WorldWideScience

Sample records for basin paleoenvironmental studies

  1. Great Basin paleoenvironmental studies project; Technical progress report: First quarter (January--August 1993)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Project goals, project tasks, progress on tasks, and problems encountered are described and discussed for each of the studies that make up the Great Basin Paleoenvironmental Studies Project for Yucca Mountain. These studies are: Paleobotany, Paleofauna, Geomorphology, and Transportation. Budget summaries are also given for each of the studies and for the overall project.

  2. Great Basin paleoenvironmental studies project; Technical progress report, second quarter, September--November, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Progress is described in the four tasks associated with this project. Task 1, Paleobotanical studies in the Great Basin, has as its objective the reconstruction of the response of vegetation to climate in order to identify periods of mesic climate at Yucca Mountain during the last 20,000 to 50,000 years. Past extremes in infiltration rates are expected to serve as estimates of climate that may be expected during the next 10,000 years at Yucca Mtn. Task 2, Paleofaunas, will construct a history of Great Basin vertebrates that will provide empirical evidence of past environmental and climatic conditions. The objective of Task 3, Geomorphology, is to document the responses of surficial processes and landforms to the climatic changes documented by studies of packrat middens, pollen, and faunal distributions. The goal of Task 4, Transportation, is to compare the results from three models that have been suggested as appropriate for evaluating flood flows on alluvial fans with the results obtained from the traditional one-dimensional, stochastic model used in previous research for Yucca Mountain. This research looked at three alluvial fans with rail transportation alignments crossing them.

  3. Pleistocene soil development and paleoenvironmental dynamics in East Africa: a multidisciplinary study of the Homo-bearing Aalat succession, Dandiero Basin

    Science.gov (United States)

    Scarciglia, Fabio; Mercatante, Giuseppe; Donato, Paola; Ghinassi, Massimiliano; Carnevale, Giorgio; Delfino, Massimo; Oms, Oriol; Papini, Mauro; Pavia, Marco; Sani, Federico; Rook, Lorenzo

    2015-04-01

    Pleistocene environmental changes in East Africa, largely documented by deep marine or lacustrine records correlated with inland high-resolution, Homo-bearing stratigraphic successions, have been so far interpreted as a major cause of faunal dispersal and human evolution. However, only few studies focused on reconstruction of paleoenvironmental dynamics from continental successions, given the usually poor continuity and extension of stratigraphic records. In this work we report on a multidisciplinary study of the Early to Middle Pleistocene sedimentary fill of the Dandiero Basin (Eritrean Danakil), a morpho-tectonic depression in the East African Rift System, which represents the only continental stratigraphy including human remains of Homo erectus/ergaster and abundant fossil vertebrates in the northernmost sector of this region. Sedimentological, pedological, volcanological and paleontological investigations were performed on the Aalat section, located in the northern part of the Dandiero Basin, as tools for an integrated reconstruction of the Early-Middle Pleistocene transition in East Africa. This section is almost 300 m thick and records repeated shifts from fluvial to deltaic and lacustrine depositional environments, as a response to local tectonic activity and climate changes. Sedimentary facies distribution and paleocurrent data show that sedimentation was controlled by a NS-trending axial drainage. Some tephra layers were identified both at the bottom and the top of the section, whereas two main fossiliferous layers were detected in its lower part. Terrestrial vertebrate faunas include a typical Early to Middle Pleistocene East African mammalian assemblage, where taxa characterized by strong water dependence prevail. Also the ichthyofauna is consistent with the shallow water fluvio-lacustrine paleobiotopes. High-quality paleomagnetic analyses, integrated with radiometric dating and vertebrate paleontology, allowed to substantiate the chronological

  4. Cretaceous ostracods of the Barreirinhas Basin: Taxonomy, biostratigraphic considerations and paleoenvironmental inferences

    Science.gov (United States)

    Santos Filho, M. A. B.; Fauth, G.; Piovesan, E. K.

    2017-01-01

    Ostracods are microcrustaceans that inhabit different aquatic environments and are frequently used in paleoecological interpretations and biostratigraphic studies. The Barreirinhas Basin, Northern of Brazil, contains a well-preserved ostracod assemblage in its sedimentary rocks of early and late Cretaceous age, which have been so far poorly studied. This paper contains the first taxonomic identification of the ostracod assemblages, as well as the elaboration of paleoenvironmental and biostratigraphic inferences, for the Cretaceous of the Barreirinhas Basin. The studied material consists of 147 samples from the wells 1-MAS-1A, 1-MAS-3A, 1-MAS-4A and 1-MAS-14A. 495 specimens were recovered, distributed between 40 species, 16 genera and 9 families, including three new species. Based on previously established biozones for the Sergipe basin, two biozones were identified: the Nigeroloxoconcha aff. Nigeroloxoconcha sp. GA A 22 Range Zone, of lower Cenomanian age; and the Brachycythere sapucariensis Interval Zone, of Turonian to middle Coniacian age. Finally, three distinct ostracod assemblages were defined: Assemblage 1, dominated by Conchoecia? species; Assemblage 2, well diversified but with low abundance; and Assemblage 3, with cold water ostracods such as Krithe. Based on the ostracod assemblages identified, a middle neritic, platformal paleoenvironment was inferred for the studied interval.

  5. Paleoenvironmental reconstruction of the Early Eocene Wind River Formation in the Wind River Basin, Wyoming

    Science.gov (United States)

    Hyland, E.; Fan, M.; Sheldon, N. D.

    2011-12-01

    Terrestrial basin systems provide important information on paleoclimatic, paleoecological, and paleoenvironmental factors and how they control and respond to global changes and spatio-temporal heterogeneity. Examining these dynamics is crucial for times of major global change like the broad-scale climatic trends (warm/wet/high-CO2 conditions) of the Early Eocene Climatic Optimum (EECO). As most climatic records of such events are derived from global marine datasets, regional terrestrial studies such as these provide a better model for understanding ecological responses and the localized effects of events like the EECO. The formation of the Wind River Basin (northwestern Wyoming) has been studied for decades, but its regional climatic, environmental, and ecological dynamics have been largely overlooked. Recent work in other contemporaneous sites in the Green River Basin has suggested that the dynamics and rapidity of climate change in terrestrial interiors during the EECO may have been significantly different than what is indicated by the marine record, so to address these issues on a more regional scale we examined paleosols preserved in the fluvial, basin-margin Wind River Formation preserved near Dubois, Wyoming. Field identification of the paleosols indicated a suite that includes primarily Inceptisols and Alfisols; most exhibited significant redoximorphic features and Bg horizons that indicate a ponded floodplain paleoenvironment, while others contained deep Bk horizons (>100 cm) consistent with more well-drained, but still sub-humid to humid conditions. Based on the identification of these well-developed soil features, along with distinct horizonation and root development, paleosols were robustly correlated and sampled throughout the Formation, and environmental descriptors were assigned. To further examine the question of regional terrestrial climate/environmental change, whole rock geochemistry (XRF) samples from paleosol depth profiles were analyzed for use

  6. Paleoenvironmental reconstruction of the late Cenozoic Qaidam Basin, China

    Science.gov (United States)

    Zhang, C.; Wang, Y.; Li, Q.; Wang, X.; Deng, T.; Tseng, Z. J.; Takeuchi, G.; Xie, G.; Xu, Y.

    2011-12-01

    Reconstruction of paleoenvironments in the Tibetan region is important to understanding the linkage between tectonic force and climate change. Here we report new isotope data from the Qaidam Basin, China, which is located on the northeastern Tibetan Plateau, including stable C and O isotope analyses of a wide variety of late Cenozoic mammalian tooth enamel samples (including deer, giraffe, horse, rhino, and elephant), and O isotope compositions of phosphate (δ18Op) in fish bone samples. Mammalian tooth enamel δ13C values, when combined with fossil assemblage and other geological evidence, indicate that the Qaidam Basin was warmer and more humid during the late Miocene and early Pliocene, and that there was lush C3 vegetation with significant C4 components at that time, although the C4 plants were not consistently utilized. In contrast, the modern Qaidam Basin is dominated by C3 plants. Fish bone δ18Op values showed statistically significant enrichment from the Tuxi-Shengou-Naoge interval (late Miocene) to the Yahu interval (early Pliocene) and from the Yahu interval to the present day. This most likely reflects increases in the δ18O of lake water over time, as a result of increased aridification of the Qaidam Basin. Assuming that mammals drank exclusively from the lake, temperatures were calculated from average δ18Op values and average δ18Ow derived from large mammal tooth enamel δ18O. Temperatures were also estimated from δ18Op and δ18Ow estimated from co-ocurring large mammal tooth enamel δ18O. The temperature estimates were all lower than the average temperature of the modern Qinghai Lake surface water during the summer, and mostly too low to be reasonable, indicating that the fish and the large mammals were not in equilibrium with the same water. Assuming the relationship between salinity and δ18Ow observed for the modern Qinghai Lake and its surrounding lakes and ponds applied in the past, we calculated the paleosalinities of lake waters to be ~0 to

  7. 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

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

    Science.gov (United States)

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

    2016-08-01

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

  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. Paleoenvironmental and source rock assessment of black shales of Pennsylvanian Age, Powder River and northern Denver basins

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, J.L.; King, J.D.; Lubeck, C.M.; Leventhal, J.S.; Daws, T.A.

    1988-07-01

    Thin Middle Pennsylvanian (Desmoinesian) organic-rich black shales (cumulative thickness < 50 ft) underlie much of the northern Denver basin and southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present area of the southeastern Powder River basin and Nebraska was a shallow, at times highly saline, restricted sea. In contrast, in the present area of northeastern Colorado, black shales were deposited in a marine environment with normal salinity that was probably continuous with the Mid-Continent Pennsylvanian sea. Assessment of the paleoenvironment has been carried out using organic geochemical parameters. Shales deposited in the restricted basin setting contain abundant porphyrins (25,000-30,000 ppm relative to total extractable organic matter) and significant quantities of aryl isoprenoids. The aryl isoprenoid compounds (1) are evidence for the presence of the sulfur bacteria families Chlorobiaceae and possibly Chromatiaceae and (2) indicate that euxinic conditions existed in the water column. High ratios of sulfur to carbon in the shales support this interpretation. In contrast, extracts from black shale in the normal sea to the south contain lower porphyrin concentrations (generally less than 1000 ppm) and aryl isoprenoids are minor constituents or are absent. Sulfur/carbon ratios in these latter shales are similar to those observed for normal marine shales (that is, not euxinic conditions). Other paleoenvironmental indicators (sterane composition, alkane distribution) are consistent with these observations. Bulk organic matter in the black shales from both environments is type II and has good source potential for generation of liquid hydrocarbons during catagenesis. Pyrolysis yields of 50 kg/MT (50,000 ppm) are common, and in some shales, yield is 100 kg/MT (100,000 ppm).

  11. Facies analysis and paleoenvironmental reconstruction of Upper Cretaceous sequences in the eastern Para-Tethys Basin, NW Iran

    Energy Technology Data Exchange (ETDEWEB)

    Omidvar, M.; Safari, A.; Vaziri-Moghaddam, H.; Ghalavand, H.

    2016-07-01

    Upper Cretaceous mixed carbonate-siliciclastic sequences are among the most important targets for hydrocarbon exploration in the Moghan area, located in the eastern Para-Tethys Basin. Despite of their significance, little is known about their facies characteristics and depositional environments. Detailed facies analysis and paleoenvironmental reconstruction of these sequences have been carried out in eight surface sections. Accordingly, four siliciclastic facies, eight carbonate facies and one volcanic facies have been recognized. Detailed facies descriptions and interpretations, together with the results of facies frequency analysis, standard facies models and Upper Cretaceous depositional models of Para-Tethys Basin, have been integrated and a non-rimmed carbonate platform is presented. This platform was affected by siliciclastic influx, in the form of coastal fan delta and submarine fans in the shallow- to deep-marine parts, respectively. This model is interpreted to be shallower in the central and northeastern parts of the Moghan area. Toward the southeast and southwest, this shallow platform turns into deep marine settings along steep slopes without remarkable marginal barriers. (Author)

  12. Ichnofossil from the Cambrian succession of Parahio Valley, Spiti Basin, India: Their stratigraphic and paleoenvironmental significance

    Science.gov (United States)

    Pandey, Shivani; Parcha, Suraj Kumar

    2013-04-01

    The Spiti Basin exposes an excellent section of Neoproterozoic- Cretaceous rocks in the Tethyan Himalaya of Himachal Pradesh. The diverse assemblage of ichnofossils is present in the Cambrian succession of Parahio Valley in the Spiti Basin. In the present study nineteen ichnofossils are reported from the Cambrian succession of Parahio Valley. The ichnofossils includes Bergaueria, Chondrites, Cruziana, Didymaulichnus, Dimorphichnus, Diplichnites, Helminthorhaphe, Merostomichnites, ?Monocraterion, Monomorphichnus, Nereites, Palaeopascichnus, Palaeophycus, Phycodes, Planolites, Rusophycus, Skolithos, Scolicia, Treptichnus etc. along with annelid worm, burrow and scratch marks. The described ichnofossil assemblage indicates that the ichnocenosis is dominated by a high behavioral diversity ranging from suspension to deposit feeders. It seems that the ichnofauna present in the Cambrian succession of this section were mostly produced by trilobite and arthropods, whereas some of them were produced by crustacean, priapulid worm, polychaetes and polyphyletic vermiforms. The distribution pattern of ichnofossils shows increase in taxonomic and morphological diversity up in the section. It further indicates that the availability of nutrients significantly increased their abundance as well as spatial distribution during Cambrian. The presence of Chondrites, Treptichnus, and Phycodes at the basal part of the Cambrian indicates shallow to deep environment with anaerobic condition. Whereas, the complex forms like Rusophycus, Cruziana, Monomorphichnus and Nereites represent shelf to slope environment. The appearance of Skolithos in the upper part reflects well oxygenated high energy condition. The environmental changes in the Parahio Valley during Cambrian period was distinctly marked by an anaerobic to aerobic condition and by a faunal change from endobenthic, soft - bodied, deposit feeders to epibenthic grazers. The present ichnofossils indicates that these sediments were

  13. PaleoGeo: a Web based GIS database for paleoenvironmental studies

    Science.gov (United States)

    Song, Wonsuh; Kondo, Yasuhisa; Oguchi, Takashi

    2014-05-01

    Paleoenvironmental studies cover various fields such as paleohydrology, geomorphology, paleooceanology, paleobiology, paleoclimatology, and chronology. It is difficult for an individual researcher to collect and compile enormous data regarding these fields. We have been compiling portal data and presenting them using a web-based geographical information system (Web-GIS) called PaleoGeo for the multidisciplinary project 'Replacement of Neanderthals by Modern Humans'. The aim of the project is to reconstruct the distribution of Neanderthals and modern humans in time and space in relation to past climate change. We have been collecting information from almost three thousand articles of 13 journals regarding paleoenvironmental research (i.e., Boreas, Catena, Climatic Change, Earth Surface Processes and Landforms, Geomorphology, Journal of Quaternary Science, Palaeogeography, Palaeoclimatology, and Palaeoecology, Quaternary International, Quaternary Research, Quaternary Science Reviews, The Holocene, and The Journal of Geology). The topics of the articles were classified into six themes (paleohydrology, earth surface processes and materials, paleooceanology, paleobiology, palaeoclimatology, and chronology) and 19 subthemes (hydrology, flood, fluvial, glacier, fluvial/glacier, sedimentology, soil, slope process, periglacial, peat land, eolian, sea-level, biology, vegetation, zoology, vegetation/zoology, archaeology, climate, atmosphere, and chronology). The collected data consist of the journal name, information about each paper (authors, title, volume, year, and page numbers), site location (country name, longitude, and latitude), theme, subtheme, keywords, DOI (Digital Object Identifier), and period (era). Location data are indispensable for paleoenvironmental studies. The PaleoGeo shows information with a map, which is an advantage of this database system. However, the number of the paleoenvironmental studies is growing rapidly and we have to effectively cover them as

  14. Evidence of late Quaternary wet/dry climate episodes derived from paleoclimatic proxy data recovered from the paleoenvironmental record of the Great Basin of western North America: Paleobotanical studies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    Through the integration of several avenues of paleoclimatic proxy data, the authors intend to arrive a definite conclusions regarding the frequency of periods of wetter climate, and to drive information regarding the magnitudes of these episodes, rates of their onset and demise, and the climatic conditions under which wetter climate can occur. These will in turn lead to rough estimates of: (1) the amounts of rainfall available for recharge during past periods of effectively wetter climate; and (2) the durations and spacing of such events that provide an indication of the amount of time that the area was subjected to these inputs. To accomplish these goals the paleobotanical record over a broad region is being examined to identify periods of greater effective precipitation. Although the project focus is on a region a of about 200 km around Yucca Mountain, they have collected data in other areas of the Great Basin in order to be able to identify large-scale climatic patterns. Once identified and described these climatic patterns can be separated from purely local climatic phenomena that might hinder the understanding of the Pliestocene climates of southern Nevada and the Yucca Mountain area in particular.

  15. Paleoenvironmental reconstruction of a downslope accretion history: From coralgal-coralline sponge rubble to mud mound deposits (Eocene, Ainsa Basin, Spain)

    Science.gov (United States)

    Rodríguez-Martínez, Marta; Reitner, Joachim

    2015-12-01

    In the Lutetian intraslope Ainsa sub-basin, small, sub-spherical, carbonate mud mounds occur associated with hemipelagic marls and mixed gravity flow deposits. The studied mud mounds consist of a mixture of allochthonous, parautochthonous and autochthonous components that show evidences of reworking, bioerosion, and accretion by different fossil assemblages at different growth stages. The crusts of microbial-lithistid sponges played an important role stabilizing the rubble of coralgal-coralline sponges and formed low-relief small benthic patches in a dominant marly soft slope environment. These accidental hard substrates turned into suitable initiation/nucleation sites for automicrite production (dense and peloidal automicrites) on which the small mud mounds dominated by opportunistic epi- and infaunal heterozoan assemblages grew. A detailed microfacies mapping and paleoenvironmental analysis reveals a multi-episodic downslope accretion history starred by demosponges (coralline and lithistid sponges), agariciid corals, calcareous red algae, putative microbial benthic communities and diverse sclerobionts from the upper slope to the middle slope. The analyzed mud mound microfacies are compared with similar fossil assemblages and growth fabrics described in many fossil mud mounds, and with recent deep-water fore reefs and cave environments.

  16. Clay mineral association in the salt formation of the Transylvanian Basin and its paleoenvironmental significance

    Directory of Open Access Journals (Sweden)

    Nicoleta Bican-Bris̡an

    2006-04-01

    Full Text Available The investigated clay fraction was separated from salt samples recovered from three boreholes located in the Praid salt deposit area. For comparison, samples collected from Turda deposit (Franz Josef adit, the Rudolf and Ghizele chambers and from the salt massif from Sărăţel were also analyzed. The qualitative investigations evidenced a clay minerals association dominated by illite and chlorite accompanied by subordinate amounts of kaolinite, smectite, fibrous clays (sepiolite, palygorskite, and in minor amounts, by 14/14 chlorite/vermiculite and chlorite/smectite interstratifications. A quantitative evaluation (% including a standard graphical representation was performed only for the borehole samples (Praid, according to the vertical distribution. The genetical interpretation of the identified clay minerals association took into account the influence of the sedimentation mechanisms and the climate control on the mineral phases. The environment of formation for the salt in the Transylvanian Basin was defined by the presence of specific climatic factors, also suggested by the palynological investigations.

  17. Phytolith aided paleoenvironmental studies from the Dutch Neolithic

    Science.gov (United States)

    Persaits, Gergő; Gulyás, Sándor; Náfrádi, Katalin; Sümegi, Pál; Szalontai, Csaba

    2015-11-01

    There is increasing evidence for crop cultivation at sites of the Neolithic Swifterbant culture from ca. 4300 B.C. onwards. Presence of cereal fields at the Swifterbant S2, S3 and S4 sites has been corroborated from micro morphological studies of soil samples. Swifterbant sites with evidence for cultivated plants are still scarce though and only emerging, and have produced very low numbers of charred cereals only. The major aim of our work was to elucidate the environmental background of the Dutch Neolithic site Swifterbant S4 based on the investigation of phytolith remains retrieved from soil samples. In addition to find evidence for crop cultivation independently from other studies. Samples were taken at 1 cm intervals vertically from the soil section at the central profile of site S4. Additional samples were taken from pocket-like structures and adjacent horizons above and below. Pig coprolites yielded an astonishing phytolith assemblage which was compared to that of the soil samples. A pig tooth also yielded evaluable material via detailed investigation using SEM. The evaluation of phytolith assemblages retrieved from the soil horizons plus those ending up in the droppings of pigs feasting in the area enabled to draw a relatively reliable environmental picture of the area. All these refer to the presence of a Neolithic horticulture (cereal cultivation) under balanced micro-climatic conditions as a result of the vicinity of the nearby floodplain. These findings corroborate those of previous soil micro-morphological studies.

  18. Paleoenvironmental interpretation using fossil record: San Juan Raya Formation, Zapotitlán basin, Puebla, Mexico

    OpenAIRE

    2014-01-01

    The San Juan Raya Formation is world-wide recognized because of the high diversity and abundance of fossils. In this study nine biofacies, three ichnofacies and ten lithofacies were recognized and interpreted on the basis of the influence of several environmental factors such as water depth change, sedimentation rate, water salinity and substrate consistency. Among these factors, salinity variations were apparently crucial for developing and replacement of the different biofacies. Most of bio...

  19. Late Pliensbachian-early Toarcian paleoenvironmental changes in the Cleveland Basin: new clues from high-resolution trace element analysis

    Science.gov (United States)

    Thibault, N.; Ruhl, M.; Ullmann, C. V.; Korte, C.; Kemp, D. B.; Hesselbo, S. P.

    2013-12-01

    The early Toarcian (~183 Ma ago) was characterized by massive carbon burial and a pronounced negative carbon-isotope excursion (CIE) in marine carbonate and marine and terrestrial organic matter. These features along with the high abundance of redox sensitive trace metals in that interval led to the recognition of a major oceanic anoxic event (OAE). More recently, an earlier companion of the early Toarcian CIE has been documented at the Pliensbachian/Toarcian (Pl/To) boundary in sections of NW Europe, but its expression in the sediment and possible causes are less constrained. One of the most studied areas for this interval is the Cleveland Basin, UK, which is well-studied for litho-, bio- and chemostratigraphy. Here, we present a new dataset of high-resolution element data produced by hand-held X-ray fluorescence analysis to test for the expression of redox-sensitive trace metals and detrital elements across the late Pliensbachian to middle Toarcian of the Cleveland Basin. The Pl/To boundary CIE is associated with low Total Organic Carbon (TOCoxygenation events that prevented massive deposition of organic matter. Trends from redox-sensitive elements such as Fe, V, Mo and U are in agreement with previous findings and scenarios of basin restriction across and after the early Toarcian OAE (McArthur et al., 2008). An interval of maximum enrichment in these elements immediately after the CIE is a feature very similar to the recent observations of Hermoso et al. (2013) in the Paris Basin. This suggests a similar tempo of regional anoxia and black shale deposition in NW Europe. These results also shed light on the behaviour of elements associated with organic matter and the sulphur cycle such as Ni, Cu, Zn and As. Cu is well-correlated to the TOC whereas As shows an enrichment in the interval of black shale deposition after the CIE and two distinct correlation lines with sulphur, one before and during the event, and one after the CIE. This suggests that more As could be

  20. Late Holocene paleoenvironmental changes in Equatorial Africa as reconstructed by a diatom-based study of Lac Divangui (Gabon) sediments

    Science.gov (United States)

    Ariztegui, Daniel; Anselmetti, Flavio; Zosso, Anouk

    2016-04-01

    In recent years, an increasing number of studies have focused on the role of the tropics and the Equator as triggers of changes in the climate system at different time scales. There is, however, a remarkable paucity of continuous paleoenvironmental records in these areas preventing a better understanding of their role as climate forcing mechanisms. Lac Divangui is located at 2° south of the Equator in the forest of Rabi-Kunga, Gabon. This 1-km diameter basin attains a maximum depth of 80 m and provides a unique site to obtain a continuous archive of environmental changes through time. Previous investigations have shown that these organic-rich sediments contains large amounts of gas that, from a seismic surveying perspective, has prevented penetration of the acoustic signal. A range-finding study of the total organic fraction using Rock-Eval pyrolysis in a sedimentary core from the center of the basin showed a stable total organic content that is very high in average (~10%). A more detailed look into both the total organic fraction and certain biological remains, however, have shown substantial changes in both the quality of the total organic matter as well as the dominant diatom assemblages since 4.2 kyrs. BP. Although wet conditions appear to dominate the studied interval, several periods of dryness were identified around 2.4, 1.5 and 0.75 kyrs. BP. Since this last date the prevailing environmental conditions appear to be similar than today. These data are in agreement with observations in other African regions and are interpreted as related to the north-south movement of the Intertropical Convergence Zone (ITCZ). Gabon has the highest biodiversity of tropical Africa and previous investigations have shown that the tropical rainforest has reacted to both climate and human-induced environmental changes throughout the Holocene. Our combined sedimentological and organic remains results allow reconstructing the tropical rainforest history through time, which can be in

  1. Multi-approach study (preliminary essays) to understand the paleoenvironmental and paleoclimatic conditions related to the genesis of exotic Cu-deposits, northern Chile

    Science.gov (United States)

    Fernandez Mort, A.; Riquelme, R.; Cabezas, A.; Muñoz, S.; Pizarro, H.

    2013-12-01

    Late Cenozoic (10 Ma) secondary Cu-sulfides and, eventually, exotic Cu-deposits are considerably common within the Atacama Desert. These deposits are supposed to have a strong relationship with the paleoenvironmental and paleoclimatic conditions from that time. A study of the Tesoro Basin attempts to understand these connections using two proxies: clay mineral analysis and magnetic properties. Results obtained from both techniques are compared and related to the stratigraphic record previously determined in this area. Three main geological units are distinguished: Zanja perimetral gravels, Quebrada Los Arrieros gravels and Quebrada Los Arrieros fine-grained deposits. Clay mineral analysis results (fig. 1) help to confirm the paleoenvironmental meaning of the different facies associations located in the Quebrada Los Arrieros gravels. Variations in smectite, kaosmectite and illite contents can be explained as changes in the ability of being transported and selected in the sedimentary system. A priori, smectite crystals are smaller and form low-density agglomerates. They are probably able to be in suspension for a relatively longer time than the other clay minerals. Thus, some kind of preferential selection is expected during transportation of (detrital) clays. The magnetic properties (fig. 2) are the key to understanding the hydrologic variations through time in the Quebrada Los Arrieros fine-grained deposits. Correlation between magnetic properties and facies associations suggest that the hydrologic regime controls the amount of detrital minerals vs. neoformed ferromagnetic minerals. Higher values of magnetic susceptibility are correlated to strata with finer particles, which are interpreted as the result of higher water table periods. These results, combined with the stratigraphic record and the different paleosols observed, suggest a trend of formation commencing with a relatively humid period that progressively changes to a period of dessication. It remains

  2. Late Pliensbachian-early Toarcian paleoenvironmental changes in the Cleveland Basin: new clues from high-resolution trace element analysis

    DEFF Research Database (Denmark)

    Thibault, Nicolas Rudolph; Ruhl, Micha; Ullmann, Clemens Vinzenz

    The early Toarcian (~183 Ma ago) was characterized by massive carbon burial and a pronounced negative carbon-isotope excursion (CIE) in marine carbonate and marine and terrestrial organic matter. These features along with the high abundance of redox sensitive trace metals in that interval led...... to the recognition of a major oceanic anoxic event (OAE). More recently, an earlier companion of the early Toarcian CIE has been documented at the Pliensbachian/Toarcian (Pl/To) boundary in sections of NW Europe, but its expression in the sediment and possible causes are less constrained. One of the most studied...... elements across the late Pliensbachian to middle Toarcian of the Cleveland Basin. The Pl/To boundary CIE is associated with low Total Organic Carbon (TOC

  3. Biogeochemistry of selenium isotopes: processes, cycling and paleoenvironmental applications. (Utrecht Studies in Earth Sciences 24)

    OpenAIRE

    Mitchell, K.A.

    2012-01-01

    Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has been suggested as a potentially powerful environmental tracer and paleoenvironmental proxy. Chapter 1 provides a literature review of the Se cycle. While the Se cycle shares some similarities with the S cycle, there are major differences that become apparent from a synthesis of the existing literature, we therefore compare the oceanic cycles of Se and S in Chapter 2. The biogeochemi...

  4. The microfauna assemblages as indicators of paleoenvironmental changes in the Miocene fluvial- lacustrine cycles (NE Duero Basin, Spain

    Directory of Open Access Journals (Sweden)

    A. Herrero-Hernández

    2016-11-01

    Full Text Available The siliclastic and carbonate deposits are interbedded in the Villadiego area (Miocene, NE Duero Basin. They have been subdivided into two high-rank depositional sequences: DDS and CDS. The sedimentary analysis of these units and the study of the microfauna content, mainly ostracods, led to the identification of lacustrine-fluvial interaction systems. The sedimentary characteristics reveal the existence of fluvial systems of gravel, flood plains and lacustrine systems that were interconnected and intimately related in north-south direction. In the sedimentological analysis, thirteen types of fluvial and lacustrine lithofacies and six genetic facies associations were recognized. The top of DDS is the result of lake level risings. The CDS shows a deepening-shallowing cycle. The ostracod micropaleontological analysis of the sediments have been studied, with the aim of reconstructing the palaeoenvironmental evolution of this area. These microfauna assemblages integrated with the analysis of the sedimentary facies allowed to conclude the existence of lakes with a water-bearing level of few tens of meters. A change in the chemical conditions of the waters, which evolved from oligohaline and carbonated to mesohaline and sulphated is concluded.

  5. Fossil invertebrates records in cave sediments and paleoenvironmental assessments: a study of four cave sites from Romanian Carpathians

    Directory of Open Access Journals (Sweden)

    O. T. Moldovan

    2015-06-01

    Full Text Available Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new for science, and most of them are indicative for either warm/cold stages or dry/wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures, and hydraulic regimes could be gathered. This paper analyses the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

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

    Science.gov (United States)

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

    2010-05-01

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

  7. Taphonomy of Condensed Shell Storm beds of the Teresina Formation in Rio Preto (State of Paraná, Middle Permian, Paraná Basin: Paleoenvironmental Implications

    Directory of Open Access Journals (Sweden)

    Jacqueline Peixoto Neves

    2011-12-01

    Full Text Available The deposits of the Permian Teresina Formation are mainly characterized by fi ne-grained siliciclastic rocks and centimetricintercalations of tempestites (bioclastic sandstones and coquinas. Despite the relevance of the bivalve-rich carbonate bedsof the Teresina Formation to paleoenvironmental studies, their taphonomy is still poorly studied. The fossil concentrationstudied in this work was found in a quarry in the city of Irati, Rio Preto district, Paraná State. The fossil concentration is locatedin the middle/upper portion of the unit, far from the top. The studied bed is a bioclastic, intraclastic, peloidal, grainstone/packstone, with abundant bivalve shell fragments, pelitic and micritic intraclasts, peloids, rare ooids and oncoids, as well aspermineralized of Lycophyta microphylles and fi sh scales. The grains of this carbonate concentration show: high degree oftime-averaging, variable degree of packing (dense to disperse, no sorting and chaotic orientation. Notably, the concentrationincludes a mixture of elements which are indicative of: a restrictive, low energy, carbonate environment (peloids, ooidsand oncoids; b subaerial environment surrounding the main body of water (Lycophyta microphylles and c quiet-waterenvironment punctuated by storm events, where the suspension-feeding bivalves thrived. At least four depositional eventscaused by storm fl ows were recorded. The amalgamated nature of the bed is a result of storm events in an intracratonic basinwith very low seafl oor slope and low rates of sedimentation and subsidence.

  8. Palynofacies as indicators of paleoenvironmental changes in a Cretaceous succession from the Larsen Basin, James Ross Island, Antarctica

    Science.gov (United States)

    Carvalho, Marcelo de A.; Ramos, Renato R. Cabral; Crud, Monika Beatriz; Witovisk, Luciana; Kellner, Alexander W. A.; Silva, Helder de P.; Grillo, Orlando N.; Riff, Douglas; Romano, Pedro S. R.

    2013-09-01

    In order to reconstruct the paleoenvironment of one of the most extensive marine Cretaceous successions in the Southern Hemisphere, palynofacies analyses were conducted on 83 samples from the Whisky Bay (Albian-Turonian), Hidden Lake (Coniacian) and Santa Marta (Santonian-Campanian) formations in the Larsen Basin, James Ross Island, Antarctica. Categories of particulate organic matter were counted and investigated by cluster analysis. The trends and parameters of palynofacies constituents were used to reconstruction paleoenvironments based on the existing sedimentological interpretation. The stratigraphic distribution of the four identified palynofacies associations (A-D) reflects a continuous terrestrial influx throughout the succession. From base to top, a conspicuous increase in woody elements, especially non-opaque particles, is observed. This increase in continental elements occurs despite the presence of marine elements. This finding corroborates the sedimentological interpretation of a deeper water paleoenvironment during deposition of the Whisky Bay Formation and initiation of a shallowing-upward trend in the Hidden Lake Formation, culminating with shallow marine shelf environment of the Santa Marta Formation.

  9. Archaeological and paleoenvironmental investigations in the Ash Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an archeological and paleoenvironmental study of Ash Meadows NWR. Archaeological and paleoenvironmental studies were conducted by the Quaternary Sciences...

  10. Paleoenvironmental change as derived from loess sediment properties: Examples of last glacial loess sites from the Carpathian Basin

    Science.gov (United States)

    Lehmkuhl, Frank; Zeeden, Christian; Bösken, Janina; Eckmeier, Eileen; Hambach, Ulrich; Hauck, Thomas; Klasen, Nicole; Markovic, Slobodan; Obreht, Igor; Schulte, Philipp; Sümegi, Pal; Chu, Wei; Timar-Gabor, Alida; Veres, Daniel

    2015-04-01

    The project B1 within the CRC 806 "Our way to Europe" focuses on the "Eastern Trajectory" of modern human migration from Africa into Europe. The Middle East, and SE Europe constitute the principal areas to be investigated. SE Europe has become a special research focus since two early Homo sapiens individuals have been found at Oase Cave in the southern Banat. The fossils lack any stratigraphic context; cultural and environmental circumstances of these findings have remained unclear. In the neighbourhood of Oase Cave, however, several early Upper Palaeolithic sites, embedded in loess sequences were known since the 1950's. Some sites were re-investigated by our research team. Conceptionally we are following the idea of upland-lowland interaction, which combines parameters as sedimentary transport, sediment distribution, and paleosol development in different altitudes, all influenced by paleoclimate in space and time. Furthermore, some detailed studies concerning site-formation processes and the quality of open-air sites (sedimentary development, paleoecology, multilayering, reworking, human impact on soils and sediments) are being conducted at selected localities. Recent investigations of the loess-paleosol sequences (LPS) in SE Europe provided important environmental information which differ from "classical" ecological approaches derived from other European loess provinces. New luminescence dating results provide a sensitive chronology of environmental changes recorded in the LPS from both upland and lowland positions, giving the potential to link these.

  11. THE SEQUENCE OF PALEOENVIRONMENTAL CHANGES SINCE ABOUT 4KA B. P., RECORDED BY NIYA SECTION IN SOUTHERN MARGIN OF TARIM BASIN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Through synthetic researches of multi-index geological records of Niya section, which are of high resolu tion in southern margin of Tarim Basin, this paper has reconstructed the sequences of paleoclimate in this region during historical times (since about 4000a B. P. ). During the last 4000 years, the area has experienced alternations of rela tive cold-moisture and relative warm-dry periods. Three evident cold-moisture periods and three warm-dry periods are identi fing. The study shows that the human activities have an intimate relation with the evolution of paleoclimate in the south ern Xinjiang. Paleoclimate has played very important role in influencing human being′s agricultural activities.

  12. Rare Carboniferous and Permian glacial and non-glacial bryophytes and associated lycophyte megaspores of the Paraná Basin, Brazil: A new occurrence and paleoenvironmental considerations

    Science.gov (United States)

    Ricardi-Branco, Fresia; Rohn, Rosemarie; Longhim, Marcia Emilia; Costa, Juliana Sampaio; Martine, Ariel Milani; Christiano-de-Souza, Isabel Cortez

    2016-12-01

    Fossil bryophytes are rare because their preservation is compromised by the presence of a thin cuticle (if any) and a lack of lignin. Except for the occurrence of one bryophyte in the glacial Dwyka Group of the Karoo Basin, the other rare Late Paleozoic records in Gondwana are notably from the Paraná Basin in Southeast/South Brazil. Four bryophyte sites (including a newly discovered one) were found in the lower part of the thick Permo-Carboniferous glacial succession of the Itararé Group, and one was found in the Guadalupian Teresina Formation, which was roughly assigned to an epeiric sea (or "lake") dominated by a warm, semi-arid climate. This study describes the fossils from the new occurrence from the Itararé Group and discusses the context in which the bryophyte beds originated in the basin. The new samples confirm that all of the bryophytes of the Itararé Group can be classified as Dwykea araroii Ricardi-Branco et al. (a possible pleurocarp) and are associated with the lycophyte megaspore Sublagenicula brasiliensis (Dijkstra) Dybová-Jachowicz. In the much younger Teresina Formation, the bryophytes are Yguajemanus yucapirus Cristiano-de-Souza et al. and Capimirinus riopretensis Cristiano-de-Souza et al., and abundant charophytes and rare dwarf lycophyte stems and bracts are present in the same layers. Although the two stratigraphic units represent distinct paleoenvironments and climates, they seem to share some characteristics: a) the bryophyte assemblages were transported very little; b) they were deposited in very calm environments; c) they were the main components (along with some lycophytes) of local or poorly diversified regional vegetation. The low number of species, which is characteristic of opportunistic communities, can be explained by local or regional conditions that would have been stressful for the vascular plants in other areas. During the deposition of the Itararé Group, the main control was probably the cold climate in addition to a

  13. Composition index of n-alkanes and paleoenvironmental study in sediments of the Arctic

    Institute of Scientific and Technical Information of China (English)

    Lu Bing; Zhou Huaiyang; Wang Zipan; Lu Douding

    2001-01-01

    This paper reports different concentration patterns of n-alkanes distribution in the sediments from the Chukchi Sea, the Bering Sea in the Arctic. Factor statistical analysis method is used for studying the source of n-alkanes and paleoenviroment. The result shows that n-alkanes is in the range of nC15~nC33 and n-alkane distribution patterns are characterized by two modes. The first mode belongs to the higher molecular with MH being nC25~ nC27, CPI> 1 and with remarkable odd-even dominance.They are of terrigenous plant origin. The second one belongs to lower carbon range with MH being nC17 ~nC20, CPI> 1 and with indistinct odd-even dominance. Therefore they are contributed by marine biological inputs. The contribution of land origin is larger than that of marine source. Pr/Ph is lower than 1 in the investigated area, which indicates the depositional environment of reducing reaction with lower oxygen. The result of factor analysis has good agreement with composition characteristics of n-alkanes in the sediment.

  14. Paleomagnetic chronology and paleoenvironmental records from drill cores from the Hetao Basin and their implications for the formation of the Hobq Desert and the Yellow River

    Science.gov (United States)

    Li, Baofeng; Sun, Donghuai; Xu, Weihong; Wang, Fei; Liang, Baiqing; Ma, Zhiwei; Wang, Xin; Li, Zaijun; Chen, Fahu

    2017-01-01

    Reconstructing the Cenozoic environmental history of Hetao Basin, in the northern part of the Ordos Plateau in North China, is important not only for revealing the evolution of the Yellow River, but also for understanding the formation of the Hobq Desert. Here we present the stratigraphic framework of drill core DR01 with length of 2503.18 m, and the results of magnetostratigraphic and ESR dating and multi-proxy analyses of drill core WEDP05 with length of 274.60 m, from the Hetao Basin. The magnetostratigraphic and ESR results indicate that core WEDP05 spans the last ∼1.68 Ma. Stratigraphic sequence of core DR01 indicates that the Hetao area was uplifted and eroded during the early Cenozoic, before subsiding to form a sedimentary basin. Subsequently, the basin was a fluvio-lacustrine environment during the Pliocene and then experienced alternating desert and fluvio-lacustrine conditions during the Quaternary. Sedimentary facies and multi environmental-proxy analyses of core WEDP05 indicate that the basin was occupied by a fluvio-lacustrine system during the following intervals: ∼1.47 - ∼1.30 Ma, ∼1.17 - ∼1.07 Ma, ∼0.68 - ∼0.60 Ma and from ∼0.47 Ma to the last interglacial; and that a desert environment developed during the lake regression phases of ∼1.30 - ∼1.17 Ma, ∼1.07 - ∼0.68 Ma and ∼0.60 - ∼0.47 Ma. The presence of aeolian sand at the base of core WEDP05 suggests that the origin of the Hobq Desert can be traced back to the early Pleistocene, and resulted from the erosion and transportation of exposed fluvio-lacustrine sediments by near-surface winds associated with the Asian winter monsoon. A large river channel in the Hetao Basin may have existed as early as the Pliocene, which was occupied by the Yellow River when its upper reaches formed by at least ∼1.6 Ma. Subsequently, at least since ∼1.2 Ma, the Yellow River formed its drainage system around the Hetao Basin and controlled the paleoenvironment evolution of the basin.

  15. Carbon and oxygen isotopic records from Lake Tuosu over the last 120 years in the Qaidam Basin, Northwestern China: The implications for paleoenvironmental reconstruction

    Science.gov (United States)

    Li, Xiangzhong; Zhou, Xin; Liu, Weiguo; Wang, Zheng; He, Yuxin; Xu, Liming

    2016-06-01

    Isotopic compositions of total organic carbon (TOC) and authigenic carbonate in lakes have been widely used to reconstruct paleoclimatic changes and the depositional environments of lake sediments. However, since these proxies are often controlled by multiple environmental factors, detailed examinations of modern environmental processes is necessary before further applying them into paleoclimatic studies, especially in arid/semi-arid northwestern China. Here we generate High-resolution multi-proxy sedimentary records from Lake Tuosu, a hydrologically closed, saline and alkaline lake located at the north margin of the Qaidam Basin, through analysis of carbon isotope of TOC, and δ18O and δ13C values of ostracods over the last 120 years. Together with the meteorological data (precipitation and temperature), lake area record, and other tree-ring evidence, we examine how these sedimentary indices respond to changes in hydrologic balance and climate at interannual to decadal timescales. We found that sedimentary δ13Corg values resemble the variation of lake areas of Lake Tuosu over the last 40 years, suggesting that δ13Corg values would be an ideal indicator of lake area/level fluctuations and thus effective moisture variations (precipitation vs. evaporation). However, ostracod δ18O, which was previously used as proxies of effective precipitation, is not well correlated with δ13Corg values in Lake Tuosu. Therefore, the changes of ostracod δ18O values cannot be straightforwardly explained as the effective precipitation. Instead, the isotopic composition of carbonate would be additionally controlled by other factors including isotopic compositions of input water and drainage pattern.

  16. The PRISM3D paleoenvironmental reconstruction

    OpenAIRE

    H. Dowsett; M. Robinson; Haywood, A. M.; Salzmann, U.; Hill, Daniel; L. E. Sohl; Chandler, M.; Williams, Mark; Foley, K; D. K. Stoll

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additio...

  17. La flora cretácica de Cuenca Neuquina, su significadopaleoambiental y paleoclimático The Cretaceous flora of the Neuquén Basin,its paleoenvironmental and paleoclimatic significance

    Directory of Open Access Journals (Sweden)

    Eduardo G. Ottone

    2009-10-01

    Full Text Available Se sumariza el significadopaleoambiental y paleoclimático de la flora cretácica de cuenca Neuquina. Lasasociaciones palinológicas del Berriasiano-Barremiano están dominadas por Araucariaceaey Cheirolepidiaceae, con Podocarpaceae, helechos, licópsidas y briofitassubordinadas que habrían progresado en un clima templado y húmedo. Losdinoflagelados del Tithoniano- Barremiano temprano mayormente poseen afinidadesmediterráneas. Los niveles evaporíticos del Barremiano superior representan lafinalización del ciclo marino de depositación relacionado con el océanoPacífico en la cuenca. En el Aptiano aparece el primer grano de polen deangiosperma. Las asociaciones palinológicas continentales delAptiano-Cenomaniano se caracterizan por presentar elementos del Gondwanaseptentrional tales como Afropollis y los granos de polen elaterados.Tempskyaceae y Ginkgoales están también presentes en el Cretácico Tempranotardío. Los estratos continentales del Turoniano- Campaniano inferior incluyenprincipalmente madera petrificada y carofitas. Los estratos del Campanianosuperior- Maastrichtiano preservan una rica asociación palinológica de origencontinental compuesta por Nothofagaceae, Podocarpaceae, Cheirolepidiaceae,Araucariaceae, Salviniales y angiospermas, aunque también hay dinoflageladosque reflejan el comienzo de una transgresión marina relacionada con el océanoAtlántico. La presencia y abundancia local de cycas y palmeras sugiere el desarrollode un clima templado cálido y relativamente húmedo hacia fines del Cretácico.The paleoenvironmental and paleoclimaticsignificance of Cretaceous flora in the Neuquén Basin is summarized. Berriasian-Barremianterrestrial palynological assemblages are dominated by Araucariaceae andCheirolepidiaceae, with subordinated podopcarps, ferns, lycopsids andbryophytes that progressed in a mild and humid climate. Tithonian-Barremiandinoflagellates mostly possess Mediterranean affinities. Upper

  18. Paleoenvironmental reconstitution of Motuca and Sambaíba formations, Permian-Triassic of the Parnaíba Basin in southwest Maranhão state, Brazil

    Directory of Open Access Journals (Sweden)

    Francisco Romério Abrantes Júnior

    2013-09-01

    Full Text Available The interval between the Late Paleozoic and Early Mesozoic was marked by paleogeographic and paleoclimatic global changes, partly attributed to catastrophic events. The intense continentalization of the supercontinent Pangaea of End-Permian propitiated the development of extensive deserts that succeeded the coastal and platform environments of Early Permian. The records of these events in northern Brazil are found in intracratonic basins, particularly in the Permo-triassic succession of the Parnaíba Basin. The facies and stratigraphic outcrops analysis of this succession allowed the individualization of 14 sedimentary facies grouped into four facies associations (FA: FA1 and FA2 related to deposits of Motuca Formation and, FA3 and FA4, representative of the base of Sambaíba Formation. The FA1 – Shallow lake/Mudflat consists of red laminated mudstone with lenses of gypsum, calcite and marl, besides lobes of sigmoidal sandstones. The FA2 – Saline pan consists of lenticular bodies of laminated gypsum, nodular gypsum and gypsarenite, overlapped by greenish mudstones with dolomite nodules and palygorskite. The FA3 – sand sheet and FA4 – dunes field are formed, respectively, for orange cream sandstones with even parallel stratification and medium- to large-scale cross-bedding. In the contact between Motuca and Sambaíba formations occurs a deformed interval, laterally continuous for hundreds of kilometers. Brecciated and contorted bedded siltstones and mudstone (Motuca Formation and sandstone with sinsedimentary faults/microfaults, convolute lamination and mud-filled injection dykes (Sambaíba Formation are interpreted as seismites triggered by high magnitude earthquakes (> 8 according Richter scale.

  19. The Potential of Uranium-Series Disequilibrium in Marine and Lacustrine Diatom Frustules as a Tool for Geochronological and Paleoenvironmental Studies

    Science.gov (United States)

    Luo, S.; Tsai, Y.

    2008-12-01

    Accurate age dating of deep-sea sediment records from the polar region remains one of the major challenging issues in paleoceanographic and paleoclimatologic studies. As diatom is ubiquitous in aquatic systems, in particular in cold waters of the polar region, this study seeks to explore the utilities of uranium- series disequilibrium in diatom frustules as a chronometer for absolute age dating and/or as a proxy for paleo-environmental studies. In the uranium series, uranium-238, with a half-life of 4.468 billion year, decays to a stable nuclide lead-206 through a series of shorter-lived radionuclides. Uranium-238 and all of its daughter nuclides will achieve secular equilibrium on a time scale of about one million years in an igneous rock. Disequilibrium between the daughter and parent nuclides would occur in aquatic environments, such as in oceans and lakes, as a result of various naturally-occurring physical/chemical processes. This study shows that diatom acquires its uranium isotope composition from its ambient seawater, creating significant radioactive disequilibrium between uranium and its daughter nuclides in diatom frustules. This salient feature makes diatom frustules very useful for absolute age dating as well as for assessing the past changes of many geophysical and geochemical processes in the ocean and on the continents.

  20. THE SEQUENCE OF PALEOENVIRONMENTAL CHANGES SINCE ABOUT 4KA B. P., RECORDED BY NIYA SECTION IN SOUTHERN MARGIN OF TARIM BASIN

    Institute of Scientific and Technical Information of China (English)

    ZHONG; Wei

    2001-01-01

    Ke-qin, 1997. Paleoclimatic and environmental change since 2000a B. P. recorded in ice Core[J]. The Front of Ceo-science, 4(1): 95-100.(in Chiniese)[13]ZHANG Zhen-ke, WU Rui-jin, WANG Su-min, 1998. Paleoenvironmeal evolution during historic time reflected by frequency susceptibility of the lacustrine sediment in Daihai[J]. Geography Reaserch. 17(3) :297-300. (in Chinese)[14]ZHANG Pi-yuan, 1996. Climatic Changes During Historic Time in China[J]. Jinan: Shandong Science and Technology Press, 434-435. (in Chinese)[15]ZHANG Pi-yuan, GE Quan-sheng, 1997. The stage and abrupt ness of climatic evolution[J]. The Front of Geo-science, 4(1):122-126. (in Chinese)[16]ZHONG Wei, XIONG Hei-gang, Tashplati etal., 1998a. The preliminary study on the Spore-pollen combination of the Tagele section in Cele oasis[J]. Arid Zone Research, 15 (3):14-17. (in Chinese)[17]ZHONG Wei, XIONG Hei-gang, 1998b. Preliminary study on paleoclimatic evolution since about 12ka B.P. in Bosten Lake, southern Xinjiang, China[J]. Journal of Arid Land Resources and Enviorment, 12(3) :28-35. (in Chinese)[18]ZHU Ke-zhen. 1973, Preliminary study of climatic changes since about 5000 years in China[J]. Science in China, (2):291-296. (in Chinese)

  1. Paleo-Environmental Reconstruction Using Ancient DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther

    The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context...... solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms...... of the sampling methods and strategies (taphonomic processes), the more fundamental molecular methodologies (e.g. extraction and sequencing) and eventually the bioinformatic processing. In the enclosed studies we have tried to take some principal steps towards improving this, firstly by reviewing previous...

  2. Oil generation potential assessment and paleoenvironmental interpretation based on bio markers and stable carbon isotopes of the Pliensbachian - lower Toarcian (Lower Jurassic) of the Peniche region (Lusitanian Basin, Portugal); Avaliacao do potencial gerador de petroleo e interpretacao paleoambiental com base em biomarcadores e isotopos estaveis de carbono da secao Pliensbaquiano - Toarciano inferior (Jurassico Inferior) da regiao de Peniche (Bacia Lusitanica, Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luiz Carlos Veiga de; Rodrigues, Rene; Duarte, Luis Vitor; Lemos, Valesca Brasil [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Bioestratigrafia e Paleoecologia]. E-mail: lcveiga@petrobras.com.br

    2006-05-15

    The Lusitanian Basin (Portugal) is located on the western margin of the Iberian Plate with maximum sedimentary thickness around 5 km. In spite of containing promising petroleum systems and more than a hundred wells, its hydrocarbon generation potential has not been fully evaluated yet. These sediments range from upper Triassic to upper Cretaceous, mainly from the Jurassic age. The Lower Jurassic is particularly well represented in the Lusitanian Basin, specifically in the Peniche region, where there are more than 450 m thick outcrops of carbonate rocks aged between Sinemurian and Toarcian. This study presents the evaluation of the hydrocarbon generation potential of the Pliensbachian . lower Toarcian of the Peniche section; which includes the Vale das Fontes Formation, Lemede Formation and Cabo Carvoeiro Formation (CC1 and CC2 members) based on 233 rock samples analyzed for total organic carbon (TOC), Rock-Eval pyrolysis and bio markers. Available data of oxygen and carbon stable isotopes were also used in the paleoenvironmental interpretation. Marls and limestones with the bituminous facies (Mlbf) of the Vale das Fontes Formation, present the highest TOC values, up to 14.95%, corresponding to the ibex (upper part), davoei and margaritatus ammonites zones and part of the NJ4a and NJ4b nanno fossils bio zones (Pliensbachian). In thermal immature sections (T max about 430 deg C), this member also shows high S{sub 2} values (10 to 50 mgHC/g rock) and Hydrogen index (HI: 200 to 555 mgHC/g TOC). The correlation between HI x OI shows that type II kerogen is predominant in the portion of the section where TOC values are higher. The good positive correlation between TOC values and the bio markers ratio P/nC17 and sterane (C{sub 27}/C{sub 29}) throughout the Mlbf Member suggests a gradual increase of anoxia and higher contribution of algae in relation to terrestrial organic matter. Usually {delta}{sup 18}O variations observed in the basins of the Iberian Peninsula have been

  3. High Precision Thermal Ionization Mass Spectrometric Dating of Corals and Its Application to Paleo-Environmental Study

    Institute of Scientific and Technical Information of China (English)

    王兆荣; 张兆峰; 彭子成; 马志邦

    2001-01-01

    Global change has become a hot spot in Quaternary geology, and high-precision,high-sensitivity dating is also an urgent problem which needs to be solved. This paper presents some achievements in U-series dating of marine corals by thermal ionization mass spectrometry (TIMS) and its application to the study of paleo-environments. Recently, coral samples were determined for their ages on a MAT-262 mass spectrometer and satisfactory results have been obtained.

  4. Paleo-environmental study on the growth of magnetotactic bacteria and precipitation of magnetosomes in Chinese loess-paleosol sequences

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    405 samples were collected from L5-S5-L6 in consideration of obvious variations in susceptibility of the geological sections, which are section Xifeng in Gansu Province and section Duanjiapo in Shaanxi Province for study of magnetotactic bacteria (MB) and magnetosomes (MS)in Chinese loess-paleosol sequences. MB in each sample were observed by TEM after being cultured under 8-18℃, room temperature (RT), 25℃, 26℃ and 30℃ conditions. In general, MB are distributed widely in loess-paleosol sequences, fewer in loess layers with predomination of vibriod in shape. However, there are more MB in paleosol layers with morphological varieties such as roddish, vibriod and occasionally approximately coccus. The magnetosomes (MS) in MB of paleosol are usually arranged in chains along the cells. It was also found that MB growth and MS formation are associated with the environment in which MB live. It can be inferred from the distributions of MB and MS that the paleoclimates fluctuated during the formation of loess-paleosol sequences in the Chinese Loess Plateau. The climate became gradually warmer but displayed more frequent fluctuations from the northwest to the southeast of the Plateau.

  5. Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans

    Directory of Open Access Journals (Sweden)

    Vizcaíno Sergio F

    2004-04-01

    Full Text Available Abstract Background Comparative genomic data among organisms allow the reconstruction of their phylogenies and evolutionary time scales. Molecular timings have been recently used to suggest that environmental global change have shaped the evolutionary history of diverse terrestrial organisms. Living xenarthrans (armadillos, anteaters and sloths constitute an ideal model for studying the influence of past environmental changes on species diversification. Indeed, extant xenarthran species are relicts from an evolutionary radiation enhanced by their isolation in South America during the Tertiary era, a period for which major climate variations and tectonic events are relatively well documented. Results We applied a Bayesian approach to three nuclear genes in order to relax the molecular clock assumption while accounting for differences in evolutionary dynamics among genes and incorporating paleontological uncertainties. We obtained a molecular time scale for the evolution of extant xenarthrans and other placental mammals. Divergence time estimates provide substantial evidence for contemporaneous diversification events among independent xenarthran lineages. This correlated pattern of diversification might possibly relate to major environmental changes that occurred in South America during the Cenozoic. Conclusions The observed synchronicity between planetary and biological events suggests that global change played a crucial role in shaping the evolutionary history of extant xenarthrans. Our findings open ways to test this hypothesis further in other South American mammalian endemics like hystricognath rodents, platyrrhine primates, and didelphid marsupials.

  6. Sanmenxia Loess and Paleoenvironmental Change

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Caocun(曹村) loess profile of Zhangbianyuan (张汴塬)is located at the southeast margin of the Loess Plateau,Which is a typical representative of loess stratum in the Sanmenxia(三门峡) area.In the 145 m thick profile,a loess-paleosol sequence occurs from L1 to L33,underlain by a red clay bed.The B/M boundary was recorded at the bottom of L7, the Jaramillo event at S11 to S12, the Olduval event at L23 to L26 , and the M/G boundary at the bottom of L33 near the red clay.The magnetic susceptibility of the loess deposits, as well as the carbonate and granularity components, indicates that there have been many periodic paleoclimate changes, including a total of 13 cold events that each lasted more than 40 000 a.A high-resolution chronostratigraphic profile has been established using an age model according to grain characteristics.A clear correlation exists between records of the paleomonsoon in the Caocun loess succession and SPECMAP from 3 × 105 a B.P.to the present.The Caocun profile can act as a control site in the southeastern Loess Plateau.Its paleoenvironmental records relate to eastern Asian paleomonsoon theory.

  7. The Cretaceous Polar and Western Interior seas: paleoenvironmental history and paleoceanographic linkages

    Science.gov (United States)

    Schröder-Adams, Claudia

    2014-03-01

    This study reviews the Cretaceous histories of the Polar and Western Interior seas as recorded in the Canadian High Arctic Sverdrup Basin, Beaufort-Mackenzie Basin of northwest Canada and Western Canadian Foreland Basin. Newly emerging stratigraphic, paleoclimatic and paleoenvironmental interpretations from the polar realm allow for a fresh look at the response of this oceanic system to global climatic trends and sea-level histories over 35 Ma. Sverdrup basin localities on Axel Heiberg and Ellef Ringnes islands represent shelf to slope environments that contrasted with the shallow water and low gradient settings of the Canadian Western Interior Sea. Both marine systems, connected throughout Aptian to Maastrichtian time, responded to global transgressive-regressive cycles resulting in dynamic paleogeographic changes. The upper Aptian to Campanian succession of the Polar Sea shows at least two unconformable boundaries; one at the Albian/Cenomanian transition and another within the upper Cenomanian. The shallow basin setting and in particular the forebulge and backbulge settings of the Western Canadian Foreland Basin are characterized by multiple erosional surfaces throughout the Cretaceous succession. The Upper Albian disconformity is widely discernible close to the entrance of the Western Interior Sea to the Polar Sea. This suggests a short-lived closure of the latest Albian Mowry Sea that might have been responsible for the large loss of benthic foraminiferal species at this time. Several oceanic anoxic events are documented in these basins representing their response to global climate dynamics. During the Late Cretaceous temperature maximum benthic foraminiferal communities were severely restricted by bottom water hypoxia in both basins. A stratified water column might have been the result of increased freshwater runoff under warm, humid conditions. These conditions supported vegetation up into the polar latitudes that added abundant organic matter to marine shelf

  8. Projection of Favorable Gas-Producting Areas From Paleoenvironmental Data

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, R.E.; Dixon, J. A.; McIver, R. D.; Reaugh, A. B.

    1979-12-31

    Paleoenvironmental biofacies analysis of recent wells in dark Devonian shales in the Applachian Basin has shown that these facies can be projected to areas with no control points. In particular, the facies distribution in Perry County, Kentucky, were found to be precisely those that were predicted earlier from biofacies and organic geochemical data from the VA-1 well in Wise County, Virginia, and the KY-2 well in Martin County, Kentucky. This demonstrates the importance of these data in assessing the volume of gas in the shale throughout the basin as well as in selecting future test sites. The recent biofacies and geochemical work together with a review of the tectonics of the basin have contributed to an evolving interpretation of the geologic control of the biofacies. While a marine environment persisted throughout the Upper Devonian over the Applachian and Illinois Basin (and probably the Michigan Basin), dynamic emergent areas controlled an intermittent introduction of large amounts of organic matter. Large amounts of non-marine organic matter were periodically transported in the basin from a dynamic source province to the Southeast; massive "blooms" of Tasmanites intermittently spread both east and west from the edges of the emerging Cincinnati Arch. At times one or the other of these organic types swept entirely across the basins; at other times a more normal open marine biota flourished and was deposited, probably under the influence of connections to the open seas to the south and northwest, the north being closed by the collision and suturing of continental plates and the east by the growing Applachian Mountains.

  9. Paleogeography of the Central Asian proto-Paratethys Sea in the Eocene: Controlling mechanisms and paleoenvironmental impacts (Utrecht Studies in Earth Sciences 038)

    NARCIS (Netherlands)

    Bosboom, R.E.

    2013-01-01

    The Cretaceous and Paleogene sediments of the Central Asian basins include remnants of the easternmost extent of a large epicontinental sea. Before this sea retreated westward and eventually separated as the Paratethys Sea, it extended across Eurasia from the Mediterranean Tethys to the Tarim Basin

  10. The Relative Rates of Secondary Hydration in Basalt and Rhyolite, and the use of δD as a Paleoclimate Indicator: Implications for Paleoenvironmental and Volcanic Degassing Studies

    Science.gov (United States)

    Seligman, A. N.; Bindeman, I. N.

    2014-12-01

    The δD-H2O correlation is important for volcanic degassing and secondary hydration trends. We utilize the caibration of the TC/EA - MAT 253 continuous flow system, which permits us to analyze wt.% H2O and its δD extracted from 1-8 mg of glass with as little as 0.1 wt% H2O. Tephra that has been secondarily hydrated with meteoric water is widely used as a paleoenvironmental tool, but the rate of secondary hydration, the relative amounts of primary magmatic (degassed) and secondary meteoric water, and the retention of primary and secondary δD values are not well understood. To quantify these processes, we use a natural experiment involving dated Holocene tepha in Kamchatka and Oregon. Our research illustrates the drastic difference in hydration rates between silicic (hydrated after ~1.5 ka) and mafic tephra, which is not hydrated in the Holocene (similar to results for submarine volcanic glasses), and andesitic tephra with intermediate degrees of hydration. The 0.05-7.3 ka basaltic scoria from Klyuchevskoy volcano retains ≤0.45 wt.% primary magmatic H2O, with δD values from -99 to -121 ‰. Four other 0.05-7.6 ka basaltic tephra units from Kamchatka with andesitic tephra have slightly higher water contents (0.9-3.0 %) and slightly lower δD values (-113 - -146 ‰). Seven 0.3-7.9 ka silicic samples with SiO2 >65 wt.% have higher (1.5 -3.4) wt.% H2O and δD values between -115 - -160 ‰. We interpret the lower δD values and higher water contents (opposite of the magmatic degassing trend) to be a characteristic of secondary hydration in regions of higher latitude such as Kamchatka and Oregon. We are also investigating 7.7 ka Mt. Mazama tephra in Oregon that are known to be fully hydrated and cover nearly 5000 km2 northeast of Crater Lake and range in elevation from ~1.3-1.9 km to understand the δD and δ18O details of the hydrated water's correspondence with local Holocene meteoric waters. In the future, we plan to use a combination of δD in mid-high latitude

  11. Neotectonic of subsiding basins : case of studies from Marañon and Beni basins, Peru and Bolivia

    OpenAIRE

    Dumont, Jean-Francois

    1994-01-01

    Climatic conditions make the fluvial processes very sensitive in the extended flood plain of subandean basins, giving typical morphostructures. Because of high subsidence rate, these basins are case for the understanding of neotectonics in subsiding basins. Recent anciente fluvial traces are used in combination with sub surface structures, neotectonic and seismotectonic data to study the neotectonic evolution of the Peruvian and Bolivian active foreland basins. These basins, the Marañon Basin...

  12. The PRISM3D paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  13. 柴达木盆地大浪滩梁-ZK02孔的磁性地层及其古环境研究%Magnetostratigraphy of Liang-ZK02 Borehole in Dalangtan, Qaidam Basin and Its Paleoenvironmental Significance

    Institute of Scientific and Technical Information of China (English)

    秦永鹏; 侯献华; 郑绵平; 杨振宇; 李洪普; 施林峰

    2012-01-01

    对柴达木盆地西部大浪滩盐湖梁-ZK02孔岩芯进行详细的磁性地层研究,确定钻孔岩芯的B-M界线位于315m,Jaramillo位于405~430m,Olduvai位于772 ~ 816m.在磁性年代学框架基础上,以蒸发岩沉积序列作为主要依据,结合碎屑岩变化以及孢粉分析,认为该地区在第四纪发生过三次较大的沉积环境变化,分别发生在2.5~2.2Ma,1.2~0.7Ma与0.4Ma.青藏高原第四纪的隆升是造成上述三次变化的主要原因,其中早更新世末—中更新世早期的隆升对柴达木盆地的气候影响较大,导致柴达术盆地的气候由温凉湿润转换为寒冷干旱.高原隆升引起的气候干旱并非简单的逐渐加剧,而是早更新世末期以来,气候湿润期表现得更为湿润,这种现象可能由高原隆升增加了夏季风的强度导致,冰川和积雪面积的增大也起到了叠加效应.%A detailed magnetostratigraphic investigation has been carried out on a 1000-m-thick sequence of Liang-ZK02 Borehole in Dalangtan, northwest of the Qaidam Basin. Magnetostratigraphic results show that the B-M boundary of borehole is located in 315m, Jaramillo subchron and Olduvai subchron are located in 405 ~430m and 772 ~816m, respectively. Three large environmental changes in Quaternary, occurred around 2.5 ~ 2. 2Ma, 1. 2 ~0. 7Ma and 0.4Ma, are identified based on integrated analysis of evaporites, clastic rock and sporo-pollen record. The uplift of Xizang ( Tibetan) Plateau was probably the main reason for these environmental changes, paleoclimate of Qaidam Basin transferred from cool, wet climate to cold, dry climate in the end of Early Pleistocene to early Middle Pleistocene because of the uplift of the Xizang( Tibetan) Plateau. The trend of aridification caused by uplift is not intensified gradually, the climate became wetter in humid period since the end of Early Pleistocene, which might result from intensified strength of summer monsoon caused through uplift of Xizang

  14. Geochemistry of fine-grained sediments of the upper Cretaceous to Paleogene Gosau Group (Austria, Slovakia: Implications for paleoenvironmental and provenance studies

    Directory of Open Access Journals (Sweden)

    Gerald Hofer

    2013-07-01

    Full Text Available Bulk rock geochemistry of 169 fine-grained sediment samples of the upper Cretaceous to Paleogene Gosau Group (Northern Calcareous Alps, Austria and Slovakia from borehole and outcrop localities was performed to separate non-marine and marine deposits. Geochemical characteristics of different Gosau depositional systems, basins and sediment provenance using major-, trace-, and rare earth elements were also investigated. Geochemical proxies such as boron concentrations were tested for seeking the possibilities of paleosalinity indicators. Due to the fact that several pelagic sections are represented by extremely low boron contents, B/Al* ratios are recognized as more robust and differentiate reliably between marine (mean: 160 ± 34 and non-marine (mean: 133 ± 33 samples. Using statistical factor analysis, hemipelagic to pelagic samples from the Gießhübl Syncline and Slovakian equivalents can be differentiated from marginal-marine to non-marine samples from the Grünbach and Glinzendorf Syncline related to terrigenous (SiO2, Al2O3, K2O, Th, Rb, Zr and others and pelagic indicative elements (CaO, Sr, TOT/C and B/Al*. A clear indication for ophiolitic provenance is traced by high amounts of chromium and nickel. Only non-marine successions of the Glinzendorf Syncline show higher Cr and Ni concentrations (up to 250 and 400 ppm, respectively and enriched Cr/V and Y/Ni ratios trending to an ultramafic source.

