the Cimarron-Texas County line. Simulated recharge due to irrigation ranges from 24 percent for the 1940s and 1950s to 2 percent for the 1990s. Estimated recharge due to dryland cultivation is about 3.9 percent of precipitation. The mean difference between the simulated and observed waterlevel changes from predevelopment to 1998 at 162 observation points in

  8. 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.

  9. 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 (44S - 48.5S and 323.5E - 329E) 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.

  10. 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.

  11. 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.

  12. Employer Preferences Regarding Resume Content, Appearance, and Format. A Replication in Northwest Missouri of a Study of South Georgia's Hiring Officials.

    ERIC Educational Resources Information Center

    Williams, Stephanie; And Others

    In 1991, Griffin and Anderson examined the preferences of a sample of South Georgia employees regarding resume content, appearance, and format. The Georgia study was replicated with a sample of 60 hiring officials from a variety of companies in northwestern Missouri to determine if geographic location is a factor in hiring officials' preferences

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Molecular sex identification of dry human teeth specimens from Sokoto, Northwestern Nigeria

    PubMed Central

    Zagga, AD; Ahmed, H. OON; Ismail, SM; Tadros, AA

    2014-01-01

    Background: The advent of molecular techniques has revolutionized the ability of scientists to estimate the sex of individuals. Forensic odontology plays an important role in establishing the sex of victims with bodies mutilated beyond recognition due to major disaster. The genetic difference between males and females is defined by the presence or absence of the Y-chromosome. The use of alphoid-repeat primers in sex estimation was first applied on dried blood. Generally, the X, Y alphoid repeats blind test attest to the accuracy of genetic testing, and also point the potential for occasional error in morphometric sexing. Aim: To estimate genetic sex of dry human teeth specimens from Sokoto, Northwestern Nigeria, using polymerase chain reaction (PCR). Materials and Methods: A single-blind study of DNA analysis for sex estimation of nine dry human teeth specimens from Sokoto, Northwestern Nigeria, through PCR, using alphoid repeats primers, was undertaken. Results: The genetic sex of each group of the teeth samples were accurately (100%) identified. For each group of teeth, PCR Sensitivity = 100%, Specificity = 0%, Predictive value of positive test = 100%, Predictive value of negative test = 0%, False positive rate = 0%, False negative rate = 0%, Efficiency of test = 100%. Fisher's exact probability test P = 1. Z-test: z- and P values were invalid. Conclusion: This study has demonstrated the successful use of alphoid-repeat primers in genetic sex identification of human dry teeth samples from Sokoto, Northwestern Nigeria. This is the first known study estimating the sex of human dry teeth specimens by means of PCR in Nigeria. There is need for further studies in Nigeria to complement the findings of this study. PMID:25125922

  19. 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 68124 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 20042005, these species have not been reported previously in the northwestern Gulf of Mexico. PMID:25561830

  20. Fukushima-derived radiocesium in the northwestern Pacific Ocean in February 2012.

    PubMed

    Kumamoto, Yuichiro; Murata, Akihiko; Kawano, Takeshi; Aoyama, Michio

    2013-11-01

    We measured radiocesium ((134)Cs and (137)Cs) in seawaters collected at stations in the northwestern Pacific Ocean in February 2012. Activity concentration of Fukushima-derived radiocesium was highest in the transition area between the subarctic and subtropical regions, which was due to the direct discharge. The direct discharged radiocesium was transported southwardly across the Kuroshio Extension along isopycnal mixing. More than 80% of the Fukushima-derived radiocesium at stations both in the transition area and subtropical region was derived from the direct discharge. PMID:23582498

  1. 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

  2. Contribution of ocean current to the increase in N abundance in the Northwestern Pacific marginal seas

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Kyu; Chang, Kyung-Il; Kim, Bongguk; Cho, Yang-Ki

    2013-01-01

    In the northwestern Pacific marginal seas, there has been a rapid temporal increase and spatial variability in the relative abundance of dissolved inorganic nitrogen over dissolved inorganic phosphate. The cause and mechanisms of this temporal and spatial variation is under debate. Recently, atmospheric deposition of nitrogen has been shown to be the major cause of the spatio-temporal variation in the concentration ratio of dissolved nitrogen and phosphate. We show that the transport by ocean currents is a more crucial factor causing the spatio-temporal variation in the ratio of dissolved nitrogen and phosphate in the study area.

  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. 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.

  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. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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 (3414.83'N, 7635.25'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

  14. 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

  15. 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...

  16. 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

  17. Quaternary tectonics and present stress tensor of the inverted northern Falcn Basin, northwestern Venezuela

    NASA Astrophysics Data System (ADS)

    Audemard M, Franck A.

    2001-02-01

    The Tertiary Falcn Basin in northwestern Venezuela has a privileged position in the geodynamic puzzle of northwestern South America, occurring in a region where several major plates (Caribbean, South America and Nazca) and minor lithospheric blocks (Maracaibo, Bonaire and Western Colombia) are interacting. A combination of good exposures due to aridity and a near-continuous sedimentary record in a now inverted basin helps to unravel the Neogene and Quaternary geodynamic evolution of this region. A neotectonic and microtectonic investigation of the Plio-Quaternary sedimentary rocks of the northern Falcn Basin reveals that this region is subject to a compressive to transpressive regime at present. This regime is characterized by a NNW-SSE oriented maximum horizontal stress, and a ENE-WSW trending intermediate (or minimum) horizontal stress, as is confirmed by focal mechanism solutions. This stress field is in agreement both with the NNE-directed extrusion of the Maracaibo and Bonaire blocks in Western Venezuela, where the Falcn Basin is located, and present-day transpression along the Caribbean-South America plate boundary zone.

  18. Contemporary horizontal crustal movement estimation for northwestern Vietnam inferred from repeated GPS measurements

    NASA Astrophysics Data System (ADS)

    Duong, Nguyen Anh; Sagiya, Takeshi; Kimata, Fumiaki; To, Tran Dinh; Hai, Vy Quoc; Cong, Duong Chi; Binh, Nguyen Xuan; Xuyen, Nguyen Dinh

    2013-12-01

    We present a horizontal velocity field determined from a GPS network with 22 sites surveyed from 2001 to 2012 in northwestern Vietnam. The velocity is accurately estimated at each site by fitting a linear trend to each coordinate time series, after accounting for coseismic displacements caused by the 2004 Sumatra and the 2011 Tohoku earthquakes using static fault models. Considering the coseismic effects of the earthquakes, the motion of northwestern Vietnam is 34.3 0.7 mm/yr at an azimuth of N108 0.7E in ITRF2008. This motion is close to, but slightly different from, that of the South China block. The area is in a transition zone between this block, the Sundaland block, and the Baoshan sub-block. At the local scale, a detailed estimation of the crustal deformation across major fault zones is geodetically revealed for the first time. We identify a locking depth of 15.3 9.8 km with an accumulating left-lateral slip rate of 1.8 0.3 mm/yr for the Dien Bien Phu fault, and a shallow locking depth with a right-lateral slip rate of 1.0 0.6 mm/yr for the Son La and Da River faults.

