Cretaceous-Paleogene ostracods from the Paraíba Basin, northeastern Brazil

Science.gov (United States)

de Lima Barros, Cecília; Piovesan, Enelise Katia; Oliveira Agostinho, Sonia Maria

2018-04-01

This work presents a detailed taxonomic study on the marine ostracods from the Paraíba Basin, northeastern Brazil, in wells from the wells Itamaracá-1IT-03-PE and Poty-1PO-01-PE, which record the Maastrichtian-Danian boundary. Besides the taxonomic data, this paper contributes to the paleoenvironmental knowledge of Cretaceous-Paleogene ostracods from the Paraíba Basin. The analysis of 98 samples of the well Itamaracá-1IT-03-PE and 59 samples of the Poty-1PO-01-PE resulted in the record of 34 ostracode species, all representative of a marine environment with normal salinity. Seven new species are proposed: Cytherella centrocompressa sp. nov.; Cytherella paraibensis sp. nov.; Neonesidea potyensis sp. nov.; Bythoceratina spinosa sp. nov.; Eucytherura ventrotuberculata sp. nov.; Langiella fauthi sp. nov. and Protobuntonia punctatum sp. nov.

Paleoenvironmental conditions and strontium isotope stratigraphy in the Paleogene Gafsa Basin (Tunisia) deduced from geochemical analyses of phosphatic fossils

Science.gov (United States)

Kocsis, László; Ounis, Anouar; Chaabani, Fredj; Salah, Neili Mohamed

2013-06-01

Fossil shark teeth and coprolites from three major phosphorite occurrences in the Gafsa Basin (southwestern Tunisia) were investigated for their geochemical compositions to improve local stratigraphy and to better assess paleoenvironmental conditions. 87Sr/86Sr isotope ratios of shark teeth from the Early Maastrichtian El Haria Formation and from the Early Eocene Métlaoui s.s. Formation yielded Sr isotope ages of 68 ± 1 and 47.9 ± 1.3 Ma, respectively, which accord with the expected stratigraphic positions of these sediments. Conversely, shark teeth from the Paleocene-Eocene Chouabine Formation have large variation in Sr isotope ratios even within individual layers. After statistical treatment and then elimination of certain outlier samples, three age-models are proposed and discussed. The most reasonable solution includes three subsequent Sr ages of 61.8 ± 2.2 Ma, 57.2 ± 1.8 and 54.6 ± 1.6 for layer IX, layers VIII-V and layers IV-0, respectively. Three scenarios are discussed for explanation of the presence of the outliers: (1) diagenesis, (2) re-working and (3) locally controlled seawater Sr isotope ratio. The most plausible account for the higher 87Sr/86Sr ratios relative to the global ocean in some fossils is enhanced intrabasinal re-working due to low sea level. Conversely, the sample with lower 87Sr/86Sr than the global seawater may link to diagenesis or to seawater influenced by weathering of Late Cretaceous marine carbonates, which latter is supported by model calculation as well. The ɛNd values of these fossils are very similar to those reported for Paleogene and Late Cretaceous Tethyan seawater and are compatible with the above interpretations. The relatively low oxygen isotope values in shark teeth from the topmost phosphate bed of the Chouabine Formation, together with the Sr isotope results, point toward recovering better connections with the open sea. These δ18O data reflect elevated ambient temperature, which may link to the Early Eocene

Biogeochemistry of selenium isotopes: processes, cycling and paleoenvironmental applications

NARCIS (Netherlands)

Mitchell, K.A.

2012-01-01

Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has been suggested as a potentially powerful environmental tracer and paleoenvironmental proxy. Chapter 1 provides a literature review of the Se cycle. While the Se cycle shares some

Paleo-Environmental Reconstruction Using Ancient DNA

DEFF Research Database (Denmark)

Pedersen, Mikkel Winther

The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context...... solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms...... research on ancient and modern environmental DNA (Paper 1), secondly by setting up a comparative study (Paper 2) to investigate how an ancient plant DNA (mini)-barcode can reflect other traditional methods (e.g. pollen and macrofossils) for reconstructing floristic history. In prolongation of the results...

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.

Post-Glacial and Paleo-Environmental History of the West Coast of Vancouver Island

Science.gov (United States)

Dallimore, A.; Enkin, R. J.

2005-12-01

Annually laminated sediments in anoxic fjords are potentially ideal paleoclimate recorders, particularly once proxy measurements for atmospheric, oceanographic and sedimentological conditions have been calibrated. On the west coast of Canada, these sediments also record the changing environment as glaciers retreated from this area about 12 ka y BP. In Effingham Inlet, a 40 m core taken from the French ship the Marion Dufresne as part of the international IMAGES/PAGES program, gives evidence of an isolation basin at maximum glacial isostatic rebound and lowest paleo-sea level followed by eustatic sea level rise about 10 ka y BP. The Late Pleistocene record also marks dramatic changes in glacial sedimentary source and transport. Excellent chronological control is provided by complementary yet independent dating methods including radiocarbon dates on both plants and shells, identification of the Mazama Ash, varve counting and paleomagnetic, paleosecular variation correlations in the lower, pro-glacial section of the core which does not contain organic material. Paleoenvironmental evidence from this core provides information on immediate post-glacial conditions along the coast and rapid climatic changes throughout the Holocene, with implications for the possibility of early human migration routes and refugia.

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

International Nuclear Information System (INIS)

Zouari, K.; Chkir, N.; Ouda, B.

2002-01-01

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)

Paleoenvironmental changes and influence on Operculodinium centrocarpum during the Quaternary in the Campos Basin, southwestern Brazil

Science.gov (United States)

Santos, Alessandra; de Araujo Carvalho, Marcelo; de Oliveira, Antônio Donizeti; Mendonça Filho, João Graciano

2017-12-01

The purpose of this paper is to document the changes observed in the Quaternary dinoflagellate assemblages from 80 core samples from the Campos Basin. The Interglacial (Subzone X1), Glacial (Subzones Y5 to Y2), Last Glacial Maximum (Subzone Y1) and Post-Glacial (Zone Z) intervals were identified. High abundance of Operculodinium centrocarpum suggests the warm, high salinity and nutrient-poor water conditions dominated the upper water column of the Campos Basin. The climate and oceanic current dynamic of the continental slope of the Campos Basin appears to has been a significant controlling factor in the distribution of dinocysts, particularly of O. centrocarpum, during the Pleistocene/Holocene transition.

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

International Nuclear Information System (INIS)

Del Puerto, L.; Bracco, R.; Inda, H.; Garcia, F.; Panario, D.; Castineira, C.; Capdepont, I.

2012-01-01

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

Studies in living and fossil foraminifers from seasonally productive regions

NARCIS (Netherlands)

Barmawidjaja, D.M.

1991-01-01

Paleoecological and paleoenvironmental analysis of benthic and planktonic foraminiferal associations from sediments from the northern Adriatic Sea, the Kau Basin (Halmahera) and the Molucca Sea shed new light on the way in which various environmental factors influence foraminiferal distribution

Record of continental to marine transition from the Mesoproterozoic Ampani basin, Central India: An exercise of process-based sedimentology in a structurally deformed basin

Science.gov (United States)

Chakraborty, Partha Pratim; Saha, Subhojit; Das, Kaushik

2017-08-01

The Mesoproterozoic Ampani Group of rocks, a structurally deformed sedimentary package hosted within the Bastar Craton in central India, was studied for process-based facies and paleoenvironmental analyses. Outcrop mapping on 1:1500 scale, deconvolution of deformation pattern, and process-based facies analyses have led to the identification of fifteen facies types, clubbed under four facies associations. A range of paleoenvironmental settings varying from continental fluvial to distal marine shelf is inferred. Deductive paleohydrology revealed poorly-efficient 'dirty river' character for the Ampani River system with low water discharge. However, at times of catastrophic sheet floods release of sediments trapped at the river mouth in form of hyperpycnal underflows triggered formation of river mouth delta. Reworking of delta front sediment in wave-dominated coastline resulted development of beach-foreshore and shoreface (proximal to distal). Variation in the relative proportion of bar and interbar products within the shoreface successions exposed at different studied sections is interpreted as signature of relative bathymetric variation. The pro-deltaic Ampani shelf was storm infested. Tectonic perturbance in the basin hinterland in course of Ampani sedimentation is inferred from occurrence of a disparately thick lobate high-density flow deposit towards the top of shoreface succession and increase in feldspar content upward within the shoreface succession. Addition of detritus from a ∼1600 Ma Mesoproterozoic provenance in upper part of shoreface also strengthen the contention. Deconvolution of deformation pattern and delineation of environmental products ranging between continental and deep marine allowed us to infer the Ampani sediment package as fining-upward in character evolved in a transgressive mode.

Paleoenvironmental conditions in the late Paleogene, Sumatra, Indonesia

Science.gov (United States)

O'shea, Natalie; Arthur Bettis, E.; Zaim, Yahdi; Rizal, Yan; Aswan, Aswan; Gunnell, Gregg F.; Zonneveld, John-Paul; Ciochon, Russell L.

2015-11-01

A stratified paleosol sequence exposed in an open pit mine in central Sumatra provides a record of the paleoenvironmental conditions in the lower reaches of a large river system in the late Paleogene (latest Eocene or Oligocene). Morphological, geochemical, and stable isotope data suggest that the sequence represents a mosaic of local environmental conditions changing from estuarine to riverine up section. Weakly expressed soils formed on low-lying estuary surfaces, while more well expressed soils formed on higher, better drained surfaces. Peatlands (coal) with clayey subsoils were along the estuary margins. Well-expressed soils with evidence of clay translocation and chemical weathering become more common higher in the section where alluvial deposits associated with a meandering river are dominant. Stable carbon isotope ratios support a paleolandscape dominated by C3 plants with input by C4 vegetation limited to a few intervals. Finally, whole-rock geochemistry suggests moderate chemical weathering consistent with a tropical locality. This multi-proxy paleoenvironmental reconstruction suggests a highly productive lowland forest environment at this locality in the late Paleogene and provides the first direct examination of the terrestrial environment in Sumatra at this time. The limited fossil record in Island Southeast Asia during this time period is likely a result of poor bone and shell preservation in tropical forest environments combined with a general lack of systematic prospecting. However, our continuing work in this area has produced a relatively diverse assemblage of fossil vertebrates, now including fishes, amphibians, turtles, crocodiles, and mammals, as well as a growing diversity of fossil plants.

Use-inspired Paleoenvironmental Science and Data: A Deep Whole-Earth Time Dimension

Science.gov (United States)

Overpeck, J. T.

2016-12-01

The field of paleoenvironmental science has matured dramatically over the last 30 years, and paleo-data are now widely used to inform policy and other decision-making. The IPCC now incorporates paleo-perspectives in a prominent manner - centuries to millennia-long paleo records are key to assessing the full range of possible climate system behavior, how the Earth's climate system responds to large changes in forcing, how climate change may impact ecological, hydrological, oceanographic and many other systems that humans are concerned about. Paleohydroclimatic data increasingly are used by water managers, just as forest managers use paleo-fire data to understand the natural rhythms and processes so critical to healthy ecosystems and the services they provide. Paleo-data are now widely used for model evaluation, and for understanding what models may be missing - in this sense, the millennia-long observational record provided by paleoenvironmental data helps us avoid costly surprises. Success comes with responsibility, however. The more paleo-data and paleo-based understanding informs policy and other decisions, the more critical it is that paleo-data and the results built on them need to be openly shared, easily accessible and reproducible. The value of paleo-data grows with use, and thus data sharing serves to grow value to the society that ultimately pays for the research. The tradition of sharing paleo-data is built on an even longer tradition of sharing samples, and yet innovations are still needed to make sure samples are managed for future use, particularly as natural archives like glaciers, caves and corals are lost to climate change and other human activity. Scientific journals and data centers are constantly innovating; paleoenvironmental scientists must all play their part as well.

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

International Nuclear Information System (INIS)

Graybill, D.A.; Rose, M.R.; Nials, F.L.

1994-01-01

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

Regionally heterogeneous paleoenvironmental responses in the West African and South American monsoon systems on glacial to millennial timescales

Science.gov (United States)

Shanahan, T. M.; Hughen, K. A.; van Mooy, B.; Overpeck, J. T.; Baker, P. A.; Fritz, S.; Peck, J. A.; Scholz, C. A.; King, J. W.

2008-12-01

Although millennial-scale paleoenvironmental changes have been well characterized for high latitude sites, short-term climate variability in the tropics is less well understood. While the Intertropical Convergence Zone may act as an integrator of tropical climate changes, regional factors also play an important role in controlling the tropical response to climate forcing. Understanding these influences, and how they modulate the response to global climate forcing under different mean climate states is thus important for assessing how the tropics may respond to future climate change. Here, we examine new centennial-resolution records of paleoenvironmental change from isotopic and relative abundance data from molecular biomarkers in sediment cores from Lake Bosumtwi and Lake Titicaca. We assess the relative response of the West African and South American monsoon systems to millennial and suborbital-scale climate variability over the last ca. 30,000 years. While there is evidence for synchronous climate variability in the two systems, the dominant paleoenvironmental changes appear largely decoupled, highlighting the importance of regional climatology in controlling the response to climate forcing in tropical regions.

Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications

Science.gov (United States)

Qiang, Xiaoke; Xu, Xinwen; Zhao, Hui; Fu, Chaofeng

2018-05-01

The ferrimagnetic iron sulfide greigite (Fe3S4) occurs widely in sulfidic lacustrine and marine sedimentary environments. Knowledge of its formation and persistence is important for both magnetostratigraphic and paleoenvironmental studies. Although the formation mechanism of greigite has been widely demonstrated, the sedimentary environments associated with greigite formation in lakes, especially on relatively long timescales, are poorly understood. A long and continuous sequence of Pleistocene lacustrine sediments was recovered in the Heqing drill core from southwestern China, which provides an outstanding record of continental climate and environment. Integrated magnetic, geochemical, and paleoclimatic analysis of the lacustrine sequence provides an opportunity to improve our understanding of the environmental controls on greigite formation. Rock magnetic and scanning electron microscope analyses of selected samples from the core reveal that greigite is present in the lower part of the core (part 1, 665.8-372.5 m). Greigite occurs throughout this interval and is the dominant magnetic mineral, irrespective of the climatic state. The magnetic susceptibility (χ) record, which is mainly controlled by the concentration of greigite, matches well with variations in the Indian Summer Monsoon (ISM) index and total organic carbon (TOC) content, with no significant time lag. This indicates that the greigite formed during early diagenesis. In greigite-bearing intervals, with the χ increase, Bc value increase and tends to be stable at about 50 mT. Therefore, we suggest that χ values could estimate the variation of greigite concentration approximately in the Heqing core. Greigite favored more abundant in terrigenous-rich and organic-poor layers associated with weak summer monsoon which are characterized by high χ values, high Fe content, high Rb/Sr ratio and low TOC content. Greigite enhancement can be explained by variations in terrigenous inputs. Our studies demonstrate

Sedimentologic and paleontologic study of the southeast coast of Buenos Aires province, Argentina: A late Pleistocene Holocene paleoenvironmental reconstruction

Science.gov (United States)

Aramayo, S. A.; Téllez, B. Gutiérrez; Schillizzi, R. A.