  15. Turonian palynostratigraphy of the Laranjeiras area, Sergipe-Alagoas Basin: paleoenvironmental and paleoclimatic inferences; Palinoestratigrafia do Turoniano na area de Laranjeiras, Bacia de Sergipe-Alagoas: inferencias paleoambientais e paleoclimaticas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Paulo Roberto Silva [PETROBRAS (Brazil). Unidade de Negocio de Exploracao e Producao de Sergipe Alagoas. Gerencia de Gerencia de Sedimentologia e Estratigrafia], e-mail: proberto@PETROBRAS.com.br

    2007-11-15

    The Cenomanian-Turonian boundary is recognized worldwide as the most important eustatic event of sea-level rise in the Cretaceous, correlated with a global oceanic anoxic event, which induced the widespread formation of organic-rich pelitic deposits, potential source rocks of hydrocarbon. in Brazil this section is predominantly found in subsurface, in land and offshore oil wells. One of the best outcrops of this interval is found in the Votorantim Quarry, in Laranjeiras, Sergipe State, Brazil. Through a semi-quantitative palynological study, based on mining cores drilled in the quarry, a palynostratigraphic framework with additional paleoecological inferences and interpretation based in Sequence Stratigraphy.(author)

  16. High resolution stratigraphy and paleoenvironmental changes in the southern North Sea during the Neogene : An integrated study of Late Cenozoic marine deposits from the northern part of the Dutch offshore area

    NARCIS (Netherlands)

    Kuhlmann, G.

    2004-01-01

    This thesis is the result of a multidisciplinary study on the prograding marine Neogene sedimentary succession of the southern North Sea Basin. To date, sediment material available from the Neogene North Sea is very scarce. Its location between 400 and 1500 m below the seabed in the depocentre of th

  17. High resolution stratigraphy and paleoenvironmental changes in the southern North Sea during the Neogene : an integrated study of Late Cenozoic marine deposits from the northern part of the Dutch offshore area

    NARCIS (Netherlands)

    Kuhlmann, Gesa

    2004-01-01

    This thesis is the result of a multidisciplinary study on the prograding marine Neogene sedimentary succession of the southern North Sea Basin. To date, sediment material available from the Neogene North Sea is very scarce. Its location between 400 and 1500 m below the seabed in the depocentre of th

  18. Seismological study at the Kyungsang basin 2

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Heon Cheol; Jun, Myung Soon; Jeon, Jeong Soo; Shin, In Chul [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The end of 1994, five seismic observation stations were constructed with digital seismograph and 3-component seismometers. In this study, the epicentral distribution around the Kyungsang basin was obtained from one-year earthquake data (1994/12 - 1995/11) and compared with the annual earthquake report of KMA (Korea Meteorological Agency). The geological structure at the middle of the Ulsan fault was also investigated by the electrical resistivity method. The epicenters show high concentration at the Wolsung area. They show a linear alignment and their depths tend to be deeper as they approach to the coast line of the East Sea. These imply that they are probably correlated together. Another remarkable feature on land is the linear epicentral distribution along Jiri mountain to the Kimcheon and Sangju. This line is well coincident with newly recognized lineament. The other is the epicentral distribution at the Straits of Korea and East Sea. Even though some far earthquakes were missed or truncated due to the pre-setup of limited delay time (pre-event time), the epicentral determination in this study is highly accurate compared with the KMA result. This difference of epicenter locations is mostly due to the discrepancy between digital (KIGAM) and analog (KMA) data. The result of electrical resistivity survey at the middle of the Ulsan fault is that the strike is in the NS direction and the dip is inclined by 40-50 degree E. These are very similar to the apparent feature of outcrop fault. In addition, the another fault line is discovered just near the outcrop fault. (author). 5 refs., 20 figs., 4 tabs.

  19. Atchafalaya Basin (Water and Land Resources), Louisiana Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atchafalaya Basin (Water and Land Resources), Louisiana, study is being conducted in response to resolutions adopted by the United States Senate and House of...

  20. Transient electromagnetic study of basin fill sediments in the Upper San Pedro Basin, Mexico

    Science.gov (United States)

    Bultman, M.W.; Gray, F.

    2011-01-01

    The Upper San Pedro River Basin in Mexico and the United States is an important riparian corridor that is coming under increasing pressure from growing populations and the associated increase in groundwater withdrawal. Several studies have produced three-dimensional maps of the basin fill sediments in the US portion of the basin but little work has been done in the Mexican portion of the basin. Here, the results of a ground-based transient electromagnetic (TEM) survey in the Upper San Pedro Basin, Mexico are presented. These basin fill sediments are characterized by a 10-40 m deep unsaturated surficial zone which is composed primarily of sands and gravels. In the central portion of the basin this unsaturated zone is usually underlain by a shallow clay layer 20-50 m thick. Beneath this may be more clay, as is usually the case near the San Pedro River, or interbedded sand, silt, and clay to a depth of 200-250 m. As you move away from the river, the upper clay layer disappears and the amount of sand in the sediments increases. At 1-2 km away from the river, sands can occupy up to 50% of the upper 200-250 m of the sediment fill. Below this, clays are always present except where bedrock highs are observed. This lower clay layer begins at a depth of about 200 m in the central portion of the basin (250 m or more at distances greater than 1-2 km from the river) and extends to the bottom of most profiles to depths of 400 m. While the depth of the top of this lower clay layer is probably accurate, its thickness observed in the models may be overestimated due to the relatively low magnetic moment of the TEM system used in this study. The inversion routine used for interpretation is based on a one-dimensional geologic model. This is a layer based model that is isotropic in both the x and y directions. Several survey soundings did not meet this requirement which invalidates the inversion process and the resulting interpretation at these locations. The results from these

  1. Application of carbon and oxygen isotope data from bulk samples to stratigraphic and paleo-environmental studies; Aplicacao dos dados isotopicos de carbono e oxigenio, de rocha-toral, em estudos paleoambientais

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Ricardo Latge Milward de; Rodrigues, Rene [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Setor de Bioestratigrafia e Paleoecologia; Takaki, Tikae [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Setor de Geoquimica

    1997-12-01

    The usefulness of oxygen and carbon stable ({delta}{sup 18} O and {delta}{sup 13} C) isotopes from bulk samples has been evaluated in a Quaternary section of the Campos Basin. Comparisons were made with values found in benthic and planktonic foraminifera. There are limits inherent to bulk samples but, results suggest that isotopic studies are applicable in such samples. This method has the advantage of being less expensive and time-consuming. The isotopic curves for the Campos Basin section were compared with a Quaternary section data of the Ocean Drilling Program, which were drilled in the equatorial Pacific. The curves are equivalent and prove the stratigraphic meaning of isotopic results, allowing conclusions to be drawn about the paleo-oceanographic conditions during the last 40,000 years. (author)

  2. Chemical and mineralogical proxies of erosion episodes in the dried lake sediments (Amik Lake, Southern Turkey): paleoenvironmental implications

    Science.gov (United States)

    El Ouahabi, Meriam; Hubert-Ferrari, Aurélia; Lebeau, Héléne; Fagel, Nathalie; Vander Auwera, Jacquelinec; Karabacak, Volkan; Schmidt, Sabine

    2016-04-01

    The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record. High resolution of mineralogical (XRD) and geochemical (XRF) analyses were performed. Quantitative mineralogical phases of sediments by the Rietveld method were computed using Topaz software. The age of the record is constrained combining radionuclide and radiocarbon dating, and checked using the correlation between the earthquake history and rapidly deposited layer identified. A high sedimentation rate of 0.12 cm/yr was inferred at the coring site. The 4000 years old record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand leaded to punctual dryings of the lake at the end of the Bronze/Iron transition marked by the collapse of the Hittite Empire and during the Dark ages. At that time, the riverine was carrying a large terrigenous input linked to strong soil erosion related to deforestation, exploitation of mineral resources and the beginning of upland cultivation. During the Roman Period and in the later periods, upland soils were partly depleted and the riverine system completely transformed by channelization that leaded to a mashification of the Amik Basin. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation

  3. Operational river discharge forecasting in poorly gauged basins: the Kavango River basin case study

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Jensen, Iris Hedegaard; Guzinski, R.;

    2015-01-01

    Operational probabilistic forecasts of river discharge are essential for effective water resources management. Many studies have addressed this topic using different approaches ranging from purely statistical black-box approaches to physically based and distributed modeling schemes employing data...... assimilation techniques. However, few studies have attempted to develop operational probabilistic forecasting approaches for large and poorly gauged river basins. The objective of this study is to develop open-source software tools to support hydrologic forecasting and integrated water resources management...

  4. California Basin Studies (CaBS). Final contract report

    Energy Technology Data Exchange (ETDEWEB)

    Gorsline, D.S.

    1991-12-31

    The California Continental Borderland`s present configuration dates from about 4 to 5 X 10{sup 6} years Before Present (B.P.) and is the most recent of several configurations of the southern California margin that have evolved after the North America Plate over-rode the East Pacific Rise about 30 X 10{sup 6} years ago. The present morphology is a series of two to three northwest-southeast trending rows of depressions separated by banks and insular ridges. Two inner basins, Santa Monica and San Pedro, have been the site for the Department of Energy-funded California Basin Study (CaBS) Santa Monica and San Pedro Basins contain post-Miocene sediment thicknesses of about 2.5 and 1.5 km respectively. During the Holocene (past 10,000 years) about 10-12 m have accumulated. The sediment entered the basin by one or a combination of processes including particle infall (mainly as bioaggregates) from surface waters, from nepheloid plumes (surface, mid-depths and near-bottom), from turbidity currents, mass movements, and to a very minor degree direct precipitation. In Santa Monica Basin, during the last century, particle infall and nepheloid plume transport have been the most common processes. The former dominates in the central basin floor in water depths from 900 to 945 m. where a characteristic silt-clay with a typical mean diameter of about 0.006 mm, phi standard deviation.

  5. K-Basin gel formation studies

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M.A.

    1998-07-23

    A key part of the proposed waste treatment for K Basin sludge is the elimination of reactive uranium metal by dissolution in nitric acid (Fkirnent, 1998). It has been found (Delegard, 1998a) that upon nitric acid dissolution of the sludge, a gel sometimes forms. Gels are known to sometimes impair solid/liquid separation and/or material transfer. The purpose of the work reported here is to determine the cause(s) of the gel formation and to determine operating parameters for the sludge dissolution that avoid formation of gel. This work and related work were planned in (Fkunent, 1998), (Jewett, 1998) and (Beck, 1998a). This report describes the results of the tests in (Beck, 1998a) with non-radioactive surrogates.

  6. Utilizing Gravity Methods for Regional Studies in Basin Delineation: Case Study at Jornada del Muerto basin, New Mexico

    Science.gov (United States)

    Villalobos, J. I.

    2005-12-01

    The modeling of basin structures is an important step in the development of plans and policies for ground water management. To facilitate in the analysis of large scale regional structures, gravity data is implemented to examine the overall structural trend of the region. The gravitational attraction of structures in the upper mantle and crust provide vital information about the possible structure and composition of a region. Improved availability of gravity data via internet has promoted extensive construction and interpretation of gravity maps in the analysis of sub-surface structural anomalies. The utilization of gravity data appears to be particularly worthwhile because it is a non-invasive and inexpensive means of addressing the subsurface tectonic framework of large scale regions. In this paper, the author intends to illustrate 1) acquisition of gravity data and its processing; 2) interpretation of gravity data; and 3) sources of uncertainty and errors by using a case study of the Jornada del Muerto basin in South-Central New Mexico where integrated gravity data inferred several faults, sub-basins and thickness variations within the basins structure. The author also explores the integration of gravity method with other geophysical methods to further refine the delineation of basins.

  7. 488-D Ash Basin Vegetative Cover Treatibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

    2003-01-01

    The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

  8. The Neuquén basin, Argentina: A case study in sequence stratigraphy and basin dynamics

    Institute of Scientific and Technical Information of China (English)

    Alberto C. Riccardi

    2006-01-01

    @@ As stated in one of the contributions to this volume, the Neuquen Basin-covering more than 160,000 km2 between c. 32° and 42° S and 68° and 71° W, and containing a Meso-zoic-Cenozoic sedimentary succession at least 7 km thick-is perhaps one of the most thoroughly prospected areas in Argentina. Its geological study goes back to the 19th Century, and shows an exponential increase throughout the 20th, when it became the main source of Argentine oil and gas production.

  9. Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A B [Centre for Marine and Environmental Research (CIMA), Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: abarbosa@ualg.pt

    2009-01-01

    Phytoplankton is the dominant primary producer in aquatic ecosystems and is considered a gauge of ecological condition and change. Some phytoplankton groups, namely diatoms, dinoflagellates, and coccolithophores, produce morphological or chemical fossils that can be used for paleoenvironmental reconstruction. This study aims to review the processes that regulate dynamics in living phytoplankton and to highlight how this knowledge is used in paleoecological studies. The distribution patterns of phytoplankton in present-day aquatic ecosystems are shaped by the interplay between processes that regulate cell growth and cell death. Cell growth and cell death are regulated by the internal environment of phytoplankton (e.g., specific environmental tolerances, resource uptake properties, cell size, density and morphology, alternative nutritional strategies such as mixotrophy or N{sub 2} uptake, motility, intracellular storage capacities, grazing resistance properties), and by its external environment. The external environment includes variables dependent on the availability of resources (e.g., light intensity, concentration of CO{sub 2} and dissolved inorganic macronutrients and micronutrients, availability of living prey in case of mixotrophs) and variables independent of resources (e.g., temperature, salinity, turbulence, ultraviolet radiation, bioactive compounds, activity of grazers, viruses, and eukaryotic parasites). The importance of recently described loss processes, such as grazing by phagotrophic protists, viral lyses, and programmed cell death, is discussed in the context of its potential impact upon phytoplankton vertical fluxes. Examples of the use of different phytoplankton metrics (e.g. abundance, species composition, species morphology, and elemental composition) to infer contemporaneous as well as past environmental and ecological conditions are critically evaluated.

  10. Growth and high-resolution paleoenvironmental signals of rhodoliths (coralline red algae): A new biogenic archive

    Science.gov (United States)

    Halfar, Jochen; Zack, Thomas; Kronz, Andreas; Zachos, James C.

    2000-09-01

    We investigated rhodoliths (coralline red algae) from a subtropical locality in the Gulf of California (Lithothamnium crassiusculum) and a subarctic locality in Newfoundland (Lithothamnium glaciale) for their potential as paleoenvironmental archives using microanalytical geochemical techniques to measure variations in δ18O, Mg, and Ca. Rhodoliths are potentially well suited as recorders of shallow water paleoenvironmental signals because they (1) have worldwide distribution from the tropics to polar regions, (2) are long lived from decades to centuries, and (3) display well-developed growth bands. Our results indicate that rhodolith growth bands preserve ultrahigh-resolution records of paleoceanographic-paleoclimatic change and likely constitute an important new archive for reconstructing the paleoenvironmental history of littoral-neritic areas in which these algae are found. The δ18O content of individually sampled rhodolith growth bands ranges from -2.4 to -4.6‰ in L. crassiusculum and from -3.2 to -0.3‰ in L. glaciale. In both cases, the range of δ18O values suggests a slightly lower amplitude of variation in sea surface temperature than that actually measured in the ocean at the two study sites. Both L. crassiusculum and L. glaciale show a negative offset from isotopic equilibrium. Electron microprobe analysis of magnesium and calcium in growth bands reveals cyclic variations with values ranging between 7.7-18.5 mol % MgCO3 in L. glaciale and 13.2-22.5 mol % MgCO3 in L. crassiusculum. In addition, electron microprobe element maps highlight individual growth bands, provide a powerful approach to study rhodolith formation, and indicate that the specimens we analyzed have vertical growth rates of 250-450 μm/yr.

  11. USING SRTM TO QUANTIFY SIZE PARAMETERS AND SPATIAL DISTRIBUTION OF ENDORHEIC BASINS IN SOUTHERN SOUTH AMERICA

    Directory of Open Access Journals (Sweden)

    Ralf Hesse

    2008-08-01

    Full Text Available The SRTM data set is the highest resolution DEM with global or continental coverage. It is therefore theDEM of choice for continental-scale geomorphological mapping and quantitative analysis. In this study,SRTM data are used for the identification and characterisation of endorheic basins in southern SouthAmerica (south of 19°S. The results show the feasibility of continental-scale quantitative geomorphologybased on SRTM data and provide insights into the distribution of closed basins. The largest endorheicbasin is located in the Puna region and consists of several interconnected sub-basins. This basin accountsfor 38.6 % (7877 km3 of the total volume of the endorheic basins identified in this study. Analyses of thegeographic distribution show a narrow longitudinal distribution between 64.5 and 71.5° W and a multimodallatitudinal distribution which is characterised by two groups of basins at 22.5–27.5°S and 37.5–50.0° Sand an almost complete absence of basins between 27.5 and 37.5° S. Problems and sources ofmisinterpretation arising from data quality and resolution are discussed. Further research, targeting in particularthe genesis and potential for paleoenvironmental reconstruction of closed basins in southern Argentina, iscalled for.

  12. Exploring Sedimentary Basins with High Frequency Receiver Function: the Dublin Basin Case Study

    Science.gov (United States)

    Licciardi, A.; Piana Agostinetti, N.

    2015-12-01

    The Receiver Function (RF) method is a widely applied seismological tool for the imaging of crustal and lithospheric structures beneath a single seismic station with one to tens kilometers of vertical resolution. However, detailed information about the upper crust (0-10 km depth) can also be retrieved by increasing the frequency content of the analyzed RF data-set (with a vertical resolution lower than 0.5km). This information includes depth of velocity contrasts, S-wave velocities within layers, as well as presence and location of seismic anisotropy or dipping interfaces (e.g., induced by faulting) at depth. These observables provides valuable constraints on the structural settings and properties of sedimentary basins both for scientific and industrial applications. To test the RF capabilities for this high resolution application, six broadband seismic stations have been deployed across the southwestern margin of the Dublin Basin (DB), Ireland, whose geothermal potential has been investigated in the last few years. With an inter-station distance of about 1km, this closely spaced array has been designed to provide a clear picture of the structural transition between the margin and the inner portion of the basin. In this study, a Bayesian approach is used to retrieve the posterior probability distributions of S-wave velocity at depth beneath each seismic station. A multi-frequency RF data-set is analyzed and RF and curves of apparent velocity are jointly inverted to better constrain absolute velocity variations. A pseudo 2D section is built to observe the lateral changes in elastic properties across the margin of the basin with a focus in the shallow portion of the crust. Moreover, by means of the harmonic decomposition technique, the azimuthal variations in the RF data-set are isolated and interpreted in terms of anisotropy and dipping interfaces associated with the major fault system in the area. These results are compared with the available information from

  13. Polyphase basin evolution of the Vienna Basin inferred from 3D visualization of sedimentation setting and quantitative subsidence

    Science.gov (United States)

    Lee, Eun Young; Novotny, Johannes; Wagreich, Michael

    2016-04-01

    This study analyzed and visualized data from 210 wells using a MATLAB-based program (BasinVis 1.0) for 3D visualization of sediment distribution, thickness, and quantitative subsidence of the northern and central Vienna Basin. The sedimentation settings for selected horizons were visualized to 3D sediment distribution maps, isopach maps, and cross-sections. Subsidence of the study area resulted in 3D subsidence depth and rate maps of basement and tectonic subsidences. Due to the special position of the Vienna Basin, the basin evolution was influenced by the regional tectonics of surrounding units. The 2D/3D maps provided insights into the polyphase evolution of the Vienna Basin, which is closely related to changes in the changing regional stress field and the paleoenvironmental setting. In the Early Miocene, the sedimentation and subsidence were shallow and E-W/NE-SW trending, indicating the development of piggy-back basins. During the late Early Miocene, maps show wider sedimentation and abruptly increasing subsidence by sinistral strike-slip faults, which initiated the Vienna pull-apart basin system. The sediments of the Early Miocene were supplied through a small deltaic system entering from the south. After thin sedimentation and shallow subsidence of the early Middle Miocene, the development of the Vienna Basin was controlled and accelerated mainly by NE-SW trending synsedimentary normal faults, especially the Steinberg fault. From the Middle Miocene, the subsidence was decreasing overall, however the tectonic subsidence show regionally different patterns. This study suggests that a major tensional regime change, from transtension to E-W extension, caused laterally varying subsidence across the Vienna Basin. The Late Miocene was characterized by the slowing down of basement and tectonic subsidence. From the middle Middle to Late Miocene, enormous amount of sediments supplied by a broad paleo-Danube delta complex on the western flank of the basin. The latest

  14. Regional scale groundwater modelling study for Ganga River basin

    Science.gov (United States)

    Maheswaran, R.; Khosa, R.; Gosain, A. K.; Lahari, S.; Sinha, S. K.; Chahar, B. R.; Dhanya, C. T.

    2016-10-01

    Subsurface movement of water within the alluvial formations of Ganga Basin System of North and East India, extending over an area of 1 million km2, was simulated using Visual MODFLOW based transient numerical model. The study incorporates historical groundwater developments as recorded by various concerned agencies and also accommodates the role of some of the major tributaries of River Ganga as geo-hydrological boundaries. Geo-stratigraphic structures, along with corresponding hydrological parameters,were obtained from Central Groundwater Board, India,and used in the study which was carried out over a time horizon of 4.5 years. The model parameters were fine tuned for calibration using Parameter Estimation (PEST) simulations. Analyses of the stream aquifer interaction using Zone Budget has allowed demarcation of the losing and gaining stretches along the main stem of River Ganga as well as some of its principal tributaries. From a management perspective,and entirely consistent with general understanding, it is seen that unabated long term groundwater extraction within the study basin has induced a sharp decrease in critical dry weather base flow contributions. In view of a surge in demand for dry season irrigation water for agriculture in the area, numerical models can be a useful tool to generate not only an understanding of the underlying groundwater system but also facilitate development of basin-wide detailed impact scenarios as inputs for management and policy action.

  15. Recent developments in study of the typical superimposed basins and petroleum accumulation in China:Exemplified by the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    JIN Zhijun; WANG Qingchen

    2004-01-01

    Most of petroliferous sedimentary basins in China have experienced multiple phases of tectonic evolution and deposition, and are characterized by tectonic and depositional superimposition. The term "superimposed basin" is suggested to describe those basins which consist of two or more simple prototype basins superimposing vertically and/or coalescing laterally. The characteristics of petroliferous superimposed basins are "multiple stages of basin forming and reworking, multiple layers of source rocks, multiple periods of hydrocarbon generation and expulsion, multiple periods of petroleum migration-accumulation-escape". Therefore,applying the wave process analysis method to studying the process of basin formation, hydrocarbon generation, and reservoir formation, and then establishing theory of "petroleum accumulation system" is helpful to enhancing petroleum exploration efficiency in superimposed basins.This paper will, based on case study in the Tarim basin, report the major developments in studying basin formation, hydrocarbon generation and petroleum accumulation. In study of basin formation, (1) geophysical comprehensive profiles reveal that the Tarim plate has been subducted beneath the Tianshan orogenic belt with an interfinger structure and that the deep structure in the eastern section of the Tianshan orogenic belt is different from that in the western section. (2) The vertical variation in debris and geochemical composition reveals the nature and Mesozoic-Cenozoic evolution history of the Kuqa Depression. (3) Field investigation and paleostress reconstruction show that the Kuqa Depression has undergone gravity-driven extension in sedimentary cover when the Tianshan uplifted vertically. In hydrocarbon generation study, new developments include (1) setting environmental index to judge high grade source rocks in marine carbonates, and (2) establishing the lower limit of the organic carbon content for effective carbonate source rocks. In petroleum accumulation

  16. Recent developments in study of the typical superimposed basins and petroleum accumulation in China: Exemplified by the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    JIN; Zhijun; WANG; Qingchen

    2004-01-01

    Most of petroliferous sedimentary basins in China have experienced multiple phases of tectonic evolution and deposition, and are characterized by tectonic and depositional superimposition. The term "superimposed basin" is suggested to describe those basins which consist of two or more simple prototype basins superimposing vertically and/or coalescing laterally. The characteristics of petroliferous superimposed basins are "multiple stages of basin forming and reworking, multiple layers of source rocks, multiple periods of hydrocarbon generation and expulsion, multiple periods of petroleum migration-accumulation-escape". Therefore,applying the wave process analysis method to studying the process of basin formation, hydrocarbon generation, and reservoir formation, and then establishing theory of "petroleum accumulation system" is helpful to enhancing petroleum exploration efficiency in superimposed basins.This paper will, based on case study in the Tarim basin, report the major developments in studying basin formation, hydrocarbon generation and petroleum accumulation. In study of basin formation, (1) geophysical comprehensive profiles reveal that the Tarim plate has been subducted beneath the Tianshan orogenic belt with an interfinger structure and that the deep structure in the eastern section of the Tianshan orogenic belt is different from that in the western section. (2) The vertical variation in debris and geochemical composition reveals the nature and Mesozoic-Cenozoic evolution history of the Kuqa Depression. (3) Field investigation and paleostress reconstruction show that the Kuqa Depression has undergone gravity-driven extension in sedimentary cover when the Tianshan uplifted vertically. In hydrocarbon generation study, new developments include (1) setting environmental index to judge high grade source rocks in marine carbonates, and (2) establishing the lower limit of the organic carbon content for effective carbonate source rocks. In petroleum accumulation

  17. Operational river discharge forecasting in poorly gauged basins: the Kavango River Basin case study

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Jensen, Iris Hedegaard; Guzinski, R.

    2014-01-01

    assimilation techniques. However, few studies have attempted to develop operational probabilistic forecasting approaches for large and poorly gauged river basins. This study is funded by the European Space Agency under the TIGER-NET project. The objective of TIGER-NET is to develop open-source software tools...... to support integrated water resources management in Africa and to facilitate the use of satellite earth observation data in water management. We present an operational probabilistic forecasting approach which uses public-domain climate forcing data and a hydrologic–hydrodynamic model which is entirely based...... on open-source software. Data assimilation techniques are used to inform the forecasts with the latest available observations. Forecasts are produced in real time for lead times of 0 to 7 days. The operational probabilistic forecasts are evaluated using a selection of performance statistics and indicators...

  18. A study on drought trend in Han River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hung-Soo [Sun Moon University, Chonan(Korea); Moon, Jang-Won; Kim, Jae-Hyung; Kim, Joong-Hoon [Korea Univ., Seoul(Korea)

    2000-08-31

    The drought analysis is performed by applications of truncation level method and conditional probability concept for hydrologic time series in Han river basin. The distributed trend of conditional probability is determined using kriging method for the time series. This study uses daily flowrate, monthly rainfall, and daily high temperature data sets. The daily flowrate data of 12 years(1986-1997) is used for the analysis. Also, the 14 years' data sets(1986-1999) for monthly rainfall and daily high temperature obtained from the National Weather Service of Korea are used in this study. In the cases of flowrate and rainfall data sets, the estimated value corresponding to the truncation level is decreased as the truncation level is increased but in the high temperature data, the value is increased as the truncation level is increased. The conditional probability varies according to the observations and sites. However, the distributed trend of drought is similar over the basin. As a result, the possibility of the drought is high in the middle and lower parts of Han river basin and thus it is recommended the distributed trend of drought be considered when the plan or measures for drought are established. (author). 10 refs., 9 tabs., 5 figs.

  19. Outcrop and core integrative ichnofabric analysis of Miocene sediments from Lepe, Huelva (SW Spain): Improving depositional and paleoenvironmental interpretations

    Science.gov (United States)

    Rodríguez-Tovar, Francisco J.; Dorador, Javier; Mayoral, Eduardo; Santos, Ana

    2017-03-01

    the integrative ichnofabric analysis, including outcrop and core materials, in sedimentary basin analysis, assessing paleoenvironmental conditions and improving sequence stratigraphy characterization.

  20. Biostratigraphy, sedimentology and paleoenvironments of the northern Danube Basin: Ratkovce 1 well case study

    Directory of Open Access Journals (Sweden)

    Rybár Samuel

    2015-02-01

    Full Text Available The Ratkovce 1 well, drilled in the Blatné depocenter of the northern Danube Basin penetrated the Miocene sedimentary record with a total thickness of 2000 m. Biostratigraphically, the NN4, NN5 and NN6 Zones of calcareous nannoplankton were documented; CPN7 and CPN8 foraminifer Zones (N9, 10, 11 of the global foraminiferal zonation; and MMi4a; MMi5 and MMi6 of the Mediterranean foraminiferal zonation were recognized. Sedimentology was based on description of well core material, and together with SP and RT logs, used to characterize paleoenvironmental conditions of the deposition. Five sedimentary facies were reconstructed: (1 fan-delta to onshore environment which developed during the Lower Badenian; (2 followed by the Lower Badenian proximal slope gravity currents sediments; (3 distal slope turbidites were deposited in the Lower and Upper Badenian; (4 at the very end of the Upper Badenian and during the Sarmatian a coastal plain of normal marine to brackish environment developed; (5 sedimentation finished with the Pannonian-Pliocene shallow lacustrine to alluvial plain deposits. The provenance analysis records that the sediment of the well-cores was derived from crystalline basement granitoides and gneisses and from the Permian to Lower Cretaceous sedimentary cover and nappe units of the Western Carpathians and the Eastern Alps. Moreover, the Lower Badenian volcanism was an important source of sediments in the lower part of the sequence.

  1. The Bucaco Basin (Portugal): Organic petrology and geochemistry study

    Energy Technology Data Exchange (ETDEWEB)

    Flores, D.; Ribeiro, J.; Marques, M.M.; Ribeiro, M.A.; Bobos, I.; de Jesus, A. Pinto [Departamento e Centro de Geologia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Pereira, L.C. Gama; Pina, B. [Departamento de Ciencias da Terra e Centro de Geofisica, Universidade de Coimbra, 3000-272 Coimbra (Portugal)

    2010-04-01

    The Bucaco Basin includes a Carboniferous/Permian sequence that comprises, from bottom to top, the following stratigraphic sequence: Algeriz Formation, Vale da Mo Formation and Monsarros Formation. Algeriz Formation is constituted by deposits of basal breccia with variable thickness and alternating layers of siltstone, mudstone and conglomerate. Vale da Mo Formation corresponds to lacustrine deposits comprising massive red beds in the base, that pass alternatively to silty-mudstones, shales and grey mudstones with organic matter; this formation also includes a thin coal seam. Monsarros Formation includes fluvial conglomeratic deposits prevalent in the base and top, separated by layers of siltstone and mudstone, redder to the top. The Bucaco Basin opens as a pull-apart basin, into the Porto-Coimbra-Tomar shear zone and later is affected by the clockwise (dextral) movement of this N10 W shear zone. The petrographic study of samples from Vale da Mo Formation showed that the organic matter corresponds to a type III kerogen, derived from higher land plants (gas-prone). The thermal maturation level of the strata was determined using random vitrinite reflectance, with values ranging from 0.72% to 0.80% (%Rr). Rock-Eval pyrolysis showed that Vale da Mo Formation is the only one with potential to generate hydrocarbons, an observation consistent with the petrographic characteristics. TOC ranges from 0.08% to 1.52%. Monsarros Formation reported the highest values for S1/TOC index. (author)

  2. Paleoenvironmental changes during the late Quaternary as inferred from foraminifera assemblages in the Laizhou Bay

    Institute of Scientific and Technical Information of China (English)

    YAO Jing; YU Hongjun; XU Xingyong; YI Liang; CHEN Guangquan; SU Qiao

    2014-01-01

    Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon 14C (AMS14C) and opti-cally stimulated luminescence (OSL) ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of ma-rine isotopic stage 7 (MIS7), the last interglacial period (MIS5) and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the fora-minifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.

  3. Alluvial basin statistics of the Southwest Principal Aquifers (SWPA) study.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — SWPA_alvbsn is a vector dataset of alluvial-fill basin statistics for the Southwest United States. Statistics for each basin include physical details such as area,...

  4. Linking microbial assemblages to paleoenvironmental conditions from the Holocene and Last Glacial Maximum times in Laguna Potrok Aike sediments, Argentina

    Science.gov (United States)

    Vuillemin, Aurele; Ariztegui, Daniel; Leavitt, Peter R.; Bunting, Lynda

    2014-05-01

    Laguna Potrok Aike is a closed basin located in the southern hemisphere's mid-latitudes (52°S) where paleoenvironmental conditions were recorded as temporal sedimentary sequences resulting from variations in the regional hydrological regime and geology of the catchment. The interpretation of the limnogeological multiproxy record developed during the ICDP-PASADO project allowed the identification of contrasting time windows associated with the fluctuations of Southern Westerly Winds. In the framework of this project, a 100-m-long core was also dedicated to a detailed geomicrobiological study which aimed at a thorough investigation of the lacustrine subsurface biosphere. Indeed, aquatic sediments do not only record past climatic conditions, but also provide a wide range of ecological niches for microbes. In this context, the influence of environmental features upon microbial development and survival remained still unexplored for the deep lacustrine realm. Therefore, we investigated living microbes throughout the sedimentary sequence using in situ ATP assays and DAPI cell count. These results, compiled with pore water analysis, SEM microscopy of authigenic concretions and methane and fatty acid biogeochemistry, provided evidence for a sustained microbial activity in deep sediments and pinpointed the substantial role of microbial processes in modifying initial organic and mineral fractions. Finally, because the genetic material associated with microorganisms can be preserved in sediments over millennia, we extracted environmental DNA from Laguna Potrok Aike sediments and established 16S rRNA bacterial and archaeal clone libraries to better define the use of DNA-based techniques in reconstructing past environments. We focused on two sedimentary horizons both displaying in situ microbial activity, respectively corresponding to the Holocene and Last Glacial Maximum periods. Sequences recovered from the productive Holocene record revealed a microbial community adapted to

  5. Study on snowmelt runoff simulation in the Kaidu River basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiChi; LI BaoLin; BAO AnMing; ZHOU ChengHu; CHEN Xi; ZHANG XueRen

    2007-01-01

    Alpine snowmelt is an important generation mode for runoff in the source region of the Tarim River basin, which covers four subbasins characterized by large area, sparse gauge stations, mixed runoff supplied by snowmelt and rainfall, and remarkably spatially heterogeneous precipitation. Taking the Kaidu River basin as a research area, this study analyzes the influence of these characteristics on the variables and parameters of the Snow Runoff Model and discusses the corresponding determination strategy to improve the accuracy of snowmelt simulation and forecast. The results show that: (i) The temperature controls the overall tendency of simulated runoff and is dominant to simulation accuracy,as the measured daily mean temperature cannot represent the average level of the same elevation in the basin and that directly inputting it to model leads to inaccurate simulations. Based on the analysis of remote sensing snow maps and simulation results, it is reasonable to approximate the mean temperature with 0.5 time daily maximum temperature. (ii) For the conflict between the limited gauge station and remarkably spatial heterogeneity of rainfall, it is not realistic to compute rainfall for each elevation zone. After the measured rainfall is multiplied by a proper coefficient and adjusted with runoff coefficient for rainfall, the measured rainfall data can satisfy the model demands. (iii) Adjusting time lag according to the variation of snowmelt and rainfall position can improve the simulation precision of the flood peak process. (iv) Along with temperature, the rainfall increases but cannot be completely monitored by limited gauge stations, which results in precision deterioration.

  6. Using the stratigraphic record to document tectonic-geomorphologic interactions in a foreland basin setting: outcrop study of the Ainsa Basin, Spain

    Science.gov (United States)

    Pyles, D. R.; Moody, J.; Gordon, G.; Hoffman, M.; Moss-Russell, A.; Silalahi, H.; Setiawan, P.; Clark, J.; Bracken, B.; Guzofski, C.

    2013-12-01

    Eocene strata of the Ainsa Basin (Spain) contain clastic and carbonate strata deposited in a relatively small (100 km^2), structurally active piggyback foreland basin. The basin is bounded by the Mediano Anticline to the east and the Boltana Anticline to the west. Clastic strata were sourced by an eastern fluvial-deltaic system whereas carbonate strata were sourced from shallow-water carbonate systems that rimmed the southern and western margins of the basin. Four time-stratigraphic units, which form an upward transect through the basin-fill succession, were studied in detail: Ainsa, Morillo, Guaso, Sobrarbe-Escanilla. The study uses the stratigraphic record to document linkages between progressive uplift of the basin-bounding structures, spatial-temporal changes in the amount and location of subsidence, and temporal changes in the landscape. The Ainsa unit contains submarine channels that entered the basin from the east and exited the basin to the northwest, although some channels locally transfer to lobes near the northwest end of the basin. The Morillo unit contains submarine channels that entered the basin from the east, dispersed onto the basin floor, then converged at the western end of the basin where they continued onto the longitudinally adjacent Jaca Basin. The Guaso unit contains submarine channels that entered the basin from the east and transfer to a ponded distributive submarine fan at the center of the basin. The Escanilla-Sobrarbe unit contains a linked shelf-to-basin system that prograded from south to north and records the final filling of the basin. Four lines of evidence collectively support the basin-fill succession was deposited during structural growth. First, the depocenter, which is interpreted to reflect the position of maximum subsidence during deposition, of the systems systematically shifted westward as the basin filled. Second, the axial part of the clastic sediment systematically shifted southward as the basin filled. Third, the

  7. Application of nuclear logging to porosity studies in Itaborai basin

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo Tadeu, E-mail: milena@lin.ufrj.br, E-mail: inaya@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Ferrucio, Paula Lucia; Borghi, Leonardo, E-mail: ferrucio@acd.ufrj.br, E-mail: borghi@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Geociencias. Dept. de Geologia; Abreu, Carlos Jorge, E-mail: jo_abreu@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias

    2011-07-01

    Nuclear logging provides information on bulk density and porosity variations by measuring the intensity of the scattered radiation induced on the formation by radioactive sources. In this study, nuclear logging was employed to analyze the pore-space system of the 2-ITAB-1-RJ well placed on the Itaborai limestone basin, in the state of Rio de Janeiro. This is one of the smallest sedimentary basin in Brazil and it is formed by clastic deposits and travertine limestone rocks which are fractured. Understanding the pore-space system of carbonate rocks has become important subject for the oil industry, specially in Brazil. A Density Gamma Probe (LSD) and a Neutron Probe (NEUT) were used for data acquisition, which nuclear logging was carried out in part of the well, with continuous detection for about 50 m of deep. The detection speed was 4 m/min for the LSD and 5 m/min for the NEUT. The results obtained by nuclear logging showed that the 2-ITAB-1-RJ well consists of three different intervals with rocks ranging from low to moderate porosity present in travertine, marls and gneisses. (author)

  8. Organic geochemistry of the Callovo-Oxfordian argillo-carbonated sedimentary series of the East of the Paris basin and of England. Variabilities and paleo-environmental implications; Geochimie organique des series argilo-carbonatees du Callovo-Oxfordien de l'Est du bassin de Paris et d'Angleterre: Variabilites et implications paleoenvironnementales

    Energy Technology Data Exchange (ETDEWEB)

    Hautevelle, Y

    2005-12-15

    The Callovo-Oxfordian clay-stones from the East of the Paris basin are studied by ANDRA in order to test the feasibility of a possible storage of radioactive waste. The molecular analysis of their organic matter indicates that they can be considered as homogenous from their organic content point of view because they are characterized by only one molecular facies. However, the transition to the surrounding limestones is underlined by a major evolution of the molecular facies indicating a change and an increase of the variability of the deposition and diagenesis conditions. The evolution of the distribution of the plant bio-markers indicates, at the end of the Lower Oxfordian, a paleo-floristic change characterized by the increase of the proportion of Pinaceae (a conifer family) or their forerunners on the London-Brabant massif. This paleo-floristic evolution reflects a paleo-climatic change characterized by the increase of aridity at the global scale. Other complementary results get on other sedimentary series of similar ages highlight the occurrence of a period of water anoxia during the Middle Callovian which certainly happened on the major part of the Western Europe. This event could be at the origin of the crisis of the carbonate production at the Dogger/Malm transition. On the other hand, an experimental technique based on artificial maturation of extant plants has been developed and will allow the acquisition of new palaeo-chemo-taxonomic data. These data will contribute to a better interpretation of plant bio-marker assemblages in terms of palaeo-floristic composition. (author)

  9. Incentive compatibility and conflict resolution in international river basins: A case study of the Nile Basin

    Science.gov (United States)

    Wu, Xun; Whittington, Dale

    2006-02-01

    Nation-states rarely go to war over water, but it is equally rare that water conflicts in an international river basin are resolved through cooperation among the riparian countries that use the shared resources. Gains from cooperation will mean little to individual riparians unless the required cooperative behaviors are incentive compatible. Cooperative game theory offers useful insights for assessing cooperative solutions for water conflicts in international river basins. Applying cooperative game theory concepts such as core, nucleolus, and Shapley value to Nile water conflicts, we examine the incentive structure of both cooperative and noncooperative strategies for different riparian countries and establish some baseline conditions for incentive-compatible cooperation in the Nile basin.

  10. Sedimentary basin analysis using airborne gravity data: a case study from the Bohai Bay Basin, China

    Science.gov (United States)

    Li, Wenyong; Liu, Yanxu; Zhou, Jianxin; Zhou, Xihua; Li, Bing

    2016-11-01

    In this paper, we discuss the application of an airborne gravity survey to sedimentary basin analysis. Using high-precision airborne gravity data constrained by drilling and seismic data from the Bohai Bay Basin in eastern China, we interpreted faults, structural elements, sedimentary thickness, structural styles and local structures (belts) in the central area of the Basin by the wavelet transform method. Subsequently, these data were subtracted from the Bouguer gravity to calculate the residual gravity anomalies. On this basis, the faults were interpreted mainly by linear zones of high gravity gradients and contour distortion, while the sedimentary thicknesses were computed by the Euler deconvolution. The structural styles were identified by the combination of gravity anomalies and the local structures interpreted by the first vertical derivative of the residual gravity. The results showed evidence for seven faults, one sag and ten new local structure belts.

  11. Review of the stratigraphy and paleoclimatology study of the Paleogene-Neogene Longzhong Basin%陇中盆地古近纪-新近纪地层学与古气候学研究进展

    Institute of Scientific and Technical Information of China (English)

    张鹏; 敖红; 安芷生

    2016-01-01

    Background aim and scope The well-developed long continuous Paleogene—Neogene fluvio-lacustrine strata (the Tertiary red beds) are exposed in the Longzhong Basin, Northwestern China. The abundant mammalian faunas and phytolite in the red beds provide valuable material for the stratigraphic correlation and paleoenvironmental reconstruction. In recent decades, paleontological, sedimentological, magnetostratigraphical and palynological studies have been conducted in the Longzhong Basin (e.g., Xining Basin, Lanzhou Basin and Linxia Basin). The environmental evolution in the Longzhong Basin since Cenzoic is likely to be associated with the land-sea redistributions the uplift of the Tibetan Plateau and/or the global cooling. Materials and methods In this study, we review the achievements mentioned above based on the stratigraphic and paleoclimatic research published in recent decades and bring out questions to be solved in future studies. Results The Tertiary beds in the Xining Basin unconformably overlie the Cretaceous Minhe Group, and the initiation of Tertiary beds began at least 55—52 Ma ago. Between 52—17 Ma, the continuous deposits in this basin implied a relatively stable sedimentary environment. The Tertiary beds of the Lanzhou Basin unconformably overlie the Cretaceous Hekou Group with an basal age of over 58 Ma. Given the formation of the basin systems in and around the Tibetan Plateau at that time, we speculate that the initiation of Paleogene deposits in these two basins at 58—52 Ma may be linked to the Indian-Eurasian continental collision at 65—55 Ma. The low sedimentary rate before late Paleogene (32—29 Ma) implied a relatively weak tectonic activity in the northeast margin of the Tibetan Plateau after the collision of Indian and Eurasian continent. However, the sedimentary rate increased from 32—29 Ma in both basins and a hiatus was observed in the Lanzhou Basin at the boundary of Yehucheng Formation and Xianshuihe Formation (~31 Ma

  12. Mechanism of Varve Formation and Paleoenvironmental Research at Lake Bolterskardet, Svalbard, the Arctic

    Institute of Scientific and Technical Information of China (English)

    CHU Guoqiang; LIU Jiaqi; GAO Denyi; SUN Qing

    2006-01-01

    On the basis of observation of thin sections and 137Cs data, laminations in sediment are interpreted to be varves in Bolterskardet Lake (78°06' N, 16°01' E), Svalbard, the Arctic. Varves appear under a petrologic microscope as couplets of dark-silt and light-clay layers. The mechanism of varve formation is surmized as follows: each silt layer is the production of sediment inflow interpreted as mainly derived from snowmelt during summer; each clay layer was deposited in a stillwater environment during an ice-cover period. A light -clay layer provides an important index bed to identify the annual interface. The high accumulation rates, long period of ice cover, and topographically closed basin are probably all critical factors in forming and preserving varves. Varve thickness is known to be controlled mainly by summer temperature. The variation of varve thickness in Lake Bolterskardet can then be used to reconstruct summer temperature. The varve series show that there has been distinct decade-scale variability of summer temperature over the past 150 years. Warm periods occurred in the 1860s, around 1900, the 1930s, 1950s, and 1970s, and in the last 20 years. The varved sediments of Lake Bolterskarde preserve an ideal record for high-resolution paleoclimatic and paleoenvironmental research in this data-sparse area.

  13. Assessing water footprint at river basin level: a case study for the Heihe River Basin in northwest China

    NARCIS (Netherlands)

    Zeng, Z; Liu, J.; Koeneman, P.H.; Zarate, E.; Hoekstra, A.Y.

    2012-01-01

    Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this stu

  14. Assessing water footprint at river basin level: a case study for the Heihe River Basin in Northwest China

    NARCIS (Netherlands)

    Zheng, Z.; Liu, J.; Koeneman, P.H.; Zarate, E.; Hoekstra, A.Y.

    2012-01-01

    Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this stu

  15. Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin

    Directory of Open Access Journals (Sweden)

    Kaiglová Jana

    2014-03-01

    Full Text Available This paper presents the results of testing the applicability of the MIKE Basin model for simulating the efficiency of scenarios for reducing water pollution. The model has been tested on the Olšava River Basin (520 km2 which is a typical rural region with a heterogeneous mix of pollution sources with variable topography and land use. The study proved that the model can be calibrated successfully using even the limited amount of data typically available in rural basins. The scenarios of pollution reduction were based on implementation and intensification of municipal wastewater treatment and conversion of arable land on fields under the risk of soil erosion to permanent grassland. The application of simulation results of these scenarios with proposed measures proved decreasing concentrations in downstream monitoring stations. Due to the practical applicability of proposed measures, these could lead to fulfilment of the water pollution limits required by the Czech and EU legislation. However, there are factors of uncertainty that are discussed that may delay or limit the effect of adopted measures in small rural basins.

  16. Assessing Vulnerability under Uncertainty in the Colorado River Basin: The Colorado River Basin Water Supply and Demand Study

    Science.gov (United States)

    Jerla, C.; Adams, P.; Butler, A.; Nowak, K.; Prairie, J. R.

    2013-12-01

    Spanning parts of the seven states, of Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming, the Colorado River is one of the most critical sources of water in the western United States. Colorado River allocations exceed the long-term supply and since the 1950s, there have been a number of years when the annual water use in the Colorado River Basin exceeded the yield. The Basin is entering its second decade of drought conditions which brings challenges that will only be compounded if projections of climate change are realized. It was against this backdrop that the Colorado River Basin Water Supply and Demand Study was conducted. The Study's objectives are to define current and future imbalances in the Basin over the next 50 years and to develop and analyze adaptation and mitigation strategies to resolve those imbalances. Long-term planning in the Basin involves the integration of uncertainty with respect to a changing climate and other uncertainties such as future demand and how policies may be modified to adapt to changing reliability. The Study adopted a scenario planning approach to address this uncertainty in which thousands of scenarios were developed to encompass a wide range of plausible future water supply and demand conditions. Using Reclamation's long-term planning model, the Colorado River Simulation System, the reliability of the system to meet Basin resource needs under these future conditions was projected both with and without additional future adaptation strategies in place. System reliability metrics were developed in order to define system vulnerabilities, the conditions that lead to those vulnerabilities, and sign posts to indicate if the system is approaching a vulnerable state. Options and strategies that reduce these vulnerabilities and improve system reliability were explored through the development of portfolios. Four portfolios, each with different management strategies, were analyzed to assess their effectiveness at

  17. FLORISTIC STUDY IN THE LOWER PAPAGAYO RIVER BASIN, GUERRERO, MEXICO

    Directory of Open Access Journals (Sweden)

    Blanca Estela Carreto-Pérez

    2015-11-01

    Full Text Available We present the floristic composition of the Papagayo river basin, Guerrero, México.Field work was carried out from June 2011 to June 2012. We identified a total of 204 species of vascular plants, including 73 families and 163 genus. Families Fabaceae,Poaceae, Asteraceae, Euphorbiaceae and Rubiaceae represented 41% of all species and 38% of the genus in the study area. The herbaceous plant life form was the best represented with 81 species (40%. Were determined 10 vegetation types, of which the tropical deciduous forest covers the largest area and has the richest flora. Eleven species were recorded under the category of threatened by NOM-059-SEMARNAT-2010, of which one is endemic to Mexico (Rhizophora mangle.

  18. Interdisciplinary cooperation and studies in geoscience in the Carpathian Basin

    Directory of Open Access Journals (Sweden)

    Marcel MINDRESCU

    2012-06-01

    Full Text Available An interdisciplinary approach to geoscience is particularly important in this vast research field, as the more innovative studies are increasingly crossing discipline boundaries and thus benefitting from multiple research methods and viewpoints. Grasping this concept has led us to encourage interdisciplinary cooperation by supporting and promoting the creation of “meeting places” able to provide a framework for researchers and scholars involved in geoscience research to find common grounds for discussion and collaboration. Most recently, this was achieved by organizing the 1st Workshop on “Interdisciplinarity in Geosciences in the Carpathian Basin” (IGCB held in the Department of Geography at the University of Suceava (Romania, between the 18th and 22nd October 2012. This event brought together both an international group of scientists and local researchers which created opportunities for collaboration in research topics such as geography, environment, geology and botany, biology and ecology in the Carpathian Basin.

  19. Geochemical evolution of groundwater salinity at basin scale: a case study from Datong basin, Northern China.

    Science.gov (United States)

    Wu, Ya; Wang, Yanxin

    2014-05-01

    A hydrogeochemical investigation using integrated methods of stable isotopes ((18)O, (2)H), (87)Sr/(86)Sr ratios, Cl/Br ratios, chloride-mass balance, mass balance and hydrogeochemical modeling was conducted to interpret the geochemical evolution of groundwater salinity in Datong basin, northern China. The δ(2)H, δ(18)O ratios in precipitation exhibited a local meteoric water line of δ(2)H = 6.4 δ(18)O -5 (R(2) = 0.94), while those in groundwater suggested their meteoric origin in a historically colder climatic regime with a speculated recharge rate of less than 20.5 mm overall per year, in addition to recharge from a component of deep residual ancient lake water enriched with Br. According to the Sr isotope binary mixing model, the mixing of recharges from the Shentou karst springs (24%), the western margins (11%) and the eastern margins (65%) accounts for the groundwater from the deep aquifers of the down-gradient parts in the central basin is a possible mixing mechanism. In Datong, hydrolysis of silicate minerals is the most important hydrogeochemical process responsible for groundwater chemistry, in addition to dissolution of carbonate and evaporites. In the recharge areas, silicate chemical weathering is typically at the bisiallitization stage, while that in the central basin is mostly at the monosiallitization stage with limited evidence of being in equilibrium with gibbsite. Na exchange with bound Ca, Mg prevails at basin scale, and intensifies with groundwater salinity, while Ca, Mg exchange with bound Na locally occurs in the east pluvial and alluvial plains. Although groundwater salinity increases with the progress of water-rock/sediment interactions along the flow path, as a result of carbonate solubility control and continuous evapotranspiration, Na-HCO3 and Na-Cl-SO4 types of water are usually characterized respectively in the deep and the shallow aquifers of an inland basin with a silicate terrain in an arid climatic regime.

  20. Impact of prehistoric cooking practices on paleoenvironmental proxies in shell midden constituents

    Science.gov (United States)

    Müller, Peter; Staudigel, Philip; Murray, Sean T.; Westphal, Hildegard; Swart, Peter K.

    2016-04-01

    Paleoenvironmental proxy records such as oxygen isotopes of calcareous skeletal structures like fish otoliths or mollusk shells provide highest-resolution information about environmental conditions experienced by the organism. Accumulations of such skeletal structures by ancient coastal populations in so called "shell midden" deposits provide us with sub-seasonally resolved paleoclimate records covering time spans up to several millennia. Given their high temporal resolution, these deposits are increasingly used for paleoclimate reconstructions and complement our understanding of ancient climate changes. However, gathered as comestibles, most of these skeletal remains were subject to prehistoric cooking methods prior to deposition. The associated alteration of the chemical proxy signatures as well as the subsequent error for paleoenvironmental reconstructions remained almost entirely neglected so far. Here, we present clumped isotope, conventional oxygen and carbon isotopes as well as element:Ca ratios measured in modern bivalve shells after exposing them to different prehistoric cooking methods. Our data show that most cooking methods considerably alter commonly used paleoclimate proxy systems which can lead to substantial misinterpretations of ancient climate conditions. Since the magnitude of chemical alteration is not distinguishable from natural temperature variability in most coastal settings, the alteration of shell midden constituents by prehistoric cooking remains likely unnoticed in most cases. Thus, depending on the cooking method, pre-depositional heating might have introduced considerable errors into previous paleoclimate studies. However, our data also show that clumped isotope thermometry represents a suitable diagnostic tool to detect such pre-depositional cooking events and also allows differentiating between the most commonly applied prehistoric cooking methods.

  1. Description of the Columbia Basin Wind Energy Study (CBWES)

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Larry K.; Pekour, Mikhail S.; Nelson, Danny A.

    2012-10-01

    The purpose of this Technical Report is to provide background information about the Columbia Basin Wind Energy Study (CBWES). This study, which was supported by the U.S. Department of Energy’s Wind and Water Power Program, was conducted from 16 November 2010 through 21 March 2012 at a field site in northeastern Oregon. The primary goal of the study was to provide profiles of wind speed and wind direction over the depth of the boundary layer in an operating wind farm located in an area of complex terrain. Measurements from propeller and vane anemometers mounted on a 62 m tall tower, Doppler Sodar, and Radar Wind Profiler were combined into a single data product to provide the best estimate of the winds above the site during the first part of CBWES. An additional goal of the study was to provide measurements of Turbulence Kinetic Energy (TKE) near the surface. To address this specific goal, sonic anemometers were mounted at two heights on the 62 m tower on 23 April 2011. Prior to the deployment of the sonic anemometers on the tall tower, a single sonic anemometer was deployed on a short tower 3.1 m tall that was located just to the south of the radar wind profiler. Data from the radar wind profiler, as well as the wind profile data product are available from the Atmospheric Radiation Measurements (ARM) Data Archive (http://www.arm.gov/data/campaigns). Data from the sonic anemometers are available from the authors.

  2. The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Moucha, Robert; Forte, Alessandro; Mitrovica, Jerry X.; Pound, Matthew; Salzmann, Ulrich; Robinson, Marci M.; Chandler, Mark; Foley, Kevin M.; Haywood, Alan M.

    2016-01-01

    The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian ( ∼ 3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

  3. Long-term tritium monitoring to study river basin dynamics: case of the Danube River basin

    Science.gov (United States)

    Aggarwal, Pradeep; Araguas, Luis; Groening, Manfred; Newman, Brent; Kurttas, Turker; Papesch, Wolfgang; Rank, Dieter; Suckow, Axel; Vitvar, Tomas

    2010-05-01

    During the last five decades, isotope concentrations (O-18, D, tritium) have been extensively measured in precipitation, surface- and ground-waters to derive information on residence times of water in aquifers and rivers, recharge processes, and groundwater dynamics. The unique properties of the isotopes of the water molecule as tracers are especially useful for understanding the retention of water in river basins, which is a key parameter for assessing water resources availability, addressing quality issues, investigating interconnections between surface- and ground-waters, and for predicting possible hydrological shifts related to human activities and climate change. Detailed information of the spatial and temporal changes of isotope contents in precipitation at a global scale was one of the initial aims of the Global Network of Isotopes in Precipitation (GNIP), which has provided a detailed chronicle of tritium and stable isotope contents in precipitation since the 1960s. Accurate information of tritium contents resulting of the thermonuclear atmospheric tests in the 1950s and 1960s is available in GNIP for stations distributed world-wide. Use of this dataset for hydrological dating or as an indicator of recent recharge has been extensive in shallow groundwaters. However, its use has been more limited in surface waters, due to the absence of specific monitoring programmes of tritium and stable isotopes in rivers, lakes and other surface water bodies. The IAEA has recently been compiling new and archival isotope data measured in groundwaters, rivers, lakes and other water bodies as part of its web based Water Isotope System for Data Analysis, Visualization and Electronic Retrieval (WISER). Recent additions to the Global Network of Isotopes in Rivers (GNIR) contained within WISER now make detailed studies in rivers possible. For this study, we are re-examining residence time estimates for the Danube in central Europe. Tritium data are available in GNIR from 15

  4. Effect of volatiles erupted from Mesozoic and Cenozoic volcanic activities on paleo-environmental changes in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the determination of composition of volcanic volatiles and petrologic estimation of the total mass of volatiles erupted,we showed important advances in the study of the impact of Mesozoic and Cenozoic volcanic activities on paleo-environmental changes in China.The volcanic activities include western Liaoning and Zhangjiakou Mesozoic intermediate-acidic explosive eruptions,southern Tibet and Shanwang Cenozoic volcanism,and Mt.Changbai volcanic eruption around one thousand years ago.The paper predominantly discusses the earth's surface temperature changes,ozone depletion,acidic rain formation and mass mortalities of vertebrate induced by the Mesozoic and Cenozoic volcanism in China.

  5. Petroleum generation and migration in the Berkine (Ghadames) Basin, Eastern Algeria. An organic geochemical and basin modelling study

    Energy Technology Data Exchange (ETDEWEB)

    Yahi, N.

    1999-07-01

    In this study the petroleum system of one of the most important hydrocarbon bearing basins in Algeria, the Berkine Basin, was reconstructed by combining the geological knowledge of the basin and the results of geochemical and basin modelling studies. In this order, total organic carbon (C{sub org}) measurements, Rock-Eval pyrolyses, vitrinite reflectance measurements, gas chromatography (GC) analyses as well as gas chromatography-mass spectrometry (GC-MS) analyses were performed in order to evaluate the source rocks with respect to organic richness, kerogen type, depositional environment and maturity. Following the previous evaluation, the burial, erosion and temperature developments within the basin were reconstructed applying both one-dimensional (PDI/1D) and two-dimensional (PetroMod/2D) basin modelling programs. The hydrocarbon generation history of two major Palaeozoic source rocks was reconstructed based on the predetermined temperature history and kinetic model for hydrocarbon (oil and gas) generation. The basin has the benefit of multiple hydrocarbon sources deposited duirng the Silurian and the Frasnian periods within a continental shelf environment. The development of anoxic to dysoxic bottom water conditions was a prerequisite for the deposition of these organic rich units. While increasing the commercial value of the basin by increasing the hydrocarbon potential, these source rocks by generating hydrocarbons at different epochs during the basin evolution generally complicate the understanding of the petroleum system and the oil and gas accumulations. Therefore, the 2D finite element program PetroMod was used to discuss the history of hydrocarbon generation, expulsion and accumulation along a 205 km long selected transect which crosses various oil and gas fields. The major goal was to understand these hydrocarbon accumulations of which the origin and emplacement are still unsolved up to date. The understanding of such important petroleum geology aspects

  6. Glof Study in Tawang River Basin, Arunachal Pradesh, India

    Science.gov (United States)

    Panda, R.; Padhee, S. K.; Dutta, S.

    2014-11-01

    Glacial lake outburst flood (GLOF) is one of the major unexpected hazards in the high mountain regions susceptible to climate change. The Tawang river basin in Arunachal Pradesh is an unexplored region in the Eastern Himalayas, which is impending to produce several upcoming hydro-electric projects (HEP). The main source of the river system is the snow melt in the Eastern Himalayas, which is composed of several lakes located at the snout of the glacier dammed by the lateral or end moraine. These lakes might prove as potential threat to the future scenario as they have a tendency to produce flash flood with large quantity of sediment load during outbursts. This study provides a methodology to detect the potential lakes as a danger to the HEP sites in the basin, followed by quantification of volume of discharge from the potential lake and prediction of hydrograph at the lake site. The remote location of present lakes induced the use of remote sensing data, which was fulfilled by Landsat-8 satellite imagery with least cloud coverage. Suitable reflectance bands on the basis of spectral responses were used to produce informational layers (NDWI, Potential snow cover map, supervised classification map) in GIS environment for discriminating different land features. The product obtained from vector overlay operation of these layers; representing possible water area, was further utilized in combination with Google earth to identify the lakes within the watershed. Finally those identified lakes were detected as potentially dangerous lakes based on the criteria of elevation, area, proximity from streamline, slope and volume of water held. HEC-RAS simulation model was used with cross sections from Google Earth and field survey as input to simulate dam break like situation; hydrodynamic channel routing of the outburst hydrograph along river reach was carried out to get the GLOF hydrograph at the project sites. It was concluded from the results that, the assessed GLOF would be a

  7. A comparative study of institutional adaptive capacity : South Saskatchewan River Basin, Canada, and Elqui River Basin, Northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Sauchyn, D.; Diaz, P.; Gauthier, D. [Regina Univ., SK (Canada)

    2005-07-01

    This presentation discussed the strategies and materials developed for a five-year study of the capacity of institutions in two dryland regions (the South Saskatchewan River Basin in western Canada and the Elqui River Basin of north-central Chile) to adapt to the impacts of climate change. The purpose of the project was to obtain a systematic and comprehensive understanding of the capacities of regional institutions to formulate and implement strategies of adaptation to climate change risks and the forecasted impacts of climate change on the supply and management of water resources in dryland environments. Both regions are at different stages of social and environmental vulnerability and yet have a dry climate adjacent to a major mountain system and landscapes at risk of desertification, as well as an agricultural economy dependent on irrigation water derived from mountain snow and glaciers. tabs., figs.

  8. Assessing water footprint at river basin level: a case study for the Heihe River Basin in northwest China

    Directory of Open Access Journals (Sweden)

    Z. Zeng

    2012-05-01

    Full Text Available Increasing water scarcity places considerable importance on the quantification of water footprint (WF at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this study is to quantify WF within the Heihe River Basin (HRB, a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m3 yr−1 in the HRB over 2004–2006. Agricultural production was the largest water consumer, accounting for 96% of the WF (92% for crop production and 4% for livestock production. The remaining 4% was for the industrial and domestic sectors. The "blue" component of WF was 811 million m3 yr−1. This indicates a blue water proportion of 46%, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than green WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid regions.

  9. Study on stepped type basin in a solar still

    Directory of Open Access Journals (Sweden)

    A. Alaudeen

    2014-07-01

    Full Text Available In this work a stepped solar still is used to enhance the productivity of the solar still. The concept of integrating the stepped solar still along with inclined flat plate collector is introduced in this research work. In this stepped type solar still, a conventional basin of area 1 m2, was placed at the bottom. Another absorber plate, stepped type was fixed on the top of the conventional basin. It consists of subsequent trays and inclined flat plate collectors. This ensures an additional exposure area which augments the evaporation rate. Experiments were conducted with various depths in the conventional basin. A conventional still was fabricated and run parallel with the experimental set up for comparison. Sensible heat storage mediums such as rocks, pebbles were added to the top basin of stepped trays and bottom conventional basins to increase the temperature of water in the still. Wicks were placed on the inclined flat plate collector to augment the evaporation rate due to capillarity. A higher evaporation rate is obtained in the packing material with wicks and pebbles in tray combinations. Theoretical analysis was performed and it agrees with experimental values. Efficiency of the system was also compared with conventional solar still.

  10. No evidence for anoxia during the Valanginian carbon isotope event—An organic-geochemical study from the Vocontian Basin, SE France

    Science.gov (United States)

    Kujau, Ariane; Heimhofer, Ulrich; Ostertag-Henning, Christian; Gréselle, Benjamin; Mutterlose, Jörg

    2012-07-01

    The Valanginian time interval (Early Cretaceous) is characterized by a positive carbon isotope excursion (CIE) which represents the first of several prominent Cretaceous δ13C anomalies. A combined chemostratigraphic and organic-geochemical approach has been chosen to investigate the composition and distribution of sedimentary organic matter (OM) deposited before the Valanginian CIE, during its onset and plateau-phase. This was done to test whether this CIE is accompanied by changes in marine primary production and/or OM preservation. Biostratigraphically well-calibrated deposits from two hemipelagic sections located in the Vocontian Basin of SE France are used as sedimentary archives. A newly established high-resolution δ13C record covering the composite succession shows a characteristic Valanginian pattern and enables a detailed correlation with existing carbon isotope curves from the northern Tethyan margin. The analyzed solvent extractable fraction of the sedimentary OM is mainly composed of a marine origin with an admixture of land plant material. Variations in specific biomarkers for cyanobacteria (2α-methyl-hopanes), dinoflagellates (dinosterane or 4-desmethyl-23,24-dimethyl steranes) and terrigenous plant-derived OM (odd-numbered long-chain n-alkanes) as well as the sterane/hopane ratio, the C35 hopane index and the isoprenoids pristane and phytane were investigated. In contrast to the well-studied mid-Cretaceous Oceanic Anoxic Events (OAEs), neither significant OM enrichment nor prominent fluctuations in the selected biomarker abundances can be observed during the build-up phase of the Valanginian CIE. This points to relatively stable marine paleoenvironmental conditions with well-oxygenated bottom waters. Prior to the CIE, four cm-thick, finely laminated, dark layers (known as Barrande layers) with total organic carbon content reaching up to 4% show an exception from the generally stable biomarker pattern. Sedimentological and biomarker evidence support

  11. 中国油气盆地研究新阶段:数字盆地%DIGITAL BASIN: A NEW STAGE FOR STUDYING THE CHINESE PETROLIFEROUS BASINS

    Institute of Scientific and Technical Information of China (English)

    高长林; 何将启; 黄泽光; 刘光祥; 方成名; 潘文蕾

    2009-01-01

    Based on the analysis of exploration history and basin research history, the study of the Chinese petroliferous basins can be divided into the tectonic stage(1945-) and the basin analysis and basin computer simulation stage(1980-). Digital basin stage was occurred in present(2000-).There are different research domains between digital basin and digital oil fields.The digital basin is comprehensive application of the digitized geological datum by using modern geological theory and digital technological method. The aim of digital basin is provided the technological support for evaluation of petroliferous basins. The most inportant task of the digital basin is the construction of data warehouse. There are 12 databases in the basin evaluation data warehouse.%通过对中国油气盆地勘探历史和盆地研究历史的分析,认为我国油气盆地研究历史经过石油大地构造盆地研究阶段(1945-),盆地分析和盆地模拟阶段(1980-),现已进入数字盆地研究阶段(2000-).数字盆地和数字油田各自具有不同的研究领域.数字盆地是综合运用现代盆地系统研究理论和现代数字信息技术,进行油气盆地地质资料的数字化,为油气盆地评价提供技术支撑.数字盆地的核心问题是油气盆地评价数据库的建设,数据库应由12个子库组成.

  12. Case study applications of the BASINS climate assessment tool (CAT)

    Science.gov (United States)

    This EPA report will illustrate the application of different climate assessment capabilities within EPA’s BASINS modeling system for assessing a range of potential questions about the effects of climate change on streamflow and water quality in different watershed settings and us...

  13. GAMA-LLNL Alpine Basin Special Study: Scope of Work

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, M J; Visser, A; Esser, B K; Moran, J E

    2011-12-12

    For this task LLNL will examine the vulnerability of drinking water supplies in foothills and higher elevation areas to climate change impacts on recharge. Recharge locations and vulnerability will be determined through examination of groundwater ages and noble gas recharge temperatures in high elevation basins. LLNL will determine whether short residence times are common in one or more subalpine basin. LLNL will measure groundwater ages, recharge temperatures, hydrogen and oxygen isotopes, major anions and carbon isotope compositions on up to 60 samples from monitoring wells and production wells in these basins. In addition, a small number of carbon isotope analyses will be performed on surface water samples. The deliverable for this task will be a technical report that provides the measured data and an interpretation of the data from one or more subalpine basins. Data interpretation will: (1) Consider climate change impacts to recharge and its impact on water quality; (2) Determine primary recharge locations and their vulnerability to climate change; and (3) Delineate the most vulnerable areas and describe the likely impacts to recharge.

