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  1. Rifting Thick Lithosphere - Canning Basin, Western Australia

    Science.gov (United States)

    Czarnota, Karol; White, Nicky

    2016-04-01

    The subsidence histories and architecture of most, but not all, rift basins are elegantly explained by extension of ~120 km thick lithosphere followed by thermal re-thickening of the lithospheric mantle to its pre-rift thickness. Although this well-established model underpins most basin analysis, it is unclear whether the model explains the subsidence of rift basins developed over substantially thick lithosphere (as imaged by seismic tomography beneath substantial portions of the continents). The Canning Basin of Western Australia is an example where a rift basin putatively overlies lithosphere ≥180 km thick, imaged using shear wave tomography. Subsidence modelling in this study shows that the entire subsidence history of the Canning Basin is adequately explained by mild Ordovician extension (β≈1.2) of ~120 km thick lithosphere followed by post-rift thermal subsidence. This is consistent with the established model, described above, albeit with perturbations due to transient dynamic topography support which are expressed as basin-wide unconformities. In contrast the Canning Basin reveals an almost continuous period of normal faulting between the Ordovician and Carboniferous (βCanning Basin to rifting of thick lithosphere beneath the eastern part, verified by the presence of ~20 Ma diamond-bearing lamproites intruded into the basin depocentre. In order to account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted in density by 50-70 kg m-3, which is in line with estimates derived from modelling rare-earth element concentrations of the ~20 Ma lamproites and global isostatic considerations. Together, these results suggest that thick lithosphere thinned to > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. Our results show that variations in lithospheric thickness place a fundamental control on basin architecture

  2. Upper Devonian microvertebrates from the Canning Basin, Western Australia

    Science.gov (United States)

    Roelofs, Brett; Playton, Ted; Barham, Milo; Trinajstic, Kate

    2015-03-01

    A diverse microvertebrate fauna is described from the Virgin Hills and Napier formations, Bugle Gap Limestone Canning Basin, Western Australia. Measured sections at Horse Spring and Casey Falls (Virgin Hills Formation) and South Oscar Range (Napier Formation) comprise proximal to distal slope carbonates ranging in age from the Late Devonian Frasnian to middle Famennian. A total of 18 chondrichthyan taxa are identified based on teeth, including the first record of Thrinacodus tranquillus, Cladoides wildungensis, Protacrodus serra and Lissodus lusavorichi from the Canning Basin. A new species, Diademodus dominicus sp. nov. is also described and provides the first record of this genus outside of Laurussia. In addition, the upper range of Australolepis seddoni has been extended to Late Devonian conodont Zone 11, making it the youngest known occurrence for this species. The Virgin Hills and Napier formations microvertebrate faunas show close affinities to faunas recovered from other areas of Gondwana, including eastern Australia, Iran, Morocco and South China, which is consistent with known conodont and trilobite faunas of the same age.

  3. Paleomagnetic Study of the Devonian Reef Complexes of the Canning Basin, Western Australia

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    Yan, M.; Tohver, E.; Cawood, P. A.; Kirschvink, J.; Peek, S.; Playton, T.; Hocking, R.; Haines, P.; Montgomery, P.

    2008-12-01

    The reef systems in the Canning Basin, Western Australia perhaps are the best exposed and least deformed examples of ancient reef systems known in the world. The recently commenced multi-disciplinary research project in the Devonian reef complex of the Canning Basin is a broad investigation of the depositional history of a carbonate platform using paleomagnetic, stable isotope geochemistry (inorganic and organic), sedimentology, and biostratigraphy. By focusing on the world-class exposures in the Canning Basin, this project seeks to provide a global stratigraphic reference frame for key intervals in life history such as the Frasnian-Fammenian mass extinction event, as well as providing a useful analogue for resource models of other carbonate reef systems elsewhere in the world. This reference frame will consist of a high resolution magnetostratigraphic profile to supplement the presently-sparse Global Polarity Timescale (GPTS) for the Devonian, as well as a chemostratigraphic profile (chiefly carbon isotopes) to identify possible shifts in the global carbon budget associated with biotic crises and/or climate change. Additional goals include identification of the conditions leading up to, and possible causes of the mass extinction event, and testing for a possible mid-Paleozoic episode of True Polar Wander. We report here on a paleomagnetic study of two magnetostratigraphic sections in the Canning Basin to address the goals mentioned above. Paleomagnetic samples have been drilled on the Late Frasnian limestones in the north of the Windjana Gorge National Park, with a total number of 400 core samples. So far preliminary paleomagnetic analysis on pilot samples reveals two characteristic remanent components. One component has a blocking temperatures less than 400 degree Celsius, probably a component of secondary overprint; another component has a blocking temperature around 580 and around 680 degree Celsius, indicating the presence of magnetite and hematite

  4. Famennian mud-mounds in the proximal fore-reef slope, Canning Basin, Western Australia

    Science.gov (United States)

    Webb, Gregory E.

    2001-12-01

    Famennian (Late Devonian) carbonate buildups and, in particular, mud-mounds, are poorly known, in general, and few have been documented in detail. Relatively small Famennian mud-mounds occur in proximal fore-reef slope settings in the Canning Basin, Western Australia. The Famennian platform margin facies passes from typical shoaling carbonate facies in the back reef, through massive, calcimicrobial, cement-rich reef-margin facies, to relatively steeply dipping (20-30°), well-bedded fore-reef slope facies containing shelf-derived, winnowed grainy sediments and extremely coarse reef-block debris. Isolated or coalescing mounds occur in the proximal slope, immediately adjacent to and, in some cases, possibly grading into the margin facies. Mounds are elongate perpendicular to the margin and some had synoptic relief greater than 2 m. Mounds are lithologically variable and consist of varying proportions of micrite, multiple generations of marine cement, abundant Rothpletzella, Renalcis, poorly preserved sparry microbial crusts and sporadically distributed laminar stromatoporoids. Surrounding grainy slope facies abut and slope off of mound flanks. Mound facies are very similar to nearby reef-margin facies, with the exceptions that stromatoporoids have not been observed in margin facies and solenoporoid algae, which occur in the margin, have not been observed in the mounds. Stromatolites are conspicuously absent from both facies. Mound facies appear to be more closely related to Frasnian and Famennian calcimicrobe cement-dominated reef-margin facies than to Famennian deep-water stromatolite-sponge-mound facies, such as those that occur elsewhere in the Canning Basin. The observed Canning Famennian reef and mound frameworks were constructed by communities that appear to be very similar to earlier Frasnian communities, despite the Frasnian-Famennian extinction event, and provide good examples of microbial reef framework construction in a high energy setting.

  5. The Geohydrology of MVT-Ore Genesis in the Canning Basin, Western Australia

    Science.gov (United States)

    Garven, G.; Wallace, M. M.

    2009-05-01

    In the Lennard Shelf, Western Australia, epigenetic MVT-type Pb-Zn mineralization occurs in Middle Devonian evaporitic dolomites which were part of a barrier reef system (Hurley & Lohmann, 1989). Ore mineralization exhibits a strong structural control at the basin scale and normal faults probably controlled pathways for brine and petroleum migration that affected ore deposition (Wallace et al., 1999). For the Canning basin, finite element simulations show that compaction was the most important process for creating overpressures and driving basinal fluids in this thick extensional basin. Basinal fluids are shown to have been driven across the Fitzroy Trough through permeable and deeply buried Silurian-Ordovician aquifer units. The fluids then migrated upwards at rates of m/yr up during periods of episodic extension (Braun, 1992) where fluid flow was channeled by major normal fault zones like the Cadjebut and Pinnacles Faults. Reactive flow simulations test a petroleum-reservoir model for mineralization whereby metal-bearing brines mix with accumulated hydrocarbons (Anderson & Garven, 1987). The results show that compaction-driven flow, as proposed by Beales & Jackson (1966) and Jackson & Beales (1967), works rather well in this ore district--other mechanisms such as sealevel tidal pumping (Cathles, 1988) or topographic drive (Solomon & Groves, 1994) are more tenuous and really unnecessary from a mass transport or geohydrologic basis.

  6. The environmental response of Middle Ordovician large organic walled microfossils from the Goldwyer and Nita Formations, Canning Basin, Western Australia.

    Science.gov (United States)

    Winchester-Seeto, T; Foster, C; O'Leary, T

    2000-12-01

    Middle Ordovician large organic walled microfossils (chitinozoans, scolecodonts, hydrozoans and foraminiferal linings) were recovered from the upper Goldwyer and lower Nita formations, Canning Basin, Western Australia, from three cores (WMC Santalum 1A, Kunzea 1 and Acacia 2). Petrophysical logs of these cores reveal an overall upward shallowing supersequence, overprinted by numerous transgression/regression couplets that can be correlated over 100km.Analysis of the abundance of the microfossils with respect to the gamma log signatures reveals that both chitinozoan abundance and diversity decrease as water depth shallows; however, the opposite is not always true and other factors probably intervene. Scolecodonts show an increase in abundance in transgressions, while hydrozoans and foraminiferal linings show no consistent response to trangressive or regressive phases. Cyathochitina hunderumensis tends to dominate chitinozoan assemblages where there is a transgression, while species of Belonechitina replace Cy. hunderumensis in regressive phases.

  7. Controls on syndepositional fracture patterns, Devonian reef complexes, Canning Basin, Western Australia

    Science.gov (United States)

    Frost, Edmund L., III; Kerans, Charles

    2010-09-01

    Syndepositional fractures are an important feature of high-relief carbonate systems and exert a profound control on many facets of platform evolution and reservoir development. Based on data collected from the Canning Basin's Devonian reef complexes this study characterizes syndepositional fracture patterns as a function of variations in: lithofacies, depositional position, stratigraphic architecture, and mechanical stratigraphy. Fracture parameters, such as extension and fracture intensity, are documented to vary strongly as a function of lithofacies. The highest syndepositional extension values occurring in the microbial facies of the Famennian platform margin, with extension values three times higher than observed in equivalent Frasnian strata. Position along the depositional profile exerts a strong control on fracture patterns, with an approximate two-fold increase in syndepositional extension and fracture intensity typically observed from the platform interior to the platform margin. Syndepositional fracture intensity is shown to vary systematically with changes in platform-margin trajectory, with high fracture intensities observed in strongly progradational platforms and decreased fracture development in aggradational and retrogradational platforms. Evidence for the temporal evolution of the mechanical stratigraphy of the Devonian reef complexes is presented, with early-lithified strata effectively behaving as a single, large-scale (50-150 m) mechanical unit during syndepositional fracture development, while secondary fractures become increasingly affected by bed-scale (0.25-5 m) mechanical heterogeneity introduced by progressive diagenesis. The results presented here potentially provide a tool for predicting fracture characteristics (e.g., intensity, orientation, location, and vertical extent) from limited subsurface data and provide a method for characterizing syndepositional deformation in other systems.

  8. Late Devonian carbonate magnetostratigraphy from the Oscar and Horse Spring Ranges, Lennard Shelf, Canning Basin, Western Australia

    Science.gov (United States)

    Hansma, Jeroen; Tohver, Eric; Yan, Maodu; Trinajstic, Kate; Roelofs, Brett; Peek, Sarah; Slotznick, Sarah P.; Kirschvink, Joseph; Playton, Ted; Haines, Peter; Hocking, Roger

    2015-01-01

    The Late Devonian was a time of major evolutionary change encompassing the fifth largest mass extinction, the Frasnian-Famennian event. In order to establish a chronological framework for global correlation before, during, and following the Frasnian-Famennian mass extinction, we carried out a coupled magnetostratigraphic and biostratigraphic study of two stratigraphic sections in the Upper Devonian carbonate reef complexes of the Lennard Shelf, in the Canning Basin, Western Australia. Magnetostratigraphy from these rocks provides the first high-resolution definition of the Late Devonian magnetic polarity timescale. A 581-m-reference section and an 82-m overlapping section through the marginal slope facies (Napier Formation) of the Oscar Range as well as a 117-m section at Horse Spring (Virgin Hills Formation) were sampled at decimeter to meter scale for magnetostratigraphy. Conodont biostratigraphy was used to correlate both sections, and link magnetostratigraphic polarity zones to a globally established biostratigraphy. A stable, Characteristic Remanent Magnetization (ChRM) with dual polarities (NE, shallowly upward and SW, shallowly downward) is recovered from ∼ 60% of all samples, with magnetite inferred to be the chief magnetic carrier from thermal demagnetization characteristics. These directions define a geomagnetic pole at 49.5°S/285.8°E and α95 = 2.4 (n = 501), placing the Canning Basin at 9.9°S during the Late Devonian, consistent with carbonate reef development at this time. A conservative interpretation of the magnetostratigraphy shows the recovery of multiple reversals from both sections, not including possible cryptochrons and short duration magnetozones. Field tests for primary remanence include positive reversal tests and matching magnetozones from an overlapping section in the Oscar Range. A strong correlation was found between magnetic polarity stratigraphies of the Oscar Range and Horse Spring sections, and we correlate 12

  9. Platform margins, reef facies, and microbial carbonates; a comparison of Devonian reef complexes in the Canning Basin, Western Australia, and the Guilin region, South China

    Science.gov (United States)

    Shen, Jian-Wei; Webb, Gregory E.; Jell, John S.

    2008-05-01

    Devonian reef complexes were well developed in Western Australia and South China, but no detailed direct comparison has been made between reef building in the two regions. The regions differ in several respects, including tectonic, stratigraphic and palaeoceanographic-palaeogeographic settings, and the reef building styles reflect minor differences in reef builders and reef facies. Similarities and differences between the two reef complexes provide insights into the characteristics of platform margins, reef facies and microbial carbonates of both regions. Here we present a comparison of platform margin types from different stratigraphic positions in the Late Devonian reef complex of the Canning Basin, Western Australia and Middle and Late Devonian margin to marginal slope successions in Guilin, South China. Comparisons are integrated into a review of the reefal stratigraphy of both regions. Reef facies, reef complex architecture, temporal reef builder associations, 2nd order stratigraphy and platform cyclicity in the two regions were generally similar where the successions overlap temporally. However, carbonate deposition began earlier in South China. Carbonate complexes were also more widespread in South China and represent a thicker succession overall. Platforms in the Canning Basin grew directly on Precambrian crystalline basement or early Palaeozoic sedimentary rocks, but in South China, carbonate complexes developed conformably on older Devonian siliciclastic strata. Pre-Frasnian reef facies in South China had more abundant skeletal frameworks than in Canning Basin reefs of equivalent age, and Famennian shoaling margins containing various microbial reefs may have been more common and probably more diverse in South China. However, Late Devonian platform margin types have been documented more completely in the Canning Basin. Deep intra-platform troughs (deep depressions containing non-carbonate pelagic sediments — Nandan-type successions) that developed along

  10. Orthorhombic fault fracture patterns and non-plane strain in a synthetic transfer zone during rifting: Lennard shelf, Canning basin, Western Australia

    Science.gov (United States)

    Miller, John McL.; Nelson, E. P.; Hitzman, M.; Muccilli, P.; Hall, W. D. M.

    2007-06-01

    A complex series of faults occur within transfer zones normal to the WNW-trending rifted northern margin of the Canning basin (Western Australia). These zones controlled basinal fluid flow and the formation of some carbonate-hosted Mississippi Valley-type Zn-Pb deposits along the basin margin during Devonian to Carboniferous rifting. The study area has a regional fault geometry similar to a synthetic overlapping transfer zone. Surface and underground mapping in this transfer zone, combined with 3D modelling, indicate the faults and related extension fractures have an orthorhombic geometry. The orthorhombic fault-fracture mesh developed in response to three-dimensional non-plane strain in which the intermediate finite extension magnitude was non-zero. Pre-mineralisation marine calcite fill in the fault-fracture mesh indicates that it formed early in the deformation history. Later deformation that overprints the Zn-Pb mineralisation and fault-fracture mesh, was associated with a different maximum extension direction and this modified and reactivated the faults with both dip-slip and oblique-slip movement and tilting of earlier structures. The orthorhombic geometry is not observed at a regional scale (>10 × 10 km), indicating probable scale-dependant behaviour. This study indicates that this transfer zone developed either by (1) strain partitioning with synchronous strike-slip structures and adjacent zones of non-plane extension, or (2) by a component of non-plane extension sub-parallel to the basin margin followed by subsequent transtensional overprint of the system (preferred model). Synthetic overlapping transfer zones are inferred to be key regions where orthorhombic fault geometries may develop.

  11. Rare earth element geochemistry of Late Devonian reefal carbonates, Canning Basin, Western Australia: confirmation of a seawater REE proxy in ancient limestones

    Science.gov (United States)

    Nothdurft, Luke D.; Webb, Gregory E.; Kamber, Balz S.

    2004-01-01

    Rare earth element and yttrium (REE+Y) concentrations were determined in 49 Late Devonian reefal carbonates from the Lennard Shelf, Canning Basin, Western Australia. Shale-normalized (SN) REE+Y patterns of the Late Devonian samples display features consistent with the geochemistry of well-oxygenated, shallow seawater. A variety of different ancient limestone components, including microbialites, some skeletal carbonates (stromatoporoids), and cements, record seawater-like REE+Y signatures. Contamination associated with phosphate, Fe-oxides and shale was tested quantitatively, and can be discounted as the source of the REE+Y patterns. Co-occurring carbonate components that presumably precipitated from the same seawater have different relative REE concentrations, but consistent REE+Y patterns. Clean Devonian early marine cements ( n = 3) display REE+Y signatures most like that of modern open ocean seawater and the highest Y/Ho ratios (e.g., 59) and greatest light REE (LREE) depletion (average Nd SN/Yb SN = 0.413, SD = 0.076). However, synsedimentary cements have the lowest REE concentrations (e.g., 405 ppb). Non-contaminated Devonian microbialite samples containing a mixture of the calcimicrobe Renalcis and micritic thrombolite aggregates in early marine cement ( n = 11) have the highest relative REE concentrations of tested carbonates (average total REE = 11.3 ppm). Stromatoporoid skeletons, unlike modern corals, algae and molluscs, also contain well-developed, seawater-like REE patterns. Samples from an estuarine fringing reef have very different REE+Y patterns with LREE enrichment (Nd SN/Yb SN > 1), possibly reflecting inclusion of estuarine colloidal material that contained preferentially scavenged LREE from a nearby riverine input source. Hence, Devonian limestones provide a proxy for marine REE geochemistry and allow the differentiation of co-occurring water masses on the ancient Lennard Shelf. Although appropriate partition coefficients for quantification of

  12. A Re-Examination of the Bedout High, Offshore Canning Basin, Western Australia - Possible Impact Site for the Permian-Triassic Mass Extinction Event?

    Science.gov (United States)

    Becker, L.; Nicholson, C.; Poreda, R. J.

    2002-12-01

    The Bedout High, located offshore Canning basin in Western Australia, is an unusual structure and its origin remains problematic. K-Ar dating of volcanic samples encountered at total depth in the Lagrange-1 exploration well indicated an age of about 253+/-5 Ma consistent with the Permian-Triassic boundary event. Gorter (PESA News, pp. 33-34, 1996) speculates that the Bedout High is the uplifted core (30 km) of a circular feature, some 220 km across, formed by the impact of a large bolide (cometary or asteroidal) with the Earth near the end-Permian. Accepting a possible impact origin for the Bedout structure, with the indicated dimensions, would have had profound effects on global climate as well as significant changes in lithotratigraphic, biostratigraphic and chemostratigraphic indicators as seen in several Permian-Triassic boundary locations worldwide. In this work, we re-examine some of the structural data previously presented by Gorter (1996) using some additional seismic lines. We have also evaluated several impact tracers including iridium, shocked quartz, productivity collapse, helium-3, chromium-53 and fullerenes with trapped noble gases from some Permian-Triassic boundary sites in the Tethys and Circum-Pacific regions. Our findings suggest that the Bedout structure is a good candidate for an oceanic impact at the end Permian, triggering the most severe mass extinction in the history of life on Earth.

  13. Nutrient transport to the Swan-Canning Estuary, Western Australia

    Science.gov (United States)

    Peters, Norman E.; Donohue, Robert

    2001-09-01

    Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (25 km wide), sandy coastal plain. Nitrogen (N) and phosphorus (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0·06 mg l-1 and 0·12 mg l-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0·21 mg l-1) than the streams (0·12 mg l-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0·76 mg l-1 and 1·5 mg l-1 respectively) than the streams (0·31 mg l-1 and 1·2 mg l-1 respectively). The Avon River, which drains 98·5% of the 121 000 km2 catchment area, contributes most of the N (0·03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0·01 kg ha-1

  14. Nutrient concentrations and fluxes in tributaries to the Swan-Canning estuary, Western Australia

    Science.gov (United States)

    Peters, N.E.; Donohue, R.

    1999-01-01

    In Western Australia, catchment nutrient availability on an areal basis is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly in coastal areas. The coastal areas receive notably higher rainfall and have more intense horticulture and animal production than inland areas, and are undergoing rapid urbanization, particularly adjacent to the estuary. Also, the surficial aquifers on the coastal plain are generally sandy having a low nutrient retention capacity and rapidly transmit soluble and colloidal material through the subsurface. In the Swan-Canning basin, high air and soil temperatures and seasonally arid conditions cause rapid mineralization of nitrogen and phosphorus. The nutrients are subsequently available for transport during the onset of seasonal wet weather, which typically begins during the period from late April to June. In addition to the rapid mobility of nutrients in streamwater from agricultural areas during the wet season, drains in urban areas, which typically have high nutrient concentrations, also are an important source of nutrients as the drains flow directly to the estuary throughout the year.

  15. Temporal variability of phytoplankton in a salt wedge estuary, the Swan-Canning Estuary, Western Australia

    Science.gov (United States)

    Thompson, Peter A.

    2001-09-01

    The temporal cycles of variation in salinity, temperature and river flow in the Swan-Canning Estuary plus rainfall in the vicinity are examined. A normal pattern is defined for rainfall and river flow based on long-term median monthly values from available historical data. Long-term monthly median rainfall and median monthly river flow were highly correlated. Deviations from the normal patterns of rainfall and river flow are documented. Three years of detailed data on the temporal distribution of the algal biomass and phytoplankton community composition from the Swan-Canning Estuary are presented and discussed. Significant interannual variability in the phytoplankton biomass was observed with 1996 having a significantly lower median chlorophyll a concentration than 1995 or 1997. Different years also had pronounced differences in the timing, persistence and occurrence of algal blooms. Links with, and between, rainfall, river flow, nutrient concentrations and phytoplankton biomass are made by careful examination of the temporal patterns. Deviations from the proposed normal temporal pattern of physical and chemical environmental factors relevant to the growth of phytoplankton biomass are assessed. Deviations from normal rainfall and river flow, depending upon their timing and intensity, appear to be associated with occurrence of algal blooms. For example, the lack of a dinoflagellate bloom in December 1996 or January 1997 appears to be associated with a wetter than normal spring. Based upon the observed data, published reports and basic principles of algal ecology a set of predicted responses to variation in the major environmental variables (rainfall and river flow) are tabulated. The tabulated predictions are proposed as a useful tool for resource managers.

  16. Reserves in western basins

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, R.H.; Cotton, B.W. [Scotia Group, Dallas, TX (United States)

    1995-04-01

    The objective of this project is to investigate the reserves potential of tight gas reservoirs in three Rocky Mountain basins: the Greater Green River (GGRB), Uinta and Piceance basins. The basins contain vast gas resources that have been estimated in the thousands of Tcf hosted in low permeability clastic reservoirs. This study documents the productive characteristics of these tight reservoirs, requantifies gas in place resources, and characterizes the reserves potential of each basin. The purpose of this work is to promote understanding of the resource and to encourage its exploitation by private industry. At this point in time, the GGRB work has been completed and a final report published. Work is well underway in the Uinta and Piceance basins which are being handled concurrently, with reports on these basins being scheduled for the middle of this year. Since the GGRB portion of the project has been completed, this presentation win focus upon that basin. A key conclusion of this study was the subdivision of the resource, based upon economic and technological considerations, into groupings that have distinct properties with regard to potential for future producibility, economics and risk profile.

  17. High-Resolution Magnetic Susceptibility Stratigraphy Spanning Late Devonian Global Change from a New Scientific Drillcore in Canning Basin, Northwest Australia

    Science.gov (United States)

    Diamond, M. R.; Raub, T. D.; Kirschvink, J. L.; Playton, T. E.; Hocking, R. M.; Haines, P.; Tulipani, S.

    2010-12-01

    New shallow scientific drillcore has been recovered through the Frasnian-Famennian extinction boundary in northwest Australia’s Canning Basin. Previous work in the McWhae Ridge outcrop belt has identified patterns of turnover in trilobites and other fauna, change from sponge- and coral-dominated reefs to post-extinction microbial-dominated reefs, apparent sea level changes, and carbon isotopic evidence of late Devonian crisis. Continuous magnetic susceptibility (MS) stratigraphy yields highly structured oscillations spanning ~42 m of reef-slope carbonate. These oscillations appear to identify late Frasnian “Kellwasser” events and they may record sedimentary response to orbital variations, establishing a high-resolution relative chronostratigraphy of late Devonian global change. Magnetic susceptibility stratigraphy has been proposed as a generally useful chronometer for late Devonian time. Most of fifteen published MS stratigraphies crossing the Frasnian-Famennian boundary appear to share major excursions with the new McWhae Ridge result. Although upland tectonism in Canning Basin may be a caveat to straightforward eustatic interpretation of magnetic susceptibility variations, we suggest the higher-resolution and fresh drillcore context of this result prioritizes it as a standard for Frasnian-Famennian magnetic susceptibility variation.

  18. Sequence development of a latest Devonian-Tournaisian distally-steepened mixed carbonate-siliciclastic ramp, Canning Basin, Australia

    Science.gov (United States)

    Seyedmehdi, Zahra; George, Annette D.; Tucker, Maurice E.

    2016-03-01

    The sequence development and evolution of latest Devonian-earliest Carboniferous Fairfield Group in the Canning Basin have been established through integration of detailed sedimentological analysis of core, petrophysical data, existing biostratigraphic data and new seismic interpretations. The Fairfield Group on the Lennard Shelf was deposited on a mixed carbonate-siliciclastic distally-steepened ramp with a broad inner ramp, narrow mid ramp and steepened outer ramp. The majority of facies associations (FA1-FA8) were formed in intertidal-shallow subtidal conditions in proximal to distal inner ramp including siliciclastic tidal flats (FA1), carbonate intertidal flats (FA2), tidal flats and channels (FA3), lagoons (FA4-FA5), and shallow subtidal (FA6), backshoal (FA7) and fore-shoal areas (FA8). Bioclastic muddy sandstone (FA9) and bioclastic mudstone (FA10) are the dominant mid-ramp facies. Recognition of turbiditic facies of middle to lower slope of the outer ramp (FA11-FA13) led to the identification of a distally-steepened ramp. Antecedent topography exerted a significant control on platform morphology and the development of the widespread inner-ramp facies on the Lennard Shelf. A sequence-stratigraphic analysis reveals that the Fairfield Group ramp deposits consists of four third-order sequences (S1-S4) that were largely deposited during sea-level highstands (HST) characterized by progradational trends and dominant shallow subtidal inner-ramp facies associations. Transgressive systems tracts (TST) are well developed in S1 and S3 and have a retrogradational facies pattern with dominant deep subtidal mid-outer ramp facies associations. Lowstand systems tracts, characterized by lowstand wedges and turbiditic facies, are identified in the lower parts of S2 and S3. Coarse and fine-grained siliciclastic facies are mixed with carbonate facies as a result of coeval deposition on the inner and mid ramp, and reciprocal deposition on the outer ramp. A temporal variation in

  19. Home Canning and Botulism

    Science.gov (United States)

    ... 1. Use proper canning techniques. Make sure your food preservation information is always current with up-to-date, ... the following sources: The National Center for Home Food Preservation USDA Complete Guide to Home Canning The state ...

  20. Bioavailability, Composition and Fate of Dissolved Organic Matter in the Swan-Canning Catchment, South-Western Australia

    Science.gov (United States)

    Petrone, K. C.; Hughes, C. S.; Norris, J. R.; Grierson, P. F.

    2007-12-01

    Dissolved organic nitrogen (DON) comprises the bulk of the total nitrogen load to the N-limited Swan-Canning river and estuary that bisects Perth, WA, yet its ecological role is largely unknown. Our objective was to assess the bioavailability and composition of dissolved organic matter (DOM), particularly its DON component, and the potential of DOM to supply dissolved inorganic nitrogen (DIN) to the estuary during the summer months when algal blooms are common. We compared water samples from 10 sub-catchments of the Swan-Canning that vary in land-use: eucalypt forests on the Darling Scarp most distant from the estuary, mixed (agriculture/ residential) catchments on the metropolitan perimeter, and urban catchments on the Swan Coastal Plain near Perth CBD. We inoculated water samples with a common bacterial inoculum and measured changes in DOC, DON and DIN over time. We found that 2 to 17 per cent of DOC and 18 to 44 per cent of the DON was consumed during the experiment and DIN was produced in 8 of 10 catchments. DOC and DON consumption were linearly related to concentration across sites and were greatest in the urban catchments. However, DOC and DON consumption were not significantly related, suggesting that C and N are concentrated in different fractions of DOM. Using resin fractionation techniques, we found that DOC was concentrated in the hydrophobic fraction, followed by transphilics, and lesser amounts of charged and neutral hydrophilics. Ongoing analyses will examine the N content of resin fractions and the amino acid composition of streams to determine how N composition relates to DOM decomposition. We are currently examining organic matter leached from native plants (Corymbia, Melaleuca) in coastal plain wetlands in order to characterize allochthonous DOM. Further examination of algal- derived DOM and point sources will enable us to determine the bioavailability and composition of in-stream and anthropogenic sources. These studies provide much needed

  1. Basin and Range Province, Western US, USGS Grids, #1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  2. Basin and Range Province, Western US, USGS Grids #5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  3. Basin and Range Province, Western US, USGS Grids #3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  4. Studies on canning Psenopsis cyanea

    OpenAIRE

    Balachandran, K.K.; P. K. Vijayan

    1989-01-01

    Suitability of Psenopsis cyanea, a deep sea fish caught on board FORV Sagar Sampada from a depth of 350m off Cochin for processing into canned product was studied. The fish having high fat content around 52% (DWB) and white attractive meat renders itself well for canning yielding a product good in organoleptic characteristics. However to have a presentable appearance to the product the fish has to be skinned prior to canning. Gentle agitation of P. cyanea in 0.25% aqueous solution of lactic a...

  5. Western Gas Sands Project: stratigrapy of the Piceance Basin

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S. (comp.)

    1980-08-01

    The Western Gas Sands Project Core Program was initiated by US DOE to investigate various low permeability, gas bearing sandstones. Research to gain a better geological understanding of these sandstones and improve evaluation and stimulation techniques is being conducted. Tight gas sands are located in several mid-continent and western basins. This report deals with the Piceance Basin in northwestern Colorado. This discussion is an attempt to provide a general overview of the Piceance Basin stratigraphy and to be a useful reference of stratigraphic units and accompanying descriptions.

  6. Classification of Complex Reservoirs in Superimposed Basins of Western China

    Institute of Scientific and Technical Information of China (English)

    PANG Xiongqi; ZHOU Xinyuan; LIN Changsong; HUO Zhipeng; LUO Xiaorong; PANG Hong

    2010-01-01

    Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins.The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation,stratigraphic structure and stratigraphic stress-strain action over geological history.Based on the correlation of chronological age on structural sections,superimposed basins can be divided into five types in this study:(1)continuous sedimentation type superimposed basins,(2)middle and late stratigraphic superimposed basins,(3)early and late stratigraphic superimposed basins,(4)early and middle stratigraphic superimposed basins,and(5)long-term exposed superimposed basins.Multiple source-reservoir-caprock assemblages have developed in such basins.In addition,multi-stage hydrocarbon generation and expulsion,multiple sources,polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment,reformation and destruction have occurred in these basins.The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs,and the root causes of this are folding,denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage,diffusion,spilling,oxidation,degradation and cracking.Based on their genesis characteristics,complex reservoirs are divided into five categories:(1)primary reservoirs,(2)trap adjustment type reservoirs,(3)component variant reservoirs,(4)phase conversion type reservoirs and(5)scale-reformed reservoirs.

  7. RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

    Energy Technology Data Exchange (ETDEWEB)

    Robert Caldwell

    1998-04-01

    Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies

  8. Magnetic Lineations in Marginal Basins of the Western Pacific

    Science.gov (United States)

    Weissel, J. K.

    1981-03-01

    This paper separates the small oceanic basins around the western perimeter of the Pacific Ocean into marginal basins that have formed through back-arc extension and those that apparently have not, and reviews our knowledge of magnetic lineation patterns observed in possible and probable back-arc basins. Magnetic lineations in these basins resemble lineations commonly associated with the world's mid-oceanic spreading systems, indicating that similar processes of crustal accretion occur in both tectonic environments. In some back-arc basins of the southwestern Pacific, magnetic lineation and other evidence suggest that back-arc basins can evolve through the interaction and growth of 'multi-plate' systems. Because of the small time and space characteristics of back-arc basins compared with the world's major oceanic spreading systems, tectonic conditions favourable for the generation of back-arc basins are either relaxed rapidly or easily interrupted. Models proposed to account for back-arc basin development include (a) 'local' models, where back-arc extension is mechanically driven by the downgoing slab, and (b) global plate kinematics models, where conditions favourable for back-arc extension are governed by the motion of the overriding plate relative to the trench axis.

  9. Canning Tests on Mushroom Strain

    OpenAIRE

    Gormley, T. R. (Thomas Ronan); MacCanna, C.

    1980-01-01

    Canning tests were carried out on 5 mushroom strains from 2 flushes of 4 separate crops. Particular attention was given to the ratio of whole closed canned mushrooms to that of whole closed canned mushrooms plus canned stems and pieces - i.e. total yield. Factors considered in the tests included grading prior to processing, blanching and retort losses, shrinkage in size and mushroom whiteness. Cream and off-white strains had the highest level of open and misshapen mushrooms prior to processin...

  10. Reserves in western basins: Part 1, Greater Green River basin

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  11. Reserve estimates in western basins. Part 2: Piceance Basin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This study characterizes an extremely large gas resource located in low permeability, sandstone reservoirs of the Mesaverde group in the Piceance Basin, Colorado. Total in place resource is estimated at 307.3 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 5.8 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. About 82.6% of the total evaluated resource is contained within sandstones that have extremely poor reservoir properties with permeabilities considered too low for commerciality using current frac technology. Cost reductions and technology improvements will be required to unlock portions of this enormous resource. Approximately 2.7% of the total resource is contained within sandstone reservoirs which do not respond to massive hydraulic fracture treatments, probably due to their natural lenticular nature. Approximately 6.8% of the total resource is located in deeply buried settings below deepest established production. Approximately 7.9% of the total resource is considered to represent tight reservoirs that may be commercially exploited using today`s hydraulic fracturing technology. Recent technology advances in hydraulic fracturing practices in the Piceance Basin Mesaverde has resulted in a marked improvement in per well gas recovery which, where demonstrated, has been incorporated into the estimates provided in this report. This improvement is so significant in changing the risk-reward relationship that has historically characterized this play, that previously uneconomic areas and resources will graduate to the economically exploitable category. 48 refs., 96 figs., 18 tabs.

  12. Tectonic differences between eastern and western sub-basins of the Qiongdongnan Basin and their dynamics

    Science.gov (United States)

    Liu, Jianbao; Sun, Zhen; Wang, Zhenfeng; Sun, Zhipeng; Zhao, Zhongxian; Wang, Zhangwen; Zhang, Cuimei; Qiu, Ning; Zhang, Jiangyang

    2015-03-01

    The central depression of the Qiongdongnan Basin can be divided into the eastern and western sub-basins by the Lingshui-Songnan paleo-uplift. To the northwest, the orientation of the faults turns from NE, to EW, and later to NW; In the southwest, the orientation of the faults turns from NE, to NNE, and then to NW, making the central depression much wider towards the west. In the eastern sub-basin, the NE-striking faults and the EW-striking faults made up an echelon, making the central depression turn wider towards the east. Fault activity rates indicate that faulting spreads gradually from both the east and west sides to the middle of the basin. Hence, extensional stress in the eastern sub-basin may be related to the South China Sea spreading system, whereas the western sub-basin was more under the effect of the activity of the Red River Fault. The extreme crustal stretching in the eastern sub-basin was probably related to magmatic setting. It seems that there are three periods of magmatic events that occurred in the eastern sub-basin. In the eastern part of the southern depression, the deformed strata indicate that the magma may have intruded into the strata along faults around T60 (23.3 Ma). The second magmatic event occurred earlier than 10.5 Ma, which induced the accelerated subsidence. The final magmatic event commenced later than 10 Ma, which led to today's high heat flow. As for the western sub-basin, the crust thickened southward, and there seemed to be a southeastward lower crustal flow, which happened during continental breakup which was possibly superimposed by a later lower crustal flow induced by the isostatic compensation of massive sedimentation caused by the right lateral slipping of the Red River Fault. Under the huge thick sediment, super pressure developed in the western sub-basin. In summary, the eastern sub-basin was mainly affected by the South China Sea spreading system and a magma setting, whereas the western sub-basin had a closer

  13. Conductivity models for the North Perth Basin, Western Australia

    Science.gov (United States)

    Hoskin, T. E.; Regenauer-Lieb, K.; Jones, A. G.

    2013-12-01

    Exploration for geothermal resources in the North Perth basin, Western Australia, led to acquisition of new, high resolution Magnetotelluric (MT) and Audio-Magnetotelluric (AMT) data, the first of its kind in the area. Electromagnetic (EM) techniques are widely used in geothermal exploration and ground water investigations and they are well suited for application in the Perth basin. Two east-west transects investigating the structure of the onshore basin and its eastern margin, the Darling Fault Zone, are compared with existing geological models and geophysical data. Down-hole temperature data and depth-to-basement models were used to define areas of investigation in the basin, but there are limited geophysical data available. 1D, 2D and 3D modeling of electromagnetic data have been used to produce new conductivity models using existing data to constrain modelling. EM data complement existing gravity and seismic data and support published models in the upper 4-6km. However in deeper parts of the basin, MT data provide additional information allowing for revision of depth-to-basement. In addition to this, we clearly identify a conductivity anomaly associated with the Darling Fault Zone and are able to image this anomaly penetrating into the upper mantle. Fault zone conductors have been imaged on other lithosphere faults around the world, with one explanation being fluids in the enhanced permeability of the damage zone. Evidence to explain the fault zone conductor of the Darling Fault is presented and discussed as it could have significant implications in the identification of new areas, prospective for geothermal resources in the basin.

  14. NEW TECHNOLOGICAL APPROACHES TO CANNING CEPHALOPOD MOLLUSKS

    OpenAIRE

    Shul'gina, L.; Dolbnina, N.; Lazhentseva, L.; Shul'gin, Yu

    2013-01-01

    With significant stocks and catches of cephalopod mollusks in the Far Eastern seas, their small output as canned goods is due to a low yield of the finished product. Research was conducted on the rational use of frozen raw cephalopod mollusks in the production of sterilized canned goods. New technological approaches to canning cephalopod mollusks that ensure canning profitability and replenish the consumer market of functional seafood are justified. It was established that the exclusion of th...

  15. The first stages of evolution of the Western Somali Basin

    Science.gov (United States)

    Labails, Cinthia; Gaina, Carmen; Skogseid, Jakob; Pilskog, Bjørn; Graue, Knut

    2010-05-01

    The rifted and transform margins created by the separation of Madagascar and Africa offer an opportunity to jointly investigate the structural and geodynamic evolution of conjugate continental passive margins. It is generally accepted that the continental breakup of Gondwana in the East African region began with the onset of the southward drift of Madagascar (then connected with Antarctica and India) along the Davie Fracture Zone probably during the Middle Jurassic, and subsequently led to the opening of the western Somali Basin. Although published kinematic models are able to explain and date some of the broad scale features of the Somali and Mozambique oceanic basins, the exact timing of rifting, the early stages of seafloor spreading and the timing of seafloor cessation in the western Somali Basin remain debatable. Our new study aims to investigate the relationship between the long history of rifting along the East African margins and the breakup structures by constructing a consistent database that contains structural elements and information about their evolution from updated published literature. Next, a thorough investigation of the potential field data (magnetic and gravity anomalies) is undertaken in order to establish the structure (and possibly timing) of the early seafloor spreading. An analysis of multichannel seismic reflection, gravity, magnetic and bathymetric datasets is aimed to identify deep crustal structure and continent-ocean transition zone in the study area. We present preliminary results showing the evolution of the East African margin (along Somali and Mozambique basins), the location of the transition zone between the continental and oceanic crust, and a regional kinematic analysis of the Jurassic-mid Cretaceous tectonic events.

  16. Sequence stratigraphy of the Orange basin, western offshore South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Muntingh, A. (SOEKOR Ltd., Parow (South Africa))

    1991-03-01

    A seismic/sequence-stratigraphic framework for the siliciclastic fluvial to deepwater Cretaceous strata of the Orange basin has been constructed. Sequence-stratigraphic concepts developed by Exxon were used to interpret 10,000 km of seismic data and logs from 31 exploration boreholes within an area of 90,000 km{sup 2}. The sequence stratigraphy of the western margin exhibits 34 cyclical depositional sequences interpreted to document the response of the passive margin to cyclical changes in relative sea-level from Mid-Aptian to Late Maastrichtian times. All but one of the sequence boundaries are type 1 unconformities displaying intense erosion on the shelf and interpreted to develop during periods of rapid fall in relative sea-level. Basin-wide sequence boundaries (type 1 and 2 unconformities) were correlated with the third-order cycles of Exxon's global cycle chart utilizing SOEKOR's paleontological dating of a limited number of marine condensed sections. Higher-order cycles are recognized and best developed along the flanks of the structural arches where lower subsidence rates permitted impact of higher frequency cycles. Component depositional systems tracts inferred to have resulted from changes in relative sea level were interpreted and paleogeographic maps were constructed outlining incised valley systems on the shelf, shelf edge canyons, prograding wedges, basin floor fan, and slope fan systems. Distal marine shales and marine condensed sections provide both seal and hydrocarbon source. The chronostratigraphic and depositional framework being used to predict prospective play areas for hydrocarbon exploration on the western offshore of South Africa is also applicable to the Namibian offshore.

  17. 29 CFR 784.134 - “Canning.”

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âCanning.â 784.134 Section 784.134 Labor Regulations... First Processing, Canning, Or Packing of Marine Products Under Section 13(a)(5) § 784.134 “Canning.” The term “canning” was defined in the legislative history of the 1949 amendments (House (Conference)...

  18. Thermal evolution of a hyperextended rift basin, Mauléon Basin, western Pyrenees

    Science.gov (United States)

    Hart, Nicole R.; Stockli, Daniel F.; Lavier, Luc L.; Hayman, Nicholas W.

    2017-06-01

    Onshore and offshore geological and geophysical observations and numerical modeling have greatly improved the conceptual understanding of magma-poor rifted margins. However, critical questions remain concerning the thermal evolution of the prerift to synrift phases of thinning ending with the formation of hyperextended crust and mantle exhumation. In the western Pyrenees, the Mauléon Basin preserves the structural and stratigraphic record of Cretaceous extension, exhumation, and sedimentation of the proximal-to-distal margin development. Pyrenean shortening uplifted basement and overlying sedimentary basins without pervasive shortening or reheating, making the Mauléon Basin an ideal locality to study the temporal and thermal evolution of magma-poor hyperextended rift systems through coupling bedrock and detrital zircon (U-Th)/He thermochronometric data from transects characterizing different structural rifting domains. These new data indicate that the basin was heated during early rifting to >180°C with geothermal gradients of 80-100°C/km. The proximal margin recorded rift-related exhumation/cooling at circa 98 Ma, whereas the distal margin remained >180°C until the onset of Paleocene Pyrenean shortening. Lithospheric-scale numerical modeling shows that high geothermal gradients, >80°C/km, and synrift sediments >180°C, can be reached early in rift evolution via heat advection by lithospheric depth-dependent thinning and blanketing caused by the lower thermal conductivity of synrift sediments. Mauléon Basin thermochronometric data and numerical modeling illustrate that reheating of basement and synrift strata might play an important role and should be considered in the future development of conceptual and numerical models for hyperextended magma-poor continental rifted margins.

  19. Western Gas Sands Project Quarterly Basin Activities Report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C H

    1979-04-30

    This quarterly basin activities report is a summation of three months drilling and testing activities in the Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin. Detailed information is given for each study area for the first quarter of 1979.

  20. Western Gas Sands Project. Quarterly Basin Activities Report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C H

    1979-01-31

    This report is a summation of 3 months' drilling and testing activities in the four primary WGSP study areas: Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin. The monitoring of basin activities is part of resource assessment. (DLC)

  1. Status of canning cycle optimization study

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, T.W.

    1963-12-23

    A concentrated study of the present manufacturing process was initiated in the Process Engineering Unit, the purpose of the study being to optimize the present operations, procedures, and methods of the AlSi canning process. It is the purpose of this document to report the findings and accomplishments for that portion of the study concerned with the optimization of component preparation and fabrication within the canning furnace. To date, this study has consisted mainly of heating rate studies of the various components used in the fuel element fabrication with some work being done on the optimization of the heating cycle for these components. This work necessarily serves as the basis for further optimization study.

  2. The role of strain partitioning on intermontane basin inception and isolation, External Western Gibraltar Arc

    Science.gov (United States)

    Jiménez-Bonilla, A.; Expósito, I.; Balanyá, J. C.; Díaz-Azpiroz, M.; Barcos, L.

    2015-12-01

    The intermontane Ronda Basin, currently located in the Western Betics External Zones, started as an embayment of the Betic foreland basin during the Tortonian. We have characterized a post-Serravallian, basin-related deformation event that overprinted the former fold-and-thrust belt. Updated structural and kinematic maps allow us to identify NW-SE basinward-dipping normal faults at the southwestern and northeastern boundaries of the basin and NE-SW shortening structures (large-scale folds and reverse faults) affecting both the outcropping basement and partially the basin infill. In order to test the possible tectonic activity of these structures during the last 5 Ma, exhaustive geomorphologic analyses in the Ronda Basin area have been done. This included the qualitative study of relief and drainage network, together with the characterization of quantitative indices (SLk, Smf, Vf and HI). These results obtained from this analysis are coherent with structural data and suggest that the identified post-Serravallian structures were active up to at least 5 Ma. We also conclude that the Ronda Basin was generated by along strike segmentation of the relief in the Western Betics induced by NE-SW (arc-parallel) stretching accompanied with NW-SE shortening. In the NW basin boundary, the strain was partitioned into ENE-WSW dextral strike-slip faults and NE-SW shortening structures, which gave rise to a Messinian transpressive structural high that disconnected the former Ronda Basin from its parental foreland basin.

  3. Paleogene palaeogeography and basin evolution of the Western Carpathians, Northern Pannonian domain and adjoining areas

    Science.gov (United States)

    Kováč, Michal; Plašienka, Dušan; Soták, Ján; Vojtko, Rastislav; Oszczypko, Nestor; Less, György; Ćosović, Vlasta; Fügenschuh, Bernhard; Králiková, Silvia

    2016-05-01

    The data about the Paleogene basin evolution, palaeogeography, and geodynamics of the Western Carpathian and Northern Pannonian domains are summarized, re-evaluated, supplemented, and newly interpreted. The presented concept is illustrated by a series of palinspastic and palaeotopographic maps. The Paleogene development of external Carpathian zones reflects gradual subduction of several oceanic realms (Vahic, Iňačovce-Kričevo, Szolnok, Magura, and Silesian-Krosno) and growth of the orogenic accretionary wedge (Pieniny Klippen Belt, Iňačovce-Kričevo Unit, Szolnok Belt, and Outer Carpathian Flysch Belt). Evolution of the Central Western Carpathians is characterized by the Paleocene-Early Eocene opening of several wedge-top basins at the accretionary wedge tip, controlled by changing compressional, strike-slip, and extensional tectonic regimes. During the Lutetian, the diverging translations of the northward moving Eastern Alpine and north-east to eastward shifted Western Carpathian segment generated crustal stretching at the Alpine-Carpathian junction with foundation of relatively deep basins. These basins enabled a marine connection between the Magura oceanic realm and the Northern Pannonian domain, and later also with the Dinaridic foredeep. Afterwards, the Late Eocene compression brought about uplift and exhumation of the basement complexes at the Alpine-Carpathian junction. Simultaneously, the eastern margin of the stretched Central Western Carpathians underwent disintegration, followed by opening of a fore-arc basin - the Central Carpathian Paleogene Basin. In the Northern Hungarian Paleogene retro-arc basin, turbidites covered a carbonate platform in the same time. During the Early Oligocene, the rock uplift of the Alpine-Carpathian junction area continued and the Mesozoic sequences of the Danube Basin basement were removed, along with a large part of the Eocene Hungarian Paleogene Basin fill, while the retro-arc basin depocentres migrated toward the east

  4. Variability of aerosol optical properties in the Western Mediterranean Basin

    Science.gov (United States)

    Pandolfi, M.; Cusack, M.; Alastuey, A.; Querol, X.

    2011-08-01

    Aerosol light scattering, absorption and particulate matter (PM) concentrations were measured at Montseny, a regional background site in the Western Mediterranean Basin (WMB) which is part of the European Supersite for Atmospheric Aerosol Research (EUSAAR). Off line analyses of 24 h PM filters collected with Hi-Vol instruments were performed for the determination of the main chemical components of PM. Mean scattering and hemispheric backscattering coefficients (@ 635 nm) were 26.6±23.2 Mm-1 and 4.3±2.7 Mm-1, respectively and the mean aerosol absorption coefficient (@ 637 nm) was 2.8±2.2 Mm-1. Mean values of Single Scattering Albedo (SSA) and Ångström exponent (å) (calculated from 450 nm to 635 nm) at MSY were 0.90±0.05 and 1.3±0.5 respectively. A clear relationship was observed between the PM1/PM10 and PM2.5/PM10 ratios as a function of the calculated Ångström exponents. Mass scattering cross sections (MSC) for fine mass and sulfate at 635 nm were 2.8±0.5 m2 g-1 and 11.8±2.2 m2 g-1, respectively, while the mean aerosol absorption cross section (MAC) was 10.4±2.0 m2 g-1. The variability in aerosol optical properties in the WMB were largely explained by the origin and ageing of air masses over the measurement site. The MAC values appear dependent of particles aging: similar to the expected absorption cross-section for fresh emissions under Atlantic Advection episodes and higher under aerosol pollution episodes. The analysis of the Ångström exponent as a function of the origin the air masses revealed that polluted winter anticyclonic conditions and summer recirculation scenarios typical of the WMB led to an increase of fine particles in the atmosphere (å = 1.5±0.1) while the aerosol optical properties under Atlantic Advection episodes and Saharan dust outbreaks were clearly dominated by coarser particles (å = 1.0±0.4). The sea breeze played an important role in transporting pollutants from the developed WMB coastlines towards inland rural areas

  5. Enlatamento de abacaxi Canning experiments with pineapples

    Directory of Open Access Journals (Sweden)

    Ary de Arruda Veiga

    1958-01-01

    Full Text Available Êste trabalho reune resultados de vários processos de enlatamento de abacaxis (Ananas sativus (Lindley Schultes f. sob a forma de compota. Visa, principalmente, contribuir com dados e informações que possam, de certo modo, orientar os interessados no aproveitamento industrial de abacaxis de polpa branca, como é o caso das frutas da variedade "Pérola" (branco de Pernambuco. Observou-se que êstes abacaxis podem fornecer compotas enlatadas de bom sabor e que a polpa, dividida em quartos em vez de fatias ou rodelas, conserva tôdas as suas propriedades orga-nolépticas durante mais de 21 meses após o enlatamento, pela adoção de um dos processos ensaiados.In pineapple growing areas of São Paulo and other parts of Brazil there is an increasing interest in the cultivation of white pulped varieties. This paper presents the data from tests in which five canning methods were compared for the preservation of white pineapples. The results from the tests indicated that it is possible to obtain a product of flood flavor and quality when the peeled fruit is sliced in quarters and preserved by the most suitable process of canning and sterilization. The state of preservation of the product and its organoleptic qualities were quite satisfactory 21 months after canning. The most satisfactory process consisted in the immersion of the sliced quarters in a syrup of 35° Bé at 77-84°C during 10 minutes. The initial cooking syrup had 45° Brix (25° Bé and the final concentration in the can was 35° Brix. Before closing the cans they were exhausted for 5 minutes. The final sterilization consisted in boiling the cans in water for 12 minutes, followed by immersion in cold water for 30 minutes.

  6. Variability of aerosol optical properties in the Western Mediterranean Basin

    Directory of Open Access Journals (Sweden)

    M. Pandolfi

    2011-08-01

    Full Text Available Aerosol light scattering, absorption and particulate matter (PM concentrations were measured at Montseny, a regional background site in the Western Mediterranean Basin (WMB which is part of the European Supersite for Atmospheric Aerosol Research (EUSAAR. Off line analyses of 24 h PM filters collected with Hi-Vol instruments were performed for the determination of the main chemical components of PM. Mean scattering and hemispheric backscattering coefficients (@ 635 nm were 26.6±23.2 Mm−1 and 4.3±2.7 Mm−1, respectively and the mean aerosol absorption coefficient (@ 637 nm was 2.8±2.2 Mm−1. Mean values of Single Scattering Albedo (SSA and Ångström exponent (å (calculated from 450 nm to 635 nm at MSY were 0.90±0.05 and 1.3±0.5 respectively. A clear relationship was observed between the PM1/PM10 and PM2.5/PM10 ratios as a function of the calculated Ångström exponents. Mass scattering cross sections (MSC for fine mass and sulfate at 635 nm were 2.8±0.5 m2 g−1 and 11.8±2.2 m2 g−1, respectively, while the mean aerosol absorption cross section (MAC was 10.4±2.0 m2 g−1. The variability in aerosol optical properties in the WMB were largely explained by the origin and ageing of air masses over the measurement site. The MAC values appear dependent of particles aging: similar to the expected absorption cross-section for fresh emissions under Atlantic Advection episodes and higher under aerosol pollution episodes. The analysis of the Ångström exponent as a function of the origin the air masses revealed that polluted winter anticyclonic conditions and summer recirculation scenarios typical of the WMB led to an increase of fine particles in the atmosphere (å = 1.5±0.1 while the aerosol optical properties under Atlantic Advection episodes and Saharan dust outbreaks were clearly

  7. Engineering-geological conditions of the formations in the Western Thessaly basin, Greece

    Science.gov (United States)

    Apostolidis, Emmanuel; Koukis, George

    2013-09-01

    An engineering-geological map of the Western Thessaly basin has been compiled, providing a valuable guide to both urban planning and industrial development of the wider area. This map contributes significantly to the optimization of land use and improved planning of technical work. Additionally, the engineering-geological conditions of the formations encountered in the Western Thessaly basin are examined. The formations are grouped into thirteen (13) engineering-geological entities, with regard to their geotechnical behaviour. This entire study was based on both in situ investigations and geotechnical information extracted from 1,039 boreholes. Furthermore, a landslide inventory map of the Western Thessaly basin has been compiled. In addition, the surface subsidence ruptures, due to ground-water overexploitation, have been examined in the eastern part of the study area.

  8. Geothermal systems of the Mono Basin-Long Valley region, eastern California and western Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, C.T.; Flynn, T.; Chapman, R.H.; Trexler, D.T.; Chase, G.R.; Bacon, C.F.; Ghusn, G. Jr.

    1985-01-01

    The region that includes Mono Basin, Long Valley, the Bridgeport-Bodie Hills area, and Aurora, in eastern California and western Nevada was studied to determine the possible causes and interactions of the geothermal anomalies in the Mono Basin-Long Valley region as a whole. A special goal of the study was to locate possible shallow bodies of magma and to determine their influence on the hydrothermal systems in the region. (ACR)

  9. Assessment of undiscovered conventional oil and gas resources of the Western Canada Sedimentary Basin, Canada, 2012

    Science.gov (United States)

    Higley, Debra

    2013-01-01

    The U.S. Geological Survey recently completed a geoscience-based assessment of undiscovered oil and gas resources of provinces within the Western Canada Sedimentary Basin. The Western Canada Sedimentary Basin primarily comprises the (1) Alberta Basin Province of Alberta, eastern British Columbia, and the southwestern Northwest Territories; (2) the Williston Basin Province of Saskatchewan, southeastern Alberta, and southern Manitoba; and (3) the Rocky Mountain Deformed Belt Province of western Alberta and eastern British Columbia. This report is part of the U.S. Geological Survey World Petroleum Resources Project assessment of priority geologic provinces of the world. The assessment was based on geoscience elements that define a total petroleum system (TPS) and associated assessment unit(s). These elements include petroleum source rocks (geochemical properties and petroleum generation, migration, and accumulation), reservoir description (reservoir presence, type, and quality), and petroleum traps (trap and seal types, and timing of trap and seal formation relative to petroleum migration). Using this framework, the Elk Point-Woodbend Composite TPS, Exshaw-Fernie-Mannville Composite TPS, and Middle through Upper Cretaceous Composite TPS were defined, and four conventional assessment units within the total petroleum systems were quantitatively assessed for undiscovered resources in the Western Canada Sedimentary Basin.

  10. Structural and stratigraphic analysis of the paleozoic Murzuk and Ghadames basins, western Libya

    Science.gov (United States)

    Karasek, R. M.

    The intracratonic basins in western Libya are characterized by extensional basement controlled faulting along northwest and northeast trends. The northwest southeast trending Tripoli-Soda, Ben Ghenma and Hasi Atshan subsurface arches were uplifted from Cambian through Devonian time. The anomalous west-southwest trending Gargaf Arch acted as a hinge line from Silurian through Devonian time, with consequent paleoslopes to the northwest (Ghadames Basin) and southeast (Murzuk Basin). Paleozoic detrital sediments are up to 1500 m thick in the Murzuk Basin and 2500 m thick in the Ghadames Basin. Five depositional sequences comprise transgressive-regressive cycles of deposition from parallic (coarse grained) to marine (fine-grained). Detailed environmental interpretation of the sequences is based on outcrop models for the Middle Devonian-Lower Carboniferous Aouinet Ouenine and Shatti Formations.

  11. Geology and hydrocarbon potential of the Hamada and Murzuq basins in western Libya

    Energy Technology Data Exchange (ETDEWEB)

    Kirmani, K.U.; Elhaj, F.

    1988-08-01

    The Hamada and Murzuq intracratonic basins of western Libya form a continuation of the Saharan basin which stretches from Algeria eastward into Tunisia and Libya. The tectonics and sedimentology of this region have been greatly influenced by the Caledonian and Hercynian orogenies. Northwest- and northeast-trending faults are characteristic of the broad, shallow basins. The Cambrian-Ordovician sediments are fluvial to shallow marine. The Silurian constitutes a complete sedimentary cycle, ranging from deep marine shales to shallow marine and deltaic sediments. The Devonian occupies a unique position between two major orogenies. The Mesozoic strata are relatively thin. The Triassic consists of well-developed continental sands, whereas the Jurassic and Cretaceous sediments are mainly lagoonal dolomites, evaporites, and shales. Silurian shales are the primary source rock in the area. The quality of the source rock appears to be better in the deeper part of the basin than on its periphery. The Paleozoic has the best hydrocarbon potential. Hydrocarbons have also been encountered in the Triassic and Carboniferous. In the Hamada basin, the best-known field is the El Hamra, with reserves estimated at 155 million bbl from the Devonian. Significant accumulations of oil have been found in the Silurian. Tlacsin and Tigi are two fields with Silurian production. In the Murzuq basin the Cambrian-Ordovician has the best production capability. However, substantial reserves need to be established before developing any field in this basin. Large areas still remain unexplored in western Libya.

  12. Late Quaternary environmental change in the Bonneville basin, western USA

    Science.gov (United States)

    Madsen, D.B.; Rhode, D.; Grayson, D.K.; Broughton, J.M.; Livingston, S.D.; Hunt, J.; Quade, Jay; Schmitt, D.N.; Shaver, M. W.

    2001-01-01

    Excavation and analyses of small animal remains from stratified raptor deposits spanning the last 11.5 ka, together with collection and analysis of over 60 dated fossil woodrat midden samples spanning the last 50 ka, provide a detailed record of changing climate in the eastern Great Basin during the late Pleistocene and Holocene. Sagebrush steppe dominated the northern Bonneville basin during the Full Glacial, suggesting that conditions were cold and relatively dry, in contrast to the southern basin, which was also cold but moister. Limber pine woodlands dominated ???13-11.5 ka, indicating increased dryness and summer temperatures ???6-7??C cooler than present. This drying trend accelerated after ???11.5 ka causing Lake Bonneville to drop rapidly, eliminating 11 species of fish from the lake. From ???11.5-8.2 ka xerophytic sagebrush and shadscale scrub replaced more mesophilic shrubs in a step-wise fashion. A variety of small mammals and plants indicate the early Holocene was ???3??C cooler and moister than at present, not warmer as suggested by a number of climatic models. The diversity of plants and animals changed dramatically after 8.2 ka as many species disappeared from the record. Some of the upland species returned after ???4 ka and Great Salt Lake became fresh enough at ???3.4 and ???1.2 ka to support populations of Utah chub. ?? 2001 Elsevier Science B.V.

  13. From stretching to mantle exhumation in a triangular backarc basin (Vavilov basin, Tyrrhenian Sea, Western Mediterranean)

    Science.gov (United States)

    Milia, A.; Torrente, M. M.; Tesauro, M.

    2017-07-01

    In this study, we describe the mode of extension of the Vavilov, a fossil backarc basin, triangle-shaped (approximately 240 km-wide and 200 km-long), located between Sardinia margin to the west and Campania margin to the east. We combine the analysis of recent geophysical and geological data, in order to investigate the relationship between the crustal/sedimentary structure and the tectonic evolution of both apex and bathyal parts of the basin. With this aim, we interpret a large data set of multichannel seismic reflection profiles and several well logs. We observe that the apex basin corresponds to a sediment-balanced basin, with a sedimentary infill recording the episodes of basin evolution. In contrast, the distal basin corresponds to an underfilled basin, characterized by localized volcanic activity and a thin sedimentary succession that covers the exhumed mantle. The basin architecture reveals the occurrence of rift and supradetachment basins in the Vavilov rift zone. We find that the rifting of the Vavilov triangular basin was synchronous from the apex to distal regions around a single Euler pole located in Latium, between 5.1 and 1.8 Ma. The kinematic evolution of the Vavilov basin occurred in two stages: initial pure shear mode (5.1-4.0 Ma) that produced high-angle normal faults and syn-sedimentary wedges, followed by simple shear mode (4.0-1.8 Ma) that caused supradetachment basins filled by a Transgressive-Regressive succession that documents high subsidence rates (1.22 mm/y) in the apex region. The final stage of extension in the distal region led to: (i) complete embrittlement of the crust; (ii) direct continuation of crustal faults to upper mantle depth; (iii) serpentinization and mantle exhumation. Based on constraints on the present-day crustal structure of the Vavilov basin, we obtain a stretching value (β = 3.5) and extension rates (3 cm/y) in the bathyal zone analogous to those reported for magma-poor rifted margins. We propose a synchronous

  14. 75 FR 22423 - Pick-Sloan Missouri Basin Program, Eastern and Western Division Proposed Project Use Power Rate

    Science.gov (United States)

    2010-04-28

    ... Bureau of Reclamation Pick-Sloan Missouri Basin Program, Eastern and Western Division Proposed Project... of the Pick-Sloan Missouri Basin Program, Eastern and Western Divisions, Proposed Project Use Power Rate Adjustment. ] SUMMARY: The Bureau of Reclamation is reopening the comment period for the...

  15. Tectonic history and structural development of the Zallah-Dur al Abd Sub-basin, western Sirt Basin, Libya

    Science.gov (United States)

    Abdunaser, Khalifa M.; McCaffrey, Ken J. W.

    2015-04-01

    The Zallah-Dur al Abd Sub-basin area lies in the western part of the Sirt Basin of Libya. 2D seismic data covering an area of about 32,000 km² were studied along with the formation tops from 240 wells. We mapped a complex network of normal and probable strike-slip faults, generally striking NNW-SSE that control the asymmetry of the basin. Subordinate NE-SW structures acted as transverse faults controlling local depocentres that segment the Zallah-Dur al Abd Sub-basin. A number of active faults in the intra-basin area have been identified in seismic sections with generally moderate to high dip angles, and displaying evidence for positive and negative flower structures. The bordering extensional fault (the Gedari fault) passes at depth into a moderately SW-dipping structure crossing most of the Upper Mesozoic to Cenozoic stratigraphic section. Thickness variations adjacent to other major faults suggest also an original extensional system where inherited high-angle faults were reactivated throughout this time. A detailed analysis of the available seismic reflection and drill hole data shows that an obliquely rifted, multi-cyclic, NNW-SSE trending basin developed during the complex Upper Mesozoic Cenozoic rearrangement of Mediterranean tectonics. Multiple phases of rifting can be observed in the study area affecting a number of different horizons from Upper Cretaceous to Eocene. In the study area, the basin was initiated as a result of a Tethyan oblique extensional rift system that began in the Early Cretaceous and peaked in the Late Cretaceous. The basin reached its rift maturation phase during the Upper Cretaceous as a result of the continuing extensional tectonics on the marginal bounding NNW-SSE trending normal growth faults. During the Alpine-related tectonic pulses of Middle-Late Eocene the Sirt Basin underwent compression resulted in northward tilting of the basin, causing abrupt subsidence in the north and uplift on the basin southern shoulders, possibly

  16. The petroleum potential of the passive continental margin of South-Western Africa : a basin modelling study

    OpenAIRE

    Schmidt, Sabine

    2004-01-01

    The Petroleum Potential of the Continental Margin of South-Western Africa - A Basin Modelling Study The hydrocarbon potential of the continental margin of south-western Africa was assessed with means of a 2D basin modelling study of the hydrocarbon generation, migration and accumulation of the Kudu gas field. The basin model is based on well and seismic data from offshore Namibia and constrained by geochemical data on source rocks, natural gas samples and hydrocarbons desorbed from near-surfa...

  17. Western spotted frog (Rana pretiosa) distribution in the Bonneville Basin of western Utah: Research in progress

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides information on the western spotted frog (Rana pretiosa) which occurs in Tule Valley, Utah. The following topics are discussed; general...

  18. Critical factors in the exploration of an Atlas intramontane basin: the Western Hodna Basin of northern Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mekireche, K. [Sonatrach, Algiers (Algeria). D.E.S. Div. Exploration; Sabaou, N.; Zazoun, R.-S. [Sonatrach, Algiers (Algeria). Centre de Recherche et Developpement

    1998-12-31

    The acquisition and evaluation of a substantial integrated surface outcrop and well database over the western Hodna Basin allows the identification of three critical factors (reservoir quality, source maturity and timing and hydrodynamic regime) to which well failures to date can largely be attributed. Reservoir quality is variable in Cretaceous sandstones, because of a high degree of quartz cementation, but improves to the south. Reservoir quality in Eocene limestones is related to the development of vuggy porosity and can now be mapped out from well control. Potential Cretaceous source rocks lie at moderate to high degrees of maturity, with expulsion probably preceding the Miocene phases of structure development. Based on the interpretations derived from structural, palaeogeography, diagenetic and hydrodynamic studies, the basin can be divided into three areas, which are ranked on the basis of their prospectivity. Each of the factors also needs to be critically assessed in analogous regions of the Atlas, in which such good geological control may not exist. (author)

  19. Tectonic and stratigraphic evolution of the Western Alboran Sea Basin in the last 25 Myrs

    Science.gov (United States)

    Do Couto, Damien; Gorini, Christian; Jolivet, Laurent; Lebret, Noëmie; Augier, Romain; Gumiaux, Charles; d'Acremont, Elia; Ammar, Abdellah; Jabour, Haddou; Auxietre, Jean-Luc

    2016-05-01

    The Western Alboran Basin (WAB) formation has always been the subject of debate and considered either as a back-arc or a forearc basin. Stratigraphic analyses of high-resolution 2D seismic profiles mostly located offshore Morocco, enabled us to clarify the tectonic and stratigraphic history of the WAB. The thick pre-rift sequence located beneath the Miocene basin is interpreted as the topmost Malaguide/Ghomaride complex composing the Alboran domain. The structural position of this unit compared with the HP-LT exhumed Alpujarride/Sebtide metamorphic basement, leads us to link the Early Miocene subsidence of the basin with an extensional detachment. Above the Early Miocene, a thick Serravallian sequence marked by siliciclastic deposits is nearly devoid of extensional structures. Its overall landward to basinward onlap geometry indicates that the WAB has behaved as a sag basin during most of its evolution from the Serravallian to the late Tortonian. Tectonic reconstructions in map view and in cross section further suggest that the basin has always represented a strongly subsiding topographic low without internal deformation that migrated westward together with the retreating slab. We propose that the subsidence of the WAB was controlled by the pull of the dipping subducting lithosphere hence explaining the considerable thickness (10 km) of the mostly undeformed sedimentary infill.

  20. Lineament and Morphometric Analysis for Watershed Development of Tarali River Basin, Western India

    Directory of Open Access Journals (Sweden)

    Vikrant Bartakke

    2013-06-01

    Full Text Available Tarali river is major tributary of River Krishna, which is flowing in western India. The study area lies between latitude 17°23' to 17°38' N and longitude 73°48' to 74°7' E. The area has steep to moderate slope and elevation ranges from 584 - 1171m above mean sea level. Basin exhibits hilly and mountain terrain forming ridges and Western Ghats with deep valley, plateaus and plain. The whole area can be obtained in topographical maps i.e. 47 G/14, 47 G/15 47 K/2, 47 K/3 covering area of about 627 sq.km, acquired from Survey of India. Present study includes lineament and morphometric analysis of Tarali River basin for management and conservation of watershed.

  1. Interbasinal marker intervals——A case study from the Jurassic basins of Kachchh and Jaisalmer, western India

    Institute of Scientific and Technical Information of China (English)

    PANDEY; Dhirendra; Kumar; FüRSICH; Franz; Theodor

    2009-01-01

    The Kachchh Basin and the Jaisalmer Basin are two neighboring Mesozoic sedimentary basins at the western margin of the Indian craton. The Jurassic succession of the Kachchh Basin is more complete and more fossiliferous than that of the Jaisalmer Basin. Consequently, intrabasinal correlation of the sedimentary units has been possible in the Kachchh Basin, but not in the Jaisalmer Basin. However, some marker beds existing in the Kachchh Basin can be recognized also in the Jaisalmer Basin. Ammonite evidence shows that they are time-equivalent. The following four units form marker intervals in both basins: (1) the pebbly rudstone unit with Isastrea bernardiana and Leptosphinctes of the Kaladongar Formation (Kachchh Basin) and the Isastrea bernardiana-bearing rudstone of the Jaisalmer Formation (Jaisalmer Basin) both represent transgressive systems tract deposits dated as Late Bajocian; (2) bioturbated micrites with anomalodesmatan bivalves within the Goradongar Yellow Flagstone Member (Kachchh Basin) and bioturbated units in the Fort Member (Jaisalmer Basin) represent maximum flooding zone deposits of the Middle to Late Bathonian; (3) trough-crossbedded, sandy packto grainstones of the Raimalro Limestone Member (Kachchh Basin) and the basal limestone-sandstone unit of the Kuldhar section of the Jaisalmer Formation (Jaisalmer Basin) correspond to Late Bathonain transgressive systems tract deposits; and (4) ferruginous ooid-bearing carbonates with hardgrounds of the Dhosa Oolite member (Kachchh Basin) and the middle part of the Jajiya Member (Jaisalmer Basin) are Oxfordian transgressive systems tract deposits. The fact that in both basins similar biofacies prevailed during certain time intervals demonstrates a common control of their depositional history. As the two basins represent different tectonic settings, the most likely controlling factors were the relative sea-level changes produced by eustatic processes, a common subsidence history of the northwestern margin of

  2. Lunar impact basins and crustal heterogeneity - New western limb and far side data from Galileo

    Science.gov (United States)

    Belton, Michael J. S.; Head, James W., III; Pieters, Carle M.; Greeley, Ronald; Mcewen, Alfred S.; Neukum, Gerhard; Klaasen, Kenneth P.; Anger, Clifford D.; Carr, Michael H.; Chapman, Clark R.

    1992-01-01

    Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (greater than 2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.

  3. Further Recognition of Petroleum Exploration Potential of Marine Carbonates in Western Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Lü Xiuxiang; Yang Haijun; Yang Ning; Zhao Fengyun; Ma Yujie

    2007-01-01

    A series of significant discoveries in marine carbonate rocks show great petroleum exploration potential in the Tarim Basin. However, the oil and gas fields discovered in the carbonate rocks are mainly distributed around the Manjiaer Sag in the eastern Tarim Basin. Some explorations occurred and no oil or gas field was discovered around the Awati Sag in the western Tarim Basin. Information from wells and outcrops reveals that there are excellent oil and gas source rock conditions around the Awati Sag. Transformed reef-shoal reservoirs could be formed in the Ordovician carbonate rocks with paleo-geographic background and hydrothermal conditions. Therefore, it is necessary to make a systematical study and overall evaluation of the potential of the periphery of the Awati Sag in terms of source rock evolution, resource potential, high-grade reservoir formation and distribution, and main factors controlling hydrocarbon migration and accumulation.

  4. XXI Century Climatology of Snow Cover for the Western River Basins of the Indus River System

    CERN Document Server

    Hasson, Shabeh ul; Lucarini, Valerio

    2012-01-01

    Under changing climate, freshwater resources of Hindu Kush-Karakoram-Himalaya (HKH) region can be affected by changes in temperature and in amount, type and distribution of precipitation. This can have serious implications for the water supply and in turn threaten the food security and economic wellbeing of Indus basin. Using MODIS daily snow products (Terra & Aqua), this study focuses on the assessment of the 2000-2010 snow cover dynamics on seasonal/annual basis against geophysical parameters (aspect, elevation and slope) for the so called western river basins of Indus River System (IRS), namely Indus, Kabul, Jhelum, Astore, Gilgit, Hunza, Swat, Shigar and Shyok basins. Results show that inputs from MODIS instrument provide unprecedented better opportunity to study by using GIS techniques the snow cover dynamics in the remote areas like HKH region at such hyper-temporal and finer planar resolution. Adapted non-spectral cloud filtering techniques have significantly reduced cloud coverage and improved sno...

  5. 78 FR 69095 - Agency Information Collection Activities; Proposed Collection; Comment Request; Food Canning...

    Science.gov (United States)

    2013-11-18

    ... Collection; Comment Request; Food Canning Establishment Registration, Process Filing, and Recordkeeping for... collection entitled ``Food Canning Establishment Registration, Process Filing, and Recordkeeping for... comment period to request comment on a proposed collection of information related to ``Food...

  6. Geochemistry of Brines from Salt Ore Deposits in Western Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    马万栋; 马海州; 谭红兵; 董亚萍; 张西营; 孙国芳

    2004-01-01

    In the geological evolution of the Tarim Basin, many transgressions and relictions happened. So there have been plentiful sources of salt. Moreover, because of uttermost drought, a lot of salt has been deposited. It is possible to find potash salt in this area. In our fieldwork, we have found salt and brine in western Tarim Basin. Based on a geological survey and the characteristics of sedimentary facies and paleogeography, this paper deals with the geochemical parameters and discusses the possibility of formation of potash salt in terms of the chemical analyses of samples collected from western Tarim Basin. Results of brine analysis lead to some conclusions: most of these salt brines have eluviated from very thick halite beds, mainly chloride-type salt and this kind of halite does not reach the stage of potash deposition in all aspects; WKSL (Wukeshalu) occupies a noticeable place, and we should attach importance to this district because there have been some indicators of the occurrence of potash deposits as viewed from the contents of Br and K. Finally, low Br contents are recognized in the Tarim Basin as a result of salt aggradation, and this point of view has been proved by the results of this experiment and the data available. It cannot depend upon the index of Br to judge the evolution stage of halite. We must look for other facies of potash except marine facies.