2005-10-01

A paleoenvironmental reconstruction of the southeast coast of Buenos Aires province, Argentina, is made mainly on the basis of paleontological and paleoichnological studies, supported by sedimentological analyses and radiocarbon dating. Continental late Pleistocene and continental, transitional, and marine Holocene stratigraphic units are identified. The former comprises fossil mammals and ichnites of 16000-12,000 BP. The continental early Holocene time, ca. 8100 BP, is represented by an interdune paleoenvironment in which shallow brackish ponds were colonized by diatoms, fish, rodents, and birds. A transitional paleoenvironment in the middle Holocene—6930-6570 BP—is recorded by deposits formed by estuarine crabs. During the late Holocene, between 5000 and 4800 BP, a marine transgression was recorded by a rich mollusc fauna.

Paleoenvironmental reconstruction of the Oligocene-Miocene deposits of the Tethyan Seaway, Qom Formation, Central Iran

Science.gov (United States)

Dabaghi Sadr, Fatemeh; Schmiedl, Gerhard

2017-04-01

The Cenozoic climate transition from greenhouse to icehouse conditions was associated with major paleogeographic changes in the Tethyan realm. The closure of the Tethyan Seaway and its Iranian gateways during the terminal Paleogene and early Neogene, between approximately 28 and 18 million years, influenced the latitudinal exchange of water masses and energy and is documented in sediment successions of the Qom formation in central Iran. Little is known on the spatial expression and the exact depositional histories of the Qom Formation on orbital time-scales, including a lack of quantitative sea-level reconstructions and studies on the impact of climatic and tectonic changes on marine ecosystems and sedimentation processes. The PhD project focuses on the investigation of lithostratigraphy, biostratigraphy, paleoecology and paleoenvironmental evolution of the Iranian gateways based on late Oligocene to early Miocene foraminiferal faunas and carbonate facies from selected sediment sections of the Qom Basin. The Qom Formation was deposited in the Central Iranian back-arc basin during the Oligocene-Miocene. In this study foraminiferal faunas and carbonate microfacies were studied based on total 191 samples of two section of Qom Formation. One of them is Molkabad section, which is located northwest of Molkabad mountains, southeast of Garmsar. The section mainly consists of limestones, calcareous marls, marls, and gypsum-bearing marls with a total thickness of 760 meters. The Qom Formation at Molkabad section overlies Eocene rocks with an unconformity and consists of the following lithostratigraphic units (from the lower to upper part): Lithothamnium Limestone, Lower Marl Limestone, Bryozoa Limestone, and Upper Marl Group. The Molkabad fault separates the Qom Formation from the overlying Upper Red Formation. The other section is located at Navab anticline in Qom Formation .The section mainly consist of limestone, marl, and gypsum with a total thickness of 318 meters Navab

Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

Science.gov (United States)

Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

2017-10-01

study for Crasna river basin, with the use of MIKE HYDRO Basin advanced hydroinformatic tool for integrated hydrographical basin analysis, planning and management.

Late Eocene sea retreat from the Tarim Basin (west China) and concomitant Asian paleoenvironmental change

NARCIS (Netherlands)

Bosboom, R.E.; Dupont-Nivet, G.; Houben, A.J.P.; Brinkhuis, H.; Villa, G.; Mandic, O.; Stoica, M.; Zachariasse, W.J.; Guo, ZJ.; Li, CX.; Krijgsman, W.

2011-01-01

The Paleogene sediments of the southwest Tarim Basin along the West Kunlun Shan in western China include the remnants of the easternmost extent of a large epicontinental sea. This shallow sea once extended across the Eurasian continent before it retreated westward and eventually separated as the

Landslide Frequency and Failure Mechanisms at NE Gela Basin (Strait of Sicily)

Science.gov (United States)

Kuhlmann, J.; Asioli, A.; Trincardi, F.; Klügel, A.; Huhn, K.

2017-11-01

Despite intense research by both academia and industry, the parameters controlling slope stability at continental margins are often speculated upon. Lack of core recovery and age control on failed sediments prevent the assessment of failure timing/frequency and the role of prefailure architecture as shaped by paleoenvironmental changes. This study uses an integrated chronological framework from two boreholes and complementary ultrahigh-resolution acoustic profiling in order to assess (1) the frequency of submarine landsliding at the continental margin of NE Gela Basin and (2) the associated mechanisms of failure. Accurate age control was achieved through absolute radiocarbon dating and indirect dating relying on isotope stratigraphic and micropaleontological reconstructions. A total of nine major slope failure events have been recognized that occurred within the last 87 kyr ( 10 kyr return frequency), though there is evidence for additional syndepositional, small-scaled transport processes of lower volume. Preferential failure involves translational movement of mudflows along subhorizontal surfaces that are induced by sedimentological changes relating to prefailure stratal architecture. Along with sequence-stratigraphic boundaries reflecting paleoenvironmental fluctuations, recovered core material suggests that intercalated volcaniclastic layers are key to the basal confinement and lateral movement of these events in the study area. Another major predisposing factor is given by rapid loading of fine-grained homogenous strata and successive generation of excess pore pressure, as expressed by several fluid escape structures. Recurrent failure, however, requires repeated generation of favorable conditions, and seismic activity, though low if compared to many other Mediterranean settings, is shown to represent a legitimate trigger mechanism.

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

Paleoenvironmental inference models from sediment diatom assemblages in Baffin Island lakes (Nunavut, Canada) and reconstruction of summer water temperature

Energy Technology Data Exchange (ETDEWEB)

Joynt, E. H. III; Wolfe, A. P. [Colorado Univ., Inst. of Arctic and Alpine Research, Boulder, CO (United States)

2001-06-01

Lake sediments are attractive repositories for paleoclimate proxy data because they are temporally continuous, undisturbed and datable. It is particularly true of lakes which are ubiquitous throughout the Arctic regions, enabling dense spatial coverage of sampling sites. In more recent times diatoms have been applied to a a variety of paleoenvironmental questions. However, these studies have been of limited usefulness because they lack a regional training set that would facilitate making quantitative paleoenvironmental inferences. This article provides this inferential tool, together with an example of its application. Conductivity, pH, summer lake water temperature, and mean annual air temperature have been identified as the significant controls over diatom assemblages from the surface sediments of 61 lakes on Baffin Island. Using weighted-averaging regression and calibration, predictive models for these parameters have been developed. Results show that the summer lake water temperature model provides realistic reconstructions when compared with other paleoenvironmental records. Over the past 5000 years the amplitude of reconstructed summer lake water temperature was found to be on the order of 4 degrees C, expressed primarily as progressive neoglacial cooling culminating in the Little Ice Age. Diatom-inferred summer water temperatures have increased by about 2 degrees C in the past 150 years, which is also in agreement with independent paleoclimatic reconstructions. The data obtained in this study complements similar efforts from the western Canadian Arctic and the northern reaches of Scandinavia, however, this is the first training set developed for lakes situated entirely north of the tree line. As such, it extends the applicability of diatoms for paleotemperature reconstructions well into the Arctic tundra biome. 45 refs., 1 tab., 10 figs., 1 appendix.

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.

U-Pb Geochronology of non-marine Upper Triassic strata of the Colorado Plateau (western North America): implications for stratigraphic correlation and paleoenvironmental reconstruction

Science.gov (United States)

Rasmussen, C.; Mundil, R.; Irmis, R. B.; Keller, C. B.; Giesler, D.; Gehrels, G. E.

2017-12-01

The Triassic is a critical period in Earth history that witnessed the origin of modern ecosystems and frequent climate fluctuations, as well as major environmental events such as flood basalt volcanism and bolide impacts. The Chinle Formation contains a primary non-marine archive for past ecosystems in North America due to its fossil richness and well-studied sedimentology. Moreover, within these highly fossiliferous strata, a biotic turnover has been reported that has been hypothesized to coincide with one or more of the aforementioned environmental events. Unfortunately, few radioisotopic ages have been published for the Late Triassic, limiting our ability for lithological and paleoenvironmental correlations. In addition, the superposition of the Chinle Formation remains illusive due to frequent lateral facies changes and discontinuous outcrops across the Colorado Plateau. The 520 m long core 1A of the Colorado Plateau Coring Project from Petrified Forest National Park (PFNP) (Arizona) provides, for the first time, a continuous section of these early Mesozoic sedimentary strata. Many of the sand- and siltstones from this continuous succession throughout most of the Upper Triassic Chinle Formation contain euhedral zircons suitable for U-Pb analyses. We analyzed >300 crystals each from 10 samples using LA-ICPMS; these results indicated abundant Late Triassic crystals that appear to be closely associated with the depositional age of the host rock. We then selected the youngest grains from these samples to obtain precise CA-TIMS U-Pb single zircon ages in order to constrain the maximum depositional ages (using quantitative methods) of these formations. We are able to revise the proposed time scale (based on outcrop samples) for Upper Triassic strata at PFNP and evaluate whether the biotic turnover observed within the Sonsela Member of these strata coincides with the Manicouagan bolide impact event. This revised chronostratigraphic framework allows intercalibration

Paleoenvironmental conditions at the loess paleosol sequence Bodrogkeresztúr in NE Hungary

Science.gov (United States)

Bösken, Janina; Obreht, Igor; Zeeden, Christian; Klasen, Nicole; Hambach, Ulrich; Sümegi, Pál; Lehmkuhl, Frank

2017-04-01

Loess paleosol sequences (LPS) have the ability to preserve past environmental and climatic conditions. Therefore, they are a widely used terrestrial archive for the reconstruction of paleoclimatic dynamics. In this study, we use several proxies (grain size distributions, geochemical analysis, rock magnetism, and color measurements) to study past environmental changes in a LPS covering the MIS 2/MIS 3 transition. Geochronological control is given by post infrared infrared stimulated luminescence dating of polymineral fine grains. The research aim lies in the reconstruction of the paleoenvironmental conditions at the loess-paleosol sequence Bodrogkeresztúr in northeastern Hungary using a multi-proxy approach. The sequence is located at the foot of the Kopasz hill, the southernmost part of the Tokaj Mountains, which belong to the Carpathian mountain range. The area is famous for the Bodrogkeresztúr-Henye Gravettian site (Lengyel, 2015). The profile contains eolian loess deposits intercalated by two paleosols. The lower paleosol overlays possibly fluvial clay (fine overbank deposits) forming the base of the profile. The luminescence samples have been tested thoroughly and have been measured with the pIR50IR290 protocol (Thiel et al., 2011). The final age assessment between 28.0±2.1 ka and 33.5±2.5 ka fits well to the established geochronologies of the Kopasz hill (Sümegi and Hertelendi, 1998) and the Tokaj section (Schatz et al., 2012). Paleoenvironmental conditions are investigated through the multi-proxy approach. The measurement of the anisotropy of magnetic susceptibility is interpreted in regard of paleowind directions. The magnetic susceptibility is enhanced in paleosols, especially in the lower one, indicating strong pedogenesis. Grain size parameters also show high clay contribution in the lower paleosol, but also indicate two distinct features of stronger wind dynamics in the loess layer in the middle of the profile (double sigmoidal fluctuations in all

Foraminiferal and seismic stratigraphy, paleoenvironments and depositional cycles in the Georges Bank Basin

Science.gov (United States)

Poag, C. W.

Biostratigraphic analyses of foraminiferal assemblages sampled from rotary cuttings taken at 10 ft to 90 ft intervals were used with interpretation of seismic sequences to determine the presence of nonconformities and to establish a chronostratigraphic framework for COST G-1 and G-2 wells. The chronostratigraphic sequences were then used to calculate sediment accumulation rates. Lithostratigraphic and chronostratigraphic units were compared with those of the Scotian Basin of Canada, and correlations were established between the COST G-2 and the Shell Mohican L-100 wells. Paleoenvironmental analysis was based on the microfossil record of the G-1 and G-2 wells and on interpretation of seismic facies along USGS multichannel line 19.

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

NARCIS (Netherlands)

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.

2016-01-01

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

Hydrologic studies within the Pasco Basin

International Nuclear Information System (INIS)

Spane, F.A. Jr.

1982-09-01

As part of the Basalt Waste Isolation Project (BWIP), hydrologic studies are being performed to provide an evaluation of groundwater systems within the Columbia River Basalt Group. These studies are focused on the Hanford Site, which is located within the Pasco Basin in south-central Washington. Hydrologic studies within the Pasco Basin involve the areal and vertical characterization of hydraulic head, hydrologic properties, and hydrochemical content for the various basalt groundwater systems. Currently, in excess of 150 test intervals have been tested for hydraulic properties, while in excess of 80 horizons have been analyzed for hydrochemical characteristics at about 30 borehole sites within the Pasco Basin. Data obtained from these studies provide input for numerical modeling of groundwater flow and solute transport. Results from numerical modeling are used for evaluating potential waste migration as a function of space and time. In the Pasco Basin, geologic structures influence groundwater flow patterns within basalt aquifer systems. Potentiometric data and hydrochemical evidence collected from recent studies indicate that geologic structures act as areal hydrologic barriers and in some instances, regions of enhanced vertical conductivity. 8 figures

California Basin Studies (CaBS)

International Nuclear Information System (INIS)

Gorsline, D.S.

1991-01-01

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

Evaluation of long-term geological and climatic changes in the Spanish programme

International Nuclear Information System (INIS)

Torres, T.; Ortiz, J.E.; Cortes, A.; Delgado, A.