  19. Northwestern Argentina: a center of genetic diversity of lemon verbena (Aloysia citriodora PALU, Verbenaceae).

    PubMed

    Di Leo Lira, Paola; van Baren, Catalina M; Lpez, Simon; Molina, Ana; Heit, Cecilia; Viturro, Carmen; de Lampasona, Marina P; Cataln, Cesar A; Bandoni, Arnaldo

    2013-02-01

    The aerial parts of lemon verbena (Aloysia citriodora PALU) 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

  20. 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.

  1. 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

  2. Mating system of Brassica napus and its relationship with morphological and ecological parameters in northwestern Spain.

    PubMed

    Soengas, Pilar; Velasco, Pablo; Vilar, Marta; Cartea, Maria Elena

    2013-01-01

    Mating systems play a central role in determining population genetic structure and the methods to be used to develop new cultivars and preserve the variability of a crop. A Brassica napus crop called nabicol is grown in northwestern Spain. Knowledge on its mating system is needed in order to manage the germplasm correctly and design breeding strategies. The aims of this work were to study the mating system of nabicol under field conditions and the relationship of different traits with the mating system. We analyzed 2 populations with microsatellites using a multilocus approach, finding that both had a mixed mating system with an outcrossing rate of 30%. This system would allow application of breeding methods for both autogamous and allogamous species in order to improve nabicol populations. Nabicol populations should be multiplied in isolation conditions in the same way as allogamous species in order to avoid contamination and preserve genetic integrity. The relationship of outcrossing rate, phenological, ecological, and morphological traits was studied, but the model explained only a small percentage of the variability. None of the traits studied could be used as indirect selection criteria for a type of mating system under the conditions of northwestern Spain. This is the first work that studies in depth the possible causes of the mixed mating system of B. napus, finding that, surprisingly, it is not related to the most obvious factors. PMID:23530142

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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...

  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. 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…

  17. 75 FR 3487 - Notice of Public Meeting: Recreation Subcommittee of the Sierra Front-Northwestern Great Basin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... the Sierra Front-Northwestern Great Basin, Northeastern Great Basin, and Mojave- Southern Great Basin... to discuss fee proposals at the Red Rock Canyon National Conservation Area (NCA) Scenic Loop managed... and Forest Service managed Federal lands and waters according to a national interagency...

  18. 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)

  19. 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…

  20. 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

    ..., Nevada AGENCY: Bureau of Land Management, Interior. ACTION: Notice of public meetings. SUMMARY: In...-Northwestern Great Basin Resource Advisory Council (RAC), will hold two meetings in Nevada in fiscal year 2013..., 5665 Morgan Mill Road in Carson City, Nevada and a field trip on April 5; August 8-9 at the...

  1. 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...

  2. 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…

  3. 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.

  4. 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

  5. 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.

  6. 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

    2015-08-01

    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 Nio-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.

  7. Morpho-tectonic analysis of the Tekeze River and the Blue Nile drainage systems on the Northwestern Plateau, Ethiopia

    NASA Astrophysics Data System (ADS)

    Ismail, Elamin H.; Abdelsalam, Mohamed G.

    2012-07-01

    This study examines the morpho-tectonic evolution of the drainage system in the Northwestern Plateau in Ethiopia dominated by the Tekeze River and the Blue Nile. The Northwestern Plateau is underlain by Precambrian crystalline rocks, followed by Mesozoic sedimentary section and topped with Oligocene-Quaternary volcanic rocks. The plateau is bounded in the east and southeast by the Afar Depression and the Main Ethiopian Rift, respectively. Digital Elevation Models (DEMs) from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) data are analyzed to extract morpho-tectonic parameters including the Normalized Steepness Index (Ksn), the Concavity (?) and the Regression Fit (r2) between the observed and predicted channel profiles from the sub-basins and the tributaries of the Tekeze River and the Blue Nile. Analysis of these morpho-tectonic parameters has shown that the evolution of the drainage systems on the Northwestern Plateau was influenced by three tectonic and geological events. The first event resulted in a broad and regional uplift of the plateau, most likely due to the rise of the Afar mantle plume 30 Ma. This regional uplift was accompanied by moderate incision rate of the Tekeze River and the Blue Nile drainage systems within the entire Northwestern Plateau. The second event, which was in the form of shield volcanoes build-up, occurred at 22 Ma and resulted in localized increase in the incision rate around these volcanoes. The third event is manifested by rift-flank uplift at 11 Ma on the western escarpments of the Afar Depression and the northwestern escarpments of the Main Ethiopian Rift. This event resulted in an increase in the incision rate of the Tekeze River and the Blue Nile drainage systems, but this increase seems to diminish towards the west and northwest leaving the drainage systems in the lower reaches of the two rivers relatively tectonically undisturbed, hence allowing for the establishment of a long-lived hydrological stability.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Assessment of water resources in some drainage basins, northwestern coast, Egypt

    NASA Astrophysics Data System (ADS)

    Yousif, Mohamed; Abd, El Sayed El; Baraka, Ahmed

    2013-06-01

    The main objective of this research paper is to monitor the current situation of water resources in some of the drainage basins in the northwestern coast of Egypt and reach to a plan for the development of these resources. The selected basins were chosen for the present study according to their special conditions, where they have a shortage of water for human and agriculture proposes. However, the area of study has a population growth and agricultural activities, which require necessary development of groundwater. The study area has two aquifers: Pleistocene, and Middle Miocene aquifers. The recharge to these aquifers comes either from the direct infiltration of the rainfall, and/or from the surface runoff. The groundwater in the area of study is evaluated for drinking, domestic, livestock and agricultural purposes. The present study reaches out for some recommendations to develop the surface and groundwater in the study area.

  18. Factors associated with self-reported symptoms of acute pesticide poisoning among farmers in northwestern Jamaica.

    PubMed

    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. The authors conducted a population survey among farmers in 3 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 1 or more incidents of acute pesticide poisoning within the last 2 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

  19. 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.

  20. 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".

