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Sample records for basin paleoenvironmental studies

  1. Tree-rings and climate: Implications for Great Basin paleoenvironmental studies

    International Nuclear Information System (INIS)

    The Quaternary Sciences Center of the Desert Research Institute is currently conducting a multi-phased study of floral, faunal, and geomorphic response to long- and short-term climate change and extremes in assessing Yucca Mountain's suitability as a high-level nuclear waste repository. Preliminary results of these studies indicate synchronous responses in late Holocene tree-ring, palynology and geomorphic records. A tree-ring chronology for paleoclimatic reconstruction is developed by collection of multiple cores from 20-60 living trees and a similar number of dead trees in a climate-sensitive location. Samples are cross-dated and every growth layer in each specimen is measured to the nearest .001 mm. The measured ring width series potentially contain a variety of climatic, biological, and anthropogenic signals. Each ring width series is subjected to a numerical standarization procedure that removes an age-related biological growth trend, reduces endogeneous and exogenous stand disturbance factors, and maximizes any climatic signal that is present. Each of these empirically defined components can be graphically portrayed and subjected to further analyses. The geophysical signal analysis techniques involved in the standarized protocol are well-documented and established. The final result is a tree-ring chronology that represents regional paleoclimatic variability over the time represented by the sample population

  2. Messinian paleoenvironmental changes in the easternmost Mediterranean Basin: Adana Basin, southern Turkey

    OpenAIRE

    FARANDA, Costanza; Gliozzi, Elsa; CIPOLLARI, Paola; Grossi, Francesco; Darbaş, Güldemin

    2013-01-01

    We present detailed Messinian paleoenvironmental reconstructions for the Adana Basin based on a multidisciplinary approach that utilizes the fossil content of the Kuzgun and Handere Formations. To reconstruct the paleoenvironmental changes that affected the Adana Basin during the Messinian, we analyzed mollusk, ostracod, planktonic and benthonic foraminifer, and calcareous nannofossil assemblages from 2 stratigraphic sections near Kabasakal village (Adana, southern Turkey). To determine if th...

  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. Messinian paleoenvironmental evolution in the lower Guadalquivir Basin (SW Spain) based on benthic foraminifera.

    OpenAIRE

    Pérez-Asensio, J.N.; Aguirre, J.; Schmiedl, G.; Civis Llovera, J.

    2012-01-01

    Benthic foraminiferal assemblages of a drill core from the lower Guadalquivir Basin (northern Gulf of Cádiz, SW Spain) have been analyzed in order to reconstruct the paleoenvironmental evolution in the vicinity of the Betic seaways during the Messinian. The core consists of marine sediments ranging from the latest Tortonian to the early Pliocene. Changes in the abundance of certain marker species, planktonic/benthic ratio (P/B ratio), paleodepth estimated with a transfer function, content of ...

  5. Holocene paleoenvironmental reconstruction in the Eastern Amazonian Basin: Comprido Lake

    Science.gov (United States)

    Moreira, L. S.; Moreira-Turcq, P.; Cordeiro, R. C.; Turcq, B.; Caquineau, S.; Viana, J. C. C.; Brandini, N.

    2013-07-01

    Two sediment cores were studied from Comprido Lake, a black water floodplain lake located near Monte Alegre City, Eastern Amazonian Basin. The total organic carbon (TOC), nitrogen content (TN), δ13CTOC, sedimentary chlorophyll, diatom record and mineralogical composition revealed different hydrological and climatic regimes during the Holocene. Between 10,300 and 7800 cal yr BP, a dry climate was suggested by low values of TOC and chlorophyll derivatives concentrations that are related to the development of a C4 grasses on unflooded mud banks. A gap in sedimentation due to a complete dryness of the lake occurred between 7800 and 3000 cal years BP corresponding to the Middle Holocene dry phase. From 3000 cal years BP onwards a gradual increase of the TOC, chlorophyll derivatives and Aulacoseira sp. suggest an increase in the productivity and in water lake level due to the high water flow of the Amazon River and the catchment area as well. The Comprido Lake record indicates that the Late Holocene in this region was characterized by a wetter climate, as also observed in other records of the Amazonian Basin.

  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. Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain

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    Juan Cruz Larrasoaña

    2014-03-01

    Full Text Available Although recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than has been previously reported, their significance for paleomagetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain. Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization and that we term a bio-depositional remanent magnetization (BDRM. Some studied polarity reversals record paleomagnetic directions that appear to be delayed by 60-70 kyr. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization (BGRM that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes broadly coincides with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC, an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our study highlights the importance of magnetofossils as carriers of high-quality paleomagnetic and

  8. Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain.

    Science.gov (United States)

    Larrasoaña, Juan C; Liu, Qingsong; Hu, Pengxiang; Roberts, Andrew P; Mata, Pilar; Civis, Jorge; Sierro, Francisco J; Pérez-Asensio, José N

    2014-01-01

    Although recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than have been previously reported, their significance for paleomagnetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain). Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization, which we term a bio-depositional remanent magnetization. Some studied polarity reversals record paleomagnetic directions with an apparent 60-70 kyr recording delay. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes coincides broadly with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC), an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our results highlight the importance of magnetofossils as carriers of high-quality paleomagnetic and paleoenvironmental signals even in

  9. 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

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

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

    2016-03-01

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

  11. 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).

  12. 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).

  13. 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

  14. Lignin phenols in sediments of Lake Baikal, Siberia: Application to paleoenvironmental studies

    Science.gov (United States)

    Orem, W.H.; Colman, Steven M.; Lerch, H.E.

    1997-01-01

    Sediments from three cores obtained from distinct depositional environments in Lake Baikal, Siberia were analyzed for organic carbon, total nitrogen and lignin phenol concentration and composition. Results were used to examine changes in paleoenvironmental conditions during climatic cycles of the late Quaternary (lignin phenol contents were generally lower in the late Pleistocene compared to the Holocene, but with several peaks in concentration during the late Pleistocene. These late Pleistocene peaks in total sedimentary lignin content (dated at about 80, 50 and 30 ka) directly precede or occur during peaks in sedimentary biogenic silica contents. These periods likely represent relatively warm interstadial times, with increased precipitation producing the observed increase in terrestrial runoff and aquatic productivity. Lignin phenol ratios (S/V, C/V and P/V) were used to examine changes in terrestrial vegetation type resulting from changes in paleoenvironmental conditions during the late Pleistocene. A degree of caution must be used in the interpretation of these ratios with regard to vegetation sources and paleoenvironmental conditions, because of potential compositional changes in lignin resulting from biodegradation. Nevertheless, results show that long glacial periods were characterized by terrestrial vegetation composed of a mix of non-woody angiosperm vegetation and minor gymnosperm forest. Shorter interstadial periods are defined by a change to dominant gymnosperm forest and were observed at about 80, 75, 63, 50 and 30 ka, ranging from about 2-6 kyr in duration. These interstadial periods of the late Pleistocene defined by lignin phenol ratios generally occur during longer periods of enhanced sedimentary biogenic silica content (about 10-15 ka in duration), providing corroborative evidence of these warm interstadial periods.Sediments obtained in Lake Baikal were analyzed for organic carbon, total nitrogen and lignin phenol composition and used to study

  15. 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.

  16. 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

    International Nuclear Information System (INIS)

    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

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

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    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.

  18. Phytolith aided paleoenvironmental studies from the Dutch Neolithic

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    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.

  19. Paleoenvironmental significance of ichnofossils from the Kand Formation of the Cambay Basin, Gujarat, India

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    Shyam N. Mude

    2012-03-01

    Full Text Available The present paper documents five ichnospecies from the sediments of the Kand Formation (late Miocene of the Narmada Block of the Cambay Basin, namely, Laevicyclus mongraensis, Planolites berverlensis, Planolite montanus, Thalassonoids paradoxicum and Thalassonoids suevicus. Both the vertical and horizontal biogenic structures are common in the calcareous sandstone, but the horizontal biogenic structures dominate. The ichnofossils, namely, Laevicyclus mongraensis, Thalassonoids paradoxicum and Thalassonoids suevicus are ethologically domichnia, these dwelling biogenic structures formed by suspension feeders (fish, crustaceans, bivalves, sponges, cnidarians etc, in search of food at sediment water interface. The ichnofossils, namely, Planolites berverlensis and Planolite montanus are ethologically fodinichnia, these are feeding biogenic structures formed by deposit feeders (earthworms, sea stars, crabs, polychaetes etc. The present ichnofossils from the Kand Formation indicate that the sediments of the Kand Formation were deposited in shallow water marine environment with moderate to low energy conditions, all the burrows were made in soft substrate before the consolidation of the sediments and the sediments (calcareous sandstone had good nutrients for the survival of both suspension and deposit feeders.

  20. Miocene woods from the Qaidam Basin on northern Qinghai-Tibet Plateau with implications for paleoenvironmental change

    Science.gov (United States)

    Cheng, Ye-Ming; Yang, Xiao-Nan

    2016-02-01

    The Qaidam Basin with the most complete Cenozoic sedimentary preservation in northern Qinghai-Tibet Plateau is a key area for studying uplift and environmental change of the plateau. Three types of woods, Ulmus (Ulmaceae), Leguminosae (?) (angiosperm) and Cupressaceae (gymnosperm) were recognized from the large-scale preservation of fossil woods in late Miocene Shang Youshashan Formation in northern Qaidam Basin on the Qinghai-Tibet Plateau. Both investigations of their Nearest Living Relatives (NLRs) and previous grassland mammal evidences suggest that there have been temperate deciduous broad-leaved forest and needle-leaved forest with grass in northern Qaidam Basin during the late Miocene in contrast to the desert vegetation found there nowadays. The presence of the ancient forest steppe further implies that the southern part of the plateau used to be adequately low, so that the Indian and East Asian monsoons could approach the northern area and to accommodate the vegetation in late Miocene.

  1. 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

  2. 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 (TOCagreement 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 incorporated in pyrite in the Cleveland Basin after the CIE, because the availability of sulphur was more limited after the global anoxia

  3. A new chronology for the Dacian Basin (Romania) : Consequences for the kinematic and paleoenvironmental evolution of the Paratethys region

    NARCIS (Netherlands)

    Vasiliev, I.

    2006-01-01

    This PhD thesis presents new chronostratigraphic results from the Dacian Basin and adjacent regions as part of the Paratethys paleoprovince. In the first three chapters, a new chronology for the Upper Miocene to Pliocene deposits (approximately 8 to 3 Ma) of the Dacian Basin is presented based on hi

  4. Tectonic and paleoenvironmental evolution of Mesozoic sedimentary basins along the Andean foothills of Argentina (32°-54°S)

    Science.gov (United States)

    Franzese, Juan; Spalletti, Luis; Pérez, Irene Gómez; Macdonald, David

    2003-05-01

    Chronoenvironmental and tectonic charts are presented for Mesozoic basins located along the Andean foothills of the South American plate. On the basis of the main tectonic events, pre-Andean basins, break-up-related basins, extensional back-arc basins, and Andean foreland basins are recognized. The pre-Andean basins were formed by continental extension and strike-slip movement before the development of the Mesozoic-Cenozoic Andean magmatic arc. Upper Permian to Middle Triassic extension along Palaeozoic terrane sutures resulted in rifting, bimodal magmatism (Choiyoi group), and continental deposition (Cuyo basin). From the Late Triassic to the Early Jurassic, continental extension related to the collapse of the Gondwana orogen initiated a series of long, narrow half-grabens that filled with continental volcaniclastic deposits. These depocenters were later integrated into the Neuquén basin. Coeval development of the shallow marine Pampa de Agnia basin (42-44°S) is related to short-lived extension, probably driven by dextral displacement along major strike-slip faults (e.g. the Gastre fault system). Widespread extension related to the Gondwana breakup (180-165 Ma) and the opening of the Weddell Sea reached the western margin of the South American plate. As a result, wide areas of Patagonia were affected by intraplate volcanism (Chon Aike province), and early rifting occurred in the Magallanes basin. The Andean magmatic arc was almost fully developed by Late Jurassic times. A transgressive stage with starvation and anoxia characterized the Neuquén basin. In western Patagonia, back-arc and intra-arc extension produced the opening of several grabens associated with explosive volcanism and lava flows (e.g. Rı´o Mayo, El Quemado). To the south, a deep marginal basin floored by oceanic crust (Rocas Verdes) developed along the back-arc axis. In mid-to late Cretaceous times, Andean compressional tectonics related to South Atlantic spreading caused the inversion of

  5. A new chronology for the Dacian Basin (Romania) : Consequences for the kinematic and paleoenvironmental evolution of the Paratethys region

    OpenAIRE

    Vasiliev, I.

    2006-01-01

    This PhD thesis presents new chronostratigraphic results from the Dacian Basin and adjacent regions as part of the Paratethys paleoprovince. In the first three chapters, a new chronology for the Upper Miocene to Pliocene deposits (approximately 8 to 3 Ma) of the Dacian Basin is presented based on high resolution magneto-biostratigraphic data from the Romanian Carpathians foredeep. The new age control permits the calculation of accumulation rates for each polarity zone, which shows a significa...

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

    Science.gov (United States)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2016-01-01

    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 to science, and most of them are indicative for either warm and/or cold stages or dry and/or 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 analyzes the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  7. 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...... 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<2%), a high degree of pyritization (S/Fe) and enrichments in Cu, Zn and Ni, which together suggest that water-mass restriction and anoxia occurred in.......J., 2008. Basinal restriction, black shales, Re-Os dating, and the Early Toarcian (Jurassic) oceanic anoxic event. Paleoceanography 23, PA4217, doi: 10.1029/2008PA001607....

  8. Paleoenvironmental reconstructions based on rocks magnetic proxies from Miocene lake deposits in the Sokolov Basin (NW Bohemia)

    Czech Academy of Sciences Publication Activity Database

    Kadlec, Jaroslav; Chadima, Martin; Schnabl, Petr; Šifnerová, Kristýna; Čuda, J.; Rojík, P.; Martínek, K.

    Olomouc: Palacký University, 2014 - (Bábek, O.; Matys Grygar, T.; Uličný, D.). s. 38-38 ISBN 978-80-244-4098-9. [Central European Meeting of Sedimentary Geology : an international conference. 09.06.2014-13.06.2014, Olomouc] Institutional support: RVO:67985530 ; RVO:67985831 Keywords : palaeomagnetism * Miocene * lake deposits * Sokolov Basin Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  9. Paleoenvironmental changes during the late Miocene (Messinian)–Pliocene transition (Bajo Segura Basin, southeastern Spain): sedimentological and ichnological evidence

    OpenAIRE

    Caracuel Martín, Jesús Esteban; Corbí, Hugo; Giannetti, Alice; Monaco, Paolo; Soria Mingorance, Jesús Miguel; Tent-Manclus, Jose Enrique; Yébenes Simón, Alfonso

    2011-01-01

    A detailed sedimentological and paleontological analysis of the uppermost Miocene (Messinian)–Pliocene boundary at the northern border of the Bajo Segura Basin, southeastern Spain, was carried out in order to describe the evolution of the regional paleocoastline during the Pliocene reflooding of the Mediterranean immediately after the sea-level fall related to the Messinian Salinity Crisis. Multiple trace fossils typical of firm- and hardgrounds were recognized, allowing identification of Glo...

  10. 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

  11. Distribution of sulfur and pyrite in coal seams from Kutai Basin (East Kalimantan, Indonesia): Implications for paleoenvironmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Widodo, Sri [Department of Mining Engineering, Moslem University of Indonesia, Jln. Urip Sumoharjo, Makassar (Indonesia); Oschmann, Wolfgang [Institute of Geosciece, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany); Bechtel, Achim; Sachsenhofer, Reinhard F. [Department of Applied Geoscience and Geophysics, University of Leoben, Peter-Tunner-Str.5, A-8700 Leoben (Austria); Anggayana, Komang [Department of Mining Engineering, Bandung Institute of Technology, Jln. Ganesa 10, I-40132 Bandung (Indonesia); Puettmann, Wilhelm [Institute of Atmospheric and Environmental Sciences, Dapartment of Analytical Enviromental Chemistry, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany)

    2010-03-01

    Thirteen Miocene coal samples from three active open pit and underground coal mines in the Kutai Basin (East Kalimantan, Indonesia) were collected. According to our microscopical and geochemical investigations, coal samples from Sebulu and Centra Busang coal mines yield high sulfur and pyrite contents as compared to the Embalut coal mine. The latter being characterized by very low sulfur (< 1%) and pyrite contents. The ash, mineral, total sulfur, iron (Fe) and pyrite contents of most of the coal samples from the Sebulu and Centra Busang coal mines are high and positively related in these samples. Low contents of ash, mineral, total sulfur, iron (Fe) and pyrite have been found only in sample TNT-32 from Centra Busang coal mine. Pyrite was the only sulfur form that we could recognize under reflected light microscope (oil immersion). Pyrite occurred in the coal as framboidal, euhedral, massive, anhedral and epigenetic pyrite in cleats/fractures. High concentration of pyrite argues for the availability of iron (Fe) in the coal samples. Most coal samples from the Embalut coal mine show lower sulfur (< 1 wt.%) and pyrite contents as found within Centra Busang and Sebulu coals. One exception is the coal sample KTD-38 from Embalut mine with total sulfur content of 1.41 wt.%. The rich ash, mineral, sulfur and pyrite contents of coals in the Kutai Basin (especially Centra Busang and Sebulu coals) can be related to the volcanic activity (Nyaan volcanic) during Tertiary whereby aeolian material was transported to the mire during or after the peatification process. Moreover, the adjacent early Tertiary deep marine sediment, mafic igneous rocks and melange in the center of Kalimantan Island might have provided mineral to the coal by uplift and erosion. The inorganic matter in the mire might also originate from the ground and surface water from the highland of central Kalimantan. (author)

  12. Carbon and oxygen stable isotope data as paleoenvironmental indicators for limestones from the Campos, Santos and Espirito Santo Basins, Brazil

    International Nuclear Information System (INIS)

    Carbon and oxygen isotope data of limestones from Campos, Santos and Espirito Santo basins provided additional information on the sedimentation environments of these carbonates. The predominance of δ 13C values between + 1,0 per mille and - 1,0 per mille samples from the Tertiary and the middle section of the Jiquia Stage (Lower Cretaceous) could indiccate, for both carbonate sequences, deposition in a normal marine environment. However, the absence of marine fossils in the Jiquia Stage but not in the Tertiary allows to suggest a normal marine environment for the latter and saline lakes for the former. More positive δ 13C values in the upper portion of the Jiquia Stage and in the Alagoas Stage suggest a restricted marine environment, with a tendency to hypersalinity. During the Albian the carbonate sedimentation could have occurred in a marine enrironment with an above normal salinity, as indicated by values of δ 13C between + 3,0 per mille and + 4,0 per mille. According to δ 18O data, the surface waters were warm, with a tendency of becoming gradually cooler towards the top of the Tertiary. (Author)

  13. Paleoenvironmental Malakofaunistic Records of Late Pleniglacial on the Upper Paleolithic Site Doroshivtsi 3 (the Middle Dniester Basin

    Directory of Open Access Journals (Sweden)

    Yana POPIUK

    2014-11-01

    Full Text Available Fauna of molluscs is one of the most important paleoenvironment indicators, which is very sensitive to environmental conditions. It relatively quickly and accurately reflects changes in characteristics and structure of landscapes, their types, etc. The importance of this method in the study of Pleistocene sediments is determined by few factors: 1 shellfish, especially terrestrial, are quite sensitive to environmental conditions (heat, humidity, etc. and pretty good indicate them in sediments; 2 among fossil faunal remains the molluscs are the most common group of organisms; 3 the features of fine-grained sediments contribute to the good preservation of shells, facilitating their study.

  14. Paleoenvironmental changes in the Black Sea region during the last 26,000 years : a multi-proxy study of lacustrine sediments from the western Black Sea

    OpenAIRE

    Kwiecien, Olga

    2008-01-01

    Paleoenvironmental records provide ample information on the Late Quaternary climatic evolution. Due to the great diversity of continental mid-latitude environments the synthetic picture of the past mid-latitudinal climate changes is, however, far from being complete. Owing to its significant size and landlocked setting the Black Sea constitutes a perfect location to study patterns and mechanisms of climate change along the continental interior of Central and Eastern Europe and Asia Minor. Pre...

  15. Geology of the Cenozoic Indus Basin sedimentary rocks: Paleoenvironmental interpretation of sedimentation from the western Himalaya during the early phases of India-Eurasia collision

    OpenAIRE

    Henderson, Alexandra L.; Najman, Yani; Parrish, Randall; BouDagher‐Fadel, Marcelle; Barford, Dan; Garzanti, Eduardo; Andò, Sergio

    2010-01-01

    This study reassesses the stratigraphy, sedimentology, and provenance of the Indus Basin sedimentary rocks, deposited within the Indus Tsangpo Suture Zone (ITSZ) during the early phases of India-Eurasia collision. Using field observations, biostratigraphy, and petrographic and isotopic analyses we create a paleodepositional reconstruction within the paleotectonic setting of the early phases of India-Eurasia collision. We then re-examine existing constraints to the timing of India-Eurasia coll...

  16. Paleoenvironmental dynamics of Western Beringia - New studies from the Yedoma key site Duvanny Yar (Lower Kolyma River, Siberia)

    Science.gov (United States)

    Strauss, Jens; Schirrmeister, Lutz; Wetterich, Sebastian

    2010-05-01

    Duvanny Yar is a stratigraphic key site for the late Quaternary in Western Beringia. It is characteristic for ice-rich permafrost sequences of the so-called Yedoma Suite in north-east Siberia (e.g. KAPLINA et al. 1978; SHER et al. 1979) and is an important reference site for the late Pleistocene history of Beringia (HOPKINS 1982). The aim of our study was to reconstruct the paleoenvironmental dynamics at the Duvanny Yar site during the late Quaternary using its terrestrial archive. A multidisciplinary approach using geocryological, geochronological, sedimentological, hydrochemical, isotope geochemical, and paleoecological methods was applied to obtain multiproxy records. Sediment samples were analysed for ice contents, grain size parameters, biogeochemistry (total carbon, total organic carbon, total nitrogen, stable carbon isotopes), mineral density, mass specific magnetic susceptibility, and for radiocarbon age. Stable isotopes of water were measured for ground ice (ice wedges, segregated ice, and pore ice), modern surface waters and modern precipitation. Six profiles along the riverbank were sampled in August 2008. They contained Eemian lacustrine deposits, long sequences of Ice Complex deposits of the Late Pleistocene Yedoma, Holocene lacustrine and boggy deposits in thermokarst depressions. All profiles showed very bad sorted sediment of fine to coarse silt. A homogenous and polymodal grain size distribution for the ice rich (~30 to 60 wt %) Yedoma Suite revealed a polygenetic origin and disproves the pure "arctic loess" hypothesis for these deposits. Measurements of bulk density, ice content and total organic carbon content (TOC) enable for a relative TOC content in Ice Complex deposits at Duvanny Yar. The mean value of organic carbon at Duvanny Yar is 16 ± 11 kg/m^3. Geochronological results based on 11 new AMS ages revealed that the Yedoma Suite was continuously formed from the end of the Middle Weichselian (~ 40000 years BP) and at least until the Late

  17. Effects of different peak fitting strategies for XRF-spectra and their implications for paleoenvironmental studies: an example from powdered loess-paleosol samples

    Science.gov (United States)

    Profe, Jörn; Neumann, Lena; Ohlendorf, Christian; Zolitschka, Bernd; Frechen, Manfred; Barta, Gabriella

    2015-04-01

    X-ray fluorescence (XRF) core scanning is influenced by numerous sample-specific effects such as water content, sediment matrix and grain size. All these parameters affect the characteristics of fluorescent X-rays recorded by the detector. Subsequently, the recorded spectra are translated into element-specific counts by mathematical peak fitting strategies allowing for qualitative element tracking along a sediment profile. Down-core changes of these element counts or ratios often serve as a basis for paleoenvironmental interpretation. However, for such studies detailed information about peak fitting procedures is rarely provided. Therefore, we investigate the influence of different peak fitting strategies on elemental count rates derived from XRF (Mo-tube) scanning of powdered samples from the Süttő loess-paleosol sequence, Hungary - a sequence chosen due to its pronounced lithological changes between loess and paleosol sections. In contrast to sediment cores, for dried and powdered samples the effects related to grain size and water content are minimized whereas those related to sediment matrix and lithology are emphasized. Using the ITRAX XRF core-scanner (Cox analytical systems) peak fitting is accomplished by the processing software Q-Spec (version 8.60). In this software, the mean square error (MSE) indicates the goodness-of-fit of the mathematical model to the actually measured energies. To consider all different lithologies occurring within a sediment profile, a sum-spectrum of all individual sample spectra is calculated. Despite optimizing the fit for the sum-spectrum, first results indicate that drastic changes between loess and paleosols can cause the MSE to increase (reduce the goodness-of-fit) and thus alter the modelled element counts within paleosols. Therefore, succeeding samples with a poor fit are collected in a subset based on a user-defined MSE threshold. Subsequently, a new sum-spectrum is calculated and fitted for this subset separately

  18. Fossil-bearing deposits from the Bukpyeong Formation (Miocene) in the Bukpyeong Basin at Donghae city, Gangwon-do, South Korea: occurrences, taphonomy and paleoenvironmental implications

    Science.gov (United States)

    Kim, Hyun Joo; Jeong, Eun Kyoung; Uemura, Kazuhiko; Kim, Kyungsik; Paik, In Sung

    2016-04-01

    Abundant and diverse plant fossils such as land plants and subaqueous plants, freshwater mollusc fossils and invertebrate trace fossils are found in the Miocene Bukpyeong Formation at Donghae city, Gangwon-do, South Korea. Occurrences and taphofacies of the fossil-bearing deposits from the Bukpyeong Formation are described and their taphonomy and paleoenvironmental implications are interpreted. Based on fossil occurrences, lithofacies and sedimentary features of the fossil-bearing deposits, eight taphofacies are classified as the following: (1) Taphofacies 1: Gastropod fossils in massive silty mudstone; (2) Taphofacies 2: Bivalve fossils in massive silty mudstone; (3) Taphofacies 3: Plant fossils (leaf fossils) in massive silty mudstone; (4) Taphofacies 4: Gastropod and plant fossils in massive silty mudstone; (5) Taphofacies 5: Plant fossils in weakly fissile silty mudstone; (6) Taphofacies 6: Plant fossils (leaf fossils) in thin-bedded and graded silty mudstone to mudstone (claystone); (7) Taphofacies 7: Plant fragment fossils in thin-bedded and graded silty mudstone to mudstone (claystone); (8) Taphofacies 8: Plant debris in planar- to cross-laminated fine-grained sandstone. Taphonomy of taphofacies 1, 2, and 4 including freshwater mollusc fossils is interpreted to have been reworked or transported by turbidity currents after death and deposited in shallow lake to open lake. Taphonomy of taphofacies 3, 5, 6, and 7 including plant fossils is interpreted to have been transported by input of episodic flooding in the land and deposited by settling down in open lake. Taphofacies 8 including plant debris has been deposited in shallow lake by input of intensive episodic flooding from the land. The occurrences and taphofacies of the fossil-bearing deposits indicate that most of the fossils were transported by turbidity current induced by input of episodic flooding in the land and deposited in shallow lake to open lake. Moreover, plant fossils from the Bukpyeong

  19. Pasco Basin hydrometeorological study

    International Nuclear Information System (INIS)

    This report provides detailed precipitation and evapotranspiration distributions for the Pasco Basin for use in groundwater recharge calculations. The results are shown on precipitation and evapotranspiration distribution maps. The parameters, calculation methods, sensitivity determinations, and fitting methods used in the development of these maps are also discussed

  20. 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

    International Nuclear Information System (INIS)

    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)

  1. 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.

  2. 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.

  3. The Mackenzie Basin impacts study

    International Nuclear Information System (INIS)

    In 1989, a commitment was made to begin development of a framework for an integrated regional impact assessment of global warming scenarios in the Mackenzie Basin, the most populated region of Canada's north. The project, called Mackenzie Basin Impact Study (MBIS), is led by a multidisciplinary working group from government and non-governmental organizations with interests in the Basin. Objectives of MBIS include defining the direction and magnitude of regional-scale impacts of global warming scenarios on the physical, biological, and human systems of the Basin. MBIS will also identify regional sensitivities to climate, inter-system linkages, uncertainties, policy implications, and research needs. MBIS research activities as of March 1992 are outlined and policy concerns related to global warming are listed. Two new methodologies are being developed by MBIS to address particular economic and policy concerns: a socio-economic resource accounting framework and an integrated land assessment framework. Throughout MBIS, opportunities will be presented for western science and traditional native knowledge to be integrated

  4. Paleoenvironmental reconstruction using microfossils : terrestrial

    International Nuclear Information System (INIS)

    The following section provides a brief summary of the use of pollen and chironomids in terrestrial paleoenvironmental reconstruction and lists some key references and general text addressing the history, methods and development of these techniques in Quaternary paleoclimate research and their application in New Zealand. (author). 52 refs., 8 figs

  5. Sedimentological dynamics of the Orlovat loess-paleosol sequence (Northern Serbia) show both local and regional paleoenvironmental fluctuations

    Science.gov (United States)

    Obreht, Igor; Zeeden, Christian; Eckmeier, Eileen; Schulte, Philipp; Hambach, Ulrich; Timar-Gabor, Alida; Lehmkuhl, Frank

    2015-04-01

    The last glacial cycle as recorded in the Orlovat loess section (Northern Serbia) gives insight into both local and regional paleoenvironmental conditions. The Orlovat section is a unique section in the Carpathian Basin and it is characterized by irregularities in sedimentology, magnetic susceptibility, geochemistry and other paleoproxies. Therefore the local conditions need to be understood before making claims on a regional scale. Especially the grain size distribution indicates that the Orlovat site was influenced by specific paleoenvironmental conditions. Relatively coarse grained sand was delivered during interglacials, probably from the Deliblato sands by the Košava wind. However, commonly applied methods such as grain size and rock magnetic investigations could not explain the unique situation during the MIS 3, where a paleosol is missing. Therefore, for the first time in the studies of the region, we applied high resolution X-ray fluorescence analysis to trace the changing source areas of sediment material during the Last Glacial. These changes in the provenance of the sediment might be associated with stronger river activities and erosion. This study highlights the importance of a sedimentological understanding for a reliable paleoenvironmental evaluation.

  6. 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)

  7. Revised Chronology for the Mio-Pliocene Successions of the Eastern Paratethys: Towards a Better Understanding of Paleoenvironmental Change

    Science.gov (United States)

    Krijgsman, W.; Chang, L.; Baak, C. V.; Palcu, D.; Vasiliev, I.

    2014-12-01

    Paratethys is a large epicontinental sea, stretching from Germany to China at the beginning of the Oligocene (~34 Myr ago), that progressively retreated by a complex combination of basin infill, glacio-eustatic sea-level lowering and tectonic uplift to its present-day remnants: Black Sea, Caspian Sea and Aral Lake. Paratethys experienced major paleoenvironmental changes towards anoxic, hypersaline, and fresh water conditions. An accurate geological time scale (GTS) is crucial to understand the timing and rates of these change and to determine the underlying mechanisms. Geological time scales for the Paratethys region are notoriously controversial and encompass mainly regional stages, which are all defined on the basis of characteristic faunal assemblages (mainly mollusks and ostracods) endemic to the Paratethys Sea. During the last decade, we have performed numerous integrated magneto-biostratigraphic studies on the Mio-Pliocene sedimentary successions of the Eastern Paratethys, which resulted in revised chronological frameworks for the Dacian, Black Sea and Caspian Sea basins. This allows high-resolution stratigraphic correlations between the individual Paratethys subbasins and with the Mediterranean successions and help to better understand the dramatic paleoenvironmental changes in the region, such as the Messinian Salinity Crisis. Rock magnetic analyses of the sedimentary sequences of the Paratethys indicate that greigite is the main magnetic carrier and that a range of magnetic properties cannot be explained by the presence of diagenetic greigite, but are instead consistent with those expected for a biogenetic (bacterial) origin.

  8. 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.

  9. Oxygen isotopic composition of mammal bones as a new tool for studying ratios of paleoenvironmental water and paleoclimates

    International Nuclear Information System (INIS)

    The purpose of this study is to try to establish quantitative relationships between the average oxygen isotopic composition of local meteoric water, the oxygen isotopic composition of mammal body water and the oxygen isotopic composition of phosphate in mammal bones. These relationships, after calibration of the method on living specimens, would allow quantitative paleoclimatological research based on the measurement of delta18O(PO43-) of fossil mammal bones

  10. Mineral magnetic study of lacustrine sediments from Lake Pumoyum Co, southern Tibet, over the last 19 ka and paleoenvironmental significance

    Science.gov (United States)

    Su, Youliang; Gao, Xing; Liu, Qingsong; Wang, Junbo; Haberzettl, Torsten; Zhu, Liping; Li, Jinhua; Duan, Zongqi; Tian, Lide

    2013-03-01

    High-resolution proxy records from Tibetan Plateau are essential to understand the past climatic and environmental changes. In this work, we conducted systematic environmental magnetic studies on lacustrine sediments from Lake Pumoyum Co, southern Tibet, spanning from the last deglaciation (~ 19 ka) to present. We correlated the magnetic proxies in the lake core with environmental changes. The magnetic proxies from the 3 units were studied. Both Unit 3 (19-13.2 ka) and Unit 2 (13.2-8.4 ka) contain evidences for an anoxic or sub-anoxic environment. Fine-grained greigite dominates the bulk magnetic properties of Unit 3, while both magnetite and greigite coexist in Unit 2. Overall, this reveals a transition from an anoxic environment to an oxic environment. In contrast, Unit 1 (8.4 ka-present) spans the Holocene when the lake environment was oxic. There is an increasing trend in the concentration of magnetic minerals, which reflects an increasing transport of magnetic minerals from the catchment into the lake due to the increased post-glacial melt-water flow. Although different mechanisms affect the magnetic assemblage and associated magnetic properties in the different units, our results suggest that the magnetic proxies of the local lake environment on southern Tibet are sensitive to environmental changes.

  11. KE Basin water dispositioning engineering study

    International Nuclear Information System (INIS)

    This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation

  12. 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

  13. Late Pleistocene dust deposition in the Patagonian steppe - extending and refining the paleoenvironmental and tephrochronological record from Laguna Potrok Aike back to 55ka

    OpenAIRE

    Haberzettl, Torsten; Anselmetti, Flavio S.; Bowen, Sabine W.; Fey, Michael; Mayr, Christoph; Zolitschka, Bernd; Ariztegui, Daniel; Mauz, Barbara; Ohlendorf, Christian; Kastner, Stephanie; Lücke, Andreas; Schäbitz, Frank; Wille, Michael

    2009-01-01

    Paleoenvironmental records extending well into the last glacial period are scarce in the steppe regions of southern South America. Here, we present a continuous record for the past 55 ka from the maar lake Laguna Potrok Aike (51°58′ S, 70°23′ W, southern Patagonia, Argentina). Previous studies on a sedimentary core from a lake level terrace near the northern margin of the lake covered parts of Oxygen Isotope Stage (OIS) 3 (59–29 ka) whereas a second core from the centre of the basin comprised...

  14. Albian Phyto geography and environment in Santa Lucia basin, Uruguay: a study based on palynomorphs

    International Nuclear Information System (INIS)

    This paper presents bioestratigraphic results on the Castellanos and Migues formations, Upper Cretaceous of the Santa Lucia basin, Uruguay. The samples are from six exploratory wells drilled by Ancap and YPF, in 50 th and 70 th decades. The palynological data have been used to determine the paleoenvironmental evolution, the paleoclimate as well as the paleogeografic reconstruction for this area, in the Albian time. (author).

  15. A molecular and stable carbon isotope study of organic matter in immature Miocene Monterey sediments (Pismo Basin)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schouten, S.; Schoell, M.; Rijpstra, W.I.C.

    1997-01-01

    The 300 m section of the Miocene Monterey Formation outcropping at Shell Beach (Pismo basin; ca. 15-11 Ma) is composed of calcareous phosphatic (15.1–14.5 Ma) and siliceous facies (14.5–11.0 Ma). An objective of this paper is to document lateral paleoenvironmental changes in the Miocene Moneterey Fo

  16. ALLUVIUM RUNOFF STUDY IN GILORT HYDROGRAPHIC BASIN

    Directory of Open Access Journals (Sweden)

    GRIGORE CIOCĂZAN

    2012-04-01

    Full Text Available The study aims the characterization of the solid runoff in the Gilort hydrographic basin, analyzing the variations in time (for the period 1982-2007 and in space (for the three major relief units in the basin of this parameter. The data came from the three hydrometric stations where are performed the measurements for the alluvium runoff: Ciocadia, Târgu-Cărbuneşti (Gilort river and Turburea.

  17. California Basin Studies (CaBS)

    International Nuclear Information System (INIS)

    The California Continental Borderland's present configuration dates from about 4 to 5 X 106 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 106 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

  18. End-Pleistocene to Holocene paleoenvironmental record from piston corer samples and the challenge of stratigraphic correlation of playa sediment data with a connected alluvial apron from Damghan Basin, Iran

    Science.gov (United States)

    Büdel, Christian; Hoelzmann, Philipp; Wennrich, Volker; Majid Padashi, Sajed; Baumhauer, Roland

    2015-04-01

    The study yields a first characterization and correlation of the end-Pleistocene to Holocene sediment archive of playa and playa lake deposits in the Damghan Basin, northern Iran. The Basin sediments are deposited since Mio- and Pliocene, which is valid for the connected alluvial fans, too. These are covering the area between the playa and mountains and while prograding from the mountain ranges they deliver gravels and fine-sediments to the basins sink. The processes on the studied alluvial apron are described and dated already and can be explained in seven morphodynamic phases, which are linked to a general lake level high-stand in north-east Iran at about 8000-9000 years ago. If and how these phases are passed on from the alluvial record down to the playa sediment record is aim of this study. Today the salt pans margins are highly affected by salt tectonic drifting and access was suboptimal. Only here drilling could be performed through about 280 centimeters of salt-crust unfrequently intercalated with loamy layers. For yielding undisturbed playa sediment records sampling was performed with inliner-tubes deployed in a piston corer (Kullenberg type). Thus at two different drilling sites in summation seven cores could be taken, down to a maximum depth of 129 cm and 1000 cm. Back in Germany the cores had been opened and initially described, photographed and optically scanned with a core logger. Regarding future studies, the aim was a best possible comprehensive documentation of the cores. Therefore basically grainsize measurements (laser diffraction), multi element analyses (XRF, ICP-OES, titrimetry) and mineralogical measurements (XRD) had been deployed on samples taken from every single previously identified layer. Continuous elemental data was secured by use of a XRF-scanning core logger. The sedimentological description together with laboratory element analyses shows saline conditions in the first three meters coincide with general coarser grain sizes. The next

  19. Dating and assessing the recent sediments of three deep basins of the Baltic Sea: Indication of natural and anthropogenic changes

    DEFF Research Database (Denmark)

    Kunzendorf, H.

    1999-01-01

    A 3-years EU-MAST-3 project (Baltic Sea System Study, BASYS) recovered short and long sediment cores from 3 deep basins of the Baltic Sea (Bornholm Basin, Gotland Basin and North Central Basin). During a paleoenvironmental study, lead-210 dating andgeochemical data were generated.Dating of cores...... rhodochrosite formation which is thought to be coupled to saltwater inflows in that oxygen and HCO_3- rich saltwater converts bacterially re-dissolved Mninto the carbonate mineral. There is a clear indication for cyclic rhodochrosite deposition in that about 300 year long periods with relatively high Ca-Mn are...

  20. 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

  1. K Basin sludge dissolution engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Westra, A.G.

    1998-08-28

    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  2. Mackenzie Basin impact study: Interim report 1

    International Nuclear Information System (INIS)

    The Mackenzie Basin Impact Study (MIBS) is a six-year study undertaken to assess the potential impacts on the Mackenzie River Basin region and its inhabitants. The study framework, structure, organization, methods, and data are described. Highlights of work to date are reviewed. The MBIS employs scenarios of future warmer climates and changes in population and economic conditions. Research is coordinated by an interagency working committee and research activities cover 28 areas including permafrost, hydrology, sea ice, boreal ecosystems, freshwater fish, wildlife, forestry, agriculture, tourism, community studies, and defense. Six issues have been identified: interjurisdictional water management, sustainability of native lifestyles, economic development opportunities, infrastructure and buildings, and sustainability of ecosystems. An integrated assessment approach is used in the MBIS, combining scientific and indigenous traditional knowledge and attempting to include all interactions that occur between sectors. Two methods are being developed: socio-economic integration using a resource accounting framework, and an integrated land assessment framework. Four scenarios of warmer climates have been developed, all showing increased precipitation for the basin as a whole. Moderate growth in the resource sector is predicted. Preliminary results of some research are reported, including a lengthened open-water season in the Beaufort Sea accompanied by a greater extent of open water. 44 figs., 16 tabs

  3. 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...

  4. Paleoclimatic and paleoenvironmental reconstruction for middle and late holocene in Uruguay southeastern New contributions

    International Nuclear Information System (INIS)

    This work is about the study carried out within the framework of the environmental evolution and the prehistoric human occupation on coastal lagoons in the east of Uruguay. The analysis of the sediments in the zone enable the reconstruction of the Holocene climate history as well as the construction of the Paleoclimatic and paleoenvironmental model belong to the middle and late Holocene

  5. A molecular and stable carbon isotope study of organic matter in immature Miocene Monterey sediments (Pismo Basin)

    OpenAIRE

    Sinninghe Damsté, J.S.; Schouten, S.; Schoell, M.; Rijpstra, W.I.C.

    1997-01-01

    The 300 m section of the Miocene Monterey Formation outcropping at Shell Beach (Pismo basin; ca. 15-11 Ma) is composed of calcareous phosphatic (15.1–14.5 Ma) and siliceous facies (14.5–11.0 Ma). An objective of this paper is to document lateral paleoenvironmental changes in the Miocene Moneterey Formation by comparing the Shell Beach (SB) profile with the Naples Beach (NB) section in the Santa Barbara-Ventura basin (Schouten et al., 1997) which is ~80 km to the south. Eight samples (one samp...

  6. Some relationships between lithology, basin form and hydrology : a case study from the Thames Basin, UK

    OpenAIRE

    Bloomfield, J. P.; S. H. Bricker; Newell, A. J.

    2011-01-01

    The role of lithology in influencing basin form and function is explored empirically by investigating correlations between a range of catchment variables, where the spatial unit of analysis is not surface catchments but lithologically coherent groundwater units. Using the Thames basin, UK, as a case study, nine groundwater units have been identified. Values for 11 hydrological and geomorphological variables, including rainfall, drainage density, Baseflow Index, aquifer porosity, storage coeff...

  7. 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)

  8. 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

  9. 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

  10. Holocene paleo-environmental reconstruction in central Tibetan plateau inferred from a lacustrine sediment record

    OpenAIRE

    Cheung, Man-ching; 張敏青

    2014-01-01

    Previous studies on reconstructing the paleoclimate on the Tibetan Plateauare commonly based on a single proxy, and have thus limited the usage of their results. Therefore this study was designed firstly to evaluate the applicability of organic carbon isotopes from modern plants in the Tibetan Plateau as a paleo-environmental proxy, and secondly to apply palynology, organic geochemistry and biomarkers to the reconstructions ofpaleo-environmental history of central Tibet. The new, comprehensiv...

  11. Postglacial paleoenvironmental history of the Southern Patagonian Fjords at 53°S

    OpenAIRE

    Francois, Jean-Pierre

    2014-01-01

    Southern Patagonia (50°-56°S) is as key region for paleoenvironmental studies, in particular, for addressing fundamental paleoclimatic and paleoecological questions. This is due to a number of physical and biotic characteristics of the region: (i) its location allows to examine and reconstruct changes of the Southern Westerly Wind (SWW) belt, (ii) the presence of the Andes, which intercepts the flux of the SWWs creating a strong orographic precipitation gradient on a west-east axis, and (iii)...

  12. Hydrological studies in experimental and representative basins in Pernambuco State, Brazil

    OpenAIRE

    Montenegro, S.M.G.L.; da Silva, B. B.; A. C. D. Antonino; J. R. S. Lima; E.S. Souza; de Oliveira, L. M. M.; de Moura, A. E. S. S.; Souza, R. M. S.