2004-01-01

The Bio-molecular Stratigraphy Laboratory of the Madrid School of Mines has been largely involved in the analysis of long-term paleo-environmental changes in the Iberian Peninsula during the Quaternary. Some of the research projects were UE funded: Paleo-climatological Revision of Climate Evolution in Western Mediterranean Region. Evaluation of Altered Scenarios, Evidence from Quaternary Infill Paleo-hydrogeology, Sequential Biosphere modelling function of Climate evolution models; Paleo-hydrogeological Data Analysis and Model Testing. Other projects were funded by the National Company for Radioactive Waste Management (ENRESA) and the Spanish Nuclear Safety Council (CSN): 'Paleo-climate reconstruction from Middle Pleistocene times through dating and isotopic analysis of tufa deposits'; 'Paleo-environmental evolution of the southern part of the Iberian Peninsula'; 'Paleo-climate'. On a minor scale the laboratory was also involved in the study of some argillaceous media: 'Organic Geochemistry of some deep Spanish argillaceous formations' and 'Effects of climatic change on the argillaceous series of the Duero and Ebro basins'. Here we will present some of the results obtained from tufa deposits analysis and paleo-environmental information from the Guadix-Baza Basin composite-stratigraphical-type-section study. (authors)

The Mackenzie Basin impacts study

International Nuclear Information System (INIS)

Cohen, S.J.

1993-01-01

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

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

Directory of Open Access Journals (Sweden)

Mauro B. de Toledo

2009-12-01

Full Text Available 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.Apesar da indiscutível importância da identificação de análogos modernos para estudos de Paleoecologia, relativamente poucos estudos procuraram integrar amostras modernas e fósseis em reconstruções paleoambientais. Na Palinologia este padrão não é diferente de outras áreas da Paleoecologia. Este estudo demonstra a aplicação prática de dados de deposição polínica atual em reconstruções paleoambientais baseadas em pólen fóssil utilizando an

Ichnological analysis of the Upper Miocene in the ANH-Tumaco-1-ST-P well: assessing paleoenvironmental conditions at the Tumaco Basin, in the Colombian Pacific

Science.gov (United States)

Giraldo-Villegas, Carlos A.; Celis, Sergio A.; Rodríguez-Tovar, Francisco J.; Pardo-Trujillo, Andrés; Vallejo-Hincapié, Diego F.; Trejos-Tamayo, Raúl A.

2016-11-01

Tumaco is a frontier basin located on the SW Colombian Pacific coast. It is composed of a thick siliciclastic sequence up to reach 10,000 m-thick. In recent years, the National Hydrocarbon Agency-ANH has promoted new exploration wells in order to understand the sedimentary dynamic and its relationship with petroleum systems. One of them, the ANH-Tumaco-1-ST-P well has ∼3000 m (12,000 feet). We carried out sedimentological, geochemical, and micropaleontological detailed analyses with special attention to the ichnology on a 55 m-cored interval (from 1695.3 to 1640.4 m = 5563-5382 ft) in order to assess paleoenvironmental conditions. Beds are composed of green and gray mudrocks interbedded with lithic sandstones and fine-grained tuffs. Calcareous microfossil assemblages defined by the recovery of Uvigerina carapitana, Uvigerina laviculata, Uvigerina pigmaea, Globigerina woodi, Globigerionoides obliquus, Discoaster bellus gr., Catinaster coalitus, Reticulofenestra pseudoumbilicus and Sphenolithus abies indicated a Tortonian age, between CN6/CN7 biozones. Six sedimentary facies were identified: (1, 2) massive and laminated mudrocks, (3, 4) massive and normal-graded sandstones, (5) heterolithic beds, and in some cases (6) sandstones with soft-deformation structures. These rocks were accumulated in a shallowing platform-prodelta environment with continuous volcanic influence. Ichnotaxonomic analysis, conducted for the first time in the Colombian Pacific, allowed the identification of eighteen ichnogenera: Alcyonidiopsis, Asterosoma, Chondrites, Conichnus, Cylindrichnus, Diplocraterion, Ophiomorpha, Palaeophycus, Phycosiphon, Planolites, Rhyzocorallium, Schaubcylindrichnus, Scolicia, Siphonichnus, Taeinidum, Teichichnus, Thalassinoides, and Zoophycos. The ichnological association belongs to the archetypal Cruziana ichnofacies and its "distal" expression. By integrating lithofacies and ichnological results, two segments have been distinguished: 1) the lower one (1695

Reconnaissance coal study in the Susitna basin, 2014

Science.gov (United States)

David L. LePain,; Stanley, Richard G.; Harun, Nina T.; Helmold, Kenneth T.; Tsigonis, Rebekah

2015-01-01

The Alaska Division of Geological & Geophysical Surveys (DGGS) conducted fieldwork during the summer of 2014 in the Susitna basin as part of an ongoing evaluation of the hydrocarbon potential of frontier basins, particularly those near the Railbelt region (for example, Decker and others, 2013; Gillis and others, 2013). Topical studies associated with this recent work include sedimentary facies analysis (LePain and others, 2015) and structural geology investigations (Gillis and others, 2015). The Susitna basin contains coal-bearing Paleogene and Neogene strata correlative with formations that host oil and gas in Cook Inlet basin to its south. Isotopic signatures of natural gas reservoired in the Miocene/Pliocene Sterling and Miocene Beluga Formations suggest a biogenic origin for Cook Inlet gas (Claypool and others, 1980). To assess the biogenic gas potential of the Susitna basin, it is important to obtain information from its coal-bearing units.Characteristics of coal, such as maturity/rank and cleat development are key parameters influencing viability of a biogenic gas system (Laubach and others, 1998). In an early study of the Susitna basin (Beluga–Yentna region), Barnes (1966) identified, analyzed, and recognized potentially valuable subbituminous coal resources at Fairview Mountain, Canyon Creek, and Johnson Creek. Merritt (1990), in a sedimentological study to evaluate surface coal mining potential of the Tertiary rocks of the Susitna basin (Susitna lowland), concluded that the basin contained several billion tons of mineable reserves. This preliminary report offers a brief summary of new information on coals in the Susitna Basin acquired during associated stratigraphic studies (see LePain and others, 2015). 

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

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...... Europe after the CIE. Detrital elements (Al, Si, Ti, Zr) are used as proxies for sea-level change and match well previous sequence stratigraphic interpretations in the Cleveland Basin. Black shale deposition and anoxia were favored by a major transgression and appear to be paced by 3rd to 4th order sea...... elements across the late Pliensbachian to middle Toarcian of the Cleveland Basin. The Pl/To boundary CIE is associated with low Total Organic Carbon (TOCZn and Ni, which together suggest that water-mass restriction and anoxia occurred...

Ecology of non marine Ostracoda from la Fe reservoir (El Retiro, Antioquia) and their potential application in paleoenvironmental studies

International Nuclear Information System (INIS)

Saldarriaga, Andrea; Torres, Martinez Jose Ignacio.

2010-01-01

Littoral macrophytes from the La Fe reservoir (El Retiro, Antioquia) were sampled for ostracoda during June and September of 2008. This allowed the identification of four genera and six species of ostracoda belonging to the Cyprididae and Candonidae families, where Chlamydotheca and Cypridopsis were found to be the dominant genera. Chlamydotheca unispinosa was the most abundant species in the assemblage. Furthermore, the environmental variables: temperature, electric conductivity, dissolved oxygen, and pH were also measured, in order to establish their relation to ostracoda taxa, using Canonical Correspondence Analysis (CCA). Results confirm the cosmopolitan character of Cypridopsis vidua and evidence the importance of plant substrate on the occurrence and distribution of the Cyprididae family. The possible application of the recorded ostracoda assemblage in paleoenvironmental interpretations is discussed.

K Basin sludge dissolution engineering study

International Nuclear Information System (INIS)

Westra, A.G.

1998-01-01

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

Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

Energy Technology Data Exchange (ETDEWEB)

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

2009-01-01

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

Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

International Nuclear Information System (INIS)

Barbosa, A B

2009-01-01

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

EFFECTS OF HUMAN IMPACTS AND CLIMATE VARIATION ON FORESTS: THE RIETI BASIN SINCE MEDIEVAL TIME

Directory of Open Access Journals (Sweden)

S. Mensing

2013-03-01

Full Text Available A number of recent paleoenvironmental studies have argued that abrupt changes in climate have been the primary cause for societal collapse. Many social scientists, including anthropologists and environmental historians, reject environmental explanations as deterministic and overly simplistic. They argue that socio-political decisions contribute to environmental change and that efforts to study societal vulnerability within a human-environment system must include analysis of complex social structures. There is a gap in our understanding of how past societies responded to climate change because there are very few interdisciplinary studies that integrate both physical and behavioral sciences in paleoenvironmental reconstructions. While there is a general sense that modern societies are more insulated than pre-industrial societies from the effects of climate change, this may not prove to be true. A more complete understanding of how both natural and human-caused changes have affected the environment in the past can potentially guide decisions aimed at promoting future sustainability. Here we present a project funded by the United States National Science Foundation that will explicitly integrate paleoenvironmental reconstruction with socioeconomic history in a local context to identify linkages between social and environmental change associated with climate variability.

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.

paleoenvironmental settings and assemblage changes

African Journals Online (AJOL)

Kasanzu

shallow borehole drilled in the southern coastal basin of Tanzania with the aim of characterizing foraminifera and palynomorphs assemblage changes aiming at reconstructing ..... decline in temperature at EOT which caused the extinction of ...

Heritability of the Structures and 13C Fractionation in Tomato Leaf Wax Alkanes: A Genetic Model System to Inform Paleoenvironmental Reconstructions

Directory of Open Access Journals (Sweden)

Amanda L. D. Bender

2017-06-01

Full Text Available Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs between two interfertile Solanum (tomato species: S. lycopersicum cv M82 (hereafter cv M82 and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso- to total alkanes. Between Solanum pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2–1.4‰ over n-alkanes. The broad-sense heritability values (H2 of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13–0.19, suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments

Heritability of the structures and 13C fractionation in tomato leaf wax alkanes: a genetic model system to inform paleoenvironmental reconstructions

Science.gov (United States)

Bender, Amanda L. D.; Chitwood, Daniel H.; Bradley, Alexander S.

2017-06-01

Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2-1.4‰ over n-alkanes. The broad-sense heritability values (H2) of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13-0.19), suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments reflects

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

Directory of Open Access Journals (Sweden)

Nicoleta Bican-Bris̡an

2006-04-01

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

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

Science.gov (United States)

Bultman, M.W.; Gray, F.

2011-01-01

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

First record of Annonaceae wood for the Neogene of South America, Amazon Basin, Brazil

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Emilio Alberto Amaral Soares

Full Text Available ABSTRACT: The relief of the regions of Manaus and Itacoatiara, Central Amazon, is supported by Neogene siliciclastic rocks, bounded at the base and top by lateritic paleosols and covered by quaternary sedimentary deposits from the Solimões-Amazon river system. This unit is informally assigned to the Novo Remanso Formation, consists of usually reddish and ferruginized sandstones, conglomerates and pelites, with few identified fossil records, a fact that has hindered its stratigraphic position, and the paleoenvironmental reconstruction of the last phase of the Amazon Basin settling. This study describes, for the first time, the occurrence of fossil wood in outcroppings of the left bank of the Amazon River, where anatomical and morphological data has enabled its characterization to the species level. Thus, the data marks the record of the Annonaceae in South America, as well as the depositional processes related to incorporation of organic material in the sandy layer and the fossilization processes that allowed its preservation. In an unprecedented way, this study has described Duguetiaxylon amazonicum nov. gen and sp. and provided information on the anatomical and systematic character, as well as data on plant-insect interaction, and a better understanding of the family.

KE Basin water dispositioning engineering study

International Nuclear Information System (INIS)

Hunacek, G.S.; Gahir, S.S.

1994-01-01

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

Multi-proxy paleoenvironmental reconstruction of saline lake carbonates: Paleoclimatic and paleogeographic implications (Priabonian-Rupelian, Issirac Basin, SE France)

Science.gov (United States)

Lettéron, Alexandre; Fournier, François; Hamon, Youri; Villier, Loïc; Margerel, Jean-Pierre; Bouche, Alexandre; Feist, Monique; Joseph, Philippe

2017-08-01

A 200-m thick carbonate succession has been deposited in shallow-water, saline lake environments during the Priabonian-Rupelian in the Issirac Basin (South-East France). The palaeoenvironmental and palaeogeographic significance of such saline lake carbonates has been characterized on the basis of a multi-proxy analysis including 1) depositional and diagenetic features, 2) biological components (molluscs, ostracods, benthic foraminifers, characean) and 3) carbon, oxygen and strontium stable isotopes. Biological associations are indicative of dominantly shallow (climate (dry versus humid) are the three key factors controlling the water composition, carbonate production and depositional environments in the Issirac lake. Although the ASCI (Alès-Issirac-Saint-Chaptes) lacustrine system likely represents an athalassic (inland) lake system evolving through times, the stable isotope composition (C, O and Sr) of carbonates strongly suggests the occurrence of transient connections of the ASCI lake water with water bodies influenced by seawater and/or fed with sulfates deriving from Triassic evaporites. The Issirac Basin may be therefore interpreted as a sill area connecting the ASCI lacustrine system with the Rhône valley (Mormoiron and Valence) saline lake systems during maximum flooding periods. Finally, changes in depositional features, biota and stable isotope composition of carbonates in unit U3 suggest a transition from relatively dry to more humid climate during the uppermost Priabonian or earliest Rupelian.

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

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A. Herrero-Hernández

2016-11-01

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

The PRISM3D paleoenvironmental reconstruction

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

2010-01-01

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

Diagenetic Iron Cycling in Ancient Alkaline Saline Lacustrine Sedimentary Rocks: A Case Study on the Jurassic Brushy Basin Member of the Morrison Formation, Colorado Plateau, USA

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Potter-McIntyre, S. L.; Chan, M. A.; McPherson, B. J. O. L.