  14. Integrated geophysical studies of the Fort Worth Basin (Texas), Harney Basin (Oregon), and Snake River Plain (Idaho)

    Science.gov (United States)

    Khatiwada, Murari

    Geophysical methods such as seismic, gravity, magnetics, electric, and electromagnetics are capable of identifying subsurface features but each has a different spatial resolution. Although, each of these methods are stand-alone tools and have produced wonderful and reliable results for decades to solve geological problems, integrating geophysical results from these different methods with geological and geospatial data, adds an extra dimension towards solving geological problems. Integration techniques also involve comparing and contrasting the structural and tectonic evolution of geological features from different tectonic and geographic provinces. I employed 3D and 2D seismic data, passive seismic data, and gravity and magnetic data in three studies and integrated these results with geological, and geospatial data. Seismic processing, and interpretation, as well as filtering techniques applied to the potential filed data produced many insightful results. Integrated forward models played an important role in the interpretation process. The three chapters in this dissertation are stand-alone separate scientific papers. Each of these chapters used integrated geophysical methods to identify the subsurface features and tectonic evolution of the study areas. The study areas lie in the southeast Fort Worth Basin, Texas, Harney Basin, Oregon, and Snake River Plain, Idaho. The Fort Worth Basin is one of the most fully developed shale gas fields in North America. With the shallow Barnett Shale play in place, the Precambrian basement remains largely unknown in many places with limited published work on the basement structures underlying the Lower Paleozoic strata. In this research, I show how the basement structures relate to overlying Paleozoic reservoirs in the Barnett Shale and Ellenburger Group. I used high quality, wide-azimuth, 3D seismic data near the southeast fringe of the Fort Worth Basin. The seismic results were integrated with gravity, magnetic, well log, and

  15. Dta points used in assessment of coal in the southern Piceance basin study area (psptg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a shapefile and point coverage of 627 data points used in the assessment of coal in the southern Piceance Basin study area. Information in this file includes...

  16. Review and analysis of existing Alberta data on drinking water quality and treatment facilities for the Northern River basins study. Northern River Basins Study project report No. 55

    Energy Technology Data Exchange (ETDEWEB)

    Prince, D.S.; Smith, D.W.; Stanley, S.J.

    1995-12-31

    This report summarizes the results of a project conducted to gather existing information about drinking water quality, drinking water facilities, and water treatment effectiveness in the area covered by the Northern River Basins Study (Peace, Slave, and Athabasca River basins in northern Alberta). The report includes a comparison of water treatment performance to the Canada Drinking Water Quality Guidelines. The appendices contain summaries of parameters in the treated water survey, of the comparisons between raw and treated water, and of samples not meeting the Guidelines, as well as an inventory of treatment facilities giving facility name and location, water source, community population, treatment method used, raw storage capacity, and treated volumes.

  17. LIQUID EFFLUENT RETENTION FACILITY (LERF) BASIN 42 STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB

    2004-10-29

    This report documents laboratory results obtained under test plan RPP-21533 for samples submitted by the Effluent Treatment Facility (ETF) from the Liquid Effluent Retention Facility (LERF) Basin 42 (Reference 1). The LERF Basin 42 contains process condensate (PC) from the 242-A Evaporator and landfill leachate. The ETF processes one PC campaign approximately every 12 to 18 months. A typical PC campaign volume can range from 1.5 to 2.5 million gallons. During the September 2003 ETF Basin 42 processing campaign, a recurring problem with 'gelatinous buildup' on the outlet filters from 60A-TK-I (surge tank) was observed (Figure 1). This buildup appeared on the filters after the contents of the surge tank were adjusted to a pH of between 5 and 6 using sulfuric acid. Biological activity in the PC feed was suspected to be the cause of the gelatinous material. Due to this buildup, the filters (10 {micro}m CUNO) required daily change out to maintain process throughput.

  18. Case Study: Sensitivity Analysis of the Barataria Basin Barrier Shoreline Wetland Value Assessment Model

    Science.gov (United States)

    2014-07-01

    Barrier Shoreline Wetland Value Assessment Model1 by S. Kyle McKay2 and J. Craig Fischenich3 OVERVIEW: Sensitivity analysis is a technique for...relevance of questions posed during an Independent External Peer Review (IEPR). BARATARIA BASIN BARRIER SHORELINE (BBBS) STUDY: On average...scale restoration projects to reduce marsh loss and maintain these wetlands as healthy functioning ecosystems. The Barataria Basin Barrier Shoreline

  19. Holocene paleoenvironmental change in southeastern Africa (Makwe Rockshelter, Zambia): Implications for the spread of pastoralism

    Science.gov (United States)

    Robinson, Joshua R.; Rowan, John

    2017-01-01

    The paleoenvironmental conditions surrounding the origins of pastoralism and the movement of herders from eastern to southern Africa sometime between ∼4000 and 2000 ybp have been much debated. We lack, however, detailed paleoenvironmental data from sites sampling the hunter-to-herder transition in southeastern Africa, the likely corridor from eastern to southern Africa for early pastoralists. Here we report on new paleoenvironmental data from a site in the under-sampled area of eastern Zambia, Makwe Rockshelter, which has two aggregates of archaeological horizons representing the mid-Holocene (∼5700-5000 ybp) and the late Holocene (∼1600-800 ybp). The mid-Holocene sediments at Makwe document a foraging society, whereas the late Holocene sediments include both wild game and domestic livestock. Using stable carbon isotopes (δ13C) of herbivore enamel (n = 107), we show that the shift from mid-Holocene to late Holocene paleoenvironments was characterized by an increase in C4 vegetation. These data are complemented by paleoenvironmental records from Lake Malawi that show that C4 vegetation peaked after ∼2000 ybp and was coincident with the onset of cooler, more arid climates. This combined paleoenvironmental record has implications for the spread of pastoralism across southeastern Africa between ∼3000 and 2000 ybp and potential 'animal disease barriers' these early herders may have faced.

  20. Response to paleoatmospheric CO2 concentration of Solenites vimineus (Phillips) Harris (Ginkgophyta) from the Middle Jurassic of the Yaojie Basin, Gansu Province, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Solenites vimineus (Phillips) Harris (Ginkgophyta) specimens with well-preserved cuticles were collected from five different beds in the oil shale member of the Middle Jurassic Yaojie Formation in the Yaojie Basin, Gansu Province, northwestern China. Gross morphology and fine structures of the fossil leaves were studied, and stomatal parameters were analyzed, according to which, the paleoatmospheric CO2 concentration can be deduced as 1512-1896 ppm that would have caused an increase in mean temperature of about 6.5-7.4℃. Carbon isotopes from the fossils indicate that the carbon isotopic discrimination and water use efficiency (WUE) of S. vimineus were raised nearly obtaining the ideal physiologic state in increased CO2 concentrations and temperature conditions, suggesting that S. vimineus records the paleoenvironmental information of the Middle Jurassic Yaojie Basin and can be used for environmental reconstruction.

  1. A key continental archive for the last 2 Ma of climatic history of the central Mediterranean region: A pilot drilling in the Fucino Basin, central Italy

    Science.gov (United States)

    Giaccio, B.; Regattieri, E.; Zanchetta, G.; Wagner, B.; Galli, P.; Mannella, G.; Niespolo, E.; Peronace, E.; Renne, P. R.; Nomade, S.; Cavinato, G. P.; Messina, P.; Sposato, A.; Boschi, C.; Florindo, F.; Marra, F.; Sadori, L.

    2015-12-01

    An 82 m long sedimentary succession was retrieved from the Fucino Basin, the largest intermountain tectonic depression of the central Apennines. The basin hosts a succession of fine-grained lacustrine sediments (ca. 900 m-thick) possibly continuously spanning the last 2 Ma. A preliminary tephrostratigraphy study allows us to ascribe the drilled 82 m long record to the last 180 ka. Multi-proxy geochemical analyses (XRF scanning, total organic/inorganic carbon, nitrogen and sulfur, oxygen isotopes) reveal noticeable variations, which are interpreted as paleohydrological and paleoenvironmental expressions related to classical glacial-interglacial cycles from the marine isotope stage (MIS) 6 to present day. In light of the preliminary results, the Fucino sedimentary succession is likely to provide a long, continuous, sensitive, and independently dated paleoclimatic archive of the central Mediterranean area.

  2. The use of remote sensing and geographic information systems for the evaluation of river basins: a case study for Turkey, Marmara River Basin and Istanbul.

    Science.gov (United States)

    Ulugtekin, Necla; Balcik, Filiz Bektas; Dogru, Ahmet O; Goksel, Cigdem; Alaton, Idil Arslan; Orhon, Derin

    2009-03-01

    The aim of this study was to determine sensitive river basins and specific areas that urgently need planning activities for sustainable resource and environmental management. In this context, a combination of remote sensing (RS) and geographic information systems (GIS) were employed. For that purpose, a comprehensive overview of the current situation of Turkish river basins in terms of existing spatial data was provided and all tabular data gathered from the national authorities on regional basis was assessed in combination with the geometric data of Turkish river basins in a GIS environment. Considering the GIS studies that covered all 26 Turkish basins, the Marmara River Basin was selected as the model sensitive region and was studied in more detail by using 2000 dated Landsat 7 ETM mosaic satellite image. Results of this comprehensive study indicated that Istanbul, which is located in the basin under study and the largest metropolitan of Turkey, was determined as the most populated and urbanized area of the region. Istanbul was further examined to determine the expansion of urban areas over a time period of 16 years using Landsat images dated 1984, 1992 and 2000. Finally, interpretations were done by combining the demographic and statistical data on urban wastewater treatment plants to present the prevailing situation of the water treatment facilities in Istanbul. Our study not only delineated the importance of applying environmental policies correctly for the efficient installation and operation of urban wastewater treatment plants in Istanbul but also demonstrated that effective urban wastewater management is a nationwide problem in Turkey.

  3. Identifying the groundwater basin boundaries, using environmental isotopes: a case study

    Science.gov (United States)

    Demiroğlu, Muhterem

    2016-12-01

    Groundwater, which is renewable under current climatic conditions separately from other natural sources, in fact is a finite resource in terms of quality and fossil groundwater. Researchers have long emphasized the necessity of exploiting, operating, conserving and managing groundwater in an efficient and sustainable manner with an integrated water management approach. The management of groundwater needs reliable information about changes on groundwater quantity and quality. Environmental isotopes are the most important tools to provide this support. No matter which method we use to calculate the groundwater budget and flow equations, we need to determine boundary conditions or the physical boundaries of the domain. The Groundwater divide line or basin boundaries that separate the two adjacent basin recharge areas from each other must be drawn correctly to be successful in defining complex groundwater basin boundary conditions. Environmental isotope data, as well as other methods provide support for determining recharge areas of the aquifers, especially for karst aquifers, residence time and interconnections between aquifer systems. This study demonstrates the use of environmental isotope data to interpret and correct groundwater basin boundaries giving as an example the Yeniçıkrı basin within the main Sakarya basin.

  4. Sedimentological study of the Meirama Tertiary basin - an example of a sedimentary basin over a strike-slip fault

    Energy Technology Data Exchange (ETDEWEB)

    Monge Ganuzas, C.

    1987-01-01

    The sedimentary basin of Meirama (Coruna, N.W. Spain), is developed over a strike slip fault of regional extent, whose movements controlled in the past the character and sedimentation processes there and determined the basin morphology and the deformation suffered by the sediments. The sedimentary register at Meirama is represented by one essentially lignitiferous unit and three other terrigenous-detrital. The nature and facies shown by the sediments are not constant within one unit and depend fundamentally on the source area for each unit, either the metasediments of Ordes (Ordenes) Serie (S-Se marginal basin) or the granodiorite of Xalo unit (N-NW marginal basin).

  5. Benthic foraminifera morphology: A tool for paleoenvironmental and paleowater depth interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Gary, A.C. (Univ. of South Carolina, Columbia (United States))

    1991-03-01

    Quantitative analysis of morphologic variation within recent benthic foraminiferal species from the northwestern Gulf of Mexico reveals changes in some populations that parallel environmental gradients (i.e., morphoclines). Such relationships likely reflect the influence of particular environmental variables on the morphology of the individual during its development and can be used as an indicator of paleoenvironment and paleowater depth. The specimens studied were taken from the top 5 cm of sediment of box cores collected on the shelf and slope. The two-dimensional outline of each specimen was converted to a Fourier series in closed form, and patterns in the data and their correlation to physical parameters were explored using SAWVEC and correlation analysis. Of the specimens studied, seven exhibited a correlation between morphology and environment: Bolivina albatrossi, Bolivina subaenariensis mexicana, Bolivina subspinescens, Bulimina marginata, Cibicidoides pachyderma, Sphaeroidina bulloides, and Uvigerina peregrina. Paleowater depth and paleoenvironmental interpretations based on environmentally induced morphologic changes within species complement techniques presently being used based on species distributions by utilizing some different species and providing greater precision in the upper- and middle-bathyal zones.

  6. Miocene-Pleistocene Paleoclimate and Paleoenvironment in the Meade Basin, Kansas

    Science.gov (United States)

    Snell, K. E.; Uno, K. T.; Fetrow, A. C.; Burgess, C.; Lukens, W. E.; Fox, D. L.; Fox-Dobbs, K.; Polissar, P. J.

    2015-12-01

    The Meade Basin in southwestern Kansas preserves a unique record of paleovegetation and small mammal faunal change from the Miocene to the Pleistocene. Many of the paleosols preserved in this basin contain paleosol carbonate nodules, thick calcretes and abundant organic-rich horizons, which makes it ideally suited for a multiproxy study that explores the role of paleoenvironmental change in driving floral and faunal change. Here we focus on the carbonate samples where we measured carbon and oxygen isotopes (δ13Cc and δ18Oc, respectively); used clumped isotope thermometry (Δ47) to estimate soil temperature and soil water δ18O; and assessed the preservation state and additional paleoenvironmental features of the samples using optical and cathodoluminescence (CL) microscopy. The carbon isotope record matches previous studies from the region and shows an increase in the relative abundance of C4 biomass on the landscape since the late Miocene. The Δ47 temperatures and the δ18O of soil water, while variable, show no significant change in average values through time. The textural and luminescenece characteristics suggest some samples have undergone moderate to extensive diagenetic alteration from groundwater fluids, perhaps causing some of the variability in the geochemical records. Soil depth may also account for some of the variability. Overall, these data suggest that temperature is unlikely to be the dominant factor driving paleovegetation and faunal change in this region from the Miocene to Pleistocene. In addition, these data highlight the importance of assessing preservation for all carbonate samples, regardless of whether or not the samples have been deeply buried.

  7. Simulating the impacts of climate variation and land-cover changes on basin hydrology: A case study of the Suomo basin

    Institute of Scientific and Technical Information of China (English)

    CHEN; Junfeng; LI; Xiubin

    2005-01-01

    Impacts of land cover changes on watershed hydrology have been a long-term academic concern with acute dispute. But little attention has been paid to such effects on mesoscale river basins, where the society has a closer link to river hydrology. The present study focuses on a mesoscale river basin, the Suomo Basin that is located on the upper reaches of the Yangtze River. Land covers in the basin in the years 1970, 1986 and 1999 were mapped. A lumped hydrologic model, CHARM, and a distributed hydrologic model, SWAT, were used to model the impacts of both land-cover change and climate variation on river runoff during the past four decades. The results show that the contribution of climate variation to the change of runoff regime makes up 60%-80%, while that of land cover changes only 20%.

  8. Preliminary study on land surface characteristics over Huaihe River Basin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The analysis of the flux observation dada from the Huaihe River Basin Experiment (HUBEX) shows that, in semi-humid monsoon regions, latent heat flux is as important as sensible heat flux in most situations. Moreover, it can even dominate the sensible heat flux in cropland and paddy field. This is distinct from that for arid and semi-arid regions where the sensible heat flux is dominant. Under clear sky conditions, the soil temperatures in different vertical layers all exhibit certain diurnal variations, and the magnitude decreases with depth to less than 1℃ at a depth of 60 cm. This depth is considered as the transition layer for the soil moisture variation. On the other hand, the vertical profile of soil water content varies with the soil texture and even weather conditions, and the layer with maximum soil water content can also be found in Jiangji station during June 1998.

  9. Formation Water Geochemistry and Its Controlling Factors: Case Study on Shiwu Rifted Sub-basin of Songliao Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A common way to trace fluid flow and hydrocarbon accumulation is by studying the geochemistry of formation water. This paper focuses on the spacial distribution of the geochemical features of the formation water in the Shiwu Rifted Basin and its indication of the water-rock interaction processes. The hydrodynamic field controls the spacial distribution of formation water. Due to the penetration of meteoric water, the salinity is below 4,500mg/L at the basin margin and the severely faulted central ridge and increases basin ward to 7,000-10,000mg/L. The vertical change of formation water can be divided into 3 zones, which correspond respectively to the free replacement zone (<1,250m), the obstructed replacement zone (1,250m-1,650m) and thelagged zone (>1,650m) in hydrodynamics. In the free replacement zone, the formation water is NaHCO3-type with its salinity increased to 10,000mg/L. The formation water in the obstructed replacement zone is Na2SO4-type with its salinity decreased to 5,000mg/L-7,000mg/L because of the dehydration of mud rocks. The formation water in the lagged zone is CaCl2-type, but its salinity decreases sharply at a depth of 1,650m and then increases vertically downward to 10,000mg/L. This phenomenon can be best explained by the osmosis effect rather than the dehydration of mud rocks. The relationships between Cl--HCO3- and Na++K+-Ca2+ show that the initial water-rock interaction is the dissolution of NaCl and calcium-bearing carbonate, causing an increase of Na+-K+-Ca2+-Cl- and salinity. The succeeding water-rock interaction is albitization, which leads to a decrease of Na+ and an increase of Ca2+ simultaneously, and generates CaCl2-type fluid. The above analysis shows that the geochemical evolution of formation water is governed by the water-rock interactions, while its spacial distribution is controlled by the hydrological conditions. The water-rock interaction processes are supported by other geological observations, suggesting that

  10. 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...

  11. A study of interaction between surface water and groundwater using environmental isotope in Huaisha River basin

    Institute of Scientific and Technical Information of China (English)

    SONG; Xianfang; LIU; Xiangchao; XIA; Jun; YU; Jingjie; TANG; Changyuan

    2006-01-01

    The surface water and groundwater are important components of water cycle,and the interaction between surface water and groundwater is the important part in water cycle research.As the effective tracers in water cycle research,environmental isotope and hydrochemistry can reveal the interrelationships between surface water and groundwater effectively.The study area is the Huaisha River basin,which is located in Huairou district,Beijing.The field surveying and sampling for spring,river and well water were finished in 2002 and 2003.The hydrogen and oxygen isotopes and water quality were measured at the laboratory.The spatial characteristics in isotope and evolution of water quality along river lines at the different area were analyzed.The altitude effect of oxygen isotope in springs was revealed,and then using this equation,theory foundation for deducing recharge source of spring was estimated.By applying the mass balance method,the annual mean groundwater recharge rate at the catchment was estimated.Based on the groundwater recharge analysis,combining the hydrogeological condition analysis,and comparing the rainfall-runoff coefficients from the 1960s to 1990s in the Huaisha River basin and those in the Chaobai River basin,part of the runoff in the Huaisha River basin is recharged outside of this basin,in other words,this basin is an un-enclosed basin.On the basis of synthetically analyses,combining the compositions of hydrogen and oxygen isotopes and hydrochemistry,geomorphology,geology,and watershed systems characteristics,the relative contributions between surface water and groundwater flow at the different areas at the catchments were evaluated,and the interaction between surface water and groundwater was revealed lastly.

  12. An Investigation of the Poverty- Environmental Degradation Nexus: A Case Study of Katonga Basin in Uganda

    Directory of Open Access Journals (Sweden)

    Niringiye Aggrey

    2010-04-01

    Full Text Available This study aimed at identifying the poverty/environment nexus in Katonga basin. Our analysis focused on spatial relations between poverty levels and environmental problems at the district level. Our study identified a poverty/environment nexus for cases where poverty levels exhibited strong spatial correlation with two of the four principal environmental problems. Deforestation and wetland degradation were shown to be positively linked with poverty in a spiral web compared to access to clean w ater, access to toilets, and access to electricity and use of charcoal and firewood that exhibited no significant linkage. We conclude that the welfare of the poor in Katonga basin would be significantly enhanced by close integration of poverty-alleviation and environmental strategies aimed at reducing deforestation and wetlands conversion. A geographic focus on the poorest districts in Katonga basin would appear to be most beneficial.

  13. Large-diameter burrows of the Triassic Ischigualasto Basin, NW Argentina: paleoecological and paleoenvironmental implications.

    Directory of Open Access Journals (Sweden)

    Carina E Colombi

    Full Text Available Large-diameter ichnofossils comprising three morphotypes have been identified in the Upper Triassic Ischigualasto and Los Colorados formations of northwestern Argentina. These burrows add to the global record of the early appearance of fossorial behavior during early Mesozoic time. Morphotypes 1 and 2 are characterized by a network of tunnels and shafts that can be assigned to tetrapod burrows given similarities with previously described forms. However, differences in diameter, overall morphology, and stratigraphic occurrence allow their independent classification. Morphotype 3 forms a complex network of straight branches that intersect at oblique angles. Their calcareous composition and surface morphology indicate these structures have a composite biogenic origin likely developed due to combined plant/animal interactions. The association of Morphotypes 1 and 2 with fluvial overbank lithologies deposited under an extremely seasonal arid climate confirms interpretations that the early appearance of burrowing behavior was employed by vertebrates in response to both temperature and moisture-stress associated with seasonally or perpetually dry Pangean paleoclimates. Comparisons of burrow morphology and biomechanical attributes of the abundant paleovertebrate fauna preserved in both formations permit interpretations regarding the possible burrow architects for Morphotypes 1 and 2. In the case of the Morphotype 1, the burrow constructor could be one of the small carnivorous cynodonts, Ecteninion or Probelesodon. Assigning an architect for Morphotype 2 is more problematic due to mismatches between the observed burrow morphology and the size of the known Los Colorados vertebrates.

  14. Geological evolution of the North Sea: Cross-border basin modeling study on the schillground high

    NARCIS (Netherlands)

    Heim, S.; Lutz, R.; Nelskamp, S.; Verweij, J.M.; Kaufmann, D.; Reinhardt, L.

    2013-01-01

    This study presents the results of a basin modeling study covering the cross-border area of the southern Schillground High in the Dutch-German offshore area. A high resolution petroleum system model has been constructed with the aim to evaluate the hydrocarbon generation potential of Carboniferous s

  15. Raingauge Network Optimization and Gis: A Case Study of the Mananga Basin

    NARCIS (Netherlands)

    Van Dijk, M.J.; Rientjes, T.H.M.

    1993-01-01

    The study area of this case study is the river basin of the Mananga river, one of the main rivers on Cebu-island, the Philippines. Today the Mananga is used as discharge river, in the near future this river may be used for drinking water purposes of the region around Cebucity, some 25 kilometres eas

  16. Preliminary Study of Natural Radioactivity in the Lake Bosumtwi Basin

    Directory of Open Access Journals (Sweden)

    Simon Adu

    2011-08-01

    Full Text Available The concentrations of 238U, 232Th, and 40K in water from Lake Bosumtwi and bore-holes in selected towns around the Bosumtwi basin of the Ashanti region of Ghana have been determined. The concentrations were determined for water samples from 24 boreholes and 12 points across the lake using a High-Purity Germanium (HPGe (γ-ray spectrometry. The water samples from the lake were found to contain acceptable levels of radionuclides with mean activity concentrations of 7.9, 89.7 and 0.6 mBq/L for 238U, 40K, and 232Th, respectively. The water samples from the boreholes recorded mean activity concentrations of 7.7, 85.5, and 3.3 mBq/L for 238U, 40K and 232Th, respectively. The annual effective dose calculated for the lake varied from 0.244 to 1.121 μSv with an average of 0.763 μSv and that calculated for the boreholes varied from 0.296 to 2.173 μSv with an average of 1.166 μSv. The radionuclides concentrations in water from the bore-holes and that of the lake, which serve as sources of water supply to the surrounding communities are negligible and pose no radiological hazards to the public.

  17. Coal and petroleum resources in the Appalachian basin: index maps of included studies: Chapter B.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ruppert, Leslie F.; Trippi, Michael H.; Kinney, Scott A.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    This chapter B.1 of U.S. Geological Survey (USGS) Professional Paper 1708 provides index maps for many of the studies described in other chapters of the report. Scientists of the USGS and State geological surveys studied coal and petroleum resources in the central and southern Appalachian structural basins. In the southern Appalachian basin, studies focused on the coal-bearing parts of the Black Warrior basin in Alabama. The scientists used new and existing geologic data sets to create a common spatial geologic framework for the fossil-fuel-bearing strata of the central Appalachian basin and the Black Warrior basin in Alabama.

  18. Large scale facies change in the middle Eocene South-Pyrenean foreland basin: The role of tectonics and prelude to Cenozoic ice-ages

    Science.gov (United States)

    Huyghe, Damien; Castelltort, Sébastien; Mouthereau, Frédéric; Serra-Kiel, Josep; Filleaudeau, Pierre-Yves; Emmanuel, Laurent; Berthier, Benoît; Renard, Maurice

    2012-05-01

    The present study reports a sedimentological analysis of the Guara Limestone Formation deposited during the Lutetian in the Sierras Exteriores, in the South-Pyrenean foreland basin. We provide a detailed facies analysis of the carbonates to precise the paleoenvironmental context during their deposition. We show that those limestones are mainly composed of shallow-water foraminifers and were deposited in relative shallow-water environments (Jaca basin, this event correlates with a marked increase in subsidence rate. However, this deformation event is local and the carbonate systems in the Pyrenean foreland resisted to many deformation events during the whole basin history before. Paleobathymetric reconstructions in the Jaca basin, where shallow marine sections outcrop, suggest an increase of the amplitude of high-frequency sea-level cycles. This increase is contemporaneous with several climatic evidences, which suggest the appearance of early ice-sheets near the Lutetian-Bartonian boundary. The demise of carbonate producers seems, therefore, to be the result of a major environmental shift in the basin accompanying increased subsidence rates, switching from low nutrient oligotrophic conditions - favourable for shallow water benthic foraminifers - to eutrophic conditions due to the increase of erosion and terrigenous nutrient input associated with higher-frequency sea-level changes and river destabilization.

  19. Spatial Misfit in Participatory River Basin Management: Effects on Social Learning, a Comparative Analysis of German and French Case Studies

    Directory of Open Access Journals (Sweden)

    Ilke Borowski

    2008-06-01

    Full Text Available With the introduction of river basin management, as prescribed by the European Water Framework Directive (WFD, participatory structures are frequently introduced at the hydrological scale without fully adapting them to the decision-making structure. This results in parallel structures and spatial misfits within the institutional settings of river basin governance systems. By analyzing French and German case studies, we show how social learning (SL is impeded by such misfits. We also demonstrate that river basin-scale institutions or actors that link parallel structures are essential for promoting river basins as management entities, and for encouraging SL between actors at the river basin scale. In the multi-scale, multi-level settings of river basin governance, it is difficult to fully exclude spatial misfits. Thus, it is important to take our insights into account in the current transition of water management from the administrative to the hydrological scale to get the greatest benefit from SL processes.

  20. A Climatic Sequence Stratigraphic Model in the Terrestrial Lacustrine Basin:A Case Study of Green River Formation,Uinta Basin,USA

    Institute of Scientific and Technical Information of China (English)

    WANG Junling; ZHENG Herong; XIAO Huanqin; ZHONG Guohong; Ronald STEEL; YIN Peigui

    2009-01-01

    In recent years,with the development of terrestrial sequence stratigraphy,more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are preferred by researchers.Under the guidance of the theory of sequence stratigraphy,the findings of this paper indicate that climate is a major factor controlling the formation of the fourth-order sequence,based upon the study of the sequence stratigraphy in the Green River Formation of the Uinta basin in the USA.It also divides the fourth-order sequence in the terrestrial lacustrine basin into two system tracts:the wet(rising)half-cycle and the dry(falling)half-cycle,establishing a new-style fourth-order sequence stratigraphic model for the terrestrial lacustrine basin,that is,the climate-genetic sequence stratigraphic model.As a result, the theory of sequence stratigraphy is greatly enriched.

  1. Paleo-environmental imprint on microbiology and biogeochemistry of coastal quaternary sediments

    Directory of Open Access Journals (Sweden)

    M. Beck

    2010-07-01

    Full Text Available To date, North Sea tidal flat sediments have been intensively studied down to a depth of 5 m below sea floor (mbsf. However, little is known about the biogeochemistry, microbial abundance, and activity of sulfate reducers as well of methanogens in deeper layers. For this study, we hypothesized that the imprint of the paleo-environment is reflected in current microbiogeochemical processes. Therefore, 20 m-long cores were retrieved from the tidal-flat area of Spiekeroog Island, NW Germany. Two drill sites were selected with a close distance of only 900 meters, but where sedimentation occurred under different environmental conditions: first, a paleo-channel filled with Holocene sediments and second, a mainly Pleistocene sedimentary succession. In general, the numbers of bacterial 16S rRNA genes are one to two orders of magnitude higher than those of Archaea. The abundances of key genes for sulfate reduction and methanogenesis (dsrA and mcrA correspond to the sulfate and methane profiles. A co-variance of these key genes at sulfate-methane interfaces and enhanced potential AOM rates suggest that anaerobic oxidation of methane may occur in these layers. Microbial and biogeochemical profiles are vertically stretched relative to 5 m-deep cores from shallower sediments in the same study area. Compared to the deep marine environment, the profiles are transitional between the shallow subsurface and the marine deep biosphere. Our interdisciplinary analysis shows that the microbial abundances and metabolic rates are elevated in the Holocene compared to Pleistocene sediments. However, this is mainly due to present environmental conditions such as pore water flow and organic matter availability. The paleo-environmental imprint is still visible but superimposed by these processes.

  2. Tectono-geomorphic study of the Karewa Basin of Kashmir Valley

    Science.gov (United States)

    Dar, Reyaz Ahmad; Romshoo, Shakil Ahmad; Chandra, Rakesh; Ahmad, Ishtiaq

    2014-10-01

    The Karewa Basin nestled between the Pir Panjal Range and the Great Himalayan Range, in Northwest India, has been studied to understand its tectono-geomorphic evolution on the basis of geomorphic indices and morphotectonic parameters supported by the field evidences. Satellite data, topographic maps and digital elevation model (DEM) were used to extract various parameters at various spatial scales. Four watersheds, representative of the entire Karewa Basin, were chosen for detailed studies on the basis of the researchable evidence of the complete sequence of the stratigraphic record and the preservation of geomorphic landscapes. The integrated analysis of the geomorphic and morphometric data provides evidence of the relative variations in the tectonic activity among the watersheds. Geomorphic indices suggest a relatively high degree of tectonic activity along the Pir Panjal side of the Karewa Basin. This variation in the relative degree of tectonic activity is consistent with the field evidence, fault/lineament locations and the landscape geometry of the Karewa Basin. Based on the results from this study, it is suggested that Late Quaternary climate changes, tectonic uplift and erosion of the Pir Panjal Range and changing geometry of the Karewa Lake have played a key role in the evolution of the geomorphic landscape of the Kashmir Valley.

  3. Sedimentation Study on Upstream Reach of Selected Rivers in Pahang River Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    Mohd Khairul Amri Kamarudin

    2017-02-01

    Full Text Available The sedimentation study on the upstream reach of Pahang River is located in the Bentong River Basin. The detail hydrographic survey for each river in the Bentong River Basin was carried out in May 2016. Nine stations were selected to represent the sediment concentration at Bentong River, Pahang, Malaysia. Bentong River Basin is one of the river catchment in Pahang River Basin, Malaysia. Before this, Bentong River deterioration in water quality, resulting from the sedimentation problems and unsustainable development management around the river basin. This study was implemented to prove the sedimentation problem, especially the formation of Total  Suspended Solid (TSS in the Bentong River. There are two important parameters were quantified in this study such as the concentration of suspended solid (mg/L and the river discharge (Q values (m³/s. The method used in this study to analysis the concentration of TSS using Gravimetric Method. The result showed the sedimentation in the Bentong River was unstable and the highest of TSS up to 367.6 mg/L that is categorized under the class V which > 300 mg/L based on the National Water Quality Standard (NWQS result showed the coefficient correlation between the observed Q and the TSS concentration in the Bentong River is significant R² = 0.919, there are strong positive relationship between TSS concentration production and the river discharge value in the Bentong River. The study found that the contributors to the high sedimentation problems resulting from the sediments generated from the unsustainable land use, which effectively trapping the bed sediments, rainfall intensity, backflow that carries out high sediments as well as sedimentation produced due to the river bank erosion.

  4. Assessment of droughts at a continental scale under different climate change scenarios. Case study: La Plata Basin

    Science.gov (United States)

    Sordo-Ward, Alvaro; Iglesias, Ana; Garrote, Luis; Bejarano, Maria Dolores; Asenjo, Victor; Bianucci, Paola

    2016-04-01

    In this study, we characterized and diagnosed the droughts across La Plata Basin for the reference (1961 - 2005) and future (2007 - 2040, 2041 - 2070 and 2071 - 2099) scenarios. La Plata Basin is located in the Centre-South of South America and comprises 3.174.229 km2 and five countries. Despite the significant impact of droughts on agriculture, cattle, water supply, natural water courses and wetlands, droughts are still difficult to predict in the region, both in time and space. We used the Standardized Precipitation-Evapotranspiration Index (SPEI) to characterize droughts based on Potential Evapotranspiration (PET) and Precipitation (P) at a monthly scale. PET and P were obtained for all 10 x 10 km-size cells within the basin by using the regional climatic model Eta, under the boundary conditions of the HadGEM2-ES model and the CO2 emissions scenario RCP 4.5. Cell to cell information was integrated into a sub-basin level in order to show and analyze the results. For each sub-basin, climate scenario, and temporal scale of SPEI (1, 3, 6 and 12 months), we identified the beginning of each drought, calculated its duration, magnitude, maximum and mean intensities, and the duration between drought events. Additionally, for each SPEI temporal scale and sub-basin, we described the spatial coverage of droughts for the temporal series of all climate scenarios. Spatially, we found a decrease of PET from North to South. Temporally, results showed a future increase of PET for the Paraguay river basin and upper Parana river basin but similar to present values for the remaining basin. Results showed that P will be similar in the future for the Paraguay river basin and upper Parana river basin, but will increase within the remaining basin. During the 2007 - 2040 scenario, we expect that the northern sub-basins suffer from several droughts while the southern ones have wetter climate with few short drought events. As we analyzed more distant future scenarios the wet climate

  5. Preservation of REE and Fe isotopes in altered stromatolites and the paleo-environmental record

    Science.gov (United States)

    Nies, S. M.; Shapiro, R. S.; Lalonde, S.

    2015-12-01

    Geochemical proxies are increasingly being used to unravel ancient ecosystems and environmental perturbations back to the earliest rock record on Earth. Along with more traditional fossils (stromatolites) and other biosignatures (e.g., lipids), the geochemical record is used specifically to evaluate biogenecity and to understand oxygenation of the atmosphere and ocean in the Archean and Paleoproterozoic. However, the effects of diagenesis, metamorphism, and other modes of secondary alteration are still poorly constrained, particularly as technological advances allow us to expand farther across the periodic table. Our study focused on the robustness and preservation of rare earth element (REE) and Fe isotope compositions of two stromatolitic units that have undergone contact and regional metamorphism. 18 samples were collected from cores, open pit mines, and field locations in Minnesota and Ontario from silicified iron formation (Biwabik-Gunflint formations). The samples were carefully constrained to one of two meter-scale stromatolitic units. Metamorphic grade ranged from essentially unmetamorphosed through prehnite-pumpellyite up to amphibolite (fayalite+hypersthene). Samples were also collected that represented deep secondary weathering, likely related to Cretaceous climatic extremes. Polished samples were first analyzed by electron microprobe and selected samples were further analyzed via laser ablation HR-ICP-MS to constrain trace element (n=13) and Fe isotopic variations (n=8). Preliminary results indicate that transition metal concentrations are surprisingly resilient to high-temperature metamorphic recrystallization. REE concentrations were analyzed in individual iron oxide grains, with full resolution (La to Lu) achieved for some samples and partial resolution (La to Nd) achieved for all samples. Core samples exhibited a relatively stable positive Ce anomaly occurring from low to extremely high alteration. Outcrop and mine samples indicate a shift from a

  6. A study of ecological red-line area partitioning in the Chishui River Basin in Guizhou

    Science.gov (United States)

    Yang, S. F.; An, Y. L.

    2016-08-01

    Maintaining ecosystem balance and realizing the strategic goal of sustainable development are key objectives in the field of environmental sciences. Accordingly, drawing ecological red lines in sensitive and vulnerable environmental areas and important ecological function areas, determining the distribution range of ecological red-line areas, providing scientific guidance for developmental activities, and effectively managing the ecological environment are significant work tasks supported by policy guidance from the State Council and from knowledge gained in educational circles. Taking the Chishui River Basin in Guizhou as the study object, this research selected water and soil loss sensitivity, as well as assessments of karst rocky desertification sensitivity as background assessments of the eco-environment. Furthermore, the functions of soil conservation, water conservation, and biodiversity protection were integrated with exploitation-prohibited areas, and an organic combination of ecological needs and social service functions was created. Spatial comprehensive overlay analysis and processing revealed that the combination marked nine major ecological red-line areas in a total area of 5,030.58 km2, which occupied 44.16% of the total basin area. By combining the current eco-environmental situation of the Chishui River Basin with the marked out red-line areas, this research proposed corresponding ecological red-line area management suggestions. These suggestions are expected to provide a scientific foundation for eco-environmental protection and subsequent scientific research in Chishui River Basin.

  7. Study on dynamics of tectonic evolution in the Fushun Basin, Northeast China

    Institute of Scientific and Technical Information of China (English)

    吴冲龙; 汪新庆; 刘刚; 李绍虎; 毛小平; 李星

    2002-01-01

    The updated study shows that the taphrogenesis of basement of the Fushun Basin is not a kind of instantaneous process. It intensified gradually and went to extreme in the sedimentary stage of the Guchengzi formation, and then, it weakened rapidly and stopped soon afterwards; the depression did not take place after the taphrogenesis. On the contrary, it almost happened simultaneously with the taphrogenesis. The depression went at a high speed from the beginning of the sedimentary period of the Xilutian formation, and then weakened gradually in the sedimentary period of the Gengjiajie formation. The evolution course of the synsedimentary structure of the Fushun Basin can be summarized as the following six stages: slow taphrogenesis and high speed depression to accelerated taphrogenesis and high speed depression to high speed taphrogenesis and high speed depression to retarded taphrogenesis and high speed depression to gradual halt of taphrogenesis and reduced depression to slow depression and gradual halt of depression. The tectonic evolution resulted in the formation of the "lower taphrogenesis and upper depression" structure. The formation of the binary structure might be due to the suspension of taphrogenesis and the change of the regional structure stress field, but the depression kept going. The result of calculation combining the analysis of the synsedimentary structural frame, the back-stripping method of the subsidence history of the basin basement and the simulation of thermo-settlement history indicates that the great sedimentary space required by the "upper depression part" consists of two parts, namely, 40% from compaction of sediments and 60% from slow depression of the basin basement during a long period of time. Gradual halt of the depression in the Fushun Basin may be attributed to the reversal of the lithosphere hot-recession and gravity isostasy adjustment which may be the result of new hot-events in the depths and accompanied invasion of extremely

  8. Application of Fluid Inclusions in the Study of Natural Gas Geology in Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    FAN Ai-ping; YANG Ren-chao; FENG Qiao; LIU Yi-qun; HAN Zuo-zhen

    2006-01-01

    The new recently demonstrated reserves of oil and gas in the Ordos basin are found at the top of petroliferous basins in China. Gas pools discovered in recent years in the Permian system have become the main natural gas resource in the basin. Therefore, synthetic research on fluid inclusions should be done in order to ascertain the pool-forming stage, the maturity of organic matters and the properties of Paleo-fluids. The main types of fluid inclusions in the Permian system in the basin include brine inclusions, carbon dioxide inclusions and organic inclusions. Homogenization temperatures (HT) of brine inclusions can be divided into four intervals: 66-83 ℃, 86-108 ℃, 112-138 ℃ and 142-153 ℃. The fluid inclusions in the interval of 112-138 ℃ are much more than that of other intervals, indicating that the second stage of hydrocarbon migration associated with the third temperature interval is the most important stage of gas pool formations. The fluid inclusion has extensive applications in the study of gas geology, not only in ascertaining the formation stage of gas pools, but also in estimating the maturity of organic matter and restoring Paleo-fluids. The result of testing the HT of brine inclusions shows that there are two stages of gas pool formations in the Permian system occurring ±150 Ma and ±100 Ma. The maturity of organic matter is moderate to high, a conclusion based on the color of fluid inclusions (radiated by fluorescence). The high salinity of Paleo-fluids of the NaCl-H2O and CaCl2-H2O systems shows good preservation conditions of the Paleo-fluids. Two stages of reservoir filling, high maturity of organic matter and good preservation conditions are factors favorable for the formation and preservation of large-scale gas pools in the Permian system in the Ordos basin.

  9. Hydraulic Characteristics of the San Gregorio Creek Drainage Basin, California: a Preliminary Study.

    Science.gov (United States)

    Davis, J. R.; Snow, M. K.; Pestrong, R.; Sklar, L. S.; Vavro, M.; Sawachi, A.; Talapian, E.; Bailey, E.

    2004-12-01

    Population pressures within the greater San Francisco Bay Area are forcing development into nearby rural communities, and are impacting local environments. This study of the San Gregorio Creek Watershed is designed as a baseline for evaluating the effect increasing development within the drainage basin has on its river system. We hope to provide evidence for that impact through laboratory and field studies that provide a snap-shot of this drainage basin's current characteristics. The San Gregorio Creek watershed, in the Coast Ranges, is located in the southwestern portion of San Mateo County, California. It drains the western slopes of the Santa Cruz Mountains, in the Coast Ranges into the Pacific Ocean at the town of San Gregorio. Most of its fingertip tributaries flow into the trunk from the north and west, with elevations as high as 2050 feet. The watershed includes an area of approximately 51.6 square miles and San Gregorio Creek, the trunk stream, is roughly 12 miles long. San Gregorio Creek is a fourth order perennial stream. It is fed by a number of major tributaries, the largest of which are Alpine, Mindego, and La Honda creeks. The U.S. Geological Survey maintains a stream gauging station for San Gregorio Creek at the town of San Gregorio, where it has been monitoring stream flows for more than 30 years through its Water Resources Department. The resulting data indicate a mean discharge of 36.4 cfs. Map studies of hydraulic geometry for the drainage basin reveal geometric characteristics for San Gregorio Creek that coincide with similar streams in comparable climatic and environmental settings. Stream table studies are used to further investigate fundamental stream processes. Field studies at selected reaches throughout the drainage basin will document hydraulic characteristics. The results of this study will contribute to more comprehensive studies demonstrateing channel response to changing environmental conditions.

  10. Status and understanding of groundwater quality in the Northern Coast Ranges study unit, 2009: California GAMA Priority Basin Project

    Science.gov (United States)

    Mathany, Timothy M.; Belitz, Kenneth

    2015-01-01

    Groundwater quality in the 633-square-mile (1,639-square-kilometer) Northern Coast Ranges (NOCO) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program and the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. The study unit is composed of two study areas (Interior Basins and Coastal Basins) and is located in northern California in Napa, Sonoma, Lake, Colusa, Mendocino, Glenn, Humboldt, and Del Norte Counties. The GAMA-PBP is being conducted by the California State Water Resources Control Board in collaboration with the USGS and the Lawrence Livermore National Laboratory.

  11. The Studies of Regional Water Circulation Patterns in the Yerqiang River Basin

    Institute of Scientific and Technical Information of China (English)

    REN Jiaguo; WU Qianqian; ZHENG Xilai; XU Mo

    2006-01-01

    Based on the characteristic of ‘one river one oasis' in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circulation pattern is investigated through the analysis of 60 groups of isotope data in the basin. From the phreatic evaporation data analysis of different soils, we study the law of phreatic evaporation, complete the research of the main consumption path of the groundwater,and improve the assessment precision of water resources. The transformation mount of regional water resources are predicted by calculation, which provides a scientific basis for water resources assessment and allocation in arid regions, and offers a new method for the study of regional water circulation patterns.

  12. Paleoecologic and biostratigraphic models for pleistocene through miocene foraminiferal assemblages of the Gulf Coast Basin

    Energy Technology Data Exchange (ETDEWEB)

    Breard, S.Q.; Callender, A.D.; Nault, M.J. (Paleo Control Inc., Houston, TX (United States))

    1993-09-01

    We have developed operationally oriented paleoecologic models used in hydrocarbon exploration of the Gulf Coast basin for Pleistocene through Miocene foraminifera and an updated, refined biostratigraphic chart. We also present estimated paleoecologic tolerances for major benthic and planktic foraminiferal markers, and discuss a number of rules and problems encountered in oil industry paleoenvironmental reconstruction. Key benthic paleoenvironmental markers for particular depth zones are graphically presented for the Pleistocene through Miocene. Improvements over previous models include greater use of calcareous and arenaceous foraminiferal species not used or recognized in earlier studies. Finer subdivisions of bathyal paleoenvironments are of particular significance due to current Gulf of Mexico deep-water exploration. Operationally, the abyssal environmental is difficult to recognize due to a reliance of faunal abundance to delineate abyssal from bathyal and the lack of abyssal zone markers. A number of genera and species are identified as having changed habitat preference through time. Some forms have moved progressively into deeper water (Ceratobulimina Cyclammina cancellata and Nonion pompiloides). Conversely, the movement of species into progressively shallower occurrences through time (Pullenia bullodies) appears to be less common. The widespread occurrence of known Gulf of Mexico foraminiferal species from countries such as Mexico, Venezuela, Ecuador, Jamaica, Trinidad, and the Dominican Republic, suggest that these; models have direct application to Neogene studies in Central America, South America, the Caribbean, and the U.S. Gulf Coast. We introduce a variety of deep-water benthic marker foraminifera, many for the first time. These taxa help fill gaps for deeper-water sections where standard benthic marker foraminifera do not occur, helping debunk the popular myth that benthic foraminifera are useless as markers in the exploration of deep-water sections.

  13. Megascopic lithologic studies of coals in the Powder River basin in Wyoming and in adjacent basins in Wyoming and North Dakota

    Science.gov (United States)

    Trippi, Michael H.; Stricker, Gary D.; Flores, Romeo M.; Stanton, Ronald W.; Chiehowsky, Lora A.; Moore, Timothy A.

    2010-01-01

    Between 1999 and 2007, the U.S. Geological Survey (USGS) investigated coalbed methane (CBM) resources in the Wyoming portion of the Powder River Basin. The study also included the CBM resources in the North Dakota portion of the Williston Basin of North Dakota and the Wyoming portion of the Green River Basin of Wyoming. This project involved the cooperation of the State Office, Reservoir Management Group (RMG) of the Bureau of Land Management (BLM) in Casper, Wyo., and 16 independent gas operators in the Powder River, Williston, and Green River Basins. The USGS and BLM entered into agreements with these CBM operators to supply samples for the USGS to analyze and provide the RMG with rapid, timely results of total gas desorbed, coal quality, and high-pressure methane adsorption isotherm data. This program resulted in the collection of 963 cored coal samples from 37 core holes. This report presents megascopic lithologic descriptive data collected from canister samples extracted from the 37 wells cored for this project.

  14. Application of Discriminant Analysis for Studying the Source Rock Potential of Probable Formations in the Lorestan Basin, Iran

    Directory of Open Access Journals (Sweden)

    Amir Negahdari

    2014-06-01

    Full Text Available Understanding the performance and role of each formation in a petroleum play is crucial for the efficient and precise exploration and exploitation of trapped hydrocarbons in a sedimentary basin. The Lorestan basin is one of the most important hydrocarbon basins of Iran, and it includes various oil-prone potential source rocks and reservoir rocks. Previous geochemical studies of the basin were not accurate and there remain various uncertainties about the potential of the probable source rocks of the basin. In the present research, the geochemical characteristics of four probable source rocks of the Lorestan basin are studied using Rock-Eval pyrolysis and discriminant analysis. In achieving this goal, several discriminant functions are defined to evaluate the discriminant factor for the division of samples into two groups. The function with the highest discriminant factor was selected for the classification of probable source rocks into two groups: weak and strong. Among the studied formations, Garau and Pabdeh had the richest and poorest source rocks of the Lorestan basin, respectively. The comparison of the obtained results with the previous literature shows that the proposed model is more reliable for the recognition of the richness of source rock in the area.

  15. Reconnaissance Study of Water Quality in the Mining-Affected Aries River Basin, Romania

    Science.gov (United States)

    Friedel, Michael J.; Tindall, James A.; Sardan, Daniel; Fey, David L.; Poputa, G.L.

    2008-01-01

    The Aries River basin of western Romania has been subject to mining activities as far back as Roman times. Present mining activities are associated with the extraction and processing of various metals including Au, Cu, Pb, and Zn. To understand the effects of these mining activities on the environment, this study focused on three objectives: (1) establish a baseline set of physical parameters, and water- and sediment-associated concentrations of metals in river-valley floors and floodplains; (2) establish a baseline set of physical and chemical measurements of pore water and sediment in tailings; and (3) provide training in sediment and water sampling to personnel in the National Agency for Mineral Resources and the Rosia Poieni Mine. This report summarizes basin findings of physical parameters and chemistry (sediment and water), and ancillary data collected during the low-flow synoptic sampling of May 2006.

  16. Study of evaluation of groundwater in Gadilam basin using hydrogeochemical and isotope data.

    Science.gov (United States)

    Prasanna, Mohan Viswanathan; Chidambaram, S; Shahul Hameed, A; Srinivasamoorthy, K

    2010-09-01

    Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mines and other industrial complexes. It is also due to extensive depressurization of Cuddalore aquifer, and bore wells for New Veeranam Scheme are constructed downstream of the basin. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemistry. Chemical parameters of groundwater such as pH, electrical conductivity, total dissolved solids, sodium (Na(+)), potassium (K(+)), calcium (Ca(+)), magnesium (Mg(+)), bicarbonate (HCO(-)(3)), sulfate (SO(-)(4)), phosphate (PO(-)(4)), and silica (H(4)SiO(4)) were determined. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock-water interaction with significant evaporation prevails in hard rock region.

  17. Phase I Focused Corrective Measures Study/Feasibility Study for the L-Area Oil and Chemical Basin (904-83G)

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-02-01

    This report presents the completed Resource Conservation and Recovery Act (RCRA) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Focused Corrective Measures Study/Feasibility Study (CMS/FS) for the L-Area Oil and Chemical Basin (LAOCB)/L-Area Acid Caustic Basin (9LAACB) Solid Waste Management Unit/Operable Unit (SWMU/OU) at the Savannah River Site (SRS).

  18. Study on kinetics of hydrocarbon generation from coals in the Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    DUAN Yi; WU Baoxiang; ZHENG Chaoyang; WANG Chuanyuan; ZHANG Hui; TAO Mingxin; LIU Jinzhong; ZHANG Xiaojun

    2005-01-01

    A new method for the quantitative assessment of hydrocarbon generation potential from coals by means of the chemical reaction kinetics has been developed gradually over the recent years. In this paper, the kinetic parameters of hydrocarbon gas generation are determined by high temperature and pressure, and closed- system thermal simulation for Late Paleozoic coals in the Qinshui Basin and the kinetic characteristics and the histories of hydrocarbon gas generation were studied using the parameters obtained. Results show that during the longer period from the Triassic (T) to the Middle Jurassic (J2), the coal-derived methane yield increased more slowly under lower palaeogeotemperature in the Qinshui Basin; however, the shorter period from Late Jurassic to Early Cretaceous, the coal-derived methane yield increased more rapidly under higher palaeogeotemperature. The correlation between the thermal simulation and the factual data shows that C1/ (C1+C2―4) coefficients computed by the histories of methane and C2―C4 hydrocarbon generation can provide evidence for the identification of the genesis of coal bed gas in the different areas of the Qinshui Basin. The kinetic simulating experiment of hydrocarbon generation for the peat considered as the original matter of coal formation was performed for the first time and the simulated results were compared with the characteristics of hydrocarbon generation from coals undergoing various palaeogeotemperature in the Qinshui Basin. The result indicates that the peat has a higher potential of hydrocarbon generation than that of coals. Therefore, the hydrocarbon generation results obtained from kinetic simulation for coal with higher maturation rank could not stand for their original hydrocarbon generation potential and thus would lead to an underestimation for coal-bed gas resource. The generative amount of coal-derived gas in the Qinshui Basin was predicted using kinetic simulation results for the peat and their maximum was

  19. Wyodak-Anderson coal zone study limit in the Powder River Basin, Wyoming and Montana (wabndg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This ArcView shapefile contains a polygon representing the study area for the Wyodak-Anderson coal zone in the Powder River Basin, Wyoming and Montana. This theme...

  20. Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This product "Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area" is a 1:250,000-scale vector dataset...

  1. Study limit boundaries for the Ferris 23, 25, 31, 50 and 65 coal zones, Hanna Basin, Wyoming (fer*stdyg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of the study areas for the Ferris coal zones in the Ferris coalfield, Hanna Basin, Wyoming. These datasets were...

  2. Elements for an integrated resource planning in the framework of river basins: a study for the Cuiaba River Basin; Elementos para um planejamento integrado de recursos no ambito de bacias hidrograficas: um estudo para a bacia do rio Cuiaba

    Energy Technology Data Exchange (ETDEWEB)

    Dorileo, Ivo Leandro; Bajay, Sergio Valdir [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico. Dept. de Energia], e-mail: ildorileo@sigmanet.com.br, e-mail: bajay@fem.unicamp.br

    2008-07-01

    A new approach in energy planning in Brazil, IRP - Integrated Resources Planning for River Basins, gathers three main determinants of development: water, electricity and piped gas. This paper argues, briefly, the need of this planning, of indicative character, integrated with the River Basin Plans, and it presents a retrospective analysis concerning water, electricity and LPG demands of the economy sectors from Cuiaba River Basin region, priority elements to aid the prospective studies and to carry out process related to the IRP. (author)

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

    Science.gov (United States)

    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. Tidal River Management (TRM and Tidal Basin Management (TBM: A case study on Bangladesh

    Directory of Open Access Journals (Sweden)

    Talchabhadel Rocky

    2016-01-01

    Full Text Available Bangladesh is the biggest delta of the world. Construction of numbers of polders is one of the flood resilient approach. But the presence of coastal polders de-linked the flood plain. The siltation in river causes riverbeds to become higher than the adjacent crop lands, and vast area under the polders became permanently water logged rendering large tract of land uncultivable. The current practice is temporarily de-poldering by cutting embankment. This is a natural water management process with very little human interventions but it needs strong participation and consensus with a great deal of sacrifice by the stakeholders for a specific period (3 to 5 years or even more[1]. An attempt has been made to study the phenomena of tidal basin management reviewing some secondary data and processes involved in successfully operated tidal basins of Bangladesh. And preliminary laboratory experiments are carried out to precisely look into the suspended sediment transport. With varying outflow discharge and sediment supply, the transport processes are investigated. 3D sediment transport model developed using openFOAM has good agreement with experimental result and can be used to better understand effectiveness of tidal basin management.

  5. Deep seismic reflection study over the Vindhyans of Rajasthan: Implications for geophysical setting of the basin

    Indian Academy of Sciences (India)

    B Rajendra Prasad; V Vijaya Rao

    2006-02-01

    This paper presents results of high-resolution deep seismic reflection profiling of the Proterozoic Vindhyan basin of the Rajasthan area along the Chandli –Bundi –Kota –Kunjer pro file.Seismic images have been used to estimate the thickness of Vindhyan strata as well as to understand the tectonic framework of the basin.The results are constrained by gravity,magnetic and magne-totelluric data.The study reveals gentle SE-dipping reflection bands representing the Vindhyan strata.The seismic sections depict gradual thickening of the Vindhyan succession towards south-east from Bundi.The velocities of the upper and lower Vindhyans are identified as 4.6 –4.8 km/s and 5.1 –5.3 km/s.The NW limit of the Vindhyan basin is demarcated by the Great Boundary Fault (GBF)that manifests as a 30 km wide NW dipping thrust fault extending to a depth of 30 km.

  6. An experimental study on single basin solar still augmented with evacuated tubes

    Directory of Open Access Journals (Sweden)

    Sampathkumar K.

    2012-01-01

    Full Text Available The productivity of the solar still is determined by the temperature of water in the basin and the glass temperature. Various active methods have been adopted to increase the temperature of the basin, so as to improve the productivity of solar still. Most of the previous research works have been focusing on flat plate collector and concentrating collector. In this experimental study, a single slope solar still directly augmented with evacuated tubes was used to increase the daily productivity by reducing heat losses. Evacuated tubes were directly coupled to the lower side of the single slope solar still with an area of 1m2. Black gravel is used to increase the productivity by means of reducing quantity of water in the basin. Extensive experiments were conducted to explore the performance of solar still in several modes namely still alone, still with black stones, still with evacuated tubes, and still with evacuated tubes and black gravel. The experimental setup was designed and installed at Solar Energy Park, Tamilnadu College of Engineering, Coimbatore (77˚E, 11˚N, Tamilnadu, India. These experiments were conducted using tap water as feed. It was found that, after augmentation of the evacuated tubes, the daily production rate has increased by 49.7 % and it increased by 59.48% with black stones. Economic analysis was also done and payback period of this experimental setup is 235 days.

  7. Lanthanides in the study of lithologic discontinuity in soils from the Piracicaba river basin

    Energy Technology Data Exchange (ETDEWEB)

    De Nadai Fernandes, E.A.; Martins Bacchi, F.A. [Sao Paulo Univ., Piracicaba (Brazil). Centro de Energia Nuclear na Agricultura

    1998-07-24

    This study was designed with the objective of using lanthanides to confirm the occurrence of lithologic discontinuities, formerly highlighted by morphological and mineralogical studies and recognized by field evidence, in three soil profiles from the Piracicaba river basin, Brazil. Comparison of lanthanide concentrations in the horizons and underlying rocks indicated the presence of allochthonous soils. Application of principal component analysis to the measured elements yielded well-defined segregation into groups with cumulative variances higher than 90% for the first two components. Lanthanides were confirmed as versatile indicators to corroborate parent material discontinuities for the soil profiles studied. (orig.) 12 refs.

  8. Evaluation of climate change impact on Blue Nile Basin Cascade Reservoir operation – case study of proposed reservoirs in the Main Blue Nile River Basin, Ethiopia

    OpenAIRE

    2015-01-01

    This study mainly deals with evaluation of climate change impact on operation of the Blue Nile Basin Cascade Reservoir. To evaluate the impact of climate change, climate change scenarios of evapotranspiration and precipitation were developed for three periods. Output of ECHAM5 with RCM for the A1B emissions scenario were used to develop the future climate change scenarios. A hydrological model, HEC-HMS, was used to simulate current and future inflow volume to the reservoirs. The projected fut...

  9. Summary of 2012 reconnaissance field studies related to the petroleum geology of the Nenana Basin, interior Alaska

    Science.gov (United States)

    Wartes, Marwan A.; Gillis, Robert J.; Herriott, Trystan M.; Stanley, Richard G.; Helmold, Kenneth P.; Peterson, C. Shaun; Benowitz, Jeffrey A.

    2013-01-01

    The Alaska Division of Geological & Geophysical Surveys (DGGS) recently initiated a multi-year review of the hydrocarbon potential of frontier sedimentary basins in Alaska (Swenson and others, 2012). In collaboration with the Alaska Division of Oil & Gas and the U.S. Geological Survey we conducted reconnaissance field studies in two basins with recognized natural gas potential—the Susitna basin and the Nenana basin (LePain and others, 2012). This paper summarizes our initial work on the Nenana basin; a brief summary of our work in the Susitna basin can be found in Gillis and others (in press). During early May 2012, we conducted ten days of helicopter-supported fieldwork and reconnaissance sampling along the northern Alaska Range foothills and Yukon–Tanana upland near Fairbanks (fig. 1). The goal of this work was to improve our understanding of the geologic development of the Nenana basin and to collect a suite of samples to better evaluate hydrocarbon potential. Most laboratory analyses have not yet been completed, so this preliminary report serves as a summary of field data and sets the framework for future, more comprehensive analysis to be presented in later publications.

  10. North Atlantic Ocean deep-water processes and depositional environments: A study of the Cenozoic Norway Basin

    Science.gov (United States)

    Oline Hjelstuen, Berit; Andreassen, Elin V.

    2015-04-01

    Despite the enormous areas deep-water basins occupy in modern oceans, our knowledge about them remains poor. At depths of greater than 2000 m, the Cenozoic Norway Basin in the northernmost part of the Atlantic Ocean, is one such basin. Interpretation of 2D multichannel seismic data suggests a three-stage evolution for the Norway Basin. (1) Eocene-Pliocene. This time period is characterised by deposition of ooze-rich sediments in a widening and deepening basin. (2) Early-Middle Pleistocene. A significant shift in sedimentary processes and depositional environments took place in the Early Pleistocene. Mass failures initiated on the Norwegian continental slope, and three Early and Middle Pleistocene slide debrites, with maximum thicknesses of 600 m and sediment volumes of up to 25000 km3, were deposited. With ages estimated at c. 2.7-1.7 Ma, 1.7-1.1 Ma and 0.5 Ma, these slide deposits are among the largest identified worldwide, and among the oldest mapped along the entire NE Atlantic continental margin. (3) Late Pleistocene-Present. Since c. 0.5 Ma the Norway Basin has been effected by glacigenic debris flows, the Storegga Slide and hemipelagic-glacimarine sedimentation. These sedimentary processes were active during a time of repeated shelf-edge ice advances along the NE Atlantic continental margin. This study shows that deep-water basins represent dynamic depositional environments reflecting regional tectonic and climatic changes trough time.

  11. Paleoenvironmental Implications of Clay Minerals at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Bristow, Thomas F.; Blake, David F.

    2014-01-01

    The Mars Science Laboratory (MSL) Rover, Curiosity spent approx 150 sols at Yellowknife Bay (YKB) studying a section of fluvio-lacustrine sedimentary rocks (with potential indications of volcanic influence), informally known as the Yellowknife Bay formation. YKB lies in a distal region of the Peace Vallis alluvial fan, which extends from the northern rim of Gale Crater toward the dune field at the base of Mt Sharp. Sedimentological and stratigraphic observations are consistent with the Yellowknife Bay formation being part of a distal fan deposit, which could be as young as middle Hesperian to even early Amazonian in age (approx. 3.5 to 2.5 Ga). The Yellowknife Bay formation hosts a unit of mudstone called the Sheepbed member. Curiosity obtained powdered rock samples from two drill holes in the Sheepbed Member, named John Klein and Cumberland, and delivered them to instruments in Curiosity. Data from CheMin, a combined X-ray diffraction (XRD)/X-ray fluorescence instrument (XRF), has allowed detailed mineralogical analysis of mudstone powders revealing a clay mineral component of approx. 20 wt.% in each sample. The clay minerals are important indicators of paleoenvironmental conditions and sensitive recorders of post-depositional alteration processes. The XRD pattern of John Klein reveals a 02l band consistent with a trioctahedral phyllosilicate. A broad peak at approx. 10A with a slight inflexion at approx. 12A indicates the presence of 2:1 type clay minerals in the John Klein sample. The trioctahedral nature of the clay minerals, breadth of the basal reflection, and presence of a minor component with larger basal spacing suggests that John Klein contains a trioctahedral smectite (probably saponite), whose interlayer is largely collapsed because of the low-humidity conditions. The XRD patterns show no evidence of corrensite (mixed-layer chlorite/smectite) or chlorite, which are typical diagenetic products of trioctahedral smectites when subjected to burial and

  12. Paleoenvironmental change in central Chile as inferred from OSL dating of ancient coastal sand dunes

    Science.gov (United States)

    Andrade, Belisario; Garcia, Juan L.; Lüthgens, Christopher; Fiebig, Markus

    2013-04-01

    To present day, the climatic and geographic expression of glacials and interglacials in the semiarid coast of central Chile remains unclear. The lack of well dated paleoclimatic records has up to now precluded firm conclusions whether maximum glacials evident in the Andes mountain range probably coincide with wetter (e.g., pluvials) or drier conditions at the coast. The natural region locally known as "Norte Chico" represents a transitional semiarid area between the extreme Atacama Desert to the North and the wetter, Mediterranean-like type of climate, to the South. In this semiarid region of Chile several generations of eolian sand dunes, some of them separated by paleosoils, have been preserved. In addition to the occurrence of paleosoils, thick debris flow deposits in some places overly ancient dune bodies, likely indicating significant environmental changes during the formation of these archives. However, the exact timing of these processes within the mid to late Pleistocene and Holocene is still unclear. A key aspect is that some of the ancient dunes are recently hanging above rocky coastlines, where no supply of sand exists today, likely implying their formation during a lower than present, probably glacio-eustatically induced sea level. The location of the research area in a key mid-latitude region of the eastern Pacific in combination with the preserved landform record offers a chance to reconstruct climatic shifts during the Quaternary by studying the variability of morphogenetic conditions throughout time, in order to promote knowledge about possible forcing factors driving climatic variability. Within this pilot study, samples for optically stimulated luminescence (OSL) dating were taken from three different stratigraphic sections that denote a complex environmental variability as indicated by paleosoils and debris flow units intercalated in ancient sand dunes. First dating results inferred from OSL measurements using a post-IR IRSL (pIRIR) protocol for

  13. Environmental Isotopes Study on Geothermal Water in Guanzhong Basin, Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    MA Zhi-yuan; WU Wen-di; FAN Ji-jiao; SU Yan

    2007-01-01

    There exists abundant thermal water recourses in Guanzhong basin, Shaanxi province (northwestern China).With the deepening of exploitation for thermal aquifer nowadays, the information about the origin and movement of thermal water is limited by using traditional methods. This paper applies environmental isotope techniques to offer direct constraints on the recharge and movement of thermal water and improve the geological and hydrogeological database in Guanzhong Basin. The research on the environmental isotopes shows that the geothermal water of the area is mainly recharged by meteoric water. The temperature of meteoric water which replenishes geothermal water in the study area is -16℃. The estimated age of recharging the geothermal water is 13.3-28.2 ka based on the isotope analysis, belonging to the last glacial period in Late Quaternary. The source of replenishment of the geothermal water is thought to have been derived from glacial snow-melt water with an elevation higher than 1 500 m (ASL) in the north side of Qinling Mountain. The isotopic analysis denotes that the geothermal water in the southern Guanzhong basin is the mixture of net thermal water and normal temperature groundwater. Based on calculating the percentage of the mixture, nearly half of cold groundwater had participated the circulating of the geothermal water. However, in the center part of the basin, some artificial factors such as mismanage of pumping are probably the reason for the mixturing. The temperature range of the geothermal reservoirs in the basin is estimated at about 80-121℃ based on calculation of both SiO2 geothermometer and thermal water saturation index, which are basically in accordance with the measured temperature of thermal water. Based on the replenishment time and mixture extent with cold water, the thermal water in the studied area can be classified into three parts: mixed thermal water replenished by modern meteoric water; mixed thermal water replenished by both

  14. Hydrocarbon Potentials, Thermal and Burial History in Herwa-1 Well from the Nigerian Sector of the Chad Basin: An Implication of 1-D Basin Modeling Study

    Directory of Open Access Journals (Sweden)

    Abubakar Mijinyawa

    2013-06-01

    Full Text Available This research study attempt to evaluate the hydrocarbon potentials, thermal and burial history and the timing of hydrocarbon generation in Herwa-1 well within the Nigerian Sector of the Chad basin. Organic geochemical study of some ditch cuttings samples from Herwa-1 well and a One-dimensional basin modeling study was carried out. The result of the geochemical analysis revealed a moderate to good TOC greater than 0.5wt% in Fika and Gongila formation, the Hydrogen Index (HI ranges from 150-300 (mgHC/g and the Tmax values falls within the range of greater than or equal to 430°C. The hydrocarbon potentials in Herwa-1 well was further supported with the values of S1+S2 which is greater than or equal to 2 mg/g of rock in almost all the samples, suggesting a good hydrocarbon potentials. The 1-D basin model was constructed for Herwa-1 well in order to assess the burial history and thermal maturity of the potential source rocks in the Nigerian sector of the Chad basin. The modeling results indicate that maximum burial occurred in the late Miocene and suggesting erosion might have been the cause of the thinning of the Tertiary sediments in the present time. The calibration of Vitrinite reflectance against Temperature revealed the present day heat flow to be at 60 mW/m2 and Paleo heat flow falls within the range of 68 mW/m2. However, it is also revealed that Oil Window begins at (0.60-1.30% VRr at the depth of (2000-3000 m in the middle Cretaceous and the Gas Window start during the late Cretaceous to Tertiary with a value of (1.3-2.5% VRr at a depth greater than (3500 m.

  15. Regional Studies Program. Biological aspects of surface coal mine reclamation, Black Mesa and San Juan Basin

    Energy Technology Data Exchange (ETDEWEB)

    Green, B.B.