  7. Pluvial lakes in the Great Basin of the western United States: a view from the outcrop

    Science.gov (United States)

    Reheis, Marith C.; Adams, Kenneth D.; Oviatt, Charles G.; Bacon, Steven N.

    2014-01-01

    Paleo-lakes in the western United States provide geomorphic and hydrologic records of climate and drainage-basin change at multiple time scales extending back to the Miocene. Recent reviews and studies of paleo-lake records have focused on interpretations of proxies in lake sediment cores from the northern and central parts of the Great Basin. In this review, emphasis is placed on equally important studies of lake history during the past ∼30 years that were derived from outcrop exposures and geomorphology, in some cases combined with cores. Outcrop and core records have different strengths and weaknesses that must be recognized and exploited in the interpretation of paleohydrology and paleoclimate. Outcrops and landforms can yield direct evidence of lake level, facies changes that record details of lake-level fluctuations, and geologic events such as catastrophic floods, drainage-basin changes, and isostatic rebound. Cores can potentially yield continuous records when sampled in stable parts of lake basins and can provide proxies for changes in lake level, water temperature and chemistry, and ecological conditions in the surrounding landscape. However, proxies such as stable isotopes may be influenced by several competing factors the relative effects of which may be difficult to assess, and interpretations may be confounded by geologic events within the drainage basin that were unrecorded or not recognized in a core. The best evidence for documenting absolute lake-level changes lies within the shore, nearshore, and deltaic sediments that were deposited across piedmonts and at the mouths of streams as lake level rose and fell. We review the different shorezone environments and resulting deposits used in such reconstructions and discuss potential estimation errors. Lake-level studies based on deposits and landforms have provided paleohydrologic records ranging from general changes during the past million years to centennial-scale details of fluctuations during the

  8. 29 CFR 784.147 - Employees “employed in” canning.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Employees âemployed inâ canning. 784.147 Section 784.147... Fishing and Aquatic Products âcanningâ § 784.147 Employees “employed in” canning. All employees whose activities are directly and necessarily a part of the canning of the specified aquatic forms of life...

  9. 78 FR 57391 - Agency Information Collection Activities; Proposed Collection; Comment Request; Food Canning...

    Science.gov (United States)

    2013-09-18

    ... Collection; Comment Request; Food Canning Establishment Registration, Process Filing, and Recordkeeping for... technology. Food Canning Establishment Registration, Process Filing, and Recordkeeping for Acidified Foods... respondents respondent responses response Sec. Sec. 108.25(c)(1) and 108.35(c)(2); Food canning 2541 645 1...

  10. Reserve estimates in western basins: Unita Basin. Final report, Part III

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This study characterizes an extremely large gas resource located in low permeability, sandstone reservoirs of the Mesaverde group and Wasatch formation in the Uinta Basin, Utah. Total in-place resource is estimated at 395.5 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 3.8 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Two plays were included in this study and each was separately analyzed in terms of its tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources; in other words, to convert those resources to economically recoverable reserves. About 82.1% of the total evaluated resource is contained within sandstones that have extremely poor reservoir properties with permeabilities considered too low for commerciality using current frac technology.

  11. Mechanism of petroleum migration and accumulation in western China's superposed basins

    Institute of Scientific and Technical Information of China (English)

    Kang Yongshang; Li Peijun; Qi Xuefeng; Wen Yonghong; Li Shuijing

    2012-01-01

    In western China.most petroliferous basins are superposed due to their multi-periodic tectonic evolution,and the mechanisms of petroleum migration and accumulation are so complex that much more sophisticated methodologies are necessary for depiction of these mechanisms and identification of petroleum occurrences.For this purpose,in this article,a new methodology was formulated which includes:(1) vertical identification of petroleum migration and accumulation fluid dynamic systems in the superposed basins;(2) analysis of the effect of large scale regional faults and fault combinations on the fluids exchange between the vertically identified different systems;(3) analysis of petroleum migration and accumulation in each vertically identified system,and establishment of appropriate geological model of petroleum migration and accumulation for each vertically identified system.Using this methodology,the satisfactory results obtained in the Lunnan Uplift of Tarim Basin and Ludong Uplift of Jungar Basin case studies are:(1) existence of different vertical fluid dynamic systems in western China's superposed basins which are very necessary for understanding the mechanism of petroleum migration and accumulation;(2) in deep system,long-distance lateral petroleum migration and accumulation mainly take place along the long time exposed unconformity with weathered,fractured or karst reservoir rocks;(3) regional faults are the main conducts for fluids migration from deep system up to middle and/or upper systems.As to middle and/or upper systems,regional faults play a role of "petroleum source".Small faults within middle and/or upper systems conduct petroleum to carrier beds with less impeding force;(4) petroleum migrated from deep system vertically up to middle and/or upper systems will migrate laterally in carrier beds of these systems and accumulate to form pools near or far from faults.

  12. Hydrological processes in glacierized high-altitude basins of the western Himalayas

    Science.gov (United States)

    Jeelani, Ghulam; Shah, Rouf A.; Fryar, Alan E.; Deshpande, Rajendrakumar D.; Mukherjee, Abhijit; Perrin, Jerome

    2017-09-01

    Western Himalaya is a strategically important region, where the water resources are shared by China, India and Pakistan. The economy of the region is largely dependent on the water resources delivered by snow and glacier melt. The presented study used stable isotopes of water to further understand the basin-scale hydro-meteorological, hydrological and recharge processes in three high-altitude mountainous basins of the western Himalayas. The study provided new insights in understanding the dominant factors affecting the isotopic composition of the precipitation, snowpack, glacier melt, streams and springs. It was observed that elevation-dependent post-depositional processes and snowpack evolution resulted in the higher isotopic altitude gradient in snowpacks. The similar temporal trends of isotopic signals in rivers and karst springs reflect the rapid flow transfer due to karstification of the carbonate aquifers. The attenuation of the extreme isotopic input signal in karst springs appears to be due to the mixing of source waters with the underground karst reservoirs. Basin-wise, the input-output response demonstrates the vital role of winter precipitation in maintaining the perennial flow in streams and karst springs in the region. Isotopic data were also used to estimate the mean recharge altitude of the springs.

  13. Late Cenozoic continuous aridification in the western Qaidam Basin: evidence from sporopollen records

    Directory of Open Access Journals (Sweden)

    Y. F. Miao

    2013-03-01

    Full Text Available Cenozoic climate changes in inner Asia provide a basis for understanding linkages between global cooling, the Tibetan Plateau uplift, and possibly the development of the East Asian monsoon. Based on the compiled palynological results from the western Qaidam Basin, this study reconstructed an 18 Ma record of changing vegetation and paleoclimates since the middle Miocene. Thermophilic taxa percentages were highest between 18 and 14 Ma and decreased after 14 Ma, corresponding closely with the Middle Miocene Climatic Optimum (MMCO between 18 and 14 Ma and the following global climatic cooling. After 3.6 Ma, the thermophilic taxa percentages further decreased, showing the inevitable relations with the ice-sheets enlargement in the North Hemisphere. During the same period of time, the increase in xerophytic taxa percentages and decrease in conifers percentages imply aridification in both the basin and surrounding mountains since 18 Ma. These results indicate that global cooling mainly controlled the climate change from a relative warm-wet stage to a cold-dry stage during the late Cenozoic at the western Qaidam Basin, and that the Tibetan Plateau uplift also contributed in contrast to the East Asian summer monsoon.

  14. Crustal structure of the western Yamato Basin, Japan Sea, revealed from seismic survey

    Science.gov (United States)

    No, T.; Sato, T.; Kodaira, S.; Miura, S.; Ishiyama, T.; Sato, H.

    2015-12-01

    The Yamato Basin is the second largest basin of the Japan Sea. This basin is important to clarify its formation process. Some studies of crustal structure had been carried out in the Yamato Basin (e.g. Ludwig et al., 1975; Katao, 1988; Hirata et al., 1989; Sato et al., 2006). However, the relationship between formation process and crustal structure is not very clear, because the amount of seismic exploration data is very limited. In addition, since there is ODP Leg 127 site 797 (Tamaki et al., 1990) directly beneath our seismic survey line, we contributed to the study on the formation of the Yamato Basin by examining the relation between the ODP results and our results. During July-August 2014, we conducted a multi-channel seismic (MCS) survey and ocean bottom seismometer (OBS) survey to study the crustal structure of the western Yamato Basin. We present an outline of the data acquisition and results of the data processing and preliminary interpretations from this study. As a result of our study, the crust, which is about 12 km thick, is thicker than standard oceanic crust (e.g., Spudich and Orcutt, 1980; White et al., 1992) revealed from P-wave velocity structure by OBS survey. A clear reflector estimated to be the Moho can be identified by MCS profiles. The characteristics of the sedimentary layer are common within the survey area. For example, a strong coherent reflector that is estimated to be an opal-A/opal-CT BSR (bottom simulating reflector) (Kuramoto et al., 1992) was confirmed in the sediment of all survey lines. On the other hand, a coherent reflector in the crust was confirmed in some lines. It is identified as this reflector corresponding with the deformation structure in the sediment and basement.

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

    Science.gov (United States)

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

    2014-12-01

    Groundwater recharge is the primary source of aquifer replenishment, an important source of freshwater for human consumption and riparian area sustainability in semi-arid regions. It is critical to understand the current groundwater recharge regimes in groundwater basins throughout the Western U.S. and how those regimes might shift in the face of climate change, land use change and management manipulations that impact the availability and composition of groundwater resources. Watersheds in the Basin and Range Province are characterized by a variable precipitation regime of wet winters, and variable summer precipitation. The horst-graben structure of these basins lends itself to orographic and continental precipitation effects that make mountain block and mountain front recharge critical components of annual recharge. The current assumption is that the relative contributions to groundwater recharge by summer and winter precipitation vary throughout the province, with winter precipitation dominating in the northern parts of the region, and summer monsoonal precipitation playing a more significant role in the south, where the North American Monsoon extends its influence. To test this hypothesis, stable water isotope data of groundwater and precipitation from sites in Sonora, Mexico and the U.S. states of California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas were examined to characterize and compare groundwater recharge regimes throughout the region. Preliminary stable water isotope results from the southernmost Rio San Miguel Basin in Sonora, Mexico indicate that groundwater is composed of 64%±14% summer monsoon precipitation, in contrast to more northern basins where winter precipitation is the source of 79-90% of basin groundwater.

  16. Structure of the western Cumberland Basin : implications for coalbed-methane exploration

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, J.W.F. [Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences; Rygel, M.C. [Nebraska-Lincoln Univ., Lincoln, NE (United States). Dept. of Geosciences

    2006-07-01

    The Athol Syncline is a prominent structure in the western Cumberland Basin of Nova Scotia. The basin contains a Carboniferous succession and is currently a target for exploration for coalbed methane. Subsidence and tectonism in the Cumberland Basin were partly controlled by differential flow of Windsor Group evaporites. The Joggins Formation in the Athol Syncline is famous for preserved upright fossil trees. New seismic profiles reveal that the Athol Syncline has potential traps for conventional hydrocarbons where thick fluvial sand units rest against salt walls at the margins of minibasins. The Cumberland Group is thin and lacks significant coals. A basinwide comparison showed that salt withdrawal at depth was responsible for much of the subsidence responsible for the preservation of the coal-bearing Joggins Formation. Contouring of reflections in the seismic profiles provided better definition of the subsurface geometries and potential extent of coal-bearing units in the Athol syncline. The subsurface geometries revealed some new exploration targets for this and similar depocentres in the Maritimes Basin. Coal distribution was found to be influenced by both tectonism and differential withdrawal of evaporites.

  17. Cool-Season Moisture Delivery and Multi-Basin Streamflow Anomalies in the Western United States

    Science.gov (United States)

    Malevich, Steven B.

    Widespread droughts can have a significant impact on western United States streamflow, but the causes of these events are not fully understood. This dissertation examines streamflow from multiple western US basins and establishes the robust, leading modes of variability in interannual streamflow throughout the past century. I show that approximately 50% of this variability is associated with spatially widespread streamflow anomalies that are statistically independent from streamflow's response to the El Nino-Southern Oscillation (ENSO). The ENSO-teleconnection accounts for approximately 25% of the interannual variability in streamflow, across this network. These atmospheric circulation anomalies associated with the most spatially widespread variability are associated with the Aleutian low and the persistent coastal atmospheric ridge in the Pacific Northwest. I use a watershed segmentation algorithm to explicitly track the position and intensity of these features and compare their variability to the multi-basin streamflow variability. Results show that latitudinal shifts in the coastal atmospheric ridge are more strongly associated with streamflow's north-south dipole response to ENSO variability while more spatially widespread anomalies in streamflow most strongly relate to seasonal changes in the coastal ridge intensity. This likely reflects persistent coastal ridge blocking of cool-season precipitation into western US river basins. I utilize the 35 model runs of the Community Earth System Model Large Ensemble (CESMLE) to determine whether the model ensemble simulates the anomalously strong coastal ridges and extreme widespread wintertime precipitation anomalies found in the observation record. Though there is considerable bias in the CESMLE, the CESMLE runs simulate extremely widespread dry precipitation anomalies with a frequency of approximately one extreme event per century during the historical simulations (1920 - 2005). These extremely widespread dry events

  18. Agribusiness geothermal energy utilization potential of Klamath and Western Snake River Basins, Oregon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.

    1978-03-01

    Resource assessment and methods of direct utilization for existing and prospective food processing plants have been determined in two geothermal resource areas in Oregon. Ore-Ida Foods, Inc. and Amalgamated Sugar Company in the Snake River Basin; Western Polymer Corporation (potato starch extraction) and three prospective industries--vegetable dehydration, alfalfa drying and greenhouses--in the Klamath Basin have been analyzed for direct utilization of geothermal fluids. Existing geologic knowledge has been integrated to indicate locations, depth, quality, and estimated productivity of the geothermal reservoirs. Energy-economic needs and balances, along with cost and energy savings associated with field development, delivery systems, in-plant applications and fluid disposal have been calculated for interested industrial representatives.

  19. Dating the Late Cenozoic glacial sequence, Pieman River basin, western Tasmania, Australia

    Science.gov (United States)

    Augustinus, Paul C.

    1999-10-01

    The Pieman River basin, western Tasmania, displays one of the most complete Middle to Early Pleistocene glacial sequences from a Southern Hemisphere mid-latitude site. Most of the glacial deposits exceed the 14C limit, although mapping of the depositional units using morphostratigraphic, post-depositional weathering criteria and magnetostratigraphy, shows that the sediments of the Boco and Bobadil glaciation were deposited during the Brunhes normal chron (ferricretes and peat developed within and upon the sediment bodies whereby the deposits of the Boco and Bobadil glaciation are shown to be broadly correlative with Oxygen Isotope Stages 6 and 8, respectively. An older mid-Pleistocene glacial event (Animal Creek Glaciation) has also been recognised and dated to >275 kyr. Late Last (Margaret) Glaciation advances in the Pieman basin are much more restricted in extent and display evidence for multiple stillstand-readvance phases during the decay of the system, with most of the ice having disappeared by ˜14 kyr BP.

  20. Kinematic Evolution of the Western Pyrenees Thrust Front From Paleomagnetic Analysis on its Foreland Basin.

    Science.gov (United States)

    Almar, Y.; Beamud, E.; Muñoz, J. A.; Garcés, M.; Murelaga, X.

    2007-12-01

    The Pyrenees is a collisional orogen formed during the Alpine orogeny. Its southwestern frontal thrust was originated as a result of the Cenozoic inversion of preexisting extensional faults. The emplacement of the frontal thrust in the Western Pyrenees generated a foreland basin, which locally accumulated more than 4,500 meters of Tertiary sediments. The kinematic evolution of the Western Pyrenees thrust front is poorly constrained due to the scarcity of reliable age constraints within the Tertiary sediments. However, the good exposure conditions of syntectonic continental deposits in its foreland basin makes it an excellent scenario to carry out paleomagnetic and structural studies in order to unravel the kinematic history, geometry and evolution of the thrust front. A magnetostratigraphic composite section along the continental basin infill was sampled covering up to 3,000 m of succession. Correlation of the local magnetostratigraphy with the GPTS was helped by a new mammal fossil locality found in continental sediments and attributed to the Agenian local biozone Y (MN2D). The cronostratigraphy of the tectosedimentary units, ranging from lower Oligocene (Cr12r) to lower Miocene, provides further constraints on the timing of two main tectosedimentary events recorded as major unconformities within the basin infill. From this study, sedimentation rates have been also obtained. The analysis of several paleomagnetic sites revealed that no vertical axes rotations occurred in the Tertiary sediments regardless superimposed folding with oblique axes could be observed, and the proximity of adjacent structures as the Estella diapir and the Pamplona fault. Finally, the analysis of the anisotropy of magnetic susceptibility together with collected sedimentary data suggests that magnetic fabrics record both, a depositional and tectonic fabric.

  1. POSSIBILITIES FOR WASTE WATER UTITLIZATION FROM CANNING INDUSTRY

    Directory of Open Access Journals (Sweden)

    A. Kraevska

    2014-03-01

    Full Text Available Waste waters from the different processing sectors (branch, activities of the canning factories was investigated. It was established that the greatest organic pollution is a result of the production of frozen half-fried potatoes. The possibilities of reducing of the organic pollution by cultivating fungi of the genus Aspergillus and Trichoderma in the waste waters was studied.

  2. One step HIP canning of powder metallurgy composites

    Science.gov (United States)

    Juhas, John J. (Inventor)

    1990-01-01

    A single step is relied on in the canning process for hot isostatic pressing (HIP) powder metallurgy composites. The binders are totally removed while the HIP can of compatible refractory metal is sealed at high vacuum and temperature. This eliminates outgassing during hot isostatic pressing.

  3. Heat penetration and thermocouple location in home canning.

    Science.gov (United States)

    Etzel, Mark R; Willmore, Paola; Ingham, Barbara H

    2015-01-01

    We processed applesauce, tomato juice, and cranberries in pint jars in a boiling water canner to test thermal processing theories against home canning of high-acid foods. For each product, thermocouples were placed at various heights in the jar. Values for f h (heating), f cl (cooling), and F 82.2°C (lethality) were determined for each thermocouple location, and did not depend substantially on thermocouple location in accordance with heat transfer theory. There was a cold spot in the jar, but the cold spot during heating became the hot spot during cooling. During heating, the geometric center was the last to heat, and remained coldest the longest, but during coooling, it was also the last to cool, and remained hottest the longest. The net effect was that calculated lethality in home canning was not affected by thermocouple location. Most of the lethality during home canning occurred during air cooling, making cooling of home canned foods of great importance. Calculated lethality was far greater than the required 5-log reduction of spores in tomato juice and vegetative cells in cranberries, suggesting a wide margin of safety for approved home-canning processes for high-acid foods.

  4. Inferring lateral density variations in Great Geneva Basin, western Switzerland from wells and gravity data.

    Science.gov (United States)

    Carrier, Aurore; Lupi, Matteo; Clerc, Nicolas; Rusillon, Elme; Do Couto, Damien

    2017-04-01

    In the framework of sustainable energy development Switzerland supports the growth of renewable energies. SIG (Services Industriels de Genève) and the Canton of Geneva intend to develop the use of hydrothermal energy in western Switzerland. As a Mesozoïc-formed sedimentary basin, the Great Geneva Basin (GGB) shares geological and petrophysical similarities with the Munich area (Baviera, Germany) and Paris Basin (France). The latter already provide significant amounts of geothermal energy for district heating. The prospection phase has been launched in 2014 by SIG and aims at identifying relevant geological units and defining their geometries. Lower Cretaceous and Tertiary geological units have first been targeted as potential layers. At the depth we find these units (and according to the normal geothermal gradient), low enthalpy geothermal resources are rather expected. In this framework, our study aims at constraining and refining lateral and vertical heterogeneities of Quaternary to Cretaceous sedimentary layers in GGB. Linear velocity law is inverted at wells and then interpolated to the whole basin for each geological layer. Using time pickings from available data and Quaternary information from previous studies time to depth conversion is performed. Thickness map of every geological unit is then produced. Tertiary thickness ranges from 0 m at the NW border of the GGB at the foothill of the Jura Mountains to 3000 m in the SE of the GGB at the border with the French Alps. These observations are consistent with field and well observations. The produced thickness map will be used as a geometry support for gravity data inversion and then density lateral variations estimation. Unconstrained, and a priori constrained inversion has been performed in GGB using Gauss-Newton algorithms. Velocity versus density relationships will then enable to refine velocity law interpolation. Our procedure allowed us to reduce the uncertainty of key target formation and represents an

  5. The influence of industrial-scale canning on cadmium and lead levels in sardines and anchovies from commercial fishing centres of the Mediterranean Sea.

    Science.gov (United States)

    Galitsopoulou, Augoustina; Georgantelis, Dimitrios; Kontominas, Michael

    2012-01-01

    The current study encompassed a survey on the levels of toxic trace elements in two highly consumed fish species in commercial fishing centres of western, central and eastern Mediterranean Sea. A Zeeman GTA-AAS graphite furnace atomic absorption spectrometry system was used throughout the study. Toxicological evaluation of the samples revealed a low Cd content in the raw samples, ranging between 0.003 and 0.027 mg kg⁻¹. Pb presented significantly higher values, from 0.037 to 0.297 mg kg⁻¹, occasionally reaching the limit of 0.3 mg kg⁻¹. Heavy metal levels were particularly higher in bones, thus raising queries about the safe consumption of fish intended to be eaten as a whole, a very common practice for small fish and canned products. The influence of industrial-scale canning showed that canning enhanced heavy metal levels by 35%-80%. The effect of canning depended on metal type and reduction of moisture loss after the steam-roasting step of the canning procedure.

  6. Evolution of the Paleogene succession of the western Himalayan foreland basin

    Directory of Open Access Journals (Sweden)

    B.P. Singh

    2013-03-01

    Full Text Available The Paleogene succession of the Himalayan foreland basin is immensely important as it preserves evidence of India-Asia collision and related records of the Himalayan orogenesis. In this paper, the depositional regime of the Paleogene succession of the Himalayan foreland basin and variations in composition of the hinterland at different stages of the basin developments are presented. The Paleogene succession of the western Himalayan foreland basin developed in two stages, i.e. syn-collisional stage and post-collisional stage. At the onset, chert breccia containing fragments derived from the hanging walls of faults and reworked bauxite developed as a result of erosion of the forebulge. The overlying early Eocene succession possibly deposited in a coastal system, where carbonates represent barriers and shales represent lagoons. Up-section, the middle Eocene marl beds likely deposited on a tidal flat. The late Eocene/Oligocene basal Murree beds, containing tidal bundles, indicate that a mixed or semi-diurnal tidal system deposited the sediments and the sedimentation took place in a tide-dominated estuary. In the higher-up, the succession likely deposited in a river-dominated estuary or in meandering rivers. In the beginning of the basin evolution, the sediments were derived from the Precambrian basement or from the metasediments/volcanic rocks possessing terrains of the south. The early and middle Eocene (54.7–41.3 Ma succession of the embryonic foreland possibly developed from the sediments derived from the Trans-Himalayan schists and phyllites and Indus ophiolite of the north during syn-collisional stage. The detrital minerals especially the lithic fragments and the heavy minerals suggest the provenance for the late Eocene/Oligocene sequences to be from the recycled orogenic belt of the Higher Himalaya, Tethyan Himalaya and the Indus-suture zone from the north during post-collisional stage. This is also supported by the paleocurrent

  7. Seismic Structural Setting of Western Farallon Basin, Southern Gulf of California, Mexico.

    Science.gov (United States)

    Pinero-Lajas, D.; Gonzalez-Fernandez, A.; Lopez-Martinez, M.; Lonsdale, P.

    2007-05-01

    Data from a number of high resolution 2D multichannel seismic (MCS) lines were used to investigate the structure and stratigraphy of the western Farallon basin in the southern Gulf of California. A Generator-Injector air gun provided a clean seismic source shooting each 12 s at a velocity of 6 kts. Each signal was recorded during 6- 8 s, at a sampling interval of 1 ms, by a 600 m long digital streamer with 48 channels and a spacing of 12.5 m. The MCS system was installed aboard CICESE's (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada) 28 m research vessel Francisco de Ulloa. MCS data were conventionally processed, to obtain post- stack time-migrated seismic sections. The MCS seismic sections show a very detailed image of the sub-bottom structure up to 2-3 s two-way travel time (aprox. 2 km). We present detailed images of faulting based on the high resolution and quality of these data. Our results show distributed faulting with many active and inactive faults. Our study also constrains the depth to basement near the southern Baja California eastern coast. The acoustic basement appears as a continuous feature in the western part of the study area and can be correlated with some granite outcrops located in the southern Gulf of California islands. To the East, near the center of the Farallon basin, the acoustic basement changes, it is more discontinuous, and the seismic sections show a number of diffracted waves.

  8. Geochemical evaluation of oils and source rocks from the Western Siberian basin, U. S. S. R

    Energy Technology Data Exchange (ETDEWEB)

    Peters, K.E.; Huizinga, B.J. (Chevron Overseas Petroleum, Inc., San Ramon, CA (United States)); Moldowan, J.M. (Chevron Oil Field Research Co., Richmond, CA (United States)); Kontorovich, A.E.; Stasova, O. (Siberian Scientific Research Institute for Geology, Geophysics and Mineral Resources, Novobsibirsk (Russian Federation)); Demaison, G.J.

    1991-03-01

    Although the Western Siberian basin is among the most prolific in the world, there has been disagreement among Soviet geoscientists on the origin of the petroleum within this basin. Screening geochemical analyses were used to select several oils and potential source rocks for a preliminary study using detailed biomarker and supporting geochemistry. Possible sources for this petroleum include rocks of Middle Jurassic, Upper Jurassic, and Lower Cretaceous age. Results indicate that most of the analyzed Western Siberian oils, occurring in reservoirs from Middle Jurassic to Late Cretaceous in age, are derived from the Upper Jurassic Bazhenov Formation. The locations of the samples in the study generally correspond to the distribution of the most effective oil-generative parts of the Bazhenov Formation. Analyses show that the Bazhenov rock samples contain abundant marine algal and bacterial organic matter, preserved under anoxic depositional conditions. Biomarkers show that thermal maturities of the samples range from the early to late oil-generative window and that some are biodegraded. For example, the Salym No. 114 oil, which flowed directly from the Bazhenov Formation, shows a maturity equivalent to the late oil window. The Van-Egan no. 110 oil shows maturity equivalent to the early oil window and is biodegraded. This oil shows preferential microbial conversion of lower homologs of the 17{alpha}, 21{beta}(H)-hopanes to 25-nor-17{alpha}(H)-hopanes.

  9. Characteristics of Heavy Minerals in Tertiary System of Western Qaidamu Basin

    Institute of Scientific and Technical Information of China (English)

    PENG De-hua; WANG Chao-yong

    2005-01-01

    According to tectonic position and mineral inclusions, supply resource in western Qaidamu basin is divided into the front of Aerjinshan mountain and the front of Qimantageshan mountain. The former is mainly composed of zircon, garnet inclusions, indicating that its mother rocks are mainly metamorphic rocks. Gas and zircon, iron ore, carbon grain inclusions is common in the front of Qimantage mountain, indicating that its mother rock are mainly magmatite and mixed metamorphic rocks. The supply resource is abundant and tectonic movement is active in the joint of the two mountains. The western Qaidamu basin is further divided into 6 heavy mineral sub-regions according to their features of association and stable coefficient of heavy mineral. They are approximately corresponding to their sedimentary environment. Of the 6 sub-regions, the unstable region is corresponding to fluvial fan, middle stable region is corresponding to river-alluvial plain-delta, stable region is corresponding to river-alluvial plain -delta-offshore. The fragment transported distance is presumed based on stable coefficient. In vertical, stable coefficient of heavy mineral becomes small from Xiaganchai formation to Xiayoushashan formation, indicating that the supply resource became nearer and nearer.

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

    Science.gov (United States)

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

    2015-12-01

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

  11. Tectonic and Structural Controls of Geothermal Activity in the Great Basin Region, Western USA

    Science.gov (United States)

    Faulds, J. E.; Hinz, N.; Kreemer, C. W.

    2012-12-01

    We are conducting a thorough inventory of structural settings of geothermal systems (>400 total) in the extensional to transtensional Great Basin region of the western USA. Most of the geothermal systems in this region are not related to upper crustal magmatism and thus regional tectonic and local structural controls are the most critical factors controlling the locations of the geothermal activity. A system of NW-striking dextral faults known as the Walker Lane accommodates ~20% of the North American-Pacific plate motion in the western Great Basin and is intimately linked to N- to NNE-striking normal fault systems throughout the region. Overall, geothermal systems are concentrated in areas with the highest strain rates within or proximal to the eastern and western margins of the Great Basin, with the high temperature systems clustering in transtensional areas of highest strain rate in the northwestern Great Basin. Enhanced extension in the northwestern Great Basin probably results from the northwestward termination of the Walker Lane and the concomitant transfer of dextral shear into west-northwest directed extension, thus producing a broad transtensional region. The capacity of geothermal power plants also correlates with strain rates, with the largest (hundreds of megawatts) along the Walker Lane or San Andreas fault system, where strain rates range from 10-100 nanostrain/yr to 1,000 nanostrain/yr, respectively. Lesser systems (tens of megawatts) reside in the Basin and Range (outside the Walker Lane), where local strain rates are typically geothermal fields catalogued, step-overs or relay ramps in normal fault zones serve as the most favorable setting, hosting ~32% of the systems. Such areas have multiple, overlapping fault strands, increased fracture density, and thus enhanced permeability. Other common settings include a) intersections between normal faults and strike-slip or oblique-slip faults (27%), where multiple minor faults connect major structures and

  12. Late Cenozoic pollen records and paleoclimate in the western Qaidam Basin, Northern Tibetan Plateau

    Science.gov (United States)

    Miao, Y.

    2013-12-01

    Y. F. Miao1, X. M. Fang2*, F. L. Wu2, M. T. Cai2, C. H. Song3, Q. Q. Meng3 1 Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Institute, Chinese Academy of Sciences, Lanzhou, 730000, China 2 Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100085, China 3 School of Earth Science, Lanzhou University, Lanzhou, 730000, China * Corresponding author, E-mail address: fangxm@itpcas.ac.cn (X.M. Fang). Abstract: Cenozoic climate changes in inner Asia provide a basis for understanding linkages between global cooling, the Tibetan Plateau uplift, and possibly the development of the East Asian monsoon. Based on a compilation of palynological results from the western Qaidam Basin, this study reconstructed a 15 million years (Ma) record of changing vegetation and paleoclimates spanning the middle Miocene to present (comprising two series: ~18-5 Ma and ~3.1-0 Ma, respectively). The thermophilic percentages were highest between 18 and 14 Ma, and decreased after 14 Ma, closely corresponding to the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and the following global climatic cooling between 14 and 5 Ma. At the same time, decreases in the xerophytic and coniferous taxa percentages, and the increasing logarithmic ratio of non-arboreal pollen to arboreal pollen (ln (NAP/AP)), reveal the continuous aridification across both the basin and surrounding mountains. Between ~3.1-0 Ma, the percentages of the thermophilic, xerophytic and coniferous pollen as well as the ln (NAP/AP) imply further cooling and drying in this region since 3.1 Ma. We argue that these vegetation and climate patterns during the late Cenozoic western Qaidam Basin are primarily a result of the global cooling, with the Tibetan Plateau uplift and East Asian summer monsoon having contributions of lesser importance.

  13. Gas-and water-saturated conditions in the Piceance Basin, Western Colorado: Implications for fractured reservoir detection in a gas-centered coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T.E.; Decker, A.D.

    1995-10-01

    Mesaverde Group reservoirs in the Piceance Basin, Western Colorado contain a large reservoir base. Attempts to exploit this resource base are stymied by low permeability reservoir conditions. The presence of abundant natural fracture systems throughout this basin, however, does permit economic production. Substantial production is associated with fractured reservoirs in Divide Creek, Piceance Creek, Wolf Creek, White River Dome, Plateau, Shire Gulch, Grand Valley, Parachute and Rulison fields. Successful Piceance Basin gas production requires detailed information about fracture networks and subsurface gas and water distribution in an overall gas-centered basin geometry. Assessment of these three parameters requires an integrated basin analysis incorporating conventional subsurface geology, seismic data, remote sensing imagery analysis, and an analysis of regional tectonics. To delineate the gas-centered basin geometry in the Piceance Basin, a regional cross-section spanning the basin was constructed using hydrocarbon and gamma radiation logs. The resultant hybrid logs were used for stratigraphic correlations in addition to outlining the trans-basin gas-saturated conditions. The magnitude of both pressure gradients (paludal and marine intervals) is greater than can be generated by a hydrodynamic model. To investigate the relationships between structure and production, detailed mapping of the basin (top of the Iles Formation) was used to define subtle subsurface structures that control fractured reservoir development. The most productive fields in the basin possess fractured reservoirs. Detailed studies in the Grand Valley-Parachute-Rulison and Shire Gulch-Plateau fields indicate that zones of maximum structural flexure on kilometer-scale structural features are directly related to areas of enhanced production.

  14. Benthic macrofaunal production for a typical shelf-slope-basin region in the western Arctic Ocean

    Science.gov (United States)

    Lin, Heshan; Wang, Jianjun; Liu, Kun; He, Xuebao; Lin, Junhui; Huang, Yaqin; Zhang, Shuyi; Mou, Jianfeng; Zheng, Chengxing; Wang, Yu

    2016-02-01

    Secondary production by macrofaunal communities in the western Arctic Ocean were quantified during the 4th and 5th Chinese Arctic Scientific Expeditions. The total production and P/B ratio for each sector ranged from 3.8 (±7.9) to 615.6 (±635.5) kJ m-2 yr-1 and 0.5 (± 0.2) to 0.7 (± 0.2) yr-1, respectively. The shallow shelves in the western Arctic Ocean exhibited particularly high production (178.7-615.6 kJ m-2 yr-1), particularly in the two "hotspots" - the southern and northeastern (around Barrow Canyon) Chukchi Sea. Benthic macrofaunal production decreased sharply with depth and latitude along a shelf-slope-basin transect, with values of 17.0-269.8 kJ m-2 yr-1 in slope regions and 3.8-10.1 kJ m-2 yr-1 in basins. Redundancy analysis indicated that hydrological characteristics (depth, bottom temperature and salinity) and granulometric parameters (mean particle size, % sand and % clay) show significant positive/negative correlations with total production. These correlations revealed that the dominant factors influencing benthic production are the habitat type and food supply from the overlying water column. In the Arctic, the extreme environmental conditions and low temperature constrain macrofaunal metabolic processes, such that food and energy are primarily used to increase body mass rather than for reproduction. Hence, energy turnover is relatively low at high latitudes. These data further our understanding of benthic production processes and ecosystem dynamics in the context of rapid climate change in the western Arctic Ocean.

  15. Origin of fine carbonaceous particulate matter in the Western Mediterranean Basin: fossil versus modern sources

    Science.gov (United States)

    Cruz Minguillón, María.; Perron, Nolwenn; Querol, Xavier; Szidat, Sönke; Fahrni, Simon; Wacker, Lukas; Reche, Cristina; Cusack, Michael; Baltensperger, Urs; Prévôt, André S. H.

    2010-05-01

    The present work was carried out in the frame of the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean). The objective of this campaign is to study the aerosol pollution episodes occurring at regional scale during winter and summer in the Western Mediterranean Basin. As part of this campaign, this work focuses on identifying the origin of fine carbonaceous aerosols. To this end, fine particulate matter (PM1) samples were collected during two different seasons (February-March and July 2009) at two sites: an urban site (Barcelona, NE Spain) and a rural European Supersite for Atmospheric Aerosol Research (Montseny, NE Spain). Subsequently, 14C analyses were carried out on these samples, both in the elemental carbon (EC) fraction and the organic carbon (OC) fraction, in order to distinguish between modern carbonaceous sources (biogenic emissions and biomass burning emissions) and fossil carbonaceous sources (mainly road traffic). Preliminary results from the winter period show that 40% of the OC at Barcelona has a fossil origin whereas at Montseny this percentage is 30%. These values can be considered as unexpected given the nature of the sites. Nevertheless, the absolute concentrations of fossil OC at Barcelona and Montseny differ by a factor of 2 (the first being higher), since the total OC at Montseny is lower than at Barcelona. Further evaluation of results and comparison with other measurements carried out during the campaign are required to better evaluate the origin of the fine carbonaceous matter in the Western Mediterranean Basin. Acknowledgements: Spanish Ministry of Education and Science, for a Postdoctoral Grant awarded to M.C. Minguillón in the frame of Programa Nacional de Movilidad de Recursos Humanos del Plan nacional de I-D+I 2008-2011. Spanish Ministry of Education and Science, for the Acción Complementaria DAURE CGL2007-30502-E/CLI.

  16. Pre-mesozoic palinspastic reconstruction of the eastern great basin (Western United States).

    Science.gov (United States)

    Levy, M; Christie-Blick, N

    1989-09-29

    The Great Basin of the western United States has proven important for studies of Proterozoic and Paleozoic geology [2500 to 245 million years ago (Ma)] and has been central to the development of ideas about the mechanics of crustal shortening and extension. An understanding of the deformational history of this region during Mesozoic and Cenozoic time (245 Ma to the present) is required for palinspastic reconstruction of now isolated exposures of older geology in order to place these in an appropriate regional geographic context. Considerable advances in unraveling both the crustal shortening that took place during Mesozoic to early Cenozoic time (especially from about 150 to 50 Ma) and the extension of the past 37 million years have shown that earlier reconstructions need to be revised significantly. A new reconstruction is developed for rocks of middle Proterozoic to Early Cambrian age based on evidence that total shortening by generally east-vergent thrusts and folds was at least 104 to 135 kilometers and that the Great Basin as a whole accommodated approximately 250 kilometers of extension in the direction 287 degrees +/- 12 degrees between the Colorado Plateau and the Sierra Nevada. Extension is assumed to be equivalent at all latitudes because available paleomagnetic evidence suggests that the Sierra Nevada experienced little or no rotation with respect to the extension direction since the late Mesozoic. An estimate of the uncertainty in the amount of extension obtained from geological and paleomagnetic uncertainties increases northward from +/-56 kilometers at 36 degrees 30N to (-87)(+108) kilometers at 40 degrees N. On the basis of the reconstruction, the original width of the preserved part of the late Proterozoic and Early Cambrian basin was about 150 to 300 kilometers, about 60 percent of the present width, and the basin was oriented slightly more north-south with respect to present-day coordinates.

  17. Coupled basin-detachment systems as paleoaltimetry archives of the western North American Cordillera

    Science.gov (United States)

    Gébelin, Aude; Mulch, Andreas; Teyssier, Christian; Page Chamberlain, C.; Heizler, Matthew

    2012-06-01

    Stable isotope paleoaltimetry data from the Snake Range metamorphic core complex (MCC) and Sacramento Pass Basin (NV, USA) document that extensional mylonite zones and kinematically linked syntectonic basins reliably record paleotopography in the continental interior of western North America when compared to a sea-level reference. Here we show that this basin-MCC pair tracks meteoric fluid flow at different levels of actively extending crust in a high-topography region during Oligo-Miocene extension of the Basin and Range Province. For paleoaltimetry purposes we compare multi-proxy oxygen (δ18O) and hydrogen (δD) isotope data as well as geochronological information from the Snake Range MCC to a time-equivalent (ca. 20 Ma) stable isotopic proxy record from the Buckskin Mountains MCC (AZ, USA), which developed next to the Pacific Coast near Miocene sea level. We complement this paleoaltimetry study by comparing the Buckskin Mountains MCC data with older (˜35 Ma) lacustrine stable isotope and paleofloral records from the nearby House Range (UT, USA), whose paleoelevation has been determined independently through paleobotanical analysis. Each of the investigated compartments of the paleohydrologic system within the Snake Range MCC depicts a coherent scenario of low Oligo-Miocene δ18O and δD values of meteoric water that reflect precipitation sourced at high elevation. A 77‰ difference in δDwater between the Snake Range (δDwater˜-113‰) and the Buckskin Mountains (δDwater˜-36‰) is consistent with minimum mean paleoelevation of the Snake Range of about 3850±650 m above Miocene sea level. Additional support for such elevations comes from a comparison between the Buckskin Mountains MCC and the Eocene House Range basin (UT, USA) where differences in δ18Owater values are consistent with 2300±500 m minimum paleoelevation of the House Range. Based on the presence of brecciated rock-avalanche deposits within the Sacramento Pass Basin, we conclude that the

  18. Madagascar's escape from Africa: A high-resolution plate reconstruction for the Western Somali Basin and implications for supercontinent dispersal

    Science.gov (United States)

    Phethean, Jordan J. J.; Kalnins, Lara M.; van Hunen, Jeroen; Biffi, Paolo G.; Davies, Richard J.; McCaffrey, Ken J. W.

    2016-12-01

    Accurate reconstructions of the dispersal of supercontinent blocks are essential for testing continental breakup models. Here, we provide a new plate tectonic reconstruction of the opening of the Western Somali Basin during the breakup of East and West Gondwana. The model is constrained by a new comprehensive set of spreading lineaments, detected in this heavily sedimented basin using a novel technique based on directional derivatives of free-air gravity anomalies. Vertical gravity gradient and free-air gravity anomaly maps also enable the detection of extinct mid-ocean ridge segments, which can be directly compared to several previous ocean magnetic anomaly interpretations of the Western Somali Basin. The best matching interpretations have basin symmetry around the M0 anomaly; these are then used to temporally constrain our plate tectonic reconstruction. The reconstruction supports a tight fit for Gondwana fragments prior to breakup, and predicts that the continent-ocean transform margin lies along the Rovuma Basin, not along the Davie Fracture Zone (DFZ) as commonly thought. According to our reconstruction, the DFZ represents a major ocean-ocean fracture zone formed by the coalescence of several smaller fracture zones during evolving plate motions as Madagascar drifted southwards, and offshore Tanzania is an obliquely rifted, rather than transform, margin. New seismic reflection evidence for oceanic crust inboard of the DFZ strongly supports these conclusions. Our results provide important new constraints on the still enigmatic driving mechanism of continental rifting, the nature of the lithosphere in the Western Somali Basin, and its resource potential.

  19. Risk zones of human Leishmaniases in the Western Mediterranean basin: correlations between vector sand flies, bioclimatology and phytosociology.

    Science.gov (United States)

    Rispail, Philippe; Dereure, Jacques; Jarry, Daniel

    2002-06-01

    Correspondence analysis was applied to sand fly sampling in 865 stations from the Western Mediterranean basin. The position of each of 24 species was determined with respect to the bioclimatic belts. Thus, the multidimensional analyses manifest clear correlations between bioclimatic belts and their expression in the area, the phytosociological groupings, and vector species of visceral and cutaneous leishmaniases. The transfer of these data to usual maps allows to delimit the geographical distribution of these diseases in the Western Mediterranean basin and contributes to the determination, in a rational manner, of the high risk zones.

  20. Regional variations in home canning practices and the risk of foodborne botulism in the Republic of Georgia, 2003.

    Science.gov (United States)

    Tarkhashvili, N; Chokheli, M; Chubinidze, M; Abazashvili, N; Chakvetadze, N; Imnadze, P; Kretsinger, K; Varma, J; Sobel, J

    2015-04-01

    Foodborne botulism is a severe, paralytic illness caused by ingestion of preformed neurotoxins produced by Clostridium botulinum. In 2003, we conducted a population-based household survey of home canning practices to explore marked regional variations in botulism incidence in the Republic of Georgia (ROG). We designed a cluster sampling scheme and subdivided each of the 10 regions of the ROG into a variable number of strata. Households were selected from each stratum using a two-step cluster sampling methodology. We administered a questionnaire about home canning practices to household members responsible for food preparation. Using multivariate logistic regression analysis, we modeled high (eastern ROG) against low (western ROG) incidence areas. Overall, we surveyed 2,742 households nationwide. Home canning with a capping device hermetically sealing the lid covering the jar was practiced by 1,909 households (65.9%; 95% confidence interval [CI]: 59.8 to 72.1%). Canning was more prevalent in regions of low botulism incidence (34 versus 32%; P canning vegetables and consuming them (adjusted odds ratio [aOR] = 2.1; 95% CI: 1.3 to 3.5) and adding any of the following ingredients to the jar at time of preparation: >1 tablespoon of salt per liter (aOR = 5.1; 95% CI: 1.2 to 22.6); vinegar (aOR = 2.2; 95% CI: 1.3 to 3.7), and greens (aOR = 5.6; 95% CI: 1.7 to 18.2). The following practices were associated with a decreased risk in high-botulism areas: >57 jars canned per household annually (aOR = 0.5; 95% CI: 0.3 to 0.9), covering or immersing vegetables in boiling water before placing them into the jar (aOR = 0.3 95% CI: 0.2 to 0.6), covering or immersing vegetables in boiling water after placing them into the jar (aOR = 0.4; 95% CI: 0.2 to 0.9), or adding garlic (aOR = 0.2; 95% CI: 0.1 to 0.5) or aspirin (aOR = 0.1; 95% CI: 0.1 to 0.2) to the jar at the time of preparation.

  1. Quantification of sediment supply : a method and an example from Triassic of Western European basins

    Science.gov (United States)

    Peron, S.; Bourquin, S.; Duran, M.; Fluteau, F.; Guillocheau, F.

    2003-04-01

    Triassic is a key period of Earth history, with tectonic, climatic and eustatic events. It corresponds to (i) the initial fragmentation of the Pangea, (ii) a transition from Paleozoic ice house to Mesozoic green house, (iii) a sea-level rise from Upper Triassic, followed by an eustatic fall during Lias. This special geological setting has led to the formation of large Mesozoic basins, mainly characterized by a continental sedimentation, with fluvial and/or evaporitic environments, well-conserved in Pangean supercontinent. This Triassic specificity implies a total free space for sedimentation, i.e. accommodation (A), balanced with an important sediment supply (S), as SgeA.The purpose of this study is to develop a good methodology for understanding the S parameter in past geological systems, as Triassic. Firstly, by considering three key periods of Triassic : (1) the Lower Scythian, (2) the Lower Ladinian, (3) the Carnian-Norien ; we have realized paleogeographic and paleotopographic maps either for Western Europe or entire world. These reconstructions allow us to precise (i) erosional or sedimentary areas, (ii) coastal lines and sebkha boundaries, (iii) river basins and continental systems associated. Moreover, by using an atmospheric general circulation model (AGCM), we are actually simulating the climatic response by applying data of maps for Triassic European areas. By this way, we are able to obtain different parameters of climate (rainfall, temperature variations,...) in order to test the effect on topography, evaporitic plains and climate interactions. In parallel, paleoenvironmental maps allow us to separate three main fluvial systems developed during the Triassic period : (1) larged braided alluvial systems in vast endoreic basins that characterize the transitional stage between the Zeichstein system (Permian) and the Tethyan system (Triassic) ; (2) anastomosed systems whose preservation is controlled by sea-level (Anisian and Middle Carnian) ; (3) alluvial

  2. Ceramic clays from the western part of the Tamnava Tertiary Basin, Serbia: Deposits and clay types

    Directory of Open Access Journals (Sweden)

    Radosavljević Slobodan

    2014-01-01

    Full Text Available Based on geological, mineralogical, physical, chemical and technological investigations in the Tamnava Tertiary Basin near Šabac town (western Serbia, deposits of ceramic clays were studied. These ceramic clays are composed of kaolin-illite with a variable content of quartz, feldspars, mica, iron oxides and hydroxides, and organic matter. Four main types of commercial clays were identified: i red-yellow sandy-gravely (brick clays; ii grey-white poor sandy (ceramic clays; iii dark-carbonaceous (ceramic clays; and iv lamellar (“interspersed” fatty, poor sandy (highly aluminous and ferrous clays. Ceramic clays are defined as medium to high plastic with different ranges of sintering temperatures, which makes them suitable for the production of various kinds of materials in the ceramic industry. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016

  3. The "Teflon basin" myth: Snow-soil interactions in mountain catchments in the western US

    Science.gov (United States)

    Williams, M. W.; Cowie, R. M.

    2015-12-01

    In much of western North America, snow and snowmelt provide the primary means for storage of winter precipitation, effectively transferring water from the relatively wet winter season to the typically dry summers. A common assumption is that high-elevation catchments in the western United States behave like "Teflon basins" and that water released from seasonal storage in snow packs flows directly into streams with little or no interaction with underlying soils. Here I present information from a variety of catchments in the Colorado Front Range on snowmelt/soil interactions using isotopic, geochemical, nutrient and hydrometric data in 2- and 3- component hydrograph separations, along with end-member mixing analysis (EMMA). For most catchments we measured these parameters in weekly precipitation, the seasonal snowpack, snowmelt before contact with the ground, discharge, springs, soil solution, and groundwater. We ran EMMA at the catchment scale for catchments that represent the rain-snow transition zone in the montane forest, the seasonally snow covered sub-alpine to alpine transition zone, and a high-elevation alpine zone near the continental divide. In all catchments three end-members were the source waters for about 95% of discharge. Two end-members were the same in all catchments, snow and groundwater. For the alpine catchment talus springs was the third water source, while rain was the third water source in the two lower-elevation catchments. For all three catchments, soil solution plotted with stream waters along or near a line connecting the snow and groundwater end-members. Thus, for seasonally snow-covered catchments from montane to alpine ecosystems, snowmelt infiltrates underlying soils before snowmelt recharges groundwater reservoirs and contributes to surface flows. Seasonally snow-covered catchments are not Teflon basins. Rather, snowmelt infiltrates soils where solute concentrations are changed by biological and geochemical processes.

  4. Surface exposure dates of cirque basin deglaciation along a western Ireland transect

    Science.gov (United States)

    Barth, A. M.; Clark, J.; Clark, P. U.; McCabe, A.

    2013-12-01

    During the last deglaciation (20ka -11ka), variations in the Atlantic Meridional Overturning Circulation (AMOC), accompanied by changes in North Atlantic Deep Water production, caused centennial-to-millennial abrupt climate change. Because of Ireland's proximity to North Atlantic deep-water convection sites, changes in climate associated with variations in the AMOC would be particularly pronounced there, and are recorded by fluctuations of the Irish Ice Sheet. Many of Ireland's mountains also hosted cirque glaciers during the last glaciation, which would have been particularly sensitive to abrupt climate changes of the last deglaciation. Dating of cirque glacier moraines with cosmogenic nuclides can provide a millennial-scale reconstruction of variability in these highly sensitive cirque glaciers. We report 11 new 10Be ages from two cirques basins in County Mayo, western Ireland. A moraine adjacent to Lougaharry Lough near Killary Harbour suggests deglaciation at 13.81 × 0.14 ka during the Bølling-Allerød interval. Two moraines, one inner and one outer, at Lough Accorymore on Achill Island returned ages of 17.04 × 0.31 ka and 18.43 × 0.79 ka, respectively. Both Accorymore dates are Oldest Dryas in age and suggest variability during the millennial-scale Clogher Head Stadial in Ireland. To develop a more regional reconstruction of glacier-climate variability during the last deglaciation, we have also sampled moraines from cirque basins spanning western Ireland from County Kerry in the south to County Donegal in the north. Boulders were sampled from a total of 23 moraines from seven additional cirques to provide this more expansive coverage.

  5. Preliminary study on avian fauna of the Krishna River basin Sangli District, Western Maharashtra, India.

    Science.gov (United States)

    Kumbar, Suresh M; Ghadage, Abhijit B

    2014-11-01

    The present study on avifaunal diversity carried out for three years at the Krishna River Basin, Sangli District revealed a total of 126 species of birds belonging to 30 families, of which 91 species were resident, 16 migratory, 12 resident and local migratory and 7 species were resident and migratory. Among the migrant birds, Rosy Starling Sturnus roseus was dominant in the study area. Commonly recorded resident bird species were, Red vented bulbul, Jungle crow, House sparrow, Common myna, Brahminy myna, Rock pigeon, Spotted dove, Rose ringed parakeet, Indian robin, White-browed fantail-flycatcher and Small sunbird. Most of the families had one or two species, whereas Muscicapidae family alone had 16 species. Forty one species of waterfowls were recorded in this small landscape. Out of 126 bird species, 38 were insectivorous, 28 piscivorous, 25 omnivorous, 19 carnivorous, 9 granivorous, 5 frugivorous and 2 species were nectar sucker and insectivorous. These results suggest that richness of avifauna in the Krishna River Basin, Western Maharashtra might be due to large aquatic ground, varied vegetations and favourable environmental conditions.

  6. Hydrogeological evolution of the Luni river basin, Rajasthan, western India: A review

    Indian Academy of Sciences (India)

    V N Bajpai

    2004-09-01

    The Luni river basin has been evolved as a result of typical hydrogeomorphic processes of arid zone, operating under the influence of active tectonic lineaments. A detailed analysis of stream morphology in relation to geology and lineaments carried out on selected windows indicated the morphological control of the streams while flowing over the lineaments from the eastern to the western part of the basin. Typical valley fills indicated by dark green tone on digitally processed images and the pediments showing greenish white tone appear in sharp contrast and indicate respectively the graben and horst structures. A detailed identification of lineaments for the georesources and geological evaluation has been carried out. Earlier analysis carried out on Bouguer anomalies correlate with graben and horst structures in the subsurface. Quaternary sequences have been dated from 80 ka to 3 ka indicating a range of fluvial to aeolian deposits reflecting prevailing climatic conditions. However, the changes in sediment type from coarse and mixed of all size grades to fine in a vertical litho-column warrant further studies on fine resolution stratigraphy and high resolution stratigraphy for understanding climatic variations in the region.

  7. Water mass characteristics in the deep layers of the western Ionian Basin observed during May 2003

    Science.gov (United States)

    Hainbucher, D.; Rubino, A.; Klein, B.

    2006-03-01

    CTD measurements carried out in the southern Adriatic Sea and in the western Ionian basin (Eurafrican Mediterranean Sea) during May 2003 by the German research vessel Poseidon (Poseidon cruise 298) and numerical simulations are used to elucidate aspects of the abyssal circulation of this oceanic region. The observations reveal that dense waters of Adriatic origin were strongly diluted along their way on the Italian continental slope, whilst their characteristics remained better preserved in a region located further east. Numerical simulations carried out by means of a nonlinear, reduced-gravity plume model confirm the observations and contribute to explain their cause: The very steep topographic slope along the Italian shelf in the region of the Gulf of Taranto induces strong entrainment of intermediate waters in the bottom layers. Instead, the bottom waters of Adriatic origin which, along their path further east, encounter gentler topographic variations, are weakly diluted by turbulent mixing and, therefore, better preserve their original characteristics. The remarkable differences in the simulated turbulent mixing along these two different paths are accentuated by the presence of a noticeable zonal gradient of potential density existing in the near-bottom layers of the northern Ionian basin.

  8. Application of the European water framework directive in a Western Mediterranean basin (Málaga, Spain)

    Science.gov (United States)

    Carrasco, F.; Sánchez, D.; Vadillo, I.; Andreo, B.; Martínez, C.; Fernández, L.

    2008-04-01

    The water framework directive (WFD) is applied within the Guadalhorce river basin, a Western Mediterranean basin in the Málaga province (South Spain). Criteria defining different surface and groundwater bodies are described. The basic hydrographic network is constituted of low-mountain and low-altitude Mediterranean mineralized rivers. Heavily modified surface water bodies correspond (1) to areas where dams regulate the main watercourses, (2) to areas downstream of reservoirs, where river flow is reduced, and (3) to the coastal sector of the river where artificial channelling has caused morphological variations. Groundwater bodies are related to carbonate and porous aquifers and, locally, to aquifers influenced by dissolution of evaporites. The main impacts to water bodies are irrigated lands and livestock farming. There are also point sources of pollution, such as wastewater, landfills, golf courses, industrial zones, quarries and petrol stations. In addition, groundwater is frequently pumped for human supply and irrigation. Qualitative status of groundwater bodies was done by chemical analysis of samples from a monitoring network and the quantitative status by examining variations in piezometric levels. Both revealed the existence of water bodies at risk of not meeting the environmental objectives of the WFD. The main indicators of pollution are nitrates related to agricultural activities, and total organic carbon (TOC), PO{4/3-} and NH{4/+} in relation to wastewater.

  9. Late Quaternary stratigraphic development in the lower Luni, Mahi and Sabarmati river basins, western India

    Indian Academy of Sciences (India)

    M Jain; S K Tandon; S C Bhatt

    2004-09-01

    This study reviews the Quaternary alluvial stratigraphy in three semi-arid river basins of western India i.e., lower Luni (Rajasthan), and Mahi and Sabarmati (Gujarat alluvial plains). On the basis of OSL chronologies, it is shown that the existing intra-valley lithostratigraphic correlations require a revision. The sand, gravel and mud facies are present during various times in the three basins, however, the fluvial response to climate change, and the resulting facies associations, was different in the Thar desert as compared to that at the desert margin; this makes purely lithostratigraphic correlations unviable. It is further shown that the rivers in the Thar desert were more sensitive to climate change and had small response times and geomorphic thresholds as compared to the desert-margin rivers. This is illustrated during the early OIS 1, when the Luni river in the Thar desert was dynamic and showed frequent variations in fluvial styles such as gravel bedload braided streams, sand-bed ephemeral streams and meandering streams, all followed by incision during the early Holocene. The coeval deposits in Sabarmati, however, only show a meandering, floodplain-dominated river. Late Quaternary alluvial deposits in these basins unconformably overlie some older deposits that lack any absolute chronology. Based on the facies types and their associations, and the composition and architecture of the multistoried gravel sheets in the studied sections, it is suggested that older deposits are of pre-Quaternary age. This hypothesis implies the presence of a large hiatus incorporating much of the Quaternary period in the exposed sections.

  10. Multiproxy Study of a Holocene Record From Western Pescadero Basin, Gulf of California, Mexico: Paleoclimatic inferences

    Science.gov (United States)

    Perez-Cruz, L. L.; Valdez, M.; Roy, P. D.

    2013-12-01

    A sedimentary sequence (gravity core T-56, 256 cm length) from Pescadero Basin on the western side of the Gulf of California is analyzed as part of a multiproxy study. The core was collected within the Oxygen Minimum Zone (OMZ) at 597 m depth, aboard of the R/V "El Puma". Pescadero basin is located at mouth of the gulf; in a location sensitive to record the changes in the gulf and the Eastern Pacific Ocean. The sedimentary sequence is analyzed to contribute to understanding the climatic variability in the southern part of the gulf of California during the Holocene using geochemistry (major and trace elements and Corg), magnetic properties and benthic foraminifera assemblages as proxy of changes in paleoproductivity, paleoprecipitation and bottom water oxygenation. The core is characterized by silty-clay sediments, and exhibits a turbidite between 130 and 235 cm, distinguished by sandy sediments and reworking material. From 130 cm to the top it shows a visible laminated structure. Chronology is based on six AMS radiocarbon dates, and estimated sedimentation rates are 0.22, 0.18, 0.17 and 0.05 mm/yr. The core covers c. last 10,500 years. Variations in major and trace elements (Ti, K, Al, K, Zr) and magnetic susceptibility indicate fluctuations in terrigenous input related to changes in hydrological conditions, Benthic foraminifera assemblages and Corg along the sequence indicate that Pescadero basin is sensitive to paleoceanographic changes. Corg and benthic foraminiferal assemblages show downcore variations related to paleoproductivity changes. For the Early Holocene, low values of Corg and epifaunal benthic foraminifera suggest oxic conditions in bottom waters and strong stratification with low productivity. Organic carbon shows higher values towards the bottom of the core, for the last 1300 years.

  11. Structural modelling of thrust zones utilizing photogrammetry: Western Champsaur basin, SE France

    Science.gov (United States)

    Totake, Yukitsugu; Butler, Rob; Bond, Clare

    2016-04-01

    Recent advances in photogrammetric technologies allow geoscientists to easily obtain a high-resolution 3D geospatial data across multiple scales, from rock specimen to landscape. Although resolution and accuracy of photogrammetry models are dependent on various factors (a quality of photography, number of overlapping photo images, distance to targets, etc), modern photogrammetry techniques can even provide a comparable data resolution to laser scanning technologies (modelling of various geological objects. Another advantages of photogrammetry techniques, high portability and low costs for infrastructures, ease to incorporate these techniques with conventional geological surveys. Photogrammetry techniques have a great potential to enhance performances of geological surveys. We present a workflow for building basin-scale 3D structural models utilizing the ground-based photogrammetry along with field observations. The workflow is applied to model thrust zones in Eocene-Oligocene turbidite sequences called Champsaur Sandstone (Gres du Champsaur) filling an Alpine fore-deep basin, Western Champsaur basin, in southeastern France. The study area is located ca. 20km northeast from Gap, and approximately extends 10 km from east to west and 6 km from north to south. During a 2-week fieldwork, over 9400 photographs were taken at 133 locations by a handheld digital camera from ground, and were georeferenced with a handheld GPS. Photo images were processed within software PhotoScan to build a 3D photogrammetric model. The constructed photogrammetry model was then imported into software Move to map faults and geological layers along with georeferenced field data so that geological cross sections and 3D surfaces are produced. The workflow succeeded to produce a detailed topography and textures of landscape at ~1m resolution, and enabled to characterize thrust systems in the study area at bed-scale resolution. Three-dimensionally characterized architectures of thrust zones at high

  12. Sedimentary Basins in the Western White Nile, Sudan, as Indicated by a Gravity Survey

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An academic geophysical research as a regional gravity survey was made during 1994 in the Western White Nile to infer the shallow crustal structures in the area. The result of the survey was compiled as a Bouguer anomaly map with a contour interval of 2 ×10-5m/s2. It is found that the negative residual anomalies are related to the Upper Cretaceous sediments (Nubian Sandstone Formation) filling all depressions in the Basement complex surface while the positive residual anomalies are attributed to the relatively shallow or outcropping Basement rocks and the steep gravity gradients are resulting from the sharp contacts between the sedimentary infill and the Basement rocks. To define the geological structures in the area, 9 profiles were studied. For each of the profiles, measured and computed Bouguer gravity anomalies, crustal density model, subsurface geology evaluation were performed. A G-model computer program was applied in the gravity modeling, which is based on the line-integral method of gravity computation. A geological/structural map was proposed showing inferred sedimentary basins, faulting troughs and uplifted Basement block and tectonic trends. The basins are believed to be fault-controlled which developed by extensional tectonics (pull-apart mechanism). As for the mechanism and cause of faulting, the area is considered as a part of the Central Sudan rift system which had been subjected to several tectonic events since Early Cambrian to Tertiary times which resulted in the formation of several fracture systems associated with block subsidence, rifting and basin formation.

  13. Snow cover trend and hydrological characteristics of the Astore River basin (Western Himalayas) and its comparison to the Hunza basin (Karakoram region).

    Science.gov (United States)

    Tahir, Adnan Ahmad; Chevallier, Pierre; Arnaud, Yves; Ashraf, Muhammad; Bhatti, Muhammad Tousif

    2015-02-01

    A large proportion of Pakistan's irrigation water supply is taken from the Upper Indus River Basin (UIB) in the Himalaya-Karakoram-Hindukush range. More than half of the annual flow in the UIB is contributed by five of its snow and glacier-fed sub-basins including the Astore (Western Himalaya - south latitude of the UIB) and Hunza (Central Karakoram - north latitude of the UIB) River basins. Studying the snow cover, its spatio-temporal change and the hydrological response of these sub-basins is important so as to better manage water resources. This paper compares new data from the Astore River basin (mean catchment elevation, 4100 m above sea level; m asl afterwards), obtained using MODIS satellite snow cover images, with data from a previously-studied high-altitude basin, the Hunza (mean catchment elevation, 4650 m asl). The hydrological regime of this sub-catchment was analyzed using the hydrological and climate data available at different altitudes from the basin area. The results suggest that the UIB is a region undergoing a stable or slightly increasing trend of snow cover in the southern (Western Himalayas) and northern (Central Karakoram) parts. Discharge from the UIB is a combination of snow and glacier melt with rainfall-runoff at southern part, but snow and glacier melt are dominant at the northern part of the catchment. Similar snow cover trends (stable or slightly increasing) but different river flow trends (increasing in Astore and decreasing in Hunza) suggest a sub-catchment level study of the UIB to understand thoroughly its hydrological behavior for better flood forecasting and water resources management.

  14. 75 FR 1408 - Pick-Sloan Missouri Basin Program, Eastern and Western Division Proposed Project Use Power Rate

    Science.gov (United States)

    2010-01-11

    ... Bureau of Reclamation Pick-Sloan Missouri Basin Program, Eastern and Western Division Proposed Project Use Power Rate AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of Proposed Pick-Sloan Missouri... Reclamation (Reclamation) is proposing a rate adjustment (proposed rate) for Project Use Power for the...

  15. Cenozoic uplift of the Tibetan Plateau: Evidence from the tectonic–sedimentary evolution of the western Qaidam Basin

    Directory of Open Access Journals (Sweden)

    Yadong Wang

    2012-03-01

    Full Text Available Geologists agree that the collision of the Indian and Asian plates caused uplift of the Tibet Plateau. However, controversy still exists regarding the modes and mechanisms of the Tibetan Plateau uplift. Geology has recorded this uplift well in the Qaidam Basin. This paper analyzes the tectonic and sedimentary evolution of the western Qaidam Basin using sub-surface seismic and drill data. The Cenozoic intensity and history of deformation in the Qaidam Basin have been reconstructed based on the tectonic developments, faults growth index, sedimentary facies variations, and the migration of the depositional depressions. The changes in the sedimentary facies show that lakes in the western Qaidam Basin had gone from inflow to still water deposition to withdrawal. Tectonic movements controlled deposition in various depressions, and the depressions gradually shifted southeastward. In addition, the morphology of the surface structures in the western Qaidam Basin shows that the Cenozoic tectonic movements controlled the evolution of the Basin and divided it into (a the southern fault terrace zone, (b a central Yingxiongling orogenic belt, and (c the northern fold-thrust belt; divided by the XI fault (Youshi fault and Youbei fault, respectively. The field data indicate that the western Qaidam Basin formed in a Cenozoic compressive tectonic environment caused by the India–Asia plate collision. Further, the Basin experienced two phases of intensive tectonic deformation. The first phase occurred during the Middle Eocene–Early Miocene (Xia Ganchaigou Fm. and Shang Ganchaigou Fm., 43.8–22 Ma, and peaked in the Early Oligocene (Upper Xia Ganchaigou Fm., 31.5 Ma. The second phase occurred between the Middle Miocene and the Present (Shang Youshashan Fm. and Qigequan Fm., 14.9–0 Ma, and was stronger than the first phase. The tectonic–sedimentary evolution and the orientation of surface structures in the western Qaidam Basin resulted from the Tibetan

  16. Climate change and land-use change impact on Western African river basins

    Science.gov (United States)

    Mariotti, Laura; Coppola, Erika; Giorgi, Filippo

    2010-05-01

    The main resource in western Africa is agriculture and therefore availability and quality of fresh water resources threaten food production in many regions. Quantifying the impact of climate and land-use change in very vulnerable regions like western Africa is therefore of crucial importance for developing appropriate adaptation and mitigation strategies. In this work the International Center for theoretical Physic (ICTP) regional climate model (RegCM3) is used to perform a 120 (1980-2100) years climate change simulation under the A1B scenario using ECHAM5 as boundary condition (BC). To further investigate which it would be the combined effect of the land-use change together with the climate change a 10 years time simulation has been completed using the future projected land-use from IIASA (The International Institute for Applied Systems Analysis). Both simulations have been coupled with a physical based fully distributed hydrological model (CHyM) to asses which it would be the final effect of climate and land-use change on the river discharge. The two rivers used for this analysis are the Niger and Volta basin. The CHyM model has been validated coupling fist the hydrological model with a perfect boundary regional model simulation using ERA-interim as BC and using the runoff observations available along the two river basins. The model is able to reproduce the monthly seasonal cycle in both river basins reasonably well, therefore this allow us to use the same setting for a climate and land-use change simulation. Two hydrological time slice simulations have been performed with and without land-use change included. Results are presented and discussed for the monsoon season (JJA) on a station based, for the same stations used for validation purposed, but also the spatial change in discharge is presented in both cases and compared with the simple precipitation change observed in the region. Although the portion of change in precipitation due to the green house gases

  17. Late Holocene record of sedimentologic and paleooceanographic events in western Guaymas Basin, Gulf of California

    Science.gov (United States)

    McGann, M.; Paull, C. K.; Herguera, J. C.; Barron, J. A.; Gwiazda, R.; Anderson, K.; Lundsten, E. M.; Edwards, B. D.; Caress, D. W.

    2015-12-01

    Transects of ≤1.5 m-long vibracores obtained with MBARI's ROV Doc Ricketts reveal late Holocene sedimentologic and paleooceanographic events in western Guaymas Basin, Gulf of California (GOC) (~26.87°N, 111.338°W). Cores were located where layered near-seafloor sediments and subtle bedforms occur in 1793 to 1863 m water depths on the SW flank of the basin using detailed bathymetry and chirp profiles. Color banding was observed in the cores and gamma-density, XRF, grain size, and stable isotope data show that most of the banding is attributed to distal deposition from two turbidities. Distinctive white bands ~4 cm thick are present in three cores dispersed across ~300 m. The white bands are diatom oozes composed primarily of Thalassiothrix longissima as well as lesser abundances of Fragilariopsis doliolus and are probably a result of aggregations of Thalassiothrix-dominated mats that settle through the water column and accumulate on the seafloor. An AMS14C date taken ~3 cm above the white band in one core suggests this event occurred shortly before cal AD 1290±30. The core sites were most likely located beneath an important oceanographic front between nutrient-rich and oligotrophic water masses, probably as the result of well-mixed upper intermediate and surface waters in the mid-GOC and better-stratified tropical waters to the south. This implies the existence of a deeper mixed layer to the N in the mid GOC region most likely controlled by equatorial La Niña events fueled by stronger and more persistent NW winds along the GOC. A substantial reduction in diatom abundance evident by low specimen counts and lack of white bands following this mat-forming event seem to correlate with an abrupt decline in biosiliceous productivity and increases in the abundance of tropical diatoms and silicoflagellates in core MD02-2517 (887 m water depth; western Guaymas Basin slope) at the end of the Medieval Climate Anomaly and transition to the Little Ice Age (~AD 1200-1300).

  18. Western Gas Sands Project. Quarterly basin activities report, October 1-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    This report is a summation of three months drilling and testing activitie in the four primary study areas of the WGSP: Greater Green River Basin, Northern Great Plains Province, Piceance Basin, and Uinta Basin.

  19. Water vapour accumulation mechanisms in the Western Mediterranean Basin and the development of European extreme rainfalls

    Directory of Open Access Journals (Sweden)

    E. Sáez de Cámara

    2011-01-01

    Full Text Available This paper examines the role of a recently described warm season circulation at the middle troposphere of northern Africa and that of the recirculation-accumulation mode of the Western Mediterranean Basin (WMB in the initiation of rainfall episodes in central and eastern Europe. Both of these atmospheric mechanisms can accumulate not only soil dust and pollutants for several days but also water vapour by evaporation both over the subtropical Atlantic and the western and central Mediterranean. Accumulation layers are vented off into the surrounding area after the irruption of perturbations. In particular, this work explores the exportation of water vapour under perturbed conditions associated with the passage of ‘Vb’ cyclones. The exceptional rainfall experienced over large areas of central Europe (Elbe/Danube floods during August 11-13, 2002 is exposed as a case study. The procedure to simulate the mechanisms involves a combination of the Regional Atmospheric Modelling System and HYbrid PArticle Concentration and Transport modelling systems. MODIS water vapour products, radio-soundings, wind profiler radars and surface-satellite precipitation data are used to verify the simulation outputs. Our results show that most of the precipitation occurring in the target area during the initiation and deepening of the episode was very likely originated in an air mass exported from the WMB. After our tracking experiment, that air mass, with an initial Atlantic origin, entered the WMB and circulated during 4 days (August 6-9 within the marine boundary layer and the coastal range of mountains of the WMB, accumulating vapour. Then, most of it was transported on August 10, after the irruption of the 'Vb' cyclone Ilse, through the Italian Peninsula and the Adriatic Sea, across the Western Balkans into the target area. The transported vapour together with evaporation en route initiated the rainfall episode.

  20. Seismic and Gravity Investigations of the Western Espanola Basin, Rio Grande Rift, New Mexico

    Science.gov (United States)

    Braile, L. W.; Coldren, B. G.; Baca, A.; Fontana, J.; Olheiser, M.; Ziff, M.; Keske, A.; Rhode, A.; Martin-Short, R.; Allen, W.; Denton, K. M.; Harper, C.; Baldridge, W.; Biehler, S.; Ferguson, J. F.; McPhee, D.; Snelson, C. M.

    2013-12-01

    The SAGE (Summer of Applied Geophysical Experience) program collected new seismic, gravity, electromagnetic and down-hole temperature data in 2013 in the western Espanola basin of the Rio Grande rift area of northern New Mexico. The location, about 25 km NW of Santa Fe, has been identified as a potential geothermal resources area based on relatively high temperature gradients in drill holes. The SAGE 2013 data collection was part of an integrated geophysical study of the area initiated in 2011. Seismic data consisted of a 4.8 km W to E profile (120 three-component stations in four overlapping deployments, 20 m station spacing, using a Vibroseis source - 20 m spacing for reflection VPs; 800 m spacing for refraction VPs) with both refraction and CMP reflection coverage. About 55,000 seismograms were recorded. The surface conditions (dry unconsolidated sediments) increased surface wave energy and limited the signal-to-noise level of the refraction and reflection arrivals. Utilizing longer source-receiver offsets improved the shot-gather record sections by emphasizing wider angle reflections which are very strong and coherent. The refraction data were modeled with first arrival travel time methods. The reflection data were processed to produce a CMP stacked record section. Strong reflectors from basin-filling sedimentary rocks (mostly Tertiary in age) are visible above reflections from a thin section of Paleozoic rocks and the basement. The lower reflections have an apparent dip to the west of about 12 degrees. Eighty-one new gravity measurements (detailed data at 200 m spacing along the seismic profile, and regional stations) were collected and combined with existing regional data for modeling. Interpretation of the seismic and gravity data was aided by refraction velocities, the existence of a nearby regional seismic reflection profile from industry, and lithologies and well-logs from a deep well. The sedimentary basin interpreted from the seismic and gravity data

  1. Hydrogeochemical comparison and effects of overlapping redox zones on groundwater arsenic near the Western (Bhagirathi sub-basin, India) and Eastern (Meghna sub-basin, Bangladesh) margins of the Bengal Basin

    Science.gov (United States)

    Mukherjee, Abhijit; von Brömssen, Mattias; Scanlon, Bridget R.; Bhattacharya, Prosun; Fryar, Alan E.; Hasan, Md. Aziz; Ahmed, Kazi Matin; Chatterjee, Debashis; Jacks, Gunnar; Sracek, Ondra

    2008-07-01

    Although arsenic (As) contamination of groundwater in the Bengal Basin has received wide attention over the past decade, comparative studies of hydrogeochemistry in geologically different sub-basins within the basin have been lacking. Groundwater samples were collected from sub-basins in the western margin (River Bhagirathi sub-basin, Nadia, India; 90 samples) and eastern margin (River Meghna sub-basin; Brahmanbaria, Bangladesh; 35 samples) of the Bengal Basin. Groundwater in the western site (Nadia) has mostly Ca-HCO3 water while that in the eastern site (Brahmanbaria) is much more variable consisting of at least six different facies. The two sites show differences in major and minor solute trends indicating varying pathways of hydrogeochemical evolution However, both sites have similar reducing, postoxic environments (pe: + 5 to - 2) with high concentrations of dissolved organic carbon, indicating dominantly metal-reducing processes and similarity in As mobilization mechanism. The trends of various redox-sensitive solutes (e.g. As, CH4, Fe, Mn, NO3-, NH4+, SO42-) indicate overlapping redox zones, leading to partial redox equilibrium conditions where As, once liberated from source minerals, would tend to remain in solution because of the complex interplay among the electron acceptors.