2014-12-01

The upper part of the Brushy Basin Member in the Four Corners region of the U.S. was deposited in an ephemeral alkaline saline lake system with copious input of volcanic ash. The variegated shale formation provides a setting for the study of early diagenetic iron cycling that records the action of alkaline saline fluid chemistries reacting with volcaniclastic sediments in the presence of microbes. A bull's-eye pattern of authigenic minerals with increasing alteration towards the basinal center similar to modern alkaline saline lakes provides evidence for an extreme paleoenvironmental interpretation. The purpose of this research is to document specific factors, such as reactive sediments, microbial influences, and grain size that affect concretion formation and iron cycling in an ancient extreme environment. Three broad diagenetic facies are interpreted by color and associated bioturbation features: red, green and intermediate. Diagenetic facies reflect meter-scale paleotopography: red facies represent shallow water to subaerial, oxidizing conditions; green facies reflect saturated conditions and reducing pore water chemistry shortly after deposition, and intermediate facies represent a combination of the previous two conditions. Evidence of biotic influence is abundant and trace fossils exhibit patterns associated with the diagenetic facies. Red diagenetic facies typically contain burrows and root traces and green diagenetic facies exhibit restricted biotic diversity typically limited to algal molds (vugs). Microbial fossils are well-preserved and are in close proximity to specific iron mineral textures suggesting biotic influence on the crystal morphology. Three categories of concretions are characterized based on mineralogy: carbonate, iron (oxyhydr)oxide and phosphate concretions. Concretion mineralogy and size vary within an outcrop and even within a stratigraphic horizon such that more than one main category is typically present in an outcrop. Variation in

The distribution of organic carbon fractions in a typical loess-paleosol profile and its paleoenvironmental significance

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Qingqing Zhang

2018-04-01

Full Text Available Background The loess-paleosol sequence on the Loess Plateau has been considered an important paleoclimatic archive to study global climatic and environmental changes in the Quaternary. So far, little attention has been paid to the characteristics of soil organic carbon fractions in loess-paleosol sequences, which may provide valuable information for exploring the evolution of climate and environment in the Quaternary on the Loess Plateau. Methods In order to explore the significance of mineral-associated organic carbon to total organic carbon (MOC/TOC ratios in the loess-paleosol sequence for reconstructing paleoenvironmental and paleoclimatic evolution in the Quaternary on the Loess Plateau, we selected a typical loess-paleosol profile in Chunhua county, Xianyang city, Shaanxi province, as the research object. The content of total organic carbon (TOC and MOC/TOC ratio in each loess and paleosol layers of the Chunhua loess-paleosol profile were analyzed, together with the paleoclimatic proxies, such as soil grain size, CaCO3 content and their correlations with organic carbon parameters. Results The main results were as follows: (1 the total content of soil organic carbon and MOC/TOC ratios were generally higher in paleosol layers than in the underlying loess layers of the Chunhua loess-paleosol profile. Compared to total organic carbon content, MOC/TOC ratios changed more obviously in soil layers below a paleosol layer S8; (2 soil clay content and median grain size (Md (ϕ were higher in paleosol than in the underlying loess, while CaCO3 content showed an opposite tendency. In the Chunhua profile, the distribution characteristics of the three paleoclimatic proxies showed good indications of paleoclimate changes in the Quaternary; (3 in the Chunhua loess-paleosol profile, MOC/TOC ratios were positively correlated with clay content and median grain size (ϕ, while negatively correlated with CaCO3 content, and the correlations were more significant

The distribution of organic carbon fractions in a typical loess-paleosol profile and its paleoenvironmental significance

Science.gov (United States)

Hu, Feinan; Huo, Na; Shang, Yingni; Chang, Wenqian

2018-01-01

Background The loess-paleosol sequence on the Loess Plateau has been considered an important paleoclimatic archive to study global climatic and environmental changes in the Quaternary. So far, little attention has been paid to the characteristics of soil organic carbon fractions in loess-paleosol sequences, which may provide valuable information for exploring the evolution of climate and environment in the Quaternary on the Loess Plateau. Methods In order to explore the significance of mineral-associated organic carbon to total organic carbon (MOC/TOC) ratios in the loess-paleosol sequence for reconstructing paleoenvironmental and paleoclimatic evolution in the Quaternary on the Loess Plateau, we selected a typical loess-paleosol profile in Chunhua county, Xianyang city, Shaanxi province, as the research object. The content of total organic carbon (TOC) and MOC/TOC ratio in each loess and paleosol layers of the Chunhua loess-paleosol profile were analyzed, together with the paleoclimatic proxies, such as soil grain size, CaCO3 content and their correlations with organic carbon parameters. Results The main results were as follows: (1) the total content of soil organic carbon and MOC/TOC ratios were generally higher in paleosol layers than in the underlying loess layers of the Chunhua loess-paleosol profile. Compared to total organic carbon content, MOC/TOC ratios changed more obviously in soil layers below a paleosol layer S8; (2) soil clay content and median grain size (Md (ϕ)) were higher in paleosol than in the underlying loess, while CaCO3 content showed an opposite tendency. In the Chunhua profile, the distribution characteristics of the three paleoclimatic proxies showed good indications of paleoclimate changes in the Quaternary; (3) in the Chunhua loess-paleosol profile, MOC/TOC ratios were positively correlated with clay content and median grain size (ϕ), while negatively correlated with CaCO3 content, and the correlations were more significant in soil

Hydrogeological and geochemical studies in the Perch Lake basin

International Nuclear Information System (INIS)

Barry, P.J.

1979-08-01

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)

Diets and environments of late Cenozoic mammals in the Qaidam Basin, Tibetan Plateau: Evidence from stable isotopes

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Zhang, Chunfu; Wang, Yang; Li, Qiang; Wang, Xiaoming; Deng, Tao; Tseng, Zhijie J.; Takeuchi, Gary T.; Xie, Gangpu; Xu, Yingfeng

2012-06-01

The timing history and driving mechanisms of C4 expansion and Tibetan uplift are hotly debated issues. Paleoenvironmental evidence from within the Tibetan Plateau is essential to help resolve these issues. Here we report results of stable C and O isotope analyses of tooth enamel samples from a variety of late Cenozoic mammals, including deer, giraffe, horse, rhino, and elephant, from the Qaidam Basin in the northeastern Tibetan Plateau. The enamel-δ13C values are diets and only a few individuals (besides the exceptional rhino CD0722) may have consumed some C4 plants. Based on geological evidence, however, the Qaidam Basin was probably warmer and more humid during the late Miocene and early Pliocene than today. Thus, these δ13C values likely indicate that many individuals had significant dietary intakes of C4 plants, and the Qaidam Basin had more C4 plants in the late Miocene and early Pliocene than today. Moreover, the Qaidam Basin likely had much denser vegetation at those times in order to support such large mammals as rhinos and elephants. While the δ18O values did not increase monotonously with time, the range of variation seems to have increased considerably since the early Pliocene, indicating increased aridification in the basin. The mean δ18O values of large mammals and those reconstructed for local meteoric waters display a significant negative shift in the late Miocene, consistent with the marine δ18O record which shows a cooling trend in the same period. Taken together, the isotope data suggest a warmer, wetter, and perhaps lower Qaidam Basin during the late Miocene and early Pliocene. Increased aridification after the early Pliocene is likely due to a combined effect of regional tectonism, which resulted in a more effective barrier preventing moisture from the Indian Ocean or Bay of Bengal from reaching the basin, and global cooling.

Facies and depositional environments for the coquinas of the Morro do Chaves Formation, Sergipe-Alagoas Basin, defined by taphonomic and compositional criteria

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Ana Carolina Tavares

Full Text Available Lacustrine carbonate rocks form important hydrocarbon accumulations along the Brazilian continental margin, some of which are contained in oil fields in which coquinas are one of the main reservoirs (viz. Campos Basin. The complexity and heterogeneity of these deposits make them a challenge in terms of reservoir description. For the necessary classification and paleoenvironmental interpretation of the coquinas, it is essential to evaluate many aspects including biological (such as carbonate productivity, sedimentological (energy regime in the depositional environment, transport of bioclasts, terrigenous supply, taphonomic (fragmentation of shells, abrasion and diagenetic processes. The facies analysis applied in this study is considered a more appropriate classification approach to understand these coquinas, since it is more flexible and comprehensive than the existing classifications for carbonate rocks. The material investigated here consists of rock samples of the coquinas from the Atol Quarry of the Morro do Chaves Formation (Barremian/Aptian, Sergipe-Alagoas Basin. These rocks that crop out in the Atol quarry complex can be considered as a case study for similar coquinas reservoirs found in the Brazilian continental margin basins. Six sedimentary facies were described, using the main taphonomic (fragmentation of shells and compositional (presence of micrite and siliciclastic matrix features as a diagnostic criteria. Two carbonate facies, two mixed carbonate-siliciclastic facies and two siliciclastic facies (mudstones were identified. From the facies succession, combined with a review of the literature on the subject, the following depositional paleoenvironments were defined: high-energy lake platform, lacustrine delta in a high-energy lake platform and lake-centre. In this paper, a new facies model for the studied coquinas succession is proposed.

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

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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

Characteristics and seasonal variation of hydrochemistry in the Tangra Yumco basin, central Tibetan Plateau, and its response to Indian summer monsoon

Science.gov (United States)

Wang, Junbo; Qiao, Baojin; Huang, Lei; Zhu, Liping

2016-04-01

Lake Tangra Yumco, located in central Tibetan Plateau, is the deepest lake recorded on the Plateau with a maximum water depth of 230m. Several studies have been conducted focused on paleoenvironmental changes utilizing lake sediemts cores and high lake terraces. The results revealed a significant lake level decreasing up to 180m from early Holocene and Tangra Yumco was separated from two other adjacent lakes since then. A high resolution continuous lake sediment record covering the past 17.4 cal ka has been established. However, compared with the high lake level and paleoenvironmental studies, modern investigations on the water in this basin are still lack. A comprehensive investigation of hydrochemistry is helpful to understand the modern environment and its response to climate change. This study focuses on the characteristics, seasonal variation and controlling mechanism of hydrochemistry in Tangra Yumco basin, including lake water, river water and rainfall water. Lake water, river water and rainfall water were collected for analyzing major ionic composition in Tangra Yumco basin during 2013-2014. The results showed that Na+ is the major cation of lake water; Ca2+ is the major cation of river and rainfall water, whereas the major anion of all samples is HCO3-. Comparison of the concentration of calcium in river water, lake water and surface sediments reveals a significant carbonate precipitation process within the lake. The chemical composition of lake is mainly controlled by evaporation and crystallization, whereas river water and rainfall water are mainly controlled by carbonate weathering. Among all rivers, DR10 and DR1 locate in the north and west part of Tangra Yumco where dense local populations live nearby show the highest and second highest total dissolved solid (TDS) with a small catchment and a high content of SO42-, indicating that anthropogenic input and planting have likely a strong influence on chemical compositions of both rivers. The TDS of lake

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)

1994-01-01

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

Middle Miocene paleoenvironmental crises in Central Eurasia caused by changes in marine gateway configuration

Science.gov (United States)

Palcu, D. V.; Golovina, L. A.; Vernyhorova, Y. V.; Popov, S. V.; Krijgsman, W.

2017-11-01

Marine gateways prove to be important factors for changes in the ecology and biochemistry of marginal seas. Changes in gateway configuration played a dominant role in the Middle Miocene paleogeographic evolution of the Paratethys Sea that covered Central Eurasia. Here, we focus on the connection between the Central (CP) and Eastern Paratethys (EP) to understand the paleoenvironmental changes caused by the evolution of this marine gateway. We first construct an integrated magneto-biostratigraphic framework for the late Langhian-Serravallian (Chokrakian-Karaganian-Konkian-Volhynian) sedimentary record of the eastern domain, which allows a correlation to the well-dated successions west of the gateway. The magneto-biostratigraphic results from the Zelensky-Panagia section on the Black Sea coast of Russia show that the Chokrakian/Karaganian boundary has an age of 13.8 Ma, the Karaganian/Konkian boundary is dated at 13.4 Ma, and the Konkian/Volhynian boundary at 12.65 Ma. We identify three major phases on gateway functioning that are reflected in specific environmental changes. During the Karaganian, the EP turned into a lake-sea that supplied a unidirectional flow of low-salinity waters to the west, where the CP sea experienced its Badenian Salinity Crisis. This configuration is remarkably similar to the Mediterranean during its Messinian Salinity Crisis. The second phase is marked by a marine transgression from the west, reinstalling open-marine conditions in the CP and causing marine incursions in the EP during the Konkian. The Volhynian is characterized by a new gateway configuration that allows exchange between CP and EP, creating unified conditions all over the Paratethys. We hypothesize that a density driven pumping mechanism is triggered by the increase in connectivity at the Konkian/Volhynian boundary, which simultaneously caused major paleoenvironmental changes at both sides of the gateway and led to the Badenian-Sarmatian extinction event in the CP.

Mackenzie Basin impact study: Interim report 1

International Nuclear Information System (INIS)

Cohen, S.J.

1993-01-01

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

The Yapeyu paleosurface : stratigraphific and paleoenvironmental signified in the evolution of superior cretaceous of Uruguay

International Nuclear Information System (INIS)

Pazos, P.; Tofalo, M.; Gonzalez

1998-01-01

The named Yapeyu paleosurface placed between Yapeyu and del Palacio Members of the Asencio Formations is anlalyzed in outcrops of the Pedro Chico, Gruta del Palacio and Cca. Arroyo Coquimbo localities. Herrein, its morphologic and paleoenvironmental features are considered to attribute an paleosoil origin for this. This paleosurface is indicative of an important break in the sedimentation and contain several indicators of paleoclimatic tropical and humid conditions. Following allostratigraphic schemes, the paleosurface represent the lower contact of the Asencio Formation constituting a new stratigraphic proposal. Finally, taking into account sedimentalogical features the alluvial origin by the conglomerates of del Palacio Member is rejected. (author)

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

International Nuclear Information System (INIS)

Gant, R.G.