    2014-01-01

    Hydrological studies in experimental and representative basins are of fundamental importance for water resources management. This paper presents some activities of hydrological research in experimental and representative basins of the State of Pernambuco, Brazil. The study areas are located at Tapacurá and Mundaú representative basins and at the Gameleira experimental basin, and in experimental plots in Pajeú basin. In the Tapacurá basin, three studies were performed: (1) different monthly co...

  13. Hydrogeological and geochemical studies in the Perch Lake basin

    International Nuclear Information System (INIS)

    The Perch Lake basin is a small drainage system along the Ottawa River about 200 km west of Ottawa on the Canadian Shield. Since 1975, groups of scientists from several Canadian universities and government departments have been studying the hydrological, geological and geochemical properties of the basin. The object of these studies is to develop and test simulation models used to describe the time-dependent mass flow rates of water and dissolved and suspended substances through the basin. To review progress, a symposium/workshop was held at Chalk Rier in 1978 April. This report contains 24 extended summaries of the material presented verbally at the workshop. Subject matters include atmospheric sources and sinks, mass flows through the surface and subsurface regimes in the drainage basins and interactions occurring in the lake. (author)

  14. Testing multivariate analysis in paleoenvironmental reconstructions using pollen records from Lagoa Salgada, NE Rio de Janeiro State, Brazil.

    Science.gov (United States)

    Toledo, Mauro B de; Barth, Ortrud M; Silva, Cleverson G; Barros, Marcia A

    2009-12-01

    Despite the indisputable significance of identification of modern analogs for Paleoecology research, relatively few studies attempted to integrate modern and fossil samples on paleoenvironmental reconstructions. In Palynology, this general pattern is not different from other fields of Paleoecology. This study demonstrates the practical application of modern pollen deposition data on paleoenvironmental reconstructions based on fossil pollen by using multivariate analysis. The main goal of this study was to use Detrended Correspondence Analysis (DCA) to compare pollen samples from two sediment cores collected at Lagoa Salgada, a coastal lagoon located at northeastern Rio de Janeiro State. Furthermore, modern surface samples were also statistically compared with samples from both cores, providing new paleoecological insights. DCA demonstrated that samples from both cores are more similar than previously expected, and that a strong pattern, related to a paleoenvironmental event, is present within the fossil data, clearly identifying in the scatter plot samples that represent pre- and post-environmental change. Additionally, it became apparent that modern vegetation and environmental conditions were established in this region 2500 years before present (BP). Multivariate Analysis allowed a more reliable integration of modern and fossil pollen data, proving to be a powerful tool in Paleoecology studies that should be employed more often on paleoclimate and paleoenvironmental reconstructions. PMID:19893900

  15. 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

  16. K-Basin gel formation studies

    International Nuclear Information System (INIS)

    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

  17. Geohydrologic study of the West Lake Basin

    Energy Technology Data Exchange (ETDEWEB)

    Gephart, R.E.; Eddy, P.A.; Arnett, R.C.; Robinson, G.A.

    1976-10-01

    The purpose of this investigation was to (1) collect and interpret geochemical data on the surface, unconfined, and confined waters of the West Lake Basin, and (2) evaluate the potential for radiochemical contamination of the uppermost confined aquifers. The report assesses the suitability of Gable Mountain Pond for receiving waste water from 200 East Area operations and applies a predictive digital computer model to assess the impacts to the groundwater regime of maintaining, increasing, or decreasing water discharge into Gable Mountain Pond. East of the 200 East Area lies a natural depression which has been dammed and used as a liquid waste disposal site (B Pond). B Pond waste waters directly recharge the underlying unconfined aquifer. This report will examine the suitability of using B Pond for receiving additional waste waters which would otherwise be discharged to Gable Mountain Pond. A predictive digital computer model will be used for assessments involving various discharges into B Pond.

  18. Paleoenvironmental history of the West Baray, Angkor (Cambodia)

    Science.gov (United States)

    Day, Mary Beth; Hodell, David A.; Brenner, Mark; Chapman, Hazel J.; Curtis, Jason H.; Kenney, William F.; Kolata, Alan L.; Peterson, Larry C.

    2012-01-01

    Angkor (Cambodia) was the seat of the Khmer Empire from the 9th to 15th century AD. The site is noted for its monumental architecture and complex hydro-engineering systems, comprised of canals, moats, embankments, and large reservoirs, known as barays. We infer a 1,000-y, 14C-dated paleoenvironmental record from study of an approximately 2-m sediment core taken in the largest Khmer reservoir, the West Baray. The baray was utilized and managed from the time of construction in the early 11th century, through the 13th century. During that time, the West Baray received relatively high rates of detrital input. In the 14th century, linear sedimentation rates diminished by an order of magnitude, yielding a condensed section that correlates temporally with episodes of regional monsoon failure during the late 14th and early 15th century, recorded in tree ring records from Vietnam. Our results demonstrate that changes in the water management system were associated with the decline of the Angkorian kingdom during that period. By the 17th century, the West Baray again functioned as a limnetic system. Ecologic and sedimentologic changes over the last millennium, detected in the baray deposits, are attributed to shifts in regional-scale Khmer water management, evolving land use practices in the catchment, and regional climate change.

  19. Neotectonic Studies of the Lake Ohrid Basin (FYROM/Albania)

    Science.gov (United States)

    Nadine, H.; Liermann, A.; Glasmacher, U. A.; Reicherter, K. R.

    2010-12-01

    The Lake Ohrid Basin located on 693 m a.s.l. at the south-western border of Macedonia (FYROM) with Albania is a suitable location for neotectonic studies. The lake is set in an extensional basin-and-range-like situation, which is influenced by the roll-back and detachment of the subducted slab of the Northern Hellenic Trench. The seismicity record of the area lists frequent shallow earthquakes with magnitudes of up to 6.6, which classifies the region as one of the highest risk areas for Macedonia and Albania. A multidisciplinary approach was chosen to reveal the stress history of the region. Tectonic morphology, paleostress analysis, remote sensing and geophysical investigations have been taken out to trace the landscape evolution. Furthermore, apatite fission-track (A-FT) analysis and t-T-path modelling was performed to constrain the thermal history and the exhumation rates. The deformation history of the basin can be divided in three major phases. This idea is also supported by paleostress data collected around the lake: 1. NW-SE shortening from Late Cretaceous to Miocene with compression, thrusting and uplift; 2. Uplift and diminishing compression in Late Miocene causing strike-slip and normal faulting; 3. Vertical uplift and E-W extension from Pliocene to present associated with local subsidence and (half-) graben formation. The initiation of the Ohrid Basin can be dated to Late Miocene to Pliocene. The morphology of the basin itself shows features, which characterize the area as an active seismogenic landscape. The elongated NS-trending basin is limited by the steep flanks of Galicica and Mokra Mountains to the E and W, which are tectonically controlled by normal faulting. This is expressed in linear step-like fault scarps on land with heights between 2 and 35 m. The faults have lengths between 10 and 20 km and consist of several segments. Post-glacial bedrock fault scarps at Lake Ohrid are long-lived expressions of repeated surface faulting in tectonically

  20. Morphotectonic study of the Brahmaputra basin using geoinformatics

    Science.gov (United States)

    Nath Sarma, Jogendra; Acharjee, Shukla; murgante, Beniamino

    2013-04-01

    The Brahmaputra River basin occupies an area of 580,000 km2 lying in Tibet (China), Bhutan, India and Bangladesh. It is bounded on the north by the Nyen-Chen-Tanghla mountains, on the east by the Salween River basin and Patkari range of hills, on the south by Nepal Himalayas and the Naga Hills and on the west by the Ganga sub-basin. Brahmaputra river originates at an elevation of about 5150 m in south-west Tibet and flows for about 2900 km through Tibet (China), India and Bangladesh to join the Ganga.. The Brahmaputra River basin is investigated to examine the influence of active structures by applying an integrated study on geomorphology, morphotectonics, Digital Elevation Model (DEM) using topographic map, satellite data, SRTM, and seismic data. The indices for morphotectonic analysis, viz. basin elongation ratio (Re) indicated tectonically active, transverse topographic symmetry (T = 0.018-0.664) indicated asymmetric nature, asymmetric factor (AF=33) suggested tilt, valley floor width to valley height ratio (Vf = 0.0013-2.945) indicated active incision and mountain-front sinuosity (Smf = 1.11-1.68) values indicated active tectonics in the area. A great or major earthquake in the modern times, in this region may create havoc with huge loss of life and property due to high population density and rapidly developing infrastructure. Keywords: .Morphotectonic, Brahmaputra river, earthquake

  1. Sprague River geomorphology studies, Klamath Basin, Oregon

    Science.gov (United States)

    McDowell, P. F.; O'Connor, J. E.; Lind, P.

    2005-12-01

    The Sprague River drains 4050 square kilometers with a mean annual discharge of 16.3 m3/s before emptying into the Williamson River and then upper Klamath Lake in southcentral Oregon. The alternating wide alluvial segments and narrow canyon reaches of this 135-km-long westward flowing river provide for a variety of valued ecologic conditions and human uses along the river corridor, notably fisheries (including two endangered species of suckers, and formerly salmon), timber harvest, agriculture, and livestock grazing. The complex history of land ownership and landuse, water control and diversion structures, and fishery alterations, provides several targets for attributing historic changes to channel and floodplain conditions. Recently, evolving societal values (as well as much outside money) are inspiring efforts by many entities to 'restore' the Sprague River watershed. In cooperation with the U.S. Fish and Wildlife Service, the Klamath Tribes, and many local landowners, we are launching an analysis of Sprague River channel and floodplain processes. The overall objective is to guide restoration activities by providing sound understanding of local geomorphic processes and conditions. To do this we are identifying key floodplain and channel processes, and investigating how they have been affected by historic floodplain activites and changes to the watershed. This is being accomplished by analysis of historic aerial photographs and maps, stratigraphic analysis of floodplain soils and geologic units, mapping of riparian vegetation conditions and changes, and quantitative analysis of high resolution LiDAR topography acquired for the entire river course in December 2004. Preliminary results indicate (1) much of the coarser (and more erodible) floodplain soils are largely composed of pumice deposited in the basin by the 7700 year BP eruption of Mount Mazama; and (2) the LiDAR digital elevation models provide a ready means of subdividing the river into segments with

  2. Paleoenvironmental evidence for first human colonization of the eastern Caribbean

    Science.gov (United States)

    Siegel, Peter E.; Jones, John G.; Pearsall, Deborah M.; Dunning, Nicholas P.; Farrell, Pat; Duncan, Neil A.; Curtis, Jason H.; Singh, Sushant K.

    2015-12-01

    Identifying and dating first human colonization of new places is challenging, especially when group sizes were small and material traces of their occupations were ephemeral. Generating reliable reconstructions of human colonization patterns from intact archaeological sites may be difficult to impossible given post-depositional taphonomic processes and in cases of island and coastal locations the inundation of landscapes resulting from post-Pleistocene sea-level rise. Paleoenvironmental reconstruction is proving to be a more reliable method of identifying small-scale human colonization events than archaeological data alone. We demonstrate the method through a sediment-coring project across the Lesser Antilles and southern Caribbean. Paleoenvironmental data were collected informing on the timing of multiple island-colonization events and land-use histories spanning the full range of human occupations in the Caribbean, from the initial forays into the islands through the arrival and eventual domination of the landscapes and indigenous people by Europeans. In some areas, our data complement archaeological, paleoecological, and historical findings from the Lesser Antilles and in others amplify understanding of colonization history. Here, we highlight data relating to the timing and process of initial colonization in the eastern Caribbean. In particular, paleoenvironmental data from Trinidad, Grenada, Martinique, and Marie-Galante (Guadeloupe) provide a basis for revisiting initial colonization models of the Caribbean. We conclude that archaeological programs addressing human occupations dating to the early to mid-Holocene, especially in dynamic coastal settings, should systematically incorporate paleoenvironmental investigations.

  3. Colorado River Basin Water Supply and Demand Study

    Science.gov (United States)

    Prairie, J. R.; Jerla, C.

    2012-12-01

    The Colorado River Basin Water Supply & Demand Study (Study), part of the Basin Study Program under the Department of the Interior's WaterSMART Program, is being conducted by the Bureau of Reclamation and agencies representing the seven Colorado River Basin States. The purpose of the Study is to assess future water supply and demand imbalances in the Colorado River Basin over the next 50 years and develop and evaluate options and strategies to resolve those imbalances. The Study is being conducted over the period from January 2010 to September 2012 and contains four major phases: Water Supply Assessment, Water Demand Assessment, System Reliability Analysis, and Development and Evaluation of Opportunities for balancing supply and demand. To address the considerable amount of uncertainty in projecting the future state of the Colorado River system, the Study has adopted a scenario planning approach that has resulted in four water supply scenarios and up to six water demand scenarios. The water supply scenarios consider hydrologic futures derived from the observed historical and paleo-reconstructed records as well as downscaled global climate model (GCM) projections. The water demand scenarios contain differing projections of parameters such as population growth, water use efficiency, irrigated acreage, and water use for energy that result in varying projections of future demand. Demand for outdoor municipal uses as well as agricultural uses were adjusted based on changing rates of evapotranspiration derived from downscaled GCM projections. Water supply and demand scenarios are combined through Reclamation's long-term planning model to project the effects of future supply and demand imbalances on Colorado River Basin resources. These projections lend to an assessment of the effectiveness of a broad range of options and strategies to address future imbalances.

  4. Stable isotope-based paleoenvironmental reconstructions of Neogene terrestrial archives

    OpenAIRE

    Lüdecke, Tina

    2016-01-01

    The stable isotope geochemistry of pedogenic and lacustrine carbonate and fossil herbivore tooth enamel is a powerful tool to study the evolution of terrestrial paleoenvironments. This thesis aims to reconstruct Neogene ecosystems in the Karonga Basin in the southern part the East African Rift (EAR) and the Central Anatolian Plateau (CAP). Karonga Basin: Understanding the development of East African savanna biomes is crucial for reconstructing the evolution, migration and dietary behaviors...

  5. 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.

  6. Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

    International Nuclear Information System (INIS)

    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 N2 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 CO2 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.

  7. 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.

  8. Hydrological study of La Paz river basin

    International Nuclear Information System (INIS)

    This work aims to determine the hydrological parameters for the La Paz river, by using tracer techniques and also the determination of the water quality parameters for the study of the behavior along the stream. This study intends the prediction and control of the water contamination by using mathematical modelling

  9. HYDROGEOLOGICAL INVESTIGATIONS OF SANDIKLI BASIN (AFYONKARAHISAR)-PRELIMINARY STUDIES

    OpenAIRE

    Seyman Aksever, Arş. Gör. Fatma; Davraz, Doç.Dr.Ayşen; Karagüzel, Prof.Dr.Remzi

    2011-01-01

    ABSTRACT The aims of this research are to determine hydrogeological and hydrogeochemical investigations of Sandıklı (Afyonkarahisar) basin and to plan of optimum groundwater management of the basin. The Sandıklı basin is situated in the west of the Aegean region and discharge to the Büyük Menderes Basin. The research area is occurred from Sandıklı Kuruçay basin and Küçük Sincanlı basin. It has 1556 km2 recharge area. The basin has a semi-closed basin property due to discharge to Kestel Ri...

  10. 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.

  11. Dynamics of soils degradation, study on Indian ocean basins

    OpenAIRE

    Payet, Évelyne

    2015-01-01

    Since the 20th centuries, the Southwest of Indian Ocean is particularly affected by anthropogenic degradations. This study aims to analyze degradations on drainage basin scale, which allows a suitable monitoring of critical areas, in the southwest of Indian Ocean. It focus on the assessment of land degradation and its causes, land cover change and erosion.The main difficulty stands in the implementation of reproducible methods and proceeds for developed and developing countries. In light of t...

  12. Maintenance and Operations study for K basins sludge treatment

    International Nuclear Information System (INIS)

    This study evaluates maintenance and operating concepts for the chemical treatment of sludge from the 100 K Basins at Hanford. The sludge treatment equipment that will require remote operation or maintenance was identified. Then various maintenance and operating concepts used in the nuclear industry were evaluated for applicability to sludge treatment. A hot cell or cells is recommended as the best maintenance and operating concept for a sludge treatment facility

  13. Spatial heterogeneity study of vegetation coverage at Heihe River Basin

    Science.gov (United States)

    Wu, Lijuan; Zhong, Bo; Guo, Liyu; Zhao, Xiangwei

    2014-11-01

    Spatial heterogeneity of the animal-landscape system has three major components: heterogeneity of resource distributions in the physical environment, heterogeneity of plant tissue chemistry, heterogeneity of movement modes by the animal. Furthermore, all three different types of heterogeneity interact each other and can either reinforce or offset one another, thereby affecting system stability and dynamics. In previous studies, the study areas are investigated by field sampling, which costs a large amount of manpower. In addition, uncertain in sampling affects the quality of field data, which leads to unsatisfactory results during the entire study. In this study, remote sensing data is used to guide the sampling for research on heterogeneity of vegetation coverage to avoid errors caused by randomness of field sampling. Semi-variance and fractal dimension analysis are used to analyze the spatial heterogeneity of vegetation coverage at Heihe River Basin. The spherical model with nugget is used to fit the semivariogram of vegetation coverage. Based on the experiment above, it is found, (1)there is a strong correlation between vegetation coverage and distance of vegetation populations within the range of 0~28051.3188m at Heihe River Basin, but the correlation loses suddenly when the distance greater than 28051.3188m. (2)The degree of spatial heterogeneity of vegetation coverage at Heihe River Basin is medium. (3)Spatial distribution variability of vegetation occurs mainly on small scales. (4)The degree of spatial autocorrelation is 72.29% between 25% and 75%, which means that spatial correlation of vegetation coverage at Heihe River Basin is medium high.

  14. 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 in...... Africa. 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...

  15. Constrained basin stability for studying transient phenomena in dynamical systems

    Science.gov (United States)

    van Kan, Adrian; Jegminat, Jannes; Donges, Jonathan F.; Kurths, Jürgen

    2016-04-01

    Transient dynamics are of large interest in many areas of science. Here, a generalization of basin stability (BS) is presented: constrained basin stability (CBS) that is sensitive to various different types of transients arising from finite size perturbations. CBS is applied to the paradigmatic Lorenz system for uncovering nonlinear precursory phenomena of a boundary crisis bifurcation. Further, CBS is used in a model of the Earth's carbon cycle as a return time-dependent stability measure of the system's global attractor. Both case studies illustrate how CBS's sensitivity to transients complements BS in its function as an early warning signal and as a stability measure. CBS is broadly applicable in systems where transients matter, from physics and engineering to sustainability science. Thus CBS complements stability analysis with BS as well as classical linear stability analysis and will be a useful tool for many applications.

  16. Multi-National River Basin Cooperation and Management Case Study: Senegal River Basin

    OpenAIRE

    Ayaa, Patricia

    2012-01-01

    With increasing populations, urbanization and thus increasing demand for water, conflict on International River basins has been increasing over the years which has necessitated formation of International River frameworks to devise means of cooperation among the countries sharing the river basins. The main modes of cooperation in international river basins include allocating the waters of the river to the sharing countries such that each country manages its own water resources, or treating the...

  17. 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

  18. Isotope study of the Oruro-Caracollo basin (Bolivia)

    International Nuclear Information System (INIS)

    The isotope study was carried out on the Oruro-Caracollo fluvio-lacustrine basin on the Bolivian altiplano (mean altitude 3700 m a.s.l.) 250 km south of La Paz near the town of Oruro and its famous tin, silver and antimony mines. On interpretation, the distributions of natural isotopes (18O, 2H, 3H and 14C) revealed the presence of three different water types: (1) water from the surface aquifer through the alluvial cones at the foot of the Cordillera Oriental to the east; (2) thermal waters on the edges of the sedimentary basin which have little effect on the aquifers studied; (3) and deep circulation water through the Tertiary volcanic basement rock (San Jose mines). It was demonstrated that flooding on the Oruro plateau plays no part in recharge and is totally lost to evaporation. On the basis of 14C activity, a general direction of flow from northeast to southeast was deduced, with an estimated rate of flow of 1 m/a. The isotope data suggest that there is a hydrological division in the basement of the basin between the Kala Kaja and Challapampita well fields; it is also suggested that there is a line or fault running northeast to southeast in Kala Kaja along which water of deep origin rises. (author). 6 refs, 6 figs, 3 tabs

  19. 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

  20. 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

  1. 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.

  2. 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,...

  3. New aerogeophysical study of the Eurasia Basin and Lomonosov Ridge: Implications for basin development

    DEFF Research Database (Denmark)

    Brozena, J.M.; Childers, V.A.; Lawver, L.A.;

    2003-01-01

    In 1998 and 1999, new aerogeophysical surveys of the Arctic Ocean's Eurasia Basin produced the first collocated gravity and magnetic measurements over the western half of the basin. These data increase the density and extend the coverage of the U.S. Navy acromagnetic data from the 1970s. The new...... Norwegian-Greenland Sea. With the opening of the Labrador Sea, Greenland began similar to200 km of northward movement relative to North America and eventually collided with Svalbard, Ellesmere Island, and the nascent Eurasia ocean basin. Both gravity and magnetic data sets reconstructed to times prior to...

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

    OpenAIRE

    Blanca Estela Carreto-Pérez; Ángel Almazán-Juárez; Pablo Sierra-Morales; R. Carlos Almazán-Núñez

    2015-01-01

    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 t...

  5. 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

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

    Directory of Open Access Journals (Sweden)

    P. Bauer-Gottwein

    2014-10-01

    Full Text Available 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 modelling schemes employing data 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. The forecasting system delivers competitive forecasts for the Kavango River, which are reliable and sharp. Results indicate that the value of the forecasts is greatest for intermediate lead times between 4 and 7 days.

  7. hydrological study of the basin of Tunja using isotopics technical

    International Nuclear Information System (INIS)

    In the carried out study, it is analyzed the generalities in the first place on the city of Tunja, keeping in mind the aspects of Topography, Climate Population and the projection of this last one until the year 2020, and of equal it forms the demand of drinkable water for these same projections. Then it is the Superficial Hydrology of the area in study, keeping in mind the physiographic parameters of the basin, behavior pluviometrical graphic, flows and evapotranspiration, towards them to calculate this way the infiltration and power to end up determining the hydraulic balance of the area. In the concerning to Geology, this it was carried out on the base of the rising of stratigraphic columns made in having traveled by different roads and roads bordering to the study area; based on this columns it was carried out a geologic map with all the characteristics of the formations in the area

  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. 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.

  10. Eocene benthic foraminiferal assemblages from Central Anatolia (Turkey): Biostratigraphy, stable isotope data, paleoenvironmental and paleontological interpretations

    Science.gov (United States)

    Dinçer, Feyza

    2016-02-01

    Stable isotope (δ13C and δ18O) values from Eocene aged shallow marine deposits in two different basins (Haymana and Kırşehir-Kaman) of Central Anatolia and benthic foraminiferal biostratigraphy's corresponding sequences were analyzed to determine paleontological and paleoenvironmental changes. The shallow marine units (Çayraz and Altıpınar formations), deposited as a result of different geological processes in the same period, show differences in paleontological and geochemical properties of the tests. The geological process controlled by environmental factors affect the formation of the chemical structure of foraminiferal calcite. These Lutetian and Bartonian aged formations are represented by five Shallow Benthic Zones. While, the Çayraz section is represented by SBZ 14-18, Boztepe section is represented by SBZ 13-17. With an increase in temperature, the variety of benthic foraminifera decreased, and Assilina exponens became the dominant species in the warm conditions. The most important proxy is δ13C, which reflects the paleoproductivity (food supply) where benthic foraminifera lived. In addition, food supply can be considered to be a more important factor than temperature, as it controls the diversity and abundance of benthic foraminifera.

  11. 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

    2015-12-01

    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.

  12. Engineering study: 105KE to 105KW Basin fuel and sludge transfer. Final report

    International Nuclear Information System (INIS)

    In the last five years, there have been three periods at the 105KE fuel storage basin (KE Basin) where the reported drawdown test rates were in excess of 25 gph. Drawdown rates in excess of this amount have been used during past operations as the primary indicators of leaks in the basin. The latest leak occurred in March, 1993. The reported water loss from the KE Basin was estimated at 25 gph. This engineering study was performed to identify and recommend the most feasible and practical method of transferring canisters of irradiated fuel and basin sludge from the KE Basin to the 105KW fuel storage basin (KW Basin). Six alternatives were identified during the performance of this study as possible methods for transferring the fuel and sludge from the KE Basin to the KW Basin. These methods were then assessed with regard to operations, safety, radiation exposure, packaging, environmental concerns, waste management, cost, and schedule; and the most feasible and practical methods of transfer were identified. The methods examined in detail in this study were based on shipment without cooling water except where noted: Transfer by rail using the previously used transfer system and water cooling; Transfer by rail using the previously used transfer system (without water cooling); Transfer by truck using the K Area fuel transfer cask (K Area cask); Transfer by truck using a DOE shipping cask; Transfer by truck using a commercial shipping cask; and Transfer by truck using a new fuel shipping cask

  13. Wekiva Basin onsite sewage treatment and disposal system study

    OpenAIRE

    Booher, Paul

    2006-01-01

    Existing onsite systems and aquifer vulnerability in the Wekiva Basin. Recommendations from the Bureau of Onsite Sewage Programs, Division of Environmental Health, Florida Department of Health. (11 slides)

  14. High Arctic paleoenvironmental and Paleoclimatic changes in the Mid-Cretaceous

    Science.gov (United States)

    Herrle, Jens; Schröder-Adams, Claudia; Selby, David; Du Vivier, Alice; Flögel, Sascha; McAnena, Alison; Davis, William; Pugh, Adam; Galloway, Jennifer; Hofmann, Peter; Wagner, Thomas

    2014-05-01

    Although major progress in Cretaceous (145-66 Ma) paleoclimate and paleoceanography has been made during the last decades (e.g., Hay, 2008, 2011; Föllmi, 2012 and references therein), our knowledge of high latitudinal environmental change remains largely unknown compared to low- and mid-latitude marine and terrestrial environments. Drilling the Arctic Ocean remains challenging and expensive, whereas the Sverdrup Basin provides excellent exposures on land. To fully understand the climate and paleoceanographic dynamics of the warm, equable greenhouse world of the Cretaceous Period it is important to determine polar paleotemperatures and to study paleoceanographic changes in a well-established and continuous bio- and chemostratigraphic context. Exceptional exposures of Cretaceous sediments on the central to southern part of Axel Heiberg Island at a Cretaceous paleolatitude of about 71°N (Tarduno et al., 1998) provide a unique window on the Cretaceous Arctic paleoenvironment and climate history (Schröder-Adams et al., 2014). Here we present high-resolution records combining sedimentological studies, U-Pb zircon geochronology, marine organic carbon isotopes and initial 187Os/188Os data, TEX86-derived sea-surface temperatures (SST) and climate modelling, that constrain the timing and magnitude of major Oceanic Anoxic Events (OAEs) and climate events constructed from a ~1.8 km sedimentary succession exposed on Axel Heiberg and Ellef Ringnens islands in the Canadian Arctic Archipelago. The first high latitude application of initial 187Os/188Os data are agreeable with global profiles (Du Vivier et al., 2014) indicating the widespread magmatic pulse of the Caribbean Large Igneous Province (LIP) at the onset of OAE2 but also record the emplacement of local High Arctic LIP prior to the OAE2 in the Sverdrup Basin. Initial SST data suggest a slightly lower meridional temperature gradient during the Middle/Late Albian compared to present and a similar to the present one during

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Rain shadow development and paleoenvironmental change in the southern Central Anatolian Plateau

    Science.gov (United States)

    Meijers, Maud J. M.; Mulch, Andreas; Brocard, Gilles Y.; Whitney, Donna L.

    2015-04-01

    Ongoing Arabia-Eurasia convergence in the eastern Mediterranean region has led to the westward escape of the Anatolian microplate and the formation of the Central Anatolian Plateau (CAP). The US-NSF CD-CAT (Continental Dynamics-Central Anatolian Tectonics) project aims at understanding the surface-to-mantle coupling during the transition from collision to escape tectonics and plateau formation in Anatolia. Within the CD-CAT project, this study aims at determining the paleoenvironmental conditions and the age of plateau (margin) uplift by integrating stable isotope geochemistry and absolute dating techniques (40Ar/39Ar geochronology and magnetostratigraphy) on middle Miocene to Pliocene lacustrine sedimentary rocks. The low-relief CAP (~1.5 km average elevation) is characterized by high-relief mountain ranges at its southern and northern margins. The Tauride mountain belt forms the southern plateau margin of the CAP with a relief of up to 3 km. Uplift of Tortonian marine sediments in the central Taurides to modern elevations of up to 2 km constrain the onset of surface uplift of the southern plateau margin to ~8 Ma (Schildgen et al. 2012a,b). Proxy records of oxygen isotopes (δ18O) in precipitation allow to reconstruct the development of the present-day Tauride rain shadow and hence the surface elevation history of the southern plateau margin. Here we evaluate δ18O and δ13C records of seven lacustrine basins situated along a SW-NE swath in the lee of the modern Tauride mountains in order to track the development of a Tauride rain shadow and changes in open to closed lake conditions through the late Miocene to Pliocene. We focus on lacustrine sections with available mammal ages and integrate these with 40Ar/39Ar geochronology of widespread volcanics of the Central Anatolian Volcanic Province and magnetostratigraphy where possible. Our results from seven sections of ~12-4 Ma in lacustrine deposits and pedogenic soil carbonates of ~3-2.5 Ma show a decrease of δ18O

  20. 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

  1. Simulation of the catastrophic floods caused by extreme rainfall events - Uh River basin case study

    OpenAIRE

    Pekárová, Pavla; Halmová, Dana; Mitková, Veronika

    2005-01-01

    The extreme rainfall events in Central and East Europe on August 2002 rise the question, how other basins would respond on such rainfall situations. Such theorisation helps us to arrange in advance the necessary activity in the basin to reduce the consequence of the assumed disaster. The aim of the study is to recognise a reaction of the Uh River basin (Slovakia, Ukraine) to the simulated catastrophic rainfall events from August 2002. Two precipitation scenarios, sc1 and sc2, were created. Th...

  2. Plant DNA: A new substrate for carbon stable isotope analysis and a potential paleoenvironmental indicator

    Science.gov (United States)

    Jahren, A. Hope; Petersen, Gitte; Seberg, Ole

    2004-03-01

    The δ13C value of fossil plant materials can be used to gain insight into the dominant photosynthetic pathway, as well as other environmental attributes, of ancient plant ecosystems. Nucleotide sequences from land plant nucleic acids extracted from 400 ka fossil sediments have been recognized as the oldest authenticated fossil deoxyribonucleic acid (DNA), making the inference of plant taxonomy possible in substrates devoid of plant macrofossils and microfossils. If the C isotope relationship between bulk plant tissue and associated plant nucleic acids were known, fossil plant nucleic acids could be analyzed for δ13C value and used as land plant isotopic substrates within mixed organic material. Toward this end, we present δ13C analyses of nucleic acids isolated from 12 higher plant species that span the full phylogenetic diversity of seed plants. Extracted nucleic acids were dominated by double-stranded DNA containing fragments of rbcL gene ˜350 base pairs in length. The C isotope compositions of plant nucleic acids were found to be enriched in 13C relative to bulk plant tissue by a constant value = 1.39‰. This study represents the first comparison of the δ13C value of nucleic acids to the δ13C value of bulk tissue for multicellular organisms; our results contrasted with the minimal fractionations reported for microorganisms. Because the isotopic enrichment is constant across tracheophytes, the δ13C value of fossil plant DNA can be used as a paleoenvironmental indicator, eliminating the need for morphological recognition of fossil plant material in paleoenvironmental studies.

  3. Peak temperature in intracratonic basins constrained by magnetic studies:Example of the Illinois Basin

    Science.gov (United States)

    Uz, E.; Ferre, E. C.; Rimmer, S.; Morse, D. G.; Crockett, J. E.

    2012-12-01

    Deciphering the thermal evolution of a package of sedimentary rocks through time constitutes an essential element in exploration for oil and gas. Classic geothermometers based on illite crystallinity, vitrinite reflectance, the Rock-Eval method or conodont coloration index are limited to rocks containing sufficient amounts of one of the index materials. Magnetic approaches to geothermometry have intrinsic advantages due to the quasi-ubiquitous presence of magnetically remanent grains in sedimentary environments. Previous attempts to correlate burial temperature with magnetic properties focused on the low-field bulk magnetic susceptibility Km (Hrouda et al., 2003) or on the low-temperature magnetic parameter PM in pyrrhotite-magnetite assemblages (MagEval method of Aubourg and Pozzi, 2010). We simultaneously investigate the variation of an array of magnetic parameters with temperature. These parameters include low-field magnetic susceptibility, saturation isothermal magnetic remanence, saturation magnetization, coercitive force and coercivity of magnetic remanence. Tracking multiple magnetic parameters offers the advantage of being sensitive not only to heating-induced mineralogical changes but also to heating-induced magnetic domain changes. This multi-parameter method also has the benefit of being applicable to a broad range of sedimentary lithologies. To demonstrate the principles of this method we begin examining intracontinental basins because they are broadly undeformed and their thermal histories remain, in general, relatively simple. Igneous intrusions and basinal hydrothermal fluids may, however, complicate matters. The Illinois Basin, an oil- and gas-producing basin, provides an accessible test area for the geothermometric tests. The Mount Simon Sandstone constitutes the first lithological unit investigated because it sits at the deepest level in the basin and is therefore likely to have recorded the highest burial temperatures. The proposed method

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-03-23

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

  5. Seismic refraction studies in the San Juan Basin, Northwest New Mexico

    Science.gov (United States)

    Evans, D.H.; Jaksha, L.H.

    1984-01-01

    The U.S. Geological Survey is studying some of the features of the earth's crust in the San Juan Basin region, northwest New Mexico. As a part of this study seismic refraction-reflection measurements were made in and around the basin using explosions and earthquakes as energy sources. Record sections and traveltime tables were derived from the measurements.

  6. 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.

  7. 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.

  8. 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.

  9. Multispectral Study of the Schrödinger Impact Basin

    Science.gov (United States)

    Shankar, B.; Osinski, G.; Antonenko, I.; Stooke, P. J.

    2009-05-01

    The Schrödinger impact basin is located on the lunar far side near the south pole (76oS, 134oE) and is one of only two young multiring impact basins on the lunar surface [1]. With a diameter size of 312 km and basin floor 2-3 km deep, Schrödinger is the least modified impact basin of its size. A peak ring structure 150 km in diameter lies on the basin floor, formed by uplift of pre-Schrödinger crustal materials. Ejecta material, smooth in texture, covers the basin walls and extends out onto the surrounding surface up to 100 km in all directions. The first geological map published of Schrödinger was generated using preliminary Clementine data [1]. The map described the geology and geomorphology within the inner basin with smooth and rough plains of shocked material occupying most of the basin floor. The rough plains are identified by presence of hummocks, swales, and low knobs. Smooth plains have no discernable features identifiable. Ghost craters are found along both smooth and rough patches. A volcanic vent in the inner eastern corner of Schrödinger is interpreted as a source for pyroclastic eruptions within the area. Located along the volcanic vent is a north-east trending graben. There are thin patches of impact melt sheets along the basin walls and peak ring. A lobate ridge located near the centre of the inner basin is interpreted as having formed by buckling of the melt sheet. A more recent geologic map using high resolution Clementine UVVIS data and topography data is in agreement with the proposed geology within the Schrödinger basin [2]. Contacts between various units are better outlined in the recent map. Using spectra derived from high resolution Clementine UVVIS images and Lunar Prospector data we determine the composition of impact melt, impact ejecta, and the extent of proposed cryptomare deposits [3]. We also use Fe, Th, and Ti abundance in determining the composition of these units. Our goal is to determine the abundance and distribution of

  10. Constrained basin stability for studying transient phenomena in dynamical systems

    OpenAIRE

    van Kan, Adrian; Jegminat, Jannes; Donges, Jonathan; Kurths, Jürgen

    2016-01-01

    Transient dynamics are of large interest in many areas of science. Here, a generalization of basin stability (BS) is presented: constrained basin stability (CBS) that is sensitive to various different types of transients arising from finite size perturbations. CBS is applied to the paradigmatic Lorenz system for uncovering nonlinear precursory phenomena of a boundary crisis bifurcation. Further, CBS is used in a model of the Earth's carbon cycle as a return time-dependent stability measure of...

  11. 105KE and 105KW Basins fuel and sludge consolidation study, summary report

    International Nuclear Information System (INIS)

    This study is a summary report that examines and evaluates the feasibility of consolidating irradiated fuel and sludge currently in KE Basin with that in the KW Basin. This study was conducted in support of TPA Milestone (target date) M-34-00-T03. The report summarizes three supporting engineering studies involving: (1) spent fuel consolidation into the single basin, (2) transport of the encapsulated fuel between KE and KW Basins, and (3) dispositioning contaminated water remaining in KE Basin. From the three reports, and preferred storage method, transfer method and water disposition method were defined. These consolidation methods were then evaluated against the no action alternative of continued storage using both KE and KW Basins. The report concluded that the fuel and sludge currently stored in KE Basin not be consolidated in the KW Basin, primarily due to increased cost and radiation exposure required to consolidate the fuel and sludge. Consolidation is more attractive for storage periods beyond the year 2002, which is the study period of the report

  12. Underground flux studies in waste basin of CIPC using natural and artificial tracers (volume I)

    International Nuclear Information System (INIS)

    This report presents studies to be done in wastes basin of CIPC in order to verify the contamination possibility of Rio das Antas basin, by infiltration in subsoil, of liquid wastes proceeding from mineral and industrial complex of Pocos de Caldas to be done up to February/82. (author)

  13. 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

  14. Hydrological studies in experimental and representative basins in Pernambuco State, Brazil

    Science.gov (United States)

    Montenegro, S. M. G. L.; da Silva, B. B.; Antonino, A. C. D.; Lima, J. R. S.; de Souza, E. S.; de Oliveira, L. M. M.; de Moura, A. E. S. S.; Souza, R. M. S.

    2014-09-01

    Hydrological studies in experimental and representative basins are of fundamental importance for water resources management. This paper presents some activities of hydrological research in experimental and representative basins of the State of Pernambuco, Brazil. The study areas are located at Tapacurá and Mundaú representative basins and at the Gameleira experimental basin, and in experimental plots in Pajeú basin. In the Tapacurá basin, three studies were performed: (1) different monthly coefficients "k" of the Thornthwaite method were tested to calculate the effective temperature and, consequently, the reference evapotranspiration, giving rise to the method identified as Modified Thornthwaite; (2) the spatial variability of the retention curve and hydraulic conductivity parameters were analysed using the Beerkan method; (3) changes in vegetation cover were evaluated through the NDVI and NDWI indexes using TM-Landsat 5 images. In the Mundaú representative basin, the performance of different evapotranspiration methods was evaluated and compared to the FAO standard method, Penman-Monteith. In the Pajeú basin, the experimental plot is covered by pasture and sensors were installed to monitor the following variables: rainfall, air temperature, the energy balance components (net radiation, latent and sensible heat, and soil heat flux), wind velocity and CO2 flux into atmosphere, soil moisture and runoff.

  15. 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.

  16. 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

    2012-08-01

    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" (surface- and groundwater 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" (soil water 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.

  17. 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

  18. The Eastern Lau Basin Integrated Studies Site (ISS)

    Science.gov (United States)

    Wiens, D.

    2003-12-01

    A new venue for Ridge 2000 (R2K) Integrated Studies, the Eastern Lau Spreading Center (ELSC) adds the element of a spreading center in a back-arc basin to the R2K program. The ELSC, located in the western Pacific near Tonga, is a 390 km-long first-order ridge segment that displays a broad range of effects of the back-arc environment. At its southern end it is only 40 km from the Tonga arc volcanic front and is propagating southward into a back-arc rift. At its northern end it is 100 km from the volcanic front and terminates at a large, non-transform offset. The ELSC displays substantial and systematic changes in multiple parameters: spreading rate, magma source and lava chemistry, axial depth and morphology, melt lens characteristics, and crustal thickness and structure. A main focus of the work at the ELSC is to determine how changes in these forcing functions affect key parameters such as magma source composition, crustal structure, and characteristics of hydrothermal venting such as temperature, chemistry, and faunal composition and abundance. Prior reconnaissance investigation shows that these hydrothermal field characteristics also vary within the southernmost segments, and show distinct differences compared with well-studied mid-ocean ridge sites. Four R2K cruises are planned for the ELSC in 2004. The first cruise (PI: Martinez) will investigate interrelationships among crustal structure, volcanism, and hydrothermal activity using deep tow, CTD's, and Tow-Yo. A second cruise (PI: Langmuir) will focus on petrological and water column properties using dredging, CTD's and ABE. The next cruise (PI: Tivey) will provide an initial characterization of vent fields, fluid chemistry, mineralogy, and biodiversity using Jason II and net tows, and a final cruise (PI: Childress) will investigate community ecology using Jason II. An additional study (PI: Thurnherr) will deploy autonomous floats to investigate hydrothermal plume circulation and dispersal . An overview of the

  19. Study of local interactions between earthquakes in Pannonian basin

    International Nuclear Information System (INIS)

    Different hypotheses on the nature of seismotectonic processes in Vrancea seismogenic region inside Pannonian basin are investigated via a statistical study of properties of earthquake sequences. Vrancea seismogenic region produces large destructive earthquakes with intermediate depth of focus which may seriously affect vulnerable constructions such as nuclear power plants, chemical plants, large dams, pipelines, etc. on a wide territory of Central Europe up to Moscow City. The nature of intermediate depth earthquakes has attracted increased attention recently of the part of seismologists in an attempt to find out the adequate source mechanism which would produce wave forms in the far field similar to the normal earthquakes despite of radical difference in their confining pressure, temperature, physical and chemical composition of minerals in rupture zone. The properties under study are the following: positive and negative influence of large initial earthquakes on the intensity flow of successive seismic events, their relation to seismic cycle concept and velocity and Q-factor structure of the region. The method of investigation is the so called local statistics technique. For a better understanding of possible mechanisms of positive and negative interaction between earthquakes in Vrancea region similar local statistics are calculated for the flow of events in mathematical model of this region. The lithosphere structure is considered in the model as absolutely rigid 3-D blocks, separated by infinitely thin layers of visco-elastic material. The external forces (tectonic and gravitational) deform the system with a finite velocity of accumulation of stress in inter-blocks media. Accumulated stress is released completely when it reaches critical value at some cell of the discrete grid covering all boundaries between blocks. Immediately afterwards the neighbour boundary areas are a subject of stress redistribution according to laws of static. 11 refs, 11 tabs

  20. River Sinuosity Classification - Case study in the Pannonian Basin

    Science.gov (United States)

    Petrovszki, J.; Székely, B.; Timár, G.

    2012-04-01

    A new evaluation method is proposed to classify the multiple window-size based sinuosity spectrum, in order to minimize the possible human interpretation error. If the river is long enough for the analysis, the classification could be similarly useful as the sinuosity spectrum is, but sometimes it is more straightforward. Furthermore, for the classification, we did not need the main parameters of the river, e.g. the bankfull discharge. The river sinuosity values were studied in the Pannonian Basin in order to reveal neotectonic influence on their abrupt changes. The map sheets of the Second Military Survey of the Habsburg Empire were used to digitize the natural, pre-regulation meandering river thalwegs. 28 rivers were studied, and the connection between the known fault lines and the river sinuosity changes was detected in 36 points, along 26 structural lines. An unsupervised ISOCLASS classification was carried out on these data, and the sinuosity values were divided into 5 classes. Because of the sinuosity calculation method, 25 kilometer-long river sections are missing at the two endpoints of the channel. So sometimes the displayed section of the river does not cross to the faults represented on the neotectonic map. In the other cases, where the faults are crossing the rivers, the results are corresponding with the results of the sinuosity spectrum: the river-points on the two sides of the faults belong to different classes. The connection between these fault lines and the change of river sinuosity classes was detected in 23 points, along 16 structural lines The research is made in the frame of project OTKA-NK83400 (SourceSink Hungary). The European Union and the European Social Fund also have provided financial support to the project under the grant agreement no. TÁMOP 4.2.1./B-09/1/KMR-2010-0003.