  2. Groundwater quality in the Western San Joaquin Valley study unit, 2010: California GAMA Priority Basin Project

    Science.gov (United States)

    Fram, Miranda S.

    2017-06-09

    Water quality in groundwater resources used for public drinking-water supply in the Western San Joaquin Valley (WSJV) was investigated by the USGS in cooperation with the California State Water Resources Control Board (SWRCB) as part of its Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The WSJV includes two study areas: the Delta–Mendota and Westside subbasins of the San Joaquin Valley groundwater basin. Study objectives for the WSJV study unit included two assessment types: (1) a status assessment yielding quantitative estimates of the current (2010) status of groundwater quality in the groundwater resources used for public drinking water, and (2) an evaluation of natural and anthropogenic factors that could be affecting the groundwater quality. The assessments characterized the quality of untreated groundwater, not the quality of treated drinking water delivered to consumers by water distributors.The status assessment was based on data collected from 43 wells sampled by the U.S. Geological Survey for the GAMA Priority Basin Project (USGS-GAMA) in 2010 and data compiled in the SWRCB Division of Drinking Water (SWRCB-DDW) database for 74 additional public-supply wells sampled for regulatory compliance purposes between 2007 and 2010. To provide context, concentrations of constituents measured in groundwater were compared to U.S. Environmental Protection Agency (EPA) and SWRCB-DDW regulatory and non-regulatory benchmarks for drinking-water quality. The status assessment used a spatially weighted, grid-based method to estimate the proportion of the groundwater resources used for public drinking water that has concentrations for particular constituents or class of constituents approaching or above benchmark concentrations. This method provides statistically unbiased results at the study-area scale within the WSJV study unit, and permits comparison of the two study areas to other areas assessed by the GAMA Priority Basin Project

  3. Empirical models to predict the volumes of debris flows generated by recently burned basins in the western U.S.

    Science.gov (United States)

    Gartner, J.E.; Cannon, S.H.; Santi, P.M.; deWolfe, V.G.

    2008-01-01

    Recently burned basins frequently produce debris flows in response to moderate-to-severe rainfall. Post-fire hazard assessments of debris flows are most useful when they predict the volume of material that may flow out of a burned basin. This study develops a set of empirically-based models that predict potential volumes of wildfire-related debris flows in different regions and geologic settings. The models were developed using data from 53 recently burned basins in Colorado, Utah and California. The volumes of debris flows in these basins were determined by either measuring the volume of material eroded from the channels, or by estimating the amount of material removed from debris retention basins. For each basin, independent variables thought to affect the volume of the debris flow were determined. These variables include measures of basin morphology, basin areas burned at different severities, soil material properties, rock type, and rainfall amounts and intensities for storms triggering debris flows. Using these data, multiple regression analyses were used to create separate predictive models for volumes of debris flows generated by burned basins in six separate regions or settings, including the western U.S., southern California, the Rocky Mountain region, and basins underlain by sedimentary, metamorphic and granitic rocks. An evaluation of these models indicated that the best model (the Western U.S. model) explains 83% of the variability in the volumes of the debris flows, and includes variables that describe the basin area with slopes greater than or equal to 30%, the basin area burned at moderate and high severity, and total storm rainfall. This model was independently validated by comparing volumes of debris flows reported in the literature, to volumes estimated using the model. Eighty-seven percent of the reported volumes were within two residual standard errors of the volumes predicted using the model. This model is an improvement over previous models in

  4. Orbital forcing in the early Miocene alluvial sediments of the western Ebro Basin, Northeast Spain

    Science.gov (United States)

    Garces, M.; Larrasoaña, J. C.; Muñoz, A.; Margalef, O.; Murelaga, X.

    2009-04-01

    Paleoclimatic reconstructions from terrestrial records are crucial to assess the regional variability of past climates. Despite the apparent direct connection between continental sedimentary environments and climate, interpreting the climatic signature in ancient non-marine sedimentary sequences is often overprinted by source-area related signals. In this regard, foreland basins appear as non-ideal targets as tectonically-driven subsidence and uplift play a major control on the distribution and evolution of sedimentary environments and facies. Foreland basins, however, often yield among the thickest and most continuous stratigraphic records available on continents. The Ebro Basin (north-eastern Spain) is of particular interest among the circum-mediterranean alpine foreland basins because it evolved into a land-locked closed basin since the late Eocene, leading to the accumulation of an exceptionally thick (>5500 m) and continuous sequence of alluvial-lacustrine sediments over a period of about 25 Myr. In this paper we present a detailed cyclostratigraphic study of a 115 m thick section in the Bardenas Reales de Navarra region (western Ebro Basin) in order to test orbital forcing in the Milankovitch frequency band. The study section corresponds to the distal alluvial-playa mud flats which developed in the central sector of the western Ebro Basin, with sediments sourced from both the Pyrenean and Iberian Ranges. Sediments consist of brown-red alluvial clay packages containing minor fine-grained laminated sandstones sheet-beds and channels, grey marls and thin bedded lacustrine limestones arranged in 10 to 20 m thick fining-upwards sequences. Red clayed intervals contain abundant nodular gypsum interpreted as representing a phase of arid and low lake level conditions, while grey marls and limestones indicate wetter intervals recording the expansion of the inner shallow lakes. A magnetostratigraphy-based chronology indicates that the Peñarroya section represents a

  5. Stress Map 2.0: Updating the Stress Map of the Western Canadian Sedimentary Basin

    Science.gov (United States)

    Mallyon, D.; Schmitt, D. R.; Currie, C. A.; Gu, Y. J.; Heidbach, O.

    2015-12-01

    The greatest horizontal compression in much of the Western Canada Sedimentary Basin appears to uniformly trend NE-SW. Beyond this, major gaps remain in our knowledge of stress magnitudes and even faulting regimes. This lack of quantitative information impedes a proper understanding of seismic events that appear to be linked to hydraulic fracturing stimulations. Apart from this immediate concern, such seismicity could impact long term green-house gas sequestration and geothermal energy development. As part of the Helmholtz-Alberta geothermal collaboration, we are developing a program to update this crustal stress state information. The program consists of more immediate studies related to conventional analysis of borehole image logs, core fractures, and transient pressure records as can be made available. Data sets analyzed to date include logs to 3.5 km depth from areas experiencing induced seismicity, from 2.5 km depth within the Precambrian craton in NE Alberta, and to 400 m depth within a large carbonate platform. All these data largely confirm the NE-SW stress directions. In some cases, the configurations of drilling induced tensile fractures and borehole breakouts allow the faulting regime to be constrained. The addition of new seismometers to the region is also allowing for the refinement of earthquake focal mechanisms. Finally, a dramatic contrast in lithosphere thickness, composition and geothermal gradient exists at the contact between the Cordillera and the North American craton; therefore, lithosphere-scale numerical models are also being developed to quantify the relative contribution of geodynamic processes, such as mantle flow and contact geometry, to the observed stress regime within the basin.

  6. Classification scheme for acid rock drainage detection - the Hamersley Basin, Western Australia

    Science.gov (United States)

    Skrzypek, Grzegorz; Dogramaci, Shawan; McLean, Laura

    2017-04-01

    In arid environment where precipitation and surface water are very limited, groundwater is the most important freshwater resource. For this reasons it is intensively exploited and needs to be managed wisely and protected from pollutants. Acid rock drainage often constitutes a serious risk to groundwater quality, particularly in catchments that are subject to mining, large scale groundwater injection or abstraction. However, assessment of the potential acid rock drainage risk can be challenging, especially in carbonate rich environment, where the decreasing pH that usually accompanies pyrite oxidation, can be masked by the high pH-neutralisation capacity of carbonate minerals. In this study, we analysed 73 surface and groundwater samples from different water bodies and aquifers located in the Hamersley Basin, Western Australia. Although the majority of samples had a neutral pH, there was a large spatial variability in the dissolved sulphate concentrations that ranged from 1 mg/L to 15,000 mg/L. Waters with high dissolved sulphate concentration were found in areas with a high percentage of sulphide minerals (e.g. pyrite) located within the aquifer matrix and were characterised by low δ34SSO4 values (+1.2‰ to +4.6) consistent with signatures of aquifer matrix pyritic rock samples (+1.9‰ to +4.4). It was also found that the SO4 concentrations and acidity levels were not only dependent on δ34SSO4 values and existence of pyrite but also on the presence of carbonate minerals in the aquifer matrix. Based on the results from this study, a classification scheme has been developed for identification of waters impacted by acid rock drainage that also encompasses numerous concomitant geochemical processes that often occur in aqueous systems. The classification uses five proxies: SO4, SO4/Cl, SI of calcite, δ34SSO4 and δ18OSO4 to improve assessment of the contribution that oxidation of sulphide minerals has to overall sulphate ion concentrations, regardless of acidity

  7. Tube structures of probable microbial origin in the Neoarchean Carawine Dolomite, Hamersley Basin, Western Australia.

    Science.gov (United States)

    Murphy, M A; Sumner, D Y

    2008-01-01

    The approximately 2.63 Ga Carawine Dolomite, Hamersley Basin, Western Australia, preserves tube structures of probable microbial origin that formed in a low energy environment. The tubes are 0.4-1.8 cm in diameter and at least 10-16 cm long in outcrop. The tubes are defined by dark, 45-microm-thick dolomicritic walls, whereas the tube fill and host rock are composed of 30 microm, cloudy dolomite crystals and rare 170- to 425-microm-wide, dark well-sorted clasts. Closely spaced, rarely discontinuous laminae coat the insides of tubes; less closely spaced, peaked, discontinuous laminae coat the outsides of tubes. The laminae on the outsides of tubes are often intercalated with mammilate structures. The presence of probable microbial coatings on both the insides and the outsides of the tube walls requires that the tubes formed above the sediment-water interface. These tube structures probably formed during gas-charged fluid escape, similar to tubes observed in ancient and modern hydrocarbon seeps and cylindrical water transfer structures in sandstones. The laminae that coat the tubes have very similar geometries to modern biofilms that form in both turbulent and laminar flow, and their geometries probably reflect flow conditions during the fluid escape. The identification of these structures suggests that the preserved interaction between fluid escape and microbial growth in carbonates may be more common than previously thought.

  8. Delineation of uplifting and subsiding zones in the Western Pannonian Basin using sinousity analysis

    Science.gov (United States)

    Gál, Judit; Kovács, Gábor; Zámolyi, András.; Pál, Lénárd; Székely, Balázs

    2010-05-01

    The recent tectonic setting of the Pannonian-basin is partly caracterised by different uplift and subsident pattern. Our study area the western part of the Bakony-Hill is currently uplifting while the neighbouring Little Hungarian Plane subsides. The contact zone of this two domain can be outline only from seismic profiles and borehole data. This normal faulting represented displacement int he seismic profile, however cannot be traced up to the surface. The depth conditions can only be partly recontsructed because we use TWT data, but there is evidence that early pannonian strata are faulted. In order to trace the faulted we analysed several seismic profile. We anticipate, that there motions inply surface this placement. Slope angles are therefore are disturbed, the valley slopes are modified and the river courses are sensitive to that change and accomodate to the new setting, restoring the original channel slope. Analysing the sinousity of these river course. We can inply to the differential uplift pattern. Historic maps were used for river course velineation, The Second Military Survey of the Habsburg Empire (1806-1869) perfect possibility for that. This mapsheets record the pre-regulation conditions of the hidrological system, this situation is the closest to the natural unmodified state.

  9. Regional trends in radiogenic heat generation in the Precambrian basement of the Western Canadian Basin

    Science.gov (United States)

    Jones, F. W.; Majorowicz, J. A.

    Radiogenic heat generation values for 381 basement samples from 229 sites in the western Canadian basin exhibit a lognormal frequency distribution. The mean value = 2.06 (S.D. = 1.22) µWm-3 is larger than the radiogenic heat generation values reported for the shield in the Superior (ca. 1.2 µWm-3, Jessop and Lewis, 1978) and Churchill (ca. 0.7 µWm-3, Drury, 1985) provinces. When equal Log A contour intervals are used to map the basement heat generation, three large zones of relatively high heat generation are found. One coincides with the Peace River Arch basement structure and one with the Athabasca axis (Darnley, 1981). There is no apparent indication of increased heat flow through the Paleozoic formations associated with these two zones. The third zone, in southwestern Saskatchewan, coincides with a high heat flow zone in the Swift Current area. The lack of correlation between heat flow and heat generation in Alberta may be due to the disturbance to the heat flow in the Paleozoic formations by water motion, or may indicate that the heat is from uranium, thorium and potassium isotope enrichment near the basement surface rather than enrichment throughout the entire upper crust.

  10. Managing the Cumulative Impacts of Land Uses in the Western Canadian Sedimentary Basin: A Modeling Approach

    Directory of Open Access Journals (Sweden)

    Richard, R. Schneider

    2003-07-01

    Full Text Available This case study from northeastern Alberta, Canada, demonstrates a fundamentally different approach to forest management in which stakeholders balance conservation and economic objectives by weighing current management options from the point of view of their long-term effects on the forest. ALCES®, a landscape-scale simulation model, is used to quantify the effects of the current regulatory framework and typical industrial practices on a suite of ecological and economic indicators over the next 100 yr. These simulations suggest that, if current practices continue, the combined activities of the energy and forestry industries in our 59,000 km2 study area will cause the density of edge of human origin to increase from 1.8 km/km 2 to a maximum of 8.0 km/km2. We also predict that older age classes of merchantable forest stands will be largely eliminated from the landscape, habitat availability for woodland caribou will decline from 43 to 6%, and there will be a progressive shortfall in the supply of softwood timber beginning in approximately 60 yr. Additional simulations involving a suite of "best practices" demonstrate that substantial improvements in ecological outcome measures could be achieved through alternative management scenarios while still maintaining a sustainable flow of economic benefits. We discuss the merits of our proposed approach to land use planning and apply it to the Western Canadian Sedimentary Basin.

  11. Inception and demise of a Neoproterozoic ocean basin: evidence from the Ougda complex, western Hoggar (Algeria)

    Science.gov (United States)

    Dostal, J.; Caby, R.; Dupuy, C.; Mevel, C.; Owen, J. V.

    1996-12-01

    The Neoproterozoic Ougda magmatic complex occurs within platformal carbonate rocks in the western part of the Pan-African fold belt of the Tuareg shield (NW Africa). It is composed of - 800 Ma old, relatively high P-T (i.e., Grt + Cpx-bearing: P > 5 kbar; T≈900'Q, tholeiitic mafic/ultramafic cumulates and related rocks intruded by intermediate to mafic calcalkali plutons (e.g., Cpx+Hbl-bearing gabbro) and dikes. Apparent contrasts in structural level of crystallization indicate that the calc-alkali rocks are significantly younger than the tholeiites, which temporally correlate with a period of regional extension in this part of Africa. Intrusion of the calc-alkali rocks may have occurred during the formation of an arc after the tholeiitic rocks had been (diapirically?) emplaced within the shelf carbonates, and prior to (> 630 Ma) the Pan-African orogeny. Data reported herein indicate that the Ougda complex records the inception and demise of a Neoproterozoic ocean basin. Similar crustal sections have been described from collisional (e.g., Aleutian islands) and extensional (e.g., Ivreä-Verbano zone) settings, indicating that processes operating in both environments can generate nearly indistinguishable igneous suites; the prevalence of shallow-level calc-alkali rocks in both settings may mask the presence of more mafic, tholeiitic rocks at depth.

  12. Tritium clouds environmental impact in air into the Western Mediterranean Basin evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Castro, P., E-mail: paloma.castro@ciemat.es [EURATOM-CIEMAT Association, LNF Fusion National Laboratory, BBTU, Avda Complutense,40 28040 Madrid (Spain); Velarde, M. [ETSII Nuclear Fusion Institute: DENIM, Madrid (Spain); Ardao, J. [AEMET, Environmental Applications Service, 28040 Madrid (Spain); Perlado, J.M. [ETSII Nuclear Fusion Institute: DENIM, Madrid (Spain); Sedano, L. [EURATOM-CIEMAT Association, LNF Fusion National Laboratory, BBTU, Avda Complutense,40 28040 Madrid (Spain)

    2012-08-15

    The paper considers short-term releases of tritium (mainly but not only tritium hydride (HT)) to the atmosphere from a potential ITER-like fusion reactor located in the Mediterranean Basin and explores if the short range legal exposure limits are exceeded (both locally and downwind). For this, a coupled Lagrangian ECMWF/FLEXPART model has been used to follow real time releases of tritium. This tool was analyzed for nominal tritium operational conditions under selected incidental conditions to determine resultant local and Western Mediterranean effects, together with hourly observations of wind, to provide a short-range approximation of tritium cloud behavior. Since our results cannot be compared with radiological station measurements of tritium in air, we use the NORMTRI Gaussian model. We demonstrate an overestimation of the sequence of tritium concentrations in the atmosphere, close to the reactor, estimated with this model when compared with ECMWF/FLEXPART results. A Gaussian 'mesoscale' qualification tool has been used to validate the ECMWF/FLEXPART for winter 2010/spring 2011 with a database of the HT plumes. It is considered that NORMTRI allows evaluation of tritium-in-air-plume patterns and its contribution to doses.

  13. Evolution of Rotations in the Fish Creek Vallecito Basin, Western Salton Trough, CA

    Science.gov (United States)

    Housen, B. A.; Dorsey, R. J.; Janecke, S. U.; Axen, G. J.

    2006-12-01

    Rocks in the Western Salton Trough region record the history of slip on the transtensional West Salton detachment fault and initiation of younger strike-slip faults in this plate boundary zone. Spatial and temporal patterns of vertical axis rotations as determined by paleomagnetism can be used to provide valuable constraints on the structural-tectonic evolution of this area. Prior work includes the magnetostratigraphy of Plio-Pleistocene sedimentary rocks in the Fish Creek-Vallecito Basin (FCVB) (Opdyke et al., 1977; Johnson et al., 1983), who found that these rocks contain a complete record of geomagnetic field reversals spanning Pliocene-Pleistocene time. Johnson et al. (1983) also concluded that the FCVB had undergone 35° of CW rotation during the past 0.9 Ma. We resampled and reanalyzed their section, and sampled additional sedimentary and plutonic rocks in the Western Salton Trough in order to better document the history of vertical axis rotation recorded by these rocks. Results from 29 sites in the FCVB have well-defined magnetizations with two components. The first removed component in all samples is unblocked between 90 and 220 °C, and the second-removed components are unblocked between 300 and 590 °C. The second-removed components have either normal or reversed polarity. Sites from the Diablo Fm are predominantly reversed and have a mean of D = 204, I = -48.3, k = 37, α95 = 12.7°, N = 5. Sites from the middle of the section (Olla and Tapiado Fms) are predominantly normal and have a mean of D = 8.1, I = 48, k = 32, α95= 8.7°, N = 10. Sites from the upper portion of the section (Hueso Fm) have predominantly reversed polarity with means of D = 179.6, I = -43.4, k = 82, α95 = 10.2°, N = 4. Results from weakly-magnetized and deformed rocks of the La Posta pluton, on the south side of Whale Peak, have well-defined magnetizations with a group mean direction of D = 16.3, I = 37.3, k = 44, α95 = 7.4°, N = 10. The stratigraphic distribution of declination

  14. Nature of the crust in the Laxmi Basin (14°-20°N), western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Rao, D.G.; Sar, D.

    ; Courtillot et al., 1988; White and McKenzie, 1989). The Deccan basalts erupted by the R?;union hotspot (68.5-62 Ma) are found as continental flood basalts on western Indian shield as well as on the Praslin Island in the Seychelles micro-continent (Devey.... The boundary is well expressed in the shelf region and was interpreted by Chaubey et al. (2002) as Miocene unconformity. The unconformity was also identified on our seismic profiles that extend in deep offshore regions (Figure 2). In the Western Basin thin...

  15. Regional Variations in Home Canning Practices and the Risk of Foodborne Botulism in the Republic of Georgia, 2003

    Science.gov (United States)

    TARKHASHVILI, N.; CHOKHELI, M.; CHUBINIDZE, M.; ABAZASHVILI, N.; CHAKVETADZE, N.; IMNADZE, P.; KRETSINGER, K.; VARMA, J.; SOBEL, J.

    2015-01-01

    Foodborne botulism is a severe, paralytic illness caused by ingestion of preformed neurotoxins produced by Clostridium botulinum. In 2003, we conducted a population-based household survey of home canning practices to explore marked regional variations in botulism incidence in the Republic of Georgia (ROG). We designed a cluster sampling scheme and subdivided each of the 10 regions of the ROG into a variable number of strata. Households were selected from each stratum using a two-step cluster sampling methodology. We administered a questionnaire about home canning practices to household members responsible for food preparation. Using multivariate logistic regression analysis, we modeled high (eastern ROG) against low (western ROG) incidence areas. Overall, we surveyed 2,742 households nationwide. Home canning with a capping device hermetically sealing the lid covering the jar was practiced by 1,909 households (65.9%; 95% confidence interval [CI]: 59.8 to 72.1%). Canning was more prevalent in regions of low botulism incidence (34 versus 32%; P 1 tablespoon of salt per liter (aOR = 5.1; 95% CI: 1.2 to 22.6); vinegar (aOR = 2.2; 95% CI: 1.3 to 3.7), and greens (aOR = 5.6; 95% CI: 1.7 to 18.2). The following practices were associated with a decreased risk in high-botulism areas: >57 jars canned per household annually (aOR = 0.5; 95% CI: 0.3 to 0.9), covering or immersing vegetables in boiling water before placing them into the jar (aOR = 0.3 95% CI: 0.2 to 0.6), covering or immersing vegetables in boiling water after placing them into the jar (aOR = 0.4; 95% CI: 0.2 to 0.9), or adding garlic (aOR = 0.2; 95% CI: 0.1 to 0.5) or aspirin (aOR = 0.1; 95% CI: 0.1 to 0.2) to the jar at the time of preparation. PMID:25836400

  16. Structural differences between the western and eastern Qiongdongnan Basin: evidence of Indochina block extrusion and South China Sea seafloor spreading

    Science.gov (United States)

    Zhang, Cuimei; Wang, Zhenfeng; Sun, Zhipeng; Sun, Zhen; Liu, Jianbao; Wang, Zhangwen

    2013-12-01

    Located at the intersection between a NW-trending slip system and NE-trending rift system in the northern South China Sea, the Qiongdongnan Basin provides key clues for us to understand the proposed extrusion of the Indochina Block along with Red River Fault Zone and extensional margins. In this paper we for the first time systematically reveal the striking structural differences between the western and eastern sector of the Qiongdongnan Basin. Influenced by the NW-trending slip faults, the western Qiongdongnan Basin developed E-W-trending faults, and was subsequently inverted at 30-21 Ma. The eastern sector was dominated by faults with NE orientation before 30 Ma, and thereafter with various orientations from NE, to EW and NW during the period 30-21 Ma; rifting display composite symmetric graben instead of the composite half graben or asymmetric graben in the west. The deep and thermal structures in turn are invoked to account for such deformation differences. The lithosphere of the eastern Qiongdongnan Basin is very hot and thinned because of mantle upwelling and heating, composite symmetric grabens formed and the faults varied with the basal plate boundary. However, the Southern and Northern Uplift area and middle of the central depression is located on normal lithosphere and formed half grabens or simple grabens. The lithosphere in the western sector is transitional from very hot to normal. Eventually, the Paleogene tectonic development of the Qiongdongnan Basin may be summarized into three stages with dominating influences, the retreat of the West Pacific subduction zone (44-36 Ma), slow Indochina block extrusion together with slab-pull of the Proto-South China Sea (36-30 Ma), rapid Indochina block extrusion together with the South China Sea seafloor spreading (30-21 Ma).

  17. Mass balance and fluid flow constraints on regional-scale dolomitization, Late Devonian, Western Canada Sedimentary Basin

    Energy Technology Data Exchange (ETDEWEB)

    Machel, H.G. [Alberta Univ., Edmonton, AB (Canada); Mountjoy, E.M. [McGill Univ., Montreal, PQ (Canada). Dept. of Earth and Planetary Sciences; Amthor, J.E. [Shell Internationale Research Maatschappij NV, The Hague (Netherlands)

    1996-09-01

    Flow mechanisms that resulted in regionally pervasive, replacive dolomitization of the Upper Devonian carbonates in the Western Canada Sedimentary Basin (WCSB), were discussed. In critiquing the hydrogeological model proposed by Shields and Brady (1995), these interveners noted three major problems: (1) brine recharge area not isotropic or homogeneous, (2) hydrogeologic model does not match the conceptual geological model, (3) the aspect ratio of the hydrogeologic model is inconsistent with other explanations of brine reflux flushing. While these authors agree that seepage reflux of evaporite brines account for some of the dolomites in the basin, they believe that available geological, petrographic, paragenetic, and geochemical evidence invalidate regional brine reflux as the mechanism of basin-wide pervasive dolomitization, as proposed by Shields and Brady. (A response to this critique from Shields and Brady is presented on pages 572-573 of this issue of the Bulletin). 27 refs., 1 fig.

  18. Risk Zones of Human Leishmaniases in the Western Mediterranean Basin: Correlations between Vector Sand Flies, Bioclimatology and Phytosociology

    OpenAIRE

    Rispail Philippe; Dereure Jacques; Jarry Daniel

    2002-01-01

    Correspondence analysis was applied to sand fly sampling in 865 stations from the Western Mediterranean basin. The position of each of 24 species was determined with respect to the bioclimatic belts. Thus, the multidimensional analyses manifest clear correlations between bioclimatic belts and their expression in the area, the phytosociological groupings, and vector species of visceral and cutaneous leishmaniases. The transfer of these data to usual maps allows to delimit the geographical dist...

  19. Killer Whale (Orcinus orca) Predation on Beaked Whales (Mesoplodon spp.) in the Bremer Sub-Basin, Western Australia.

    Science.gov (United States)

    Wellard, Rebecca; Lightbody, Keith; Fouda, Leila; Blewitt, Michelle; Riggs, David; Erbe, Christine

    2016-01-01

    Observations of killer whales (Orcinus orca) feeding on the remains of beaked whales have been previously documented; however, to date, there has been no published account of killer whales actively preying upon beaked whales. This article describes the first field observations of killer whales interacting with, hunting and preying upon beaked whales (Mesoplodon spp.) on four separate occasions during 2014, 2015 and 2016 in the Bremer Sub-Basin, off the south coast of Western Australia.

  20. Increasingly, Data Availability Limits Model Predictive Capacity: the Western Lake Erie Basin, a Case Study

    Science.gov (United States)

    Behrman, K. D.; Johnson, M. V. V.; Atwood, J. D.; Norfleet, M. L.

    2016-12-01

    Recent algal blooms in Western Lake Erie Basin (WLEB) have renewed scientific community's interest in developing process based models to better understand and predict the drivers of eutrophic conditions in the lake. At the same time, in order to prevent future blooms, farmers, local communities and policy makers are interested in developing spatially explicit nutrient and sediment management plans at various scales, from field to watershed. These interests have fueled several modeling exercises intended to locate "hotspots" in the basin where targeted adoption of additional agricultural conservation practices could provide the most benefit to water quality. The models have also been used to simulate various scenarios representing potential agricultural solutions. The Soil and Water Assessment Tool (SWAT) and its sister model, the Agricultural Policy Environmental eXtender (APEX), have been used to simulate hydrology of interacting land uses in thousands of scientific studies around the world. High performance computing allows SWAT and APEX users to continue to improve and refine the model specificity to make predictions at small-spatial scales. Consequently, data inputs and calibration/validation data are now becoming the limiting factor to model performance. Water quality data for the tributaries and rivers that flow through WLEB is spatially and temporally limited. Land management data, including conservation practice and nutrient management data, are not publicly available at fine spatial and temporal scales. Here we show the data uncertainties associated with modeling WLEB croplands at a relatively large spatial scale (HUC-4) using site management data from over 1,000 farms collected by the Conservation Effects Assessment Project (CEAP). The error associated with downscaling this data to the HUC-8 and HUC-12 scale is shown. Simulations of spatially explicit dynamics can be very informative, but care must be taken when policy decisions are made based on models

  1. Biodegradation and origin of oil sands in the Western Canada Sedimentary Basin

    Institute of Scientific and Technical Information of China (English)

    Zhou Shuqing; Huang Haiping; Liu Yuming

    2008-01-01

    The oil sands deposits in the Western Canada Sedimentary Basin (WCSB) comprise of at least 85% of the total immobile bitumen in place in the world and are so concentrated as to be virtually the only such deposits that are economically recoverable for conversion to oil.The major deposits are in three geographic and geologic regions of Alberta: Athabasca,Cold Lake and Peace River.The bitumen reserves have oil gravities ranging from 8 to 12° API,and are hosted in the reservoirs of varying age,ranging from Devonian (Grosmont Formation) to Early Cretaceous (Mannville Group).They were derived from light oils in the southern Alberta and migrated to the north and east for over 100 km during the Laramide Orogeny,which was responsible for the uplift of the Rocky Mountains.Biodegradation is the only process that transforms light oil into bitumen in such a dramatic way that overshadowed other alterations with minor contributions.The levels of biodegradation in the basin increasing from west (non-biodegraded) to east (extremely biodegraded) can be attributed to decreasing reservoir temperature,which played the primary role in controlling the biodegradation regime.Once the reservoir was heated to approximately 80 ℃,it was pasteurized and no biodegradation would further occur.However,reservoir temperature could not alone predict the variations of the oil composition and physical properties.Compositional gradients and a wide range of biodegradation degree at single reservoir column indicate that the water-leg size or the volume ratio of oil to water is one of the critical local controls for the vertical variations of biodegradation degree and oil physical properties.Late charging and mixing of the fresh and degraded oils ultimately dictate the final distribution of compositions and physical properties found in the heavy oil and oil sand fields.Oil geochemistry can reveal precisely the processes and levels that control these variations in a given field,which opens the

  2. Early 21st century snow cover state over the western river basins of the Indus River system

    Science.gov (United States)

    Hasson, S.; Lucarini, V.; Khan, M. R.; Petitta, M.; Bolch, T.; Gioli, G.

    2014-10-01

    In this paper we assess the snow cover and its dynamics for the western river basins of the Indus River system (IRS) and their sub-basins located in Afghanistan, China, India and Pakistan for the period 2001-2012. First, we validate the Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow products from Terra (MOD10A1) and Aqua (MYD10A1) against the Landsat Thematic Mapper/Enhanced Thematic Mapper plus (TM/ETM+) data set, and then improve them for clouds by applying a validated non-spectral cloud removal technique. The improved snow product has been analysed on a seasonal and annual basis against different topographic parameters (aspect, elevation and slope). Our results show a decreasing tendency for the annual average snow cover for the westerlies-influenced basins (upper Indus basin (UIB), Astore, Hunza, Shigar and Shyok) and an increasing tendency for the monsoon-influenced basins (Jhelum, Kabul, Swat and Gilgit). Seasonal average snow cover decreases during winter and autumn, and increases during spring and summer, which is consistent with the observed cooling and warming trends during the respective seasons. Sub-basins at relatively higher latitudes/altitudes show higher variability than basins at lower latitudes/middle altitudes. Northeastern and northwestern aspects feature greater snow cover. The mean end-of-summer regional snow line altitude (SLA) zones range from 3000 to 5000 m a.s.l. for all basins. Our analysis provides an indication of a descending end-of-summer regional SLA zone for most of the studied basins, which is significant for the Shyok and Kabul basins, thus indicating a change in their water resources. Such results are consistent with the observed hydro-climatic data, recently collected local perceptions and glacier mass balances for the investigated period within the UIB. Moreover, our analysis shows a significant correlation between winter season snow cover and the North Atlantic Oscillation (NAO) index of the previous autumn

  3. Variability of mineral dust deposition in the western Mediterranean basin and South-East of France

    Directory of Open Access Journals (Sweden)

    J. Vincent

    2015-12-01

    deposition events are recorded at only one station, suggesting that the dust provenance, transport, and deposition processes (i.e. wet vs. dry of dust are different and specific for the different deposition sites in the Mediterranean studied area. The results also show that wet deposition is the main way of deposition for mineral dust in the western Mediterranean basin, but the contribution of dry deposition is far to be negligible, and contributes by 15 to 46 % to the major dust deposition events, depending on the sampling site.

  4. Formation mechanisms of heavy oils in the Liaohe Western Depression,Bohai Gulf Basin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Liaohe Oilfield in the Liaohe Western Depression of the Bohai Gulf Basin is the third-largest oil producing province and the largest heavy oil producing oilfield in China. A total of 65 oil samples,35 rock samples and 36 reservoir sandstone samples were collected and analyzed utilizing conventional geochemical and biogeochemical approaches to unravel the mechanisms of the formation of the heavy oils. Investigation of the oils with the lowest maturity compared with the oils in the Gaosheng and Niuxintuo oilfields indicates no apparent relation between the maturity and physical properties of the heavy oils. It is suggested that the heavy oil with primary origin is not likely the main mechanism re-sponsible for the majority of the heavy oils in the Liaohe Western Slope. The absence and/or depletion of n-alkanes etc.,with relatively low molecular weight and the occurrence of 25-norhopane series in the heavy oils as well as the relatively high acidity of the oils all suggest that the majority of the heavy oils once experienced secondary alteration. The fingerprints of the total scanning fluorescence (TSF) of the inner adsorbed hydrocarbons on the reservoir grains and the included hydrocarbons in fluid inclusions are similar to that of the normal oils in the area but are different from the outer adsorbed and reser-voired free oils at present,further indicating that most of the heavy oils are secondary in origin. Analyses of bacteria (microbes) in 7 oil samples indicate that anaerobic and hyperthermophilic Ar-chaeoglobus sp. are the dominant microbes relevant to oil biodegradation,which coincides with the shallow commercial gas reservoirs containing anaerobic bacteria derived gas in the Gaosheng and Leijia teotonic belts. The biodegradation most likely occurs at the water/oil interface,where the forma-tion water is essential for microbe removal and nutrient transportation. We think that biodegradation,water washing and oxidization are interrelated and are the main

  5. Rapid inundation estimates using coastal amplification laws in the Western Mediterranean basin

    Science.gov (United States)

    Gailler, Audrey; Hébert, Hélène; Schindelé, François

    2016-04-01

    Numerical tsunami propagation and inundation models are well developed and have now reached an impressive level of accuracy, especially in locations such as harbors where the tsunami waves are mostly amplified. In the framework of tsunami warning under real-time operational conditions, the main obstacle for the routine use of such numerical simulations remains the slowness of the numerical computation, which is strengthened when detailed grids are required for the precise modeling of the coastline response of an individual harbor. Thus only tsunami offshore propagation modeling tools using a single sparse bathymetric computation grid are presently included within the French Tsunami Warning Center (CENALT), providing rapid estimation of tsunami impact at Western Mediterranean and NE Atlantic basins scale. We present here a work that performs quick estimates of the coastal impact at individual harbors from these high sea forecasting tsunami simulations. The method involves an empirical correction based on the Green's theoretical amplification law. The main limitation is that its application to a given coastal area would require a large database of previous observations, in order to define the empirical parameters of the correction equation. As no tide gage records of significant tsunamis are available for the Western Mediterranean French coasts, we use a set of points of interest distributed along these coasts, where maximum water heights are calculated for both fake events and well-known historical tsunamigenic earthquakes in the area. This synthetic dataset is obtained through accurate numerical tsunami propagation and inundation modeling by using several nested bathymetric grids of increasingly fine resolution close to the shores. Non linear shallow water tsunami modeling performed on a single 2' coarse bathymetric grid are compared to the values given by time-consuming nested grids simulations, in order to check to which extent the simple approach based on the

  6. Geological and production characteristics of the Lewis Shale, San Juan Basin, USA: an ongoing study with applications to other foreland basins of the Western Interior, USA and Canada

    Energy Technology Data Exchange (ETDEWEB)

    Bereskin, R. [Tesseract Corporation, Park City, UT (United States)

    2001-07-01

    The geological characteristics of the Lewis Shale, San Juan Basin, New Mexico is examined to provide information about ways to characterize productive wells. Logs of Cretaceous shale need to be examined more closely. The lithology, environment of deposition, and porosity types shown by a type log of Lewis shale and the utility of a FMI log for indicating various features are described. Integrated use of core, FMI, gamma ray, and neutron log techniques improve target identification. Lewis shale analogues likely exist along lengths of the Western Interior and Canada. 21 figs.

  7. Early middle Miocene tectonic uplift of the northwestern part of the Qinghai–Tibetan Plateau evidenced by geochemical and mineralogical records in the western Tarim Basin

    NARCIS (Netherlands)

    Wang, Chaowen; Hong, Hanlie; Abels, Hemmo A.; Li, Zhaohui; Cao, Kai; Yin, Ke; Song, Bowen; Xu, Yadong; Ji, Junliang; Zhang, Kexin

    2016-01-01

    The Tarim Basin in western China has been receiving continuous marine to lacustrine deposits during the Cenozoic as a foreland basin of the Qinghai–Tibetan Plateau (QTP). Clay mineralogy and geochemical proxy data from these sedimentary archives can shed light on climate and tectonic trends. Here we

  8. Exceptionally Preserved Caddisfly Larval Cases (Insecta) from the Lower Cretaceous of the Liupanshan Basin, Western China

    Institute of Scientific and Technical Information of China (English)

    Xin He; Zhong-Qiang Chen; Zongsheng Lu; Jun Li; Wei Hu; Shengfu Li; Zhitao Xu

    2015-01-01

    Abundant well-preserved tubular fossils of caddisfly (Insecta: Trichoptera) larval cases are reported from the Early Cretaceous Madongshan and Naijiahe formations of the Liupanshan Basin, Ningxia Province, western China. Most cases were mainly preserved in life position and densely packed in various layers. Individual cases in each layer tended to be same in size and were erect and parallel to one another and open at both ends. In a transverse section cut perpendicular to the long axis of the cases, individual case appears to form a rounded ring. Small cases are elliptic in a cross-section oblique to the long axis of the cases. Tube walls are nearly subparallel to one another in longitudinal section with both ends being open. The caudal end of the case slightly tapers and usually points downward. The cases were closely packed, almost touching with one another and lacking bifurcate or connecting struc-ture. The overwhelming majority of cases were partially or fully filled with calcite. The case wall em-braces a medium particle layer flanked by inner and outer organic layers. Individual particles are ovate in outline and comprise cryptocrystalline or ganic pellets. SEM imaging shows that those pellets are sub-cylindrical in outline and elliptic in cross section, and are made primarily of calcium carbonate. All features observed justify the assignment of the Liupanshan caddisfly cases to ichnogenus Coprindusia. The extinct insect Ningxiapsyche fangi was found in association with the Liupanshan caddisfly larval cases, and thus could be the candidate of the potential trace-maker.

  9. Forest Composition and Structure Under Various Disturbance Regimes in the Alaknanda River Basin, Western Himalaya

    Directory of Open Access Journals (Sweden)

    Upma Manral

    2017-08-01

    Full Text Available This study explored the resilience of mountain forests in a protected area in Alaknanda River basin, Western Himalaya, to various disturbance scenarios. The resource dependency of village communities in the Kedarnath Wildlife Sanctuary Landscape was studied through a questionnaire survey in 10 villages situated along an elevational gradient. Vegetation sampling was done in government-owned sanctuary forests and community-owned forests, both visited by villagers. Forest community composition, regeneration status, and tree population structure were studied to understand the impact of disturbance on forests and their resistance to anthropogenic alterations. Results indicated a reduction in both fuelwood and fodder consumption with decreasing elevation, with villages at higher elevations and located inside the sanctuary depending more on forest resources. Forests showed evidence of disturbance in the form of lower basal cover, mean canopy cover, regeneration, and disturbance-influenced distribution of shrubs. However, despite the signs of secondary succession, Quercus leucotrichophora forest has retained the original tree species composition. Vegetation recovery on 3 landslide sites at varying successional stages was also studied. The old successional site had higher species richness than early successional sites. The only tree species with adult individuals recorded in early successional sites was Alnus nepalensis, an early successional nitrogen-fixing species. The community composition of the old successional site, at Bandwara, included young individuals of Q. leucotrichophora, the climax species of forests in that elevational range. The current forest structure of both disturbed forest and vegetation recovery on the old succession site indicate the resilient dynamism of native Himalayan forests. Considering the role of mountain forests in achieving sustainable development, it is imperative to study the dynamics of changes in forest community and

  10. Gravity anomalies, crustal structure and rift tectonics at the Konkan and Kerala basins, western continental margin of India

    Indian Academy of Sciences (India)

    Sheena V Dev; M Radhakrishna; Shyam Chand; C Subrahmanyam

    2012-06-01

    Litho-stratigraphic variation of sedimentary units constructed from seismic sections and gravity anomaly in the Konkan and Kerala basins of the western continental margin of India (WCMI) have been used to model processes such as lithospheric rifting mechanism, its strength, and evolution of flank uplift topography that led to the present-day Western Ghats escarpment. Based on the process-oriented approach, two lithospheric models (necking and magmatic underplating) of evolution of the margin were tested. Both, necking and underplating models suggest an effective elastic thickness (Te) of 5 km and 10 km along Konkan and Kerala basins, respectively and a deep level of necking at 20 km at both basins. Model study suggests that the necking model better explains the observed gravity anomalies in the southern part of the WCMI. A synthesis of these results along with the previously published elastic thickness estimates along the WCMI suggests that a low-to-intermediate strength lithosphere and a deeper level of necking explains the observed flank-uplift opography of the Western Ghats. Process-oriented gravity modeling further suggests that the lateral variations in the lithospheric strength, though not very significant, exist from north to south within a distance of 600 km in the Konkan and Kerala basins along the WCMI at the time of rifting. A comparison with previous Te estimates from coherence analysis along the WCMI indicates that the lithospheric strength did not change appreciably since the time of rifting and it is low both onshore and offshore having a range of 5–15 km.

  11. Nahcolite and halite deposition through time during the saline mineral phase of Eocene Lake Uinta, Piceance Basin, western Colorado

    Science.gov (United States)

    Johnson, Ronald C.; Brownfield, Michael E.

    2013-01-01

    Halite and the sodium bicarbonate mineral nahcolite were deposited during the saline phase of Eocene Lake Uinta in the Piceance Basin, western Colorado. Variations in the area of saline mineral deposition through time were interpreted from studies of core and outcrop. Saline minerals were extensively leached by groundwater, so the original extent of saline deposition was estimated from the distribution of empty vugs and collapse breccias. Vugs and breccias strongly influence groundwater movement, so determining where leaching has occurred is an important consideration for in-situ oil shale extraction methods currently being developed. Lake Uinta formed when two smaller fresh water lakes, one in the Uinta Basin of eastern Utah and the other in the Piceance Basin of western Colorado, expanded and coalesced across the Douglas Creek arch, an area of comparatively low subsidence rates. Salinity increased shortly after this expansion, but saline mineral deposition did not begin until later, after a period of prolonged infilling created broad lake-margin shelves and a comparatively small deep central lake area. These shelves probably played a critical role in brine evolution. A progression from disseminated nahcolite and nahcolite aggregates to bedded nahcolite and ultimately to bedded nahcolite and halite was deposited in this deep lake area during the early stages of saline deposition along with rich oil shale that commonly shows signs of slumping and lateral transport. The area of saline mineral and rich oil shale deposition subsequently expanded, in part due to infilling of the compact deep area, and in part because of an increase in water flow into Lake Uinta, possibly due to outflow from Lake Gosiute to the north. Finally, as Lake Uinta in the Piceance Basin was progressively filled from north to south by volcano-clastic sediment, the saline depocenter was pushed progressively southward, eventually covering much of the areas that had previously been marginal shelves

  12. Early 21st century climatology of snow cover for the western river basins of the Indus River System

    Science.gov (United States)

    Hasson, S.; Lucarini, V.; Khan, M. R.; Petitta, M.; Bolch, T.; Gioli, G.

    2013-11-01

    In this paper we assess the snow cover and its dynamics for the western river basins of the Indus River System (IRS) and their sub-basins located in Afghanistan, China, India and Pakistan for the period 2001-2012. Moderate Resolution Imaging Spectro-radiometer (MODIS) daily snow products from Terra (MOD) and Aqua (MYD) have been first improved and then analysed on seasonal and annual basis against different topographic parameters (aspect, elevation and slope). Our applied cloud filtering technique has reduced the cloud cover from 37% (MOD) and 43% (MYD) to 7%, thus improving snow cover estimates from 7% (MOD) and 5% (MYD) to 14% for the area of interest (AOI) during the validation period (2004). Our results show a decreasing tendency for the annual average snow cover for the westerlies-influenced basins (Upper Indus Basin, Astore, Hunza, Shigar, Shyok) and an increasing tendency for the monsoon-influenced basins (Jhelum, Kabul, Swat and Gilgit). Regarding the seasonal snow cover, decrease during winter and autumn and increase during spring and summer has been found, which is consistent with the observed cooling and warming trends during the respective seasons. Sub-basins at relatively higher latitude/altitude show higher variability than basins at lower latitude/mid-altitude. Northeastern and northwestern aspects feature larger snow cover. The mean regional snow line altitude (SLA) zones range between 3000 and 5000 m a.s.l. for all basins. Our analysis provides an indication of a decrease in the regional SLA zone, thus indicating a change in the water resources of the studied basins, particularly for the Upper Indus Basin (UIB). Such results are consistent with the observed hydro-climate data, recently collected local perceptions and glacier mass balances for the investigated period. Moreover, our analysis suggests some potential for the seasonal stream flow forecast as a significant negative correlation has been detected for the inter-annual variability of winter

  13. Office of Inspector General report on audit of the Western Area Power Administration`s contract with Basin Electric Power Cooperative

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-25

    At the request of the Western Area Power Administration (Western), an audit of 17 areas was conducted with respect to possible overcharges on a power contract between Western and Basin Electric Power Cooperative (Basin), Contract No. DE-MP65-82WP-19001. The contract for Western`s purchase of electric power from Basin was entered into on April 15, 1982, and was in effect from January 1, 1986, through October 31, 1990. During this 58-month period, Basin billed Western approximately $197.6 million. Overall, it was found that Basin overcharged Western approximately $23.8 million. These overcharges occurred because Basin: (1) did not recognize or amortize as gain its overestimate of completion and correction costs for Antelope Valley Station (AVS) Unit 2; (2) did not amortize the gain on the sale/leaseback of AVS Unit 2 as an offset to lease costs; (3) billed Western prematurely for lease and interest costs; (4) overcharged for the cost of coal by including administrative and general expenses and profit, as well as incorrectly calculating discounts, royalty payments, and imputed interest costs; (5) made faulty calculations of amortization rates for deferred costs; (6) used a shorter depreciation period for AVS common facilities than it had used for other power plants; (7) retained tax benefit transfers; and (8) charged Western for interest and depreciation that had been paid by others. In addition to the $23.8 million in overcharges, interest accrued on the overcharges through December 31, 1996 was estimated to be approximately $22.1 million, resulting in a total of $45.9 million due Western.

  14. An Overview of the DAURE Campaign: Aerosols Emissions and Evolution in the Western Mediterranean Basin

    Science.gov (United States)

    Pandolfi, Marco; Querol, Xavier; Alastuey, Andrés.; Jimenez, Jose L.

    2010-05-01

    DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean) is a multidisciplinary international measurement campaign mainly aimed at estimating the sources and origin of atmospheric fine aerosols in the Western Mediterranean Basin (WMB), with particular attention to the carbonaceous fraction. Main focuses of the campaign are the study of the origin of the intense pollution episodes frequently occurring at regional scale in summer and winter in the WMB (Perez et al., 2008) and the emission, formation, transport and transformation of aerosols during these polluted scenarios. The peculiar atmospheric dynamics in the WMB, regulated by complex climatic and orographic effects (Millán et al., 1997), together with the large pollutant emissions from densely populated areas, large industrial areas and ports located along the coastline, give rise to a complex phenomenology for aerosol formation and transformation. In this context, extremely high concentrations of fine particulate matter (mainly PM1, particulate matter with aerodynamic diameter MAAP, CPC, SMPS, Rotating Drum Impactor, among others) and remote sensing techniques (LIDAR, sunphotometer) have been applied together with state-of-the-art methods such as 14C (Szidat et al., 2006), Proton-Transfer Reaction Mass Spectrometry (PTRMS) for VOCs, and High-Resolution Aerosol Mass Spectrometer (AMS) (DeCarlo et al., 2006). These state-of-the-art techniques have been applied for the first time in the Western Mediterranean region within DAURE. Particular attention was devoted to quantitatively understand the sources and formation mechanisms of secondary inorganic and organic aerosols (SIA and SOA) in the WMB and the effects caused by anthropogenic activities in SOA formation at local and regional level. Here we give an overview of the objective of the DAURE campaign, groups involved and measurements performed. The main results of the DAURE winter and summer

  15. Loess in the foothills of the western Carpathians and its importance for paleoenvironmental reconstruction towards the Carpathian Basin

    Science.gov (United States)

    Obreht, Igor; Lehmkuhl, Frank; Kels, Holger; Hambach, Ulrich; Schulte, Philipp; Eckmeier, Eileen; Klasen, Nicole; Bösken, Janina; Krauss, Lydia; Zeeden, Christian

    2016-04-01

    The CRC 806 "Our way to Europe" focuses on the first arrival and dispersal of anatomically modern humans (AMH) from Africa to Europe. Within the second phase of this project, a subproject investigates the eastern trajectory of AMH dispersal through the Levant and Balkan Peninsula. Special attention is given to the Carpathian Basin and the surrounding foothills of the Carpathian Mountains. To this date, most Paleolithic sites in this region have been found in the foothills. To test the hypothesis whether this observation presents a valid pattern, or if it may be biased by the fact that the lowlands of the Carpathian Basin are covered by thick loess deposits overlying the archaeologic remains of AMH, beside improved archeological perspective it is also necessarily to understand the regional past climatic conditions from the time of the first AMH appearance in Europe around 40 ka ago. Loess-paleosol sequences (LPS) from the lowlands of the Carpathian Basin preserve almost continuous records of past environmental changes from this region. During the last decade, LPS were intensively investigated resulting in a good overall understanding of general paleoenvironmental conditions in the Carpathian Basin itself. However, short LPS from the surrounding mountains have only been studied in few localities and not well understood yet. This presents a challenge in understanding the past environmental conditions of the foothill areas which are hypothesized to be a preferred habitat of the AMH. As an attempt to bridge this gap, we are presenting the initial results from the Şanoviţa section (western Romania), located at the transition from lowlands to foothills of the Carpathians. Based on a multi-proxy study (grain-size, rock magnetism, color and geochemical analysis) of last glacial sediments, we improve the understanding of paleoenvironmental conditions between the Carpathian Basin and the western flank of the Carpathian Mountains. Şanoviţa is located at the upper end of a

  16. Distribution behaviour of acaricide cyflumetofen in tomato during home canning.

    Science.gov (United States)

    Liu, Na; Dong, Fengshou; Chen, Zenglong; Xu, Jun; Liu, Xingang; Duan, Lifang; Li, Minmin; Zheng, Yongquan

    2016-05-01

    The distribution behaviour of cyflumetofen in tomatoes during home canning was studied. The targeted compound cyflumetofen was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each process step, which included washing, peeling, homogenisation, simmering and sterilisation. Results indicated that more cyflumetofen was removed by washing with detergent solution compared with tap water, 2% NaCl solution and 2% CH3COOH solution. Peeling resulted in 90.2% loss of cyflumetofen and was the most effective step at removing pesticide residues from tomatoes. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PF of the peeling process for cyflumetofen was 0.28.

  17. Distinguishing and estimating recharge to karst springs in snow and glacier dominated mountainous basins of the western Himalaya, India

    Science.gov (United States)

    Jeelani, Ghulam; Shah, Rouf A.; Deshpande, Rajendrakumar D.; Fryar, Alan E.; Perrin, Jerome; Mukherjee, Abhijit

    2017-07-01

    Recharge assessment is a challenge in snow and glacier dominated Himalayan basins. Quantification of recharge to karst springs in these complex geological environments is important both for hydrologic understanding and for effective water resource management. We used spring hydrographs and environmental tracers (isotopes and solutes) to distinguish and estimate the sources of spring water and to identify the flow paths of the recharging waters in three mountainous basins of the western Himalaya. The karst springs are perennial with high discharge amplitudes. The results indicate that ambient temperature has a strong influence on the hydrological behavior of the springs. Although the spring flow is dominantly controlled by the melting of snow and/or glaciers, rain events produce sharp spikes in spring hydrographs. The facies patterns in springs within the Bringi basin (Ca-HCO3) and the Liddar basin (Ca-HCO3 and Ca-Mg-HCO3) suggest flow dominantly through limestone and dolomite. Higher concentrations of SO42- and Na+ in warm springs of the Kuthar basin indicate flow through carbonate, silicate and other rocks. The isotopic composition (δ18O, δ2H) of precipitation, snowpacks, glacier melt and karst springs show wide variation both in space and time, and are strongly influenced by the basin relief and meteorology. The tracer-based two- and three-component mixing models suggest that the snowmelt dominantly contributes to the spring flow (55-96%), followed by glacier melt (5-36%) and rain (4-34%). Based on tracer tests with good recovery rates, springs are dominantly recharged through point sources rather than by diffuse infiltration. Changes in the timing, form, and amount of winter precipitation substantially affect the timing and magnitude of spring discharge during the rest of the year.

  18. Demographics and limiting factors of tundra nesting birds at the Canning River products

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Products resulting from the Arctic NWR project "Demographics and limiting factors of tundra nesting birds at the Canning River" (PRIMR survey FF07RARC00-010).

  19. Bird populations and habitat use, Canning River Delta, Alaska: Report to Arctic National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bird populations and use of habitat at the Canning River Delta, Arctic National Wildlife Refuge, was the subject of a study during the summer of 1979 and 1980....

  20. Petroleum resources assessment on the western part of the Kunsan Basin

    Energy Technology Data Exchange (ETDEWEB)

    Park, K.S.; Park, K.P.; Sunwoo, D.; Yoo, D.G.; Cheong, T.J.; Oh, J.H.; Bong, P.Y.; Son, J.D.; Lee, H.Y.; Ryu, B.J.; Son, B.K.; Hwang, I.G.; Kwon, Y.I.; Lee, Y.J.; Kim, H.J. [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    Palynomorphs including spores, pollen and organic-walled microfossils and calcareous microfossils such as ostracods, charophytes and gastropods were studied for the biostratigraphic work of Kachi-1 and IIH-1Xa wells. All the microfossils yielded from two wells indicate nonmarine environment ranging from shallow lacustrine to fluvial one. The paleoclimates have been fluctuated between subtropical and cool temperate with arid/humid alternating conditions. The fluvial sandstone of the interval between 2017 m and 2021 m could be a potential reservoir rock in the well Kachi-1. The sandstone from 1587 m to 1592 could be also a potential reservoir rock even if further study is necessary for the cap rock. Content of organic matter is very low and the type is compared to III in the section penetrated by the above two wells. Thermal maturity might reach top of oil window at depth about 1200 m by Tmax and about 1300 m by biomarker analysis in the Kachi-1 well. On the basis of illite crystallinity, the top of oil generation zone could be located at the depth 1600 m. The thermal maturity could not be determined in the IIH-1Xa well, because of the extremely low organic matter content or bad state of samples. Hydrocarbon genetic potential is almost null in the both well except for a few sample in the thermally immature interval. Analysis of approximately 3,300 Line-km of multichannel seismic data integrated with 3 well data provides an insight of structural evolution of the western part of the Yellow Sea Basin. Tectonics of the rifting phase have been established on the basis of structural and stratigraphic analyses of depositional sequences and their seismic expressions. Based on available well data, the rifting probably began in the Cretaceous time had continued until Paleocene. It is considered that compressional force immediately after rifting event deformed sedimentary sections. During the period of Paleocene to middle Miocene, the sediments were deposited in stable

  1. Intraplate seismicity along the Gedi Fault in Kachchh rift basin of western India

    Science.gov (United States)

    Joshi, Vishwa; Rastogi, B. K.; Kumar, Santosh

    2017-08-01

    The Kachchh rift basin is located on the western continental margin of India and has a history of experiencing large to moderate intraplate earthquakes with M ≥ 5. During the past two centuries, two large earthquakes of Mw 7.8 (1819) and Mw 7.7 (2001) have occurred in the Kachchh region, the latter with an epicenter near Bhuj. The aftershock activity of the 2001 Bhuj earthquake is still ongoing with migration of seismicity. Initially, epicenters migrated towards the east and northeast within the Kachchh region but, since 2007, it has also migrated to the south. The triggered faults are mostly within 100 km and some up to 200 km distance from the epicentral area of the mainshock. Most of these faults are trending in E-W direction, and some are transverse. It was noticed that some faults generate earthquakes down to the Moho depth whereas some faults show earthquake activity within the upper crustal volume. The Gedi Fault, situated about 50 km northeast of the 2001 mainshock epicenter, triggered the largest earthquake of Mw 5.6 in 2006. We have carried out detailed seismological studies to evaluate the seismic potential of the Gedi Fault. We have relocated 331 earthquakes by HypoDD to improve upon location errors. Further, the relocated events are used to estimate the b value, p value, and fractal correlation dimension Dc of the fault zone. The present study indicates that all the events along the Gedi Fault are shallow in nature, with focal depths less than 20 km. The estimated b value shows that the Gedi aftershock sequence could be classified as Mogi's type 2 sequence, and the p value suggests a relatively slow decay of aftershocks. The fault plane solutions of some selected events of Mw > 3.5 are examined, and activeness of the Gedi Fault is assessed from the results of active fault studies as well as GPS and InSAR results. All these results are critically examined to evaluate the material properties and seismic potential of the Gedi Fault that may be useful

  2. Fog water collection and reforestation at mountain locations in a western Mediterranean basin region

    Science.gov (United States)

    Valiente, Ja; Estrela, Mj; Corell, D.; Fuentes, D.; Valdecantos, A.

    2010-07-01

    Previous studies carried out by the authors have shown the potential of fog water collection at several mountain locations in the Valencia region (western Mediterranean basin). This coastal region features typical conditions for a dry Mediterranean climate characterized by a pluviometric regime ranging from 400 to 600 mm with a strong annual dependence. Dry conditions together with land degradation that frequently results after recurrent fires occurred in the past make a difficult self-recovery for native forest vegetation so that some kind of human intervention is always recommended. In plots reforested with Mediterranean woody species, periods of more than 120 days without significant precipitation (>5 mm) result in mortality rates above 80% during the first summer in the field. The good potential of fog-water collection at certain mountain locations is considered in this study as an easily available water resource for the reforestation of remote areas where native vegetation cannot be reestablished by itself. A large flat panel made of UV-resistant HD-polyethylene monofilament mesh was deployed at a mountain location for bulk fog water harvesting. Water was stored in high-capacity tanks for the whole length of the experimental campaign and small timely water pulses localized deep in the planting holes were conducted during the summer dry periods. Survival rates and seedling performance of two forest tree species, Pinus pinaster and Quercus ilex, were quantified and correlated to irrigation pulses in a reforestation plot that took an area of about 2500 m2 and contained 620 1-year-old plants. Before and concurrently to the flat panel deployment, a passive omnidirectional fog-water collector of cylindrical shape was set in the area in combination to other environmental instruments such as a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Proper orientation of the large flat panel was possible once the direction of local winds

  3. Sources and mixing state of summertime background aerosol in the north-western Mediterranean basin

    Directory of Open Access Journals (Sweden)

    J. Arndt

    2017-06-01

    Full Text Available An aerosol time-of-flight mass spectrometer (ATOFMS was employed to provide real-time single particle mixing state and thereby source information for aerosols impacting the western Mediterranean basin during the ChArMEx-ADRIMED and SAF-MED campaigns in summer 2013. The ATOFMS measurements were made at a ground-based remote site on the northern tip of Corsica. Twenty-seven distinct ATOFMS particle classes were identified and subsequently grouped into eight general categories: EC-rich (elemental carbon, K-rich, Na-rich, amines, OC-rich (organic carbon, V-rich, Fe-rich and Ca-rich particles. Mass concentrations were reconstructed for the ATOFMS particle classes and found to be in good agreement with other co-located quantitative measurements (PM1, black carbon (BC, organic carbon, sulfate mass and ammonium mass. Total ATOFMS reconstructed mass (PM2. 5 accounted for 70–90 % of measured PM10 mass and was comprised of regionally transported fossil fuel (EC-rich and biomass burning (K-rich particles. The accumulation of these transported particles was favoured by repeated and extended periods of air mass stagnation over the western Mediterranean during the sampling campaigns. The single particle mass spectra proved to be valuable source markers, allowing the identification of fossil fuel and biomass burning combustion sources, and was therefore highly complementary to quantitative measurements made by Particle into Liquid Sampler ion chromatography (PILS-IC and an aerosol chemical speciation monitor (ACSM, which have demonstrated that PM1 and PM10 were comprised predominantly of sulfate, ammonium and OC. Good temporal agreement was observed between ATOFMS EC-rich and K-rich particle mass concentrations and combined mass concentrations of BC, sulfate, ammonium and low volatility oxygenated organic aerosol (LV-OOA. This combined information suggests that combustion of fossil fuels and biomass produced primary EC- and OC-containing particles, which

  4. Reconstruction of Topography and Lithosphere Dynamics Within the Basin and Range of Western North America Since 36 Ma

    Science.gov (United States)

    Holt, W. E.; Bahadori, A.; Liu, L.; Flesch, L. M.; Piccione, G.; Rasbury, T.; Badgley, C.; Smiley, T.; Smith, R.

    2016-12-01

    The complex deformation history of the western U.S. since 36 Ma involved a dramatic transition from a subduction-dominated to a transform-dominated margin, with widespread extension within the interior Basin and Range region. This deformation history altered the topography and drainage patterns and basins throughout the southwest. We perform a comprehensive analysis of the dynamics of the plate boundary zone in the western U.S. since 36 Ma, focusing on the U.S. Basin and Range region, with the goal of understanding the link between mantle dynamics, crustal deformation history, and topography evolution. Using position estimates from McQuarrie and Wernicke [2005], we determine lithospheric strain rates through time and integrate these to determine estimates of crustal thickness evolution. We generate dynamic models to test a number of paleotopographic models (which produce effective body forces) that, together with the mantle contribution, produce compatible directions and magnitudes of extension and shear strain rate through time in the lithosphere. The mantle coupling input is determined using adjoint solutions to move tomography-constrained convection simulations backward. We simultaneously calculate the dynamics of subducting oceanic lithosphere and tomography-driven mantle buoyancy anomalies. These convection simulations provide the lower boundary conditions in the dynamic models. Topography estimates not only incorporate crustal thickness estimates over time, they also include time-dependent dynamic topography estimates from the convection simulations. Our effort on the dynamics will be combined with other independent geochemical constraints provided by the dating of fluorite deposits within fault-associated veins. These fluorite deposits are proposed to be used as a timing constraint for mantle fluid input. Furthermore, our topography, stress, and strain rate models are being used to test the hypothesis that topographic roughness has provided a major control

  5. Spatial variation in biofouling of a unionid mussel (Lampsilis siliquoidea) across the western basin of Lake Erie

    Science.gov (United States)

    Larson, James H.; Evans, Mary; Richardson, William B.; Schaeffer, Jeff; Nelson, John

    2016-01-01

    Invasion of North American waters by nonnative Dreissena polymorpha and D. rostriformis bugensishas resulted in declines of the Unionidae family of native North American mussels. Dreissenid mussels biofoul unionid mussels in large numbers and interfere with unionid movement, their acquisition of food, and the native mussels' ability to open and close their shells. Initial expectations for the Great Lakes included extirpation of unionids where they co-occurred with dreissenids, but recently adult and juvenile unionids have been found alive in several apparent refugia. These unionid populations may persist due to reduced dreissenid biofouling in these areas, and/or due to processes that remove biofoulers. For example locations inaccessible to dreissenid veligers may reduce biofouling and habitats with soft substrates may allow unionids to burrow and thus remove dreissenids. We deployed caged unionid mussels (Lampsilis siliquoidea) at 36 sites across the western basin of Lake Erie to assess spatial variation in biofouling and to identify other areas that might promote the persistence or recovery of native unionid mussels. Biofouling ranged from 0.03 – 26.33 g per mussel, reached a maximum in the immediate vicinity of the mouth of the Maumee River, and appeared to primarily consist of dreissenid mussels. A known mussel refugium in the vicinity of a power plant near the mouth of the Maumee actually exhibited very high biofouling rates, suggesting that low dreissenid colonization did not adequately explain unionid survival in this refugium. In contrast, the southern nearshore area of Lake Erie, near another refugium, had very low biofouling. A large stretch of the western basin appeared to have low biofouling rates and muddy substrates, raising the possibility that these open water areas could support remnant and returning populations of unionid mussels. Previous observations of unionid refugia and the occurrence of low biofouling rates in large areas of the western

  6. Tropical Cyclones and Climate Controls in the Western Atlantic Basin during the First Half of the Nineteenth Century

    Science.gov (United States)

    Mock, C. J.; Dodds, S. F.; Rodgers, M. D.; Patwardhan, A.

    2008-12-01

    This study describes new comprehensive reconstructions of individual Western Atlantic Basin tropical cyclones for each year of the first half of the nineteenth century in the Western Atlantic Basin that are directly compatible and supplement the National Hurricane Center's HURDAT (Atlantic basin hurricane database). Data used for reconstructing tropical cyclones come from ship logbooks, ship protests, diaries, newspapers, and early instrumental records from more than 50 different archival repositories in the United States and the United Kingdom. Tropical cyclone strength was discriminated among tropical storms, hurricanes, major hurricanes, and non-tropical lows at least at tropical storm strength. The results detail the characteristics of several hundred storms, many of them being newly documented, and tracks for all storms were mapped. Overall, prominent active periods of tropical cyclones are evident along the western Atlantic Ocean in the 1830s but Caribbean and Gulf coasts exhibit active periods as being more evident in the 1810s and 1820s. Differences in decadal variations were even more pronounced when examining time series of activity at the statewide scale. High resolution paleoclimate and historical instrumental records of the AMO, NAO, ENSO, Atlantic SSTs, West African rainfall, and volcanic activity explain how different modes in these forcing mechanisms may explain some of the multidecadal and interannual variations. The early nineteenth century active hurricane activity appears to be particularly unique in corresponding with a low (negative index) AMO period, and as they relate to particular synoptic-scale patterns in the latter part of the Little Ice Age. Model simulations offer some hypotheses on such patterns, perhaps suggesting increased baroclinic-related storms and a slight later possible shift in the seasonal peak of tropical cyclones for some areas at times. Some years, such as 1806, 1837, 1838, 1842, and 1846 have particularly very active

  7. Road kills of amphibians in different land use areas from Sharavathi river basin, central Western Ghats, India

    Directory of Open Access Journals (Sweden)

    K.S. Seshadri

    2009-11-01

    Full Text Available A survey of amphibian mortality on roads was carried out in the Sharavathi river basin in the central Western Ghats. Road kills in three different land use areas: agricultural fields, water bodies and forests were recorded for four days along three 100m stretches in each type of area. One-hundred-and-forty-four individuals belonging to two orders, eight families, 11 genera and 13 species were recorded in the survey. Kills/km observed were: in forest 55, agricultural fields 38 and water bodies 27, for an overall average of 40 kills/km. Kill species compositions varied significantly between land use areas, but not overall kill rates.

  8. Application of teleseismic tomography to the study of shallow structure beneath Shizigou in the western Qaidam basin

    Institute of Scientific and Technical Information of China (English)

    Xiaoming Xu; Yinsheng Ma; Danian Shi; Xiaofeng Wang; Chengming Yin

    2009-01-01

    Teleseismic body wave traveltime tomography is used to inverse the three-dimensional seismic velocity structure beneath Shizigou in the western Qaidam basin. The travel time are picked from the continuous observation data on a small seismic array of stations deployed during 2004-2007. The tomographic results obtained indicate that a NW-trending low velocity anomaly just beneath the target region insert northeastwards with a high dip angle, to the north, northeast and east of the low velocity anomaly, some high-velocity anomalies distribute with the same strike and coverage as those of Shizigou anticline.

  9. Stratigraphy and Ar/Ar geochronology of the Miocene lignite-bearing Tunçbilek-Domaniç Basin, western Anatolia

    Science.gov (United States)

    Helvacı, C.; Ersoy, E. Y.; Billor, M. Z.

    2016-08-01

    The Tunçbilek-Domaniç Basin is one of the Neogene basins containing economic coal deposits in western Anatolia, Turkey. The basin fill represents fluvial to lacustrine sedimentary units which are interlayered with volcanic rocks with bimodal composition. In order to reveal the stratigraphy and the exact ages of the basin fill and coal deposits, and to explore the tectonic evolution of the basin, we present new field data and Ar/Ar age data from the volcanic units. The field studies and the age data indicate that the whole basin fills were deposited between ~23 and ~19 Ma (Aquitanian-Early Burdigalian) without any unconformity. Taking into account the ages of the coal-bearing sedimentary units in the other Neogene basins in the region, it is concluded that most of the economic coal deposits in the western Anatolia were formed during Aquitanian. The field studies also show that the deposition of the sedimentary units in the basin was controlled by the NE-SW-trending strike- to oblique-slip normal faults. In a regional scale, tectonic evolution of the Tunçbilek-Domaniç Basin is linked to the differential stretching in the hanging wall of the southerly located, a crustal-scale low-angle detachment fault (the Simav detachment fault) that controlled the Early Miocene exhumation of the Menderes Extensional Core Complex.

  10. Review of the Upper Jurassic-Lower Cretaceous stratigraphy in Western Cameros basin, Northern Spain

    DEFF Research Database (Denmark)

    Vidal, Maria del Pilar Clemente

    2010-01-01

    which consists of fresh water lacustrine carbonates and Golmayo representing a fluvial dominated coastal plain with marly lakes. The Oliván Group encompasses three formations of fluvial deposits: La Gallega, Castrillo de la Reina and Cuerda del Pozo. The Salas Group consists of two formations Cabezón de......: Señora de Brezales and Magaña. The Oncala Group is represented by two formations of fluvial deposits, Jaramillo de la Fuente and Río del Salcedal and a third formation, Rupelo of lacustrine /coastal carbonates and evaporites. The Peñacoba Formation is an independent formation made of biogenic lacustrine...... of subsidence and terrigenous supply. The onlap of the syn-rift mega-sequence on the basin margins, the extra-basinal fluvial systems and shallow carbonate lakes together with its condensed character and the preservation of pre-rift mega-sequence at the basin margins point towards a basin with low...

  11. ENVIRONMENTS AND FAUNAL PATTERNS IN THE KACHCHH RIFT BASIN, WESTERN INDIA, DURING THE JURASSIC

    OpenAIRE

    FRANZ THEODOR FÜRSICH; Callomon, John H.; DHIRENDRA K. PANDEY; ANAND K. JAITLY

    2004-01-01

    Marine Jurassic sediments (Bajocian-Tithonian) of the Kachchh Basin were deposited in a ramp setting. Except during the Middle and Late Bathonian, when a carbonate regime became established, the fill of the basin consists predominantly of siliciclastics. The sediments represent environments that range from coastal plains (rivers and associated flood plains with caliche nodules), deltas, brackish water lagoons, nearshore sand and iron-oolite bars of the inner ramp, generally situated above fai...

  12. THE OLIGOCENE MOLLUSC FAUNA OF THE PIEDMONT BASIN (NORTH-WESTERN ITALY I. SCAPHOPODA AND ARCHAEOGASTROPODA

    Directory of Open Access Journals (Sweden)

    M. CRISTINA BONCI

    2000-07-01

    Full Text Available The aim of the present work is to study the Oligocene Scaphopoda and Archaeogastropoda of the Tertiary Piedmont Basin (T.P.B., aiming towards an overall revision of the Oligocene mollusc fauna of this Basin. Five taxa of Scaphopoda and twenty-eight taxa of Archaeogastropoda have been analysed; among these a new species of Nerita (Theliostyla is proposed. 

  13. Rainfall and flow of the Riozinho do Rôla Basin on Western Amazon

    OpenAIRE

    Maria Lúcia Hall de Souza; Elias Silva; Edson Alves de Araújo; Herly Carlos Teixeira Dias; France Maria Gontijo Coelho; Maria de Nazaré Costa de Macêdo

    2013-01-01

    The present study was conducted to analyze the factors influencing the hydrological behavior of the Riozinho do Rôla hydrographic basin, and was based on descriptive analysis tools. Fourteen pluviometers were set up in order to conduct a representative analysis of the rainfall in the basin. Residents of the area voluntarily participated in collection of the rainfall data in the years 2007 and 2008; the residents were trained to collect the data before the pluviometers were installed. ArcGis 9...

  14. Discriminant analysis for characterization of hydrochemistry of two mountain river basins of contrasting climates in the southern Western Ghats, India.

    Science.gov (United States)

    Thomas, Jobin; Joseph, Sabu; Thrivikramji, K P

    2015-06-01

    Discriminant analysis (DA) was performed on river hydrochemistry data for three seasons (i.e., monsoon (MON), post-monsoon (POM), and pre-monsoon (PRM)) to examine the spatio-temporal hydrochemical variability of two mountain river basins (Muthirapuzha River Basin (MRB) and Pambar River Basin (PRB)) of the southern Western Ghats, India. Although the river basins drain tropical mountainous terrain, climate and degree of anthropogenic disturbances show significant differences (i.e., humid, more disturbed MRB vs semiarid, less disturbed PRB). In MRB, TDS, Na(+), pH, Mg(2+), and K(+) are the attributes responsible for significant hydrochemical variations between the seasons, while Cl(-), TH, and Na(+) are the predictors in PRB. The temporal discriminant models imply the importance of rainfall pattern, relative contribution of groundwater toward stream discharge and farming activities in hydrochemistry between the seasons. Inclusion of hydrochemical attributes (in the temporal discriminant functions) that can be derived from both natural and anthropogenic sources suggests that ionic enrichment strongly depends on the seasons, and is mainly due to the variability in the intensity of anthropogenic activities as well as fluctuations in river discharge. In spatial discriminant models, Cl(-) is the only variable responsible for hydrochemical variations between the basins (during MON), whereas Si discriminates during POM and PRM, implying the role of atmospheric supply, anthropogenic modifications as well as intensity of weathering. In the spatial discrimination models, misclassification of hydrochemistry data between MRB and PRB can be attributed to the overlapping effect of humid climate of MRB extending toward the upstream of (semiarid) PRB. This study underscores the versatility of DA in deciphering the significance of climatic controls on hydrochemical composition of tropical mountain rivers.