1994-01-01

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

Paleoenvironmental evolution and geomorphic dynamics recorded in the Homo-bearing Pleistocene stratigraphic succession of Aalat (Eritrea, East Africa): A pedological perspective

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

2017-04-01

The Aalat stratigraphic succession represents a 300 m-thick continental archive in the northern sector of the African Rift Valley (Dandiero basin, Eritrea). Based on high-resolution magnetostratigraphy, along with tephrostratigrapic, paleontological and paleoanthropological data and correlations, the chronological constraints for the emplacement of this succession can be fixed at two stages characterized by normal polarity of the Earth's magnetic field, i.e. the base of the Jaramillo event and the lower part of the Brunhes chron, marking the Early to Middle Pleistocene transition. Remains of Homo erectus/ergaster and abundant fossil vertebrates were identified. Despite nowadays the study area has a typical arid, hot desert climate, the sedimentary succession records repeated shifts from fluvial to lacustrine facies, in line with dominant mammalian taxa characterized by strong water dependence and ichthyofauna typical of shallow-water fluvio-lacustrine paleoenvironments. The dominance of these water-controlled depositional environments over more than 250 ka suggests a major tectonic control, even though a clear overprinting of Pleistocene climate changes can be detected. The main morphological soil features, along with physico-chemical, mineralogical, geochemical and micromorphological data of selected soil profiles and horizons depict an overall poor to moderate degree of soil development, coherently with high rates of sedimentation of about 1 mm/year and local erosive phases. Nonetheless, the presence of calcic and especially petrocalcic horizons and one petrogypsic horizon at different stratigraphic heights clearly indicates cyclical phases of geomorphic stability, which allowed important leaching and accumulation of carbonate (or gypsum). Their complex, polygenetic fabric, often showing brecciation and re-dissolution features, points to a polyphased genesis, caused by changes in soil moisture conditions over time. This finding, together with the alternation of

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

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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.

Carbonate and lignite cycles in the Ptolemais Basin: Orbital control and suborbital variability (Late Neogene, northern Greece)

Science.gov (United States)

Weber, M. E.; Tougiannidis, N.; Ricken, W.; Rolf, C.; Kleineder, M.; Bertram, N.; Antoniadis, P.

2009-04-01

We recently commenced a project to investigate deep drillings as well as outcrops in the Ptolemais Basin, northern Greece, for paleoenvironmental and paleoclimate change. Specific attention is paid to mining sites Achlada, Vevi, Vegora, Amynteon, North Field, South Field, and Lava. The sediment archive comprises Upper Miocene to Quaternary continental lake deposits (up to 800 m thick) with an extended Lower Pliocene section. The Upper Miocene sections are composed of diatomaceous mud and gray marls. Pliocene lake sediments commence with the Kyrio member (lignite/grey marl), followed by the Theodoxus member (beige marl/lignite), and the Notio member (marl with intercalated sand /lignite). The limnic deposits show striking rhythmic bedding of (mostly) carbonates and lignites, reflecting orbital-induced humidity and temperature changes in this small NW-SE elongated continental basin. First, we retrieved chronometric information by determining magnetic polarity changes on three sites as independent stratigraphic ground-truth in combination with palynological evidence and published data. Then we conducted a number of high-resolution (1 - 6 cm increment), non-destructive measurements to obtain paleoclimate proxies: photospectrometry (colors L, a, b), magnetic susceptibility, and natural gamma. Accordingly, we achieved a multi-proxy insight into paleoclimate and paleoenvironmental evolution at unprecedented temporal resolution (up to a few decades!) over long time series and at a number of key sites. Using the newly-developed ESALab software, we conducted spectral and evolutionary spectral analysis to evaluate the cyclo-stratigraphic development. As for orbital variability, spectral power is concentrated on precession, hemi-precession, and eccentricity, with only minor impact of orbital tilt. We used this information to increase the temporal resolution of our age models by tuning as many precession (insolation) maxima as possible to carbonate minima (lignite maxima

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.

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)

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.

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...... data reveal prominent bends in the isochrons that provide solid geometrical constraints for plate reconstructions. Tentative identification of anomaly 25 in the Eurasia Basin links early basin opening to spreading in the Labrador Sea before the locus of spreading in the North Atlantic shifted...... to the 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...

Development of a high resolution chemostratigraphy for the Late Triassic-Early Jurassic Newark Basin

Science.gov (United States)

Kinney, S.; Olsen, P. E.; Chang, C.

2017-12-01

The 6.7 km of continuous core recovered from the paleo-tropical Triassic-Jurassic Newark rift basin during the Newark Basin Coring Project (NBCP) has provided a wealth of data since the conclusion of drilling 25 years ago. These cores comprise the longest ( 30 Myr) continuously-cored record of orbitally-paced environmental change and have informed our understanding in several different areas including tropical climate change, history of CO­2, mass extinctions, the geological time scale, and solar system dynamics. Despite the utility of NBCP cores for these endeavors, a critical missing dataset is a comprehensive characterization of their geochemical variations relevant to paleoenvironmental and paleoclimatic interests, largely a consequence of the cost of analyses at an appropriate resolution using conventional techniques. With the advent of new technology permitting the rapid acquisition of reliable geochemical data, such limitations may no longer be an obstacle for constructing a high-resolution chemostratigraphic record for the NBCP. We present the results of a proof-of-concept study using both ICP-MS-calibrated scanning ITRAX XRF and handheld Laser Induced Breakdown Spectroscopy (LIBS) using the SciAps Z-300. We will show elemental abundances at resolutions as high as 500 mm obtained using these methods from correlative sections of the Titusville and Nursery cores (Lockatong Fm.). These sections are sufficiently long to capture orbital variations and include the range of lithologies present throughout the entire section. Our preliminary results are consistent with previous, semi-quantitative means (e.g., depth ranks) of assessing Milankovitch-scale orbital variations and are also consistent with core and hole geophysical data, demonstrating that these methods can acquire meaningful geochemical data from the entire NBCP. With continued work, we aim to provide an objective characterization of orbitally-paced lake level cyclicity using geochemical proxy

Micromorphology of Paleosols of the Marília Formation and their Significance in the Paleoenvironmental Evolution of the Bauru Basin, Upper Cretaceous, Southeastern Brazil

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Márcio Luiz da Silva

Full Text Available ABSTRACT Deduction of associated paleoenvironments and paleoclimate, definition of the chronosequence of paleosols, and paleogeographic reconstruction have become possible through the application of micromorphology in paleopedology. Micromorphology has also been useful in recognition of weathering processes and definition of minerals formed in succession. In this respect, the objective of this study was to identify the development of pedogenic processes and discuss their significance in the paleoclimate evolution of the Marília Formation (Maastrichtian of Bauru Basin. Three sections of the Marília Formation (A1, A2, and A3 were described, comprising nine profiles. Micromorphologic al analysis was carried out according to the specialized literature. In the Marília Formation, the paleosols developed in sandstones have argillic (Btkm, Bt and carbonate (Bk horizons with different degrees of cementation, forming mainly calcretes. The evolution of pedogenic processes, in light of micromorphological analysis, evidenced three moments or stages for the genesis of paleosols with Bkm, Btk, and Bt horizons, respectively. In the Maastrichtian in the Bauru Basin, the paleosols with Bkm are older and more arid environments, and those with Bt were formed in wetter weather, but not enough to lead to the genesis of enaulic-related distributions, typical of current Oxisols.

AUTOCHTHONOUS BIOFACIES IN THE PLIOCENE LORETO BASIN, BAJA CALIFORNIA SUR, MEXICO

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MICHELE PIAZZA

1998-07-01

Full Text Available The present paper examines the molluscan and/or echinoid assemblages recovered from two lithostratigraphic units (Piedras Rodadas Sandstone and Arroyo de Arce Norte Sandstone outcropping in the Pliocene Loreto Basin, Baja California Sur, Mexico. Ten biofacies have been identified, i.e. Trachycardium procerum-Trachycardium senticosum Biofacies, Chione compta-Transennella modesta Biofacies, Laevicardium elenense-Chione kelletii Biofacies, Xenophora sp. 1-Strombus subgracilior Biofacies, Crassostrea californica osunai Biofacies, Myrakeena angelica Biofacies, Vermetid-Nodipecten Biofacies, Argopecten abietis abietis Biofacies, Aequipecten dallasi Biofacies and Encope Biofacies. The first four biofacies have been defined on the basis of statistical analyses (cluster analysis, MDS. The other six, which are monospecific or definitely low-diversity, were already identified during field work. The deduced paleoecological bearing of biofacies, largely relying upon the comparison to their closest modern counterparts, provides the basis for the paleoenvironmental reconstruction. The latter also considers sedimentological evidence and is framed within the tectonic and sedimentary context recently proposed by American workers. Biofacies point toward environments differing in terms of substrate texture, presence/absence of vegetal cover, energy level, variously distributed within the low tide mark-40 m bathymetric range. 

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

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

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

On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa.

Science.gov (United States)

Lupo, Karen D; Schmitt, Dave N; Kiahtipes, Christopher A; Ndanga, Jean-Paul; Young, D Craig; Simiti, Bernard

2015-01-01

An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories.

Hydrological Modeling in temporary streams: A case study in Pardiela basin, Southern Portugal

OpenAIRE

PEDRO, A.; MORAIS, M.; ROSADO, J.; SILVA, H.; SERAFIM, A.; NEVES, R.; BRITO, D.; POTES, M.; SALGADO, R.; LILLEBØ, I.; CHAMBEL, A.

2011-01-01

The project “Conservation and rehabilitation strategies for temporary Mediterranean river corridors: a case study on Pardiela basin, southern Portugal (Guadiana basin)", is being carried out,with the collaboration of researchers from diverse scientific areas, in order to increase the knowledge on temporary streams. The project includes different approaches at reach and basin scales, regarding the study of temporal interactions among different ecological components such as climate, morph...

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

International Nuclear Information System (INIS)

Gant, R.G.

1994-01-01

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

Appraising timing response of paleoenvironmental proxies to the Bond cycle in the western Mediterranean over the last 20 kyr

Science.gov (United States)

Rodrigo-Gámiz, Marta; Martínez-Ruiz, Francisca; Rodríguez-Tovar, Francisco J.; Pardo-Igúzquiza, Eulogio; Ortega-Huertas, Miguel

2018-04-01

The timing of climate responses to the Bond cycle is investigated in the western Mediterranean. Periodicities had been previously reported in a marine sediment record from this region spanning the last 20 kyr, and registered by diverse paleoenvironmental proxies, in particular those associated with terrigenous input, redox conditions, productivity, sea surface temperature (SST) and salinity. Further cross-spectral analyses on these time series reveal leads-lags in the 1400 year climate cycle. Considering as reference a terrigenous input proxy (the K/Al ratio), all the paleoenvironmental proxies displayed time shifts varying from ca. 700 year to ca. 350 year. SST and salinity variations show a first leaded response with the inflow of cold and less salty Atlantic waters. Followed by a time lead of 525 year, progresively arid conditions with an increase of eolian dust transport to the area, given by the Zr/Al signal, are observed. The intensification of dust transport could have triggered a latest biological response, lead by 350 year, with an increase of productivity, as suggested by the Ba/Al ratio. Lastly changes in the Mediterranean thermohaline circulation, indicated by a selected redox proxy (the U/Th ratio), are observed. These results support that the oceanic response triggered the atmospheric response to the Bond cycle in the western Mediterranean. Changes in the North Atlantic Oscillation mode and in the Inter-Tropical Convergence Zone migrations with variations in the monsoon activity or Saharan winds system, are considered as main forcing mechanisms, with a complex relationship of the involved phenomena.

Paleoecology of benthic foraminifera from the Miocene of the San Jacinto Basin, Colombia

Science.gov (United States)

Poveda, John Sebastian; Fiorini, Flavia; Andres Trejos, Raul; Vallejo, Diego Felipe; Pardo, Andres

2015-04-01

Quantitative benthic foraminifera analysis was conducted on 34 samples collected from a borehole core (393.72m deep) drilled by Colombian Hydrocarbon Agency (ANH) on 2009 in the San Jacinto basin (Northern Colombia). The aims of the research were to define a taxonomical data-bank of Miocene benthic foraminifera for this region, to use the benthic foraminifera assemblages to interpret the paleoenvironment and to identify paleoenvironmental changes. The bottom of the section was dated between lowest Burdigalian to middle Langhian (20.393-17.721 Ma) based on calcareous nannofossils bioevents: LO Helicosphaera ampliaperta, HCO Sphenolithus belemnos and LCO Sphenolithus heteromorphus. The benthic foraminifera fauna identified in the studied samples is composed for the majority of calcareous hyaline tests and is dominated by infaunal taxas. Species belonging to the genera Uvigerina and Lenticulina are commonly occurring in the studied section together with other species typical of outer-shelf upper-bathyal environment. Cibicidoides spp., abundant in the lower part of the section, abruptly decreases in abundance in the upper part. Species belonging to the opportunistic genera Bulimina and Bolivina are more abundant in the upper part of the section. Variability in the abundance of opportunistic species can be associated with tectonic disturbance on the Sinu-San Jacinto fold belt (NW of Colombia) as a result of collision of the Caribbean plate against NW of South America. The tectonics could lead a perturbation on deep ocean sedimentation and circulation.

High resolution carbon isotope stratigraphy and glendonite occurrences of the Christopher Formation, Sverdrup Basin (Axel Heiberg Island, Canada): implications for mid Cretaceous high latitude climate change

Science.gov (United States)

Herrle, Jens O.; Schröder-Adams, Claudia J.; Galloway, Jennifer M.; Pugh, Adam T.

2013-04-01

Understanding the evolution of Canada's Arctic region, as a crucial component of Earth's climate system, is fundamental to assess short and long-term climate, environmental, and paleogeographic change. However, the stratigraphy and paleoenvironmental evolution of the Cretaceous Arctic is poorly constrained and a detailed bio- and chemostratigraphic correlation of major mid-Cretaceous paleoceanographic turning points such as Oceanic Anoxic Events, cold snaps, and biotic turnovers with key locations of the high- and low latitudes is missing. Here we present for the first time a high resolution bio- and carbon isotope stratigraphy of the Arctic Albian Christopher Formation of the Sverdrup Basin at Glacier Fiord in the southern part of Axel Heiberg Island, Canadian High Arctic. By using these techniques we developed a high temporal framework to record major environmental changes as it is indicated by the occurrence of glendonites and sandstone intervals of our studied Albian succession. The Albian Christopher Formation is a shale dominated marine unit with a thickness of approximately 1200 m. Several transgressive/ regressive cycles can be recognized by prograding shoreface units that break up mudrock deposition. In addition, glendonites are mainly found in the lower part of the Christopher Formation. Glendonites are pseudomorphs of calcite, after the metastable mineral ikaite, and have been often described from high latitude Permian, Jurassic and Cretaceous marine environments from the Canadian Arctic, Spitsbergen and Australia. The formation of glendonites takes place in the uppermost layer of the sediment and requires near-freezing temperatures, high salinity, and orthophosphate-rich bottom water. Although the presence of glendonites implies a range of paleoenvironmental conditions there is a consensus in the scientific literature that they reflect cooler paleoenvironmental conditions. Preliminary bio- and carbon isotope stratigraphic results suggest that the

High-precision U-Pb geochronologic constraints on the Late Cretaceous terrestrial cyclostratigraphy and geomagnetic polarity from the Songliao Basin, Northeast China

Science.gov (United States)

Wang, Tiantian; Ramezani, Jahandar; Wang, Chengshan; Wu, Huaichun; He, Huaiyu; Bowring, Samuel A.