    1977-08-01

    This report discusses case study data on surface mine reclamation accumulated at selected mines in the Southwest, specifically the Black Mesa Mine in Arizona and the Navajo Mine located south of Fruitland, New Mexico, in the San Juan Basin. Experimental results have made it apparent that reclamation of disturbed lands cannot begin and end with planting seed. The report therefore considers hydrologic, edaphic, and biotic factors, as well as land use and management, as important aspects of land reclamation. Recommendations are made to initiate, broaden, and intensify research studies in plant succession, productivity, species selection, and attendant soil characteristics, along with grazing practices and land use potential.

  16. Clumped isotope geochemistry of mid-Cretaceous (Barremian-Aptian) rudist shells: paleoclimatic and paleoenvironmental implications

    Science.gov (United States)

    Huck, S.; Steuber, T.; Bernasconi, S.; Weissert, H.

    2012-04-01

    . Carbonate clumped isotope geochemistry (thermometry) is not only a robust new tool for reconstructing changes in temperature, but also enables paleoclimatic and paleoenvironmental implications, e.g. estimates about freshwater influx or evaporation intensity at ancient tropical shallow-water settings. In combination with high-resolution δ18O, clumped isotope analysis has the potential to differentiate between temperature and salinity changes and this may help to evaluate the significance of meridional temperature gradients. The assumed strong seasonality of low-latitudinal mid-Cretaceous temperatures, based on intra-shell δ18O variations in sclerochronological sections of rudist bivalves (Steuber et al., 2005), is going to become verified or falsified during the current study.

  17. On the Use of Hydrological Models and Satellite Data to Study the Water Budget of River Basins Affected by Human Activities: Examples from the Garonne Basin of France

    Science.gov (United States)

    Martin, Eric; Gascoin, Simon; Grusson, Youen; Murgue, Clément; Bardeau, Mélanie; Anctil, François; Ferrant, Sylvain; Lardy, Romain; Le Moigne, Patrick; Leenhardt, Delphine; Rivalland, Vincent; Sánchez Pérez, José-Miguel; Sauvage, Sabine; Therond, Olivier

    2016-03-01

    Natural and anthropogenic forcing factors and their changes significantly impact water resources in many river basins around the world. Information on such changes can be derived from fine scale in situ and satellite observations, used in combination with hydrological models. The latter need to account for hydrological changes caused by human activities to correctly estimate the actual water resource. In this study, we consider the catchment area of the Garonne river (in France) to investigate the capabilities of space-based observations and up-to-date hydrological modeling in estimating water resources of a river basin modified by human activities and a changing climate. Using the ISBA-MODCOU and SWAT hydrological models, we find that the water resources of the Garonne basin display a negative climate trend since 1960. The snow component of the two models is validated using the moderate-resolution imaging spectroradiometer snow cover extent climatology. Crop sowing dates based on remote sensing studies are also considered in the validation procedure. Use of this dataset improves the simulated evapotranspiration and river discharge amounts when compared to conventional data. Finally, we investigate the benefit of using the MAELIA multi-agent model that accounts for a realistic agricultural and management scenario. Among other results, we find that changes in crop systems have significant impacts on water uptake for agriculture. This work constitutes a basis for the construction of a future modeling framework of the sociological and hydrological system of the Garonne river region.

  18. Biostratigraphy and paleoecologic tolerances of Oligocene through Paleocene foraminiferal assemblages of the Gulf Coast Basin

    Energy Technology Data Exchange (ETDEWEB)

    Breard, S.Q.; Nault, M.J.; Callender, A.D. [Applied Biostratigraphix, Houston, TX (United States)

    1994-12-31

    Operationally oriented biostratigraphic and paleoecologic models are developed for Paleocene, Eocene, and Oligocene foraminifera of the Gulf Coast Basin. This paper is a companion to Breard et al. (1993), which describes models of significant paleoecologic and biostratigraphic foraminifera of the Miocene through Pleistocene of this region. Key benthic paleoenvironmental markers for particular depth zones of the Paleogene are graphically presented with updated biostratigraphic charts. Estimates of environment ranges for optimal stratigraphic utility are listed for all marker species on the biostratigraphic charts. Species depth ranges on the two biostratigraphic charts are for their zones of optimum stratigraphic utility. It is also possible to find deeper water species ranging into shallower zones in the lower bathyal to abyssal zones of the Eocene and Paleocene, where species considered characteristic of these zones range above those environments. Because relatively few wells have penetrated such deep environments in the Eocene and Paleocene, we have relied on the literature for Paleogene deep-water sections of Mexico and Trinidad to supplement our list of environmentally important species. Published material on foraminifera from deep-water Eocene and Paleocene sections penetrated in oil and gas exploration wells is almost nonexistent. Combination of data from this paper with that of Breard et al.(1993) will allow explorationists to estimate environmental tolerances for the entire Gulf Coast Cenozoic biostratigraphic column. This should serve as a predictive tool for foraminiferal studies useful in the exploration and production of oil and gas for the post-Mesozoic strata of the Gulf Coast basin and beyond.

  19. Integrated interpretation to improve subsalt imaging: a case study from the Nordkapp Basin, Norwegian Barents Sea

    Science.gov (United States)

    Olaf Müller, Christian; Brönner, Marco; Götze, Hans-Jürgen

    2015-04-01

    Seismic imaging of subsalt structures is still a difficult task and remaining uncertanties in the salt geometries makes exploration in the vicinity of such complex structures challenging. Gravity and magnetic data have proofed in the past their potential in combination with seismics to better delineate the shape of such salt structures. The current work deals with the improvement of subsalt imaging by combined interpretation of seismic and potential field data examined at a case study from the southern Nordkapp Basin. The Nordkapp Basin is a deep, narrow saliferous basin located in the southwestern Barents Sea. It comprises more than 30 salt diapirs, which are likely to create traps for hydrocarbons at their flanks and overhangs. Consequently exploration of the Nordkapp Basin with seismic methods started already in the 1980s, but until today solely seismics was not sufficient to reveal the nature and geometry for large parts of the basin. Therefore 2D and 3D seismic data were interpreted and used as stratigraphic constraints for the potential field modeling. For this purpose high resolution gravity and full tensor gravity gradient (FTG) data as well as a regional magnetic dataset were available. After processing the potential field data the 3D modeling was conducted by means of the interactive gravity and magnetic modeling software IGMAS+. Furthermore constraints for the rock properties, provided by well logs and susceptibility measurements of adjacent sedimentary well cores, were integrated. The favoured models indicate for both major salt structures a bulky base and a small root. The depth of the base of salt can vary in a range of about ± 300 m. Remaining mother salt is found in the northern part of the survey area and has no connection to the diapiric salt. Due to its higher sensibility to shallower sources the FTG data was used to model the flanks of the salt diapirs. In agreement with adjacent diapirs and encountered sequences a cap rock coverage was

  20. Paleoclimatic and paleoenvironmental context of the Early Pleistocene hominins from Dmanisi (Georgia, Lesser Caucasus) inferred from the herpetofaunal assemblage

    Science.gov (United States)

    Blain, Hugues-Alexandre; Agustí, Jordi; Lordkipanidze, David; Rook, Lorenzo; Delfino, Massimo

    2014-12-01

    Dmanisi is currently the oldest Early Palaeolithic site discovered out of Africa. It has produced over 40 hominin remains, including a set of very informative skulls, in direct association with faunal remains and numerous lithic artifacts. Given the relevance of this locality, every effort is being made to reconstruct the landscapes where these hominins once lived. Amphibian and reptile remains from Dmanisi are here described for the first time and used as paleoclimatic and paleoenvironmental proxies. They comprise at least six taxa: a green toad (Bufo gr. Bufo viridis), the Greek tortoise (Testudo graeca), a green lizard (Lacerta gr. Lacerta viridis), a four-lined snake (Elaphe gr. Elaphe quatuorlineata), an indeterminate colubrid and a water snake (Natrix sp.). As these taxa are not extinct and their ecology can be directly studied, they can contribute to the reconstruction of the landscape and climate. The application of the Mutual Climatic Range method provides quantitative data indicating that during the hominin presence at Dmanisi climate was warm and dry, similar to the present-day Mediterranean climate. In comparison with today climate of Dmanisi, estimated mean annual temperature was 3.1 °C higher, with a greater increase of temperature in summer (+7.1 °C) than in winter (+4.7 °C). The mean annual precipitation was slightly lower (-65 mm) than the current level, with precipitation higher than current one during winter (+104 mm) but strongly lower during the other seasons, suggesting a stronger contrast in the rainfall regime during the year. From a paleoenvironmental point of view, fossil amphibians and reptiles all suggest the predominance of arid environments, from steppe or semi-desert to open Mediterranean forest, with stony or rocky substrate and bushy areas. The presence of permanent aquatic environments is also documented. These results mainly agree with those for large mammals, small mammals and the archaeobotanical analysis that indicate an

  1. Improved paleoenvironmental interpretations at the intersection between paleontology and biogeochemistry

    Science.gov (United States)

    Lyons, T. W.

    2012-04-01

    Paleoenviromental reconstructions, particularly those focused of oxygen levels in the ancient ocean, often rely on geochemical or paleoecological approaches but too infrequently exploit the added strength that comes with a combined approach. Trace metal, organic biomarker, and iron paleoredox proxies do well in distinguishing between ancient oxic water columns and anoxic, Fe-rich (ferruginous) and anoxic, sulfidic (euxinic) settings. Molybdenum isotope approaches may even allow us to estimate the amount of hydrogen sulfide in the ancient seawater. Where the challenges often arise are at intermediate redox states marked by episodes of only transient anoxia/euxinia where diagnostic geochemical end-member enrichments are muted. Unfortunately, rapid detrital sedimentation and depleted seawater metal inventories under anoxic/euxinic conditions on basin and ocean scales can yield similarly tempered metal enrichments. Intermediate geochemical signatures can also mark conditions of extremely low bottom-water oxygen (often referred to as 'suboxic') but with sulfide confined to the pore fluids and a lack of appreciable and persistent Fe availability in the water column. Also possible are protracted episodes of true anoxia that lack Fe or sulfide in the water column because of limited availability of the organic matter required to drive bacterial Fe and sulfate reduction. In contrast, benthic ecological relationships, both trace and body fossil, are very sensitive to redox fluctuations at the low oxygen end, even brief episodes of oxygenation, and across subtle spatiotemporal redox gradients, although they are not readily effective at distinguishing between ferruginous and euxinic bottom waters. The talk will explore the mechanistic underpinnings of some of the most important geochemical proxies and then view their relative strengths and weaknesses in light of the added insight gleaned via coupled paleoecological analysis. Beyond stronger interpretations of Phanerozoic

  2. The role of microorganisms in the formation of a stalactite in Botovskaya Cave, Siberia – paleoenvironmental implications

    Directory of Open Access Journals (Sweden)

    M. Pacton

    2013-09-01

    Full Text Available Calcitic speleothems in caves can form through abiogenic or biogenic processes, or through a combination of both. Many issues conspire to make the assessment of biogenicity difficult, especially when focusing on old speleothem deposits. This study reports on a multiproxy analysis of a Siberian stalactite, combining high-resolution microscopy, isotope geochemistry and microbially enhanced mineral precipitation laboratory experiments. The contact between growth layers in a stalactite exhibits a biogenic isotopic signature; coupled with morphological evidence, this supports a microbial origin of calcite crystals. SIMS δ13C data suggest that microbially mediated speleothem formation occurred repeatedly at short intervals before abiotic precipitation took over. The studied stalactite also contains iron and manganese oxides that have been mediated by microbial activity through extracellular polymeric substance (EPS-influenced organomineralization processes. The latter reflect paleoenvironmental changes that occurred more than 500 000 yr ago, possibly related to the presence of a peat bog above the cave at that time. Microbial activity can initiate calcite deposition in the aphotic zone of caves before inorganic precipitation of speleothem carbonates. This study highlights the importance of microbially induced fractionation that can result in large negative δ13C excursions. The microscale biogeochemical processes imply that microbial activity has only negligible effects on the bulk δ13C signature in speleothems, which is more strongly affected by CO2 degassing and the host rock signature.

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

    Institute of Scientific and Technical Information of China (English)

    Wu Xiantao

    2007-01-01

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

  4. The disappearing Environmental Kuznets Curve: a study of water quality in the Lower Mekong Basin (LMB).

    Science.gov (United States)

    Wong, Yoon Loong Andrew; Lewis, Lynne

    2013-12-15

    The literature is flush with articles focused on estimating the Environmental Kuznets Curve (EKC) for various pollutants and various locations. Most studies have utilized air pollution variables; far fewer have utilized water quality variables, all with mixed results. We suspect that mixed evidence of the EKC stems from model and error specification. We analyze annual data for four water quality indicators, three of them previously unstudied - total phosphorus (TOTP), dissolved oxygen (DO), ammonium (NH4) and nitrites (NO2) - from the Lower Mekong Basin region to determine whether an Environmental Kuznets Curve (EKC) is evident for a transboundary river in a developing country and whether that curve is dependent on model specification and/or pollutant. We build upon previous studies by correcting for the problems of heteroskedasticity, serial correlation and cross-sectional dependence. Unlike multi-country EKC studies, we mitigate for potential distortion from pooling data across geographically heterogeneous locations by analyzing data drawn from proximate locations within a specific international river basin in Southeast Asia. We also attempt to identify vital socioeconomic determinants of water pollution by including a broad list of explanatory variables alongside the income term. Finally, we attempt to shed light on the pollution-income relationship as it pertains to trans-boundary water pollution by examining data from an international river system. We do not find consistent evidence of an EKC for any of the 4 pollutant indicators in this study, but find the results are entirely dependent on model and error specification as well as pollutant.

  5. Assessing the paleoenvironmental potential of Pliocene to Holocene tufa deposits along the Ghaap Plateau escarpment (South Africa) using stable isotopes

    Science.gov (United States)

    Doran, Taylor Louise; Herries, Andy I. R.; Hopley, Philip J.; Sombroek, Hank; Hellstrom, John; Hodge, Ed; Kuhn, Brian F.

    2015-07-01

    The tufa deposits of the Ghaap Plateau escarpment provide a rich, yet minimally explored, geological archive of climate and environmental history coincident with hominin evolution in South Africa. This study examines the sedimentary and geochemical records of ancient and modern tufas from Buxton-Norlim Limeworks, Groot Kloof, and Gorrokop, to assess the potential of these sediments for providing reliable chronologies of high-resolution, paleoenvironmental information. Chronometric dating demonstrates that tufa formation has occurred from at least the terminal Pliocene through to the modern day. The stable isotope records show a trend toward higher, more variable δ18O and δ13C values with decreasing age from the end of the Pliocene onwards. The long-term increase in δ18O values corresponds to increasingly arid conditions, while increasing δ13C values reflect the changing proportion of C3/C4 vegetation in the local environment. Analysis of the Thabaseek Tufa, in particular, provides valuable evidence for reconstructing the depositional and chronological context of the enigmatic Taung Child (Australopithecus africanus). Collectively, the results of the present study demonstrate the potential of these deposits for developing high-precision records of climate change and, ultimately, for understanding the causal processes relating climate and hominin evolution.

  6. Study on rain-runoff process in the peripheral mountainous area of tne Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    FU Bin; WANG Yu-kuan; REN Yi; LIU Cheng; XU Pei

    2008-01-01

    Studies on rain.runoff process in the peripheral mountainous area of the Sichuan Basin,which is re-garded as a key ecological shelter,will contribute to flood control and environmental protection for the Upper Yang-tze River Basin.In two typical catchments--the Fujiang River Catchment and the Wujiang River Catchment,rainfall simulations have been conducted to study the rain-runoff processes of yellow soil and limestone soil in three types of land use-forestland.farmland and grassland.Results showed that(1)within the same rainfall process,overland flow occurs first on farmland,then on grassland,and finally on forestland;(2)soil surface coverage has a great im-pact on the occurrence and amount of overland flow.The runoff amount Can increase 2-4 times after the coverage iS removed;(3)the infiltration before the occurrence of overland flow will decrease because of higher gravel contents of soil.but it takes no effect on infiltration once,overland flow becomes stable;(4)the runoff coefficient of the lime-stone soil forestland iS greater than that of the yellow soil forest land,but less than that of the farmland;(5)threeempirical infiltration models,including Horton'model,Kostiakov'model,and modified Kostiakov'model,were compared by using the observed results under rainfall simulation.The results showed that the Kostiakov'model per-formed better than both the Horton'model and modified Kostiakov model.According to the results of this research,the Kostiakov's model Can be used to simulate rainfall infiltration when water erosion is modeled in the peripheral mountainous area of the Sichuan Basin.

  7. Reconnaissance Study for the Western Lake Huron Basin, Watershed Study, Michigan, Section 905(b)

    Science.gov (United States)

    2012-05-01

    Basin, NPS pollution most commonly results from sediment, nutrients, or chemicals, such as pesticides, antibiotics , or hormones (TNC 2010). Altered...to be caused by stormwater/septics  b. CAFO/Agriculture   i. Significant CAFOs (60 – 70K dairy cows; 100K+ beef cattle; 600K+  chickens )  ii. Need an

  8. On the intensity and type transition of land use at the basin scale using RS/GIS: a case study of the Hanjiang River Basin.

    Science.gov (United States)

    Yu, Guangming; Zeng, Qun; Yang, Shan; Hu, Limei; Lin, Xiaowei; Che, Yi; Zheng, Yuge

    2010-01-01

    The purpose of this study is to investigate the land use intensity and land use change type at the basin scale in the middle and lower reaches of the Hanjiang River Basin (in Hubei Province, China) by combining the Landsat TM images in 1995 and 2000 with the land use database (in scale 1:10,000) and relative data. In this study, the basic data is acquired from the interpretation of remote sensing (RS) images. The intensity of land use and the rate of change in double-directions of land use dynamics are calculated with the support of software ARC/INFO. The intensity of land use is indicated by the intensity coefficient of land use, and the transition of land use types is quantified as the rate of change in double-direction of land use types and also expressed as the transition matrix of land use types. The results are expressed in space by Geographic Information System (GIS) software. Results of this study show that (1) the intensity of land use is high in the study region, the intensity coefficients of land use in 1995 and 2000 are 260.025 and 290.526, respectively, and the intensity of development and utilization of land is trend to increscent; and (2) the rate of land use change in double directions in the whole study region is 0.52 with great spatial variation and the differentiation of land use types. In the differentiation of land use types, the unutilized land (with the rate to 4.391) is developed fast, the grassland (with 2.836) and water area (with 1.664) are disturbed severely, and these changes will influence the eco-environment in the Hanjiang River Basin and all the Yangtze Basin. The rates of the farmland and the woodland are 0.424 and 0.344, respectively, meaning that the fundamentals of regional human-environmental system are relative stable. With this study, we can conclude that (1) the patterns of land use are increasingly changing in the study region, the environmental impacts are escalated on this stage, and the further outcomes are destined to

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

    Science.gov (United States)

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

    2016-06-01

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

  10. A Geochemical study of the groundwater in the Misli basin and environmental implications

    Science.gov (United States)

    Yuce, Galip

    2007-01-01

    The aim of this study was to determine geochemical properties of groundwater and thermal water in the Misli Basin and to assess thermal water intrusion into shallow groundwater due to over-extraction. According to isotope and hydrochemical analyses results, sampled waters can be divided into three groups: cold, thermal, and mixed waters. Only a few waters reach water rock chemical equilibrium. Thermal waters in the area are characterized by Na+ Cl- HCO{3/-}, while the cold waters by CaHCO3 facies. On the basis of isotope results, thermal waters in the Misli basin are meteoric origin. In particular, δ18O and δ2H values of shallow groundwater vary from -10.2 to -12.2‰ and -71.2 to -82‰, while those of thermal waters range from -7.8 to -10.1‰ and from -67 to -74‰, respectively. The tritium values of shallow groundwater having short circulation as young waters coming from wells that range from 30 to 70 m in depth vary from 10 to 14 TU. The average tritium activity of groundwater in depths more than 100 m is 1.59 ± 1.16, which indicates long circulation. The rapid infiltration of the precipitation, the recycling of the evaporated irrigation water, the influence of thermal fluids and the heterogeneity of the aquifer make it difficult to determine groundwater quality changes in the Misli Basin. Obtained results show that further lowering of the groundwater table by over-consumption will cause further intrusion of thermal water which resulted in high mineral content into the fresh groundwater aquifer. Because of this phenomenon, the concentrations of some chemical components which impairs water quality in terms of irrigation purposes in shallow groundwaters, such as Na+, B, and Cl-, are highy probably expected to increase in time.

  11. 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.

  12. Chad Basin: Paleoenvironments of the Sahara since the Late Miocene

    Science.gov (United States)

    Schuster, Mathieu; Duringer, Philippe; Ghienne, Jean-François; Roquin, Claude; Sepulchre, Pierre; Moussa, Abderamane; Lebatard, Anne-Elisabeth; Mackaye, Hassan Taisso; Likius, Andossa; Vignaud, Patrick; Brunet, Michel

    2009-08-01

    Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly paleontological field investigations of the Miocene-Pliocene of the Chad Basin. This article synthesizes some of the results of the MPFT, with focus on the Chad Basin development during the Neogene. We propose an overview of the depositional paleoenvironments of this part of Africa at different scales of time and space, based on a multidisciplinary approach (sedimentary geology, geomorphology, geophysic, numerical simulations and geochronology). The Miocene-Pliocene paleoenvironments are examined through the sedimentary archives of the early hominids levels and the Holocene Lake Mega-Chad episode illustrates the last major paleoenvironmental change in this area. The sedimentary record of the Chad Basin since the Late Miocene can be schematized as the result of recurrent interactions from lake to desert environments.

  13. A quantified study method and its application to sustainable management of water resources in arid basins

    Institute of Scientific and Technical Information of China (English)

    ZUO QiTing; ZHOU KeFa; XIA Jun; CHEN Xi; WANG YongQin

    2007-01-01

    According to the features of the basins in arid areas, in this paper a quantified study framework of sustainable management of water resources is developed, and the contents include mainly the quantification rules, index system, basic models and quantification method. A quantified study method (M-D method) about sustainable management of water resources is put forward based on the simulation and integrative development degree. In the method, the fuzzy subordinatness description and the multi-rule integration are used to calculate the integrative development degree so as to quantitatively describe the sustainable development degree of economic society; the mathematical simulation is used to quantitatively describe the interactions between water resources, economic society and ecosystems so as to lay a foundation for quantitatively giving expression to the development situation of economic society related to the management of water resources; based on the organic combination of these two,quantification rules and other constraint conditions, a quantified model of water resources management is developed. The M-D method is applied to developing a scientific scheme of water resources management in the Bosten Lake Basin, Xinjiang, China.

  14. Computational Studies of Hard Disks: Contact Percolation, Fragility, Frictional Families and Basin Volumes

    Science.gov (United States)

    Shen, Tianqi

    This thesis presents four computational and theoretical studies of the structural, mechanical, and vibrational properties of purely repulsive disks, dimer-, and ellipse-shaped particles with and without friction. The first study investigated the formation of interparticle contact networks below jamming onset at packing fraction φJ, where the pressure of the system becomes nonzero. We generated ensembles of static packings of frictionless disks over a range of packing fraction. We find that the network of interparticle contacts forms a system spanning cluster at a critical packing fraction φP missing contacts relative to the isostatic value N0c We show that the probability Pm(micro) to obtain a static packing with m missing contacts at micro can be expressed as a power series in micro. Using Pm(micro), we find that the average contact number versus micro agrees quantitatively with that from simulations of the Cundall-Strack model for frictional disks. In the final project, we performed calculations of the structure of the basin volumes of mechanically stable packings in configuration space as a function packing fraction. Using the basin volumes, we show that the probability to obtain a given MS packing depends strongly on the packing fraction of the initial configuration.

  15. Biostratigraphy and Paleoenvironment in Cheju Sedimentary Basin, Determined by Materials from Exploration Wells Geobuk-1 and Okdom-1

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@A micropaleontological analysis was made using materials from exploration wells Geobuk-1 (Td: 2 722. 5.m) and Okdom-1 (Td: 2 903.7 m) for the purpose of biostratigraphic and paleoenvironmental interpretation of the Cheju sedimentary basin. Two wells yield relatively abundant microfossils such as dinoflagellates, calcareous nannofossils, pollen and spores. The biostratigraphic and paleoenvironmental settings analyzed by microfossil assemblages seem to be closely related to the framework of the local tectonics, seismostraigraphy,and sedimentang environment of the Cheju basin. The diversity and abundance varied significantly throughout the cores.These changes are considered to be related to sea-level fluctuation. The marine transgression and regression are probably caused by the local tectonic movement rather than the eustatic change of seal level, referred to the global sea-level curve.

  16. Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

    Science.gov (United States)

    Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

    2010-01-01

    . Lastly, it describes several categories of limitations and discusses ways of extending the regional model to address issues at the local scale. Results of the simulations portray a regional groundwater-flow system that, over time, has largely maintained its natural predevelopment configuration but that locally has been strongly affected by well withdrawals. The quantity of rainfall in the Lake Michigan Basin and adjacent areas supports a dense surface-water network and recharge rates consistent with generally shallow water tables and predominantly shallow groundwater flow. At the regional scale, pumping has not caused major modifications of the shallow flow system, but it has resulted in decreases in base flow to streams and in direct discharge to Lake Michigan (about 2 percent of the groundwater discharged and about 0.5 cubic foot per second per mile of shoreline). On the other hand, well withdrawals have caused major reversals in regional flow patterns around pumping centers in deep, confined aquifers - most noticeably in the Cambrian-Ordovician aquifer system on the west side of Lake Michigan near the cities of Green Bay and Milwaukee in eastern Wisconsin, and around Chicago in northeastern Illinois, as well as in some shallow bedrock aquifers (for example, in the Marshall aquifer near Lansing, Mich.). The reversals in flow have been accompanied by large drawdowns with consequent local decrease in storage. On the west side of Lake Michigan, groundwater withdrawals have caused appreciable migration of the deep groundwater divides. Before the advent of pumping, the deep Lake Michigan groundwater-basin boundaries extended west of the Lake Michigan surface-water basin boundary, in some places by tens of miles. Over time, the pumping centers have replaced Lake Michigan as the regional sink for the deep flow system. The regional model is intended to support the framework pilot study of water availability and use for the Great Lakes Basin (Reeves, in press).

  17. Study on Law of Groundwater Evolution under Natural and Artificial Forcing with Case study of Haihe River Basin

    Science.gov (United States)

    You, Jinjun; Gan, Hong; Wang, Lin; Bi, Xue; Du, Sisi

    2010-05-01

    The evolution of groundwater is one of the key problems of water cycle study. It is a result of joint effect of natural condition and human activities, but until now the driving forces of groundwater system evolution were not fully understood due to the complexity of groundwater system structures and the uncertainty of affecting factors. Geology, precipitation and human activity are the main factors affecting the groundwater system evolution and interact each other, but the influence of such three factors on groundwater system are not clarified clearly on a macroscopic scale. The precipitation changes the volume of water recharge and the groundwater pumping effect the discharge of groundwater. Another important factor influencing balance of groundwater storage is the underlaying that affects the renewablility of groundwater. The underlaying is decided mainly by geological attributes but also influenced by human activited. The macroscopic environment of groundwater evolves under the natural and anthropic factors. This paper study the general law of groundwater evolution among the factors based on the case study in Haihe River Basin, a typical area with dramatic groundwater change under natural precipitation attenuation and gradually increase of water suuply. Haihe River Basin is located in north-China, covers an area of 320,041 km2 with over 40% plain areas. The plain area of Haihe Basin is densely populated with many large and medium-sized cities, including metropolis of Beijing and Tianjin, and concentrated irrigated areas, playing important roles in China's economy and food production. It is the unique basin where groundwater occupies majority of total water supply in China. Long-term groundwater over-exploitation causes a series of ecological and environmental problems that threats the sustainable development. In this paper, the historical process of groundwater balance in Haihe Basin is divided into three phases by decrease of rainfall and increase of water

  18. Impact of Topography and Land-Sea Distribution on East Asian Paleoenvironmental Patterns

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Much geological research has illustrated the transition of paleoenvironmental patterns during the Cenozoic from a planetary-wind-dominant type to a monsoon-dominant type, indicating the initiation of the East Asian monsoon and inland-type aridity. However, there is a dispute about the causes and mechanisms of the transition, especially about the impact of the Himalayan/Tibetan Plateau uplift and the Paratethys Sea retreat. Thirty numerical sensitivity experiments under different land-sea distributions and Himalayan/Tibetan Plateau topography conditions are performed here to simulate the evolution of climate belts with emphasis on changes in the rain band, and these are compared with the changes in the paleoenvironmental patterns during the Cenozoic recovered by geological records. The consistency between simulations and the geological evidence indicates that both the Tibetan Plateau uplift and the Paratethys Sea retreat play important roles in the formation of the monsoon-dominant environmental pattern. Furthermore, the simulations show the monsoon-dominant environmental pattern comes into being when the Himalayan/Tibetan Plateau reaches 1000-2000 m high and the Paratethys Sea retreats to the Turan Plate.

  19. Tertiary weathering profiles in central Nigeria as indicators of paleoenvironmental conditions

    Science.gov (United States)

    Zeese, Reinhard

    1996-05-01

    In central Nigeria the Fluviovolcanic Series of the Jos Plateau are composed by deeply weathered volcanic rocks and sediments. The sequence is often capped by ferricretes. Ferricretes, remains of former soils, are also intercalated in the series. Profile sections between two ferricretes are deep (> 10 m). The repeated saprolite/solum sequence sometimes exceeds 100 m. It can be separated into a lower section without bauxitisation, but often with total bleaching of the saprolite, a middle section with bauxite and hematite in the saprolite and an upper kaolinitic section with hematite and goethite. Bleaching by total removal of Fe 2+ and bauxitisation by total desilification are both indicators of wet and hot climates with a high biomass production. In the first case the groundwater was permanently high, in the latter a well drained fluctuating groundwater can be assumed. Changing groundwater conditions may be the result of plateau uplift. Paleoenvironmental changes are, thus, reflected in relatively datable paleosols. Undatable paleosoils with comparable characteristics on the planation surfaces of Central and Northeast Nigeria also result from paleoenvironmental conditions. Consequently, concepts of landscape evolution must take into account changing environments.

  20. A generalized land-use scenario generator: a case study for the Congo basin.

    Science.gov (United States)

    Caporaso, Luca; Tompkins, Adrian Mark; Biondi, Riccardo; Bell, Jean Pierre

    2014-05-01

    The impact of deforestation on climate is often studied using highly idealized "instant deforestation" experiments due to the lack of generalized deforestation scenario generators coupled to climate model land-surface schemes. A new deforestation scenario generator has been therefore developed to fulfill this role known as the deforestation ScenArio GEnerator, or FOREST-SAGE. The model produces distributed maps of deforestation rates that account for local factors such as proximity to transport networks, distance weighted population density, forest fragmentation and presence of protected areas and logging concessions. The integrated deforestation risk is scaled to give the deforestation rate as specified by macro-region scenarios such as "business as usual" or "increased protection legislation" which are a function of future time. FOREST-SAGE was initialized and validated using the MODerate Resolution Imaging Spectroradiometer Vegetation Continuous Field data. Despite the high cloud coverage of Congo Basin over the year, we were able to validate the results with high confidence from 2001 to 2010 in a large forested area. Furthermore a set of scenarios has been used to provide a range of possible pathways for the evolution of land-use change over the Congo Basin for the period 2010-2030.

  1. Preliminary study on assessment of nutrient transport in the Taihu Basin based on SWAT modeling

    Institute of Scientific and Technical Information of China (English)

    LAI; Geying; YU; Ge; GUI; Feng

    2006-01-01

    With the Taihu Basin as a study area, using the spatially distributed and mechanism-based SWAT model, preliminary simulations of nutrient transport in the Taihu Basin during the period of 1995~2002 has been carried out. The topography, soil, meteorology and land use with industrial point pollution discharge, the loss of agricultural fertilizers, urban sewerage, and livestock drainages were all considered in the boundary conditions of the simulations. The model was calibrated and validated against water quality monitoring data from 2001 to 2002. The results show that the annual total productions of nitrogen (TN) and phosphorus (TP) into Lake Taihu are 40000t and 2000t respectively. Nutrient from the Huxi Region is a major resource for Lake Taihu. The non-point source (surface source) pollution is the main form of catchment sources of nutrients into Lake Taihu,occupied TN 53% and TP 56% respectively. TN and TP nutrients from industrial point pollution discharge are 30% and 16%, and sewerage in both forms of point source and non-point source are TN 31% and TP 47%. Both the loss of agricultural fertilizers and livestock drainages from the catchment should be paid more attention as an important nutrient source. The results also show that SWAT is an effective model for the simulation of temporally and spatially nutrient changes and for the assessment of the trends in a catchment scale.

  2. Palynofacial analysis in alkaline soils and paleoenvironmental implications: The Paso Otero 5 archaeological site (Necochea district, Buenos Aires province, Argentina)

    Science.gov (United States)

    Grill, S.; Borromei, A.; Martínez, G.; Gutierrez, M. A.; Cornou, M. E.; Olivera, D.

    2007-06-01

    The combination of palynofacial and sedimentological analyses constitutes a valuable method for paleoenvironmental and paleoclimatic reconstructions, especially when fossil pollen information is scarce or absent. This methodology elucidates a late Pleistocene/Holocene sequence at the Paso Otero 5 archaeological site in the middle basin of the Quequén Grande River, Necochea district, Buenos Aires province, Argentina. Although the main factor responsible for the destruction of pollen grains is pH, biochemical and chemical oxidation and mechanical damage contribute to the deterioration as well. The site sequence indicates that extremely arid climatic conditions without vegetation cover prevailed during the late Pleistocene (˜12,000 14C yr BP), after which the climate changed to semiarid conditions associated with a disturbed environment due to strong eolian activity (Palynofacies 1 and 2; pre-10,400 14C yr BP). During the Pleistocene/Holocene transition (Palynofacies 3 and 4; ˜10,400-9400 14C yr BP), loamy facies associated with paleosoils reflected stable conditions and temporary ponds (spring deposits). Similar conditions occurred near the end of early Holocene (Palynofacies 5-9; ˜9400-6600 14C yr BP), whereas sandy and silty facies are associated with the flood margins of streams or rivers in the middle and late Holocene (Palynofacies 10-14; 6600-2500 14C yr BP). The top of the sequence (Palynofacies 15 and 16) consists of alluvium sediments and reflects locally humid conditions and modern vegetation with anthropic influence. One of the earliest Pampean sites with evidence of humans (10,450-10,200 14C yr BP), Paso Otero 5, provides a variety of megafauna bone specimens associated with ``fish-tail" projectile points, a lithic artifact diagnostic of early human occupations in South America. The site contains a complete stratigraphic record from the late Pleistocene to the present. The evidence presented herein supports the hypothesis that human colonization, at

  3. Study of landwater variation over Chao Phraya river basin using GRACE, satellite altimetry and in situ data

    Science.gov (United States)

    Yamamoto, K.; Fukuda, Y.; Nakaegawa, T.; Taniguchi, M.

    2009-12-01

    A project to assess the effects of human activities on the subsurface environment in Asian developing cities has been in progress (Research Institute for Humanity and Nature, Japan, 2009). Bangkok, Thailand is one of the study cities in this project. Using GRACE satellite gravity data, we previously recovered landwater mass variation over the Chao Phraya river basin, where Bangkok is located on downstream. However, mainly because of insufficient spatial resolution of the GRACE data then released, it was difficult to distinguish mass variation over the Chao Phraya basin with the ones of the neighboring Mekong, Irrawaddy and Salween river basins. Recently, some new versions of GRACE data sets have been available, and thus we estimated again the mass variations over these basins using version 2 of CNS/GRGS data set. The result shows that mass variations of the each basin could be distinguished due to improvement of the spatial resolution of the data. One of the interesting things is that a negative interannual mass trend is observed only over the Chao Phraya river basin, while the other basins show positive trend values. One of our concerns was which of the landwater components were decreasing. Because GRACE can only detect total terrestrial water storage, we further used satellite altimeter data to separate surface- and groundwater components. EnviSat data were mainly used as satellite altimetry data in this study, because the mission period is overlapping with GRACE mission and the ground track separation is relatively small. River water levels were recovered from satellite altimetry data, and converted to river water storage. Estimated river water storage was subtracted from the GRACE data. Thus, interannual surface- and groundwater trends were discussed separately. Another concern is whether the landwater decrease is caused by meteorological factors or factors of human activities. Thus, we also compared above results with global hydrological simulation model and

  4. Detrital zircon provenance and paleogeography implications for Furnas Formation in the northwest of Paraná Basin

    Directory of Open Access Journals (Sweden)

    Thais Borba Santos

    2015-06-01

    Full Text Available In the northwest of the Paraná Basin, between the states of Mato Grosso and Goiás, there are exposures of the Furnas Formation, where the Transbrasiliano Lineament is also recognized. From the analysis of magnetic maps, the geological and geophysical framework of the study area was defined, with six main domains separated by 5 lineaments. The contact between Paraguay Belt and the Goiás Magmatic Arc is marked by the main direction of the Transbrasiliano Lineament in the study area. Other lineaments that occur associated with the deformation direction of the Paraguay Belt have been identified as a minor component of Transbrasiliano Lineament. The description of outcrops along the northwest border of the Paraná Basin allowed the recognition of units I, II and III of the Furnas Formation. The U-Pb data from detrital zircon from the Furnas Formation showed predominance of grain with Neoproterozoic ages (560 - 800 Ma, with a minimum age of 526 Ma, and the occurrence of grain with Paleoproterozoic (≈1750/2100 Ma and Archean (≈2700/2800/3100 Ma ages. The study of detrital zircons provenance of the Furnas Formation using U-Pb age determination, associated with the structural framework of the foundation of the basin, and the comparison with paleoenvironmental data were the basis for assessing the paleogeography of the northwestern portion of the Paraná Basin during the aggradation of the Furnas Formation. Ages indicate an important Neoproterozoic contribution similar to the ages of the rocks found in the Goias Magmatic Arc, which associated with data of paleocurrents towards northwest allow us to infer that the arc rocks constituted high terrain, oriented in the NE-SW direction.

  5. The Stratigraphy of the Aquitanian-Burdigalian Asmari Formation of Lorestan Sub-Basin, Iran: an Inclusive Study

    Science.gov (United States)

    Lankarani, M.; Amini, A.; Swennen, R.

    2012-04-01

    The Asmari Formation is the most important hydrocarbon reservoir in the oilfields of the Zagros pro-foreland basin. The shallow carbonates of this formation have been producing oil for nearly one century. However, detailed stratigraphic aspects of this significant rock unit in some parts of the basin, especially Lorestan sub-basin, are poorly studied. So, because of the necessity, several outcrops of the Asmari Formation in this region were inclusively studied in the framework of this project. The Lorestan sub-basin is a narrow, northwest-southeast trending intrashelf depression in the Zagros basin which is created during the Mesozoic. By the end of Mesozoic, continental collision between Iran and Arabian plates resulted in the formation of the Zagros fold-thrust belt and its associated pro-foreland basin, in which the Asmari Formation was deposited. Detailed paleontological investigations done by this study (based on the distribution of the index fossils) showed that age range of the Asmari Formation in this region is Aquitanian-Burdigalian. The main grain associations forming the facies of the formation were found rhodoliths, large benthic foraminifera (rotaliids), green algae, bivalves (mostly oysters), bryozoans, and echinoderms. The biotic associations suggest that carbonate sedimentation took place in tropical waters under oligotrophic conditions. This Aquitanian-Burdigalian carbonate deposits, which were deposited on an oligotrophic tropical carbonate ramp developed in a foredeep tectonic setting, have unconformable boundaries with the overlying and underlying formations. Comprehensive sequence stratigraphic investigations proved that deposition of the Asmari Formation in the studied region has been generally coincident with a transgressive event during the time of global second order sea-level highstand. So, the whole Asmari rock unit in the Lorestan sub-basin comprises a supersequence formed as a result of the second-order eustatic sea-level changes

  6. Dynamic changes of the ecological environment quality in a river basin: a case study of the main stream of Songhua river basin.

    Science.gov (United States)

    Cheng, Y; Wang, L; Ma, F; Du, C

    2011-01-01

    This paper reports the investigation and analysis of the status and dynamic changes of ecological environment quality in the main stream of Songhua river basin. The evaluation index system was established and the eco-environment quality in the year of 2000 and 2008 was studied in depth. Based on our research, the trend of dynamic changes of the eco-environment quality and its origins have been further discussed: In the year of 2000, the range of evaluation index covered from 0.31 to 0.47. Harbin and Yichun was relatively better than the rest of study areas. In the year of 2008, except districts of Daqing and Qitaihe, the environmental quality of Songhua river basin has entirely improved, wherein the evaluation index of the eco-environment covered from 0.31 to 0.57. Particularly, the eco-environment quality of Hegang and Shuangyashan has obtained significant improvement, whereas the improvement of Jiamusi was not obvious. According to the evaluation results, the environmental quality in the study area has an upward trend with the average growth rate 0.13% per year.

  7. Technical Studies of Treatment Basins and Ravines of Area of Sanghe (Senegal

    Directory of Open Access Journals (Sweden)

    M.L. Lo

    2013-11-01

    Full Text Available he Sustainable Management Project (RSM of Sanghe area, Rural Community (RC of Notto Diobass, region of Thies in Senegal, is the implementation of control technologies against water erosion that is the main soil degradation in the rural community region. It affects about 80% of the area and, to address this degradation, extensive diagnostic recommendations made by the Senegalese Institute of Agricultural Research (ISRA focus on comprehensive care of this deterioration through actions in trays, basins and crop areas. To do this, several meetings and site visits were conducted. They led to the concerted following decision: the first action will be used to apply treatment technologies to trays and secondly to slope sand areas of crops recovered. The present study aims mainly the second action that is to say, the technical study for the treatment of slopes and ravines of the Sanghe area.

  8. Studying Iron Mineralogy to Understand Redox Conditions in the Mesoproterozoic Belt Basin, USA Using Complementary Microscopic, Spectroscopic, and Magnetic Techniques

    Science.gov (United States)

    Slotznick, S. P.; Webb, S.; Kirschvink, J. L.; Fischer, W. W.

    2015-12-01

    Observations of iron chemistry and mineralogy over time provide a valuable tool for studying paleoenvironments, but questions still remain as to the redox character of Proterozoic basins after the rise of oxygen. To evaluate the mechanisms of iron mineralization in Proterozoic samples, we developed an approach that pairs the microscale textural techniques of light microscopy, magnetic scanning microscopy, and (synchrotron-based) microprobe x-ray spectroscopy with sensitive bulk rock magnetic experiments. Samples were collected from stratigraphic sections across the ~1.4 Ga lower Belt Group, Belt Supergroup, MT and ID, USA with a focus on excellently preserved sedimentary rocks, but also including those altered by a variety of diagenetic, metamorphic, and metasomatic events. Results show that even in the best-preserved parts of the Belt Basin, late diagenetic and/or metasomatic fluids affected (in some cases very mildly) the primary iron phases as evidenced by prevalent post-depositional alterations such as rare base metal sulfides. In more heavily altered rocks, the appearance of pyrrhotite and other minerals signaled transformations in iron mineralogy through metamorphism and metasomatism. Despite these secondary phases crystallizing in an open fluid-rich system, primary records of redox chemistry were preserved in the recrystallized early diagenetic framboidal pyrite and (sub)micron-sized detrital magnetite grains. Detrital magnetite is not the most abundant iron-bearing phase in any of the samples (typically <0.01 wt%), but is widely observed in both proximal and deeper basin facies, illustrating an important detrital flux of iron to the basin and a highly reactive iron source for early diagenetic pyrite. Based on our analyses, we interpret the shallow waters of the Belt Basin to be oxic with sulfidic pore fluids and deeper waters in parts of the basin as likely euxinic, consistent with the results of some bulk geochemical proxies. This redox reconstruction also

  9. Assymmetric eddy populations in adjacent basins – a high resolution numerical study of the Tyrrhenian and Ligurian Seas

    Directory of Open Access Journals (Sweden)

    E. Casella

    2012-11-01

    Full Text Available A high-resolution ocean circulation modelling system forced with a high-resolution numerical wind product was used to study the mesoscale and sub-mesoscale eddy population of the North-Western Mediterranean Sea, contrasting eddy-activity between the Tyrrhenian and Ligurian sub-basins. Numerical solutions reproduced some of the known regional dynamics, namely the occurrence and oceanic implications of Mistral events, the convective cell leeward of the Gulf of Lion, as well as the Balearic frontal system. Calculated transport across the Corsica Channel followed a similar trend, when compared to the transport computed from a moored current meter. The analysis of the results showed that surface eddy activity is mostly confined to the boundary-currents, whereas in the deeper layers most eddies are concentrated on the central-deeper part of the basins. The Liguro-Provençal basin shows a much higher concentration of intermediate and deep-water eddies, when compared to the Tyrrhenian basin. Sub-mesoscale surface eddies tend to merge and migrate vertically onto intermediate waters. Intense eddy activity in the boundary-current surrounding the Liguro-Provençal Gyre, concentrate high-productivity, manifested by higher concentrations of mean sea surface chlorophyll, in the central part of the gyre, defined herein as the Ligurian Productive Pool (LPP. On average, the Tyrrhenian was mostly oligotrophic except for a small productive vortice in the south-eastern (leeward side of Corsica. The transport in the Tyrrhenian Gyre, and across the basin is one order of magnitude higher than the transport calculated for the Liguro-Provençal basin. A high concentration of eddies in the passage between the Balearic Archipelago and Sardinia suggests retention and longer residence times of nutrient rich water in the "Ligurian pool", compared to a "fast draining" Tyrrhenian basin. Previous studies support the cyclonic gyre circulation generated in the Liguro

  10. Stable Carbon and Oxygen Isotopes of Pedogenic Carbonates in Ustic Vertisols: Implications for Paleoenvironmental Change

    Institute of Scientific and Technical Information of China (English)

    HUANG Cheng-Min; WANG Cheng-Shan; TANG Ya

    2005-01-01

    Pedogenic carbonates, found extensively in arid and semiarid regions, are important in revealing regional climatic and environmental changes as well as the carbon cycle. In addition, stable carbon and oxygen isotopic compositions of pedogenic carbonates have been used to rebuild paleoecology (biomass and vegetation) and to estimate paleotemperature and paleoprecipitation during past geological time. By utilizing the stable carbon and oxygen isotopic compositions (δ13C and δ18O) of secondary nodules in Ustic Vertisols, this study looked into the climatic and environmental changes in the dry valleys of the Yuanmou Basin, Yunnan Province, in southwestern China. The results showed that during the early Holocene, a warm-humid or hot-humid climate existed in the Yuanmou Basin, but since then fluctuations in climate have occurred, with a dry climate prevailing. A highly significant correlation (r = 0.92, n= 9) between δ13C and δ18O values of carbonates illustrated that there had been a continual shifting between cold-humid and warm-dry climates in southwestern China including the Yuanmou Basin since the early Holocene.

  11. California GAMA Program: Ground-Water Quality Data in the Northern San Joaquin Basin Study Unit, 2005

    Science.gov (United States)

    Bennett, George L.; Belitz, Kenneth; Milby Dawson, Barbara J.

    2006-01-01

    Growing concern over the closure of public-supply wells because of ground-water contamination has led the State Water Board to establish the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. With the aid of the U.S. Geological Survey (USGS) and Lawrence Livermore National Laboratory, the program goals are to enhance understanding and provide a current assessment of ground-water quality in areas where ground water is an important source of drinking water. The Northern San Joaquin Basin GAMA study unit covers an area of approximately 2,079 square miles (mi2) across four hydrologic study areas in the San Joaquin Valley. The four study areas are the California Department of Water Resources (CADWR) defined Tracy subbasin, the CADWR-defined Eastern San Joaquin subbasin, the CADWR-defined Cosumnes subbasin, and the sedimentologically distinct USGS-defined Uplands study area, which includes portions of both the Cosumnes and Eastern San Joaquin subbasins. Seventy ground-water samples were collected from 64 public-supply, irrigation, domestic, and monitoring wells within the Northern San Joaquin Basin GAMA study unit. Thirty-two of these samples were collected in the Eastern San Joaquin Basin study area, 17 in the Tracy Basin study area, 10 in the Cosumnes Basin study area, and 11 in the Uplands Basin study area. Of the 32 samples collected in the Eastern San Joaquin Basin, 6 were collected using a depth-dependent sampling pump. This pump allows for the collection of samples from discrete depths within the pumping well. Two wells were chosen for depth-dependent sampling and three samples were collected at varying depths within each well. Over 350 water-quality field parameters, chemical constituents, and microbial constituents were analyzed and are reported as concentrations and as detection frequencies, by compound classification as well as for individual constituents, for the Northern San Joaquin Basin study unit as a whole and for each individual study area

  12. A Case Study: Climate Change Decision Support for the Apalachicola, Chattahoochee, Flint Basins

    Science.gov (United States)

    Day, G. N.; McMahon, G.; Friesen, N.; Carney, S.

    2011-12-01

    Riverside Technology, inc. has developed a Climate Change Decision Support System (DSS) to provide water managers with a tool to explore a range of current Global Climate Model (GCM) projections to evaluate their potential impacts on streamflow and the reliability of future water supplies. The system was developed as part of a National Oceanic and Atmospheric Administration (NOAA) Small Business Innovation Research (SBIR) project. The DSS uses downscaled GCM data as input to small-scale watershed models to produce time series of projected undepleted streamflow for various emission scenarios and GCM simulations. Until recently, water managers relied on historical streamflow data for water resources planning. In many parts of the country, great effort has been put into estimating long-term historical undepleted streamflow accounting for regulation, diversions, and return flows to support planning and water rights administration. In some cases, longer flow records have been constructed using paleohydrologic data in an attempt to capture climate variability beyond what is evident during the observed historical record. Now, many water managers are recognizing that historical data may not be representative of an uncertain climate future, and they have begun to explore the use of climate projections in their water resources planning. The Climate Change DSS was developed to support water managers in planning by accounting for both climate variability and potential climate change. In order to use the information for impact analysis, the projected streamflow time series can be exported and substituted for the historical streamflow data traditionally applied in their system operations models for water supply planning. This paper presents a case study in which climate-adjusted flows are coupled with the U.S. Army Corps of Engineers (USACE) ResSim model for the Apalachicola, Chattahoochee, and Flint (ACF) River basins. The study demonstrates how climate scenarios can be used

  13. Solid waste disposal site selection with GIS and AHP methodology: a case study in Senirkent-Uluborlu (Isparta) Basin, Turkey.

    Science.gov (United States)

    Sener, Sehnaz; Sener, Erhan; Karagüzel, Remzi

    2011-02-01

    The appropriate site selection for waste disposal is one of the major problems in waste management. Also, many environmental, economical, and political considerations must be adhered to. In this study, landfill site selection is performed using the Geographic Information System (GIS), the Analytical Hierarchy Process (AHP), and the remote sensing methods for the Senirkent-Uluborlu Basin. The basin is located in the Eğirdir Lake catchment area, which is one of the most important fresh water in Turkey. So, waste management must be regulated in the basin. For this aim, ten different criteria (lithology, surface water, aquifer, groundwater depth, land use, lineaments, aspect, elevation, slope, and distance to roads) are examined in relation to landfill site selection. Each criterion was identified and weighted using AHP. Then, each criterion is mapped using the GIS technique, and a suitability map is prepared by overlay analyses. The results indicate that 96.3% of the area in the basin is unsuitable; 1.6%, moderately suitable; and 2.1%, most suitable. Finally, suitable regions in the basin are determined for solid waste landfill disposal and checked in the field. The selected and investigated regions are considered to be suitable for the landfill.

  14. Late Quaternary paleoenvironmental records from the Chatanika River valley near Fairbanks (Alaska)

    Science.gov (United States)

    Schirrmeister, Lutz; Meyer, Hanno; Andreev, Andrei; Wetterich, Sebastian; Kienast, Frank; Bobrov, Anatoly; Fuchs, Margret; Sierralta, Melanie; Herzschuh, Ulrike

    2016-09-01

    Perennially-frozen deposits are considered as excellent paleoenvironmental archives similar to lacustrine, deep marine, and glacier records because of the long-term and good preservation of fossil records under stable permafrost conditions. A permafrost tunnel in the Vault Creek Valley (Chatanika River Valley, near Fairbanks) exposes a sequence of frozen deposits and ground ice that provides a comprehensive set of proxies to reconstruct the late Quaternary environmental history of Interior Alaska. The multi-proxy approach includes different dating techniques (radiocarbon-accelerator mass spectrometry [AMS 14C], optically stimulated luminescence [OSL], thorium/uranium radioisotope disequilibria [230Th/U]), as well as methods of sedimentology, paleoecology, hydrochemistry, and stable isotope geochemistry of ground ice. The studied sequence consists of 36-m-thick late Quaternary deposits above schistose bedrock. Main portions of the sequence accumulated during the early and middle Wisconsin periods. The lowermost unit A consists of about 9-m-thick ice-bonded fluvial gravels with sand and peat lenses. A late Sangamon (MIS 5a) age of unit A is assumed. Spruce forest with birch, larch, and some shrubby alder dominated the vegetation. High presence of Sphagnum spores and Cyperaceae pollen points to mires in the Vault Creek Valley. The overlying unit B consists of 10-m-thick alternating fluvial gravels, loess-like silt, and sand layers, penetrated by small ice wedges. OSL dates support a stadial early Wisconsin (MIS 4) age of unit B. Pollen and plant macrofossil data point to spruce forests with some birch interspersed with wetlands around the site. The following unit C is composed of 15-m-thick ice-rich loess-like and organic-rich silt with fossil bones and large ice wedges. Unit C formed during the interstadial mid-Wisconsin (MIS 3) and stadial late Wisconsin (MIS 2) as indicated by radiocarbon ages. Post-depositional slope processes significantly deformed both, ground

  15. Comparative Study Of Alluvial Cnidion-Type Meadows In The Lower Danube River Basin

    Directory of Open Access Journals (Sweden)

    Schneider-Binder Erika

    2014-10-01

    Full Text Available Alluvial Cnidion-type meadows (Habitat type 6440 of the Habitats Directive, mostly characteristic for the lower courses of large rivers in continental climate conditions of Europe are presented from the Lower Danube upstream the municipality of Giurgiu (river-km 510-524. The ecological requirements of the characteristic species, as well as their sensitivity to human-induced changes that derive from regular flooding, drainage, intensification of use and/or abandonment, are highlighted; these changes frequently lead to a decrease of biodiversity of the Cnidion-type meadows or to their total loss The studied meadows are compared with similar alluvial meadows from other sites of the lower Danube River basin. Finally, the strong interlocking of Cnidion type meadows with those of the Agropyro-Rumicion, Molinion and Deschampsion caespitosae alliances are discussed.

  16. Study of Sub-basin Scale Groundwater Variations in Asia Using GRACE, Satellite Altimetry and in-situ Data

    Science.gov (United States)

    Yamamoto, K.; Fukuda, Y.; Taniguchi, M.

    2008-12-01

    A project to assess the effects of human activities on the subsurface environment in Asian developing cities is now in progress (Research Institute for Humanity and Nature., 2008). In the project, precise in situ gravity and landwater observations combined with GRACE (Gravity Recovery and Climate Experiment) satellite gravity data is proposed to evaluate local groundwater level changes of the developing urban areas in Asia. It is necessary for precise and accurate estimation of the local groundwater variations to separate local groundwater level changes from regional or global scale landwater variations. GRACE data is useful to estimate large scale landwater variations. Using GRACE Level 2 monthly gravity field solutions, we previously recovered landwater mass variation around Bangkok, in Thailand, which is one of the test areas of the project and located on the downstream of Chao Phraya river basin in the Indochina Peninsula. However, it is difficult to distinguish landwater signal of Chao Phraya river basin itself with the neighboring 3 large river basins because of the limitation of the spatial resolution of the GRACE monthly solutions. In this study, we recovered mass variation of Chao Phraya river basin using GRACE"fs along track range rate data instead of the monthly solutions. We used the method developed by Chen et al (2007), which uses GRACE"fs line-of-sight range acceleration measurements. We also tested the recoveries of landwater mass variations in other small scale river basins including Jakarta, Seoul and Taipei, which are also study areas of the project. Using the sub-basin scale landwater mass variation recovered by GRACE, we estimated groundwater level change in the project study areas by combing with in situ landwater and gravity observations. Satellite altimetry data is also used to separate groundwater variation from other landwater components as a constraint of river water storage variations.

  17. Models for Initial Allocation of Emission Permits in a River Basin During Industrial Development: A Case Study of Huaihe River Basin,China

    Institute of Scientific and Technical Information of China (English)

    Yu Shutong; Huang Xianjin; Cheng Xushui; Wan Yi; Ma Tianqi

    2010-01-01

    At present,water pollutant emission trading plays an increasingly important role in pollution control in many foreign countries,and its pilot studies and demonstration have also been started in China.In order to solve the problem of initial allocation of emission permits: premise and basis of emission trading in a river basin,basic principles on initial allocation of actual emission permits in China are put forward.And it is thought that local development stage of industry should be taken into full account for initial allocation model of emission permits.There are five different allocation models in different development stages of industry,including models like distribution according to needs,improved same-rate reduction,performance,integration and environmental capacity,etc.The initial allocation of emission permits in various basins should choose a suitable model in accordance with their respective development stages.It is suggested in this article that integrated allocation model should be a main choice for current development stage of industry in China.

  18. Feasibility study of heavy oil recovery in the Permian Basin (Texas and New Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.K.; Johnson, W.I.

    1993-05-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production. Each report covers select areas of the United States. The Permian Basin of West Texas and Southeastern New Mexico is made up of the Midland, Delaware, Val Verde, and Kerr Basins; the Northwestern, Eastern, and Southern shelves; the Central Basin Platform, and the Sheffield Channel. The present day Permian Basin was one sedimentary basin until uplift and subsidence occurred during Pennsylvanian and early Permian Age to create the configuration of the basins, shelves, and platform of today. The basin has been a major light oil producing area served by an extensive pipeline network connected to refineries designed to process light sweet and limited sour crude oil. Limited resources of heavy oil (10'' to 20'' API gravity) occurs in both carbonate and sandstone reservoirs of Permian and Cretaceous Age. The largest cumulative heavy oil production comes from fluvial sandstones of the Cretaceous Trinity Group. Permian heavy oil is principally paraffinic and thus commands a higher price than asphaltic California heavy oil. Heavy oil in deeper reservoirs has solution gas and low viscosity and thus can be produced by primary and by waterflooding. Because of the nature of the resource, the Permian Basin should not be considered a major heavy oil producing area.

  19. Feasibility study of heavy oil recovery in the Permian Basin (Texas and New Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.K.; Johnson, W.I.

    1993-05-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production. Each report covers select areas of the United States. The Permian Basin of West Texas and Southeastern New Mexico is made up of the Midland, Delaware, Val Verde, and Kerr Basins; the Northwestern, Eastern, and Southern shelves; the Central Basin Platform, and the Sheffield Channel. The present day Permian Basin was one sedimentary basin until uplift and subsidence occurred during Pennsylvanian and early Permian Age to create the configuration of the basins, shelves, and platform of today. The basin has been a major light oil producing area served by an extensive pipeline network connected to refineries designed to process light sweet and limited sour crude oil. Limited resources of heavy oil (10`` to 20`` API gravity) occurs in both carbonate and sandstone reservoirs of Permian and Cretaceous Age. The largest cumulative heavy oil production comes from fluvial sandstones of the Cretaceous Trinity Group. Permian heavy oil is principally paraffinic and thus commands a higher price than asphaltic California heavy oil. Heavy oil in deeper reservoirs has solution gas and low viscosity and thus can be produced by primary and by waterflooding. Because of the nature of the resource, the Permian Basin should not be considered a major heavy oil producing area.

  20. Assessment of bio-physical drought hazards. A case study of Karkheh River basin in Iran

    Science.gov (United States)

    Kamali, Bahareh; Abbaspour, Karim; Houshmand Kouchi, Delaram; Yang, Hong

    2016-04-01

    Iran has been affected by frequent droughts. Climate change is expected to intensify the situation in the future. Extreme drought events have had serious impacts on hydrological and agricultural sector. Thus, identification of bio-physical drought hazard is critically important for formulating effective adaptive measures to improve water and food security. This study aims to investigate temporal and spatial pattern of drought hazards in meteorological, hydrological, and agricultural (inclusively biophysical) sectors in the Karkheh River Basin of Iran in the historical and future climate change context. To do so, drought hazard indices were built based on the severity and frequency of standardized precipitation index (SPI), standardized runoff index (SRI), and standardized soil moisture index (SSMI), which represent the three aspects of drought hazards. Variables required for calculating these indices were obtained from SWAT (Soil and Water Assessment Tool) model constructed for the basin. The model was calibrated based on monthly runoff using the Sequential Uncertainty Fitting (SUFI-2) algorithm in SWAT-CUP. Based on the climate variability and drought analysis, three drought hazard classes, namely low, medium and high, were defined. This help identify how agricultural and hydrological sectors are related to meteorological droughts. Additionally, the bio-physical drivers of drought hazards were identified for each class. Comparing the results during historic and future scenarios revealed that the frequency of high- severity hazards will increase, whereas the same is not predicted for the area with medium hazard intensity. Inferred from findings of this study, the combined application of the SWAT model with bio-physical drought hazard concept helps better understanding of climate risks to water and food security. The developed approach is replicable at different scales to provide a robust planning tool for policy makers.

  1. Primary Study on Quantitative Reconstruction of Middle-Late Eocene Climate in Jianghan Basin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper reports our primary effort in the quantitative reconstruction of paleoclimate based on the thrine in phytoecology of the affinity parent plants in the stratigraphic pollen records. The Eocene pollen data come from our former study on the Mingjia borehole 1 in the Jianghan basin. The fluctuating trend in the parameter curve of climate shows that the climate in the Middle Eocene in the Jianghan basin was more or less comparable with that of the present 22°-26°N, characteristic of a humid, semi-humid central-southern subtropical climate. The annual temperature at that time dropped by 1 ℃-4 ℃ in the Late Eocene, approximately equal to that of the present 23°-28°N of northern-central subtropical climate. However, the climate composite at that time, characterized by higher temperature, small annual range and big fluctuation in precipitation, was quite different from the present one. The average temperature in January in the Middle Eocene, higher than that of today, ranged between 5 ℃ and 9 ℃, indicating that no effect of winter monsoon occurred in the Middle Eocene, though such an effect may have occurred occasionally in the Late Eocene. Major temperature decline is recognized at the depth of 2 100 m in the borehole, as was indicated by the decline in average January temperature, the increase in annual range, and the increase in the deciduous broad-leaved types of trees in the spore-pollen assemblage. The sharp fluctuation in the annual precipitation, usually raging from 300 to 1 700 mm, was favorable for the migration and accumulation of salty deposit. When the precipitation was lower than 1 000 mm, ephemera shrub increased at the same depth as that of the salty deposit. It is, therefore, deduced that the formation of the salty deposit was attributed mainly to the dry and hot environment in the high mountains and deep basins. The small annual precipitation and the intense fluctuation are favorable for the sustainable accumulation of the salts

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  3. Paleoenvironmental analysis.

    Science.gov (United States)

    Arobba, Daniele; Boscato, Paolo; Boschian, Giovanni; Falgueres, Christophe; Fasani, Leone; Peretto, Carlo; Sala, Benedetto; Hohenstein, Ursula Thun; Tozzi, Carlo

    2004-06-01

    New analysis has been carried out concerning the palaeoenvironmental reconstruction of some Italian sites dating from the Middle Pleistocene to the Bronze Age. Different aspects have been investigated on each site considering the data collected. The following sites have been analyzed: Isernia La Pineta (Molise); Visogliano and Caverna degli Orsi (Tieste); Toirano Caves (Liguria); Grotta Paglicci (Gargano); Riparo del Molare (Salerno); Grotta del Cavallo (Lecce); Castellaro Lagusello (Monzambano, Mantova).

  4. Origin and Distribution Of Glacial Lakes: A Case Study In Tista Basin, India

    Science.gov (United States)

    Kulkarni, A. V.

    2015-12-01

    Himalayan glaciers are experiencing retreat due to changes in the temperature and precipitation pattern. Retreating glaciers depending upon the underlying bed topography can cause lake formation near terminus. Therefore formation and draining of lakes in the glaciated terrain of Himalaya is commonly observed. However, few lakes became stable under suitable geomorphologic conditions and grow sufficiently large to threaten population and infrastructure in downstream. In this investigation changes in glacial lakes in Tista basin were studied using satellite images for a period between 1989 and 2010. The Tista basin in Sikkim covers approximately 7096 sq km area and the total glaciated area is 501± 29 sq km. During the period of investigation the lake area is increased from 6.6 ± 0.8 km2 to 9.6 ± 1.1 km2 due to formation of new lakes and also due to expansion of existing lake. Out of 23 lakes, 16 showed variable increase in area. We have also observed formation of stable proglacial lake due to coalescence of small supra glacial lakes on Changsang and South Lhonak Glacier. The size of lake near South Lhonak Glacier was increased from 18 to 126 ha from 1978 to 2014 (Figure). Therefore detail field investigations were carried out to understand volume and extent of ice in end moraine. The water volume was estimated as 53 million m3 using bathymetric survey and ice at the core of terminal moraines was mapped using resistivity survey. These investigations suggests a possibility of catastrophic outburst flood, if moraine dam breached under extreme weather conditions. Therefore, mitigation strategy is needed to improve safety of people living in the region. In addition, numerous remote sensing based investigations have mapped more than 300 lakes in the glaciated terrain in India, therefore, a national program to monitor glacier lakes and strategy to mitigate possible disaster is needed. Figure: Expansion of the lake near South Lhonak glacier from year 1990 to 2014.

  5. Paleoenvironmental and Paleoecological Reconstruction of the Ancient Maya Port Site of Vista Alegre, Quintana Roo, Mexico

    Science.gov (United States)

    Rissolo, D.; Jaijel, R.; Glover, J. B.; Goodman, B.; Beddows, P. A.; Carter, A.; Smith, D.

    2013-12-01

    Ancient Maya ports along the largely unstudied northeast coast of the Yucatan Peninsula once supported a network of trade routes linking people, goods, and ideas from across Mesoamerica. The Costa Escondida Project has focused on the interrelationships between the ancient Maya and their dynamic coastal environment along the shores of the Laguna Holbox. Central to our interdisciplinary efforts is a paleoenvironmental and paleoecological reconstruction of the key port of Vista Alegre - a low-lying island surrounded by a complex mosaic of costal ecosystems, sedimentological facies, and hydrological conditions. Geoarchaeological field methods, such as sediment coring, have made possible multiproxy analyses that enable us to better understand sea level fluctuations and the morphology of the shoreline and harboring locations over time, as well as changes in ecosystem biodiversity, which would have presented the maritime Maya with unique challenges and opportunities.

  6. Experimental and numerical study on the design of a deposition basin outlet structure at a mountain debris cone

    Directory of Open Access Journals (Sweden)

    B. Gems

    2013-07-01

    Full Text Available Mountain debris cones in the Alpine region often provide space for dense population and cultivation. Hence, a great number of buildings are exposed to torrential hazards. In order to protect the settlement areas against flooding and overbank sedimentation, torrent defence structures are implemented directly at the debris cones. In many cases, these protection measures include a deposition basin at the head of the debris cone and/or a confined channel that passes or tracks through the settlement. The work presented within this paper deals with the effect of specific outlet structure layouts, situated at the lower end of a selected deposition basin, on bed-load transport processes and flood protection. A case study analysis was accomplished comprising of a 3-D-numerical model (FLOW-3D and a physical scale model test (1:30. The subject of investigation was the deposition basin of the Larsennbach torrent in the Austrian Northern Limestone Alps. The basin is situated on a large debris cone and opens out into a paved channel. Since the basin is undersized and the accumulation of sediment in the outlet section reduces the available cross section during floods, adjoining settlements are considerably endangered of lateral overtopping of both clear water and sediment. Aiming for an upgrade in flood protection, certain layouts for a "closing-off structure" at the outlet were tested within this project. For the most efficient design layout, its effect on flood protection, a continuous bed-load output from the basin and the best possible use of the retention volume are pointed out. The simple design of the structure and the key aspects, that have to be taken into consideration for implementation, are highlighted.