  1. A study on the role and importance of irrigation management in integrated river basin management.

    Science.gov (United States)

    Koç, Cengiz

    2015-08-01

    The purpose of this paper is to identify the role and the importance of irrigation management in integrated river basin management during arid and semi-arid conditions. The study has been conducted at Büyük Menderes Basin which is located in southwest of Turkey and where different sectors (irrigation, drinking and using, industry, tourism, ecology) related to the use and distribution of water sources compete with each other and also where the water demands for important ecological considerations is evaluated and where the river pollution has reached important magnitudes. Since, approximately 73% of the water resources of the basin are utilized for irrigation; as a result, irrigation management becomes important for basin management. Irrigation operations have an effect on basin soil resources, water users, and environmental and ecological conditions. Thus, the determination of the role and importance of irrigation management require an integrated and interdisciplinary approach. In the studies conducted in Turkey, usually the environmental reactions have been analyzed in the basin studies and so the other topics related to integrated river basin management have not been taken into account. Therefore, this study also is to address these existing gaps in the literature and practice. PMID:26148688

  2. 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...

  3. The Titicaca basin: a paradigmatic region for multidisciplinary studies

    CERN Document Server

    Sparavigna, Amelia Carolina

    2010-01-01

    We propose a survey of the literature about archaeological and geophysical researches and on the paleoclimatology of the basin of Titicaca Lake, in connection with the agricultural system of the raised fields. Here again we discuss the use of Google Maps and satellite imagery as fundamental tools to understand this ancient agricultural system and its role in the history of pre-Incaic cultures.

  4. 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.

  5. Ensemble streamflow forecasting experiments in a tropical basin: The São Francisco river case study

    Science.gov (United States)

    Fan, Fernando Mainardi; Collischonn, Walter; Meller, Adalberto; Botelho, Luiz César Mendes

    2014-11-01

    The present study shows experiments of ensemble forecasting applied to a large tropical river basin, where such forecasting methodologies have many potential applications. The case study is the Três Marias hydroelectric power plant basin (Brazil), on the São Francisco river, where forecast results are particularly important for reservoir operation and downstream flood control. Results showed some benefits in the use of ensembles, particularly for the reservoir inflow on flooding events, and in comparison to the deterministic values given by the control member of the ensemble and by the ensemble mean. The study also discusses the improvements that must be tested and implemented in order to achieve better results, what is particularly important for the smaller basins within the study case. Despite the necessary improvements mentioned, the results suggest that benefits can result from the application of ensemble forecasts for hydropower plants with large basins within the Brazilian energy system.

  6. 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...

  7. Underground flux studies in waste basin of CIPC using natural and artificial tracers - v.1

    International Nuclear Information System (INIS)

    Underground flux studies in waste basin of CIPC is presented, with the description of the regions and the wells, the techniques with artificial tracers and the results and conclusion, based in field campaign realized till february/82. (author)

  8. Separation of hydrograph components using stable isotopes case study: Guvenc basin, Ankara

    International Nuclear Information System (INIS)

    In this paper, a stable environmental isotope study was carried out from analysis of water samples collected from rainfall, runoff (total discharge), springs (subsurface flows), and wells (groundwater) between 1996-2000. The research site was Guvenc basin located near Yenimahalle-Ankara having a drainage area of about 16.125 km2 . There are many representative hydrologic basins established in Turkey by the General Directorate of Rural Services (GDRS). In these basins, the precipitation and runoff values are recorded continuously and relationship between these values are also investigated in the last ten-twenty years. Guvenc basin, the study area, is one of these representative basins. On this basin, a stream gaging, station and five rain gages have been installed to collect and analyze runoff and rainfall data. A small dam was constructed at the outlet of the basin to store and provide water for distribution to agricultural areas. The characteristics of precipitation data are collected at raingage station, installed near the runoff measuring. To monitor the groundwater isotopic composition regular samples are also collected from a dug well near runoff station

  9. Water Allocation Challenges in Rural River Basins: A Case Study from the Walawe River Basin,Sri Lanka

    OpenAIRE

    Weragala, D. K. Neelanga

    2010-01-01

    This dissertation evaluates the water allocation challenges in the rural river basins of the developing world, where demands are growing and the supply is limited. While many of these basins have yet to reach the state of closure, their water users are already experiencing water shortages. Agricultural crop production in rural river basins of the developing world plays a major role in ensuring food security. However, irrigation as the major water consumer in these basins has low water use eff...

  10. THE FLOOD RISK IN THE IALOMITA RIVER BASIN CASE STUDY: THE JULY 1975 FLASH FLOOD

    OpenAIRE

    M. RETEGAN; MIHAELA BORCAN

    2014-01-01

    Te flood risk in the Ialomita river basin case study: the july 1975 flash flood. Since over the last four decades the Ialomita River Basin has been affected by several catastrophic hydrological events, of which the most important were the ones in 1975, 2001 and 2005, for a better management of the extreme situations generated by such episodes we propose a new methodology regarding the estimation of the flash-flood appearance potential in this particular river basin, as well as an analysis of ...

  11. Stratigraphic variations of lacustrine sediment gravity flow deposits and their recurrence intervals in the Middle Pleistocene Miyajima Formation, northeastern Japan: an implication for paleoenvironmental analysis

    Science.gov (United States)

    Sasaki, Hana; Onishi, Yuri; Ishihara, Yoshiro

    2016-04-01

    Lacustrine sediment gravity flow deposits have been proposed as archives for flood and earthquake events. Holocene lacustrine deposits are especially valuable because they can be correlated with historical records and other detailed paleoenvironmental indices. When sediment gravity flow deposits are intercalated in varved deposits, they can potentially be used for high resolution reconstruction of recurrence intervals of events in addition to environmental changes. The Shiobara Group in the Shiobara Basin, Tochigi Prefecture, northeastern Japan, consists of the upper Miyajima Formation and the lower Kamishiobara Formation. The Miyajima Formation includes varved deposits distributed at the center of the basin. These units are interpreted as lake floor deposits of the Paleo-Shiobara Caldera Lake. The varved deposits of the Miyajima Formation consist of cyclic repetitions of light-colored seasonal sub-layers mainly composed of diatoms (Stephanodiscus niagarae) and dark-colored seasonal sub-layers mainly composed of river inflow deposits. For this study, we measured lacustrine deposits of the Miyajima Formation and analyzed stratigraphic variation of varved deposits. Stratigraphic units of approximately 4 m in total thickness were studied, which included 416 events of sediment -gravity flow deposition over ca. 700 years. Sedimentary facies of the lacustrine sediment gravity flow deposits: The sediment gravity flow deposits can be classified by their erosional and internal features: whether they have an erosional base, whether they are graded, and whether they have rip-up clasts. Because high density currents were suggested from above features, most of the deposits are interpreted as the result of hyperpycnal flow. Also, the features suggest that the sediment gravity flow deposits originated from rivers around the lake. Stratigraphic variation of varved deposits: Average thicknesses of varves decrease from the lower and middle portions of the section to the upper part

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

    OpenAIRE

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

    2014-01-01

    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 mor...

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

    International Nuclear Information System (INIS)

    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

  14. Palynological study of the upper Devonian and lower carboniferous levels of the Illizi basin

    Energy Technology Data Exchange (ETDEWEB)

    Attar, A.; Fournier, J.; Candilier, A.M.; Coquel, R.

    To better define the hydrocarbon-bearing zones of the Algerian Sahara, geologists studied the microflora found in the Djebel Illerene, Issendjel, Asekaifaf, Oubarakat, and El Adeb Larache formations in the Illizi basin. The data distinguished six palynozones in the interval between the uppermost Devonian and the Namurian. The findings are compared with those by Lanzoni and Magloire (Grand Erg Occidental, Algerian Sahara) and Massa et al. (Rhadames Basin, western Libya).

  15. Paleoenvironmental and sclerochronological reconstruction of Crassostrea gryphoides Miocene biostromes from Crete island (Greece)

    Science.gov (United States)

    Koskeridou, E.; Agiadi, K.

    2012-04-01

    The mangrove oyster Crassostrea gasar (Adanson, 1757) is a keystone species mainly along the African Atlantic coasts. It forms biostromes on muddy coasts and typically associated with river mouths in the intertidal zone in depths of 0.60 up to 1 m1. Similarly, many biostrome structures of the fossilized Crassostrea gryphoides are found within Cenozoic deposits of Greece2. Since Crassostrea gasar is the phyllogenetically corresponding species of Crassostrea gryphoides, it is investigated whether the fossil biostromes formed under environmental conditions similar to those favored by modern Crassostrea gasar and if growth rate and longevity are comparable. A biostrome from the Tortonian of Heraklion district, Crete island (southern Greece) was studied to investigate the paleoenvironmental conditions and the life history of these oysters. The shells are big, ranging up to 40 cm in length, thick and positioned mainly horizontally. The biostrome is approximately 2 m in thickness and a few meters in length. Individual oysters, associated fauna and lithologic samples were collected. Paleoenvironmental interpretation was based on the analysis of the oyster taphonomy, the associated fauna and the sclerochronology/stable isotopic geochemistry of the oyster shells. The biostrome is observed in sandy marl which laterally contains Veneridae, Melongena, Terebralia bidentata and oligospecific microfossils, mainly Ammonia beccarii and Miliolids. Borings by many ichnotaxa occur on the external and internal surface of the oyster shells during the pre and /or post-mortem. Using a micromill, successive samples were taken along the hinge/ligament region of an oyster for isotopic analyses. The δ18O values ranged from -2.9 to 0.1. The wide range of values supports the interpretation of changing environmental conditions. The δ13C values ranged from -2.6 to -0.1. A correlation between δ18O and δ13C was observed. The profiles exhibit cyclicity with respect to isotopic and Sr/Ca ratios

  16. 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.

  17. The architecture of the Trofaiach pull-apart Basin (Eastern Alps): An integrated geophysical and structural study

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, W.; Sachsenhofer, R.F.; Kofler, N.; Decker, K. [Joanneum Research, Leoben (Austria). Inst. of Water Resources Management

    2004-08-01

    Te Trofaiach Basin was studied integrating different geophysical techniques (gravity, seismics, magnetics), digital elevation models, microtectonic and maturity data. Basin formation is related to the E-W trending Trofaiach strike slip fault, which enters the basin at its eastern tip. The northern basin margin is controlled by a terminating branch of this fault, while the main movement was transferred through the basin along subvertical faults in the central basin and along its southern rim. (Oblique) normal faults define the western basin margin. The basin depth reaches a maximum of 800 to 900 m. A fluvial and shallow lacustrine environment was interpreted from seismic facies and borehole data. Clinoform geometries and petrographic evidence indicate sediment supply mainly from the South. Localized coal seams developed in different stratigraphic positions. Several erosional events are part of the evolution of the basin. An early erosional phase followed southward tilting of the oldest basin fill and uplift of basement rocks north-west of the basin. A second event caused a major erosional unconformity in the central basin. Finally, related to post-Middle Badenian compression, more than 1 km of strata have been eroded.

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

    OpenAIRE

    Underdown, R; Redfern, J

    2008-01-01

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

  19. 3D NUMERICAL INVESTIGATION ON SETTLING BASIN LAYOUT: A case study on Mai Khola Hydropower Project, Nepal

    OpenAIRE

    Shrestha, Bishwo Vijaya

    2012-01-01

    This study is about 3D Numerical Investigation of Settling basin layout by using numerical modeling program SSIIM. This study is carried out by using SSIIM windows version 1 (SSIIM 1.0). SSIIM is numerical modeling software, developed at NTNU by Professor Nils Reidar B. Olsen. This program has been used for investigation numerical modeling of hydraulic and sediment transport for different layouts geometry of settling basin.In this study a case study has carried out on settling basin layout of...

  20. 3D NUMERICAL INVESTIGATION ON SETTLING BASIN LAYOUT : A case study on Mai Khola Hydropower Project, Nepal

    OpenAIRE

    Shrestha, Bishwo Vijaya

    2012-01-01

    This study is about 3D Numerical Investigation of Settling basin layout by using numerical modeling program SSIIM. This study is carried out by using SSIIM windows version 1 (SSIIM 1.0). SSIIM is numerical modeling software, developed at NTNU by Professor Nils Reidar B. Olsen. This program has been used for investigation numerical modeling of hydraulic and sediment transport for different layouts geometry of settling basin.In this study a case study has carried out on settling basin layout of...

  1. New insights into Gondwana paleography based on palinological data from Morro do Chaves Formation (Sergipe-Alagoas Basin, Brazil)

    Science.gov (United States)

    Gonçalves Garcia, Gustavo; Vasconcellos Garcia, Antônio Jorge; Henriques, Maria Helena

    2016-04-01

    The Sergipe-Alagoas basin (NE Brazil) has been widely studied in the frame of oil exploration, because it displays the most complete exposition of the stratigraphic sequences from the basins of the Brazilian continental margin. In this context, the aim of this workis to present the results of the bio-stratigraphic and paleo-environmental analysis of Morro do Chaves Formation (Lower Cretaceous), in Alagoas Sub-basin, part of the transitional section situated between the rift phase and restricted marine environment associated with the South Atlantic ocean opening. The material was analyzed from the palynological point of view and was collected in the InterCement quarry, located in São Miguel dos Campos, State of Alagoas. From 17 outcrop rock samples collected, nine had palynological content; among these only six were considered for biostratigraphic analysis purposes. In addition to outcrop samples, 28 samples were processed from four core drill. The paleoenvironmental analysis was based on the palynological content of the collected samples and on the paleontological and geological information available. The studied sedimentary package corresponds to carbonate and fine siliciclastic deposits, with approximately 70.0 m in thickness. The unit in question is formed by carbonatic "coquinóides" rocks interspersed with shale levels of dark green color. Palinofloristic assemblages were recuperated between 5.0 m and 70.0 m of the outcropping section. In the recovered material it was possible to identify 9 kinds of spores and 8 kinds of pollen grains, and two genera of fungi. Due to the degree of preservation of the material, age was established by the occurrence of Dicheiropollis etruscus specimens, which has enabled the recognition of the Dicheiropollis etruscus palinozone (upper Barremian). In microscopic observations under fluorescent light some algalic vesicles components were also recognized and classified as possible algae of the Prasinophyceae class, indicating

  2. Discriminating Between Tectonic and Climatic Controls on Early Hominin Paleoenvironments From the Koobi Fora Region, Northeastern Turkana Basin, Kenya: Part I

    Science.gov (United States)

    Lepre, C. J.; Quinn, R. L.

    2004-12-01

    Understanding controls on environmental records from Plio-Pleistocene Africa is critical for interpreting human origins. Recent geological studies from East Africa have focused on the relationship between Plio-Pleistocene patterns of hominin evolution, environmental change, and climate preserved in stratigraphic records of sedimentary basins (e.g. deMenocal, 2004; Wynn, 2004). Despite the fact that tectonics is a primary control on sedimentation in East African basins (e.g. Baker, 1986; Frostick, 1997), relatively few studies have either investigated its potential influence on early hominin evolution or attempted to discriminate between tectonic and climate controls on paleoenvironmental change. Presented is a study that explores these issues. Within the Koobi Fora Formation, between 4.0 and 2.5 Ma, environmental change is related to an overall trend of linear rates of tectonic subsidence. However, smaller-scale fluctuations in subsidence rates established lakes during times of increased subsidence followed by the transition to rivers during times of decreased subsidence and basin infilling (Feibel, 1994a, 2000). In contrast, environmental change during the period between 2.5 and 1.5 Ma was forced by changes in half-graben propagation, fault movement, and subsidence. This change is recorded within a stratigraphic sequence that is defined by major (erosional) boundary surface unconformities. The sequence is internally comprised of stable-lacustrine; stable-lacustrine, delta, and ephemeral-lacustrine; and fluvial environments of deposition. This environmental progression defines lowstand, transgressive, and highstand systems tracts respectively. Transition between systems tracts and depositional environments was controlled by rates of tectonic subsidence. The formation of stable-lacustrine environments of deposition during the lowstand systems tract was due to subsidence rates out-pacing sedimentation rates that was associated with a major tectonic event

  3. A quarter-million years of paleoenvironmental change at Bear Lake, Utah and Idaho

    Science.gov (United States)

    Kaufman, D.S.; Bright, Jordon; Dean, W.E.; Rosenbaum, J.G.; Moser, K.; Anderson, R. Scott; Colman, Steven M.; Heil, C.W., Jr.; Jiménez-Moreno, Gonzalo; Reheis, M.C.; Simmons, K.R.

    2009-01-01

    A continuous, 120-m-long core (BL00-1) from Bear Lake, Utah and Idaho, contains evidence of hydrologic and environmental change over the last two glacial-interglacial cycles. The core was taken at 41.95??N, 111.31??W, near the depocenter of the 60-m-deep, spring-fed, alkaline lake, where carbonate-bearing sediment has accumulated continuously. Chronological control is poor but indicates an average sedimentation rate of 0.54 mm yr-1. Analyses have been completed at multi-centennial to millennial scales, including (in order of decreasing temporal resolution) sediment magnetic properties, oxygen and carbon isotopes on bulk-sediment carbonate, organic- and inorganiccarbon contents, palynology; mineralogy (X-ray diffraction), strontium isotopes on bulk carbonate, ostracode taxonomy, oxygen and carbon isotopes on ostracodes, and diatom assemblages. Massive silty clay and marl constitute most of the core, with variable carbonate content (average = 31 ?? 19%) and oxygen-isotopic values (??18O ranging from -18??? to -5??? in bulk carbonate). These variations, as well as fluctuations of biological indicators, reflect changes in the water and sediment discharged from the glaciated headwaters of the dominant tributary, Bear River, and the processes that influenced sediment delivery to the core site, including lake-level changes. Although its influence has varied, Bear River has remained a tributary to Bear Lake during most of the last quarter-million years. The lake disconnected from the river and, except for a few brief excursions, retracted into a topographically closed basin during global interglaciations (during parts of marine isotope stages 7, 5, and 1). These intervals contain up to 80% endogenic aragonite with high ??18O values (average = -5.8 ?? 1.7???), indicative of strongly evaporitic conditions. Interglacial intervals also are dominated by small, benthic/tychoplanktic fragilarioid species indicative of reduced habitat availability associated with low lake levels

  4. 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.

  5. Analytical data from phases I and II of the Willamette River basin water quality study, Oregon

    Science.gov (United States)

    Harrison, Howard E.; Anderson, Chauncey W.; Rinella, Frank A.; Gasser, Timothy M.; Pogue, Ted R., Jr.

    1995-01-01

    This report presents trace-element, organic-compound (pesticides, volatile and semivolatile organic compounds, and dioxin and furan compounds), and nutrient concentration data from the analyses of water column, suspended-sediment, and bed-sediment samples collected by the U.S. Geological Survey as part of Phases I and II of the comprehensive Willamette River Basin Water Quality Study in western Oregon. The overall study was designed by the Oregon Department of Environmental Quality to acquire the technical and regulatory knowledge necessary to protect and enhance water quality in the Willamette River Basin.

  6. 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.

  7. Designing principles of an ecological water storage basin on coastal saline: a case study

    Institute of Scientific and Technical Information of China (English)

    LIU Ping-ping; YIN Cheng-qing; QU Jiu-hui; ZHANG Guang-yun; FENG Wen-qing; LIU Jun-xin; ZHONG Zhi

    2005-01-01

    The degradation of water source environment becomes serious problems accompanying with rapid urbanization in China.Ecological engineering provides ecologically sound and cost-effective solution to solving this problem. As a case study, a 15 hm2 ecological water storage basin for a water plant was designed and constructed on the TEDA area in Tianjin City. Located on saline, the construction of this project has to face serious difficulties, such as high salinity, scarce seed banks of macrophytes, and strong winds. Freshwater replacement, soil emendation and macrophytes planting at the basinshore, wooden water breaker and plastic membrane installation and other measures were conducted for the assistance of plant community establishment. The result showed that the chloride concentration in the basin water decreased from 11600 mg/L to less than 100 mg/L, and the chloride content in the basin sediment decreased from 2.1% to0.35 % after freshwater soaking. The introduced macrophytes of 8 species all survived and 11 other macrophytes species were occurred in the basin. A new ecosystem was created with increased biological diversity in the original saline, and the water quality was improved. This ecological water storage basin also provided a pleasing landscape for local people.

  8. Digital-model study of ground-water hydrology, Columbia Basin Irrigation Project Area, Washington

    Science.gov (United States)

    Tanaka, H.H.; Hansen, A.J., Jr.; Skrivan, J.A.

    1974-01-01

    Since 1952 water diverted from the Columbia River at Grand Coulee Dam has been used to irrigate parts of the Columbia Basin Irrigation Project area in eastern Washington, and as a result ground-water levels generally have risen in the area. The rapid increases in ground-water inflow, outflow, and storage from irrigation have created a need for a better understanding of the ground-water system before and after the start of irrigation to establish guidelines necessary for management of the area's ground-water resource. Data and information from previous geologic and hydrologic studies were used as a basis for quantitative analyses of ground-water inflow and outflow by means of digital computer models representing three major areas--Quincy Basin, Pasco Basin, and Royal Slope.

  9. Study on tertiary in-situ leachable uranium mineralization conditions in South Songliao basin

    International Nuclear Information System (INIS)

    Tertiary in-situ leachable mineralization in Songliao Basin was analyzed in theory in the past. Since 1998, regional investigation at 1:200000 scale has been done with about 120 holes drilled. Based on drill holes recording, section compiling and sample analysis, the authors investigate into the Tertiary in-situ leachable conditions including rock character, sedimentary facies, rock chemistry, organic substances, uranium content, sandstone porosity, sandstone bodies, interlayer oxidation, and hydro-dynamic value. The study would play important role in prospecting for in-situ leachable uranium in South Songliao basin

  10. 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. PMID:19184706

  11. 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.

  12. BASINS and WEPP Climate Assessment Tools (CAT): Case Study Guide to Potential Applications (External Review Draft)

    Science.gov (United States)

    This draft report supports application of two recently developed water modeling tools, the BASINS and WEPP climate assessment tools. The report presents a series of short case studies designed to illustrate the capabilities of these tools for conducting scenario based assessments...

  13. Paleo relief study of insular shelf electric sounding in Amarillo level basin Rivera distric in Uruguay

    International Nuclear Information System (INIS)

    In the framework of the Uranium project the geophysical team composed by BRGM and DINAMIGE members have carried out a study of insular shelf morphology. It was a sedimentary basin level in the middle of the Isla Cristalina. The following topics were developed: geographical location, geologic framework, developed works and materials, methods and results

  14. Computerized processing of Kosovo Coal Basin on a study scale. [Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Jovicic, R.

    1983-01-01

    This paper is the first of a series dealing with the computerized processing of the Kosovo Coal Basin. A study programme was initiated requiring the collection and processing of material to form as comprehensive a data base as possible. The project did not include a detailed analysis of the information, which dealt with coal, overburden, hydrological conditions, land costs, compension for subsidence, communications, etc.

  15. 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)

    Bernhard Barraqué

    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.

  16. The Greenland ice sheet margin as a source of paleo-environmental data

    International Nuclear Information System (INIS)

    Oxygen-18 records measured on surface ice samples from Greenland ice sheet margins show that ice of pre-Holocene age is present at many locations along the ice margin. Several records have been obtained from West, North, and Northeast Greenland. At all locations where pre-Holocene ice is found, it constitutes a band running parallel to the ice edge. However, the width of the band varies greatly from one location to another, ranging between 30 m and 1,500 m. So far, the most detailed oxygen-18 record has been obtained from a West Greenland ice margin location. It spans the last glacial (the Wisconsinan), the last inter-glacial (Sangamon, Eem), and part of the previous glacial (the Illinoian). A correlation with the oxygen-18 records from the Greenland deep ice cores from Camp Century and Dye-3 indicates that neither of these records reach back to the previous glacial, probably due to substantial thinning and retreat of the ice sheet in North and South Greenland in the Eemian inter-glacial. The oxygen-18 record has been translated into a Greenland temperature record covering the past 150,000 years. The isotopic temperatures indicate large temperature variations in marine isotopic stage 5, with a climate warmer than at present not only in sub-stage 5c, but also in sub-stage 5c and in a short period of sub-stage 5a. The ice margin studies indicate that Greenland ice sheet margins have a large potential as sources of paleo-environmental information. Large volumes of ice can easily be mined e.g. for Carbon-14 dating and other measurements that require large amounts of ice. Therefore, ice margin studies are an important supplement to deep drilling programs in the interior regions of the ice sheet

  17. Heat transfer and fluid flow modelling in supra-detachment basins: a case study of the Devonian basins of western Norway

    Science.gov (United States)

    Souche, A.; Dabrowski, M.; Andersen, T. B.; Medvedev, S.

    2012-04-01

    The Devonian basins of western Norway are supra-detachment basins located above a large crustal-scale detachment system, so-called the Nordfjord Sogn Detachment Zone. These basins are characterised by a thick succession (>10km) of siliciclastic sediments ranging in size from coarse conglomerates to fine grain sandstones and organized into narrow half-graben systems. Their architecture and geometry is closely controlled by the development of the coeval (i.e. Early to Middle Devonian) detachment acting as a normal fault/shear zone beneath the basins. The exhumation of rocks within the footwall of the detachment was subsequently followed by an increase of the geothermal gradient at the base of the sedimentary successions. Shear heating resulting from the intense rock deformation within the shear zone also played a role in increasing the temperature at the base of the basins. These two significant processes might have in turn contributed to the fluid mobility in the basins. In this study, we explore the feasibility of porous convection to occur spontaneously in sedimentary basins due to a regional increase of the geothermal gradient. Such process can be approximated by Darcy flow through porous media where the fluid density in the system might introduce a buoyancy-driven instability between lighter hot fluids at the base and denser cold fluids at the top of the basin. In geological systems porous flow might be inhibited by the closing of pores with depth, which leads to a reduced permeability and a limited amount of heat carrying fluids. Also, geological heterogeneities inherited from the layered structure of the sedimentary strata introduce large variations in the rock transport properties. We address these problems numerically by modelling heat and mass transport in porous media assuming quasi-incompressible Darcy flow. The fluid (water) density, viscosity, and specific heat are computed from the pore fluid pressure and the temperature. We investigate the onset of

  18. New insights in postglacial paleoclimatic and paleoenvironmental changes in Central Europe derived from isotope analyses of laminated lake sediments and peat deposits

    International Nuclear Information System (INIS)

    Isotope ratio determinations in concert with geochemical and palynological analyses performed on material from German continental archives (lake sediments, peat cores) provided information about paleoclimatic and paleoenvironmental changes in Central Europe throughout the last 15,000 years. Oxygen isotope ratio variations of (i) bulk carbonates from lake sediments (Lake Steisslingen) and of (ii) cellulose extracted from peat cores suggest the following climatic trends: an early postglacial climate optimum in the Boelling; a distinct cooling phase during the Younger Dryas; an early Holocene warming period in the Preboreal; another warming phase in the Boreal leading into the mid-Holocene warm period; a gradual decrease of mean annual air temperatures since the mid- Holocene warm period. Evaluation of other isotopic proxy data in concert with geochemical and palynological information revealed that the above-described climatic variations in Central Europe triggered marked paleoenvironmental changes in the study region between the Boelling and the onset of the mid-Holocene warm period. Elevated organic carbon contents in lake sediments and increasing δ13C values of organic carbon were typically associated with climatic warm phases and seem to indicate enhanced in-lake productivity. Pollen counts and biomarker data suggest a predominance of Betula during climatic warm phases and a predominance of Pinus during colder periods. The Mid Younger Dryas event was observable in pollen and biomarker data, but oxygen isotope ratios of bulk carbonates from Lake Steisslingen did not record temperature variations at that time. The data presented for the chronozones Bolling through Boreal provide evidence that the elucidation of paleoclimatic and paleoenvironmental variations on our continents can benefit greatly from a joint interpretation of isotope analyses, palynological evidence, and inorganic and organic geochemistry data derived from continental archives. (author)

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

    OpenAIRE

    Da-wei Zhang; Jin Quan; Hong-bin Zhang; Fan Wang; Hong Wang; Xiao-yan He

    2015-01-01

    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 t...

  20. ENVIRONMENTAL STUDIES IN THE NEMUNAS RIVER BASIN, LITHUANIA

    Science.gov (United States)

    Selected research results from a joint environmental studies project that began in 1988 between Lithuania and the United States of America are presented. hemical and hydrological studies address hazardous chemicals, including trace metals, n surface waters of Lithuania; methods f...

  1. 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

  2. Evaluation of seismic reflection data in the Davis and Lavender Canyons study area, Paradox Basin, Utah

    International Nuclear Information System (INIS)

    Seismic reflection data purchased from petroleum industry brokers and acquired through group speculative surveys were interpreted for information on the regional subsurface geologic structure and stratigraphy within and surrounding the Davis and Lavender Canyons study area in the Paradox Basin of southeastern Utah. Structures of interest were faults, folds, joints, and collapse structures related to salt dissolution. The seismic reflection data were used to interpret stratigraphy by identifying continuous and discontinuous reflectors on the seismic profiles. Thickening and thinning of strata and possible areas of salt flowage or dissolution could be identified from the seismic data. Identifiable reflectors included the tops of the Precambrian and Mississippian, a distinctive interbed close to the middle of the Pennsylvanian Paradox salt formation (probably the interval between Salt Cycles 10 and 13), and near the top of the Paradox salt. Of the 56 faults identified from the seismic reflection interpretation, 33 trend northwest, west-northwest, or west, and most affect only the deeper part of the stratigraphic section. These faults are part of the deep structural system found throughout the Paradox Basin, including the fold and fault belt in the northeast part of the basin. The faults bound basement Precambrian blocks that experienced minor activity during Mississippian and early Pennsylvanian deposition, and showed major displacement during early Paradox salt deposition as the Paradox Basin subsided. Based on the seismic data, most of these faults appear to have an upward terminus between the top of the Mississippian and the salt interbed reflector

  3. Sensitivity and uncertainty in crop water footprint accounting: A case study for the Yellow River Basin

    OpenAIRE

    Zhuo, L.; M. M. Mekonnen; A. Y. Hoekstra

    2013-01-01

    Water Footprint Assessment is a quickly growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of water footprint estimates to changes in important input variables and quantifies the size of uncertainty in water footprint estimates. The study focuses on the green and blue water footprint of producing maize, soybean, rice and wheat in the Yellow River Basin in the period 1996-2005. A grid-based daily water bal...

  4. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River basin

    OpenAIRE

    Zhuo, L.; M. M. Mekonnen; A. Y. Hoekstra

    2014-01-01

    Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t−1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat at the scale of the Yellow River basin in the p...

  5. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River Basin

    OpenAIRE

    Zhuo, L.; M. M. Mekonnen; A. Y. Hoekstra

    2014-01-01

    Water Footprint Assessment is a quickly growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of water footprint estimates to changes in important input variables and quantifies the size of uncertainty in water footprint estimates. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat in the Yellow River Basin in the period 1996...

  6. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River Basin

    OpenAIRE

    Zhuo, L.; M. M. Mekonnen; A. Y. Hoekstra

    2014-01-01

    Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t−1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat at the scale of the Yellow River basin in the p...

  7. Onshore offshore correlation of Pleistocene rhyolitic eruptions from New Zealand: implications for TVZ eruptive history and paleoenvironmental construction

    Science.gov (United States)

    Alloway, Brent V.; Pillans, Brad J.; Carter, Lionel; Naish, Tim R.; Westgate, John A.

    2005-08-01

    , and their correlation to Wanganui Basin and other onshore sites is a significant advance as it provides: (1) an even more detailed history of the TVZ than can be currently achieved from the near-source record, (2) a high-resolution tephrochronologic framework for future onshore-offshore paleoenvironmental reconstructions, and (3) well-dated tephra beds correlated from the offshore ODP sites with astronomically tuned timescales provide an opportunity to critically evaluate the chronostratigraphic framework for onshore Plio-Pleistocene sedimentary sequences (e.g. Wanganui Basin, cf. Naish et al. [1998. Quaternary Science Reviews 17 695-710].

  8. Diacritical Seismic Signatures for Complex Geological Structures: Case Studies from Shushan Basin (Egypt and Arkoma Basin (USA

    Directory of Open Access Journals (Sweden)

    Mohamed I. Abdel-Fattah

    2014-01-01

    Full Text Available Seismic reflection techniques show an imperative role in imaging complex geological structures and are becoming more acceptable as data interpreting tools in 2D/3D view. These subsurface geological structures provide complex seismic signature due to their geometrical behavior. Consequently, it is extremely difficult to interpret these seismic sections in terms of subsurface configuration. The main goal of this paper is to introduce seismic attributes as a powerful tool to interpret complex geological structures in different geological settings. In order to image these complex geological features, multiple seismic attributes such as coherence and curvature have been applied to the seismic data generated over the Shushan Basin (Egypt and Arkoma Basin (USA. Each type of geological structure event usually generates a unique seismic “signature” that we can recognize and identify by using these seismic attributes. In Shushan Basin (Egypt, they provide a framework and constraint during the interpretation and can help prevent mistakes during a 3D structural modeling. In Arkoma Basin (USA, the seismic attributes results provide useful information for broader analyses of the complex structural relations in the region where the Ouachita orogenic belt intersects with the southern Oklahoma aulacogen. Finally, complex geological structures provide dramatically diacritical seismic signatures that can be easily interpreted by collaborating conventional seismic interpretation techniques with multiple seismic attributes.

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

    Institute of Scientific and Technical Information of China (English)

    WU; Chonglong(吴冲龙); WANG; Xinqing(汪新庆); LIU; Gang(刘刚); LI; Shaohu(李绍虎); MAO; Xiaoping(毛小平); LI; Xing(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

  10. 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.

  11. Alpine lake sediment archives and catchment geomorphology : causal relationships and implications for paleoenvironmental reconstructions

    OpenAIRE

    Rubensdotter, Lena

    2006-01-01

    Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. The aim of this project was to enhance the understanding of minerogenic lake sedimentation in alpine lakes and improve their use as environmental archives. Catchment ge...

  12. Occurrence of greigite in the Pliocene sediments of Lake Qinghai, China, and its paleoenvironmental and paleomagnetic implications

    Science.gov (United States)

    Fu, Chaofeng; Bloemendal, Jan; Qiang, Xiaoke; Hill, Mimi J.; An, Zhisheng

    2015-05-01

    Lake Qinghai in North China is the largest interior plateau lake in Central Asia and is climatically sensitive. An almost continuous 626 m long sediment core was drilled in an infilled part of the southern lake basin of Lake Qinghai. The magnetic susceptibility record reveals the presence of two distinct peaks within an interval of fine-grained lacustrine sediments of Lower Pliocene age. We selected a depth interval of approximately 40 m spanning the magnetic susceptibility peaks for detailed rock magnetic and geochemical analyses in order to identify the magnetic mineralogy responsible and to assess its possible paleoenvironmental and paleomagnetic implications. Rock magnetic, X-ray diffraction analysis, scanning electron microscopy (SEM), and energy dispersive analysis of X-ray (EDAX) analyses reveal that the main magnetic carrier is greigite (Fe3S4). The greigite is of early diagenetic origin and formed in an inerval of high lake level and inferred relatively warm, humid climate. The greigite-enriched zones are separated by an interval of relatively high total sulfur and organic carbon content, and we infer that in the adjacent greigite-bearing zones, the lower concentrations of sulfur and organic carbon, and high levels of reactive iron, arrested the process of pyritization resulting in the preservation of the greigite on a time scale of several million years. The greigite zones contain narrow intervals of normally magnetized sediments which may be previously unrecognized cryptochrons within the Gilbert Chron, or alternatively they may reflect the continued formation of greigite long after the age of deposition of the surrounding sediment matrix.

  13. 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.

  14. Regional summary and recommended study areas for the Texas Panhandle portion of the Permian Basin

    International Nuclear Information System (INIS)

    This report summarizes the regional geologic and environmental characterizations that have been completed for the Permian region of study, and describes the procedure used to identify study areas for the next phase of investigation. The factors evaluated in the Permian region fall into three broad areas: health and safety, environmental and socioeconomic, and engineering and economic considerations. Health and safety considerations included salt depth and thickness, faults, seismic activity, groundwater, salt dissolution, energy and mineral resources, presence of boreholes, and interactive land uses. Salt depth and thickness was the key health and safety factor, and when mapped, provded to be a discriminator. The evaluation of environmental and socioeconomic conditions focused primarily on the presence of urban areas and on designated land uses such as parks, wildlife areas, and historic sites. Engineering and economic considerations centered primarily on salt depth, which was already evaluated in the health and safety area. The Palo Duro and Dalhart basins are recommended for future studies on the basis of geology. In these two basins, salt depth and thickness appear promising, and there is less likelihood of past or future oil and gas exploratory holes. Environmental and socioeconomic factors did not preclude any of the basins from further study. 66 references, 16 figures, 2 tables

  15. Visual aesthetics study: Gibson Dome area, Paradox Basin, Utah

    International Nuclear Information System (INIS)

    The Visual Aesthetics study was performed as an initial assessment of concerns regarding impacts to visual resources that might be associated with the construction of a geologic nuclear waste repository and associated rail routes in the Gibson Dome location of southeastern Utah. Potential impacts to visual resources were evaluated by predicting visibility of the facility and railway routes using the US Forest Service (USFS) computer program, VIEWIT, and by applying the Bureau of Land Management (BLM) Visual Resource Management (VRM) methodology. Five proposed facility sites in the Gibson Dome area and three proposed railway routes were evaluated for visual impact. 10 references, 19 figures, 5 tables

  16. THE HUMAN RISKS CAUSED BY DEINDUSTRIALI-SATION. CASE STUDY: CERNA RIVER BASIN (HUNEDOARA COUNTY

    Directory of Open Access Journals (Sweden)

    G. C. SOFIA

    2015-03-01

    Full Text Available Human Risks caused by deindustrialization. Case Study: Cerna River Basin (Hunedoara County. Industrial restructuring during economic transition has affected the population, causing loss of jobs, reduced income, increased poverty and emphasizing social inequalities and marginalization phenomenon. These have led to population decline, massive emigration, difficulties in finding a job as well as an increased incidence of certain diseases, negatively influencing socio-economic development of the area.

  17. Isotope hydrology study of Kalamos region (Attiki) and of the Assopos river basin

    International Nuclear Information System (INIS)

    The isotopic composition of the water was used to determine the mechanism of recharge of the Assopos river basin and that of the Kalamos springs issuing brackish water near the coast. The results of the study permitted the catchment of the water before its salinization. A quantity of 73000 m3 per day is now pumped and used as additional drinkable water for the major area of Athens covering about the 1/6 of the corresponding mean daily consumption. (T.A.)

  18. SMART-1/CLEMENTINE Study of Humorum and Procellarum Basins

    Science.gov (United States)

    Carey, William; Foing, Bernard H.; Koschny, Detlef; Pio Rossi, Angelo; Josset, Jean-Luc

    A study undertaken by ESA to define a European Reference Architecture for Space Exploration is due to be completed in September 2008. The development of this architecture over the past twelve months has identified a number of key capabilities, among them a lunar lander system, which could form the basis for Europe's contribution to the future exploration of space in collaboration with International Partners. The focus of this paper will be on the lunar lander system, and will present the results of an analysis of possible payloads that could be accommodated by the lander. As the industrial study is at the Phase 0 or Pre-Phase A level, the design of such a lander system is at a very early stage in its development, but an estimation of the payload capacity allows a general assessment of the types of possible payloads that could be carried, currently this capacity is estimated at 1.1 tonnes of gross payload mass to the lunar surface (assuming an Ariane 5 ECA launch). An important characteristic of the lunar lander is that it provides a versatile and flexible system for utilisation in a broad range of lunar missions which include: - Independent lunar exploration missions for science, technology demonstration and research. - Delivery of logistics and cargo to support human surface sortie missions. - Delivery of logistics to a lunar base/outpost. - Deployment of individual infrastructure elements in support of a lunar base/outpost. Based on the above different types of missions, a number of configurations of "reference payload" sets are in the process of being defined that cover specific exploration objectives related primarily to capability demonstration, exploration enabling research and enabled science. Aspects covered include: ISRU, robotics, mobility, human preparation, life science and geology. This paper will present the current status of definition of the Reference Payload sets.

  19. Environmental isotope and hydrochemical study of the shallow and deep groundwater in the Azraq Basin, Jordan

    International Nuclear Information System (INIS)

    Since the country depends mostly on ground water resources especially for domestic water supply, investigation and management of the limited water resources takes importance and priority on governmental level as well as for the decision makers in the water Authority of Jordan. Azraq basin took importance in the whole water policy of the country, since the ground water abstraction for different water uses influences the natural environment of the Azraq Oasis. One of the aims of the study is to define the origin and source of recharge of AWSA water supply well field and the interrelationship between the Azraq depression and the situation in northern Azraq basin. Also quantitative and qualitative identification of the interrelationship between the upper and the deep aquifers become necessary. Many springs and wells in the Azraq area have been sampled for isotope analyses during the past 30 years by independent projects. The isotope analyses for the present project have been carried out by the Isotope Laboratory of the Water Authority of Jordan. This is existed within the frame work of the IAEA Regional Technical Cooperation Project entitled ''Isotope Hydrology in the Middle East''. Some hydrological and hydrogeological data from the Water Resources Studies Department of the Water Authority of Jordan have been used in the interpretation and evaluation. The overall evaluation of the environmental isotope data for both upper and deep aquifer systems in Azraq basin is presented in this study. (author). 7 refs, 18 figs, 3 tabs

  20. Study on Basin-Filling and Reservoir Sedimentology of Zhu Ⅲ Depression of Pearl River Mouth Basin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Through basin-filling analysis, one coarsening-upward and two fining-upward sequences have been identified in Zhu Ⅲ depression. In accondance with the general model proposed by Ravnas and Steel (1998), the basin-filling has two large cycles-rift (sediment-balanced and -overfilied)and postrift (sediment-underfilled and -starved). During the rifting process, the rifted lake developed through three stages: early, climax and late. The sedimentary characteristics of reservoir rocks show that barrier bar, lagoon and tidal channel facies well developed in Zhuhai Formation;offshore, tidal and barrier bar well developed in Zhujiang Formation. Neighborly, Shenhu , Wenchang and Enping formations deposited in rifted lakes during Paleogene time ; Zhujiang Formation deposited in bay, lagoon and shorefnce in late Paleogene. Zhujiang and other formations deposited in offshore and open shallow sea to shelf.

  1. Powder River Basin Coalbed Methane Development and Produced Water Management Study

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Resources International

    2002-11-30

    Coalbed methane resources throughout the entire Powder River Basin were reviewed in this analysis. The study was conducted at the township level, and as with all assessments conducted at such a broad level, readers must recognize and understand the limitations and appropriate use of the results. Raw and derived data provided in this report will not generally apply to any specific location. The coal geology in the basin is complex, which makes correlation with individual seams difficult at times. Although more than 12,000 wells have been drilled to date, large areas of the Powder River Basin remain relatively undeveloped. The lack of data obviously introduces uncertainty and increases variability. Proxies and analogs were used in the analysis out of necessity, though these were always based on sound reasoning. Future development in the basin will make new data and interpretations available, which will lead to a more complete description of the coals and their fluid flow properties, and refined estimates of natural gas and water production rates and cumulative recoveries. Throughout the course of the study, critical data assumptions and relationships regarding gas content, methane adsorption isotherms, and reservoir pressure were the topics of much discussion with reviewers. A summary of these discussion topics is provided as an appendix. Water influx was not modeled although it is acknowledged that this phenomenon may occur in some settings. As with any resource assessment, technical and economic results are the product of the assumptions and methodology used. In this study, key assumptions as well as cost and price data, and economic parameters are presented to fully inform readers. Note that many quantities shown in various tables have been subject to rounding; therefore, aggregation of basic and intermediate quantities may differ from the values shown.