2016-07-01

The Cretaceous continental sedimentary records are essential to our understanding of how the terrestrial geologic and ecologic systems responded to past climate fluctuations under greenhouse conditions and our ability to forecast climate change in the future. The Songliao Basin of Northeast China preserves a near-complete, predominantly lacustrine, Cretaceous succession, with sedimentary cyclicity that has been tied to Milankocitch forcing of the climate. Over 900 meters of drill-core recovered from the Upper Cretaceous (Turonian to Campanian) of the Songliao Basin has provided a unique opportunity for detailed analyses of its depositional and paleoenvironmental records through integrated and high-resolution cyclostratigraphic, magnetostratigraphic and geochronologic investigations. Here we report high-precision U-Pb zircon dates (CA-ID-TIMS method) from four interbedded bentonites from the drill-core that offer substantial improvements in accuracy, and a ten-fold enhancement in precision, compared to the previous U-Pb SIMS geochronology, and allow a critical evaluation of the Songliao astrochronological time scale. The results indicate appreciable deviations of the astrochronologic model from the absolute radioisotope geochronology, which more likely reflect cyclostratigraphic tuning inaccuracies and omitted cycles due to depositional hiatuses, rather than suspected limitations of astronomical models applied to distant geologic time. Age interpolation based on our new high-resolution geochronologic framework and the calibrated cyclostratigraphy places the end of the Cretaceous Normal Superchon (C34n-C33r chron boundary) in the Songliao Basin at 83.07 ± 0.15 Ma. This date also serves as a new and improved estimate for the global Santonian-Campanian stage boundary.

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.

Molecular marker to identify radiolarian species -toward establishment of paleo-environmental proxy-

Science.gov (United States)

Ishitani, Y.

2017-12-01

Marine fossilized unicellular plankton are known to have many genetically divergent species (biological species) in the single morphological species and these biological species show the species-specific environments much more precisely than that of morphological species. Among these plankton, Radiolaria are one of the best candidates for time- and environmental-indicators in the modern and past oceans, because radiolarians are the only group which represent entire water column from shallow to deep waters. However, the ecology and evolution of radiolarian were traditionally studied in paleontology and paleoceanography by morphological species. Even Radiolaria has a huge potential for novel proxy of wide and deep environments, there is no criterion to identify the biological species. The motivation for this study is setting the quantitative delimitation to establish the biological species of radiolarians based on molecular data, for leading the future ecological and paleo-environmental study. Identification of the biological species by ribosomal DNA sequences are mainly based on two ways: one is the evolutionary distance of the small subunit (SSU) rDNA, the internal transcribed spacer region of ribosomal DNA (ITS1 and 2), and the large subunit (LSU) rDNA; and the other is the secondary structure of ITS2. In the present study, all four possible genetic markers (SSU, ITS1, ITS2, and LSU rDNA) were amplified from 232 individuals of five radiolarian morphological species and applied to examine the evolutionary distance and secondary structure of rDNA. Comprehensive survey clearly shows that evolutionary distance of ITS1 rDNA and the secondary structure of ITS2 is good to identify the species. Notably, evolutionary distance of ITS1 rDNA is possible to set the common delimitation to identify the biological species, as 0.225 substitution per site. The results show that the ITS1 and ITS 2 rDNA could be the criterion for radiolarian species identification.

RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

Energy Technology Data Exchange (ETDEWEB)

Robert Caldwell

1998-04-01

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

Preliminary mineralogical and paleoenvironmental study of the diatomites from Adamclisi, South Dobrogea, Romania

Science.gov (United States)

Dumitras, Delia-Georgeta; Sebe-Radoi, Oana-Gabriela; Marincea, Stefan; Costea, Constantin

2017-04-01

Diatomite samples taken from the Urluia - Adamclisi localities, South Dobrogea region (Romania) have been studied by X-ray fluorescence, wet-chemical analysis, scanning electron microscopy (SEM), FTIR and X-ray powder diffraction. The diatomaceous earth from Adamclisi occurs as beds and lenses in alternance with bentonitic clays and limestones. The diatomite levels are chalk-like, soft, friable, earthy, very fine-grained, and have a white - yellow color. The mineralogy of all but one sample is characterized by the presence of quartz, amorphous silica, feldspars and clay minerals. Based on the broad hump registered between 15 and 20° 2 theta on XRD patterns and on the characters and intensities of the bands centered around 3350 and 1630 cm-1 in the FTIR spectra, the amorphous silica from the diagenesis-affected diatom frustules was identified as opal-A. The associated mineral species are quartz (up to 5 wt.%), opal-Ct (up to 15 wt%), clay minerals (up to 60 wt.%), and minor feldspar (up to 20 wt.%). The micro-paleontological study shows that benthic pennate diatoms prevail (more than 60%), with a low rate of species diversity. Large chain-forming centric diatoms also occur together with other microfossils (dinoflagellates, phytolites, sponge spicules, different types of fish teeth) assemblages common for the Sarmatian (middle Miocene) marine deposits of Eastern Paratethys. The diatomaceous formation afforded exceptional fossilization. The diatom assemblages characterize a shallow marine basin environment, with littoral or freshwater contributions. Both at the basis and on the top of the profile, the marine diatoms prevail. At the basis of profile, the marine species (e.g., Actinocyclus ehrenbergii, Amphora crassa, Amphora crassa-punctata, Caloneis liber, Camylodiscus kutzingii, Grammatophora stricta, etc.) form up to 80 % of the rock volume, being associated with marine-brackish species such as Achnanthes brevipes and Cocconeis scutelum (up to 25 %) and with

On Intensive Late Holocene Iron Mining and Production in the Northern Congo Basin and the Environmental Consequences Associated with Metallurgy in Central Africa

Science.gov (United States)

Lupo, Karen D.; Schmitt, Dave N.; Kiahtipes, Christopher A.; Ndanga, Jean-Paul; Young, D. Craig; Simiti, Bernard

2015-01-01

An ongoing question in paleoenvironmental reconstructions of the central African rainforest concerns the role that prehistoric metallurgy played in shaping forest vegetation. Here we report evidence of intensive iron-ore mining and smelting in forested regions of the northern Congo Basin dating to the late Holocene. Volumetric estimates on extracted iron-ore and associated slag mounds from prehistoric sites in the southern Central African Republic suggest large-scale iron production on par with other archaeological and historically-known iron fabrication areas. These data document the first evidence of intensive iron mining and production spanning approximately 90 years prior to colonial occupation (circa AD 1889) and during an interval of time that is poorly represented in the archaeological record. Additional site areas pre-dating these remains by 3-4 centuries reflect an earlier period of iron production on a smaller scale. Microbotanical evidence from a sediment core collected from an adjacent riparian trap shows a reduction in shade-demanding trees in concert with an increase in light-demanding species spanning the time interval associated with iron intensification. This shift occurs during the same time interval when many portions of the Central African witnessed forest transgressions associated with a return to moister and more humid conditions beginning 500-100 years ago. Although data presented here do not demonstrate that iron smelting activities caused widespread vegetation change in Central Africa, we argue that intense mining and smelting can have localized and potentially regional impacts on vegetation communities. These data further demonstrate the high value of pairing archeological and paleoenvironmental analyses to reconstruct regional-scale forest histories. PMID:26161540

Paleo-environmental Reconstruction of Oligocene to Early Miocene ...

African Journals Online (AJOL)

ADOWIE PERE

province on the West African continental margin. It lies mainly in the ... basin are favorable for the generation, accumulation ... reconstruction as well as recognition of oil and gas deposits .... zone which covers from 1640ft to 11,100ft of the well.

Impact of land-use and climatic changes on hydrology of the Himalayan Basin: A case study of the Kosi Basin

Science.gov (United States)

Sharma, Keshav Prasad

1997-10-01

Land-use and climatic changes are of major concern in the Himalayan region because of their potential impacts on a predominantly agriculture-based economy and a regional hydrology dominated by strong seasonality. Such concerns are not limited to any particular basin but exist throughout the region including the downstream plain areas. As a representative basin of the Himalayas, we studied the Kosi basin (54,000 km2) located in the mountainous area of the central Himalayan region. We analyzed climatic and hydrologic information to assess the impacts of existing and potential future land-use and climatic changes over the basin. The assessment of anthropogenic inputs showed that the population grew at a compound growth rate of about one percent per annum over the basin during the last four decades. The comparison of land-use data based on the surveys made in the 1960s, and the surveys of 1978-79 did not reveal noticeable trends in land-use change. Analysis of meteorological and hydrological trends using parametric and nonparametric statistics for monthly data from 1947 to 1993 showed some increasing tendency for temperature and precipitation. Statistical tests of hydrological trends indicated an overall decrease of discharge along mainstem Kosi River and its major tributaries. The decreasing trends of streamflow were more significant during low-flow months. Statistical analysis of homogeneity showed that the climatological as well as the hydrological trends were more localized in nature lacking distinct basinwide significance. Statistical analysis of annual sediment time series, available for a single station on the Kosi River did not reveal a significant trend. We used water balance, statistical correlation, and distributed deterministic modeling approaches to analyze the hydrological sensitivity of the basin to possible land-use and climatic changes. The results indicated a stronger influence of basin characteristics compared to climatic characteristics on flow

Regional scale groundwater modelling study for Ganga River basin

Science.gov (United States)

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

2016-10-01

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

Multivariate study of trace element distribution in the geological record of Roñanzas Peat Bog (Asturias, N. Spain). Paleoenvironmental evolution and human activities over the last 8000 calyr BP.

Science.gov (United States)

Gallego, José Luis R; Ortiz, José E; Sierra, Carlos; Torres, Trinidad; Llamas, J F

2013-06-01

Trace element concentrations in the Roñanzas peat bog record reveal a contribution of natural processes but the influence of anthropogenic factors predominates in the last two millenniums, particularly aerosol deposition linked to mining and industrial activities in northern Spain. We observed that the Roñanzas record can be considered a preserved environment, suitable to search for local (major elements. Our study design represents a novel approach to assign natural vs. human contributions in peatlands. Therefore, synergies obtained by the simultaneous study of multivariate statistics and enrichment factors allow robust conclusions about paleoenvironmental evolution and human activities. Anthropogenic influence has also been reported in similar records in other parts of Europe, thereby suggesting large-scale sources for atmospheric pollution. However, here we revealed remarkable particularities, such as the association of Cd, Zn and Pb, mainly linked to regional and local factors (mining and more recently the metallurgical industry), whereas we propose that the occurrence of Hg is associated with a combination of regional factors and global atmospheric pollution. Copyright © 2013 Elsevier B.V. All rights reserved.

Drainage basins features and hydrological behaviour river Minateda basin

International Nuclear Information System (INIS)

Alonso-Sarria, F.

1991-01-01

Nine basin variables (shape, size and topology) have been analyzed in four small basins with non-permanent run off (SE of Spain). These geomorphological variables have been selected for their high correlation with the Instantaneous unit hydrograph parameters. It is shown that the variables can change from one small basin to another within a very short area; because of it, generalizations about the behaviour of the run off are not possible. In conclusion, it is stated that the variations in geomorphological aspects between different basins, caused mainly by geological constraints, are a very important factor to be controlled in a study of geoecological change derived from climatic change

Origin, transport and deposition of leaf-wax biomarkers in the Amazon Basin and the adjacent Atlantic

Science.gov (United States)

Häggi, Christoph; Sawakuchi, André O.; Chiessi, Cristiano M.; Mulitza, Stefan; Mollenhauer, Gesine; Sawakuchi, Henrique O.; Baker, Paul A.; Zabel, Matthias; Schefuß, Enno

2016-11-01

Paleoenvironmental studies based on terrigenous biomarker proxies from sediment cores collected close to the mouth of large river systems rely on a proper understanding of the processes controlling origin, transport and deposition of biomarkers. Here, we contribute to the understanding of these processes by analyzing long-chain n-alkanes from the Amazon River system. We use the δD composition of long-chain n-alkanes from river bed sediments from the Amazon River and its major tributaries, as well as marine core-top samples collected off northeastern South America as tracers for different source areas. The δ13C composition of the same compounds is used to differentiate between long-chain n-alkanes from modern forest vegetation and petrogenic organic matter. Our δ13C results show depleted δ13C values (-33 to -36‰) in most samples, indicating a modern forest source for most of the samples. Enriched values (-31 to -33‰) are only found in a few samples poor in organic carbon indicating minor contributions from a fossil petrogenic source. Long-chain n-alkane δD analyses show more depleted values for the western tributaries, the Madeira and Solimões Rivers (-152 to -168‰), while n-alkanes from the lowland tributaries, the Negro, Xingu and Tocantins Rivers (-142 to -154‰), yield more enriched values. The n-alkane δD values thus reflect the mean annual isotopic composition of precipitation, which is most deuterium-depleted in the western Amazon Basin and more enriched in the eastern sector of the basin. Samples from the Amazon estuary show a mixed long-chain n-alkane δD signal from both eastern lowland and western tributaries. Marine core-top samples underlying the Amazon freshwater plume yield δD values similar to those from the Amazon estuary, while core-top samples from outside the plume showed more enriched values. Although the variability in the river bed data precludes quantitative assessment of relative contributions, our results indicate that long

Integrated study of basins in the Four Corners region

Science.gov (United States)

Fagbola, Olamide Olawumi

2007-12-01

This dissertation is an integrated study of basins in the four corners area of the central part of the Colorado Plateau. The Colorado Plateau is a structurally unique part of the Rocky Mountain region because it has only been moderately deformed when compared to the more intensely deformed areas around it. The Colorado Plateau covers a portion of Utah, Colorado, New Mexico and Arizona. The study area extends from latitude 34°N-40°N to longitude 106°W-111W° encompassing a series of major basins and uplifts: the San Juan, Black Mesa, Paradox, and the Blanding basins; and the Zuni, Defiance, Four Corners, Monument uplifts and the San Juan dome and volcanic field. An analysis of gravity anomalies, basement and crustal structure for basins in the four corners region was carried out. This involved using gravity, magnetic, well, outcrop, seismic estimates of crustal thickness, and geologic data in an integrated fashion. Six filtered gravity and three filtered magnetic maps were generated to aid in the interpretation of the gravity and magnetic anomalies in the study area. A detailed comparison of these maps was carried out. The results show a deep seated mafic structure in the basement acting as a crustal boundary separating the high gravity anomalies from the low. These maps also show that the sources of these anomalies are quite shallow resulting from the upper crust in the study area. The structures in the study area are characterized by northwest and northeast trends which correspond to the Precambrian and the Late Paleozoic structures, respectively. A crustal thickness map of the area was also constructed from seismic estimates of crustal thickness. A comparison was done between the crustal thickness map and the 45 km upward continuation Bouguer anomaly map. The result of this comparison shows that areas of thicker ix crust corresponded to low gravity while areas of thinner crust means mantle material is closer to the surface, thereby producing a high gravity

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

Science.gov (United States)

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

2013-12-01

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

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

Science.gov (United States)

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

2014-01-01

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

Susquehanna River Basin Flood Control Review Study

Science.gov (United States)

1980-08-01

and made recommendations for an intergrated water plan for the Basin and included a specific Early Action Plan. Concerning flood damage reduction, the...transportation and by agriculture as a source of income and occupation. The river served as a source of transportation for trade and commerce and also as a... trade patterns, and labor market areas. The Susquehanna River Basin is largely comprised of BEA economic areas 011, 012, 013, and 016. Figure II shows the

Stable isotopes in modern ostrich eggshell: a calibration for paleoenvironmental applications in semi-arid regions of southern Africa

Science.gov (United States)

Johnson, Beverly J.; Fogel, Marilyn L.; Miller, Gifford H.