  1. Soil-Transmitted Helminth Infections and Associated Risk Factors among Schoolchildren in Durbete Town, Northwestern Ethiopia

    PubMed Central

    Alelign, Tilahun; Degarege, Abraham; Erko, Berhanu

    2015-01-01

    Identifying determinants of soil transmitted helminth infection is vital to design control strategy for the disease. This study assessed the prevalence of STH infections and associated factors among schoolchildren in Durbete town, northwestern Ethiopia. Data about the sociodemographic and socioeconomic status of the children were collected using a questionnaire and stool samples were diagnosed using thick Kato-Katz smear. STH infection was more common among school-age children in Durbete town. Hookworm was the most frequent helminth species detected. The prevalence of STH infection was more in children who did not practice wearing shoes and washing hands before eating and in those who were older in age. Deworming of school-age children in the study area would be important. In addition, provision of health education about helminths and the importance of wearing shoes and washing hands before eating would be important to reduce the burden of STH infection in the study area. PMID:26161265

  2. Flood of June 13-15, 1981, in the Blanchard River basin, northwestern Ohio

    USGS Publications Warehouse

    Webber, E.E.

    1982-01-01

    The flood of June 13-15, 1981, in the Blanchard River basin in northwestern Ohio caused major damage in Findlay, Ottawa, and adjacent rural areas. Approximately 25 percent of Findlay and 55 percent of Ottawa were flooded. Estimated crop damage was $12 million in Hancock Country, $7 million in Wyandot Country, and $3 million in Putnam Country. During the flood, the maximum gage height of the Blanchard River at the U.S. Geological Survey gaging station near Findlay was 17.43 feet, gage datum. This was 0.67 foot higher than the previous peak of 16.76 feet, February 11, 1959. The corresponding peak discharge, 13,000 cubic feet per second, was estimated to have a recurrence interval of 50 years. Recurrence intervals of peak flows at other locations on the Blanchard River and on tributary streams were estimated to range from 25 to more than 100 years.

  3. 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

  4. 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.

  5. 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 (Medelln, 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

  6. 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.

  7. [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

  8. 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.

  9. A new species of Paratanais Dana, 1852 (Crustacea, Peracarida, Tanaidacea, Paratanaidae) from Puerto Rico, northwestern Atlantic

    PubMed Central

    Morales-Nez, Andrs G.; Heard, Richard W.

    2014-01-01

    Abstract Paratanais rosadi sp. n. described from Puerto Rican coastal waters represents the first species of the genus from the northwestern Atlantic. It is distinguished from the other Paratanais species by a combination of characters, including article-2 of the maxilliped palp with a geniculate, finely-serrulate seta on inner margin; chela with stiff, geniculate, seta arising from propodus between fixed finger and dactylus and with short, stout, finely serrulate, seta on inner distal face of propodus adjacent to base of dactylus; carpus of pereopods 4?6 having three, instead of four stout modified spiniform setae distally, uropodal exopod distinctly shorter than endopodal article-1; and uropodal endopod with articles of about of equal in length. A key for the separation of Paratanais species from the Atlantic Ocean is presented. PMID:24715797

  10. 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.

  11. Advancing Integration Through Evidence Informed Practice: Northwestern Health Sciences Universitys Integrated Educational Model

    PubMed Central

    Taylor, Barry; Delagran, Louise; Baldwin, Lori; Hanson, Linda; Leininger, Brent; Vihstadt, Corrie; Evans, Roni; Jo Kreitzer, Mary; Sierpina, Victor

    2012-01-01

    A consistent theme running through the healthcare debate is the need for new care models that include collaborative, team-based care. There is also growing recognition that interprofessional education is critical to achieving collaborative, patient-centered care. Not unlike conventional, biomedical professions, CAM (complementary and alternative medicine) professions have also educated students in silos with little interaction between various disciplines. Northwestern Health Sciences University, under their NIH NCCAM-funded R-25 grant, is breaking new ground in requiring that their students in chiropractic, massage, and OAM complete a common course in evidence informed practice. A previous Explore column described the core competencies that the students are required to achieve. This column focuses on the practicalities and challenges of offering a course to students enrolled in three different degree programs. Perhaps it will stimulate readers to consider how we might achieve interprofessional education that brings together all health professional students, biomedical and CAM. PMID:22051565

  12. Increasing N Abundance in the Northwestern Pacific Ocean Due to Atmospheric Nitrogen Deposition

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Wook; Lee, Kitack; Najjar, Raymond G.; Jeong, Hee-Dong; Jeong, Hae Jin

    2011-10-01

    The relative abundance of nitrate (N) over phosphorus (P) has increased over the period since 1980 in the marginal seas bordering the northwestern Pacific Ocean, located downstream of the populated and industrialized Asian continent. The increase in N availability within the study area was mainly driven by increasing N concentrations and was most likely due to deposition of pollutant nitrogen from atmospheric sources. Atmospheric nitrogen deposition had a high temporal correlation with N availability in the study area (r = 0.74 to 0.88), except in selected areas wherein riverine nitrogen load may be of equal importance. The increase in N availability caused by atmospheric deposition and riverine input has switched extensive parts of the study area from being N-limited to P-limited.

  13. Fasciola hepatica in goats from north-western Spain: Risk factor analysis using a capture ELISA.

    PubMed

    Prez-Creo, Ana; Daz, Pablo; Lpez, Ceferino; Bjar, Juan Pablo; Martnez-Sernndez, Victoria; Panadero, Rosario; Dez-Baos, Pablo; Ubeira, Florencio M; Morrondo, Patrocinio

    2016-02-01

    In order to study the seroprevalence of Fasciola hepatica infection in goats from north-western Spain, a total of 603 serum samples from 47 herds were tested using a capture ELISA (MM3-SERO). The identification of risk factors was assessed by a mixed-effects logistic regression analysis. The results showed that F.hepatica is widespread in this area with 57.4% of the herds and 22.7% of the animals testing positive. Breed and age were identified as determining factors for caprine F.hepatica infection. Seroprevalence in cross-bred animals was significantly higher than in the autochthonous Cabra Galega breed. A significantly higher seroprevalence was observed in older animals. The use of locally adapted breeds and the implementation of suitable management practices could provide a substantial improvement over the current F.hepatica control measures carried out in goat herds and should be considered when designing new F.hepatica control programs. PMID:26888193

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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 1,500pgg(-1) in approximately 1991, followed by an exponential decrease to the sediment-water interface. Current concentrations of ?PCBs are similar to levels predating the episodic input of PCBs in sediments dated coincident with the 1991 Arabian Gulf war. The spike in ?PCB concentrations during the war may be related to the destruction of PCB-laden transformers during the conflict. The 15-fold decrease in ?PCB 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

  19. 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

  20. Phylogeography of the finless porpoise (genus Neophocaena): testing the stepwise divergence hypothesis in the northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Lin, Wenzhi; Frre, Cline H.; Karczmarski, Leszek; Xia, Jia; Gui, Duan; Wu, Yuping

    2014-10-01

    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.

  1. Ground-water recharge through active sand dunes in northwestern Nevada

    USGS Publications Warehouse

    Berger, D.L.