  7. The evidence of fission-track data for the study of tectonic thermal history in Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    REN Zhanli; XIAO Hui; LIU Li; ZHANG Sheng; QIN Yong; WEI Chongtao

    2005-01-01

    The thermal history of the Qinshui Basin has been studied by using the fission-track analysis of apatite and zircon, integrated analysis of tectonic evolution, magmatic activity and other palaeogeothermal analysis data. Results indicate that the palaeogeothermal gradient between the latePaleozoic era and the medium-Mesozoic era is relatively low and the palaeogeothermal gradient in the late-Mesozoic is up to 5.56℃/100 m in the middle, and the values are relatively higher in the north and south margins of the basin, reaching over 8.00℃/100 m, which indicates that there was an anomalous tectonic thermal event in the thermal history of Qinshui Basin. This event happened in 110- 140 Ma, and the main peak value was between 120 and 140 Ma. This anomalous tectonic thermal event is controlled by the strengthening thermal mobility of the lithosphere and magmatic intrusion.The maturity of the Permo-Carboniferous coal series mainly was controlled by this anomalous thermal field. The apatite fission track date of samples across the basin shows that a rapid tectonic uplifting with cooling existed 26.2-11.5 Ma ago and the upliftings in the north and south of the basin happened earlier than that in the middle. The Permo-Carboniferous strata had been completely annealed in the early 50 Ma, palaeotemperature over 125℃. Since then, especially from Oligocene-Miocene epoch, the strata which experienced large-scale tectonic upliftings with rapid cooling have been kept out of the annealing belt (70-125℃) in a relative low temperature environment. The late Mesozoic tectonic thermal event control hydrocarbon production peak (late Jurassic to early Cretaceous period) of Permo-Carboniferous strata in Qinshui Basin. When the strata experienced upliftings with rapid cooling since Oligocene-Miocene epoch, the hydrocarbon generation of coal series had stopped.

  8. Paleoenvironmental reconstruction of deep-water carbonate mound initiation in the Porcupine Seabight, NE Atlantic

    Science.gov (United States)

    Raddatz, J.; Rüggeberg, A.; Liebetrau, V.; Margreth, S.; Eisenhauer, A.; Dullo, C.

    2009-12-01

    The understanding of the paleoenvironment during initiation and early development of deep-water carbonate mounds in the NE Atlantic is still under debate. The Integrated Ocean Drilling Program Expedition 307 sailed in 2005 to the Porcupine Seabight in order to investigate for the first time sediments from the base of a giant carbonate mound (155 m, Challenger Mound). First results indicate initiation and start-up phase of this carbonate mound coincides with the beginning of the Northern Hemisphere Glaciation (NHG) at around 2.7 Ma. Further carbonate mound development seems to be strongly dependent on rapid changes in paleoceanographic and climatic conditions at the Pliocene-Pleistocene boundary, especially characterized and caused by intermediate water masses. To investigate this specific time interval of ~2.7 Ma we use well-developed proxies such as δ18O and δ13C of planktonic (Globigerina bulloides) and a collection of benthic foraminifera (Fontbotia wuellerstorfi, Discanomalina coronata, Lobatula lobatula, Lobatula antartica, and Planulina ariminensis) as well as grain size analysis. Additionally we provide δ88/86Sr paleotemperatures from cold water coral Lophelia pertusa. This multi proxy approach made it possible to determine the paleoenvironmental and paleoecological setting favourable for the initial coral colonization. Stable oxygen and carbon isotope records of the benthic foraminiferal assemblages indicate that Lobatula lobatula provides a reliable isotopic signature for paleoenvironmental reconstructions and that enhanced bottom currents of intermediate water masses of southern origin (Mediterranean, Bay of Biscay) intensified at the start-up of the NHG. During initiation and early mound development, temperatures of these intermediate waters decreased to favourable 9 °C and reconstructed current strength and nutrient concentrations (phosphate and nitrate) stayed in the range of reported tolerance supporting the rapid growth of cold-water corals and

  9. Dealing with uncertainties in impact studies of climate change on hydrometeorological series over Segura River Basin (Spain)

    Science.gov (United States)

    Garcia Galiano, S. G.; Garcia Cardenas, R.; Tetay Botia, C.; Giraldo Osorio, J.; Erena Arrabal, M.; Baille, A.

    2011-12-01

    The Segura River Basin (SRB) located in the South East of Spain, is affected by recurrent drought and water scarcity episodes. This basin presents the lowest percentage of renewable water resources of all the Spanish basins. Intensive reforestation has been carried out in the region, to halt desertification and erosion, which added to climate change and variability, do not allow the default assumption of stationarity in the water resources systems. Therefore, the study of effects in hydrometeorological series should be addressed by nonstationary probabilistic models that allow describing the time evolution of their probability distribution functions (PDFs). In the present work, the GAMLSS (Generalized Additive Models for Location, Scale and Shaper) approach is applied to identify of spatio-temporal trends in observed precipitation (P) and potential evapotranspiration (PET), at basin scale. Several previous studies have addressed the potential impacts of climate change in water supply systems, focusing on the sensitivity analysis of runoff to climate. Considering the use of a conceptual hydrological model with few parameters, the impacts on runoff and its trend from historical data, are assessed. The conclusions of this study represent a breakthrough in the development of methodologies to understand and anticipate the impacts on water resources systems, in the light of current and future climate conditions, considering hydroclimatic non-stationarity. These findings are expected to contribute to the management of conditions of water resources scarcity and droughts, such as the observed in the SRB, as support to decision-making process by stakeholders.

  10. The hydrodynamics of the Big Horn Basin: a study of the role of faults

    Science.gov (United States)

    Bredehoeft, J.D.; Belitz, K.; Sharp-Hansen, S.

    1992-01-01

    A three-dimensional mathematical model simulates groundwater flow in the Big Horn basin, Wyoming. The hydraulic head at depth over much of the Big Horn basin is near the land surface elevation, a condition usually defined as hydrostatic. This condition indicates a high, regional-scale, vertical conductivity for the sediments in the basin. Our hypothesis to explain the high conductivity is that the faults act as vertical conduits for fluid flow. These same faults can act as either horizontal barriers to flow or nonbarriers, depending upon whether the fault zones are more permeable or less permeable than the adjoining aquifers. -from Authors

  11. Flash flood hazard mapping: a pilot case study in Xiapu River Basin, China

    Directory of Open Access Journals (Sweden)

    Da-wei Zhang

    2015-07-01

    Full Text Available Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of the Xinanjiang model, which is widely used in humid and semi-humid regions in China. The developed model employs the geomorphological unit hydrograph method, which is extremely valuable when simulating the overland flow process in ungauged catchments, as compared with the original Xinanjiang model. The model was tested in the pilot study area, and the results agree with the measured data on the whole. After calibration and validation, the model is shown to be a useful tool for flash flood calculation. A practicable method for flash flood hazard mapping using the calculated peak discharge and digital elevation model data was presented, and three levels of flood hazards were classified. The resulting flash flood hazard maps indicate that the method successfully predicts the spatial distribution of flash flood hazards, and it can meet the current requirements in China.

  12. Comparative assessment of predictions in ungauged basins – Part 2: Flood and low flow studies

    Directory of Open Access Journals (Sweden)

    J. L. Salinas

    2013-07-01

    Full Text Available The objective of this paper is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 14 low flow prediction studies reported in the literature involving 3112 catchments, and 20 flood prediction studies involving 3023 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the regionalisation method. The results indicate that both flood and low flow predictions in ungauged catchments tend to be less accurate in arid than in humid climates and more accurate in large than in small catchments. There is also a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region, while geostatistical methods tend to perform better than other methods. Of the various flood regionalisation approaches, index methods show significantly lower performance in arid catchments than regression methods or geostatistical methods. For low flow regionalisation, regional regressions are generally better than global regressions.

  13. Paleo-environmental evolution based on high-resolution phytolith since 26 ka B. P. in Huanghe River Delta

    Institute of Scientific and Technical Information of China (English)

    LI Ping; DU Jun; DU Na; GAO Wei

    2016-01-01

    The Huanghe River Delta is one of the world's large rivers, the Huanghe River Delta paleoenvironmental evolution in the Huanghe River has been a hot issue since the Last Glacial. Based on the core time series established by combining AMS14C dating of Core DYZK1 sediments in submerged of Huanghe River Delta and acoustic sequence on sub-bottom profile, phytolith analyses are carried out on 96 sediment samples. The grain size parameters, magnetic susceptibility are combined with the vertical changes of biostratum to reconstruct the paleo-sedimentary and climatic conditions in the Huanghe River Delta. The study results show that there is a significant vertical change law in the index parameters, and that sedimentary environment of Huanghe River Delta experienced an evolutionary process of fluvial facies-sealand transition facies-tidal flat facies-neritic facies-delta facies since 26.0 ka B. P.. The phytolith analyses results are as following. Firstly, The phytoliths are divided into lanceolate, smooth-elongated, spiny-elongated, rondel, long rectangular, bulliform and other types. In different sedimental environment, the phytolith content changes regularly, indicating that the phytolith assembles in the same sedimentary environment has a certain degree of stability. Secondly, The lanceolate, smooth-elongated and spiny-elongated categories of phytoliths have greater contents in the tidal flat facies and delta deposition, while have a smaller contents in the neritic facies and fluvial facies environment. Thirdly, Through comparative analysis of variation coefficient, the content of major phytolith categories in the sediment has a greater change amplitude in the sealand transition facies and fluvial facies deposition, while being more stable in the tidalflat facies and delta facies deposition.

  14. Mineralogy and geochemistry of the main glauconite bed in the Middle Eocene of Texas: paleoenvironmental implications for the verdine facies.

    Directory of Open Access Journals (Sweden)

    Sherie C Harding

    Full Text Available The Main Glauconite Bed (MGB is a pelleted greensand located at Stone City Bluff on the south bank of the Brazos River in Burleson County, Texas. It was deposited during the Middle Eocene regional transgression on the Texas Gulf Coastal Plain. Stratigraphically it lies in the upper Stone City Member, Crockett Formation, Claiborne Group. Its mineralogy and geochemistry were examined in detail, and verdine facies minerals, predominantly odinite, were identified. Few glauconitic minerals were found in the green pelleted sediments of the MGB. Without detailed mineralogical work, glaucony facies minerals and verdine facies minerals are easily mistaken for one another. Their distinction has value in assessing paleoenvironments. In this study, several analytical techniques were employed to assess the mineralogy. X-ray diffraction of oriented and un-oriented clay samples indicated a clay mixture dominated by 7 and 14Å diffraction peaks. Unit cell calculations from XRD data for MGB pellets match the odinite-1M data base. Electron microprobe analyses (EMPA from the average of 31 data points from clay pellets accompanied with Mössbauer analyses were used to calculate the structural formula which is that of odinite: Fe(3+ 0.89 Mg0.45 Al0.67 Fe(2+ 0.30 Ti0.01 Mn0.01 Σ = 2.33 (Si1.77 Al0.23 O5.00 (OH4.00. QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy data provided mineral maps of quantitative proportions of the constituent clays. The verdine facies is a clay mineral facies associated with shallow marine shelf and lagoonal environments at tropical latitudes with iron influx from nearby runoff. Its depositional environment is well documented in modern nearshore locations. Recognition of verdine facies clays as the dominant constituent of the MGB clay pellets, rather than glaucony facies clays, allows for a more precise assessment of paleoenvironmental conditions.

  15. Mineralogy and geochemistry of the main glauconite bed in the Middle Eocene of Texas: paleoenvironmental implications for the verdine facies.

    Science.gov (United States)

    Harding, Sherie C; Nash, Barbara P; Petersen, Erich U; Ekdale, A A; Bradbury, Christopher D; Dyar, M Darby

    2014-01-01

    The Main Glauconite Bed (MGB) is a pelleted greensand located at Stone City Bluff on the south bank of the Brazos River in Burleson County, Texas. It was deposited during the Middle Eocene regional transgression on the Texas Gulf Coastal Plain. Stratigraphically it lies in the upper Stone City Member, Crockett Formation, Claiborne Group. Its mineralogy and geochemistry were examined in detail, and verdine facies minerals, predominantly odinite, were identified. Few glauconitic minerals were found in the green pelleted sediments of the MGB. Without detailed mineralogical work, glaucony facies minerals and verdine facies minerals are easily mistaken for one another. Their distinction has value in assessing paleoenvironments. In this study, several analytical techniques were employed to assess the mineralogy. X-ray diffraction of oriented and un-oriented clay samples indicated a clay mixture dominated by 7 and 14Å diffraction peaks. Unit cell calculations from XRD data for MGB pellets match the odinite-1M data base. Electron microprobe analyses (EMPA) from the average of 31 data points from clay pellets accompanied with Mössbauer analyses were used to calculate the structural formula which is that of odinite: Fe(3+) 0.89 Mg0.45 Al0.67 Fe(2+) 0.30 Ti0.01 Mn0.01) Σ = 2.33 (Si1.77 Al0.23) O5.00 (OH)4.00. QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) data provided mineral maps of quantitative proportions of the constituent clays. The verdine facies is a clay mineral facies associated with shallow marine shelf and lagoonal environments at tropical latitudes with iron influx from nearby runoff. Its depositional environment is well documented in modern nearshore locations. Recognition of verdine facies clays as the dominant constituent of the MGB clay pellets, rather than glaucony facies clays, allows for a more precise assessment of paleoenvironmental conditions.

  16. GIS based quantitative morphometric analysis and its consequences: a case study from Shanur River Basin, Maharashtra India

    Science.gov (United States)

    Pande, Chaitanya B.; Moharir, Kanak

    2015-06-01

    A morphometric analysis of Shanur basin has been carried out using geoprocessing techniques in GIS. These techniques are found relevant for the extraction of river basin and its drainage networks. The extracted drainage network was classified according to Strahler's system of classification and it reveals that the terrain exhibits dendritic to sub-dendritic drainage pattern. Hence, from the study, it is concluded that remote sensing data (SRTM-DEM data of 30 m resolution) coupled with geoprocessing techniques prove to be a competent tool used in morphometric analysis and evaluation of linear, slope, areal and relief aspects of morphometric parameters. The combined outcomes have established the topographical and even recent developmental situations in basin. It will also change the setup of the region. It therefore needs to analyze high level parameters of drainage and environment for suitable planning and management of water resource developmental plan and land resource development plan. The Shanur drainage basin is sprawled over an area of 281.33 km2. The slope of the basin varies from 1 to 10 %, and the slope variation is chiefly controlled by the local geology and erosion cycles. The main stream length ratio of the basin is 14.92 indicating that the study area is elongated with moderate relief and steep slopes. The morphometric parameters of the stream have been analyzed and calculated by applying standard methods and techniques viz. Horton (Trans Am Geophys Union 13:350-361, 1945), Miller (A quantitative geomorphologic study of drainage basin characteristics in the clinch mountain area, Virginia and Tennessee Columbia University, Department of Geology, Technical Report, No. 3, Contract N6 ONR 271-300, 1953), and Strahler (Handbook of applied hydrology, McGraw Hill Book Company, New York, 1964). GIS based on analysis of all morphometric parameters and the erosional development of the area by the streams has been progressed well beyond maturity and lithology is

  17. Potential ground water resources of Hat Yai Basin in Peninsular Thailand by gravity study

    Directory of Open Access Journals (Sweden)

    Warawutti Lohawijarn

    2005-05-01

    Full Text Available Residual gravity anomaly with a minimum of about -140 mm s-2 with approximately NS trend and a limited axial length was observed over Hat Yai Basin in Peninsular Thailand. The modeled Hat Yai basin is about 1 km deep at its deepest, 60 km long and 20 km wide. The porosity of basin sediment and the amount of potential ground water reserves within the basin are estimated to be 39% and 121.7±0.8 km3 respectively, assuming full saturation. Within the topmost 80 m of ground where the present extraction is concentrated, the estimated ground water reserve is 12.5±0.5 km3.

  18. Comparative study of vent and seep macrofaunal communities in the Guaymas Basin

    Directory of Open Access Journals (Sweden)

    M. Portail

    2015-06-01

    Full Text Available Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico, the presence of seeps and vents in the absence of biogeographic barrier, comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep and vent common abiotic factors including methane and hydrogen sulphide concentrations. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. Surprisingly, the presence of vent environmental specificities, with higher temperature, higher metal concentrations and lower pH was not significant in explaining community patterns. Moreover, Guaymas seep and vent shared an important number of common species suggesting frequent connections between the two ecosystems. Finally, this study provides further support for the hypothesis of continuity among deep-sea seep and vent ecosystems.

  19. Geothermal energy from the Main Karoo Basin (South Africa): An outcrop analogue study of Permian sandstone reservoir formations

    Science.gov (United States)

    Campbell, Stuart A.; Lenhardt, Nils; Dippenaar, Matthys A.; Götz, Annette E.

    2016-04-01

    The geothermal potential of the South African Main Karoo Basin has not been addressed in the past, although thick siliciclastic successions in geothermal prone depths are promising target reservoir formations. A first assessment of the geothermal potential of the Karoo Basin is based on petro- and thermophysical data gained from an outcrop analogue study of Permian sandstones in the Eastern Cape Province, and evaluation of groundwater temperature and heat flow values from literature. A volumetric approach of the sandstones' reservoir potential leads to a first estimation of 2240 TWh (8.0 EJ) of power generation within the central and southern part of the basin. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Karoo for future geothermal resource exploration, development and production. The mainly low permeability lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas auto-convective thermal water circulation might be expected and direct heat use becomes reasonable. The data presented here serve to identify exploration areas and are valuable attributes for reservoir modeling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization.

  20. A nonparametric multivariate standardized drought index for characterizing socioeconomic drought: A case study in the Heihe River Basin

    Science.gov (United States)

    Huang, Shengzhi; Huang, Qiang; Leng, Guoyong; Liu, Saiyan

    2016-11-01

    Among various drought types, socioeconomic drought is the least investigated type of droughts. Most existing drought indicators ignore the role of local reservoirs and water demand in coping with climatic extremes. In this study, a Multivariate Standardized Reliability and Resilience Index (MSRRI) combining inflow-demand reliability index (IDR) and water storage resilience index (WSR) was applied to examine the evolution characteristics of the socioeconomic droughts in the Heihe River Basin, the second largest inland river basin in northwestern China. Furthermore, the cross wavelet analysis was adopted to explore the associations between annual MSRRI series and El Niño Southern Oscillation (ENSO)/Atlantic Oscillation (AO). Results indicated that: (1) the developed MSRRI is more sensitive to the onset and termination of socioeconomic droughts than IDR and WSR, owing to its joint distribution function of IDR and WSR, responding to changes in either or both of the indices; (2) the MSRRI series in the Heihe River Basin shows non-significant trends at both monthly and annual scales; (3) both ENSO and AO contribute to the changes in the socioeconomic droughts in the Heihe River Basin, and the impacts of ENSO on the socioeconomic droughts are stronger than those of AO.

  1. Chemometric Study of Trace Elements in Hard Coals of the Upper Silesian Coal Basin, Poland

    Directory of Open Access Journals (Sweden)

    Adam Smoliński

    2014-01-01

    Full Text Available The objective of the study was the analysis of trace elements contents in coals of the Upper Silesian Coal Basin (USCB, which may pose a potential threat to the environment when emitted from coal processing systems. Productive carbon overburden in central and southern zones of the USCB is composed mostly of insulating tertiary formations of a thickness from a few m to 1,100 m, and is represented by Miocene and Pliocene formations. In the data study the geological conditions of the coal seams of particular zones of the USCB were taken into account and the hierarchical clustering analysis was applied, which enabled the exploration of the dissimilarities between coal samples of various zones of the USCB in terms of basic physical and chemical parameters and trace elements contents. Coals of the northern and eastern zones of the USCB are characterized by high average Hg and low average Ba, Cr, and Ni contents, whereas coals of southern and western zones are unique due to high average concentrations of Ba, Co, Cu, Ni, and V. Coals of the central part of the USCB are characterized by the highest average concentration of Mn and the lowest average concentrations of As, Cd, Pb, V, and Zn.

  2. Modeling of meteorology, tracer transport and chemistry for the Uintah Basin Winter Ozone Studies 2012 and 2013

    Science.gov (United States)

    Ahmadov, R.; McKeen, S. A.; Angevine, W. M.; Frost, G. J.; Roberts, J. M.; De Gouw, J. A.; Warneke, C.; Peischl, J.; Brown, S. S.; Edwards, P. M.; Wild, R. J.; Pichugina, Y. L.; Banta, R. M.; Brewer, A.; Senff, C. J.; Langford, A. O.; Petron, G.; Karion, A.; Sweeney, C.; Schnell, R. C.; Johnson, B.; Zamora, R. J.; Helmig, D.; Park, J.; Evans, J.; Stephens, C. R.; Olson, J. B.; Trainer, M.

    2013-12-01

    The Uintah Basin Winter Ozone Studies (UBWOS) field campaigns took place during winter of 2012 and 2013 in the Uintah Basin, Utah. The studies were aimed at characterizing meteorology, emissions of atmospheric constituents and air chemistry in a region abundant with oil and gas production, with associated emissions of various volatile organic compounds (VOCs) and NOx. High ozone pollution events were observed throughout the Uintah Basin during the winter of 2013, but not during the winter of 2012. A clear understanding of the processes leading to high ozone events is still lacking. We present here high spatiotemporal resolution simulations of meteorology, tracer transport and gas chemistry over the basin during January-February, 2012 and 2013 using the WRF/Chem regional photochemical model. Correctly characterizing the meteorology poses unique challenges due to complex terrain, cold-pool conditions, and shallow inversion layers observed during the winter of 2013. We discuss the approach taken to adequately simulate the meteorology over the basin and present evaluations of the modeled meteorology using surface, lidar and tethersonde measurements. Initial simulations use a passive tracer within the model as a surrogate for CH4 released from oil and gas wells. These tracer transport simulations show that concentrations of inert, emitted species near the surface in 2013 were 4-8 times higher than 2012 due to much shallower boundary layers and reduced winds in 2013. This is supported by in-situ measurements of CH4 made at the Horse Pool surface station during the field campaigns. Full photochemical simulations are forced by VOC and NOx emissions that are determined in a top-down approach, using observed emission ratios of VOC and NOx relative to CH4, along with available information of active wells, compressors, and processing plants. We focus on differences in meteorology, temperature, and radiation between the two winters in determining ozone concentrations in the

  3. Rapid Climatic Change at the End of the Last Glacial as Determined from Palynological Analysis of Sediments from the Cariaco Basin, Venezuela

    Science.gov (United States)

    Delusina, I.; Peterson, L. C.; Spero, H.

    2005-05-01

    We report the first palynological study of a deep marine sediment core from the anoxic Cariaco Basin, off the coast of Venezuela. The Cariaco Basin acts as a natural sediment trap for rapidly accumulating sediments of marine and terrestrial origin. This situation creates favorable conditions for studying short-term paleoenvironmental change. Our pollen analyses indicate unique pollen assemblages which mirror the complex altitudinal zonation of coastal vegetation and its dynamics. The pollen analyses encompass the interval from 3 to 9 m in core MD03-2620, spanning the Glacial/Holocene transition and including the Younger Dryas and the beginning of the Preboreal. Our data indicate large changes during the time of Heinrich event 1 (ca 16-14 Kyr BP) with high arboreal/nonarboreal pollen ratios (2/8) and a dominance of wormwood changing to a cereals/sedge community. Another characteristic of this interval is the lowest pollen concentration, indicating the coldest and driest observed conditions. The disappearance of mangrove pollen at the time of the coldest episodes provides additional indirect evidence for the deterioration of climate conditions and for a drop in sea level. Maximum forest vegetation is found from the middle of the Bolling/Allerod and the middle of the Younger Dryas. This is followed by a similar, though less intense, interval of cooling between the Younger Dryas and the Preboreal. Variations in both the diversity of species and the pollen concentration correlate well with changes in sediment color and with the marine oxygen isotope record.

  4. Aerosol Composition in the Los Angeles Basin Studied by High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Hayes, P. L.; Ortega, A. M.; Cubison, M.; Hu, W.; Toohey, D. W.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; Alvarez, S. L.; Rappenglueck, B.; Allan, J. D.; Taylor, J.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; De Gouw, J. A.; Massoli, P.; Zhang, X.; Weber, R.; Zhao, Y.; Cliff, S. S.; Wexler, A. S.; Isaacman, G. A.; Worton, D. R.; Kreisberg, N. M.; Hering, S. V.; Goldstein, A. H.; Jimenez, J. L.

    2011-12-01

    transported from the western basin over 3-4 hours. Also, the Pasadena slope is consistent with recent studies of SOA aging via fragmentation reactions leading to carboxylic acids and/or concurrent functionalization with carboxylic acids and alcohols.

  5. Early Callovian ingression in southwestern Gondwana. Palaeoenvironmental evolution of the carbonate ramp (Calabozo Formation) in southwestern Mendoza, Neuquen basin, Argentina

    Science.gov (United States)

    Armella, Claudia; Cabaleri, Nora G.; Cagnoni, Mariana C.; Panarello, Héctor O.

    2013-08-01

    The carbonatic sequence of the Calabozo Formation (Lower Callovian) developed in southwestern Gondwana, within the northern area of the Neuquén basin, and is widespread in thin isolated outcrops in southwestern Mendoza province, Argentina. This paper describes the facies, microfacies and geochemical-isotopic analysis carried out in five studied localities, which allowed to define the paleoenvironmental conditions of a homoclinal shallow ramp model, highly influenced by sea level fluctuations, where outer, mid and inner ramp subenvironments were identified. The outer ramp subenvironment was only recognized in the south of the depocenter and is characterized by proximal outer ramp facies with shale levels and interbedded mudstone and packstone layers. The mid ramp subenvironment is formed by low energy facies (wackestone) affected by storms (packstones, grainstones and floatstones). The inner ramp subenvironment is the most predominant and is characterized by tidal flat facies (wackestones, packstones and grainstones) over which a complex of shoals (grainstones and packstones) dissected by tidal channels (packstone, grainstones and floatstones) developed. In the north area, protected environment facies were recorded (bioturbated wackestones and packstones). The vertical distribution of facies indicates that the paleoenvironmental evolution of the Calabozo Formation results from a highstand stage in the depocenter, culminating in a supratidal environment, with stromatolitic levels interbedded with anhydrite originated under restricted water circulation conditions due to a progressive isolation of the basin. δ13C and δ18O values of the carbonates of the Calabozo Formation suggest an isotopic signature influenced by local palaeoenvironmental parameters and diagenetic overprints. The δ13C and δ18O oscillations between the carbonates of the different studied sections are related with lateral facies variations within the carbonate ramp accompanied with dissimilar

  6. Magnetostratigraphy and pa-vleo-environmental record of Tertiary deposits of Lanzhou Basin

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Tertiary deposits of the Yongdeng section, the Lanzhou Basin were studied by means of magnetostratigraphy. The magnetostratigraphic sequences from Paleocene to Miocene were established, and the time scale for the corresponding stratigraphy and mammalian faunas was also established by referring to their correlation to the GPTS of BKSA95 (The geomagnetic polarity time scale which was thoroughly revised and updated by Berggreen et al. in 1995). In the end the paleo-environmental records and their relationship with the uplifting of the Tibetan Plateau were discussed. The results are as follows. The top boundary of the Xiliugou Formation is dated to be 51 Ma, i.e. Eocene. The Yehucheng Formation covers the time span of 51-31.5 Ma, i.e. from late Early Eocene to early Early Oligocene. The Xianshuihe Formation covers the time span of 31.5-15 Ma, i.e. from Early Oligocene to Middle Miocene. The lower member of the Xianshuihe Formation spans from 31.5 to 20.0 Ma, i.e. from Early Oligocene to early Early Miocene. The middle member is from 20.0 to 16.5 Ma, i.e. in the middle Early Miocene.

  7. The refinement of geomorphical and geochemical statistical techniques in the study of clay-basin tectonics: the Era basin (central Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, S. [Rome, Univ. `La Sapienza` (Italy). Dept. of Earth Sciences; Serafini, S.; Zarlenga, F. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dept. of Environment; Ciotoli, G.

    1997-12-31

    A comparative approach to neotectonic studies is presented, which encompasses the integration of geochemical, morphological and structural analyses. Nine-hundred-nineteen soil gas samples were collected in the Era basin (Tuscany, Central Italy) and their helium contents were measured. Helium distribution has been compared with location and orientation of known brittle deformations (faults and fractures) and morphological features obtained by air-photo interpretation and drainage network analyses. Obtained data were statistically compared by means of rose diagram plots concerning the investigated parameters and locally studied by associating the observed helium anomaly ridges with the known morphological and structural elements. The statistical approach showed a good convergence between the applied methodologies. Data from geo morphological , meso structural, and geochemical surveys are consistent with the NE-SW and NW-SE orientations, i.e. Apennine and anti-Apennine trend of the known structural pattern. Moreover the apparent N-S and E-W trending helium anomalies are thought to be due to the Middle Pleistocene deformation phase along these directions. The relationship between helium distribution and the strain field is strengthen by the good correspondence, at local scale, among geochemical data and results of the structural and geo morphological features (Orciatico-Montecatini val di Cecina and Peccioli areas). However helium soil gas technique showed to be a sensible tool for neotectonic studies in clay basin, as soil gas defines the leakage of deep seated gas along tectonic discontinuities even if they have no surface evidence and where the clay deposit is hundreds of meters thick. [Italiano] In questo lavoro viene presentata una nuova metodologia di infagine volta agli studi di neotettonica nei bacini argillosi e basata sull`integrazione di dati geochimici, morfologici e strutturali. I dati geochimici si riferiscono alle analisi delle concentrazioni di elio in

  8. Neogene-quaternary Ostracoda and paleoenvironments, of the Limón basin, Costa Rica, and Bocas del Toro basin, Panama

    Science.gov (United States)

    Borne, P.F.; Cronin, T. M.; Hazel, J.E.

    1999-01-01

    Tropical marine ostracodes from Neogene and Quaternary sediments of the Central American Caribbean region have been the subject of biostratigraphic, ecological, taxonomic, and evolutionary studies. As part of the Panama Paleontology Project (PPP), Neogene and Quaternary ostracodes are being studied from the Central American region. The overall goal of this research is to evaluate the impact of the emergence of the Central American Isthmus as a land barrier between the Caribbean/tropical Atlantic and the Pacific oceans on marine ostracode biodiversity and the oceanic environments in which extant ostracodes evolved. Due to the ecological specificity of many living tropical ostracode species, they are ideally suited for reconstructing paleoenvironments on the basis of their occurrence in fossil assemblages, which in turn can lead to a better understanding of the tropical climatic and tectonic history of Central America. The principal aims of this chapter are: (a) to document the composition of the ostracode assemblages from the Limón Basin of Costa Rica and the Bocas del Toro Basin of Panama, two areas yielding extensive ma rine ostracode assemblages; (b) to describe the environments of deposition within these basins; and (c) to document the stratigraphic distribution of potentially agediagnostic ostracode species in the Limón and Bocas del Toro basins in order to enhance their use in Central American biostratigraphy. A secondary, but none-the-less important goal is to assemble a database on the distribution of modem ostracode species in the Caribbean and adjacent areas as a basis for comparison with fossil assemblages. Although the ecological, biostratigraphic and paleoenvironmental conclusions presented here will improve as additional material is studied, these fossil and modem ostracode databases constitute the foundation for future evolutionary and geochernical studies of tropical Caribbean and eastern Pacific Ocean ostracodes. Moreover, we present here evidence

  9. Towards an integrated analysis of rural systems: the case study of the Alento basin

    Science.gov (United States)

    Quaranta, Giovanni; Salvia, Rosanna

    2014-05-01

    The role and the functions of rural areas are undergoing considerable change due to economic, social and environmental drivers. The outcome of the transformation is the production of highly heterogeneous landscapes, rural mosaics, which are home to varying degrees of intensity of land-use and processes of deactivation, abandonment and land degradation. The identification of rural mosaics has implications both for determining the impacts on the stock of connected natural resources and for defining measures and policies able to support the resilience of rural territories and the identification of sustainable strategies for development. The study proposes a methodology for the integrated analysis of the rural territory which combines the analysis of land cover dynamics, using GIS, with an assessment of socio-economic dynamics, reconstructed through the combined use of indicators and local history, and which is aware that the differences and peculiarities within rural territories are the result of actions taken over time and of the different adaptive strategies undertaken by communities operating in different fields, under the influence of specific ecologic and environmental conditions. The methodology, applied to a socio-ecological system which is representative of the Mediterranean basin, is proposed as a tool to support the territorialisation of polices, opening the process up to perspectives able to better comprehend the dynamic evolution of rural territories, internalising that evolution in the definition of the instruments and measures to adopt.

  10. Geomechanical Characteristics of Gas Shales: A Case Study in the North Perth Basin

    Science.gov (United States)

    Rasouli, Vamegh; Sutherland, Andrew

    2014-11-01

    Gas shales are one type of unconventional reservoirs which have attracted significant attention for gas production in recent years. Gas production from very tight shales requires employment of hydraulic fracturing as a stimulation technique. To design hydraulic fracture operation the mechanical properties of the targeted and surrounding formations should be estimated. Also, the magnitude and orientation of in situ stresses in the field need to be known to estimate the fracture initiation and propagation pressures. This study focuses on gas shale characteristics in the North Perth Basin and uses data corresponding to well Arrowsmith-2 (AS-2) which is the first dedicated shale gas well drilled in Western Australia. A log-based analysis was used to build the rock mechanical model (RMM). The RMM results were used to set up a hydraulic fracturing laboratory experiment. The test was done in the presence of three principal stresses to mimic the real field stress conditions. The test results include the pressure-time curve which was used to estimate the initiation and propagation pressure at that depth. The results were used to draw some practical conclusions related to hydraulic fracturing operation in the field.

  11. A mesoscale modeling study of wind blown dust on the Mexico City Basin

    Science.gov (United States)

    Villasenor, Rafael; López-Villegas, M. T.; Eidels-Dubovoi, S.; Quintanar, Arturo; Gallardo, J. C.

    The latest phase of the program to improve the air quality in the Valley of Mexico, also known, as Pro Aire is about to go into effect for the next 10 years. Pro Aire puts emphasis on agricultural wind erosion and associated dust emissions impacting downwind air quality. The main objective of this investigation was to use an empirical USEPA erosion model coupled to a meteorological/transport-dispersion prediction model, CALMET/CALPUFF, to estimate dust emissions and concentrations in the Mexico City Basin. The model simulations for particulate matter (PM 10) are validated against observations taken at the most recent research field study, the IMADA-AVER field campaign, conducted during the spring of 1997 to provide information about high ozone, particulate matter concentrations and visibility impairment. The spatial and temporal PM distribution in the region is presented for a specific wind blown dust event consisting of two IMADA days, in order to understand how soil dust emissions from agricultural fallow land affect downwind areas during the dry season. Results show good agreement with the main spatial features of the local wind circulation and wind blown dust concentrations. A correlation coefficient of nearly 0.8 between predictions and observations for a modeled day suggests that an important portion of the total measured concentration had geological origin. This work constitutes an essential advancement on the mesoscale air quality problem on the MCMA due to wind erosion.

  12. USING THE FOURNIER INDEXES IN ESTIMATING RAINFALL EROSIVITY. CASE STUDY - THE SECAŞUL MARE BASIN

    Directory of Open Access Journals (Sweden)

    M. COSTEA

    2012-03-01

    Full Text Available Using the Fournier Index in Estimating Rainfall Erosivity. Case Study - The Secaşul Mare Basin. Climatic aggressiveness is one of the most important factors in relief dynamic. Of all climatic parameters, rainfall is directly involved in versant dynamic, in the loss of soil quality and through pluvial denudation and the processes associated with it, through the erosivity of torrential rain. We analyzed rainfall aggressiveness based on monthly and annual average values through the Fournier's index (1970 and Fournier's index modified by Arnoldus (1980. They have the advantage that they can be used not only for evaluating the land susceptibility to erosion and the calculation of erodibility of land and soil losses, but also in assessing land susceptibility to sliding (Aghiruş, 2010. The literature illustrates the successful use of this index which provides a summary assessment of the probability of rainfall with significant erosive effects. The results obtained allow observation of differences in space and time of the distribution of this index.

  13. Lithologic identification and characterization using ETM+ (Landsat 7. Study case of the Upsala glacier basin, Argentine

    Directory of Open Access Journals (Sweden)

    A. Lo Vecchio

    2016-06-01

    Full Text Available The object of this study aims to evaluate and analyze digital image processing techniques applied to the Enhanced Thematic Mapper Plus (ETM+, in order to demark and characterize the outcropping lithologies on the Upsala Glacier basin, Santa Cruz, Argentine Republic. The prolific technological and spatial development experienced in the last decades has given place to the generation, without precedents, of multiple remote sensors capable of capturing information of the terrestrial surface and also the improvement of digital image processing techniques and software; amongst them, the amazing possibilities in the detection and differentiation of diverse covers present on the terrestrial surface can be highlighted, such as glaciers, volcanoes, vegetation, soils, water, types of rock outcrops, etc. This situation improves mapping and monitoring of natural phenomenon in the Earth Sciences field. The proposed methodology includes radiometric corrections, elimination of unwanted covers, statistical evaluation in the combination of the most appropriate bands, application of the Z index, discretization of the statistical series, entailing tasks of spectral classification with field samples and a later validation. Valuable results were obtained by means of digital processing of images, that were validated yielding a 82% of accuracy in the proposed classification, which are good results taking into account the diversity of covers present and the lithological heterogeneity that makes up each pixel (30m. These results were also validated with existing geological maps, obtaining a good agreement.

  14. Natural and human forcing in recent geomorphic change; case studies in the Rio de la Plata basin.

    Science.gov (United States)

    Bonachea, Jaime; Bruschi, Viola M; Hurtado, Martín A; Forte, Luis M; da Silva, Mario; Etcheverry, Ricardo; Cavallotto, José L; Dantas, Marcilene F; Pejon, Osni J; Zuquette, Lázaro V; Bezerra, Maria Angélica de O; Remondo, Juan; Rivas, Victoria; Gómez-Arozamena, José; Fernández, Gema; Cendrero, Antonio

    2010-06-01

    An analysis of geomorphic system's response to change in human and natural drivers in some areas within the Río de la Plata basin is presented. The aim is to determine whether an acceleration of geomorphic processes has taken place in recent years and, if so, to what extent it is due to natural (climate) or human (land-use) drivers. Study areas of different size, socio-economic and geomorphic conditions have been selected: the Río de la Plata estuary and three sub-basins within its watershed. Sediment cores were extracted and dated ((210)Pb) to determine sedimentation rates since the end of the 19th century. Rates were compared with time series on rainfall as well as human drivers such as population, GDP, livestock load, crop area, energy consumption or cement consumption, all of them related to human capacity to disturb land surface. Data on river discharge were also gathered. Results obtained indicate that sedimentation rates during the last century have remained essentially constant in a remote Andean basin, whereas they show important increases in the other two, particularly one located by the São Paulo metropolitan area. Rates in the estuary are somewhere in between. It appears that there is an intensification of denudation/sedimentation processes within the basin. Rainfall remained stable or varied very slightly during the period analysed and does not seem to explain increases of sedimentation rates observed. Human drivers, particularly those more directly related to capacity to disturb land surface (GDP, energy or cement consumption) show variations that suggest human forcing is a more likely explanation for the observed change in geomorphic processes. It appears that a marked increase in denudation, of a "technological" nature, is taking place in this basin and leading to an acceleration of sediment supply. This is coherent with similar increases observed in other regions.

  15. Comparative study of transport processes of nitrogen, phosphorus, and herbicides to streams in five agricultural basins, USA

    Science.gov (United States)

    Domagalski, J.L.; Ator, S.; Coupe, R.; McCarthy, K.; Lampe, D.; Sandstrom, M.; Baker, N.

    2008-01-01

    Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage pathways in humid environments are important because the loads may be transported in tile drains, or through varying combinations of ground water discharge, and overland flow. In most cases, overland flow contributed the greatest loads, but a significant portion of the annual load of nitrate and some pesticide degradates can be transported under base-flow conditions. The highest basin yields for nitrate were measured in a semiarid irrigated system that used imported water and in a stream dominated by tile drainage in a humid environment. Pesticide loads, as a percent of actual use (LAPU), showed the effects of climate and geohydrologic conditions. The LAPU values in the semiarid study basin in Washington were generally low because most of the load was transported in ground water discharge to the stream. When herbicides are applied during the rainy season in a semiarid setting, such as simazine in the California basin, LAPU values are similar to those in the Midwest basins. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  16. Flood modeling using WMS model for determining peak flood discharge in southwest Iran case study: Simili basin in Khuzestan Province

    Science.gov (United States)

    Hoseini, Yaser; Azari, Arash; Pilpayeh, Alireza

    2016-10-01

    It is of high importance to determine the flood discharge of different basins, in studies on water resources. However, it is necessary to use new models to determine flood hydrograph parameters. Therefore, it will be beneficial to conduct studies to calibrate the models, keeping in mind the local conditions of different regions. Therefore, this study was carried out to determine the peak flood discharge of a basin located in Southwest Iran, using the TR-20, TR55, and HEC-1 methods of the WMS model (watershed modeling system). The obtained results were compared with empirical values, as well as those of the soil conservation service (SCS) approach. Based on the results obtained, the TR55 method of the WMS model recorded the highest agreement with empirical values in Southwest Iran.

  17. Understanding arsenic mobilization using reactive transport modeling of groundwater hydrochemistry in the Datong basin study plot, China.

    Science.gov (United States)

    Mapoma, Harold Wilson Tumwitike; Xie, Xianjun; Pi, Kunfu; Liu, Yaqing; Zhu, Yapeng

    2016-03-01

    This paper discusses the reactive transport and evolution of arsenic along a selected flow path in a study plot within the central part of Datong basin. The simulation used the TOUGHREACT code. The spatial and temporal trends in hydrochemistry and mineral volume fraction along a flow path were observed. Furthermore, initial simulation of major ions and pH fits closely to the measured data. The study shows that equilibrium conditions may be attained at different stress periods for each parameter simulated. It is noted that the variations in ionic chemistry have a greater impact on arsenic distribution while reducing conditions drive the mobilization of arsenic. The study concluded that the reduction of Fe(iii) and As(v) and probably SO4/HS cycling are significant factors affecting localized mobilization of arsenic. Besides cation exchange and water-rock interaction, incongruent dissolution of silicates is also a significant control mechanism of general chemistry of the Datong basin aquifer.

  18. Organic geochemical paleoenvironmental and paleoclimatic reconstructions from Argentina Loess/Loessoid deposits

    Science.gov (United States)

    Heil, C. W.; Huang, Y.; Wegener, P.; King, J. W.; Schultz, P. H.

    2013-12-01

    The loess/loessoid sediments of Argentina have accumulated since the Late Miocene (~10-12 Ma) and are an important terrestrial archive for much of the Late Cenozoic. These sedimentary sequences contain an extensive fossil vertebrate record, which provides the foundation for the South American Land Mammal Ages (SALMA) stratigraphy, and an extensive meteorite impact record. Previous work by our group has focused on using environmental magnetic parameters to characterize changes in depositional and post-depositional processes in relation to meteorite impacts, moisture transport, wind patterns, and temperature over the last ~3.5 Ma. This work has provided the foundation for ocean-atmosphere-terrestrial models to explain paleoenvironmental and paleoclimatic changes associated with several major global climate transitions/states. Although the environmental magnetic proxies provide a high-resolution record, they are limited in their ability to unambiguously or quantitatively define changes in moisture or temperature, especially when both are changing at the same time. To address these uncertainties, we have used a combination of organic geochemical paleoenvironmental and paleoclimate proxies (carbon isotopes, hydrogen isotopes, and bacterially generated compounds) in order to calibrate the high-resolution environmental magnetic parameters. These proxies include compound specific hydrogen isotopic ratios (δD) and carbon isotope ratios (δ13C) from plant leaf waxes and the distribution of glycerol dialkyl glycerol tetraethers (branched GDGTs). Our preliminary results show that leaf wax n-alkyl lipids and branched GDGTs are sufficiently abundant for compound specific hydrogen and carbon isotopic analysis as well as paleotemperature reconstructions. Analysis of the most recent interglacial/glacial cycle indicates that interglacial temperature estimates are consistent with mean January temperatures for the region (20-24 οC) while the glacial to interglacial temperature

  19. Reducing the basin vulnerability by land management practices under past and future climate: a case study of the Nam Ou River Basin, Lao PDR

    Science.gov (United States)

    Maharjan, M.; Babel, M. S.; Maskey, S.

    2014-08-01

    This research evaluates different land management practices for the Nam Ou River Basin in Northern Laos for reducing vulnerability of the basin due to erosion and sediment yield under existing and future climate conditions. We use climate projection data (precipitation and temperature) from three general circulation models (GCMs) for three greenhouse gas emission scenarios (GHGES), namely B1, A1B and A2 and three future periods, namely 2011-2030, 2046-2065 and 2080-2099. These large resolution GCM data are downscaled using the Long Ashton Research Station-Weather Generator (LARS-WG). The Soil and Water Assessment Tool (SWAT), which is a process based hydrological model, is used to simulate discharge and sediment yield and a threshold value of annual sediment yield is applied to identify vulnerable sub-basins. Results show that the change in the annual precipitation is expected to be between -7.60 to 2.64% in 2011-2030, -8.98 to 11.85% in 2046-2065, and -11.04 to 25.84% in 2080-2099. In the meantime, the changes in mean monthly temperature vary from 0.3 to 1.3 °C in the 2011-2030, 1.3 to 2.9 °C in the 2046-2065 and 1.9 to 4.9 °C in the 2080-2099. Five sub-basins are identified vulnerable (critical) under the current climate. Our results show that terracing is the most effective land management practice to reduce sediment yield in these sub-basins followed by strip-cropping and filter strip. Appropriate land management practices applied under future climate scenarios show significant reduction in sediment yield (i.e. up to the tolerance limit) except for some sub-basins. In these exceptional sub-basins, designing an optimum combination of management practices is essential to reduce the vulnerability of the basin.

  20. Paleoenvironmental and paleoclimatic significance of freshwater bivalves in the Upper Jurassic Morrison Formation, Western Interior, USA

    Science.gov (United States)

    Good, Steven C.

    2004-05-01

    isolated storm turbidity. Vetulonaia sp. from the Tidwell Member, Green River, Utah, and from Tidwell-equivalent beds at Como Bluff, Wyoming, exhibits continuous growth with no annual banding, suggesting that seasonality of climate and discharge did not vary appreciable during the year. Hadrodon sp. from the Salt Wash Member in Colorado National Monument, Colorado, exhibits annual banding with subequal light and dark bands indicating seasonal cyclicity. Vetulonaia sp. from the Cleveland-Lloyd locality, Utah, exhibits complex banding that indicates a combination of annual and pseudoannual bands. This suggests seasonal cyclicity and intermittent periods of environmental stress (predation, storm-produced turbidity and/or volcanic ash falls). Specimens of Vetulonaia sp. from Dinosaur National Monument, Utah, are replaced by chert with faint ghosts of bands that are too poorly preserved for environmental interpretations. Preliminary growth band studies suggest a change from a uniform optimum habitat in the Tidwell Member to strongly developed annual growth banding in the Salt Wash Member, suggesting cyclic annual precipitation, and finally to irregular banding produced by a complex interaction of weakly developed annual growth bands and pseudoannual bands in the Brushy Basin Member.

  1. Nitrogen uptake and regeneration pathways in the equatorial Pacific: a basin scale modeling study

    Directory of Open Access Journals (Sweden)

    R. Le Borgne

    2009-11-01

    Full Text Available It is well known that most primary production is fueled by regenerated nitrogen in the open ocean. Therefore, studying the nitrogen cycle by focusing on uptake and regeneration pathways would advance our understanding of nitrogen dynamics in the marine ecosystem. Here, we carry out a basin-scale modeling study, by assessing model simulations of nitrate and ammonium, and rates of nitrate uptake, ammonium uptake and regeneration in the equatorial Pacific. Model-data comparisons show that the model is able to reproduce many observed features of nitrate, ammonium, such as the deep ammonium maximum (DAM. The model also reproduces the observed de-coupling of ammonium uptake and regeneration, i.e., regeneration rate greater than uptake rate in the lower euphotic zone. The de-coupling largely explains the observed DAM in the equatorial Pacific Ocean. Our study indicates that zooplankton excretion and remineralization of organic nitrogen play a different role in nitrogen regeneration. Rates of zooplankton excretion vary from <0.01 mmol m−3 d−1 to 0.1 mmol m−3 d−1 in the upper euphotic zone while rates of remineralization fall within a narrow range (0.015–0.025 mmol m−3 d−1 . Zooplankton excretion contributes up to 70% of total ammonium regeneration in the euphotic zone, and is largely responsible for the spatial variability of nitrogen regeneration. However, remineralization provides a steady supply of ammonium in the upper ocean, and is a major source of inorganic nitrogen for the oligotrophic regions. Overall, ammonium generation and removal are approximately balanced over the top 150 m in the equatorial Pacific.

  2. Nitrogen uptake and regeneration pathways in the equatorial Pacific: a basin scale modeling study

    Directory of Open Access Journals (Sweden)

    X. Wang

    2009-08-01

    Full Text Available It is well known that most primary production is fueled by regenerated nitrogen in the open ocean. Therefore, studying the nitrogen cycle by focusing on uptake and regeneration pathways would advance our understanding of nitrogen dynamics in the marine ecosystem. Here, we carry out a basin-scale modeling study, by assessing model simulations of nitrate and ammonium, and rates of nitrate uptake, ammonium uptake and regeneration in the equatorial Pacific. Model-data comparisons show that the model is able to reproduce many observed features of nitrate, ammonium, such as the deep ammonium maximum (DAM. The model also reproduces the observed de-coupling of ammonium uptake and regeneration, i.e. regeneration rate greater than uptake rate in the lower euphotic zone. The de-coupling largely explains the observed DAM in the equatorial Pacific Ocean. Our study indicates that zooplankton excretion and remineralization of organic nitrogen play a different role in nitrogen regeneration. Rates of zooplankton excretion vary from <0.01 mmol m−3 d−1 to 0.1 mmol m−3 d−1 in the upper euphotic zone while rates of remineralization fall within a narrow range (0.015–0.025 mmol m−3 d−1. Zooplankton excretion contributes up to 70% of total ammonium regeneration in the euphotic zone, and is largely responsible for the spatial variability of nitrogen regeneration. However, remineralization provides a steady supply of ammonium in the upper ocean, and is a major source of inorganic nitrogen for the oligotrophic regions. Overall, ammonium generation and removal are approximately balanced over the top 150 m in the equatorial Pacific.

  3. SWAT use of gridded observations for simulating runoff – a Vietnam river basin study

    Directory of Open Access Journals (Sweden)

    M. T. Vu

    2011-12-01

    Full Text Available Many research studies that focus on basin hydrology have used the SWAT model to simulate runoff. One common practice in calibrating the SWAT model is the application of station data rainfall to simulate runoff. But over regions lacking robust station data, there is a problem of applying the model to study the hydrological responses. For some countries and remote areas, the rainfall data availability might be a constraint due to many different reasons such as lacking of technology, war time and financial limitation that lead to difficulty in constructing the runoff data. To overcome such a limitation, this research study uses some of the available globally gridded high resolution precipitation datasets to simulate runoff. Five popular gridded observation precipitation datasets: (1 Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE, (2 Tropical Rainfall Measuring Mission (TRMM, (3 Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN, (4 Global Precipitation Climatology Project (GPCP, (5 modified Global Historical Climatology Network version 2 (GHCN2 and one reanalysis dataset National Centers for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR are used to simulate runoff over the Dakbla River (a small tributary of the Mekong River in Vietnam. Wherever possible, available station data are also used for comparison. Bilinear interpolation of these gridded datasets is used to input the precipitation data at the closest grid points to the station locations. Sensitivity Analysis and Auto-calibration are performed for the SWAT model. The Nash-Sutcliffe Efficiency (NSE and Coefficient of Determination (R2 indices are used to benchmark the model performance. This entails a good understanding of the response of the hydrological model to different datasets and a quantification of the uncertainties in

  4. Modeling the Hydropower–Food Nexus in Large River Basins: A Mekong Case Study

    Directory of Open Access Journals (Sweden)

    Jamie Pittock

    2016-09-01

    Full Text Available An increasing global population and growing wealth are raising demand for energy and food, impacting on the environment and people living in river basins. Sectoral decision-making may not optimize socio-economic benefits because of perverse impacts in other sectors for people and ecosystems. The hydropower–food supply nexus in the Mekong River basins is assessed here in an influence model. This shows how altering one variable has consequent effects throughout the basin system. Options for strategic interventions to maximize benefits while minimizing negative impacts are identified that would enable national and sub-national policy makers to take more informed decisions across the hydropower, water and food supply sectors. This approach should be further tested to see if it may aid policy making in other large river systems around the world.

  5. 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

  6. Mapping of groundwater quality in the Turonian aquifer of Oum Er-Rabia Basin, Morocco: a case study

    Science.gov (United States)

    Ettazarini, Said

    2006-08-01

    This study takes the groundwater of the Moroccan limestone aquifer of Oum Er-Rabia as an example of statistical and cartographical approaches in water resources management. Statistical analyses based on frequency distribution and PCA methods revealed the homogeneity of waters with the existence of abnormal points and have helped to assess correlations between the studied variables. The mapping approach illustrated that waters are influenced by the lithology of the surrounding rocks and are of Ca Mg HCO3, Ca Mg Cl SO4, and mixed types according to the Piper classification. The quality of water is of high to medium, north of the basin, but it is of medium to bad, NE and south, due to excessive contents of chloride, sulfate and nitrate. According to the US Salinity Laboratory classification, water used for irrigation in the eastern and the southern parts of the basin should take into consideration the drainage conditions, the nature of plants and the addition of gypsum doses.

  7. Geophysical Studies of Seismic Hazard in the Tahoe City Sub-basin, Lake Tahoe, California

    Science.gov (United States)

    Muehlberg, J. M.; Schweickert, R. A.; McHugh, J.; Rasmussen, T.; Louie, J. N.

    2003-12-01

    The Lake Tahoe basin has the potential for serious earthquakes and earthquake-related tsunamis. The history of lake level fluctuations should be recorded in sediments beneath the Lake's outlet at Tahoe City. Borehole data show the sediments consist primarily of a thick sequence of lacustrine silts and clays with interbedded sands. Beneath this unit is an older Q-T (?) sand and gravel sequence of unknown origin. The lacustrine deposits locally rest upon 2.0 Ma latites, which in turn rest upon the older sand and gravel sequence. Near the outlet, several fault scarps displace units less than 2.0 m.y. old. These scarps may influence the stability of the dam across the outlet and the sequence and extent of lake level high stands. Our project is integrating geophysical and stratigraphic data to further define and describe the Tahoe City sub-basin. We collected new gravity data to provide an estimate of basin depths across the outlet and help define subsurface faults. Preliminary data suggest the maximum basin depth is 180 m, near the outlet. Refraction microtremor surveys yielded information about stratigraphy and shear velocities of the Quaternary deposits. The average shear wave velocity to 30-m depth obtained for this area is 334 m/s. These values correspond to a NEHRP soil hazard class of D, similar to that found in other lacustrine basins of the region. Soils in this NEHRP class tend to show a significant amplification of shaking, posing increased hazard to structures. We are combining stratigraphic with gravity and seismic data to produce geologic cross sections having information on basin depths and Quaternary faults.

  8. Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

    Science.gov (United States)

    Davis, Tracy A.; Kulongoski, Justin T.

    2016-10-03

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory.The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors.The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N-nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non

  9. Modeling and analysis of Soil Erosion processes by the River Basins model: The Case Study of the Krivacki Potok Watershed, Montenegro

    Science.gov (United States)

    Vujacic, Dusko; Barovic, Goran; Mijanovic, Dragica; Spalevic, Velibor; Curovic, Milic; Tanaskovic, Vjekoslav; Djurovic, Nevenka

    2016-04-01

    The objective of this research was to study soil erosion processes in one of Northern Montenegrin watersheds, the Krivacki Potok Watershed of the Polimlje River Basin, using modeling techniques: the River Basins computer-graphic model, based on the analytical Erosion Potential Method (EPM) of Gavrilovic for calculation of runoff and soil loss. Our findings indicate a low potential of soil erosion risk, with 554 m³ yr-1 of annual sediment yield; an area-specific sediment yield of 180 m³km-2 yr-1. The calculation outcomes were validated for the entire 57 River Basins of Polimlje, through measurements of lake sediment deposition at the Potpec hydropower plant dam. According to our analysis, the Krivacki Potok drainage basin is with the relatively low sediment discharge; according to the erosion type, it is mixed erosion. The value of the Z coefficient was calculated on 0.297, what indicates that the river basin belongs to 4th destruction category (of five). The calculated peak discharge from the river basin was 73 m3s-1 for the incidence of 100 years and there is a possibility for large flood waves to appear in the studied river basin. Using the adequate computer-graphic and analytical modeling tools, we improved the knowledge on the soil erosion processes of the river basins of this part of Montenegro. The computer-graphic River Basins model of Spalevic, which is based on the EPM analytical method of Gavrilovic, is highly recommended for soil erosion modelling in other river basins of the Southeastern Europe. This is because of its reliable detection and appropriate classification of the areas affected by the soil loss caused by soil erosion, at the same time taking into consideration interactions between the various environmental elements such as Physical-Geographical Features, Climate, Geological, Pedological characteristics, including the analysis of Land Use, all calculated at the catchment scale.

  10. Impacts of Land Use on Surface Water Quality in a Subtropical River Basin: A Case Study of the Dongjiang River Basin, Southeastern China

    Directory of Open Access Journals (Sweden)

    Jiao Ding

    2015-08-01

    Full Text Available Understanding the relationship between land use and surface water quality is necessary for effective water management. We estimated the impacts of catchment-wide land use on water quality during the dry and rainy seasons in the Dongjiang River basin, using remote sensing, geographic information systems and multivariate statistical techniques. The results showed that the 83 sites can be divided into three groups representing different land use types: forest, agriculture and urban. Water quality parameters exhibited significant variations between the urban-dominated and forest-dominated sites. The proportion of forested land was positively associated with dissolved oxygen concentration but negatively associated with water temperature, electrical conductivity, permanganate index, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen and chlorophyll-a. The proportion of urban land was strongly positively associated with total nitrogen and ammonia nitrogen concentrations. Forested and urban land use had stronger impacts on water quality in the dry season than in the rainy season. However, agricultural land use did not have a significant impact on water quality. Our study indicates that urban land use was the key factor affecting water quality change, and limiting point-source waste discharge in urban areas during the dry season would be critical for improving water quality in the study area.

  11. The Santa Barbara Channel - Santa Maria Basin Study: Wind Measurements and Modeling Resolving Coastal Mesoscale Meteorology

    Science.gov (United States)

    Dorman, C. E.; Koracin, D.

    2002-12-01

    The importance of winds in driving the coastal ocean has long been recognized. Pre-World War II literature links wind stress and wind stress curl to coastal ocean responses. Nevertheless, direct measurements plausibly representative of a coastal area are few. Multiple observations on the scale of the simplest mesoscale atmospheric structure, such as the cross-coast variation along a linear coast, are even less frequent. The only wind measurements that we are aware of in a complicated coastal area backed by higher topography are in the MMS sponsored, Santa Barbara Channel/Santa Marina basin study. Taking place from 1994 to present, this study had an unheard of dense surface automated meteorological station array of up to 5 meteorological buoys, 4 oil platforms, 2 island stations, and 11 coastal stations within 1 km of the beach. Most of the land stations are maintained by other projects. Only a large, a well funded project with backed by an agency with the long-view could dedicate the resources and effort into filling the mesoscale "holes" and maintaining long-term, remotely located stations. The result of the MMS funded project is a sufficiently dense surface station array to resolve the along-coast and cross-coast atmospheric mesoscale wind structure. Great temporal and spatial variation is found in the wind, wind stress and the wind stress curl, during the extended summer season. The MM5 atmospheric mesoscale model with appropriate boundary layer physics and high-resolution horizontal and vertical grid structure successfully simulates the measured wind field from large scale down to the lower end of the mesoscale. Atmospheric models without appropriate resolution and boundary layer physics fail to capture significant mesoscale wind features. Satellite microwave wind measurements generally capture the offshore synoptic scale temporal and spatial scale in twice-a-day snap shots but fail in the crucial, innermost coastal waters and the diurnal scale.

  12. Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

    Science.gov (United States)

    Davis, Tracy A.; Kulongoski, Justin T.

    2016-10-03

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory.The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors.The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N-nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non

  13. Testing the influence of rain gauges' density and distribution on hydrological modeling results, a case study of Xiangjiang River basin

    Science.gov (United States)

    Xu, H.

    2012-04-01

    Hydrological models are important tools for flood forecasting, for the assessment of water resources under current and a changing climate. However, the accuracy of hydrological models is limited by many factors, of which, the most important one is perhaps the errors in the input data. For the lumped and semi-distributed hydrological models, the main input is the estimated areal precipitation, and the quality of which is very much dependent on the spatial distribution and density of rain gauges. Many researches have been reported on the development, calibration and validation of hydrological models, however, the influence of the precipitation gauges density and network distribution on the modeling results has received much less attention. One of the reasons for the limited study of this important issue is it needs a catchment with sufficient size, wide diversity of topography and climate, and dense raingauges with long and good quality data. In this study, a famous and widely used hydrological model, the Xinanjiang Model was applied to Xiangjiang River basin to examine the influence of rain gauges' density and distribution on the performance of the model in simulating the streamflow and other water balance components, like actual evapotranspiration and soil moisture content. The Xiangjiang River basin, one of the most important economic belts in Hunan Province, China and the primary inflow basin of Dongting Lake - China's second largest freshwater lake, has dense rain gauge network with long and high quality data. To perform the study, 18 different input data scenarios representing different density and distribution situations are used as input to the Xinanjiang model. The influences of different input scenarios on the modeling results as measured by Nash-Sutcliffe coefficient, relative bias, and peak errors are compared, and guidance for optimal planning of rain gauges is proposed. Keywords: Xinanjiang Model; Xiangjiang River basin; precipitation gauges network

  14. Assessment the Economic Damage of Inter-Basin Water Transfer on Cropping Pattern and Farmers’ Income Situation in the Origin Basin (Case Study: Water Transfer of Alamoutrood to Qazvin Plain

    Directory of Open Access Journals (Sweden)

    A. Parhizkari

    2016-03-01

    building the dam, canals, streams and aqueducts. Even today, many projects are implemented in Iran that water transfer project of Alamoutrood to Qazvin plain is one of the most important of these projects. According to reports of Regional Water Company of Qazvin province and the specifications of inter-basin water transfer project of Alamoutrood to Qazvin plain will be out from the farmers availability of Alamut region about 370 million cubic meters of irrigation water. This issue has the huge impacts on cropping pattern and farmers economic and livelihood condition in the origin basin (Alamout region. Therefore, in this study a hydrological-economic modeling system to analysis the effects of water transfer project of Alamoutrood to Qazvin plain on cropping pattern, farmers gross profit and economic value of irrigation water in the Alamut region (origin basin was used. Materials and Methods: Nowadays different methods to analysis of the issues related to the management of water resources and agriculture are used. One of the most important of these methods is mathematical programming that in recent years are in use to solve problems of water resource management sector and analysis of the agricultural policies. In this study a hydrological-economic modeling system consists of the Positive Mathematical Programming (PMP and product function with Constant Elasticity of Substitution (CES to analysis of the effects of inter-basin water transfer on land use, farmers income situation and economic value of irrigation water in the origin basin (Alamout region was used. The first time PMP model developed by Howitt (1995 to calibrate agricultural supply models have been used to link biophysical and economic information in an integrated biophysical and economic modelling framework and to assess impacts of agricultural policies and scenarios. These models are also accepted for analysing the impact of water resources management policies and scenarios. PMP model used in this paper is a

  15. 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

  16. Theory of annual runoff evolution under natural-artificial dual mode and case study of Wuding River basin on the middle Yellow River

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; WANG Chengming; WANG Jianhua; ZHOU Zuhao; CHEN Yiming

    2004-01-01

    Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitative analysis of the water resources condition in varied environment and prediction of the law of the water resources evolution in the future because year-based time span may best reflect the law of the water resources evolution driven by the nature and human activities in the river basin. This paper advances the theory of annual runoff evolution under natural-artificial dual mode based on the dual mode of the water resources evolution, and the theory is applied for the Wuding River Basin on the middle Yellow River as a case study. A thorough analysis of the precipitation-runoff relationship is made in the case of dynamic variation of ground surface conditions of the Wuding River basin, and the concept of water-soil conservation index area that indicates adoption of various measures for water and soil conservation to reflect ground surface conditions. Furthermore, precipitation-runoff empirical model is developed to reflect dynamic variation of the ground surface conditions of the river basin.The study may lay a solid foundation for the integrated theoretical platform of the law of the water resources evolution in the Yellow River basin and the dual model of the evolution.

  17. A parametric study of dispersion processes in semi-enclosed basins

    Energy Technology Data Exchange (ETDEWEB)

    Buffoni, G. [ENEA, Centro Ricerche S. Teresa, La Spezia (Italy). Dipt. di Innovazione; Bellucci, A.; Zambianchi, E. [Istituto Universitario Navale, Neapel (Italy); Griffa, A. [Consiglio Nazionale delle Ricerche, La Spezia (Italy)

    1999-07-01

    The dispersion processes in semi-enclosed basins with stationary flows have been studied by means of an Eulerian advection-diffusion model. Special interest have been given to quantities which characterize the macroscopic state of the system: the normalized total quantity C(t) (C (0) = 1) of a tracer inside the basin, and its residence time T. Also the principal eigenvalue {tau}{sub 0} of the advection-diffusion problem has been considered, since for stationery flows C (t) attains, for time t long enough, an exponential decay shape C{sub 0}exp (-t/{tau}{sub 0} ). The focus is one the comparison between cases where the flow is rotational with re circulations, represented by a flow with a gyre at the outflow. The sensitivity of the results to a number of parameters, including initial and boundary conditions and the eddy diffusivity coefficient, have been studied. It is found that for small Peclet numbers, when the flow is highly diffusive, the results do not depend strongly on the flow structure. {tau}{sub 0} tends to a constant limit (dependent on the boundary conditions) at decreasing Peclet number, and T is approximated by T asymptotically equal to {tau}{sub 0}. For high Peclet numbers, instead, the rotational and irrotational cases are qualitatively different. For rotational flows, {tau}{sub 0}, tends to zero at increasing Peclet number, and T tends toward the advective time scale. For flows with re circulations, in which the tracer tends to be trapped inside the gyre, {tau}{sub 0} increases at increasing Peclet numbers and T asymptotically equal to {tau}{sub 0}, for all initial and boundary conditions. The values of T and {tau}{sub 0} do not change significantly in the range of realistic Peclet numbers considered. This suggests that, for flows with re circulations, the macroscopic dispersion properties depend only weakly on the eddy diffusion coefficient. [Italian] Processi di dispersione in bacini semi-chiusi caratterizzati da flussi stazionari sono stati

  18. Using Geochemical Method to Distinguish Lateral Migration and Vertical Migration in Rifted Basin: A Case Study from Eastern Lujiapu Depression in the Kailu Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shuqing; HUANG Haiping; LIU Yuming

    2008-01-01

    Migration fractionation diagnosis is complicated in rifted basins where migration distance is generally short and lateral migration in sandy beds and vertical migration along faults are co-existed. Quantitative data from GC-MS analysis makes it possible to distinguish lateral and vertical migration effects. Oils discovered from the Jiaolige oilfield, eastern Lujiapu Depression are derived from single source rock with similar maturity, which is an ideal case to study the migration fractionation effects. Compositional differences among oils are largely caused by the migration fractionation either laterally in sand beds or vertically along the faults. Subtle maturity differences are assessed by the classic saturated hydrocarbon parameters which have certain influence on nitrogen compounds. In a certain maturity range, the ratios of shield and semi-shield isomers to the exposed isomers of alkylcarbazoles change with maturity in an opposite direction with migration fractionation, which may conceal the migration influence. However, migration and maturation have the same effects on absolute concentrations of aikylated carbazoles and benzocarhazole [a]/([a]+[c]) ratios, which provides an ideal tool for migration direction assessment. Continuous variations among different samples reflect increased migration distance in sandy beds, while abrupt changes may indicate the change of migration conduit systems. Integrated both geochemical interpretation and geological constrains, not only migration direction can be determined, but also the conduit systems through the sandy beds or the. faults can be recognized.

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

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

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

  20. Multibeam bathymetric, gravity and magnetic studies over 79 degrees E fracture zone, central Indian basin

    Digital Repository Service at National Institute of Oceanography (India)

    KameshRaju, K.A.; Ramprasad, T.; Kodagali, V.N.; Nair, R.R.

    A regional scale bathymetric map has been constructed for the 79 degrees E fracture zone (FZ) in the Central Indian Basin between 10 degrees 15'S and 14 degrees 45'S lat. and 78 degrees 55'E and 79 degrees 20'E long. using the high...