  2. Powder River Basin Coalbed Methane Development and Produced Water Management Study

    International Nuclear Information System (INIS)

    Coalbed methane resources throughout the entire Powder River Basin were reviewed in this analysis. The study was conducted at the township level, and as with all assessments conducted at such a broad level, readers must recognize and understand the limitations and appropriate use of the results. Raw and derived data provided in this report will not generally apply to any specific location. The coal geology in the basin is complex, which makes correlation with individual seams difficult at times. Although more than 12,000 wells have been drilled to date, large areas of the Powder River Basin remain relatively undeveloped. The lack of data obviously introduces uncertainty and increases variability. Proxies and analogs were used in the analysis out of necessity, though these were always based on sound reasoning. Future development in the basin will make new data and interpretations available, which will lead to a more complete description of the coals and their fluid flow properties, and refined estimates of natural gas and water production rates and cumulative recoveries. Throughout the course of the study, critical data assumptions and relationships regarding gas content, methane adsorption isotherms, and reservoir pressure were the topics of much discussion with reviewers. A summary of these discussion topics is provided as an appendix. Water influx was not modeled although it is acknowledged that this phenomenon may occur in some settings. As with any resource assessment, technical and economic results are the product of the assumptions and methodology used. In this study, key assumptions as well as cost and price data, and economic parameters are presented to fully inform readers. Note that many quantities shown in various tables have been subject to rounding; therefore, aggregation of basic and intermediate quantities may differ from the values shown

  3. A Study on the Biodiversity of Natural Food Production to Support Community Upstream of Chi Basin, Thailand

    OpenAIRE

    Pramuk Srichaiwong; Luckhana Kwewjai; Patarapong Kroeksakul

    2013-01-01

    This biodiversity study of natural food production to supporting the communities upstream of Chi River Basin aims at collecting the name and species of natural food plants in the forest around the upstream areas of Chi River Basin. This is a phenomenal study of species and potential benefits of forest food. Qualitative methodology was mainly used to collect data; the study relied on the knowledge of the local people had to recall the local data, which significantly focused on the species of n...

  4. Effect of rainfall variability on the hydrological behavior of urban basins : A simulation study based on weather radar data

    OpenAIRE

    MORENA, F; Andrieu, H.; RODRIGUEZ, F; CREUTIN, JD

    2002-01-01

    The objective herein is to study the influence of the spatial rainfall variability on the resulting variability of the unit hydrograph of urban basins. This simulation study concerns two basins of surface areas of 460 ha and 180 ha represented by a distributed rainfall-runoff model. The forcing of the model with radar rainfall measurements at a 250 m spatial resolution is studied and compared with the forcing of the model with spatially uniform rainfall rates. A theoretical formulation,...

  5. 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. PMID:19609693

  6. Hydrogeological study in the catalonian potassic tertiary basin. Sallent-Barcelona, Spain

    International Nuclear Information System (INIS)

    The Catalonian Potassic Basin is described as a tick regressive-sedimentary Tertiary basin that includes marine, evaporitic-transitional and continental facies, overlying by no-consolidated quaternary alluvial sediments. The intense underground mining activity used in the exploitation of salts with rich K contents in the CPC during the last century, has provoked some problems related to surface and groundwater contamination and the existence of subsidence areas. The objective of the hydrogeological studies in the CPC area are focused in the characterization of the Tertiary aquifer and the definition of their conceptual model of behaviour. The last challenge of the project is to determine the relationship between subsidence and hydrogeology in these salt bodies. (Author) 14 refs.

  7. 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.

  8. An isostatic study of the Karoo basin and underlying lithosphere in 3-D

    Science.gov (United States)

    Scheiber-Enslin, Stephanie E.; Ebbing, Jörg; Webb, Susan J.

    2016-08-01

    A 3-D density model of the crust and upper mantle beneath the Karoo basin is presented here. The model is constrained using potential field, borehole and seismic data. Uplift of the basin by the end of the Cretaceous has resulted in an unusually high plateau (>1000 m) covering a large portion of South Africa. Isostatic studies show the topography is largely compensated by changes in Moho depths (˜35 km on-craton and >45 km off-craton) and changes in lithospheric mantle densities between the Kaapvaal Craton and surrounding regions (˜50 kg m-3 increase from on- to off-craton). This density contrast is determined by inverted satellite gravity and gravity gradient data. The highest topography along the edge of the plateau (>1200 m) and a strong Bouguer gravity low over Lesotho, however, can only be explained by a buoyant asthenosphere with a density decrease of around 40 kg m-3.

  9. 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).

  10. 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.

  11. Study on soil erosion in Hudan River basin based on TM imagery

    Science.gov (United States)

    Chao, Zhenhua; Yang, Yongshun; Gao, Xiaohong

    2014-11-01

    Huangyuan county is located in the eastern part of Qinghai province and is the transition zone of Loess Plateau and Qinghai-Tibet Plateau. While the ecological environment in Huangyuan county is fragile and is mainly characterized as serous soil erosion, frequent natural disasters. It is very important to study the soil erosion. Hudan river basin was selected to study the soil erosion in Huangyuan county. The soil erosion information was extracted from Landsat 5 TM data in 1987, 2000 and 2010. To classify and grade soil erosion was according to the classification standard, Classification Standard for Soil Erosion, issued by the Ministry of Water Resources of the People's Republic of China. The types of soil erosion in the basin were classified as water erosion, freeze-thaw erosion and engineering erosion based on TM imagery, field survey and historical data. Water erosion was the most important part and accounted for more than 90% of the whole area. Weak water erosion increased significantly during the period, mainly distributing in the north of the basin. Slight-degree water erosion increased from 1987 to 2000, while there was a steep reduce during the period from 2000 to 2010. Freeze-thaw erosion distributed mainly in northern areas with high altitude. What Engineering erosion affected were narrow valley areas suitable for human settlements and agricultural production.

  12. Provenance study of the Castellanos and Migues formation: Santa Lucia basin, Uruguay

    International Nuclear Information System (INIS)

    A geochemical provenance study was conducted on the shales of Castellanos and Migues formations (Lower Cretaceous), which conform part of the filling of the Santa Lucía basin, southwest of Uruguay. The main features observed indicate that the shales are dominated by illite and smectite, subordinately appears kaolinite. Besides, feldspar, hematite and calcite are observed. Shale chemical composition is enriched in Cr and V with respect to the PAAS, NASC and Upper Continental Crust. From the application of the geochemical indexes of alteration (CIA, CIW and ICV) and of ternary diagrams ACNK and ACNK-FM, a low weathering degree is determined for the source areas, together with compositional immaturity. The use of other geochemical indexes and diagrams of geotectonic discrimination and source rock shows similar chemical composition with respect to the Río de la Plata Craton lithologies, which were established as the basin source rocks. It is concluded that the climatic conditions were arid to semi-arid with variable humidity at the time of the deposition. In addition, the establishment of Río de la Plata Craton as the basin source area suggests that the craton was not covered by Paleozoic sediments at the time of deposition of the studied units

  13. Provenance study of the Castellanos and Migues formation: Santa Lucia basin, Uruguay

    International Nuclear Information System (INIS)

    A geochemical provenance study was conducted on the shales of Castellanos and Migues formations (Lower Cretaceous), which conform part of the filling of the Santa Lucia basin, southwest of Uruguay. The main features observed indicate that the shales are dominated by illite and smectite, subordinately appears kaolinite. Besides, feldspar, hematite and calcite are observed. Shale chemical composition is enriched in Cr and V with respect to the PAAS, NASC and Upper Continental Crust. From the application of the geochemical indexes of alteration (CIA, CIW and ICV) and of ternary diagrams ACNK and ACNK-FM, a low weathering degree is determined for the source areas, together with compositional immaturity. The use of other geochemical indexes and diagrams of geo tectonic discrimination and source rock shows similar chemical composition with respect to the Rio de la Plata Craton lithologies, which were established as the basin source rocks. It is concluded that the climatic conditions were arid to semi-arid with variable humidity at the time of the deposition. In addition, the establishment of Rio de la Plata Craton as the basin source area suggests that the craton was not covered by Paleozoic sediments at the time of deposition of the studied units

  14. Study of silting on basin streams of Bodocongó, Campina Grande, State of Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Joelma Sales Santos

    2008-12-01

    Full Text Available The study aimed to produce thematic maps that reflect the expansion of space-time silting of the basin's Creek Bodocongó for the period from 1989 to 2007. The study area is located in the marsh west of the state of Paraiba in the city of Campina Grande. Analysis of images TM/Landsat-5, SSC / CBERS - 2 and data from work the field were made. The digital processing of Landsat images was performed from SPRING - 4.3. The results showed that the basin presented a reduction in the mirror of the water dam around 19% over 18 years. Between the years 1989 and 2007, this dam had 27.28 ha of mirror of water, already in April 2007 this area was reduced to 22.17 ha, according to analysis from CBERS images. The silting is one of the most aggravating consequences of degradation due to poor storage conditions, lack of supervision of public agencies and control the activities found along the whole basin.

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

    Science.gov (United States)

    Yousif, Mohamed; Bubenzer, Olaf

    2012-03-01

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

  16. Geologic framework for the national assessment of carbon dioxide storage resources: Arkoma Basin, Kansas Basins, and Midcontinent Rift Basin study areas: Chapter F in Geologic framework for the national assessment of carbon dioxide storage resources

    Science.gov (United States)

    Buursink, Marc L.; Craddock, William H.; Blondes, Madalyn S.; Freeman, Phillip A.; Cahan, Steven M.; DeVera, Christina A.; Lohr, Celeste D.

    2013-01-01

    2007 Energy Independence and Security Act (Public Law 110–140) directs the U.S. Geological Survey (USGS) to conduct a national assessment of potential geologic storage resources for carbon dioxide (CO2). The methodology used by the USGS for the national CO2 assessment follows that of previous USGS work. This methodology is non-economic and intended to be used at regional to subbasinal scales. This report identifies and contains geologic descriptions of three storage assessment units (SAUs) in Upper Cambrian to Mississippian sedimentary rocks within the Arkoma Basin study area, and two SAUs in Upper Cambrian to Mississippian sedimentary rocks within the Kansas Basins study area. The Arkoma Basin and Kansas Basins are adjacent with very similar geologic units; although the Kansas Basins area is larger, the Arkoma Basin is more structurally complex. The report focuses on the characteristics, specified in the methodology, that influence the potential CO2 storage resource in the SAUs. Specific descriptions of the SAU boundaries as well as their sealing and reservoir units are included. Properties for each SAU, such as depth to top, gross thickness, porosity, permeability, groundwater quality, and structural reservoir traps, are usually provided to illustrate geologic factors critical to the assessment. Although assessment results are not contained in this report, the geologic information herein was employed, as specified in the USGS methodology, to calculate a probabilistic distribution of potential storage resources in each SAU. The Midcontinent Rift Basin study area was not assessed, because no suitable storage formations meeting our size, depth, reservoir quality, and regional seal guidelines were found. Figures in this report show study area boundaries along with the SAU boundaries and cell maps of well penetrations through sealing units into the top of the storage formations. The cell maps show the number of penetrating wells within one-square mile and are

  17. 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...

  18. 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...

  19. Integral study of the quantity and quality of the underground water in the Santa Lucia basin in Uruguay

    International Nuclear Information System (INIS)

    This work study different aspects about the underground water in the Santa Lucia sedimentary basin in Uruguay. It is situated between the San Jose and Santa Lucia river as well as the adyacent Rio de La Plata coast.

  20. 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...

  1. Calcareous assemblages of the southeastern Mediterranean low-tide estuaries - Seasonal dynamics and paleo-environmental implications

    Science.gov (United States)

    Avnaim-Katav, Simona; Agnon, Amotz; Sivan, Dorit; Almogi-Labin, Ahuva

    2016-02-01

    The study of estuarine ecosystems is essential for protecting and reestablishing their threatened biota. In this research the spatio-temporal variations in the distribution patterns of foraminifera, ostracods and molluscs are analyzed in surficial sediments sampled in 2012/13 at six low-tide estuaries of the southeastern Mediterranean coast. Live assemblages are studied using multivariate statistical analyses to determine their ecological preferences and seasonal dynamics whereas the dead assemblages are used to establish a reference baseline for future paleoenvironmental reconstruction. The statistical analysis indicates that salinity, TOC and % carbonate are the main environmental factors explaining 60% of the cumulative variance and controlling the distribution pattern of the different brackish taxa encountered in these estuaries. The foraminifera Ammonia tepida and some miliolids (Quinqueloculina and Varidentella) inhabit most estuaries during summer when salinities of 13-18 psu and temperatures of 26-34 °C occur. At the Naaman stream the agglutinated species Birsteiniolla macrostoma and Trichohyalus aguayoi dominate the assemblage during autumn and winter, respectively when salinities of 3-7 psu and temperature of 18-24 °C prevail. High abundance of the monospecific assemblage of the ostracod Cyprideis torosa was encountered at the Tanninim year round in oligohaline water. The gastropod Heleobia phaeniciaca prefers living at the Naaman and Tanninim streams while Pyrgophorus sp., an invasive and low salinity species, continue colonizing more stream reaches along the Israeli coast. The dead assemblages are composed of high numbers of local and transported species. It includes post storm-surge sediments containing high numbers of inland fresh and brackish water species transported by the floods. Those are mixed with inner to mid-shelf benthic and planktonic foraminifera, ostracods and molluscs. Transportation of the marine organisms a few hundred of meters

  2. Sedimentary records of environmental evolution in the Sanmen Lake Basin and the Yellow River running through the Sanmenxia Gorge eastward into the sea

    Institute of Scientific and Technical Information of China (English)

    王苏民; 吴锡浩; 张振克; 蒋复初; 薛滨; 童国榜; 田国强

    2002-01-01

    A series of independent faulted basins developed in the present middle reaches of the Yellow River during late Cenozoic, among which the Sanmen Lake Basin is located in the east edge of the Loess Plateau, a transitional zone between the second and third macromorphological step of China. The thick strata of the Sanmen Group deposited in the large basin. The Sanmen Group is a perfect place for the study on paleoenvironmental change, tectono-climatic cycles as well as the formation and evolution of the Yellow River. In this paper, the paleoenvironmental changes, regional tectonic movement and the evolutionary process of the Sanmen Lake Basin during the past 5 Ma were reconstructed based on the analysis of paleomagnetic stratigraphy, pollen, TOC and carbonate content from the Huangdigou outcrop near the Sanmenxia Reservoir, Pinglu County, Shanxi Province. The sedimentary records from the outcrop indicate that the basin was first formated by fault activity at about 5.4 MaBP, and after the strong tectonic movement at 3.6 MaBP the lake enlarged and the rainfall of summer monsoon increased. There was no great climatic transition near 2.6 MaBP, corresponding to the bottom age of loess in the Loess Plateau. After Olduvai event (about 1.77 MaBP) the Picea and Abies were presented in the sediments, which indicates a colder climate. The tectonic movement at 1.2 MaBP caused the light angular discordance between the upper and lower Sanmen Group. The sedimentary records show a cold and wet climate during the prosperous periods of loess accumulation such as L15, L9, L6. The tectonic intensification periods of the Sanmen Basin correspond with the tectonic movements in the Qinghai-Xizang Plateau chronologically. The earliest age of the outflow from the Paleo-Sanmen Lake or the partly cutting off of the Sanmenxia Gorge was about 0.41- 0.35 MaBP. The age of cutting thoroughly the Sanmenxia Gorge by the Yellow River and the disappearance of the Paleo-Sanmen Lake was about 0.15 Ma

  3. 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)

  4. Geochronological constaints on the evolution of the Witwatersrand basin, as deduced from single zircon U/Pb ion microprobe studies

    International Nuclear Information System (INIS)

    The economic importance of the Witwatersrand Supergroup has resulted in this basin being one of the most extensively studied of its kind. The Witwatersrand basin has traditionally been grouped together with the underlying Dominion Group and the overlying Ventersdorp Supergroup into the so-called Witwatersrand triad. The present study has sought, by means of single zircon U-Pb age determinations using ion microprobe SHRIMP, to establish a precise and accurate chronostratigraphy for the Witwatersrand triad. 4 refs., 2 figs

  5. 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

  6. 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

  7. Prediction for Natural Recharging In Langat Basin and Ukm Campus as Case Study

    Directory of Open Access Journals (Sweden)

    Mohammad Fawzi Al Ajlouni

    2011-06-01

    Full Text Available Various water budget elements such as water supply to the, ground water recharge, and change in storage are predicted by Water Budget Method for a period of 2.5 years. The predicted water budget elements are evaluated by UKM Meteorological station data. The results show that the modelling undertaken is on the flow of the water and calculation of the water balance for the constructed wetlands using the water budget equation in order to determine the potential underground water resources of the UKM Bangi, Campus. The modeling will be based on the known geology of the area from previous research and Water availability from the known sources, e.g. Engineering and Golf lakes, which are being used as alternative water sources for the Campus. The volume of water that can be held by the UKM aquifer is about 1.4 million m3, which agrees with the estimate by JICA (2002 for the Langat river basin, that the recharging rate is 4.8% of the annual rainfall, from this study the recharging rate is 5% of the annual rainfall. The close approximation of the results for Langat Basin and UKM campus supports the contention that the UKM catchment is just a sub-catchment of the Langat River basin and should have similar properties.

  8. Regional Flood Frequency Analysis Utilizing L-Moments: A Case Study of Narmada Basin

    Directory of Open Access Journals (Sweden)

    Amit Dubey

    2014-02-01

    Full Text Available Accurate estimation of flood frequency is needed for the designing of various hydraulic structures such as dam, spillways, barrage etc. Different approaches were presented which uses the conventional moments to extract order statistics such as mean, standard deviation, skewness, kurtosis. Due to problems arising from data quality, such as short record and outliers, conventional moments are problematic. Hosking (1990 developed L-Moments which are linear combinations of order statistics. The main advantage of L-Moments over conventional moments is that they suffer less from the effects of sampling variability. They are more robust to outliers and virtually unbiased for small samples. In this study the L-Moments based method of Regional Flood Frequency Analysis is mentioned and Narmada Basin is considered as a case. The L-Moments have been used for parameter estimation of Generalized Extreme Value (GEV distribution. Regional flood frequency relationship for the chosen basin is developed utilizing GEV distribution. A relationship between mean annual flood and catchment area is obtained which is further employed to generate Regional Flood Formula for ungauged catchment of Narmada Basin. The developed Regional flood formula is used for T-Year return period flood estimation, knowing only one parameter i.e. catchment area of ungauged watershed.

  9. 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.

  10. A feasibility study of geological CO2 sequestration in the Ordos Basin, China

    Science.gov (United States)

    Jiao, Z.; Surdam, R.C.; Zhou, L.; Stauffer, P.H.; Luo, T.

    2011-01-01

    The Shaanxi Province/Wyoming CCS Partnership (supported by DOE NETL) aims to store commercial quantities of CO2 safely and permanently in the Ordovician Majiagou Formation in the northern Ordos Basin, Shaanxi Province, China. This objective is imperative because at present, six coal-to-liquid facilities in Shaanxi Province are capturing and venting significant quantities of CO2. The Wyoming State Geological Survey and the Shaanxi Provincial Institute of Energy Resource and Chemical Engineering conducted a feasibility study to determine the potential for geological CO2 sequestration in the northern Ordos Basin near Yulin. The Shaanbei Slope of the Ordos Basin is a huge monoclinal structure with a high-priority sequestration reservoir (Majiagou Formation) that lies beneath a 2,000+ meter-thick sequence of Mesozoic rocks containing a multitude of lowpermeability lithologies. The targeted Ordovician Majiagou Formation in the location of interest is more than 700 meters thick. The carbonate reservoir is located at depths where pressures and temperatures are well above the supercritical point of CO2. The targeted reservoir contains high-salinity brines (20,000-50,000 ppm) that have little or no economic value. The targeted reservoir is continuous as inferred from well logs, and cores show that porosity ranges from 1 to 15% with average measured porosity of 8%, and that permeability ranges from 1-35 md. This paper focuses on calculations that will help evaluate the capacity estimates through the use of high-resolution multiphase numerical simulation models, as well as a more simple volumetric approach. The preliminary simulation results show that the Ordovician Majiagou Formation in the Ordos Basin has excellent potential for geological CO2 sequestration and could store the CO2 currently emitted by coal-to-liquid facilities in Shaanxi Province for hundreds of years (i.e., 9 Mt/year CO2; 450 Mt over a 50-year period at one injection site). ?? 2011 Published by Elsevier Ltd.

  11. The Alleret Maar lacustrine sequence (French Massif Central): a 150 ka long early-middle Pleistocene continental paleoenvironmental record.

    Science.gov (United States)

    Nomade, S.; Pastre, J.; Guillou, H.; Gauthier, A.; Scaillet, S.

    2008-12-01

    Lacustrine maar sequences of the French Massif Central are of great interest for paleoclimatic and paleoenvironmental reconstructions of mid-latitudes Quaternary continental environments. In particular, the western Velay region yields exceptional sequences spanning the last 450 ka (Reille et al., J. Quat. Sci. 2000). However, older sequences remain largely unknown despite the presence of interbedded alkaline tephras allowing precise absolute radiochronological control of many lacustrine squences. The Alleret maar is a 1500 m wide phreatomagmatic crater that provides a long lacustrine sequence (41 m). The upper part of this sequence (AL2 core, 14.6 m) was studied between 2005 and 2006 (Pastre et al., C. R. Acad Sci, 2007). A 39Ar/40Ar date (557 ± 5ka) obtained from an interbedded tephra layer located at 7m as well as the associated pollen data attribute the beginning of this sequence to the MIS 15. Thanks to the AL3 core recovered in 2005 (40.6 m, CNRS Meudon) several new tephra layers were discovered in the bottom part of this lacustrine sequence. Three new 39Ar/40Ar ages (single crystal analyses) from trachytic tephra layers were obtained at the LSCE Argon Laboratory (France). These layers are located at -30.2, -36.2 and -39.2m. Ages obtained relative to the ACR-2 flux standard (1,201Ma, Kuiper et al., Science, 2008) range from 692 ± 6 ka (MSWD: 2.3, n=18) for the youngest (-30.2m) to 726 ± 9Ka Ka (MSWD: 2.2, n=12) for the lowest tephra located at -39.2m. These new dates indicate a relatively homogeneous deposition rate of 3.5cm/ka and that the last 10 meters cover the MIS 17-MIS18 period. According to these current radiochronological data the complete lacustrine sequence last more than 150ka. Ongoing sedimentary and pollen studies will allow to extend the paleoenvironmental and paleoclimatic records of the French Massif Central towards the beginning of the early middle Pleistocene.

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

    International Nuclear Information System (INIS)

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

  13. Repeated fault rupture recorded by paleoenvironmental changes in a wetland sedimentary sequence ponded against the Alpine Fault, New Zealand

    Science.gov (United States)

    Clark, K.; Berryman, K. R.; Cochran, U. A.; Bartholomew, T.; Turner, G. M.

    2010-12-01

    At Hokuri Creek, in south Westland, New Zealand, an 18 m thickness of Holocene sediments has accumulated against the upthrown side of the Alpine Fault. Recent fluvial incision has created numerous exposures of this sedimentary sequence. At a decimetre to metre scale there are two dominant types of sedimentary units: clastic-dominated, grey silt packages, and organic-dominated, light brown peaty-silt units. These units represent repeated alternations of the paleoenvironment due to fault rupture over the past 7000 years. We have located the event horizons within the sedimentary sequence, and identified evidence to support earthquake-driven paleoenvironmental change (rather than climatic variability), and developed a model of paleoenvironmental changes over a typical seismic cycle. To quantitatively characterise the sediments we use high resolution photography, x-ray imaging, magnetic-susceptibility and total carbon analysis. To understand the depositional environment we used diatom and pollen studies. The organic-rich units have very low magnetic susceptibility and density values, with high greyscale and high total carbon values. Diatoms indicate these units represent stable wetland environments with standing water and predominantly in-situ organic material deposition. The clastic-rich units are characterised by higher magnetic susceptibility and density values, with low greyscale and total carbon. The clastic-rich units represent environments of flowing water and deep pond settings that received predominantly catchment-derived silt and sand. The event horizon is located at the upper contact of the organic-rich horizons. The event horizon contact marks a drastic change in hydrologic regime as fault rupture changed the stream base level and there was a synchronous influx of clastic sediment as the catchment responded to earthquake shaking. During the interseismic period the flowing-water environment gradually stabilised and returned to an organic-rich wetland. Such

  14. 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.

  15. Real time Measurement of Nitrate in Stream Water for a Paired Basin Study within the Choptank River Watershed, Maryland, USA.

    Science.gov (United States)

    McCarty, Greg

    2013-04-01

    For this study, a robust water quality monitoring system was designed to measure nitrate and sediment using a commercially available UV-Vis spectrometer probe. To increase reliability for monitoring highly dynamic small streams and reduce susceptibility to vandalism in public place installations, an innovative the monitoring system was implemented around the use of a flow cell attachment for the probe with automated stream water sample delivery using a peristaltic pump. This permitted all instrumentation and electronics to be housed in secure enclosures with maximum flexibility in sampling location in the dynamic stream cross section. Monitoring systems were successfully deployed at two USGS stream gauge stations located at public parks near the towns of Ruthsburg and Greensboro within the Choptank Watershed which established a paired basin comparison of water quality. Both basins have a mixed land use of cropland in largely corn - soybean rotation and forests containing extensive wetland complexes. The basins have very similar amounts of cropland area but the Greensboro basin contains more wetlands and cropland formed from wetland drainage. Monitoring data has shown that the Ruthsburg basin exports about 25% more nitrate per area of cropland than the Greensboro basin. These results are indicative of greater landscape processing of nitrate in the Greensboro basin due to greater prevalence of wetlands and poorly drained soils in crop production.

  16. Importance of isotope hydrology techniques in water resources management: A case study of the Makutupora basin in Tanzania

    International Nuclear Information System (INIS)

    Makutupora groundwater basin has been the main source of water supply for Dodoma town since 1950s. the water is mainly used for domestic water supply to over one million inhabitants, for industrial purposes and livestock watering. Conventional hydrogeological investigations have been carried out in the basin to gather information on the groundwater potential of the basin to meet the ever-increasing demand for water. However, firm conclusions could not be reached with conventional methods. This paper highlights on the isotope techniques applied in an integrated manner with conventional hydrogeological methods to study the groundwater regime of the Makutupora basin. Results of isotope techniques have provided adequate information on recharge locations, recharge rates and age of groundwater in the basin, that is very important and open up prospects for further investigations using isotope techniques. The ongoing investigation in the basin regarding pollution and depletion of the groundwater resource, has not succeeded in defining specific pumping limits or groundwater protection zones. Isotope data are sought to provide a clear basis for regulatory and future groundwater management in the Makutupora basin. (author)

  17. 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

  18. 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.

  19. Study on geochronology of sandstone-type uranium mineralization in western Hailaer basin

    International Nuclear Information System (INIS)

    The study on U-Pb isotopic dating of sandstone-type uranium mineralization in western Hailaer basin, namely, Xihulitu and Kelulun depressions, has been carried out. The ages of 81 ± 2 Ma, 44 ± 2 Ma, 9 ± 2 Ma, 2 ± 0 Ma for sandstone-type uranium mineralization in Xihulitu depression and 51 ± 8 Ma, 67 ± 5 Ma for sandstone-type uranium mineralization in Kelulun depression have been obtained for the first time by U-Pb isochron dating. These mineralization ages are in good accordance with the tectonic and climatic evolution histories of the study area

  20. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River Basin

    OpenAIRE

    Zhuo, L.; M. M. Mekonnen; A. Y. Hoekstra

    2014-01-01

    Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t−1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat at the scale of the Yellow River basin in the period 1996–2005. A...

  1. Magnetic and electrical study of a roll-front uranium deposit in the Denver basin, Colorado

    International Nuclear Information System (INIS)

    Electrical and magnetic surface geophysical techniques have been used to study a shallow uranium deposit in the Denver basin. Both magnetic and resistivity lows correlate with the main ore deposit. Indications are that the resistivity anomaly extends from the near surface down through the ore sand. Data from this shallow deposit can be used to predict the scale of anomalies to be expected from deeper deposits. Further studies to determine the geophysical character of shallow deposits could be useful in the exploration for deeper deposits by borehole geophysical techniques

  2. Use of a computer to study the Kosovo coal basin (Yugoslavia)

    Energy Technology Data Exchange (ETDEWEB)

    Jovicic, R.

    1983-01-01

    Program of work is developed for preparation of a data base according to which it is initially necessary to collect and process the necessary data and to introduce them into the computer in order to use them in the process of further study. A detailed analysis is stipulated for the raw material data base (coal content, stripping, hydrogeological characteristics, general conditions, etc.), outlays under conditions of development associated with the nature of the locality, outlays for movement of the populated areas or for compensation for the cost of these areas, outlays for piping, power transmission lines, etc. These are the first studies of the Kosovskiy coal basin using a computer.

  3. 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

  4. 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.

  5. BRACKISH MARSH BENTHIC MICROFAUNA AND PALEOENVIRONMENTAL CHANGES DURING THE LAST 6000 YEARS AT THE COASTAL PLAIN OF MARATHON (SE GREECE

    Directory of Open Access Journals (Sweden)

    MARIA V.TRIANTAPHYLLOU

    2003-11-01

    Full Text Available The present study, based mainly on the analysis of foraminifers and ostracodes, provides evidence of paleoenvironmental changes on the coastal plain of Marathon (E. Greece during the last 6.000 yrs. Three sedimentary units -lagoonal formations - were recognized and identified as A, B and C. They range in time between before 5500BP-3500BP, 3500BP-2500BP and 2500BP-recent, respectively. The study of the brackish marsh microfauna of the Marathon plain Holocene sediments reveals the presence, during the last 5500 yrs., of three distinct biofacies in the sedimentary units already established. Alternating mesohaline - oligohaline (MO, oligohaline - fresh water (OFW and mesohaline - oligohaline to oligohaline - fresh water (MO-OFW biofacies in the framework of the sedimentary units indicate a general trend landward along the plain suggesting a slowing of sea-level rise probably correlated with a relevant tectonic uplift. One prominent feature of this study is the clarification of the ecological preference of the species Trichohya1us aguayoi (Bermudez, 1935, which is dominant in oligohaline conditions under an influence of fresh water input (salinity less than 15 ‰. 

  6. Integrated regional assessment of global climatic change. Lessons from the Mackenzie Basin Impact Study (MBIS)

    International Nuclear Information System (INIS)

    This paper outlines the potential role integrated regional assessments of global climatic change scenarios could play in building better links between science and related policy concerns. The concept is illustrated through description of an ongoing case study from Canada-the Mackenzie Basin Impact Study (MBIS). As part of the Government of Canada's Green Plan, the Global Warming Science Program includes a study of regional impacts of global warming scenarios in the Mackenzie Basin, located in northwestern Canada. The MBIS is a six-year program focussing on potential climate-induced changes in the land and water resource base, and the implications of four scenarios of global climatic change on land use and economic policies in this region. These policy issues include interjurisdictional water management, sustainability of native lifestyles, economic development opportunities (agriculture, forestry, tourism, etc.), sustainability of ecosystems and infrastructure maintenance. MBIS is due to be completed in 1997. MBIS represents an attempt to address regional impacts by incorporating a 'family of integrators' into the study framework, and by directly involving stakeholders in planning and research activities. The experience in organizing and carrying out this project may provide some lessons for others interested in organizing regional or country studies

  7. Integrated regional assessment of global climatic change: lessons from the Mackenzie Basin Impact Study (MBIS)

    Science.gov (United States)

    Cohen, Stewart J.

    1996-04-01

    This paper outlines the potential role integrated regional assessments of global climatic change scenarios could play in building better links between science and related policy concerns. The concept is illustrated through description of an ongoing case study from Canada—the Mackenzie Basin Impact Study (MBIS). As part of the Government of Canada's Green Plan, the Global Warming Science Program includes a study of regional impacts of global warming scenarios in the Mackenzie Basin, located in northwestern Canada. The MBIS is a six-year program focussing on potential climate-induced changes in the land and water resource base, and the implications of four scenarios of global climatic change on land use and economic policies in this region. These policy issues include interjurisdictional water management, sustainability of native lifestyles, economic development opportunities (agriculture, forestry, tourism, etc.), sustainability of ecosystems and infrastructure maintenance. MBIS is due to be completed in 1997. MBIS represents an attempt to address regional impacts by incorporating a "family of integrators" into the study framework, and by directly involving stakeholders in planning and research activities. The experience in organizing and carrying out this project may provide some lessons for others interested in organizing regional or country studies.

  8. Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex

    Science.gov (United States)

    Vogel, Sebastian; Märker, Michael

    2010-05-01

    , present-day digital elevation model (DEM) was generated. A detailed terrain analysis yielded 15 different primary and secondary topographic indices of the present-day DEM. Then, a classification and regression model was generated combining the present-day topographic indices to predict the depth of the pre-AD 79 surface. This model was calibrated with the measured depth of the pre-AD 79 surface from the drilling data. To gain a pre-AD 79 digital elevation model (DEM) the modeled depth of the pre-AD 79 surface was subtracted from the present-day DEM. To reconstruct some paleo-environmental features, such as the paleo-coast and the paleo-river network and its flood plain, the modeled pre-AD 79 DEM was compared with the classified characteristic of the pre-AD 79 stratum, identified from the drilling documentation. It is the first time that the paleo-topography and paleo-environmental features of the Sarno River basin were systematically reconstructed using a detailed database of input variables and sophisticated data mining technologies. Keywords: Sarno River Basin, Roman paleo-topography, paleo-environment, stratigraphical core drillings, Classification and Regression Trees

  9. Geology and geohydrology of the east Texas Basin. Report on the progress of nuclear waste isolation feasibility studies (1979)

    International Nuclear Information System (INIS)

    The program to investigate the suitability of salt domes in the east Texas Basin for long-term nuclear waste repositories addresses the stability of specific domes for potential repositories and evaluates generically the geologic and hydrogeologic stability of all the domes in the region. Analysis during the second year was highlighted by a historical characterization of East Texas Basin infilling, the development of a model to explain the growth history of the domes, the continued studies of the Quaternary in East Texas, and a better understanding of the near-dome and regional hydrology of the basin. Each advancement represents a part of the larger integrated program addressing the critical problems of geologic and hydrologic stabilities of salt domes in the East Texas Basin

  10. Geology and geohydrology of the east Texas Basin. Report on the progress of nuclear waste isolation feasibility studies (1979)

    Energy Technology Data Exchange (ETDEWEB)

    Kreitler, C.W.; Agagu, O.K.; Basciano, J.M.

    1980-01-01

    The program to investigate the suitability of salt domes in the east Texas Basin for long-term nuclear waste repositories addresses the stability of specific domes for potential repositories and evaluates generically the geologic and hydrogeologic stability of all the domes in the region. Analysis during the second year was highlighted by a historical characterization of East Texas Basin infilling, the development of a model to explain the growth history of the domes, the continued studies of the Quaternary in East Texas, and a better understanding of the near-dome and regional hydrology of the basin. Each advancement represents a part of the larger integrated program addressing the critical problems of geologic and hydrologic stabilities of salt domes in the East Texas Basin.

  11. 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.

  12. Geo archaeology in Cerro Lutz site, paleoenvironmental and palaeo geographic implications. Province of Entre Rios, Argentina

    International Nuclear Information System (INIS)

    The aim of this paper is to present the geo morphological evolution of the Cerro Lutz archaeological site located in the Lower Par ana Delta, Argentina River (Gualeguaychu Department). This is to add information to the paleogeographic and paleoenvironmental scheme during the occupation of site and add data to refine the regional evolution of deltaic advance against the Parana River.The geomorphology of the delta is composed of landforms resulting from fluvial modeling, coastal ( wave and tidal ) and to a lesser extent wind.They have different relative ages and dating from the late Pleistocene to the present

  13. Provenance studies in Amazon basin by means of chemical composition obtained by INAA

    International Nuclear Information System (INIS)

    This study determines the provenance of the 106 sediments samples deposited by the Solimoes and Negro rivers in the tectonic depressions in Manaus, Amazon state, Brazil. Twenty-four chemical elements in the sediment samples collected before the confluence of Negro and Solimoes rivers have been determined using instrumental neutron activation analysis, INAA. It is inferred from the multivariate statistical methods that samples from the basin of the Solimoes river and tectonic depression 1 (the most significant of the region) are not significantly different. These results indicate the contribution this river in the sedimentary fill during the evolution in the Quaternary. (author)

  14. Study on uranium distribution in ore samples of Nong Son Basin (Viet Nam)

    International Nuclear Information System (INIS)

    Geological studies show that uranium ore bodies in Nong Son basin (Quang Nam province, Viet Nam) are lens, chain of lenses with uranium content of U3O8 ≥ 0.01%. In one bed of uranium bearing rock, the uranium contents widely vary from 0.001 to 0.675%. Knowledge of the uranium distribution in mined ore is very important for preconcentration processes. The study has conducted classification by radioactivity measurement for each ore grain (size of 25-200 mm) and determine uranium content in respective ore sample. To determine radioactivity, gamma spectrometer (thallium- activated sodium iodide crystals NaI(Tl) 80x80 mm and multi-channel analytical system of model MCA-2003-001,VNEC) were used. Uranium contents were determined by coloriphotometry (Spectronic 20 D+, USA). Based on the results obtained from the study of uranium distribution in ore samples of the above area it was concluded that (1) the uranium distribution levels are not even in the studied ore samples and (2) it is possible to use radiometric sorting to enrich ores from Nong Son basin

  15. 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.

  16. Hydrogeochemistry of high iodine groundwater: a case study at the Datong Basin, northern China.

    Science.gov (United States)

    Li, Junxia; Wang, Yanxin; Xie, Xianjun; Zhang, Liping; Guo, Wei

    2013-04-01

    High iodine concentrations in groundwater have seldom been reported and there have been few systematic studies on high iodine groundwater worldwide. To better understand the sources and processes responsible for iodine enrichment in the groundwater of the Datong Basin, the hydrochemical characteristics of groundwater and geochemical features of aquifer sediments were studied. High iodine groundwater mainly occurs in the center of the Datong Basin with iodine concentrations ranging between 3.31 and 1890 μg L(-1). Most samples with iodine concentrations higher than 500 μg L(-1) are from wells with depths between 75 and 120 m. High pH and a reducing environment are favorable for iodine enrichment in the groundwater, with iodide as the dominant species that accounts for 63.2-99.3% of the total iodine. Sediment samples from a borehole specifically drilled for this study contain 0.18-1.46 mg kg(-1) iodine that is moderately correlated with total organic carbon (TOC). The results of sequential extraction experiments show that iodine is mostly bound to iron oxyhydroxides and organic matter in the sediments. The mobilization processes of iodine are proposed to include reductive dissolution of iron oxyhydroxides and transformations among iodide, iodate and organic iodine driven by microbial activities under alkaline and reducing conditions. PMID:23478640

  17. Investigation of potential alternate study areas in the Paradox Basin region, Utah

    International Nuclear Information System (INIS)

    The Paradox Basin was re-evaluated to determine if any parts of the Basin that had not been identified in previous studies might be suitable for a more detailed evaluation as a nuclear waste repository site. The factors used in this re-evaluation were depth to salt and dedicated lands, because these factors directly address the engineering and environmental feasibility of a repository. Six areas (Happy Canyon, Green River, Dolores River, Expectation Mountain, Dark Canyon, and Kane Springs Canyon) were identified on this basis as potentially suitable areas for further study. These areas were assessed in more detail to review the feasibility of siting a repository. None of the six areas was recommended for further study as a repository site because the size of the areas, thickness of the salt beds, topography, and engineering factors resulting from the loading of nearby mesas generally did not allow the construction of a feasible repository. The content of this report was effective as of May 1983. 41 references, 17 figures

  18. Evaluation of area studies of the US Gulf Coast Salt Dome Basins: location recommendation report

    International Nuclear Information System (INIS)

    This document presents the evaluation methodology used for the area characterization studies in salt domes of the interior basins of the Gulf Coast region along with background information on salt domes, the site qualification process, criteria used for dome evaluation, and the technical approach applied. The geologic and environmental data are briefly summarized with reference to pertinent documents that contain details of the area characterization studies. Three recommendations are made as a result of the evaluaton: (1) to eliminate one dome from further study because of a safety flaw; (2) to eliminate three domes from further study for failure to meet site performance criteria; and (3) to continue further studies at the four domes which meet minimum standards for further consideration

  19. Geology and geohydrology of the East Texas Basin. A report on the progress of nuclear waste isolation feasibility studies (1980)

    International Nuclear Information System (INIS)

    The third year of research was highlighted by the integration of regional basinal studies with growth histories for specific domes, studies of cap-rock diagenesis and salt deformation, preliminary studies of ground-water flow and geochemistry around Oakwood Dome, and preliminary studies of microseismicity in the Mount Enterprise fault zone. 119 figures, 15 tables

  20. C-14 dated paleoenvironmental changes on Lake Kolon during the last 25000 years

    International Nuclear Information System (INIS)

    Complete text of publication follows. One of Hungary's geological and environmental treasures is nestled in the heart of the Great Hungarian Plain. The catchment basin of Lake Kolon was subjected to detailed environmental historical studies starting in 2005. Undisturbed cores taken along transects of the basin were subjected to detailed sedimentological, paleoecological, and geochemical studies (Figure 1). To establish a reliable timeframe of the lacustrine and marshland sedimentary sequence identified, 22 samples were analyzed by accelerator mass spectrometry (AMS) in the radiocarbon laboratories of Poznan and Tucson. With the new results in hand (Figure 2), we had the opportunity to elucidate the geological evolution of the area for the past 25,000 yr. This sequence is highly beneficial, as it is probably the most well-dated profile of the Quaternary from the area studied. The new absolute dates enabled the comparison of local geological evolution of the studied area with those of global climatic changes. As seen from our findings, the geological evolution of the catchment basin was congruent with major climatic events during the Pleistocene and the entire Holocene. However, a very peculiar trajectory was identified for the terminal part of the Pleistocene and the opening of the Holocene regarding the evolution of the landscape, the vegetation, and the fauna of this part of the Great Hungarian Plain.

  1. Preliminary hydrologic budget studies, Indian Creek watershed and vicinity, Western Paradox Basin, Utah

    International Nuclear Information System (INIS)

    Preliminary quantitative estimates of ground-water discharge into the Colorado River System in the western Paradox Basin were prepared on the basis of existing climatological and streamflow records. Ground-water outflow to the river was deduced as a residual from hydrologic budget equations for two different study areas: (1) the region between gaging stations at Cisco, Green River, and Hite, Utah; and (2) the Indian Creek watershed. An empirical correlation between recharge rates and precipitation amounts derived for several basins in eastern Nevada was applied to estimate recharge amounts for the Indian Creek watershed. A simple Darcian flow model was then used to approximate the ground-water flux outward from the watershed for comparison. Salinity measurements in the Colorado River were also used to approximate ground-water outflow to a river reach in Cataract Canyon in order to provide another comparison with the hydrologic budget results. Although these estimates should be considered only gross approximations, all approaches used provide values of ground-water outflow that are much less than estimates of similar parameters provided by the US Geological Survey in recent hydrologic reconnaissance reports. Estimates contained herein will be refined in future numerical modeling and data collection studies

  2. 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.