1998-07-01

An isotopic study of modern ostrich eggshell (OES) is presented as a calibration for terrestrial paleoenvironmental applications. The stable carbon and nitrogen isotope fractionations of OES were determined for various organic fractions of eggshell by measuring the isotopic ratios of modern OES samples collected from controlled settings (i.e., zoos and farms) and corresponding ostrich diet. These fractionations were used to evaluate the relationship between the isotope composition of OES laid by free-range birds living in South Africa and their environment. The carbon isotope composition of the total organic and inorganic fractions of OES were enriched by 2 and 16‰, respectively, relative to the diet. In natural settings, the δ 13C values of both the organic and inorganic fractions of OES reflected that of ambient vegetation, with a noted dietary preference for C 3 plants. The nitrogen isotope composition of the total organic fraction of OES was 3‰ enriched relative to the diet, and varied inversely with mean annual precipitation (MAP) in natural settings. A decrease in MAP of 100 mm was accompanied by an increase in δ 15N values of approximately 1‰. The oxygen isotope composition of the inorganic fraction of the OES varied linearly with that of the drinking water in controlled settings. However, in natural settings, the δ 18O of OES values were highly variable and are thought to be controlled primarily by the δ 18O of ingested plant leaf-water. The stability of the isotopic signal in the organic fraction of OES through geologic time was evaluated through a series of heating experiments. The δ 13C and δ 15N values of the total organic fraction of heated OES increased by less than 0.6 and 0.2‰ for carbon and nitrogen, respectively, in spite of extensive diagenetic alteration and changes in the amino acid composition of the samples. The results of this study indicate that the stable carbon and nitrogen isotope composition of OES is relatively stable

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

A Case Study of the Densu Basin, Ghana

African Journals Online (AJOL)

komla

and middle sections of the basin are covered with semi-deciduous forest with a lush growth of thick and tall trees. ... and scrub forest vegetation with only few isolated trees. There are ... which underlie the south-eastern part of the basin and the area south of Weija to the estuary. The rocks of ...... Association, Washington, D.C.

Finite Element Modelling of the Indo-Gangetic Basin to Study Site Amplification

Science.gov (United States)

Sivasubramonian, J.; Jaya, D.; Raghukanth, S. T. G.; Mai, P. M.

2017-12-01

We have developed a finite-element model of the 3D velocity structure of the Indo-Gangetic basin (IG basin) to quantify site amplifications due to seismic waves emanated from regional earthquakes. Estimating seismic wave amplifications is difficult in case of limited instrumentation, thus motivating us to propose a new simulation-based approach. The input required for the finite-element model include the spatial coordinates and the material properties (density, P-wave and S-wave velocities, Q factor) of the basin. Recent studies in the basin demarcate sediment layers of varying thickness, reaching down to a depth of 6 km and S-wave velocities ranging from 0.4-2.4 km/s (Srinivas et al., 2013). In the present study, our regional model has dimensions 900 x 900 x 80 km in x, y and z directions, discretized into 320 x 320 x 53 hexahedral elements. The top 6 km of the IG basin is divided into 8 different sediment layers with varying material properties. We use kinematic rupture models for the earthquake sources to simulate past as well as hypothetical future events. Two past earthquakes (Mw4.9, Delhi; Mw5.2, Chamoli) and two hypothetical earthquakes (Mw7.1; Mw8.5) are considered in our study. The rupture plane dimensions (L and W) and the slip distribution are estimated using the method of Mai and Beroza (2002). Based on focal-mechanism solutions and the depths of seismicity, we define the strike (580, 3090), the dip (650, 210), the rake (160, 770), and the depth of top edge of fault (5 km, 19 km) for the two large hypothetical earthquakes. Based on these parameters, the Centroid Moment Tensor (CMT) solution of the source is obtained. Ground motions are then simulated by solving the three-dimensional wave equation using the spectral element method (Komatitsch and Tromp, 1999). The key observations from our results are: 1) basin amplification factors for Peak Ground Velocity (PGV) are twice as high as Peak Ground Displacement (PGD) 2) PGV amplifications are as high as a

Gas desorption and adsorption isotherm studies of coals in the Powder River basin, Wyoming and adjacent basins in Wyoming and North Dakota

Science.gov (United States)

Stricker, Gary D.; Flores, Romeo M.; McGarry, Dwain E.; Stillwell, Dean P.; Hoppe, Daniel J.; Stillwell, Cathy R.; Ochs, Alan M.; Ellis, Margaret S.; Osvald, Karl S.; Taylor, Sharon L.; Thorvaldson, Marjorie C.; Trippi, Michael H.; Grose, Sherry D.; Crockett, Fred J.; Shariff, Asghar J.

2006-01-01

The U.S. Geological Survey (USGS), in cooperation with the State Office, Reservoir Management Group (RMG), of the Bureau of Land Management (BLM) in Casper (Wyoming), investigated the coalbed methane resources (CBM) in the Powder River Basin, Wyoming and Montana, from 1999 to the present. Beginning in late 1999, the study also included the Williston Basin in Montana and North and South Dakota and Green River Basin and Big Horn Basin in Wyoming. The rapid development of CBM (referred to as coalbed natural gas by the BLM) during the early 1990s, and the lack of sufficient data for the BLM to fully assess and manage the resource in the Powder River Basin, in particular, gave impetus to the cooperative program. An integral part of the joint USGS-BLM project was the participation of 25 gas operators that entered individually into confidential agreements with the USGS, and whose cooperation was essential to the study. The arrangements were for the gas operators to drill and core coal-bed reservoirs at their cost, and for the USGS and BLM personnel to then desorb, analyze, and interpret the coal data with joint funding by the two agencies. Upon completion of analyses by the USGS, the data were to be shared with both the BLM and the gas operator that supplied the core, and then to be released or published 1 yr after the report was submitted to the operator.

Study on metallogenetic prospect of interlayer oxidation zone sandstone type uranium deposit in Shanganning basin

International Nuclear Information System (INIS)

Wang Jinping

1998-01-01

As Compared with orogenic zone basin, which the interlayer oxidation zone sandstone type uranium deposits are found, the Shanganning basin a continental platform type basin is distinct either in the geodynamic background and the post-basin hydrogeological evolution or in the appearance of the metallogenetic dynamics-orogenesis. The prediction criteria summarized for interlayer oxidation zone type U-deposits in Middle Asia therefore can not be completely applied in such a basin. Based on analysis of the typical regional geological setting, the hydrogeology of the Meso-Cenozoic cover is studied in detail. Three hydrogeological cycles have been divided, and prospects of uranium deposits have been clarified and the most promising target have been proposed

Comparative Research on River Basin Management in the Sagami River Basin (Japan and the Muda River Basin (Malaysia

Directory of Open Access Journals (Sweden)

Lay Mei Sim

2018-05-01

Full Text Available In the world, river basins often interwoven into two or more states or prefectures and because of that, disputes over water are common. Nevertheless, not all shared river basins are associated with water conflicts. Rivers in Japan and Malaysia play a significant role in regional economic development. They also play a significant role as water sources for industrial, domestic, agricultural, aquaculture, hydroelectric power generation, and the environment. The research aim is to determine the similarities and differences between the Sagami and Muda River Basins in order to have a better understanding of the governance needed for effectively implementing the lessons drawn from the Sagami River Basin for improving the management of the Muda River Basin in Malaysia. This research adopts qualitative and quantitative approaches. Semi-structured interviews were held with the key stakeholders from both basins and show that Japan has endeavored to present policy efforts to accommodate the innovative approaches in the management of their water resources, including the establishment of a river basin council. In Malaysia, there is little or no stakeholder involvement in the Muda River Basin, and the water resource management is not holistic and is not integrated as it should be. Besides that, there is little or no Integrated Resources Water Management, a pre-requisite for sustainable water resources. The results from this comparative study concluded that full support and participation from public stakeholders (meaning the non-government and non-private sector stakeholders is vital for achieving sustainable water use in the Muda River Basin. Integrated Water Resources Management (IWRM approaches such as the introduction of payments for ecosystems services and the development of river basin organization in the Muda River Basin should take place in the spirit of political willingness.

Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

Science.gov (United States)

Schöpfer, Kateřina; Hinsch, Ralph

2017-04-01

The Vøring and the Faroe-Shetland basins are offshore deep sedimentary basins which are situated on the outer continental margin of the northeast Atlantic Ocean. Both basins are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both basins share several common features: (i) Pre-Cretaceous faults that are distributed across the entire basin width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two basins: (i) The Faroe-Shetland Basin was a fault-controlled basin during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring Basin is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-basinal and marginal highs. In addition, the Cretaceous strata in the Vøring Basin are folded. (ii) In the Vøring Basin, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western basin margin, whereas in the Faroe-Shetland Basin Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

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EMILIANO C. OLIVEIRA

Full Text Available ABSTRACT This paper presents a sedimentological and stratigraphical study of Quaternary (Middle to Late Pleistocene/Holocene continental carbonates outcrops inside Pantanal Basin and its surroundings, especially in Serra da Bodoquena, Pantanal do Miranda and Corumbá/Ladário plateau, in the state of Mato Grosso do Sul, as well as in Serra das Araras, in the state of Mato Grosso. The aim is to understand the depositional paleoenvironments and analyse climate and tectonic influences in their genesis and evolution. The results show that the deposition of these continental carbonates started in the Middle to Late Pleistocene and have continued, with some interruptions, until the present days. Sedimentary successions were identified in the different areas, without complete correlation. Two sedimentary successions separated by an erosional surface were described in Serra da Bodoquena and Serra das Araras. In Corumbá and Pantanal do Miranda, only one succession was described. These successions were deposited in elongated lakes parallel to fault planes; small lakes, related plains and plateaus; springs related to cliffs produced by faulting; rivers conditioned by topographic variation. The climatic interpretation, without proper temporal resolution, obtained by the stable-isotope composition and stratigraphic interpretation, indicates alternation of dry and wet periods. The Neoproterozoic faults with their neotectonics and the subsidence of the Pantanal Basin, are the major control for carbonated water flow and development of depositional areas, gradually turning plateaus into slight tilted areas, allowing the evolution of depositional systems from lakes to rivers.

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).

Mapping Monthly Water Scarcity in Global Transboundary Basins at Country-Basin Mesh Based Spatial Resolution.

Science.gov (United States)

Degefu, Dagmawi Mulugeta; Weijun, He; Zaiyi, Liao; Liang, Yuan; Zhengwei, Huang; Min, An

2018-02-01

Currently fresh water scarcity is an issue with huge socio-economic and environmental impacts. Transboundary river and lake basins are among the sources of fresh water facing this challenge. Previous studies measured blue water scarcity at different spatial and temporal resolutions. But there is no global water availability and footprint assessment done at country-basin mesh based spatial and monthly temporal resolutions. In this study we assessed water scarcity at these spatial and temporal resolutions. Our results showed that around 1.6 billion people living within the 328 country-basin units out of the 560 we assessed in this study endures severe water scarcity at least for a month within the year. In addition, 175 country-basin units goes through severe water scarcity for 3-12 months in the year. These sub-basins include nearly a billion people. Generally, the results of this study provide insights regarding the number of people and country-basin units experiencing low, moderate, significant and severe water scarcity at a monthly temporal resolution. These insights might help these basins' sharing countries to design and implement sustainable water management and sharing schemes.

Intra- and inter-basin mercury comparisons: Importance of basin scale and time-weighted methylmercury estimates

International Nuclear Information System (INIS)

Bradley, Paul M.; Journey, Celeste A.; Brigham, Mark E.; Burns, Douglas A.; Button, Daniel T.; Riva-Murray, Karen

2013-01-01

To assess inter-comparability of fluvial mercury (Hg) observations at substantially different scales, Hg concentrations, yields, and bivariate-relations were evaluated at nested-basin locations in the Edisto River, South Carolina and Hudson River, New York. Differences between scales were observed for filtered methylmercury (FMeHg) in the Edisto (attributed to wetland coverage differences) but not in the Hudson. Total mercury (THg) concentrations and bivariate-relationships did not vary substantially with scale in either basin. Combining results of this and a previously published multi-basin study, fish Hg correlated strongly with sampled water FMeHg concentration (ρ = 0.78; p = 0.003) and annual FMeHg basin yield (ρ = 0.66; p = 0.026). Improved correlation (ρ = 0.88; p < 0.0001) was achieved with time-weighted mean annual FMeHg concentrations estimated from basin-specific LOADEST models and daily streamflow. Results suggest reasonable scalability and inter-comparability for different basin sizes if wetland area or related MeHg-source-area metrics are considered. - Highlights: ► National scale mercury assessments integrate small scale study results. ► Basin scale differences and representativeness of fluvial mercury samples are concerns. ► Wetland area, not basin size, predicts inter-basin methylmercury variability. ► Time-weighted methylmercury estimates improve the prediction of mercury in basin fish. - Fluvial methylmercury concentration correlates with wetland area not basin scale and time-weighted estimates better predict basin top predator mercury than discrete sample estimates.