  1. TRANSGRESSIVE SEQUENCES ON FORELAND MARGINS: A CASE STUDY OF THE NEOGENE CENTRAL GUADALQUIVIR BASIN, SOUTHERN SPAIN

    Directory of Open Access Journals (Sweden)

    J. GABRIEL PENDÓN

    2004-07-01

    Full Text Available The Guadalquivir foreland basin, located between the Iberian basement northward and the Betic orogen to the South, represents the western sector of the earlier foredeep basin of the Betic Cordillera. Along the northern foreland margin, the sedimentary fill of this basin includes a Tortonian Basal Transgressive Complex (BTC, composed of five internal sequences bounded by transgressive surfaces. Two main parts are distinguished within each sequence: the lower transgressive lag deposits, and the upper stillstand/prograding sediments. Three facies associations were distinguished within this stratigraphic succession along the central sector of this basin margin: unfossiliferous conglomerates and coarse-grained sands (A, fossiliferous conglomerates and coarse-grained sands (B, and yellow medium-coarse-grained fossiliferous sands (C. A fourth facies association (D: blue silty marlstones and shales overlies the BTC. Deposits of alluvial sediments (facies association A and shallow-marine/foreshore sediments (facies association C, were recurrently interrupted by transgressive pulses (facies associations B and C. Every pulse is recorded by an erosional, cemented sandy-conglomerate bar with bivalves (Ostreidae, Isognomon, balanids, gastropods and other marine bioclasts; or their transgressive equivalents. The lateral facies changes in each individual sequence of the BTC are related to: (1 the influence on the northern foreland margin of the tectonic activity of the southern orogenic margin; (2 the palaeorelief formed by irregularities of the substrate which controls the sediment dispersal; and (3 the evolution stages of the sedimentary systems. 

  2. 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.

  3. Source rock contributions to the Lower Cretaceous heavy oil accumulations in Alberta: a basin modeling study

    Science.gov (United States)

    Berbesi, Luiyin Alejandro; di Primio, Rolando; Anka, Zahie; Horsfield, Brian; Higley, Debra K.

    2012-01-01

    The origin of the immense oil sand deposits in Lower Cretaceous reservoirs of the Western Canada sedimentary basin is still a matter of debate, specifically with respect to the original in-place volumes and contributing source rocks. In this study, the contributions from the main source rocks were addressed using a three-dimensional petroleum system model calibrated to well data. A sensitivity analysis of source rock definition was performed in the case of the two main contributors, which are the Lower Jurassic Gordondale Member of the Fernie Group and the Upper Devonian–Lower Mississippian Exshaw Formation. This sensitivity analysis included variations of assigned total organic carbon and hydrogen index for both source intervals, and in the case of the Exshaw Formation, variations of thickness in areas beneath the Rocky Mountains were also considered. All of the modeled source rocks reached the early or main oil generation stages by 60 Ma, before the onset of the Laramide orogeny. Reconstructed oil accumulations were initially modest because of limited trapping efficiency. This was improved by defining lateral stratigraphic seals within the carrier system. An additional sealing effect by biodegraded oil may have hindered the migration of petroleum in the northern areas, but not to the east of Athabasca. In the latter case, the main trapping controls are dominantly stratigraphic and structural. Our model, based on available data, identifies the Gordondale source rock as the contributor of more than 54% of the oil in the Athabasca and Peace River accumulations, followed by minor amounts from Exshaw (15%) and other Devonian to Lower Jurassic source rocks. The proposed strong contribution of petroleum from the Exshaw Formation source rock to the Athabasca oil sands is only reproduced by assuming 25 m (82 ft) of mature Exshaw in the kitchen areas, with original total organic carbon of 9% or more.

  4. Seismic studies of coal bed methane content in the west coal mining area of Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    Zou Guangui⇑; Peng Suping; Yin Caiyun; Xu Yanyong; Chen Fengying; Liu Jinkai

    2013-01-01

    The coal bed methane content (CBMC) in the west mining area of Jincheng coalfield, southeastern Qinshui Basin, is studied based on seismic data and well-logs together with laboratory measurements. The results show that the Shuey approximation has better adaptability according to the Zoeppritz equation result;the designed fold number for an ordinary seismic data is sufficient for post-stack data but insufficient for pre-stack data regarding the signal to noise ratio (SNR). Therefore a larger grid analysis was created in order to improve the SNR. The velocity field created by logging is better than that created by stack velocity in both accuracy and effectiveness. A reasonable distribution of the amplitude versus offset (AVO) attributes can be facilitated by taking the AVO response from logging as a standard for calibrating the amplitude distribution. Some AVO attributes have a close relationship with CBMC. The worst attri-bute is polarization magnitude, for which the correlation coefficient is 0.308; and the best attribute is the polarization product from intercept, of which the correlation coefficient is ?0.8136. CBMC predicted by AVO attributes is better overall than that predicted by direct interpolation of CBMC; the validation error of the former is 14.47%, which is lower than that of the latter 23.30%. CBMC of this area ranges from 2.5 m3/t to 22 m3/t. Most CBMC in the syncline is over 10 m3/t, but it is below 10 m3/t in the anticline;on the whole, CBMC in the syncline is higher than that in anticline.

  5. Paleoenvironmental reconstruction of marginal marine environments from combined paleoecological and geochemical analyses on ostracods

    Science.gov (United States)

    Anadón, P.; Gliozzi, E.; Mazzini, I.

    Marginal marine environments are complex systems, which show physico-chemical instability due to seawater/fresh water interactions. During the Quaternary these features have been more complicated by the global climatic and sea level variations. Consequently, the use of ostracod shell chemistry (trace elements, δ13C, δ18O and 87Sr/86Sr) to decode the paleohydrochemical characters often is not enough to understand the paleoenvironmental changes. But, if geochemistry is coupled with the classic taxonomical/paleoecological analyses, it may provide a more unambiguous reconstruction. Combined geochemical and paleoecological analyses on ostracods were applied to two boreholes drilled in Quaternary sequences in central Italy. At Migliara (Latium), the inferred salinity deduced from ecology and geochemical data on Cyprideis shells suggests a simple mixing between marine and fresh water, mainly caused by sea-level oscillations. The lack of correlation between ostracod ecology and geochemical data in the Albinia core (Tuscany) can be explained by the mixing of waters from at least three different sources

  6. Application of the environmental Gini coefficient in allocating water governance responsibilities: a case study in Taihu Lake Basin, China.

    Science.gov (United States)

    Zhou, Shenbei; Du, Amin; Bai, Minghao

    2015-01-01

    The equitable allocation of water governance responsibilities is very important yet difficult to achieve, particularly for a basin which involves many stakeholders and policymakers. In this study, the environmental Gini coefficient model was applied to evaluate the inequality of water governance responsibility allocation, and an environmental Gini coefficient optimisation model was built to achieve an optimal adjustment. To illustrate the application of the environmental Gini coefficient, the heavily polluted transboundary Taihu Lake Basin in China, was chosen as a case study. The results show that the original environmental Gini coefficient of the chemical oxygen demand (COD) was greater than 0.2, indicating that the allocation of water governance responsibilities in Taihu Lake Basin was unequal. Of seven decision-making units, three were found to be inequality factors and were adjusted to reduce the water pollutant emissions and to increase the water governance inputs. After the adjustment, the environmental Gini coefficient of the COD was less than 0.2 and the reduction rate was 27.63%. The adjustment process provides clear guidance for policymakers to develop appropriate policies and improve the equality of water governance responsibility allocation.

  7. Assessment of soil erosion by RUSLE model using remote sensing and GIS - A case study of Nethravathi Basin

    Directory of Open Access Journals (Sweden)

    B.P. Ganasri

    2016-11-01

    Full Text Available Soil erosion is a serious problem arising from agricultural intensification, land degradation and other anthropogenic activities. Assessment of soil erosion is useful in planning and conservation works in a watershed or basin. Modelling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. In the present study, the soil loss model, Revised Universal Soil Loss Equation (RUSLE integrated with GIS has been used to estimate soil loss in the Nethravathi Basin located in the southwestern part of India. The Nethravathi Basin is a tropical coastal humid area having a drainage area of 3128 km2 up to the gauging station. The parameters of RUSLE model were estimated using remote sensing data and the erosion probability zones were determined using GIS. The estimated rainfall erosivity, soil erodibility, topographic and crop management factors range from 2948.16 to 4711.4 MJ/mm·ha−1hr−1/year, 0.10 to 0.44 t ha−1·MJ−1·mm−1, 0 to 92,774 and 0 to 0.63 respectively. The results indicate that the estimated total annual potential soil loss of about 473,339 t/yr is comparable with the measured sediment of 441,870 t/yr during the water year 2002–2003. The predicted soil erosion rate due to increase in agricultural area is about 14,673.5 t/yr. The probability zone map has been derived by the weighted overlay index method indicate that the major portion of the study area comes under low probability zone and only a small portion comes under high and very high probability zone. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Nethravathi Basin.

  8. Assessment of soil erosion by RUSLE model using remote sensing and GIS-A case study of Nethravathi Basin

    Institute of Scientific and Technical Information of China (English)

    B.P. Ganasri; H. Ramesh

    2016-01-01

    Soil erosion is a serious problem arising from agricultural intensification, land degradation and other anthropogenic activities. Assessment of soil erosion is useful in planning and conservation works in a watershed or basin. Modelling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. In the present study, the soil loss model, Revised Universal Soil Loss Equation (RUSLE) integrated with GIS has been used to estimate soil loss in the Nethravathi Basin located in the southwestern part of India. The Nethravathi Basin is a tropical coastal humid area having a drainage area of 3128 km2 up to the gauging station. The parameters of RUSLE model were estimated using remote sensing data and the erosion probability zones were deter-mined using GIS. The estimated rainfall erosivity, soil erodibility, topographic and crop management factors range from 2948.16 to 4711.4 MJ/mm$ha?1hr?1/year, 0.10 to 0.44 t ha?1$MJ?1$mm?1, 0 to 92,774 and 0 to 0.63 respectively. The results indicate that the estimated total annual potential soil loss of about 473,339 t/yr is comparable with the measured sediment of 441,870 t/yr during the water year 2002 e2003. The predicted soil erosion rate due to increase in agricultural area is about 14,673.5 t/yr. The probability zone map has been derived by the weighted overlay index method indicate that the major portion of the study area comes under low probability zone and only a small portion comes under high and very high probability zone. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Nethravathi Basin.

  9. Yellowstone River Basin study unit boundary, National Water-Quality Assessment Program, scale 1:100,000, Montana, North Dakota, and Wyoming

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the U.S. Geological Survey's National Water-Quality Assessment Program, an investigation of the Yellowstone River Basin study unit is being conducted to...

  10. Sources of sedimentary biomarkers and proxies with potential paleoenvironmental significance for the Baltic Sea

    Science.gov (United States)

    Kaiser, Jérôme; Arz, Helge W.

    2016-07-01

    The Baltic Sea is a shallow, semi-enclosed and intra-continental shelf sea characterized by anoxic bottom waters in the deepest basins, allowing for the preservation of sedimentary organic matter. In the present study, the most abundant, naturally-occurring lipids in surface sediments from the entire Baltic Sea and the Skagerrak area were identified and their potential sources were assigned. Together with long-chain n-alkanes derived from land plant leaf waxes, diploptene and branched glycerol dialkyl glycerol tetraethers (GDGTs) are of allochthonous origin, while isoprenoid GDGTs, hydroxylated isoprenoid GDGTs (OH-GDGTs), n-C25:1, n-C27:1 and n-C29:1 alkenes are autochthonous lipids. The isoprenoid and OH-GDGTs are probably derived from Thaumarchaeota and the long-chain n-alkenes from phototrophic organisms. Significant correlations were found between indexes based on isoprenoid and OH-GDGTs and Baltic Sea surface and bottom temperatures. The calibrations obtained for surface temperature have statistically similar slopes, but different intercepts than calibrations established for the Nordic Seas. The branched and isoprenoid tetraether index can be used to estimate the percentage of soil (terrestrial) organic matter in the sediments of the Baltic Sea. High values of the Paq' ratio (defined here as the ratio of odd numbered n-C23 and n-C25 over n-C23 to n-C29 alkanes) in the northern Baltic Sea originate from the presence of both Sphagnum mosses in the drainage basin and submerged macrophytes, such as Potamogeton sp. and Myriophyllum sp., in the freshwater to brackish water of the coastal areas. The Paq' ratio may thus reflect fluctuations in the regional expansion of freshwater to brackish coastal environments in the Baltic Sea.

  11. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S. P.; Finley, R. J.; Galloway, W. E.; Gustavson, T. C.; Handford, C. R.; Presley, M. W.

    1979-01-01

    Early in 1977 the Bureau of Economic Geology was invited to assemble and evaluate geologic data on several salt-bearing basins within the State of Texas as a contribution to the national nuclear repository program. In response to this request, the Bureau, acting as a technical research unit of the University of Texas at Austin and the State of Texas, initiated a long-term program to assemble and interpret all geologic and hydrologic information necessary for delineation, description, and evaluation of salt-bearing strata in the Panhandle area. The technical program can be subdivided into three broad research tasks, which are addressed by a basin analysis group, a surface studies group, and a basin geohydrology group. The basin analysis group has assembled the regional stratigraphic and structural framework of the total basin fill, initiated evaluation of natural resources, and selected stratigraphic core sites for sampling the salt and associated beds. Two drilling sites have provided nearly 8000 feet (2400 m) of core material for analysis and testing of the various lithologies overlying and interbedded with salt units. Concurrently, the surface studies group has collected ground and remotely-sensed data to describe surficial processes, including carbonate and evaporate solution, geomorphic evolution, and fracture system development. The newly formed basin geohydrology group will evaluate both shallow and deep circulation of fluids within the basins. This paper, a summary report of progress, reviews principal conclusions and illustrates the methodologies used and the types of data and displays generated.

  12. Annual report on paleoclimate studies for the Yucca Mountain project site characterization conducted by the Desert Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The prospect that Yucca Mountain may become a repository for high-level radionuclides with especially long half-lives means that the intended waste containment area must be well beyond the reach of the hydrologic system for at least ten millennia. Through the integration of several avenues of paleoclimatic proxy data, the authors intend to arrive at definite conclusions regarding rates of change, and extremes and stabilities of past climate regimes. These will in turn lead to rough estimates of: the amounts of rainfall available for recharge during past periods of effectively wetter climate, and the durations and frequencies of recharge periods. The paper gives summaries of the following studies: Late Quaternary and Holocene climate derived from vegetation history and plant cellulose stable isotope records from the Great basin of western North America; Accomplishments of paleofaunal studies, 1993--1994; Geomorphology studies in the Great Basin; Alluvial fan response to climatic change, Buena Vista Valley, central Nevada; Sedimentology, stratigraphy, and chronology of lacustrine deposition in the Fernley Basin, west-central Nevada; Tree-rings, lake chronologies, alluvial sequences and climate--Implications for Great Basin paleoenvironmental studies; Stable isotopic validation studies--Fossil snails; and Late Pleistocene and Holocene eolian activity in the Mojave Desert.

  13. The effects of drainage basin geomorphometry on minimum low flow discharge: the study of small watershed in Kelang River Valley in Peninsular Malaysia

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This study investigate the relationships between geomorphometric properties and the minimum low flow discharge of undisturbeddrainage basins in the Taman Bukit Cahaya Seri Alam Forest Reserve, Peninsular Malaysia.The drainage basins selected were third-orderbasins so as to facilitate a common base for sampling and performing an unbiased statistical analyses.Three levels of relationships were observedin the study.Significant relationships existed between the geomorphometric properties as shown by the correlation network analysis; secondly,individual geomorphometric properties were observed to influence minimum flow discharge; and finally, the multiple regression model set upshowed that minimum flow discharge( Q min) was dependent of basin area(AU), stream length( LS ), maximum relief( Hmax), average relief(HAV) and stream frequency (SF).These findings further enforced other studies of this nature that drainage basins were dynamic andfunctional entities whose operations were governed by complex interrelationships occurring within the basins.Changes to any of thegeomorphometric properties would influence their role as basin regulators thus influencing a change in basin response.In the case of the basin's minimum low flow, a change in any of the properties considered in the regression model influenced the "time to peak" of flow.A shorter timeperiod would mean higher discharge, which is generally considered the prerequisite to flooding.This research also conclude that the role ofgeomorphometric properties to control the water supply within the stream through out the year even though during the drought and lessprecipitations months.Drainage basins are sensitive entities and any deteriorations involve will generate reciprocals and response to the watersupply as well as the habitat within the areas.

  14. The Amaranth Formation of the Williston Basin: Paleomagnetic, Petrologic and Geochemical studies

    Science.gov (United States)

    Szabo, E.; Cioppa, M. T.; Al-Aasm, I.

    2008-12-01

    Major debate continues to exist concerning the time of deposition of the Amaranth Formation in the Williston Basin of North America, with postulated ages of Pennsylvanian, Permian, Triassic, Lower and Middle Jurassic. A multidisciplinary study of the lower member of the Amaranth Formation was conducted in six wells in Manitoba. The lower Amaranth red beds are composed of red carbonate-rich and carbonate-poor interbedded sandstones/siltstones/shales containing dolomite and anhydrite and lacking diagnostic fossils. Preliminary analysis of the oxygen and carbon isotope values measured for replacive and cement dolomite show variations related to particular lithologies that can be correlated to the types of dolomite present in the rocks. The siliciclastic sections are dominated by detrital, zoned dolomite that has recrystallized rims, whereas in the more carbonate-rich and evaporitic samples with little to no clastic content, replacive matrix dolomite is the dominant phase. Dolomite samples from the siliciclastic sections are characterized by relatively depleted carbon and oxygen isotope values, the dolomite matrix samples have relatively enriched oxygen and carbon isotope values and a few samples containing replacement matrix dolomite with minor clastic input have intermediate isotope values. These variations reflect primary and diagenetic overprints. Hematite is the major magnetization carrier, with occasional softer magnetic minerals such as magnetite. Optical microscopy revealed the existence of two types of hematite: detrital specular hematite and very fine red pigment hematite. The paleomagnetic data reveals at least three episodes of magnetization. The most pervasive magnetization, B, was formed during the Permian-Carboniferous Kiaman Reverse Superchron. An isolated magnetization in a couple of wells, C, suggests a remagnetization event that happened sometime between mid-Jurassic and Neogene, possibly resulting from a localized oxidizing fluid flow event. The

  15. Hydrological modeling as a tool for sustainable water resources management: a case study of the Awash River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Tessema, Selome M.

    2011-07-01

    The growing pressure on the world's fresh water resources is enforced by population growth that leads to conflicts between demands for different purposes. A main concern on water use is the conflict between the environment and other purposes like hydropower, irrigation for agriculture and domestic and industry water supply, where total flows are diverted without releasing water for ecological conservation. As a consequence, some of the common problems related to water faced by many countries are shortage, quality deterioration and flood impacts. Hence, utilization of integrated water resources management in a single system, which is built up by river basin, is an optimum way to handle the question of water. However, in many areas, when planning for balancing water demands major gaps exist on baseline knowledge of water resources. In order to bridge these gaps, hydro-logical models are among the available tools used to acquire adequate understanding of the characteristics of the river basin. Apart from forecasting and predicting the quantity and quality of water for decision makers, some models could also help in predicting the impacts of natural and anthropogenic changes on water resources and also in quantifying the spatial and temporal availability of the resources. However, main challenges lie in choosing and utilizing these models for a specific basin and managerial plan. In this study, an analysis of the different types of models and application of a selected model to characterize the Awash River basin, located in Ethiopia, is presented. The results from the modeling procedure and the performance of the model are discussed. The different possible sources of uncertainties in the modeling process are also discussed. The results indicate dissimilar predictions in using different methods; hence proper care must be taken in selecting and employing available methods for a specific watershed prior to presenting the results to decision makers

  16. Remapping annual precipitation in mountainous areas based on vegetation patterns: a case study in the Nu River basin

    Science.gov (United States)

    Zhou, Xing; Ni, Guang-Heng; Shen, Chen; Sun, Ting

    2017-02-01

    Accurate high-resolution estimates of precipitation are vital to improving the understanding of basin-scale hydrology in mountainous areas. The traditional interpolation methods or satellite-based remote sensing products are known to have limitations in capturing the spatial variability of precipitation in mountainous areas. In this study, we develop a fusion framework to improve the annual precipitation estimation in mountainous areas by jointly utilizing the satellite-based precipitation, gauge measured precipitation, and vegetation index. The development consists of vegetation data merging, vegetation response establishment, and precipitation remapping. The framework is then applied to the mountainous areas of the Nu River basin for precipitation estimation. The results demonstrate the reliability of the framework in reproducing the high-resolution precipitation regime and capturing its high spatial variability in the Nu River basin. In addition, the framework can significantly reduce the errors in precipitation estimates as compared with the inverse distance weighted (IDW) method and the TRMM (Tropical Rainfall Measuring Mission) precipitation product.

  17. 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.

  18. Reducing the basin vulnerability by land management practices under past and future climate: a case study of the Nam Ou River Basin, Lao PDR

    Directory of Open Access Journals (Sweden)

    M. Maharjan

    2014-08-01

    Full Text Available This research evaluates different land management practices for the Nam Ou River Basin in Northern Laos for reducing vulnerability of the basin due to erosion and sediment yield under existing and future climate conditions. We use climate projection data (precipitation and temperature from three general circulation models (GCMs for three greenhouse gas emission scenarios (GHGES, namely B1, A1B and A2 and three future periods, namely 2011–2030, 2046–2065 and 2080–2099. These large resolution GCM data are downscaled using the Long Ashton Research Station-Weather Generator (LARS-WG. The Soil and Water Assessment Tool (SWAT, which is a process based hydrological model, is used to simulate discharge and sediment yield and a threshold value of annual sediment yield is applied to identify vulnerable sub-basins. Results show that the change in the annual precipitation is expected to be between −7.60 to 2.64% in 2011–2030, −8.98 to 11.85% in 2046–2065, and −11.04 to 25.84% in 2080–2099. In the meantime, the changes in mean monthly temperature vary from 0.3 to 1.3 °C in the 2011–2030, 1.3 to 2.9 °C in the 2046–2065 and 1.9 to 4.9 °C in the 2080–2099. Five sub-basins are identified vulnerable (critical under the current climate. Our results show that terracing is the most effective land management practice to reduce sediment yield in these sub-basins followed by strip-cropping and filter strip. Appropriate land management practices applied under future climate scenarios show significant reduction in sediment yield (i.e. up to the tolerance limit except for some sub-basins. In these exceptional sub-basins, designing an optimum combination of management practices is essential to reduce the vulnerability of the basin.

  19. Successor Characteristics of the Mesozoic and Cenozoic Songliao Basins

    Institute of Scientific and Technical Information of China (English)

    LI Zhongquan; Timothy KUSKY; YING Danlin; GUO Xiaoyu; LI Hongkui

    2008-01-01

    The Songliao basin is a complex successor basin that was initiated in the Mesozoic and experienced multiple periods of reactivation. Based on seismic and drilling data, as well as regional geologic research, we suggest that the Songliao basin contains several different successor basins resting on top of Carboniferous-Permian folded strata forming the basement to the Songliao basin. These basins include the Triassic-Mid Jurassic Paleo-foreland basin, the Late Jurassic-Early Cretaceous downfaulted basin, and an early Cretaceous depressed basin (since the Denglouku Group). This paper presents a systematic study of the basin-mountain interactions, and reveals that there are different types of prototype basin at different geologic times. These prototype basins sequentially superimposed and formed the large Songliao basin. Discovery of the Triassic-early Middle Jurassic paleo-foreland basin fills a Triassic-early Middle Jurassic gap in the geologic history of the Songliao basin. The paleoforeland basin, downfaulted basin, and depressed thermal subsidence basin all together represent the whole Mesozoic-Cenozoic geologic history and deformation of the Songliao basin. Discovery of the Triassic-early Middle Jurassic paleo-foreland basin plays an important role both for deep natural gas exploration and the study of basin-mountain coupling in north China and eastern China in general. This example gives dramatic evidence that we should give much more attention to the polyphase tectonic evolution of related basins for the next phase of exploration and study.

  20. Water reuse in the Apatlaco River Basin (México): a feasibility study.

    Science.gov (United States)

    Moeller-Chávez, G; Seguí-Amórtegui, L; Alfranca-Burriel, O; Escalante-Estrada, V; Pozo-Román, F; Rivas-Hernández, A

    2004-01-01

    The aim of this work is to determine the technical and economic feasibility of implementing different reclamation and reuse projects that improve the quality of the Apatlaco river basin located in the central part of Mexico. A special methodology based on a decision support system was developed. This methodology allows to decide if it is convenient or not to finance a reclamation or reuse project for the most common water uses in the basin. This methodology is based on the net present value criteria (NPV) of the effective cash flow during the useful life of the project. The results obtained reveal a technical and economical feasibility for industrial reuse in Jiutepec and for agricultural reuse in Zacatepec and Emiliano Zapata. On the other hand, sanitation projects are not feasible in all cases analyzed. Therefore, Mexican Regulation (Ley Federal de Derechos en Materia de Agua) as currently implemented, does not promote and support this kind of projects.

  1. Characterization of bedded salt for storage caverns -- A case study from the Midland Basin, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hovorka, Susan D.; Nava, Robin

    2000-06-13

    The geometry of Permian bedding salt in the Midland Basin is a product of interaction between depositional facies and postdepositional modification by salt dissolution. Mapping high-frequency cycle patterns in cross section and map view using wireline logs documents the salt geometry. Geologically based interpretation of depositional and dissolution processes provides a powerful tool for mapping and geometry of salt to assess the suitability of sites for development of solution-mined storage caverns. In addition, this process-based description of salt geometry complements existing data about the evolution of one of the best-known sedimentary basins in the world, and can serve as a genetic model to assist in interpreting other salts.

  2. Geoarchaeologic and paleopedologic evidences for the holocene paleoenvironmental evolution of the Crisuri plain (Western Romania

    Directory of Open Access Journals (Sweden)

    Nicolae Josan

    2007-12-01

    Full Text Available This study is based mainly on the correlation established between the fossil soils identified within several archaeological sites from Crisuri Plain as well as the information that could be obtained by analysing their content in artefacts and paleozoological remains and takes into account the validity of some consecrated points of view, almost unanimously accepted concerning the paleoenvironmental evolution of the North Western part of Romania. Some very popular "clichés" such as the supposition of the warm and pregnant humid climate during the Atlantic period, fact which determined the wide spreading of the forests or that explains the appearance of the steppe and forest-steppe elements as a result of an intense deforestation process, seems to be contested by paleopedologic and geoarchaelogic arguments that prove the existence of several periods of climatic optimum separated by paleoenvironmental crisis periods.L'étude a pour objectif de préciser l'évolution holocène des secteurs inférieurs de la Plaine de Crişuri, domaine marqué par des mouvements de subsidence et par une tectonique encore active. La méthode utilisée s'appuie sur les relations entre différents éléments : les sols fossiles dans lesquels ont été trouvés des fragments de céramiques dont l'appartenance culturelle et de l'âge peuvent être déterminés à l'aide des méthodes archéologiques ; le rapport spatial entre les sites archéologiques et les facteurs géomorphologiques ; les données des recherches paléobotaniques et paléozoologiques existantes ; les connaissances sur les sols fossiles dont des profils représentatifs sont décrits dans des études récentes sur l'évolution holocène des paysages de la Plaine de la Transylvanie ; les travaux récents sur la reconstruction paléoenvironnementale de l'Holocène supérieur de l'Europe Centrale.Les sites contenant des vestiges de plusieurs périodes successives sont nombreux dans la plaine de Cri

  3. Paleo-environmental gateways in the eastern Canadian arctic - Recent isotope hydrology and diatom oxygen isotopes from Nettilling Lake, Baffin Island, Canada

    Science.gov (United States)

    Chapligin, B.; Narancic, B.; Meyer, H.; Pienitz, R.

    2016-09-01

    Nettilling Lake is located on Baffin Island, Nunavut, Canada between the areas of past warming (Canadian High Arctic to the North) and climatic stability (Northern Quebec and Labrador region to the South). Despite being the largest lake in the Nunavut region with a postglacial marine to lacustrine transition history only a few paleo-environmental investigations were completed in this area. The oxygen isotope composition of diatoms (δ18Odiatom) can provide valuable insights into paleo-environmental conditions. Here, the recent (isotope) hydrology and hydrochemical data from the lake are presented to facilitate the interpretation of a δ18Odiatom record from an 82 cm sediment core (Ni-2B). The well-mixed lake (δ18Owater = -17.4‰) is influenced by a heavier (less negative) isotope composition (-18.80‰) from Amadjuak River draining Amadjuak Lake to the South and water of lighter (more negative) isotopic composition (-16.4‰) from the Isurtuq River originating from Penny Ice Cap in the North-East. From the δ18Owater and δ18Odiatom of the topmost sample of core Ni-2B a Δ18Osilica-water of 1000 ln α(silica-water) = 40.2‰ for sub-recent diatoms of Nettilling Lake was calculated matching the known water-silica fractionation for fossil sediments well and thereby showing the general applicability of this proxy for paleo-reconstructions in this region. Extremely large δ18Odiatom variations in the core of more than 13‰ are mainly induced by changes in the isotopic composition of the lake water due to a shift from glaciomarine (δ18Odiatom = +34.6‰) through brackish (+23.4 to +27.2‰) towards lacustrine (+21.5‰) conditions (transition zones glaciomarine to brackish at 69 cm/7300 yr cal. BP and brackish to lacustrine at 35 cm/6000 yr cal. BP) associated with a shift in the degree of salinity. Our study provides the first evidence that paleo-salinity can be reconstructed by δ18Odiatom. Additionally, for the lacustrine section it could be demonstrated that

  4. Status of groundwater quality in the San Fernando--San Gabriel study unit, 2005--California GAMA Priority Basin Project

    Science.gov (United States)

    Land, Michael; Kulongoski, Justin T.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the approximately 460-square-mile San Fernando--San Gabriel (FG) study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study area is in Los Angeles County and includes Tertiary-Quaternary sedimentary basins situated within the Transverse Ranges of southern California. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA FG study was designed to provide a spatially unbiased assessment of the quality of untreated (raw) groundwater in the primary aquifer systems (hereinafter referred to as primary aquifers) throughout California. The assessment is based on water-quality and ancillary data collected in 2005 by the USGS from 35 wells and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifers were defined by the depth interval of the wells listed in the CDPH database for the FG study unit. The quality of groundwater in primary aquifers may be different from that in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. This study assesses the status of the current quality of the groundwater resource by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifers of the FG study unit, not the treated drinking water delivered to consumers by water purveyors.

  5. Fracture Distribution Characteristics within Low-Permeability Reservoirs:Cases Studies from Three Types of Oil-bearing Basins,China

    Institute of Scientific and Technical Information of China (English)

    Zeng Lianbo

    2006-01-01

    The permeability or/and porosity in low-permeability reservoirs mainly depends on fracture system.Wthin this kind of low-permeability reservior, fractures play a very important role on exploration and development. Because there are so many differences, such as basin properties and tectonic characteristics,among the eastern, western and central basins, the types and distribution characteristics of fractures are also obviously different. Quantitative information on fracture distribution is very important. Through the contrastive study of 7 oilfield, the differences and distribution characteristics of fractures in three types of oil-bearing basins are summarized.Due to the different geological conditions and stress state during the formation of fractures, the fracture systems in three types of basins are also different. Fractures are mainly composed of tectonic fractutres related to normal faultes in eastern basins, related to folds and reverse faultes in western basins, and regional fractures which widely distributed not only in outcrops but also at depth of the relatively undeformed strata in central basins. So, besides jointed-fractures, we can often see faulted-fractures similar to normal faults in eastern basins and similar to reverse faults in western basins.According to statistical data, fracture spacing generally has a lognormal distribution and is linearly proportional to layer thickness. The development degree of fractures is controlled by lithology, bed thickness,sedimentary microfacies and faults or folds, etc. The permeability, aperture and connectedness of fractures are related to the modern stress field. Though there are 3-4 sets of fractures in a oilfield, the fractures parallel to the maximum principal stress direction are main for the pattern arrangement of low-permeability reservoirs.

  6. Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

    NARCIS (Netherlands)

    Shrestha, B.; Babel, M.S.; Maskey, S.; Van Griensven, A.; Uhlenbrook, S.; Green, A.; Akkharath, I.

    2013-01-01

    This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) a

  7. Late Pleistocene to Holocene alluvial tableland formation in an intra-mountainous basin in a tectonically active mountain belt - A case study in the Puli Basin, central Taiwan

    NARCIS (Netherlands)

    Tseng, Chia Han; Lüthgens, Christopher; Tsukamoto, Sumiko; Reimann, Tony; Frechen, Manfred; Böse, Margot

    2016-01-01

    The morphology in Taiwan is a product of high tectonic activity at the convergent margin and East Asian monsoon climate. Tablelands are prominent geomorphic features in the Puli Basin in central Taiwan. These tablelands provide an archive to understand links between past climatic evolution and te

  8. “盆”“山”耦合在异常高压盆地流体研究中的应用%Application of basin-orogeny coupling in study of abnormally high pressured basin fluids

    Institute of Scientific and Technical Information of China (English)

    吴根耀; 梁江平; 杨建国; 朱德丰; 陈均亮; 申家年

    2012-01-01

    这是以“盆”“山”耦合理论指导盆地异常高压研究的首次尝试.异常高压的成因和分布特征主要取决于区域构造应力场,在挤压型盆地中形成异常高压的主控因素是挤压应力和天然气(油气)充注,异常高压呈平行造山带的(宽)带状或连续的面状分布;拉张型盆地和剪切—拉分盆地的主控因素是热作用.异常高压在拉张型盆地中为散点状或被分隔的面状分布,在剪切型盆地中呈点状或散点状分布.不同类型的盆地内断裂的产状不同,决定了异常高压有不同的传导方向,挤压—反转时异常高压的保存或释放(泄压)也各具特点.这为“盆”“山”耦合从指导盆地动态演化的研究发展引伸为指导储层和流体动态演化的研究跨出了重要的一步.%The basin-orogeny coupling theory was applied to study the abnormally high pressure in basin for the first time in this paper. The formation and distribution of abnormally high pressure were controlled by regional stress fields. In compressed basins, the key contributing factors for abnormally high pressure were compressive stress and charging of natural gas (or oil-gas), where the abnormally high pressure distributed zonaly or planar-ly. In extended and pull-apart basins, the abnormally high pressure was mainly resulted from thermal activities. In extended basins, the abnormally high pressure distributed in the shape of scattered points or restricted planes, and it distributed pointedly or in the shape of scattered points in sheared basins. The reverse, normal and strike -slip faults had different occurrences, which decided the oblique or vertical conductions of abnormally high pressure. There were different ways for pressure reservation or releasing in compression or reversion. From the dynamic evolution of basin to the dynamic evolution of reservoir and fluid, it was an important step for the application of basin-orogeny coupling theory.

  9. 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

  10. Multiproxy Paleoenvironmental Records Spanning the INTIMATE Timescale from Auckland Maar Lakes, New Zealand

    Science.gov (United States)

    Augustinus, Paul; D'Costa, Donna; Stephens, Tom; Atkin, Dan; Shane, Phil; Cochran, Ursula; Snowball, Ian; Nilsson, Andreas; Street-Perrott, Alayne; Davies, Sarah

    2010-05-01

    High-resolution Late Quaternary paleoclimate archives are preserved in the lake sediment records contained in several maar craters from the Auckland region in northern New Zealand. Tephrochronology, AMS 14C and Ar/Ar -based chronostratigraphies were developed with several lakes containing laminated sediment records spanning much of the last glacial cycle. A multi-proxy approach was taken to construct a reliable record of local and regional paleoenvironments including: pollen and diatom paleoecology, environmental magnetism, grain size, XRF geochemistry, TOC, TN, TS, organic matter δ13C, δ15N and δD, as well as δ18O in biogenic silica. Pollen and diatom analysis of records spanning the last ca 60 ka show marked vegetation changes that reflect orbital forcing, although diatoms suggest significant hydrological changes that are not reflected in the pollen. Reduction of forest with expansion of grass and shrublands at the start of the LGM (29 ka BP), is accompanied by cool, dry and windy conditions, although the situation is complex with multiple brief warmer phases punctuating the LGM. Post-glacial warming commenced ca 17.9 ka BP and is reflected in several proxies, although the pollen record does not display the marked changes displayed in many of the other proxies during the LGIT and Holocene. Some of the inferred environmental changes are similar to the nature and timing of short-duration events during the last glacial cycle from the North Atlantic region, although others appear to reflect a southern polar forcing. The multi-proxy approach used has produced one of the most complete, well-dated and high-resolution paleoenvironmental records spanning the INTIMATE timescale from the mid-latitude Southern Hemisphere with implications for the nature, timing and forcings of climate change in the Southwest Pacific region.

  11. Paleoenvironmental significance of clay mineral assemblages in the southeastern Arabian Sea during last 30 kyr

    Indian Academy of Sciences (India)

    Siddhartha Sankar Das; Ajai K Rai; Vaseem Akaram; Dhananjai Verma; A C Pandey; Koushik Dutta; G V Ravi Prasad

    2013-02-01

    A gravity core SK-221 recovered from the southeastern Arabian Sea near Laccadive–Chagos Ridge was examined to identify the sources of detrital clay minerals and to decipher paleoenvironmental changes for the last 30 kyr. The clay mineral assemblages predominantly consist of illite, kaolinite and chlorite with small amounts of smectite. Quartz, feldspar and occasionally gibbsite are the clay-sized non-clay minerals present in the examined section. The detrital clay minerals primarily originated from the hinterland and were supplied to the present site by the numerous small rivers draining western India during preglacial and Holocene periods, and partly by the strong reworking of Indian continental shelf during glacial period. The low values of humidity proxies (kaolinite content, kaolinite to illite and smectite to illite ratios) and better illite crystallinity indicate relatively weak summer monsoon condition that resulted in reduced chemical weathering during glacial period, which was interrupted by a discrete event of winter monsoon intensification at ∼20–17 ka. The increased kaolinite content, higher values of humidity indices and poorer illite crystallinity reflect high humidity that resulted in strong hydrolysis activity during the preglacial and Holocene periods. The increased CaCO3 during above periods also indicates less terrigenous dilution and intensified southwest monsoon-led upwelling which result in higher surface biogenic productivity. The characteristic clay mineral associations broadly suggest dry to semi-drier conditions during Heinrich Events H1, H2, and H3 and also during Younger Dryas. The low values of biogenic carbonate and organic carbon also indicate low productivity associated with weak summer monsoons during Heinrich Events. Abrupt increased humidity was recorded at 15–12.7 ka (Bølling/Allerød Event) sandwiched between two lows of Heinrich Events. Cycles of millennial timescale variations 2300, 1800, 1300 and 1000 yr have been

  12. Palaeomagnetic studies in the Permian Basin of Largentière and implications for the Late Variscan rotations in the French Massif Central

    Science.gov (United States)

    Henry, B.; Becq-Giraudon, J. F.; Rouvier, H.

    1999-07-01

    Detailed geological observations and palaeomagnetic analyses were carried out in the Largentière Stephano-Autunian basin and on the Stephanian deposits of the Alès coalfield, both located at the southeastern margin of the French Massif Central. Because of unfavourable rock types, the Alès Stephanian deposits did not yield any results. The palaeomagnetic pole (164.9 degE, 45.4 degN, K=89, A_95=4.1 deg) deduced from a study of the Autunian sediments of the Largentière Basin agrees very well with the reference pole for stable Europe. The Lodève-Largentière area, that is the southeastern border of the Massif Central, has been stable since Early Permian time with respect to stable Europe, whereas the western part (the Saint-Affrique Rodez Basin and, probably, the Brive Basin) has been rotated counterclockwise.

  13. Identifying stakeholder-relevant climate change impacts: a case study in the Yakima River Basin, Washington, USA

    Science.gov (United States)

    Jenni, K.; Graves, D.; Hardiman, Jill M.; Hatten, James R.; Mastin, Mark C.; Mesa, Matthew G.; Montag, J.; Nieman, Timothy; Voss, Frank D.; Maule, Alec G.

    2014-01-01

    Designing climate-related research so that study results will be useful to natural resource managers is a unique challenge. While decision makers increasingly recognize the need to consider climate change in their resource management plans, and climate scientists recognize the importance of providing locally-relevant climate data and projections, there often remains a gap between management needs and the information that is available or is being collected. We used decision analysis concepts to bring decision-maker and stakeholder perspectives into the applied research planning process. In 2009 we initiated a series of studies on the impacts of climate change in the Yakima River Basin (YRB) with a four-day stakeholder workshop, bringing together managers, stakeholders, and scientists to develop an integrated conceptual model of climate change and climate change impacts in the YRB. The conceptual model development highlighted areas of uncertainty that limit the understanding of the potential impacts of climate change and decision alternatives by those who will be most directly affected by those changes, and pointed to areas where additional study and engagement of stakeholders would be beneficial. The workshop and resulting conceptual model highlighted the importance of numerous different outcomes to stakeholders in the basin, including social and economic outcomes that go beyond the physical and biological outcomes typically reported in climate impacts studies. Subsequent studies addressed several of those areas of uncertainty, including changes in water temperatures, habitat quality, and bioenergetics of salmonid populations.

  14. Water allocation assessment in low flow river under data scarce conditions: a study of hydrological simulation in Mediterranean basin.

    Science.gov (United States)

    Bangash, Rubab F; Passuello, Ana; Hammond, Michael; Schuhmacher, Marta

    2012-12-01

    River Francolí is a small river in Catalonia (northeastern Spain) with an average annual low flow (~2 m(3)/s). The purpose of the River Francolí watershed assessments is to support and inform region-wide planning efforts from the perspective of water protection, climate change and water allocation. In this study, a hydrological model of the Francolí River watershed was developed for use as a tool for watershed planning, water resource assessment, and ultimately, water allocation purposes using hydrological data from 2002 to 2006 inclusive. The modeling package selected for this application is DHI's MIKE BASIN. This model is a strategic scale water resource management simulation model, which includes modeling of both land surface and subsurface hydrological processes. Topographic, land use, hydrological, rainfall, and meteorological data were used to develop the model segmentation and input. Due to the unavailability of required catchment runoff data, the NAM rainfall-runoff model was used to calculate runoff of all the sub-watersheds. The results reveal a potential pressure on the availability of groundwater and surface water in the lower part of River Francolí as was expected by the IPCC for Mediterranean river basins. The study also revealed that due to the complex hydrological regime existing in the study area and data scarcity, a comprehensive physically based method was required to better represent the interaction between groundwater and surface water. The combined ArcGIS/MIKE BASIN models appear as a useful tool to assess the hydrological cycle and to better understand water allocation to different sectors in the Francolí River watershed.

  15. SWAT use of gridded observations for simulating runoff - a Vietnam river basin study

    Science.gov (United States)

    Vu, M. T.; Raghavan, S. V.; Liong, S. Y.

    2012-08-01

    Many research studies that focus on basin hydrology have applied the SWAT model using station data to simulate runoff. But over regions lacking robust station data, there is a problem of applying the model to study the hydrological responses. For some countries and remote areas, the rainfall data availability might be a constraint due to many different reasons such as lacking of technology, war time and financial limitation that lead to difficulty in constructing the runoff data. To overcome such a limitation, this research study uses some of the available globally gridded high resolution precipitation datasets to simulate runoff. Five popular gridded observation precipitation datasets: (1) Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE), (2) Tropical Rainfall Measuring Mission (TRMM), (3) Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN), (4) Global Precipitation Climatology Project (GPCP), (5) a modified version of Global Historical Climatology Network (GHCN2) and one reanalysis dataset, National Centers for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR) are used to simulate runoff over the Dak Bla river (a small tributary of the Mekong River) in Vietnam. Wherever possible, available station data are also used for comparison. Bilinear interpolation of these gridded datasets is used to input the precipitation data at the closest grid points to the station locations. Sensitivity Analysis and Auto-calibration are performed for the SWAT model. The Nash-Sutcliffe Efficiency (NSE) and Coefficient of Determination (R2) indices are used to benchmark the model performance. Results indicate that the APHRODITE dataset performed very well on a daily scale simulation of discharge having a good NSE of 0.54 and R2 of 0.55, when compared to the discharge simulation using station data (0.68 and 0.71). The GPCP proved to be the

  16. SWAT use of gridded observations for simulating runoff – a Vietnam river basin study

    Directory of Open Access Journals (Sweden)

    M. T. Vu

    2012-08-01

    Full Text Available Many research studies that focus on basin hydrology have applied the SWAT model using station data to simulate runoff. But over regions lacking robust station data, there is a problem of applying the model to study the hydrological responses. For some countries and remote areas, the rainfall data availability might be a constraint due to many different reasons such as lacking of technology, war time and financial limitation that lead to difficulty in constructing the runoff data. To overcome such a limitation, this research study uses some of the available globally gridded high resolution precipitation datasets to simulate runoff. Five popular gridded observation precipitation datasets: (1 Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE, (2 Tropical Rainfall Measuring Mission (TRMM, (3 Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN, (4 Global Precipitation Climatology Project (GPCP, (5 a modified version of Global Historical Climatology Network (GHCN2 and one reanalysis dataset, National Centers for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR are used to simulate runoff over the Dak Bla river (a small tributary of the Mekong River in Vietnam. Wherever possible, available station data are also used for comparison. Bilinear interpolation of these gridded datasets is used to input the precipitation data at the closest grid points to the station locations. Sensitivity Analysis and Auto-calibration are performed for the SWAT model. The Nash-Sutcliffe Efficiency (NSE and Coefficient of Determination (R2 indices are used to benchmark the model performance. Results indicate that the APHRODITE dataset performed very well on a daily scale simulation of discharge having a good NSE of 0.54 and R2 of 0.55, when compared to the discharge simulation using station data (0

  17. Study on source rock potential and source rocks spatial distribution in the Manghan Faulted Sag, Kailu Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Manghan Faulted Sag is an exploratory target area in Kailu Basin. In order to determine its exploration prospect, the effectiveness of its source rocks is evaluated by organic geochemical behavior analysis of the samples, and their distributions are predicted using trace integration seismic inversion technology. Studies on their organic matter abundance, type and maturity indicate that the source rocks in the Sag have great generating potentials. Furthermore, it is found that, based on the spatial distribution predication, the source rocks in the Sag are well developed. Therefore, the Sag has a promising prospect for exploration.

  18. Study of the Factors Affecting the Abundance of Organic Matter in Jurassic Carbonate Rocks in Qiangtang Basin, Tibet

    Institute of Scientific and Technical Information of China (English)

    文志刚; 胡明毅; 龚文平; 肖传桃

    2004-01-01

    Field and laboratory analyses of carbonate rock samples from the Qiangtang Basin,Tibet, indicate that carbonate source rocks are mainly developed in the Middle Jurassic Xiali Formation and Upper Jurassic Suowa Formation. Comprehensive studies showed that the Suowa Formation carbonate source rocks have a favorable hydrocarbon-generating potential. The abundance of organic matter in the carbonate rocks is controlled mainly by sedimentary environment and inorganic compounds in the rocks, which is higher in the restricted platform facies than in the open platform facies. Organic carbon contents decrease with increasing CaO contents in the source rocks.

  19. Determination of paleo-pressure for a natural gas pool formation based on PVT characteristics of fluid inclusions in reservoir rocks--A case study of Upper-Paleozoic deep basin gas trap of the Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    MI Jingkui; XIAO Xianming; LIU Dehan; SHEN Jiagui

    2004-01-01

    It has been proved to be a difficult problem to determine directly trapping pressure of fluid inclusions. Recently, PVT simulation softwares have been applied to simulating the trapping pressure of petroleum inclusions in reservoir rocks, but the reported methods have many limitations in practice. In this paper, a method is suggested to calculating the trapping pressure and temperature of fluid inclusions by combining the isochore equations of a gas-bearing aqueous inclusion with its coeval petroleum inclusions. A case study was conducted by this method for fluid inclusions occurring in the Upper-Paleozoic Shanxi Formation reservoir sandstones from the Ordos Basin. The results show that the trapping pressure of these inclusions ranges from 21 to 32 MPa, which is 6-7 MPa higher than their minimum trapping pressure although the trapping temperature is only 2-3℃ higher than the homogenization temperature. The trapping pressure and temperature of the fluid inclusions decrease from southern area to northern area of the basin.The trapping pressure is obviously lower than the state water pressures when the inclusions formed. These data are consistent with the regional geological and geochemical conditions of the basin when the deep basin gas trap formed.

  20. Study of human occupation impacts in the Batedor river basin in the Mantiqueira Mountain in the municipal district of Cruzeiro, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo dos Santos Targa

    2008-04-01

    Full Text Available The study of hydrographic basins as territorial units integrating the management of hydric resources is essential to guarantee sustainable use of natural resources in these basins. The establishment of the Paraíba do Sul hydrographic basins committee, in 1994, determined the need for management planning and action integration in the Paraíba do Sul basin which incorporates a variety of industries and intense land use. The Batedor river, in the municipality of Cruzeiro, SP, flows into the Passa Vinte which is an affluent of Paraíba do Sul river. Its mouth is located at 22°31’0.63”S and 45°01’2.07”W. Its farthest water contributing source lies about 8.5 km, near the Itaguaré peak 2,308 m high, in the Mantiqueira Mountain on the border of São Paulo and Minas Gerais States. To characterize land use in the Batedor hydrographic basin, Landsat imagery and topographic charts were analyzed based on remote sensing and geoprocessing techniques. This paper describes the study of impacts related to land and water resources use in the Batedor river basin and the generation of educational environmental material. Results have shown that this basin has good water supply, has no flooding risk and has several springs running down the Mantiqueira Moutain slopes that form young creeks with few meanders. Irregular human occupation for housing and subsistence agriculture, mainly banana plantations can be seen in deep slopes and riparian areas, as well as degraded pastures that indicate inappropriate land use and no conformance to pertinent legislation. The decrease in forest vegetation cover can cause severe erosion with significant soil loss and sediment deposition in the river, thus reducing water quality and quantity during the dry season. This basin is currently responsible for 70% of the Cruzeiro, SP water supply.

  1. Study of human occupation impacts in the Batedor river basin in the Mantiqueira mountain in the municipality of Cruzeiro, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo dos Santos Targa

    2008-04-01

    Full Text Available The study of hydrographic basins as territorial units integrating the management of hydric resources is essential to guarantee sustainable use of natural resources in these basins. The establishment of the Paraíba do Sul hydrographic basins committee, in 1994, determined the need for management planning information and integration actions in the Paraíba do Sul basin which incorporates a variety of industries and intense land use. The Batedor river, in the municipality of Cruzeiro, SP, flows into the Passa Vinte which is an affluent of Paraíba do Sul river. Its mouth is located at 22°31’0.63”S and 45°01’2.07”W. Its farthest water contributing source lies about 8.5 km, near the Itaguaré peak 2,308 m high, in the Mantiqueira mountain on the border of São Paulo and Minas Gerais States. To characterize land use in the Batedor hydrographic basin, Landsat imagery and topographic charts were analyzed based on remote sensing and geoprocessing techniques. This paper describes the study of impacts related to land and water resources use in the Batedor river basin and the generation of support material for environmental education. Results has shown that this basin has good water supply, has no flooding risk and has several springs running down the Mantiqueira Moutain slopes that form young creeks with few meanders. Irregular human occupation for housing and subsistence agriculture, mainly banana plantations can be seen in deep slopes and riparian areas, as well as degraded pastures that indicate inappropriate land use and no conformance to pertinent legislation. The decrease in forest vegetation cover can cause severe erosion with significant soil loss and sediment deposition in the river, thus reducing water quality and regulated quantity. This basin is currently responsible for 70% of the water supply for the city of Cruzeiro, SP.

  2. Contribution of the airborne geophysical survey to the study of the regolith : A case study in southern Paris Basin.

    Science.gov (United States)

    Prognon, Francois; Lacquement, Fréderic; Deparis, Jacques; Martelet, Guillaume; Perrin, José

    2010-05-01

    Studies of soil and subsoil, also called regolith, are at the crossroads of scientific new challenging questions as well as new environmental needs. Historically, geological maps were focussed on solid geology. Present societal needs increasingly require knowledge of regolith properties: superficial studies combining geology, geochemistry and geophysics become essential to better understand the natural processes which govern the repartition and evolution of subsoil formations. Such progress is critical to better orient the use and management of natural and groundwater resources. Among other techniques, airborne geophysics is appropriate to provide information on near surface, because of i) its high spatial coverage ii) the rapidity of acquisition and iii) the variety of available sensors (magnetic, spectral radiometry, electromagnetic …). We illustrate the results of an airborne geophysical survey carried out in France, in "Région Centre" administrative region in the southern part of the Paris Basin. Spectral radiometry data were collected throughout "Région Centre" with a line spacing of 1 km. This method provides maps of potassium (K), uranium (U) and thorium (Th) which are the only naturally occurring elements with direct or indirect radioisotopes that produce gamma rays of sufficient intensity to be measured at airborne survey heights. Gamma-rays emitted from the Earth surface are related to the primary mineralogy and geochemistry of the bedrock and/or the nature of secondary weathering including regolith materials. Obtained images are confronted with former geological investigations (1:50 000e geological maps). Geophysical data and geological maps are generally consistent on most of the covered area since the first-rate information delivered by the spectrometry derives from the geochemistry of the solid geology. Second-rate gamma-ray responses come from superimposed allochtonous deposits as well as in situ geochemical modifications. For instance

  3. Trilobites, scolecodonts and fish remains occurrence and the depositional paleoenvironment of the upper Monte Alegre and lower Itaituba formations, Lower - Middle Pennsylvanian of the Amazonas Basin, Brazil

    Science.gov (United States)

    Moutinho, Luciane Profs; Nascimento, Sara; Scomazzon, Ana Karina; Lemos, Valesca Brasil

    2016-12-01

    This study aims to characterize the scolecodonts, trilobite pygidium fragments and fish remains of an outcropped region in the southern Amazonas Basin, comprising the uppermost section of the Monte Alegre Formation and the basal section of the Itaituba Formation. These, correspond to part of the marine portion of the Tapajós Group, related to an intracratonic carbonate platform. The Monte Alegre Formation includes a deposition of fluvial-deltaic and aeolian sandstones, siltstones and shales of interdunes and lakes, intercalated with transgressive carbonates of a shallow restrict nearshore marine environment. The Itaituba Formation comprises a thickest deposit of marine carbonates, representing the establishment of widespread marine conditions, and is the richest interval containing organisms of shallow marine environment in the Pennsylvanian of the Amazonas Basin. The associated fauna includes brachiopods, bivalves, gastropods, crinoids, echinoids, bryozoans, corals, foraminifers, sponges, ostracods, trilobites, scolecodonts, fish remains and conodonts, mainly in the packstones, and subordinately in the wackestones and mudstones. Conodonts Neognathodus atokaensis, Diplognathodus orphanus, Idiognathodus incurvus, and foraminifers Millerella extensa, Millerella pressa, Millerella marblensis, Eostaffella ampla, Eostaffella pinguis and Eostaffella advena characterizes a predominant Atokan age to the analyzed profile. The fossil association herein presented is taxonomically diversified and biologically interesting, comprising an important and well preserved, for the first time occurrence of two molds and two fragments of Proetida trilobites. Well preserved Eunicida and Phyllodocida scolecodonts and paleonisciform fish remains. These fossils help in the paleoenvironmental establishment of the studied interval in the Amazonas Basin and as a potential biostratigraphic and paleoecological tool to correlate regionally and globally the Pennsylvanian.

  4. A comparative study of physical property measurements collected around the Sudbury basin

    Science.gov (United States)

    Parry, Devon G.

    Throughout the Sudbury basin, physical property measurements have been taken in boreholes in order to extract information about the geology close to the borehole. Due to a large number of geophysical instruments currently being deployed for the purpose of downhole logging, it is difficult to determine the strengths and weaknesses of each probe. Since each system uses different physical principles, measurement frequencies and calibration procedures, results from different instruments can vary greatly. By qualitatively comparing newly acquired data to information previously collected, strengths and weaknesses of each system can be identified. The instruments compared in this study were the Geonics EM39, the IFG BIC-01 and the IFG BMP-06. Conductivity was also collected during surveys completed by DGI Geosciences. The DGI surveys collected conductivity measurements using both a galvanic and an inductive technique. The downhole measurements were also compared to conductivity values collected on diamond drill core hand samples. The surveys of the hand samples were not expected to produce the same results as the measurements collected downhole because the rock being measured in the hand samples is under much less pressure, is dry and is a smaller volume of rock measured than in the downhole measurements. The inductive methods provided results that showed similar trends to one another but dramatically different values. This was due to the sensors being spaced much further apart in the EM39 than the other instruments. This created an averaging effect which caused zones of patchy mineralization to appear as one large range of conductive material. The IFG inductive tools were able to detect the changes from patchy mineralization to resistive host rock. Since the EM39 was designed for groundwater measurements, the instrument appeared to have an upper limit of 3 S/m which was often reached in zones of mineralization. Above this threshold, no accurate results could be measured

  5. Experimental study on supercritical CO2 adsorption on coals from Upper Silesian coal Basin

    Science.gov (United States)

    Weishauptová, Zuzana; Přibyl, Oldřich; Sýkorová, Ivana

    2014-05-01

    of drill cores from exploration boreholes in the Bohemian part of the Upper Silesian Basin, and were characterized by a narrow range of the degree of coalification and extremely different petrographic composition. A positive correlation has been found between the equilibrium moisture in the coal samples and the total abundance of oxygen functional groups determined by FTIR. The experimental isotherm data were fitted partly by the modified Langmuir sorption isotherm, partly by the modified Dubinin-Radushkevich sorption isotherm. The calculated values of sorption capacities were compared. After recalculation to the mineral-matter free basis, a positive trend has been observed in the studied samples in the dependence of the sorption capacity on the micropore volume, as well as a positive trend in the dependence on percentage of vitrinite and collotelinite, which forms a major part of vitrinite. On the contrary, a negative trend has been found in the dependence on inertinite percentage.

  6. Site effects and soil-structure resonance study in the Kobarid basin (NW Slovenia using microtremors

    Directory of Open Access Journals (Sweden)

    A. Gosar

    2010-04-01

    Full Text Available The town of Kobarid is located in one of three areas with the highest seismic hazard in Slovenia. It was hit by several 1976–1977 Friuli sequence earthquakes and recently by the 1998 and 2004 Krn Mountains earthquakes which caused damage of intensity up to VII EMS-98 scale. The town is located in a small basin filled with heterogeneous glaciofluvial Quaternary sediments in which site effects due to soft sediments are expected. The existing microzonation which is based on surface geological data only is inadequate, and no borehole or geophysical data are available in the basin that would allow a modelling approach of site effects assessment. The microtremor horizontal-to-vertical spectral ratio (HVSR method was therefore applied in order to assess the fundamental frequency of the sediments. Investigations were performed on a 100×100 m dense grid and 106 free-field measurements acquired. Clear HVSR peaks were obtained in the majority of the surveyed area. The eastern part of the basin is characterized by two well separated peaks which indicate distinct shallow and deep impedance contrasts. The iso-frequency map of sediments shows a distribution in a broad range of 1.8–22.2 Hz. The observed frequencies can be related to the total thickness of Quaternary sediments (sand, gravel in the western part of the basin only. They are deposited over bedrock built of Cretaceous flysch. In the eastern part the obtained fundamental frequencies are influenced by the presence of a shallow conglomerate layer inside sandy gravel or lacustrine chalk. The extent of these layers was not known before. Microtremor measurements were also performed inside 19 characteristic buildings of various heights (from two to four stories, and longitudinal and transverse fundamental frequencies determined from amplitude spectra. A potential of soil-structure resonance was assessed by comparing building frequencies with the free-field sediments frequencies derived from the iso

  7. Global Spent Fuel Logistics Systems Study (GSFLS). Volume 4. Pacific basin spent fuel logistics system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    This report summarizes the conceptual framework for a Pacific Basin Spent Fuel Logistics System (PBSFLS); and preliminarily describes programatic steps that might be taken to implement such a system. The PBSFLS concept is described in terms of its technical and institutional components. The preferred PBSFLS concept embodies the rationale of emplacing a fuel cycle system which can adjust to the technical and institutional non-proliferation solutions as they are developed and accepted by nations. The concept is structured on the basis of initially implementing a regional spent fuel storage and transportation system which can technically and institutionally accommodate downstream needs for energy recovery and long-term waste management solutions.

  8. Evidence for seagrass meadows and their response to paleoenvironmental changes in the early Eocene (Jafnayn Formation, Wadi Bani Khalid, N Oman)

    Science.gov (United States)

    Tomás, Sara; Frijia, Gianluca; Bömelburg, Esther; Zamagni, Jessica; Perrin, Christine; Mutti, Maria

    2016-07-01

    The recognition and understanding of vegetated habitats in the fossil record are of crucial importance in order to investigate paleoecological responses and indirectly infer climate and sea-level changes. However, the low preservation potential of plants and macroalgae hampers a direct identification of these environments in the geological past. Here we present sedimentological and paleontological evidences as tool to identify the presence of different seagrass-vegetated environments in the shallow marine settings of the lower Eocene Jafnayn platform of Oman and their responses to paleoenvironmental changes. The studied lower Eocene deposits consist of well bedded, nodular packstones dominated by encrusting acervulinid and alveolinid foraminifera passing upward to an alternance of packstones with echinoids and quartz grains and grainstones rich in Orbitolites, smaller miliolid foraminifera and quartz grains. The presence of seagrass is inferred by the occurrence of encrusting acervulinids and soritid Orbitolites, as well as by their test morphologies together with further sedimentological criteria. The clear shift observed in the faunal assemblages and sedimentary features may be related to a major reorganization of the carbonate system passing from a carbonate platform to a ramp-like platform with increased terrigenous sedimentation. Heterotroph tubular acervulinids and oligotroph alveolinids of the carbonate platform were replaced upward by more heterotroph organisms such as large, discoidal Orbitolites and smaller miliolids, most likely due to enhanced nutrient levels which would have led to a change of phytal substrate, from cylindrical-leaf dominated grasses into flat-leafed ones.

  9. Exploring the Geomorphology of the Amazon's Planalto with Imaging Radar: Understanding the Origins of the Modern Amazon Basin

    Science.gov (United States)

    McDonald, K. C.; Campbell, K.; Islam, R.; Azarderakhsh, M.; Cracraft, J.

    2013-12-01

    Amazonia is Earth's most iconic center of biological diversity and endemism and, owing to its contributions to global systems ecology, is arguably Earth's most important terrestrial biome . Amazonia includes a vast landscape of mostly lowland rainforest found in Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela. It harbors the world's highest species diversity, the largest fresh-water ecosystem in the world, and contributes substantially to shaping the Earth's atmospheric gasses and oceans and consequently its climate. Despite this global importance, we still have an incomplete understanding of how this biodiversity-rich biome developed over time. Knowing its history is crucially important for understanding how the short and long-term effects of biodiversity loss and climate change will impact the region, and the globe, in the future. Hence, we seek to understand the evolutionary and environmental-ecological history of Amazonia over the past 10 million years through a comparative approach that integrates across the disciplines of systematic biology, population biology, ecosystem structure and function, geology, Earth systems modeling and remote sensing, and paleoenvironmental history. During springtime 2013, the NASA/JPL airborne imaging radar, UAVSAR, conducted airborne studies over many regions of South America including portions of the western Amazon basin. We utilize UAVSAR imagery acquired over the Madre de Dios region of southeastern Peru in an assessment of the underlying geomorphology of the Amazon's planalto, its relationship to the current distribution of vegetation, and its relationship to geologic processes through deep time. In the late Neogene, the Amazonian lowlands comprised either a series of independent basins or a single sedimentary basin. The Amazonian planalto is variously described as either an erosional surface or a surface of deposition. We employ UAVSAR data collections to assess (1) the utility of these high quality imaging radar

  10. Impact of climate change on sediment yield in the Mekong River Basin: a case study of the Nam Ou Basin, Lao PDR

    Directory of Open Access Journals (Sweden)

    B. Shrestha

    2012-03-01

    Full Text Available This paper evaluates the impact of climate change on sediment yield in the Nam Ou Basin located in Northern Laos. The Soil and Water Assessment Tool (SWAT is used to assess future changes in sediment flux attributable to climate change. Future precipitation and temperature series are constructed through a delta change approach. As per the results, in general, temperature as well as precipitation show increasing trends in both scenarios, A2 and B2. However, monthly precipitation shows both increasing and decreasing trends. The simulation results exhibit that the wet and dry seasonal and annual stream discharges are likely to increase (by up to 15, 17 and 14% under scenario A2; and 11, 5 and 10% under scenario B2 respectively in the future, which will lead to increased wet and dry seasonal and annual sediment yields (by up to 39, 28 and 36% under scenario A2; and 23, 12 and 22% under scenario B2 respectively. A higher discharge and more sediment flux are expected during the wet seasons, although the changes, percentage-wise, are observed to be higher during the dry months. In conclusion, the sediment yield from the Nam Ou Basin is likely to increase with climate change, which strongly suggests the need for basin-wide sediment management strategies in order to reduce the negative impact of this change.

  11. Comprehensive assessment of soil erosion risk for better land use planning in river basins: Case study of the Upper Blue Nile River.

    Science.gov (United States)

    Haregeweyn, Nigussie; Tsunekawa, Atsushi; Poesen, Jean; Tsubo, Mitsuru; Meshesha, Derege Tsegaye; Fenta, Ayele Almaw; Nyssen, Jan; Adgo, Enyew

    2017-01-01

    In the drought-prone Upper Blue Nile River (UBNR) basin of Ethiopia, soil erosion by water results in significant consequences that also affect downstream countries. However, there have been limited comprehensive studies of this and other basins with diverse agroecologies. We analyzed the variability of gross soil loss and sediment yield rates under present and expected future conditions using a newly devised methodological framework. The results showed that the basin generates an average soil loss rate of 27.5tha(-1)yr(-1) and a gross soil loss of ca. 473Mtyr(-1), of which, at least 10% comes from gully erosion and 26.7% leaves Ethiopia. In a factor analysis, variation in agroecology (average factor score=1.32) and slope (1.28) were the two factors most responsible for this high spatial variability. About 39% of the basin area is experiencing severe to very severe (>30tha(-1)yr(-1)) soil erosion risk, which is strongly linked to population density. Severe or very severe soil erosion affects the largest proportion of land in three subbasins of the UBNR basin: Blue Nile 4 (53.9%), Blue Nile 3 (45.1%), and Jema Shet (42.5%). If appropriate soil and water conservation practices targeted ca. 77.3% of the area with moderate to severe erosion (>15tha(-1)yr(-1)), the total soil loss from the basin could be reduced by ca. 52%. Our methodological framework identified the potential risk for soil erosion in large-scale zones, and with a more sophisticated model and input data of higher spatial and temporal resolution, results could be specified locally within these risk zones. Accurate assessment of soil erosion in the UBNR basin would support sustainable use of the basin's land resources and possibly open up prospects for cooperation in the Eastern Nile region.