  15. Diet and environment of a mid-Pliocene fauna in the Zanda Basin (western Himalaya): Paleo-elevation implications

    Science.gov (United States)

    Wang, Y.; Xu, Y.; Khawaja, S. N.; Wang, X.; Passey, B. H.; Zhang, C.; Li, Q.; Tseng, Z. J.; Takeuchi, G.; Deng, T.; Xie, G.

    2011-12-01

    A mid-Pliocene fauna (3.1-4.0 Ma) was recently discovered in the Zanda Basin in western Himalaya, at an elevation of about 4200 m above sea level. These fossil materials provide a unique window for examining the linkage among tectonic, climatic and biotic changes. Here we report the initial results from isotopic analyses of this fauna and of modern herbivores in the Zanda Basin. The δ13C values of enamel samples from modern wild Tibetan ass, horse, cow and goat from the Zanda Basin are -9.1±2.1%, which indicate a diet comprising predominantly of C3 plants and are consistent with the current dominance of C3 vegetation in the area. The enamel-δ13C values of the fossil horse, rhino, deer, and bovid are -9.6±0.8%, indicating that these ancient mammals, like modern herbivores in the area, fed primarily on C3 vegetation and lived in an environment dominated by C3 plants. The enamel-δ18O values of mid-Pliocene obligate drinkers (i.e., horse and rhino) are lower than those of their modern counterpart, most likely indicating a shift in climate to much drier conditions after ~3-4 Ma. Preliminary paleo-temperature estimates derived from a fossil-based temperature proxy as well as the "clumped isotope" thermometer for the mid-Pliocene Zanda Basin, although somewhat equivocal, are close to the present-day mean annual temperature in the area, suggesting that the paleo-elevation of the Zanda Basin in the mid-Pliocene was similar to its present-day elevation.

  16. Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt

    Directory of Open Access Journals (Sweden)

    M. El Bastawesy

    2013-04-01

    Full Text Available This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases, which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM and Enhanced Thematic Mapper (ETM+ were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM digital elevation model (DEM has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and

  17. Giant polygons and circular graben in western Utopia basin, Mars: Exploring possible formation mechanisms

    Science.gov (United States)

    Buczkowski, Debra L.; Seelos, Kim D.; Cooke, Michele L.

    2012-08-01

    Large-scale fracture systems surrounding the Utopia basin include giant polygons and circular graben. Data covering the northern Utopia basin now allow high-resolution mapping of these features in all regions of the basin. Giant polygons to the north and south of the basin are different in both size and morphology, leading to the polygon classifications (1) S-style, (2) subdued S-style, (3) northern S-style and (4) N-style. Also, ten circular graben have been identified to the north of the Utopia basin. These have generally larger diameters than southern circular graben, and their fracture morphology is similar to N-style giant polygons. As with southern circular graben, the surface relief of the depression inside the northern circular graben scales directly with diameter. However, northern circular graben have less steep trend slopes, larger average diameters and greater ring spacing compared to southern circular graben of the same diameter and similar distance to the center of the Utopia basin. Both the giant polygons and circular graben of Utopia Planitia are consistent with formation by volumetric compaction of a fine-grained sedimentary material covering an uneven buried surface. Giant polygon size variations can be explained by the material being wet to the south but frozen or partially frozen to the north, while differences between northern and southern circular graben may be attributed to changes in cover thickness. Differences in fracture morphology can be explained by subsequent alteration of the northern troughs due to polar processes.

  18. Crustal structure and magnetic lineation along two geo-traverses from western continental margin of India to Eastern Somali Basin, NW Indian Ocean

    Science.gov (United States)

    Chaubey, A. K.; Anshu, A.; Sreejith, K.; Pandey, A.

    2012-12-01

    Shipborne gravity and magnetic data along two parallel geo-traverses spanning from western continental margin of India to off Seychelles are used to delineate crustal structure and magnetic pattern of major structural features - western continental margin of India, Laxmi Basin, Laxmi Ridge, Arabian Basin, slow spreading Carlsberg Ridge and Eastern Somali Basin. The seismically constrained gravity models along the geo-traverses suggest considerable variation in crustal thickness - about 38 km on continental shelf of western India to about 4 km of the Eastern Somali Basin. The Eastern Somali Basin is characterized by thin oceanic crustal thickness (~3 to 4 km) as compared to its conjugate Arabian Basin where thickness varies from 5 to 6 km. The magnetic anomalies along the geo-traverse reveal three distinct zones: (i) a zone of relative high frequency short wavelength younger anomalies over the axial parts of the Carlsberg Ridge, (ii) a zone of well developed Early Tertiary magnetic anomalies in both the Arabian and Eastern Somali basins, and (iii) relative magnetic quiet zone, between the above two zones, representing a hiatus in spreading. Based on the results, we present a comparative analysis of crustal configuration and magnetic pattern of major structural features of the study area and discuss its tectonic evolution.

  19. Socio-hydrologic Perspectives of the Co-evolution of Humans and Water in the Tarim River Basin, Western China

    Science.gov (United States)

    Liu, Ye; Tian, Fuqiang; Hu, Heping; Liu, Dengfeng; Sivapalan, Murugesu

    2013-04-01

    Socio-hydrology studies the co-evolution of coupled human-water systems, which is of great importance for long-term sustainable water resource management in basins suffering from serious eco-environmental degradation. Process socio-hydrology can benefit from the exploring the patterns of historical co-evolution of coupled human-water systems as a way to discovering the organizing principles that may underpin their co-evolution. As a self-organized entity, the human-water system in a river basin would evolve into certain steady states over a sufficiently long time but then could also experience sudden shifts due to internal or external disturbances that exceed system thresholds. In this study, we discuss three steady states (also called stages in the social sciences, including natural, human exploitation and recovery stages) and transitions between these during the past 1500 years in the Tarim River Basin of Western China, which a rich history of civilization including its place in the famous Silk Road that connected China to Europe. Specifically, during the natural stage with a sound environment that existed before the 19th century, shifts in the ecohydrological regime were mainly caused by environmental changes such river channel migration and climate change. During the human exploitation stages in the 5th and again in the 19th-20th centuries, however, humans gradually became the main drivers for system evolution, during which the basin experienced rapid population growth, fast socio-economic development and intense human activities. By the 1970s, after 200 years of colonization, the Tarim River Basin evolved into a new regime with vulnerable ecosystem and water system, and suffered from serious water shortages and desertification. Human society then began to take a critical look into the effects of their activities and reappraise the impact of human development on the ecohydrological system, which eventually led the basin into a treatment and recovery stage

  20. STRUCTURAL AND GEOCHEMICAL CHARACTERISTICS OF SECONDARY DOLOMITIC BODIES OF CRETACEOUS COLIMA-JALISCO BASIN, WESTERN MEXICO

    Science.gov (United States)

    Zarate, P. F.

    2009-12-01

    The cretaceous Colima-Jalisco basin, at western Mexico, is characterized by the development of volcano sedimentary sequences belonging to the Late Jurassic-Early Cretaceous Alisitos-Teloloapan arc-island and the formation of volcanogenic massive sulphide deposits ("El Cuale", "La Minita", "Talpa de Allende"). Some bodies of dolomite have been described and have been classified into two groups in accordance with its secondary origin: sabkha (diagenetic) and hydrothermal. In both cases the primary dolomitized limestone belongs to the reef facies of the Tepalcatepec Formation (TF) of Albian-Cenomanian characterized by the next geochemical content: MgO (0.42%), CaO (53.7%), SiO2 (0.15%), Pb (140 ppm) and Zn (50 ppm). Diagenetical dolomite is characterized by an stratiform body and its contacts are consistent with the structural attitude of TF to which it belongs. In the dolomites formed by hydrothermal replacement process is limited by faults and fractures, thus its morphology is irregular and their contacts are discordant, adopting domic or columnar forms. Occasionally hydrothermal dolomite can be associated with concentrations of lead, zinc, silver and barite. The dolomitic body called "Cerro El Puro", (19° 3.7' N; 103° 36.7' W), located at 20 km SE 30° from Colima City, consists in a carbonate horizon of 300 m thick and over 5 km in length and is consistent with the structural attitude (N30°W; NE50°) of the southwestern flank of the syncline Tepames-Amarradero, in which southeast extreme an evaporitic stratiform deposits. The dolomite of this body is of ankeritic type, hence its typical light reddish brown. The geochemical content is shown on Table 1. After the structural and geochemical features of this dolomite, it is classified as sabkha with a diagenetic origin. The other dolomitic outcrop studied is called “Cerro Bola” (18°54'N; 103°47.5'W) which is located 40 km S10°W from Colima City, and consists of a single dolomitic outcrop, black in color

  1. Age and position of the sedimentary basin of the Ocoee Supergroup western Blue Ridge tectonic province, southern Appalachians

    Energy Technology Data Exchange (ETDEWEB)

    Unrug, R.; Unrug, S. (Wright State Univ., Dayton, OH (United States). Dept. of Geological Sciences); Ausich, W.I. (Ohio State Univ., Columbus, OH (United States). Dept. of Geological Sciences); Cuffey, R.J. (Pennsylvania State Univ., University Park, PA (United States). Dept. of Geosciences); Mamet, B.L. (Univ. de Montreal, Quebec (Canada). Dept. de Geologie); Palmes, S.L. (Florida State Univ., Tallahassee, FL (United States). Dept. of Geology)

    1994-03-01

    The stratigraphic continuity of the Ocoee Supergroup established recently allows one to extrapolate the Paleozoic age of the Walden Creek Group determined on paleontological evidence to the entire Ocoee succession. The Walden Creek Group rocks contain a fossil assemblage of fenestrate bryozoan, algal, trilobite, ostracod, brachiopod and echinozoan fragments and agglutinated foraminifer tests that indicate Silurian or younger Paleozoic age. The fossils occur in carbonate clasts in polymict conglomerates, and debris-flow breccia beds, and in olistoliths of bedded carbonate and shale, and calcarenite turbidite beds. These carbonate lithologies form a minor, but characteristic constituent of the Walden Creek Group. Fossil have been found also in shale and mudstone siliciclastic lithologies of the Walden Creek Group. The fossils are fragmented and poorly preserved because of several cycles of cementation and solution in the carbonate rocks and a pervasive cleavage in the fine-grained siliciclastic rocks. Recently reported Mississippian plant fossils from the Talladega belt indicate widespread occurrence of Middle Paleozoic basins in the Western Blue Ridge. These pull-apart basins formed in the stress field generated by northward movement of Laurentia past the western margin of Gondwana after the Taconian-Famatinian collision in the Ordovician.

  2. Fluvial and glacial implications of tephra localities in the western Wind River basin, Wyoming, U. S. A

    Energy Technology Data Exchange (ETDEWEB)

    Jaworowski, C. (Univ. of Wyoming, Laramie, WY (United States). Dept. of Geology)

    1993-04-01

    Examination of Quaternary fluvial and glacial deposits in the western Wind River Basin allows a new understanding of the Quaternary Wind River fluvial system. Interbedded fluvial sediments and volcanic ashes provide important temporal information for correlation of Quaternary deposits. In the western Wind River Basin, six mid-Pleistocene localities of tephra, the Muddy Creek, Red Creek, Lander, Kinnear, Morton and Yellow Calf ashes are known. Geochronologic studies confirm the Muddy Creek, Red Creek, Kinnear and Lander ashes as the 620--650ka Lava Creek tephra from the Yellowstone region in northwestern Wyoming. The stratigraphic position and index of refraction of volcanic glass from the Morton and Yellow Calf ashes are consistent with identification as Lava Creek tephra. Approximately 350 feet (106 meters) above the Wind River and 13 miles downstream from Bull Lake, interbedded Wind River fluvial gravels, volcanic glass and pumice at the Morton locality correlate to late (upper) Sacajawea Ridge gravels mapped by Richmond and Murphy. Associated with the oxygen isotope 16--15 boundary, the ash-bearing terrace deposits reveal the nature of the Wind River fluvial system during late glacial-early interglacial times. The Lander and Yellow Calf ashes, are found in terrace deposits along tributaries of the Wind River. Differences in timing and rates of incision between the Wind River and its tributary, the Little Wind River, results in complex terrace development near their junction.

  3. Stress distribution and seismicity patterns of the 2011 seismic swarm in the Messinia basin, (South-Western Peloponnesus, Greece

    Directory of Open Access Journals (Sweden)

    G. Chouliaras

    2013-01-01

    Full Text Available In this investigation we examine the local stress field and the seismicity patterns associated with the 2011–2012 seismicity swarm in the Messinia basin, south-western Peloponnesus, Greece, using the seismological data of the National Observatory of Athens (NOA. During this swarm more than 2000 events were recorded in a 12 month period by the Hellenic Unified Seismological Network (HUSN and also by the additional local installation of four portable broadband seismographic stations by NOA.

    The results indicate a Gaussian distribution of swarm activity and the development of a seismicity cluster in a pre-existing seismic gap within the Messinia basin. Centroid Moment Tensor solutions demonstrate a normal fault trending northwest–southeast and dipping to the southwest primarily due to an extensional stress field. During this seismicity swarm an epicentre migration of the three largest shocks is observed, from one end of the rupture zone in the north-western part of the cluster, towards the other edge of the rupture in the south-eastern part of the cluster. This migration is found to follow the Coulomb failure criterion that predicts the advancement and retardation of the stress field and the patterns of increases and decreases of the seismicity rate (b-value of the frequency–magnitude relation.

  4. The late Paleozoic palynological diversity in southernmost Paraná (Uruguay), Claromecó and Paganzo basins (Argentina), Western Gondwana

    Science.gov (United States)

    Beri, Ángeles; Gutiérrez, Pedro R.; Balarino, M. Lucía

    2015-12-01

    This study explores the changes in palynoflora diversity of the late Paleozoic in boreholes DI.NA.MI.GE. 254 (26 samples) and DI.NA.MI.GE. 221 (14 samples) of the Paraná Basin in Uruguay and in 18 surface samples of the La Deheza Formation (Paganzo Basin) and 10 samples of borehole UTAL.CMM1.La Estrella.x-1 (Claromecó Basin) in Argentina. Possible relationships among biostratigraphic zones, diversity levels, facies and climatic evolution patterns in Western Gondwana are studied. Diversity curves of boreholes 221 and 254 and the La Deheza Formation outcrop exhibit similar diversity evolution patterns, i.e., an increase in lower strata diversity and a decrease in upper strata diversity. The disappearance events are determined to be more prominent in biozones of the Cisuralian to the Guadalupian age and less prominent in biozones of the early Cisuralian age. The number of genera raises from the glaciomarine facies, through the deltaic and the marine facies, up to the shallow marine or lagoon facies, in which the disappearance rates become more prominent. . The diversity of the lower part of the La Estrella borehole is lesser than that of the other sequences These diversity, disappearance and appearance behaviors may reflect post-glacial climatic amelioration patterns and the beginning of an arid phase.

  5. Application of YHyM/BTOPMC to evaluate hydrological response of Kali Gandaki River Basin (KGRB) in Western Nepal

    Science.gov (United States)

    Manandhar, S.; Pandey, V. P.; Ishidaira, H.; Kazama, F.

    2011-12-01

    Snowmelt runoff is an important source of water resources in the mountainous basins of Nepal. Modeling snowmelt runoff is challenging especially when snow observations are unavailable. In order to overcome the data shortage, YHyM/BTOPMC, a physically-based distributed hydrological model integrated with a simple degree-day based snow accumulation/melt sub-model was applied to evaluate hydrological response of Kali Gandaki River Basin (KGRB) in Western Nepal. It is apparent that temperature in Nepal is increasing, progressively higher for high elevations and precipitation is becoming more erratic. Hence, the snowmelt process, river runoff and water availability in KGRB is sensitive to the increasing climate change. The objective of this study is to assess the hydrological response of the basin to different climatic perturbation. Assessing the runoff pattern/water availability situation is very important in flood risk management, water use planning and in overall management of water resources. Public domain global data along with daily measured temperature and rainfall data were used in this study. The model was calibrated and validated using daily observed discharges and the stream flow in KGRB can be predicted with an acceptable degree of accuracy. The model performance was tested through the Nash-Sutcliffe efficiency objective function and by the volume ratio of simulated to observed discharge. Annual temporal variability of stream-flow was also plotted to ensure the response of KGRB to temperature and precipitation changes.

  6. Regional and Local Trends in helium isotopes, basin and rangeprovince, western North America: Evidence for deep permeablepathways

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack; van Soest, Matthijs C.

    2005-07-15

    Fluids from the western margin of the Basin and Range have helium isotope ratios as high as {approx}6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to ''background'' values of around 0.6 Ra, and then gradually decrease toward the east to low values of {approx}0.1 Ra at the eastern margin of the Basin and Range. Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and local geology indicate that these ''He-spikes'' are not related to current or recent magmatic activity, suggesting that the spikes may reflect either localized zones deep mantle melting or deep permeable pathways (faults) with high vertical fluid flowrates. A detailed study of one of the He-spikes (Dixie Valley and the Stillwater Range Front Fault system), indicates that features with high 3He/4He ratios are confined to the range front normal faults characteristic of the extensional regime in the Basin and Range, suggesting that these faults are deep permeable pathways. However, not all range front fault systems transmit fluids with a mantle signature, implying that not all have deep permeable pathways.

  7. The Neogene-Quaternary geodynamic evolution of the central Calabrian Arc: A case study from the western Catanzaro Trough basin

    Science.gov (United States)

    Brutto, F.; Muto, F.; Loreto, M. F.; Paola, N. De; Tripodi, V.; Critelli, S.; Facchin, L.

    2016-12-01

    The Catanzaro Trough is a Neogene-Quaternary basin developed in the central Calabrian Arc, between the Serre and the Sila Massifs, and filled by up to 2000 m of continental to marine deposits. It extends from the Sant'Eufemia Basin (SE Tyrrhenian Sea), offshore, to the Catanzaro Basin, onshore. Here, onshore structural data have been integrated with structural features interpreted using marine geophysical data to infer the main tectonic processes that have controlled the geodynamic evolution of the western portion of the Catanzaro Trough, since Upper Miocene to present. The data show a complex tectonostratigraphic architecture of the basin, which is mainly controlled by the activity of NW-SE and NE-SW trending fault systems. In particular, during late Miocene, the NW-SE oriented faults system was characterized by left lateral kinematics. The same structural regime produces secondary fault systems represented by E-W and NE-SW oriented faults. The ca. E-W lineaments show extensional kinematics, which may have played an important role during the opening of the WNW-ESE paleo-strait; whereas the NE-SW oriented system represents the conjugate faults of the NW-SE oriented structural system, showing a right lateral component of motion. During the Piacenzian-Lower Pleistocene, structural field and geophysical data show a switch from left-lateral to right-lateral kinematics of the NW-SE oriented faults, due to a change of the stress field. This new structural regime influenced the kinematics of the NE-SW faults system, which registered left lateral movement. Since Middle Pleistocene, the study area experienced an extensional phase, WNW-ESE oriented, controlled mainly by NE-SW and, subordinately, N-S oriented normal faults. This type of faulting splits obliquely the western Catanzaro Trough, producing up-faulted and down-faulted blocks, arranged as graben-type system (i.e Lamezia Basin). The multidisciplinary approach adopted, allowed us to constrain the structural setting of

  8. Implications of Spatial Variability in Heat Flow for Geothermal Resource Evaluation in Large Foreland Basins: The Case of the Western Canada Sedimentary Basin

    Directory of Open Access Journals (Sweden)

    Simon Weides

    2014-04-01

    Full Text Available Heat flow and geothermal gradient of the sedimentary succession of the Western Canada Sedimentary Basin (WCSB are mapped based on a large thermal database. Heat flow in the deep part of the basin varies from 30 mW/m2 in the south to high 100 mW/m2 in the north. As permeable strata are required for a successful geothermal application, the most important aquifers are discussed and evaluated. Regional temperature distribution within different aquifers is mapped for the first time, enabling a delineation of the most promising areas based on thermal field and aquifer properties. Results of previous regional studies on the geothermal potential of the WCSB are newly evaluated and discussed. In parts of the WCSB temperatures as high as 100–210 °C exist at depths of 3–5 km. Fluids from deep aquifers in these “hot” regions of the WCSB could be used in geothermal power plants to produce electricity. The geothermal resources of the shallower parts of the WCSB (>2 km could be used for warm water provision (>50 °C or district heating (>70 °C in urban areas.

  9. Late Cretaceous stratigraphy of the Upper Magdalena Basin in the Payandé-Chaparral segment (western Girardot Sub-Basin), Colombia

    Science.gov (United States)

    Barrio, C. A.; Coffield, D. Q.

    1992-02-01

    The Cretaceous section on the western margin of the Girardot Sub-Basin, Upper Magdalena Valley, is composed of the Lower Sandstone (Hauterivian-Barremian?), Tetuán Limestone (pre-Aptian?), and Bambuca Shale (pre-Aptian?), and the following formations: Caballos (Aptian-Albian), Villeta (Albian-Campanian), Monserrate (Campanian-Maastrichtian), and Guaduas (Maastrichtian-Paleocene). The Lower Sandstone is composed of quartz arenites with abundant calcareous cement; the Tetuúan Limestone is a succession of fossiliferous limestones and calcareous shales; the the Bambuca Shale is composed of black shales that grade upward to micritic limestones and calcarenites. The Caballos Formation comprises three members: a lower member of quartz arenites, a middle member of black shales and limestones, and an upper member of crossbedded, coarsening-upward quartz arenites. The Villeta Formation is a sequence of shales intercalated with micritic limestones and calcarenites. Two levels of chert (Upper and Lower Chert) are differentiated within the Villeta Formation throughout the study area, with a sandstone unit (El Cobre Sandstone) to the north. The Monserrate Formation is composed of quartz arenites, with abundant crossbedding, and locally of limestone breccias and coarse-grained fossiliferous packstones. The Guaduas Formation is a monotonous succession of red shales and lithic sandstones. Our data suggest three major transgressive-regressive cycles in the Girardot Sub-Basin. The first cycle (Hauterivian?-lower Aptian) is represented by the Lower Sandstone-Tetuán-Bambuca-lower Caballos succession, the second cycle (Aptian-Albian) by the middle-upper Caballos members, and the third cycle (Albian-Paleocene) by the lower Villeta-Monserrate-Guaduas succession. Previous studies proposed a eustatic control during deposition of the Upper Cretaceous in the Upper Magdalena Valley. The lowermost transgressive-regressive cycle was not previously differentiated in the study area, and this

  10. Bentonite chemical features as proxy of late Cretaceous provenance changes: A case study from the Western Interior Basin of Canada

    Science.gov (United States)

    Fanti, Federico

    2009-05-01

    Bentonite beds are fairly common in both marine and terrestrial Upper Cretaceous (Campanian-Maastrichtian) deposits of the Western Interior Basin of western Canada and northwestern United States. A detailed stratigraphic, sedimentologic, geochemical (X-ray fluorescence), and mineralogical (X-ray diffraction) study of twenty-one bentonites from the Puskwaskau and Wapiti formations in the Grande Prairie area (west-central Alberta, Canada) is here presented. Major and trace-element concentrations from altered volcanic ashes document the presence in the study area of predominantly trachyandesitic and rhyolitic volcanogenic products, resulted from intense volcanic arc to within-plate pyroclastic activity. Concentration values of high field strength elements (HFSE) and selected large ion lithophile elements (LILE) (e.g. Nb, Zr, Th, and Y) obtained by X-ray fluorescence spectroscopy strongly support the presence of multiple volcanic sources. Integrated paleoenvironmental and geochemical criteria for provenance determination indicate a bimodal occurrence of basic and acid volcanic products interpreted as reflection of source areas characterized by different tectonic setting and magmatic composition. A comparative analysis of geochemical compositions between Grande Prairie bentonites and 30 known volcanic beds from central and southern Alberta, Manitoba and Montana 1. documents a trend toward more acidic and alkali-depleted volcanic products during the late Campanian-early Maastrichtian interval, and 2. suggests a well constrained stratigraphic and geographic subdivision of the non-marine successions of the foreland basin on the basis of geochemical characteristic of volcanic ash beds. Furthermore, geochemical "fingerprints" of several decimeter to meter thick bentonite beds have been coupled with volcanic ash subsurface signature in order to investigate their role as marker beds. This multiple-approach provides a reliable tool for basin-scale identification and correlation

  11. Characteristics and evolution of strike-slip tectonics of the Liaohe Western Sag,Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    Tong Hengmao; Yu Fusheng; Geng Changbo

    2008-01-01

    Because of its rich oil and gas resources and the special tectonic location of the Liaohe Western Sag(the Tanlu Fault traverses the sag),Bohai Bay Basin,a detailed study of its strike-slip tectonics is significant in revealing the sag's tectonic evolution,its control on hydrocarbon accumulation,and the activity history of the northern section of the Tanlu Fault in the Cenozoic.Through systematic structure analysis of 3D seismic data of the Liaohe Western Sag,combined with balanced section analysis,a variety of structural features in relation to right-lateral strike-slip faults,such as echelon normal faults, "comb"structure," flower"structure, "interpretable" and "buried" strike-slip faults have been revealed exist in the Liaohe Western Sag.According to the research in this paper,the complex structural phenomena in the Liaohe Western Sag could be reasonably interpreted as right-lateral strike-slip activity and the strikeo-slip activities of the Liaohe Western Sag began in the early Oligocene.The activity was weak at the beginning(E3S1-2),then strengthened gradually and reached its strongest level in the late Oligocene(E3dl).In the Miocene,the strike-slip activity was low and then strengthened significantly once again from the Pliocene to the present.It is speculated that the entire northern section of the Tanlu Fault has had a similar evolution history since the Oligocene.

  12. Production by microphytobenthos in the Swan-Canning Estuary

    Science.gov (United States)

    Masini, R. J.; McComb, Arthur J.

    2001-09-01

    Intact sediment cores containing microphytobenthos, dominated by episammic diatoms, were collected from shallow sand flats of the Swan-Canning Estuary, Perth, southwestern Australia, and their photosynthesis-light relations deduced from changes in oxygen (17 cores) or pH (13 cores). The theoretical saturating light intensity Ik determined from O2 was 107 µE m-2 s-1, and the light intensity at which photosynthesis is saturated, Isat, was about 1100 µE m-2 s-1. Mean gross production and respiration increased with temperature. Infaunal contributions to total respiration were measured for two cores at about 30%.The sediment photic zone was estimated as 0·5 mm in fine sediments of the upper estuary and 3·5 mm in coarse sediments of the lower estuary. Microalgae from below the photic zone photosynthesized on exposure to light. Biomass (measured as chlorophyll a) decreased down the sediment profile and was linearly correlated with net and gross maximum photosynthesis. Relative photosynthetic efficiencies were high, and light compensation increased with increasing depth in the sediment.Q

  13. Density-dependent surface water-groundwater interaction and nutrient discharge in the Swan-Canning Estuary

    Science.gov (United States)

    Smith, Anthony J.; Turner, Jeffrey V.

    2001-09-01

    Salinity in the Swan-Canning Estuary, Western Australia, varies seasonally from freshwater conditions in winter up to the salinity of seawater in summer. Field observations show that the resulting seasonal density contrasts between the estuary and the adjacent fresh groundwater system are sufficient to drive mixed-convection cells that give rise to circulation of river water in the aquifer. In this study, we examine the role of steady density-driven convection as a mechanism that contributes to the exchange of dissolved nutrients, particularly ammonium, between the Swan-Canning Estuary and the local groundwater system. We present results from two-dimensional (section) and three-dimensional density-coupled flow and mass transport modelling, in comparison with Glover's abrupt-interface solution for saltwater intrusion. The modelling is focused on developing an understanding of the physical processes that influence the long-term or mean convective behaviour of groundwater beneath the estuary. It is shown that the convective stability depends fundamentally on the interplay between two factors: (1) the downward destabilizing buoyancy effect of density contrasts between the estuary and aquifer; and (2) the upward stabilizing influence of regional groundwater discharge. The structure of convection cells beneath the estuary and recirculation rates of estuary water within the groundwater system are shown to be related to a flow-modified Rayleigh number that depends critically on the aquifer anisotropy and estuary meander pattern. The recirculation of estuary water by these mechanisms is responsible for transport of high concentrations of ammonium, observed in pore fluids in the estuary bed sediments, into groundwater and its eventual return to the estuary.

  14. Source rocks and related petroleum systems of the Chelif Basin, (western Tellian domain, north Algeria)

    NARCIS (Netherlands)

    Arab, Mohamed; Bracène, Rabah; Roure, François; Zazoun, Réda Samy; Mahdjoub, Yamina; Badji, Rabie

    2015-01-01

    In the Chelif basin, the geochemical characterization reveals that the Upper Cretaceous and Messinian shales have a high generation potential. The former exhibits fair to good TOC values ranging from 0.5 to 1.2% with a max. of 7%. The Messinian series show TOC values comprised between 0.5 and 2.3% a

  15. Studies of the coal facies in Western Ukraine (the Lvov-Volyn basin)

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, Ariadna; Zaitseva, Lyudmila [O. Gonchar str., 55b, Kiev 01054 (Ukraine)

    2004-04-23

    The authors reviewed shortly the recent state of knowledge in the field of petrographic compositions and origins of the Carboniferous age coals in the Lvov-Volyn coal basin (LVB) as well as make the proper conclusions about the conditions of peat-accumulation, according to the results of former investigations performed by themselves and other researchers.

  16. Plio-Quaternary kinematic development and paleostress pattern of the Edremit Basin, western Turkey

    Science.gov (United States)

    Gürer, Ömer Feyzi; Sangu, Ercan; Özburan, Muzaffer; Gürbüz, Alper; Gürer, Aysan; Sinir, Hasan

    2016-06-01

    The Edremit Basin and Kazdağ High are the most prominent morphological features of the Biga Peninsula in northwest Anatolia. There is still no consensus on the formation of Edremit Basin and debates are on whether the basin evolved through a normal, a right-lateral or a left-lateral strike-slip faulting. In this study, the geometric, structural and kinematic characteristics of the Edremit Basin are investigated to make an analytical approach to this problem. The structural and kinematic features of the faults in the region are described according to field observations. These fault-slip data derived from the fault planes were analyzed to determine the paleostress pattern of faulting in the region. According to the performed analysis, the southern end of the Biga Peninsula is under the influence of the ENE-WSW-trending faults of the region, such as the Yenice-Gönen, the Edremit, the Pazarköy and the Havran-Balıkesir Fault Zones. The right step-over geometry and related extension caused to the development of the Edremit Basin as a transtensional pull-apart basin between the Havran-Balıkesir Fault Zone and the Edremit Fault Zone. Field observations showed that the Plio-Quaternary faults at the Edremit Gulf and adjacent areas are prominently right-lateral strike-slip faults. Our paleostress analyses suggest a dominant NE-SW extension in the study area, as well as NW-SE direction. This pattern indicates the major effects of the North Anatolian Fault System and the component of Aegean Extensional System in the region. However, our kinematic analysis represents the dominant signature of the North Anatolian Fault System in basin bounding faults. The field observations and kinematic findings of this study are also consistent with the regional GPS, paleomagnetic and seismological data. This study concludes that the North Anatolian Fault System is the prominent structure in the current morphotectonic framework of the Edremit Gulf and adjacent areas.

  17. River Basin Scale Management and Governance: Competing Interests for Western Water

    Science.gov (United States)

    Lindquist, Eric

    2015-04-01

    One of the most significant issues in regard to how social scientists understand environmental and resource management is the question of scale: what is the appropriate scale at which to consider environmental problems, and associated stakeholders (including hydrologists) and their interests, in order to "govern" them? Issues of scale touch on the reality of political boundaries, from the international to the local, and their overlap and conflict across jurisdictions. This presentation will consider the questions of environmental management and governance at the river basin scale through the case of the Boise River Basin (BRB), in southwest Idaho. The river basin scale provides a viable, and generalizable, unit of analysis with which to consider theoretical and empirical questions associated with governance and the role of hydrological science in decision making. As a unit of analysis, the "river basin" is common among engineers and hydrologists. Indeed, hydrological data is often collected and assessed at the basin level, not at an institutional or jurisdictional level. In the case of the BRB much is known from the technical perspective, such as infrastructure and engineering factors, who manages the river and how, and economic perspectives, in regard to benefits in support of major agricultural interests in the region. The same level of knowledge cannot be said about the political and societal factors, and related concepts of institutions and power. Compounding the situation is the increasing probability of climate change impacts in the American West. The geographic focus on the Boise River Basin provides a compelling example of what the future might hold in the American West, and how resource managers and other vested interests make or influence river basin policy in the region. The BRB represents a complex and dynamic environment covering approximately 4,100 square miles of land. The BRB is a highly managed basin, with multiple dams and diversions, and is

  18. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    Directory of Open Access Journals (Sweden)

    George Hinson

    2015-04-01

    Full Text Available Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is located at the south western part of the Voltaian basin at latitudes 07o 00 N and 08o 00 N and longitudes 02o 00 W and 01o 00 W respectively. Airborne gravity and magnetic survey methods were employed in the data collection. The field data correction and error reduction were applied to the two raw data on the field after which Geosoft Oasis Montaj 7.01 Encom Profile Analysis P.A 11 and 13 Model Vision 12 and ArcGIS 10.0 were used to process enhance e.g. reduce to pole at low latitude first vertical derivative etc. model the reduced and corrected airborne magnetic data and also to produce maps from them data. Low-to-moderate-to-high gravity and magnetic anomalies were obtained in the complete Bouguer anomaly CBA and total magnetic intensity TMI reduced to pole at low latitude with many of these anomalies trending NE-SW by which the Birimian Metasediments and Metavolcanics can be said to be part of the causative structures of these anomalies with cross-cut NW-SE faults. From the quantitative point of view the intrusive granitic bodies of the study area have a mean depth location of 1.7 km while the isolated anomaly is located at a depth of 1.4 km computed from Euler deconvolution. The NE-SW trending anomalies show the trend direction of their causative structures which are the basement rocks and the basinal intrusive bodies.

  19. Neolithic flint mines of Treviño (Basque-Cantabrian Basin, Western Pyrenees, Spain

    Directory of Open Access Journals (Sweden)

    Antonio Tarriño

    2014-09-01

    Full Text Available English:The prehistoric Treviño flint mine complex is located in the Sierra de Araico-Cucho (Berantevilla, Alava - Condado de Treviño, Burgos, inside the lacustrine-palustrine Cenozoic (Aquitanian, Miocene materials of the South-Pyrenean syncline of the Basque-Cantabrian Basin. It is a landscape unit constituted by a set of carbonated layers with abundant nodular and stratiform silicifications. The extraction mining works (often referred to as ‘tailing’ are usually identified as dumps or trenches, subtly visible and associated with archaeological materials.An archaeological excavation was carried out in one potential mining structure (dump or pit that was detected by LiDAR (Light Detection and Ranging in the mountain pass of “Pozarrate” near the villages of Grandival and Araico (Treviño, Burgos. In this work we present the results of the excavation of the last two years. The existence of a Neolithic mining dump (the tailings with a chronology ca. 5000 cal. BC was confirmed. The base rock level with nodular flint was reached and the impressions of the exploited nodules have been identified. As well, the extraction front which reaches about 4.0-5.0 metres in height was delimited. Thousands of lithic remains associated with the extraction and the initial processing (shaping of flint were collected, as along with mining tools. We have found and described three types of mining structures: trenches, linear dumps and crescent-shaped (or “half-moon-shaped” dumps.This site is one of the few prehistoric flint mines dated in the Iberian Peninsula. Recent investigations in the Cantabrian Mountains and Western Pyrenees indicate that the circulation and use of Treviño flint during Prehistory reached many Holocene and Pleistocene archaeological sites, located hundreds of kilometres away from the outcrops.Español:El complejo prehistórico minero de sílex de Treviño se sitúa en la Sierra de Araico-Cucho (Berantevilla, Alava - Condado de Trevi

  20. Cenozoic evolution of tectono-fluid and metallogenic process in Lanping Basin,western Yunnan Province, Southwest China: Constraints from apatite fission track data

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoming; SONG Yougui

    2006-01-01

    Since the Mesozoic, abundant metal and salt deposits have been formed in the Lanping Basin, western Yunnan Province, Southwest China, constituting a well-known hydrothermal ore belt in China. Most of the deposits are meso-epithermal hydrothermal deposits. This paper preliminarily deals with the mineralization ages of hydrothermal deposits in the Lanping Basin by using the apatite fission track method, and integrates the spatial distribution of the deposits and their regional geological backgrounds, to give the preliminary viewpoints as follows: (1) the apatite fission track ages acquired range from 19.9 Ma to 52.8 Ma, much younger than those of their host strata, so they may be considered to be mineralization ages, which represent the late mineralization period; (2) the apatite fission track ages tend to become younger from the west to the middle of the basin, indicating that the latest evolution of tectono-fluid and/or metallogenic processes of the middle basin ended later than that in the west; (3) in the Paleogene, most of the Cu deposits were formed in the western part of the basin; (4) the major metallogenic processes occur between the Paleogene and the Neogene, because the eastern and western edges of the basin were subducted into and collided with its bilateral continental blocks, respectively, and the central fault was strongly activated, which led to the processes of large-scale ore-forming fluids, and their differentiation and transport because of the variation of their physical and chemical properties. Having been squeezed and uplifted, the Lanping Basin became an intermontane basin that contains many kinds of fluid traps resulting in the formation of different types of ore deposits (for example, Pb-Zn, Cu, Ag) of different scales in the middle of the basin. Simultaneously, the fluids with volatile elements such as Hg, Sb and As were transported upwards along the central fault system and diffused into its subordinate fractures, thus leading to the

  1. The fauna of brackish ponds at Port Canning, Lower Bengal Part 1 - Introduction and Preliminary Account of the Fauna

    Digital Repository Service at National Institute of Oceanography (India)

    Annandale, N.

    A general survey the fauna of brackishwater ponds at Port Canning, Lower Bengal, India, was carried out The Port Canning is situated on the Matla river having numerous creeks which runup into the delta of the Ganges about sixty miles from the open...

  2. Holocene slip-rate of the western Altyn Tagh fault (Kuyake basin)

    Science.gov (United States)

    Pan, J.; Li, H.; van der Woerd, J.; Sun, Z.; Yun, K.; Chevalier, M. L.; Kali, E.

    2016-12-01

    As one of the largest strike-slip faults in Asia, the Altyn Tagh fault (ATF) defines the northern boundary of the Tibetan Plateau and plays a significant role in accommodating the deformation resulting from the India-Asia collision. Many studies have been conducted along the eastern and central segment of the ATF, whereas the western segment of the ATF is poorly constrained. Quaternary slip-rates along the central segment of the ATF have been constrained at 10 mm/yr, which is consistent with geodetic results. Slip-rates along the eastern segment of the ATF gradually decrease eastwards. Regarding the western segment, our recent study along one splay yields a late Quaternary slip-rate of 2 mm/yr. What is the total slip-rate along the western segment of the ATF? Does the slip-rate vary between the central and western segments, and how does it vary? To answer these questions, we performed detailed field investigation at an offset river terrace site near Kuyake, which is considered to be the boundary place between the western and central segments of the ATF. High-resolution terrestrial LiDAR survey was performed at this site, and cosmogenic nuclide 10Be depth profile samples were taken from the offset terrace riser. Our preliminary results indicate that the Holocene slip-rate along the western ATF at this site is 12.3±0.7 mm/yr, which is consistent with previous studies along the central segment of the ATF. West of the studied site, the ATF splits into several strands, and the total slip rate most likely decreases westward.

  3. Occurrence of volcanic ash in the Quaternary alluvial deposits, lower Narmada basin, western India

    Indian Academy of Sciences (India)

    Rachna Raj

    2008-02-01

    This communication reports the occurrence of an ash layer intercalated within the late Quaternary alluvial succession of the Madhumati River, a tributary of the lower Narmada River. Petrographic, morphological and chemical details of glass shards and pumice fragments have formed the basis of this study. The ash has been correlated with the Youngest Toba Tuff. The finding of ash layer interbedded in Quaternary alluvial sequences of western Indian continental margin is significant, as ash being datable material, a near precise time-controlled stratigraphy can be interpreted for the Quaternary sediments of western India. The distant volcanic source of this ash requires a fresh re-assessment of ash volume and palaeoclimatic interpretations.

  4. Music Therapy Canning and the Healing Rituals of Catholic Charismatics in Kenya

    Directory of Open Access Journals (Sweden)

    Bernard M. Kigunda

    2004-11-01

    Full Text Available In Kenya we export a variety of agricultural products such as tea and coffee. However, at the same time, some other tea and coffee is imported to Kenya. The difference is that the imported tea is canned. It is presented with names such as 'instant' tea/coffee, and is (in this case preferred even by Kenyans. Unfortunately, it is not to be afforded by a Kenyan of average income. In this essay I use canning to mean modified to acquire a new outlook, and in the case of tea and coffee, to also literally put into cans. Culture canning means social modification or change that causes suitability and/or acceptability of the modified/changed idea in a changed/changing environment. Canning thus implies reconstruction, reconstitution, reproduction and preservation with positive and negative readings.

  5. Extraction of anthocyanins from black bean canning wastewater with macroporous resins.

    Science.gov (United States)

    Wang, Xiaoxi; Hansen, Conly; Allen, Karin

    2014-02-01

    This study investigated purification of anthocyanins from black bean canning wastewater by column chromatography with 5 types of macroporous resins (Diaion Hp20, Sepabeads Sp70, Sepabeads Sp207, Sepabeads Sp700, and Sepabeads Sp710). By-product of canned black beans was partially purified by filtration, in anticipation of higher performance during column chromatography. Equilibrium adsorption isotherms were measured and analyzed using Langmuir and Freundlich isotherm models. Both Langmuir (all R² ≥ 0.98) and Freundlich (all R² ≥ 0.97) models can describe the adsorption process of anthocyanins from black bean canning wastewater using the tested resins. The adsorption and desorption behaviors of anthocyanins were studied using a dynamic method on the 5 types of resins, and Sp700 presented the highest adsorption capacity (39 ± 4 mg/g; P canning wastewater.

  6. Compositions and greenhouse gas emission factors of flared and vented gas in the Western Canadian Sedimentary Basin.

    Science.gov (United States)

    Johnson, Matthew R; Coderre, Adam R

    2012-09-01

    A significant obstacle in evaluating mitigation strategies for flaring and venting in the upstream oil and gas industry is the lack of publicly available data on the chemical composition of the gas. This information is required to determine the economic value of the gas, infrastructure and processing requirements, and potential emissions or emissions credits, all of which have significant impact on the economics of such strategies. This paper describes a method for estimating the composition of solution gas being flared and vented at individual facilities, and presents results derived for Alberta, Canada, which sits at the heart of the Western Canadian Sedimentary Basin. Using large amounts of raw data obtained through the Alberta Energy Resources Conservation Board, a relational database was created and specialized queries were developed to link production stream data, raw gas samples, and geography to create production-linked gas composition profiles for approximately half of the currently active facilities. These were used to create composition maps for the entire region, to which the remaining facilities with unknown compositions were geographically linked. The derived data were used to compute a range of solution gas composition profiles and greenhouse gas emission factors, providing new insight into flaring and venting in the region and enabling informed analysis of future management and mitigation strategies. Accurate and transparent determination of environmental impacts of flaring and venting of gas associated with oil production, and potential benefits of mitigation, is severely hampered by the lack of publicly available gas composition data. In jurisdictions within the Western Canadian Sedimentary Basin, frameworks exist for regulating and trading carbon offset credits but current potential for mitigation is limited by a lack of standardized methods for calculating CO2 equivalent emissions. The composition and emission factor data derived in this paper

  7. EVIDENCE FOR LADINIAN (MIDDLE TRIASSIC PLATFORM PROGRADATION IN THE GYULAKESZI AREA, TAPOLCA BASIN, WESTERN HUNGARY: MICROFACIES ANALYSIS AND BIOSTRATIGRAPHY

    Directory of Open Access Journals (Sweden)

    ZSOLT RÓBERT NAGY

    2014-07-01

    Full Text Available A shallowing-upward carbonate sequence was studied from the outcrop at Gyulakeszi, Tapolca Basin (western Hungary, and it is interpreted as a Middle Triassic (Curionii or younger platform progradation. Two lithostratigraphic units are distinguished. Microfacies analysis and micropaleontological investigation conducted on the red nodular, cherty limestone (Vászoly and Buchenstein formations suggest that the lower unit was deposited during the Reitzi and the Secedensis ammonoid zones. The overlying white platform limestone (upper unit is typical of a prograding platform and includes gravity-driven deposits at the base followed by periplatform facies deposited in shallow marine warm waters around the fair-weather wave base. The section at Gyulakeszi was unaffected by fabric-destructive dolomitization, which is uncharacteristic of similar platform facies in the Balaton Highland. Isopachous and radiaxial fibrous calcite cement found in the grainstone and boundstone facies are indicative of early lithification and diagenesis in the marine phreatic zone. “Evinospongiae”-type cement is described for the first time from the Balaton Highland and it is similar to the outer platform cements published previously from the Alps (Italy and Austria. The progradation could have advanced over the pelagic limestones as early as the Curionii zone, which is an undocumented event in the Veszprém Plateau. Similar event, however, is well known from the Western Dolomites, where aggradation was followed by intense progradation during the Gredleri and Archelaus ammonoid zones. The length of this progradation event at Gyulakeszi, however, is ambiguous since proven Ladinian (Longobardian rocks are not exposed in the study area and were not penetrated by boreholes in the Tapolca Basin.

  8. Coda Q in the Kachchh Basin, Western India Using Aftershocks of the Bhuj Earthquake of January 26, 2001

    Science.gov (United States)

    Gupta, S. C.; Kumar, Ashwani; Shukla, A. K.; Suresh, G.; Baidya, P. R.

    2006-08-01

    Q C -estimates of Kachchh Basin in western India have been obtained in a high frequency range from 1.5 to 24.0 Hz using the aftershock data of Bhuj earthquake of January 26, 2001 recorded within an epicentral distance of 80 km. The decay of coda waves of 30 sec window from 186 seismograms has been analysed in four lapse time windows, adopting the single backscattering model. The study shows that Q c is a function of frequency and increases as frequency increases. The frequency dependent Q c relations obtained for four lapse-time windows are: Q c =82 f 1.17 (20 50 sec), Q c =106 f 1.11 (30 60 sec), Q c =126f 1.03 (40 70 sec) and Q c =122f 1.02 (50 80 sec). These empirical relations represent the average attenuation properties of a zone covering the surface area of about 11,000, 20,000, 28,000 and 38,000 square km and a depth extent of about 60, 80, 95, 110 km, respectively. With increasing window length, the degree of frequency dependence, n, decreases marginally from 1.17 to 1.02, whereas Q 0 increases significantly from 82 to 122. At lower frequencies up to 6 Hz, Q c -1 of Kachchh Basin is in agreement with other regions of the world, whereas at higher frequencies from 12 to 24 Hz it is found to be low.

  9. A Systematic Regional Trend in Helium Isotopes Across the NorthernBasin and Range Province, Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack; van Soest, Matthijs C.

    2005-03-22

    An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g. Coso, Long Valley, Steamboat,and the Cascade volcanic complex). Moving towards the east, the ratiosdecline systematically to a background value of ~;0.1 Ra. The regionaltrend is consistent with extensive mantle melting concentrated along thewestern margin and is coincident with an east-to-west increase in themagnitude of northwest strain. The increase in shear strain enhancescrustal permeability resulting in high vertical fluid flow rates thatpreserve the high helium isotope ratios at the surface. Superimposed onthe regional trend are "helium spikes", local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

  10. The western Mediterranean basin as an aged aerosols reservoir. Insights from an old-fashioned but efficient radiotracer

    Science.gov (United States)

    Brattich, E.; Hernández-Ceballos, M. A.; Orza, J. A. G.; Bolívar, J. P.; Tositti, L.

    2016-09-01

    The long-term contemporary 210Pb time series acquired during the period 2004-2011 at two distant sites of different altitude in the Mediterranean basin, El Arenosillo (40 m a.s.l. in southwestern Spain) and Mt. Cimone (2165 m a.s.l. in northern Italy), are analyzed and compared. Besides being considered a tracer of continental air masses, 210Pb radionuclide is also a proxy of fine stable aerosol. For this reason, the measurements of PM10 mass concentrations collected at the same time and the corresponding 210Pb/PM10 ratio at the two sites are considered to gain better insights into the origin and size of the particles. Three statistical trajectory methods are applied to identify and characterize the 210Pb source regions at the two sites. The three methods yield similar outcomes in the source identification, which strengthens the robustness of our results. In addition to the importance of the transport from areas of continental Europe, this study highlights the relevant role of the Mediterranean Sea as a major 210Pb reservoir layer associated to the aged air masses that accumulate in the western Mediterranean basin. The analysis of the sources points out the significant influence of northern Africa to 210Pb increases at both sites as well, even though the most intensive episodes are not of Saharan origin.

  11. Cyclically-arranged, storm-controlled, prograding lithosomes in Messinian terrigenous shelves (Bajo Segura Basin, western Mediterranean)

    Science.gov (United States)

    Soria, Jesús M.; Giannetti, Alice; Monaco, Paolo; Corbí, Hugo; García-Ramos, Diego; Viseras, César

    2014-08-01

    This work focuses on a Messinian shallow-marine terrigenous unit, termed the La Virgen Formation, which forms part of the sedimentary infill of the Bajo Segura Basin (Betic margin of the western Mediterranean). This formation was deposited during a high sea level phase prior to the onset of the Messinian Salinity Crisis. Stratigraphically, it comprises a prograding stack of sandstone lithosomes alternating with marly intervals (1st-order cyclicity). These lithosomes are characterized by a homoclinal geometry that tapers distally, and interfinger with pelagic sediments rich in planktonic and benthic microfauna (Torremendo Formation). An analysis of sedimentary facies of each lithosome reveals a repetitive succession of sandy storm beds (tempestites), which are separated by thin marly layers (2nd-order cyclicity). Each storm bed contains internal erosional surfaces (3rd-order cyclicity) that delimit sets of laminae. Two categories of storm beds have been differentiated. The first one includes layers formed below storm wave base (SWB), characterized by traction structures associated to unidirectional flows. The second category consists of layers deposited above the SWB, which display typical high regime oscillatory flow structures. The 1st-order cyclicity recorded in the La Virgen Formation corresponds to sapropel/homogeneous marl precessional cycles formed in a pelagic basin context (Torremendo Formation).

  12. Canning process that diminishes paralytic shellfish poison in naturally contaminated mussels (Mytilus galloprovincialis).

    Science.gov (United States)

    Vieites, J M; Botana, L M; Vieytes, M R; Leira, F J

    1999-05-01

    Changes in toxin profile and total toxicity levels of paralytic shellfish poison (PSP)-containing mussels were monitored during the standard canning process of pickled mussels and mussels in brine using mouse bioassays and high-performance liquid chromatography. Detoxification percentages for canned mussel meat exceeded 50% of initial toxicity. Total toxicity reduction did not fully correspond to toxin destruction, which was due to the loss of PSP to cooking water and packing media of the canned product. Significant differences in detoxification percentages were due to changes in toxin profile during heat treatment in packing media. Toxin conversion phenomena should be determined to validate detoxification procedures in the canning industry.

  13. Oscillation of mineral compositions in Core SG-1b, western Qaidam Basin, NE Tibetan Plateau

    Science.gov (United States)

    Fang, Xiaomin; Li, Minghui; Wang, Zhengrong; Wang, Jiuyi; Li, Jiao; Liu, Xiaoming; Zan, Jinbo

    2016-09-01

    Uplift of the Tibetan Plateau since the Late Miocene has greatly affected the nature of sediments deposited in the Qaidam Basin. However, due to the scarcity of continuously dated sediment records, we know little about how minerals responded to this uplift. In order to understand this response, we here present results from the high-resolution mineral profile from a borehole (7.3–1.6 Ma) in the Basin, which shows systematic oscillations of various evaporite and clay minerals that can be linked to the variation of regional climate and tectonic history. In particular, x-ray diffraction (XRD) analyses show that carbonate minerals consist mainly of calcite and aragonite, with minor ankerite and dolomite. Evaporates consist of gypsum, celesite and halite. Clay minerals are principally Fe-Mg illite, mixed layers of illite/smectite and chlorite, with minor kaolinite and smectite. Following implications can be drawn from the oscillations of these minerals phases: (a) the paleolake was brackish with high salinity after 7.3 Ma, while an abrupt change in the chemical composition of paleolake water (e.g. Mg/Ca ratio, SO42‑ concentration, salinity) occurred at 3.3 Ma; (b) the three changes at ~6.0 Ma, 4.5–4.1 Ma and 3.3 Ma were in response to rapid erosions/uplift of the basin; (c) pore water or fluid was Fe/Mg-rich in 7.3–6.0 Ma, Mg-rich in 6.0–4.5 Ma, and K-rich in 4.1–1.6 Ma and (d) evaporation rates were high, but weaker than today’s.

  14. Paleogene and Early Neogene Lacustrine Reefs in the Western Qaidam Basin, China

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jianhua; WEN Zhifeng; GUO Zeqing; WANG Haiqiao; GAO Jianbo

    2004-01-01

    Typical reefs in the Paleogene and early Neogene strata of the Qaidam Basin, Tibetan Plateau, China, reveal their internal structures and sedimentation environments and consist mainly of algal reef, stromatolite reef and thrombolite reef with distinct reef structures, fore-reef, back-reef and reef-plateau. The fore-reef is characterized by a combination of pinnacle reef, thrombolite and algal reef. The back reef is composed of stromatolite reef and algal reef. The pinnacle reefs (micro-atoll), most of which are several tens of centimeters in diameter (whereas some exceptionally big ones are over 200 cm in diameter), and several tens of centimeter to 2 m in height, are situated on the far front-edge of the reef; the pinnacle reef is also often of recumbent form with a gravel-filled circular hole in the center. The algal reef is in the form of dome and irregular beds, and filled with algal detritus, ostracodes, spirorbis fossils, ooid and terrigenous debris, and worm traces;cavities and scour marks are often developed. The algal reef is gray commonly when fresh and weathers to a brown color.The lacustrine thrombolite in the Qaidam Basin is light gray or deep gray when fresh, white-gray or brown when weathered, dense and homogeneous with abundant pores filled by oil and bitumen. Observed under the microscope, the thrombolite consists mainly of brown or brown-black clots with a little algal debris, ooid, pellet, ostracodes, spirorbis fossils and terrigenous debris, in some cases, terrigenous debris, even gravel, is abundant. Many features of the thrombolite suggest that it is formed in a high-energy environment. The stromatolite reefs developed on the lacustrine algal reef in the Qaldam Basin are very complex whether in shape or in internal structure. The simplest ones form laminated layers and the most complex ones have intensely branching structures. The size is also variable.

  15. Gamma-ray spectrometry across the Aalenian-Bajocian boundary in the Lusitanian Basin (Western Portugal)

    Science.gov (United States)

    Santos, Marisa; Henriques, Helena; Pena, Rui

    2016-04-01

    The Aalenian - Bajocian boundary was logged for the first time at the Murtinheira (Bajocian GSSP) and the Serra da Boa Viagem II sections, located in the Lusitanian Basin (West Central Portugal) using a portable gamma ray spectrometer, and well calibrated with the ammonite-based biostratigraphical zonation. These two coeval outcrops are represented by a prograding succession of greyish marl and limestone alternations, corresponding to the distal part of a carbonate ramp, which provides rich and diversified fossil (ammonoids, brachiopods) and microfossil (benthic foraminifera, calcareous nannoplancton) record. Different bioevents have been already described for the Concavum Zone (upper Aalenian) - Discites Zone (lower Bajocian) transition in both sections, namely among the ammonites, brachiopods, calcareous nannofossils and especially among the benthic foraminiferal assemblages, which record a remarkable decrease on abundance and diversity, also detected in other coeval sections of different basins located at the northern hemisphere. The gamma-ray data across these sections shows generally low values and variability, 13 to 60 API at Murtinheira section, and 26 to 59 API at Serra da Boa Viagem II section, which are typical of these carbonate hemipelagic facies. Moreover, the Th/U ratio is generally higher than 2 throughout the two sections suggesting well-oxygenated environmental conditions (also documented by the composition of the foraminiferal assemblages), which would have prevented significant organic matter accumulation; some levels displaying low Th/U ratio may reflect depletion in thorium (typical of many marine carbonates) rather than an increase in authigenic uranium, that usually is lower than 1 ppm. Before and after the faunal impoverishment bioevent of Late Concavum - Early Discites Biochron, the K%, Th (ppm) and Th/U ratio at the two sections display a relative increase, probably related to an increment in the detrital supply, and therefore nutrient

  16. Strike slip faulting inferred from offsetting of drainages: Lower Narmada basin, western India

    Indian Academy of Sciences (India)

    Rachna Raj

    2007-10-01

    The detailed analysis of landforms,drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of stream channels was found quite demonstrable along NNW –SSE trending transverse faults.Tectonic landforms including systematic de flection of stream channels and ridges, alignment of fault scarp and saddles and displacement in the basement rocks and alluvial deposits show that the area is undergoing active deformation driven by the NSF system.

  17. Radionuclides in ground water of the Carson River Basin, western Nevada and eastern California, U.S.A.

    Science.gov (United States)

    Thomas, J.M.; Welch, A.H.; Lico, M.S.; Hughes, J.L.; Whitney, R.

    1993-01-01

    Ground water is the main source of domestic and public supply in the Carson River Basin. Ground water originates as precipitation primarily in the Sierra Nevada in the western part of Carson and Eagle Valleys, and flows down gradient in the direction of the Carson River through Dayton and Churchill Valleys to a terminal sink in the Carson Desert. Because radionuclides dissolved in ground water can pose a threat to human health, the distribution and sources of several naturally occurring radionuclides that contribute to gross-alpha and gross-beta activities in the study area were investigated. Generally, alpha and beta activities and U concentration increase from the up-gradient to down-gradient hydrographic areas of the Carson River Basin, whereas 222Rn concentration decreases. Both 226Ra and 228Ra concentrations are similar throughout the study area. Alpha and beta activities and U concentration commonly exceed 100 pCi/l in the Carson Desert at the distal end of the flow system. Radon-222 commonly exceeds 2,000 pCi/l in the western part of Carson and Eagle Valleys adjacent to the Sierra Nevada. Radium-226 and 228Ra concentrations are oxide coatings on fracture surfaces and fine-grained sediment, by adsorption on organic matter, and by coprecipitation with Fe and Mn oxides. These coated sediments are transported throughout the basin by fluvial processes. Thus, U is transported as dissolved and adsorbed species. A rise in the water table in the Carson Desert because of irrigation has resulted in the oxidation of U-rich organic matter and dissolution of U-bearing coatings on sediments, producing unusually high U concentration in the ground water. Alpha activity in the ground water is almost entirely from the decay of U dissolved in the water. Beta activity in ground water samples is primarily from the decay of 40K dissolved in the water and ingrowth of 238U progeny in the sample before analysis. Approximately one-half of the measured beta activity may not be present

  18. Review: Regional groundwater flow modeling in heavily irrigated basins of selected states in the western United States

    Science.gov (United States)

    Rossman, Nathan R.; Zlotnik, Vitaly A.

    2013-09-01

    Water resources in agriculture-dominated basins of the arid western United States are stressed due to long-term impacts from pumping. A review of 88 regional groundwater-flow modeling applications from seven intensively irrigated western states (Arizona, California, Colorado, Idaho, Kansas, Nebraska and Texas) was conducted to provide hydrogeologists, modelers, water managers, and decision makers insight about past modeling studies that will aid future model development. Groundwater models were classified into three types: resource evaluation models (39 %), which quantify water budgets and act as preliminary models intended to be updated later, or constitute re-calibrations of older models; management/planning models (55 %), used to explore and identify management plans based on the response of the groundwater system to water-development or climate scenarios, sometimes under water-use constraints; and water rights models (7 %), used to make water administration decisions based on model output and to quantify water shortages incurred by water users or climate changes. Results for 27 model characteristics are summarized by state and model type, and important comparisons and contrasts are highlighted. Consideration of modeling uncertainty and the management focus toward sustainability, adaptive management and resilience are discussed, and future modeling recommendations, in light of the reviewed models and other published works, are presented.

  19. ENVIRONMENTS AND FAUNAL PATTERNS IN THE KACHCHH RIFT BASIN, WESTERN INDIA, DURING THE JURASSIC

    Directory of Open Access Journals (Sweden)

    FRANZ THEODOR FÜRSICH

    2004-03-01

    Full Text Available Marine Jurassic sediments (Bajocian-Tithonian of the Kachchh Basin were deposited in a ramp setting. Except during the Middle and Late Bathonian, when a carbonate regime became established, the fill of the basin consists predominantly of siliciclastics. The sediments represent environments that range from coastal plains (rivers and associated flood plains with caliche nodules, deltas, brackish water lagoons, nearshore sand and iron-oolite bars of the inner ramp, generally situated above fair-weather wave-base, to the middle ramp influenced by storm-waves and by storm-generated currents, and finally to the outer ramp which is characterised by low energy, fine-grained sediments. Changes in relative sea level produced a cyclic sedimentation pattern. The rich benthic fauna of macroinvertebrates is dominated by bivalves, followed by brachiopods, gastropods, corals, serpulids, and sponges. The analysis of 370 statistical samples and more than 27, 000 specimens produced more than 40 benthic associations and assemblages. They show a relationship to several environmental parameters, two of which, salinity and climate, are briefly discussed. The spatial distribution of the facies and biota is outlined for two time slices, the Bathonian and the Callovian-Oxfordian, respectively.

  20. Climate inferences between paleontological, geochemical, and geophysical proxies in Late Pleistocene lacustrine sediments from Summer Lake, Oregon, western Great Basin

    Science.gov (United States)

    Heaton, Eric; Thompson, Greg; Negrini, Rob; Wigand, Peter

    2016-04-01

    Paleontological, geochemical, and geophysical data from western Great Basin pluvial Summer Lake, Oregon have established a high resolution paleoclimate record during the late Pleistocene Mono Lake Excursion (~34.75 ka), Dansgaard-Oeschger interstadials 6-8, and the end of Heinrich Even 4 (~38 ka). Proxies of grain-size, magnetic susceptibility, carbon/nitrogen ratio, ostracode analysis and palynology from a depocenter core show new results with improved age control regarding high amplitude, high frequency changes in lake level, lake temperature, and regional precipitation and temperature which correspond directly with colder/warmer and respectively drier/wetter climates as documented with Northern Atlantic Greenland ice core data. Results from geophysical and geochemical analysis, and the presence of ostracode Cytherissa lacustris consistently demonstrate the correspondence of low lake conditions and colder water temperatures during Dansgaard-Oeschger stadials and the Mono Lake Excursion. The opposite holds true during interstadials. Smaller grain size, increases in carbon/nitrogen ratio and consistent absence of C. lacustris suggest periods of increased discharge into the lake, increased lake level, and warmer water temperatures. Warmer/wetter climate conditions are confirmed during interstadials 7 and 8 from pollen analysis. Existence of Atriplex, Rosaceae, Chrysothamnus and Ambrosia, and pollen ratios of Juniperus/Dip Pinus and (Rosaceae+Atriplex+Poaceae+Chrysothamnus+Ambrosia)/(Pinus+Picea+T. mertensiana+Sarcobatus) suggest warmer/wetter semi-arid woodland conditions during interstadials 7 and 8. This contrasts with absences in these pollens and pollen ratios indicating colder/drier continental montane woodland conditions during stadials and the Mono Lake Excursion. Increases in Juniper/Dip Pinus ratio suggest a warmer/wetter climate during interstadial 6 however additional proxies do not demonstrate comparative warmer/wetter climate, deeper lake level or

  1. Regional and Local Controls on the Distribution of Geothermal Systems in the Great Basin, Western United States

    Science.gov (United States)

    Coolbaugh, M. F.; Blewitt, G.; Faulds, J. E.; Kreemer, C. W.

    2005-12-01

    In the Great Basin (GB) of the western United States, geothermal systems with reservoir temperatures in excess of 150 C can be classified into two main categories (magmatic and amagmatic) according to the presence or absence of shallow magmatic heat sources. Magmatic systems are restricted to the margins of the GB where they are closely associated with Quaternary silicic volcanic rocks, whereas amagmatic systems occur over a large portion of the Great Basin interior and are not spatially associated with young silicic volcanism. A tabulation of temperature gradients for known geothermal systems in the world confirms research by others indicating that both magmatic and amagmatic systems occur within areas of high temperature gradients and high heat flow. However, high heat flow alone is not sufficient to explain the abundance of high-temperature geothermal activity in the GB interior. While the distribution of favorable host rocks likely plays a role, active crustal tectonics appears instrumental in explaining patterns of geothermal activity. At a detailed scale, Quaternary faults control the location of most geothermal systems in the GB. However, hundreds of Quaternary faults are distributed throughout the GB, and most do not host high-temperature geothermal resources. Spatial statistical analysis demonstrates that high-temperature geothermal systems (more than 150 C) are preferentially associated with NE-striking Quaternary faults, which in turn are oriented roughly perpendicular to the current direction of crustal extension in the western GB. Maps of active crustal extension rates in the GB, derived from Global Positioning System (GPS) velocity measurements and estimated slip rates on Quaternary faults, correlate well with the distribution of high-temperature geothermal systems and help explain why some faults with lower slip rates or unfavorable orientations don't host geothermal activity. Many geothermal systems in the GB occur in a broad transitional region

  2. Shallow lacustrine system of the Permian Pedra de Fogo Formation, Western Gondwana, Parnaíba Basin, Brazil

    Science.gov (United States)

    Araújo, Raphael Neto; Nogueira, Afonso César Rodrigues; Bandeira, José; Angélica, Rômulo Simões

    2016-04-01

    The Permian Period of the Parnaíba Basin, northern Brazil, represented here by deposits from the Pedra de Fogo Formation, records important events that occurred in Western Gondwana near its boundary with the Mesozoic Era. The analysis of outcrop based facies from the Permian Pedra de Fogo Formation, which is 100 m thick, carried out along the eastern and western borders of the Parnaiba Basin, allowed the identification of eleven sedimentary facies, which were grouped into three distinct facies associations (FA), representative of a shallow lacustrine system associated with mudflats and ephemeral rivers. Bioturbation, desiccation cracks, silcretes and various siliceous concretions characterize the Pedra de Fogo deposits. The FA1 mudflat deposits occur predominantly at the base of the Pedra de Fogo Formation and consist of laminated claystone/mudstone, mudcrack-bearing sandstones/mudstones and sandstones exhibiting cross-lamination, massive and megaripple bedding. Popcorn-like silicified nodules and casts indicate evaporite deposits. Other common features are silica concretions, silicified tepees and silcretes. FA2 represents nearshore deposits and consists of fine-grained sandstones with evenly parallel lamination, climbing ripple cross-lamination, massive and megaripple bedding and mudstone/siltstone showing evenly parallel lamination. FA3 refers to wadi/inundite deposits, generally organized as fining-upward cycles of metric size, composed of conglomerates and medium-grained pebbly sandstones showing massive bedding and cross-stratification, as well as claystone/siltstone showing evenly parallel to undulate lamination. Scour-and-fill features are isolated in predominantly tabular deposits composed of mudstones interbedded with fine to medium-grained sandstones showing planar to slightly undulate lamination. Silicified plant remains previously classified as belonging to the Psaronius genus found in the uppermost levels of the Pedra de Fogo Formation, near the

  3. Circulation of a Meaban-like virus in yellow-legged gulls and seabird ticks in the western Mediterranean basin.

    Directory of Open Access Journals (Sweden)

    Audrey Arnal

    Full Text Available In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis, a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus, were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring

  4. Decline in snowfall in response to temperature in Satluj basin, western Himalaya

    Indian Academy of Sciences (India)

    Riyaz Ahmad Mir; Sanjay K Jain; Arun K Saraf; Ajanta Goswami

    2015-03-01

    Snow is an essential resource present in the Himalaya. Therefore, monitoring of the snowfall changes over a time period is important for hydrological and climatological purposes. In this study, variability of snowfall from 1976–2008 were analysed and compared with variability in temperature (max and min) from 1984–2008 using simple linear regression analysis and Mann–Kendall test in the Satluj Basin. The annual, seasonal, and monthly analyses of average values of snowfall and temperature (max and min) have been carried out. The study also consists an analysis of average values of annual snowfall and temperature over six elevation zones (<1500 to >4000 m amsl). During the study, it was observed that the snowfall exhibited declining trends in the basin. The snowfall trends are more sensitive to the climate change below an elevation of 4000 m amsl. Over the elevation zones of 3000–3500 and 4000–4500 m amsl, positive trends of mean annual values of snowfall were observed that may be due to higher precipitation as snowfall at these higher elevations. Although, both negative and positive snowfall trends were statistically insignificant, however, if this decreasing trend in snowfall continues, it may result in significant however, changes in future. Furthermore, the min is also increasing with statistically significant positive trend at 95% confidence level for November, winter season, annually as well as for the elevation zones of 2500–3000, 3000–3500, and 3500–4000 m amsl. There are dominantly increasing trends in max with negative trends for February, June–September, monsoon season, and for elevation zone <1500 m amls. It is important to state that in the present basin, during the months of winter season, most of the precipitation is produced as snowfall by the westerly weather disturbances. Thus, the declining nature in snowfall is concurrent with the positive trends in temperature particularly min, therefore, reflecting that the positive trends in

  5. Digital single-channel seismic-reflection data from western Santa Monica basin

    Science.gov (United States)

    Normark, William R.; Piper, David J.W.; Sliter, Ray W.; Triezenberg, Peter; Gutmacher, Christina E.

    2006-01-01

    During a collaborative project in 1992, Geological Survey of Canada and United States Geological Survey scientists obtained about 850 line-km of high-quality single-channel boomer and sleeve-gun seismic-reflection profiles across Hueneme, Mugu and Dume submarine fans, Santa Monica Basin, off southern California. The goals of this work were to better understand the processes that lead to the formation of sandy submarine fans and the role of sea-level changes in controlling fan development. This report includes a trackline map of the area surveyed, as well as images of the sleeve-gun profiles and the opportunity to download both images and digital data files (SEG-Y) of all the sleeve-gun profiles.

  6. First quantification of severe wind erosion in yardang fields using cosmogenic 10Be within the western Qaidam Basin, China

    Science.gov (United States)

    Rohrmann, A.; Heermance, R.; Kapp, P. A.; Mc-Callister, A.

    2010-12-01

    Desert environments are a major source of global loess and may undergo substantial wind-erosion as evidenced by yardangs, which are streamlined bedrock ridges sculpted from uni-directional winds. However, there are few quantitative estimates of wind erosion rates in deflationary deserts, globally. Here, we report the first quantitative rates of bedrock wind erosion determined using cosmogenic 10Be in the western Qaidam basin, China, where roughly one-third of the modern basin floor (~3.88 × 104 km2) exposes yardangs. Eleven Neogene bedrock sandstone samples and one pre-Cenozoic granite sample were analyzed for 10Be concentrations. The Neogene samples were collected from crests and limbs of broad and actively growing anticlines, where in most places strata have been wind-sculpted into yardangs. Sedimentary bedrock erosion rates vary from 0.04-0.34 mm/yr, although 60 percent (n=7) of all samples cluster tightly at 0.1 ± 0.03 mm/yr. Erosion rates assume steady-state erosion over ~10,000 years. The lowest rate of 0.0025 mm/yr was obtained from a granite bedrock sample along the Altyn-Tagh range bounding the northwestern margin of the Qaidam basin and is consistent with other 10Be bedrock erosion rates collected from granitic bedrock elsewhere on the Tibetan Plateau. These results demonstrate the importance of lithology in controlling bedrock erodibility by wind. The highest erosion rates of 0.17, 0.25, and 0.34 mm/yr were determined along a transect across an active anticline. The lowest of the three rates was obtained from the top of the structure, suggesting that wind erosion and thus wind speeds are highest on the limbs of an anticline as wind is forced around the obstacle (Bernoulli-effect), rather than flowing over it. The determined sedimentary bedrock erosion rates of 0.04-0.34 mm/yr are in good agreement with previous analysis of basin wide-average erosion rates from geological cross-sections (0.29 mm/yr) and simple erosion calculations using previous lake

  7. Effect of canning on color, protein and phenolic profile of grains from kidney bean, field pea and chickpea.

    Science.gov (United States)

    Parmar, Naincy; Singh, Narpinder; Kaur, Amritpal; Virdi, Amardeep Singh; Thakur, Sheetal

    2016-11-01

    The aim of the present study was to evaluate the effect of canning on color, protein and phenolic profile of grains of kidney bean, field pea and chickpea varieties/accession. Color of grains of different pulses was enhanced after canning. Grains L* (lightness) decreased while a* (redness to yellowness) and b* (greenness to blueness) increased after canning in all the pulses. Protein profiling of grains of different pulses after canning revealed that kidney bean and chickpea, respectively, had the least and the most thermally susceptible polypeptides. Kidney bean and chickpea showed higher Percentage washed drained weight (PWDW) than field pea. Pulse with more grain hardness and PWDW showed higher degree of grain splitting during canning. Grain splitting was also higher in dark colored accessions/varieties as compared to the light colored. Ferulic acid was the most predominant compound present in raw grains of different pulses. Raw kidney bean grains showed higher accumulation of catechin, chlorogenic, protocatechuic acid, p-coumaric acid and ferulic acid than those of chickpea and field pea. Canning caused reduction in all the phenolic compounds except gallic acid and most prominent effect of canning on protocatechuic acid, chlorogenic and ferulic acid was observed. Copyright © 2016. Published by Elsevier Ltd.

  8. Salt tectonics and associated fluid migration and entrapment in the western part of the Norwegian-Danish Basin

    Science.gov (United States)

    Sørig, Simon A.; Clausen, Ole R.; Andresen, Katrine J.

    2016-04-01

    The western part of the Norwegian-Danish Basin is part of the Northern Permian Basin and encompasses a variety of Zechstein salt structures (pillows, rollers, diapirs and salt walls). The area has been studied for decades with respect to HC prospectively associated to salt structures as well a focus area for studies on conceptual evolution of salt structures and faults associated with the salt structures. Previous local studies on fluid migration and Direct Hydrocarbon Indicators (DHI's) in the area show a close relation between halo kinetics and local fluid migration. In the present study we have used3D seismic data (approximately 3500 km2) to identify and describe A: large diapirs which have been active until the youngest Cenozoic, B: medium sized diapirs being active until the early Cenozoic, C: salt relicts creating small non active pillows, and D: small satellite structures related to type A. The salt structures are evenly distributed across the studied area, and we conclude that the structures were initiated during the late Triassic due to depositional controlled differential loading combined with differential subsidence. DHI's are identified at various stratigraphic and structural settings associated to the salt structures and each structure type has different types of DHI's associated. The DHIs observed at the type A and B diapirs are located above or at the stem of the diapirs and are here interpreted as classic structural hydrocarbon traps associated with rising salt deforming the strata. However, the DHI's associated to type C salt pillows have a relatively small lateral extent, stratigraphically restricted to the Mesozoic succession; they are located above the apex of the pillow and have in general a seismically disturbed zone located beneath the DHI. The seismically disturbed zone resembles gas chimneys, but may also be related to minor deformation of the Mesozoic strata overlying the type C pillows. A biogenic origin of the gas in at least some of the

  9. Arsenic, Prokaryotes, and Closed Basin Soda Lakes of the Western USA.

    Science.gov (United States)

    Oremland, R. S.