    1992-01-01

    Most water-resource investigations in semiarid basins of the Great Basin in western North America conclude that ground-water recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground-water recharge. The potential for this previously undocumented recharge was investigated in an area covered by sand dunes in Desert Valley, northwestern Nevada, using a deep percolation model. The model uses daily measurements of precipitation and temperature to determine energy and moisture balance, from which estimates of long-term mean annual recharge are made. For the study area, the model calculated a mean annual recharge rate of as much as 1.3 inches per year, or 17 percent of the long-term mean precipitation. Model simulations also indicate that recharge would be virtually zero if the study area were covered by vegetation rather than dunes.

  2. 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.

  3. The Silurian salt deposits in eastern Lake, northwestern Ashtabula, and northeastern Geauga Counties, Ohio

    USGS Publications Warehouse

    Norris, Stanley Eugene

    1979-01-01

    Five salt zones, comprising single or multiple salt beds interbedded with dolomite, dolomititc shale and anhydrite, occur in a 250-square-mile area in eastern Lake, northwestern Ashtabula, and northeastern Geauga Counties, Ohio. The aggregate thickness of salt-bearing rocks, from the base of the lowest salt to the top of the highest salt, ranges from about 300 feet in the northern part of the area to more than 450 feet in the southern part. The aggregate thickness of salt, exclusive of the intervening rocks, also increases southward, from about 100 feet to more than 200 feet. The thickest salt bed, the F1A salt, is 35 to 38 feet thick in the northeastern Geauga and southeatern Lake Counties.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  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. Net primary productivity (NPP) of a biological soil crust (BSC) in northwestern Queensland, Australia.

    NASA Astrophysics Data System (ADS)

    Bdel, B.; Reichenberger, H.; Williams, W.

    2012-04-01

    In the tropical savanna of northwestern Queensland, BSCs are mainly composed of cyanobacteria, liverworts and more rarely, lichens. These BSCs cover up to 30% of the soil, thus stabilizing the soil surface against erosion. One of the major BSC types there is almost completely formed by the filamentous cyanobacterium Symplocastrum sp., with scattered occurrence of different species of the liverwort genus Riccia. Because of the local dominance of these crust type, we selected it for the determination of its NPP over a period of 18 months by setting up a semi-continuous and semi-automatic CO2 - gas exchange measuring device in the natural environment at Boodjamulla National Park. We found astonishingly high CO2-fixation rates of the Sympolcastrum sp. dominated crust type and also could show the crust was adapted to extremely high temperatures (47C), at which time considerable positive net photosynthetic rates were still gained.

  11. Phylogeography of the finless porpoise (genus Neophocaena): testing the stepwise divergence hypothesis in the northwestern Pacific.

    PubMed

    Lin, Wenzhi; Frre, Cline 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

  12. Determination of the trophic situation in Gheshlagh reservoir (North-Western Iran).

    PubMed

    Rezaei, Fariba; Zadeh, Hamed Ghader; Van Damme, Patrick

    2012-01-01

    'Trophic state' is often used to classify aquatic ecosystems according to biotic productivity. Carlson trophic state indices were used to assess the trophic situation in Gheshlagh reservoir (North-Western Iran), on which a dam was constructed three decades ago. Using data from a one-year surface sampling, a comparison of the trophic state index (TSI), between four sampling points in the reservoir and one sampling point under the dam, was performed. The results of the TSI calculated based on chlorophyll a (chl. a) concentration and Secchi depth showed that the aquatic environment in the reservoir is eutrophied (50 < TSI < 80), while it is mesotrophic (40 < TSI < 50) under the dam. Moreover, the measured concentrations of chl. a and phosphate were consistent with the available data ranges on eutrophication. In addition, it was shown that algal biomass bloom occurred at the end of spring, all over the sampling points. PMID:22629625

  13. 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.

  14. Use of domesticated pigs by Mesolithic hunter-gatherers in northwestern Europe

    PubMed Central

    Krause-Kyora, Ben; Makarewicz, Cheryl; Evin, Allowen; Flink, Linus Girdland; Dobney, Keith; Larson, Greger; Hartz, Snke; Schreiber, Stefan; von Carnap-Bornheim, Claus; von Wurmb-Schwark, Nicole; Nebel, Almut

    2013-01-01

    Mesolithic populations throughout Europe used diverse resource exploitation strategies that focused heavily on collecting and hunting wild prey. Between 5500 and 4200 cal BC, agriculturalists migrated into northwestern Europe bringing a suite of Neolithic technologies including domesticated animals. Here we investigate to what extent Mesolithic Erteblle communities in northern Germany had access to domestic pigs, possibly through contact with neighbouring Neolithic agricultural groups. We employ a multidisciplinary approach, applying sequencing of ancient mitochondrial and nuclear DNA (coat colour-coding gene MC1R) as well as traditional and geometric morphometric (molar size and shape) analyses in Sus specimens from 17 Neolithic and Erteblle sites. Our data from 63 ancient pig specimens show that Erteblle hunter-gatherers acquired domestic pigs of varying size and coat colour that had both Near Eastern and European mitochondrial DNA ancestry. Our results also reveal that domestic pigs were present in the region ~500 years earlier than previously demonstrated. PMID:23982268

  15. Organochlorine pesticides in cow's milk from agricultural region in Northwestern Spain

    SciTech Connect

    La Riva, C. de ); Anadon, A. )

    1991-04-01

    During the past 30 years, the variety and usage of pesticides have increased in Spain and worldwide. Agricultural use of pesticides can be expected to result in residues in or food and feed. Several limited monitoring programs have received an extensive investigation in order to detect residues from organochlorine compounds in milk. This paper reports the findings of a pesticide residue study in cow's milk samples examined during the time period of one year between May of 1987 and March of 1988. The cow's milk samples destined to human consumption were collected from an agrarian area located at a geographic region of northwestern Spain. Analyses were conducted for DDT complex DDT{sub s}, DDD, DDE and isomers alpha, beta and gamma (lindane), aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, alpha- and beta-endosulfan, metoxichlor and mirex.