  12. Incorporating rainfall uncertainty in a SWAT model: the river Zenne basin (Belgium) case study

    Science.gov (United States)

    Tolessa Leta, Olkeba; Nossent, Jiri; van Griensven, Ann; Bauwens, Willy

    2013-04-01

    The European Union Water Framework Directive (EU-WFD) called its member countries to achieve a good ecological status for all inland and coastal water bodies by 2015. According to recent studies, the river Zenne (Belgium) is far from this objective. Therefore, an interuniversity and multidisciplinary project "Towards a Good Ecological Status in the river Zenne (GESZ)" was launched to evaluate the effects of wastewater management plans on the river. In this project, different models have been developed and integrated using the Open Modelling Interface (OpenMI). The hydrologic, semi-distributed Soil and Water Assessment Tool (SWAT) is hereby used as one of the model components in the integrated modelling chain in order to model the upland catchment processes. The assessment of the uncertainty of SWAT is an essential aspect of the decision making process, in order to design robust management strategies that take the predicted uncertainties into account. Model uncertainty stems from the uncertainties on the model parameters, the input data (e.g, rainfall), the calibration data (e.g., stream flows) and on the model structure itself. The objective of this paper is to assess the first three sources of uncertainty in a SWAT model of the river Zenne basin. For the assessment of rainfall measurement uncertainty, first, we identified independent rainfall periods, based on the daily precipitation and stream flow observations and using the Water Engineering Time Series PROcessing tool (WETSPRO). Secondly, we assigned a rainfall multiplier parameter for each of the independent rainfall periods, which serves as a multiplicative input error corruption. Finally, we treated these multipliers as latent parameters in the model optimization and uncertainty analysis (UA). For parameter uncertainty assessment, due to the high number of parameters of the SWAT model, first, we screened out its most sensitive parameters using the Latin Hypercube One-factor-At-a-Time (LH-OAT) technique

  13. Instrumental Neutron Activation Analysis- INAA: environmental studies in Das Velhas Basin, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo V, M.A.; Andrade Q, M.T. [Researcher of National Council for Scientific and Technological Development, CNPq, Center University of the East of Minas Gerais State, UNILESTE-MG (Brazil); Araujo M, R. [CDTN (Brazil); Albernaz A, I. [SCA- CNRS/USR/059, Lyon (France); Oliveira, A.H. de [Federal University of Minas Gerais State (Brazil)]. e-mail: marvv@cdtn.br

    2006-07-01

    The Instrumental Neutron Activation Analysis - INAA was applied to determine concentrations of several elements in unpolluted areas and in the mining and farming region of the Das Velhas Basin, Minas Gerais State, Brazil. INAA was applied using the TRIGA Mark I IPR - R1 reactor at the Nuclear Technology Development Center of the National Committee of Nuclear Energy (CDTN/CNEN), in Belo Horizonte city, Minas Gerais State. At 100 kW of potency the flux of neutrons is 6.6 10{sup 11} n.cm{sup -2}.s{sup -1}. The samples analyzed were: water; sediment; gravel of gold mine and forage. The obtained results for the Das Velhas Basin in water and sediment samples - mining companies region - show a high level ({mu}g/g) of contamination with the analyzed elements, mainly in the sediment samples. During the period of floods, in farming region hundreds of kilometers away, contamination is found in fish and forage, reaching and harming both people and animals that live in the marginal region. (Author)

  14. EXPERIMENTAL STUDY AND DEVELOPMENT OF A WATER BASIN USED AS SOLAR SENSOR

    Directory of Open Access Journals (Sweden)

    S. E. Laouini

    2010-06-01

    Full Text Available Energy sources play an important role in the development of humanity, with the industrial and technological evolution of our century. Energy demand is increasing every year, for this reason we must seek an alternate source of energy more specifically new and renewable energy including solar energy. Note that solar energy is abundant, especially the south-eastern Algeria, where solar radiation is significant in any year. Given that it is the cheapest of all other energy, many researches and experiments have been conducted to recover the maximum amount of renewable energy and to address the problems of use and operation to reduce and save energy traditional.This work concerns the development of a new device is a basin filled with water used as a solar plane and a storage medium. The results obtained are very important in terms of heating water, the water temperature at outlet of basin reaches up to 74 ° C, also the inlet temperature is 29 ° C.

  15. Geological study of the northern part of Chicontepec Basin, state of San Luis Potosi

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, J.M.

    The stratigraphic subdivisions, supported by paleontological evidence, comprise Triassic to Paleocene formations. The permo-Triassic basement complex is transgressed by continental clastics of upper Triassic and lower Jurassic age, which are succeeded by marine upper Jurassic that rests unconformably on the basement complex in the northern or Tamalihuale area, on Triassic clastics in the central or Palmira-San Pedro area, and on lower Jurassic clastics in the sourthern or Maguey area. The lower Cretaceous is composed of deep-water deposits, which change into the shallow water and reefoid El Abra formation in the Tamalihuale area. The upper Cretaceous changes upward from fine clastics into argillaceous limestone, while the Paleocene is characterized by arenaceous clays. Anticlines in the basin have been unsuccessfully tested with the exception of one well in the Maguey anticline that encountered distillate and gas in fractured Agua Nueve formation (Cretaceous). Electric logs indicate very irregular and poor porosity and permeability. Potential petroleum source rocks are present in the basin, but absence of reservoir rocks accounts for lack of commercial production.

  16. Quantitative studies of hydrocarbon loss of the Silurian bitumen sandstone in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The evolution of Tarim Basin experienced several tectonic movements,of which Caledonian movement caused a serious damage to reservoirs of Silurian. The earlier reservoirs size and the later hydrocarbon loss are two key factors to exploration prospect of Silurian. On the basis of net thickness of bituminous sandstone and recovery coefficient of crude oil converting to bitumen,the scale of the hydrocarbon loss of palaeo-accumulation in bitumen sandstone of Silurian was calculated (86.30×108t). The deter-mination of net thickness of bitumen sandstone was completed mainly by several methods,such as physical property demarcation,observing lithology,grains with oil inclusion (GOI) technology,and quantitative grains fluorescence (QGF) technology. The samples of black sandstone and white sand-stone were collected and compared by means of the methods mentioned above. The results showed that there was little hydrocarbon,or none,in the white sandstone. The recovery coefficient was ob-tained by the analyses of plentiful physical parameters of crude oil and bitumen sandstone,based on the hypothesis that nonhydrocarbon compounds and bitumen were invariable in the process of bitu-men forming. The calculated result,which is more scientific and actual,indicates the exploration pros-pect is more promising in Silurian of the Tarim Basin.

  17. A review of the gravity and magnetic studies in the Tyrrhenian Basin and its volcanic districts

    Directory of Open Access Journals (Sweden)

    A. Rapolla

    2008-06-01

    Full Text Available Since the Sixties, the turning point marked by the Plate Tectonics global theory has provided new ideas for the interpretation of the complex geodynamic evolution of the Mediterranean area. The renewed interest that followed gave a strong impulse to the geological and geophysical investigations of the Mediterranean area and, more specifically, of the Tyrrhenian Basin. Therefore, large scale geophysical surveys and oceanographic cruises were carried out until the end of the Eighties to fill the gap of geophysical information existing in the area until then. Afterwards, short scale surveys were prevalent to improve the detail of the information in areas of geodynamic interest. The gathered data sets allowed new models to be formulated, improving the knowledge of the crustal and lithospheric structure of the Tyrrhenian Basin (and surrounding areas and the reconstruction of its complex geodynamic evolution. In this frame, the contribution of gravity and magnetic investigations has been unquestionable and deserves a wide-ranging review both on large and small scale. The main features of the potential fields resulting from these surveys will be described and the interpretative models suggested by several authors will be summarized.

  18. Mapping subtrappean sediments and delineating structure with the aid of heliborne time domain electromagnetics: Case study from Kaladgi Basin, Karnataka

    Science.gov (United States)

    Sridhar, M.; Markandeyulu, A.; Chaturvedi, A. K.

    2017-01-01

    Mapping of subtrappean sediments is a complex geological problem attempted by many interpreters applying different geophysical techniques. Variations in thickness and resistivity of traps and underlying sediments, respectively, results in considerable uncertainty in the interpretation of geophysical data. It is proposed that the transient electromagnetic technique is an effective geophysical tool for delineation of the sub-trappean sediments, due to marked resistivity contrast between the Deccan trap, and underlying sediments and/or basement. The northern margin of the Kaladgi basin is covered under trap. A heliborne time domain electromagnetic survey was conducted to demarcate the basin extent and map the sub-trappean sediments. Conductivity depth transformations were used to map the interface between conductive trap and resistive 'basement'. Two resistivity contrast boundaries are picked: the first corresponds to the bottom of the shallow conductive unit interpreted as the base of the Deccan Volcanics and the second - picked at the base of a deeper subsurface conductive zone - is interpreted as the weathered paleo-surface of the crystalline basement. This second boundary can only be seen in areas where the volcanics are thin or absent, suggesting that the volcanics are masking the EM signal preventing deeper penetration. An interesting feature, which shows prominently in the EM data but less clearly imaged in the magnetic data, is observed in the vicinity of Mudhol. The surface geology interpreted from satellite imagery show Deccan trap cover around Mudhol. Modelling of TDEM data suggest the presence of synclinal basin structure. The depth of penetration of the heliborne TDEM data is estimated to be approximately 350 m for the study area. This suggests that heliborne TDEM could penetrate significant thicknesses of conductive Deccan trap cover to delineate structure below in the Bagalkot Group.

  19. Analysing diagenetic effects of flood basalts on sedimentary basins during Gondwanan break-up: case studies from NW Namibia.

    Science.gov (United States)

    Thompson, G. A.; Jerram, D. A.; Harris, C.; Pearson, D. G.

    2003-04-01

    ABSTRACT The eruption of large volumes of lava associated with the break-up and dispersal of the Gondwana Supercontinent is a phenomenon that has been well documented in literature. The Etendeka Flood Basalt Province of NW Namibia is correlated with the Paraná Flood Basalt Province of South America and was extruded between 139Ma for the earliest flows and 130Ma for the most recent. The passive, inflated pahoehoe lava flows have preserved bedforms within sand dunes found in the Huab Basin without significant deformation. This allows the internal structures of the palaeo-dunes to be analysed with great accuracy; a phenomenon rarely seen within the geological record. The sediments directly beneath, and interbedded with, the Etendeka Flood Basalt are lithostratigraphically similar to those in the Kudu Gas Province, offshore Namibia, where gas-bearing aeolian sands are interspersed with lava flows. Research by the authors is focussed on the diagenetic effects, both direct and indirect, of the emplacement of the lava, and the associated sills and dykes, on the aeolian sands. Specific interests include: the compartmentalisation of the basin by sills/dykes/lava: how does this affect fluid flow paths? Diagenesis along hot contacts: is the dramatic reduction in porosity/permeability along such contacts the result of the igneous bodies alone or do they need ground water present? Can large igneous events trigger the movement of hot fluids through the basin and to what extent does this cause alteration to sediments? To address these issues we have identified a number of outcrop case studies within the Huab Basin in NW Namibia. Here, excellent 3 dimensional outcrop coupled with almost 100 percent exposure allows detailed sampling strategies to be employed on locations of interest. In some cases igneous dykes have acted as flow barriers to pore fluids and have therefore altered the type and degree of cementation either side of the dyke. Geochemical analysis of the cement can

  20. Assessment of hydraulic fish habitat condition using integrated toolkit: a case study of the Geum river basin, Republic of Korea.

    Science.gov (United States)

    Park, Sangyoung; Kim, Jeongkon; Ko, Ick Hwan; Arthington, Angela; Jones, Gary; Yum, Kyung Taek

    2010-01-01

    Artificial changes of rivers, including construction and operation of dams, inevitably lead to physical and ecological changes throughout waterways and their floodplains. In this study, a conceptual model coupled with integrated numerical modeling is presented for hydraulic fish habitat assessment of the Geum River basin, Republic of Korea. Based on the major events which might have affected the ecological system, a conceptual model was formulated to guide desktop and field studies, modeling and scenario evaluations. The result of hydraulic fish habitat assessment indicated that the construction of the Daecheong Multipurpose Dam (DMD) in the Geum River basin has altered flow magnitudes and reduced the river's flow variability. Changes are evident in the magnitude of medium and small flows and the river experiences increased low flows during the dry season. Black shiner, an endangered fish species in Korea, was selected and analyzed to explore relationships between flow regime change by dams and changes to its preferred habitats. As a result, fewer sensitive riffle-benthic species were observed in the reaches downstream of DMD due to the reduction of suitable habitat conditions such as riffle-pool sequences. The proposed conceptual model and integrated toolkit would allow river managers to isolate the physical and biological effects associated with dam operation and could be useful for developing river management strategies.

  1. Ground-Water Quality Data in the Coastal Los Angeles Basin Study Unit, 2006: Results from the California GAMA Program

    Science.gov (United States)

    Mathany, Timothy M.; Land, Michael; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 860 square-mile Coastal Los Angeles Basin study unit (CLAB) was investigated from June to November of 2006 as part of the Statewide Basin Assessment Project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment was developed in response to the Ground-Water Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Coastal Los Angeles Basin study was designed to provide a spatially unbiased assessment of raw ground-water quality within CLAB, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 69 wells in Los Angeles and Orange Counties. Fifty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (?grid wells?). Fourteen additional wells were selected to evaluate changes in ground-water chemistry or to gain a greater understanding of the ground-water quality within a specific portion of the Coastal Los Angeles Basin study unit ('understanding wells'). Ground-water samples were analyzed for: a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides, polar pesticides, and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicators]; constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), 1,4-dioxane, and 1,2,3-trichloropropane (1,2,3-TCP)]; inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements]; radioactive constituents [gross-alpha and gross-beta radiation, radium isotopes, and radon-222]; and microbial indicators. Naturally occurring isotopes [stable isotopic ratios of hydrogen and oxygen, and activities of tritium and carbon-14

  2. Fine-Resolution Modeling of the Santa Cruz and San Pedro River Basins for Climate Change and Riparian System Studies

    Science.gov (United States)

    Robles-Morua, A.; Vivoni, E. R.; Volo, T. J.; Rivera, E. R.; Dominguez, F.; Meixner, T.

    2011-12-01

    This project is part of a multidisciplinary effort aimed at understanding the impacts of climate variability and change on the ecological services provided by riparian ecosystems in semiarid watersheds of the southwestern United States. Valuing the environmental and recreational services provided by these ecosystems in the future requires a numerical simulation approach to estimate streamflow in ungauged tributaries as well as diffuse and direct recharge to groundwater basins. In this work, we utilize a distributed hydrologic model known as the TIN-based Real-time Integrated Basin Simulator (tRIBS) in the upper Santa Cruz and San Pedro basins with the goal of generating simulated hydrological fields that will be coupled to a riparian groundwater model. With the distributed model, we will evaluate a set of climate change and population scenarios to quantify future conditions in these two river systems and their impacts on flood peaks, recharge events and low flows. Here, we present a model confidence building exercise based on high performance computing (HPC) runs of the tRIBS model in both basins during the period of 1990-2000. Distributed model simulations utilize best-available data across the US-Mexico border on topography, land cover and soils obtained from analysis of remotely-sensed imagery and government databases. Meteorological forcing over the historical period is obtained from a combination of sparse ground networks and weather radar rainfall estimates. We then focus on a comparison between simulation runs using ground-based forcing to cases where the Weather Research Forecast (WRF) model is used to specify the historical conditions. Two spatial resolutions are considered from the WRF model fields - a coarse (35-km) and a downscaled (10- km) forcing. Comparisons will focus on the distribution of precipitation, soil moisture, runoff generation and recharge and assess the value of the WRF coarse and downscaled products. These results provide confidence in

  3. Evaluating the impacts of climate and land-use change on the hydrology and nutrient yield in a transboundary river basin: A case study in the 3S River Basin (Sekong, Sesan, and Srepok).

    Science.gov (United States)

    Trang, Nguyen Thi Thuy; Shrestha, Sangam; Shrestha, Manish; Datta, Avishek; Kawasaki, Akiyuki

    2017-01-15

    Assessment of the climate and land-use change impacts on the hydrology and water quality of a river basin is important for the development and management of water resources in the future. The objective of this study was to examine the impact of climate and land-use change on the hydrological regime and nutrient yield from the 3S River Basin (Sekong, Srepok, and Sesan) into the 3S River system in Southeast Asia. The 3S Rivers are important tributaries of the Lower Mekong River, accounting for 16% of its annual flow. This transboundary basin supports the livelihoods of nearly 3.5 million people in the countries of Laos, Vietnam, and Cambodia. To reach a better understanding of the process and fate of pollution (nutrient yield) as well as the hydrological regime, the Soil and Water Assessment Tool (SWAT) was used to simulate water quality and discharge in the 3S River Basin. Future scenarios were developed for three future periods: 2030s (2015-2039), 2060s (2045-2069), and 2090s (2075-2099), using an ensemble of five GCMs (General Circulation Model) simulations: (HadGEM2-AO, CanESM2, IPSL-CM5A-LR, CNRM-CM5, and MPI-ESM-MR), driven by the climate projection for RCPs (Representative Concentration Pathways): RCP4.5 (medium emission) and RCP8.5 (high emission) scenarios, and two land-use change scenarios. The results indicated that the climate in the study area would generally become warmer and wetter under both emission scenarios. Discharge and nutrient yield is predicted to increase in the wet season and decrease in the dry. Overall, the annual discharge and nutrient yield is projected to increase throughout the twenty-first century, suggesting sensitivity in the 3S River Basin to climate and land-use change. The results of this study can assist water resources managers and planners in developing water management strategies for uncertain climate change scenarios in the 3S River Basin.

  4. Quartz grain surface analysis for paleoenvironmental reconstruction in Western Iberia mountain environments (Serra da Estrela, Portugal).

    Science.gov (United States)

    Nieuwendam, Alexandre; Woronko, Barbara; Schaefer, Carlos; Vieira, Gonçalo

    2014-05-01

    This work deals with the genesis and paleoenvironmental significance of relict slope deposits in Serra da Estrela, Central Portugal and is part of a wider sedimentological and dating approach. The aim is to identify what microstructures indicate frost weathering, witch mechanisms are responsible for their development and the effectiveness of frost weathering across an altitudinal profile. Our goals are to contribute to the better understanding of the morphogenetical significance of the different types of slope deposits, clarifying the role of cold environment processes and develop a chronological framework for the Late Quaternary evolution of the slope environment of the mountains of Western Iberia. Quartz grains, 0.5 mm in diameter, were collected from samples from stratified, head and debris-flow deposits. Cailleux (1942) analysis, with modifications from Gozdzik (1980), was performed allowing assessing frosting and rounding, as well as the effects of later frost weathering in vertical profiles from slope deposits. Grains were also analysed using a scanning electron microscope (SEM) following Mahaney (2002). The effects of frost weathering comprise several microstructures such as breakage blocks, conchoidal fractures and fresh surfaces. Breakage blocks microstructures are the most common. Two types of frost weathering were distinguished: weathering of the P type is mainly initiated on convex fragments of grains as the result of ice segregation, and F type is linked to the volumetric expansion of ice and usually observed within concave linear microstructures. The frost action index (FAI) was estimated from the rate of microstructures from frost weathering. FAI varies between 0 and 3. The values of the sediments from the slope deposits vary between 1.2 and 2.05. This approach was for the first time applied on slope deposits from Serra da Estrela. There is a clear correlation between deposits in weathering type. Samples that display intensive physical weathering in

  5. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C.; Presley, M.W.; Handford, C.R.; Finley, R.J.; Dutton, S.P.; Baumgardner, R.W. Jr.; McGillis, K.A.; Simpkins, W.W.

    1980-01-01

    Since early 1977, the Bureau of Economic Geology has been evaluating several salt-bearing basins within the State of Texas as part of the national nuclear repository program. The Bureau, a research unit of The University of Texas at Austin and the State of Texas, is carrying out a long-term program to gather and interpret all geologic and hydrologic information necessary for description, delineation, and evaluation of salt-bearing strata in the Palo Duro and Dalhart Basins of the Texas Panhandle. The program in FY 79 has been subdivided into four broad research tasks, which are addressed by a basin analysis group, a surface studies group, a geohydrology group, and a host-rock analysis group. The basin analysis group has delineated the structural and stratigraphic framework of the basins, initiated natural resource assessment, and integrated data from 8000 ft (2400 m) of core material into salt-stratigraphy models. Salt depth and thickness have been delineated for seven salt-bearing stratigraphic units. Concurrently, the surface studies group has collected ground and remotely sensed data to describe surficial processes, including salt solution, slope retreat/erosion mechanisms, geomorphic evolution, and fracture system development. The basin geohydrology group has begun evaluating both shallow and deep fluid circulation within the basins. The newly formed host-rock analysis group has initiated study of cores from two drilling sites for analysis of salt and the various lithologies overlying and interbedded with salt units. This paper, a summary report of progress in FY 79, presents principal conclusions and reviews methods used and types of data and maps generated.

  6. Seismic Data Interpretation: A Case Study of Southern Sindh Monocline, Lower Indus Basin, Pakistan

    Directory of Open Access Journals (Sweden)

    Shabeer Ahmed Abbasi

    2015-04-01

    Full Text Available The Sindh monocline in Lower Indus Basin is an important oil and gas producing area of Pakistan where a large number of oil, gas and condensate fields have been discovered from structural traps. This research involves the interpretation of stratigraphic and structural styles of Sindh Monocline using 2D (Two-Dimensional seismic reflection and well log. Four reflectors of different formations have been marked and were named as Reflector-1 as of Khadro Formation, Reflector-2 as Upper Goru Member, Reflector-3 as Lower Goru Formation and Reflector-4 as Chiltan Limestone. The average depth of Khadro Formation was marked at 449.0m, Upper Goru Member at 968m, Lower Goru Formation at 1938m and Chiltan Limestone at 2943m. Faults were marked on seismic sections which collectively form horsts and grabens which is the evidence of extensional tectonic in the area. Seismic interpretation was carried out through window based Kingdom Software

  7. Tephrochronological study in the quaternary Val d'Agri intermontane basin (Southern Apennines, Italy)

    Science.gov (United States)

    Zembo, Irene; Vignola, Pietro; Andò, Sergio; Bersezio, Riccardo; Vezzoli, Luigina

    2011-01-01

    In the south-eastern depocentre of the Val d'Agri basin (Southern Apennines), a volcanic ash layer crops out interbedded within poorly structured alluvial fan deposits of Late Pleistocene age. Textural, depositional and pedological features of this weathered layer suggest a primary deposition from a pyroclastic fall-out of volcanic ash. Chemical analyses of feldspars show an alkali trachytic composition and accessory minerals association allow to correlate this tephra layer with the regionally dispersed Y-7 marine tephra layer (Tufo Verde Epomeo eruption, Ischia volcano), dated at 56 ± 4 ka. The Val d'Agri tephra here described for the first time was deposited during MIS Stage 3. Its recovery and characterization permit to contribute to regional correlation of the Mediterranean climatic and volcanic events from marine to continental successions and to describe landscape evolution of the Southern Apennines during glacial-interglacial cycles.

  8. A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy

    Directory of Open Access Journals (Sweden)

    Carmelo Nasello

    2016-01-01

    Full Text Available A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy. The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

  9. Status and understanding of groundwater quality in the Sierra Nevada Regional study unit, 2008: California GAMA Priority Basin Project

    Science.gov (United States)

    Fram, Miranda S.; Belitz, Kenneth

    2014-01-01

    Groundwater quality in the Sierra Nevada Regional (SNR) study unit was investigated as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment Program Priority Basin Project. The study was designed to provide statistically unbiased assessments of the quality of untreated groundwater within the primary aquifer system of the Sierra Nevada. The primary aquifer system for the SNR study unit was delineated by the depth intervals over which wells in the State of California’s database of public drinking-water supply wells are open or screened. Two types of assessments were made: (1) a status assessment that described the current quality of the groundwater resource, and (2) an evaluation of relations between groundwater quality and potential explanatory factors that represent characteristics of the primary aquifer system. The assessments characterize untreated groundwater quality, rather than the quality of treated drinking water delivered to consumers by water distributors.

  10. Spatial and Temporal Variability of Aerosol Vertical Distribution Based on Lidar Observations: A Haze Case Study over Jinhua Basin

    Directory of Open Access Journals (Sweden)

    Wanchun Zhang

    2015-01-01

    Full Text Available The impacts of haze emphasized significance of hazards for human activities and importance of observations of aerosol vertical distribution. This study aimed to analyze the aerosol vertical distribution during a haze case at temporal and spatial aspects, using space-borne and ground-based Lidar observations over Jinhua Basin, Zhejiang province, as well as the Hybrid Single-Particle Lagrangian Integrated Trajectory (HSPLIT model and optical situ monitoring at Jinhua site. The results highlight three pollution peaks above the surface located in the upper and lower boundary layer in Jinhua Basin. The trajectory analysis shows the pollutants inside and outside the planetary boundary layer from different sources. Planetary boundary layer height (PBLH obtained from the space-borne Lidar observations was compared with that from ground-based Lidar observations. The absolute error between the two instruments is about 0.193 km. It is illustrated that the space-borne Lidar is an effective instrument for obtaining regional aerosol pollution in vertical section. Pollution transport near the ground is closely related with the terrain condition.

  11. Seasonal study of contamination by metal in water and sediment in a sub-basin in the southeast of Brazil

    Directory of Open Access Journals (Sweden)

    WAC. Chiba

    Full Text Available The spatial and temporal occurrence of heavy metals (Al, Cd, Pb, Zn, Cr, Co, Cu, Fe, Mn and Ni in water and sediment samples was investigated in a sub-basin in the southeast of Brazil (São Carlos, SP. All samples were analysed using the USEPA adapted metal method and processed in an atomic absorption spectrophotometer. The discriminant analysis demonstrated that there are significant seasonal differences of metal distribution in the water data, but there are no differences to sediment. The basin studied has high levels of contamination by toxic metals in superficial water and sediment. The superficial water, in the rainy season, presented high levels of Cr, Ni, Pb and Cd, while in the dry season it presented high levels of Zn and Ni. The Principal Component Analysis demonstrated that the season has a huge influence on the levels, types and distribution of metals found in water. The source of contamination was probably diffuse, due to products such as batteries and fluorescent lamps, whose dump discharge can contaminate the bodies of water in the region in the rainy season. Due to fires from the harvest of sugar cane, high levels of Zn were found into the environment, in the dry season.

  12. Peak-ring structure and kinematics from a multi-disciplinary study of the Schrödinger impact basin

    Science.gov (United States)

    Kring, David A.; Kramer, Georgiana Y.; Collins, Gareth S.; Potter, Ross W. K.; Chandnani, Mitali

    2016-10-01

    The Schrödinger basin on the lunar farside is ~320 km in diameter and the best-preserved peak-ring basin of its size in the Earth-Moon system. Here we present spectral and photogeologic analyses of data from the Moon Mineralogy Mapper instrument on the Chandrayaan-1 spacecraft and the Lunar Reconnaissance Orbiter Camera (LROC) on the LRO spacecraft, which indicates the peak ring is composed of anorthositic, noritic and troctolitic lithologies that were juxtaposed by several cross-cutting faults during peak-ring formation. Hydrocode simulations indicate the lithologies were uplifted from depths up to 30 km, representing the crust of the lunar farside. Through combining geological and remote-sensing observations with numerical modelling, we show that a Displaced Structural Uplift model is best for peak rings, including that in the K-T Chicxulub impact crater on Earth. These results may help guide sample selection in lunar sample return missions that are being studied for the multi-agency International Space Exploration Coordination Group.

  13. The Importance of Water Temperature Fluctuations in Relation to the Hydrological Factor. Case Study – Bistrita River Basin (Romania

    Directory of Open Access Journals (Sweden)

    Cojoc Gianina Maria

    2014-10-01

    Full Text Available The increase in most components of the climate over the past 50 years, including air and water temperature, is a real phenomenon, as attested by the numerous specialized researches according to IPCC (2013. The water temperature is one of the most important climatic components in analyzing the hydrological regime of the Bistrita River (Romania. The thermal regime of the Bistrita River basin and the frost phenomena associated with the risk factor are particularly important and frequently appear in this area. In recent years, under the Siret Water Basin Administration, this parameter was permanently monitored, so we could do an analysis, which shows that the water temperature fluctuations, influenced by air temperature, lead to the emergence of the ice jam phenomenon. The present study aims to analyze the water temperature, as compared to the air temperature, and the effect of these components on the liquid flow regime (the values were recorded at the hydrological stations on the main course of the Bistrita River. The negative effects resulted from the ice jam phenomenon require developing methods of damage prevention and defense. The frost phenomena recorded after the construction of the Bicaz dam are analyzed in this article

  14. 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.

  15. Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (SE Europe during the past 500 ka

    Directory of Open Access Journals (Sweden)

    L. Sadori

    2015-09-01

    Full Text Available Lake Ohrid is located at the border between FYROM and Albania and formed during the latest phases of Alpine orogenesis. It is the deepest, the largest and the oldest tectonic lake in Europe. To better understand the paleoclimatic and paleoenvironmental evolution of Lake Ohrid a deep drilling was carried out in 2013 within the framework of the Scientific Collaboration on Past Speciation Conditions (SCOPSCO project that was funded by the International Continental Drilling Program (ICDP. Preliminary results indicate that lacustrine sedimentation of Lake Ohrid started between 1.2 and 1.9 Ma ago. Here we present new pollen data (selected percentage and concentration taxa/groups of the uppermost ~200 m of the 569 m-long DEEP core drilled in the depocenter of Lake Ohrid. The study is the fruit of a cooperative work carried out in several European palynological laboratories. The age model is based on nine tephra layers and on tuning of biogeochemical proxy data to orbital parameters and to the global benthic isotope stack LR04. According to the age model the studied sequence covers the last ~500 000 years at a millennial-scale resolution (~1.6 ka and record the major vegetation and climate changes that occurred during the last 12 (13 only pro parte marine isotope stages (MIS. Our results indicate that there is a general good correspondence between forested/non-forested periods and glacial/interglacial cycles of marine isotope stratigraphy. Our record shows a progressive change from cooler and wetter to warmer and dryer interglacial conditions. This shift is visible also in glacial vegetation. The interglacial phase corresponding to MIS11 (pollen assemblage zone, PAZ OD-12, 488–455 ka BP and OD-19, 367–328 ka BP is dominated by montane trees such as conifers. The two younger interglacial periods, MIS5 (PAZ OD-3, 126–70 ka BP and MIS1 (PAZ OD-1, 12 ka BP to present are marked by dominance of mesophilous elements such as deciduous and semi

  16. Glendonites as a paleoenvironmental tool: Implications for early Cretaceous high latitudinal climates in Australia

    Science.gov (United States)

    De Lurio, Jennifer L.; Frakes, L. A.

    1999-04-01

    Glendonites, calcite pseudomorphs after the metastable mineral ikaite (CaCO 3 · 6H 2O), occur in the Late Aptian interval of the Bulldog Shale in the Eromanga Basin, Australia and in other Early Cretaceous basins at high paleolatitudes. Ikaite precipitation in the marine environment requires near-freezing temperatures (not higher than 4°C), high alkalinity, increased levels of orthophosphate, and high P CO2. The rapid and complete transformation of ikaite to calcite at temperatures between 5 and 8°C provides an upper limit on the oxygen isotopic composition of the pore waters: -2.6 <δ w <-3.4‰SMOW. If it is assumed that these pore waters are representative of the shallow Eromanga Basin, the calculated δ w can be used to reassess belemnite fossil oxygen isotopic paleotemperatures - temperature recorded by fauna living in the basin at the time of ikaite precipitation. Data previously reported as 11 to 16°C (assuming δ w = 0.0‰SMOW) yield paleotemperatures ranging from -1 to 5°C, squarely in the range of ikaite stability. The low δ w indicates hyposaline conditions, most likely caused by mixing high latitude meteoric waters with seawater. The 18O depleted, low temperature waters suggest that the region was at least seasonally colder than previously accepted.

  17. Major and trace elements documented paleoenvironmental and provenance signatures as inferred from the lacustrine sequence of Orog Nuur, southern Mongolia

    Science.gov (United States)

    Yu, Kaifeng; Lehmkuhl, Frank; Diekmann, Bernhard; Nottebaum, Veit; Stauch, Georg

    2016-04-01

    In arid realm, due to scarce of continuous terrestrial archives, lacustrine sequences were more often employed as the paleoenvironmental repository. However, there exist numerous spatial and temporal heterogeneities concerning existing studied sites. In the Gobi Desert of southern Mongolia, only two records i.e., Bayan Tohomin Nuur and Ulaan Nuur, were previously reported, neither of them, however, provided records older than ~15 ka. A record that spans longer time period is therefore indispensable to better understand the thermal and hydrologic pattern and their driving mechanisms. Among the suite of the multidisciplinary studies on lacustrine archive, geochemistry appears most likely the promising tool to decipher the interplay between the environmental change, source lithotype and sediment bulk-composition. Considering the late Quaternary lacustrine sediments, the bulk-geochemistry may be controlled by source terranes, authigenic or allothigenic input, which can be altered by the past environment conditions. Knowledge of the bulk-geochemistry downcore variance along with the field investigation and carefully examined geologic mapping will thereby allow us to gain a better understanding of the climate-induced provenance changes throughout the deposition process. On the other hand, surveys considering the bulk-geochemistry and corresponding environmental interpretations in the pelagic realm have been systematically conducted and reviewed, while their counterpart explanations in the lacustrine sediments still need more investigations. Two parallel cores (ONW I, 6.00 m; ONW II, 13.36 m) was retrieved from Orog Nuur, Gobi Desert of southern Mongolia. A suite of high resolution element abundances were examined based on core ONW II in an attempt to gain a better understanding of the paleoenvironment and provenance history of the catchment system over the last ~50 ka. Due to the predominant clay or silty-clay fractions in the lacustrine sediments, Al and Si display

  18. Optimization of wetland restoration siting and zoning in flood retention areas of river basins in China: A case study in Mengwa, Huaihe River Basin

    Science.gov (United States)

    Zhang, Xiaolei; Song, Yuqin

    2014-11-01

    Wetland restoration in floodplains is an ecological solution that can address basin-wide flooding issues and minimize flooding and damages to riverine and downstream areas. High population densities, large economic outputs, and heavy reliance on water resources make flood retention and management pressing issues in China. To balance flood control and sustainable development economically, socially, and politically, flood retention areas have been established to increase watershed flood storage capacities and enhance the public welfare for the populace living in the areas. However, conflicts between flood storage functions and human habitation appear irreconcilable. We developed a site-specific methodology for identifying potential sites and functional zones for wetland restoration in a flood retention area in middle and eastern China, optimizing the spatial distribution and functional zones to maximize flood control and human and regional development. This methodology was applied to Mengwa, one of 21 flood retention areas in China's Huaihe River Basin, using nine scenarios that reflected different flood, climatic, and hydraulic conditions. The results demonstrated improved flood retention and ecological functions, as well as increased economic benefits.

  19. Paleoenvironmental assessment of recent environmental changes in Florida Bay, USA: A biomarker based study

    Science.gov (United States)

    Xu, Yunping; Holmes, Charles W.; Jaffé, Rudolf

    2007-06-01

    The extractable lipid compositions in four Florida Bay cores were determined in order to understand environmental changes over the last 160 years. The most significant environmental change was recorded by oscillations in the amplitude and frequency of biomarkers during the 20th century. Two seagrass molecular proxies ( Paq and the C 25/C 27n-alkan-2-one ratio) reached a maximum post 1900, suggesting that abundant seagrass communities existed during the 20th century. A sharp drop in the Paq value from 0.65 to 0.48 in the central Bay at about 1987 seems to reflect seagrass die-off. The concentrations of microbial biomarkers (C 20 HBIs, C 25 HBIs and dinosterol) substantially increased after 1950 in the TC, BA and NB cores, reflecting an increase in algal (planktonic organism) primary productivity. However, the RB core presented the highest abundance of C 25 HBIs and dinosterol during the period of 1880-1940, suggesting historically large inputs from diatoms and dinoflagellates. A substantial rise in abundance of taraxerol (a specific biomarker of mangroves) from 20 μg/g TOC in the 1830s to 279 μg/g TOC in the l980s is likely a result of increased mangrove primary productivity along the shore of the NE Bay. These changes are most likely the result of hydrological alterations in South Florida.

  20. The Influence of Methane Venting on Benthic Foraminiferal Assemblages in Guaymas Basin, Gulf of California

    Science.gov (United States)

    Perez, E.; Herguera, J.; Paull, C.; Ussler, W.; Cortina, A.

    2004-12-01

    Fossil foraminifera are critical for paleoenvironmental reconstructions including the study of past episodes of methane venting from gas hydrate reservoirs. However, the use of benthic foraminifera as indicators of methane release remains controversial and more modern analog data is needed to understand the ecology and isotopic signatures of foraminifera in methane seeps. The objective of this investigation was to characterize the species composition and vertical distribution of living benthic foraminifera (rose Bengal stained) along known gradients of present methane venting in order to gain insight into the ecological tolerances and preferences of benthic foraminifera in methane seeps. Vertical distribution patterns are also important in determining carbon isotope variability. Samples were retrieved along the NE transform margin of the Guaymas Basin in the Gulf of California (about 1,582 m). Suites of ROV cores were collected from beds of living calyptogenid clams, tubeworms, and bacterial mats; from a methane venting site evidenced by a continuous stream of gas bubbles; and from control sites. Our data shows that foraminiferal abundance is lower in the methane-influenced sites than in the control sites. Lowest foraminiferal abundance occurs at the bacterial mats, probably caused by higher levels of sulfide. The assemblage is dominated by calcareous species that are characteristic of other organic-rich, oxygen-poor environments (e.g., Uvigerina peregrina, Bulimina mexicana, Buliminella tenuata, Globobulimina pacifica). The vertical distributions of several species are different from those of conspecifics observed in previous studies of non-seep habitats, with deeper and broader depth ranges for some species at the methane-influenced habitats in this study. Of special interest is the occurrence of Planulina wuellerstorfi, traditionally considered an epifaunal species, at sediment depths of 6 cm and with density maxima between 1 and 3 cm. This may result from

  1. 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.

  2. Sequence Stratigraphy of the Desert System:A Case Study of the Lower Cretaceous in the Kuqa Basin in Xinjiang, Northwestern China

    Institute of Scientific and Technical Information of China (English)

    MEI Mingxiang; YU Bingsong; JIN Weiguang

    2004-01-01

    The Lower Cretaceous strata in the Kuqa Basin in Xinjiang are marked by a set of arid red beds. Several types of sedimentary facies can be identified in this set of arid red beds: mudstones of the plaza and intracontinental sebkha,aeolian sandstones, sandy conglomerates of the intermittent river, conglomerates of the pluvial fan, etc. These types of sedimentary facies constitute a typical desert system. Therefore, the Cretaceous strata in the Kuqa Basin provide a favorable condition for studies of sequence stratigraphic divisions of the desert system. With the rise and fall of the base level of the sedimentary basin, cyclicity is clearly revealed in stratigraphic records, which helps the identification of the third-order sequences. Based on the cyclicity in stratigraphic records, 5 third-order sequences can be found in the strata of the Early Cretaceous in the Kuqa Basin. These sequences comprise a second-order tectonic sequence. The primary feature of these third-order sequences is of an upward-fining sedimentary succession formed by a succession of"coarse sediments of the alluvial system-fine sediments of the lake system". The result of this study shows that aeolian sandstones are the best reservoirs of natural gas in the Cretaceous strata in the Kuqa Basin, and that the Kela-2 gas field is the first large gas field dominated by aeolian sandstone reservoirs in China.

  3. Hydrogeochemical assessment of arsenic in groundwater and its policy implication: a case study in Terai Basin, Nepal

    Science.gov (United States)

    Gurung, J. K.; Upreti, B. N.; Kansakar, D. R.

    2007-12-01

    Arsenic contamination at levels above the WHO guideline (10 ìg/l) in groundwater is a worldwide problem due to its detrimental effects on health and now known to be a problem also in the Terai Basin of Nepal, posing a serious threat to more than 10 million people. The distribution of arsenic in the basin, however, is patchy. The study emphasizes on the three different types of research into an interdisciplinary package that can be immediately useful to government agencies in Nepal trying to deal with groundwater contamination. They are: hydrogeological assessment of water sources and flow, geochemical analysis of groundwater, and assessment of practical public policy. Basic geochemical analysis gives the abundance and distribution of arsenic along with other physico-chemical parameters of groundwater, whereas, the hydrogeological assessment as an integral part of this study that assist in determining process of mobilization or attenuation of arsenic. Arsenic levels and other key parameters mainly pH, electrical conductivity, chemical oxygen demand, iron, and biological parameter as E-coli were observed at the various locations with different transmissivity values. The study suggests that the flushing rate of an aquifer plays an important role in arsenic content. High flushing rates of an aquifer lead to low levels of arsenic, however the mechanism of this process is still under study. Transmissivity the property of an aquifer that measures the rate at which ground water moves horizontally through a unit is the main factor for controlling flushing. Concentration maps overlaying the base transmissivity map reveals relation of groundwater movement and arsenic concentration. Understanding the relationship between groundwater movement and arsenic content helps planners protect uncontaminated aquifers from future contamination. Also assessment of public policy related to groundwater has identified important changes needed in the existing policy.

  4. Groundwater-Quality Data in the South Coast Interior Basins Study Unit, 2008: Results from the California GAMA Program

    Science.gov (United States)

    Mathany, Timothy M.; Kulongoski, Justin T.; Ray, Mary C.; Belitz, Kenneth

    2009-01-01

    Groundwater quality in the approximately 653-square-mile South Coast Interior Basins (SCI) study unit was investigated from August to December 2008, as part of the Priority Basins Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basins Project was developed in response to Legislative mandates (Supplemental Report of the 1999 Budget Act 1999-00 Fiscal Year; and, the Groundwater-Quality Monitoring Act of 2001 [Sections 10780-10782.3 of the California Water Code, Assembly Bill 599]) to assess and monitor the quality of groundwater used as public supply for municipalities in California, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). SCI was the 27th study unit to be sampled as part of the GAMA Priority Basins Project. This study was designed to provide a spatially unbiased assessment of the quality of untreated groundwater used for public water supplies within SCI, and to facilitate statistically consistent comparisons of groundwater quality throughout California. Samples were collected from 54 wells within the three study areas [Livermore, Gilroy, and Cuyama] of SCI in Alameda, Santa Clara, San Benito, Santa Barbara, Ventura, and Kern Counties. Thirty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 19 were selected to aid in evaluation of specific water-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates, polar pesticides and metabolites, and pharmaceutical compounds], constituents of special interest [perchlorate and N-nitrosodimethylamine (NDMA)], naturally occurring inorganic constituents [trace elements, nutrients, major and minor ions, silica, total dissolved solids (TDS), and alkalinity

  5. Depositional tracts and stratigraphic architecture of the Itajaí Basin sedimentary sucessions (Neoproterozoic, northeastern Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Michel Silva Costa

    2015-06-01

    Full Text Available Neoproterozoic sedimentary successions of the Itajaí Basin show depositional trends and a stratigraphic framework characteristics of foreland basin system. The sedimentary environments have developed in basin conditions ranging from deep marine context, transitional shallow marine, to continental. Stratigraphic architecture comprises three depositional tracts (DT: DTI - submarine fans system that records the initial basin sedimentation and involves frontal and distal turbiditic deposits; DTII - transitional to shallow marine depositional system that represents the efective infill fase of basin, and includes deltaic succession with braided channels dominated plain; and DTIII - fluvial braided and alluvial fan depositional system that comprises the final stage of basin sedimentation. Arkoses and greywacke of the DTI present paleocurrent unimodals patterns and general trend to south-southeast, suggesting source area from Santa Catarina Granulitic Complex. The sandstones and conglomerates of DTII and DTIII have opposite paleocurrent pattern, indicating source area from both Metamorphic Brusque Complex and Florianópolis Batolith. Integration of paleoenvironmental and stratigraphic data, with previous information (U-Pb in detrital zircon, allowed a consistent interpretation on the sedimentary evolution and detrital sources of the basin and represent a progress on the discussions on the knowledge of the Itajaí Basin and its significance in the evolutionary context of the Dom Feliciano Belt.

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

    Science.gov (United States)

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

    2016-04-01

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

  7. A preliminary study of the calcite beef found in the Cretaceous Jinju Formation, Gyeongsang Basin, South Korea

    Science.gov (United States)

    Ha, S.; Chae, Y. U.; Son, M.; Jeong, G. Y.; Paik, I. S.; Lim, H. S.

    2015-12-01

    The term "beef" refers to fibrous minerals in bedding-parallel veins, where the fibers are approximately perpendicular to the vein margins (Cobbold et al., 2013). It mostly appears within organic-rich black shale layers in sedimentary basin. Although the veins can consist of white gangue minerals, such as calcite, gypsum, or quartz, the commonest mineral in the fibers is calcite. According to the worldwide localities of calcite beef compiled by Cobbold et al (2012), they concentrated in some areas, especially around the Atlantic Ocean. However, they have been rarely reported in the western Pacific margin, except Australia and New Zealand. Recently, calcite beefs have been found in the Cretaceous Jinju Formation, Gyeongsang Basin, Korea. As far as we know, this is the first report of calcite beef in Korea. The lacustrine Jinju Formation is about 1,200 m thick, and made up mainly of lacustrine dark grey to black mudstones. In the study area, calcite beefs were commonly found in the organic-rich black shale layers. The vein thickness is anywhere between a few millimeters to maximum 3 centimeters, and their length ranges from a few centimeters to several tens of meters. The interval between successive veins is from a few centimeters to about 1 meter. Most of them occur parallel to the bedding planes, although some of them are developed along fault planes or within deformed layers. In case of relatively thick beefs, the center of veins often shows a dark grey to black central median line, defined by fine-grained calcite grains, fluid inclusion lines, or wall rock particles. Based on the orientation of fibrous calcite, they can be divided into two types: straight and sigmoidal types. The fibrous calcites are thought to have been symmetrically grown from the median lines to top and bottom of wall rock. The formation mechanism of horizontal fractures, and the formation temperature of beefs in the study area remain as a matter to be studied further.

  8. Differences in sedimentary filling and its controlling factors in rift lacustrine basins, East China: A case study from Qikou and Nanpu sags

    Institute of Scientific and Technical Information of China (English)

    Hua WANG; Shu JIANG; Chuanyan HUANG; Hua JIANG; Huajun GAN

    2011-01-01

    The riff lacustrine basin is characterized by a variety of sediment sources, multiple sedimentary systems,and complex filling, and its sediment supply is largely influenced by climate change. The sedimentary filling and its controlling factors have always been the focuses in basin analysis. This paper first reviews the recent advancement in riff lacustrine basin investigations with an emphasis on the structural controlling on lacustrine configuration, accommodation, and directly structural controlling on basin filling characteristics. The paleogeography resulted from spatial configuration of structural styles, and the sediment supplies synergically determine the types and distribution of depositional systems. The sedimentary filling characteristics of the fourth-order sequence record the evolution of cyclic climate. The case studies are followed on the basis of the sedimentary filling analysis in typical Nanpu sag and Qikou sag in Huanghua riff lacustrine basins in East China. The comparison of sedimentary fillings within sequence stratigraphic frameworks in the two sags shows the different episodic tectonic activities, and their resulting structural frameworks mainly controlled the different sequence stratigraphic developments, their internal architectures, and depositional systems distribution. Qikou sag has more complicate sedimentary filling controlled by episodic activities of boundary and intrabasin secondary faults and sediment supplies. Based on the studies from our own and the formers, we suggest that the sedimentary filling study in rift lacustrine basin should be under the guidance of sequence stratigraphy, use high resolution seismic and all available geological data, combine tectonic evolution and structural styles to build the sequence framework, and then reconstruct the paleo-structure and paleogeography. Studying the relationship between paleogeography and paleosedimentary filling can favor the understanding of the characteristics of sedimentary

  9. Geochemistry studies in Eastern Kentucky. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Negus-de Wys, J.

    1981-04-01

    Presented here are the results of inorganic geochemical studies on well cuttings from fourteen wells in the Big Sandy Gas Field. Both x-ray fluorescence and x-ray diffraction were used in analysis. Resultant mineralic data and elemental data were mapped by computer and by hand for five intervals of Ohio Shale and for the Berea/Bedford sequence. Comparisons of the geochemistry trend maps were made with lithology, structure, thermal maturation, gas open flow, and paleoenvironment. Techniques used included visual map comparison, computer map comparison programs utilizing correlation coefficients based on grid derived data sets, cluster analysis, x-y plots, and r/sup 2/ (coefficient of determination). A limited number of regional maps are included. It is concluded that inorganic geochemical analysis can be useful in: (1) suggesting paleoenvironmental trends; (2) establishing depositional trends; (3) enhancing exploration in terms of setting limits and pinpointing potential areas for hydrocarbon recovery; and (4) identification of likely locations for large gas fields when used with other geological studies. Elemental data analysis is the most accurate, and can be done quickly and inexpensively. It is concluded that the Big Sandy gas field area is a unique stratigraphic-structural gas trap, in which sedimentary factors, depositional basin features, plant evolution and occurrence, and structural elements all played important roles. Combinations of certain of these ingredients in different amounts may exist in other parts of the basin, and thus, suggest areas for hydrocarbon accumulation and potential recovery.

  10. California GAMA Special Study: Importance of River Water Recharge to Selected Groundwater Basins

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Ate [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moran, Jean E. [California State Univ. East Bay (CalState), Hayward, CA (United States); Singleton, Michael J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-03-21

    River recharge represents 63%, 86% and 46% of modern groundwater in the Mojave Desert, Owens Valley, and San Joaquin Valley, respectively. In pre-modern groundwater, river recharge represents a lower fraction: 36%, 46%, and 24% respectively. The importance of river water recharge in the San Joaquin valley has nearly doubled and is likely the result of a total increase of recharge of 40%, caused by river water irrigation return flows. This emphasizes the importance of recharge of river water via irrigation for renewal of groundwater resources. Mountain front recharge and local precipitation contribute to recharge of desert groundwater basins in part as the result of geological features focusing scarce precipitation promoting infiltration. River water recharges groundwater systems under lower temperatures and with larger water table fluctuations than local precipitation recharge. Surface storage is limited in time and volume, as evidenced by cold river recharge temperatures resulting from fast recharge, compared to the large capacity for subsurface storage. Groundwater banking of seasonal surface water flows therefore appears to be a natural and promising method for increasing the resilience of water supply systems. The distinct isotopic and noble gas signatures of river water recharge, compared to local precipitation recharge, reflecting the source and mechanism of recharge, are valuable constraints for numerical flow models.

  11. Risk of flooding: Activities, parameters and regional peculiarities, Case study: Varbitsa watershed basin, Bulgaria

    Directory of Open Access Journals (Sweden)

    Lubenov Todor

    2009-01-01

    Full Text Available An overview of the activities overtaken during risk of flooding situations, in one of the more often flooding region - the watershed of Varbitsa river (Southeastern part of Bulgaria - has been performed. The main cognitive parameters for risk perception and risk definition, depending on regional, social and historical factors have been examined. The existing information and instructions for mass media communication in relation to the process of interaction in a disaster situation have been discussed. In connection to determination of the risky segments in the basin and plans for announcement, the prevention communication measures have been outlined. On the basis of the Bulgarian normative legislation, the activities concerning organization of communications in a risk-of-disaster situation and mutual aid between authorities, which are part of the Integrated Help System have been indicated. It has been accented on the necessity of a more effective realization of the action plans during natural disasters and especially flooding, in order to improve the partnership between authorities and participants in the communication process during risk-of-flooding situations.

  12. Stable isotopic studies of dinosaur eggshells from the Nanxiong Basin,South China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Stable carbon and oxygen isotopes have been observed in dinosaur eggshell samples,identified as Macroolithus yaotunensis,collected in two sections of the Nanxiong Basin,Guangdong Province,South China.Multiple positiveδ18O perturbations that occurred during the K/T transition of about 150 ka suggest that there may have been at least three periods of the extreme dry climate with a mean annual air temperature over 27℃.δ13C ranges from -8.37‰ to -11.60‰ of the dinosaur eggshells,added to the metabolic enrichment of 16‰,may indicate that the dinosaurs represented by this type of eggshells probably consumed the plant species of C3 type with the δ13C values of -24.3‰- -27.6‰.Moreover,the trend toward more negative δ13C values of the eggshells during the K/T transition could be an indirect consequence of a lasting increase in atmospheric CO2 concentration.

  13. A Reinterpretation of the Baturetno Formation: Stratigraphic Study of the Baturetno Basin, Wonogiri, Central Java

    Directory of Open Access Journals (Sweden)

    Purna Sulastya Putra

    2015-09-01

    Full Text Available This paper focuses on the Quaternary Baturetno Formation. An earlier research concluded that the black clay of the Baturetno Formation formed as a ‘palaeolake’ deposit. The ‘palaeolake’ was interpreted to form due to the shifting course of the Bengawan Solo Purba River in relation to Pliocene tectonic tilting in the southern Java. The stratigraphy of the Baturetno Formation was observed in the western part of the Baturetno Basin, and based on marker beds, the Baturetno Formation was classified into three units: (1 Gravel unit (GR in the upper part, (2 clay unit (CU in the middle part, and (3 sand-gravel unit (SG in the lower part. There are floating gravel fragments of andesite, claystone, coral, and limestone with diameters of up to 10 cm in the clay unit. The particle size of sediment reflects the environment, but the lake deposition occurs under very quiet conditions. The occurrence of these fragments within the clay cannot be explained if the clay was deposited within a lake environment. The occurrence of floating fragments in the black clay of Baturetno Formation can best be explained through mudflow process. The cohesive strength of the mudflow is responsible for the ability of large fragments to float within the mud matrix. In general, the Baturetno Formation is inferred to be an alluvial fan deposit. The presence of sand, gravel, and mud are characteristics of alluvial fan deposits.

  14. A Preliminary Study on the Red Beds in the Northern Heyuan Basin, Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The red beds of the northern Heyuan Basin (Guangdong Province, China) are more than 4,000 m thick.Based on the lithological characters, in ascending order these beds are divided into the Dafeng Formation, Zhutian Formation, and Zhenshui Formation of the Nanxiong Group, Shanghu Formation and Danxia Formation. The Nanxiong Group with relatively mature coarse clastic rocks attains about 2 940 m in thickness. The Dafeng Formation is 837 m thick,consisting of conglomerates and sandy conglomerates; the Zhutian Formation, which is 1,200 m thick, consists of purplish red sandstone with gravels, poorly sorted sandstone, feldspathic quartzose sandstone banded granular conglomerate,siltstone, and sandy mudstone. The Zhutian Formation is rich in calcareous concretions. Heyuannia (Oviraptoridae) and turtle fossils were found in this formation. The Zhenshui Formation deposited to a thickness of 900 m consists of coarse sediments, including granular conglomerate, and gravelly sandstone with well developed cross-beddings; the Shanghu Formation, which is 820 m thick, consists of purplish red granular conglomerate coarse sandstone intercalated with fine siltstone; the Danxia Formation characterized by the Danxia landform is composed of coarse clastic gravels and sandy gravels. The lower part of the Nanxiong Group whence dinosaur eggs and derived oviraptorosaurs come, belongs to the Late Cretaceous. No fossils are found in the Shanghu Formation or the Danxia Formation, but their stratigraphic order of superposition on the Nanxiong Group clearly shows their younger age.

  15. Studies on the biology of schistosomiasis with emphasis on the Senegal river basin

    Directory of Open Access Journals (Sweden)

    Southgate VR

    2001-01-01

    Full Text Available The construction of the Diama dam on the Senegal river, the Manantali dam on the Bafing river, Mali and the ensuing ecological changes have led to a massive outbreak of Schistosoma mansoni in Northern Senegal, associated with high intensity of infections, due to intense transmission, and the creation of new foci of S. haematobium. Data on the vectorial capacity of Biomphalaria pfeifferi from Ndombo, near Richard Toll, Senegal are presented with sympatric and allopatric (Cameroon S. mansoni. Comparisons are made on infectivity, cercarial production, chronobiology of cercarial emergence and longevity of infected snails. Recent data on the intermediate host specificity of different isolates of S. haematobium from the Lower and Middle Valley of the Senegal river basin (SRB demonstrate the existence of at least two strains of S. haematobium. The role of Bulinus truncatus in the transmission of S. haematobium in the Lower and Middle Valleys of the SRB is reviewed. Both S. haematobium and S. mansoni are transmitted in the same foci in some areas of the SRB.

  16. Assessing sedimentation rates at Usumacinta and Grijalva river basin (Southern Mexico) using OSL and suspended sediment load analysis: A study from the Maya Classic Period

    Science.gov (United States)

    Munoz-Salinas, E.; Castillo, M.; Sanderson, D.; Kinnaird, T.; Cruz-Zaragoza, E.

    2013-12-01

    Studying sedimentation rates on floodplains is key to understanding environmental changes occurred through time in river basins. The Usumacinta and Grijalva rivers flow most of their travel through the southern part of Mexico, forming a large river basin, crossing the states of Chiapas and Tabasco. The Usumacinta-Grijalva River Basin is within the 10 major rivers of North America, having a basin area of ~112 550 km2. We use the OSL technique for dating two sediment profiles and for obtaining luminescence signals in several sediment profiles located in the streambanks of the main trunk of the Usumacinta and Grijalva rivers. We also use mean annual values of suspended sediment load spanning ~50 years to calculate the sedimentation rates. Our OSL dating results start from the 4th Century, when the Maya Civilization was at its peak during the Classic Period. Sedimentation rates show a notable increase at the end of the 19th Century. The increase of the sedimentation rates seems to be related to changes in land uses in the Sierra Madre de Chiapas and Altos de Chiapas, based on deforestation and land clearing for developing new agrarian and pastoral activities. We conclude that the major environmental change in the basin of the Usumacinta and Grijalva Rivers since the Maya Classic Period was generated since the last Century as a result of an intense anthropogenic disturbance of mountain rain forest in Chiapas.

  17. GIS-Based Spatial Analysis and Modeling for Landslide Hazard Assessment: A Case Study in Upper Minjiang River Basin

    Institute of Scientific and Technical Information of China (English)

    FENG Wenlan; ZHOU Qigang; ZHANG Baolei; ZHOU Wancun; LI Ainong; ZHANG Haizhen; XIAN Wei

    2006-01-01

    By analyzing the topographic features of past landslides since 1980s and the main land-cover types (including change information) in landslide-prone area, modeled spatial distribution of landslide hazard in upper Minjiang River Basin was studied based on spatial analysis of GIS in this paper. Results of GIS analysis showed that landslide occurrence in this region closely related to topographic feature. Most areas with high hazard probability were deep-sheared gorge. Most of them in investigation occurred assembly in areas with elevation lower than 3 000 m, due to fragile topographic conditions and intensive human disturbances. Land-cover type, including its change information, was likely an important environmental factor to trigger landslide. Destroy of vegetation driven by increase of population and its demands augmented the probability of landslide in steep slope.

  18. Evaluation of drought indices at interannual to climate change timescales: a case study over the Amazon and Mississippi river basins

    Directory of Open Access Journals (Sweden)

    E. Joetzjer

    2012-11-01

    Full Text Available The present study compares three meteorological drought indices (scPDSI, SPI and SPEI respectively and their ability to account for the variations of annual mean river discharge on both interannual and climate change timescales. The Standardized Runoff Index (SRI is used as a proxy of river discharge. The Mississippi and Amazon river basins provide two contrasted testbeds for this analysis. All meteorological drought indices are derived from monthly 2-meter temperature and/or precipitation, using either gridded observations or outputs of a global climate model. The SPI based solely on precipitation is not outperformed by the SPEI (accounting for potential evapotranspiration and the scPDSI (based on a simplified water balance at detecting interannual SRI variations. Under increasing concentrations of greenhouse gases, the simulated response of the areal fraction in drought is highly index-dependent, suggesting that more physical water balance models are needed to account for the impact of global warming on hydrological droughts.

  19. Low temperatures enhance organic nitrate formation: evidence from observations in the 2012 Uintah Basin Winter Ozone Study

    Directory of Open Access Journals (Sweden)

    L. Lee

    2014-06-01

    Full Text Available Nitrogen dioxide (NO2 and total alkyl nitrates (ΣANs were measured using thermal dissociation laser induced fluorescence during the 2012 Uintah Basin Winter Ozone Study (UBWOS in Utah, USA. The observed NO2 concentration was highest before sunrise and lowest in the late afternoon, suggestive of a persistent local source of NO2 coupled with turbulent mixing out of the boundary layer. In contrast, ΣANs co-varied with solar radiation with a noontime maximum, indicating that local photochemical production combined with rapid mixing and/or deposition was the dominant factor in determining the ΣAN concentrations. We calculate that ΣANs were a large fraction (~60% of the HOx free radical chain termination and show that the temperature dependence of the alkyl nitrate yields enhances the role of ΣANs in local chemistry during winter by comparison to what would occur at the warmer temperatures of summer.

  20. Petro-mineralogical Studies of the Paleoproterozoic Phosphorites in the Sonrai basin, Lalitpur District, Uttar Pradesh, India

    Energy Technology Data Exchange (ETDEWEB)

    Dar, Shamim A., E-mail: sjshamim@gmail.com; Khan, K. F.; Khan, Saif A.; Khan, Samsuddin [Aligarh Muslim University, Department of Geology (India); Masroor Alam, M. [Aligarh Muslim University, Geology Section Department of Civil Engineering (India)

    2015-09-15

    The Paleoproterozoic phosphorites constitute an economically significant component of the Sonrai basin of Lalitpur district. These are associated with ferruginous shale, ironstone, limestone and quartz breccia. Petro-mineralogical studies of samples of the phosphorites, using X-ray diffractometry and scanning electron microscopy, reveal that the collophane (carbonate-fluorapatite) is the dominant phosphate mineral. Calcite, dolomite, quartz, mica and haematite are the dominant gangue constituents. The phosphate minerals occur as oolites mutually replaced by carbonate and silica. The presence of iron oxides has been found in most of the thin sections. There is meagre evidence of organic matter in the form of filaments of microbial phosphate laminae in the samples of phosphorite. The mineral assemblages, their texture and various forms in these phosphorites may be due to some environmental vicissitudes followed by replacement processes and biogenic activities.

  1. A Quantitative Study on Paleo—River Environment During Late Jurassic on yaojie Region,Minhe Basin

    Institute of Scientific and Technical Information of China (English)

    邵树勋; 燕永峰; 等

    2000-01-01

    Fluvial Sedimentation of alluvial facies prevailed during the Late Jrassic in the Minhe Basin.On the basis of the study of sedimentary facies of the Upper Jurassic series.this paper focuses on the river types suing the "Architecture Element" analysis method proposed by Miall,and calculated all the quantitative parameters to reflect the characteristics of the stream channel geometry and hydrodynamic conditions of paleo-rivers with the equations of ethrideg,schumm et al.Finally,we discussed the characteristics of environmental evolution of palsorivers on the quantitative basis.Our conclusion indicates that the evolution of paleo-rivers during the Late Jurassic,from early to late,shows such a tendency as alluvial fan river→ braid river→alluvial fan river→mid-sinuoisty river→ high-sinuosity river.

  2. Assessment of selected inorganic constituents in streams in the Central Arizona Basins Study Area, Arizona and northern Mexico, through 1998

    Science.gov (United States)

    Anning, David W.

    2003-01-01

    Stream properties and water-chemistry constituent concentrations from data collected by the National Water-Quality Assessment and other U.S. Geological Survey water-quality programs were analyzed to (1) assess water quality, (2) determine natural and human factors affecting water quality, and (3) compute stream loads for the surface-water resources in the Central Arizona Basins study area. Stream temperature, pH, dissolved-oxygen concentration and percent saturation, and dissolved-solids, suspended-sediment, and nutrient concentration data collected at 41 stream-water quality monitoring stations through water year 1998 were used in this assessment. Water-quality standards applicable to the stream properties and water-chemistry constituent concentration data for the stations investigated in this study generally were met, although there were some exceedences. In a few samples from the White River, the Black River, and the Salt River below Stewart Mountain Dam, the pH in reaches designated as a domestic drinking water source was higher than the State of Arizona standard. More than half of the samples from the Salt River below Stewart Mountain Dam and almost all of the samples from the stations on the Central Arizona Project Canal?two of the three most important surface-water sources used for drinking water in the Central Arizona Basins study area?exceeded the U.S. Environmental Protection Agency drinking water Secondary Maximum Contaminant Level for dissolved solids. Two reach-specific standards for nutrients established by the State of Arizona were exceeded many times: (1) the annual mean concentration of total phosphorus was exceeded during several years at stations on the main stems of the Salt and Verde Rivers, and (2) the annual mean concentration of total nitrogen was exceeded during several years at the Salt River near Roosevelt and at the Salt River below Stewart Mountain Dam. Stream properties and water-chemistry constituent concentrations were related to

  3. Significance of transition between Talchir Formation and Karharbari Formation in Lower Gondwana basin evolution — A study in West Bokaro Coal basin, Jharkhand, India

    Indian Academy of Sciences (India)

    H N Bhattacharya; Abhijit Chakraborty; Biplab Bhattacharya

    2005-06-01

    Basal part of the Gondwana Supergroup represented by Talchir and Karharbari Formations (Permo-Carboniferous) records an abrupt change-over from glacio-marine to terrestrial fluviolacustrine depositional environment. The contact between the two is an unconformity. Facies analysis of the glacio-marine Talchir Formation reveals that basal glaciogenic and reworked glaciogenic sediments are buried under storm influenced inner and outer shelf sediments. Facies associations of the Karharbari Formation suggest deposition as fluvio-lacustrine deposits in fault-controlled troughs. An attempt has been made in this paper to explain the sedimentation pattern in Talchir and Karharbari basins, and the abrupt change-over from glacio-marine to terrestrial fluviolacustrine depositional environment in terms of glacio-isostacy.

  4. Sedimentary cycles in coal and evaporite basins and the reconstruction of Paleozoic climate (Utrecht Studies in Earth Sciences 21)

    NARCIS (Netherlands)

    van den Belt, F.J.G.

    2012-01-01

    This thesis deals with large-scale processes controlling the formation of sedimentary cycles in coal and evaporite basins and their relation to large-scale fluctuations of Palaeozoic climate. Coal-clastic cycles dominate Pennsylvanian sequences in palaeo-equatorial basins from Euramerica. They forme

  5. A novel approach to estimate direct and indirect water withdrawals from satellite measurements: A case study from the Incomati basin

    NARCIS (Netherlands)

    Van Eekelen, M.W.; Bastiaanssen, W.G.M.; Jarmain, C.; Jackson, B.; Ferreira, F.; Van der Zaag, P.; Saraiva Okello, A.; Bosch, J.; Dye, P.; Bastidas-Obando, E.; Dost, R.J.J.; Luxemburg, W.M.J.

    2014-01-01

    The Incomati basin encompasses parts of South Africa, Swaziland and Mozambique, and is a water stressed basin. Equitable allocation of water is crucial to sustain livelihoods and agro-ecosystems, and to sustain international agreements. As compliance monitoring of water distribution by flow meters i

  6. River Gain and Loss Studies for the Red River of the North Basin, North Dakota and Minnesota

    Science.gov (United States)

    Williams-Sether, Tara

    2004-01-01

    The Dakota Water Resources Act passed by the U.S. Congress in 2000 authorized the Secretary of the Interior to conduct a comprehensive study of future water-quantity and -quality needs of the Red River of the North (Red River) Basin in North Dakota and of possible options to meet those water needs. To obtain the river gain and loss information needed to properly account for available streamflow within the basin, available river gain and loss studies for the Sheyenne, Turtle, Forest, and Park Rivers in North Dakota and the Wild Rice, Sand Hill, Clearwater, South Branch Buffalo, and Otter Tail Rivers in Minnesota were reviewed. Ground-water discharges for the Sheyenne River in a reach between Lisbon and Kindred, N. Dak., were about 28.8 cubic feet per second in 1963 and about 45.0 cubic feet per second in 1986. Estimated monthly net evaporation losses for additional flows to the Sheyenne River from the Missouri River ranged from 1.4 cubic feet per second in 1963 to 51.0 cubic feet per second in 1976. Maximum water losses for a reach between Harvey and West Fargo, N. Dak., for 1956-96 ranged from about 161 cubic feet per second for 1976 to about 248 cubic feet per second for 1977. Streamflow gains of 1 to 1.5 cubic feet per second per mile were estimated for the Wild Rice, Sand Hill, and Clearwater Rivers in Minnesota. The average ground-water discharge for a 5.2-mile reach of the Otter Tail River in Minnesota was about 14.1 cubic feet per second in August 1994. The same reach lost about 14.1 cubic feet per second between February 1994 and June 1994 and about 21.2 cubic feet per second between August 1994 and August 1995.

  7. Does internal climate variability overwhelm climate change signals in streamflow? The upper Po and Rhone basin case studies.

    Science.gov (United States)

    Fatichi, S; Rimkus, S; Burlando, P; Bordoy, R

    2014-09-15

    Projections of climate change effects in streamflow are increasingly required to plan water management strategies. These projections are however largely uncertain due to the spread among climate model realizations, internal climate variability, and difficulties in transferring climate model results at the spatial and temporal scales required by catchment hydrology. A combination of a stochastic downscaling methodology and distributed hydrological modeling was used in the ACQWA project to provide projections of future streamflow (up to year 2050) for the upper Po and Rhone basins, respectively located in northern Italy and south-western Switzerland. Results suggest that internal (stochastic) climate variability is a fundamental source of uncertainty, typically comparable or larger than the projected climate change signal. Therefore, climate change effects in streamflow mean, frequency, and seasonality can be masked by natural climatic fluctuations in large parts of the analyzed regions. An exception to the overwhelming role of stochastic variability is represented by high elevation catchments fed by glaciers where streamflow is expected to be considerably reduced due to glacier retreat, with consequences appreciable in the main downstream rivers in August and September. Simulations also identify regions (west upper Rhone and Toce, Ticino river basins) where a strong precipitation increase in the February to April period projects streamflow beyond the range of natural climate variability during the melting season. This study emphasizes the importance of including internal climate variability in climate change analyses, especially when compared to the limited uncertainty that would be accounted for by few deterministic projections. The presented results could be useful in guiding more specific impact studies, although design or management decisions should be better based on reliability and vulnerability criteria as suggested by recent literature.