    2006-12-01

    A number of saline, alkaline soda lakes in the Great Basin and Mojave Desert of the United States have unusually high concentrations of inorganic arsenic dissolved in their brine-waters. The arsenic originates from natural rather than anthropogenic sources, namely volcanic hydrothermal inputs. When this influx is coupled with evapo-concentration and the unique chemical behavior of arsenic oxyanions in alkaline waters, it results in extremely elevated As concentrations. For example, the salinity and arsenate levels of 3 comparable soda lakes (pH 9.8) are: Big Soda Lake, NV (27 g/L; 20 uM), Mono Lake, CA (90 g/L; 200 uM), and Searles Lake, CA (340 g/L; 3,900 uM). The arsenic oxidation state changes from As5+ (arsenate) to As3+ (arsenite) with vertical transition from their oxygenated surface water to their anoxic bottom water. Similar phenomena occur in their littoral sediments. These lakes also harbor active populations of prokaryotes that achieve these As redox changes either by using arsenate as an electron acceptor for respiration, or by employing arsenite as a chemoautotrophic electron donor. Diverse microorganisms have been identified in these systems that are involved in the biogeochemical cycling of arsenic therein, and in situ studies made with radiotracer (73As) and other means showed that these redox reactions occur at rapid rates. However, other than their use for waterfowl hunting (Big Soda Lake), as a region of scenic beauty (Mono Lake), or as a resource for the chemical industry (Searles Lake), there is little concern about the arsenic in these systems because the waters are not potable and their chemistry is too extreme to allow for the presence of fish. Nonetheless, microbial processes that govern arsenic biogeochemistry can greatly influence the hydrologic mobility and toxicity of this element in freshwater systems, such as drinking water aquifers. Moreover, anthropogenic inputs of arsenic can also occur in closed basin lakes in this region, such as

  10. Analysis of Critical Permeabilty, Capillary Pressure and Electrical Properties for Mesaverde Tight Gas Sandstones from Western U.S. Basins

    Energy Technology Data Exchange (ETDEWEB)

    Alan Byrnes; Robert Cluff; John Webb; John Victorine; Ken Stalder; Daniel Osburn; Andrew Knoderer; Owen Metheny; Troy Hommertzheim; Joshua Byrnes; Daniel Krygowski; Stefani Whittaker

    2008-06-30

    Although prediction of future natural gas supply is complicated by uncertainty in such variables as demand, liquefied natural gas supply price and availability, coalbed methane and gas shale development rate, and pipeline availability, all U.S. Energy Information Administration gas supply estimates to date have predicted that Unconventional gas sources will be the dominant source of U.S. natural gas supply for at least the next two decades (Fig. 1.1; the period of estimation). Among the Unconventional gas supply sources, Tight Gas Sandstones (TGS) will represent 50-70% of the Unconventional gas supply in this time period (Fig. 1.2). Rocky Mountain TGS are estimated to be approximately 70% of the total TGS resource base (USEIA, 2005) and the Mesaverde Group (Mesaverde) sandstones represent the principal gas productive sandstone unit in the largest Western U.S. TGS basins including the basins that are the focus of this study (Washakie, Uinta, Piceance, northern Greater Green River, Wind River, Powder River). Industry assessment of the regional gas resource, projection of future gas supply, and exploration programs require an understanding of reservoir properties and accurate tools for formation evaluation. The goal of this study is to provide petrophysical formation evaluation tools related to relative permeability, capillary pressure, electrical properties and algorithms for wireline log analysis. Detailed and accurate moveable gas-in-place resource assessment is most critical in marginal gas plays and there is need for quantitative tools for definition of limits on gas producibility due to technology and rock physics and for defining water saturation. The results of this study address fundamental questions concerning: (1) gas storage; (2) gas flow; (3) capillary pressure; (4) electrical properties; (5) facies and upscaling issues; (6) wireline log interpretation algorithms; and (7) providing a web-accessible database of advanced rock properties. The following text

  11. A new structural interpretation relating NW Libya to the Hun Graben, western Sirt Basin based on a new paleostress inversion

    Indian Academy of Sciences (India)

    K M Abdunaser; K J W McCaffrey

    2015-12-01

    The present study is based on fault-slip data (striated fault planes with known sense of slip) measured in outcrops in two structural domains located along the Hun Graben, western Sirt Basin (150 fault-slip data) and the Jifarah Basin and Nafusah Uplift, northwest Libya (200 fault-slip data). Pre-existing field data collected in two previous studies were reprocessed using standard inversion methods in MyFaultTM (v. 1.03) stereonet software, produced by Pangaea Scientific Ltd. The aim of this study was to use paleostress orientations and relative paleostress magnitudes (stress ratios), determined using the reduced stress concept, to test a new understanding of the kinematic characteristics, the relationship between the two areas and the paleostress fields that controlled the evolution of the fault systems responsible for the observed deformation. Various types of faults (normal faults, sinistral normal faults, dextral normal faults and strike-slip faults) were recorded from outcrops comprised of Mesozoic and Cenozoic sedimentary sequences in which a lineation rake is present on minor structures with displacement ranging from several centimetres to several metres. Two different domains of a NNE–SSW directed extension regime ranging from N12°E to 25°E and minor ENE–WSW and WNW–ESE compression were identified in the analysis. The results are remarkably homogeneous at all sites and consistent with progressive collisional coupling of Africa and Europe, being under approximately WNW–ESE reactivated compressional stresses during the Late Eocene-age. The new kinematic and structural conceptual model that has been proposed is a test of the prevailing tectonic models describing the Cenozoic kinematic evolution of the areas. The results show the remarkable influence of basement fabrics of different ages on the subsequent structural development of NW Libya.

  12. Physicochemical impacts of dust particles on alpine glacier meltwater at the Laohugou Glacier basin in western Qilian Mountains, China.

    Science.gov (United States)

    Dong, Zhiwen; Qin, Dahe; Chen, Jizu; Qin, Xiang; Ren, Jiawen; Cui, Xiaoqing; Du, Zhiheng; Kang, Shichang

    2014-09-15

    This work discusses the temporal variation of various physicochemical species in the meltwater runoff of Laohugou Glacier No. 12 (4260 ma.s.l.) in central Asia, and their correlation with dust particles, based on a two-year field observation in summer 2012 and 2013, mainly focusing on dust concentration and size distribution, meltwater chemistry, particles SEM-EDX analysis in the meltwater, and MODIS atmospheric optical depth fields around the Qilian Mountains in central Asia. We find that, the volume-size distribution of dust particles in the meltwater is mainly composed of three parts, which includes fine aerosol particles (with diameter of 0~3.0 μm, mainly PM 2.5), atmospheric dust (with diameter of 3.0~20 μm), and local dust particles (20~100 μm), respectively. Comparison of dust particles in the snowpack and meltwater runoff indicates that, large part of dust particles in the meltwater may have originated from atmospheric dust deposition to the snow and ice on the glacier, and transported into the meltwater runoff. Moreover, temporal variation of dust and major ions (especially crustal species) is very similar with each other, showing great influence of dust particles to the chemical constituents of the glacier meltwater. SPM and TDS implied significant influences of dust to the physical characteristics of the glacier meltwater. Results showed that, accelerated glacier melting may affect physicochemical characteristics of the meltwater at an alpine basin under global warming. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm, showed great influence of regional dust transportation over western Qilian Mountains in springtime. SEM-EDX analysis shows that dust particles in the glacier meltwater contain Si-, Al-, Ca-, K-, and Fe-rich materials, such as quartz, albite, aluminate, and fly ash, similar to that deposited in snowpack. These results showed great and even currently underestimated influences of atmospheric dust

  13. Tectonic Fractures in Tight Gas Sandstones of the Upper Triassic Xujiahe Formation in the Western Sichuan Basin,China

    Institute of Scientific and Technical Information of China (English)

    ZENG Lianbo; LI Yuegang

    2010-01-01

    The western Sichuan Basin,which is located at the front of the Longmen Mountains in the west of Sichuan Province,China,is a foreland basin formed in the Late Triassic.The Upper Triassic Xujiahe Formation is a tight gas sandstone reservoir with low porosity and ultra-low permeability,whose gas accumulation and production are controlled by well-developed fracture zones.There are mainly three types of fractures developed in the Upper Triassic tight gas sandstones,namely tectonic fractures,diagenetic fractures and overpressure-related fractures,of which high-angle tectonic fractures are the most important.The tectonic fractures can be classified into four sets,i.e.,N-S-,NE-,E-W-and NW-striking fractures.In addition,there are a number of approximately horizontal shear fractures in some of the medium-grained sandstones and grit stones nearby the thrusts or slip layers.Tectonic fractures were mainly formed at the end of the Triassic,the end of the Cretaceous and the end of the Neogene-Early Pleistocene.The development degree of tectonic fractures was controlled by lithology,thickness,structure,stress and fluid pressure.Overpressure makes not only the rock shear strength decrease,but also the stress state change from compression to tension.Thus,tensional fractures can be formed in fold-thrust belts.Tectonic fractures are mainly developed along the NE-and N-S-striking structural belts,and are the important storage space and the principal flow channels in the tight gas sandstone.The porosity of fractures here is 28.4% of the gross reservoir porosity,and the permeability of fractures being two or three grades higher than that of the matrix pores.Four sets of high-angle tectonic fractures and horizontal shear fractures formed a good network system and controlled the distribution and production of gas in the tight sandstones.

  14. Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south-western Cuddapah Basin, southern India

    Science.gov (United States)

    Rao, N. V. Chalapathi; Atiullah; Kumar, Alok; Sahoo, Samarendra; Nanda, Purnendu; Chahong, Ngazimpi; Lehmann, B.; Rao, K. V. S.

    2016-04-01

    We report mineral chemistry and whole-rock major and trace-element geochemistry for a recent find of Mesoproterozoic (~1.4 Ga) lamproites from the Garledinne (Banganapalle) cluster, south-western part of the Paleo-Mesoproterozoic Cuddapah Basin, southern India. The Garledinne lamproites occur as WNW-ESE-trending dykes that have undergone varying degree of pervasive silicification and carbonate alteration. Nevertheless, their overall texture and relict mineralogy remain intact and provide important insights into the nature of their magmas. The lamproite dykes have porphyritic to weakly porphyritic textures comprising pseudomorphed olivine macrocrysts and microphenocrysts, titanian phlogopite microphenocrysts, spinel having a compositional range from chromite to rarely magnesiochromite, Sr-rich apatite and niobian rutile. The Garledinne and other Cuddapah Basin lamproites (Chelima and Zangamarajupalle) collectively lack sanidine, clinopyroxene, potassic richterite, and titanite and are thus mineralogically distinct from the nearby Mesoproterozoic lamproites (Krishna and Ramadugu) in the Eastern Dharwar Craton, southern India. The strong correlation between various major and trace elements coupled with high abundances of incompatible and compatible trace elements imply that alteration and crustal contamination have had a limited effect on the whole-rock geochemistry (apart from K2O and CaO) of the Garledinne lamproites and that olivine fractionation played an important role in their evolution. The Garledinne lamproites represent small-degree partial melts derived from a refractory (previously melt extracted) peridotitic mantle source that was subsequently metasomatised (enriched) by carbonate-rich fluids/melts within the garnet stability field. The involvement of multiple reservoirs (sub-continental lithospheric mantle and asthenosphere) has been inferred in their genesis. The emplacement of the Garledinne lamproites is linked to extensional events, across the various

  15. Geophysical evidence and inferred triggering factors of submarine landslides on the western continental margin of the Ulleung Basin, East Sea

    Science.gov (United States)

    Cukur, Deniz; Kim, Seong-Pil; Kong, Gee-Soo; Bahk, Jang-Jun; Horozal, Senay; Um, In-Kwon; Lee, Gwang-Soo; Chang, Tae-Soo; Ha, Hun-Jun; Völker, David; Kim, Jung-Ki

    2016-12-01

    Submarine landslides form very complex depositional and erosional features on the seafloor, and their dynamics and triggering processes are yet to be understood completely. Numerous studies are being undertaken both because of the scientific significance but also for their potential harm to seafloor infrastructure and coastal areas. This study investigates the styles and causes of landsliding along the western margin of the Ulleung Basin in the East Sea, based on multiple sparker, subbottom profiler, multibeam echosounder and sediment core datasets collected in 2015. The bathymetric analyses indicate that the southern slope of the Ulleung Basin has experienced at least seven submarine failures. These failures left clear arcuate-shaped scarps that initiated at water depths of 600 m. The observed headwall scarps have heights that exceed 60 m and appear to be the result of retrogressive-type failures. Seismic reflection data clearly image the basal sliding surface that is characterized by a prominent high-amplitude reflector. Chaotic-to-transparent seismic facies occur immediately downslope of the headwall scarps; these represent 20 m thick landslide deposits. Gravity cores taken from areas adjacent to the scars suggest that these slides are older than ca. 97 ka. Interpretation of the present data shows that faults appear to cut recent sediments upslope of scarps, and that the slope may still be in an active phase of failure. Seismic data also image various overpressurized gases and/or gas fluids, as evidenced by the occurrence of pockmarks and seismic chimneys in upslope or adjacent areas of the scarps. Hence, earthquakes associated with tectonic activity and development of fluid overpressure may have acted as the main conditioning factor for destabilizing the slope sediments. Geotechnical stability analyses indicate that the sampled slope sediments are exceptionally stable under present-day conditions, even under seismic loading. This finding points to additional

  16. Effects of weathering of organic matter in the La Luna Formation, Maracaibo Basin, Western Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, N.

    1986-01-01

    The effect of weathering of organic matter in the La Luna Formation, the main source rock of Cretaceous oil in Western Venezuela was studied by means of organic petrography. Two outcrop samples from zero to about 10 cm depth were studied microscopically, both in whole rock and kerogen extract mode. This permitted recognizing some characteristics and consequences of weathering, such as: increased porosity of huminite and solid bitumens and the decrease of its reflectance (% anti Ro); disappearance of micrinite, presence of exudation substances and lower fluorescence emission of liptinite under blue light excitation. The mass reduction of the organic matter was determined by the difference of total organic carbon values, and by the weight reduction of the sample before and after extraction, in both weathered and unweathered samples. The loss of organic matter by weathering is considerable, as much as 87% in the first 0.5 cm of the weathering halo are lost.

  17. Eocene lignites from Cambay basin, Western India: An excellent source of hydrocarbon

    Directory of Open Access Journals (Sweden)

    P.K. Singh

    2016-09-01

    Full Text Available In the present paper lignites from the Cambay basin have been studied for their hydrocarbon potential. The samples were collected from three lignite fields–Vastan, Rajpardi and Tadkeshwar, and were investigated by petrography, chemical analyses and Rock-Eval pyrolysis. The results are well comparable with the empirically derived values. The study reveals that these ‘low rank C’ lignites are exceedingly rich in reactive macerals (huminite + liptinite while inertinite occurs in low concentration. These high volatile lignites generally have low ash yield except in few sections. The Rock-Eval data indicates the dominance of kerogen type-III with a little bit of type-II. The study reveals that the lignites of Vastan (lower and upper seams and Tadkeshwar upper seam are more gas-prone while Rajpardi and Tadkeshwar lower seams are oil-prone. Further, the fixed hydrocarbons are several times higher than the free hydrocarbons. The relation between TOC and fixed hydrocarbon indicates that these lignites are excellent source rock for hydrocarbon which could be obtained mainly through thermal cracking. The empirically derived values reveal a high conversion (94–96% and high oil yield (64–66% for these lignites.

  18. Eocene lignites from Cambay basin, Western India:An excellent source of hydrocarbon

    Institute of Scientific and Technical Information of China (English)

    P.K. Singh; V.K. Singh; P.K. Rajak; M.P. Singh; A.S. Naik; S.V. Raju; D. Mohanty

    2016-01-01

    In the present paper lignites from the Cambay basin have been studied for their hydrocarbon potential. The samples were collected from three lignite fieldseVastan, Rajpardi and Tadkeshwar, and were investigated by petrography, chemical analyses and Rock-Eval pyrolysis. The results are well comparable with the empirically derived values. The study reveals that these‘low rank C’ lignites are exceedingly rich in reactive macerals (huminite þ liptinite) while inertinite occurs in low concentration. These high volatile lignites generally have low ash yield except in few sections. The Rock-Eval data indicates the dominance of kerogen type-III with a little bit of type-II. The study reveals that the lignites of Vastan (lower and upper seams) and Tadkeshwar upper seam are more gas-prone while Rajpardi and Tad-keshwar lower seams are oil-prone. Further, the fixed hydrocarbons are several times higher than the free hydrocarbons. The relation between TOC and fixed hydrocarbon indicates that these lignites are excellent source rock for hydrocarbon which could be obtained mainly through thermal cracking. The empirically derived values reveal a high conversion (94e96%) and high oil yield (64e66%) for these lignites.

  19. Coarse grain deposit feature of Guantao formation in western depression Shuyi area of Liaohe basin

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-hua; LIU Chen-sheng; ZHU Mei-heng

    2005-01-01

    The extensive distribution of coarse-grained clastic rock of Guantao formation in Shuyi area of Liaohe basin was considered as a result of fluvial deposit. According to the comprehensive analysis of seism data, well log, core observation and experimental data, this kind of clastic rock is composed of pebblestone-cobblestone, microconglomerate, sand conglomerate, medium-coarse grained sandstone and fine-sandstone. According to the clast composition, sedimentary texture, structure and rock type, 3 kinds of sediment facies can be recognized ie the mixed accumulation-conglomerate dominated debris flow, pebblestone-cobblestone dominated gradient flow and sandstone dominated braided stream. Vertically, the bottom gradient current deposit and top braided stream deposit form fining-upward sediment sequence, and the debris flow deposit distributes in them at random. The sedimentary feature of coarse grain clastic of Guantao formation in Shuyi area is accordant with proximal wet alluvial fan deposited in wet climate at foreland and this kind of alluvial fan is different from the traditional one.

  20. Three-Dimensional Geothermal Fairway Mapping: Examples From the Western Great Basin, USA

    Energy Technology Data Exchange (ETDEWEB)

    Siler, Drew L [Nevada Bureau of Mines and Geology, University of Nevada, Reno; Faulds, James E [Nevada Bureau of Mines and Geology, University of Nevada, Reno

    2013-09-29

    Elevated permeability along fault systems provides pathways for circulation of geothermal fluids. Accurate location of such fluid flow pathways in the subsurface is crucial to future geothermal development in order to both accurately assess resource potential and mitigate drilling costs by increasing drilling success rates. Employing a variety of surface and subsurface data sets, we present detailed 3D geologic analyses of two Great Basin geothermal systems, the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, Nevada. 3D modeling provides the framework for quantitative structural analyses. We combine 3D slip and dilation tendency analysis along fault zones and calculations of fault intersection density in the two geothermal systems with the locations of lithologies capable of supporting dense, interconnected fracture networks. The collocation of these permeability promoting characteristics with elevated heat represent geothermal ‘fairways’, areas with ideal conditions for geothermal fluid flow. Location of geothermal fairways at high resolution in 3D space can help to mitigate the costs of geothermal exploration by providing discrete drilling targets and data-based evaluations of reservoir potential.

  1. Subsurface recharge to the Tesuque aquifer system from selected drainage basins along the western side of the Sangre de Cristo Mountains near Santa Fe, New Mexico

    Science.gov (United States)

    Wasiolek, Maryann

    1995-01-01

    Water budgets developed for basins of five streams draining the western side of the Sangre de Cristo Mountains in northern New Mexico indicate that subsurface inflow along the mountain front is recharging the Tesuque aquifer system of the Espanola Basin. Approximately 14,700 acre-feet of water per year, or 12.7 percent of average annual precipitation over the mountains, is calculated to leave the mountain block and enter the basin as subsurface recharge from the drainage basins of the Rio Nambe, Rio en Medio, Tesuque Creek, Little Tesuque Creek, and Santa Fe River. About 5,520 acre- feet per year, or about 12 percent of average annual precipitation, is calculated to enter from the Rio Nambe drainage basin; about 1,710 acre- feet per year, or about 15 percent of average annual precipitation, is calculated to enter from the Rio en Medio drainage basin; about 1,530 acre- feet, or about 10 percent of average annual precipi- tation, is calculated to enter from the Tesuque Creek drainage basin; about 1,790 acre-feet, or about 19 percent of average annual precipitation, is calculated to enter from the Little Tesuque Creek drainage basin; and about 4,170 acre-feet per year, or about 12 percent average annual precipitation, is calculated to enter from the Santa Fe River drainage basin. Calculated subsurface recharge values were used to define maximum fluxes permitted along the specified-flux boundary defining the mountain front of the Sangre De Cristo Mountains in a numerical computer model of the Tesuque aquifer system near Santa Fe, New Mexico.

  2. Effects of sources and meteorology on particulate matter in the Western Mediterranean Basin: An overview of the DAURE campaign

    Science.gov (United States)

    Pandolfi, M.; Querol, X.; Alastuey, A.; Jimenez, J. L.; Jorba, O.; Day, D.; Ortega, A.; Cubison, M. J.; Comerón, A.; Sicard, M.; Mohr, C.; Prévôt, A. S. H.; Minguillón, M. C.; Pey, J.; Baldasano, J. M.; Burkhart, J. F.; Seco, R.; Peñuelas, J.; Drooge, B. L.; Artiñano, B.; Di Marco, C.; Nemitz, E.; Schallhart, S.; Metzger, A.; Hansel, A.; Lorente, J.; Ng, S.; Jayne, J.; Szidat, S.

    2014-04-01

    DAURE (Determination of the Sources of Atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean) was a multidisciplinary international field campaign aimed at investigating the sources and meteorological controls of particulate matter in the Western Mediterranean Basin (WMB). Measurements were simultaneously performed at an urban-coastal (Barcelona, BCN) and a rural-elevated (Montseny, MSY) site pair in NE Spain during winter and summer. State-of-the-art methods such as 14C analysis, proton-transfer reaction mass spectrometry, and high-resolution aerosol mass spectrometry were applied for the first time in the WMB as part of DAURE. WMB regional pollution episodes were associated with high concentrations of inorganic and organic species formed during the transport to inland areas and built up at regional scales. Winter pollutants accumulation depended on the degree of regional stagnation of an air mass under anticyclonic conditions and the planetary boundary layer height. In summer, regional recirculation and biogenic secondary organic aerosols (SOA) formation mainly determined the regional pollutant concentrations. The contribution from fossil sources to organic carbon (OC) and elemental carbon (EC) and hydrocarbon-like organic aerosol concentrations were higher at BCN compared with MSY due to traffic emissions. The relative contribution of nonfossil OC was higher at MSY especially in summer due to biogenic emissions. The fossil OC/EC ratio at MSY was twice the corresponding ratio at BCN indicating that a substantial fraction of fossil OC was due to fossil SOA. In winter, BCN cooking emissions were identified as an important source of modern carbon in primary organic aerosol.

  3. Recent desiccation of Western Great Basin Saline Lakes: Lessons from Lake Abert, Oregon, U.S.A.

    Science.gov (United States)

    Moore, Johnnie N

    2016-06-01

    Although extremely important to migrating waterfowl and shorebirds, and highly threatened globally, most saline lakes are poorly monitored. Lake Abert in the western Great Basin, USA, is an example of this neglect. Designated a critical habitat under the Western Hemisphere Shorebird Reserve Network, the lake is at near record historic low levels and ultra-high salinities that have resulted in ecosystem collapse. Determination of the direct human effects and broader climate controls on Lake Abert illustrates the broader problem of saline lake desiccation and suggests future solutions for restoration of key habitat values. A 65-year time series of lake area was constructed from Landsat images and transformed to lake volume and salinity. "Natural" (without upstream withdrawals) conditions were calculated from climate and stream flow data, and compared to measured volume and salinity. Under natural conditions the lake would have higher volume and lower salinities because annual water withdrawals account for one-third of mean lake volume. Without withdrawals, the lake would have maintained annual mean salinities mostly within the optimal range of brine shrimp and alkali fly growth. Even during the last two years of major drought, the lake would have maintained salinities well below measured values. Change in climate alone would not produce the recent low lake volumes and high salinities that have destroyed the brine shrimp and alkali fly populations and depleted shorebird use at Lake Abert. Large scale withdrawal of water for direct human use has drastically increased the imbalance between natural runoff and evaporation during periods of drought in saline lakes worldwide but could be offset by establishing an "environmental water budget" to lay a foundation for the conservation of saline lake habitats under continued threats from development and climate change.

  4. Liquefaction in western Sichuan Basin during the 2008 Mw 7.9 Wenchuan earthquake, China

    Science.gov (United States)

    Liu-Zeng, Jing; Wang, Peng; Zhang, Zhihui; Li, Zhigang; Cao, Zhenzhong; Zhang, Jinyu; Yuan, Xiaoming; Wang, Wei; Xing, Xiuchen

    2017-01-01

    Strong ground shaking during the 2008 Mw 7.9 Wenchuan earthquake, which occurred in the foothills of the Longmen Shan in southwestern China, resulted in widespread coseismic deformation features, such as liquefaction and water ejection. We present a systematic survey of the soil liquefaction and water ejection features caused by this major earthquake. The majority of liquefaction sites occurred along major alluvial fan-building rivers, where the water table was a few meters below the surface. While there is no clear correlation between water fountain height and peak ground acceleration, 58% of liquefaction sites are located 20-35 km from the Beichuan fault. Clusters of sites with anomalously high (> 2 m) water ejections are located near the surface projection of the Range Front blind thrust and its splay faults. The density of anomalously high eruptions within the window surrounding the Range Front blind thrust is 3-6 times greater than outside this region. Our results suggest that geologic structures may play a role in augmenting liquefaction intensity and shaking-related seismic hazards in sedimentary basins. We speculate that the mechanism could be the amplification of shaking by fault zone structures. Alternatively, faults may act as pathways with increased vertical permeability, allowing fluids from deeper confined aquifers to migrate to and enhance liquefaction of the upper soil, as proposed previously by Wang (2007). Liquefaction associated with the Wenchuan earthquake thus demonstrates the importance of considering geologic structures other than the primary earthquake-producing fault in seismic hazard evaluation and earthquake resistance design in areas with similar geologic and hydrological settings.

  5. Field and synthetic experiments for virtual source crosswell tomography in vertical wells: Perth Basin, Western Australia

    Science.gov (United States)

    Almalki, Majed; Harris, Brett; Dupuis, J. Christian

    2013-11-01

    It is common for at least one monitoring well to be located proximally to a production well. This presents the possibility of applying crosswell technologies to resolve a range of earth properties between the wells. We present both field and synthetic examples of dual well walk-away vertical seismic profiling in vertical wells and show how the direct arrivals from a virtual source may be used to create velocity images between the wells. The synthetic experiments highlight the potential of virtual source crosswell tomography where large numbers of closely spaced receivers can be deployed in multiple wells. The field experiment is completed in two monitoring wells at an aquifer storage and recovery site near Perth, Western Australia. For this site, the crosswell velocity distribution recovered from inversion of travel times between in-hole virtual sources and receivers is highly consistent with what is expected from sonic logging and detailed zero-offset vertical seismic profiling. When compared to conventional walkaway vertical seismic profiling, the only additional effort required to complete dual-well walkaway vertical seismic profiling is the deployment of seismic sensors in the second well. The significant advantage of virtual source crosswell tomography is realised where strong near surface heterogeneity results in large travel time statics.

  6. Thermal-rheological structure of the lithosphere beneath two types of basins in eastern and western China

    Institute of Scientific and Technical Information of China (English)

    王良书; 李成; 刘福田; 李华; 卢华复; 刘绍文

    2000-01-01

    After calculating thermal-rheological properties of the lithosphere in the Northern Jiangsu basin, the Bohaiwan basin as well as the Jiyang depression in the east and Tarim basin in the west of China, this paper analyzes the relationship between thermal-rheological structures and tectonic evolution of the two types of basins. The results show that the thermal-rheoiogical structures of the lithosphere directly reflect the dynamic processes. Under different dynamic environments, the style of basin formation and the differences in basin evolution are closely related to the dynamic properties of the lithosphere indicated by thermal-rheological structures.

  7. Inversions for earthquake focal mechanisms and regional stress in the Kachchh Rift Basin, western India: Tectonic implications

    Science.gov (United States)

    Singh, A. P.; Zhao, L.; Kumar, Santsoh; Mishra, Smita

    2016-03-01

    More than a decade after the 2001 MW 7.7 Bhuj earthquake in western India, aftershocks up to MW 5.0 are still continuing around the rupture zone in the Kachchh Rift Basin. Over the years, some surrounding faults in the region have been activated, and a transverse fault generated an MW 5.1 earthquake in 2012. Most of the earthquakes occur in the lower crust at depths between 15 and 35 km. We have determined focal mechanism solutions of 47 earthquakes (MW 3.2-5.1) that were recorded by a 60-station broadband network during 2007-2014 within an area of 50 km radius of the 2001 main shock. South dipping nodal planes in most of the solutions correlate well with the active faults. The earthquakes near the epicenter of the 2001 main shock primarily show reverse-faulting mechanisms. The surrounding earthquakes in the area, however, show predominantly strike-slip mechanisms. The P axes of the earthquakes mostly oriented in north-south, and the T axes in east-west. However, the orientations of the P and T axes exhibit more complexity near the source area of the main shock. Stress field inversion of the solutions yields a dominant north-south compression, which is consistent with the ambient tectonic stress field owing to the northward movement of the Indian Plate with respect to the Eurasian Plate. The geodetic measurements are in reasonable agreement with our results.

  8. Strategy to design the sea-level monitoring networks for small tsunamigenic oceanic basins: the Western Mediterranean case

    Directory of Open Access Journals (Sweden)

    F. Schindelé

    2008-09-01

    Full Text Available The 26 December 2004 Indian Ocean tsunami triggered a number of international and national initiatives aimed at establishing modern, reliable and robust tsunami warning systems. In addition to the seismic network for initial warning, the main component of the monitoring system is the sea level network. Networks of coastal tide gages and tsunameters are implemented to detect the tsunami after the occurrence of a large earthquake, to confirm or refute the tsunami occurrence. Large oceans tsunami monitoring currently in place in the Pacific and in implementation in the Indian Ocean will be able to detect tsunamis in 1 h. But due to the very short time of waves propagation, in general less than 1 h, a tsunami monitoring system in a smaller basin requires a denser network located close to the seismic zones. A methodology is proposed based on the modeling of tsunami travel time and waveform, and on the estimation of the delay of transmission to design the location and the spacing of the stations. In the case of Western Mediterranean, we demonstrate that a network of around 17 coastal tide gages and 13 tsunameters located at 50 km along the shore is required to detect and measure nearly all tsunamis generated on the Northern coasts of Africa.

  9. Ichnofabrics of the Capdevila Formation (early Eocene) in the Los Palacios Basin (western Cuba): Paleoenvironmental and paleoecological implications

    Science.gov (United States)

    Villegas-Martín, Jorge; Netto, Renata Guimarães; Lavina, Ernesto Luis Correa; Rojas-Consuegra, Reinaldo

    2014-12-01

    The ichnofabrics present in the early Eocene siliciclastic deposits of the Capdevila Formation exposed in the Pinar del Rio area (Los Palacios Basin, western Cuba) are analyzed in this paper and their paleoecological and paleoenvironmental significance are discussed. Nine ichnofabrics were recognized in the dominantly sandy sedimentary succession: Ophiomorpha, Asterosoma, Thalassinoides, Palaeophycus, Scolicia, Bichordites-Thalassinoides, Rhizocorallium, Scolicia-Thalassinoides and rhizobioturbation. Diversity of ichnofauna is low and burrows made by detritus-feeding organisms in well oxygenated and stenohaline waters predominate. Suites of the Cruziana and Skolithos Ichnofacies lacking their archetypical characteristics were recognized, being impoverished in diversity and presenting dominance of echinoderm and decapods crustacean burrows as a response to the environmental stress caused by the high frequency of deposition. The ichnofabric distribution in the studied succession, its recurrence in the sandstone beds and the presence of a Glossifungites Ichnofacies suite with rhizobioturbation associated reflect a shoaling-upward event with subaerial exposure of the substrate. The integrated analysis of the ichnology and the sedimentary facies suggests deposition in a shallow slope frequently impacted by gravitational flows and high-energy events. The evidence of substrate exposure indicates the occurrence of a forced regression and suggests the existence of a sequence boundary at the top of the Capdevila Formation.

  10. Investigation of MAGMA chambers in the Western Great Basin. Final report, 9 June 1982-31 October 1985

    Energy Technology Data Exchange (ETDEWEB)

    Peppin, W.A.

    1986-02-10

    This report summarizes efforts made by the Seismological Laboratory toward the detection and delineation of shallow crustal zones in the western Great Basin, and toward the development of methods to accomplish such detection. The work centers around the recently-active volcanic center near Long Valley, California. The work effort is broken down into three tasks: (1) network operations, (2) data analysis and interpretation, and (3) the study of shallow crustal amomalies (magma bodies). Section (1) describes the efforts made to record thousand of earthquakes near the Long Valley caldera, and focusses on the results obtained for the November 1984 round Valley earthquake. Section (2) describes the major effort of this contract, which was to quantify the large volume of seismic data being recorded as it pertains to the goals of this contract. Efforts described herein include (1) analysis of earthquake focal mechanisms, and (2) the classification, categorization, and interpretation of unusual seismic phases in terms of reflections and refractions from shallow-crustal anomalous zones. Section (3) summarizes the status of our research to date on the locations of magma bodies, with particular emphasis on a location corresponding to the map location of the south end of Hilton Creek fault. Five lines of independent evidence suggest that magma might be associated with this spot. Finally, new evidence on the large magma bodies within the Long Valley caldera, of interest to the DOE deep drilling project, is presented.

  11. Assessment of In-Place Oil Shale Resources of the Green River Formation, Piceance Basin, Western Colorado

    Science.gov (United States)

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

    2009-01-01

    The U.S. Geological Survey (USGS) recently completed a reassessment of in-place oil shale resources, regardless of richness, in the Eocene Green River Formation in the Piceance Basin, western Colorado. A considerable amount of oil-yield data has been collected after previous in-place assessments were published, and these data were incorporated into this new assessment. About twice as many oil-yield data points were used, and several additional oil shale intervals were included that were not assessed previously for lack of data. Oil yields are measured using the Fischer assay method. The Fischer assay method is a standardized laboratory test for determining the oil yield from oil shale that has been almost universally used to determine oil yields for Green River Formation oil shales. Fischer assay does not necessarily measure the maximum amount of oil that an oil shale can produce, and there are retorting methods that yield more than the Fischer assay yield. However, the oil yields achieved by other technologies are typically reported as a percentage of the Fischer assay oil yield, and thus Fischer assay is still considered the standard by which other methods are compared.

  12. Noble gas constraints on hydrocarbon accumulation and groundwater flow in the central area of Western Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    樊然学

    2001-01-01

    The noble gas concentrations and isotope ratios of seven natural gas samples from the central area of the Western Sichuan Basin were measured. The samples all have 40Ar/36Ar ratios greater than the atmospheric values, and the 3He/4He ratios (R/Ra) are entirely consistent with the crustal radiogenic He values. The vertical variation of the calculated CH4/36Ar ratios with depth clearly indicates that the CH4and 36Ar are intimately associated, indicating a common reservoir intermediate to the sampled reservoirs, where they are well mixed and stored together prior to entrapment into gas reservoirs. Meanwhile, the calculated CH4/36Ar ratios range between 8×106 and 64×106 very much greater than the CH4/36Ar values for pure water and 5 mol/L NaCI brine at low temperature and hydrostatic conditions, reflecting the presence of "excess" thermogenic CH4 over that supplied by a CH4-saturated groundwater at low temperature, and the excess CH4 saturation and dissolution to be at depth greater than the sampled reserv

  13. Accumulation process and model for the Ordovician buried hill reservoir in the western Lunnan area, the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Ordovician buried hill reservoir in the western Lunnan area, a type of dissolved fracture and cavernous reservoir, is mainly composed of heavy oil. The oil is the mixture sourcing from the Middle-Lower Cambrian and Middle-Lower Ordovician, with three stages of pool forming process: (1) the destruction and parallel migration/accumulation during the late Caledonian to early Hercynian; (2) the oil and gas accumulation during the late Hercynian characterized by adjustment upward along faults and parallel migration/accumulation; (3) the formation of heavy oil during the latest Hercynian. The Ordovician buried hill reservoir is affected by the diffusion of light oil and gas but had no hydrocarbon charging during the late Yanshan period to Himalayan period, but in this period, formed the association of heavy oil and dissolved gas cracked from crude oil with dry coefficient of 0.91-0.96. The study on accumulation process of the Ordovician buried hill reservoir has important implications for the exploration potential of early oil and gas accumulation in the cratonic area of the Tarim Basin.

  14. Study on driving forces of wetland change in the Western Liaohe River basin based on random forest model

    Science.gov (United States)

    Wu, Menghong; Yang, Changbao; Zhang, Yanhong; Lin, Nan

    2017-05-01

    Based on the platform of RS and GIS, random forest progression model is used for study driving force of wetland change in western Liaohe river basin, five influencing factors which include elevation, slope, temperature, precipitation and population density are chosen to establish random forest progression model about the wetland change and the driving factors. Using the the mean value of the prediction accuracy outside the bag calculated by the model to evaluate the importance of the variables. The result indicates that the coefficient of partial correlation between precipitation and wetland density is the largest among the five influencing factors, followed by temperature, population density, elevation and slope is smallest. The influence of natural factors on the change of wetland density is mainly reflected in precipitation and temperature factors, and the precipitation is obviously higher than that of temperature, under the influence of human factors, the influence of population density factor on wetland density is higher than that of elevation and slope factor. The result shows that in the past 40 years, the human activities in the study area have increased the density of wetland to some extent, but it is not the main factor.

  15. The impact of hydroelectric project development on the ethnobotany of the Alaknanda river basin of Western Himalaya, India

    Directory of Open Access Journals (Sweden)

    Khilendra Singh Kanwal

    2015-12-01

    Full Text Available Background: This study focuses on the ethnoflora used by local communities in the Alaknanda river basin of Uttarakhand state in Western Himalaya, India. The objectives of the study are to collect ethnobotanical information, to assess the impact of hydropower projects on ethnoflora and to suggest conservation and management measures for the protection of ethnoflora. Material and Methods: A well-designed questionnaire based survey was conducted in the ten villages of the study area to collect ethnobotanical information. The conservation status of plants was also evaluated following the IUCN Red list, the Red Data Book of Indian Plants and the CITES criteria. Results: A total of 136 plant species belonging to 61 families and 112 genera were used by local communities for various ethnobotanical purposes. The majority of plant species were used for medicinal purposes (96 spp., followed by fodder (46 spp., wild edibles (31 spp., fuel (29 spp., timber (17 spp., fish poison (9 spp., agriculture implements (6 spp., fibre (6 spp., religious use (6 spp. and handicraft (1 sp.. For the preparation of herbal medicine, rural people of the region use different parts of medicinal plants such as the whole plant (20% followed by roots/rhizomes/tubers (20%, leaf (18%, fruit (10%, seed (9%, bark (9%, stem (6%, flowers (6% and resin (2%. Conclusions: Development of hydropower projects will influence the diversity and distribution of ethnoflora in the region. Therefore, for the conservation of the ethnoflora of the area, conservation and management measures have been suggested.

  16. A high-resolution Late Holocene landscape ecological history inferred from an intramontane basin in the Western Taurus Mountains, Turkey

    Science.gov (United States)

    Kaniewski, D.; Paulissen, E.; De Laet, V.; Dossche, K.; Waelkens, M.

    2007-09-01

    Late Holocene vegetation and geomorphological history is reconstructed from a 800 cm long high-resolution palynological and sedimentological record sampled from Bereket, a 6.3 km 2 semi-arid to sub-humid intramontane basin in the Western Taurus Mountains (southwest Turkey). The well-dated Bereket record provides from cal. 360 BC to cal. AD ˜400 a unique record of biennial-to-decadal landscape changes caused primarily by intensive human impacts against a background of global climate variations. During this period, land clearance with multiple fire episodes, intensive agricultural practices and grazing pressure profoundly altered the pre-existing warm mixed forest. Increasing moisture availability since cal. ˜280 BC has acted as a trigger to crop cultivation and mountain-adapted arboriculture starting with Juglans regia during the Beyşehir Occupation Phase. Pollen from olive groves have been recorded above 1400 m a.s.l. only at cal. ˜23 BC and have disappeared definitively at cal. AD ˜294. During this phase, the sediment accumulation rate was extremely high, reflecting landscape instability. From cal. AD 450 to recent times, the area has mainly recorded pasture and minor cultivation activities reflected in stable soils and thin colluvial depths.

  17. Petroleum exploration of shallow marine deposit Carboniferous volcanic tuff reservoir in the western margin of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    Wang Jianyong; Wang Xuezhong; Ma Liqun

    2013-01-01

    In 2011,petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re-alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pai 61 well ,with 855.7 ~949.6 m section,in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa· s (50℃). The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.

  18. Analysis of subsurface mound spring connectivity in shale of the western margin of the Great Artesian Basin, South Australia

    Science.gov (United States)

    Halihan, Todd; Love, Andrew; Keppel, Mark; Berens, Volmer

    2013-11-01

    Mound springs provide the primary discharge mechanism for waters of the western margin of the Great Artesian Basin (GAB), Australia. Though these springs are an important resource in an arid environment, their hydraulics as they discharge from shale are poorly defined. The springs can include extensive spring tails (groundwater-dependent wetlands) and hundreds of springs in a given spring complex. Electrical resistivity imaging (ERI) was used to evaluate spring subsurface hydraulic-connectivity characteristics at three spring complexes discharging through the Bulldog Shale. The results demonstrate that fresher GAB water appears as resistors in the subsurface at these sites, which are characterized by high-salinity conditions in the shallow subsurface. Using an empirical method developed for this work, the ERI data indicate that the spring complexes have multiple subsurface connections that are not always easily observed at the surface. The connections are focused along structural deformation in the shale allowing fluids to migrate through the confining unit. The ERI data suggest the carbonate deposits that the springs generate are deposited on top of the confining unit, not precipitated in the conduit. The data also suggest that spring-tail ecosystems are not the result of a single discharge point, but include secondary discharge points along the tail.

  19. The geochemical characteristics and genetic types of crude oils in the western depression of the Liaohe Basin, China

    Institute of Scientific and Technical Information of China (English)

    MU Guoyan; ZHONG Ningning; LIU Bao; ZHANG Ning; XU Guangjie

    2009-01-01

    The physical properties and group compositions of crude oils in the western depression of the Liaohe Basin possess such characteristics as to increase gradually in density, viscosity and wax contents, and decrease in saturated hydrocarbon and non-hydrocarbon and bitumen contents from the deep level to the shallow level and from the center of the depression to its boundary. Saturated hydrocarbons have various spectra, such as single peak and double peak patterns, front peak and rear peak patterns, and smooth peak and serated peak patterns, as well as the chromatograms of biodegraded n-alkanes. The ratios of Pr/Ph in crude oils from the southern part of the depression are generally higher than those in the northern part. The distribution of regular steranes C27-C29 is predominantly of the ramp type, and only a few samples have relatively high C28 contents in the southern part of the depression. As viewed from their physical properties and geochemical characteristics, crude oils in the study area can be divided into two types (I and II) based on oil-generating sources and sedimentary environments, and then further divided into three sub-types (Ia, Ib and Ic:IIa, IIb and IIIc, respectively) based on their degrees of maturation and secondary transformation. This will provide the reliable basis for oil-source correlation and petroleum exploration and prediction.

  20. Gone with the plate: the opening of the Western Mediterranean basin drove the diversification of ground-dweller spiders

    Directory of Open Access Journals (Sweden)

    Bidegaray-Batista Leticia

    2011-10-01

    Full Text Available Abstract Background The major islands of the Western Mediterranean--Corsica, Sardinia, and the Balearic Islands--are continental terrenes that drifted towards their present day location following a retreat from their original position on the eastern Iberian Peninsula about 30 million years ago. Several studies have taken advantage of this well-dated geological scenario to calibrate molecular rates in species for which distributions seemed to match this tectonic event. Nevertheless, the use of external calibration points has revealed that most of the present-day fauna on these islands post-dated the opening of the western Mediterranean basin. In this study, we use sequence information of the cox1, nad1, 16S, L1, and 12S mitochondrial genes and the 18S, 28S, and h3 nuclear genes, along with relaxed clock models and a combination of biogeographic and fossil external calibration points, to test alternative historical scenarios of the evolutionary history of the ground-dweller spider genus Parachtes (Dysderidae, which is endemic to the region. Results We analyse 49 specimens representing populations of most Parachtes species and close relatives. Our results reveal that both the sequence of species formation in Parachtes and the estimated divergence times match the geochronological sequence of separation of the main islands, suggesting that the diversification of the group was driven by Tertiary plate tectonics. In addition, the confirmation that Parachtes diversification matches well-dated geological events provides a model framework to infer substitution rates of molecular markers. Divergence rates estimates ranged from 3.5% My-1 (nad1 to 0.12% My-1 (28S, and the average divergence rate for the mitochondrial genes was 2.25% My-1, very close to the "standard" arthropod mitochondrial rate (2.3% My-1. Conclusions Our study provides the first unequivocal evidence of terrestrial endemic fauna of the major western Mediterranean islands, whose origin can

  1. Historical biogeography of the land snail Cornu aspersum: a new scenario inferred from haplotype distribution in the Western Mediterranean basin

    Directory of Open Access Journals (Sweden)

    Madec Luc

    2010-01-01

    Full Text Available Abstract Background Despite its key location between the rest of the continent and Europe, research on the phylogeography of north African species remains very limited compared to European and North American taxa. The Mediterranean land mollusc Cornu aspersum (= Helix aspersa is part of the few species widely sampled in north Africa for biogeographical analysis. It then provides an excellent biological model to understand phylogeographical patterns across the Mediterranean basin, and to evaluate hypotheses of population differentiation. We investigated here the phylogeography of this land snail to reassess the evolutionary scenario we previously considered for explaining its scattered distribution in the western Mediterranean, and to help to resolve the question of the direction of its range expansion (from north Africa to Europe or vice versa. By analysing simultaneously individuals from 73 sites sampled in its putative native range, the present work provides the first broad-scale screening of mitochondrial variation (cyt b and 16S rRNA genes of C. aspersum. Results Phylogeographical structure mirrored previous patterns inferred from anatomy and nuclear data, since all haplotypes could be ascribed to a B (West or a C (East lineage. Alternative migration models tested confirmed that C. aspersum most likely spread from north Africa to Europe. In addition to Kabylia in Algeria, which would have been successively a centre of dispersal and a zone of secondary contacts, we identified an area in Galicia where genetically distinct west and east type populations would have regained contact. Conclusions Vicariant and dispersal processes are reviewed and discussed in the light of signatures left in the geographical distribution of the genetic variation. In referring to Mediterranean taxa which show similar phylogeographical patterns, we proposed a parsimonious scenario to account for the "east-west" genetic splitting and the northward expansion of the

  2. Prospect evaluation of BED 3 and Sitra oilfields, Abu Gharadig Basin, North Western Desert, Egypt

    Science.gov (United States)

    Salem, Ibrahim; Ghazala, Hosni; El Diasty, Waleed

    2015-12-01

    The occurrence of hydrocarbons is closely linked to the elements of petroleum system history of the BED 3 and Sitra 8 oilfields, which has created multiple reservoir and seal combinations. BED 3 Field and Sitra concessions occupy the northwestern part of the Abu Gharadig Basin and extends between latitudes 29°45‧ and 30°05‧N and longitudes 27°30‧ and 28°10‧E. The comprehensive integration of the geo-related data and the interpretation of the well logging, geochemical, seismic data in time domain and depth and sealing mechanisms explain the occurrence of hydrocarbons in some certain reservoirs during cretaceous age and other reservoirs in the same fields don't have any hydrocarbon accumulation. Detailed seismic data interpretation was performed for the target units of BED 3 and Sitra 8 oilfields in time domain and converted to depth domain. Sitra 8 Field is a three-way dip closure bounded by NW-SE faults while BED 3 field is represented by a WNW-ESE trending horst dipping to the east. The Albian-Cenomanian Kharita Formation has a high energy shallow marine shelf environment and considered as the main pay zone in the BED 3 oilfield. On the other hand, Kharita sands are dry in the Sitra 8 Field. Also, the shallow marine shale, sandstone, limestone and dolomite interbeds of the Abu Roash G Member are another hydrocarbon bearing reservoir in the Sitra 8 Field. Sealing mechanisms were applied to explain why certain reservoirs have hydrocarbon and others don't. Allan's juxtaposition diagram for the main faults in the study area shows that Kharita sands in BED 3 area have excellent juxtaposition as Kharita juxtapose to upper Bahariya and intra Bahariya, which consist of shale and limestone. Abu Roash G sands in BED 3 area have bad juxtaposition as the Abu Roash G juxtapose to Abu Roash C sand (sand juxtaposed sand). Allan's diagram shows that the Abu Roash G reservoir (main target) in Sitra 8 is juxtaposing Abu Roash D which is composed of limestone and shale

  3. Extraction of high added value biological compounds from sardine, sardine-type fish and mackerel canning residues--a review.

    Science.gov (United States)

    Ferraro, Vincenza; Carvalho, Ana P; Piccirillo, Clara; Santos, Manuela M; Castro, Paula M L; Pintado, Manuela E

    2013-08-01

    Different valuable compounds, which can be employed in medicine or in other industries (i.e. food, agrochemical, pharmaceutical) can be recovered from by-products and waste from the fish canning industries. They include lipids, proteins, bio-polymers, minerals, amino acids and enzymes; they can be extracted from wastewaters and/or from solid residues (head, viscera, skin, tails and flesh) generated along the canning process, through the filleting, cooking, salting or smoking stages. In this review, the opportunities for the extraction and the valorisation of bioactive compounds from sardine, sardine-type fish and mackerel canning residues are examined and discussed. These are amongst the most consumed fishes in the Mediterranean area; moreover, canning is one of the most important and common methods of preservation. The large quantities of by-products generated have great potentials for the extraction of biologically desirable high added value compounds.

  4. Paleoceanographic Changes in the Lagonegro Basin (Southern Italy) during the Late Triassic Linked to Oceanic Rifting in the Western Tethyan Region

    Science.gov (United States)

    Casacci, M.; Algeo, T. J.; Bertinelli, A.; Rigo, M.

    2015-12-01

    The Lagonegro Basin was part of the southwestern branch of the western Tethys, an actively spreading young ocean during the Late Triassic (Ciarapica and Passeri, 2002, 2005). The sedimentary environment was a deepening-upward basin, bordered to the north by the Apenninic and Apulian carbonate platforms. Paleoseismic activity is evidenced by frequent debris flows on the basin margins (Passeri et al., 2005). The Lagonegro succession is characterized by Permian to Miocene formations deposited in shallow to deep basinal environments. The Upper Triassic is comprised of deep-marine sediments belonging to the Calcari con Selce ("Cherty Limestone") Formation of late Ladinian to late Norian-early Rhaetian age and the Scisti Silicei ("Siliceous Shale") Formation of late Norian-early Rhaetian to Late Jurassic age. The "Transitional Interval" between these two formations is gradational over a 20- to 40-m interval (Miconnet, 1983). The Transitional Interval was investigated in three sections (Pignola-Abriola, Monte Volturino, and Madonna del Sirino) in the Southern Apennines (southern Italy), representing a proximal-to-distal transect across the Lagonegro Basin. The transition from mainly calcareous to mainly siliceous sedimentation may have been influenced by rapid, post-rift subsidence of the Lagonegro Basin. It also coincided with a shift to warmer or more humid conditions around the Norian/Rhaetian boundary, as reflected in a pronounced increase in the chemical index of alteration (CIA), a weathering proxy (Young and Nesbitt, 1998). Redox proxies indicate mainly oxic conditions in the deep basin, although organic-rich shale beds are present at multiple levels in the otherwise organic-poor succession. The abruptness of the transitions between organic-poor and -rich sediment layers suggests major changes in paleoceanographic conditions, possibly related to switches from lagoonal circulation (linked to a net negative water balance) to estuarine circulation (linked to a net

  5. The first deep heat flow determination in crystalline basement rocks beneath the Western Canadian Sedimentary Basin

    Science.gov (United States)

    Majorowicz, Jacek; Chan, Judith; Crowell, James; Gosnold, Will; Heaman, Larry M.; Kück, Jochem; Nieuwenhuis, Greg; Schmitt, Douglas R.; Unsworth, Martyn; Walsh, Nathaniel; Weides, Simon

    2014-05-01

    Heat flow (Q) determined from bottom-hole temperatures measured in oil and gas wells in Alberta show a large scatter with values ranging from 40 to 90 mW m-2. Only two precise measurements of heat flow were previously reported in Alberta, and were made more than half a century ago. These were made in wells located near Edmonton, Alberta, and penetrated the upper kilometre of clastic sedimentary rocks yielding heat flows values of 61 and 67 mW m-2 (Garland & Lennox). Here, we report a new precise heat flow determination from a 2363-m deep well drilled into basement granite rocks just west of Fort McMurray, Alberta (the Hunt Well). Temperature logs acquired in 2010-2011 show a significant increase in the thermal gradient in the granite due to palaeoclimatic effects. In the case of the Hunt Well, heat flow at depths >2200 m is beyond the influence of the glacial-interglacial surface temperatures. Thermal conductivity and temperature measurements in the Hunt Well have shown that the heat flow below 2.2 km is 51 mW m-2 (±3 mW m-2), thermal conductivity measured by the divided bar method under bottom of the well in situ like condition is 2.5 W m-1 K-1, and 2.7 W m-1 K-1 in ambient conditions), and the geothermal gradient was measured as 20.4 mK m-1. The palaeoclimatic effect causes an underestimate of heat flow derived from measurements collected at depths shallower than 2200 m, meaning other heat flow estimates calculated from basin measurements have likely been underestimated. Heat production (A) was calculated from spectral gamma recorded in the Hunt Well granites to a depth of 1880 m and give an average A of 3.4 and 2.9 μW m-3 for the whole depth range of granites down to 2263 m, based on both gamma and spectral logs. This high A explains the relatively high heat flow measured within the Precambrian basement intersected by the Hunt Well; the Taltson Magmatic Zone. Heat flow and related heat generation from the Hunt Well fits the heat flow-heat generation

  6. Projections of temperature and precipitation extremes in the North Western Mediterranean Basin by dynamical downscaling of climate scenarios at high resolution (1971-2050)

    OpenAIRE

    Barrera Escoda, Antoni; Gonçalves Ageitos, María; Guerreiro, Dolores; Cunillera i Grañó, Jordi; Baldasano Recio, José María

    2014-01-01

    The North Western Mediterranean basin (NWMB) is characterised by a highly complex topography and an important variability of temperature and precipitation patterns. Downscaling techniques are required to capture these features, identify the most vulnerable areas to extreme changes and help decision makers to design strategies of mitigation and adaptation to climate change. A Regional Climate Model, WRF-ARW, is used to downscale the IPCC-AR4 ECHAM5/MPI-OM General Circulation Model results with...

  7. Contributions to the knowledge of the Romanian from the western Dacian Basin: The molluscs’ fauna from Răcarii de Jos (Dolj County

    Directory of Open Access Journals (Sweden)

    Ion Pătruţoiu

    2010-07-01

    Full Text Available In the western Dacian Basin, the Romanian age starts with a fauna comprised of carvedunionidae and robust viviparidae, which appear in numerous crops in Mehedinţi, Dolj and GorjCounties. The lamellibranchiate species from Răcarii de Jos are replenishing the Romanianpalaeontology inventory and are offering new data about the evolution of the retreating Pliocene lake tothe east due to the Vlach orogenesis that carried forward with the ascend of the Carpathian Mountains.

  8. The role of inherited crustal structures and magmatism in the development of rift segments: Insights from the Kivu basin, western branch of the East African Rift

    Science.gov (United States)

    Smets, Benoît; Delvaux, Damien; Ross, Kelly Ann; Poppe, Sam; Kervyn, Matthieu; d'Oreye, Nicolas; Kervyn, François

    2016-06-01

    The study of rift basin's morphology can provide good insights into geological features influencing the development of rift valleys and the distribution of volcanism. The Kivu rift segment represents the central section of the western branch of the East African Rift and displays morphological characteristics contrasting with other rift segments. Differences and contradictions between several structural maps of the Kivu rift make it difficult to interpret the local geodynamic setting. In the present work, we use topographic and bathymetric data to map active fault networks and study the geomorphology of the Kivu basin. This relief-based fault lineament mapping appears as a good complement for field mapping or mapping using seismic reflection profiles. Results suggest that rifting reactivated NE-SW oriented structures probably related to the Precambrian basement, creating transfer zones and influencing the location and distribution of volcanism. Both volcanic provinces, north and south of the Kivu basin, extend into Lake Kivu and are connected to each other with a series of eruptive vents along the western rift escarpment. The complex morphology of this rift basin, characterized by a double synthetic half-graben structure, might result from the combined action of normal faulting, magmatic underplating, volcanism and erosion processes.

  9. Overview of groundwater quality in the Piceance Basin, western Colorado, 1946--2009

    Science.gov (United States)

    Thomas, J.C.; McMahon, P.B.

    2013-01-01

    Groundwater-quality data from public and private sources for the period 1946 to 2009 were compiled and put into a common data repository for the Piceance Basin. The data repository is available on the web at http://rmgsc.cr.usgs.gov/cwqdr/Piceance/index.shtml. A subset of groundwater-quality data from the repository was compiled, reviewed, and checked for quality assurance for this report. The resulting dataset consists of the most recently collected sample from 1,545 wells, 1,007 (65 percent) of which were domestic wells. From those samples, the following constituents were selected for presentation in this report: dissolved oxygen, dissolved solids, pH, major ions (chloride, sulfate, fluoride), trace elements (arsenic, barium, iron, manganese, selenium), nitrate, benzene, toluene, ethylbenzene, xylene, methane, and the stable isotopic compositions of water and methane. Some portion of recharge to most of the wells for which data were available was derived from precipitation (most likely snowmelt), as indicated by δ2H [H2O] and δ18O[H2O] values that plot along the Global Meteoric Water Line and near the values for snow samples collected in the study area. Ninety-three percent of the samples were oxic, on the basis of concentrations of dissolved oxygen that were greater than or equal to 0.5 milligrams per liter. Concentration data were compared with primary and secondary drinking-water standards established by the U.S. Environmental Protection Agency. Constituents that exceeded the primary standards were arsenic (13 percent), selenium (9.2 percent), fluoride (8.4 percent), barium (4.1 percent), nitrate (1.6 percent), and benzene (0.6 percent). Concentrations of toluene, xylenes, and ethylbenzene did not exceed standards in any samples. Constituents that exceeded the secondary standard were dissolved solids (72 percent), sulfate (37 percent), manganese (21 percent), iron (16 percent), and chloride (10 percent). Drinking-water standards have not been established for

  10. Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin from R/Vs GORIZONT and OKEANOGRAF, 1960 - 1969 (NODC Accession 0074609)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, Silicate, Nitrite, pH and Alkalinity data collected in the Black Sea, Tyrrhenian Sea and Western Basin of the Mediterranean...

  11. Tropical Peat and Peatland Development in the Floodplains of the Greater Pamba Basin, South-Western India during the Holocene.

    Directory of Open Access Journals (Sweden)

    Navnith K P Kumaran

    Full Text Available Holocene sequences in the humid tropical region of Kerala, South-western (SW India have preserved abundance of organic-rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub-coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are essentially formed within freshwater. The combination of factors like stabilized sea level and its subsequent fall since the Middle Holocene, topographic relief and climatic conditions led to rapid peat accumulation across the coastal lowlands. The high rainfall and massive floods coupled with a rising sea level must have inundated > 75% of the coastal plain land converting it into a veritable lagoon-lake system that eventually led to abrupt termination of the forest ecosystem and also converted the floodplains into peatland where accumulation of peat almost to 2.0-3.0 m thickness in coastal lowlands and river basins during the shorter interval in the Middle Holocene. Vast areas of the coastal plains of Kerala have been converted into carbon rich peatland during the Middle Holocene and transforming the entire coastal stretch and associated landforms as one of the relatively youngest peatlands in the extreme southern tip of India. Unlike the uninterrupted formation of peatlands of considerable extent during the Holocene in Southeast Asia, the south Peninsular Indian region has restricted and short intervals of peatlands in the floodplains and coastal lowlands. Such a scenario is attributed to the topographic relief of the terrain and the prevailing hydrological regimes and environmental conditions as a consequence of monsoon variability since Middle Holocene in SW India. Considering the tropical coastal lowlands and associated peatlands are excellent repositories of carbon, they are very important for regional carbon cycling and habitat diversity. The

  12. Tropical Peat and Peatland Development in the Floodplains of the Greater Pamba Basin, South-Western India during the Holocene

    Science.gov (United States)

    Padmalal, Damodaran; Limaye, Ruta B.; S., Vishnu Mohan; Jennerjahn, Tim; Gamre, Pradeep G.

    2016-01-01

    Holocene sequences in the humid tropical region of Kerala, South-western (SW) India have preserved abundance of organic—rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub—coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are essentially formed within freshwater. The combination of factors like stabilized sea level and its subsequent fall since the Middle Holocene, topographic relief and climatic conditions led to rapid peat accumulation across the coastal lowlands. The high rainfall and massive floods coupled with a rising sea level must have inundated > 75% of the coastal plain land converting it into a veritable lagoon—lake system that eventually led to abrupt termination of the forest ecosystem and also converted the floodplains into peatland where accumulation of peat almost to 2.0–3.0 m thickness in coastal lowlands and river basins during the shorter interval in the Middle Holocene. Vast areas of the coastal plains of Kerala have been converted into carbon rich peatland during the Middle Holocene and transforming the entire coastal stretch and associated landforms as one of the relatively youngest peatlands in the extreme southern tip of India. Unlike the uninterrupted formation of peatlands of considerable extent during the Holocene in Southeast Asia, the south Peninsular Indian region has restricted and short intervals of peatlands in the floodplains and coastal lowlands. Such a scenario is attributed to the topographic relief of the terrain and the prevailing hydrological regimes and environmental conditions as a consequence of monsoon variability since Middle Holocene in SW India. Considering the tropical coastal lowlands and associated peatlands are excellent repositories of carbon, they are very important for regional carbon cycling and habitat diversity. The alarming rate of

  13. Growth Normal Faulting at the Western Edge of the Metropolitan Taipei Basin since the Last Glacial Maximum, Northern Taiwan

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    Chih-Tung Chen

    2010-01-01

    Full Text Available Growth strata analysis is an useful tool in understanding kinematics and the evolution of active faults as well as the close relationship between sedimentation and tectonics. Here we present the Shanchiao Fault as a case study which is an active normal fault responsible for the formation of the 700-m-thick late Quaternary deposits in Taipei Basin at the northern tip of the Taiwan mountain belt. We compiled a sedimentary record, particularly the depositional facies and their dated ages, at three boreholes (SCF-1, SCF-2 and WK-1, from west to east along the Wuku Profile that traverses the Shanchiao Fault at its central segment. By incorporating the global sea level change curve, we find that thickness changes of sediments and changes of depositional environments in the Wuku area are in a good agreement with a rapid sea level rise since the Last Glacial Maximum (LGM of about 23 ka. Combining depositional facies changes and their ages with their thickness, we are able to introduce a simple back-stripping method to reconstruct the evolution of growing strata across the Shanchiao Fault since the LGM. We then estimate the vertical tectonic slip rate since 23 ka, which exhibits 2.2 mm yr-1 between SCF-2 and WK-1 and 1.1 mm yr-1 between SCF-1 and SCF-2. We also obtain the Holocene tectonic subsidence rate of 2.3 mm yr-1 at WK-1 and 0.9 mm yr-1 at SCF-2 since 8.4 ka. We thus conclude that the fault zone consists of a high-angle main fault to the east between SCF-2 and WK-1 and a western lower-angle branch fault between SCF-1 and SCF-2, resembling a tulip structure developed under sinistral transtensional tectonism. We find that a short period of 600-yr time span in 9 - 8.4 ka shows important tectonic subsidence of 7.4 and 3.3 m for the main and branch fault, respectively, consistent with possible earthquake events proposed by previous studies during that time. A correlation between geomorphology and subsurface geology in the Shanchiao Fault zone shows

  14. Tropical Peat and Peatland Development in the Floodplains of the Greater Pamba Basin, South-Western India during the Holocene.

    Science.gov (United States)

    Kumaran, Navnith K P; Padmalal, Damodaran; Limaye, Ruta B; S, Vishnu Mohan; Jennerjahn, Tim; Gamre, Pradeep G

    2016-01-01

    Holocene sequences in the humid tropical region of Kerala, South-western (SW) India have preserved abundance of organic-rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub-coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are essentially formed within freshwater. The combination of factors like stabilized sea level and its subsequent fall since the Middle Holocene, topographic relief and climatic conditions led to rapid peat accumulation across the coastal lowlands. The high rainfall and massive floods coupled with a rising sea level must have inundated > 75% of the coastal plain land converting it into a veritable lagoon-lake system that eventually led to abrupt termination of the forest ecosystem and also converted the floodplains into peatland where accumulation of peat almost to 2.0-3.0 m thickness in coastal lowlands and river basins during the shorter interval in the Middle Holocene. Vast areas of the coastal plains of Kerala have been converted into carbon rich peatland during the Middle Holocene and transforming the entire coastal stretch and associated landforms as one of the relatively youngest peatlands in the extreme southern tip of India. Unlike the uninterrupted formation of peatlands of considerable extent during the Holocene in Southeast Asia, the south Peninsular Indian region has restricted and short intervals of peatlands in the floodplains and coastal lowlands. Such a scenario is attributed to the topographic relief of the terrain and the prevailing hydrological regimes and environmental conditions as a consequence of monsoon variability since Middle Holocene in SW India. Considering the tropical coastal lowlands and associated peatlands are excellent repositories of carbon, they are very important for regional carbon cycling and habitat diversity. The alarming rate of land

  15. Forecasting database for the tsunami warning center for the western Mediterranean and North-East Atlantic basins

    Science.gov (United States)

    Gailler, A.; Hebert, H.; Loevenbruck, A.; Hernandez, B.

    2011-12-01

    Improvements in the availability of sea-level observations and advances in numerical modeling techniques are increasing the potential for tsunami warnings to be based on numerical model forecasts. Numerical tsunami propagation and inundation models are well developed, but they present a challenge to run in real-time, partly due to computational limitations and also to a lack of detailed knowledge on the earthquake rupture parameters. A first generation model-based tsunami prediction system is being developed as part of the French Tsunami Warning Center that will be operational by mid 2012. It involves a pre-computed unit source functions database (i.e., a number of tsunami model runs that are calculated ahead of time and stored) corresponding to tsunami scenarios generated by a source of seismic moment 1.75E+19 N.m with a rectangular fault 25 km by 20 km in size and 1 m in slip. The faults of the unit functions are placed adjacent to each other, following the discretization of the main seismogenic faults bounding the western Mediterranean and North-East Atlantic basins. An authomatized composite scenarios calculation tool is implemented to allow the simulation of any tsunami propagation scenario (i.e., of any seismic moment). The strategy is based on linear combinations and scaling of a finite number of pre-computed unit source functions. The number of unit functions involved varies with the magnitude of the wanted composite solution and the combined wave heights are multiplied by a given scaling factor to produce the new arbitrary scenario. Uncertainty on the magnitude of the detected event and inaccuracy on the epicenter location are taken into account in the composite scenarios calculation. For one tsunamigenic event, the tool produces finally 3 warning maps (i.e., most likely, minimum and maximum scenarios) together with the rough decision matrix representation. A no-dimension code representation is chosen to show zones in the main axis of energy at the basin

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

    Science.gov (United States)

    Chen, Zhonghong; Zha, Ming; Liu, Keyu; Zhang, Yueqian; Yang, Disheng; Tang, Yong; Wu, Kongyou; Chen, Yong

    2016-09-01

    The Kebai Fault zone of the West Junggar Basin in northwestern China is a unique region to gain insights on the formation of large-scale petroleum reservoirs in volcanic rocks of the western Central Asian Orogenic Belt. Carboniferous volcanic rocks are widespread in the Kebai Fault zone and consist of basalt, basaltic andesite, andesite, tuff, volcanic breccia, sandy conglomerate and metamorphic rocks. The volcanic oil reservoirs are characterized by multiple sources and multi-stage charge and filling history, characteristic of a complex petroleum system. Geochemical analysis of the reservoir oil, hydrocarbon inclusions and source rocks associated with these volcanic rocks was conducted to better constrain the oil source, the petroleum filling history, and the dominant mechanisms controlling the petroleum accumulation. Reservoir oil geochemistry indicates that the oil contained in the Carboniferous volcanic rocks of the Kebai Fault zone is a mixture. The oil is primarily derived from the source rock of the Permian Fengcheng Formation (P1f), and secondarily from the Permian Lower Wuerhe Formation (P2w). Compared with the P2w source rock, P1f exhibits lower values of C19 TT/C23 TT, C19+20TT/ΣTT, Ts/(Ts + Tm) and ααα-20R sterane C27/C28 ratios but higher values of TT C23/C21, HHI, gammacerane/αβ C30 hopane, hopane (20S) C34/C33, C29ββ/(ββ + αα), and C29 20S/(20S + 20R) ratios. Three major stages of oil charge occurred in the Carboniferous, in the Middle Triassic, Late Triassic to Early Jurassic, and in the Middle Jurassic to Late Jurassic periods, respectively. Most of the oil charged during the first stage was lost, while moderately and highly mature oils were generated and accumulated during the second and third stages. Oil migration and accumulation in the large-scale stratigraphic reservoir was primarily controlled by the top Carboniferous unconformity with better porosity and high oil enrichment developed near the unconformity. Secondary dissolution

  17. Comparison of drier- to wetter-interval estuarine roof facies in the Eastern and Western Interior coal basins, USA

    Science.gov (United States)

    Archer, A.W.; Feldman, H.R.; Kvale, E.P.; Lanier, Wendy E.

    1994-01-01

    Many of the Carboniferous coals in the eastern interior of the US are associated with siliciclastic roof facies that were deposited within a fluvio-estuarine transition. These facies include a variety of rhythmites, some of which exhibit tidal cycles. Drier-interval coals (Westphalian B-C, Stephanian) tend to be more laterally restricted and more commonly are associated with paleovalleys. Conversely, wetter-interval coals (Westphalian D) are very widespread and are not restricted to paleovalleys. Throughout the Lake Carboniferous, wet paleoclimates associated with these coals lead to valley incision during sea-level lowstand when large tropical rivers downcut older sediments deposited during previous sea-level highstands. During subsequent rise of sea level, these fluvial valleys were flooded and converted to estuaries where tidal ranges and sedimentation rates were significantly amplified. Based on modern analogs and interpretation of many examples of Carboniferous tidal rhythmites, the localized depositional rates in these settings are exceptionally high. The estuaries became sediment sinks, trapping sediment that is pumped in from both fluvial and marine sources. As a result, sedimentation readily keeps pace with rising baselevel. Extensive intertidal flats and shallow subtidal flats are created and prograde over the valley-confined mires. Thick tidal cycles and upright trees (some with attached foliage) record rapid burial of mires. This model is supported with examples of roof facies from the Westphalian B-C of the Eastern Interior Basin, and the Stephanian of the Western Interior Basin. In these areas facies within each cycle range from well-developed, extensive paleosols and coals, to widespread marine shales or limestones. Variations in both sea level and climate resulted in a complex history of valley fill during which coals could be developed at any time (except during widespread flooding). Minable, low-sulfur and low-ash coals occur, but the coals are

  18. Understanding the Physiography, Bioclimate and Mapping of the Vegetation of the Chalakkudy River Basin, Anamalai part of Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Amitha Bachan Kandarumadathil Hyder

    2014-09-01

    Full Text Available Vegetation of an area is determined by the overall interaction of the climatic, edaphic, and biotic factors. It is important to define the bioclimate of a region to understand the Vegetation dynamics of a region especially of the Tropical Monsoonal continents with complex physiography. It is a pioneering effort to understand bioclimate and primary   vegetation of a river basin from the southern Western Ghats region. Twenty years of rainfall data were analysed and geophysical features of the Chalakkudy River basin were analysed using GIS facility. The results provide more accurate data of the length, area and other physiographic features for the Chalakkudy River basin indicating need of updating of data of other river basins of Kerala. The bioclimatic data analyzed from 20 years of rainfall and vegetation maps indicate presence of dry-moist-forest zones to ever wet-rainforest regimes in the basin. The vegetation data shows 80% catchements of the river under forest category of which primary forests dominates with 519 Km2 (36% followed by forest plantations 179.6 Km2 (12%, secondary forests 197.4 Km2 (17%, tea, coffee and other plantations constitute 198.3 Km2 (13%, degraded non forest vegetation 86.9 Km2 (6% and reservoir, streams and rivers 46.5 Km2 (3%.  Of the 361 Km2 primary wet-evergreen (Rainforests forests 294 Km2 is dense forest and 67 Km2 is degraded forests.

  19. A glacier inventory for the western Nyainqentanglha Range and the Nam Co Basin, Tibet, and glacier changes 1976–2009

    Directory of Open Access Journals (Sweden)

    T. Bolch

    2010-09-01

    Full Text Available The western Nyainqentanglha Range is located in the south-eastern centre of the Tibetan Plateau. Its north-western slopes drain into Lake Nam Co. The region is of special interest for glacio-climatological research as it is influenced by both the continental climate of Central Asia and the Indian Monsoon system, and situated at the transition zone between temperate and subcontinental glaciers. A glacier inventory for the whole mountain range was generated for the year around 2001 using automated remote sensing and GIS techniques based on Landsat ETM+ and SRTM3 DEM data. Glacier change analysis was based on data from Hexagon KH-9 and Landsat MSS (both 1976, Metric Camera (1984, and Landsat TM/ETM+ (1991, 2001, 2005, 2009. Manual adjustment was especially necessary for delineating the debris-covered glaciers and the glaciers on the panchromatic Hexagon data. In the years around 2001 the whole mountain range contained about 960 glaciers covering an area of 795.6 ± 22.3 km2 while the ice in the drainage basin of Nam Co covered 198.1 ± 5.6 km2. The median elevation of the glaciers was about 5800 m with the majority terminating around 5600 m. Five glaciers with debris-covered tongues terminated lower than 5200 m. The glacier area decreased by −6.1 ± 3% between 1976 and 2001. This is less than reported in previous studies based on the 1970s topographic maps and Landsat data from 2000. Glaciers continued to shrink during the period 2001–2009. No advancing glaciers were detected. Detailed length measurements for five glaciers indicated a retreat of around 10 m per year (1976–2009. Ice cover is higher south-east of the mountain ridge which reflects the windward direction to the monsoon. The temperature increase during the ablation period was probably the main driver of glacier wastage, but the complex glacier-climate interactions need further investigation.

  20. Fish canning wastewater treatment by activated sludge: Application of factorial design optimization

    Directory of Open Access Journals (Sweden)

    Raquel O. Cristóvão

    2015-06-01

    Full Text Available The optimization of hydraulic retention time (HRT and initial organic matter concentration for dissolved organic carbon (DOC abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM. The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC removal were fitted into a quadratic polynomial model using factorial design and RSM. The optimum process conditions were determined by analyzing the response surface of a three-dimensional plot and by solving the regression model equation. The obtained results showed a HRT of 6.4 h and an initial DOC of 406.2 mg/L as the best treatment conditions. Under these conditions, the maximum predicted DOC removal was 88.0%, confirming the feasibility and the reliability of fish canning wastewater treatment by activated sludge for organic content removal.