  16. 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

  17. 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

  18. 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

  19. 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 3cycle/yr variability that is coherent with wind and surface pressure over a broad region north of Tern. PMID:26578295

  20. 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

  1. Eriophyoid mites from Qinghai Province, northwestern China with descriptions of nine new species (Acari,Eriophyoidea)

    PubMed Central

    Li, Hao-Sen; Xue, Xiao-Feng; Hong, Xiao-Yue

    2012-01-01

    Abstract Eriophyoid mites from Qinghai Province, northwestern China were studied herein. Up to now, only six species have been reported from Qinghai Province. In field surveys, 17 eriophyoid mite species were collected, among which nine species were found new to science. The new species and their host plants are listed as follows: Acaphyllisa tuberculumae sp. n. on Populus sp. (Salicaceae); Proiectus xiningensis sp. n. on Pinus sp. (Pinaceae); Phyllocoptes beishaniensis sp. n. on Spiraea mongolica Maxim. (Rosaceae); Tetra pruniana sp. n. on Prunus tomentosa Thunb. (Rosaceae) Rupr. (Berberidaceae); Tetra pyriana sp. n. on Pyrus calleryana Decne. (Rosaceae); Tetra simonia sp. n. on Populus simonii Carr. (Salicaceae); Diptacus berberinus sp. n. on Berberis amurensis Rupr. (Berberidaceae); Diptacus mengdaensis sp. n. on Lonicera elisae Franch. (Caprifoliaceae); Rhyncaphytoptus spinus sp. n. on Lonicera rupicola Hook. f. et Thoms. (Caprifoliaceae). Aculops ulmi Hong & Xue, 2005 was re-described. PMID:22679390

  2. 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.

  3. Prevalence of Anaplasma phagocytophilum in ruminants, rodents and ticks in Gansu, north-western China.

    PubMed

    Yang, Jifei; Liu, Zhijie; Guan, Guiquan; Liu, Qing; Li, Youquan; Chen, Ze; Ma, Miling; Liu, Aihong; Ren, Qiaoyun; Luo, Jianxun; Yin, Hong

    2013-02-01

    The zoonotic rickettsial pathogen Anaplasma phagocytophilum has a broad geographical distribution and a high degree of biological and clinical diversity. To determine the prevalence of Anaplasma phagocytophilum in the Gannan Tibetan Autonomous Prefecture of Gansu Province, north-western China, four ruminant species, one rodent and one tick species were examined for Anaplasma phagocytophilum infection. DNA from Anaplasma phagocytophilum was detected by nested PCR in blood samples from 21/49 sheep (42.9?%), 35/91 goats (38.5?%), 51/158 yaks (32.3?%) and 7/20 cattle-yaks (35.0?%), and in spleen samples from 2/12 rodents (16.7?%). For samples from tick larvae and nymphs, 105 pools were tested; one of 46 larval tick pools was positive and seven of 59 nymphal tick pools were positive. For adult ticks, 40/598 female ticks (6.7?%) and 26/528 male ticks (4.9?%) were positive. The prevalence of Anaplasma phagocytophilum in female ticks was higher than that in males, although the difference was not statistically significant (P>0.05). Sequences analysis based on the 16S rRNA gene indicated that the strains in the study area were distinct from previously reported Anaplasma phagocytophilum in other continents. These results add new information on the epidemiology of Anaplasma phagocytophilum and indicate the tick-animal cycle of anaplasmosis in the area. To the best of our knowledge, this is the first report of Anaplasma phagocytophilum infection in Gansu Province in north-western China. PMID:23105025

  4. 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.

  5. Heavy metals in potable groundwater of mining-affected river catchments, northwestern Romania.

    PubMed

    Bird, Graham; Macklin, Mark G; Brewer, Paul A; Zaharia, Sorin; Balteanu, Dan; Driga, Basarab; Serban, Mihaela

    2009-12-01

    Groundwater, accessed using wells and municipal springs, represents the major source of potable water for the human population outside of major urban areas in northwestern Romania, a region with a long history of metal mining and metallurgy. The magnitude and spatial distribution of metal contamination in private-supply groundwater was investigated in four mining-affected river catchments in Maramure? and Satu Mare Counties through the collection of 144 groundwater samples. Bedrock geology, pH and Eh were found to be important controls on the solubility of metals in groundwater. Peak metal concentrations were found to occur in the Lapu? catchment, where metal levels exceed Dutch target and intervention values in up to 49% and 14% of samples, respectively. A 700 m wide corridor in the Lapu? catchment on either side of the main river channel was identified in which peak Cd (31 ?g l(-1)), Cu (50 ?g l(-1)), Pb (50 ?g l(-1)) and Zn (3,000 ?g l(-1)) concentrations were found to occur. Given the generally similar bedrock geologies, lower metal levels in other catchments are believed to reflect differences in the magnitude of metal loading to the local environment from both metal mining and other industrial and municipal sources. Sampling of groundwater in northwestern Romania has indicated areas of potential concern for human health, where heavy metal concentrations exceed accepted environmental quality guidelines. The presence of elevated metal levels in groundwater also has implications for the implementation of the EU Water Framework Directive (WFD) and achieving 'good' status for groundwater in this part of the Danube River Basin District (RBD). PMID:19301128

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Transmission cycles of Borrelia burgdorferi and B. bissettii in relation to habitat type in northwestern California

    PubMed Central

    Eisen, Lars; Eisen, Rebecca J.; Mun, Jeomhee; Salkeld, Daniel J.; Lane, Robert S.

    2008-01-01

    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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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 ?18O and ?17O 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.

  1. Use of environmental isotopes and hydrochemistry as indicators for the origin of groundwater resources in El Dabaa area, northwestern coastal zone of Egypt.

    PubMed

    Awad, M A; Hammad, F A; Aly, A I; Sadek, M A

    1994-03-01

    The EI-Dabaa area is located on the northwestern coastal zone of Egypt and is considered to be one of the most important regions for land reclamation and agriculture. In addition, it has been selected as a potential site for constructing Egypt's first nuclear power plant.In April 1989, 14 groundwater samples were collected from the area as well as collecting samples from the Mediterranean sea and from local rainwater. These samples were subjected to chemical and environmental isotope analyses. The results of the analyses for stable isotopes (oxygen-18 and deuterium) indicate that the main recharge source of the groundwater in El-Dabaa is the local precipitation during the rainy season. Variation of the environmental tritium content as well as in the chemical composition of both major cations (Na,K,Ca,Mg) and major anions (Cl,SO4,HCO3) between different groundwaters in the studied area reflect the high degree of inhomogeneity of the aquifer and different recharging conditions due to permeability of the water bearing formation.The chemical water type of the El-Dabaa groundwater is sodium sulphate (Na2SO4) and the SAR values illustrate the suitability of these groundwaters for agricultural purposes. PMID:24198175

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Studies of the Permian Phosphoria Formation and related rocks, Great Basin-Rocky Mountain region

    USGS Publications Warehouse

    Wardlaw, Bruce R.