  8. Does internal climate variability overwhelm climate change signals in streamflow? The upper Po and Rhone basin case studies

    Energy Technology Data Exchange (ETDEWEB)

    Fatichi, S., E-mail: simone.fatichi@ifu.baug.ethz.ch; Rimkus, S.; Burlando, P.; Bordoy, R.

    2014-09-15

    Projections of climate change effects in streamflow are increasingly required to plan water management strategies. These projections are however largely uncertain due to the spread among climate model realizations, internal climate variability, and difficulties in transferring climate model results at the spatial and temporal scales required by catchment hydrology. A combination of a stochastic downscaling methodology and distributed hydrological modeling was used in the ACQWA project to provide projections of future streamflow (up to year 2050) for the upper Po and Rhone basins, respectively located in northern Italy and south-western Switzerland. Results suggest that internal (stochastic) climate variability is a fundamental source of uncertainty, typically comparable or larger than the projected climate change signal. Therefore, climate change effects in streamflow mean, frequency, and seasonality can be masked by natural climatic fluctuations in large parts of the analyzed regions. An exception to the overwhelming role of stochastic variability is represented by high elevation catchments fed by glaciers where streamflow is expected to be considerably reduced due to glacier retreat, with consequences appreciable in the main downstream rivers in August and September. Simulations also identify regions (west upper Rhone and Toce, Ticino river basins) where a strong precipitation increase in the February to April period projects streamflow beyond the range of natural climate variability during the melting season. This study emphasizes the importance of including internal climate variability in climate change analyses, especially when compared to the limited uncertainty that would be accounted for by few deterministic projections. The presented results could be useful in guiding more specific impact studies, although design or management decisions should be better based on reliability and vulnerability criteria as suggested by recent literature. - Highlights:

  9. Origin, transport and deposition of leaf-wax biomarkers in the Amazon Basin and the adjacent Atlantic

    Science.gov (United States)

    Häggi, Christoph; Sawakuchi, André O.; Chiessi, Cristiano M.; Mulitza, Stefan; Mollenhauer, Gesine; Sawakuchi, Henrique O.; Baker, Paul A.; Zabel, Matthias; Schefuß, Enno

    2016-11-01

    Paleoenvironmental studies based on terrigenous biomarker proxies from sediment cores collected close to the mouth of large river systems rely on a proper understanding of the processes controlling origin, transport and deposition of biomarkers. Here, we contribute to the understanding of these processes by analyzing long-chain n-alkanes from the Amazon River system. We use the δD composition of long-chain n-alkanes from river bed sediments from the Amazon River and its major tributaries, as well as marine core-top samples collected off northeastern South America as tracers for different source areas. The δ13C composition of the same compounds is used to differentiate between long-chain n-alkanes from modern forest vegetation and petrogenic organic matter. Our δ13C results show depleted δ13C values (-33 to -36‰) in most samples, indicating a modern forest source for most of the samples. Enriched values (-31 to -33‰) are only found in a few samples poor in organic carbon indicating minor contributions from a fossil petrogenic source. Long-chain n-alkane δD analyses show more depleted values for the western tributaries, the Madeira and Solimões Rivers (-152 to -168‰), while n-alkanes from the lowland tributaries, the Negro, Xingu and Tocantins Rivers (-142 to -154‰), yield more enriched values. The n-alkane δD values thus reflect the mean annual isotopic composition of precipitation, which is most deuterium-depleted in the western Amazon Basin and more enriched in the eastern sector of the basin. Samples from the Amazon estuary show a mixed long-chain n-alkane δD signal from both eastern lowland and western tributaries. Marine core-top samples underlying the Amazon freshwater plume yield δD values similar to those from the Amazon estuary, while core-top samples from outside the plume showed more enriched values. Although the variability in the river bed data precludes quantitative assessment of relative contributions, our results indicate that long

  10. In the Land of the Sky: Recent Paleoenvironmental Research From Coastal Oaxaca, Mexico

    Science.gov (United States)

    Goman, M. F.; Joyce, A. A.; Mueller, R. G.

    2005-05-01

    The Lower Río Verde Valley of Oaxaca has had a long and complex cultural history in part shaped by significant landscape change that ocurred 2300 years ago, when the Río Verde river changed morphology from a meandering to a braided form. These changes were precipitated by anthropogenic landuse impacts in the highland valleys of Oaxaca over 125 linear km to the north. While the lower valley's geomorphic history is well studied, little is known of its paleoecology. In order to reconstruct the history of vegetation, climate, and associated land use change, sediment cores were raised from several sites throughout the region. We present stratigraphical, palynological, and charcoal data from three sites in the region. The lower drainage basin consists entirely of the Verde's coastal valley. The climate of the lower Río Verde Valley is hot and humid with mean annual rainfall of 1000 mm to 2000 mm and average temperatures range from 25°C to 28°C. We discuss the pollen and stratigraphic record from Laguna Pastoría which is a brackish estuary protected from the Pacific Ocean by a roughly east-west trending bay barrier. The bay barrier is about 500 m wide and 2 to 4 m high. Low scrub vegetation (cacti, thorny bushes, small trees and palms) grow on the barrier. The lagoon itself is approximately 9 km long and varies in depth with a 3-4 m maximum. Tides are microtidal (1 m). The lagoon supports a diverse array of mangroves (Rhizophora mangle, Laguncularia racemosa, Conocarpus erectus and Avicennia germinans). Two sediment cores were raised from the lagoon (LP1 and LP2) and provide a record of hurricane strikes and possible changes in the frequency of El Niño's. The LP1 core covers approximately the last 5000 yrs. Preliminary pollen analysis indicates that pollen is in excellent condition and is diverse (>60 taxa). Zea mays pollen was identified from sediments dating to the early Formative period (~ 3600 yr ago). The charcoal records analyzed from 2 paleomeanders of the

  11. Variability of streamflow under climate change: A study for 26 Brazilian large basins and sub-catchments.

    Science.gov (United States)

    Isidoro, Jorge; Tiezzi, Rafael

    2016-04-01

    Human activity is entirely dependent on water resources, thus highly vulnerable to the effects of rainfall variability. This work aims to analyse the impact of rainfall variability on streamflow for 26 Brazilian large basins and sub-catchments. Records form 83-years of observations (1931-2013) were compared with the results of simulations for the 2011-2100 (90-year) period. Two rainfall-runoff hydrological models were used for the numerical simulations: Soil Moisture Accounting Procedure-SMAP (process-based) and Stochastic Linear Model-MEL (stochastic). Very significant impacts were found, namely the increase in streamflow in the Southern basins that may reach almost 100%, while in the Northern and Northeastern basins, streamflow may decrease about 90%. These major changes can aggravate the history of flooding in the Southern basins and of droughts in several regions of the North and Northeast basins.

  12. Participatory Planning for the improvement of water management in uncertain conditions: Case study of the Souss-Massa basin in Morocco

    Science.gov (United States)

    Imani, Yasmina; Lahlou, Ouiam; Slimani, Imane; Joyce, Brian

    2016-04-01

    Due to its geographical location and to the natural features of its climate, Morocco is known as a drought prone and water scarce country. However, the country now faces, in the current context of Climate Change, an increasing and alarming water scarcity due to the combined effects of a strong decline of precipitations and a growing pressure on water resources induced by the economic development and demographic growth. Aware of this pressing issue, Morocco implemented a national water strategy based on the decentralization of water management at the river basin level and the establishment of Integrated Water Resources Management master plans for each basin. Unfortunately, these plans often underestimate the impact of uncertainty and this may lead to inefficient and unsustainable water management strategies. In this context, the aim of this study is to develop an innovative approach for robust decision making in uncertain conditions by coupling the WEAP (Water Evaluation and Planning System) model and the "XLRM" robust decision making framework to support the evaluation of management options and promote long-term sustainable integrated water management strategies at the basin level. The Souss-Massa basin, located in the south-western part of the country was retained as a case study because of its strategic importance but also because it now faces, as a consequence of the irrational use of water resources during the last decades significant water resources management challenges mainly due to the overexploitation of ground water resources, the increased of water demand due to the irrigation development, the urban and industrial growth and the expansion of tourism. Thus, in this study, a three step methodology was developed. First, the WEAP model were developed and calibrated for the Souss-Massa basin. In a second step, a XLRM participatory workshop gathering the basin main stakeholders were organized in order to identify the EXogenous factors (key uncertainties

  13. New tropical carcharhinids (chondrichthyes, carcharhiniformes) from the late Eocene early Oligocene of Balochistan, Pakistan: Paleoenvironmental and paleogeographic implications

    Science.gov (United States)

    Adnet, S.; Antoine, P.-O.; Hassan Baqri, S. R.; Crochet, J.-Y.; Marivaux, L.; Welcomme, J.-L.; Métais, G.

    2007-04-01

    New selachians (sharks and rays) have been collected from several late Eocene and early Oligocene marine localities in the Bugti Hills (Balochistan, Pakistan). Two new species of Requiem sharks (close to the Recent "Bull shark") are described : Carcharhinus balochensis and Carcharhinus perseus. The rest of the fauna is notable for the strong representation of Carcharhiniformes. These selachian faunas represent a unique tropical association for the Oligocene period and one of the first modern tropical selachian faunas, with modern taxa such as the two new species of "Bull sharks", Negaprion sp. and one of the first occurrences of Sphyrna sp. Moreover, these faunas permit paleoenvironmental interpretation of adjacent land masses. The relatively modern aspect of these faunas, compared with other contemporaneous and younger selachian associations from Atlantic and Mediterranean seas, suggests biogeographic isolation of selachian communities living in eastern and western parts of the Tethys before its final closure during the early-middle Miocene.

  14. Evaluation of rock mass classification schemes: a case study from the Bowen Basin, Australia

    Science.gov (United States)

    Brook, Martin; Hebblewhite, Bruce; Mitra, Rudrajit

    2016-04-01

    The development of an accurate engineering geological model and adequate knowledge of spatial variation in rock mass conditions are important prerequisites for slope stability analyses, tunnel design, mine planning and risk management. Rock mass classification schemes such as Rock Mass Rating (RMR), Coal Mine Roof Rating (CMRR), Q-system and Roof Strength Index (RSI) have been used for a range of engineering geological applications, including transport tunnels, "hard rock" mining and underground and open-cut coal mines. Often, rock mass classification schemes have been evaluated on subaerial exposures, where weathering has affected joint characteristics and intact strength. In contrast, the focus of this evaluation of the above classification schemes is an underground coal mine in the Bowen Basin, central Queensland, Australia, 15 km east of the town of Moranbah. Rock mass classification was undertaken at 68 sites across the mine. Both the target coal seam and overlying rock show marked spatial variability in terms of RMR, CMRR and Q, but RSI showed limited sensitivity to changes in rock mass condition. Relationships were developed between different parameters with varying degrees of success. A mine-wide analysis of faulting was undertaken, and compared with in situ stress field and local-scale measurements of joint and cleat. While there are no unequivocal relationships between rock mass classification parameters and faulting, a central graben zone shows heterogeneous rock mass properties. The corollary is that if geological features can be accurately defined by remote sensing technologies, then this can assist in predicting rock mass conditions and risk management ahead of development and construction.

  15. Preliminary study on the living environment of hominids at the Donggutuo site,Nihewan Basin

    Institute of Scientific and Technical Information of China (English)

    PEI ShuWen; LI XiaoLi; LIU DeCheng; MA Ning; PENG Fei

    2009-01-01

    The Donggutuo site,situated in the east margin of Nihewan basin,is one of the most important Paleolithic sites in China,characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region.Based on well-constructed sporopollen,sediment grain size analysis,magnetic susceptibility,and iron oxide analysis of the 2000-2001 excavated section,four stages of environmental change in the Nihewan Beds are identified by the authors.The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest,which is suitable for hominid occupation.The changes correspond to the stages of lake transgression and regression.The environment after the lake died out away has been cold and dry boschveld.The hominid activities at the site took place in the Early Pleistocene (1.10 Ma),which corresponds to the early three environmental stages.Therefore,it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making,procuring of raw materials for tools,concentrating stone artifacts,and hunting and butchering.In conclusion,the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site.

  16. Biogeochemical study on mud-volcano sediments from the Kumano forearc basin, Japan

    Science.gov (United States)

    Ijiri, A.; Toki, T.; Yamaguchi, Y. T.; Kawagucci, S.; Hattori, S.; Morono, Y.; Lever, M. A.; Yoshida, N.; Tsunogai, U.; Nakamura, K.; Takai, K.; Ashi, J.; Inagaki, F.

    2011-12-01

    We investigated microbial communities and biogeochemical processes in mud-volcano subsurface sediments down to 20 meters from the summit, obtained from the Kumano forearc basin in the Nankai Trough during the CK09-01 D/V Chikyu training cruise in 2009. The cored sediments contained several methane hydrates. Chemical characteristics of pore fluid indicated that the fluid in the mud volcano was supplied from the accretionary prism beneath the forearc sediments probably through faults. The cored sediments contained relatively low population of microbial cells (sediment depth (from -41 to -22%), synchronous to the increase of δ13CDIC. The significant isotopic fractionation between DIC and acetate (54.0±6.9%) indicates that the principal process producing acetate is homo-acetogenesis via the reductive acetyl-CoA pathway. Radioactive tracer experiments exhibited relatively high activities of homo-acetogenesis (14-34,900 pmol/cm3/day) compared to that of hydrogenotrophic methanogenesis (0.6-128 pmol/cm3/day). In ordinary marine sediments, homo-acetogenesis from H2 and CO2 is thermodynamically inhibited because H2 concentrations are maintained at low levels less than several nM. However, the homo-acetogenesis was thermodynamically favorable in the cored sediments because of the high concentration of H2 (>560nM). These results showed that homo-acetogenesis is dominant in the sediments around the summit of the mud volcano, while active hydrogenotrophic methanogenesis has been occurred in a deeper depth, and most portion of methane formed methane hydrates was supplied from the deep active methanogenic zone.

  17. River water quality in weathered limestone: A case study in upper Mahanadi basin, India

    Indian Academy of Sciences (India)

    B K Panigrahy; B C Raymahashay

    2005-10-01

    Stromatolitic limestone and calcareous shale belonging to Chattisgarh Supergroup of Proterozoic age dominate the upper part of the Mahanadi river basin.X-ray diffractogram (XRD)of limestone rocks show presence of a significant amount of calcite,dolomite and ankerite.Shales of various colours contain calcite and dolomite.It is observed that congruent dissolution of carbonate minerals in the Charmuria pure limestone has given rise to a typical karst topography.On the other hand, limestones are also seen to support red and black soil pro files.This indicates that the limestone bedrock undergoes a parallel incongruent weathering,which leaves a residue of decomposed rock. The XRD analyses reveal that the limestone soils thus formed contain an assemblage of quartz,clays and Fe-oxides.It is likely that the silicate component trapped during deposition of the stromatolitic limestone weathers incongruently resulting in diverse soil profiles.Carbonate and silicate mineral weathering schemes have been worked out to explain the soil formation,fixation of Al in clay minerals, and Fe in goethite.The water quality parameters such as Ca, Mg and HCO3 in the river water suggest under saturation with respect to calcite and dolomite.The mineral stability diagrams indicate that kaolinite and Ca-smectite are stable in the river water environment,hence they occur in suspended sediments and soils.The dominant influence of carbonate weathering on the water quality is observed even in the downstream part of the river outside the limestone terrain.

  18. Sedimentary and structural evolution of a Pleistocene small-scale push moraine in eastern Poland: New insight into paleoenvironmental conditions at the margin of an advancing ice lobe

    Science.gov (United States)

    Włodarski, Wojciech; Godlewska, Anna

    2016-08-01

    Recent studies of push moraines have focused on the interplay between the dynamics of ice margins and the environmental variables of the foreland into which they advance. These studies showed that the spatial distribution, geometry and style of the glaciotectonic deformation of push moraines are controlled by ice-induced stresses, the strain rate, the rheology of the deposits and hydraulic conductivity. In this work, we provide new insight into this interplay at a small spatio-temporal scale, specifically, the ancient glacial system of the Liwiec ice lobe within the younger Saalian ice sheet in eastern Poland. The paleoenvironmental variables that are analysed here refer to the dynamics of the hydrological processes that affected the patterns and sediment deposition rate on the terminoglacial fan and the resulting mechanical stratigraphy and hydraulic conductivity of the foreland. We document the progradational sequence of the fan deposits that developed as a result of the ice lobe thickening and the steepening of its stationary front. The sedimentary features of the fan, the lithology of its basement and the hydraulic conductivity of the foreland strongly influenced the geometry and kinematics of fold growth during the advance of the ice lobe. The predominance of flexural slip and the development of fractures, including fold-accommodation faults, were interpreted to be an effect of buckle folding due to horizontal shortening induced by ice advance. The partial overriding of the push moraine by the ice lobe and, thus, the submarginal conditions for deformation were inferred from the significant hinge migration and internal deformation of the strata under undrained conditions in one of the folds. The synfolding deposition pattern of the fan growth strata allowed us to suggest that the push moraine was probably formed by a sustained advance rather than surge.

  19. Geochemical fractionation of rare earth elements in lacustrine deposits from Qaidam Basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuCai; ZHANG WenXiang; CHANG FengQin; YANG LunQing; LEI GuoLiang; YANG MingSheng; PU Yang; LEI YangBin

    2009-01-01

    Based on the concentration and distribution pattern analysis of the rare earth elements (REEs) at the Shell Bar section from Qaidam Basin,we studied the geochemical fractionations of REE in paleolake deposits and their paleo-environmental significance.Our results show that the REE concentration in AS (acid soluble) and AR (acid residual) fractions are 20.9 μg/g and 95.4 μg/g (except element Y) individually,showing a strong REE differentiation between AS and AR fractions.However,the two types of fractions (AS & AR) have similar REE distribution patterns,which are slightly rich in light earth rare elements (LREEs),with slightly right-tilting and negative Eu anomaly.The LREE of AR is richer than that of AS.There were no significant correlations between the REE in AS,AR and other proxies.It indicated that the lacustrine deposition had different material sources and experienced varying geochemical procedures.Correlation analysis between the REE and the content of fine grain-size (<4 μm) of the sediments,Rb/Sr ratio and Mn concentration showed high correlation coefficients.Our results demonstrated that the REE in acid soluble and residual fractions bear different environmental significances,which are strongly dependent on local environment.The REE of acid soluble fraction is closely related to the paleoclimatic changes in the lake catchment and the evolutionary processes of lake itself.Our results suggest that δCe and (La/Yb)_n could be used as proxies of the reduction-oxidation conditions and furthermore the temperature change and the lake level fluctuations.Using these proxies,we reconstructed the paleoclimate and water level fluctuation history during the high lake level period lasting between 43.5 and 22.4 cal.ka BP.

  20. Geochemical fractionation of rare earth elements in lacustrine deposits from Qaidam Basin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the concentration and distribution pattern analysis of the rare earth elements (REEs) at the Shell Bar section from Qaidam Basin, we studied the geochemical fractionations of REE in paleolake deposits and their paleo-environmental significance. Our results show that the REE concentration in AS (acid soluble) and AR (acid residual) fractions are 20.9 μg/g and 95.4 μg/g (except element Y) individually, showing a strong REE differentiation between AS and AR fractions. However, the two types of fractions (AS & AR) have similar REE distribution patterns, which are slightly rich in light earth rare elements (LREEs), with slightly right-tilting and negative Eu anomaly. The LREE of AR is richer than that of AS. There were no significant correlations between the REE in AS, AR and other proxies. It indicated that the lacustrine deposition had different material sources and experienced varying geochemical procedures. Correlation analysis between the REE and the content of fine grain-size (<4 μm) of the sediments, Rb/Sr ratio and Mn concentration showed high correlation coefficients. Our results demonstrated that the REE in acid soluble and residual fractions bear different environmental significances, which are strongly dependent on local environment. The REE of acid soluble fraction is closely related to the paleoclimatic changes in the lake catchment and the evolutionary processes of lake itself. Our results suggest that δCe and (La/Yb)n could be used as proxies of the reduction-oxidation conditions and furthermore the temperature change and the lake level fluctuations. Using these proxies, we reconstructed the paleoclimate and water level fluctuation history during the high lake level period lasting between 43.5 and 22.4 cal. ka BP.

  1. A two-model hydrologic ensemble prediction of hydrograph: case study from the upper Nysa Klodzka river basin (SW Poland)

    Science.gov (United States)

    Niedzielski, Tomasz; Mizinski, Bartlomiej

    2016-04-01

    The HydroProg system has been elaborated in frame of the research project no. 2011/01/D/ST10/04171 of the National Science Centre of Poland and is steadily producing multimodel ensemble predictions of hydrograph in real time. Although there are six ensemble members available at present, the longest record of predictions and their statistics is available for two data-based models (uni- and multivariate autoregressive models). Thus, we consider 3-hour predictions of water levels, with lead times ranging from 15 to 180 minutes, computed every 15 minutes since August 2013 for the Nysa Klodzka basin (SW Poland) using the two approaches and their two-model ensemble. Since the launch of the HydroProg system there have been 12 high flow episodes, and the objective of this work is to present the performance of the two-model ensemble in the process of forecasting these events. For a sake of brevity, we limit our investigation to a single gauge located at the Nysa Klodzka river in the town of Klodzko, which is centrally located in the studied basin. We identified certain regular scenarios of how the models perform in predicting the high flows in Klodzko. At the initial phase of the high flow, well before the rising limb of hydrograph, the two-model ensemble is found to provide the most skilful prognoses of water levels. However, while forecasting the rising limb of hydrograph, either the two-model solution or the vector autoregressive model offers the best predictive performance. In addition, it is hypothesized that along with the development of the rising limb phase, the vector autoregression becomes the most skilful approach amongst the scrutinized ones. Our simple two-model exercise confirms that multimodel hydrologic ensemble predictions cannot be treated as universal solutions suitable for forecasting the entire high flow event, but their superior performance may hold only for certain phases of a high flow.

  2. A molecular and isotopic study of palaeoenvironmental conditions through the middle Cambrian in the Georgina Basin, central Australia

    Science.gov (United States)

    Pagès, Anais; Schmid, Susanne; Edwards, Dianne; Barnes, Stephen; He, Nannan; Grice, Kliti

    2016-08-01

    The Cambrian period marks an important point in Earth's history with profound changes in the ocean's biogeochemistry and the occurrence of the most significant evolutionary event in the history of life, the Cambrian explosion. The Cambrian explosion is described as a succession of complex cycles of extinctions and radiations. This study integrates biomarkers and their compound-specific stable carbon isotopes to investigate the palaeoenvironmental depositional conditions in middle Cambrian (Series 3) sedimentary rocks (Thorntonia Limestone, Inca Formation and Currant Bush Limestone) from two drillholes in the Undilla Sub-basin in the eastern Georgina Basin, central Australia. The occurrence of photic zone euxinia (PZE) was detected throughout these three formations by the identification of green sulfur bacteria Chlorobiaceae-derived biomarkers, including a series of 2,3,6-aryl isoprenoids and the intact biomarker isorenieratane. Pulses of enhanced PZE conditions were detected in two core intervals (90-110 mKB, Currant Bush Limestone and 170-200 mKB, Inca Formation) by an increase in the 2,3,6-aryl isoprenoids and C19 biphenyl concentrations. These enhanced PZE conditions were followed by blooms of phytoplankton, as demonstrated by the increase in algal-derived biomarker (i.e. pristane, phytane and the C19n-alkane) concentrations and compound-specific isotopes. These observations confirm that palaeoenvironmental conditions were similar to those reported for the Permian/Triassic and Triassic/Jurassic mass extinction events. The sterane distributions varied across the three formations reflecting possible changes in the phytoplanktonic communities through time. Although a rise in atmospheric oxygen during the Cambrian has been previously associated with the rapid evolution of metazoans, the ecological challenges related to widespread anoxia must have had a major influence on the evolution of life in Cambrian oceans.

  3. A study case of Baranca drainage basin flash-floods using the hydrological model of Hec-Ras

    Directory of Open Access Journals (Sweden)

    Aritina HALIUC

    2012-09-01

    Full Text Available In the last decades, the floods which occurred within Romanian territory stand as proof for the increased frequency of the extreme hydrological hazards which have negative effects on the normal pathway of the human-beings activities. The technological progress among with the increased frequency of floods events are the base for the development of informational programs for the analysis, simulation and flood management. The Baranca brook which drains a considerable part of Zamostea village (Romania was used as a pilot drainage basin for the flash-flood simulation using the Hec-Ras program and the Arcgis extension, HecGeo-Ras. The flash-floods that occurred in the summer of 2010 were used to validate the results of the simulation. Between 28.06.2010 – 29.06.2010, two flash-floods occurred in the Baranca drainage basin with a discharge oscillated between 10m3 and 70m3, a water extent which covered an area of 5.14 km2 and a depth ranging between 0.3-3m. The programs are capable to simulate the water flow and to investigate the floodway encroachments in the study area. The damages evaluated in the field along with the program’s results reveal the fact that more than half of the built-up areas of Zamostea village are established along brooks, within the floodplain area. What is more, after the 2010 floods, the expension of the habitable area was not detained by the water danger, many houses are still built on the floodplain. The programs used, taking an acceptable margin of error, may be integrated into any flood management strategy or in any watershed plan and may provide the necessary support for mitigating the risks associated with floods

  4. Impacts of climate change on streamflows under RCP scenarios: A case study in Xin River Basin, China

    Science.gov (United States)

    Zhang, Yuqing; You, Qinglong; Chen, Changchun; Ge, Jing

    2016-09-01

    Researchers often examine hydro-climatological processes via Global Circulation Model (GCM) and hydrological model, which have been shown to benefit water resources management and prediction, especially at the basin scale. In this study, the Soil and Water Assessment Tool (SWAT) and Statistical Downscaling Method (SDSM) were integrated and applied to estimate streamflows in the Xin River Basin, China, based on climate change scenarios downscaled from different GCMs (BCC-CSM1.1, CanESM2, and NorESM1-M) under three Representative Concentration Pathways (RCPs). Results confirmed that the calibrated SWAT model accurately depicts hydrological processes features at daily, monthly, and yearly scales. Three GCMs based on the calibrated SDSM showed that temperature is continually increasing in the region, however, future precipitation is highly complex and uncertain; there were significant differences among various GCM RCP scenarios. The average of the precipitation in three models showed slight and steady increase trends under RCP2.6 and RCP4.5, but a significant increase under the RCP8.5 scenario. The ensemble average of streamflow in GCMs demonstrated that many RCPs significantly decrease from May to June but increase from August to September relative to the baseline period. The ensemble mean of the multi-GCM indicated that future streamflows under RCP2.6 and RCP4.5 scenarios will be closer to the current streamflow volume. Many RCPs also revealed a significant increase in monthly streamflow dispersion coefficient in October, reflecting a tendency for drought and flood events in that month. The BCC-CSM1.1 and NorESM1-M models showed that streamflows are higher than the baseline with median probability in the future. The low monthly streamflow (10th percentile) processes for each GCM were altogether similar to the baseline, whereas the high monthly streamflows (90th percentile) showed various levels of disparity compared to the baseline.

  5. Monitoring Effects of Wildfire Mitigation Treatments on Water Budget Components: A Paired-Basin Study in the Santa Fe River Watershed, New Mexico

    Science.gov (United States)

    Lewis, A. C.

    2015-12-01

    A paired basin study in the Upper Santa Fe River watershed following forest restoration measured water budget components in a treated and untreated basin. The paired basin study was established to investigate questions that have arisen with regards to changes in the amount and timing of water yield following forest treatments. Precipitation, stream flow, soil moisture, chloride concentrations in precipitation and stream flow were measured to quantify the water budget components. While the study is ongoing, the results from six water years show a high degree of confidence in the techniques applied. The total inflow from precipitation for each integration period minus the outflow of stream flow, evapotranspiration, recharge and soil moisture leaves a remainder of less than 1%, thus most of the water is accounted for. Volume-weighted chloride concentration in precipitation ranges from 0.20 to 0.23 mg/L for the three integration periods. The annual volume-weighted chloride concentration in stream flow for the same periods ranges from 2.18 to 3.32 mg/L in the treated basin and 0.93 to 1.35 mg/L in the control basin. Based on the ratio of chloride in precipitation to the concentration in stream flow, evapotranspiration is estimated to be about 90 to 96 percent in the treated basin and 76 to 85 percent in the untreated basin for the three integration periods of the ongoing investigation. Higher evapotranspiration rates in the treated basin may be due to the change in vegetation or to a greater area at a lower elevation with a west facing slope. While no increase in stream flow in the treated basin from the forest treatments has been detected, the intensity of runoff appear to be reduced from pre-treatment to post-treatment conditions. With continued monitoring as the vegetation reestablishes to the desired "restored" condition, we will be able to track changes in the water budget.A paired basin study in the Upper Santa Fe River watershed following forest restoration

  6. Credibility of Hydrologic Models in the Context of Climate Change Impact Studies - A Case Study in the Olifants Basin, South Africa

    Science.gov (United States)

    Wagener, Thorsten; van Werkhoven, Kathryn; Singh, Riddhi

    2010-05-01

    A major challenge for hydrologic research in the coming years will be the assessment of climate change impacts on regional water resources. While more and more impact studies are being performed, the assessment of hydrologic changes across a region, particularly in less developed countries, is often severely limited by the lack of streamflow gauges to calibrate watershed models and hence large uncertainties of model predictions. Further, one has to ask the general question of how we can increase the credibility of watershed models in the context of climate change studies, where, by definition, the model's credibility cannot simply be derived from its performance in reproducing historical observations. The study region is the Olifants basin in South Africa, a UNESCO HELP basin that is characterized by severe water insecurity and regular hydrologic extreme events. We will demonstrate how we can trade space-for-time by using spatial gradients as first order approximation of temporal changes in watershed behavior to derive ensemble predictions at both gauged and ungauged sites. In general, there is an urgent need to re-think how we identify, use and evaluate hydrological models under non-stationary conditions to increase the value of studies such as this one for water resource planning and decision making.

  7. Design and Analysis of Salmonid Tagging Studies in the Columbia Basin, Volume I; Assessment of Temporal Trends in Daily Survival Estimates of Spring Chinook, 1994-1996 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, John R.; Perez-Comas, Jose A.; Lady, Jim

    1998-10-01

    This report if the first of a series of reports produced by the University of Washington for the Bonneville Power Administration under the title ''The Design and Analysis of Salmonid Tagging Studies in the Columbia Basin'', with the purpose of offering new and alternative methods to analyzing data from tagging studies in the Columbia Basin.

  8. PILOT-SCALE STUDY OF THE EFFECT OF SELECTIVE CATALYTIC REDUCTION CATALYST ON MERCURY SPECIATION IN ILLINOIS AND POWDER RIVER BASIN COAL COMBUSTION FLUE GASES

    Science.gov (United States)

    A study was conducted to investigate the effect of selective catalytic reduction (SCR) catalyst on mercury (Hg) speciation in bituminous and subbituminous coal combustion flue gases. Three different Illinois Basin bituminous coals (from high to low sulfur and chlorine) and one Po...

  9. The economic value of drought information for water management under climate change: a case study in the Ebro basin

    Directory of Open Access Journals (Sweden)

    S. Quiroga

    2011-03-01

    Full Text Available Drought events in the Mediterranean are likely to increase in frequency, duration and intensity due to climate change, thereby affecting crop production. Information about drought is valuable for river basin authorities and the farmers affected by their decisions. The economic value of this information and the resulting decisions are of interest to these two stakeholder groups and to the information providers. Understanding the dynamics of extreme events, including droughts, in future climate scenarios for the Mediterranean is being improved continuously. This paper analyses the economic value of information on drought events taking into account the risk aversion of water managers. We consider the effects of drought management plans on rice production in the Ebro river basin. This enables us to compute the willingness to compensate the river basin authority for more accurate information allowing for better decision-making. If runoff is reduced, river basin planners can consider the reduction of water allocation for irrigation in order to eliminate the risk of water scarcity. Alternately, river basin planners may decide to maintain water allocation and accept a reduction of water supply reliability, leaving farmers exposed to drought events. These two alternatives offer different risk levels for crop production and farmers' incomes which determine the value of this information to the river basin authority. The information is relevant for the revision of River Basin Management Plans of the Water Framework Directive (WFD within the context of climate change.

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

    Science.gov (United States)

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

    1999-07-01

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

  11. Geohydrologic feasibility study of the Piceance Basin of Colorado for the potential applicability of Jack W. McIntyre`s patented gas/produced water separation process

    Energy Technology Data Exchange (ETDEWEB)

    Kieffer, F.

    1994-02-01

    Geraghty & Miller, Inc. of Midland, Texas conducted geologic and hydrologic feasibility studies of the potential applicability of Jack McIntyre`s patented process for the recovery of natural gas from coalbed/sand formations in the Piceance Basin through literature surveys. Jack McIntyre`s tool separates produced water from gas and disposes of the water downhole into aquifers unused because of poor water quality, uneconomic lifting costs or poor aquifer deliverability. The beneficial aspects of this technology are two fold. The process increases the potential for recovering previously uneconomic gas resources by reducing produced water lifting, treatment and disposal costs. Of greater importance is the advantage of lessening the environmental impact of produced water by downhole disposal. Results from the survey indicate that research in the Piceance Basin includes studies of the geologic, hydrogeologic, conventional and unconventional recovery oil and gas technologies. Available information is mostly found centered upon the geology and hydrology for the Paleozoic and Mesozoic sediments. Lesser information is available on production technology because of the limited number of wells currently producing in the basin. Limited information is available on the baseline geochemistry of the coal/sand formation waters and that of the potential disposal zones. No determination was made of the compatibility of these waters. The study also indicates that water is often produced in variable quantities with gas from several gas productive formations which would indicate that there are potential applications for Jack McIntyre`s patented tool in the Piceance Basin.

  12. The impact of climate change on water provision under a low flow regime: a case study of the ecosystems services in the Francoli river basin.

    Science.gov (United States)

    Marquès, Montse; Bangash, Rubab Fatima; Kumar, Vikas; Sharp, Richard; Schuhmacher, Marta

    2013-12-15

    Mediterranean basin is considered one of the most vulnerable regions of the world to climate change and with high probability to face acute water scarcity problem in the coming years. Francolí River basin (NE Spain), located in this vulnerable region is selected as a case study to evaluate the impact of climate change on the delivery of water considering the IPCC scenarios A2 and B1 for the time spans 2011-2040, 2041-2070 and 2071-2100. InVEST model is applied in a low flow river as a new case study, which reported successful results after its model validation. The studied hydrological ecosystem services will be highly impacted by climate change at Francolí River basin. Water yield is expected to be reduced between 11.5 and 44% while total drinking water provisioning will decrease between 13 and 50% having adverse consequences on the water quality of the river. Focusing at regional scale, Prades Mountains and Brugent Tributary provide most of the provision of water and also considered highly vulnerable areas to climate change. However, the most vulnerable part is the northern area which has the lowest provision of water. Francolí River basin is likely to experience desertification at this area drying Anguera and Vallverd tributaries.

  13. Institutional Arrangements for River Basin Management: A Case Study of Comparison between the United States and China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Gang-yan

    2007-01-01

    This note compares institutional arrangements for water resources management in two river basins, namely, those of the Susquehanna River in the United States and the Yangtze River in China. The Susquehanna River Basin Commission is composed of the US federal government and the three states of New York, Pennsylvania, and Maryland through which the Susquehanna River passes. Under the authority of the Susquehanna River Basin Compact, the Commission deals with water resources problems throughout its vast drainage area. In contrast, the Changjiang(Yangtze River) Water Resources Commission (CWRC) lacks relative effectiveness in mobilizing provincial governments in transboundary water resources management.

  14. The Hominin Sites and Paleolakes Drilling Project (HSPDP): Understanding the paleoenvironmental and paleoclimatic context of human origins through continental drilling

    Science.gov (United States)

    Cohen, Andrew S.; Campisano, Christopher; Asrat, Asfawossen; Arrowsmith, Ramon; Deino, Alan; Feibel, Craig; Hill, Andrew; Kingston, John; Lamb, Henry; Lowenstein, Tim; Olago, Daniel; Bernhart Owen, R.; Renaut, Robin; Schabitz, Frank; Trauth, Martin

    2015-04-01

    The influence of climate and environmental history on human evolution is an existential question that continues to be hotly debated, in part because of the paucity of high resolution records collected in close proximity to the key fossil and archaeological evidence. To address this issue and transform the scientific debate, the HSPDP was developed to collect lacustrine sediment drill cores from basins in Kenya and Ethiopia that collectively encompass critical time intervals and locations for Plio-Quaternary human evolution in East Africa. After a 17 month campaign, drilling was completed in November, 2014, with over 1750m of core collected from 11 boreholes from five areas (1930m total drilling length, avg. 91% recovery). The sites, from oldest to youngest, include 1) N. Awash, Ethiopia (~3.5-2.9Ma core interval); 2) Baringo-Tugen Hills, Kenya (~3.3-2.5Ma); 3) West Turkana, Kenya (~1.9-1.4Ma); L. Magadi, Kenya (0.8-0Ma) and the Chew Bahir Basin, Ethiopia (~0.5-0Ma). Initial core description (ICD) and sampling for geochronology, geochemistry and paleoecology studies had been completed by mid2014, with the two remaining sites (Magadi and Chew Bahir) scheduled for ICD work in early 2015. Whereas the primary scientific targets were the lacustrine deposits from the hominin-bearing basin depocenters, many intervals of paleosols (representative of low lake stands and probable arid periods) were also encountered in drill cores. Preliminary analyses of drill core sedimentology and geochemistry show both long-term lake level changes and cyclic variability in lake levels, both of which may be indicative of climatic forcing events of interest to paleoanthropologists. Authors of this abstract also include the entire HSPDP field team.

  15. Study of rock-water-nuclear waste interactions in the Pasco Basin, Washington. Part I. Distribution and composition of secondary and primary mineral phases in basalts of the Pasco Basin, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Benson, L.V.; Teague, L.S.

    1979-09-01

    In Part I of this report the results of Task III are presented and discussed. The subject of Task III is the study and identification of secondary and primary mineral assemblages in basalts of the Pasco Basin of southeastern Washington. In particular, we have determined the relative amounts, crystallization sequence, and compositions of secondary minerals found lining vesicle and fracture surfaces. This information, together with data on the chemical composition of primary minerals and the extent to which they have undergone dissolution, has been used in theoretical simulations of mass transfer which is the subject of Part II (Task IV) of this report.

  16. Cyclostratigraphy of an orbitally-driven Tithonian-Valanginian carbonate ramp succession, Southern Mendoza, Argentina: Implications for the Jurassic-Cretaceous boundary in the Neuquén Basin

    Science.gov (United States)

    Kietzmann, Diego A.; Palma, Ricardo M.; Iglesia Llanos, Maria Paula

    2015-01-01

    Detailed sedimentological, sequence stratigraphical and cyclostratigraphical analyses have been made from four lower Tithonian-lower Valanginian sections of the Vaca Muerta Formation, exposed in the southern Mendoza area of the Neuquén Basin, Argentina. The Vaca Muerta Formation is characterized by decimetre-scale rhythmic alternations of marls, shales and limestones, and consists of five facies associations, which reflect different paleoenvironmental conditions: basin to restricted outer ramp, outer ramp, and middle ramp. Vertical organization within the Vaca Muerta Formation shows a well-ordered hierarchy of cycles, where elementary cycles, bundles and superbundles with frequencies within the Milankovitch band have been recognized. According to biostratigraphic data, elementary cycles have a periodicity of ~ 20 ky, which correlates with the precession cycle of Earth's axis. Spectral analysis based on series of cycle thickness allows us to identify frequencies of about 400 ky and 90-120 ky, which we interpret as the modulation of the precessional cycle by the Earth's orbital eccentricity. Cycles are probably driven by variations in carbonate exportation, as fluctuations in shallow-water carbonate production involve modifications in carbonate basinward exportation. Cyclostratigraphic data allowed us to build a floating orbital scale for the Tithonian-lower Valanginian interval in the Neuquén Basin. Correlation between studied sections allowed us to recognize a discontinuity between the Substeueroceras koeneni and Argentiniceras noduliferum ammonite zones in the Malargüe Anticline area. Orbital calibration of these sections is consistent with Riccardi's biostratigraphic scheme, wich place the Jurassic-Cretaceous boundary within the Substeueroceras koeneni ammonite Zone. On the other hand, the base of the Vaca Muerta Formation (Virgatosphinctes mendozanus ammonite Zone) would be probably placed in the base of the middle Tithonian rather than the lower Tithonian

  17. Reinforcement Learning Multi-Agent Modeling of Decision-Making Agents for the Study of Transboundary Surface Water Conflicts with Application to the Syr Darya River Basin

    Science.gov (United States)

    Riegels, N.; Siegfried, T.; Pereira Cardenal, S. J.; Jensen, R. A.; Bauer-Gottwein, P.

    2008-12-01

    In most economics--driven approaches to optimizing water use at the river basin scale, the system is modelled deterministically with the goal of maximizing overall benefits. However, actual operation and allocation decisions must be made under hydrologic and economic uncertainty. In addition, river basins often cross political boundaries, and different states may not be motivated to cooperate so as to maximize basin- scale benefits. Even within states, competing agents such as irrigation districts, municipal water agencies, and large industrial users may not have incentives to cooperate to realize efficiency gains identified in basin- level studies. More traditional simulation--optimization approaches assume pre-commitment by individual agents and stakeholders and unconditional compliance on each side. While this can help determine attainable gains and tradeoffs from efficient management, such hardwired policies do not account for dynamic feedback between agents themselves or between agents and their environments (e.g. due to climate change etc.). In reality however, we are dealing with an out-of-equilibrium multi-agent system, where there is neither global knowledge nor global control, but rather continuous strategic interaction between decision making agents. Based on the theory of stochastic games, we present a computational framework that allows for studying the dynamic feedback between decision--making agents themselves and an inherently uncertain environment in a spatially and temporally distributed manner. Agents with decision-making control over water allocation such as countries, irrigation districts, and municipalities are represented by reinforcement learning agents and coupled to a detailed hydrologic--economic model. This approach emphasizes learning by agents from their continuous interaction with other agents and the environment. It provides a convenient framework for the solution of the problem of dynamic decision-making in a mixed cooperative / non

  18. Mid-Cenozoic tectonic and paleoenvironmental setting of the central Arctic Ocean

    Science.gov (United States)

    O'Regan, M.; Moran, K.; Backman, J.; Jakobsson, M.; Sangiorgi, F.; Brinkhuis, Henk; Pockalny, Rob; Skelton, Alasdair; Stickley, Catherine E.; Koc, N.; Brumsack, Hans-Juergen; Willard, Debra A.

    2008-01-01

    Drilling results from the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) to the Lomonosov Ridge (LR) document a 26 million year hiatus that separates freshwater-influenced biosilica-rich deposits of the middle Eocene from fossil-poor glaciomarine silty clays of the early Miocene. Detailed micropaleontological and sedimentological data from sediments surrounding this mid-Cenozoic hiatus describe a shallow water setting for the LR, a finding that conflicts with predrilling seismic predictions and an initial postcruise assessment of its subsidence history that assumed smooth thermally controlled subsidence following rifting. A review of Cenozoic tectonic processes affecting the geodynamic evolution of the central Arctic Ocean highlights a prolonged phase of basin-wide compression that ended in the early Miocene. The coincidence in timing between the end of compression and the start of rapid early Miocene subsidence provides a compelling link between these observations and similarly accounts for the shallow water setting that persisted more than 30 million years after rifting ended. However, for much of the late Paleogene and early Neogene, tectonic reconstructions of the Arctic Ocean describe a landlocked basin, adding additional uncertainty to reconstructions of paleodepth estimates as the magnitude of regional sea level variations remains unknown.

  19. A study on the evolution of Indian Ocean triple junction and the process of deformation in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.; Rao, T.C.S.

    It is generally presumed that the intraplate deformation in the Central Indian Basin (CIB) is a direct consequence of spreading across the South East Indian Ridge and the resistance to shortening at the continental collision between India...

  20. Transport of solutes under transient flow conditions – A case study – Yamuna river sub basin (Kosi Kalan to Agra

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-09-01

    Full Text Available The imbalance between incoming and outgoing salt causes salinization of soils and sub-soils that result in increasing the salinity of stream-flows and agriculture land. This salinization is a serious environmental hazard particularly in semi-arid and arid lands. In order to estimate the magnitude of the hazard posed by salinity, it is important to understand and identify the processes that control salt movement from the soil surface through the root zone to the ground water and stream flows. In the present study, Yamuna sub-basin (both sides of Gokul dam site has been selected which has two distinct climatic zones, sub-humid (upstream of Mathura and semi-arid region (downstream of Mathura. In the upstream, both surface and ground waters are used for irrigation, whereas in the downstream mostly groundwater is used. Both soils and ground waters are more saline in downstream parts of the study area. In this study we characterized the soil salinity and groundwater quality in both areas. An attempt is also made to model the distribution of potassium concentration in the soil profile in response to varying irrigation conditions using the Soil-Water Infiltration and Movement (SWIM model. Fair agreement was obtained between predicted and measured results indicating the applicability of the model.

  1. Association between changing mortality of digestive tract cancers and water pollution: a case study in the Huai River Basin, China.

    Science.gov (United States)

    Ren, Hongyan; Wan, Xia; Yang, Fei; Shi, Xiaoming; Xu, Jianwei; Zhuang, Dafang; Yang, Gonghuan

    2014-12-23

    The relationship between the ever-increasing cancer mortality and water pollution is an important public concern in China. This study aimed to explore the association between serious water pollution and increasing digestive cancer mortality in the Huai River Basin (HRB) in China. A series of frequency of serious pollution (FSP) indices including water quality grade (FSPWQG), biochemical oxygen demand (FSPBOD), chemical oxygen demand (FSPCOD), and ammonia nitrogen (FSPAN) were used to characterize the surface water quality between 1997 and 2006. Data on the county-level changing mortality (CM) due to digestive tract cancers between 1975 and 2006 were collected for 14 counties in the study area. Most of investigated counties (eight) with high FSPWQG (>50%) distributed in the northern region of the HRB and had larger CMs of digestive tract cancers. In addition to their similar spatial distribution, significant correlations between FSP indices and CMs were observed by controlling for drinking water safety (DWS), gross domestic product (GDP), and population (POP). Furthermore, the above-mentioned partial correlations were clearly increased when only controlling for GDP and POP. Our study indicated that county-level variations of digestive cancer mortality are remarkably associated with water pollution, and suggested that continuous measures for improving surface water quality and DWS and hygienic interventions should be effectively implemented by local governments.

  2. Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

    Directory of Open Access Journals (Sweden)

    B. Shrestha

    2013-01-01

    Full Text Available This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation from four general circulation models (GCMs that are found to perform well in the Mekong region and a regional circulation model (PRECIS are downscaled using a delta change approach. The Soil and Water Assessment Tool (SWAT is used to assess future changes in sediment flux attributable to climate change. Results indicate up to 3.0 °C shift in seasonal temperature and 27% (decrease to 41% (increase in seasonal precipitation. The largest increase in temperature is observed in the dry season while the largest change in precipitation is observed in the wet season. In general, temperature shows increasing trends but changes in precipitation are not unidirectional and vary depending on the greenhouse gas emission scenarios (GHGES, climate models, prediction period and season. The simulation results show that the changes in annual stream discharges are likely to range from a 17% decrease to 66% increase in the future, which will lead to predicted changes in annual sediment yield ranging from a 27% decrease to about 160% increase. Changes in intra-annual (monthly discharge as well as sediment yield are even greater (−62 to 105% in discharge and −88 to 243% in sediment yield. A higher discharge and sediment flux are expected during the wet seasons, although the highest relative changes are observed during the dry months. The results indicate high uncertainties in the direction and magnitude of changes of discharge as well as sediment yields due to climate change. As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in both sediment management and climate change adaptation.

  3. Dynamic downscaling of near-surface air temperature at the basin scale using WRF-a case study in the Heihe River Basin, China

    Institute of Scientific and Technical Information of China (English)

    Xiaoduo PAN; Xin Li; Xiaokang SHI; Xujun HAN; Lihui LUO; Liangxu WANG

    2012-01-01

    The spatial resolution of general circulation models (GCMs) is too coarse to represent regional climate variations at the regional,basin,and local scales required for many environmental modeling and impact assessments.Weather research and forecasting model (WRF) is a nextgeneration,fully compressible,Euler non-hydrostatic mesoscale forecast model with a run-time hydrostatic option.This model is useful for downscaling weather and climate at the scales from one kilometer to thousands of kilometers,and is useful for deriving meteorological parameters required for hydrological simulation too.The objective of this paper is to validate WRF simulating 5 km/ 1 h air temperatures by daily observed data of China Meteorological Administration (CMA) stations,and by hourly in-situ data of the Watershed Allied Telemetry Experimental Research Project.The daily validation shows that the WRF simulation has good agreement with the observed data; the R2 between the WRF simulation and each station is more than 0.93; the absolute of meanbias error (MBE) for each station is less than 2℃; and the MBEs of Ejina,Mazongshan and Alxa stations are near zero,with R2 is more than 0.98,which can be taken as an unbiased estimation.The hourly validation shows that the WRF simulation can capture the basic trend of observed data,the MBE of each site is approximately 2℃,the R2 of each site is more than 0.80,with the highest at 0.95,and the computed and observed surface air temperature series show a significantly similar trend.

  4. The isotopic composition of authigenic chromium in anoxic marine sediments: A case study from the Cariaco Basin

    Science.gov (United States)

    Reinhard, Christopher T.; Planavsky, Noah J.; Wang, Xiangli; Fischer, Woodward W.; Johnson, Thomas M.; Lyons, Timothy W.

    2014-12-01

    Chromium (Cr) isotopes are an emerging proxy for tracking redox processes at the Earth's surface. However, there has been limited exploration of the Cr isotope record of modern and recent marine sediments. The basic inorganic chemistry of Cr suggests that anoxic marine basins should factor prominently in the global Cr cycle and that sediments deposited within anoxic basins may offer a valuable Cr isotope archive throughout Earth's history. Here, we present δ53Cr data from sediments of the Cariaco Basin, Venezuela-a 'type' environment for large, perennially anoxic basins with a relatively strong hydrological connection to the global oceans. We document a marked positive shift in bulk δ53Cr values following the termination of the Last Glacial Maximum, followed by relative stasis. Based on a suite of independent redox proxies, this transition marks a switch from oxic to persistently anoxic and sulfidic (euxinic) depositional conditions within the basin. We find good agreement between two independent approaches toward estimating the δ53Cr composition of authigenic Cr in euxinic Cariaco Basin sediments and that these estimates are very similar to the δ53Cr composition of modern open Atlantic Ocean seawater. These data, together with considerations of reaction kinetics and mass balance within the Cariaco Basin, are consistent with the hypothesis that anoxic marine settings can serve as a chemical archive of first-order trends in seawater δ53Cr composition. Additionally, the Cariaco Basin data suggest that there has been secular stability in the average δ53Cr value of Atlantic seawater over the last ∼15 kyr.

  5. Pawcatuck River and Narragansett Bay Drainage Basins. Water and Related Land Resources Study. Blackstone River Watershed. Appendices.

    Science.gov (United States)

    1981-08-01

    weee ir noww md Id I b Wock number) --The eight appendices to the main report provides descriptive material abbut the Blackstone River Basin. Appendices...PNB area). The team concentrated on water supply, water quality, recreation, marine management, flooding and erosion, minerals extraction and the...basin consists of gently rolling wooded hills. Peters River originates in Bellingham, Massachusetts, just north of Silver Lake. It flows southwesterly

  6. The isotopic composition of authigenic chromium in anoxic marine sediments: A case study from the Cariaco Basin

    OpenAIRE

    Reinhard, Christopher T.; Planavsky, Noah J.; Wang, Xiangli; Fischer, Woodward W.; Johnson, Thomas M.; Lyons, Timothy W.

    2014-01-01

    Chromium (Cr) isotopes are an emerging proxy for tracking redox processes at the Earth's surface. However, there has been limited exploration of the Cr isotope record of modern and recent marine sediments. The basic inorganic chemistry of Cr suggests that anoxic marine basins should factor prominently in the global Cr cycle and that sediments deposited within anoxic basins may offer a valuable Cr isotope archive throughout Earth's history. Here, we present δ^(53)Cr data from sediments of the ...

  7. Application of MODIS Products to Infer Possible Relationships Between Basin Land Cover and Coastal Waters Turbidity Using the Magdalena River, Colombia, as a Case Study

    Science.gov (United States)

    Madrinan, Max Jacobo Moreno; Cordova, Africa Flores; Olivares, Francisco Delgado; Irwin, Dan

    2012-01-01

    Basin development and consequent change in basin land cover have been often associated with an increased turbidity in coastal waters because of sediment yield and nutrients loading. The later leads to phytoplankton abundance further exacerbating water turbidity. This subsequently affects biological and physical processes in coastal estuaries by interfering with sun light penetration to coral reefs and sea grass, and even affecting public health. Therefore, consistent estimation of land cover changes and turbidity trend lines is crucial to design environmental and restoration management plans, to predict fate of possible pollutants, and to estimate sedimentary fluxes into the ocean. Ground solely methods to estimate land cover change would be unpractical and traditional methods of monitoring in situ water turbidity can be very expensive and time consuming. Accurate monitoring on the status and trends of basin land cover as well as the water quality of the receiving water bodies are required for analysis of relationships between the two variables. Use of remote sensing (RS) technology provides a great benefit for both fields of study, facilitating monitoring of changes in a timely and cost effective manner and covering wide areas with long term measurements. In this study, the Magdalena River basin and fixed geographical locations in the estuarine waters of its delta are used as a case to study the temporal trend lines of both, land cover change and the reflectance of the water turbidity using satellite technology. Land cover data from a combined product between sensors Terra and Aqua (MCD12Q1) from MODIS will be adapted to the conditions in the Magdalena basin to estimate changes in land cover since year 2000 to 2009. Surface reflectance data from a MODIS, Terra (MOD09GQ), band 1, will be used in lieu of in situ water turbidity for the time period between 2000 and present. Results will be compared with available existing data.

  8. Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim [Geology Programme, School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four seismic units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel systems (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform.

  9. Basin-Scale Study on the Multiphase Distribution, Source Apportionment and Risk Assessment of PAHs in the Hai River Water System.

    Science.gov (United States)

    Li, Rufeng; Zhang, Xian'e; Liu, Yanzhen; Yin, Su; Liu, Jingling; Feng, Chenghong

    2016-10-01

    As a systematic research at basin scale, this study explored the composition and concentration characteristics of 16 priority polycyclic aromatic hydrocarbons (PAHs) in sediments, water, and suspended particulate matter (SPM) in the water systems (rivers, lakes, and reservoirs) in the Hai River Basin through literature review. The sources and the ecosystem risks of PAHs in the sediments in the entire basin were specially discussed with diagnostic ration, PAHs composition, and an improved risk quotient method. Results showed that the total concentration of PAHs varied from 99.65 to 25,303 ng g(-1) dry weight in sediments, from 51.0 to 559.1 ng L(-1) in water, and from 4528 to 51,080 ng g(-1) dry weight in SPM, respectively. The dominant PAHs in the three examined phases were 2-3 rings in most waterbodies. PAHs in the rivers were from mixed sources (petrogenic and pyrolytic inputs), whereas those in lakes and reservoirs were mainly from biomass combustion and petroleum combustion. PAHs in the entire basin exhibited moderate to high ecological risk, and the rivers (especially Hai River, Jiyun River, Chaobai River, and Beiyun River) suffered higher ecological risk than reservoirs and lakes. Most of the rivers with higher PAHs risk flow through or around megacity Beijing and Tianjin.

  10. Representing Geospatial Environment Observation Capability Information: A Case Study of Managing Flood Monitoring Sensors in the Jinsha River Basin

    Science.gov (United States)

    Hu, Chuli; Guan, Qingfeng; Li, Jie; Wang, Ke; Chen, Nengcheng

    2016-01-01

    Sensor inquirers cannot understand comprehensive or accurate observation capability information because current observation capability modeling does not consider the union of multiple sensors nor the effect of geospatial environmental features on the observation capability of sensors. These limitations result in a failure to discover credible sensors or plan for their collaboration for environmental monitoring. The Geospatial Environmental Observation Capability (GEOC) is proposed in this study and can be used as an information basis for the reliable discovery and collaborative planning of multiple environmental sensors. A field-based GEOC (GEOCF) information representation model is built. Quintuple GEOCF feature components and two GEOCF operations are formulated based on the geospatial field conceptual framework. The proposed GEOCF markup language is used to formalize the proposed GEOCF. A prototype system called GEOCapabilityManager is developed, and a case study is conducted for flood observation in the lower reaches of the Jinsha River Basin. The applicability of the GEOCF is verified through the reliable discovery of flood monitoring sensors and planning for the collaboration of these sensors. PMID:27999247

  11. Using satellite data to study the relationship between rainfall and diarrheal diseases in a Southwestern Amazon basin.

    Science.gov (United States)

    Fonseca, Paula Andrea Morelli; Hacon, Sandra de Souza; Reis, Vera Lúcia; Costa, Duarte; Brown, Irving Foster

    2016-03-01

    The North region is the second region in Brazil with the highest incidence rate of diarrheal diseases in children under 5 years old. The aim of this study was to investigate the relationship between rainfall and water level during the rainy season principally with the incidence rate of this disease in a southwestern Amazon basin. Rainfall estimates and the water level were correlated and both of them were correlated with the diarrheal incidence rate. For the Alto Acre region, 2 to 3 days' time-lag is the best interval to observe the impact of the rainfall in the water level (R = 0.35). In the Lower Acre region this time-lag increased (4 days) with a reduction in the correlation value was found. The correlation between rainfall and diarrheal disease was better in the Lower Acre region (Acrelândia, R = 0.7) and rainfall upstream of the city. Between water level and diarrheal disease, the best results were found for the Brasiléia gauging station (Brasiléia, R = 0.3; Epitaciolândia, R = 0.5). This study's results may support planning and financial resources allocation to prioritize actions for local Civil Defense and health care services before, during and after the rainy season.

  12. Predicting future changes in climate and its impact on change in land use: a case study of Cauvery Basin

    Science.gov (United States)

    Poyil, Rohith P.; Dhanalakshmi, S.; Goyal, Pramila

    2016-05-01

    The study involves the climate change prediction and its effects over a local sub grid scale of smaller area in Cauvery basin. The consequences of global warming due to anthropogenic activities are reflected in global as well as regional climate in terms of changes in key climatic variables such as temperature, precipitation, humidity and wind speed. The key objectives of the study are to define statistical relationships between different climate parameters, to estimate the sensitivities of climate variables to future climate scenarios by integrating with GIS and to predict the land use/ land cover change under the climate change scenarios. The historical data set was analyzed to predict the climate change and its impact on land use/land cover (LULC) is observed by correlating the Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) values for two different times for the same area. It is so evident that due to the rise in temperature there is a considerable change in the land use affecting the vegetation index; increased temperature results in very low NDVI values or vegetation abundance.

  13. 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)

  14. 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.

  15. Waste storage potential of Triassic basins in southeast United States

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.E.

    1976-07-01

    Triassic basins, elongated deep basins filled with sediments, extend from Nova Scotia to Florida. The geology of the basins is discussed for each state. Their potential for liquid waste storage is assessed. Seismic risk is among the factors evaluated. It is recommended that the shallow Triassic Florence basin in northeast South Carolina be studied. 10 fig. (DLC)

  16. Basin bifurcation in quasiperiodically forced systems

    Energy Technology Data Exchange (ETDEWEB)

    Feudel, U.; Witt, A.; Grebogi, C. [Institut fuer Physik, Universitaet Potsdam, Am Neuen Palais, PF 601553, D-14415, Potsdam (Germany); Lai, Y. [Departments of Physics and Astronomy and of Mathematics, The University of Kansas, Lawrence, Kansas 66045 (United States); Grebogi, C. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States)

    1998-09-01

    In this paper we study quasiperiodically forced systems exhibiting fractal and Wada basin boundaries. Specifically, by utilizing a class of representative systems, we analyze the dynamical origin of such basin boundaries and we characterize them. Furthermore, we find that basin boundaries in a quasiperiodically driven system can undergo a unique type of bifurcation in which isolated {open_quotes}islands{close_quotes} of basins of attraction are created as a system parameter changes. The mechanism for this type of basin boundary bifurcation is elucidated. {copyright} {ital 1998} {ital The American Physical Society}

  17. A revision of communication strategies for effective disaster risk reduction: A case study of the South Durban basin, KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Chris Skinner

    2014-03-01

    Full Text Available The study examined how effective forms of communication are, or could be, impacting themore traditional forms of emergency and disaster management communication throughthe print and electronic media and how an integrated communication strategy involving allstakeholders could prove to be successful. This study was of an exploratory and descriptivenature, using a case study of the South Durban basin to demonstrate how media analysis,community discussions and internal and external evaluations of current practices in use bymajor industrial players in the basin has thus far failed to reach its full potential for effectivedisaster risk reduction. Strongly emerging from this study was the finding that, as a resultof these evaluations, new systems are now being planned to incorporate social media as anintegral part of an overall communication strategy, which could have far-reaching implicationsfor corporate communicators and strategic planners.

  18. Paleoenvironmental implications from biomarker and stable isotope investigations on the Pliocene Velenje lignite seam (Slovenia)

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, A.; Sachsenhofer, R.F.; Markic, M.; Gratzer, R.; Lucke, A.; Puttmann, W. [Montan University of Leoben, Leoben (Austria)

    2003-07-01

    A Pliocene lignite seam up to 160 m thick occurs in the Velenje basin (Slovenia). The seam originated in a topogenous mire and evolved within a non-marine, transgressive setting. Differences in soluble organic matter yield and hydrocarbon content of borehole samples from the lignite are related to differences in the composition of free lipids of microbial origin and/or hydrocarbons derived from the biogeochemical degradation of plant tissue. Variations of the redox conditions within the mire are reflected by pristane/phytane ratios. The abundance of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms, which is consistent with palynomorphic spectra dominated by pollen of the Sequoia-Taxodium-Metasequoia plant community rather than by angiosperms. Evidence is also provided that the content of land plant derived biomarkers and the preservation of plant tissue is controlled by the input of resin-rich, decay-resistant conifers.

  19. Hydrological Modeling of the Upper Indus Basin: A Case Study from a High-Altitude Glacierized Catchment Hunza

    Directory of Open Access Journals (Sweden)

    Khan Garee

    2017-01-01

    Full Text Available The Soil andWater Assessment Tool (SWAT model combined with a temperature index and elevation band algorithm was applied to the Hunza watershed, where snow and glacier-melt are the major contributor to river flow. This study’s uniqueness is its use of a snow melt algorithm (temperature index with elevation bands combined with the SWAT, applied to evaluate the performance of the SWAT model in the highly snow and glacier covered watershed of the Upper Indus Basin in response to climate change on future streamflow volume at the outlet of the Hunza watershed, and its contribution to the Indus River System in both space and time, despite its limitation; it is not designed to cover the watershed of heterogeneous mountains. The model was calibrated for the years 1998–2004 and validated for the years 2008–2010. The model performance is evaluated using the four recommended statistical coefficients with uncertainty analysis (p-factor and r-factor. Simulations generated good calibration and validation results for the daily flow gauge. The model efficiency was evaluated, and a strong relationship was observed between the simulated and observed flows. The model results give a coefficient of determination (R2 of 0.82 and a Nash–Sutcliffe Efficiency index (NS of 0.80 for the daily flow with values of p-factor (79% and r-factor (76%. The SWAT model was also used to evaluate climate change impact on hydrological regimes, the target watershed with three GCMs (General Circulation Model of the IPCC fifth report for 2030–2059 and 2070–2099, using 1980–2010 as the control period. Overall, temperature (1.39 C to 6.58 C and precipitation (31% indicated increased variability at the end of the century with increasing river flow (5%–10%; in particular, the analysis showed smaller absolute changes in the hydrology of the study area towards the end of the century. The results revealed that the calibrated model was more sensitive towards temperature and

  20. Complex Bedforms and Complex Water Masses: A Case Study from the Tertiary to Present-day, Pelotas Basin, Offshore Uruguay

    Science.gov (United States)

    Thompson, P.; Badalini, G.; Wrigley, S.; Walker, R.; Argent, J.; Hernandez-Molina, J.; de Santa Ana, H.; Soto, M.; Tomasini, J.

    2015-12-01

    Contour currents are commonly associated with bedform development on modern seabeds yet there is a general paucity of published examples from the ancient record. Recently acquired 3D seismic data, covering over 13000km2 of the Pelotas Basin, offshore Uruguay, provides a unique opportunity to study the architecture and development of a variety of bedform. The data shows that, throughout the Tertiary, contour currents were the dominant control on sedimentation along the Uruguayan margin. The first evidence of contour current activity is during the Early Tertiary in the form of a major regional unconformity that, even though it was fully subaqueous, does not show any major features associated with downslope sedimentation. In the mid-slope region, the unconformity coincides with an extensive (1500km2) intra-slope scour-field orientated parallel to the slope. Individual scours are up to 40m deep, 500m wide and 3km long. Coeval with these scours are a group of coalesced basin floor scours, which run parallel to the base of slope and extend over 400km2. Individual scours exhibit an asymmetric shape - similar to giant flute marks - that are up to 150m deep, 20km wide and extend for at least 40km along slope. The development of these scoured areas shows clear evidence of two major north-flowing water masses. Directly above this regional unconformity are a series of ribbon-like bedforms that developed oblique to the slope. Individual bedforms are up to 40km in length with wavelengths of 5km and heights up to 100m. These bedforms are overlain by a set of barchan-like dunes, up to 30km in length with wavelengths of 10km. Individual dunes are in the order of 100m thick and stack to form an overall package up to 500m thick. These features show a clear change from erosion/bypass to deposition/reworking that is linked to a decrease in ocean current velocity and/ or sediment supply. The features observed suggest a complex oceanic regime was present throughout the Tertiary that

  1. Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study

    Science.gov (United States)

    Hunt, Andrew G.; Darrah, Thomas H.; Poreda, Robert J.

    2012-01-01

    Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Therefore, efforts to understand these and other domestic and global natural gas reserves have recently increased. The suspicion of fugitive mass migration issues within current Appalachian production fields has catalyzed the need to develop a greater understanding of the genetic grouping (source) and migrational history of natural gases in this area. We introduce new noble gas data in the context of published hydrocarbon carbon (C1,C2+) (13C) data to explore the genesis of thermogenic gases in the Appalachian Basin. This study includes natural gases from two distinct genetic groups: group 1, Upper Devonian (Marcellus shale and Canadaway Group) gases generated in situ, characterized by early mature (13C[C1  C2][13C113C2]: –9), isotopically light methane, with low (4He) (average, 1  103 cc/cc) elevated 4He/40Ar and 21Ne/40Ar (where the asterisk denotes excess radiogenic or nucleogenic production beyond the atmospheric ratio), and a variable, atmospherically (air-saturated–water) derived noble gas component; and group 2, a migratory natural gas that emanated from Lower Ordovician source rocks (i.e., most likely, Middle Ordovician Trenton or Black River group) that is currently hosted primarily in Lower Silurian sands (i.e., Medina or Clinton group) characterized by isotopically heavy, mature methane (13C[C1 – C2] [13C113C2]: 3), with high (4He) (average, 1.85  103 cc/cc) 4He/40Ar and 21Ne/40Ar near crustal production levels and elevated crustal noble gas content (enriched 4He,21Ne, 40Ar). Because the release of each crustal noble gas (i.e., He, Ne, Ar

  2. Experimental studies of supercritical bedforms applied to coarse-grained turbidite deposits of the Tabernas Basin (SE Spain, late Miocene)

    Science.gov (United States)

    Cartigny, Matthieu; Postma, George; Kleverlaan, Kick

    2014-05-01

    Modern submarine canyon floors are often covered with bedform patterns linked to supercritical turbidity currents, while recognition of sedimentary structures associated with such bedforms in outcrops are rare. On the basis of experimental work on bed morphodynamics and flow structure of high-density turbidity currents, a 3-dimensional bedform stability diagram and related sedimentary facies diagram have been constructed. To allow scaling of this diagram to natural flows, four non-dimensional parameters are used: 1) densimetric Froude number, 2) modified mobility parameter, 3) dimensionless grain size and 4) basal sediment concentration. Each bedform and basal sediment concentration is then linked to a characteristic facies type. Numerical and theoretical models from the literature and observations from modern turbidite depositional systems are used to estimate characteristic siz