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

    Science.gov (United States)

    Kumbar, Suresh M; Ghadage, Abhijit B

    2014-11-01

    The present study on avifaunal diversity carried out for three years at the Krishna River Basin, Sangli District revealed a total of 126 species of birds belonging to 30 families, of which 91 species were resident, 16 migratory, 12 resident and local migratory and 7 species were resident and migratory. Among the migrant birds, Rosy Starling Sturnus roseus was dominant in the study area. Commonly recorded resident bird species were, Red vented bulbul, Jungle crow, House sparrow, Common myna, Brahminy myna, Rock pigeon, Spotted dove, Rose ringed parakeet, Indian robin, White-browed fantail-flycatcher and Small sunbird. Most of the families had one or two species, whereas Muscicapidae family alone had 16 species. Forty one species of waterfowls were recorded in this small landscape. Out of 126 bird species, 38 were insectivorous, 28 piscivorous, 25 omnivorous, 19 carnivorous, 9 granivorous, 5 frugivorous and 2 species were nectar sucker and insectivorous. These results suggest that richness of avifauna in the Krishna River Basin, Western Maharashtra might be due to large aquatic ground, varied vegetations and favourable environmental conditions. PMID:25522499

  4. Radionuclide levels in fish from Lake Athabasca February 1993. Northern River Basins Study project report no.26

    International Nuclear Information System (INIS)

    The Northern River Basins Study was initiated through the 'Canada-Alberta-Northwest Territories Agreement Respecting the Peace-Athabasca-Slave River Basin Study, Phase II - Technical Studies' which was signed September 27, 1991. The purpose of the study is to understand and characterize the cumulative effects of development on the water and aquatic environment of the Study Area by coordinating with existing programs and undertaking appropriate new technical studies. This publication reports the method and findings of particular work conducted as part of the Northern River Basins Study. As such, the work was governed by a specific terms of reference and is expected to contribute information about the Study Area within the context of the overall study as described by the Study Final Report. This report has been reviewed by the Study Science Advisory Committee in regards to scientific content and has been approved by the Study Board of Directors for public release. It is explicit in the objectives of the Study to report the results of technical work regularly to the public. This objective is served by distributing project reports to an extensive network of libraries, agencies, organizations and interested individuals and by granting universal permission to reproduce the material. This report contains referenced data obtained from external to the Northern River Basins Study. Individuals interested in using external data must obtain permission to do so from the donor agency. (author). 47 refs., 9 tabs., 2 figs

  5. Hydrogeological, chemical and isotopic studies in the Atitlan lake basin, Guatemala

    International Nuclear Information System (INIS)

    In the framework of the study of the hydrological balance of the Atitlan lake, the following results were obtained: The rainfall in the basin of the Atitlan lake is well known and reaches approximately 1150 mm/year. The real evapotranspiration in the basin of the Atitlan lake according to the reservoir measurements is approximately 1500 mm/year. The underground leaks is the result from the rainfall and evaporations which are calculated in 1020 l/s or 59 mm/year, respectively. The subterranean outflow from the Atitlan lake is only found between Sta. Teresa and the Madre Vieja river. The lake contribution to the flows in this area was calculated in 1100 l/s which agrees with the hydrological balance. The subterranean outflows follows the leaking water area of the lake, when the water level was higher. This indicate, that due to the decrease in the water level of the Atitlan lake the superficial discharge was stop while the subterranean discharge continues. In other parts of the spring to the Pacific area specially in the Chicacao area, there are no contributions of the lake Atitlan to the rivers flows of this area. (author). 4 refs, 4 figs, 2 tabs

  6. Hydrogeological, isotopic and hydrochemical study of the Valencia Lake basin, Venezuela

    International Nuclear Information System (INIS)

    The Lake Valencia basin extends over 2600 Km2, of which 1200 form an intra-mountainous plain filled with fluvio-lacustrine sediments. In the past, the lake discharged into the Orinoco basin, but at present, the discharge only takes place through ground waters. Lake Valencia collects untreated waste waters leading to a progressive eutrophization and deterioration of its waters. During the last years a sharp decline in the quality of groundwaters was observed as a result of over-exploitation of the aquifers and to the recharge of surface waters heavily polluted. The hydrogeological, geochemical and isotopic studies have shown that groundwaters derive from the mixing of three components: a) surface waters derived from reservoirs; b) deep groundwater, with high sulphate content; and c) surface waters characterized by their low salinity. The underground discharges seem to be linked to the presence of fracture zones, and according to the regional water balance, the minimum value estimated for the discharge is 43 mm/a. (author). 6 refs, 12 figs, 1 tab

  7. Preliminary study of the hydrologic response of an urban drainage basin at two different scales

    Science.gov (United States)

    Ferreira, Carla; Ferreira, António; Coelho, Celeste; de Lima João, Pedroso

    2010-05-01

    Predicted changes in climate and urban sprawl areas are expected to cause significant modification in rainfall pattern and hydrological regimes. Urbanization can alter the hydrologic response by increasing streamflow, reducing time of concentration, altering soil moisture levels and increasing overland flow, thereby increasing the size, frequency and speed of peak flow responses. However, despite the profusion of works, effective methodologies to investigate the impacts of potential land-use change on how spatial variability of soil moisture and precipitation affect runoff production at a range of scales and on different land uses remain largely undeveloped. This has important implications for flood prediction accuracy. The main aim of this work is to assess the hydrological response and to understand the influence of different land uses. The study is based on a small urban drainage basin (7 Km2), undergoing rapid urbanization, located in central Portugal: Ribeira dos Covões. It considers a combined approach of field survey and data acquisition to access spatiotemporal dynamics and land uses contributions to surface hydrology, based on drainage basins and small plot scales. At drainage basin scale, the study is based on three years rainfall and stream flow data analysis (collected through an automatic water level recorder and rain gauges). Rainfall-runoff relationship was assessed over the time and isolated events were studied. To understand land uses on the hydrology, rainfall simulations were conducted at the small plot scale (0.25 m2) during a dry period, in forested and deforested areas, agricultural areas, including tilled and abandoned areas, as well as built-up areas (21 experiments with 1 hour duration, with a rain intensity of 43±3 mm h-1). During the experiments hydrophobicity was monitored (Molarity of an Ethanol Droplet technique), soil moisture content was assessed every minute, and runoff volume was measured every 5 minutes. This work has shown the

  8. Drought in the Nile Basin: characterizing variability, quantifying uncertainty, and studying processes with the Nile Land Data Assimilation System

    Science.gov (United States)

    Alo, C. A.; Zaitchik, B. F.; Habib, S.; Anderson, M. C.; Ozdogan, M.

    2010-12-01

    The Nile Land Data Assimilation System (Nile LDAS) has been developed to support studies of hydrologic variability, land cover patterns, and climate change impacts in the countries that share the Nile basin. Here we present results of retrospective Nile LDAS simulations that examine climatic and hydrologic variability across the basin in recent decades. Use of Nile LDAS in this study allows us to compare patterns of drought as captured by different precipitation datasets—including Tropical Rainfall Measurement Mission (TRMM) precipitation products, the CPC Merged Analysis of Precipitation (CMAP), and multiple meteorological reanalyses—different land surface models—including Noah Land Surface Model, the Common Land Model, and Catchment LSM—and independent satellite observations—including the Gravity Recovery and Climate Experiment (GRACE). Results of Nile LDAS simulations show distinct temporal and spatial patterns of drought across the climatic gradients of the Nile basin. These results also demonstrate that diagnosis of drought patterns is sensitive to choice of meteorological dataset and land surface model. We present an objective classification of drought susceptibility zones based on the results of these Nile LDAS simulations, including assessment of confidence and uncertainty. Lastly, we discuss the possible drivers of hydrological variability at the local to the basin scale. Follow-on studies are in progress to merge, compare, and improve Nile LDAS datasets in order to provide optimal estimates of hydrological states and fluxes in the Nile basin, with the ultimate objective of improving drought analysis and response in an evolving climate.

  9. Paleoenvironmental and paleoclimatic investigations on Isla de los Estados, Argentina

    Science.gov (United States)

    Björck, S.; Fernandez, M.; Hjort, C.; Ljung, K.; Martinez, O.; Möller, P.; Ponce, F.; Rabassa, J.; Roig, F.; Unkel, I.; Wohlfarth, B.

    2007-05-01

    The expedition in November-December 2005 to Isla de los Estados (Staten Island) off the southeastern tip of South America was a cooperative venture between Lund University (LU) and Stockholm University (SU) in Sweden and the CADIC-CONICET Institute in Ushuaia, Argentina. The aim of the expedition was threefold: (1) to extend the Swedish paleoclimatic "ATLANTIS"-project (Greenland, Iceland, Faroe Islands, Azores, Grenada, Tristan da Cunha; PI S Björck) to the southern part of the South American continent, (2) to connect earlier glacial and climate history reconstructions from the Antarctic Peninsula to equivalents north of the Drake Passage in southernmost South America, and (3) to complement paleo-information available from the Tierra del Fuego mainland with information from Isla de los Estados. Focus was on two areas in the northern and north-western part of the island, Bahía Colnett and Bahia Crossley. Detailed geomorphologic and stratigraphic mapping of glacial deposits were combined with sampling sediments for OSL dating. To reconstruct the paleoclimatic development of Isla de los Estados since the last ice retreat, four main peat bog/lake sites were cored and sampled. In addition, living trees of Nothofagus and old logs preserved in the peat were sampled for dendrochronological and dendroclimatological studies. Preliminary results show that the deglaciation of the study area occurred before 16500 cal yr BP. Detailed multi- proxy analyses of the four sequences are under way and first results will be presented.

  10. Eolian sediments in arctic Alaska as sources of paleoenvironmental data

    International Nuclear Information System (INIS)

    Eolian sand, silt, and associated fluvial and lacustrine sediments are widespread in Alaska north of the Brooks Range. These sediments and intercalated paleosols record late Quaternary episodes of widespread eolian sediment transport separated by periods of relative landscape stability and the growth of organic soils. The eolian sediments represent paleoenvironments much different from the modem one, in which eolian sediment transport is principally limited to areas adjacent to sediment sources, such as flood plains. Information about these paleoenvironments and their contemporary climates can be obtained by studying the morphology, distribution, and sedimentology of the sediments, and the fossil fauna and flora they contain. Fossils such as beetles and ostracods contained in the fluvial and lacustrine sediments can yield information regarding summer temperature and changes in evaporation/precipitation ratios. Furthermore, the sediments and paleosols can be dated by thermoluminescence and radiocarbon to provide a chronology of paleoclimatic and pale-environmental change. Present data suggest three major episodes of widespread eolian sediment movement during the latest glacial/inter-glacial cycle: (1) a long period coincident with the Wisconsin glaciation during which climate was cooler and drier than today and much of the North Slope was a polar desert; (2) an interval during the latest Pleistocene and early Holocene in which climate was warmer and surface moisture conditions were drier than today; and; (3) one or more brief late Holocene intervals during which climate was probably cooler and drier than today. These eolian sediments and intercalated paleosols are being studied in detail as part of the USGS Climate Change Program in order to understand how past environments in arctic Alaska have responded to climatic change

  11. Acute effects of air pollution changes in schoolchildren: the Gardanne coal basin study

    Science.gov (United States)

    Charpin, D.; Kleisbauer, J. P.; Fondarai, A.; Francheterre, A.; Fondarai, J.; Graland, B.; Viala, A.

    1988-12-01

    In the literature, studies devoted to shortterm effects of air pollution episodes in children have provided controversial results. To evaluate if acute air pollution changes in the Gardanne coal basin (France) could have deleterious effects on children's pulmonary function, we studied 160 children on two different days. Each in-school examination consisted of a short questionnaire and a spirometric assessment. The area included districts of high and low pollution levels. In the former, the two examinations took place at different air pollution levels whereas, in the latter, the air pollution levels were comparable. We obtained higher spirometric values during the second examination, regardless of air pollution changes and suggesting a learning effect, which vanished when we used FEV1/FVC ratio. The difference in FEV1/FVC between days of low and high pollution was significant but merely equal to 2%. There was no change of clinical symptom score.

  12. Isotope techniques in hydrological studies: application to Chacabuco-Polpaico basin

    International Nuclear Information System (INIS)

    A hydrogeological study was carried out in a small alluvial valley, 45 kms. north of Santiago, Chile. Although the main economical activity is the agriculture, the valley only has small seasonal rivers. The irrigation water comes from a near basin through a channel of about 100 kms. and from the ground water. The study include aspects like: pumping tests evaluations, well stratigraphy, potentiometric surface fluctuation, water chemistry, stable isotopes and water balances. Isotopes, oxygen-18 and deuterium were used to identify the origin of the ground water in different sections of the valley and the importance of the infiltration. Also experiences were made to evaluate the evaporation of a small damm, using isotopes and the classical water balance methods. (O.S.)

  13. Geochemical and isotopic (Sr, U) variations of lake waters in the Ol'khon Region, Siberia, Russia: Origin and paleoenvironmental implications

    Science.gov (United States)

    Chabaux, François; Granet, Mathieu; Larqué, Philippe; Riotte, Jean; Skliarov, Eugeni V.; Skliarova, Olga; Alexeieva, Ludmilla; Risacher, François

    2011-07-01

    The geochemical study of springs and lake waters from the Ol'khon Region, Siberia, confirms the strong chemical variability of these water samples, more particularly regarding their salinity. Such variability does not result from a simple mixing process between surface freshwaters and deeper saline waters. The variability, observed at the scale of a few square kilometers, would preferentially result from a secondary concentration processes (evaporation and/or cryogenesis) of lake waters of variable intensity from one lake to another. The U-disequilibria data suggest that the duration of the secondary process is certainly an important parameter to be considered to account for the variable salinity of these lakes. The data indicate that the lakes, however modest in size, could be as old as several ky, confirming therefore that the lake sedimentary deposits could represent relevant paleoenvironmental recorders for the last thousands years.

  14. 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.

  15. Do coralline red algal growth increment widths archive paleoenvironmental information?

    Science.gov (United States)

    Halfar, J.; Winsborough, C.; Omar, A.; Hetzinger, S.; Steneck, R. S.; Lebednik, P. A.

    2009-04-01

    Over the past decade coralline red algae have received increased attention as archives of paleoclimate information. Encrusting coralline red algae, which deposit annual growth increments in a High-Mg calcite skeleton, are amongst the longest-lived marine organisms. In fact, a live-collected plant has recently been shown to have lived for at least 850 years based on radiometric dating. While a number of investigations have successfully utilized geochemical information obtained from coralline red algal skeletons to reconstruct climate, no study has yet examined the potential of using growth increment widths as a proxy for past water temperatures. Here we explore the relationship between growth and environmental parameters in Clathromorphum nereostratum from the Bering Sea. A 120-year long annual growth record shows a significant but weak correlation to regional sea surface temperature data (r=0.24), which requires much of the observed annual growth increment width variability to be explained by other factors. We therefore examined coralline red algal growth for a 20-year period in multiple specimens collected along a depth transect from 10 to 35 m water depth. Results demonstrate a significant decrease in average annual growth increment widths with increasing water depth. Due to intense wind-induced mixing in the region the upper water column exhibits near uniform temperatures and salinities, leaving the decreasing amount of light with depth as the dominant variable influencing vertical extension. This was further tested by examining specimens collected at 10 m water depth at different locations receiving distinct amounts of shading provided by 100%, 50%, and 0% kelp canopy coverage. Results indicate a negative relationship between percent kelp canopy coverage and annual growth increment width. It can therefore be concluded that the dominant factor controlling vertical growth in C. nereostratum is light, with temperature only accounting for a small portion of growth

  16. 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.

  17. Application of the Sequence Stratigraphy in the Study of Cretaceous Tertiary of the Tarim Basin, Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    DING Xiaozhong; GUO Xianpu; PENG Yang; JI Yunlong; WANG Yineng

    2001-01-01

    According to the comprehensive study of the depositional sequence of the outcrop sections from Cretaceous to Tertiary of the Tarim Basin, and the analyses of the seismic sequence and drilling data,the strata of Cretaceous-Tertiary of the Tarim Basin can be subdivided into 30 3rd-order depositional sequences in the southwestern depression and 22 3rd-order dpositional sequences in the northwestern depression. This indicates that the 3rd-order sequences can not be correlated directly one by one because of their different tectonic settings and sedimentary environments. Whereas, based on the study of 2nd-order supersequence, the strata from Cretaceous to Tertiary can be divided into 4 supersequences and correlated isochronously in these two areas of the Tarim Basin.

  18. A study of migration of radionuclides in Yenisei River basin. Characteristics of radioactive contamination and estimate of exposure dose

    International Nuclear Information System (INIS)

    With reference to the significance of a study of migration of radionuclides in a river basin, two research projects for the Yenisei River Basin were reviewed. The first one, the International Science and Technology Center Project no.748, provided a new data set on the source and the characteristics of radioactive contamination in the basin, including transuranic elements. The second one, that was conducted by the International Institute for Applied Systems Analysis, encompassed dose evaluation in various scenarios based on considerations of source conditions and a hydrodynamic transport model of suspended sediment in a flood event. These studies exemplified that the assessment of physiological influences due to any environmental contaminants requires following issues: considerations on various ''axes'' in geographical space and phenomena, the use of an adequately simplified'' mathematical model of their migration, and the adoption of ''easily recognizable endpoint'' to quantify the influences. (author)

  19. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River Basin

    Directory of Open Access Journals (Sweden)

    L. Zhuo

    2014-01-01

    Full Text Available Water Footprint Assessment is a quickly growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of water footprint estimates to changes in important input variables and quantifies the size of uncertainty in water footprint estimates. The study focuses on the green (from rainfall and blue (from irrigation water footprint of producing maize, soybean, rice, and wheat in the Yellow River Basin in the period 1996–2005. A grid-based daily water balance model at a 5 by 5 arcmin resolution was applied to compute green and blue water footprints of the four crops in the Yellow River Basin in the period considered. The sensitivity and uncertainty analysis focused on the effects on water footprint estimates at basin level (in m3 t−1 of four key input variables: precipitation (PR, reference evapotranspiration (ET0, crop coefficient (Kc, and crop calendar. The one-at-a-time method was carried out to analyse the sensitivity of the water footprint of crops to fractional changes of individual input variables. Uncertainties in crop water footprint estimates were quantified through Monte Carlo simulations. The results show that the water footprint of crops is most sensitive to ET0 and Kc, followed by crop calendar and PR. Blue water footprints were more sensitive to input variability than green water footprints. The smaller the annual blue water footprint, the higher its sensitivity to changes in PR, ET0, and Kc. The uncertainties in the total water footprint of a crop due to combined uncertainties in climatic inputs (PR and ET0 were about ±20% (at 95% confidence interval. The effect of uncertainties in ET0 was dominant compared to that of precipitation. The uncertainties in the total water footprint of a crop as a result of combined key input uncertainties were on average ±26% (at 95% confidence level. The sensitivities and uncertainties differ across crop types, with

  20. EXPERIMENTAL STUDY OF EFFECT OF END SILL ON STILLING BASIN PERFORMANCE

    Directory of Open Access Journals (Sweden)

    H.L.Tiwari,

    2011-04-01

    Full Text Available This research paper presents an experimental study of end sill for new stilling basin models in dissipation of energy for a rectangular shaped pipe outlet of size 10.8cm x 6.3 cm. The models were tested for three Froude numbers namely 1.85, 2.85 and 3.85 in the laboratory. The new models are developed by changing the shape of end sill. The scour (magnitude and location after the end sill were measured for each model. The results have indicated that for all flow conditions, the sloping end sill is more effective in lowering the downstream kinetic energy than other end sills tested,

  1. Comparison of long term oil evaporation in laboratory and wave basin studies

    International Nuclear Information System (INIS)

    The role and reliability of predictive models in oil spill management are discussed. Predictive models require both oil specific properties and some data from observations at the spill site. Because it is difficult to measure many of the characteristics of oil spills, it is difficult to determine the reliability of spill model predictions. Two meso-scale oil spills in a wave basin have been studied and compared to laboratory tray evaporations to determine the reliability of model predictions based on both the Mackay evaporation equation and on an evaporation index proposed in the literature. Results of the experiment indicate that if average values for the properties of spilled oil can be established, the Mackay formulation will provide a reliable determination of a meso-scale spill evaporation. An alternative approach may be to use the weathering index derived from gas chromatography analyses and weight loss measurements on a laboratory scale. 8 refs., 9 figs

  2. 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.

  3. Hydrogen isotopic compositions of individual alkanes as a new approach to petroleum correlation: case studies from the Western Canada Sedimentary Basin

    Energy Technology Data Exchange (ETDEWEB)

    Maowen Li; Obermajer, M.; Chunqing Jiang; Snowdon, L.R.; Fowler, M.G. [Geological Survey of Canada, Calgary (Canada); Yongsong Huang [Brown University, Providence, RI (United States). Department of Geological Science

    2001-07-01

    Isotopic compositions of carbon-bound hydrogen in individual n-alkanes and acyclic isoprenoid alkanes, from a number of crude oil samples, were measured using gas chromatography-thermal conversion-isotope ratio mass spectrometry. The precision of this technique is better than 3 per cent for most alkanes, compared to the large range of {delta}D variation among the samples (up to 160 per cent). The oils were selected from major genetic oil families in the Western Canada Sedimentary Basin, with source rocks ranging in age from Ordovician (and possibly Cambrian) to Cretaceous. The hydrogen isotopic composition of alkanes in crude oils is controlled by three factors: isotopic compositions of biosynthetic precursors, source water {delta}D values, and postdepositional processes. The inherited difference in the lipid's biosynthetic origins and/or pathways is reflected by a small hydrogen isotopic variability within n-alkanes, but much larger differences in the {delta}D values between n-alkanes and pristane/phytane. The shift toward lighter hydrogen isotopic compositions from Paleozoic to Upper Cretaceous oils in the WCSB reflects a special depositional setting and/or a minor contribution of terrestrial organic matter. The strong influence of source water {delta}D values is demonstrated by the distinctively lower {delta}D values of lacustrine oils than marine oils, and also by the high values for oils with source rocks deposited in evaporative environments. Thermal maturation may alter the {delta}D values of the alkanes in the oil to some extent, but secondary oil migration does not appear to have had any significant impact. The fact that oils derived from source rocks that could be of Cambrian age still retain a strong signature of the hydrogen isotopic compositions of source organic matter, and source water, indicates that {delta}D values are very useful for oil-source correlation and for paleoenvironmental reconstructions. (author)

  4. 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.

  5. Study on the Industrial Ecological Compensation in Inter-basin Regions

    OpenAIRE

    Yachen Liu

    2010-01-01

    Aiming at the inter-basin pollution of water sources, the meaning, the content, and the system of the industrial ecological compensation are proposed in this article and the corresponding inter-basin industrial ecological compensation institution is suggested to be established.

  6. 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.

  7. 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.

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

    International Nuclear Information System (INIS)

    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

  9. 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

  10. A STUDY OF THE REFERENCE CLIMATIC PARAMETERS AND THEIR IMPACT UPON THE HYDROLOGICAL REGIME. CASE STUDY: IALOMITA HYDROGRAPHIC BASIN

    Directory of Open Access Journals (Sweden)

    Mihaela Borcan

    2009-10-01

    Full Text Available The paper provides an analysis for the evolution and spatio-temporal variation of two climatic parameters (precipitation and evapotranspiration and one hydrological parameter (the flown water volume over a common period of time (1970-2007 in Ialomita Hydrographical Basin which has been recently affected by extended periods of drought. In achieving this aim we started our analysis from the equation of the water balance in a large hydrographical basin over a long period of time. Among the elements of this equation the amount of rainfall (precipitation and evapotranspiration are further called the reference climatic parameters since they are the ones that influence the volume of the surface run-off. The evolution of the above mentioned parameters has been accomplished by taking into account the recorded data from 6 meteorological and hydrological posts that can be considered characteristic for Ialomita River Basin. They have been used to identify the tendency of these reference climatic parameters and establish their influence upon the hydrological regime. The parallel study of these three parameters may offer valuable data upon their tight connection in a regional context.We often use the air temperature as an indicator of how comfortable we will feel when we are involved in sports or other physical activities. However, the air temperature is only one factor in the assessment of thermal stress. Human thermal comfort depends on environmental and personal factors. The four environmental factors are: airflow (wind, air temperature, air humidity, and radiation from the sun and nearby hot surfaces. The personal factors are the clothing being worn and the person's level of physical activity.

  11. 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.

  12. Isotopic studies of environmental changes in the Caspian and Aral Sea Basins

    International Nuclear Information System (INIS)

    Full text: During the last thirty years environmental change studies in the Caspian and Aral Seas, lakes Issyk Kul, Balkhash, Yakhsan and a number of rivers of the Central Asian region were carried out. Isotopes in water masses and natural archives in bottom sediments, granulometry, mineralogy, X-ray and diffractometry, magnetic susceptibility, organic carbon, pollen, diatoms, fossil remains of organisms and coarse grained minerals, salinity of pore water, CaCO3 and MgCO3 contents, and C-14 dating were used for the study. The results of investigation of the past and present-day hydrologic regime, water dynamics, sea level variation and sedimentation process as impact of climate variation are presented in the paper. The time interval covering the study is Late Pleistocene-Holocene. The main findings and conclusions of the work are as follows: (1) Sedimentation rate in the southern and central basins of the Caspian Sea had in time a mirror reverse character. Within the interval of 24,000 to 11,000 years the average rate of sedimentation in the central basin was about 0.12 mm/year, whereas since 11,000 to 6,000 years it grew by en order of magnitude and amounted 1.2 mm/year. On the contrary, in the southern basin intensive sedimentation up to 0.9 mm/year took place from 23,000 to 17,000 years and decreasing within 17,000 to 6,000 years to 0.19 mm/year. (2) It was found from isotopic composition of oxygen and carbon in the carbonate fraction, that in the period of increased sedimentation the isotopically light river waters were discharged, alternatively, from the south and north. (3) The chemical composition of the pore water demonstrate that simultaneous salinization of the both basins began approximately 22,000 years ago due to intensive water discharge from the south. During that period, the sea level was higher then today up to 70 m, and the sea had hydraulic link with the Black Sea basin. (4) The analysis of transport and accumulation of the clastic particles with

  13. New test basin for experimental studies on oil spill in ice

    International Nuclear Information System (INIS)

    The Hamburg Ship Model Basin has converted one of its ice tanks into an environmental test basin for cold regions. The test basin is 30 m long, 6 m wide and 1.5 m deep. Special features of the basin are ice making facilities that can achieve 2 mm/h of ice growth, a mobile wave generator, a current device which is used together with a longitudinal bulkhead to operate the basin as a circulating water channel, and oil recovery devices. Typical sea ice conditions which can be simulated include homogeneous level ice of constant thickness, pack ice fields, rafted ice, and pressure ridges. A joint industry research program has been proposed to investigate weathering, fate, and spreading of various oils in different ice conditions with and without currents. Laboratory testing will also be dedicated to the development of suitable techniques for combatting oil spills in ice-covered areas. 2 figs

  14. 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.

  15. 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.

  16. Effects of temperature on flood forecasting: analysis of an operative case study in Alpine basins

    Science.gov (United States)

    Ceppi, A.; Ravazzani, G.; Salandin, A.; Rabuffetti, D.; Montani, A.; Borgonovo, E.; Mancini, M.

    2013-04-01

    In recent years the interest in the forecast and prevention of natural hazards related to hydro-meteorological events has increased the challenge for numerical weather modelling, in particular for limited area models, to improve the quantitative precipitation forecasts (QPF) for hydrological purposes. After the encouraging results obtained in the MAP D-PHASE Project, we decided to devote further analyses to show recent improvements in the operational use of hydro-meteorological chains, and above all to better investigate the key role played by temperature during snowy precipitation. In this study we present a reanalysis simulation of one meteorological event, which occurred in November 2008 in the Piedmont Region. The attention is focused on the key role of air temperature, which is a crucial feature in determining the partitioning of precipitation in solid and liquid phase, influencing the quantitative discharge forecast (QDF) into the Alpine region. This is linked to the basin ipsographic curve and therefore by the total contributing area related to the snow line of the event. In order to assess hydrological predictions affected by meteorological forcing, a sensitivity analysis of the model output was carried out to evaluate different simulation scenarios, considering the forecast effects which can radically modify the discharge forecast. Results show how in real-time systems hydrological forecasters have to consider also the temperature uncertainty in forecasts in order to better understand the snow dynamics and its effect on runoff during a meteorological warning with a crucial snow line over the basin. The hydrological ensemble forecasts are based on the 16 members of the meteorological ensemble system COSMO-LEPS (developed by ARPA-SIMC) based on the non-hydrostatic model COSMO, while the hydrological model used to generate the runoff simulations is the rainfall-runoff distributed FEST-WB model, developed at Politecnico di Milano.

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

    Science.gov (United States)

    Gems, B.; Wörndl, M.; Gabl, R.; Weber, C.; Aufleger, M.

    2014-02-01

    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 at various locations within catchments. Directly at the debris cones, these protection measures often include a deposition basin at the fan apex and/or a confined channel that passes 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 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Z.L.; Xiao, H.; Liu, L.; Zhang, S.; Qin, Y.; Wei, C.T. [North West University of Xian, Xian (China)

    2005-12-15

    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 late-Paleozoic era and the mid-Mesozoic era is relatively low and the palaeogeothermal gradient in the late-Mesozoic is up to 5.56 {sup o}C/100 m in the middle, and the values are relatively higher in the north and south margins of the basin, reaching over 8.00{sup o}C/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{sup o}C. 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{sup o}C) 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.

  19. 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.

  20. 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.

  1. Application of fission track and other new technics in the study of geothermal history for Liaohe Basin

    International Nuclear Information System (INIS)

    Mainly based on the study of fission track of the apatites, as well as geochronology, stable isotope composition and inclusion analysis, the principle and method of studying the geothermal history of sedimentary basin have been expounded systematically, and the source of sediment materials, and the geothermal characteristics of five section areas in Liaohe Basin were determined. The results of apatites and zircons U-Pb dating indicate that the materials of Shahejie Group in Liaohe Basin derived from the Shanhaiguan old land, and the record time of fission track of the apatites started at 172 Ma ago. On the basis of the studies of fission track characters of 100 apatite samples, stable isotopes and inclusion analysis, the annealing zone of fission track, oil generation zone and the old geothermal gradient were determined respectively in the western slope, southern part of western depression, Niuju area, Huangjindai area of eastern depression and Shallow sea area. It has provided the important scientific basis of reevaluating oil resources in Liaohe Basin. (2 tabs.)

  2. Sustainable development of living sources, case-study of Karkheh's Dam basin

    International Nuclear Information System (INIS)

    The watershed basins with a plain system has been recognized as the factors which has direct effect on environment and human life. The beginning source of disturbing natural basins is where the unnecessary demands appears. Because of increasing demand for food in future, there fore, with increasing destruction on environment in world wide activity, on the other hand, it force use improving new technique and systems to over-come our demands. This reason seems to be enough for use to grow our activity through sustainable development of living sources. The present paper try to define and Explain the sustainable development and permanent stability base on general characteristics of Karkheh's watershed basin

  3. 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.

  4. Identifying induced seismicity in active tectonic regions: A case study of the San Joaquin Basin, California

    Science.gov (United States)

    Aminzadeh, F.; Göbel, T.

    2013-12-01

    Understanding the connection between petroleum-industry activities, and seismic event occurrences is essential to monitor, quantify, and mitigate seismic risk. While many studies identified anthropogenically-induced seismicity in intraplate regions where background seismicity rates are generally low, little is known about how to distinguish naturally occurring from induced seismicity in active tectonic regions. Further, it is not clear how different oil and gas operational parameters impact the frequency and magnitude of the induced seismic events. Here, we examine variations in frequency-size and spatial distributions of seismicity within the Southern Joaquin basin, an area of both active petroleum production and active fault systems. We analyze a newly available, high-quality, relocated earthquake catalog (Hauksson et al. 2012). This catalog includes many seismic events with magnitudes up to M = 4.5 within the study area. We start by analyzing the overall quality and consistence of the seismic catalog, focusing on temporal variations in seismicity rates and catalog completeness which could indicate variations in network sensitivity. This catalog provides relatively homogeneous earthquake recordings after 1981, enabling us to compare seismicity rates before and after the beginning of more pervasive petroleum-industry activities, for example, hydraulic-fracturing and waste-water disposals. We conduct a limited study of waste-water disposal wells to establish a correlation between seismicity statistics (i.e. rate changes, fractal dimension, b-value) within specific regions and anthropogenic influences. We then perform a regional study, to investigate spatial variations in seismicity statistics which are then correlated to oil field locations and well densities. In order to distinguish, predominantly natural seismicity from induced seismicity, we perform a spatial mapping of b-values and fractal dimensions of earthquake hypocenters. Seismic events in the proximity to

  5. Case study on rehabilitation of a polluted urban water body in Yangtze River Basin.

    Science.gov (United States)

    Wu, Juan; Cheng, Shuiping; Li, Zhu; Guo, Weijie; Zhong, Fei; Yin, Daqiang

    2013-10-01

    In the past three decades, the fast development of economy and urbanization has caused increasingly severe pollutions of urban water bodies in China. Consequently, eutrophication and deterioration of aquatic ecosystem, which is especially significant for aquatic vegetation, inevitably became a pervasive problem across the Yangtze River Basin. To rehabilitate the degraded urban water bodies, vegetation replanting is an important issue to improve water quality and to rehabilitate ecosystem. As a case study, a representative polluted urban river, Nanfeihe River, in Hefei City, Anhui Province, was chosen to be a rehabilitation target. In October 2009 and May 2010, 13 species of indigenous and prevalent macrophytes, including seven species emergent, one species floating leaved, and five species submersed macrophytes, were planted along the bank slopes and in the river. Through 1.5 years' replanting practice, the water quality and biodiversity of the river had been improved. The concentrations of total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen (NH4 (+)-N) declined by 46.0, 39.5, and 60.4 %, respectively. The species of macrophytes increased from 14 to 60, and the biodiversity of phytoplankton rose significantly in the river (p<0.05). The biomasses of zooplankton and benthos were also improved after the vegetation replanting. The study confirmed that vegetation replanting could alleviate the increasing water pollution and rehabilitate the degraded aquatic ecosystem. The case study would be an example for polluted urban waters restoration in the middle-downstream area of Yangtze River Base. PMID:23247519

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

    Science.gov (United States)

    Portail, M.; Olu, K.; Escobar-Briones, E.; Caprais, J. C.; Menot, L.; Waeles, M.; Cruaud, P.; Sarradin, P. M.; Godfroy, A.; Sarrazin, J.

    2015-09-01

    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 a biogeographic barrier, and 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 sulfide concentrations, whereas vent environmental specificities (higher temperature, higher metal concentrations and lower pH) were not significant. 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. At the family level, seep and vent similarity reached at least 58 %. All vent families were found at seeps and each seep-specific family displayed low relative abundances (< 5 %). Moreover, 85 % of the identified species among dominant families were shared between seep and vent ecosystems. This study provides further support to the hypothesis of continuity among deep-sea seep and vent ecosystems.

  7. Palynostratigraphic study of Lower Karoo rocks in the Moatize-Minjova coal basin, Mozambique - preliminary results

    OpenAIRE

    Lopes, Gilda; Pereira, Zélia; Fernandes, Paulo; Marques, João

    2014-01-01

    The Karoo Supergroup (KSG) is one of the most important geological units of Southern Africa. The KSG is well represented in the Tete Province along the Zambezi River in several horst and graben basins.

  8. 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.

  9. Morphology and tectonics of Mahanadi Basin, northeastern continental margin of India from geophysical studies

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Subrahmanyam, A; Murty, G.P.S.; Murthy, K.S.R.

    and gravity data resembles a series of coast-parallel structural highs and depressions and their shearing pattern in the Mahanadi offshore Basin. The Chilika offshore lineament and Dhamara offshore lineament constitute the southern and northern boundaries...

  10. 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

  11. Study of the Ouarzazate basin structure by seismic reflection: hydrogeological implications

    Directory of Open Access Journals (Sweden)

    Jaffal, M.

    2009-12-01

    Full Text Available A large number of seismic reflection lines have been carried out in the Ouarzazate basin by the oil industry. The present study is concerned with the interpretation of a part of these data in order to characterize the structure of the Eocene aquifer system. The reflector corresponding to the base of this system, made up of sandstone and limestone, was first identified then digitized on each time-migrated seismic section. An isochrone map of this reflector was realized. The analysis of this map shows that the area under study is subdivided into two structurally contrasted domains. The first, the northern one, is intensively deformed; while the second, the southern one, is slightly folded. The results of this study provide a better understanding of the deep geological structure of the Ouarzazate basin. This allows us to better comprehend the functioning of the Eocene aquifer system, and to rationalize the future potential underground water exploration in the Ouarzazate basin.

    Les campagnes d’exploration pétrolière menées dans le bassin d’Ouarzazate ont permis l’acquisition d’une importante base de données de sismique réflexion. La présente étude concerne l’interprétation d’une partie de ces données dans l’objectif de caractériser la tectonique de l’Eocène et la structure de son système aquifère. Dans un premier temps, le réflecteur correspondant à la base de cet étage, représenté de grès et de calcaires, a été identifié, puis numérisé sur les différentes sections sismiques migrées-temps; ce qui nous a permis d’en établir une carte d’isochrones. Celle-ci montre que le secteur étudié est subdivisé en deux domaines très contrastés d’un point de vue structural. Le premier, septentrional, est affecté par une structuration intense de direction atlasique, tandis que le second, méridional, est faiblement plissé. Les résultats de la présente étude permettent une meilleure connaissance de la

  12. Paleoenvironmental reconstruction in the western lacustrine plain of Llancanelo Lake, Mendoza, Argentina

    Science.gov (United States)

    Violante, R.; Osella, A.; Vega, M. de la; Rovere, E.; Osterrieth, M.

    2010-04-01

    Lakes are key sites for studying paleoclimates. Llancanelo Lake (southern Mendoza Province, western Argentina) is an endoreic, highly saline water body located in the southern extreme of a tectonic basin, the Central or Huarpes Depression. The lake is located between the Andean Cordillera, San Rafael Block and Payenia Volcanic Field. The lake evolved as a major regional depocenter during the Pliocene-Quaternary, hence it contains important thicknesses of intra and extra basinal clastic and evaporitic sediments mainly dominated by volcaniclastic products. The main conditioning factors in the lake evolution were arc and back-arc volcanism as well as climatic changes. Geomorphological and sedimentary evidence supports the hypothesis that the lake was in past times larger than in present days. This paper estimates the lake's former extension on the western lacustrine plain using electromagnetic induction (EMI) and geoelectricity (Multielectrode Resistivity Meter) surveys, as well as shallow wells, along an 8 km long transect perpendicular to the lake's western shoreline. The geophysical and sedimentological information, as well as microfaunal studies, lab analysis and petrographic/EDAX determinations, support the presence, in the subsoil, of a lacustrine sequence at least 30 m thick composed mainly of volcaniclastic sediments. Volcanic eruptions and climatic changes influenced the evolution of the lake, producing intercalations in the lacustrine sedimentary sequences of ash layers, evaporites, soils, and eolian and swamp deposits.

  13. Palaeomagnetic study of the Xitle-Pedregal de San Angel lava flow, southern Basin of Mexico

    Science.gov (United States)

    Urrutia-Fucugauchi, J.

    1996-10-01

    A detailed study of the ˜ 2000 years old Xitle-Pedregal de San Angel volcanic field in the southern Basin of Mexico was undertaken to assess the reliability of the palaeomagnetic record as derived from fresh well-preserved and exposed lava flows. The Xitle vent is on the slope of the Ajusco volcano, which results in a topographic difference of over 800 m in less than 12 km of horizontal distance. Most sites present a mean direction, with a small within-site dispersion, around the dipolar direction for the locality, but some sites, particularly in the basin sector of flat relief away from the vent, show shallow inclinations. Anisotropy of magnetic susceptibility (AMS) shows normal 'flow' fabrics with horizontal foliation planes and small anisotropy degree. AMS lineations correlate with observed flow directions. The magnetic properties vary systematically across flow units, but directions do not show a consistent pattern. Secular variation effects do not apparently contribute to the shallow inclinations or directional scatter. Some lava structures like pressure crests and blocky fronts give shallow inclinations and scattered directions, respectively. The resulting overall mean direction is well defined and close to the dipolar direction ( B = 26, Dec = 359.8°, Inc = 32.8°, k = 167, α95 = 2.2°), but this excludes two apparent directional groups. The mean direction for one group, with B = 19, Dec = 359.0°, Inc = 35.1°, k = 247, α95 = 2.1°, may be the representative estimate for the field. Shallow inclinations are considered anomalous and associated to a characteristic specific to given sectors of lava flows. Palaeointensity determinations have been obtained for six samples from five sites by using the Thellier and Shaw methods. Results agree well with previous studies, however, the standard deviation calculated for the mean value remains high after incorporation of the new data. Mean palaeointensity based on five new determinations and eight early data is N

  14. Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River basin

    Science.gov (United States)

    Zhuo, L.; Mekonnen, M. M.; Hoekstra, A. Y.

    2014-06-01

    Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t-1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of producing maize, soybean, rice, and wheat at the scale of the Yellow River basin in the period 1996-2005. A grid-based daily water balance model at a 5 by 5 arcmin resolution was applied to compute green and blue water footprints of the four crops in the Yellow River basin in the period considered. The one-at-a-time method was carried out to analyse the sensitivity of the crop water footprint to fractional changes of seven individual input variables and parameters: precipitation (PR), reference evapotranspiration (ET0), crop coefficient (Kc), crop calendar (planting date with constant growing degree days), soil water content at field capacity (Smax), yield response factor (Ky) and maximum yield (Ym). Uncertainties in crop water footprint estimates related to uncertainties in four key input variables: PR, ET0, Kc, and crop calendar were quantified through Monte Carlo simulations. The results show that the sensitivities and uncertainties differ across crop types. In general, the water footprint of crops is most sensitive to ET0 and Kc, followed by the crop calendar. Blue water footprints were more sensitive to input variability than green water footprints. The smaller the annual blue water footprint is, the higher its sensitivity to changes in PR, ET0, and Kc. The uncertainties in the total water footprint of a crop due to combined uncertainties in climatic inputs (PR and ET0) were about ±20% (at 95% confidence interval). The effect of uncertainties in ET0was dominant compared to that of PR. The uncertainties in the total water footprint of a crop as a result of combined key input

  15. Geothermal energy from the Pannonian Basins System: An outcrop analogue study of exploration target horizons in Hungary

    Science.gov (United States)

    Götz, Annette E.; Sass, Ingo; Török, Ákos

    2015-04-01

    The characterization of geothermal reservoirs of deep sedimentary basins is supported by outcrop analogue studies since reservoir characteristics are strongly related to the sedimentary facies and thus influence the basic direction of geothermal field development and applied technology (Sass & Götz, 2012). Petro- and thermophysical rock properties are key parameters in geothermal reservoir characterization and the data gained from outcrop samples serve to understand the reservoir system. New data from the Meso- and Cenozoic sedimentary rocks of Budapest include carbonates and siliciclastics of Triassic, Eocene, Oligocene and Miocene age, exposed on the western side of the river Danube in the Buda Hills (Götz et al., 2014). Field and laboratory analyses revealed distinct horizons of different geothermal potential and thus, enable to identify and interpret corresponding exploration target horizons in geothermal prone depths in the Budapest region as well as in the Hungarian sub-basins of the Pannonian Basins System (Zala and Danube basins, Great Plain) exhibiting geothermal anomalies. References Götz, A.E., Török, Á., Sass, I., 2014. Geothermal reservoir characteristics of Meso- and Cenozoic sedimentary rocks of Budapest (Hungary). German Journal of Geosciences, 165, 487-493. Sass, I., Götz, A.E., 2012. Geothermal reservoir characterization: a thermofacies concept. Terra Nova, 24, 142-147.

  16. A geochemical study on mud volcanoes in the Junggar Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Ryoichi, E-mail: ryo-nakada@hiroshima-u.ac.jp [Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Takahashi, Yoshio [Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Tsunogai, Urumu [Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, Kita-10 Nishi-8, Kita-ku, Sapporo 060-0810 (Japan); Zheng Guodong [Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, 382 West Donggang Road, Lanzhou 730000 (China); Shimizu, Hiroshi [Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hattori, Keiko H. [Department of Earth Science, University of Ottawa, Ottawa, ON, K1N 6N5 (Canada)

    2011-07-15

    Highlights: > Gases released from Xinjiang mud volcanoes are dominated by thermogenic origin. > Secondary microbial activities occurring closer to the surface dramatically changed the {delta}{sup 13}C{sub CO2}. > The water-rock interaction occurred at deeper level than gas and petroleum reservoir. - Abstract: A comprehensive study was performed to characterize, for the first time, the mud, water, and gases released from onshore mud volcanoes located in the southern margin of the Junggar Basin, northwestern China. Chemical compositions of mud, along with the geology of the basin, suggest that a source of the mud is Mesozoic or Cenozoic shale. Oxygen and H isotope compositions of the released water suggest a local meteoric origin. Combined with the positive Eu anomalies of the water, a large {sup 18}O shift of the water suggests extensive interaction with rocks. Gases discharged from the mud volcanoes are predominantly thermogenic hydrocarbons, and the high {delta}{sup 13}C values (>+20 per mille VPDB) for CO{sub 2} gases and dissolved carbonate in muddy water suggest secondary methanogenesis with CO{sub 2} reduction after oil biodegradation. The enrichments of Eu and {sup 18}O in water and the low thermal gradient of the area suggest that the water-rock interactions possibly occur deeper than 3670 {+-} 200 m. On the other hand, considering the relationship to the petroleum reservoir around the mud volcanoes, the depth of the gases can be derived from about 3600 m, a depth that is greater than that generally estimated for reservoirs whose gas is characterized by {sup 13}C-enriched CO{sub 2}. Oil biodegradation with CO{sub 2} reduction likely occurs at a shallower depth along the seepage system of the mud volcano. The results contribute to the worldwide data set of gas genesis in mud volcanoes. Moreover, they further support the concept that most terrestrial mud volcanoes release thermogenic gas produced in very deep sediments and may be early indicators of oil

  17. Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (SE Europe) during the past 500 ka

    OpenAIRE

    Sadori, L.; Koutsodendris, A.; Masi, A; Bertini, A.; Combourieu-Nebout, N.; A. Francke; K. Kouli; Joannin, S.; A. M. Mercuri; Panagiotopoulos, K.; O. Peyron; Torri, P.; Wagner, B.; G. Zanchetta; Donders, T. H.