    1979-01-01

    PART A: The transgression of the Permian Retort Phosphatic Shale Member of the Phosphoria Formation is dated by the occurrence of diagnostic brachiopods. The complex pattern of this transgression reflects the paleogeography and indicates two initial basins of deposition: one in southwestern Montana and one in southeastern Idaho. PART B: A new formation is proposed for middle Permian rocks of a transitional facies positioned laterally between the Rex Chert Member of the Phosphoria Formation in northeastern Utah and southeastern Idaho and the Plympton Formation in northeastern Nevada and northwestern Utah. PART C: The relationships of the Permian Park City Group to the Phosphoria and Park City Formations are clarified by the stratigraphy of four sections in northwestern Utah, northeastern Nevada, and southern Idaho. PART D: Five biostratigraphic zones based on the distribution of brachiopods and conodonts are proposed for the Park City Group. They are: the Peniculauris ivesi-Neostreptognathodus prayi Zone, the Peniculauris bassi-Neostreptognathodus sulcoplicatus Zone, the Peniculauris bassi-Neostreptognathodus sp. C Zone, the Thamnosia depressa Zone, and the Yakovlevia. multistriata-Neogondolella bitteri Zone. They range in age from Leonardian to Wordian.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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 Gnyz pluton, Northwest Anatolia, Turkey. International Geology Review, 50, 931-947. Ozgenc I. and Ilbeyli, N. 2008. Petrogenesis of the Late Cenozoic Egrigz 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Secondary salinization and evapotranspiration under mulched drip irrigation condition in Tarim River basin of northwestern China

    NASA Astrophysics Data System (ADS)

    Tian, Fuqiang; Hu, Hongchang; Zhang, Zhi; Hu, Heping

    2013-04-01

    The secondary salinization induced by irrigation has been presented as a crucial threat to agriculture all over the world, especially in semi-arid and arid regions. Mulched drip irrigation (MDI), as a new micro-irrigation approach incorporating surface drip irrigation method and film mulching technique, has been widely applied in water scarce regions including Tarim River basin of northwestern China. However, salts are likely to build up in the surface soil due to the deficient leaching water in such an irrigation condition. To explore this new kind of secondary salinization issue, the oasis eco-hydrology experimental research station were established in 2008 in a cotton field of Xinjiang, northwestern China. More than 40,000 soil samples were collected to monitor soil moisture and salinity condition within the 1.5 meter depth. The patterns of soil salinity distribution under MDI along the horizontal direction as well as vertical direction have been explored. The results did show that secondary salinization tends to occur in the experimental field under mulched drip irrigation, and winter flush could leach most soil salt in the root zone into groundwater and keep salt balance to mitigate the soil salinization. Meanwhile, soil salt always migrates with the soil water flux such as irrigation and groundwater recharge. Therefore the understanding of water balance is of great importance for estimating soil salinity accumulation, of which evapotranspiration (ET) is the key process, especially in the semi-arid and arid area. In our study, in order to quantify the relation between salinity balance and water balance, ET were derived from a range of measurement systems including eddy covariance, soil water budget (gravimetric methods, Hydra probe, TDT probe and groundwater table sensor, et al.), sap flow and portable photosynthetic system during cotton growing period. Our study is unique in its focus on ET scale issue ranging from leaf and plant scale to field. The up-scale methods of ET from point measurement to field average status are developed and verified. The characteristics of ET under mulched drip irrigation are analyzed over varied spatial scales.

  1. 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.

  2. 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 4.7610(-6) (95% CI=7.2510(-8) 1.9210(-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 2.7310(6) animals (90% CI=10,674-5.910(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

  3. Morphology of sea ice pressure ridges in the northwestern Weddell Sea in winter

    NASA Astrophysics Data System (ADS)

    Tan, Bing; Li, Zhi-Jun; Lu, Peng; Haas, Christian; Nicolaus, Marcel

    2012-06-01

    To investigate the morphology and distribution of pressure ridges in the northwestern Weddell Sea, ice surface elevation profiles were measured by a helicopter-borne laser altimeter during Winter Weddell Outflow Study with the German R/V Polarstern in 2006. An optimal cutoff height of 0.62 m, derived from the best fits between the measured and theoretical ridge height and spacing distributions, was first used to separate pressure ridges from other sea ice surface undulations. It was found that the measured ridge height distribution was well modeled by a negative exponential function, and the ridge spacing distribution by a lognormal function. Next, based on the ridging intensity Ri (the ratio of mean ridge sail height to mean spacing), all profiles were clustered into three regimes by an improved k-means clustering algorithm: Ri ? 0.01, 0.01 < Ri ? 0.026, and Ri > 0.026 (denoted as C1, C2, and C3 respectively). Mean (and standard deviation) of sail height was 0.99 (0.07) m in Regime C1, 1.12 (0.06) m in C2, and 1.17 (0.04) m in C3, respectively, while the mean spacings (and standard deviations) were 232 (240) m, 54 (20) m, and 31 (5.6) m. These three ice regimes coincided closely with distinct sea ice regions identified in a satellite radar image, where C1 corresponded to the broken ice in the marginal ice zone and level ice formed in the Larsen Polynya, C2 corresponded to the deformed first- and second-year ice formed by dynamic action in the center of the study region, and C3 corresponded to heavily deformed ice in the outflowing branch of the Weddell Gyre. The results of our analysis showed that the relationship between the mean ridge height and frequency was well modeled by a logarithmic function with a correlation coefficient of 0.8, although such correlation was weaker when considering each regime individually. The measured ridge height and frequency were both greater than those reported by others for the Ross Sea. Compared with reported values for other parts of the Antarctic, the present ridge heights were greater, but the ridge frequencies and ridging intensities were smaller than the most extreme of them. Meanwhile, average thickness of ridged ice in our study region was significantly larger than that of the Coastal Ross Sea showing the importance of deformation and ice age for ice conditions in the northwestern Weddell Sea.

  4. Assessment of chlorophyll variability along the northwestern coast of Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Picado, A.; Alvarez, I.; Vaz, N.; Varela, R.; Gomez-Gesteira, M.; Dias, J. M.

    2014-10-01

    The northwestern coast of the Iberian Peninsula is characterized by a high primary production mainly supported by coastal upwelling, creating an extraordinary commercial interest for fisheries and aquaculture. Considering chlorophyll-a (Chl-a) as an indicator of primary production, its spatio-temporal variability was researched in this study in the surface water of this upwelling region from 1998 to 2007. Satellite derived Chl-a, Sea Surface Temperature (SST) and Ekman transport data as well as the inflow of the main rivers discharging into the study area were used to investigate the origin of the Chl-a concentration. Empirical Orthogonal Function (EOF) analysis of weekly Chl-a images was performed, as well as correlation analysis between Chl-a concentration, Ekman transport and river discharge. EOF results suggest that the highest Chl-a concentration occurs near the coast up to 60 km offshore. The interannual variability of Chl-a, SST and Ekman transport was also studied considering summer and winter months. Generally, 2005, 2006 and 2007 were the most productive years during the summer months with high Chl-a concentrations along the coast associated to the strong upwelling conditions observed. Otherwise, 1998 seemed to be the most productive year during winter. The absence of upwelling favorable conditions together with localized low SST and considerable discharges, suggests that the high Chl-a concentrations observed during this period are mainly due to the entrance of nutrients through river runoff. However, in winter, high concentrations of colored dissolved organic matter (CDOM), associated with river runoff, are present in the ocean surface, leading to an erroneous strong signal of the satellite. During winter correlations of 0.58 and 0.49 were found between Chl-a concentration and Douro and Minho discharges, respectively, evidencing that high Chl-a concentration was related with river runoff. Otherwise, during summer, Chl-a and Ekman transport exhibited a correlation of - 0.38 indicating that high Chl-a is associated to upwelling events. In summary, it was found that the spatio-temporal variability of Chl-a along the northwestern coast of Iberian Peninsula exhibited the clear influence of upwelling events during summer. Conversely, the variability during winter was mainly due to entrance of nutrients through the rivers discharge which flow into the area.