  1. Organic-rich shales from internal Betic basins (SE Spain): potential source rocks analogs for the pre-Messinian Salt play in the western Mediterranean

    Energy Technology Data Exchange (ETDEWEB)

    Permanyer, A.; Jorge, R.; Baudino, R.; Gilbert, L.

    2016-07-01

    Southeastern Spain has a large number of Late Neogene basins with substantial evaporitic deposits that developed under an overall NNW-SSE compressional regime related to the African-European tectonic plates collision. Located in the Betic Cordillera, they can be considered as marginal Mediterranean basins that became gradually isolated during the Tortonian and Early Messinian due to tectonic uplift. Different evaporitic units accumulated in these basins during isolation and, in several cases, evaporitic conditions were associated to episodes of important organic matter accumulation. Results obtained from Late Tortonian to Early Messinian shales collected from boreholes, mines and outcrops in the internal Betic basins of Las Minas de Hellín, Cenajo and Socovos are presented. The organic matter was studied under fluorescence and scanning electron microscopy (SEM), and the main geochemical characteristics defined. They show a relation between organic-rich intervals with high potential of hydrocarbon generation, native sulfur, bio-induced dolomite and evaporitic deposits. These organicrich shales can be found before, during and after the evaporitic episodes. Results from the present study are compared with those previously obtained in the pre-evaporitic deposits of the Lorca Basin that showed high oil generation potential, a restricted-marine origin of the organic matter and a low degree of maturity. The occurrence of such potential source rocks in several basins points to a broad regional distribution. At a larger scale, in the Mediterranean Basin, organic-rich sediments were deposited before and during the Messinian Salinity Crisis. The studied examples could represent analogs for potential source rocks of the pre-Messinian salt play in the Western Mediterranean. (Author)

  2. Petrographic and geochemical analyisis for determination of provenance of the Slovenj Gradec Miocene Basin fill (Western Central Paratethys)

    Science.gov (United States)

    Ivančič, Kristina; Trajanova, Mirka; Skaberne, Dragomir; Šmuc, Andrej

    2017-04-01

    The Slovenj Gradec Basin (SGB) is located in northern Slovenia between eastern margin of the Northern Karavanke and the western Pohorje Mts. Structurally, it belongs to Eastern Alps. It is filled with Miocene clastic sediments. Modal composition of sandstones was determined on thin sections by point-counter and presented with the QFL and QmFLt diagrams. Their geochemical composition was determined by classical method and by Inductively Coupled Plasma-Mass Spectrometry. Based on petrography, sedimentary fill of the SGB consists mostly of lithic grains and quartz, derived from metamorphic and carbonate rocks. Locally, fragments of granitoids occur. Binder consists of carbonate, subordinately quartz cement, and carbonate matrix. Recycled orogen (lithic and transitional recycled) provenance of the grains was determined. Geochemical composition shows that: - Sandstones from the SGB belong to the fields of shale, wacke, litharenite, arkose and subarkose (Pettijohn, 1972). - In the ternary diagram of weathering trends (cf. Nesbitt & Young 1984), the samples group near the CaO+Na2OAl2O3 conjunctive. Calculated minimum CIA (Fedo et al., 1995) is 40.06, indicating that the source rocks were not subjected to considerable weathering. - According to discriminant function (cf. Roser & Korsch, 1988) all samples from SGB originate from quartzose sedimentary rocks. - For determination of tectonic setting of source rocks (Verma & Armstrong-Altrin, 2013) the studied samples plot in the field of collision zone. - In the multidimensional discriminant function diagram for the discrimination of active and passive margin after Verma and Armstrong (2016), the samples plot into the field of passive margin. The data indicate that source rocks of the SGB sedimentary fill were derived from Eastern Alps and Southern Alps. It is suggested that SGB was detached from the Styrian and Mura-Zala Basins in the course of the Pohorje Mts. oblique transpressive uplift during the late Miocene to Pliocene

  3. Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios.

    Science.gov (United States)

    Yen, Haw; White, Michael J; Arnold, Jeffrey G; Keitzer, S Conor; Johnson, Mari-Vaughn V; Atwood, Jay D; Daggupati, Prasad; Herbert, Matthew E; Sowa, Scott P; Ludsin, Stuart A; Robertson, Dale M; Srinivasan, Raghavan; Rewa, Charles A

    2016-11-01

    Complex watershed simulation models are powerful tools that can help scientists and policy-makers address challenging topics, such as land use management and water security. In the Western Lake Erie Basin (WLEB), complex hydrological models have been applied at various scales to help describe relationships between land use and water, nutrient, and sediment dynamics. This manuscript evaluated the capacity of the current Soil and Water Assessment Tool (SWAT) to predict hydrological and water quality processes within WLEB at the finest resolution watershed boundary unit (NHDPlus) along with the current conditions and conservation scenarios. The process based SWAT model was capable of the fine-scale computation and complex routing used in this project, as indicated by measured data at five gaging stations. The level of detail required for fine-scale spatial simulation made the use of both hard and soft data necessary in model calibration, alongside other model adaptations. Limitations to the model's predictive capacity were due to a paucity of data in the region at the NHDPlus scale rather than due to SWAT functionality. Results of treatment scenarios demonstrate variable effects of structural practices and nutrient management on sediment and nutrient loss dynamics. Targeting treatment to acres with critical outstanding conservation needs provides the largest return on investment in terms of nutrient loss reduction per dollar spent, relative to treating acres with lower inherent nutrient loss vulnerabilities. Importantly, this research raises considerations about use of models to guide land management decisions at very fine spatial scales. Decision makers using these results should be aware of data limitations that hinder fine-scale model interpretation. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Baseline monitoring of the western Arctic Ocean estimates 20% of Canadian basin surface waters are undersaturated with respect to aragonite.

    Science.gov (United States)

    Robbins, Lisa L; Wynn, Jonathan G; Lisle, John T; Yates, Kimberly K; Knorr, Paul O; Byrne, Robert H; Liu, Xuewu; Patsavas, Mark C; Azetsu-Scott, Kumiko; Takahashi, Taro

    2013-01-01

    Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index) for the western Arctic Ocean. This data set documents aragonite undersaturation in ≈ 20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean's largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  5. Rainwater harvesting possibility under climate change: A basin-scale case study over western province of Saudi Arabia

    Science.gov (United States)

    Almazroui, Mansour; Islam, M. Nazrul; Balkhair, Khaled S.; Şen, Zekâi; Masood, Amjad

    2017-06-01

    Groundwater reservoirs are important water resources all over the world. Especially, they are of utmost significance for arid and semi-arid regions, and therefore, a sustainable exploitation of these reservoirs needs to be ensured. The natural and most exclusive water supplier to groundwater reservoirs in Saudi Arabia is rainfall, which is characterized by sporadic and random temporal and spatial distributions, particularly under the impacts of climate change; giving rise to uncertainty in groundwater recharge quantification. Although in Saudi Arabia, intense and frequent rainfall events are rare, but they generate significant flash floods with huge amounts of surface water. Under such circumstances, any simple but effective water storage augmentation facility such as rainwater harvesting (RWH) structures gain vital importance for sustainability of water supply and survivals in arid and semi-arid regions. The objective of this study is to explore the possibility of RWH over a basin in the western province of Saudi Arabia called Wadi Al-Lith under climate change. Climatic data is obtained from the IPCC AR5 GCMs, which is further downscaled using a regional climate model RegCM4 for the Arabian Peninsula domain. The RegCM4 is driven to simulate climatic parameters including rainfall at 25 km grid resolution for the present climate (1971-2000), and future climate (2006-2099) with representative concentration pathways, RCP4.5 and RCP8.5. Results indicate that more durable and longer wet durations are expected with increasing surplus rainfall amounts in the far future because of climate change impacts. Consequently, future climate scenarios are expected to enhance floods and flash floods occurrences, which call for progressive measures to harness the RWH opportunity.

  6. Variability of fine and coarse aerosol over the Western Mediterranean Basin during the Minerva 2015 research cruise campaign

    Science.gov (United States)

    Castagna, Jessica; Carbone, Francesco; Naccarato, Attilio; Moretti, Sacha; Esposito, Giulio; Bencardino, Mariantonia; D'Amore, Francesco; Sprovieri, Francesca; Pirrone, Nicola

    2016-04-01

    The Mediterranean Basin, due to its semi-enclosed configuration, is heavily affected by air pollution and it is becoming, in the last years, a region of particular interest of study for its implications regarding both health effects and environmental impacts. The area is surrounded by a densely populated as well as industrialized coast, and even affected by natural sources. So, it is important to know how the various sources contributes to increase air pollution levels and discriminate among them. With special regard to aerosol pollution, natural sources, like Saharan dust, volcanoes, and fires, as well as anthropogenic sources, such as industry, road and marine traffic, and fuel combustion from heating, can equally increase the values of this dangerous pollutant. While on the land we can find numerous monitoring sites, there are not continuous measurements on the sea. For this reason, since 2000 the Institute of Atmospheric Pollution of the National Research Council (CNR-IIA) is conducting regular oceanographic campaigns of measurements in the Mediterranean Sea. In this context, here we report the results obtained during the last cruise campaign, which took place in the Western Mediterranean sector and was conducted on-board the Italian research vessel Minerva during summer 2015 (from June 27th to July 13th). Fine (PM2.5) and Coarse (PM2.5-10) particulate size fractions were collected on PTFE membrane filters (Advantec MFS) and their mass concentrations determined gravimetrically. Successively, all the filters were digested with a mixture of HNO3/H2O2 in an microwaves digestion system and then analyzed by ICP-MS for the determination of the major and trace elements. Outcomes regarding the particulate mass concentration, the content and the distribution of the analyzed elements over both PM size fractions will be discussed taking into account potential contributing sources as well as different meteorological conditions.

  7. A new impulse-stage sand fracturing technology and its pilot application in the western Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Bin Qi

    2015-03-01

    Full Text Available A better placement of proppants has been always the goal pursued in sand fracturing in order to get longer effective fractures and higher flow conductivity. However, it is always difficult to achieve satisfactory effects by conventional processes. On the basis of theoretical analysis and simulation with FracproPT software, basic experiments, and innovative physical modeling experiment, a new impulse-stage fracturing process has been developed by combining a special pumping process with fiber, liquid and other auxiliary engineering means. Compared with conventional fracturing, the open seepage channel created by the new fracturing process has an obvious edge in effective fracture length and flow conductivity. Moreover, the open seepage channel can also improve fracture cleanliness and reduce pressure loss in artificial fractures, thus reaching the goal of prolonging the single-well production time and maximizing productivity. After the research on principles and optimal design of this new process, on-site pilot test and detailed post-fracturing evaluation were conducted. The results indicated that (1 the new process is highly operable and feasible; (2 compared with the adjacent wells with similar geological conditions, the proppant' cost is reduced by 44%–47%, the ratio of effective fracture length to propped fracture length is increased by about 16%, the fracturing fluid recovery rate is up to 63% after 18 h in the test, and the normalized production is 1.9–2.3 times that of the adjacent wells; and (3 the new process can significantly lower the cost and enhance production. The process has a broad application prospect in shallow-middle sand gas reservoirs and shale gas reservoirs in western Sichuan Basin.

  8. Large-scale Watershed Modeling: NHDPlus Resolution with Achievable Conservation Scenarios in the Western Lake Erie Basin

    Science.gov (United States)

    Yen, H.; White, M. J.; Arnold, J. G.; Keitzer, S. C.; Johnson, M. V. V.; Atwood, J. D.; Daggupati, P.; Herbert, M. E.; Sowa, S. P.; Ludsin, S.; Robertson, D. M.; Srinivasan, R.; Rewa, C. A.

    2016-12-01

    By the substantial improvement of computer technology, large-scale watershed modeling has become practically feasible in conducting detailed investigations of hydrologic, sediment, and nutrient processes. In the Western Lake Erie Basin (WLEB), water quality issues caused by anthropogenic activities are not just interesting research subjects but, have implications related to human health and welfare, as well as ecological integrity, resistance, and resilience. In this study, the Soil and Water Assessment Tool (SWAT) and the finest resolution stream network, NHDPlus, were implemented on the WLEB to examine the interactions between achievable conservation scenarios with corresponding additional projected costs. During the calibration/validation processes, both hard (temporal) and soft (non-temporal) data were used to ensure the modeling outputs are coherent with actual watershed behavior. The results showed that widespread adoption of conservation practices intended to provide erosion control could deliver average reductions of sediment and nutrients without additional nutrient management changes. On the other hand, responses of nitrate (NO3) and dissolved inorganic phosphorus (DIP) dynamics may be different than responses of total nitrogen and total phosphorus dynamics under the same conservation practice. Model results also implied that fewer financial resources are required to achieve conservation goals if the goal is to achieve reductions in targeted watershed outputs (ex. NO3 or DIP) rather than aggregated outputs (ex. total nitrogen or total phosphorus). In addition, it was found that the model's capacity to simulate seasonal effects and responses to changing conservation adoption on a seasonal basis could provide a useful index to help alleviate additional cost through temporal targeting of conservation practices. Scientists, engineers, and stakeholders can take advantage of the work performed in this study as essential information while conducting policy

  9. Assessing linkages between spatial facies changes and dimensional variations of glaciers in the upper Indus Basin, western Himalaya

    Science.gov (United States)

    Ali, Iram; Shukla, Aparna; Romshoo, Shakil A.

    2017-05-01

    The present study provides an insight into the heterogeneous response of 45 glaciers in the Lidder and Sindh river basins, western Himalaya, and explores the linkages between glacier facies variability and changing glacier parameters. Results show that the region has undergone an overall deglaciation of 12 ± 1.5% (11.9 ± 1.4 km2) from 1996 to 2014. Fluctuations in the temperature and precipitation patterns seem to be the primary factor controlling the changes in glacier dimensions (R2 > 0.82 in all cases). Glacier facies changes suggest depletion in snow-ice cover ( 18 ± 2.3%) and an increase in ice-mixed debris ( 4 ± 1.4%), supraglacial debris ( 6 ± 1.5%), and periglacial debris ( 17 ± 1.2%). These glacier facies transitions are possibly the result of ice-melting; however, its relative rate and elevation decides the nature of facies conversion. An increase in the proportion of supraglacial debris has led to the conversion of 11 clean glaciers to sparsely debris-covered glaciers and 5 sparsely debris-covered glaciers to debris-covered glaciers. The size of the glaciers greatly influenced the rate of conversion of glaciers, and glaciers glaciers also experienced maximum shrinkage. Further, the glaciers with varying supraglacial debris cover respond differently, as sparsely debris-covered glaciers exhibit the highest rates of retreat (25 ± 7.3 m/y), followed by clean (23.7 ± 7.3 m/y) and debris-covered glaciers (13.1 ± 7.3 m/y). Thus, the findings of this work clearly show that the climate change driven dimensional changes of glaciers and variations in the spatial distribution of glacier facies have strong mutual control on each other.

  10. Evolution of a Permian Arid Lake System, Upper Pedra de Fogo Formation, Western Border of the Parnaiba Basin

    Directory of Open Access Journals (Sweden)

    Luiz Saturnino de Andrade

    2014-12-01

    Full Text Available Stratigraphic and facies analysis in the Filadélfia region, TO, BR, at the western of the Parnaíba Basin, allowed redefine the paleoenvironment of the upper portion of the Pedra de Fogo Formation of Permian age. The studied deposits are a series of approximately 100 m thick, predominantly siliciclastic, with subordinate carbonates and evaporites, where were defined 21 sedimentary facies that could be grouped into six facies associations (AF: AF1 Lacustrine with ephemeral river deposits; AF2 Storm wave-influenced lake deposits; AF3 Continental sabkha deposits; AF4 Central lake deposits; AF5 Eolian dunes field deposits; and AF6 Lake/oasis deposits with inunditos. These associations indicate that during Permian, an extensive lacustrine arid system developed adjacent to eolian dunes fields and continental sabkha, as well as with contributions from ephemeral rivers. Fluvial incursions into lakes propitiated the formation of suspension lobes and sheet flows (AF1. Sabkha plains (AF3 were formed in the marginal portions of the lake that eventually were influenced by storms waves (AF2, while central zone were site of intense pelitic deposition (AF4. The low supply of eolian sand in this system resulted in the formation of restricted dune fields (AF5, with development of interdune lakes (oasis, where proliferating giant ferns, sporadically flooded by ephemeral rivers (AF6. The facies associations data, corroborated by the paleogeography of the region during the Late Permian, indicate that settling of the top part of the Pedra de Fogo Formation was laid during a hot and arid climate.

  11. Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios

    Science.gov (United States)

    Yen, Haw; White, Michael J.; Arnold, Jeffrey G.; Keitzer, S. Conor; Johnson, Mari-Vaughn V; Atwood, Jay D.; Daggupati, Prasad; Herbert, Matthew E.; Sowa, Scott P.; Ludsin, Stuart A.; Robertson, Dale; Srinivasan, Raghavan; Rewa, Charles A.

    2016-01-01

    Complex watershed simulation models are powerful tools that can help scientists and policy-makers address challenging topics, such as land use management and water security. In the Western Lake Erie Basin (WLEB), complex hydrological models have been applied at various scales to help describe relationships between land use and water, nutrient, and sediment dynamics. This manuscript evaluated the capacity of the current Soil and Water Assessment Tool (SWAT2012) to predict hydrological and water quality processes within WLEB at the finest resolution watershed boundary unit (NHDPlus) along with the current conditions and conservation scenarios. The process based SWAT model was capable of the fine-scale computation and complex routing used in this project, as indicated by measured data at five gaging stations. The level of detail required for fine-scale spatial simulation made the use of both hard and soft data necessary in model calibration, alongside other model adaptations. Limitations to the model's predictive capacity were due to a paucity of data in the region at the NHDPlus scale rather than due to SWAT functionality. Results of treatment scenarios demonstrate variable effects of structural practices and nutrient management on sediment and nutrient loss dynamics. Targeting treatment to acres with critical outstanding conservation needs provides the largest return on investment in terms of nutrient loss reduction per dollar spent, relative to treating acres with lower inherent nutrient loss vulnerabilities. Importantly, this research raises considerations about use of models to guide land management decisions at very fine spatial scales. Decision makers using these results should be aware of data limitations that hinder fine-scale model interpretation.

  12. A new troodontid theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America.

    Directory of Open Access Journals (Sweden)

    Lindsay E Zanno

    Full Text Available BACKGROUND: Troodontids are a predominantly small-bodied group of feathered theropod dinosaurs notable for their close evolutionary relationship with Avialae. Despite a diverse Asian representation with remarkable growth in recent years, the North American record of the clade remains poor, with only one controversial species--Troodon formosus--presently known from substantial skeletal remains. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a gracile new troodontid theropod--Talos sampsoni gen. et sp. nov.--from the Upper Cretaceous Kaiparowits Formation, Utah, USA, representing one of the most complete troodontid skeletons described from North America to date. Histological assessment of the holotype specimen indicates that the adult body size of Talos was notably smaller than that of the contemporary genus Troodon. Phylogenetic analysis recovers Talos as a member of a derived, latest Cretaceous subclade, minimally containing Troodon, Saurornithoides, and Zanabazar. MicroCT scans reveal extreme pathological remodeling on pedal phalanx II-1 of the holotype specimen likely resulting from physical trauma and subsequent infectious processes. CONCLUSION/SIGNIFICANCE: Talos sampsoni adds to the singularity of the Kaiparowits Formation dinosaur fauna, which is represented by at least 10 previously unrecognized species including the recently named ceratopsids Utahceratops and Kosmoceratops, the hadrosaurine Gryposaurus monumentensis, the tyrannosaurid Teratophoneus, and the oviraptorosaurian Hagryphus. The presence of a distinct troodontid taxon in the Kaiparowits Formation supports the hypothesis that late Campanian dinosaurs of the Western Interior Basin exhibited restricted geographic ranges and suggests that the taxonomic diversity of Late Cretaceous troodontids from North America is currently underestimated. An apparent traumatic injury to the foot of Talos with evidence of subsequent healing sheds new light on the paleobiology of deinonychosaurians

  13. Baseline monitoring of the western Arctic Ocean estimates 20% of Canadian basin surface waters are undersaturated with respect to aragonite.

    Directory of Open Access Journals (Sweden)

    Lisa L Robbins

    Full Text Available Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index for the western Arctic Ocean. This data set documents aragonite undersaturation in ≈ 20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean's largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  14. Early 21st century climatology of snow cover for the western river basins of the Indus River System: effects of changes on hydrological balance and society.

    Science.gov (United States)

    Hasson, Shabeh; Lucarini, Valerio; Riaz Khan, Mobushir; Petitta, Marcello; Bolch, Tobias; Gioli, Giovanna

    2014-05-01

    In this study we assess the snow cover and its dynamics for the western river basins of the Indus River System (IRS) and their sub-basins located in Afghanistan, China, India and Pakistan for the period 2001-2012. Moderate Resolution Imaging Spectro-radiometer (MODIS) daily snow products from Terra (MOD) and Aqua (MYD) have been first improved and then analysed on seasonal and annual basis against different topographic parameters (aspect, elevation and slope). Our applied cloud filtering technique has reduced the cloud cover from 37% (MOD) and 43% (MYD) to 7%, thus improving snow cover estimates from 7% (MOD) and 5% (MYD) to 14% for the area of interest (AOI) during the validation period (2004). Our results show a decreasing tendency for the annual average snow cover for the westerlies-influenced basins (Upper Indus Basin, Astore, Hunza, Shigar, Shyok) and an increasing tendency for the monsoon-influenced basins (Jhelum, Kabul, Swat and Gilgit). Regarding the seasonal snow cover, decrease during winter and autumn and increase during spring and summer has been found, which is consistent with the observed cooling and warming trends during the respective seasons. Sub-basins at relatively higher latitude/altitude show higher variability than basins at lower latitude/mid-altitude. Northeastern and northwestern aspects feature larger snow cover. The mean regional snow line altitude (SLA) zones range between 3000 and 5000 m a.s.l. for all basins. Our analysis provides an indication of a decrease in the regional SLA zone, thus indicating a change in the water resources of the studied basins, particularly for the Upper Indus Basin (UIB). Such results are consistent with the observed hydro-climate data, recently collected local perceptions and glacier mass balances for the investigated period. Moreover, our analysis suggests some potential for the seasonal stream flow forecast as a significant negative correlation has been detected for the inter-annual variability of winter

  15. Distribution and variation of the inorganic fraction of Devonian to Bashkirian black shales in the north-western part of the Dniepr-Donets Basin, Ukraine

    Science.gov (United States)

    Wegerer, Eva; Sachsenhofer, Reinhard; Misch, David; Aust, Nicolai

    2016-04-01

    Mineralogical data of 112 core samples from 12 wells are used to investigate lateral and vertical variations in the lithofacies of Devonian to Bashkirian black shales in the north-western part of the Dniepr-Donets-Basin. Sulphur and carbonate contents as well as organic geochemical parameters, including TOC and Hydrogen Index have been determined on the same sample set within the frame of an earlier study (Sachsenhofer et al. 2010). This allows the correlation of inorganic and organic composition of the black shales. Aims of the study are to distinguish between detrital and authigenic minerals, to relate the lithofacies of the black shales with the tectono-stratigraphic sequences of the Dniepr-Donets Basin, to contribute to the reconstruction of the depositional environment and to relate diagenetic processes with the thermal history of the basin. Mineral compositions were determined primarily using XRD-measurements applying several measurement procedures, e.g. chemical and temperature treatment, and specific standards. Major differences exist in the mineralogical composition of the black shales. For example, clay mineral contents range from less than 20 to more than 80 Vol%. Kaolinite contents are significantly higher in rocks with a Tournaisian or Early Visean age than in any other stratigraphic unit. This is also true for two Lower Visean coal samples from the shallow north-westernmost part of the basin. Chlorite contents reach maxima in uppermost Visean and overlying rocks. Quartz contents are often high in Upper Visean rocks and reach maxima in Bashkirian units. Feldspar-rich rocks are observed in Devonian sediments from the north-western part of the study area and may reflect the proximity to a sediment source. Carbonate contents are typically low, but reach very high values in some Tournaisian, Lower Visean and Serpukhovian samples. Pyrite contents reach maxima along the basin axis in Tournaisian and Visean rocks reflecting anoxic conditions. Mixed layer

  16. Trace Element Geochemistry of Matrix Glass from the Bedout Impact Structure,Canning Basin NW Australia

    Science.gov (United States)

    Poreda, R. J.; Basu, A. R.; Chakrabarti, R.; Becker, L.

    2004-12-01

    We report on geochemical and petrographic analysis of separated matrix glass from Lagrange-1 and Bedout-1 drill cores that penetrated the Bedout structure offshore NW Australia. The results support the conclusion that the Bedout structure was produced by a a major ET impact at the end-Permian that generated shock melted glass and impact breccias (Becker et al., Science, v.304, p.1469, 2004) The Bedout structure is a 30 km, circular, 1.5 km uplifted basment high that occurs on the passive margin offshore NW Australia. The isolated feature, covered by 3 km of Triassic to Recent sediments,is not consistent with any typical volcanic province (i.e. arc or hotspot volcanism). This hypothesis is supported by the unique mineralogy and chemistry of the matrix glass. At Lagrange, major elements crudely resemble low-K, Fe-Ti basalts while the trace element patterns have two distinct signatures. The lower 250 m of Lagrange (3260 - 3010 m depth) have essentially flat REE and "spider" patterns that superficially resemble some E-MORB; a signal not typically found in arc, hotspot or continental margin settings. The upper 150 meters (3000 - 2850m) of Lagrange and the entire Bedout core (3030 - 3070m) have similar light REE-enriched patterns but low levels of alkalis, alkaline-earths and high field strength elements. Again, the chemistry is not consistent with an arc or hotspot setting, based on the low Ba and extremely low Sr (30-110 ppm) concentrations. Based on the geophysical, chemical and petrologic evidence, we hypothesize that the Bedout structure formed as the result` of an ET impact with Permian age rift margin basalts and continental sediment. The basalts did not completely melt as evidenced by the abundance of large (1 mm) An50 plagioclase,that exist as both crystalline plag and shock melted maskelynite. Plagioclase is the major repository of Sr in basalts and the lack of a plagioclase contribution to the melt glass is reflected in the low Sr abundance. Shock-transformed plagioclase glass that still retains the lath shape and chemistry of An50 are one of the major indicators of the impact origin for Bedout.

  17. The riverine source of CH4 and N2O from the Republic of Congo, western Congo Basin

    Science.gov (United States)

    Upstill-Goddard, Robert C.; Salter, Matthew E.; Mann, Paul J.; Barnes, Jonathan; Poulsen, John; Dinga, Bienvenu; Fiske, Gregory J.; Holmes, Robert M.

    2017-05-01

    We discuss concentrations of dissolved CH4, N2O, O2, NO3- and NH4+, and emission fluxes of CH4 and N2O for river sites in the western Congo Basin, Republic of Congo (ROC). Savannah, swamp forest and tropical forest samples were collected from the Congo main stem and seven of its tributaries during November 2010 (41 samples; wet season) and August 2011 (25 samples; dry season; CH4 and N2O only). Dissolved inorganic nitrogen (DIN: NH4++ NO3-; wet season) was dominated by NO3- (63 ± 19 % of DIN). Total DIN concentrations (1.5-45.3 µmol L-1) were consistent with the near absence of agricultural, domestic and industrial sources for all three land types. Dissolved O2 (wet season) was mostly undersaturated in swamp forest (36 ± 29 %) and tropical forest (77 ± 36 %) rivers but predominantly supersaturated in savannah rivers (100 ± 17 %). The dissolved concentrations of CH4 and N2O were within the range of values reported earlier for sub-Saharan African rivers. Dissolved CH4 was found to be supersaturated (11.2-9553 nmol L-1; 440-354 444 %), whereas N2O ranged from strong undersaturation to supersaturation (3.2-20.6 nmol L-1; 47-205 %). Evidently, rivers of the ROC are persistent local sources of CH4 and can be minor sources or sinks for N2O. During the dry season the mean and range of CH4 and N2O concentrations were quite similar for the three land types. Wet and dry season mean concentrations and ranges were not significant for N2O for any land type or for CH4 in savannah rivers. The latter observation is consistent with seasonal buffering of river discharge by an underlying sandstone aquifer. Significantly higher wet season CH4 concentrations in swamp and forest rivers suggest that CH4 can be derived from floating macrophytes during flooding and/or enhanced methanogenesis in adjacent flooded soils. Swamp rivers also exhibited both low (47 %) and high (205 %) N2O saturation but wet season values were overall significantly lower than in either tropical forest or

  18. Geochemistry of Late Triassic pelitic rocks in the NE part of Songpan-Ganzi Basin, western China: Implications for source weathering, provenance and tectonic setting

    Directory of Open Access Journals (Sweden)

    Yan Tang

    2012-09-01

    Full Text Available Major, trace and rare earth element (REE concentrations of Late Triassic sediments (fine-grained sandstones and mudstones from Hongcan Well 1 in the NE part of the Songpan-Ganzi Basin, western China, are used to reveal weathering, provenance and tectonic setting of inferred source areas. The Chemical Index of Alteration (CIA reflects a low to moderate degree of chemical weathering in a cool and somewhat dry climate, and an A-CN-K plot suggests an older upper continental crust provenance dominated by felsic to intermediate igneous rocks of average tonalite composition. Based on the various geochemical tectonic setting discrimination diagrams, the Late Triassic sediments are inferred to have been deposited in a back-arc basin situated between an active continental margin (the Kunlun-Qinling Fold Belt and a continental island arc (the Yidun Island Arc. The Triassic sediments in the study area underwent a rapid erosion and burial in a proximal slope-basin environment by the petrographic data, while the published flow directions of Triassic turbidites in the Aba-Zoige region was not supported Yidun volcanic arc source. Therefore, we suggest that the Kunlun-Qinling terrane is most likely to have supplied source materials to the northeast part of the Songpan-Ganzi Basin during the Late Triassic.

  19. Clinopyroxene with diverse origins in alkaline basalts from the western Pannonian Basin: Implications from trace element characteristics

    Science.gov (United States)

    Jankovics, M. Éva; Taracsák, Zoltán; Dobosi, Gábor; Embey-Isztin, Antal; Batki, Anikó; Harangi, Szabolcs; Hauzenberger, Christoph A.

    2016-10-01

    Clinopyroxene crystals of various origins occur in the unusually crystal- and xenolith-rich alkaline basalts of the Bondoró-hegy and the Füzes-tó scoria cone, which are the youngest eruptive centres in the Bakony-Balaton Highland Volcanic Field, western Pannonian Basin. The clinopyroxenes show diverse textural and zoning features as well as highly variable major and trace element chemistry. Xenocryst, megacryst and phenocryst crystal populations can be distinguished on the basis of their compositional differences. The trace element patterns of green clinopyroxene cores display a large range in composition and indicate that most of them have a metamorphic origin. Most of them were incorporated from lower crustal mafic granulite wall rocks, while only a few of them are of magmatic origin representing pyroxenite (Type II) cumulates. The colourless clinopyroxene xenocrysts reflect the texturally and geochemically diverse nature of the subcontinental lithospheric mantle beneath the studied area, mainly representing regions characterised by various stages of metasomatism. The colourless and green megacrysts are genetically related to each other, having crystallised as early and late crystallisation products, respectively, from petrogenetically related melts as part of a fractional crystallisation sequence. These melts represent earlier alkaline basaltic magmas (as represented by the Type II xenoliths), having stalled and crystallised near the crust-mantle boundary in the uppermost part of the mantle. This serves as evidence that the deep magmatic systems beneath monogenetic volcanic fields are complex, involving several phases of melt generation, accumulation and fractionation at variable depths. We show that in situ trace element analysis is necessary in order to unravel the origins and relationships of the diverse clinopyroxene populations. Such studies significantly contribute to our understanding of the ascent histories of alkaline basaltic magmas and provide

  20. The linkage between fluvial meander-belt morphodynamics and the depositional record improves paleoenvironmental interpretations, Western Interior Basin, Alberta, Canada

    Science.gov (United States)

    Durkin, P.; Hubbard, S. M.

    2016-12-01

    -belt scale, analysis of changes in morphology over time reveal a decrease in channel-belt width/thickness ratio and sinuosity, which we attribute to the landward migration of the paleo-backwater limit due to the oncoming and overlying transgression of the Cretaceous Boreal Sea into the Western Interior Basin.

  1. Hydrochemical and stable isotope indicators of pyrite oxidation in carbonate-rich environment; the Hamersley Basin, Western Australia

    Science.gov (United States)

    Dogramaci, Shawan; McLean, Laura; Skrzypek, Grzegorz

    2017-02-01

    Sulphur (S) is a commonly occurring element in most aquifers, primarily in oxidised (sulphates) and reduced (sulphides) forms. Sulphides often constitute a risk to groundwater quality due to acid rock drainage, especially in catchments that are subject to mining excavations or groundwater injection. However, in semi-arid regions detection of the acid rock drainage risk can be challenging and traditional methods based on observations of increasing SO4 concentrations or SO4/Cl ratios in surface and groundwater, are not necessarily applicable. In addition, decreasing pH, usually accompanying pyrite oxidation, can be masked by the high pH-neutralisation capacity of carbonate and silicate minerals. Analysis of 73 surface and groundwater samples from different water bodies and aquifers located in the Hamersley Basin, Western Australia found that most of the samples are characterised by neutral pH but there was also a large spatial variability in the dissolved sulphate (SO4) concentrations that ranged from 1 mg/L to 15,000 mg/L. Not surprisingly, groundwater in aquifers that contained pyrite had high sulphate concentrations (>1000 mg/L). This was associated with low δ34SSO4 values (+1.2‰ to +4.6‰) and was consistent with the values obtained from aquifer matrix pyritic rock samples (-1.9‰ to +4.4‰). It was also found that the SO4 concentrations and acidity levels were not only dependent on δ34SSO4 values and existence of pyrite but also on the presence of carbonate minerals in the aquifer matrix. The groundwater in aquifers containing both pyrite and carbonate minerals had a neutral pH and was also saturated with respect to gypsum and had high magnesium concentrations of up to 2200 mg/L suggesting de-dolomitisation as the process buffering the acidity generated by pyrite oxidation. Based on the findings from this study, a classification scheme has been developed for identification of the acid rock drainage contribution to groundwater that encompasses a myriad of

  2. Contributions to the phytocoenological study of pure european beech forests in Oraştie river basin (central-western Romania

    Directory of Open Access Journals (Sweden)

    Petru BURESCU

    2012-05-01

    Full Text Available În the current paper we present a phytocoenologic study of the phytocoenoses of the association Festuco drymejaeFagetum Morariu et al. 1968 (Syn.: Fagetum sylvaticae transylvaticum facies with Festuca drymeja I. Pop et al. 1974, found in the pure European beech forests of the Orăştie river basin, lying in the central-western part of Romania. The characterisation of the association under analysis as well as the presentation of the synthetic table have been done byselecting the most representative relevées of pure European beech forests belonging to the Orăştie river basin. The phytocoenoses of these beech forests were analysed in terms of physiognomy and floristic composition, life forms spectrum, floristic elements, and ecological indices.

  3. Evidence for multi-cycle sedimentation and provenance constraints from detrital zircon U-Pb ages: Triassic strata of the Lusitanian basin (western Iberia)

    Science.gov (United States)

    Pereira, M. F.; Gama, C.; Chichorro, M.; Silva, J. B.; Gutiérrez-Alonso, G.; Hofmann, M.; Linnemann, U.; Gärtner, A.

    2016-06-01

    Laser ablation ICP-MS U-Pb analyses were conducted on detrital zircons of Triassic sandstone and conglomerate from the Lusitanian basin in order to: i) document the age spectra of detrital zircon; ii) compare U-Pb detrital zircon ages with previous published data obtained from Upper Carboniferous, Ordovician, Cambrian and Ediacaran sedimentary rocks of the pre-Mesozoic basement of western Iberia; iii) discuss potential sources; and iv) test the hypothesis of sedimentary recycling. U-Pb dating of zircons established a maximum depositional age for this deposit as Permian (ca. 296 Ma), which is about sixty million years older compared to the fossil content recognized in previous studies (Upper Triassic). The distribution of detrital zircon ages obtained points to common source areas: the Ossa-Morena and Central Iberian zones that outcrop in and close to the Porto-Tomar fault zone. The high degree of immaturity and evidence of little transport of the Triassic sediment suggests that granite may constitute primary crystalline sources. The Carboniferous age of ca. 330 Ma for the best estimate of crystallization for a granite pebble in a Triassic conglomerate and the Permian-Carboniferous ages (< ca. 315 Ma) found in detrital zircons provide evidence of the denudation of Variscan and Cimmerian granites during the infilling of continental rift basins in western Iberia. The zircon age spectra found in Triassic strata are also the result of recycling from the Upper Carboniferous Buçaco basin, which probably acted as an intermediate sediment repository. U-Pb data in this study suggest that the detritus from the Triassic sandstone and conglomerate of the Lusitanian basin is derived from local source areas with features typical of Gondwana, with no sediment from external sources from Laurussia or southwestern Iberia.

  4. Neogene basin development around Söke-Kuşadası (western Anatolia) and its bearing on tectonic development of the Aegean region

    Science.gov (United States)

    Gürer, Ömer Feyzi; Bozcu, Mustafa; Yılmaz, Kamil; Yılmaz, Yücel

    There is a N-S lying narrow strip of Neogene outcrop between the towns of Kuşadası and Söke in western Anatolia. It contains remnants of successive Neogene graben basins. The first graben began to form under the control of a N40-70°E-trending oblique fault system during the Early Miocene. At the initial phase of the opening coarse clastic rocks were deposited in front of the fault-elevated blocks as scree deposits and fanglomerates. Later the graben advanced into a large lake basin. Towards the end of the Middle Miocene the lacustrine sediments of the Early-Middle Miocene age underwent an approximately N-S compressional deformation and elevated above the lake level, and were partly eroded. During the Late Miocene a new graben basin began to form as a consequence of the development of E-W-trending normal faults, formed under the N-S extensional regime. This graben also turned later into a lake environment. The lake extended far beyond the limits of the fault zones, and covered the entire regions stretching from the south of Bafa Lake in the south to Kuşadası and beyond in the north. Micritic clayey limestones were predominantly deposited in the lake. A severe erosional phase followed the termination of the lake basin. This corresponds to the cessation of the N-S extension. When the N-S extension regenerated during the Pliocene(?)-Pleistocene, the Büyük Menderes graben system began to form. In the western part of the graben, a conjugated pair of oblique faults, the Priene-Sazlı fault and the Kuşadası fault, have formed. The faults having important strike-slip components, bounded a tectonic wedge, which began to move westward into the Aegean Sea region. Major morphological features of the region were formed under the effective control of these fault zones.

  5. Lithosphere, crust and basement ridges across Ganga and Indus basins and seismicity along the Himalayan front, India and Western Fold Belt, Pakistan

    Science.gov (United States)

    Ravi Kumar, M.; Mishra, D. C.; Singh, B.

    2013-10-01

    Spectral analysis of the digital data of the Bouguer anomaly of North India including Ganga basin suggest a four layer model with approximate depths of 140, 38, 16 and 7 km. They apparently represent lithosphere-asthenosphere boundary (LAB), Moho, lower crust, and maximum depth to the basement in foredeeps, respectively. The Airy's root model of Moho from the topographic data and modeling of Bouguer anomaly constrained from the available seismic information suggest changes in the lithospheric and crustal thicknesses from ˜126-134 and ˜32-35 km under the Central Ganga basin to ˜132 and ˜38 km towards the south and 163 and ˜40 km towards the north, respectively. It has clearly brought out the lithospheric flexure and related crustal bulge under the Ganga basin due to the Himalaya. Airy's root model and modeling along a profile (SE-NW) across the Indus basin and the Western Fold Belt (WFB), (Sibi Syntaxis, Pakistan) also suggest similar crustal bulge related to lithospheric flexure due to the WFB with crustal thickness of 33 km in the central part and 38 and 56 km towards the SE and the NW, respectively. It has also shown the high density lower crust and Bela ophiolite along the Chamman fault. The two flexures interact along the Western Syntaxis and Hazara seismic zone where several large/great earthquakes including 2005 Kashmir earthquake was reported. The residual Bouguer anomaly maps of the Indus and the Ganga basins have delineated several basement ridges whose interaction with the Himalaya and the WFB, respectively have caused seismic activity including some large/great earthquakes. Some significant ridges across the Indus basin are (i) Delhi-Lahore-Sargodha, (ii) Jaisalmer-Sibi Syntaxis which is highly seismogenic. and (iii) Kachchh-Karachi arc-Kirthar thrust leading to Sibi Syntaxis. Most of the basement ridges of the Ganga basin are oriented NE-SW that are as follows (i) Jaisalmer-Ganganagar and Jodhpur-Chandigarh ridges across the Ganga basin intersect

  6. Linking Genetic Variation in Adaptive Plant Traits to Climate in Tetraploid and Octoploid Basin Wildrye [Leymus cinereus (Scribn. & Merr. A. Love] in the Western U.S.

    Directory of Open Access Journals (Sweden)

    R C Johnson

    Full Text Available Few studies have assessed how ploidy type within a species affects genetic variation among populations in relation to source climates. Basin wildrye (Leymus cinereus (Scribn. & Merr. A. Love is a large bunchgrass common in the intermountain Western U.S. found in both octoploid and tetraploid types. In common gardens at two sites over two years differences in both ploidy type and genetic variation within ploidy were observed in phenology, morphology, and production traits on 57 octoploid and 52 tetraploid basin wildrye from the intermountain Western U.S. (P<0.01. Octoploids had larger leaves, longer culms, and greater crown circumference than tetraploids but the numerical ranges of plant traits and their source climates overlapped between ploidy types. Still, among populations octoploids often had greater genetic variation for traits and occupied more diverse climates than tetraploids. Genetic variation for both ploidy types was linked to source climates in canonical correlation analysis, with the first two variates explaining 70% of the variation. Regression of those canonical variates with seed source climate variables produced models that explained 64% and 38% of the variation, respectively, and were used to map 15 seed zones covering 673,258 km2. Utilization of these seed zones will help ensure restoration with adaptive seed sources for both ploidy types. The link between genetic traits and seed source climates suggests climate driven natural selection and adaptive evolution in basin wildrye. The more diverse climates occupied by octoploids and higher trait variation suggests a higher capacity for ecological differentiation than tetraploids in the intermountain Western U.S.

  7. Morphometric analysis of wadi Khumal basin, western coast of Saudi Arabia, using remote sensing and GIS techniques

    Science.gov (United States)

    Abboud, Iyad Ahmed; Nofal, Ramadan A.

    2017-02-01

    Wadi Khumal, a triangular drainage system basin located at the Radwa Mountains of the south Red Sea, Saudi Arabia, has been chosen to assess certain morphometric parameters that influence water supply for basin hydrology. Shuttle Radar Topographic Mission (SRTM) information was used to produce Digital Elevation Model (DEM), aspect network, and descent graphs. Geographic Information System (GIS) is utilized for the assessment of linear, areal, and relief landmarks of morphometric aspects. Morphometric analysis of the drainage system network and the Khumal basin showed it has fifth-order wadi network with an elongated shape and possesses dendritic to sub-dendritic drainage pattern. These pattern points in the Khumal basin have similarity of lithology, moderate to steep slope, and an effective structural system. The various values of bifurcation ratios (Rb) versus low form factor results with circularity ratio (Rc) and elongation ratio (Re) highly suggested a geologically higher permeability and a structurally planned drainage system through intermediate to low drainage density (Dd), moderate stream frequency (Fs); moderately coarse drainage texture (Rt) with high relief indicates tectonic activity with high slope terrain made from loose materials with good permeability efficient for the recharging of ground water. The low value of asymmetrical factor (AF) showed great distortion quotient of the lithology in all sub-basins proving the great and broad tectonic influence in the Khumal basin. A high relief ratio (Rh) of 0.028, with low zigzag path and a highly steep ridge during the Khumal basin indicated a continuation of youth of the basin with continuously local uplifting. A very low value Rt of 0.646 versus a very low Fs of 0.177 and a Dd of 556.33 m/km2 demonstrated that the basin was having extremely resistant rocks in a very high relief ground which indicates late tectonic activity.

  8. Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania

    National Research Council Canada - National Science Library

    Levei, Erika; Frentiu, Tiberiu; Ponta, Michaela; Tanaselia, Claudiu; Borodi, Gheorghe

    2013-01-01

    The objective of this study was to examine the potential environmental risk of tailings resulted after precious and base metal ores processing, stored in seven impoundments located in the Aries river basin, Romania...

  9. Contemporary suspended sediment dynamics within two partly glacierized mountain drainage basins in western Norway (Erdalen and Bødalen, inner Nordfjord)

    Science.gov (United States)

    Beylich, Achim A.; Laute, Katja; Storms, Joep E. A.

    2017-06-01

    This paper focuses on environmental controls, spatiotemporal variability and rates of contemporary fluvial suspended sediment transport in the neighboring, partly glacierized and steep Erdalen (79.5 km2) and Bødalen (60.1 km2) drainage basins in the fjord landscape of the inner Nordfjord in western Norway. Field work, including extended samplings and measurements, was conducted since 2004 in Erdalen and since 2008 in Bødalen. The distinct intra- and inter-annual temporal variability of suspended sediment transport found is mostly controlled by meteorological events, with most suspended sediment transport occurring during pluvial events in autumn (September-November), followed by mostly thermally determined glacier melt in summer (July-August), and by mostly thermally determined snowmelt in spring (April-June). Extreme rainfall events (> 70 mm d- 1) in autumn can trigger significant debris-flow activity that can cause significant transfers of suspended sediments from ice-free surface areas with sedimentary covers into main stream channels and is particularly important for fluvial suspended sediment transport. In years with occurring relevant debris-flow activity the total annual drainage-basin wide suspended sediment yields are strongly determined by these single extreme events. The proportion of glacier coverage, followed by steepness of slopes, and degree of vegetation cover in ice-free surface areas with sedimentary covers are the main controls for the detected spatial variability of suspended sediment yields. The contemporary sediment supply from glacierized surface areas and the Jostedalsbreen ice cap through different defined outlet glaciers shows a high spatial variability. The fact that the mean annual suspended sediment yield of Bødalen is with 31.3 t km- 2 yr- 1 almost twice as high as the mean annual suspended sediment yield of Erdalen (16.4 t km- 2 yr- 1) is to a large extent explained by the higher proportion of glacier coverage in Bødalen (38% of

  10. Andean Basin Evolution Associated with Hybrid Thick- and Thin-Skinned Deformation in the Malargüe Fold-Thrust Belt, Western Argentina

    Science.gov (United States)

    Horton, B. K.; Fuentes, F.

    2015-12-01

    Andean deformation and basin evolution in the Malargüe fold-thrust belt of western Argentina (34-36°S) has been dominated by basement faults influenced by pre-existing Mesozoic rift structures of the hydrocarbon-rich Neuquen basin. However, the basement structures diverge from classic inversion structures, and the associated retroarc basin system shows a complex Mesozoic-Cenozoic history of mixed extension and contraction, along with an enigmatic early Cenozoic stratigraphic hiatus. New results from balanced structural cross sections (supported by industry seismic, well data, and surface maps), U-Pb geochronology, and foreland deposystem analyses provide improved resolution to examine the duration and kinematic evolution of Andean mixed-mode deformation. The basement structures form large anticlines with steep forelimbs and up to >5 km of structural relief. Once the propagating tips of the deeper basement faults reached cover strata, they fed slip to shallow thrust systems that were transported in piggyback fashion by newly formed basement structures, producing complex structural relationships. Detrital zircon U-Pb ages for the 5-7 km-thick basin fill succession reveal shifts in sedimentation pathways and accumulation rates consistent with (1) local basement sources during Early-Middle Jurassic back-arc extension, (2) variable cratonic and magmatic arc sources during Late Jurassic-Cretaceous postrift thermal subsidence, and (3) Andean arc and thrust-belt sources during irregular Late Cretaceous-Cenozoic shortening. Although pulses of flexural subsidence can be attributed to periods of fault reactivation (inversion) and geometrically linked thin-skinned thrusting, fully developed foreland basin conditions were only achieved in Late Cretaceous and Neogene time. Separating these two contractional episodes is an Eocene-lower Miocene (roughly 40-20 Ma) depositional hiatus within the Cenozoic succession, potentially signifying forebulge passage or neutral to

  11. Fast and Accurate Non-destructive Testing System for Inspection of Canning Tubes

    DEFF Research Database (Denmark)

    Gundtoft, Hans Erik; Nielsen, E.

    1973-01-01

    The authors describe the development of an inspection bench for the non-destructive examination of canning tubes. The bench is original in that the internal diameter is calculated from exact measurement of the outer diameter and the wall thickness. The transducers for inspection and control...... are rotated around the tube. Thus all measurements are made externally to the tube. The result of these inovations is that non-destructive examination can be made in a single pass of the tube, and the assessment is more accurate, economical, and faster than that possible with existing techniques....

  12. Gas genetic type and origin of hydrogen sulfide in the Zhongba gas field of the western Sichuan Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Guangyou; Zhang Shuichang [Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083 (China)] [State Key Laboratory for Enhanced Oil Recovery, Beijing 100083 (China); Huang Haiping, E-mail: huah@ucalgary.ca [School of Energy Resource, China University of Geosciences, Beijing 100083 (China)] [Department of Geosciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4 (Canada); Liang Yingbo; Meng, Shucui [Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083 (China); Li Yuegang [Northwest Sichuan Gas Field, PetroChina Southwest Oil and Gas Field Company, Jiangyou, 621101 Sichuan (China)

    2011-07-15

    Highlights: > Natural gases discovered from the Zhongba gas field have two genetic types. > TSR is the main origin of H{sub 2}S. > Supportive evidences of TSR are derived from gas carbon isotopic values, sulfur isotopic values and formation water compositions. > Incomplete TSR reaction ceased in the Late Cretaceous. - Abstract: Natural gases and associated condensate oils from the Zhongba gas field in the western Sichuan Basin, China were investigated for gas genetic types and origin of H{sub 2}S by integrating gaseous and light hydrocarbon geochemistry, formation water compositions, S isotopes ({delta}{sup 34}S) and geological data. There are two types of natural gas accumulations in the studied area. Gases from the third member of the Middle Triassic Leikoupo Formation (T{sub 2}l{sup 3}) are reservoired in a marine carbonate sequence and are characterized by high gas dryness, high H{sub 2}S and CO{sub 2} contents, slightly heavy C isotopic values of CH{sub 4} and widely variable C isotopic values of wet gases. They are highly mature thermogenic gases mainly derived from the Permian type II kerogens mixed with a small proportion of the Triassic coal-type gases. Gases from the second member of the Upper Triassic Xujiahe Formation (T{sub 3}x{sup 2}) are reservoired in continental sandstones and characterized by low gas dryness, free of H{sub 2}S, slightly light C isotopic values of CH{sub 4}, and heavy and less variable C isotopic values of wet gases. They are coal-type gases derived from coal in the Triassic Xujiahe Formation. The H{sub 2}S from the Leikoupo Formation is most likely formed by thermochemical SO{sub 4} reduction (TSR) even though other possibilities cannot be fully ruled out. The proposed TSR origin of H{sub 2}S is supported by geochemical compositions and geological interpretations. The reservoir in the Leikoupo Formation is dolomite dominated carbonate that contains gypsum and anhydrite. Petroleum compounds dissolved in water react with aqueous SO

  13. Eco-environmental problems and effective utilization of water resources in the Kashi Plain, western Terim Basin, China

    Science.gov (United States)

    Lin, Nian-Feng; Tang, Jie; Han, Feng-Xiang

    2001-02-01

    Since ancient times, water resources, mainly from melting snow in the high mountains, have nourished a large area of an oasis in the Kashi Plain in the western Terim Basin, China. In the last half-century, however, the rapid growth of population and the overexploitation of water, soil, and biological resources have led to drought, salinization, and desertification in the area, and consequently have hindered the development of sustainable agriculture. In this study, groundwater reservoirs with sustainable water supplies equivalent to 44.65×108 m3/year were identified, which has made it possible to implement several projects in the area to improve the ecological and agricultural environment. Three strategies are proposed for the integrated development and management of both surface-water and groundwater resources in the area. Résumé. Depuis des temps anciens, les ressources en eaux, provenant surtout de la fonte des neiges en montagne, ont alimenté une large part d'une oasis de la plaine de Kashi, dans le bassin occidental de Terim (Chine). Au cours des derniers cinquante ans, toutefois, l'accroissement rapide de la population et la surexploitation de l'eau, des sols et des ressources biologiques ont provoqué la sécheresse, la salinisation et la désertification de la région cela a eu pour conséquence d'entraver le développement d'une agriculture durable. Cette étude identifie les réserves en eau souterraine, susceptibles de fournir durablement 44,65×108 m3/an, ce qui a permis de réaliser plusieurs projets dans cette région pour améliorer l'environnement écologique et agricole. Trois stratégies sont proposées pour le développement intégré et la gestion simultanée des ressources en eau de surface et en eau souterraine de cette région. Resumen. Los recursos hídricos, procedentes fundamentalmente del deshielo en alta montaña, han nutrido desde tiempo inmemorial una gran área de un oasis situado en las llanuras de Kashi, en la cuenca occidental

  14. Lithosphere-Asthenosphere boundary from a petrological perspective: Results form the Basin and Range, Western USA (Invited)

    Science.gov (United States)

    Gazel, E.; Plank, T.; Rau, C. J.; Forsyth, D. W.

    2010-12-01

    The lithosphere is the strong lid at the surface of the earth that defines the different tectonic plates and consists of the crust and rigid uppermost-mantle that moves on top of the viscous asthenospheric mantle. Magmas carry in their chemical codes the conditions of their mantle origin, and can be powerful tools for constraining the location of the LAB. Isotopic and trace element data are the traditional means by which magmas are ascribed to sub-continental lithospheric vs. asthenospheric sources, despite the fact that these tools provide no information on the depths or temperatures of melting. The causes of mantle melting and widespread mafic volcanism across the Basin and Range (B&R), Western USA, over the past 10 Ma is still debated. Lithospheric extension, mantle hydration, and local convective upwellings are different possible mechanisms. Constraining mantle temperature, compositional structure, and the relationship to the continental lithosphere are key to understanding the conditions of melt generation. Quantitative information is now becoming available due to improved mantle-melt thermobarometers, and our new data on the water content and oxidation state (fO2) of magmas in the B&R. Our work focuses on modeled primary magmas calibrated with data from undegassed melt inclusions trapped in olivine from young cinders. Preliminary work reveals large variations in melting conditions across the region, from cool (< 1300°C) and shallow (40-50 km) melting beneath in the west volcanic fields (e.g., Big Pine, CA) to higher temperatures (~1450°C) and deeper melting (80-100km) in the east volcanic fields (e.g., Hurricane, UT). These melting pressures are interpreted as the final melting pressures and coincide with a boundary at the top of the low velocity region in recent surface wave models using EarthScope data. Recent work on Big Pine lavas suggests that the depth of melting relates to the trace element composition of the magmas (e.g., Ce/Pb). Deeper melts have

  15. Lignite deposits of the Kutch Basin, western India: Carbon isotopic and palynological signatures of the early Eocene hyperthermal event ETM2

    Science.gov (United States)

    Agrawal, Shailesh; Verma, Poonam; Rao, M. R.; Garg, Rahul; Kapur, Vivesh V.; Bajpai, Sunil

    2017-09-01

    This study presents new results of combined palynological and stable carbon isotope (δ13C) investigations carried out in the well known lignite sequence at Panandhro, District Kutch, in the Gujarat state of western India. Dinoflagellate cysts and associated spore-pollen assemblage assign an early Eocene (Ypresian) age to the lignitic succession at Panandhro. Furthermore, a pronounced negative Carbon Isotope Excursion (CIE) of about 2.7‰, correlated to the Second Eocene Thermal Maximum (53.7 Ma), a globally recognized hyperthermal event, was discovered in the middle part of the succession, consistent with the palynological constraints. This is the first record of an Eocene hyperthermal event (ETM2) from the Kutch Basin. Our data has regional implications for the age of the lignitic sequences across western India as it demonstrates that there is no significant age difference between the lignite deposits of the Kutch and Cambay basins. Our results also support a Lutetian age for the previously described vertebrate fossils, including whales, from the Panandhro mine section.

  16. Potential field studies of the central San Luis Basin and San Juan Mountains, Colorado and New Mexico, and southern and western Afghanistan

    Science.gov (United States)

    Drenth, Benjamin John

    This dissertation includes three separate chapters, each demonstrating the interpretive utility of potential field (gravity and magnetic) geophysical datasets at various scales and in various geologic environments. The locations of these studies are the central San Luis Basin of Colorado and New Mexico, the San Juan Mountains of southwestern Colorado, and southern and western Afghanistan. The San Luis Basin is the northernmost of the major basins that make up the Rio Grande rift, and interpretation of gravity and aeromagnetic data reveals patterns of rifting, rift-sediment thicknesses, distribution of pre-rift volcanic and sedimentary rocks, and distribution of syn-rift volcanic rocks. Syn-rift Santa Fe Group sediments have a maximum thickness of ˜2 km in the Sanchez graben near the eastern margin of the basin along the central Sangre de Cristo fault zone. Under the Costilla Plains, thickness of these sediments is estimated to reach ˜1.3 km. The Santa Fe Group sediments also reach a thickness of nearly 1 km within the Monte Vista graben near the western basin margin along the San Juan Mountains. A narrow, north-south-trending structural high beneath San Pedro Mesa separates the graben from the structural depression beneath the Costilla Plains. Aeromagnetic anomalies are interpreted to mainly reflect variations of remanent magnetic polarity and burial depth of the 5.3-3.7 Ma Servilleta basalt of the Taos Plateau volcanic field. Magnetic-source depth estimates indicate patterns of subsidence following eruption of the basalt and show that the Sanchez graben has been the site of maximum subsidence. One of the largest and most pronounced gravity lows in North America lies over the rugged San Juan Mountains in southwestern Colorado. A buried, low-density silicic batholith related to an Oligocene volcanic field coincident with the San Juan Mountains has been the accepted interpretation of the source of the gravity low since the 1970s. However, this interpretation was

  17. Sensitivity of digital elevation models:The scenario from two tropical mountain river basins of the Western Ghats, India

    Institute of Scientific and Technical Information of China (English)

    Jobin Thomas; Sabu Joseph; K.P. Thrivikramji; K.S. Arunkumar

    2014-01-01

    The paper evaluates sensitivity of various spaceborne digital elevation models (DEMs), viz., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mapping Mission (SRTM) and Global Multi-resolution Terrain Elevation Data 2010 (GMTED), in comparison with the DEM (TOPO) derived from contour data of 20 m interval of Survey of India topographic sheets of 1:50,000 scale. Several topographic attributes, such as elevation (above mean sea level), relative relief, slope, aspect, curvature, slope-length and -steepness (LS) factor, terrain ruggedness index (TRI), topo-graphic wetness index (TWI), hypsometric integral (Ihyp) and drainage network attributes (stream number and stream length) of two tropical mountain river basins, viz., Muthirapuzha River Basin and Pambar River Basin are compared to evaluate the variations. Though the basins are comparable in extent, they differ in respect of terrain characteristics and climate. The results suggest that ASTER and SRTM provide equally reliable representation of topography portrayed by TOPO and the topographic attributes extracted from the spaceborne DEMs are in agreement with those derived from TOPO. Despite the coarser resolution, SRTM shows relatively higher vertical accuracy (RMSE ¼ 23 and 20 m respectively in MRB and PRB) compared to ASTER (RMSE ¼ 33 and 24 m) and GMTED (RMSE ¼ 59 and 48 m). Vertical accuracy of all the spaceborne DEMs is influenced by relief of the terrain as well as type of vegetation. Further, GMTED shows significant deviation for most of the attributes, indicating its inability for mountain-river-basin-scale studies.

  18. Continental pollution in the Western Mediterranean basin: large variability of the aerosol single scattering albedo and influence on the direct shortwave radiative effect

    Science.gov (United States)

    Di Biagio, Claudia; Formenti, Paola; Doppler, Lionel; Gaimoz, Cécile; Grand, Noel; Ancellet, Gerard; Attié, Jean-Luc; Bucci, Silvia; Dubuisson, Philippe; Fierli, Federico; Mallet, Marc; Ravetta, François

    2016-08-01

    Pollution aerosols strongly influence the composition of the Western Mediterranean basin, but at present little is known on their optical properties. We report in this study in situ observations of the single scattering albedo (ω) of pollution aerosol plumes measured over the Western Mediterranean basin during the TRAQA (TRansport and Air QuAlity) airborne campaign in summer 2012. Cases of pollution export from different source regions around the basin and at different altitudes between ˜ 160 and 3500 m above sea level were sampled during the flights. Data from this study show a large variability of ω, with values between 0.84-0.98 at 370 nm and 0.70-0.99 at 950 nm. The single scattering albedo generally decreases with the wavelength, with some exception associated to the mixing of pollution with sea spray or dust particles over the sea surface. The lowest values of ω (0.84-0.70 between 370 and 950 nm) are measured in correspondence of a fresh plume possibly linked to ship emissions over the basin. The range of variability of ω observed in this study seems to be independent of the source region around the basin, as well as of the altitude and aging time of the plumes. The observed variability of ω reflects in a large variability for the complex refractive index of pollution aerosols, which is estimated to span in the large range 1.41-1.77 and 0.002-0.097 for the real and the imaginary parts, respectively, between 370 and 950 nm. Radiative calculations in clear-sky conditions were performed with the GAME radiative transfer model to test the sensitivity of the aerosol shortwave Direct Radiative Effect (DRE) to the variability of ω as observed in this study. Results from the calculations suggest up to a 50 and 30 % change of the forcing efficiency (FE), i.e. the DRE per unit of optical depth, at the surface (-160/-235 W m-2 τ-1 at 60° solar zenith angle) and at the Top-Of-Atmosphere (-137/-92 W m-2 τ-1) for ω varying between its maximum and minimum value

  19. Water-quality assessment of the upper Snake River basin, Idaho and western Wyoming; environmental setting, 1980-92

    Science.gov (United States)

    Maupin, Molly A.

    1995-01-01

    The 35,800-square-mile upper Snake River Basin is one of 20 areas studied as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. Objectives of NAWQA are to study ground- and surface-water quality, biology, and their relations to land-use activities. Major land and water uses that affect water quality in the basin are irrigated agriculture, grazing, aquaculture, food processing, and wastewater treatment. Data summarized in this report are used in companion reports to help define the relations among land use, water use, water quality, and biological conditions.

  20. From hyper-extended rifts to orogens: the example of the Mauléon rift basin in the Western Pyrenees (SW France)

    Science.gov (United States)

    Masini, E.; Manatschal, G.; Tugend, J.

    2011-12-01

    An integral part of plate tectonic theory is that the fate of rifted margins is to be accreted into mountain belts. Thus, rift-related inheritance is an essential parameter controlling the evolution and architecture of collisional orogens. Although this link is well accepted, rift inheritance is often ignored. The Pyrenees, located along the Iberian and European plate boundary, can be considered as one of the best places to study the reactivation of former rift structures. In this orogen the Late Cretaceous and Tertiary convergence overprints a Late Jurassic to Lower Cretaceous complex intracontinental rift system related to the opening of the North Atlantic. During the rifting, several strongly subsiding basins developed in the axis of the Pyrenees showing evidence of extreme crustal extension and even locale mantle exhumation to the seafloor. Although the exact age and kinematics of rifting is still debated, these structures have an important impact in the subsequent orogenic overprint. In our presentation we discuss the example of the Mauléon basin, which escaped from the most pervasive deformations because of its specific location at the interface between the western termination of the chain and the Bay of Biscay oceanic realm. Detailed mapping combined with seismic reflection, gravity data and industry wells enabled to determine the 3D rift architecture of the Mauléon basin. Two major diachronous detachment systems can be mapped and followed through space. The Southern Mauléon Detachment (SMD) develops first, starts to thin the crust and floors the Southern Mauléon sub-Basin (SMB). The second, the Northern Mauléon Detachment (SMD) is younger and controls the final crustal thinning and mantle exhumation to the north. Both constitute the whole Mauléon basin. Like at the scale of the overall Pyrenees, the reactivation of the Mauléon Basin increases progressively from west to east, which enables to document the progressive reactivation of an aborted hyper

  1. Cenozoic foreland basin evolution during Andean shortening in the Malargüe region of western Argentina (35°S)

    Science.gov (United States)

    Ramirez, S. G.; Horton, B. K.; Fuentes, F.

    2015-12-01

    Cenozoic clastic deposits in western Argentina provide key opportunities to evaluate the timing and duration of Andean deformation and uplift. We studied the Malargüe segment of the Andean foreland basin at 35°S to better understand latest Cretaceous to Pliocene deformation and eastward propagation of Andean retroarc shortening. Our multi-technique approach included logging of a well-exposed ~1500m Paleocene-Miocene stratigraphic succession, paleocurrent measurements, conglomerate clast counts, and detrital zircon U-Pb geochronological analyses of basin fill exposed in the Sosneado region along the Rio Atuel. The Pircala and Coihueco Formations define the lowermost ~180 m of the section and are represented by fine to medium sandstones, siltstones, claystones and marls interpreted as distal fluvial floodplain and localized lacustrine deposits. Pircala paleocurrents show a major reversal from west- to east-directed flow. These finer deposits of the lower succession are separated from the overlying coarser-grained ~800 m thick Agua de la Piedra Formation by a conspicuous unconformity that spans up to roughly 20 Myr. The Agua de la Piedra Formation is composed of upward-coarsening amalgamated beds of massive medium to coarse sandstones and lenticular conglomerates interpreted as a prograding proximal fluvial to alluvial fan system. Conglomerate clast counts show initial dominance by Mesozoic detritus from the pre-Andean Neuquen basin system, with a progressive upsection increase in Cenozoic volcanic detritus from the Andean magmatic arc. Collectively, the paleocurrents, clast compositions, sedimentary facies associations, and emerging U-Pb results suggest a long-term shift, commencing in the Paleocene, from eastern cratonic sources to magmatic-arc and thrust-belt sources during a systematic eastward propagation of deformation, with a pronounced phase of Miocene magmatism and shortening that incorporated the proximal foreland basin into the advancing thrust belt.

  2. Strath terraces on the western High Plains indicate climatically-driven variations in sediment supply from source basins in the Colorado Front Range

    Science.gov (United States)

    Foster, M. A.; Dühnforth, M.; Anderson, R. S.

    2013-12-01

    Large strath terraces adjacent to the Colorado Front Range record the local history of fluvial planation and incision into the erodible rocks of the Denver basin over the last 2 million years. Terrace surfaces have been correlated into ~6 alluvial units using elevation and soil development; each alluvial unit was thought to represent a fairly consistent elevation of the Denver basin during various stages of exhumation, driven by base-level fall of the South Platte River. Here we show instead that (1) strath terraces in the western High Plains cannot be correlated based on elevation alone and (2) exhumation of the Denver basin is likely spatially and temporally variable due to climatically-driven variations in sediment supply from the source basins. We collected samples for cosmogenic radionuclide (CRN) profiles (10Be and 26Al) and a soil chronosequence from three strath terraces adjacent to Lefthand Creek near Boulder, CO. 10Be profile data on the upper- and middle-elevation terraces yield dates of 95 ka and 91 ka; these dates are much younger than the correlative alluvial units to the south of Boulder, which date to 1.5 Ma and 250 ka, respectively. Soils on the upper and middle terraces are similar in soil development and clast weathering, consistent with the narrow time window obtained from CRN dating of the two units. 10Be-derived rates for catchment-wide paleo-denudation are ~8.0 cm/ka from the flat and broad upper-terrace gravels and ~3.5 cm/ka from the steeper and narrower middle-terrace gravels. Young terraces at Lefthand Canyon are more consistent with a model of fluvial incision and aggradation driven by climate-controlled variations in sediment production from source basins in the Front Range. High catchment-wide denudation rates generate a high sediment supply, leading to aggradation and lateral planation. Terrace sediments are likely deposited and eroded multiple times during periods of lateral planation; the most recent occupation is preserved in the

  3. The Environmental Context of Gastropods on Western Laurentia (Basin and Range Province) during the Great Ordovician Biodiversification Event

    Science.gov (United States)

    Dahl, Robyn Mieko

    2015-01-01

    Gastropods are a major component of modern marine ecosystems and can be found in nearly every type of marine ecosystem. They experienced their first notable radiation during the Great Ordovician Biodiversification Event (~470 Ma), during which their diversity tripled. This study examines the gastropod assemblage preserved in the Basin and Range…

  4. Chemical and Microbiology Characteristic of Smoked and Seasoned African Catfish Fillet Affected by Canning Processing

    Directory of Open Access Journals (Sweden)

    Yusuf Kalingga Murda

    2016-08-01

    Full Text Available African catfish (Clarias gariepinus many cultivated by the farmers, however if not treated quicklydamaged. One treatment that can maintain quality product african catfish is by smoked and canning. Theaim of this study was to determine the chemical and microbiological characteristics of smoked Africancatfish fillet with seasoning packaged cans during storage. Preparation of research carried out by soakingthe African catfish fillet into seasonings and liquid smoke concentration of 10% by immersion for 1minute, and then next process of curing and drying. Products that are ripe weighed 110 g and signedinto cans sized Ø 301x205. Added medium brine concentration 5% and vegetable oil as much as 100ml, a process exhausting and seaming. The last stage is performed a sterilization process (126oC for 20minutes, cooling and incubation (24oC for 2 weeks. Observations deterioration of product quality ofsmoked African catfish fillet with seasoning performed at weeks 0, 2, 4, 6 and 8. Tests conducted includechemical test which includes test TVB, pH and peroxide value and microbiological testing in the formof TPC. The results showed that the combined treatment of the fumigation and the addition of medium(saline 5% and solution of vegetable oil combined with treatment canning able to maintain productquality of smoked African catfish fillet with seasoning, based TVB, pH, peroxide value and TPC duringstorage.

  5. Miocene and early Pliocene epithermal gold-silver deposits in the northern Great Basin, western United States: Characteristics, distribution, and relationship to Magmatism

    Science.gov (United States)

    John, D.A.

    2001-01-01

    Numerous important Miocene and early Pliocene epithermal Au-Ag deposits are present in the northern Great Basin. Most deposits are spatially and temporally related to two magmatic assemblages: bimodal basalt-rhyolite and western andesite. These magmatic assemblages are petrogenetic suites that reflect variations in tectonic environment of magma generation. The bimodal assemblage is a K-rich tholeiitic series formed during continental rifting. Rocks in the bimodal assemblage consist mostly of basalt to andesite and rhyolite compositions that generally contain anhydrous and reduced mineral assemblages (e.g., quartz + fayalite rhyolites). Eruptive forms include mafic lava flows, dikes, cinder and/or spatter cones, shield volcanoes, silicic flows, domes, and ash-flow calderas. Fe-Ti oxide barometry indicates oxygen fugacities between the magnetite-wustite and fayalite-magnetite-quartz oxygen buffers for this magmatic assemblage. The western andesite assemblage is a high K calc-alkaline series that formed a continental-margin are related to subduction of oceanic crust beneath the western coast of North America. In the northern Great Basin, most of the western andesite assemblage was erupted in the Walker Lane belt, a zone of transtension and strike-slip faulting. The western andesite assemblage consists of stratovolcanoes, dome fields, and subvolcanic plutons, mostly of andesite and dacite composition. Biotite and hornblende phenocrysts are abundant in these rocks. Oxygen fugacities of the western andesite assemblage magmas were between the nickel-nickel oxide and hematite-magnetite buffers, about two to four orders of magnitude greater than magmas of the bimodal assemblage. Numerous low-sulfidation Au-Ag deposits in the bimodal assemblage include deposits in the Midas (Ken Snyder), Sleeper, DeLamar, Mule Canyon, Buckhorn, National, Hog Ranch, Ivanhoe, and Jarbidge districts; high-sulfidation gold and porphyry copper-gold deposits are absent. Both high- and low

  6. Adjustment of the basin-scale circulation at 26° N to variations in Gulf Stream, deep western boundary current and Ekman transports as observed by the Rapid array

    Directory of Open Access Journals (Sweden)

    S. A. Cunningham

    2009-04-01

    Full Text Available The Rapid instrument array across the Atlantic Ocean along 26° N provides unprecedented monitoring of the basin-scale circulation. A unique feature of the Rapid array is the combination of full-depth moorings with instruments measuring temperature, salinity, pressure time series at many depths with co-located bottom pressure measurements so that dynamic pressure can be measured from surface to bottom. Bottom pressure measurements show a zonally uniform rise (and fall of bottom pressure of 0.015 dbar on a 5 to 10 day time scale, suggesting that the Atlantic basin is filling and draining on a short time scale. After removing the zonally uniform bottom pressure fluctuations, bottom pressure variations at 4000 m depth against the western boundary compensate instantaneously for baroclinic fluctuations in the strength and structure of the deep western boundary current so there is no basin-scale mass imbalance resulting from variations in the deep western boundary current. After removing the mass compensating bottom pressure, residual bottom pressure fluctuations at the western boundary just east of the Bahamas balance variations in Gulf Stream transport. Again the compensation appears to be especially confined close to the western boundary. Thus, fluctuations in either Gulf Stream or deep western boundary current transports are compensated in a depth independent (barotropic manner very close to the continental slope off the Bahamas. In contrast, compensation for variations in wind-driven surface Ekman transport appears to involve fluctuations in both western basin and eastern basin bottom pressures, though the bottom pressure difference fluctuations appear to be a factor of 3 too large, perhaps due to an inability to resolve small bottom pressure fluctuations after removal of larger zonal average, baroclinic, and Gulf Stream pressure components. For 4 tall moorings where time series dynamic height (geostrophic pressure profiles can be estimated from

  7. Role of structural inheritances and major transfer fault-zones in the tectonic history of the Alboran Basin (Western Mediterranean)

    Science.gov (United States)

    Comas, Menchu; Crespo-Blanc, Ana; Balanya, Juan Carlos

    2014-05-01

    The geodynamic evolution of the Gibraltar Arc System (GAS), which involves the origin and development of the Alboran back-arc basin, occurred during the Neogene related to the westward moving of the Alboran Domain (the Betic-Rifean hinterland) within a context of NNW-SSE plate-tectonic convergence. In this contribution we document shallow-crustal structures, deformation partitioning, and the different structural domains from the tectonic framework beneath the Alboran Sea. Furthermore, we focus the critical role of inherited crustal structures and major transfer faults within a coherent sequence of Miocene to Recent deformation phases. Early Miocene extensional processes conditioned substantial thinning and the exhumation of the metamorphic Alboran Domain before the opening of the Alboran Basin. Beneath the Alboran Sea, an ENE-SSW directed back-arc extension (from about 16 to 8.5 Ma, late Burdigalian to late Tortonian) affected both the metamorphic basement (the crustal Alboran Domain) and the overlying Miocene sedimentary units. This extension resulted in major low-angle normal faults, and NNW-SSE trending grabens connected by ENE-SSW transtensional transfer-faults, both happening in concomitance with the westward migration (around 200 km) of the Alboran Domain. The geometry of the extensional structures constrains the manner, timing and amount of the coeval crustal thinning. In the late Tortonian (about 8.5 Ma) a dominant N-S directed compressional phase caused inversions of former extensional faults, discrete folding, and strike-slip faulting. This compressional event triggered the spectacular West Alboran shale-diapirism from over-pressured basal units. At the South and Eastern Alboran and at the transition to the Algeria basins, a pervasive period of NW-SE directed compressional deformation (from about 7 Ma onwards) that affected the whole basin is patent. Long lasting compressional conditions since the late Tortonian resulted in a dramatic structural

  8. The Pasadena Aerosol Characterization Observatory (PACO: chemical and physical analysis of the Western Los Angeles Basin aerosol

    Directory of Open Access Journals (Sweden)

    S. P. Hersey

    2011-02-01

    Full Text Available The Pasadena Aerosol Characterization Observatory (PACO represents the first major aerosol characterization experiment centered in the Western/Central Los Angeles Basin. The sampling site, located on the campus of the California Institute of Technology in Pasadena, was positioned to sample a continuous afternoon influx of transported urban aerosol with a photochemical age of 1–2 h and generally free from major local contributions. Sampling spanned 5 months during the summer of 2009, which were broken into 3 regimes on the basis of distinct meteorological conditions. Regime I was characterized by a series of low pressure systems, resulting in high humidity and rainy periods with clean conditions. Regime II typified early summer meteorology, with significant morning marine layers and warm, sunny afternoons. Regime III was characterized by hot, dry conditions with little marine layer influence.