    2015-01-01

    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 In...

  18. Creative Realization of the Interdisciplinary Approach to the Study of Foreign Languages in the Experience of the Danube Basin

    OpenAIRE

    Olga Demchenko

    2013-01-01

    The article provides a brief overview of the experience of the Danube Basin universities, with an emphasis on the importance of studying Maritime English as a language of international communication. The phenomenon of “interdisciplinarity” and dominants of the interdisciplinary approach to the study of a foreign language is considered. Due to the need to train competent professionals for the maritime fleet with knowledge of professionally oriented foreign language and the lack of theoreticall...

  19. Impacts of Land Cover Changes on Hydrologic Responses: A Case Study of Chi River Basin, Thailand

    Science.gov (United States)

    Homdee, Tipaporn; Pongput, Kobkiat; Kanae, Shinjiro

    Land use and land cover (LULC) have been continuously changing, through human activities, leading to variations in hydrological cycle. In this study, we applied SWAT model to investigate potential impacts of LULC on water budget of the Chi river basin in Thailand. Five plausible scenarios of land use change were evaluated, including an conversion of forested area, expansion of farmland, switching of rice paddy fields to energy crops and two scenarios involving conversion of farmland to rice and sugarcane plantation. The results indicated that different land use scenarios contributed to various effects in annual and seasonal water yield and evapotranspiration (ET). Conversion of forested area and farmland showed slightly small changes on water flows and ET. Substitution of paddy fields by sugarcane plantation showed clearly reduced water flows and increased ET by almost 5.0% in dry season. Particularly, in case of expansion of rice paddy fields to farmland, small changes occur on annual flow and ET but more significant effect occur on seasonal flows. The results showed decrease in ET by nearly 12.0%, leading to increase of water yield by up to 5.1% during dry season. Finally, conversion of farmland to sugarcane plantation for biofuel production showed significant effect on seasonal ET, mainly decreasing in dry season by 4.5 % but small changes were detected on water yields.

  20. 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.

  1. 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.

  2. Pollution from animal husbandry in China: a case study of the Han River Basin.

    Science.gov (United States)

    Sun, Chen; Wu, Hongjuan

    2012-01-01

    Animal husbandry is one of the major agricultural pollution sources in China. The Xiangyang Reach of the Han River Basin was used as a case study to identify pollutants from animal rearing. The gross amount of pollutants from livestock and poultry rearing in the Xiangyang Reach was estimated using two empirical models with different data sets. The pig, cattle, sheep, and poultry population in 2009 amounted to 2.6, 0.6, 0.5, and 39.2 million head, respectively. The total annual pollutant loads generated from the feces and urine of livestock and poultry were 270,400 t of chemical oxygen demand; 228,900 t of biochemical oxygen demand; 26,500 t of ammonia nitrogen; 16,500 t of total phosphorus; and 63,900 t of total nitrogen. Approximately 12% of these pollutant loads were estimated to enter the Han River through the watershed outlet. Animal breeding has been one of the main pollution sources in this area, followed by domestic sewage and industrial wastewater. Cattle produced the most pollution, with the heaviest pollution load in downtown Xiangyang City. Several recommendations are presented to control the pollution caused by livestock and poultry breeding. PMID:22766880

  3. Hydrology and model study of the proposed Prosperity Reservoir, Center Creek Basin, southwestern Missouri

    Science.gov (United States)

    Harvey, Edward Joseph; Emmett, Leo F.

    1980-01-01

    A reservoir has been proposed on Center Creek, Jasper County, southwestern Missouri. Ground-water levels in the limestone uplands adjacent to the reservoir will rise when the impoundment is completed. The site is a few miles upstream from the Oronogo-Duenweg belt in the Tri-State zinc district. Grove Creek joins Center Creek downstream from the reservoir separating it from the mining belt. A model study indicates water-level rises varying from about 20 feet near the reservoir to 0.5 to 1.0 foot in the southern part of the Grove Creek drainage basin. A significant rise in the water table adjacent to the reservoir could increase mine-water discharge if Grove Creek is not an effective drain. However, it is probable that Grove Creek is an effective drain, and the higher ground-water levels in the reservoir area will increase ground-water discharge to Grove Creek, and in turn, Center Creek. The increase in ground-water discharge to Grove Creek will have the beneficial effect of diluting mine-water discharge from the Oronogo-Duenweg belt during periods of low flow. (USGS)

  4. Geomechanical reservoir models. A case study from the Sirte Basin / Libya

    Energy Technology Data Exchange (ETDEWEB)

    Henk, Andreas [Freiburg Univ. (Germany). Inst. fuer Geowissenschaften; Frischbutter, Andreas [Wintershall Holding AG, Kassel (Germany); Tawengi, Khaeri Segayer [National Oil Company, Tripoli (Libya)

    2010-03-15

    Geomechanical reservoir models on the basis of numerical simulation techniques provide a tool for the prediction of tectonic stresses and fractures. The workflow to set up and calibrate a geomechanical reservoir model includes import of the subsurface geometry as well as assignment of mechanical properties and boundary conditions. If well data are available, calculated stresses and fractures can be calibrated against observed data. Modeling results are relevant for a variety of tasks ranging from borehole stability and fault slip analysis to planning of hydraulic fracs. Application to a data set from a reservoir in the Eastern Sirte basin of Libya illustrates the practical potential of the modelling approach. The case study shows that stress orientations including local perturbations can be predicted with considerable accuracy even if the reservoir and fault geometries are primarily derived from seismic data, i.e. if well data is sparse. By nature, fracture prediction is less robust as it has to build on several poorly constrained input parameters like magnitude and orientation of paleo-stresses, paleo-pore pressures and former rock mechanical properties. Consequently, sufficient well data with fracture orientations observed on borehole image logs are required to calibrate the geomechanical model and provide a reliable base for fracture prognoses in the inter-well space. (orig.)

  5. 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.

  6. 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

  7. 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

    2016-03-16

    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. PMID:26857449

  8. Comparison of long-term geochemical interactions at two natural CO2-analogues : Montmiral (Southeast Basin, France) and Messokampos (Florina Basin, Greece) case studies

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) capture and storage is considered to be a viable strategy to reduce the amount of greenhouse gases released to the atmosphere. When assessing the feasibility of current or future CO2 storage projects, mineral trapping within a reservoir is considered as a key mechanism for the permanent sequestration of CO2. There are many occurrences worldwide, where natural CO2 has been trapped in geological reservoirs. These natural CO2 analogues provide a unique opportunity to study the reactivity, due to CO2 interactions, which occurred in the reservoirs over a geologic timeframe. Therefore, the study of analogous natural CO2-rich reservoirs, which act as long-term laboratories, are an important part of the assessment of the long-term geochemical effects of geological CO2 storage. This paper referred to 2 natural CO2 sites studied under the Natural Analogues for the Storage of CO2 in the Geological Environment (NASCENT) Project. The Montmiral reservoir in France's Southeast Basin is a high-temperature and high-pressure reservoir at great depth (100 degrees C and 36 MPa). The Messokampos reservoir in Greece's Florina Basin is a shallow, low temperature and low-pressure reservoir (25 degrees C and 0.5 MPa). Both are sandstone reservoirs, and feldspar alteration is the key interaction in both cases between dissolved CO2, the formation water and the reservoir rock. Both natural analogues were studied in detail petrographically and through geochemical modelling in order to characterize and explain the water-rock-gas interactions in the different geological contexts. The purpose was to assess the consequences of these interactions on CO2 storage capacity and porosity of the host rock. It was concluded that the reservoir's temperature and pressure conditions determine the impact of CO2 interactions, with elevated temperatures significantly increasing the reaction rates of mineral-trapping reactions. This is particularly significant when choosing future CO2

  9. Comparison of long-term geochemical interactions at two natural CO{sub 2}-analogues : Montmiral (Southeast Basin, France) and Messokampos (Florina Basin, Greece) case studies

    Energy Technology Data Exchange (ETDEWEB)

    Gaus, I.; Le Guern, C.; Pauwels, H. [Bureau de Recherches Geologiques et Minieres, Orleans (France); Pearce, J.; Shepherd, T. [British Geological Survey, Nottingham (United Kingdom); Hatziyannis, G.; Metaxas, A. [Inst. of Geology and Mineral Exploration, Athens (Greece)

    2005-07-01

    Carbon dioxide (CO{sub 2}) capture and storage is considered to be a viable strategy to reduce the amount of greenhouse gases released to the atmosphere. When assessing the feasibility of current or future CO{sub 2} storage projects, mineral trapping within a reservoir is considered as a key mechanism for the permanent sequestration of CO{sub 2}. There are many occurrences worldwide, where natural CO{sub 2} has been trapped in geological reservoirs. These natural CO{sub 2} analogues provide a unique opportunity to study the reactivity, due to CO{sub 2} interactions, which occurred in the reservoirs over a geologic timeframe. Therefore, the study of analogous natural CO{sub 2}-rich reservoirs, which act as long-term laboratories, are an important part of the assessment of the long-term geochemical effects of geological CO{sub 2} storage. This paper referred to 2 natural CO{sub 2} sites studied under the Natural Analogues for the Storage of CO2 in the Geological Environment (NASCENT) Project. The Montmiral reservoir in France's Southeast Basin is a high-temperature and high-pressure reservoir at great depth (100 degrees C and 36 MPa). The Messokampos reservoir in Greece's Florina Basin is a shallow, low temperature and low-pressure reservoir (25 degrees C and 0.5 MPa). Both are sandstone reservoirs, and feldspar alteration is the key interaction in both cases between dissolved CO{sub 2}, the formation water and the reservoir rock. Both natural analogues were studied in detail petrographically and through geochemical modelling in order to characterize and explain the water-rock-gas interactions in the different geological contexts. The purpose was to assess the consequences of these interactions on CO{sub 2} storage capacity and porosity of the host rock. It was concluded that the reservoir's temperature and pressure conditions determine the impact of CO{sub 2} interactions, with elevated temperatures significantly increasing the reaction rates of

  10. 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. PMID:20381129

  11. Magnesium isotope fractionation in biogenic and abiogenic carbonates: implications for paleoenvironmental proxies

    Science.gov (United States)

    Saenger, Casey; Wang, Zhengrong

    2014-04-01

    Geochemical variations in marine biogenic carbonates that are preserved in the geological record serve as proxies of past environmental change. However, interpreting most proxies is complicated by biologically-mediated vital effects, highlighting the need to develop new tools for reconstructing paleoenvironmental change. Recently, magnesium (Mg) isotope variability in carbonates has been explored extensively to determine its utility as a paleoenvironmental proxy. We review the results of these works, which have yielded valuable information on the factors affecting Mg isotope fractionation between carbonates and solution (Δ26Mgcarb-sol) in biogenic and abiogenic carbonate minerals. Strong evidence exists for a mineralogical control on Δ26Mgcarb-sol, with the negative offset from 0‰ following the sequence aragonite ˜3 mol/mol) and saturation states (Ω >˜3) that are similar to seawater suggest that Δ26Mgcarb-sol has a temperature dependence of ˜0.01‰ °C-1 and is insensitive to precipitation rate. In contrast, a significant precipitation rate dependence is observed in calcites precipitated from solutions with relatively low Mg/Ca ratios (precursors, ion attachment/detachment kinetics, surface entrapment and Mg speciation. High-Mg calcite organisms, which likely precipitate from relatively unmodified seawater, also exhibit a temperature dependence of ˜0.01‰ °C-1, albeit sometimes with a systematic offset toward smaller fractionations. In contrast, strong vital effects in low-Mg calcite organisms, which exclude Mg from their calcifying fluids, lead to Δ26Mgcarb-sol values that exhibit no clear temperature dependence and are offset from abiogenic experiments. The majority of biogenic aragonites have Δ26Mgcarb-sol values that are slightly more positive than those in abiogenic experiments, but bivalves and one sclerosponge species can exhibit significantly larger fractionations. Although vital effects and analytical uncertainties will limit Δ26Mgcarb

  12. 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

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

    OpenAIRE

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

    2014-01-01

    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 a...

  14. Methods for dating very old groundwater: eastern and central Great Artesian Basin case study. Chapter 13

    International Nuclear Information System (INIS)

    The Great Artesian Basin extends across 1.7 × 106 km2 or one fifth of the Australian continent. Annual rainfall ranges from 100 mm in the arid western parts to a maximum of 600 mm near the main recharge areas along the eastern basin margin. Average annual runoff is less than 10 mm and generally less than 5 mm. Ephemeral rivers dominate the land surface of the basin, except for a few perennial rivers in the most northern, tropical parts of the region. Most interior rivers drain into Lake Eyre (a dry salt pan at 12 m below sea level); however, the river waters often evaporate or infiltrate before reaching Lake Eyre because of the long distances. With little or no surface water present in the dry, hot and harsh climate of Australia’s interior, the ability of the early settlers to explore and exploit the resources of this region were limited.

  15. K Basin spent fuel sludge treatment alternatives study. Volume 2, Technical options

    International Nuclear Information System (INIS)

    Approximately 2100 metric tons of irradiated N Reactor fuel are stored in the KE and KW Basins at the Hanford Site, Richland, Washington. Corrosion of the fuel has led to the formation of sludges, both within the storage canisters and on the basin floors. Concern about the degraded condition of the fuel and the potential for leakage from the basins in proximity to the Columbia River has resulted in DOE's commitment in the Tri-Party Agreement (TPA) to Milestone M-34-00-T08 to remove the fuel and sludges by a December 2002 target date. To support the planning for this expedited removal action, the implications of sludge management under various scenarios are examined. This report, Volume 2 of two volumes, describes the technical options for managing the sludges, including schedule and cost impacts, and assesses strategies for establishing a preferred path

  16. 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.

  17. Lithofacies control in detrital zircon provenance studies: Insights from the Cretaceous Methow basin, southern Canadian Cordillera

    Science.gov (United States)

    DeGraaff-Surpless, K.; Mahoney, J.B.; Wooden, J.L.; McWilliams, M.O.

    2003-01-01

    High-frequency sampling for detrital zircon analysis can provide a detailed record of fine-scale basin evolution by revealing the temporal and spatial variability of detrital zircon ages within clastic sedimentary successions. This investigation employed detailed sampling of two sedimentary successions in the Methow/Methow-Tyaughton basin of the southern Canadian Cordillera to characterize the heterogeneity of detrital zircon signatures within single lithofacies and assess the applicability of detrital zircon analysis in distinguishing fine-scale provenance changes not apparent in lithologic analysis of the strata. The Methow/Methow-Tyaughton basin contains two distinct stratigraphic sequences of middle Albian to Santonian clastic sedimentary rocks: submarine-fan deposits of the Harts Pass Formation/Jackass Mountain Group and fluvial deposits of the Winthrop Formation. Although both stratigraphic sequences displayed consistent ranges in detrital zircon ages on a broad scale, detailed sampling within each succession revealed heterogeneity in the detrital zircon age distributions that was systematic and predictable in the turbidite succession but unpredictable in the fluvial succession. These results suggest that a high-density sampling approach permits interpretation of finescale changes within a lithologically uniform turbiditic sedimentary succession, but heterogeneity within fluvial systems may be too large and unpredictable to permit accurate fine-scale characterization of the evolution of source regions. The robust composite detrital zircon age signature developed for these two successions permits comparison of the Methow/Methow-Tyaughton basin age signature with known plutonic source-rock ages from major plutonic belts throughout the Cretaceous North American margin. The Methow/Methow-Tyaughton basin detrital zircon age signature matches best with source regions in the southern Canadian Cordillera, requiring that the basin developed in close proximity to the

  18. Hydrocarbons prospecting using an integrated approach of petrography, geochemistry and modeling of organic matter transformation. Analysis and reconstitution of the thermal history of the central carboniferous basins of Asturias (Spain) and of the Sabinas - Piedras Negras basin (Coahuila, Mexico); Prospection des hydrocarbures par une approche integree de petrographie, geochimie et modelisation de la transformation de la matiere organique. Analyse et reconstitution de l'histoire thermique des Bassins Carbonifere Central des Asturies (Espagne) et Sabinas - Piedras Negras (Coahuila, Mexique)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, N.

    2004-09-01

    Solid knowledge of the transformation and evolution of organic matter during hydrocarbon generation in sedimentary basins serves to improve natural gas exploration. With this geological problem in mind, the thermal influence on organic matter was analyzed in two basins containing different characteristics (age, composition of organic matter, litho-stratigraphy, depth, thickness of the layers of rock, the maturation of organic matter, etc.) in order to understand the natural processes in generating oil and natural gas. With a view to studying this geological phenomenon, this work outlines the study of the chemical and macerals composition, the coal rank and geochemical characteristics of organic matter in these two sedimentary basins for the first time: The Asturian Central Carboniferous Basin (Spain) and Sabinas - Piedras Negras Basin (Mexico). Moreover, an approach to shed light on the thermal history and evolution of organic matter through 1D modeling in the two basins is developed. The Central Carboniferous Basin in Asturias is an important coal mining area where coal types range from bituminous carbons with high content in volatile matter to anthracite. The petrographical and geochemical study in this region has shown that at the moment of oil and gas exploration, the coals correspond to an efficient expulsion of oil and have been formed in an environment of swamp with a facies rich in vitrinite, low in sulfur and ash and varying in mineral content. As regards the paleo-environmental reconstruction, the bio-markers suggest a swamp with a relatively high water table and a humid climate. The coal type, the vitrinite reflectance and the volatile matter content in the basin show a N-S trend which could be correlated to the paleo-temperatures calculated in this study. These data point to the influence of two thermal gradients in the region: A normal thermal gradient of long duration and an oblique thermal gradient of short duration due to a pluton. The evolution of

  19. The hydrochemistry of a semi-arid pan basin case study: Sua Pan, Makgadikgadi, Botswana

    International Nuclear Information System (INIS)

    This study presents results on the fluid and salt chemistry for the Makgadikgadi, a substantial continental basin in the semi-arid Kalahari. The aims of the study are to improve understanding of the hydrology of such a system and to identify the sources of the solutes and the controls on their cycling within pans. Sampling took place against the backdrop of unusually severe flooding as well as significant anthropogenic extraction of subsurface brines. This paper examines in particular the relationship between the chemistry of soil leachates, fresh stream water, salty lake water, surface salts and subsurface brines at Sua Pan, Botswana with the aim of improving the understanding of the system's hydrology. Occasionally during the short wet season (December-March) surface water enters the saline environment and precipitates mostly calcite and halite, as well as dolomite and traces of other salts associated with the desiccation of the lake. The hypersaline subsurface brine (up to TDS 190,000 mg/L) is homogenous with minor variations due to pumping by BotAsh mine (Botswana Ash (Pty) Ltd.), which extracts 2400 m3 of brine/h from a depth of 38 m. Notable is the decrease in TDS as the pumping rate increases which may be indicative of subsurface recharge by less saline water. Isotope chemistry for Sr (87Sr/86Sr average 0.722087) and S (δ34S average 34.35) suggests subsurface brines have been subject to a lithological contribution of undetermined origin. Recharge of the subsurface brine from surface water including the Nata River appears to be negligible

  20. The hydrochemistry of a semi-arid pan basin case study: Sua Pan, Makgadikgadi, Botswana

    Energy Technology Data Exchange (ETDEWEB)

    Eckardt, Frank D. [Environmental and Geographical Science, University of Cape Town, Rondebosch 7700 (South Africa)], E-mail: frank.eckardt@uct.ac.za; Bryant, Robert G. [Department of Geography, University of Sheffield, Department of Geography, Winter Street, Sheffield S10 2TN (United Kingdom); McCulloch, Graham [Department of Zoology, University of Dublin, Trinity College, Dublin 2 (Ireland); Spiro, Baruch [Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Wood, Warren W. [Department of Geological Sciences, Michigan State University, East Lansing, MI 48824 (United States)

    2008-06-15

    This study presents results on the fluid and salt chemistry for the Makgadikgadi, a substantial continental basin in the semi-arid Kalahari. The aims of the study are to improve understanding of the hydrology of such a system and to identify the sources of the solutes and the controls on their cycling within pans. Sampling took place against the backdrop of unusually severe flooding as well as significant anthropogenic extraction of subsurface brines. This paper examines in particular the relationship between the chemistry of soil leachates, fresh stream water, salty lake water, surface salts and subsurface brines at Sua Pan, Botswana with the aim of improving the understanding of the system's hydrology. Occasionally during the short wet season (December-March) surface water enters the saline environment and precipitates mostly calcite and halite, as well as dolomite and traces of other salts associated with the desiccation of the lake. The hypersaline subsurface brine (up to TDS 190,000 mg/L) is homogenous with minor variations due to pumping by BotAsh mine (Botswana Ash (Pty) Ltd.), which extracts 2400 m{sup 3} of brine/h from a depth of 38 m. Notable is the decrease in TDS as the pumping rate increases which may be indicative of subsurface recharge by less saline water. Isotope chemistry for Sr ({sup 87}Sr/{sup 86}Sr average 0.722087) and S ({delta}{sup 34}S average 34.35) suggests subsurface brines have been subject to a lithological contribution of undetermined origin. Recharge of the subsurface brine from surface water including the Nata River appears to be negligible.

  1. 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.

  2. The Influence of Policy Discourses on multilevel water governance: a case study of the Equatorial Nile Basin

    OpenAIRE

    Hissen, Nina F.

    2014-01-01

    This research assesses how discourses on climate change and water security during policy making impact on actual water management, analysing the Equatorial Nile Basin and its riparian countries (Uganda, Kenya, Tanzania, Burundi, Rwanda and DR Congo) as a case study. The thesis looks at the significance of informal policy networks for water governance, and critically discusses the extent to which the framing of issues by these networks are reflected in the practical implementation of mul...

  3. Association between Changing Mortality of Digestive Tract Cancers and Water Pollution: A Case Study in the Huai River Basin, China

    OpenAIRE

    Hongyan Ren; Xia Wan; Fei Yang; Xiaoming Shi; Jianwei Xu; Dafang Zhuang; Gonghuan Yang

    2014-01-01

    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 characte...

  4. Spatial heterogeneity and transboundary pollution: a contingent valuation study on the Xijiang River drainage basin in south China

    OpenAIRE

    Jie He; Anping Huang; Luodan Xu

    2015-01-01

    This article examines whether and how transboundary river water pollution spillover may affect resident’s Willingness to Pay (WTP) for a river water quality improvement project. Based on a CVM survey conducted in 20 cities located in the Xijiang river basin located in south China, our study demonstrates that the downstream city respondents report lower WTP when the water quality in the immediate upstream city is more polluted. This negative externality decreases with distance and relative b...

  5. 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.

  6. Near-infrared spectroscopy of lacustrine sediments in the Great Salt Lake Desert: An analog study for Martian paleolake basins

    Science.gov (United States)

    Lynch, Kennda L.; Horgan, Briony H.; Munakata-Marr, Junko; Hanley, Jennifer; Schneider, Robin J.; Rey, Kevin A.; Spear, John R.; Jackson, W. Andrew; Ritter, Scott M.

    2015-03-01

    The identification and characterization of aqueous minerals within ancient lacustrine environments on Mars are a high priority for determining the past habitability of the red planet. Terrestrial analog studies are useful both for understanding the mineralogy of lacustrine sediments, how the mineralogy varies with location in a lacustrine environment, and for validating the use of certain techniques such as visible-near-infrared (VNIR) spectroscopy. In this study, sediments from the Pilot Valley paleolake basin of the Great Salt Lake desert were characterized using VNIR as an analog for Martian paleolake basins. The spectra and subsequent interpretations were then compared to mineralogical characterization by ground truth methods, including X-ray diffraction, automated scanning electron microscopy, and several geochemical analysis techniques. In general, there is good agreement between VNIR and ground truth methods on the major classes of minerals present in the lake sediments and VNIR spectra can also easily discriminate between clay-dominated and salt-dominated lacustrine terrains within the paleolake basin. However, detection of more detailed mineralogy is difficult with VNIR spectra alone as some minerals can dominate the spectra even at very low abundances. At this site, the VNIR spectra are dominated by absorption bands that are most consistent with gypsum and smectites, though the ground truth methods reveal more diverse mineral assemblages that include a variety of sulfates, primary and secondary phyllosilicates, carbonates, and chlorides. This study provides insight into the limitations regarding the use of VNIR in characterizing complex mineral assemblages inherent in lacustrine settings.

  7. Holocene Sea-Level Fluctuations and Paleo-environmental changes in Maputo Bay, Mozambique, using stable isotopes

    Science.gov (United States)

    Martinez de Lecea, Ander; Green, Andrew; Wiles, Errol; Strachan, Kate; Cooper, Andrew

    2015-04-01

    Mozambique has been classified as a "hot-spot" for potential impacts derived from sea-level rise, yet there is little knowledge on past sea-level fluctuation in this part of the world. Further understanding of sea-level fluctuations in the region would be of great benefit. To this end a high resolution record of paleo-environmental changes in Maputo Bay, Mozambique, are determined. Stable isotope analyses (δ13Corg; δ15N; δ18O) are conducted on the sediment organic matter and foraminifera Elphidium crispum from two cores, a 3.6 m long core collected at 5m below mean sea-level (m.s.l.) (Core V13) and a 6.2 m long core collected at 13.5m below m.s.l. (Core V40). Evolution of the region is informed through a seismic study and dating of cores is under-way using 14C analysis. The two cores analysed in this study showed evidence of catastrophic flooding events, as well as environmental changes. Core V13 represents a higher resolution of environmental changes, while core V40 shows a longer period, with the system changing from terrestrial dominated environment to marine, to terrestrially dominated once again before settling at the present system of marine dominated environment. The deepest layer of Core V13 is of marine origin with evidence of beachrock formation occurring, indicating a beach environment, while the top 190 cm indicate repeated alternation between marine and terrestrial environments, representing a contemporary highstand bay-head delta highly influenced by terrestrial input. This is further supported by the seismic interpretation. Enriched δ15N signatures from the terrestrial layers from the top 190 cm, could suggest the settling of early Europeans in the area (~1,544 AD). Core V40's deepest layer is of terrestrial origin, and terminates abruptly in marine sand, most likely due to the sudden, catastrophic collapse of the dune barrier following sea-level rise. Comparisons of preliminary results with existing studies suggests that this core covers a time

  8. Hydrological and geochemical studies on the Sahelo-Sudanian basin of the Niger River

    International Nuclear Information System (INIS)

    African drought and rainfall deficits observed during the last twenty years had important repercussions on the runoff of the Niger River (annual deficit of 20 % during the 70's and of 46 % during the 80's). A large reduction of the groundwater storage explains the persistent degradation of the hydrological resource. The inner Delta of the Niger River is a particular system submitted to Sahelian and sub-desertic climatic conditions, and is characterized by large flood plains. Time series of input water volumes in the inner Delta and of the water losses inside it show that the water losses, due to the intense evaporation, vary from 40 km3 to 6 km3. The water losses are maximum during the wettest years, up to 47 %, and minimum during the driest years, only 32 %, due to the reduction of the flooded area. Since 1990 the EQUANIS program associates hydrological and chemical measurements in the study of the dissolved and suspended matter flows in the Niger River's flows to the Sahel. The specific sediment load vary between 7 or 8 t dm2 year-1 for the upper Niger River and 3 t km2 year-1 for the Bani River. The specific dissolved load vary between 10 or 12 t km2 year-1 for the Niger River and 2,5 t km2 year-1 for the Bani River. The annual input in the inner Delta was about 2,2 Mt in 1992-1993. Seasonal variations of the matter fluxes are very different between the upper and the lower parts of the inner Delta, due to the breaking of the annual flood and to the more important flood plains in the upper Delta. The preliminary results indicate that both rivers have a low level in dissolved element concentration. The inner Delta is not an old sedimentary basin and the actual deposits of matter should characterize its working during the lasting deficit of the water resources of the Niger River. (author)

  9. Hydrological, isotopic and hydrochemical study of the basin of Lake Valencia, Venezuela

    International Nuclear Information System (INIS)

    The basin of Lake Valencia lies in a tectonic graben in the coastal cordillera to the southwest of Caracas. It is an endorheic valley with an area of 3250 km2. For a number of years the groundwater quality has been deteriorating, especially through an increase in sulphur content. This may be related to the following factors: (a) penetration of sulphate-containing water from the lake into the acquifers; (b) penetration into the shallow aquifers of high-sulphate-content deep groundwater; (c) recharge on the aquifers with irrigation water enriched in chemical components by evaporation and containing agrochemicals. By combining the conventional methods of study with interpretation of stable environmental isotopes, the present paper seeks to contribute to a better understanding of groundwater movements and the water balance. In the eastern zone of the lake one can clearly differentiate the mixture of three components in the water: (1) water with low mineralization coming from the topmost parts of the aquifers; (2) water stored in the Taguaiguay dam contributing evaporated water to the aquifers; (3) deep groundwater with high sulphate concentrations but without tritium and about 10,000 years old. No contributions from the lake to the aquifers are observed. The western part of Lake Valencia, between La Culebra and Flor Amarilla, shows the presence of evaporated water resulting from the mixture of the lake water and local groundwater; there are also underground outflows to the river Paito. To the north and northwest of the lake there is a geothermal zone with hot or tepid water enriched in 18O. (author). 5 refs, 13 figs, 1 tab

  10. A radiochemical, hydrochemical and dissolved gas study of groundwaters in the Molasse basin of Upper Austria

    International Nuclear Information System (INIS)

    The Innviertel (Ottnangian) formation of the Molasse zone of Upper Austria is of major importance as a source of potable water. A hydrochemical, radiochemical and dissolved gas study was undertaken to establish the flow pattern in the Innviertel and its relationship to groundwaters in deeper formations in the Molasse basin. The Innviertel groundwaters could be differentiated into three groups on the basis of their chemical compositions. Waters from shallow boreholes which sampled very localised systems are oxidising waters of the Ca-bicarbonate type and may have high 3H contents. A transition to reducing groundwaters occurs in the second and third groups, with Na+ replacing Ca2+ as the dominant cation and sulphate being reduced to sulphide. The uranium solution chemistry also changes systematically with this change in redox conditions. The 234U/238U activity ratios are enhanced for group 2 groundwaters and decrease again in group 3 groundwaters. The low Cl contents of all the Innviertel groundwaters indicate that the marine sediments have been completely flushed by meteoric water and this is confirmed by the stable isotope composition of the water. Groundwater residence times have been estimated from hydrological data, radiogenic 4He accumulation rates and palaeotemperatures of recharge which were estimated from noble gas contents. The 3He/4He ratio shows that most radiogenic He diffuses from the basement granite and the He flux was estimated on the basis of diffusion theory. Groundwater residence times were assessed from this diffusive flux of helium and together with the recharge temperatures, indicate that the envolved groundwaters of the Innviertel were recharged during the interstadial which preceded the last glaciation. (orig.)

  11. A STUDY OF THE REFERENCE CLIMATIC PARAMETERS AND THEIR IMPACT UPON THE HYDROLOGICAL REGIME. CASE STUDY: IALOMITA HYDROGRAPHIC BASIN

    OpenAIRE

    Mihaela Borcan

    2009-01-01

    The paper provides an analysis for the evolution and spatio-temporal variation of two climatic parameters (precipitation and evapotranspiration) and one hydrological parameter (the flown water volume) over a common period of time (1970-2007) in Ialomita Hydrographical Basin which has been recently affected by extended periods of drought. In achieving this aim we started our analysis from the equation of the water balance in a large hydrographical basin over a long period of time. Among the el...

  12. Geochronologic study of sediments deposition of two lakes from the Rio Negro basin, Amazonas State, Brazil

    International Nuclear Information System (INIS)

    Since 1963 the radionuclide 210Pb became an important tool for dating (geochronology) recent sediments (up to 120 years). In this work the sedimentary geochronology of two lakes from the Negro River Basin was determined, using different radiochemical separation methods for 210Pb and 226Ra. (author)

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

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.

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

  14. 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...

  15. CONTRIBUTIONS TO THE STUDY OF AQUATIC VEGETATION IN THE VASLUI RIVER BASIN

    Directory of Open Access Journals (Sweden)

    IRINA BLAJ – IRIMIA

    2007-12-01

    Full Text Available This paper presents two associations from the Lemnetea minoris de Bolós et Masclans 1955 class and one from the Potametea pectinati Klika in Klika et Novák 1941 class identified in Vaslui river basin, described in a phytocoenological table and analysed from the point of view of bioforms, floristic elements, and ecological indices

  16. 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

  17. 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.

  18. Exploration for unconformity-associated uranium deposits: Learning from EXTECH IV, Athabasca basin multidisciplinary study, Canada

    International Nuclear Information System (INIS)

    Unconformity-associated uranium (U) deposits in the Athabasca Basin (hereafter 'the Basin') are pods, veins and disseminations of uraninite spatially associated with the basal unconformity of relatively flat, 1-2 km, unmetamorphosed but pervasively diagenetically altered, Paleo- to Mesoproterozoic, red siliciclastic strata. This is one of four such basins in the northwestern Canadian Shield that were filled by westerly flowing rivers with local complexities related to growth faults. Basement metamorphic belts are folded and interleaved Archean and Paleoproterozoic granitoid and supracrustal rocks. The intensely paleoweathered unconformity preserves variable thicknesses of red hematitic, clay-altered saprolite grading down through a green chloritic zone to fresh rock. The world's largest known highgrade unconformity-associated U deposits are along the basement Wollaston-Mudjatik transition domain. Cigar Lake and McArthur River deposits contain 131,400 and ∼190,000 tonnes U at grades of 15% and 23% U, respectively. Uranium dominates in monometallic (generally basement-hosted) deposits and is the principle commodity in polymetallic deposits with variable amounts of Ni + Co + As and traces of Au, Pt, Cu etc. Elsewhere in the basin, high grades have been mined and excellent prospects are being explored. EXTECH IV was a multidisciplinary field and laboratory project to enhance and preserve geoscience data and improve exploration methods for unconformity-associated U deposits. Regional to detailed research was coordinated at exploration sites across the Basin and focused at McArthur River. This report presents the results by discipline, with implications for exploration. New regional basement geology and revised Athabasca group stratigraphy and geological map were reported. Faults, basin and ore deposits are linked, structurally reworked ore is consistent with multiple ore-forming events, paleo-valleys are spatially associated with some Athabasca ore deposits, new

  19. 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.

  20. 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

    Science.gov (United States)

    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 tectonic events resulting in the formation of the present-day landforms. To establish a geochronological framework for the alluvium underlying the tablelands in the Puli Basin, optically stimulated luminescence dating was applied to obtain burial ages. The numerical data indicate an accumulation phase of alluvial fans in the Late Pleistocene to Early Holocene transition. The study area in the Taomi River catchment, an obvious longer precursor of the Taomi River, originating from west of the Yuchih Basin, transported the sediments forming the present-day southern tablelands. During the Pleistocene-Holocene transition, the climate changed to wetter and warmer conditions, so that slope processes might have changed and an increasing transport in the fluvial system was stimulated. Fluvial and fan terraces in other river catchments in Taiwan also indicate a period of increased fluvial transport and deposition. A geomorphic evolution model in the Puli Basin is reconstructed on the basis of the chronological framework and of sedimentological features. Fluvial processes controlled by climatic change and accompanied by tectonic activities have created the diverse topography in the Puli Basin.

  1. 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...

  2. The project for the study of Wurno irrigation scheme area in the Rima hydrological basin, Sokoto State, Nigeria for Fadama irrigation and water supply, using isotope techniques

    International Nuclear Information System (INIS)

    This publication summarizes the result of the project on the use of isotope techniques for the study of recharge and discharge of the Sokoto-Rima hydrological basin in the semi-arid and northwestern part of Nigeria

  3. Study-area boundary for "Structure, outcrop, and subcrop of the bedrock aquifers along the western margin of the Denver Basin, Colorado." Hydrologic Atlas 742

    Science.gov (United States)

    Rafferty, Sharon

    1998-01-01

    This digital geospatial data set consists of outlines of the study area in the report "Structure, Outcrop, and Subcrop of the Bedrock Aquifers Along the Western Margin of the Denver Basin, Colorado" (Robson and others, 1998).

  4. 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.

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

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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.

  8. Study of uranium mineralization in rock samples from marwat range bannu basin by fission track analysis technique

    International Nuclear Information System (INIS)

    The Geophysics Division, Atomic Energy Minerals Centre (AEMC), Lahore has planned a uranium exploration program in Marwat Range, Bannu Basin. In this connection 30 thin sections of rock samples, collected from four areas; namely, Darra Tang, Simukili, Karkanwal and Sheikhillah from Marwat Range, and one from Salt Range were provided to Nuclear Geology Group of Physics Research Division, PINSTECH for the study of nature and mechanism of uranium mineralization These studies are aimed to help in designing uranium exploration strategy by providing the loci of uranium sources in the Marwat and Salt Ranges. The samples have been studied using fission track analysis technique. (author)

  9. Natural Gas Hydrates in the Offshore Beaufort-Mackenzie Basin-Study of a Feasible Energy Source II

    International Nuclear Information System (INIS)

    In the offshore part of Beaufort-Mackenzie Basin depth of methane hydrate stability reaches more than 1.5 km. However, there are areas in the western part of the basin where there are no conditions of methane hydrate stability. Construction of the first contour maps displaying thickness of hydrate stability zones as well as hydrate stability zone thicknesses below permafrost in the offshore area, shows that these zones can reach 1200 m and 900 m, respectively. Depth to the base of ice-bearing relict permafrost under the sea (depth of the -1oC isotherm-ice-bearing permafrost base) and regional variations of geothermal gradient are the main controlling factors. Hydrostatic pressures in the upper 1500 m are the rule. History of methane hydrate stability zone is related mainly to the history of permafrost and it reached maximum depth in early Holocene. More recently, the permafrost and hydrate zone is diminishing because of sea transgression. Reevaluation of the location of possible gas hydrate occurrences is done from the analysis of well logs and other indicators in conjunction with knowledge of the hydrate stability zone. In the offshore Beaufort-Mackenzie Basin, methane hydrate occurs in 21 wells. Nine of these locations coincides with underlying conventional hydrocarbon occurrences. Previous analyses place some of the hydrate occurrences at greater depths than proposed for the methane hydrate-stability zone described in this study. Interpretation of geological cross sections and maps of geological sequences reveals that hydrates are occurring in the Iperk-Kugmallit sequence. Hydrate-gas contact zones, however, are possible in numerous situations. As there are no significant geological seals in the deeper part of the offshore basin (all hydrates are within Iperk), it is suggested that overlying permafrost and hydrate stability zone acted as the only trap for upward migrating gas during the last tens of thousand of years (i.e., Sangamonian to Holocene)

  10. Water Induced Hazard Mapping in Nepal: A Case Study of East Rapti River Basin

    Science.gov (United States)

    Neupane, N.

    2010-12-01

    This paper presents illustration on typical water induced hazard mapping of East Rapti River Basin under the DWIDP, GON. The basin covers an area of 2398 sq km. The methodology includes making of base map of water induced disaster in the basin. Landslide hazard maps were prepared by SINMAP approach. Debris flow hazard maps were prepared by considering geology, slope, and saturation. Flood hazard maps were prepared by using two approaches: HEC-RAS and Satellite Imagery Interpretation. The composite water-induced hazard maps were produced by compiling the hazards rendered by landslide, debris flow, and flood. The monsoon average rainfall in the basin is 1907 mm whereas maximum 24 hours precipitation is 456.8 mm. The peak discharge of the Rapati River in the year of 1993 at station was 1220 cu m/sec. This discharge nearly corresponds to the discharge of 100-year return period. The landslides, floods, and debris flows triggered by the heavy rain of July 1993 claimed 265 lives, affected 148516 people, and damaged 1500 houses in the basin. The field investigation and integrated GIS interpretation showed that the very high and high landslide hazard zones collectively cover 38.38% and debris flow hazard zone constitutes 6.58%. High flood hazard zone occupies 4.28% area of the watershed. Mitigation measures are recommendated according to Integrated Watershed Management Approach under which the non-structural and structural measures are proposed. The non-structural measures includes: disaster management training, formulation of evacuation system (arrangement of information plan about disaster), agriculture management practices, protection of water sources, slope protections and removal of excessive bed load from the river channel. Similarly, structural measures such as dike, spur, rehabilitation of existing preventive measures and river training at some locations are recommendated. The major factors that have contributed to induce high incidences of various types of mass

  11. CO2-induced mechanical behaviour of Hawkesbury sandstone in the Gosford basin: An experimental study

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) sequestered in saline aquifers undergoes a variety of chemically-coupled mechanical effects, which may cause CO2-induced mechanical changes and time-dependent reservoir deformation. This paper investigates the mineralogical and microstructural changes that occur in reservoir rocks following injection of CO2 in deep saline aquifers and the manner in which these changes influence the mechanical properties of the reservoir rocks. In this study, cylindrical sandstone specimens, 38 mm in diameter and 76 mm high, obtained from the Gosford basin, were used to perform a series of unconfined compressive strength (UCS) tests. Different saturation conditions: dry, water- and brine-saturated sandstone samples with and without scCO2 (super-critical carbon dioxide) injection, were considered in the study to obtain a comprehensive understanding of the impact of scCO2 injection during the CO2 sequestration process on saline aquifer mechanical properties. An acoustic emission (AE) system was employed to identify the stress threshold values of crack closure, crack initiation and crack damage for each testing condition during the whole deformation process of the specimens. Finally, scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were performed to evaluate the chemical and mineralogical changes that occur in reservoir rocks during CO2 injection. From the test results, it is clear that the CO2-saturated samples possessed a lower peak strength compared to non-CO2 saturated samples. According to SEM, XRD and XRF analyses, considerable quartz mineral corrosion and dissolution of calcite and siderite were observed during the interactions of the CO2/water/rock and CO2/brine/rock systems, which implies that mineralogical and geochemical rock alterations affect rock mechanical properties by accelerating the collapse mechanisms of the pore matrix. AE results also reveal the weakening effect of rock pore structure with CO2

  12. 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

    Although coal seams, besides saline aquifers and depleted oil and gas reservoirs, have the lowest capacity for deposition of carbon dioxide yet this relatively new technology is considered advantageous from an economical standpoint, especially in the case of location of a repository in the vicinity of a power plant producing carbon dioxide. Another appreciable positive aspect is injection of carbon dioxide into unmineable methane-bearing seams, which simultaneously increases production of coal methane as a valuable energetic resource. Suitability of coal seams as carbon dioxide repositories is given by exceptional properties of coal, which during the coalification process retained in its interior spatial arrangement a substantial part of the porous structure of the original plant material with predominance of cavities of an effective size carbon dioxide under the conditions corresponding to the situation in situ. Among the basic parameters for selection of a suitable repository based on simulation of the deposition process there is determination of its sorption capacity. The capacity can be determined in a laboratory by measuring the amount of carbon dioxide captured in a coal sample at a pressure and temperature corresponding to supercritical conditions in situ using high pressure sorption techniques. Similarly, the amount of methane bound in coal is based on high pressure measurement of it sorbed amount The present study has been aimed at investigation of the effect of the coal properties on the carbon dioxide and methane sorption capacities. High pressure sorption experiments with carbon dioxide and methane were carried out at the temperature 45 oC and the pressure up to 15 MPa with three samples of methane-bearing, medium rank coals in a moisture equilibrated state using a manometric method. The samples were taken from selected positions of drill cores from exploration boreholes in the Bohemian part of the Upper Silesian Basin, and were characterized by a

  13. 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.

  14. Bransfield Basin and Cordilleran Orogenesis

    Science.gov (United States)

    Dalziel, I. W.; Austin, J. A.; Barker, D. H.; Christensen, G. L.