  5. Stable isotopic compositions of carbonates from the Mesoproterozoic Bangemall Group, northwestern Australia

    NASA Technical Reports Server (NTRS)

    Buick, R.; Des Marais, D. J.; Knoll, A. H.

    1995-01-01

    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 limestones to dolomitic shales). The only major excursions from the norm seem related to unusual environmental or post-depositional processes, as they are correlated with large enrichments (to -3%) or depletions (to -16%) in 18O. Relatively heavy delta 13C-values, up to +2.5%, occur in a single bed of brecciated ferruginous dolostone at a single locality; these abnormal values may result from local evaporitic conditions. Limey and shaley nodular dolostones have delta 13C-values as low as -4.3%, probably caused by remineralization of organic matter during late and patchy dolomitization. Most notably, sharp negative excursions in delta 13C, up to -8.4%, occur in bleached kerogen-free rocks with mineral assemblages of dolomite + quartz + calcite +/- tremolite + talc, reflecting isotopic re-equilibration in thick metamorphic aureoles around dolerite intrusions. General environmental variations are minor, with delta 13C-values of peritidal facies tending to be slightly positive whereas those of subtidal facies are slightly negative. There are no strong secular trends, but subtle fluctuations within the range -2 to +l% can be correlated along the northwestern margin of the basin. This resembles the pattern seen in other Mesoproterozoic successions, but is markedly unlike the heavy background (> +5%) and extreme variations (up to l0%) in delta 13C evident in Neoproterozoic successions of similar thickness and environmental setting. Hence, in contrast to the Neoproterozoic, the global rate of organic carbon burial was probably fairly constant during deposition of the Bangemall Group, and perhaps generally during the Mesoproterozoic, as was the redox state of the atmosphere and hydrosphere.

  6. Thermal supplementing soil nutrients through biocomposting of night-soil in the northwestern Indian Himalaya.

    PubMed

    Oinam, Santaram S; Rawat, Yashwant S; Kuniyal, Jagdish C; Vishvakarma, S C R; Pandey, Dinesh C

    2008-01-01

    Agriculture is one of the prime activities of the hill people residing in the northwestern Indian Himalaya. However, poor soil fertility in these areas is a big hurdle to sustainable farming. The effects of washout of topsoil and its nutrients, year after year, due to the abundance of snowfall, avalanches, landslides and erosion further add to the woes of the farmers. In the cold and harsh climatic conditions of the region, with grass and vegetation cover being scanty, it is not possible to maintain large herds of cattle for the adequate production of farmyard manure. Faced with this situation, the locals have relied heavily on obtaining organic manure derived from composting of human excreta. In earlier times the dire necessity of the farmers helped them overcome the revulsion associated with the practice of handling human excreta, but now with the advent of modernisation and the easy availability of chemical fertilisers, the people are distancing themselves from this age-old practice. More and more people are opting for modern toilets and leaving behind the traditional toilets that made possible the harvesting of manure from night-soil. As a result, this primitive practice is on the verge of extinction. This eco-friendly practice, that has sustained the land for so many generations, needs to be continued and strengthened as the long-term consequences of excessive and indiscriminant use of chemical fertilisers are becoming too obvious to ignore. Traditional knowledge needs to be combined with modern scientific know-how to make this practice safer and more acceptable. If the composting operation is managed properly, the handling will be less loathsome and the concerns of health and hygiene too will stand addressed. The present study attempts a detailed profile of the practice of 'supplementing soil nutrients through biocomposting of night-soil' in the cold desert region of Lahaul Valley. Four villages running from the northwestern part to the southeastern part of the valley were selected. The study is broadly based on a direct interview of heads of the various households in the selected villages of Kuthar (2600m), Hinsa (2700m), Jahlma (3000m) and Khoksar (3200m). PMID:17490873

  7. Temporal and spatial variation of 10-day mean air temperature in Northwestern China

    NASA Astrophysics Data System (ADS)

    Li, Xuemei; Li, Lanhai; Yuan, Shanlin; Yan, Haowen; Wang, Guigang

    2015-01-01

    Both inter- and intra-annual changes in air temperature are impacted by global climate change. Sine curves, such as T = Asin(? t + ?), adjust the 10-day mean air temperature T contributed by the corresponding number of 10-day t within a year. Based on the curve, relative indices were defined as follows: A, indicating the annual maximum 10-day air temperature; t LIP(0) and t RIP(0), representing the starting and ending time of the warm season; t LIP(10) and t RIP(10), indicating the starting and ending time of the growing season; l ws and l gs , denoting the length of the warm and growing seasons. The objective of this study was to evaluate the inter- and intra-annual distribution characteristics of the 10-day mean air temperature and the associated spatial patterns, changing trends, and abrupt points in 128 meteorological stations across Northwestern China during 1961 to 2010 by using the selected indices. The results showed that the 2010s had the fastest increase in air temperature during the study period across the study area. Altitude was an important factor affecting the selected indices. Annual mean air temperature ( T mean ) and A were high in low-altitude areas, where the warm and growing season came earlier and ended later, and vice versa. The values of T mean and A had increased by 1.65 and 0.65 C during the past 50 years, respectively. The warm and growing season had come earlier by 9 and 7.5 days and ended later by 7.5 and 6 days during the past 50 years, respectively. Therefore, the warm season has gotten longer by 16 days and the growing season by 14 days in the study area during the past 50 years. The abrupt increase of T mean , A, t LIP(0), t RIP(0), t LIP(10), t RIP(10), l ws , and l gs detected at the 0.05 significance level took place in the late 1960s and that of A occurred in the late 1980s. The inter- and intra-annual distribution of air temperature in Northwestern China has changed during the last five decades, and it is reasonable to expect those changes to continue for a period under global climate change.

  8. 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, Herv

    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 0.03C) 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).

  9. 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.

  10. Bacterioplankton and phytoplankton biomass and production during summer stratification in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Pedrs-Ali, Carlos; Caldern-Paz, Juan-Isidro; Guixa-Boixereu, Nria; Estrada, Marta; Gasol, Josep M.