    Organic aerosol (OA is the most significant constituent of Los Angeles aerosol (42, 43, and 55% of total submicron mass in regimes I, II, and III, respectively, and that the overall oxidation state remains relatively constant on timescales of days to weeks (O:C = 0.44 ± 0.08, 0.55 ± 0.05, and 0.48 ± 0.08 during regimes I, II, and III, respectively, with no difference in O:C between morning and afternoon periods. Periods characterized by significant morning marine layer influence followed by photochemically favorable afternoons displayed significantly higher aerosol mass and O:C ratio, suggesting that aqueous processes may be important in the generation of secondary aerosol and oxidized organic aerosol (OOA in Los Angeles.

    Water soluble organic mass (WSOM reaches maxima near 14:00–15:00 local time (LT, but the percentage of AMS organic mass contributed by WSOM remains relatively constant throughout the day. Sulfate and nitrate reside predominantly in accumulation mode aerosol, while afternoon SOA production coincides with the

  9. The Pasadena Aerosol Characterization Observatory (PACO): chemical and physical analysis of the Western Los Angeles basin aerosol

    Science.gov (United States)

    Hersey, S. P.; Craven, J. S.; Schilling, K. A.; Metcalf, A. R.; Sorooshian, A.; Chan, M. N.; Flagan, R. C.; Seinfeld, J. H.

    2011-08-01

    The Pasadena Aerosol Characterization Observatory (PACO) represents the first major aerosol characterization experiment centered in the Western/Central Los Angeles Basin. The sampling site, located on the campus of the California Institute of Technology in Pasadena, was positioned to sample a continuous afternoon influx of transported urban aerosol with a photochemical age of 1-2 h and generally free from major local contributions. Sampling spanned 5 months during the summer of 2009, which were broken into 3 regimes on the basis of distinct meteorological conditions. Regime I was characterized by a series of low pressure systems, resulting in high humidity and rainy periods with clean conditions. Regime II typified early summer meteorology, with significant morning marine layers and warm, sunny afternoons. Regime III was characterized by hot, dry conditions with little marine layer influence. Regardless of regime, organic aerosol (OA) is the most significant constituent of nonrefractory submicron Los Angeles aerosol (42, 43, and 55 % of total submicron mass in regimes I, II, and III, respectively). The overall oxidation state remains relatively constant on timescales of days to weeks (O:C = 0.44 ± 0.08, 0.55 ± 0.05, and 0.48 ± 0.08 during regimes I, II, and III, respectively), with no difference in O:C between morning and afternoon periods. Periods characterized by significant morning marine layer influence followed by photochemically favorable afternoons displayed significantly higher aerosol mass and O:C ratio, suggesting that aqueous processes may be important in the generation of secondary aerosol and oxidized organic aerosol (OOA) in Los Angeles. Online analysis of water soluble organic carbon (WSOC) indicates that water soluble organic mass (WSOM) reaches maxima near 14:00-15:00 local time (LT), but the percentage of AMS organic mass contributed by WSOM remains relatively constant throughout the day. Sulfate and nitrate reside predominantly in accumulation

  10. The Pasadena Aerosol Characterization Observatory (PACO: chemical and physical analysis of the Western Los Angeles basin aerosol

    Directory of Open Access Journals (Sweden)

    S. P. Hersey

    2011-08-01

    Full Text Available The Pasadena Aerosol Characterization Observatory (PACO represents the first major aerosol characterization experiment centered in the Western/Central Los Angeles Basin. The sampling site, located on the campus of the California Institute of Technology in Pasadena, was positioned to sample a continuous afternoon influx of transported urban aerosol with a photochemical age of 1–2 h and generally free from major local contributions. Sampling spanned 5 months during the summer of 2009, which were broken into 3 regimes on the basis of distinct meteorological conditions. Regime I was characterized by a series of low pressure systems, resulting in high humidity and rainy periods with clean conditions. Regime II typified early summer meteorology, with significant morning marine layers and warm, sunny afternoons. Regime III was characterized by hot, dry conditions with little marine layer influence. Regardless of regime, organic aerosol (OA is the most significant constituent of nonrefractory submicron Los Angeles aerosol (42, 43, and 55 % of total submicron mass in regimes I, II, and III, respectively. The overall oxidation state remains relatively constant on timescales of days to weeks (O:C = 0.44 ± 0.08, 0.55 ± 0.05, and 0.48 ± 0.08 during regimes I, II, and III, respectively, with no difference in O:C between morning and afternoon periods. Periods characterized by significant morning marine layer influence followed by photochemically favorable afternoons displayed significantly higher aerosol mass and O:C ratio, suggesting that aqueous processes may be important in the generation of secondary aerosol and oxidized organic aerosol (OOA in Los Angeles. Online analysis of water soluble organic carbon (WSOC indicates that water soluble organic mass (WSOM reaches maxima near 14:00–15:00 local time (LT, but the percentage of AMS organic mass contributed by WSOM remains relatively constant throughout the day. Sulfate and nitrate reside predominantly

  11. Correlation of basinal carbonate cycles to nearshore parasequences in the late Cretaceous Greenhorn seaway, Western Interior USA

    Science.gov (United States)

    Elder, W.P.; Gustason, E.R.; Sageman, B.B.

    1994-01-01

    In the central basin in Colorado and Kansas, these sedimentary cycles are represented by limestone-shale and marlstone-shale couplets ~0.5-1.0m in thickness. More calcareous parts of these couplets may be correlated westward into condensed, fossiliferous concretion and shell beds in proximal offshore lithofacies of Arizona and Utah. These concretion and shell beds are physically traceable farther landward (westward) into bioturbated, fossil-rich, transgressive lag deposits that bound 10-20m thick coarsening-upward progradational strand-plain deposits (parasequences) in southwestern Utah. We consider Milankovitch-style orbital forcing of climate and tectonically induced fluctuations in rates of foredeep basin subsidence as possible forcing mechanisms for these basinwide events. -from Authors

  12. Setting the baseline before geothermal exploration begins: the search of microseismic activity in the Geneva Basin, Western Switzerland

    Science.gov (United States)

    Antunes, Verónica; Lupi, Matteo; Carrier, Aurore; Planès, Thomas; Martin, François

    2017-04-01

    Switzerland is moving towards the development of renewable energies. Following this trend, SIG (Services Industriels de Genève) and the Canton of Geneva is investing in the exploration of geothermal energy. Before the exploration takes place it is crucial to understand the rate of seismic activity in the region and its relationship with the existing faults. Historical and instrumental times suggest the presence of active faults in the region but to date little is known about the seismic activity in the Geneva Basin. Tectonic maps show the presence of major faults crossing the basin and recent seismic events indicate that such systems are still active on a regional scale. However, available data indicate infrequent and dispersed activity. This can be partially due to the small number of permanent stations in the area. To understand where micro-seismic activity may be located around and within the Geneva Basin we have deployed a temporary network composed of 20 broadband stations. With the densification of the network it could be possible to capture and localise small magnitude seismic events (i.e. M less than 1). Here we present the preliminary results obtained during the first months of the temporary network deployment.

  13. Peat swamps at Giral lignite field of Barmer basin, Rajasthan,Western India: understanding the evolution through petrological modelling

    Institute of Scientific and Technical Information of China (English)

    Prakash K.Singh; P.K.Rajak; M.P.Singh; V.K.Singh; A.S.Naik; Alok K.Singh

    2016-01-01

    The lignite samples collected from Giral lignite field of Barmer basin have been subjected to petrological investigation.The data generated has been discussed to understand the evolution of the paleomires of these lignites.The present study reveals that these low rank C coals are chiefly composed of huminite group macerals,mainly telohuminite and detrohuminite,while liptinite and inertinite group macerals occur in subordinate amounts.Not much variation in the maceral composition from Seam-I to Seam-Ⅷ has been observed.Barmer lignites are characterized by a very high GI (>10) and moderate TPI indicating topogenous mire in the basin which was permanently flooded.The GI and TPI values and the petrography-based facies critical models indicate that these lignites originated mostly under wet forest swamp to clastic marsh having telmatic to limno-telmatic conditions with a moderate rate of subsidence and a very slow fall in ground water table.Further,the GWI and VI values are suggestive of mesotrophic to rheotrophic hydrological conditions having the dominance of herbaceous to marginal aquatic vegetation.There were spells of periodic drowning of peat especially during the formation of Seam-Ⅶ.Moderately high concentration of calcium in these lignites along with the presence of framboidal pyrite indicate enhanced sulphate-reducing bacterial activity present in carbonate and sulphate-rich waters in the basin during peat formation.

  14. Holocene late Pleistocene non-tropical carbonate sediments and tectonic history of the western rift basin margin of the southern Gulf of California

    Science.gov (United States)

    Halfar, Jochen; Godinez-Orta, Lucio; Goodfriend, Glenn A.; Mucciarone, David A.; Ingle, James C.; Holden, Peter

    2001-10-01

    Using high-resolution seismic reflection profiling and dating of (1) shallow marine vibracores and (2) sediments collected from uplifted marine terraces we reconstruct the tectonic history and sediment accumulation patterns of Holocene to late Pleistocene warm-temperate to subtropical carbonates in the southern Gulf of California, Mexico. The study was conducted in the vicinity of La Paz where carbonates form along the fault bounded narrow western shelf of the tectonically active Gulf of California rift basin. The non-tropical nature of the setting is responsible for (1) poor cementation of the bioclastic carbonates, and (2) a composition which is dominated by rhodoliths (coralline red algae), corals and mollusks. Unrimmed carbonate flats forming in small pocket bays and a rhodolith bioherm, which has a surface area of more than 20 km 2 and is up to 16 m thick, constitute the major carbonate factories. Holocene carbonate accumulation rates were deduced from seismic and core data and are highest on the rhodolith bioherm (260 cm/ka) and in subtidal zones of pocket bays (210 cm/ka), and lowest on the inner and middle shelf (100 cm/ka). Taken together, rates of carbonate accumulation are intermediate in magnitude between higher rates recorded in fully tropical carbonate settings and lower rates typical of cool-water carbonates. Seismic reflection profiles demonstrate that Isla Espiritu Santo in the center of the study area is a west dipping fault block, which is tectonically influenced by two distinct faults, the La Paz and Espiritu Santo faults. The latter fault accommodates at least 700 m of east-side down normal offset, and forms a steep eastern escarpment leading into the La Paz slope basin. Some of the sediments produced in the shallow carbonate factories of the narrow La Paz shelf are transported across this escarpment and are redeposited in the slope basin at a water depth of 750 m. Uranium-series dates of marine terraces exposed on Isla Espiritu Santo indicate

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

    Science.gov (United States)

    Li, Di; He, Dengfa; Tang, Yong

    2016-05-01

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

  16. Thermal-rheological structure of lithosphere beneath the northern flank of Tarim Basin, western China:Implications for geodynamics

    Institute of Scientific and Technical Information of China (English)

    LIU; Shaowen; WANG; Liangshu; LI; Cheng; LI; Hua; HAN; Yong

    2004-01-01

    Based on the data of geo-temperature and thermophysical parameters of rocks in the Kuqa Depression and the Tabei Uplift, northern flank of the Tarim Basin, in terms of the analytical solution of 1-D heat transfer equation, the thermal structure of the lithosphere under this region is determined. Our results show that the average surface heat flow of the northern flank of the Tarim Basin is 45 mW/m2, and the mantle heat flow is between 20 and 23 mW/m2; the temperature at crust-mantle boundary (Moho) ranges from 514℃ to 603℃ and the thermal lithosphere where the heat conduction dominates is 138-182 km thick. Furthermore, in combination with the P wave velocity structure resulting from the deep seismic sounding profile across this region and rheological modeling, we have studied the local composition of the lithosphere and its rheological profile, as well as the strength distribution. We find that the rheological stratification of the lithosphere in this region is apparent. The lowermost of the lower crust is ductile; however,the uppermost of the mantle and the upper and middle parts of the crust are both brittle layers,which is typically the so-called sandwich-like structure. Lithospheric strength is also characterized by the lateral variation, and the uplift region is stronger than the depression region. The lithospheric strength of the northem flank of the Tarim Basin decreases gradually from south to north; the Kuqa Depression has the lowest strength and the south of the Tabei Uplift is strongest.The total lithospheric strength of this region is 4.77× 1012-5.03 × 1013 N/m under extension, and 6.5 × 1012-9.4× 1013 N/m under compression. The lithospheric brittle-ductile transition depth is between 20 km and 33 km. In conclusion, the lithosphere of the northern flank of the Tarim Basin is relatively cold with higher strength, so it behaves rigidly and deforms as a whole, which is also supported by the seismic activity in this region. This rigidity of the

  17. The role of active and ancient geothermal processes in the generation, migration, and entrapment of oil in the basin and Range Province, western USA. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Hulen, J.B.; Collister, J.W.; Curtiss, D.K. [and others

    1997-06-01

    The Basin and Range (B&R) physiographic province of the western USA is famous not only for its geothermal and precious-metal wealth, but also for its thirteen oil fields, small but in some cases highly productive. The Grant Canyon field in Railroad Valley, for example, for years boasted production of more than 6000 barrels of oil (BO) per day from just two wells; aggregate current production from the Blackburn field in Pine Valley commonly exceeds 1000 BO per day. These two and several other Nevada oil fields are unusually hot at reservoir depth--up to 130{degrees}C at depths as shallow as 1.1 km, up to three times the value expected from the prevailing regional geothermal gradient.

  18. The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya.

    Science.gov (United States)

    Cook, Elizabeth Anne Jessie; Grossi-Soyster, Elysse Noel; de Glanville, William Anson; Thomas, Lian Francesca; Kariuki, Samuel; Bronsvoort, Barend Mark de Clare; Wamae, Claire Njeri; LaBeaud, Angelle Desiree; Fèvre, Eric Maurice

    2017-07-01

    Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5-1.3). The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1-1.4, pKenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further evidence for RVFV circulation in western Kenya.

  19. Integrating geologic and satellite radar data for mapping dome-and-basin patterns in the In Ouzzal Terrane, Western Hoggar, Algeria

    Science.gov (United States)

    Deroin, Jean-Paul; Djemai, Safouane; Bendaoud, Abderrahmane; Brahmi, Boualem; Ouzegane, Khadidja; Kienast, Jean-Robert

    2014-11-01

    The In Ouzzal Terrane (IOT) located in the north-western part of the Tuareg Shield forms an elongated N-S trending block, more than 400 km long and 80 km wide. It involves an Archaean crust remobilized during a very high-temperature metamorphic event related to the Palaeoproterozoic orogeny. The IOT largely crops out in the rocky and sandy desert of Western Hoggar. It corresponds mainly to a flat area with some reliefs composed of Late Panafrican granites, dyke networks or Cambrian volcanic rocks. These flat areas are generally covered by thin sand veneers. They are favorable for discriminating bedrock geological units using imaging radar, backscattering measurements, and field checking, because the stony desert is particularly sensitive to the radar parameters such as wavelength or polarization. The main radar data used are those obtained with the ALOS-PALSAR sensor (L-band), in ScanSAR mode (large swath) and Fine Beam modes. The PALSAR sensor has been also compared to ENVISAT-ASAR and to optical imagery. Detailed mapping of some key areas indicates extensive Archaean dome-and-basin patterns. In certain parts, the supracrustal synforms and orthogneiss domes exhibit linear or circular features corresponding to shear zones or rolling structures, respectively. The geological mapping of these dome-and-basin structures, and more generally of the Archaean and Proterozoic lithological units, is more accurate with the SAR imagery, particularly when using the L-band, than with the optical imagery. A quantitative approach is carried out in order to estimate the backscatter properties of the main rock types. Due to the large variety of configurations, radar satellite imagery such as ALOS PALSAR represents a key tool for geological mapping in arid region at different scales from the largest (e.g., 1:500,000) to the smallest (e.g., 1:50,000).

  20. Paleoclimatic implications of magnetic susceptibility in Late Pliocene-Quaternary sediments from deep drilling core SG-1 in the western Qaidam Basin (NE Tibetan Plateau)

    Science.gov (United States)

    Zhang, Weilin; Appel, Erwin; Fang, Xiaomin; Yan, Maodu; Song, Chunhui; Cao, Liwan

    2012-06-01

    Lake sediments are important archives of paleoclimate change and erosion history. A 938.5 m long core (SG-1) of lacustrine sediments, dated at 2.77 Ma to 0.1 Ma, was obtained from the western Qaidam Basin in the northeastern Tibetan Plateau, consisting of dark grayish mudstone and grayish siltstone, intercalated with salts and fine sandstones in the upper part. Magnetic susceptibility data, combined with detailed rock magnetic properties, were analyzed for revealing the significance of ferro(i)magnetic concentration for past changes of climate and erosion. Mass-specific susceptibility (χ) shows a striking cyclic and long-term variation. Samples with high χ values are dominated by magnetite and maghemite with pseudo-single-domain properties. In contrast, samples with low χ values contain maghemite from single-domain to multidomain and, additionally, a significant fraction of hematite. The driving mechanism of χ variation can be explained by three alternative models: (1) different source regions with alternations of wind and cryoclastic erosion in a wider hinterland (dry-cold climate) and surface runoff erosion from a narrower area (more humid climate) and (2 and 3) low-temperature oxidation, occurring either in the lake sediments (dry climate) or in the catchment area during weathering (more humid climate). Trends of χ match with changes in sedimention rates and are roughly synchronous with the deep-sea δ18O record on a glacial-interglacial timescale. Therefore, the concentration of magnetic minerals in the western Qaidam Basin sediments is likely controlled by both tectonic influence and paleoenvironmental changes but can be best interpreted by alternations and trends of dry-cold and more humid periods due to Asian drying and global cooling.

  1. Isotopic composition of gypsum hydration water in deep Core SG-1, western Qaidam basin (NE Tibetan Plateau), implications for paleoclimatic evolution

    Science.gov (United States)

    Li, Jiao; Li, Minghui; Fang, Xiaomin; Zhang, Gengxin; Zhang, Weilin; Liu, Xiaoming

    2017-08-01

    The oxygen and hydrogen isotopic compositions of gypsum hydration water can be useful for determining the isotopic composition of the original brine from which gypsum precipitated. However, relatively few long-term and continuous records of the stable isotope geochemistry of gypsum hydration water in arid regions have been reported. We measured the δ18O and δD of primary gypsum hydration water from a 938.5 m-long deep core (SG-1) in the western Qaidam Basin to study the mechanisms that contributed to gypsum formation and to reconstruct potential paleoclimatic change. The measured δ18O and δD ranged from - 4.21‰ to 8.69‰ and from - 72.77‰ to 49.73‰, respectively. The linear relationship between δ18O and δD indicates that meteoric water was the original source of the gypsum hydration water. The gradient of 5.39 for the δ18O and δD plots is lower than that of global meteoric water, suggesting that paleo-lakewater evaporated and became a CaSO4-rich brine leading to gypsum deposition. The evaporation/precipitation (E/P) ratio played an important role in determining δ18O and δD. The oscillations noted in the δ18O and δD of the gypsum hydration water imply that: (a) there was a long-term and stepwise aridification after 2.2 Ma in the western Qaidam Basin; and (b) there were three increasingly dry phases at 2.2-1.2 Ma, 1.2-0.6 Ma, and 0.6-0.1 Ma, with two cold and dry events at 1 Ma and 0.6 Ma. Global cooling, especially during the Mid Pleistocene Climate Transition event (MPT), may have been the primary cause of the aridification recorded in core SG-1 in the Asian inland.

  2. Optimization of a chemical method for skinning of sardines (Sardina pilchardus during canning processing

    Directory of Open Access Journals (Sweden)

    Manuela Vaz Velho

    2014-06-01

    Full Text Available Most of sardine (Sardina pilchardus catches is used for canning purposes. The most common product presentation is a beheaded sardine with skin and bones packed in a tin can. Canned sardines can also be presented skinless and boneless. For this last type of product, after beheading and evisceration, sardines are placed in trays, cooked and then skinned by hand, one by one, and placed in the tins, a process involving high labour costs. The aim of this work was to develop a chemical process for peeling raw sardines and its subsequent application in a canning industry processing line just after the beheading and evisceration step and before cooking. Potassium hydroxide treatments (pellets a.r. 85% KOH were applied at concentrations of 2, 3 and 4% (v/v, distilled water. Frozen sardines were beheaded and eviscerated after thawing and immersed in the different potassium hydroxide solutions at 93ºC (pH respectively 13, 13 and 13.02 for 3 min and further washed with distilled water at 100°C. In this first set of experiments, fat sardines were used (average of 9.86% of fat, w/w. The best performance, with respect to skin removal, was achieved with the 2% potassium hydroxide immersion (pH 13. With this treatment the skin was totally removed after immersion. With the other tested concentrations portions of skin were always visible and in some cases changes in texture with breakdown of muscle structure and changes of colour occurred. It was decided to perform a second set of experiments using the 2% KOH treatment, but this time applied to low fat sardines (average of 4.77% of fat, w/w, following the same subsequent procedures. The results showed that the lower fat sardines are more prone to surface changes of colour and major muscle breaks than fat sardines after the potassium hydroxide treatment. In the canning industry for this type of product (skinless and boneless only fat sardines are used to assure the total removal of skin. This treatment of 2% KOH

  3. THE KULTUK VOLCANO: SPATIAL-TEMPORAL CHANGE OF MAGMATIC SOURCES AT THE WESTERN TERMINUS OF THE SOUTH BAIKAL BASIN BETWEEN 18 AND 12 MA

    Directory of Open Access Journals (Sweden)

    S. V. Rasskazov

    2015-09-01

    Full Text Available The Kultuk volcano erupted at the axial South Baikal basin of the Baikal rift zone (BRZ. Now it exhibits facies of subvolcanic bodies, land-lava eruptions and subaqueous pillow lavas and hyaloclastites. The volcano was controlled by the Obruchev fault that is currently a border of the basin which amplitude of vertical movements is rapidly decreasing in the westward direction. It is found that the Kultuk volcano was active at the beginning and end of the volcanic activity period of the Kamar, Stanovaya, and Bystrinskaya volcanic zones, which took place 18–12 Ma ago. In previous papers, it was assumed that dominant structures in the area under study were major Cenozoic shear displacements along the Main Sayan fault and/or along the Tunka rift valley; however, at the current stage of our study, linear configurations of the volcanic zones do not reveal any of such displacements. Based on analyses of distribution of volcanic rocks in the relief at the western coast of Lake Baikal, distinct vertical crustal movements are revealed; such movements started in the Early Miocene and continue to the present time. It is concluded  that volcanism was controlled by the trans-tensional system of volcanic zones. Sources are identified for the shallow lithospheric mantle melt with the substantial admixture of the low-crust component and deeper asthenospheric mantle melts in the Kamar and Stanovaya volcanic zones; for the Bystrinskaya volcanic zone, only components from the deeper source are revealed. The local shallow mantle magmatism occurred only within the lithosphere extension zone beneath the South Baikal basin. The lithosphere thinning is reflected in the change of activity from the sub-lithospheric to lithospheric sources under the Kamar zone. Rifting of the axial structure is recorded at the root of the Slyudyanka lithospheric block that was subjected to the collision-related Early Paleozoic metamorphism. Geochemical characteristics of the collision

  4. The sequence of moderate-size earthquakes at the junction of the Ligurian basin and the Corsica margin (western Mediterranean): The initiation of an active deformation zone revealed?

    Science.gov (United States)

    Larroque, Christophe; Delouis, Bertrand; Sage, Françoise; Régnier, Marc; Béthoux, Nicole; Courboulex, Françoise; Deschamps, Anne

    2016-04-01

    A new seismically active zone is found in the southern part of the Ligurian basin, 80-km west of Corsica (western Mediterranean). The activity began in February 2011 with a foreshock (ML 4) and a mainshock (ML 5.3) 5 days later, followed by numerous aftershocks. We first analyze the fore- and mainshock in detail. We compare the results obtained using classical methods (linear location in a 1D medium and focal mechanisms from P and S polarities) and new approaches (non-linear location in a 3D medium and waveform modeling for determining the seismic moment and the focal mechanism). Both methods provided similar results for location, depth (in the range of 6-13 km) and focal mechanisms, which reveal reverse faulting with nodal planes oriented N-S and NE-SW. We then locate 27 of the aftershocks in the 3D model and find a 10-km-long NE-SW alignment with a depth between 7 and 16 km. In 2012 and 2013, three other moderate-size events (ML 3.8, 4 and 4.5) occurred and confirm that this zone is still active. The epicentral area is located in the oceanic domain of the Ligurian Basin. From analysis of the bathymetry and high-resolution multi-channel seismic profiles, no morphologic anomaly at surface and no inherited fault in the shallow ~ 4 km depth were imaged, which suggest that no significant deformation occurred in the area since 5 Ma. Thus, the structure(s) activated during the 2011-2013 sequence remain unknown. In light of these results, we point out a notable difference on both sides of the Ligurian Basin: the northern margin, close to the alpine chain, suffered strong earthquakes and large cumulated deformation since 5 Ma, while the southern margin, close to the Corsica-Sardinia continental block, is poorly deformed since 5 Ma.

  5. Development, evolution, and destruction of the saline mineral area of Eocene Lake Uinta, Piceance Basin, western Colorado

    Science.gov (United States)

    Johnson, Ronald C.; Brownfield, Michael E.

    2015-01-01

    Halite and the sodium bicarbonate mineral nahcolite were deposited in Eocene-age saline Lake Uinta in the Piceance Basin, northwestern Colorado. Variations in the areal extent of saline mineral deposition through time were studied using descriptions of core and outcrop. Saline minerals have been extensively leached by groundwater, and the original extent of saline deposition was determined from the distribution of empty vugs and collapse breccias. Because vugs and breccias strongly influence groundwater movement, determining where leaching has occurred is an important consideration for in-situ oil shale extraction methods currently being developed.

  6. Integrated Geologic and Geophysical Approach for Establishing Geothermal Play Fairways and Discovering Blind Geothermal Systems in the Great Basin Region, Western USA: A Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Faulds, James E.; Hinz, Nicholas H.; Coolbaugh, Mark F.; Shevenell, Lisa A.; Siler, Drew L.; dePolo, Craig M.; Hammond, William C.; Kreemer, Corne; Oppliger, G.; Wannamaker, P.; Queen, John H.; Visser, Charles

    2015-09-02

    We have undertaken an integrated geologic, geochemical, and geophysical study of a broad 240-km-wide, 400-km-long transect stretching from west-central to eastern Nevada in the Great Basin region of the western USA. The main goal of this study is to produce a comprehensive geothermal potential map that incorporates up to 11 parameters and identifies geothermal play fairways that represent potential blind or hidden geothermal systems. Our new geothermal potential map incorporates: 1) heat flow; 2) geochemistry from springs and wells; 3) structural setting; 4) recency of faulting; 5) slip rates on Quaternary faults; 6) regional strain rate; 7) slip and dilation tendency on Quaternary faults; 8) seismologic data; 9) gravity data; 10) magnetotelluric data (where available); and 11) seismic reflection data (primarily from the Carson Sink and Steptoe basins). The transect is respectively anchored on its western and eastern ends by regional 3D modeling of the Carson Sink and Steptoe basins, which will provide more detailed geothermal potential maps of these two promising areas. To date, geological, geochemical, and geophysical data sets have been assembled into an ArcGIS platform and combined into a preliminary predictive geothermal play fairway model using various statistical techniques. The fairway model consists of the following components, each of which are represented in grid-cell format in ArcGIS and combined using specified weights and mathematical operators: 1) structural component of permeability; 2) regional-scale component of permeability; 3) combined permeability, and 4) heat source model. The preliminary model demonstrates that the multiple data sets can be successfully combined into a comprehensive favorability map. An initial evaluation using known geothermal systems as benchmarks to test interpretations indicates that the preliminary modeling has done a good job assigning relative ranks of geothermal potential. However, a major challenge is defining

  7. Gone with the plate: the opening of the Western Mediterranean basin drove the diversification of ground-dweller spiders

    OpenAIRE

    Bidegaray-Batista Leticia; Arnedo Miquel A

    2011-01-01

    Abstract Background The major islands of the Western Mediterranean--Corsica, Sardinia, and the Balearic Islands--are continental terrenes that drifted towards their present day location following a retreat from their original position on the eastern Iberian Peninsula about 30 million years ago. Several studies have taken advantage of this well-dated geological scenario to calibrate molecular rates in species for which distributions seemed to match this tectonic event. Nevertheless, the use of...

  8. Climate variability and extreme drought in the upper Solimoes River (western Amazon Basin) : Understanding the exceptional 2010 drought

    OpenAIRE

    J. C. Espinoza; Ronchail, J.; Guyot, Jean-Loup; Junquas, C.; Vauchel, Philippe; Lavado, W.; Drapeau, G; Pombosa, R.

    2011-01-01

    This work provides an initial overview of climate features and their related hydrological impacts during the recent extreme droughts (1995, 1998, 2005 and 2010) in the upper Solimoes River (western Amazon), using comprehensive in situ discharge and rainfall datasets. The droughts are generally associated with positive SST anomalies in the tropical North Atlantic and weak trade winds and water vapor transport toward the upper Solimoes, which, in association with increased subsidence over centr...

  9. Morphometric characterization of sub-basins in the municipality of Xapuri: subsidies to land management in the Western Amazon

    Directory of Open Access Journals (Sweden)

    Éllen Albuquerque Abud

    2015-04-01

    Full Text Available This work morphometrically characterized watersheds that occur in the municipality of Xapuri and constructed a model that explains the extent of watershed impact and resilience. Emphasis was given to provide a decision-making tool for non-specialists. The study area is located in the State of Acre and has four sub-basins: Alto Acre, Rio Xapuri, Xipamanu and Riozinho do Rola. A cartographic survey was conducted, to include the morphometric characteristics of the area and land use and cover features that resulted in the soil-hydrographic zoning of the municipality. Sub-basins Xapuri, Xipamanu and Riozinho do Rôla revealed drainage densities and orders that indicate low drainage efficiency, while Alto Acre presented high drainage orders (ninth order and densities, contrary the geometric indices and drainage densities, and is considered to have efficient drainage. Considerable alterations in permanent preservation areas occur in the municipality of Xapuri, with conversion to less resilient areas highly sensitive to impacts. The soil-hydrographic zoning assists in visualizing the municipality in a land management context through an ecosystem approach and a qualitative view of the possibilities and weaknesses.

  10. Basin-scale estimates of pelagic and coral reef calcification in the Red Sea and Western Indian Ocean.

    Science.gov (United States)

    Steiner, Zvi; Erez, Jonathan; Shemesh, Aldo; Yam, Ruth; Katz, Amitai; Lazar, Boaz

    2014-11-18

    Basin-scale calcification rates are highly important in assessments of the global oceanic carbon cycle. Traditionally, such estimates were based on rates of sedimentation measured with sediment traps or in deep sea cores. Here we estimated CaCO3 precipitation rates in the surface water of the Red Sea from total alkalinity depletion along their axial flow using the water flux in the straits of Bab el Mandeb. The relative contribution of coral reefs and open sea plankton were calculated by fitting a Rayleigh distillation model to the increase in the strontium to calcium ratio. We estimate the net amount of CaCO3 precipitated in the Red Sea to be 7.3 ± 0.4·10(10) kg·y(-1) of which 80 ± 5% is by pelagic calcareous plankton and 20 ± 5% is by the flourishing coastal coral reefs. This estimate for pelagic calcification rate is up to 40% higher than published sedimentary CaCO3 accumulation rates for the region. The calcification rate of the Gulf of Aden was estimated by the Rayleigh model to be ∼1/2 of the Red Sea, and in the northwestern Indian Ocean, it was smaller than our detection limit. The results of this study suggest that variations of major ions on a basin scale may potentially help in assessing long-term effects of ocean acidification on carbonate deposition by marine organisms.

  11. Diatreme-forming volcanism in a deep-water faulted basin margin: Lower Cretaceous outcrops from the Basque-Cantabrian Basin, western Pyrenees

    Science.gov (United States)

    Agirrezabala, L. M.; Sarrionandia, F.; Carracedo-Sánchez, M.

    2017-05-01

    Deep-water diatremes and related eruption products are rare and they have been mainly interpreted from seismic-based data. We present lithofacies and geochemistry analysis of two Lower Cretaceous (Albian) deep-water diatremes and associated extra-diatreme volcaniclastic deposits at a well-exposed outcrop of the northern margin of the Basque-Cantabrian Basin (north Iberia). The studied diatremes are located along a N-S trending Albian fault and present sub-circular to elongate sections, inward-dipping steep walls and smooth to very irregular contacts with the host rocks. They are filled by un-bedded mixed breccias constituted by juvenile and lithic (sedimentary, igneous and metamorphic) clasts. Their textural and structural characteristics indicate that they represent lower diatreme and root zones of the volcanic system. Mapping, geochemical and petrologic data from diatreme-fills support their genetic relationship with the extra-diatreme volcaniclastic beds, which would be generated by the eruption of an incipiently vesicular trachytic magma. Studied diatremes result from multiple explosions that lasted over an estimated period of 65 k.y. during the Late Albian (H. varicosum ammonite Zone, pro parte), and reached up to a maximum subsurface depth of ca. 370 m, whereas extra-diatreme volcaniclastic beds were formed by eruption-fed gravity-driven flows on the deep-water (200-500 m) paleoseabed. Petrological features suggest that these diatremes and related extra-diatreme deposits resulted mainly from phreatomagmatic explosions. In addition, organic geochemistry data indicate that the thermal effect of the trachytic melts on the sedimentary host caused the conversion of the abundant organic matter to methane and CO2 gases, which could also contribute significantly to the overpressure necessary for the explosive fragmentation of the magma and the host rocks. Considering the inferred confining pressures (ca. 8-11 MPa) and the possible participation of unvesiculated (or

  12. Active tectonics of the western tethyan himalaya above the underthrusting indian plate: The upper sutlej river basin as a pull-apart structure

    Science.gov (United States)

    Ni, James; Barazangi, Muawia

    1985-03-01

    Fault-bounded blocks and structural elements were mapped in the eastern Ladakh-Spiti and upper Sutlej River Basin located within the Tethyan Himalaya and to the southwest of the Karakorum fault zone mainly using LANDSAT Multispectral Scanner (MSS) band 5, band 7 (near-infrared) images with detailed analysis of smaller areas by interactive digital processing of false color images, and Returned Beam Vidicon (RBV) imagery in conjunction with available topographical, geological and seismological data. For the first time the Leo Pargil Horst and other nearby fault-bounded blocks located at the northwestern end of the upper Setlej River Basin were clearly revealed on the LANDSAT color composites. Shallow crustal seismicity is systematically related to the NNE-trending and N-trending normal faults of the Leo Pargil and nearby regions. Some of the aftershocks of the Kinnaur earthquake of January 19,1975 ( Ms = 6.8), appear to be associated with movement along the NNE-trending westbound fault of the Leo Pargil Horst and the nearby Kaurik-Chango fault. The main shock, however, is teleseismically located at about 30 km to the northwest of the Kaurik-Chango fault. Fault plane solutions of the main shock and two aftershocks indicate a large component of normal faulting. In map view, the upper Sutlej River Basin has an approximately rhomboidal shape and is located to the southwest of the Karakorum fault system. We suggest that this basin is a pull-apart between the NW-SE oriented, right-lateral, strike-slip Karakorum fault system and the high-angle faults near the southern boundary of the Tethyan Himalaya. The Leo Pargil Horst is the northwestern bounding fault block of this pull-apart. The active tectonic features in this part of the Tethyan Himalaya appear to reflect right-shear within the crust, and this is probably a consequence of oblique underthrusting of the Indian continental plate beneath the western Himalaya and southwestern Tibet during the Neogene and Quaternary

  13. Socio-hydrologic perspectives of the co-evolution of humans and water in the Tarim River Basin, Western China: the Taiji–Tire Model

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2013-10-01

    Full Text Available This paper presents a historical socio-hydrological analysis of the Tarim Basin, Xinjiang Province, Western China, from the time of the opening of the Silk Road to the present. The analysis is aimed at exploring the historical co-evolution of coupled human–water systems and at identifying common patterns or organizing principles underpinning socio-hydrological systems (SHS. As a self-organized entity, the evolution of the human–water system in the Tarim Basin reached stable states for long periods of time, then punctuated by sudden shifts due to internal or external disturbances. In this study, we discuss three steady periods (i.e. natural, human exploitation, and degradation and recovery and transitions in between during the past 2000 yr. During the "natural" stage that existed pre-18th century, with small-scale human society and sound environment, evolution of the SHS was mainly driven by natural environmental changes such as river channel migration and climate change. During the human exploitation stage, especially in the 19th and 20th centuries, it experienced rapid population growth, massive land reclamation and fast socio-economic development, and humans became the principal players of system evolution. By the 1970s, the Tarim Basin had evolved into a new regime with a vulnerable eco-hydrological system seemingly populated beyond its carrying capacity, and a human society that began to suffer from serious water shortages, land salinization and desertification. With intensified deterioration of river health and increased recognition of unsustainability of traditional development pattern, human intervention and recovery measures have been adopted. Since then, the basin has shown a reverse regime shift towards some healing of the environmental damage. Spatio-temporal variations of historical socio-hydrological co-evolution are classified into four types: primitive agricultural, traditional agricultural, industrial agricultural and urban

  14. Groundwater Dynamics under Water Saving Irrigation and Implications for Sustainable Water Management in an Oasis: Tarim River Basin of Western China

    Science.gov (United States)

    Zhang, Z.; Hu, H.; Tian, F.; Yao, X.; Sivapalan, M.

    2014-02-01

    Water is essential for life. Specifically in the oases of inland arid basins, water is a critically limited resource, essential for the development of socio-economy and sustainability of eco-environmental systems. Due to the unique hydrological regime present in arid oases, a moderate groundwater table is the goal of sustainable water management. A shallow water table induces serious secondary salinization and collapse of agriculture, while a deep water table causes deterioration of natural vegetation. From the hydrological perspective, the exchange flux between unsaturated vadose zone and groundwater reservoir is a critical link to understand regional water table dynamics. This flux is substantially influenced by anthropogenic activities. In Tarim River Basin of western China, where agriculture consumes over 90% of available water resources, the exchange flux is influenced strongly by irrigation. Recently, mulched drip irrigation, a very advanced water-saving irrigation method, has been widely applied in the Tarim River Basin, which greatly impacted the exchange flux and thus the regional groundwater dynamics. Capitalizing on recent progress in evaporation measurement techniques, we can now close the water balance and directly quantify the exchange flux at the field scale, thus gain a better understanding of regional groundwater dynamics. In this study, comprehensive observations of water balance components in an irrigated cropland were implemented in 2011 and 2012 in a typical oasis within Tarim River Basin. The water balance analysis showed that the exchange flux and groundwater dynamics were significantly altered by the application of water-saving irrigation. The exchange flux is mostly downward (310.5 mm yr-1), especially during drip irrigation period and spring flush period, while the upward flux is trivial (-16.1 mm yr-1) due to the moderate groundwater table depth (annual average depth 2.9 m). Traditional secondary salinization caused by intense phreatic

  15. Groundwater dynamics under water-saving irrigation and implications for sustainable water management in an oasis: Tarim River basin of western China

    Science.gov (United States)

    Zhang, Z.; Hu, H.; Tian, F.; Yao, X.; Sivapalan, M.

    2014-10-01

    Water is essential for life. Specifically in the oases of inland arid basins, water is a critically limited resource, essential for the development of the socio-economy and the sustainability of eco-environmental systems. Due to the unique hydrological regime present in arid oases, a moderate groundwater table is the goal of sustainable water management. A shallow water table induces serious secondary salinization and collapse of agriculture, while a deep water table causes deterioration of natural vegetation. From the hydrological perspective, the exchange flux between the unsaturated vadose zone and groundwater reservoir is a critical link to understanding regional water table dynamics. This flux is substantially influenced by anthropogenic activities. In the Tarim River basin of western China, where agriculture consumes over 90% of available water resources, the exchange flux between the unsaturated vadose zone and groundwater reservoir is influenced strongly by irrigation. Recently, mulched drip irrigation, a sophisticated water-saving irrigation method, was widely applied in the Tarim River basin, which greatly impacted the exchange flux and thus the regional groundwater dynamics. Capitalizing on recent progress in evaporation measurement techniques, we can now close the water balance and directly quantify the exchange flux at the field scale, thus gaining a better understanding of regional groundwater dynamics. In this study, comprehensive observations of water balance components in an irrigated cropland were implemented in 2012 and 2013 in a typical oasis within the Tarim River basin. The water balance analysis showed that the exchange flux and groundwater dynamics were significantly altered by the application of water-saving irrigation. The exchange flux at the groundwater table is mostly downward (310.5 mm year-1), especially during drip irrigation period and spring flush period, while the upward flux is trivial (16.1 mm year-1) due to the moderate

  16. Socio-hydrologic perspectives of the co-evolution of humans and water in the Tarim River basin, Western China: the Taiji-Tire model

    Science.gov (United States)

    Liu, Y.; Tian, F.; Hu, H.; Sivapalan, M.

    2014-04-01

    This paper presents a historical socio-hydrological analysis of the Tarim River basin (TRB), Xinjiang Uyghur Autonomous Region, in Western China, from the time of the opening of the Silk Road to the present. The analysis is aimed at exploring the historical co-evolution of coupled human-water systems and at identifying common patterns or organizing principles underpinning socio-hydrological systems (SHS). As a self-organized entity, the evolution of the human-water system in the Tarim Basin reached stable states for long periods of time, but then was punctuated by sudden shifts due to internal or external disturbances. In this study, we discuss three stable periods (i.e., natural, human exploitation, and degradation and recovery) and the transitions in between during the past 2000 years. During the "natural" stage that existed pre-18th century, with small-scale human society and sound environment, evolution of the SHS was mainly driven by natural environmental changes such as river channel migration and climate change. During the human exploitation stage, especially in the 19th and 20th centuries, it experienced rapid population growth, massive land reclamation and fast socio-economic development, and humans became the principal players of system evolution. By the 1970s, the Tarim Basin had evolved into a new regime with a vulnerable eco-hydrological system seemingly populated beyond its carrying capacity, and a human society that began to suffer from serious water shortages, land salinization and desertification. With intensified deterioration of river health and increased recognition of unsustainability of traditional development patterns, human intervention and recovery measures have since been adopted. As a result, the basin has shown a reverse regime shift towards some healing of the environmental damage. Based on our analysis within TRB and a common theory of social development, four general types of SHSs are defined according to their characteristic spatio

  17. Trends in total phosphorus and total nitrogen concentrations of tributaries to the Swan - Canning Estuary, 1987 to 1998

    Science.gov (United States)

    Donohue, R.; Davidson, W.A.; Peters, N.E.; Nelson, S.; Jakowyna, B.

    2001-01-01

    Temporal wet-season trends from 1987 to 1998 of total N and total P concentrations (TN and TP, respectively) in 14 tributaries to the Swan-Canning Estuary in Western Australia were evaluated using the Mann-Kendall or Seasonal kendall tests. Six of the catchments drained clay soils primarily on the Darling Plateau, which borders the sandy coastal plain on the east; two rural catchments drained the coastal plain; and six urban catchments drained the coastal plain. Generally, TN and TP were lower in tributaries draining clay soils than in tributaries draining siliceous sandy soils. Annual median TN and TP were relatively constant and no trends were detected in tributaries draining clay soils. TN and TP were higher (median TN = 1.6 and TP = 0.1 mg 1-1) and more variable temporally in tributaries draining the coastal plain. Statistically significant (?? < 0.01) TN trends were detected in 50% of the urban coastal plain tributaries and most were decreasing (-0.07 to +0.53 mg 1-1 year-1). Decreasing TP trends were detected at the two rural coastal plain tributaries and two of the urban drains (-0.01 to 0.15 mg 1-1 year-1 over periods from 5 to 12 years). Flow adjustment of TN and TP was responsible for removing trends in the raw data at some sites. The inter-annual variability of TN and TP of coastal plain tributaries was also related to the proximity of the water table to the land surface, which in turn was related to the annual precipitation. Fixed-interval sampling may be able to detect TN and TP changes associated with the implementation of management strategies in sandy coastal plain catchments. Tributary sampling during rainstorms and continuous monitoring of discharge are needed to better define processes controlling nutrient flux and concentration variability, and to detect trends in the urban catchments and the clay soil catchments, primarily those draining the Darling Plateau. Copyright ?? 2001 John Wiley and Sons, Ltd.

  18. Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls

    Science.gov (United States)

    Guo, Huaming; Jia, Yongfeng; Wanty, Richard B.; Jiang, Yuxiao; Zhao, Weiguang; Xiu, Wei; Shen, Jiaxing; Li, Yuan; Cao, Yongsheng; Wu, Yang; Zhang, Di; Wei, Chao; Zhang, Yilong; Cao, Wengeng; Foster, Andrea L.

    2016-01-01

    Although As concentrations have been investigated in shallow groundwater from the Hetao basin, China, less is known about U and As distributions in deep groundwater, which would help to better understand their origins and fate controls. Two hundred and ninety-nine groundwater samples, 122 sediment samples, and 14 rock samples were taken from the northwest portion of the Hetao basin, and analyzed for geochemical parameters. Results showed contrasting distributions of groundwater U and As, with high U and low As concentrations in the alluvial fans along the basin margins, and low U and high As concentrations downgradient in the flat plain. The probable sources of both As and U in groundwater were ultimately traced to the bedrocks in the local mountains (the Langshan Mountains). Chemical weathering of U-bearing rocks (schist, phyllite, and carbonate veins) released and mobilized U as UO2(CO3)22 − and UO2(CO3)34 − species in the alluvial fans under oxic conditions and suboxic conditions where reductions of Mn and NO3− were favorable (OSO), resulting in high groundwater U concentrations. Conversely, the recent weathering of As-bearing rocks (schist, phyllite, and sulfides) led to the formation of As-bearing Fe(III) (hydr)oxides in sediments, resulting in low groundwater As concentrations. Arsenic mobilization and U immobilization occurred in suboxic conditions where reduction of Fe(III) oxides was favorable and reducing conditions (SOR). Reduction of As-bearing Fe(III) (hydr)oxides, which were formed during palaeo-weathering and transported and deposited as Quaternary aquifer sediments, was believed to release As into groundwater. Reduction of U(VI) to U(IV) would lead to the formation of uraninite, and therefore remove U from groundwater. We conclude that the contrasting distributions of groundwater As and U present a challenge to ensuring safe drinking water in analogous areas, especially with high background values of U and As.

  19. Diamond drilling for geologic information in the middle Precambrian basins in the western portion of northern Michigan. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Trow, J.

    1979-10-01

    Between September 26, 1977, and May 11, 1978, six initially vertical holes probed a total of 9896 feet (1109 feet or 11.2% in overburden, 155 feet or 1.6% in Precambrian Y mafic dikes, 8386 feet or 84.7% in Precambrian X Goodrich Quartzite and Michigamme Formation, and 246 feet or 2.5% in Precambrian W basement lithologies). In addition to normal examination of core, logging, and storing of core, the holes were extensively logged geophysically, acidized core was tested for phosphate content by ammonium molybdate, splits from five out of every thirty feet of core were subjected to chemical scrutiny, thin sections of all lithologies were examined, and radiometric determinations of geologic age were made for confirmation of Precambrian W basement which was encountered in each of the three basins in Marquette County.

  20. Electrofacies in gas shale from well log data via cluster analysis: A case study of the Perth Basin, Western Australia

    Science.gov (United States)

    Torghabeh, Amir; Rezaee, Reza; Moussavi-Harami, Reza; Pradhan, Biswajeet; Kamali, Mohammad; Kadkhodaie-Ilkhchi, Ali

    2014-09-01

    Identifying reservoir electrofacies has an important role in determining hydrocarbon bearing intervals. In this study, electrofacies of the Kockatea Formation in the Perth Basin were determined via cluster analysis. In this method, distance data were initially calculated and then connected spatially by using a linkage function. The dendrogram function was used to extract the cluster tree for formations over the study area. Input logs were sonic log (DT), gamma ray log (GR), resistivity log (IND), and spontaneous potential (SP). A total of 30 reservoir electrofacies were identified within this formation. Integrated geochemical and petrophysics data showed that zones with electrofacies 3, 4, 9, and 10 have potential for shale gas production. In addition, the results showed that cluster analysis is a precise, rapid, and cost-effective method for zoning reservoirs and determining electrofacies in hydrocarbon reservoirs.

  1. Dust sources and atmospheric circulation in concert controlling Saharan dust emission and transport towards the Western Mediterranean Basin

    Science.gov (United States)

    Schepanski, Kerstin; Mallet, Marc; Heinold, Bernd; Ulrich, Max

    2017-04-01

    Dust transported from north African source regions towards Europe is a ubiquitous phenomenon in the Mediterranean region, a geographic region that is in part densely populated. Besides its impacts on the atmospheric radiation budget, dust suspended in the atmosphere results in reduced air quality, which is generally sensed as a reduction in quality of life. Furthermore, the exposure to dust aerosols enhances the prevalence of respiratory diseases, which reduces the general human wellbeing, and ultimately results in an increased loss of working hours due to illness and hospitalization rates. Characteristics of the atmospheric dust life cycle that determine dust transport will be presented with focus on the ChArMEx special observation period in June and July 2013 using the atmosphere-dust model COSMO-MUSCAT (COSMO: Consortium for Small-scale MOdeling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model). Modes of atmospheric circulation were identified from empirical orthogonal function (EOF) analysis of the geopotential height at 850 hPa for summer 2013 and compared to EOFs calculated from 1979-2015 ERA-Interim reanalysis. Generally, two different phases were identified. They are related to the eastward propagation of the subtropical ridge into the Mediterranean basin, the position of the Saharan heat low, and the predominant Iberian heat low. The relation of these centres of action illustrates a dipole pattern for enhanced (reduced) dust emission fluxes, stronger (weaker) meridional dust transport, and consequent increase (decrease) atmospheric dust concentrations and deposition fluxes. In concert, the results from this study aim at illustrating the relevance of knowing the dust source locations in concert with the atmospheric circulation. Ultimately, this study addresses the question of what is finally transported towards the Mediterranean basin and Europe from which source regions - and fostered by which atmospheric circulation pattern. Outcomes from this study

  2. Water Resources Status and Availability Assessment in Current and Future Climate Change Scenarios for Beas River Basin of North Western Himalaya

    Science.gov (United States)

    Aggarwal, S. P.; Thakur, P. K.; Garg, V.; Nikam, B. R.; Chouksey, A.; Dhote, P.; Bhattacharya, T.

    2016-10-01

    The water resources status and availability of any river basin is of primary importance for overall and sustainable development of any river basin. This study has been done in Beas river basin which is located in North Western Himalaya for assessing the status of water resources in present and future climate change scenarios. In this study hydrological modelling approach has been used for quantifying the water balance components of Beas river basin upto Pandoh. The variable infiltration capacity (VIC) model has been used in energy balance mode for Beas river basin at 1km grid scale. The VIC model has been run with snow elevation zones files to simulate the snow module of VIC. The model was run with National Centre for Environmental Prediction (NCEP) forcing data (Tmax, Tmin, Rainfall and wind speed at 0.5degree resolution) from 1 Jan. 1999 to 31 Dec 2006 for calibration purpose. The additional component of glacier melt was added into overall river runoff using semi-empirical approach utilizing air temperature and glacier type and extent data. The ground water component is computed from overall recharge of ground water by water balance approach. The overall water balance approach is validated with river discharge data provided by Bhakra Beas Management Board (BBMB) from 1994-2014. VIC routing module was used to assess pixel wise flow availability at daily, monthly and annual time scales. The mean monthly flow at Pandoh during study period varied from 19 - 1581 m3/s from VIC and 50 to 1556 m3/sec from observation data, with minimum water flow occurring in month of January and maximum flow in month of August with annual R2 of 0.68. The future climate change data is taken from CORDEX database. The climate model of NOAA-GFDL-ESM2M for IPCC RCP scenario 4.5 and 8.5 were used for South Asia at 0.44 deg. grid from year 2006 to 2100. The climate forcing data for VIC model was prepared using daily maximum and minimum near surface air temperature, daily precipitation and

  3. Adjustment of the basin-scale circulation at 26° N to variations in Gulf Stream, deep western boundary current and Ekman transports as observed by the Rapid array

    Directory of Open Access Journals (Sweden)

    S. A. Cunningham

    2009-10-01

    Full Text Available The Rapid instrument array across the Atlantic Ocean along 26° N provides unprecedented monitoring of the basin-scale circulation. A unique feature of the Rapid array is the combination of full-depth moorings with instruments measuring temperature, salinity, pressure time series at many depths with co-located bottom pressure measurements so that dynamic pressure can be measured from surface to bottom. Bottom pressure measurements show a zonally uniform rise (and fall of bottom pressure of 0.015 dbar on a 5 to 10 day time scale, suggesting that the Atlantic basin is filling and draining on a short time scale. After removing the zonally uniform bottom pressure fluctuations, bottom pressure variations at 4000 m depth against the western boundary compensate instantaneously for baroclinic fluctuations in the strength and structure of the deep western boundary current so there is no basin-scale mass imbalance resulting from variations in the deep western boundary current. After removing the mass compensating bottom pressure, residual bottom pressure fluctuations at the western boundary just east of the Bahamas balance variations in Gulf Stream transport. Again the compensation appears to be especially confined close to the western boundary. Thus, fluctuations in either Gulf Stream or deep western boundary current transports are compensated in a depth independent (barotropic manner very close to the continental slope off the Bahamas. In contrast, compensation for variations in wind-driven surface Ekman transport appears to involve fluctuations in both western basin and eastern basin bottom pressures, though the bottom pressure difference fluctuations appear to be a factor of 3 too large, perhaps due to an inability to resolve small bottom pressure fluctuations after removal of larger zonal average, baroclinic, and Gulf Stream pressure components. For 4 tall moorings where time series dynamic height (geostrophic pressure profiles can be estimated from

  4. Transport of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in late summer 2012

    Science.gov (United States)

    Kondo, Yoshiko; Obata, Hajime.; Hioki, Nanako; Ooki, Atsushi; Nishino, Shigeto; Kikuchi, Takashi; Kuma, Kenshi

    2016-10-01

    Distributions of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in September 2012 were investigated to elucidate the mechanisms behind the transport of these metals from the Chukchi Shelf to the Canada Basin. Filtered (melting sea-ice, influenced trace metal concentrations. The distribution patterns and concentration ranges were generally similar between the D and TD fractions for Ni, Zn and Cd, which indicate that Ni, Zn and Cd were present mainly in their dissolved forms, whereas the concentrations of TD-Fe and TD-Mn were generally higher than those of D-Fe and D-Mn, respectively. These results are consistent with the results of previous studies of this region. For both Fe and Mn, labile particulate (LP) concentrations (the difference between the TD and D fractions, which is acid-leachable fraction in the particles during storage at pH 1.5-1.6) were highest in the near-bottom waters of the Chukchi Shelf region. The relationships between the distance from the shelf break and the concentrations of trace metals revealed that Fe and Mn concentrations in halocline waters tended to decrease logarithmically with distance, whereas changes in the concentrations of Ni, Zn, Cd and phosphate with distance were small. These results suggest that the distributions of Fe and Mn were controlled mainly by input from shelf sediment and removal through scavenging processes. Based on the phase distributions of Fe and Mn, which were calculated as ratios between the LP and D fractions, different behaviors between Fe and Mn were expressed during lateral transportation. The concentration of TD-Fe declined rapidly via removal of LP-Fe from the water column, whereas the concentration of TD-Mn declined more slowly through the transformation of D-Mn into LP-Mn. In contrast, the concentrations of D-Cd, D-Zn and D-Ni were more strongly correlated with phosphate levels, which suggest that, like phosphate, the distributions of Cd, Zn and Ni were

  5. Lower Devonian paleomagnetic dating of a large mafic sill along the western border of the Murzuq cratonic basin (Saharan metacraton, SE Algeria).

    Science.gov (United States)

    El-M. Derder, Mohamed; Maouche, Said; Liégeois, Jean-Paul; Henry, Bernard; Amenna, Mohamed; Ouabadi, Aziouz; Bellon, Hervé; Bruguier, Olivier; Bayou, Boualem; Bestandji, Rafik; Nouar, Omar; Bouabdallah, Hamza; Ayache, Mohamed; Beddiaf, Mohamed

    2017-04-01

    The Murzuq basin located in central North Africa, in Algeria, Libya and Niger is a key area, delineating a relictual cratonic area within the Saharan metacraton (Liégeois et al., 2013). On its western border, we discovered a very large sill ("Arrikine" sill), with a thickness up to 250m and a minimum length of 35 km. It is made of mafic rocks and is interbedded within the Silurian sediments of the Tassilis series. In the vicinity, the only known post-Pan-African magmatism is the Cenozoic volcanism in the In Ezzane area. Further south in Niger, also along the SW border of the Murzuq basin, large Paleozoic dolerite (Carte géologique du Sahara central, 1962) are probably related to the "Arrikine" sill magmatism, as they are in the same stratigraphical position. Several hundred kilometers westward and southwestward of Arrikine, Paleozoic magmatic products are known: Carboniferous basic intrusives (346 Ma; Djellit et al., 2006) are located in the Tin Serririne basin and Devonian ring complexes (407 Ma; Moreau et al, 1994) in the Aïr Mountains. For the Arrikine sill, K/Ar data gave a rejuvenation age (326 Ma) related to a K-rich aplitic phase and the LA-ICP-MS U-Pb method on zircon showed that only inherited zircons are present (0.6 to 0.7, 2.0 and 2.7 Ga ages), pointing to ages from the underlying basement corresponding to the Murzuq craton covered by Pan-African sediments (Derder et al., 2016). By contrast, a well-defined paleomagnetic pole yielded an age of 410-400 Ma by comparison with the Gondwana Apparent Polar Wander Path (APWP). This age, similar to that reported for the Aïr complexes (Moreau et al., 1994), can be correlated with the deep phreatic eruption before Pragian time thought to be at the origin of sand injections, which gave circular structures observed on different borders of the Murzuq basin (Moreau et al,. 2012). This Lower Devonian magmatism had therefore a regional extension and can be related to a "Caledonian" transtensive reactivation of the

  6. A province-scale block model of Walker Lane and western Basin and Range crustal deformation constrained by GPS observations (Invited)

    Science.gov (United States)

    Hammond, W. C.; Bormann, J.; Blewitt, G.; Kreemer, C.

    2013-12-01

    The Walker Lane in the western Great Basin of the western United States is an 800 km long and 100 km wide zone of active intracontinental transtension that absorbs ~10 mm/yr, about 20% of the Pacific/North America plate boundary relative motion. Lying west of the Sierra Nevada/Great Valley microplate (SNGV) and adjoining the Basin and Range Province to the east, deformation is predominantly shear strain overprinted with a minor component of extension. The Walker Lane responds with faulting, block rotations, structural step-overs, and has distinct and varying partitioned domains of shear and extension. Resolving these complex deformation patterns requires a long term observation strategy with a dense network of GPS stations (spacing ~20 km). The University of Nevada, Reno operates the 373 station Mobile Array of GPS for Nevada transtension (MAGNET) semi-continuous network that supplements coverage by other networks such as EarthScope's Plate Boundary Observatory, which alone has insufficient density to resolve the deformation patterns. Uniform processing of data from these GPS mega-networks provides a synoptic view and new insights into the kinematics and mechanics of Walker Lane tectonics. We present velocities for thousands of stations with time series between 3 to 17 years in duration aligned to our new GPS-based North America fixed reference frame NA12. The velocity field shows a rate budget across the southern Walker Lane of ~10 mm/yr, decreasing northward to ~7 mm/yr at the latitude of the Mohawk Valley and Pyramid Lake. We model the data with a new block model that estimates rotations and slip rates of known active faults between the Mojave Desert and northern Nevada and northeast California. The density of active faults in the region requires including a relatively large number of blocks in the model to accurately estimate deformation patterns. With 49 blocks, our the model captures structural detail not represented in previous province-scale models, and

  7. Cenozoic faults and faulting phases in the western Tarim Basin (NW China): Effects of the collisions on the southern margin of the Eurasian Plate

    Science.gov (United States)

    Li, Yue-Jun; Zhang, Qiang; Zhang, Guang-Ya; Tian, Zuo-Ji; Peng, Geng-Xin; Qiu, Bin; Huang, Zhi-Bin; Luo, Jun-Cheng; Wen, Lei; Zhao, Yan; Jia, Tie-Gan

    2016-12-01

    The Bachu Rise in the western Tarim Basin is the fore-bulge of the Kunlun late Cenozoic intra-continental foreland basin system formed under the far-field effect of India-Asia collision. Cenozoic faults and faulting are abnormally developed in the Bachu Rise and its adjacent area. Taking the Niaoshan-Gudongshan area on the southern boundary of the Bachu Rise as the key study area, 5 Cenozoic faulting phases were identified in the Bachu Rise and its adjacent area after careful seismic interpretation. They are end Cretaceous ∼ beginning Paleogene (ca. 65 Ma) décollement-thrusting, end Paleogene ∼ beginning Neogene (ca. 23 Ma) décollement-thrusting, end Miocene ∼ beginning Pliocene (ca. 5 Ma) basement-involved thrusting, late Pliocene ∼ early Pleistocene (ca. 3-2 Ma) normal faulting, middle Pleistocene ∼ Holocene (ca. <1.5 Ma) décollement-thrusting and strike-slip faulting. The Middle Cambrian and Paleogene gypsum-salt layers serve as the two main décollement layers in the study area. Thrusting of ca. 65 Ma was under the far-field effect of the collision between Lhasa (part of the Cimmerian Continent) and Asia; and the other 4 Cenozoic faulting phases were all under the far-field effect of the India-Asia collision. The late Cenozoic faulting is characterized by pulse thrust. There is one tectonic pause between each two successive thrust pulses. The compressive tectonic stress is weaker and even evolved into a slight tensional tectonic stress and forms normal fault in the tectonic pauses.

  8. Comparisons of drier-interval to wetter-interval estuarine roof facies in the eastern and western interior coal basins, USA

    Energy Technology Data Exchange (ETDEWEB)

    Archer, A.W.; Feldman, H.R.; Kvale, E.P.; Lanier, W.P. (Kansas State University, Manhattan, KS (United States). Dept. of Geology)

    1994-01-01

    Many of the Carboniferous coals in the eastern interior of the US are associated with siliciclastic roof facies that were deposited within a fluvio-estuarine transition. Drier-interval coals (Westphalian B-C, Stephanian) tend to be more laterally restricted and more commonly are associated with paleovalleys. Conversely, wetter-interval coals (Westphalian D) are very widespread and are not restricted to paleovalleys. Throughout the Late Carboniferous, wet paleoclimates associated with these coals lead to valley incision during sea-level lowstand when large tropical rivers downcut sediments deposited during previous sea-level highstands. During subsequent rise of sea level, these fluvial valleys were flooded and converted to estuaries. Based on modern analogs and interpretation of many examples of Carboniferous tidal rhythmites, the localized depositional rates in these settings are exceptionally high, with the estuaries becoming sediment sinks. As a result, sedimentation readily keeps pace with rising base-level. Extensive intertidal flats and shallow subtitle flats are created and prograde over the valley-confined mires. Thick tidal cycles and upright trees record rapid burial of mires. This model is supported with examples of roof facies from the Westphalian B-C of the Eastern Interior Basin, and the Stephanian of the Western Interior Basin. In these areas facies within each cycle range from well-developed, extensive paleosols and coals, to widespread marine shales or limestones. Minable, low-sulfur and low-ash coals occur, but the coals are relatively thin and discontinuous. Conversely, the Westphalian D coals are very widespread and significant peat accumulations were not confined to paleovalleys. Nonetheless, the lowest sulfur coals are related to rapid deposition of roof facies that occurred within the paleovalley whereas high-sulfur coals were formed in areas of lower sedimentation rate of roof facies that occurred beyond the confines of the paleovalley.

  9. The eddy-mean flow interaction and the intrusion of western boundary current into the South China Sea type basin in an idealized model

    Science.gov (United States)

    Zhong, Linhao

    2016-04-01

    In this paper, an ideal model on the role of mesoscale eddies in the Kuroshio intruding into the South China Sea (SCS) is developed, which represents the northwestern Pacific and the SCS by two rectangle basins connected by a gap. In the case of only considering intrinsic ocean variability, a time-dependent western boundary current (WBC) driven by steady wind is modeled under both eddy-resolving and non-eddy-resolving resolutions. Almost all simulated WBC intrudes into the adjacent sea in the form of loop current with multiple-state transitions and eddy-shedding process, which has aperiodic variations on intraseasonal or interannual scales, determined by the eddy-induced WBC variation. For the parameters considered in this paper, the WBC intrusion exhibits a 30~90-day cycle in the presence of the subgrid-scale eddy forcing (SSEF), but a 300~500-day cycle in the absence of SSEF. Moreover, the roles of the resolved (grid-scale) and unresolved (subgrid-scale) eddies in the WBC intrusion are studied. It is found that the unresolved eddy-flow interaction strongly regulates the WBC intrusion through the PV forcing induced by shear flows and baroclinic processes. But the resolved eddy forcing, which is dominated by the eddy-eddy interaction solely through baroclinic processes, shows weak correlation to the WBC intrusion. The associated eddy-induced PV exchange between the two basins is mainly accomplished by isopycnal-thickness eddy fluxes, particularly by the cross-front PV fluxes due to the unresolved eddy. And the unresolved eddy-flow interaction, as well as resolved and unresolved eddy-eddy interactions, mainly governs the PV transport for the WBC intrusion.

  10. A Web-based planning support tool for sediment management in a meso-scale river basin in Western Central Brazil.

    Science.gov (United States)

    Lorz, C; Neumann, C; Bakker, F; Pietzsch, K; Weiß, H; Makeschin, F

    2013-09-01

    In scope of an IWRM concept for the Federal District, Western Central Brazil we developed a planning support tool, which enables non-experts to test the effects of land-use and land-cover change (LULCC) on landscape processes and landscape functions (LPF) related to sediment generation and retention. For this purpose we developed the web-based tool Letsmap do Brasil. The tool has two principal layers. The upper layer contains information on land use and its effect on LPF, i.e. sediment retention, runoff control, nitrogen loss control and agronomic value. The parameterized relation between land use and LPF is the core of the whole system. For each LPF a value specific to land use has been assigned. A second layer contains information on landscape properties and potentials (LPP), e.g. potential for sediment input in river networks and runoff potential. By linking land use and LPPs the system provides a spatially explicit assessment of effects of LULCC on landscape processes and functions (LPF). Letsmap do Brasil might have two major purposes. (1) It will support decision-making in river basin management and sediment management. By creating their own land-use/cover pattern non-expert users are enabled to test effects of LULCC on LPFs. (2) It will support and train non-experts to participate in decision processes in land-use planning. Because of its high adaptability, transparency, and simple handling Letsmap do Brasil might be used as tool in river basin management and land-use planning.

  11. Impact of riparian land-use patterns on Ephemeroptera community structure in river basins of the southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Selvakumar C.

    2014-02-01

    Full Text Available This study analysed the impact of riparian land use in structuring the larval ephemeropteran communities from 25 sites in streams and rivers of Kalakad-Mundanthurai Tiger Reserve (KMTR of the southern end of the Western Ghats, India. A total of twenty-eight species belonging to twenty-four genera of six families were collected across all the sites. Baetidae and Leptophlebiidae were the most numerous and ubiquitous families, comprising eight genera in each family and eleven and nine species, respectively. The physico-chemical parameters and species richness and abundance of mayflies varied across streams and rivers with different riparian land-use types. Species distribution was influenced by the environmental gradients. Canonical Correspondence Analysis revealed a clear separation of the mayfly assemblages along water quality and riparian land-use gradients. The results of this study suggest that Ephemeroptera taxa can be potentially used as sensitive indicators of riparian land use in lotic ecosystems.

  12. Palynofacies and palaeoenvironmental significance of the Albian - Cenomanian succession of the Epunsa-1 well, onshore Tano Basin, western Ghana

    Science.gov (United States)

    Atta-Peters, D.; Achaegakwo, C. A.

    2016-02-01

    Palynofacies analysis carried out on thirty-three (33) cutting samples between the intervals 2990-5960 ft from the Epunsa-1 well onshore Tano Basin, identified three palynofacies types (P-1 to P-3). Palynofacies 1 (P-1) reflects deposition in shallow marine environment adjacent to active fluvial sources under a mud-dominated oxic (distal shelf) condition, Palynofacies 2 (P-2) was deposited in a shallow marine to fluvio-deltaic environment under a heterolithic oxic shelf condition and Palynofacies 3 (P-3) was deposited in a fluvio-deltaic environment in proximity to the source of vegetation under a dysoxic shelf condition. Visual kerogen analysis and spore colour for evaluation of hydrocarbon potential and thermal maturation respectively indicate early mature oil/gas prone to immature gas prone source rocks in the studied interval in the Epunsa-1 well. The presence of Afropollis, Classopollis, Ephedripites, and elaterate pollen as well as pteridophytic fern spores suggest a paleoenvironment with parent plants inhabiting moist biotopes or wetlands in a humid and warm coastal plain in a semi-arid/arid climate. Biostratigraphically significant elaterate pollen and associated taxa indicate Albian - Cenomanian age for the sediments.

  13. Spent fuel disassembly and canning programs at the Barnwell Nuclear Fuel Plant (BNFP). [For storage or transport

    Energy Technology Data Exchange (ETDEWEB)

    Townes, III, George A.

    1980-10-01

    Methods of disassembling and canning spent fuel to allow more efficient storage are being investigated at the BNFP. Studies and development programs are aimed at dry disassembly of fuel to allow storage and shipment of fuel pins rather than complete fuel assemblies. Results indicate that doubling existing storage capacity or tripling the carrying capacity of existing transportation equipment is achievable. Disassembly could be performed in the BNFP hot cells at rates of about 12 to 15 assemblies per day.

  14. Diferentiation of Basements Types Using Seismic Reflection Data and 40Ar-39Ar Dating in the Western Half of the Farallon Basin (gulf of California, Mexico)

    Science.gov (United States)

    Piñero Lajas, D.; González Fernández, A.; López-Martínez, M.; Lonsdale, P.; Kluesner, J.

    2009-04-01

    The Gulf of California is an active continental rift with an oblique right lateral displacement. Defining a clear boundary between continental and oceanic crust is difficult due to the high sedimentation rate. The new crust is a mixture of sills and sediments that do not produce aligned magnetic anomalies. The main objective of this work is to identify this boundary in the western part of the Farallon Basin. In order to accomplish this goal we used multichannel 2D high-resolution seismic reflection data taken during a cruise aboard oceanographic vessel Francisco de Ulloa in 2006. We also used petrological characterization and 40Ar-39Ar dating of continental samples collected in nearby Santa Catalina, Santa Cruz and San Diego islands, Punta Botella in the Baja California Peninsula, and marine samples of the continental margin next to Las Animas island (ROCA 2008 cruise). Oceanic crust created in the Farallòn spreading axis is identified primarily by saucer-shaped structures in the seismic profiles, which are interpreted as sills. The plutonic continental basement is located on the westernmost part of the margin and is recognized by a continuous high amplitude reflector. There are also volcanic patches in this area, like the South Farallon Massif, which are evident as discontinuities in the high amplitude reflector and with a different seismic character. The Farallon Basin is affected by two different tectonic regimes, the first (compressive) is related to the subduction of the Farallon Plate under the North American Plate, when the plutonic basement was originated. It consists of granodiorites and tonalites belonging to two phases of subduction during the Upper Cretaceous and Early Miocene. Outcrops of the latter phase are exposed in the peninsula of Baja California (Conception Bay); Mexico mainland (middle Sinaloa); and dredged samples of Pescadero Basin. These are similar to the plutonic Santa Catalina Island outcrop described and dated in this study. These

  15. Propagating rift tectonics of a Caledonian marginal basin: Multi-stage seafloor spreading history of the Solund-Stavfjord ophiolite in western Norway

    Science.gov (United States)

    Dilek, Yildirim; Furnes, Harald; Skjerlie, K. P.