    2003-12-01

    Tectonic uplift of the Andean Cordillera was initiated in the mid-Cretaceous with inversion of a composite marginal basin along 7500 km of the continental margin of South America, from Peru to Tierra del Fuego and the North Scotia Ridge. In the southernmost Andes, from 50-56 degrees S, the quasi-oceanic floor of this basin is preserved in the obducted ophiolitic rocks of the Rocas Verdes (Green Rocks) basin. We suggest that the basin beneath Bransfield Strait, 61-64 degrees S, separating the South Shetland Islands from the Antarctic Peninsula, constitutes a modern analog for the Rocas Verdes basin. Marine geophysical studies of Bransfield basin have been undertaken over the past 12 years by the Institute for Geophysics, University of Texas at Austin, under the auspices of the Ocean Sciences Division and United States Antarctic Program, National Science Foundation. These studies have elucidated the structure and evolution of Bransfield basin for comparison with the Rocas Verdes basin, with a view to eventual forward modeling of the evolution of a hypothetical cordilleran orogen by compression and inversion of the basin. These are the processes that can be observed in the tectonic transformation of the Rocas Verdes basin into the southernmost Andean cordillera, as South America moved rapidly westward in an Atlantic-Indian ocean hot-spot reference frame during the mid-Cretaceous. Multi-channel reflection seismic data from the Bransfield basin reveal an asymmetric structural architecture characterized by steeply-dipping normal faults flanking the South Shetlands island arc and gently dipping listric normal faults along the Antarctic Peninsula margin. Normal fault polarity reversals appear to be related to distributed loci of magmatic activity within the basin. This architecture is remarkably similar to that deduced from field structural studies of the Rocas Verdes basin. Notably, the oceanward-dipping, low angle normal faults along the Antarctic Peninsula margin

  15. 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

  16. 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.

  17. Geochemistry and recharge studies in the Densu river basin of Ghana using classical hydrological method, numerical modeling and tracer technique

    International Nuclear Information System (INIS)

    The Densu River Basin (DRB) is a coastal river catchment located in the southwestern part of Ghana. The basin is an important agricultural area in Ghana and has a high population density. An estimated 80% of the total population in the Densu River Basin depends on groundwater for commercial, agricultural and industrial activities. However, water shortages occurred in some communities in the basin due to low yields in most of the production wells which are a crucial factor restricting sustainable socio economic development. This study was carried out to investigate the geochemistry, the genesis of groundwater flow and its characteristics recharge processes and estimation in the basin. With regards to the genesis of groundwater flow and recharge processes, the study mainly used hydrochemical and environmental isotope data employing a series of comprehensive data interpretation e.g. statistics, ionic ratios and Piper diagram to obtain a better understanding of the system functioning. The following main hydrochemical processes were identified as controlling the water quality of the groundwater system: weathering of silicate minerals, dissolution, ion exchange and slightly evaporation which seem to be more pronounced down gradient of the flow system. As groundwater flows from the recharge to discharge areas, chemical patterns evolve in the order Ca-HCO3, Ca/Mg-HCO3 to Ca/Na-Cl, Ca-Na-HCO3, and Na-Cl according to lithology. The environmental isotopes (δ2H, δ18O, 3H) measurements further revealed that groundwater in the DRB is a relatively well mixed system as evidenced by the encoded narrow range of values. However, deviation from the rainwater signature indicates combined local processes such as direct percolation through preferential channels, evaporation, probable surface water and anthropogenic contribution to the system. Furthermore, the estimation of groundwater recharge in the study area explored the potential of water balance approach using hydro meteorological

  18. 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.

  19. Indications of regional scale groundwater flows in the Amazon Basins: Inferences from results of geothermal studies

    Science.gov (United States)

    Pimentel, Elizabeth T.; Hamza, Valiya M.

    2012-08-01

    The present work deals with determination groundwater flows in the Amazon region, based on analysis of geothermal data acquired in shallow and deep wells. The method employed is based on the model of simultaneous heat transfer by conduction and advection in permeable media. Analysis of temperature data acquired in water wells indicates down flows of groundwaters with velocities in excess of 10-7 m/s at depths less than 300 m in the Amazonas basin. Bottom-hole temperature (BHT) data sets have been used in determining characteristics of fluid movements at larger depths in the basins of Acre, Solimões, Amazonas, Marajó and Barreirinhas. The results of model simulations point to down flow of groundwaters with velocities of the order of 10-8 to 10-9 m/s, at depths of up to 4000 m. No evidence has been found for up flow typical of discharge zones. The general conclusion compatible with such results is that large-scale groundwater recharge systems operate at both shallow and deep levels in all sedimentary basins of the Amazon region. However, the basement rock formations of the Amazon region are relatively impermeable and hence extensive down flow systems through the sedimentary strata are possible only in the presence of generalized lateral movement of groundwater in the basal parts of the sedimentary basins. The direction of this lateral flow, inferred from the basement topography and geological characteristics of the region, is from west to east, following roughly the course of surface drainage system of the Amazon River, with eventual discharge into the Atlantic Ocean. The estimated flow rate at the continental margin is 3287 m3/s, with velocities of the order of 218 m/year. It is possible that dynamic changes in the fluvial systems in the western parts of South American continent have been responsible for triggering alterations in the groundwater recharge systems and deep seated lateral flows in the Amazon region.

  20. An integrated river basin planning approach – Nyando case study in Kenya

    OpenAIRE

    Njogu, A.K.

    2002-01-01

    The river basin has long been acknowledged as the appropriate unit of analysis for water resources management and has also been named by the United Nations Conference on Environment and Development (UNCED 1992) as the logical unit for integrated water resources management in Agenda 21, chapter 18. The comprehensive methodology framework for analysis structures the decision making process, starting with the problem identification, through the weighing of various options to the f...

  1. Isotope techniques on groundwater contamination studies in urbanized and industrialized areas, Hat Yai Basin

    International Nuclear Information System (INIS)

    Anthropogenic activities are of a major force in changing the hydrological cycle as well as the climate warming. Assessing the impacts of human activities on hydrological environments is becoming a wide-focused topic. In this research, the authors attempt to link the urbanization, agricultural development, and the subsequent water resources exploitation with the change of water environments in Hat Yai basin, southern of Thailand. The source of water for domestic use mainly comes from Utapao River which flows through the area. Now this area is facing the shortage of water in dry season and pollution due to domestic and industrial activities. Isotope techniques in conjunction with hydrological and chemical data can play the important role for identifying recharge zone, flow dynamic, recharge mechanism and surface and groundwater interaction. By using the numerical model the information for proper groundwater management, can be obtained. As a result, the quality of ground water in Hat Yai basin was show that the quality of iron (Fe) was higher than Notification of the Ministry of Industry permissible level for groundwater quality standards for drinking purposes at many locations. Groundwater in many locations should not use to drinking water. The water types of Hat Yai Aquifer were Na-Cl and Ca-HCO3. The water type of Kliu Tao aquifer was Ca-Mg-HCO3 and Kho Hong aquifer was Ca-Mg-HCO3. The Origin of groundwater in Hat Yai aquifer is local rainfall. The Origin of groundwater in Khu Tao and Kho Hong aquifer come from ancient rainfall.The ground water from Khu Tao and Kho Hong aquifer were old water and low flow rate. The recharge zone was located west and east of Hat Yai Basin. After that the groundwater will flow to middle basin and northward to Songkhla Lake. (author)

  2. Isotope techniques in groundwater contamination studies in urbanized and industrialized areas, Hat Yai Basin

    International Nuclear Information System (INIS)

    Anthropogenic activities are mainly responsible for changing the hydrological cycle as well as the climate warming. Assessing the impacts of human activities on hydrological environments is becoming a wide-focused topic. In this research, the author attempt to link the urbanization, agricultural development, and the subsequent water resources exploitation with the change of water environments in Hat Yai Basin, southern of Thailand. The source of water for domestic use mainly comes from Utapao River which flows through the area. Now this area is facing the shortage of water in dry season and pollution due to domestic and industrial activities. Isotope techniques in conjunction with hydrological and chemical data can play the important role for identifying recharge mechanism and surface and groundwater interaction. By using the numerical model the information for proper groundwater management can be obtained. As a result, the quality of groundwater in Hat Yai Basin showed that the iron (Fe) content at many locations was higher than the permissible level for groundwater quality standards for drinking purposes in the Notification of the Ministry of Industry. Groundwater from such locations should not be used for drinking. The water types of Hat Yai aquifer were Na-Cl and Ca-HCO3, while that of Khu Tao aquifer and Kho Hong aquifer were CA-Mg-HCO3 and Ca-Mg-HCO3, respectively. The origin of groundwater in Hat Yai aquifer is local rainfall. The origin of groundwater in Khu Tao and Kho Hong aquifers come from ancient rainfall indicating old water and low flow rate. The groundwater is recharged from the zones located in the eastern and western parts of Hat Yai Basin and flows to middle basin and northward to Songkhla Lake. (author)

  3. Rock magnetic and paleomagnetic study of Cypris Formation in the Sokolov Basin (NW Bohemia)

    Czech Academy of Sciences Publication Activity Database

    Kadlec, Jaroslav; Schnabl, Petr; Chadima, Martin; Šlechta, Stanislav; Pruner, Petr; Šifnerová, K.

    Geofyzikální ústav AV ČR, v. v. i.. Roč. 39, - (2010), s. 36-36 ISSN 0231-5548. [Castle Meeting /12./. 29.08.2010-04.09.2010, Nové Hrady] R&D Projects: GA ČR GA205/09/1162 Institutional research plan: CEZ:AV0Z30130516 Keywords : rock magnetism * paleomagnetism * Cypris Formation * Sokolov Basin (NW Bohemia) Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  4. Left Behind? A Case Study of Immobile Populations in the Senegalese River Basin

    OpenAIRE

    Zickgraf, Caroline

    2014-01-01

    The Senegalese River Basin has undergone environmental transformations in recent decades that, in combination with poor infrastructure and inadequate resources, has affected the livelihood strategies and mobility patterns of its residents. As a low-lying city near the mouth of the Senegal River, Saint-Louis is highly vulnerable to flooding. Furthermore, the vulnerability of the city can be attributed to coastal land degradation, high and increasing population density and inadequate infrastruc...

  5. Degradation of the riparian wetlands in the Lake Victoria basin - Yala swamp case study.

    OpenAIRE

    Thenya, Thuita; Wassmann, Reiner; Verchot, Louis; Mungai, David

    2006-01-01

    Land degradation is as a result of broad range of scales and factors, which include biophysical, climatic, demographic and socio-economic. The aim of this paper was to provide an analysis of wetland utilisation, ecosystem degradation and their effect on the Lake Victoria (Kenya) ecosystem. This involved analysis of socioeconomic and remote sensed data. The main sources of wetland degradation in the Lake Victoria basin were identified as (1) farming activities, (2) grazing and macrophyte harve...

  6. Study of site effect in the Most basin area, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Lednická, Markéta; Kaláb, Zdeněk; Knejzlík, Jaromír

    Vol. 3. Sofia: STEF92 Technology Ltd., Bulgarian Academy of Sciences, 2015, s. 1027-1034. (Volume III). ISBN 978-619-7105-33-9. ISSN 1314-2704. [SGEM 2015 - International Multidisciplinary Scientific Geoconference /15./. Albena (BG), 18.06.2015-24.06.2015] R&D Projects: GA ČR GP13-07027P Institutional support: RVO:68145535 Keywords : blasting operation * site effect * HVNR method * Most Basin Subject RIV: JM - Building Engineering

  7. Study of site effect in the Most basin area, Czech Republic

    OpenAIRE

    Lednická, M. (Markéta); Kaláb, Z. (Zdeněk); Knejzlík, J. (Jaromír)

    2015-01-01

    Blasting operations are used as a part of mining technology in open-pit mines and this mining activity represents the main source of seismic loading of inhabited areas in the surroundings of the mine. The vibration effect caused by blasting operations takes an unusual shape at the Most Basin area. Seismic noise measurements were performed in the surroundings of the open-pit mine and gained resonant frequencies were compared to prevailing frequencies resulting from the analysed records of blas...

  8. Chemical and environmental isotope study of the basaltic aquifer systems of Yarmouk Basin (Syria)

    International Nuclear Information System (INIS)

    The water in the fissured basalt aquifer system, the Upper Jurassic aquifer of the Yarmouk Basin and the atmospheric precipitation have been investigated using chemical and environmental isotope techniques. The groundwaters flowing through the different aquifers are differentiated by their chemical ratios and their isotopic compositions. The evolution of chemical facies of groundwater from the recharge area towards the basin outlet is characterized by increasing of sodium and magnesium contents as a result of silicate leaching. The stable isotope compositions of precipitation and mountainous spring waters match the Mediterranean Meteoric Water Line, while the groundwaters from the central zone and from the major springs of the Yarmouk Basin are mixtures of freshwater, which is isotopically depleted and salty groundwater of Laja plateau area. The interpretations of tritium and radiocarbon (14 C) data indicate that the recharge zones of the groundwater in the Yarmouk Basin occur on the high-land of more than 1000 m of altitude. The residence time of the mountainous springs is short (of about 40 years or less). However, water ages corrected by Vogel's concept and Gonfiantini's Model show, in general, a range from 1000 to 11000 years for the central zone groundwater. The groundwater moves from the Mt. Hermon and Mt. Arab towards the central zone and from the north-east (i.e. the Laja plateau) towards south-west (i.e. the major springs). The radiometric flow velocities range from 20 to 60 m/year within the central zone, while the flow velocities from both sides of Mt. Hermon and Mt. Arab are lower (1-7 m/year). (author). 43 refs., 37 figs., 6 tabs

  9. THE ECOSYSTEM APPROACH TO ECOLOGICAL RESTORATION MANAGEMENT Case Study -Trotus Hydrographic Basin

    OpenAIRE

    Maricica STOICA

    2012-01-01

    Ecosystem approach proved to be the most efficient strategy for integrated management of soil, water and life which promotes conservation and sustainable use in an equitable application of the ecosystem approach helps to achieve a balance of natural components, socio-economic and weather and climate phenomena with adequate scientific methodologies multidisciplinary and transdisciplinary.Such an approach is now imposed on the European level in flood risk management, to make a river basin as th...

  10. High Resolution Integrated Hydrologic Modeling for Water Resource Management: Tahoe Basin Case Study

    Science.gov (United States)

    Rajagopal, S.; Niswonger, R. G.; Huntington, J. L.; Gardner, M.; Morton, C.; Maples, S.; Reeves, D. M.; Pohll, G.

    2014-12-01

    Water resources in the high altitude, snow-dominated Tahoe basin are susceptible to long-term climate change and extreme climatic events due to large inter-annual climate variations. Lake Tahoe and its contributing watersheds exhibit high climatic (precipitation, temperature) and hydrologic (streamflow, evaporation) variation that exert significant control over regional water supply on annual and sub-annual timescales. To adequately quantify these controls, a high resolution (300m) physically based integrated surface and groundwater model, GSFLOW, of the Tahoe basin has been developed to identify key hydrologic mechanisms that explain recent changes in water resources of the region. The model is parameterized using geographical datasets and maintains a balance between (a) accurate representation of spatial (e.g., geology, streams, and topography) and hydrologic (groundwater, stream, lake, and wetland flows and storages) features, and (b) computational efficiency, which is a necessity for exploring critical vulnerabilities of water-supplies in the region. The calibrated model reproduces multiple observations of streamflow, snow water equivalent, satellite derived snow covered area, lake stage, and groundwater head. Climate input uncertainty was significantly decreased in the model through incorporating additional precipitation station data and helped improve model simulations of observed fluxes more than adjusting model parameters alone. The model simulates fluxes at the outlet of the watershed, but is also consistent at simulating streamflow at internal nodes. This integrated modeling framework helped assess both surface and groundwater resources in a coupled manner in the Tahoe basin.

  11. 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.

  12. Use of isotope hydrology for groundwater resources study in Upper Chi river basin

    International Nuclear Information System (INIS)

    The Upper Chi river basin is located in the vicinity of Chaiyaphum province, northeastern Thailand. Groundwater management in the drought affected area of fractured Mesozoic siliciclastic rocks groundwater system was challenged by the approaches of isotope and chemical techniques. The local meteoric water line (LMWL) of the study area provide lower slope (δD = 6.8508δ18O -0.8013) and more depleted average annual rainfall (δ18O = -7.6 %ο) when compare to LMWL of Bangkok due to higher evaporation. The surface water mainly exhibits an evaporation effect and can be clearly divided into two groups, the upper reaches and the downstream areas, with approximate separated in δ18O by -4.0 %ο. The groundwater system in the area can be divided into seven subareas based on the stable isotope characteristics and groundwater dating by radiocarbon and tritium methods. Nong Bua Deang subarea, Kang Kro subarea, and Thep Satit subarea, the most upstream system which were separated by thick aquitards of Phra Wihan sandstones, are classified as the upper reach area. The groundwater samples are characterized in two traits: the upstream group shows older groundwater ages (<80.0 % modern carbon, PMC) because of less interaction with surface water and the downstream group, near main channels and reservoirs, exhibit younger groundwater ages because of contribution of surface water in the recharge area. Bamnet Narong subarea and Muang Chaiyaphum subarea are classified as the middle reach area. The groundwater shows rapidly recharge from rainfall, the results of radiocarbon provide younger ages. The downstream characteristic which is closely interaction of extremely evaporated surface, were found in Kon Sawan-Mancha Kiri subarea and Ban Phai subarea. Almost all the groundwater samples are related to younger ages except the wells near the upper tributaries. The groundwater management can be proposed by attending to conservation policy in the upper reach area, and some parts of Ban Phai

  13. Hydrothermal Prospecting and Petrological Sampling in the Lau Basin: Background Data for the Integrated Study Site

    Science.gov (United States)

    Langmuir, C. H.; German, C.; Michael, P.; Yoerger, D. R.; Fornari, D. J.; Shank, T. M.; Asimow, P. D.; Edmonds, H. N.; L 2 Team

    2004-12-01

    In the spring of 2004, Martinez and others (this meeting) carried out an extensive mapping program of the southern Lau Basin spreading centers with high resolution bathymetry and sidescan data. They were also defined the overall distribution of mantle plumes along the ridges using miniature autonomous plume recorders and CTD tow-yos. These important new data were the first step of an integrated RIDGE 2000 program of four cruises to identify the overall tectonic, petrological, hydrothermal and biological characteristics of the spreading centers to permit a well informed selection of targets for more focussed studies in coming years. During September and October of 2004, on board R/V Kilo Moana, we are carrying out the second phase of investigations, with the aim of identifying specific hydrothermal sites and providing regional sampling of lavas from the region. The primary tools of investigation for hydrothermal site discovery are the autonomous benthic explorer (ABE) as well as CTD's and bottom towed cameras. Making use of new CTD data to verify the plumes identified in the Martinez et al cruise, ABE is being used in three different modes. Phase I focusses on the water column at the level of the neutrally buoyant plume. These results enable planning of the more focussed Phase II, closer to the bottom, to provide high resolution bathymetry and characterization of the buoyant plume. Phase III provides photographic coverage of even more limited regions focussed on the vent fields defined in Phase II. Camera tows using TOWCAM are planned to provide the highest resolution images of new hydrothermal sites. This cruise represents the first attempt to use ABE in such a staged and systematic program of regional vent site discovery. Since the ship is free to carry out other investigations during the ABE dives, which can be 24 hours or more in length, high density sampling of the various Lau Spreading Centers will be carried out at the same time as the hydrothermal

  14. Comparative studies on carbon origin of dawsonite between Hailaer Basin in China and Bowen-Gunnedah-Sydney basin system in Australia

    Institute of Scientific and Technical Information of China (English)

    Yuqiao GAO; Li LIU; Qi'an MENG; Yan XU; Xiyu QU; Xianmei JIN

    2007-01-01

    Dawsonite, NaAlCO3(OH)2, is widespread as a cement, replacement and cavity filling in Hailaer Basin in China and Bowen-Gunnedah-Sydney (BGS) basin system in Australia. The origin of dawsonite is emphatically contrasted and analyzed through stable isotopic composition. Dawsonite δ13C values ranging from -4.0×10-3 to 4.1×10-3 are remarkably consistent through the BGS basin system. The calculated δ13C values of CO2 gas in isotopic equilibrium with dawsonite range from -11.3×10-3 to -4.6×10-3. These values indicate carbon of dawsonite came from inorganic CO2 gas accompanied by magmatic activity. In Hailaer Basin, the Dawsonite δ13C values ranging from -4.64×10-3 to 2.12×10-3 are also consistent. The calculated δ13C values of CO2 gas in isotopic equilibrium with dawsonite range from -11.82×10-3 to -5.11×10-3. According to the coincidence of dawsonite-bearing well and CO2 gas well with mantle source,lying along deep fracture within or adjacent to Yanshanian granite,it is concluded that CO2 gas forming dawsonite is derived from mantle related to magmatic process during the Yanshanian. A little biologic origin carbon owing to petroleum charging intervened when dawsonite formed.

  15. 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

  16. 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.

  17. 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.

  18. Annual report on paleoclimate studies for the Yucca Mountain project site characterization conducted by the Desert Research Institute for the Department of Energy

    International Nuclear Information System (INIS)

    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

  19. Assessment Fargas and BLM Models for Identification of Erosion Degree and Critical Sediment Sources (Case Study: Aghbolagh Drainage Basin, Hashtrood City)

    OpenAIRE

    Naser Abdi; Aliasghar Mohammadi

    2014-01-01

    The identification of the different areas in drainage basin (as a natural planning unit) for occurring the sedimentation and its severity in different phases of basic studies has been always one of the most important purposes of the natural resources experts. For achieving to this purpose some experimental models has been presented that Some of them have high efficiency and others have weaknesses. Fargas and BLM models are used in this research and they are run in Aghbolagh drainage basin in ...

  20. Radioactivity in the environment: a case study of the Puerco and Little Colorado River Basins, Arizona and New Mexico

    International Nuclear Information System (INIS)

    This report, written for the nontechnical reader, summarizes the results of a study from 1988-91 of the occurrence and transport of selected radionuclides and other chemical constituents in the Puerco and Little Colorado River basins, Arizona and New Mexico. More than two decades of uranium mining and the 1979 failure of an earthen dam containing mine tailings released high levels of radionuclides and other chemical constituents to the Puerco River, a tributary of the Little Colorado River. Releases caused public concern that ground water and streamflow downstream from mining were contaminated. Study findings show which radioactive elements are present, how these elements are distributed between water and sediment in the environment, how concentrations of radioactive elements vary naturally within basins, and how levels of radioactivity have changed since the end of mining. Although levels of radioactive elements and other trace elements measured in streamflow commonly exceed drinking-water standards, no evidence was found to indicate that the high concentrations were still related to uraniurn mining. Sediment radioactivity was higher at sample sites on streams that drain the eastern part of the Little Colorado River basin than that of samples from the western part. Radioactivity of suspended sediment measured in this study, therefore, represents natural conditions for the streams sampled rather than an effect of mining. Because ground water beneath the Puerco River channel is shallow, the aquifer is vulnerable to contamination. A narrow zone of ground water beneath the Puerco River containing elevated uranium concentrations was identified during the study. The highest concentrations were nearest the mines and in samples collected in the first few feet beneath the streambed. Natuxal radiation levels in a few areas of the underlying sedimentary aquifer not connected to the Puerco River also exceeded water quality standards. Water testing would enable those residents

  1. 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.

  2. 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

  3. 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.

  4. GIS-based River Flood Hazard Mapping in Urban Area (A Case Study in Kayu Ara River Basin, Malaysia)

    OpenAIRE

    Behdokht Vosoogh; Ismail Abustan; Rozi bin Abdullah; Sina Alaghmand,

    2010-01-01

    In the past decades, thousands of lives have been lost, directly or indirectly, by flooding. In fact, of all natural hazards, floods pose the most widely distributed natural hazard to life today. Sungai Kayu Ara river basin which is located in the west part of the Kuala Lumpur in Malaysia was the case study of this research. In order to perform river flood hazard mapping HEC-HMS and HEC-RAS were utilized as hydrologic and hydraulic models, respectively. The generated river flood hazard was ba...

  5. 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.

  6. A study of the TEX86 paleothermometer in the water column and sediments of the Santa Barbara Basin, California

    OpenAIRE

    Huguet, Carme; Schimmelmann, Arndt; Thunell, Robert; Lourens, Lucas J.; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2007-01-01

    Particulate organic matter collected during a 2-year period, as part of an ongoing sediment trap study, and a high-resolution sediment record from 1850 to 1987 A.D. from the Santa Barbara Basin were analyzed for TEX86, a temperature proxy based on marine crenarchaeotal membrane lipids. Highest fluxes of crenarchaeotal lipids in the water column were found in May–June 1996 and from October 1996 to January 1997 and, in general, showed a good correlation with mass fluxes. TEX86 reconstructed tem...

  7. Evaluation of the Impacts of Land Use on Water Quality: A Case Study in The Chaohu Lake Basin

    OpenAIRE

    Juan Huang; Jinyan Zhan; Haiming Yan; Feng Wu; Xiangzheng Deng

    2013-01-01

    It has been widely accepted that there is a close relationship between the land use type and water quality. There have been some researches on this relationship from the perspective of the spatial configuration of land use in recent years. This study aims to analyze the influence of various land use types on the water quality within the Chaohu Lake Basin based on the water quality monitoring data and RS data from 2000 to 2008, with the small watershed as the basic unit of analysis. The result...

  8. Implications of post-disturbance studies on the grain size of the sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    COMMUNICATIONS CURRENT SCIEN CE, VOL. 81, NO. 10, 25 NOVEMBER 2001 1365 e - mail: vals@csnio.ren.nic.in Implications of post - disturbance stu d ies on the grain size of the sediments from the Central Indian Basin Anil B. Valsangkar National... (2 to 4, 8 to 10 cm) of silty clay out of nine at BC - 13. South RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 81, NO. 10, 25 NOVEMBER 2001 Figure 1. a , Selected sample locations in INDEX area for comparative studies. ?, Box...

  9. Chemical characteristics of rainwater in Sichuan basin, a case study of Ya'an.

    Science.gov (United States)

    Li, Yun-Chun; Zhang, Meng; Shu, Man; Ho, Steven Sai Hang; Liu, Zi-Fang; Wang, Xian-Xiang; Zhao, Xiao-Qing

    2016-07-01

    Rainwater chemistry was investigated at a semi-rural site in Ya'an, Sichuan basin with rain samples collected from May 2013 to July 2014. The rainwater pH values ranged from 3.25 to 6.86, with an annual volume-weighted mean (VWM) of 4.38, and the acid rain frequency was 74 %. Such severe acidification, 15 % of the total events showed a pH below 4.0, attributed to the deficiency of Ca(2+), significant anthropogenic pollution contribution, and rainy pattern to this area. The annual VWM of total ions concentration was 477.19 μeq/L. NH4 (+) was the most abundant ionic species, followed by SO4 (2-), NO3 (-), Ca(2+), Cl(-), Na(+), K(+), Mg(2+), and F(-) in a descending order. The total ionic concentrations presented a seasonal trend of lower values in autumn and summer but higher ones in winter and spring. Based on enrichment factor, correlation analysis and principle component analysis, three factors were identified: factor 1 (NH4 (+), SO4 (2-), NO3 (-), K(+), and Cl(-), 47.45 % of the total variance) related to anthropogenic sources (coal/fuel combustion, biomass burning and agriculture), factor 2 (Ca(2+), Mg(2+), Na(+), and Cl(-), 34.01 % of the total variance) associated with natural sources, and factor 3 (H(+), 11.78 % of the total variance) related to free acidity. Back trajectory analysis indicates that the rainwater chemistry in Ya'an was mainly affected by regional air masses from Sichuan basin. Long-range transported air masses from southwest with heavy anthropogenic pollution increased the total ion concentration and acidity of rainwater. Considering its special topography, anthropogenic emissions from regional and long-range transport (especially from southwest) must be controlled effectively to improve the acid rain condition of non-urban areas in Sichuan basin. PMID:27000115

  10. Interdisciplinary studies of the Cis-Ural Neolithic (Upper Kama basin, Lake Chashkinskoe: Palaeoecological aspects

    Directory of Open Access Journals (Sweden)

    Evgeniia Lychagina

    2013-12-01

    Full Text Available In this paper we present preliminary results of the first palaeoecological investigations in the Cis-Ural region. This was an area of intensive Neolithic occupation of fluvial landscapes within the basin of the Upper Kama River, the largest river in the area. We selected the area of Lake Chashkinskoe as a key region, where around 10 sites have been found on the remains of the fluvial terraces of the Kama River. We used palaeochannel analysis, radiocarbon dating, and palynology for past landscape reconstruction.

  11. 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.

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

    International Nuclear Information System (INIS)

    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

  13. Survey of artisanal fishing gear and craft. A case study of Kainji Lake lower basin, Nigeria

    OpenAIRE

    Ogundiwin, Damilare Ibukun

    2014-01-01

    Despite the considerable importance of artisanal fishing in Kainji Lake lower basin, knowledge about gear and craft being used is deficient and outdated. Little is also known as to why fishermen adopted the diverse fishing gear and craft they use in the Lake, as well as the relationship of these input factors to the socio-economic status of the fishermen and ecology of the lake. To address these issues, a survey of sixty (60) artisanal fishers and twelve (12) village leaders drawn from 12 sel...

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

    Science.gov (United States)

    Gosar, A.

    2010-04-01

    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-frequency map. For two

  15. Estimation of flash floods in small ungauged basins in Slovakia: case studies

    Science.gov (United States)

    Hlavcova, Kamila; Horvat, Oliver; Kohnova, Silvia; Szolgay, Jan; Roncak, Peter

    2013-04-01

    In the paper application of a methodology for analysis of flash flood events in several ungauged small basins in Slovakia was evaluated. The methodology proposed within the framework of the FP6 HYDRATE project (www.hydrate.tesaf.unipd.it) is based on the post-event surveying and hydrological modelling, using a spatially distributed hydrological model with a high spatial resolution of rainfall data and physiographical basin properties. Six large flash floods which occurred in Slovakia during the last 10 years were selected, with the emphasis on their extremity and different physical and geographical basins properties. The estimation of the maximum flood peaks and flood wave volumes was provided on the base of the post-event analysis after the flood events. The areas of channel's cross-profiles were measured for maximal water level, longitudinal slope of water level was approximated to the bottom slope and roughness was estimated according to the river banks and channel bottoms. Flow velocities were estimated using Chézy equation and Manning roughness coefficient. The reconstructed flood waves were compared with the simulated discharges using the distributed event-based rainfall-runoff model KLEM. The distributed hydrological model KLEM is based on the availability of raster information of the landscape's topography, soil and vegetation properties, and radar rainfall data. The SCS-Curve Number procedure is applied on a grid for the spatially-distributed representation of runoff-generating processes, a description of the drainage system response is used for representing the runoff's routing. Digital elevation models as well as soil, geology, land use and rainfall data for the basins were prepared in the grid form (resolution of 20 m). Radar rainfall data or maps of isohyets in 15-minutes time step or were used as input precipitation in the model. Comparison of the results achieved by the KLEM model and the post-event analysis for floods showed the consistency of

  16. 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.

  17. 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.

  18. 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.

  19. 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

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

    International Nuclear Information System (INIS)

    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 1011 n.cm-2.s-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 (μg/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)

  1. 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.

  2. Method Study of Flood Hazard Analysis for Plain River Network Area, Taihu Basin, China

    Science.gov (United States)

    HAN, C.; Liu, S.; Zhong, G.; Zhang, X.

    2015-12-01

    Flood is one of the most common and serious natural calamities. Taihu Basin is located in delta region of the Yangtze River in East China (see Fig. 1). Because of the abundant rainfall and low-lying terrain, the area frequently suffers from flood hazard which have caused serious casualty and economic loss. In order to reduce the severe impacts of floods events, numerous polder areas and hydraulic constructions (including pumps, water gates etc.) were constructed. Flood Hazard Map is an effective non-structural flood mitigation tool measures. Numerical simulation of flood propagation is one of the key technologies of flood hazard mapping. Because of the complexity of its underlying surface characteristics, numerical simulation of flood propagation was faced with some special problems for the plain river network area in Taihu Basin. In this paper, a coupled one and two dimensional hydrodynamic model was established. Densely covered and interconnected river networks, numerous polder areas and complex scheduling hydraulic constructions were generalized in the model. The model was proved to be believable and stable. Based on the results of the simulation of flood propagation, flood hazard map was compiled.

  3. 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.

  4. Study of ceramics from circular archaeological sites of Amazonic Basin by geochemical methods: dating and characterization

    International Nuclear Information System (INIS)

    The aim of this work is to examine by means of characterization and dating pottery recently discovery inside archaeological sites recognized with circular earth structure in Acre State - Brazil which may contribute to the research in the reconstruction of part of the pre-history of the Amazonic Basin. These sites are located mainly in the Hydrographic Basin of High Purus River. Three of them were strategic chosen which provide the ceramics: Lobao, in Sena Madureira County at north; Alto Alegre, in Rio Branco County at east and Xipamanu I, in Xapuri County at south. The X-ray diffraction mineral analysis made possible to identify two types of crystal structures of ceramic minerals: quartz and M-Kaolinite. Neutron activation analysis in conjunction with multivariate statistical methods were applied for the ceramic characterization and classification. An homogeneous group was established by all sherds collected from Alto Alegre and was distinct from all the other two groups analyzed. Some of the sherds collected from Xipamanu I appeared in Lobao's urns, probably because they had the same fabrication process. The Lobao's urns presented a homogeneous group. Geochronology of these materials was carried out by Thermoluminescence. The Xipamanu I was the oldest site and Lobao the youngest. The average age of Xipamanu I and Alto Alegre were 2600 and 2070 years respectively. The average age of of occupation was 400 years to Alto Alegre and 970 years to Xipamanu I. The most probably date for Lobao was 1880 years. (author)

  5. The use of stable isotopes and hydrogeochemical studies to characterize water resources in the semi-arid Sokoto Basin, Nigeria

    International Nuclear Information System (INIS)

    An isotopic hydrological study was carried out on the Wei River water and shallow groundwater in the Guanzhong basin, Shaanxi, China. The study area is bordered by the Qinling Mountain in the south and by the North Mountain in the north, by the Yellow River in the east. Wei River is located in the middle of the basin and converges eastward into the Yellow River. The water supply for the major cities like Xi'an, Xianyang, Baoji and Weinan is from river and groundwater resources. Wei River and nearby shallow groundwater is largely used for fresh water supplies. With increasing use of the surface and groundwater, the water quality and groundwater table is decreasing. The over-exploitation of water resources is resulting in serious hydrogeological damage, such surface land depression and surface fracturing etc. The groundwater over 300 m depth is fresh from the foothill of the Qinling Mountain northward to the Wei River. The groundwater is brackish from the northeast foothill of the North Mountain southward to the Wei River, the salinity is decreasing westward and eastward. This hydochemical trend was the foundation of a hydrogeological model in which the groundwater is recharged mainly in the Qinling Mountain and is transported relatively quickly northward and resulting in some discharge into the Wei River. Groundwater in the north bank of the Wei River is recharged in the North Mountain and move slowly southward. New isotopic and CFC data are presented to improve the interpretation for interaction between Wei River and groundwater in the Guanzhong basin. The oxygen isotopic ratios in the shallow groundwater lie within '7' to '10', these are different from the more rich values of surface water, which reflect the weak link between the surface and groundwater. Deeper, warm groundwaters show a significant Oxygen 18 shift due to isotope exchange with lithologies, indicating long groundwater residence times, confirmed by Carbon 14 data. Most of CFC concentrations for

  6. Volcanism, sedimentation, K/Ar and palynology studies, Yayu and Delbi-Moye Basins, Southwestern Plateau of Ethiopia

    Science.gov (United States)

    Wolela, A.

    2014-05-01

    Major element, K/Ar, sedimentation and palynology data are reported on Tertiary volcanic and sedimentary rocks from the Yayu and Delbi-Moye Basins, SW Ethiopia. In the Yayu and Delbi-Moye Basins, pre-rift volcanic (basalts) and post-rift volcanic (basalts) are separated by coal and oil shale-bearing sedimentary rocks. The basalts are tholeiitic in composition. The K/Ar data on the volcanic rocks range from 10.98 ± 0.55 Ma (Lower Miocene i.e. Tortonian) to 111.19 ± 2.83 Ma (Early Cretaceous i.e. Aptian). Inter-Trappean coal and oil shale-bearing sedimentary rocks are widely distributed in the Yayu and Delbi-Moye Basins. The NNW-SSE fault system developed grabens and half-grabens for the deposition of coal and oil shale-bearing sedimentary rocks. The sedimentary successions are dominated by fine to medium-grained sandstones, siltstones, mudstones, carbonaceous shales, carbonaceous claystones, coal and oil shale seams, and are characterized by meandering river and lacustrine depositional environments. Fresh water algae Botryococcus brauni, Pediastrum sp., Polypodii sporites favus and Polypodii sporites afavus and Pachydermites diederixi, are common palynomorphs in the studied coal and oil shales, and are indicators of lacustrine environment. The presence of Peregrinipollis nigericus is consistent with Oligocene to Miocene. The presence of Euphorbiaceae, Papilionacae, Melastomtaceae sp., Dodonaea, Martretia quadricornis, Rubiaceae sp. (pollen derived from tropical shrubs), Sapotaceae spp. and Meliaceae spp. are indicative of humid, tropical rainforest conditions. Extensive bio-assemblages confirm that the age of coal and oil shale-bearing sedimentary rocks to be Oligocene to Miocene.

  7. 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

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

    Science.gov (United States)

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

    2014-05-01

    The Hei River Basin (catchment area of c. 130,000 km²) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper

  9. STUDY REGARDING DELINEATION OF FLOOD HAZARD ZONES IN THE HYDROGRAPHIC BASIN OF THE SOMEŞ RIVER, BORDER AREA

    Directory of Open Access Journals (Sweden)

    STOICA F.

    2014-03-01

    Full Text Available The hydrological studies will provide the characteristic parameters for the floods occurred for the calculus discharges with overflow probabilities of 0,1%; 1%, 5%, 10%. The hydrologic and hydraulic models will be made by using the hydro-meteorological data base and the topographical measurements on site; them calibration will be done according to the records of the historical floods. The studies on the hydrologic and hydraulic models will be necessary for the establishment of the carrying capacity of the riverbeds, for the delimitation of the flood plains and for the detection of the transit discharges at the hydro-technical installations, but also for the establishment of the parameters needed for the structural measures’ projects. These will be based on the 1D and 2D unstable hydro-dynamic models. Therefore, the users would be able to assess the proposed measures and the impact over the river’s system; of course with the potential combination of the 1D and 2D. The main objectives followed by the project are: • identification of the river basins or river sub-basins with flood risks; • regionalization of the flood hazard; • presentation of the main flash floods occurred during the last 30 years, which induced floods; • assessment of the consequences of eventual flood over the population, properties and environment; • the establishment of the protection degree, accepted for the human settlements, for the economic and social objectives, for the farm areas, etc.;

  10. Calibration of a large-scale groundwater flow model using GRACE data: a case study in the Qaidam Basin, China

    Science.gov (United States)

    Hu, Litang; Jiao, Jiu Jimmy

    2015-11-01

    Traditional numerical models usually use extensive observed hydraulic-head data as calibration targets. However, this calibration process is not applicable in remote areas with limited or no monitoring data. This study presents an approach to calibrate a large-scale groundwater flow model using the monthly Gravity Recovery and Climate Experiment (GRACE) satellite data, which have been available globally on a spatial grid of 1° in the geographic coordinate system since 2002. A groundwater storage anomaly isolated from the terrestrial water storage (TWS) anomaly is converted into hydraulic head at the center of the grid, which is then used as observed data to calibrate a numerical model to estimate aquifer hydraulic conductivity. The aquifer system in the remote and hyperarid Qaidam Basin, China, is used as a case study to demonstrate the applicability of this approach. A groundwater model using FEFLOW is constructed for the Qaidam Basin and the GRACE-derived groundwater storage anomaly over the period 2003-2012 is included to calibrate the model, which is done using an automatic estimation method (PEST). The calibrated model is then run to output hydraulic heads at three sites where long-term hydraulic head data are available. The reasonably good fit between the calculated and observed hydraulic heads, together with the very similar groundwater storage anomalies from the numerical model and GRACE data, demonstrate that this approach is generally applicable in regions of groundwater data scarcity.

  11. Paleoenvironmental conditions in the Spanish Miocene-Pliocene boundary: isotopic analyses of Hipparion dental enamel.

    Science.gov (United States)

    Domingo, Laura; Grimes, Stephen T; Domingo, M Soledad; Alberdi, M Teresa

    2009-04-01

    Expansion of C(4) grasses during Late Miocene and Early Pliocene constitutes one of the most remarkable biotic events of the Cenozoic era. The Teruel-Alfambra region (northeastern Spain) contains one of the most complete Miocene-Pliocene sequences of mammalian fossil sites in the world. In this study, stable isotope (delta (13)C and delta (18)O) analyses have been performed on the tooth enamel from the equid Hipparion from 19 localities spanning a time interval from approximately 10.9 to 2.7 Ma. This time range starts with the first appearance of this genus in Spain and ends at its extinction. An increase in delta (13)C at about 4.2 Ma has been observed, indicative of a shift toward a more open habitat. This shift may be related to a large scale vegetation change which occurred across the Miocene-Pliocene boundary when C(4) grasses expanded. This expansion might in turn be linked to global tectonic events such as the uplift of the Himalaya and/or the closure of the Panama Isthmus. However, other more regional factors may have ultimately enhanced the trend toward more open habitats in the Western Mediterranean Basin. The Messinian Salinity Crisis was a major environmental event that may have been responsible for the isotopic changes seen in the equid Hipparion from the Iberian Peninsula along with an increase in the aridity detected approximately 4.6 Ma ago in the Sahara. Even though the exact factor triggering the isotopic change observed in the Hipparion enamel remains mostly unknown, this study demonstrates that the global environmental changes detected across the Miocene-Pliocene boundary are also recorded in the realm of the Iberian Peninsula. PMID:19190888

  12. 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

  13. Assessment of SRTM for studies of deformed lake terraces, Mono Basin, CA, USA

    Science.gov (United States)

    Breier, P.; Bursik, M.; Webb, F.

    2003-04-01

    Mono Lake lies east of the Sierra Nevada, central California, USA. Late Quaternary transgressions and regressions of Mono Lake have produced well-defined terraces within the active and relict shorelands of Mono Basin, as well as on the islands within the lake, including the largest, Paoha Island. To assess the ability of SRTM data to resolve the terraces, we compared the SRTM data to TOPSAR data along topographic profiles. The accuracy of the profiles was assessed by visual and statistical comparison. Information was then extracted from the profiles to determine whether the terraces showed any evidence of warping or offset. Perhaps the most prominent terraces within the basin lie on the eastern and western sides of Paoha Island. When compared with the TOPSAR profiles across these terraces, SRTM profiles are systematically smoother and higher. Comparison of a running average of the TOPSAR data as well as TOPSAR data decimated to 30 m with the SRTM data suggests that much of the SRTM smoothness is the result of the 30 m spacing of the SRTM data as opposed to the 5 m spacing of the TOPSAR data. There is however a mean vertical difference observed between the SRTM and TOPSAR datasets that averages approximately 5 m over a large part of the basin. Near the tops of hills and ridges, the difference between the datasets is less than it is over depressions or areas of low relief. We are investigating the potential causes of the systematic difference. We are exploring the SRTM and TOPSAR data to understand their suitability for determination of deformation of shoreline features. In particular, we are interested in whether magmatic activity beneath the Mono Craters, a volcanic chain on the southern margin of Mono Lake, may be responsible for deformation of a latest Pleistocene(?) terrace at a nominal elevation of 1990 m. The elevation of the bluff-berm break in slope for this terrace was estimated to be at the point of maximum curvature in topographic profiles crossing the

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

    Science.gov (United States)

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

    2015-08-01

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

  15. Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (SE Europe) during the past 500 ka

    Science.gov (United States)

    Sadori, L.; Koutsodendris, A.; Masi, A.; Bertini, A.; Combourieu-Nebout, N.; Francke, A.; Kouli, K.; Joannin, S.; Mercuri, A. M.; Panagiotopoulos, K.; Peyron, O.; Torri, P.; Wagner, B.; Zanchetta, G.; Donders, T. H.

    2015-09-01

    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-deciduous oaks. Moreover

  16. 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

  17. Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (south-eastern Europe) during the past 500 ka

    Science.gov (United States)

    Sadori, Laura; Koutsodendris, Andreas; Panagiotopoulos, Konstantinos; Masi, Alessia; Bertini, Adele; Combourieu-Nebout, Nathalie; Francke, Alexander; Kouli, Katerina; Joannin, Sébastien; Mercuri, Anna Maria; Peyron, Odile; Torri, Paola; Wagner, Bernd; Zanchetta, Giovanni; Sinopoli, Gaia; Donders, Timme H.