    1999-06-01

    We examined bacterioplankton biomass and heterotrophic production (BHP) during summer stratification in the northwestern Mediterranean in four successive stratification seasons (June-July of 1993-1996). Values of phytoplankton biomass and primary production were determined simultaneously so that the data sets for autotrophic and heterotrophic microbial plankton could be compared. Three standard stations were set along a transect from Barcelona to the channel between Mallorca and Menorca, representing coastally influenced shelf waters, frontal waters over the slope front, and open sea waters. Conversion factors from 3H-leucine incorporation to BHP were empirically determined and varied between 0.29 and 3.25 kg C mol -1. Bacterial biomass values were among the lowest found in any marine environment. BHP values (between 0.02 and 2.5 ?g C L -1 d -1) were larger than those of low nutrient low chlorophyll areas such as the Sargasso Sea and lower than those from high nutrient low chlorophyll areas such as the equatorial Pacific. Growth rates of bacterioplankton were highest at the slope front (0.20 d -1) and lowest at the open sea station (0.04 d -1). Phytoplankton growth rates were similar at the three stations (0.50 d -1). Integrated values of bacterioplankton biomass, BHP and bacterial growth rates did not show significant differences among years, but differences between the three stations were clearly significant. Phytoplankton biomass, primary production, and phytoplankton growth rates did not show significant differences either with year or with station. As a consequence the bacterioplankton to phytoplankton biomass (BB/BPHY) and production (BHP/PP) ratios varied from the coastal to the open sea stations. The BB/BPHY ratio was 0.98 at the coast and 0.70 at the other two stations. These ratios are similar to those found in other oligotrophic marine environments. The BHP/PP ratio was 0.83 at the coast, 0.36 at the slope and 0.09 at the open sea station. The last value is also similar to values found in other oligotrophic marine environments. Vertical distribution of these ratios was also examined. The comparison of microbial parameters at the three stations indicates a different kind of relationship between bacterioplankton and phytoplankton in oligotrophic open sea waters and in coastal, nutrient-richer waters. According to such parameters and to the values of the BB/BPHY and BHP/PP ratios, open waters in the northwestern Mediterranean (despite their relatively short distance from the shore) were intermediate between the extremely oligotrophic waters of the eastern Mediterranean or the Sargasso Sea and the more productive waters of the equatorial Pacific.

  11. 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 limestones to dolomitic shales). The only major excursions from the norm seem related to unusual environmental or post-depositional processes, as they are correlated with large enrichments (to -3%) or depletions (to -16%) in 18O. Relatively heavy delta 13C-values, up to +2.5%, occur in a single bed of brecciated ferruginous dolostone at a single locality; these abnormal values may result from local evaporitic conditions. Limey and shaley nodular dolostones have delta 13C-values as low as -4.3%, probably caused by remineralization of organic matter during late and patchy dolomitization. Most notably, sharp negative excursions in delta 13C, up to -8.4%, occur in bleached kerogen-free rocks with mineral assemblages of dolomite + quartz + calcite +/- tremolite + talc, reflecting isotopic re-equilibration in thick metamorphic aureoles around dolerite intrusions. General environmental variations are minor, with delta 13C-values of peritidal facies tending to be slightly positive whereas those of subtidal facies are slightly negative. There are no strong secular trends, but subtle fluctuations within the range -2 to +l% can be correlated along the northwestern margin of the basin. This resembles the pattern seen in other Mesoproterozoic successions, but is markedly unlike the heavy background (> +5%) and extreme variations (up to l0%) in delta 13C evident in Neoproterozoic successions of similar thickness and environmental setting. Hence, in contrast to the Neoproterozoic, the global rate of organic carbon burial was probably fairly constant during deposition of the Bangemall Group, and perhaps generally during the Mesoproterozoic, as was the redox state of the atmosphere and hydrosphere. PMID:11540130

  12. 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.

  13. Annual burned area across a precipitation gradient in northwestern patagonia steppe

    NASA Astrophysics Data System (ADS)

    Oddi, Facundo; Ghermandi, Luciana; Lasaponara, Rosa

    2013-04-01

    Fire is one of the most important disturbances on the Earth affecting most terrestrial ecosystems. Evidence suggests that since the last glaciations there has been a substantial interaction among climate, vegetation and fire. In fact fire is recognized as an emergent property of climate and vegetation type, which determine that distinct regions are differently affected by wildfires. For instance, it has been suggest that relative roles of weather/climate and fuel on fire activity change along the global productivity/aridity (intermediate fire-productivity hypothesis). At one extreme of the gradient we find dry-unproductive regions (deserts) where fire is absent owing to very low fuel loads, while at the other extreme we have wet-productive environments (rain forest) with fire being unlikely due to high fuel moisture. Environments located around middle of the gradient, such as Mediterranean ecosystems, have a high fire activity but is difficult to predict if the fuel moisture conditions are a stronger constrain on the fire regime or it is constrained by biomass production (i.e. fuel load). The intermediate fire-productivity hypothesis has been tested in recent works at global scale. However, data resolution at global scale is coarse and thus is not possible know the fire variability occurring at scales of more spatial detail. Therefore, it is necessary to complement the information obtained at global scale with studies at finer scales exploring fire-productivity/aridity relationships in particular portions of the gradient. We elaborate fire cartography from Landsat temporal series (1973-2011) for a portion (560250 ha - regional scale) of northwestern Patagonian steppe. The study zone corresponds to a Mediterranean environment and is part of a gradient defined by a sharp drop in the precipitation regime (600mm to 280mm). This environmental gradient predisposes a change in fuel load and fuel moisture and therefore could be affecting the fire regime. We divided the study area in relation to precipitation gradient establishing two zones (wet and xeric). To delimit area of wildfires on Landsat scenes we used the NBR index. Then, we calculated the annual burned area in each zone, compared the annual burned area between zones and also explored relationships between that variable of the fire regime and precipitation/temperature data. We expect to contribute to the discussions about the importance of drought/fuel on the fire activity across the productivity/aridity gradient, specifically on Mediterranean environments. Finally, with this work we expect to improve future management and conservation practices in Northwestern Patagonia grasslands.

  14. 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.

  15. 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 ? 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.

  16. Clinical and epidemiological features of leishmaniasis in northwestern-Argentina through a retrospective analysis of recent cases.

    PubMed

    Garca Bustos, Mara F; Gonzlez-Prieto, Gabriela; Ramos, Federico; Mora, Mara C; Hashiguchi, Yoshihisa; Parodi, Cecilia; Basombro, Miguel A; Moreno, Sonia; Monroig, Sibila; Beckar, Josefina; Jaime, Daniela; Sajama, Jess; 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

  17. 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.

  18. 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