    1997-10-01

    The Late Ordovician Solund-Stavfjord ophiolite in western Norway represents a remnant of the Iapetus oceanic lithosphere that developed in a Caledonian marginal basin. The ophiolite contains three structural domains that display distinctively different crustal architecture that reflects the mode and nature of magmatic and tectonic processes operated during the multi-stage seafloor spreading evolution of this marginal basin. Domain I includes, from top to bottom, an extensive extrusive sequence, a transition zone consisting of dike swarms with screens of pillow breccias, a sheeted dike complex, and plutonic rocks composed mainly of isotropic gabbro and microgabbro. Extrusive rocks include pillow lavas, pillow breccias, and massive sheet flows and are locally sheared and mineralized, containing epidosites, sulfide-sulfate deposits, Fe-oxides, and anhydrite veins, reminiscent of hydrothermal alteration zones on the seafloor along modern mid-ocean ridges. A fossil lava lake in the northern part of the ophiolite consists of a >65-m-thick volcanic sequence composed of a number of separate massive lava units interlayered with pillow lavas and pillow breccia horizons. The NE-trending sheeted dike complex contains multiple intrusions of metabasaltic dikes with one- and two-sided chilled margins and displays a network of both dike-parallel normal and dike-perpendicular oblique-slip faults of oceanic origin. The dike-gabbro boundary is mutually intrusive and represents the root zone of the sheeted dike complex. The internal architecture and rock types of Domain I are analogous to those of intermediate-spreading oceanic crust at modern mid-ocean ridge environments. The ophiolitic units in Domain II include mainly sheeted dikes and plutonic rocks with a general NW structural grain and are commonly faulted against each other, although primary intrusive relations between the sheeted dikes and the gabbros are locally well preserved. The exposures of this domain occur only in the

  16. Depositional Characteristics of Lake-Floor Fan of Cretaceous Lower Yaojia Formation in Western Part of Central Depression Region,Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    Xin Renchen; Li Guifan; Feng Zhiqiang; Liang Jiangping; Lin Changsong

    2009-01-01

    Based on the integrated subsurface data,including those of over 600 m drilled cores,more than 30 drilled wells and 600 km2 three-dimensional (3D) seismic-reflection data of the study area, the characteristics of the lake-floor fan of lower Yaojia(姚家) Formation have been clarified.An evident lacustrine slope break and a steep slope belt developed in the west of Songliao(松辽)basin during depositional period of Qingshankou(青山口)-Yaojia formations(K2).The slope gradient was about 15 m/km.During the depositional period of lower Yaojia Formation,the lake shrank and the shore line of the western Songliao basin shifted to the lacustrine slope-break.The wedge-shaped sediment body,which is interpreted as the lowstand system tract of SQy1 (LSTy1),developed in the area below the slope-break.The LSTyl is pinched out in the west of the study area.As to the thickness of LSTyl,ft is thicker in the east with SO m in its thickness than in the west The LSTyl,rich in sandstone,can be divided into lower part LSTylL and upper part LSTy1u based on two onlap seismic reflection phases,and core and logging data clearly.The various sediments' gravity flow deposits developed and the complex of lake-floor fan formed in the LSTyl under the slope-break in the western part of the central depression region.The lake-floor fan consists of various sediments' gravity flow deposits,including: (1) turbidity deposits with characteristics of Bouma sequences; (2) sand-bearing muddy debrite dominated by mud and mixed by sand; (3) mud-bearing sandy debrites characterized by dominated sand and mixed by mud; (4) sandy debris laminar flow deposits with massive or inclined bedding,and (5) sandy slump deposits developed as deforma tional sedimentary structure.During the lower lake-level period (LSTy1L),the western clinoform region was erosion or sediment pass-by area; the terrigenous clastic was directly transported to deep-water area,converted to channelized sandy debris flow,and combined with slump

  17. Multiscale investigation of inhomogeneous plastic deformation of NiTi shape memory alloy based on local canning compression

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shuyong, E-mail: jiangshy@sina.com [Industrial Training Centre, Harbin Engineering University, Harbin 150001 (China); Hu, Li [College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhao, Yanan; Zhang, Yanqiu [Industrial Training Centre, Harbin Engineering University, Harbin 150001 (China); Liang, Yulong [College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)

    2013-05-01

    As a severe plastic deformation (SPD) technique, local canning compression provides a novel approach to produce bulk amorphous and nanocrystalline nickel–titanium shape memory alloy (NiTi SMA). From the macroscale, mesoscale and microscale viewpoint, physical mechanism of inhomogeneous plastic deformation of NiTi alloy under local canning compression is investigated by means of optical microscopy, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Inhomogeneous plastic deformation of NiTi alloy leads to coexistence of amorphous phase, nanocrystalline phase, B2 austenite and B19′ martensite. The interaction between the dislocations and the grain boundaries lays the profound foundation for guaranteeing the continuity and the compatibility between the grains in a polycrystalline NiTi sample subjected to inhomogeneous plastic deformation. Deformation twinning and dislocation slip are the two important deformation modes in plastic deformation of NiTi alloy under local canning compression. Based on the statistically stored dislocation and the geometrically necessary dislocation, the mechanism of the critical dislocation density plays a predominant role in the occurrence of the amorphous phase in the deformed NiTi sample. When the deformation temperature is higher than a critical temperature, the amorphous phase is not able to occur in the NiTi sample subjected to SPD.

  18. Response of a dryland fluvial system to climate–tectonic perturbations during the Late Quaternary: Evidence from Rukmawati River basin, Kachchh, western India

    Indian Academy of Sciences (India)

    Archana Das; Falguni Bhattacharya; B K Rastogi; Gaurav Chauhan; Mamata Ngangom; M G Thakkar

    2016-08-01

    Dryland rivers, dominated by short-lived, localised and highly variable flow due to discrete precipitation events, have characteristic preservation potential, which serves as suitable archives towards understanding the climate–tectonic coupling. In the present study, we have investigated the fluvial records of a major, southerly-draining river – the Rukmawati River in the dryland terrain of southern Kachchh, in western India. The sediment records along the bedrock rivers of Kachchh register imprints of the Indian summer monsoon (ISM), which is the major source of moisture to the fluvial system in western India. The Rukmawati River originates from the Katrol Hill Range in the north and flows towards the south, into the Gulf of Kachchh. The field stratigraphy, sedimentology, along with the optical chronology suggeststhat a braided-meandering system existed during 37 ka period due to an overall strengthened monsoon. A gradual decline in the monsoon strength with fluctuation facilitated the development of a braided channel system between 20 and 15 ka. A renewed phase of strengthened monsoon with seasonality after around 15 ka which persisted until around 11 ka, is implicated in the development of floodplain sequences. Two zones of relatively high bedrock uplift are identified based on the geomorphometry and morphology of the fluvial landform. These zones are located in the vicinity of the North Katrol Hill Fault (NKHF) and South Katrol Hill Fault (SKHF). Geomorphic expression of high bedrock uplift is manifested by the development of beveled bedrock prior to or around 20 ka during weak monsoon. The study suggests that the terrain in the vicinity of NKHF and SKHF is uplifting at around 0.8 and >0.3 mm/a, respectively. Simultaneously, the incision in the Rukmawati River basin, post 11 ka, is ascribed to have occurred due to lowered sea level during the LGM and early Holocene period.

  19. Response of a dryland fluvial system to climate-tectonic perturbations during the Late Quaternary: Evidence from Rukmawati River basin, Kachchh, western India

    Science.gov (United States)

    Das, Archana; Bhattacharya, Falguni; Rastogi, B. K.; Chauhan, Gaurav; Ngangom, Mamata; Thakkar, M. G.

    2016-08-01

    Dryland rivers, dominated by short-lived, localised and highly variable flow due to discrete precipitation events, have characteristic preservation potential, which serves as suitable archives towards understanding the climate-tectonic coupling. In the present study, we have investigated the fluvial records of a major, southerly-draining river - the Rukmawati River in the dryland terrain of southern Kachchh, in western India. The sediment records along the bedrock rivers of Kachchh register imprints of the Indian summer monsoon (ISM), which is the major source of moisture to the fluvial system in western India. The Rukmawati River originates from the Katrol Hill Range in the north and flows towards the south, into the Gulf of Kachchh. The field stratigraphy, sedimentology, along with the optical chronology suggests that a braided-meandering system existed during 37 ka period due to an overall strengthened monsoon. A gradual decline in the monsoon strength with fluctuation facilitated the development of a braided channel system between 20 and 15 ka. A renewed phase of strengthened monsoon with seasonality after around 15 ka which persisted until around 11 ka, is implicated in the development of floodplain sequences. Two zones of relatively high bedrock uplift are identified based on the geomorphometry and morphology of the fluvial landform. These zones are located in the vicinity of the North Katrol Hill Fault (NKHF) and South Katrol Hill Fault (SKHF). Geomorphic expression of high bedrock uplift is manifested by the development of beveled bedrock prior to or around 20 ka during weak monsoon. The study suggests that the terrain in the vicinity of NKHF and SKHF is uplifting at around 0.8 and >0.3 mm/a, respectively. Simultaneously, the incision in the Rukmawati River basin, post 11 ka, is ascribed to have occurred due to lowered sea level during the LGM and early Holocene period.

  20. Palynostratigraphy, palynofacies and depositional environment of a lignite-bearing succession at Surkha Mine, Cambay Basin, north-western India

    Directory of Open Access Journals (Sweden)

    Monga Priyanka

    2015-12-01

    successions of the Cambay and Kutch basins correlate well with the present findings.

  1. Spatiotemporal Variation and Risk Assessment of Pesticides in Water of the Lower Catchment Basin of Acheloos River, Western Greece

    Directory of Open Access Journals (Sweden)

    Nikolaos Stamatis

    2013-01-01

    Full Text Available A three-year monitoring survey (March 2005–February 2008 was conducted to investigate, on monthly basis, the presence of thirty pesticides belonging to various categories and metabolites, in Acheloos River (Western Greece, one of the most important water resources in Greece. Six sampling stations along the river were established. Water analyses were performed using solid-phase extraction combined with gas chromatography with flame thermionic detector and mass spectrometry. Statistical analysis using one-way ANOVA and Duncan’s multiple range test (P<0.05 was used to compare annual mean concentrations of pesticides, seasonal and spatial distribution. In general, the highest mean concentrations of the pesticides were recorded at the three stations downstream. The greatest average concentrations were determined during spring and summer in agreement with the pesticide application period. The observed lower concentrations after 2006 reflect the land-use change because of the elimination of tobacco, the main cultivation of the area for many decades. The compounds most frequently detected were diazinon (78.6%, DEA (69.3%, and fenthion (52.6%. Environmental risk assessment using risk quotient (RQ approach showed high risk for six insecticides in 2005 and one in 2007. A compliance with the European Environmental Quality Standards (EQS was observed for the priority pesticides.

  2. 3D Seismic Attributes for Structural Analysis in Compressional Context:A Case Study from Western Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    Bo Xu; Ancheng Xiao; Lei Wu; Liguang Mao; Youpu Dong; Lijun Zhou

    2014-01-01

    Compressional region usually forms complex thrust faults system, which is difficult to identify using traditional migration profiles. The successful application of three-dimensional (3D) seismic attributes analysis greatly reduces the difficulty, and improves the accuracy and efficiency of seismic interpretation and structural analysis. In this paper, we took Qiongxi area in the compression-al region of western Sichuan as an example, using two 3D seismic attributes, coherence and instanta-neous phase, to identify fault assemblages and variations both vertically and laterally. The results show that the study area mainly consists of NS-, NE- and NEE-trending faults. The NS-trending faults are the largest and have a component of sinistral slip controlling the formation of NEE-trending faults, while the NE-trending faults are intermediate in scale, formed earlier and were cut by the NS-trending faults. Our results demonstrate that using seismic attributes for structural analysis have the following advantages: (1) more details of major fault zones, (2) highlighting minor faults which are hardly traced in seismic migration cube, and (3) easier acquisition of accurate fault systems. The application of seismic attributes provides a new idea for deciphering fine and complicated structures, and will sig-nificantly contribute to the development of objective and precise geological interpretation in the fu-ture.

  3. Spatiotemporal variation and risk assessment of pesticides in water of the lower catchment basin of Acheloos River, Western Greece.

    Science.gov (United States)

    Stamatis, Nikolaos; Hela, Dimitra; Triantafyllidis, Vassilios; Konstantinou, Ioannis

    2013-01-01

    A three-year monitoring survey (March 2005-February 2008) was conducted to investigate, on monthly basis, the presence of thirty pesticides belonging to various categories and metabolites, in Acheloos River (Western Greece), one of the most important water resources in Greece. Six sampling stations along the river were established. Water analyses were performed using solid-phase extraction combined with gas chromatography with flame thermionic detector and mass spectrometry. Statistical analysis using one-way ANOVA and Duncan's multiple range test (P mean concentrations of pesticides, seasonal and spatial distribution. In general, the highest mean concentrations of the pesticides were recorded at the three stations downstream. The greatest average concentrations were determined during spring and summer in agreement with the pesticide application period. The observed lower concentrations after 2006 reflect the land-use change because of the elimination of tobacco, the main cultivation of the area for many decades. The compounds most frequently detected were diazinon (78.6%), DEA (69.3%), and fenthion (52.6%). Environmental risk assessment using risk quotient (RQ) approach showed high risk for six insecticides in 2005 and one in 2007. A compliance with the European Environmental Quality Standards (EQS) was observed for the priority pesticides.

  4. The Last Appearance Datum of Hipparion in Western Europe: magnetostratigraphy along the Pliocene-Pleistocene boundary in the Villarroya Basin (Northern Spain)

    Science.gov (United States)

    Pueyo, Emilio L.; Muñoz, Arsenio; Laplana, César; Parés, Josep M.

    2016-11-01

    The Villarroya Basin in Northern Spain contains one of the classic Villafranchian localities of Europe and allows about 100 m of sediments to be explored by magnetostratigraphic techniques. Besides, the occurrence of some other macro- and micro-mammifera fossils becomes Villarroya in one of the most important Villafranchian localities of Southern Europe. Therefore, we have sampled two sections (one contains the classic locality) to shed some light on its chronostratigraphy. Detailed stepwise demagnetization has revealed primary and reliable directions (carried by magnetite and hematite) in more than 250 samples and allows us building a robust local polarity scale. The correlation with the geologic time scale locates the local sequence along the Gauss and Matuyama chrons. A Réunion chron (C2r.1n) equivalent age (2.128-2.148 Ma) is here proposed for the Villarroya fossil locality since it is clearly located above the Gauss/Matuyama boundary (very well defined in the magnetostratigraphic section) and displays normal polarity. This correlation implies a new age assignment for the classic paleontological fossil locality of Villarroya and a Last Appearance Datum of Hipparion sensu lato in Western Europe significantly younger than previously established. Taking into account this new dating, the Hipparion and Equus horses could have coexisted in Europe up to the complete extinction of Hipparion in early Matuyama times.

  5. Thrust and fold tectonics and the role of evaporites in deformation in the Western Kuqa Foreland of Tarim Basin, Northwest China

    Energy Technology Data Exchange (ETDEWEB)

    Shuping Chen; Liangjie Tang; Zhijun Jin [University of Petroleum, Beijing (China). Basin and Reservoir Research Center; Key Lab. for Hydrocarbon Accumulation of Education Ministry in Petroleum Univ., Beijing (China); Chengzao Jin [PetroChina Co. Ltd., Beijing (China); Xuejun Pi [Tarim Oilfield Co., PetroChina Co. Ltd., Korla, Xinjiang (China)

    2004-09-01

    The Kuqa foreland between the Tarim basin and the Tianshan Mountains is rich in oil and gas. Based on field work and seismic profiles, the structural styles and their formation mechanisms were determined, and the role of evaporites in the deformation was demonstrated. The main structural styles in the overburden are detachment folds, large scale nappes, triangle zones, gentle and wide synclines, fault-propagation folds and pop-ups. The main structures in the substrate are small-scale thrust faults, duplexes, pop-ups and fault-bend and fault-propagation folds, and formed mainly at the end of the Pliocene under north-south compression. The evaporite layer in the lower section of the Paleogene is the decollement zone for the disharmonic deformations in the overburden and in the substrate. The detachment along the evaporite layer made it possible for compressive stresses to be transmitted farther in the overburden than in the substrate. Deformation in the overburden is more extensive than in the substrate at the leading edge of deformation. At the trailing edge of deformation, the structural highs in the overburden closely correspond to those in the substrate, which is of significance for petroleum exploration in the western Kuqa foreland. (author)

  6. Hydrogeochemical and isotopic composition of groundwater in the Horgos River Watershed in the NorthWestern Ili Basin in Sinkiang Province, China

    Science.gov (United States)

    Jin, S. H.; Jiang, J. Y.; Rao, J. P.

    2016-08-01

    In this study, hydrogeochemical and stable environmental isotopic (oxygen-18 and deuterium) data of groundwater in the Horgos River watershed in the north-western Ili Basin were examined to determine the groundwater chemical characteristics, as well as the origins of the groundwater and surface water. The quaternary aquifer's structure and spatial distribution is complex. Hydrogeochemical data shows that the groundwater is alkaline due to the presence of bicarbonate as the dominant anion. In the north, the dominant groundwater cation was Ca2+ while Mg2+ ions were highest in the south. In addition, water types varied from HCO3-SO4-Ca and HCO3-SO4-Ca-Mg to HCO3-SO4-Mg-Ca and SO4-HCO3-Mg-Ca. Overall, the groundwater in this study showed high total hardness. The dissolving and evaporation inspissation were considered the main controlling factors. Isotopic data (oxygen-18 and deuterium) indicated that the Horgos River was the main recharge source for the groundwater, which rapidly infiltrated across sandstone macropores. Furthermore, surface water and shallow groundwater were significantly affected by evaporation.

  7. Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania

    Directory of Open Access Journals (Sweden)

    Levei Erika

    2013-01-01

    Full Text Available Abstract Background The objective of this study was to examine the potential environmental risk of tailings resulted after precious and base metal ores processing, stored in seven impoundments located in the Aries river basin, Romania. The tailings were characterized by mineralogical and elemental composition, contamination indices, acid rock drainage generation potential and water leachability of hazardous/priority hazardous metals and ions. Multivariate statistical methods were used for data interpretation. Results Tailings were found to be highly contaminated with several hazardous/priority hazardous metals (As, Cu, Cd, Pb, and pose potential contamination risk for soil, sediments, surface and groundwater. Two out of the seven studied impoundments does not satisfy the criteria required for inert wastes, shows acid rock drainage potential and thus can contaminate the surface and groundwater. Three impoundments were found to be highly contaminated with As, Pb and Cd, two with As and other two with Cu. The tailings impoundments were grouped based on the enrichment factor, geoaccumulation index, contamination factor and contamination degree of 7 hazardous/priority hazardous metals (As, Cd, Cr, Cu, Ni, Pb, Zn considered typical for the studied tailings. Principal component analysis showed that 47% of the elemental variability was attributable to alkaline silicate rocks, 31% to acidic S-containing minerals, 12% to carbonate minerals and 5% to biogenic elements. Leachability of metals and ions was ascribed in proportion of 61% to silicates, 11% to acidic minerals and 6% to the organic matter. A variability of 18% was attributed to leachability of biogenic elements (Na, K, Cl-, NO3- with no potential environmental risk. Pattern recognition by agglomerative hierarchical clustering emphasized the grouping of impoundments in agreement with their contamination degree and acid rock drainage generation potential. Conclusions Tailings stored in the studied

  8. Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania

    Science.gov (United States)

    2013-01-01

    Background The objective of this study was to examine the potential environmental risk of tailings resulted after precious and base metal ores processing, stored in seven impoundments located in the Aries river basin, Romania. The tailings were characterized by mineralogical and elemental composition, contamination indices, acid rock drainage generation potential and water leachability of hazardous/priority hazardous metals and ions. Multivariate statistical methods were used for data interpretation. Results Tailings were found to be highly contaminated with several hazardous/priority hazardous metals (As, Cu, Cd, Pb), and pose potential contamination risk for soil, sediments, surface and groundwater. Two out of the seven studied impoundments does not satisfy the criteria required for inert wastes, shows acid rock drainage potential and thus can contaminate the surface and groundwater. Three impoundments were found to be highly contaminated with As, Pb and Cd, two with As and other two with Cu. The tailings impoundments were grouped based on the enrichment factor, geoaccumulation index, contamination factor and contamination degree of 7 hazardous/priority hazardous metals (As, Cd, Cr, Cu, Ni, Pb, Zn) considered typical for the studied tailings. Principal component analysis showed that 47% of the elemental variability was attributable to alkaline silicate rocks, 31% to acidic S-containing minerals, 12% to carbonate minerals and 5% to biogenic elements. Leachability of metals and ions was ascribed in proportion of 61% to silicates, 11% to acidic minerals and 6% to the organic matter. A variability of 18% was attributed to leachability of biogenic elements (Na, K, Cl-, NO3-) with no potential environmental risk. Pattern recognition by agglomerative hierarchical clustering emphasized the grouping of impoundments in agreement with their contamination degree and acid rock drainage generation potential. Conclusions Tailings stored in the studied impoundments were found to

  9. Examination of elevation dependency in observed and projected temperature change in the Upper Indus Basin and Western Himalaya

    Science.gov (United States)

    Fowler, H. J.; Forsythe, N. D.; Blenkinsop, S.; Archer, D.; Hardy, A.; Janes, T.; Jones, R. G.; Holderness, T.

    2013-12-01

    We present results of two distinct, complementary analyses to assess evidence of elevation dependency in temperature change in the UIB (Karakoram, Eastern Hindu Kush) and wider WH. The first analysis component examines historical remotely-sensed land surface temperature (LST) from the second and third generation of the Advanced Very High Resolution Radiometer (AVHRR/2, AVHRR/3) instrument flown on NOAA satellite platforms since the mid-1980s through present day. The high spatial resolution (AVHRR instrument enables precise consideration of the relationship between estimated LST and surface topography. The LST data product was developed as part of initiative to produce continuous time-series for key remotely sensed spatial products (LST, snow covered area, cloud cover, NDVI) extending as far back into the historical record as feasible. Context for the AVHRR LST data product is provided by results of bias assessment and validation procedures against both available local observations, both manned and automatic weather stations. Local observations provide meaningful validation and bias assessment of the vertical gradients found in the AVHRR LST as the elevation range from the lowest manned meteorological station (at 1460m asl) to the highest automatic weather station (4733m asl) covers much of the key range yielding runoff from seasonal snowmelt. Furthermore the common available record period of these stations (1995 to 2007) enables assessment not only of the AVHRR LST but also performance comparisons with the more recent MODIS LST data product. A range of spatial aggregations (from minor tributary catchments to primary basin headwaters) is performed to assess regional homogeneity and identify potential latitudinal or longitudinal gradients in elevation dependency. The second analysis component investigates elevation dependency, including its uncertainty, in projected temperature change trajectories in the downscaling of a seventeen member Global Climate Model (GCM

  10. Provenance and sediment dynamics within river basins in Western Peru through detrital zircons U-Pb ages

    Science.gov (United States)

    Camille, Litty; Pierre, Lanari; Marco, Burn; Fritz, Schlunegger

    2016-04-01

    U-Pb dating of detrital zircons from clastic sediments by LA-ICPMS has become a popular method in sedimentary correlation and provenance studies. Because of remarkable durability, detrital zircons may be reworked through multiple sedimentary cycles and provide an ideal material to study the sedimentary provenance in rivers and the erosional characteristics. The Western side of the Peruvian Andes has experienced multiple pluvial periods induced phases of erosion and the formation of subsequent cut-and-fill terrace sequences since the Pleistocene. The aim of the study is to estimate the source areas of the terrace and modern deposits to infer changes in sediment dynamics through time and correlate them with the climatic change and especially precipitation patterns. To this extent, we determined the provenance of 4 dated terrace deposits along with modern sediments from the same streams by matching detrital-zircon ages with crystallization ages of source rocks. Age populations of detrital zircons are derived using U-Pb LA-ICP-MS analysis of about 50 zircons. Results show changes in the sediment provenance through time. Nowadays, sediment source areas are mainly located on the uppermost reach of the rivers whereas during the Pleistocene, sediment source areas were both located in the headwaters and along the middle reach of the rivers. These differences in terms of provenance could correlate with a change in precipitation locations and rates. Indeed a scenario where the locus of precipitation occurrence shifted from the middle reaches including the Altiplano during the past, to the Altiplano only as observed today, along with higher precipitation rates during the periods of terraces formation, offers an explanation to explain the erosional patterns recorded by detrital zircons.

  11. Geochemical characterization in karst basin tributaries of the San Franciscan depression: The Corrente River, western Bahia, NE-Brazil

    Science.gov (United States)

    Lecomte, Karina L.; Bicalho, Cristina C.; Silva-Filho, Emmanoel V.

    2016-08-01

    Karst aquifers are important freshwater resources for the growing population in Brazil. The sandstones of Urucuia plateau and the limestone of Bambui Group constitute important aquifer systems in the western part of Bahia state. The Corrente River provides ∼30% of the total water flow of the São Francisco River and crosses karstified structures. Surface and groundwater samples were collected during the dry period, the beginning of the wet season, and the wet season. The main objective was to define sources and distribution of dissolved elements and to describe the geochemical processes that govern their mobility within the system. Water samples are classified into three groups, depending on the dominant weathering process. When carbonate dissolution governs, waters are bicarbonate-calcium-type; whereas when the atmospheric precipitation signal is present, the samples in siliciclastic terrain are more Cl- - Na+. Groundwaters reflect bicarbonate-mixed-type, with the highest dissolved concentrations. In contrast to the major elements, trace elements, including Rare Earth Elements (REE), show seasonal behavior: their concentrations increase with the beginning of the wet season, due to re-mobilization and release into the solution of adsorbed elements from the system and the atmospheric dust. The total dissolved REE concentration (800-7500 ng L-1) is one order of magnitude more concentrated in karsts than in siliciclastic rocks. Principal component analysis was performed, explaining >77% of the variance. First factor extracted (REE, Y, Th, Al, Fe) explain the washout and enhancement of atmospheric dust weathering throughout the beginning of the wet seasons. The second component comprises variables related to karsts lithology, representing calcite and dolomite dissolution.

  12. Model-Based Attribution of High-Resolution Streamflow Trends in Two Alpine Basins of Western Austria

    Directory of Open Access Journals (Sweden)

    Christoph Kormann

    2016-02-01

    Full Text Available Several trend studies have shown that hydrological conditions are changing considerably in the Alpine region. However, the reasons for these changes are only partially understood and trend analyses alone are not able to shed much light. Hydrological modelling is one possible way to identify the trend drivers, i.e., to attribute the detected streamflow trends, given that the model captures all important processes causing the trends. We modelled the hydrological conditions for two alpine catchments in western Austria (a large, mostly lower-altitude catchment with wide valley plains and a nested high-altitude, glaciated headwater catchment with the distributed, physically-oriented WaSiM-ETH model, which includes a dynamical glacier module. The model was calibrated in a transient mode, i.e., not only on several standard goodness measures and glacier extents, but also in such a way that the simulated streamflow trends fit with the observed ones during the investigation period 1980 to 2007. With this approach, it was possible to separate streamflow components, identify the trends of flow components, and study their relation to trends in atmospheric variables. In addition to trends in annual averages, highly resolved trends for each Julian day were derived, since they proved powerful in an earlier, data-based attribution study. We were able to show that annual and highly resolved trends can be modelled sufficiently well. The results provide a holistic, year-round picture of the drivers of alpine streamflow changes: Higher-altitude catchments are strongly affected by earlier firn melt and snowmelt in spring and increased ice melt throughout the ablation season. Changes in lower-altitude areas are mostly caused by earlier and lower snowmelt volumes. All highly resolved trends in streamflow and its components show an explicit similarity to the local temperature trends. Finally, results indicate that evapotranspiration has been increasing in the lower

  13. The ion chemistry of surface and ground waters in the Taklimakan Desert of Tarim Basin, western China

    Institute of Scientific and Technical Information of China (English)

    ZHU BingQi; YANG XiaoPing

    2007-01-01

    The physio-chemical and chemical features of water in natural conditions are controlled by the weathering of bedrocks, local climate, landforms and other geo-environmental parameters. In order to understand the characteristics of water and the origins of the dissolved loads in the rivers and in the ground waters of the Taklimakan Desert, western China, we studied the ions in the water samples collected from rivers and wells. We collected water samples from four rivers (Keriya River, Cele River, Tumiya River and Yulongkashi River) in the southern desert and ground water samples from many parts of the desert. Major cations and anions were measured using ion-chromatograph and titration with HCl. The total dissolved solids (TDS), pH and conductivity were examined on site by a portable multi-parameter analyzer. The data show that the water in the rivers of southern Taklimakan is still of fresh water quality and slight alkalinity, although the TDS is comparatively higher than that of many other rivers of the world. The ground water is fresh to slightly saline, with TDS a little higher than that of river water in the study area. The concentration of ions is slightly different between the four rivers in the southern Taklimakan. However, the chemistries of ground water in all samples are to a large degree controlled by sodium and chloride. The ions in the ground water are concluded to be mainly from dissolving of evaporites, consistent with the dry climate in the region, whereas the ions in the rivers are mainly from rock weathering. Low-level human imprints are recognized in the ground water samples also.

  14. Map of Western Copper River Basin, Alaska, Showing Lake Sediments and Shorelines, Glacial Moraines, and Location of Stratigraphic Sections and Radiocarbon-Dated Samples

    Science.gov (United States)

    Williams, John R.; Galloway, John P.

    1986-01-01

    The purpose of this report is to make available basic data on radiocarbon dating of 61 organic samples from 40 locations in the western Copper River Basin and adjacent uplands and in the uppermost Matanuska River Valley. The former distribution of late Quaternary glacial lakes and of glaciers as mapped from field work and photo interpretation is provided as background for interpretation of the radiocarbon dates and are the basic data needed for construction of the late Quaternary chronology. The glacial boundaries, formed and expressed by moraines, ice-contact margins, marginal channels, deltas, and other features, are obscured by a drape of glaciolacustrine deposits in a series of glacial lakes. The highest lake, represented by bottom sediments as high as 914 m to 975 m above sea level, extends from Fog Lakes lowland on Susitna River upstream into the northwestern part of the Copper River Basin (the part now draining to Susitna River) where it apparently was held in by an ice border. It was apparently dammed by ice from the Mt. McKinley area, by Talkeetna G1acier, and may have had a temporary drainage threshold at the headwaters of Chunilna Creek. No shorelines have been noted within the map area, although Nichols and Yehle (1961) reported shorelines within the 914-975 m range in the Denali area to the north of that mapped. Recent work by geologic consultants for the Susitna Hydroelectric Project has confirmed the early inferences (Karlstrom, 1964) about the existence of a lake in the Susitna canyon, based originally on drilling by the Bureau of Reclamation about 35 years ago. According to dating of deposits at Tyone Bluff (map locations 0, P), Thorson and others (1981) concluded that a late Wisconsin advance of the glaciers between 11,535 and 21,730 years ago was followed by a brief interval of lacustrine sedimentation, and was preceded by a long period of lake deposition broken by a lowering of the lake between 32,000 and about 25,000 years ago. An alternate

  15. Safety of tomatillos and products containing tomatillos canned by the water-bath canning method.

    Science.gov (United States)

    McKee, L H; Remmenga, M D; Bock, M A

    1998-01-01

    Three studies were conducted to evaluate the safety of tomatillos and products containing tomatillos canned by the water-bath processing method. In the first study, plain tomatillos were processed for 25, 37.5, 50 and 62.5 min. In the second study, five tomatillo/onion combinations were prepared while five tomatillo/green chile combinations were prepared in the third study. pH evaluations were conducted to determine safety in all studies using pH 4.2 as the cut-off value. No differences in the pH of plain tomatillos were detected due to processing time. All jars of plain tomatillos had pH values below 4.1. All combinations of tomatillos/onions and tomatillos/green chile containing more than 50% tomatillo had pH values below the 4.2 cut-off value. Results of the three studies indicate (1) acidification of plain tomatillos is probably unnecessary for canning by the water-bath processing method and (2) combinations of acidic tomatillos and low-acid onions or green chile must contain more than 50% tomatillos to have a pH low enough for safe water-bath processing.

  16. Allegheny County Basin Outlines Map

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This basins dataset was created to initiate regional watershed approaches with respect to sewer rehabilitation. If viewing this description on the Western...

  17. Structure, outcrop, and subcrop of the bedrock aquifers along the western margin of the Denver Basin, Colorado

    Science.gov (United States)

    Robson, Stanley G.; Van Slyke, George D.; Graham, Glenn

    1998-01-01

    ), hydrogeologic terranes in the Valley and Ridge Physiographic Province (Chapter C), and ground-water geochemistry (Chapter D).The purposes of this atlas are to summarize the hydrogeology, to describe an analysis of maps and well records, and to present a classification and map of the hydrogeologic terranes of the Blue Ridge and Piedmont Physiographic Provinces within the APRASA study area. Hydrogeologic terranes are defined for this atlas as regionally mappable areas characterized by similar water-yielding properties of a grouping of selected rock types. The hydrogeologic terranes represent areas of distinct hydrologic character. The terranes are intended to help water users locate and develop adequate water supplies and to help hydrologists interpret the regional hydrogeology.Previous investigations provide maps and descriptions of the geologic units, describe the local quantity and quality of ground water within these units, and establish the statistical methods for comparing the water-yielding propertics of these units. State geologic maps show the distribution of geologic units at a scale of 1:500,000 for Alabama (Osborne and others, 1989), Georgia (Lawton and others, 1976), North Carolina (Brown and Parker, 1985), and Virginia (Calver and Hobbs, 1963). State maps show geologic units at a scale of 1:250,000 for Maryland (Cleaves and others, 1968), New Jersey (Lewis and Kummel, 1912), Pennsylvania (Berg and others, 1980), South Carolina (Overstreet and Bell, 1965), Tennessee (Hardeman, 1966), and West Virginia (Cardwell and others, 1968). Quadrangle geologic maps show geologic units at a scale of 1:24,000 for parts of Delaware within the APRASA area (Woodruff and Thompson, 1972, 1975). Many reports have been published describing the groundwater resources of a county, parts of a county, multi-county areas, or river basins.The statistical methods used in this atlas are based largely on those used by Helsel and Hirsch (1992) and by Knopman (1990, p. 7-9). In her analysis of well

  18. Diagenetic characteristics and reservoir quality of the Lower Cretaceous Biyadh sandstones at Kharir oilfield in the western central Masila Basin, Yemen

    Science.gov (United States)

    Hakimi, Mohammed Hail; Shalaby, Mohamed Ragab; Abdullah, Wan Hasiah

    2012-06-01

    The Lower Cretaceous Biyadh Formation in the Masila Basin is an important hydrocarbon reservoir. However, in spite of its importance as a reservoir, published studies on the Biyadh Formation more specifically on the diagenesis and relate with reservoir quality, are limited. Based on core samples from one well in the Kharir oilfield, western central Masila Basin, this study reports the lithologic and diagenetic characteristics of this reservoir. The Biyadh sandstones are very fine to very coarse-grained, moderate to well sorted quartzarenite and quartzwacke. The diagenetic processes recognized include mechanical compaction, cementation (carbonate, clay minerals, quartz overgrowths, and a minor amount of pyrite), and dissolution of the calcite cement and feldspar grains. The widespread occurrences of early calcite cement suggest that the Biyadh sandstones lost a significant amount of primary porosity at a very early stage of its diagenetic history. Based on the framework grain-cement relationships, precipitation of the early calcite cement was either accompanied or followed by the development of part of the pore-lining and pore-filling clay cements. Secondary porosity development occurred due to partial to complete dissolution of early calcite cement and feldspar grains. In addition to calcite, several different clay minerals including kaolinite and chlorite occur as pore-filling and pore-lining cements. Kaolinite largely occurs as vermiform and accelerated the minor porosity loss due to pore-occlusion. Chlorite coating grains helps to retain primary porosity a by retarding the envelopment of quartz overgrowths. Porosity and permeability data exhibit good inverse correlation with cement. Thus, reservoir quality is controlled by pore occluding cement. Diagenetic history of the Biyadh sandstones as established here is expected to help better understanding and exploitation of this reservoir. The relation between diagenesis and reservoir quality is as follows: the

  19. Late Cenozoic volcanism in the western Woodlark Basin area, SW Pacific: the sources of marine volcanic ash layers based on their elemental and Sr-Nd isotope compositions

    Science.gov (United States)

    Lackschewitz, K. S.; Mertz, D. F.; Devey, C. W.; Garbe-Schönberg, C.-D.

    2002-12-01

    Tephra fallout layers and volcaniclastic deposits, derived from volcanic sources around and on the Papuan Peninsula, form a substantial part of the Woodlark Basin marine sedimentary succession. Sampling by the Ocean Drilling Program Leg 180 in the western Woodlark Basin provides the opportunity to document the distribution of the volcanically-derived components as well as to evaluate their chronology, chemistry, and isotope compositions in order to gain information on the volcanic sources and original magmatic systems. Glass shards selected from 57 volcanogenic layers within the sampled Pliocene-Pleistocene sedimentary sequence show predominantly rhyolitic compositions, with subordinate basaltic andesites, basaltic trachy-andesites, andesites, trachy-andesites, dacites, and phonolites. It was possible to correlate only a few of the volcanogenic layers between sites using geochemical and age information apparently because of the formation of strongly compartmentalised sedimentary realms on this actively rifting margin. In many cases it was possible to correlate Leg 180 volcanic components with their eruption source areas based on chemical and isotope compositions. Likely sources for a considerable number of the volcanogenic deposits are Moresby and Dawson Strait volcanoes (D'Entrecasteaux Islands region) for high-K calc-alkaline glasses. The Dawson Strait volcanoes appear to represent the source for five peralkaline tephra layers. One basaltic andesitic volcaniclastic layer shows affinities to basaltic andesites from the Woodlark spreading tip and Cheshire Seamount. For other layers, a clear identification of the sources proved impossible, although their isotope and chemical signatures suggest similarities to south-west Pacific subduction volcanism, e.g. New Britain and Tonga-Kermadec island arcs. Volcanic islands in the Trobriand Arc (for example, Woodlark Island Amphlett Islands and/or Egum Atoll) are probable sources for several volcaniclastic layers with ages

  20. Ground-water resources of the South Platte River Basin in western Adams and southwestern Weld Counties, Colorado

    Science.gov (United States)

    Smith, Rex O.; Schneider, P.A.; Petri, Lester R.

    1964-01-01

    The area described in this report consists of about 970 square miles in western Adams and southwestern Weld Counties in northeastern Colorado. It includes that part of the South Platte River valley between Denver and Kuner, Colo., all of Beebe Draw, and the lower part of the valley of Box Elder Creek. The stream-valley lowlands are separated by rolling uplands. The climate is semiarid, the normal annual precipitation being about 13 inches; thus, irrigation is essential for stable agricultural development. The area contains about 220,000 acres of irrigated land in the stream valleys. Most of the remaining 400,000 acres of land is used for dry farming or grazing because it lacks irrigation water. Most of the lowlands were brought under irrigation with surface water during the early 1900's, and now nearly all the surface water in the area is appropriated for irrigation within and downstream from the area. Because the natural flow of the streams is sometimes less than the demand for water, ground water is used to supplement the surface-water supply. Wells, drilled chiefly since 1930, supply the supplemental water and in some places are the sole supply for irrigation use. Rocks exposed in the area are of sedimentary origin and range in age from Lato Cretaceous to Recent. Those that are consolidated, called 'bedrock' in this report, consist of the Fox Hills sandstone and the Laramie and Arapahoe formations, all of Late Cretaceous age, and the Denver formation and Dawson arkose of Late Cretaceous and Tertiary age. The surface of the bedrock was shaped by ancestral streams, the valleys of which are reflected by the present surface topography. Dune sand, slope wash, and thin upland deposits of Quaternary age mantle the bedrock in the divide areas, and stream deposits ranging in thickness from 0 to about 125 feet partly fill the ancestral valleys. The valley-fill deposits consist of beds and lenses of clay, silt, sand, gravel, cobbles, and boulders. Abundant supplies of

  1. Discovery of a Devonian mafic magmatism on the western border of the Murzuq basin (Saharan metacraton): Paleomagnetic dating and geodynamical implications

    Science.gov (United States)

    Derder, M. E. M.; Maouche, S.; Liégeois, J. P.; Henry, B.; Amenna, M.; Ouabadi, A.; Bellon, H.; Bruguier, O.; Bayou, B.; Bestandji, R.; Nouar, O.; Bouabdallah, H.; Ayache, M.; Beddiaf, M.

    2016-03-01

    Intraplate deformation is most often linked to major stress applied on plate margins. When such intraplate events are accompanied by magmatism, the use of several dating methods integrated within a multidisciplinary approach can bring constraints on the age, nature and source mobilized for generating the magma and in turn on the nature of the intraplate deformation. This study focuses on the large gabbro Arrikine sill (35 km in extension) emplaced within the Silurian sediments of the western margin of the Murzuq cratonic basin in southeastern Algeria. Its emplacement is dated during the early Devonian (415-400 Ma) through the determination of a reliable paleomagnetic pole by comparison with the Gondwana Apparent Polar Wander Path (APWP). This age can be correlated with deep phreatic eruptions before Pragian time thought to be at the origin of sand injections and associated circular structures in Algeria and Libya. For the sill, the K-Ar age of 325.6 ± 7.7 Ma is related to a K-rich aplitic phase that has K-enriched by more than 20% the Devonian gabbro. Laser-ICP-MS U-Pb method dates only inherited zircons mostly at c. 2030 Ma with additional ages at c. 2700 Ma and younger ones in the 766-598 Ma age range. The Arrikine sill is a high-Ti alkaline gabbro having the geochemical composition of a hawaiite akin to several intraplate continental and oceanic provinces, including the contemporaneous Aïr ring complexes province in Niger, but also to the Mauna Loa volcano in Hawaii. This peculiar composition akin to that of the contemporaneous Aïr province is in agreement with a lower Devonian age for the Arrikine sill. The lower Devonian Arrikine sill emplacement is related to a "Caledonian" transtensive reactivation of the western metacratonic boundary of the Murzuq craton. This event also generated in the Saharan platform the so-called "Caledonian unconformity" of regional extension, the Aïr ring complexes and magmatic rocks that produced sand injections. It could be

  2. A 500 year early summer temperature reconstruction for the western Mediterranean basin based on stable carbon isotopes from Pinus nigra ssp. laricio

    Science.gov (United States)

    Szymczak, S.; Joachimski, M. M.; Bräuning, A.; Hetzer, T.; Kuhlemann, J.

    2012-04-01

    sensitive to drought stress during late summer. The strong and stable correlation of the carbon isotope ratios with May-June temperature at one study site allows a 500-year temperature reconstruction for the Western Mediterranean which will contribute to a better understanding of past climate variability in the Mediterranean basin.

  3. Use of Orbital Time Scale to Evaluate Molluscan Biozones and Evolutionary Rates during the Late Cenomanian-Early Turonian, Western Interior Basin (USA).

    Science.gov (United States)

    Sageman, B. B.; Meyers, S. R.; Hinnov, L. A.

    2001-12-01

    Cyclostratigraphic analysis of the Cenomanian-Turonian Bridge Creek Limestone Member (Cretaceous Western Interior Basin) was used to develop a new high-resolution time scale for this approximately 2 myr interval. The new time scale was derived by application of time-frequency methods (evolutive harmonic analysis) to an optical densitometry data series from the interval. Evolutive harmonic analysis permits detection of changes in sedimentation, including the quantification of hiatus, and therefore allows the construction of a time-scale that is free of the biases associated with sedimentary distortions. The new time scale permits an independent quantitative assessment of rates of geochemical and paleobiologic change in the C-T boundary interval. In this study, we compare the new orbital time scale to previous time scales, and use it to assess the validity of the "equal-duration biozone" hypothesis, an assumption that has been employed in the construction of the previous time scales. The "equal-duration biozone" approach uses scattered radiometric dates within a succession of taxonomically consistent biozones (ideally representing a lineage), and interpolates biozone boundary ages based on the assumption that each biozone is of approximately equal duration. In addition, we employ the new time scale to assess rates of evolutionary change for molluscan taxa (ammonites, bivalves, gastropods), and for the total preserved macrofauna in the study interval. The results of this analysis lead us to a discussion of two related topics: 1) the principles inherent in the development of biozonation schemes, and 2) the factors that control evolutionary rates of benthic and necktobenthic taxa. >http://www.earth.northwestern.edu/people/meyers/ paleoclimate.html

  4. Baseline monitoring of the western Arctic Ocean estimates 20% of the Canadian Basin surface waters are undersaturated with respect to aragonite

    Science.gov (United States)

    Robbins, Lisa L.; Wynn, Jonathan G.; Lisle, John T.; Yates, Kimberly K.; Knorr, Paul O.; Byrne, Robert H.; Liu, Xuewu; Patsavas, Mark C.; Azetsu-Scott, Kumiko; Takahashi, Taro

    2013-01-01

    Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index) for the western Arctic Ocean. This data set documents aragonite undersaturation in ~20% of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean’s largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.

  5. Joint inversion of PP and PS AVAZ data to estimate the fluid indicator in HTI medium: a case study in Western Sichuan Basin, China

    Science.gov (United States)

    Pan, Bei; Sen, Mrinal K.; Gu, Hanming

    2016-10-01

    The existence of fractures in an otherwise isotropic medium induces anisotropy in the medium. Because of existing in situ stress, most fractures are often aligned close to vertical, rendering a reservoir azimuthally anisotropic in character. Joint interpretation of PP and PS seismic data generally provides greater details in resolution of the estimated subsurface rock properties and geological structures than conventional PP seismic data. Here we report on the applicability of PP and PS azimuthal amplitude variation with offset (AVAZ) data in fracture characterization. The theory is based on a linear slip model and the Born formula such that PP- and PS-reflection coefficients are sensitive to fracture weaknesses. First we demonstrate numerical experiments with synthetic PP-AVAZ, PS-AVAZ and joint inversion to estimate fluid indicator. Results show that when the fractures have low saturation of gas, the fluid indicator estimated from PP-AVAZ data is fairly accurate. However, when gas saturation reaches up to 70%, joint inversion can help to improve the resulting poor quality in PP-AVAZ data inversion. For high values of gas-saturation, both PP inversion and joint inversion are sensitive to errors in background Poisson’s ratio. Based on the result of our numerical experiment with synthetic data, we analyze a field dataset from the Western Sichuan Basin in China. The inversion result is consistent with well log based interpretation. All known reservoirs are accurately depicted by the estimated fluid indicator while the false gas zones interpreted by other methods are eliminated. When displayed as an inline section, the distribution of reservoirs appears consistent with the interpretation of the stratigraphy and geological structures.

  6. Mineral provinces and matter provenance of the surficial sediments in the western Philippine Sea: implication for modern sedimentation in West Pacific marginal basin

    Institute of Scientific and Technical Information of China (English)

    REN Xiangwen; YAN Quanshu; SHI Xuefa; WANG Kunshan; JIANG Xiaoli

    2007-01-01

    The characteristics and distribution patterns of detrital minerals (0.063~0.125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment.The detrital mineral composition of 219 surface sediment samples was analysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces: (Ⅰ) province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau-Kyūshū Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate-acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau-Kyūshū Ridge. it is suggested that, (1) Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. (2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau (e.g.,Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. (3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.

  7. The hydrocarbon potential, thermal maturity, sequence stratigraphic setting and depositional palaeoenvironment of carbonaceous shale and lignite successions of Panandhro, northwestern Kutch Basin, Gujarat, Western India

    Science.gov (United States)

    Sahay, Vinay

    2011-03-01

    The objective of the present paper is to provide geochemical and palynological data to characterize lignites and carbonaceous shales from Panandhro, northwestern Kutch Basin, Gujarat, Western India, in terms of their hydrocarbon potential, thermal maturity, sequence stratigraphic settings and depositional palaeoenvironment. The samples, collected in Panandhro lignite mine, belong to Naredi Formation of Late Paleocene-Early Eocene age. The geochemical results are based on proximate analysis, ultimate analysis, X-ray diffraction and Rock-Eval py-rolysis analyses, whereas palynological data include palynofossil composition and thermal alteration index (TAI). The TOC, hydrogen index (HI), cracked hydrocarbon (S2), bitumen index (BI), quality index (QI), and the total genetic potential (S1+S2) values indicate that the studied lignites and carbonaceous shales have good source rock potential. The organic matter is predominantly of type II and type II/III kerogen, which has potential to generate oil as well as gas. Thermal maturity determined from thermal alteration index (TAI), Tmax and production index (PI) indicates that the organic matter is immature, and in the diagenesis stage of organic matter transformation. The deposition of the studied carbonaceous shales and lignites took place in palaeoenvironments varying from brackish mangrove to freshwater swamp. This study indicates that the proportion of ferns, palms, volatile matter content, S/C, H/C ratios, as well as the presence of siderite and quartz can be used as an indicator of accommodation trends in the coal depositional system. The Panandhro carbonaceous shales and lignites were deposited during the lowstand systems tract with many cycles of small magnitude trangressive-regressive phases. Thus, the geochemistry and ecological palynology are useful not only for the investigation of coal quality and origin, but also to infer accommodation space settings of the mire. This can be gainfully utilized in the coal

  8. Catchment export of carbon, nitrogen, and phosphorus across an agro-urban land use gradient, Swan-Canning River system, southwestern Australia

    Science.gov (United States)

    Petrone, Kevin C.

    2010-03-01

    Coastal regions in many regions of the world are under increasing pressure from the expansion of agriculture and urbanization associated with elevated N and P loading and eutrophication of coastal estuaries. I compared how mixed land use catchments deliver dissolved and particulate forms of C, N, and P in streamflow to the Swan-Canning estuary that bisects Perth, Western Australia. Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) composed the majority of the total C and N load, particulate C and N fluxes were minor, and P fluxes were evenly split between soluble reactive phosphorus and particulate/organic P. In contrast to current biogeochemical theory, DON export was dominant in urban and agricultural catchments in the low-gradient environment of the Swan Coastal Plain, whereas NO3 export was a greater factor in higher-gradient, forested catchments on the urban fringe. This trend suggests that hydrologic conditions that supported coastal wetlands prior to human development may still promote DON mobilization as well as dissolved inorganic nitrogen loss along hydrologic flow paths. Substantial variability in export of C, N, and P across catchments highlights the unique hydrologic properties of Australian catchments. Areal C, N, and P export was significantly related to catchment runoff which was lowest in a catchment with inland drainage, but greatest in urban catchments with impervious surfaces and shallow groundwater. The effective delivery of DOC and DON to aquatic ecosystems in urbanizing coastal catchments underscores the importance of restoration efforts that address hydrologic retention as well as the source and bioavailability of dissolved organic matter.

  9. Effects of industrial canning on the proximate composition, bioactive compounds contents and nutritional profile of two Spanish common dry beans (Phaseolus vulgaris L.).

    Science.gov (United States)

    Pedrosa, Mercedes M; Cuadrado, Carmen; Burbano, Carmen; Muzquiz, Mercedes; Cabellos, Blanca; Olmedilla-Alonso, Begoña; Asensio-Vegas, Carmen

    2015-01-01

    This study investigated the changes produced by canning in the proximate composition and in the bioactive constituents of two "ready to eat" Spanish beans. The foremost difference in the raw beans corresponded to the lectin: a higher content was found in raw Curruquilla beans (16.50 mg 100 mg(-1)) compared with raw Almonga beans (0.6 mg 100 mg(-1)). In general, industrial canning significantly increased the protein (>7%) and dietary fibre (>5%) contents of both beans varieties. However, the minerals, total α-galactosides and inositol phosphates contents were reduced (>25%) in both canned seeds. The trypsin inhibitors content was almost abolished by canning, and no lectins were found in either of the canned samples. Canned Curruquilla showed a decrease (38%) of their antioxidant activity. These "ready to eat" beans exhibited adequate nutritive profiles according to the USDA dietary recommendations. Furthermore, they had bioactive components content that are suitable for establishing a healthy lifestyle.

  10. The nonmarine Lower Cretaceous of the North American Western Interior foreland basin: New biostratigraphic results from ostracod correlations and early mammals, and their implications for paleontology and geology of the basin—An overview

    Science.gov (United States)

    Sames, Benjamin; Cifelli, Richard L.; Schudack, Michael E.

    2010-08-01

    The timespan represented by the hiatus between nonmarine Upper Jurassic (Early Berriasian?) and unconformably overlying Lower Cretaceous deposits throughout the North American Western Interior foreland basin has been under discussion for the entire 20th century and remains controversial to date. Ongoing research in revision of Early Cretaceous nonmarine ostracods of some respective North American formations leads to a breakthrough concerning the verification of their biostratigraphic utility as well as their subsequent application. These ostracods are not as endemic as hitherto believed and can be used for supraregional and regional correlation, as well as improvement of the age determination of North American units. New results strongly suggest a maximum age of Late Berriasian to Valanginian (˜ 142-138 Ma) for the lower part of the Lakota (Black Hills area, South Dakota) and Cedar Mountain (Utah) formations. A pre-Aptian maximum age for the Lakota Formation is supported by early mammals. These biostratigraphic results affect the correlatable formations as well, and therefore have broad implications on basin-related geologic and paleontologic topics that are overviewed and discussed herein. The central issue hampering an integrated synthesis of the foreland basin is its yet imprecise chronostratigraphic framework and documentation. Temporal relationships between the gologic processes of the basin and their control factors are still insufficiently calibrated or controversial. Detailed ongoing revision of North American Early Cretaceous nonmarine ostracods demonstrates their applicability, utility, and further potential as tool for improvement of the chronostratigraphy of the Western Interior foreland basin at both small and large scales. These ostracods also foster understanding of animal (e.g. early mammals and dinosaurs) and plant (angiosperms) evolution on the North American continent and show promise of providing age determinations for single-sample horizons in

  11. Three outbreaks of foodborne botulism caused by unsafe home canning of vegetables--Ohio and Washington, 2008 and 2009.

    Science.gov (United States)

    Date, Kashmira; Fagan, Ryan; Crossland, Sandra; Maceachern, Dorothy; Pyper, Brian; Bokanyi, Rick; Houze, Yolanda; Andress, Elizabeth; Tauxe, Robert

    2011-12-01

    Foodborne botulism is a potentially fatal paralytic illness caused by ingestion of neurotoxin produced by the spore-forming bacterium Clostridium botulinum. Historically, home-canned vegetables have been the most common cause of botulism outbreaks in the United States. During 2008 and 2009, the Centers for Disease Control and Prevention (CDC) and state and local health departments in Ohio and Washington State investigated three outbreaks caused by unsafe home canning of vegetables. We analyzed CDC surveillance data for background on food vehicles that caused botulism outbreaks from 1999 to 2008. For the three outbreaks described, patients and their family members were interviewed and foods were collected. Laboratory testing of clinical and food samples was done at the respective state public health laboratories. From 1999 to 2008, 116 outbreaks of foodborne botulism were reported. Of the 48 outbreaks caused by home-prepared foods from the contiguous United States, 38% (18) were from home-canned vegetables. Three outbreaks of Type A botulism occurred in Ohio and Washington in September 2008, January 2009, and June 2009. Home-canned vegetables (green beans, green bean and carrot blend, and asparagus) served at family meals were confirmed as the source of each outbreak. In each instance, home canners did not follow canning instructions, did not use pressure cookers, ignored signs of food spoilage, and were unaware of the risk of botulism from consuming improperly preserved vegetables. Home-canned vegetables remain a leading cause of foodborne botulism. These outbreaks illustrate critical areas of concern in current home canning and food preparation knowledge and practices. Similar gaps were identified in a 2005 national survey of U.S. adults. Botulism prevention efforts should include targeted educational outreach to home canners.

  12. Chapter 34: Geology and petroleum potential of the rifted margins of the Canada Basin

    Science.gov (United States)

    Houseknecht, D.W.; Bird, K.J.

    2011-01-01

    Three sides of the Canada Basin are bordered by high-standing, conjugate rift shoulders of the Chukchi Borderland, Alaska and Canada. The Alaska and Canada margins are mantled with thick, growth-faulted sediment prisms, and the Chukchi Borderland contains only a thin veneer of sediment. The rift-margin strata of Alaska and Canada reflect the tectonics and sediment dispersal systems of adjacent continental regions whereas the Chukchi Borderland was tectonically isolated from these sediment dispersal systems. Along the eastern Alaska-southern Canada margin, termed herein the 'Canning-Mackenzie deformed margin', the rifted margin is deformed by ongoing Brooks Range tectonism. Additional contractional structures occur in a gravity fold belt that may be present along the entire Alaska and Canada margins of the Canada Basin. Source-rock data inboard of the rift shoulders and regional palaeogeographic reconstructions suggest three potential source-rock intervals: Lower Cretaceous (Hauterivian-Albian), Upper Cretaceous (mostly Turonian) and Lower Palaeogene. Burial history modelling indicates favourable timing for generation from all three intervals beneath the Alaska and Canada passive margins, and an active petroleum system has been documented in the Canning-Mackenzie deformed margin. Assessment of undiscovered petroleum resources indicates the greatest potential in the Canning-Mackenzie deformed margin and significant potential in the Canada and Alaska passive margins. ?? 2011 The Geological Society of London.

  13. Residue behaviour of six pesticides in button crimini during home canning.

    Science.gov (United States)

    Du, Pengqiang; Liu, Xingang; Gu, Xiaojun; Dong, Fengshou; Xu, Jun; Kong, Zhiqiang; Li, Yuanbo; Zheng, Yongquan

    2014-01-01

    The effect of home canning (including washing, boiling, cooling, adding solution and sterilisation) on residue levels of imidacloprid, diflubenzuron, abamectin, pyriproxyfen and β-cypermethrin and chlorothalonilin on button crimini was assessed. Residues of imidacloprid, diflubenzuron, abamectin and pyriproxyfen were measured by UPLC-MS/MS; the residues of β-cypermethrin and chlorothalonil were measured by GC. Results showed that washing resulted in a 3.8% reduction of the initial residue level of imidacloprid (p ≤ 0.05). From washing to sterilisation the processing effect was significant compared with raw crimini (p ≤ 0.05), but processing through cooling and adding solution had no effect. For diflubenzuron, from raw crimini to sterilisation the processing effect was significant by comparison with the initial level (p ≤ 0.05); the processing effect was not obvious between two sequential steps, and the sequential steps have list: washing and boiling, boiling and cooling, boiling and adding of solution, cooling and adding solution. The changes in abamectin levels were also significant from raw crimini to sterilisation compared with raw crimini (p ≤ 0.05), but the changes were not obvious from boiling to adding solution and amongst them. For pyriproxyfen, washing resulted in a 39% reduction, but changes were not obvious from washing to sterilisation, p ≤ 0.05 between two consecutive steps. The whole procedure could significantly decrease residues of β-cypermethrin (p ≤ 0.05); washing could significantly reduce residues of β-cypermethrin; the effects of last procedures were complicated, and p ≤ 0.05 between two consecutive steps. Washing resulted in an 80% reduction of chlorothalonil; after washing there were no detectable residues. After the whole process, the processing factors for imidacloprid, diflubenzuron, abamectin, pyriproxyfen, β-cypermethrin and chlorothalonil were 0.40, 0.22, 0.04, 0.85, 0.28 and 0, respectively.

  14. Effects of rainfall and salt-wedge movement on phytoplankton succession in the Swan-Canning Estuary, Western Australia

    Science.gov (United States)

    Twomey, L.; John, J.

    2001-09-01

    Annual data sets, from 1980-81 and 1994-95, provide evidence that inter-annual differences in the seasonal succession of phytoplankton in the Swan River Estuary can be attributed to rainfall and salt-wedge movement. The distribution and succession of phytoplankton are influenced by seasonal variation of rainfall and its subsequent effect on the spatial distribution of salinity. The longer duration of rainfall in 1980-81 compared with 1994-95 effectively restricted the movement of the salt-water wedge, thereby delaying the progression of marine phytoplankton into the estuary. There was little difference in the phytoplankton composition and biomass in the lower estuary, while the upper estuary appeared to have more blooms of dinoflagellates in the summer and autumn of 1994-95 compared with 1980-81.The intensity and duration of rainfall appeared to affect the availability of soluble nutrients. Although there was no significant difference in phytoplankton biomass between the two periods, it was likely that the high phytoplankton biomass in the upper estuary in 1994-95 was due to availability of more soluble nutrients from internal recycling processes at the sediment/water interface.

  15. Horticultural Loss Generated by Wholesalers: A Case Study of the Canning Vale Fruit and Vegetable Markets in Western Australia

    Directory of Open Access Journals (Sweden)

    Purabi R. Ghosh

    2017-05-01

    Full Text Available In today’s economic climate, businesses need to efficiently manage their finite resources to maintain long-term sustainable growth, productivity, and profits. However, food loss produces large unacceptable economic losses, environmental degradation, and impacts on humanity globally. Its cost in Australia is estimated to be around AUS$8 billion each year, but knowledge of its extent within the food value chain from farm to fork is very limited. The present study examines food loss by wholesalers. A survey questionnaire was prepared and distributed; 35 wholesalers and processors replied and their responses to 10 targeted questions on produce volumes, amounts handled, reasons for food loss, and innovations applied or being considered to reduce and utilize food loss were analyzed. Reported food loss was estimated to be 180 kg per week per primary wholesaler and 30 kg per secondary wholesaler, or around 286 tonnes per year. Participants ranked “over supply” and “no market demand” as the main causes for food loss. The study found that improving grading guidelines has the potential to significantly reduce food loss levels and improve profit margins.

  16. Basin deconstruction-construction: Seeking thermal-tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​- Example from Faras Field, North Western Desert, Egypt

    Science.gov (United States)

    Pigott, John D.; Abouelresh, Mohamed O.

    2016-02-01

    To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy. The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of "ghost" layers

  17. Palynostratigraphical correlation of the excavated Miocene lignite seams of the Yataǧan basin (Muǧla Province, south-western Turkey)

    Science.gov (United States)

    Bouchal, Johannes Martin; Grímsson, Friðgeir; Denk, Thomas

    2016-04-01

    The excavated main lignite seams and overlying lacustrine sediments of the opencast mines Eskihisar, Salihpaşalar, and Tı naz, Muǧla Province, south-western Turkey were investigated using a high taxonomic resolution palynological approach. The Eskihisar section comprises 47m and 56 samples of which 30 were usable for palynological analysis. The Tı naz section comprises 75 m and 29 samples of which 15 were usable for palynological analysis. Finally, the Salihpaşalar section comprises 25 m and 26 samples of which 16 were usable for palynological analysis. The age of the palynological sections is middle to late Miocene based on radiometric dating and vertebrate fossils. In order to investigate dispersed pollen and spores and their botanical affinities a combined light microscopy and scanning electron microscopy approach was used. The rich palynoflora comprises: seven types of algal cysts (Botryococcus, Zygnemataceae), seventeen spore types belonging to Lycopsida (club mosses), Marsileaceae (water-clover), Osmundaceae, Pteridaceae (brake), and Polypodiaceae; 14 types of gymnosperm pollen belonging to Ephedraceae (Mormon tea), Cupressaceae, Pinaceae (Cathaya, cedar, hemlock, pine, spruce); five types of monocotyledone pollen belonging to Poaceae (grasses, common reed), and Typhaceae (bulrush, bur-reed); ca 90 dicotyledone pollen types belonging to Altingiaceae (sweet gum), Amaranthaceae (goosefoot), Anacardiaceae (sumac family), Apiaceae (parsley family), Aquifoliaceae (holly), Asteraceae (sunflower family), Betulaceae (alder, birch, hazel, hophornbeam, hornbeam), Campanulaceae (bellflower family), Cannabaceae (hackberries), Caprifoliaceae (honeysuckle, teasel family), Caryophyllaceae (pink family), Ericaceae (heather family), Eucommiaceae, Euphorbiaceae (spurge family), Fabaceae (bean family), Fagaceae (beech, oak), Geraniaceae (storkbills), Juglandaceae (hickory, walnut, wingnut), Lamiaceae (bagflower), Linaceae (flax), Lythraceae (waterwillow), Malvaceae

  18. Geometry of the inverted Cretaceous Chañarcillo Basin based on 2-D gravity and field data. An approach to the structure of the western Central Andes of northern Chile

    Directory of Open Access Journals (Sweden)

    F. Martínez

    2015-08-01

    Full Text Available This paper discusses an integrated approach that provides new ideas about the structural geometry of the NNE-striking, Cretaceous Chañarcillo Basin located along the eastern Coastal Cordillera in the western Central Andes of northern Chile (27–28° S. The results obtained from the integration of two transverse (E–W gravity profiles with previous geological information, show that the architecture of this basin is defined by a large NNE–SSE-trending and east-vergent anticline ("Tierra Amarilla Anticlinorium", which is related to the positive reactivation of a former Cretaceous normal fault (Elisa de Bordos Master Fault. Moreover, intercalations of high and low gravity anomalies and steep gravity gradients reveal a set of buried, west-tilted half-grabens associated with a synthetic normal fault pattern. These results, together with the uplift and folding style of the Cretaceous syn-rift recognized within the basin, suggest that their complete structural geometry could be explained by an inverted fault system linked to the shortening of pre-existing Cretaceous normal fault systems. Ages of the synorogenic deposits exposed unconformably over the frontal limb of the Tierra Amarilla Anticlinorium confirm a Late Cretaceous age for the Andean deformation and tectonic inversion of the basin.

  19. A conceptual socio-hydrological model of the co-evolution of humans and water: case study of the Tarim River basin, western China

    Science.gov (United States)

    Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.

    2015-02-01

    The complex interactions and feedbacks between humans and water are critically important issues but remain poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable for improving our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simplified conceptual socio-hydrological model based on logistic growth curves is developed for the Tarim River basin in western China and is used to illustrate the explanatory power of such a co-evolutionary model. The study area is the main stream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four sub-systems, i.e., the hydrological, ecological, economic, and social sub-systems. In each modeling unit, the hydrological equation focusing on water balance is coupled to the other three evolutionary equations to represent the dynamics of the social sub-system (denoted by population), the economic sub-system (denoted by irrigated crop area ratio), and the ecological sub-system (denoted by natural vegetation cover), each of which is expressed in terms of a logistic growth curve. Four feedback loops are identified to represent the complex interactions among different sub-systems and different spatial units, of which two are inner loops occurring within each separate unit and the other two are outer loops linking the two modeling units. The feedback mechanisms are incorporated into the constitutive relations for model parameters, i.e., the colonization and mortality rates in the logistic growth curves that are jointly determined by the state variables of all sub-systems. The co-evolution of the Tarim socio-hydrological system is then analyzed with this conceptual model to gain insights into the overall system dynamics and its sensitivity to the

  20. The role of anthropogenic water reservoirs within the landscapes of mining areas – a case study from the western part of the Upper Silesian Coal Basin

    Directory of Open Access Journals (Sweden)

    Jaruchiewicz Ewelina

    2014-03-01

    Full Text Available A few thousand anthropogenic water reservoirs can be found in the area of the Upper Silesian Coal Basis (USCB located in southern Poland. In this paper the role of such anthropogenic lakes in the landscape of the western part of the USCB was presented and illustrated with the example of Knurów, a mining city, and its immediate surrounding area. The study of landscape changes in this area was carried out on the basis of archival and contemporary cartographic materials, historical sources, and interviews with inhabitants and direct field observations. It was found that the origin of the majority of the water reservoirs is related to hard coal, clay and sand mining. They were created primarily as a result of filling subsidence basins and post-mining excavations with water, as well as being the result of the construction of various hydro-technical facilities (settling ponds, fire protection water reservoirs, etc. In the study area the anthropogenic water reservoirs are of different sizes, shapes and durability and play different roles in the environment. Between 1884 and 2001 their number increased 25-fold, while at the same time their total surface area increased more than 8-fold. The role of the newly created water reservoirs in the landscape primarily involves the transformation of the existing terrestrial ecosystems into wetland ecosystems. The agro-forestry landscape of the late 19th century was transformed into a typically anthropogenic landscape with a dominant share of water reservoirs, settlement ponds and mining waste heaps. The most common species of plants around the water reservoirs are Phragmites australis, Typha latifolia, Ceratophyllum demersum, Elodea canadensis, Potamogeton natans, Lemna sp., Acorus calamus, Myriophyllum verticillatum, Sagittaria sagittifolia, Alisma plantago-aquatica and Glyceria aquatica. The most valuable elements of the flora include Trapa natans and Ruppia maritima, species recognized in Poland as threatened

  1. Microbial and hydrothermal aspects of ferric oxyhydroxides and ferrosic hydroxides: the example of Franklin Seamount, Western Woodlark Basin, Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Boyd TD

    2001-09-01

    Full Text Available Deposits of Fe-Si-Mn oxyhydroxides are commonly found on the seafloor on seamounts and mid-ocean spreading centers. At Franklin Seamount located near the western extremity of Woodlark Basin, Papua New Guinea, Fe-Si-Mn oxyhydroxides are being precipitated as chimneys and mounds upon a substrate of mafic lava. Previous studies have shown that the vent fluids have a low temperature (20–30°C and are characterized by a total dissolved iron concentration of 0.038 mM kg-1, neutral pH (6.26 and no measurable H2S. The chimneys have a yellowish appearance with mottled red–orange patches when observed in situ from a submersible, but collected samples become redder within a few hours of being removed from the sea. The amorphous iron oxyhydroxides, obtained from active and inactive vents, commonly possess filamentous textures similar in appearance to sheaths and stalks excreted by the iron-oxidizing bacteria Leptothrix and Gallionella; however, formless agglomerates are also common. Textural relationships between apparent bacterial and non-bacterial iron suggest that the filaments are coeval with and/or growing outwards from the agglomerates. The amorphous iron oxyhydroxides are suggested to precipitate hydrothermally as ferrosic hydroxide, a mixed-valence (Fe2+-Fe3+ green–yellow iron hydroxide compound. Consideration of the thermodynamics and kinetics of iron in the vent fluid, suggest that the precipitation is largely pH controlled and that large amounts of amorphous iron oxyhydroxides are capable of being precipitated by a combination of abiotic hydrothermal processes. Some biologically induced precipitation of primary ferric oxyhydroxides (two-XRD-line ferrihydrite may have occurred directly from the fluid, but most of the filamentous iron micro-textures in the samples appear to have a diagenetic origin. They may have formed as a result of the interaction between the iron-oxidizing bacteria and the initially precipitated ferrosic hydroxide that

  2. Episodic Forearc Uplift Related to Subduction of the Woodlark Basin, Western Solomons Arc: Intermittent Aseismic Slip or Multi-Century Earthquake Recurrence Intervals?

    Science.gov (United States)

    Taylor, F. W.; Frohlich, C.; Mann, P.; Burr, G. S.; Beck, W.; Edwards, R. L.; Phillips, D. A.

    2003-12-01

    Aseismic subduction of very young lithosphere may occur if the downgoing plate is too young and hot to support stick-slip cycles of interplate elastic strain accumulation and rupture. However, we have found a series of discrete episodic uplift events of 1-2 m each in the Western Solomons forearc where ˜1-2 Ma Woodlark Basin lithosphere is subducting at rates on the order of 80-100 mm/yr. These uplift events produce average forearc Holocene uplift rates ranging up to 5-8 mm/yr on southern Rendova and Tetepare Islands about 25 km from the plate boundary in a forearc area lacking historical evidence for large forearc thrust events. The best evidence of paleouplifts is in central eastern Rendova where the Holocene uplift rate is ˜3 mm/yr. Here we find morphologically pristine emerged corals at ˜2 m elevation that give a cluster of radiocarbon ages (783+/-38, 799+/-28, 800+/-34 yr BP) (calib. age: 279 - 463 yr BP) that match a local solution notch at ˜2 m elevation. Additional distinct notches occur immediately above at ˜3.5 and 5 m elevation. Corals at ˜3.3 m give ages of 1286+/-43 yr BP(calib. age: 663 -787 yr BP) and at ˜ 4.75 m the age is 1436+/-39 yr BP (calib. age: 762 - 932 yr BP). Additional notches cut the lower 10 m of emerged Holocene reef that rises to 20 m maximum elevation in this area. Thus, late Holocene uplift appears to occur by discrete events on the order of 1-2 m that affect a large area of the outer forearc. Maximum uplift rates located in a zone only ˜25 km from the convergent plate boundary are best explained by subducting rugged seafloor topography causing full or at least partial locking of the interplate thrust zone from near the sea floor to ˜10-20 km depth on the interplate thrust zone. A recurrence interval of several hundred years between ruptures on a locked thrust zone could explain why seismicity in this area is depressed. However, if the interplate thrust zone is aseismic, then perhaps these uplift events are generated by

  3. Contributions to the phytocoenological study of the association Pulmonario rubrae-Fagetum (Soó 1964 Täuber 1987 in the Oraştie River basin (Central-Western Romania

    Directory of Open Access Journals (Sweden)

    Valeriu Ioan VINTAN

    2013-05-01

    Full Text Available In the current paper we present a phytocoenologic study of the phytocoenoses of the association Pulmonario rubrae-Fagetum (Soó 1964 Täuber 1987, identified in the Orăştie river basin, situated in the central-western part of Romania.The characterisation of the association under analysis as well as the presentation of the synthetic table have been done by selecting the most representative relevés performed in the mixed broadleaf-needleleaf forests of beech (Fagus sylvatica subsp. sylvatica, fir (Abies alba and spruce (Picea abies with Pulmonaria rubra belonging to the Orăştie river basin.The phytocoenoses of these forests were analysed in terms of physiognomy and floristic composition, life forms spectrum, floristic elements, and ecological indices.

  4. Segmentation of Sub-Andean Retro-Arc Foreland Basins in Western South America%南美西部次安第斯弧后前陆盆地分段特征

    Institute of Scientific and Technical Information of China (English)

    琚亮; 张光亚; 温志新; 汪伟光

    2011-01-01

    Sub-Andean retro-arc foreland basins in the western margin of South America are important petroleum accumulation and produc-tion zones,and develop in three different tectonic settings: evolvement of Caribbean plate superimposed Andean-type foreland compressive deformation in the north;Sub-Andean foreland basins were in long-term the Gondwana continental marginal setting,subsequently subducted by oceanic plate and thrusted by Andean orogenesis in the middle;the shapes and evolvement of basins in Patagonia were more influenced by Gondwana breakup and opening of Atlantic in the south.Based on the evolvements and petroleum characteristics,the sub-Andean retro-arc foreland basins in the western margin of South America could be divided into 6 segments.%发育在南美西缘的次安第斯弧后前陆盆地群为南美重要的油气产区,其形成于3个大的构造背景之下:北部为加勒比板块演化叠加安第斯前陆挤压;中部的次安第斯前陆盆地长期处于冈瓦纳古陆的大陆边缘环境,之后受到大洋板块的俯冲和安第斯山脉的隆升和冲断;南部巴塔哥尼亚各盆地的形成演化更多地受到冈瓦纳古陆裂解和大西洋形成的影响。综合安第斯山脉的形成演化以及各盆地的构造演化和石油地质特征,将其划分成6段。

  5. Transition from alkaline to calc-alkaline volcanism during evolution of the Paleoproterozoic Francevillian basin of eastern Gabon (Western Central Africa)

    Science.gov (United States)

    Thiéblemont, Denis; Bouton, Pascal; Préat, Alain; Goujou, Jean-Christian; Tegyey, Monique; Weber, Francis; Ebang Obiang, Michel; Joron, Jean Louis; Treuil, Michel

    2014-11-01

    We report new geochemical data for the volcanic and subvolcanic rocks associated with the evolution of the Francevillian basin of eastern Gabon during Paleoproterozoic times (c. 2.1-2 Ga). Filling of this basin has proceeded through four main sedimentary or volcano-sedimentary episodes, namely FA, FB, FC and FD. Volcanism started during the FB episode being present only in the northern part of the basin (Okondja sub-basin). This volcanism is ultramafic to trachytic in composition and displays a rather constant alkaline geochemical signature. This signature is typical of a within-plate environment, consistent with the rift-setting generally postulated for the Francevillian basin during the FB period. Following FB, the FC unit is 10-20 m-thick silicic horizon (jasper) attesting for a massive input of silica in the basin. Following FC, the FD unit is a c. 200-400 m-thick volcano-sedimentary sequence including felsic tuffs and epiclastic rocks. The geochemical signatures of these rocks are totally distinct from those of the FB alkaline lavas. High Th/Ta and La/Ta ratios attest for a calc-alkaline signature and slight fractionation between heavy rare-earth suggests melting at a rather low pressure. Such characteristics are comparable to those of felsic lavas associated with the Taupo zone of New Zealand, a modern ensialic back-arc basin. Following FD, the FE detrital unit is defined only in the Okondja region, probably associated with a late-stage collapse of the northern part of the basin. It is suggested that the alkaline to calc-alkaline volcanic transition reflects the evolution of the Francevillian basin from a diverging to a converging setting, in response to the onset of converging movements in the Eburnean Belt of Central Africa.

  6. Cooperative research project Amax Oil and Gas Inc., Southern UTE No. 5-7 well, San Juan Basin, Southwestern Colorado. Western cretaceous coal seam project. Topical report, September 1992-January 28, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Logan, T.L.; Robinson, J.R.; Pratt, T.J.

    1995-06-01

    A cooperative research effort was performed on one Fruitland coal gas well with AMAX Oil and Gas Inc. The well is located along the western margin of the San Juan basin where both hydraulic fracture and openhole cavity completion techniques have been used. The objective of the research effort was to: (1) determine the reservoir characteristics (gas content, sorption isotherm, absolute permeability, and reservoir pressure) of a shallow Fruitland coal interval, (2) evaluate the effectiveness of the openhole cavity completion technique in the reservoir, and (3) compare the results of this openhole cavity completed well to offset hydraulic fracture completed wells.

  7. Layoff Time Training: A Key to Upgrading Workforce Utilization and EEOC Affirmative Action. A Case Study in the Northern California Canning Industry. R & D Monograph 61.

    Science.gov (United States)

    Aller, Curtis C.; And Others

    An experimental and demonstration project wa