    2016-03-01

    Lake Ohrid is located at the border between FYROM (Former Yugoslavian Republic of Macedonia) 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, 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 Scientific 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 depocentre of Lake Ohrid. The study is the fruit of a cooperative work carried out in several European palynological laboratories. The age model of this part of the core is based on 10 tephra layers and on tuning of biogeochemical proxy data to orbital parameters. According to the age model, the studied sequence covers the last ˜ 500 000 years at a millennial-scale resolution ( ˜ 1.6 ka) and records 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 the marine isotope stratigraphy. The record shows a progressive change from cooler and wetter to warmer and drier interglacial conditions. This shift in temperature and moisture availability is visible also in vegetation during glacial periods. The period corresponding to MIS11 (pollen assemblage zone OD-10, 428-368 ka BP) is dominated by montane trees such as conifers. Mesophilous elements such as deciduous and semi-deciduous oaks dominate forest periods of MIS5 (PASZ OD-3, 129-70 ka BP) and MIS1 (PASZ OD-1, 14 ka BP to

  18. Seismic data interpretation: a case study of southern sindh monocline, lower indus basin, pakistan

    International Nuclear Information System (INIS)

    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 449.0 m, Upper Goru Member at 968 m, Lower Goru Formation at 1938 m and Chiltan Limestone at 2943 m. 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. (author)

  19. Estimation of seismogenic source faults by seismic reflection profiling: case study of the Niigata Basin

    International Nuclear Information System (INIS)

    The tectonic evolution and geological features of the Niigata basin were explained with reference to historical major earthquakes in the area, which is compressed by the subducting Pacific plate and form fold-and-thrust belt. P-wave structures have been investigated since about 2009 using dense seismic velocity profiles, including sea areas. 18% of compression and sedimentation caused from subsidence happened in the northwest-southeast direction since 5 Ma in this area, and a complicated underground structure was composed. The inverted, failed rift structure and deep geometry of the active fault have been demonstrated well by CMP seismic reflection profiling and refraction tomography. This Miocene rift structure strongly controls the geometry of seismogenic source faults. (author)

  20. Mining and environment: a case study of the Lish-Gish basins of the eastern Himalayas

    International Nuclear Information System (INIS)

    This paper calls for attention to the effects of the unscientific quarrying operations in the coal-fields of the Lish-Gish Basin which have continued intermittently since 1896. The sudden abandonment of the mining operation in 1965, taking least concern of the scars formed due to the extraction of coal have disturbed the natural equilibrium in slopes. This has already taken its toll in the form of disastrous landslips. All these, in turn, incapacitate the rivers pouring in too much detritus which raise the river-beds alarmingly (50 cm. per year) and aggravate the flood situation in times of high rainfall. Immediate steps should therefore, be taken to prevent such unhealthy and destructive processes and specially, in view of the recent attempt by the government of West Bengal, to restart the quarry operations in near future, in order to cope with the longstanding fuel demand of the local inhabitants. (author). 7 refs

  1. 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

  2. Isotopic and Hydrogeological Study for the Basaltic Aquifer in Yarmouk Basin-South Syria

    International Nuclear Information System (INIS)

    The range of the compositions of environmental isotopes has been used to distinguish the sources and processes of groundwater recharge and to estimate the age of the groundwater in the Basaltic aquifer in Yarmouk basin, SW of Syria Stable isotopic data from the groundwater in the basaltic aquifer show that the groundwater in the area is derived from meteoric water. The principal recharge areas are the Mts Al-Arab and Harmon, which is reflected the mean isotopic composition of the rainwater. The groundwater from the central zone is modified by the admixture of the influx of groundwater recharged in the Mts region and direct infiltration in lower part and Laja plateau. The groundwater has undergone a significant degree of evaporation during the mechanism of recharge. The ages of groundwater corrected by Netpath model are between 2000/y old to recent age.

  3. 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.

  4. Geology and geohydrology of the Palo Duro Basin, Texas Panhandle. Report on the progress of nuclear waste isolation feasibility studies, 1979

    International Nuclear Information System (INIS)

    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

  5. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    Science.gov (United States)

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    water and watershed management of the Wei River basin, or even the Yellow River basin. PMID:26108745

  6. Rock physical properties of Mesozoic basins on the periphery of Songliao Basin-a case study of Tuquan basin and Wulangai basin%松辽盆地外围中生代盆地的岩石物性——以突泉盆地和乌兰盖盆地为例

    Institute of Scientific and Technical Information of China (English)

    钟清; 方慧; 李晓昌; 袁永真; 刘畅往; 高保屯; 卢景奇

    2013-01-01

    Through collecting specimens and testing the density,magnetic susceptibility,residual magnetism and resistivity of rocks,the authors found that,during the evaluation of hydrocarbon resources in the oil-gas bearing basin,the real rock physical properties of the exploration targets,especially the electrical parameters,can hardly be obtained by testing specimens conventionally,because the rocks contain too much mudstone and carbonaceous matters.A comparison of the near-well logging model with core and logging curve shows that the near-well sounding technology is an effective method for obtaining the real resistivity value.In combination with physical properties data available,the physical properties of strata and rocks in Wulangai basin and Tuquan basin were arranged statistically,and the histogram of the main strata and physical properties of the study area was established.In addition,the petrophysical characteristics of strata and rocks in the basins were analyzed.The results can provide the basic information for non-seismic geophysical measurements in this area.%系统采集突泉盆地、乌兰盖盆地的地层岩石物性标本,测试了密度、磁化率、剩磁及电阻率.研究发现,由于含油气盆地勘探目标层往往含泥质、炭质成分较多,采用常规的物性标本测试方法很难获得这类地层岩石真实的物性参数,特别是电性参数.通过井旁测井模型与岩心及测井曲线对比,证明井旁测深技术是一种获取地层电性参数的有效方法.结合前人物性研究资料与本次工作结果,系统地整理了突泉盆地、乌兰盖盆地地层岩石物性参数,建立了主要地层-物性柱,分析了盆地的地层岩石物性特征,为在该地区开展非震地球物理测量提供了基础性资料.

  7. A preliminary study of the distribution of selected trace metals in the Besut River basin, Terengganu, Malaysia.

    Science.gov (United States)

    Suratman, S; Hang, H C; Shazili, N A M; Mohd Tahir, N

    2009-01-01

    This paper presents a preliminary result carried out in the Besut River basin, Terengganu, Malaysia to determine the selected trace metal concentrations. Concentrations of dissolved Pb, Cu, and Fe during the present study were in the range of 3.3-8.3 microg/L Pb, 0.1-0.3 microg/L Cu, and 1.1-12.3 microg/L Fe. For the particulate fraction concentrations of Pb, Cu, and Fe ranged from 1.0 to 3.6 microg/L, 0.3 to 2.8 microg/L, and 114 to 1,537 microg/L, respectively. The concentrations of metals in this study area, in general, were lower than those reported for other study areas. Higher metal concentrations measured in the wet monsoon season suggest that the input was mainly due to terrestrial runoff. PMID:18665317

  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. 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

  10. Comparison of Statistical Downscaling Methods for Monthly Total Precipitation: Case Study for the Paute River Basin in Southern Ecuador

    Directory of Open Access Journals (Sweden)

    L. Campozano

    2016-01-01

    Full Text Available Downscaling improves considerably the results of General Circulation Models (GCMs. However, little information is available on the performance of downscaling methods in the Andean mountain region. The paper presents the downscaling of monthly precipitation estimates of the NCEP/NCAR reanalysis 1 applying the statistical downscaling model (SDSM, artificial neural networks (ANNs, and the least squares support vector machines (LS-SVM approach. Downscaled monthly precipitation estimates after bias and variance correction were compared to the median and variance of the 30-year observations of 5 climate stations in the Paute River basin in southern Ecuador, one of Ecuador’s main river basins. A preliminary comparison revealed that both artificial intelligence methods, ANN and LS-SVM, performed equally. Results disclosed that ANN and LS-SVM methods depict, in general, better skills in comparison to SDSM. However, in some months, SDSM estimates matched the median and variance of the observed monthly precipitation depths better. Since synoptic variables do not always present local conditions, particularly in the period going from September to December, it is recommended for future studies to refine estimates of downscaling, for example, by combining dynamic and statistical methods, or to select sets of synoptic predictors for specific months or seasons.

  11. Groundwater flow and transport modeling: A case study of alluvial aquifer in the Tuul River Basin, Mongolia

    Science.gov (United States)

    Dandar, Enkhbayar; Carrera, Jesús; Nemer, Buyankhishig

    2016-04-01

    The Tuul River basin is located northern Mongolia. It includes Ulaanbaatar city, which hosts 48% of Mongolian population. Water supply to the city relies exclusively on groundwater withdrawn from alluvial aquifers along the Tuul River Basin. Water demand of the city has increased recently as a result of rapid industrial development and population growth due to migration from rural areas. The aim of this study is to characterize the aquifer by integrating existing data in a flow model. Unfortunately, existing data are not sufficient for unequivocal identification of model parameters (groundwater recharge, permeability, lateral inflow, etc.). Fluctuations of water temperature have been recognized as a natural tracer that may be used for hydrogeological characterization and model calibration. Temperatures within the aquifer are affected by the temperature of inflowing water as well as by conduction from the soil surface, which we suspect may control aquifer temperatures. Properly acknowledging these fluctuations would require a three dimensional model. Instead, we propose a semianalytical solution based on the use of memory and influence functions.

  12. Modelling Surface Water Dynamics (SWD) on Large River Basin Scale from Space: A Case Study for the Murray-Darling Basin (MDB) of Australia

    Science.gov (United States)

    Heimhuber, V.; Tulbure, M. G.; Broich, M.

    2015-12-01

    Globally, increasing demands on water resources along with climate variability and change have led to alarming declines and deterioration of terrestrial surface water resources. The usage of earth-observation data and techniques for modeling SWD and its drivers represents a promising approach for sustainable management and restoration of surface water resources across broad geographic regions. The main objective of this research was to model SWD with a focus on floods, observed in 25 years of Landsat imagery (1986 - 2011), across a large and highly regulated river basin, the MDB in Australia. SWD were modelled as a function of river flow and spatially explicit time-series data on soil moisture (Climate Change Initiative active passive microwave), evapotranspiration (Australian Water Resources Assessment land surface model) and rainfall (gauge-based). To enable a consistent modeling approach within the complex hydrological structure of the river basin, a unique spatial modeling framework was developed based on a fully directed and connected stream network, a categorization of the basin into floodplain and non-floodplain area and a regular grid of 10 by 10 km cells. Based on this framework, SWD on local floodplain units were successfully related to flow data from connected gauges by quantifying the lag time for each cell. Dynamic regression models of SWD were fitted locally for floodplains in each grid cell, with an average adjusted r2 above 0.7. Validation against 10 years of test data that was left out for model fitting showed that the models can predict the test data with an average r2 of 0.7, which makes them suitable for improving the ongoing management and allocation of environmental flows in the MDB. The models also revealed the relative importance of local climate conditions for SWD, with increased importance of soil moisture, evapotranspiration and rainfall in arid regions, in proximity to headwater catchments and on slow-draining floodplains.

  13. The middle Eocene Markushegy subbituminous coal (Hungary): Paleoenvironmental implications from petrographical and geochemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, A. [Department Angewandte Geowissenschaften und Geophysik, Montanuniversitaet Leoben, Peter-Tunner-Str. 5, A-8700 Leoben (Austria); Institute of Mineralogy and Petrology, University of Bonn, Poppelsdorfer Schloss, D-53115 Bonn (Germany); Hamor-Vido, M. [Eoetvoes Lorand Geophysical Institute of Hungary, Kolumbusz u. 17-23, 1145 Budapest (Hungary); Sachsenhofer, R.F.; Reischenbacher, D.; Gratzer, R. [Department Angewandte Geowissenschaften und Geophysik, Montanuniversitaet Leoben, Peter-Tunner-Str. 5, A-8700 Leoben (Austria); Puettmann, W. [Institute of Atmospheric and Environmental Sciences, Department of Analytical Environmental Chemistry, J. W. Goethe-University, Georg-Voigt-Str. 14, D-60054 Frankfurt a.M. (Germany)

    2007-09-03

    Samples from two coal seams of the Markushegy underground mine (Hungary) were investigated for variations in maceral composition, petrography-based facies indicators and various geochemical parameters, using three seam profiles. Both seams originate from a topogenous mire and evolved within a peneplaned coastal area covered with eutrophic swamps. The presence of foraminifera and marine algae in the marly layers is indicative of marine ingressions. Coal facies characterisation from these parameters is combined with the results from biomarker analyses of soluble organic matter in order to reconstruct the depositional environment and to relate petrography-based indicators to the molecular composition. The contents of macerals of the liptinite group are positively correlated with soluble organic matter (SOM) yields and Hydrogen Index (HI). Consistent with maceral composition and high HI values, enhanced proportions of n-alkanes of intermediate molecular weight (n-C{sub 21-25}), which are predominantly found in macrophytes, are obtained from samples of the marly shales. The final drowning of the mire is reflected by decreasing pristane/phytane ratios, due to the rise of the (ground)water table and the establishment of anaerobic conditions. The observed positive correlation between pristane/phytane ratios and inertinite percentages suggests that, at least in the Markushegy deposit, both parameters reflect variations in redox conditions of the mire. The predominance of angiosperms in the peat-forming vegetation of the Markushegy coal is evidenced by the high relative proportions of angiosperm-derived triterpenoids. The influence of the relative proportion of fossil wood on tissue preservation (TPI) is indicated by the positive relationship of the concentration of land plant-derived terpenoid hydrocarbons and TPI. The degree of gelification of plant tissue (GI) is governed by the microbial activity in the mire, as indicated by a negative relationship between GI and the steroids/hopanoids concentration ratios. The variation of the {delta}{sup 13}C values of coal is obviously governed by the relative contribution of plant lipids to the biomass. The obtained negative relationship between {delta}{sup 13}C of the coal and GI is explained by the effect of cellulose decomposition and microbial activity on the isotopic composition of the organic matter. (author)

  14. 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

  15. An Upper Pleistocene to Holocene limnic record from the Carpathian Basin near Vrsac (Vojvodina, Serbia)

    Science.gov (United States)

    Zeeden, Christian; Hambach, Ulrich; Fisher, Peter; Obreht, Igor; Schulte, Philipp; Bösken, Janina; Wennrich, Voelker; Schäbitz, Frank; Klasen, Nicole; Gavrilov, Milivoj; Veres, Daniel; Markovic, Slobodan; Vött, Andreas; Lehmkuhl, Frank

    2016-04-01

    Upper Pleistocene geoarchives in the Pannonian Basin are predominantly composed of loess-paleosol sequences accompanied by only few fluvial archives dating to this time frame. In 2015 a 10 m sediment core was recovered within an extensive loess area by means of vibracoring, with the recovered sedimentary succession mainly composed of limnic sediments. Coring was conducted within a depression northwest of Vrsac and east of the Banat Sands in the eastern Carpathian Basin (North-Eastern Serbia) in a region still lacking in paleoenvironmental records but which must have played a crucial role in the spread of modern human into Europe along the main rivers valley tributary to the Danube. Radiocarbon dating places the upper half of the core within the last ca. 20 ka, whereas luminescence dating is on going. Sedimentological analyses give evidence of phases of eolian sediment input within a predominantly limnic depositional environment. Aeolian sediment input has been altered, and early diagenesis is expected to have superimposed the eolian sediment. In addition, levels of carbonate precipitation can be observed in the core, some intervals being very rich in clay and decalcified; both show strong alteration of original sediment. No indications for fluvial input are apparent, suggesting a continuous sedimentation during the Upper Pleistocene and into the Holocene. Here preliminary results are presented including core images and description, XRF scans, grain-size data and an age model in progress. Based on these findings a detailed interpretation on the sedimentary system and (paleo)environmental processes involved are given.

  16. Integrating Global Satellite-Derived Data Products as a Pre-Analysis for Hydrological Modelling Studies: A Case Study for the Red River Basin

    Directory of Open Access Journals (Sweden)

    Gijs Simons

    2016-03-01

    Full Text Available With changes in weather patterns and intensifying anthropogenic water use, there is an increasing need for spatio-temporal information on water fluxes and stocks in river basins. The assortment of satellite-derived open-access information sources on rainfall (P and land use/land cover (LULC is currently being expanded with the application of actual evapotranspiration (ETact algorithms on the global scale. We demonstrate how global remotely sensed P and ETact datasets can be merged to examine hydrological processes such as storage changes and streamflow prior to applying a numerical simulation model. The study area is the Red River Basin in China in Vietnam, a generally challenging basin for remotely sensed information due to frequent cloud cover. Over this region, several satellite-based P and ETact products are compared, and performance is evaluated using rain gauge records and longer-term averaged streamflow. A method is presented for fusing multiple satellite-derived ETact estimates to generate an ensemble product that may be less susceptible, on a global basis, to errors in individual modeling approaches. Subsequently, monthly satellite-derived rainfall and ETact are combined to assess the water balance for individual subcatchments and types of land use, defined using a global land use classification improved based on auxiliary satellite data. It was found that a combination of TRMM rainfall and the ensemble ETact product is consistent with streamflow records in both space and time. It is concluded that monthly storage changes, multi-annual streamflow and water yield per LULC type in the Red River Basin can be successfully assessed based on currently available global satellite-derived products.

  17. Analysis of land cover change impact on flood events using remote sensing, GIS and hydrological models: a case study of the Nyando River Basin in Kenya

    International Nuclear Information System (INIS)

    In this study, land cover changes in the Nyando River basin (3500 km2) of Kenya were analyzed and their impact of floods quantified. Three Landsat satellite images for 1973, 1986 and 2000 were acquired, processed and classified based on seven major land cover classes prevalent in the basin using a hybrid of supervised and non supervised classification procedures. The detected land cover changes, together with a DEM and a soil map of the basin, were then used to estimate physically based parameters for the selected hydrological models. The models were then used to estimate local and flood peak discharges and volumes arising from selected storm events for each state of the classified land cover dataset. To further understand how changes in the land cover may impact on the flood hydrology, three scenarios that represent quite extreme alternatives were formulated to study the possible bandwidth during floods. Land cover classification results revealed immense land degradation over the span of study. Forests reduced by an area of 488 km2 representing a 20% decline, while agricultural fields expanded by 581 km2 representing a 16% increase over the same period of time (1973-2000). Hydrological modeling results indicated that the basin underwent significant increase in the peak discharge value. The flood peak discharges in the whole basin were noted to have increased by at least 16% over the period of 1973 -2000.Flood volumes were also noted to have increased by at least 10% over the same period of time. (author)

  18. The influence of subaquatic springs in lacustrine sedimentation: Origin and paleoenvironmental significance of homogenites in karstic Lake Banyoles (NE Spain)

    Science.gov (United States)

    Morellón, Mario; Anselmetti, Flavio S.; Valero-Garcés, Blas; Giralt, Santiago; Ariztegui, Daniel; Sáez, Alberto; Mata, M. Pilar; Barreiro-Lostres, Fernando; Rico, Mayte; Moreno, Ana

    2014-08-01

    Banyoles (42°08‧N, 2°45‧E) is the largest and deepest lake of karstic-tectonic origin in the Iberian Peninsula. The lake comprises two basins and six sub-circularly shaped sub-basins fed by subaquatic springs. Periods of intense groundwater inflow in the deepest sub-basins lead to the fluidization and re-suspension of previously deposited sediments and subsequent settling forming homogenite deposits on the southern basin intermediate platforms. The multiproxy analysis of sediment cores combined with high resolution seismic stratigraphy (3.5 kHz pinger and multi-frequency Chirp surveys) allows a precise reconstruction of depositional environments and related hydrological variability and groundwater inflow during the last ca. 7.6 cal kyr BP. According to the age model based on 137Cs, 210Pb and AMS 14C dating, homogenite deposition occurred between 7.2 and 5.5 cal kyr BP, stopped during the middle Holocene (5.5-2.8 cal kyr BP) and greatly increased during the last two millennia with a total of 17 homogenite layers individually up to 75 cm-thick. The onset of this unique sedimentation mode at ca. 3 cal kyr BP coincides with an increase in lake level, evidenced by the onlapping of fine-grained, distal sediments over coarser massive, carbonate-rich, littoral deposits. A detailed, multidisciplinary study of the homogenites (sedimentology, physical properties, high-resolution elemental geochemistry, mineral composition, grain-size, organic matter content and SEM) combined with seismic stratigraphy demonstrates that the fluidization events triggering the formation of the homogenites were caused by higher and more intense local groundwater inflow, related to increased rainfall during the Late Holocene and likely intensified by land use changes during the last millennium.

  19. Impacts of forest changes on hydrology: a case study of large watersheds in the upper reach of Yangtze River Basin

    OpenAIRE

    Cui, X; Liu, S; Wei, X.

    2012-01-01

    Quantifying the effects of forest changes on hydrology in large watersheds is important for designing forest or land management and adaptation strategies for watershed ecosystem sustainability. Minjiang River watershed located in the upper reach of the Yangtze River Basin plays a strategic role in environmental protection and economic and social wellbeing for both the watershed and the entire Yangtze Basin. The watershed lies in the transition zone from Sichuan Basin to Qinghai-Tibet Pla...

  20. Mineral-magnetic signal of long-term climatic variation in Pleistocene fluvio-lacustrine sediments, Nihewan Basin (North China)

    Science.gov (United States)

    Ao, Hong

    2010-11-01

    The Nihewan Basin (around 40°N, North China) is a major focus of investigations into hominid occupation in the eastern Asia during the early Pleistocene, thus the paleoenvironmental evolution in this area is crucial for understanding of early human habitation at high northern latitudes of East Asia. To retrieve reliable long-term paleoenvironmental signals from the Nihewan fluvio-lacustrine sequences, I conduct an environmental magnetic investigation on the Pleistocene Xiantai fluvio-lacustrine sequence at the eastern margin of the Nihewan Basin. Results suggest that there exist an up-section decreasing trend in magnetic mineral concentration and grain size, which is attributed to a long-term decrease in abundance of magnetic minerals in the catchments and in transportation of detrital magnetic minerals into the Nihewan paleolake. I further reveal that these long-timescale variations are related to a long-term decrease in East Asian monsoon precipitation and humidity in the Nihewan Basin during the Pleistocene. This paleoclimate inference is consistent with the increasing aridification in Asian mainland during the Pleistocene, an important climate response to increasing global ice volume.

  1. Benthic foraminifera as biostratigraphical and paleoecological indicators:An example from Oligo-Miocene deposits in the SW of Zagros basin, Iran

    Institute of Scientific and Technical Information of China (English)

    Asghar Roozpeykar; Iraj Maghfouri Moghaddam

    2016-01-01

    The Asmari Formation is a predominantly carbonate lithostratigraphic unit that outcrops in the Zagros Basin. Micropaleontological studies of the Asmari Formation in the Dehdasht area led to the identifi-cation of 51 species of foraminifera taxa. Among the foraminifera, Nummulites cf. vascus, Operculin sp., Operculina complanata, Eulepidina dilatata, Eulepidina elephantine, Ditrupa sp., Miogypsina sp., Elphidium sp. 14, and Borelis melo curdica are the most important. The Lepidocyclina-Operculina-Ditrupa assemblage zone represents the RupelianeChattian age. The Aquitanian age is also defined by co-occurrence of Miogypsina sp. and Elphidium sp. 14, and finally, the first occurrence of Borelis melo curdica represents the Burdigalian. Based on faunal assemblages, the following paleoenvironmental settings are determined for the deposition of the study section: (1) the deep, offshore settings in the aphotic zone dominated by pelagic and small benthic foraminifera;(2) the low energy, turbid and low light parts of the oligophotic zone characterized by large and flat lepidocyclinids (Eulepidina) and Nummulitidae;(3) the low turbidity, deeper part of the inner ramp dominated by Miogypsinoides, Neorotalia, Lepidocyclina, Operculina and Archias; (4) the shallow, marginal marine environment exposed to salinity fluctuations (short-term salinity fluctuations or fully marine conditions) dominated by small benthic Foraminifera (Ammonia and Elphidium); (5) highly translucent, shallowest part of the inner ramp dominated by representatives of Borelis, Meandropsina and Peneroplis. The biotic assemblages represent warm tropical waters with oligotrophic to slightly mesotrophic conditions.

  2. 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.

  3. Hydrogeochemistry and isotopic study of ground and surface water in the Ayensu Basin of the Central Region

    International Nuclear Information System (INIS)

    The Central Region is a water stressed area. Some of the boreholes drilled by the people become salty and therefore resort to surface waters which are most of the time affected by water borne diseases. The main aim of the study is to understand the hydrogeochemical and isotopic hydrology of the Ayensu Basin. It mainly used hydrochemistry, environmental isotopes and Piper diagrams to obtain an understanding of the functioning of the system. 23 borehole samples, 2 samples from hand dug wells and 4 samples form the River Ayensu were taken from the Ayensu Basin. The samples were analyzed for physical parameters, major ions as well as trace elements using spectrophotometer, atomic absorption spectrophotometry (AAS) and Neutron activation analysis. The results showed that the groundwater in the study is fresh (TDS 75.2-804mg/l) and generally mildly acidic to neutral (pH 5.53-7.21). The ground water quality of the study area was good since most of the parameters measured were within the World Health Organisation (WHO) recommended values. However, a few, such as aluminium, manganese and iron showed elevated concentrations in most of the samples. The Piper trilinear diagram shows the major water types as mainly Na-Cl, Na-HC03-Cl, Na-Cl-SO4 and Na-Mg-Cl. A plot of δ 18O versus δ 2H showed the groundwaters clustering along the local meteoric water line indicating that groundwaters do not undergo significant evaporation before recharge. The trace element concentrations were found to be generally low with Al being the highest, followed by copper and manganese, cadmium was found to be below the detection limit of 0.001mg/l. Concentrations of Cr, Zn, and As were also very small. (au)

  4. Preliminary study of the uranium potential of the Triassic Sanford basin and Colon cross structure, North Carolina

    International Nuclear Information System (INIS)

    A preliminary geologic investigation was conducted to determine if Triassic sedimentary rocks of the Sanford basin and Colon cross structure in North Carolina are favorable hosts for uranium deposits. Rocks of adjacent Carolina slate belt were also examined as a potential source of uranium. On the basis of favorability criteria for sandstone-type uranium deposits, and geologic and geophysical investigations of the study area, the most favorable sites for further investigation are (1) at the contacts between the Pekin and Cumnock and between the Pekin and Sanford Formations near the Colon cross structure and (2) at the base of the Jonesboro fault, which lies below the Sanford Formation, northwest of Sanford. The highly weathered granites southeast of the Jonesboro fault were a source of the detritus deposited on the cross structure and may have been a primary source of uranium. Uranium leached from the coarse sediment (Pekin Formation) of the cross structure may have been transported downdip and may have been precipitated by the carbonaceous shales of the Cumnock Formation on the western side of the cross structure or at the Pekin-Sanford contact to the east. The Jonesboro fault may provide an impermeable barrier to ground-water migration in the metamorphosed basement rocks below the Triassic sediments. Such a barrier would constitute a favorable site for the precipitation and retention of uranium. Scintillometer surveys and laboratory analyses indicate no anomalous surface radioactivity in the study area. However, deep surface weathering may have caused the uranium to be leached from the exposed rocks and redeposited at depth. Geologic investigations show that conditions which have proven favorable for deposition of uranium in other areas are present in the Triassic rocks of the Sanford basin and Colon cross structure. However, because of deep surface weathering, further subsurface studies are necessary to confirm the favorability of the rocks as hosts for uranium

  5. Study of groundwater in the Chicu River basin, Sabana de Bogota, Colombia

    International Nuclear Information System (INIS)

    The Rio Chicu Valley aquifer system represents one of the many sub-systems constituting the hydrogeological system of the Sabana de Bogota. The valley has a structure of a graben, covered by a quaternary alluvial formation, which has a low permeability and therefore is an aquifer of poor characteristics. Due to the thickness of this aquifer (around 300 m), the tertiary aquifers are only exploited by few deep wells. The isotopic composition of water collected from the tertiary aquifer is depleted by 1 per mille in δ18O and 8 per mille in δD. This difference is due to the altitude effect of recharge, because the tertiary aquifers outcrop on the top of the surrounding hills. In some places, the stable isotope content of water sampled in wells tapping water from the quaternary aquifer is similar to the values found in the tertiary aquifer. This fact indicates the ascending leakage from deep horizons. A rather unique characteristics of the quaternary aquifer is that in the central part of the basin the dissolved inorganic carbon DIC is very high and shows a δ13C values around +10 per mille vs PDB and 14C around 5-10 pmc. The positive values are probably related to decomposition of organic matter in anaerobic conditions. These values reflect a very low flow in the system and limited recharge. (author). 1 ref., 5 figs, 2 tabs

  6. 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.

  7. The use of the tracer caesium-137 for studying sediment movement in a drainage basin

    International Nuclear Information System (INIS)

    The environmental isotope caesium-137 (137Cs), a product of atmospheric nuclear weapons tests, was used as a tracer to assess sediment sources and sediment redistribution in the drainage of Maluna Creek, Hunter Valley, New South Wales. Caesium-137 levels were found to be significantly different between the three main land-use groups of forest, grassland and vines. Caesium-137 amounts per unit area were greatest in the forest and least in cultivated vineyards, and were attributed to accelerated soil erosion from cultivated areas. Soil losses from four runoff plots correlated positively with the loss of 137Cs (in relation to estimated input) in soils adjacent to the plots. Relative amounts of 137Cs in soil profiles in a northern tributary basin of Maluna Creek were used to trace eroded soils from vineyards to sedimentation sites in adjacent alluvial fans and a downstream farm dam reservoir. The redistribution of 137Cs in the sedimentary deposits was related to particle size, the greatest amounts of the isotope being found on finer sediments in the reservoir

  8. 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.

  9. Source rock evaluation with interpretation of wireline logs: a case study of lower indus basin, pakistan

    International Nuclear Information System (INIS)

    The qualitative interpretation of the log data succeeds in translating the inherited log responses into organic content and source rock identification. The quantitative interpretation of the petrophysical parameters helped in determination of the total organic content and source rock potential. The criteria for distinguishing shale from sedimentary layers are low density, high sonic transit time, high porosity and high resistivity of shales. The responses of wireline logs in relation to the increasing of organic matter (OM) content is detected through crossplot technique. By this way, the organic matter is identified with increasing in gamma-ray values, sonic transit-time, neutron porosity, resistivity and with reduction in the formation bulk density. The open hole well log data (DLL, FDC, BHC and CNL) of SANN-1 well of Kirthar Trough, Southern Indus Basin (Sindh province) Pakistan, is utilized to determine the organic content of Lower Goru and Sember formations. In this paper, an attempt was made to establish a quantity correlation between standard well logs (sonic, density, neutron and resistivity) and total organic carbon by means of a technique called ?LogR. In calculating total organic carbon content (TOC), porosity/resistivity overlay technique was used. TOC measured by delta logR technique at depth interval between 3270 to 3585 meters yielded an average value of 2.78% for Lower Goru Formation and 3.31% for Sember formation. These values were in agreement with the reported values in the literature. (author)

  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. Interannual variability of regional evapotranspiration under precipitation extremes: A case study of the Youngsan River basin in Korea

    Science.gov (United States)

    Song, Youngkeun; Ryu, Youngryel; Jeon, Soohyun

    2014-11-01

    Understanding basin-scale evapotranspiration (ET) is an important issue for the management of regional water resources, especially with the recent trend of intensified precipitation (P). This study assessed the spatial and temporal variations of regional ET in response to P extremes, for various types of land-cover across the Youngsan River basin in Korea. The spatial distribution of monthly P and ET from 2001 to 2009 were estimated using rainfall records from 40 weather stations located across the basin and a satellite-derived, process-based ET model Breathing Earth System Simulator (BESS) (Ryu et al., 2011), respectively. The study periods were focused on the recent years with abnormally large, small and normal P, which were identified from anomalies in the z-sores of long-term (1973-2011) rainfall records. The variation of regional ET was assessed in terms of: (1) the controlling factors, using the statistics of related meteorological and geographical data, (2) a water-energy balance, using Budyko's framework, and (3) the water balance of four selected watersheds in the region, using the partitioning of annual P into ET and riverflow discharge (Q). The total annual ET of this region decreased in abnormally large-P year and increased in small-P year, because the ET in July to August (which accounts for more than 36% of annual ET) was limited by the available energy rather than available water due to the summer monsoon. In terms of land cover types, forests showed larger interannual variability in ET than paddy fields or cropland, with the differences in ET between large and small-P years being 108 and 82 mm yr-1, respectively. The sensitivity of annual ET to P extremes was significantly related to the leaf area index (LAI), rather than soil properties, topography, or specific land-cover type (p < 0.05, generalized linear model). However, the interannual variations of ET were not large (15-18%) compared to those of annual P (51-62%) and Q (108-232%) during 2002

  12. Quantifying and identifying the sources of fine sediment input in a typical Mongolian river basin, the Kharaa River case study

    Science.gov (United States)

    Theuring, Phillip

    2013-04-01

    Mongolia is facing a tremendous change of land-use intensification due to expansions in the agricultural sector, an increase of cattle and livestock and a growth of urban settlements by migration of the rural population to the cities. With most of its area located in a semiarid to arid environment, Mongolia is vulnerable to climatic changes that are expected to lead to higher temperatures and increased evapotranspiration. It is expected that this may lead to unfavorable changes in surface water quality caused by increased nutrients and sediment bound pollutants emissions. Increased fine sediment load is associated with nutrient, heavy metal and pollutant input and therefore affects water quality. Previous studies using radionuclide fallout isotope sediment source fingerprinting investigations identified riverbank erosion as the main source of suspended sediment in the Kharaa River. Erosion susceptibility calculations in combination with suspended sediment observations showed strong seasonal and annual variabilities of sediment input and in-stream transport, and a strong connection of erosional behaviour with land-use.The objective of this study is to quantify the current water quality threats by fine sediment inputs in the 15,000 km2 Kharaa River basin in Northern Mongolia by delineating the sources of the fine sediments and estimating the sediment budget.To identify the spatial distribution of sediment sources within the catchment, more than 1000 samples from the river confluences at the outlet of each sub basin into the main tributary were collected during 5 intensive grab sediment sampling campaigns in 2009-11. The fine sediment fraction (<10μm) has been analysed using geochemical tracer techniques for spatial source identification, based on major elements (e.g. Si, Al, Mg, Fe, Na, K, P) and trace elements (e.g. Ba, Pb, Sr, Zn). The contribution of suspended sediment of each sub basin in the main tributary has been evaluated with help of a mixing model. To

  13. 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

  14. 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.

  15. Quantitative Analysis of Driving Factors of Grassland Degradation: A Case Study in Xilin River Basin, Inner Mongolia

    Directory of Open Access Journals (Sweden)

    Yichun Xie

    2012-01-01

    Full Text Available Current literature suggests that grassland degradation occurs in areas with poor soil conditions or noticeable environmental changes and is often a result of overgrazing or human disturbances. However, these views are questioned in our analyses. Based on the analysis of satellite vegetation maps from 1984, 1998, and 2004 for the Xilin River Basin, Inner Mongolia, China, and binary logistic regression (BLR analysis, we observe the following: (1 grassland degradation is positively correlated with the growth density of climax communities; (2 our findings do not support a common notion that a decrease of biological productivity is a direct indicator of grassland degradation; (3 a causal relationship between grazing intensity and grassland degradation was not found; (4 degradation severity increased steadily towards roads but showed different trends near human settlements. This study found complex relationships between vegetation degradation and various microhabitat conditions, for example, elevation, slope, aspect, and proximity to water.

  16. Quantitative analysis of driving factors of grassland degradation: a case study in Xilin River Basin, Inner Mongolia.

    Science.gov (United States)

    Xie, Yichun; Sha, Zongyao

    2012-01-01

    Current literature suggests that grassland degradation occurs in areas with poor soil conditions or noticeable environmental changes and is often a result of overgrazing or human disturbances. However, these views are questioned in our analyses. Based on the analysis of satellite vegetation maps from 1984, 1998, and 2004 for the Xilin River Basin, Inner Mongolia, China, and binary logistic regression (BLR) analysis, we observe the following: (1) grassland degradation is positively correlated with the growth density of climax communities; (2) our findings do not support a common notion that a decrease of biological productivity is a direct indicator of grassland degradation; (3) a causal relationship between grazing intensity and grassland degradation was not found; (4) degradation severity increased steadily towards roads but showed different trends near human settlements. This study found complex relationships between vegetation degradation and various microhabitat conditions, for example, elevation, slope, aspect, and proximity to water. PMID:22619613

  17. 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.

  18. Effect of Land Use on Soil Properties in Debris Flow Bottomland: A Case Study at Xiaojiang Basin, Yunnan

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiuying; LI Fadong; LIU Mengyu; SONG Xianfang; OU Guoqiang

    2006-01-01

    In order to understand the effect of different land use on soil physics and nutrients properties of the debris flow bottomland, a case study at Daqing gully (in Xiaojiang Basin, Yunnan) was conducted in 2004. Soil samples were taken at depth of 0-10,10-20,20-40,40-60,60-80 cm under three land use patterns crop bottomland(CL), forest bottomland(FL), and barren bottomland(BL). The results showed that the developing bottomland to CL promoted soil toaccumulate total phosphorus (TP) and available phosphorus (AP), pH value transferred from neutral to alkalescency, and organic matter decreased significantly. Furthermore, the contents of total nitrogen (TN) and available nitrogen (AN) in CL were lower than that of FL and BL because the growth of crops consumed more nutrients in soil. The results also showed that the contents of TP, AP and available potassium (AK) in soil were positively correlated with soil particle.

  19. 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.

  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. Petro-mineralogical Studies of the Paleoproterozoic Phosphorites in the Sonrai basin, Lalitpur District, Uttar Pradesh, India

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. 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.

  4. Stratigraphic correlation for the IODP Expedition 347 - toward an integrated Baltic Sea Basin stratigraphy

    Science.gov (United States)

    Kotilainen, Aarno; Hyttinen, Outi; Andrén, Thomas; Cotterill, Carol; Hale, Walter; IODP Expedition 347 Science Party, the

    2014-05-01

    The IODP Expedition 347 - "Baltic Sea Paleoenvironment" completed in September - November 2013 (offshore phase) was the 5th and the final mission-specific platform (MSP) expedition of the Integrated Ocean Drilling Program. The expedition used a geotechnical drillship, the Greatship Manisha equipped with a Geoquip Marine coring rig, to core and wireline-log several sub-basins within the Baltic Sea, aiming to produce new information on the history of the Baltic Sea and climate change during the last glacial cycle. During the IODP Expedition 347 altogether over 1900 meters were successfully drilled at 8 Sites (M0059 - M0067) in the Lille Belt, Kattegat, Ångermanälven Estuary, Landsort Deep, Hanö Basin and Bornholm Basin with core recovery of approximately 1600 m (expansion adjusted core recovery of 91.46%). In this presentation, we show the preliminary results of regional stratigraphic correlation and splice results for the Expedition. That information provides a solid base for stratigraphic and high-resolution paleoenvironmental studies. Stratigraphic correlation consisted of the following: (1) ensuring the maximum core recovery on site, (2) seismic-core (sedimentary facies) correlation and (3) generating composite depth scales and splice records to each site. To obtain a complete sedimentary record, multiple adjacent holes were cored with an offset in depth of 0.5-1.5 m between cores from different holes. The continuity of recovery was assessed by generating composite sections that align prominent features in physical property data from adjacent holes. With the information gained by Fast Track Multi-Sensor Core Logger (MSCL) data, it was possible to adjust coring plan before the new hole, to ensure that intervals missing in previous cores could be recovered from an adjacent hole. Correlation between seismic profiles and cores used a simple estimation sound velocity vs. sediment type. Acquired depth was tested by comparison with major core surfaces, downhole logs

  5. 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.

  6. Phytolith analysis and paleoenvironmental reconstruction from Lake Poukawa Core, Hawkes Bay, New Zealand

    Science.gov (United States)

    Carter, John A.

    2002-07-01

    As part of a multiproxy investigation, phytoliths were extracted from sediments in a 197-m core in Hawkes Bay, New Zealand. They provide a continuous vegetation-climate record spanning the time period from at least the last interglacial (marine oxygen isotope stage 5) to the present. The phytolith record demonstrates that grass/cyperaceae grew during warmer periods and woody taxa dominated the site during colder periods. During the present interglacial, the Poukawa basin is occupied by a shallow lake surrounded by an extensive fen. During colder-drier periods, the floor of the basin dried out and woody taxa occupied the basin floor. This contrasts with the pollen record, which demonstrates a converse pattern. The apparent discrepancy reflects the purely local provenance of the phytolith assemblage. Significant changes in phytolith assemblages occur at the same depth as major tephras, indicating a sharp decline in trees and shrubs and a surge in grass and cyperaceae. A series of successional changes follow each major tephra fall. Initially, the woody taxa are killed off and replaced by grass and cyperaceae that rapidly colonise the fresh surface. Trees and or shrubs succeed the grass and cyperaceae after a significant lag.

  7. Fluvial sedimentology of a major uranium-bearing sandstone - A study of the Westwater Canyon member of the Morrison Formation, San Juan Basin, New Mexico

    International Nuclear Information System (INIS)

    The Westwater Canyon Member of the Morrison Formation, the main ore-bearing sandstone in the San Juan basin, consists of a sequence of vertically stacked braided stream deposits. Three fluvial units within the sequence can be delineated in the basin. Volcanic pebbles are abundant in the middle fluvial unit, in a zone that forms a crude time line. A pronounced thickening of sandstone in the Westwater Canyon Member north of Gallup, once believed to be the apex of a large alluvial fan, is now thought to merely reflect a greater accumulation of sediment in response to downwarping of the basin in that area. Provenance studies suggest that highlands that contributed detritus to Westwater Canyon streams were located several hundred kilometers to the west and southwest of the San Juan basin, and thus fan apices would also have been several hundred kilometers upstream. The fluvial units recognized in the basin may well be coalesced distal fan deposits, but are probably best interpreted as vertically stacked braided steam sequences. Facies changes in fine-grained interbeds of the Westwater Canyon probably have greater significance in terms of localizing ore than any special attribute of the fluvial sandstones themselves. Uranium ore generally occurs in sandstones that are interbedded with greenish-gray lacustrine mudstones. Pore waters that were expelled from these mudstones are thought to have been the source of the pore-filling organic matter (humate) associated with primary uranium ore in nearby sandstones

  8. 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

  9. 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

  10. Development and Evaluation of a River-Basin-Scale High Spatio-Temporal Precipitation Data Set Using the WRF Model: A Case Study of the Heihe River Basin

    Directory of Open Access Journals (Sweden)

    Xiaoduo Pan

    2015-07-01

    Full Text Available To obtain long term accurate high resolution precipitation for the Heihe River Basin (HRB, Weather Research and Forecasting (WRF model simulations were performed using two different initial boundary conditions, with nine microphysical processes for different analysis parameterization schemes. High spatial-temporal precipitation was simulated from 2000 to 2013 and a suitable set of initial, boundary, and micro parameters for the HRB was evaluated from the Heihe Watershed Allied Telemetry Experimental Research project and Chinese Meteorological Administration data at hourly, daily, monthly, and annual time scales using various statistical indicators. It was found that annual precipitation has gradually increased over the HRB since 2000. Precipitation mostly occurs in summer and is higher in monsoon-influenced areas. High elevations experience winter snowfall. Precipitation is higher in the eastern upstream area than in the western upstream, area; however, the converse occurs in winter. Precipitation gradually increases with elevation from 1000 m to 4000 m, and the maximum precipitation occurs at the height of 3500–4000 m, then the precipitation slowly decreases with elevation from 4000 m to the top over the Qilian Mountains. Precipitation is scare and has a high temporal variation in the downstream area. Results are systematically validated using the in situ observations in this region and it was found that precipitation simulated by the WRF model using suitable physical configuration agrees well with the observation over the HRB at hourly, daily, monthly and yearly scales, as well as at spatial pattern. We also conclude that the dynamic downscaling using the WRF model is capable of producing high-resolution and reliable precipitation over complex mountainous areas and extremely arid environments. The downscaled data can meet the requirement of river basin scale hydrological modeling and water balance analysis.

  11. 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 representati