Fluvial sediment study of Fishtrap and Dewey Lakes drainage basins, Kentucky - Virginia

Science.gov (United States)

Curtis, William F.; Flint, Russell F.; George, Frederick H.; Santos, John F.

1978-01-01

Fourteen drainage basins above Fishtrap and Dewey Lakes in the Levisa Fork and Johns Creek drainage basins of eastern Kentucky and southwestern Virginia were studied to determine sedimentation rates and origin of sediment entering the two lakes. The basins ranged in size from 1.68 to 297 square miles. Sediment yields ranged from 2,890 to 21,000 tons per square mile where surface-mining techniques predominated, and from 732 to 3 ,470 tons per square mile where underground mining methods predominated. Yields, in terms of tons per acre-foot of runoff, ranged from 2.2 to 15 for surface-mined areas, and from 0.5 to 2.7 for underground-mined areas. Water and sediment discharges from direct runoff during storms were compared for selected surface-mined and underground-mined areas. Data points of two extensively surface-mined areas, one from the current project and one from a previous project in Beaver Creek basin, McCreary County, Kentucky, grouped similarly in magnitude and by season. Disturbed areas from mining activities determined from aerial photographs reached 17 percent in one study area where extensive surface mining was being practiced. For most areas where underground mining was practiced, percentage disturbed area was almost negligible. Trap efficiency of Fishtrap Lake was 89 percent, and was 62 percent for Dewey Lake. Average annual deposition rates were 464 and 146 acre-feet for Fishtrap and Dewey Lakes, respectively. The chemical quality of water in the Levisa Fork basin has been altered by man 's activities. (Woodard-USGS)

Climate stability in Central Anatolia during the Messinian Salinity Crisis

Science.gov (United States)

Meijers, Maud J.M.; Peynircioğlu, Ahmet A; Cosca, Michael A.; Brocard, Gilles Y.; Whitney, Donna L.; Langereis, Cor G.; Mulch, Andreas

2018-01-01

Deposition of large amounts of evaporites and erosion of deep canyons within the Mediterranean Basin as a result of reduced basin connectivity with the Atlantic Ocean and the epicontinental Paratethys Sea characterized the Messinian Salinity Crisis (MSC, 5.97–5.33 Ma). The influence of the MSC on Mediterranean environmental conditions within the basin itself has been intensely studied from marine records, but reconstructing the impact of the MSC on circum-Mediterranean continental climate has been hampered by the absence of continuous sedimentary archives that span the duration of the event.Here, we report results of a continental record of carbon (δ13C) and oxygen (δ18O) isotopes from lake carbonates framed by new magnetostratigraphic and 40Ar/39Ar dating, as well as by existing mammal stratigraphy (Kangal Basin, central Anatolia). The sampled section records continuous fluvio-lacustrine sedimentation from ~6.6 Ma to 4.9 Ma, which spans the MSC and the Miocene-Pliocene boundary. This dataset so far represents the only continuous continental paleoenvironmental record of the MSC in the circum-Mediterranean realm.The Kangal Basin isotope record indicates a low degree of evaporation. Furthermore, covariance between δ13C and δ18O suggests a coupling between lake water balance and biologic productivity. Variations in δ13C and δ18O therefore likely reflect changes in the amount of incoming precipitation, rather than changes in δ18O values of incoming precipitation. The most prominent spike in δ13C and δ18O occurs during the acme of the MSC and is therefore interpreted to have resulted from a decrease in the amount of incoming moisture correlative to a period of vigorous erosion and sea level lowering in the Mediterranean Basin. Major sea level lowering of Mediterranean basin waters during the acme of the MSC could have therefore led to slightly dryer conditions over Anatolia, which is also suggested by modeling studies. Overall, changes in δ13C and

Consequences of Lower Miocene CO.sub.2./sub. degassing on geological and paleoenvironmental settings of the Ahníkov/Merkur Mine paleontological locality (Most Basin, Czech Republic)

Czech Academy of Sciences Publication Activity Database

Mach, K.; Žák, Karel; Teodoridis, V.; Kvaček, Z.

2017-01-01

Roč. 285, č. 3 (2017), s. 235-266 ISSN 0077-7749 Institutional support: RVO:67985831 Keywords : geology * paleoflora * travertine formation * Most Basin * Czech Republic Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 0.777, year: 2016

Probabilistic evaluation of the water footprint of a river basin: Accounting method and case study in the Segura River Basin, Spain.

Science.gov (United States)

Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

2018-06-15

In the current study a method for the probabilistic accounting of the water footprint (WF) at the river basin level has been proposed and developed. It is based upon the simulation of the anthropised water cycle and combines a hydrological model and a decision support system. The methodology was carried out in the Segura River Basin (SRB) in South-eastern Spain, and four historical scenarios were evaluated (1998-2010-2015-2027). The results indicate that the WF of the river basin reached 5581 Mm 3 /year on average in the base scenario, with a high variability. The green component (3231 Mm 3 /year), mainly generated by rainfed crops (62%), was responsible for the great variability of the WF. The blue WF (1201 Mm 3 /year) was broken down into surface water (56%), renewable groundwater (20%) and non-renewable groundwater (24%), and it showed the generalized overexploitation of aquifers. Regarding the grey component (1150 Mm 3 /year), the study reveals that wastewater, especially phosphates (90%), was the main culprit producing water pollution in surface water bodies. The temporal evolution of the four scenarios highlighted the successfulness of the water treatment plans developed in the river basin, with a sharp decrease in the grey WF, as well as the stability of the WF and its three components in the future. So, the accounting of the three components of the WF in a basin was integrated into the management of water resources, it being possible to predict their evolution, their spatial characterisation and even their assessment in probabilistic terms. Then, the WF was incorporated into the set of indicators that usually is used in water resources management and hydrological planning. Copyright © 2018 Elsevier B.V. All rights reserved.

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

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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 ‰. 

On the paleoenvironmental potential of 253 newly discovered pine stumps from Zurich, Switzerland

Science.gov (United States)

Reinig, Frederick; Nievergelt, Daniel; Esper, Jan; Friedrich, Michael; Helle, Gerhard; Hellmann, Lena; Kromer, Bernd; Morganti, Sandro; Pauly, Maren; Sookdeo, Adam; Tegel, Willy; Treydte, Kerstin; Wacker, Lukas; Büntgen, Ulf

2017-04-01

The transition from the last Ice Age to the early Holocene 15'000-10'000 BP represents a close natural analog to the ongoing and predicted rates of anthropogenic climate change. A reduced quality and quantity of high-resolution proxy archives during this period, however, limits our understanding of the magnitude and pace of Late Glacial (LG) environmental variability. Here, we present the world's best preserved, most replicated and oldest forest remains: A total of 253 subfossil pine stumps were recently discovered in Zurich. The combined approach of tree-ring and radiocarbon (14C) measurements results in an absolutely dated Preboreal Swiss tree-ring width chronology and eight floating chronologies. With tree ages ranging between 41 and 506 years, often including pith and bark, and a mean segment length of 163 years, this exceptional find is distributed over nearly 2'000 years between the Allerød and the Preboreal. Together with 200 previously collected LG pines from the greater Zurich region, this study sets a benchmark in terms of sample replication and dating precision for stable more dynamic climatic periods such as the Laacher See eruption, the Older and Younger Dryas. The paleoenvironmental significance would even increase when annually resolved 14C-measurements help fixing a major, Northern Hemispheric gap in the absolutely dated dendro time series during the Younger Dryas. While overcoming this interlude, our results further emphasize the importance of interdisciplinary research on these striking LG climatic shifts to better understand and assess their ecological and environmental impact.

Estimating tectonic history through basin simulation-enhanced seismic inversion: Geoinformatics for sedimentary basins

Science.gov (United States)

Tandon, K.; Tuncay, K.; Hubbard, K.; Comer, J.; Ortoleva, P.

2004-01-01

A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by integrating the basin analysis and seismic inversion activities to understand the sedimentary basin evolution with respect to geodynamic parameters-but the technique also has the potential for serving as a geoinfomatics platform for understanding various physical and chemical processes operating at different scales within a sedimentary basin. Tectonic history has a first-order effect on the physical and chemical processes that govern the evolution of sedimentary basins. We demonstrate how such tectonic parameters may be estimated by minimizing the difference between observed seismic reflection data and synthetic ones constructed from the output of a reaction, transport, mechanical (RTM) basin model. We demonstrate the method by reconstructing the geothermal gradient. As thermal history strongly affects the rate of RTM processes operating in a sedimentary basin, variations in geothermal gradient history alter the present-day fluid pressure, effective stress, porosity, fracture statistics and hydrocarbon distribution. All these properties, in turn, affect the mechanical wave velocity and sediment density profiles for a sedimentary basin. The present-day state of the sedimentary basin is imaged by reflection seismology data to a high degree of resolution, but it does not give any indication of the processes that contributed to the evolution of the basin or causes for heterogeneities within the basin that are being imaged. Using texture and fluid properties predicted by our Basin RTM simulator, we generate synthetic seismograms. Linear correlation using power spectra as an error measure and an efficient quadratic

3-D basin modelling of the Paris Basin: diagenetic and hydrogeologic implications

International Nuclear Information System (INIS)

Violette, S.; Goncalves, J.; Jost, A.; Marsily, G. de

2004-01-01

A 3-D basin model of the Paris basin is presented in order to simulate through geological times fluid, heat and solute fluxes. This study emphasizes: i) the contribution of basin models to the quantitative hydrodynamic understanding of behaviour of the basin over geological times; ii) the additional use of Atmospheric General Circulation model (AGCM) to provide palaeo-climatic boundaries for a coupled flow and mass transfer modelling, constrained by geochemical and isotopic tracers and; iii) the integration of different types of data (qualitative and quantitative) to better constrain the simulations. Firstly, in a genetic way, basin model is used to reproduce geological, physical and chemical processes occurring in the course of the 248 My evolution of the Paris basin that ought to explain the present-day hydraulic properties at the regional scale. As basin codes try to reproduce some of these phenomena, they should be able to give a plausible idea of the regional-scale permeability distribution of the multi-layered system, of the pre-industrial hydrodynamic conditions within the aquifers and of the diagenesis timing and type of hydrodynamic processes involved. Secondly, climate records archived in the Paris basin groundwater suggest that climate and morphological features have an impact on the hydrogeological processes, particularly during the last 5 My. An Atmospheric General Circulation model is used with a refined spatial resolution centred on the Paris basin to reproduce the climate for the present, the Last Glacial Maximum (21 ky) and the middle Pliocene (3 My). These climates will be prescribed, through forcing functions to the hydrological code with the main objective of understanding the way aquifers and aquitards react under different climate conditions, the period and the duration of these effects. Finally, the Paris basin has been studied for a number of years by different scientific communities, thus a large amount of data has been collected. By

River basin administration

Science.gov (United States)

Management of international rivers and their basins is the focus of the Centre for Comparative Studies on (International) River Basin Administration, recently established at Delft University of Technology in the Netherlands. Water pollution, sludge, and conflicting interests in the use of water in upstream and downstream parts of a river basin will be addressed by studying groundwater and consumption of water in the whole catchment area of a river.Important aspects of river management are administrative and policy aspects. The Centre will focus on policy, law, planning, and organization, including transboundary cooperation, posing standards, integrated environmental planning on regional scale and environmental impact assessments.

Hydrogeochemical and stream-sediment survey (NURE). Preliminary report on the Smoke Creek Desert Basin pilot study (Nevada)

International Nuclear Information System (INIS)

1976-01-01

The Lawrence Livermore Laboratory (LLL) is conducting a hydrogeochemical and stream-sediment survey in the seven western states as part of ERDA's National Uranium Resources Evaluation (NURE) Program. The objective of this survey is to develop a geochemical data base for use by the private sector to locate regions of anomalous uranium content. Prior to wide area coverage, several pilot studies are being undertaken to develop and evaluate sampling and analytical techniques. The second through fifth of these studies were conducted in four playa basins in Nevada, selected to represent different regional geology and uranium occurrence. This study in the Smoke Creek Desert Basin, characterizes igneous surface geology with known uranium occurrences. The Smoke Creek Desert Basin is the largest of the four playa basins and contains an areaof about 2700 square kilometers (1003 square miles). The basin is bordered on the east by the Fox Hills and on the north and east by the Granite Ranges which are characterized by granite, pegmatites, and Tertiary rocks very similar to the lithology of the Winnemucca Basin boundary ranges (study UCID-16911-P-2). On the west the Desert is bordered by an area of extensive basalt flow. There is no known uranium occurrence in the area, and metallization of any kind is scarce. This study is applicable to the western igneous portion of the Basin and Range Province which includes southeastern Oregon, western Nevada, and southeastern California. This report contains only analytical data and sample locations

The Ogaden Basin, Ethiopia: an underexplored sedimentary basin

Energy Technology Data Exchange (ETDEWEB)

Teitz, H.H.

1991-01-01

A brief article examines the Ogaden Basin in Ethiopia in terms of basin origin, basin fill and the hydrocarbon exploration history and results. The natural gas find in pre-Jurassic sandstones, which appears to contain substantial reserves, justifies continuing investigations in this largely underexplored basin. (UK).

Tracking the source of mineralisation in the Tampere Basin (southern Finland), insights from structure, sedimentology and geophysics studies

DEFF Research Database (Denmark)

Moreau, Julien; Torvela, Taija; Kalliomäki, Henrik

2013-01-01

The ancient basins are of a wide interest to geoscientists as they archive the early development of plate tectonics, life, and ore-bearing systems. Several basins, especially those involving volcanic-derived materials, contain ore and mineral deposits. The formation of these ores is often related...... marginal basin, and the mechanics of and strain distribution during its subsequent closure. In order to investigate the deposition, the tectonic deformation and the fluid migration, geological mapping of a key area of the basin has been performed. In addition, georadar reflection profiles have been...... covered. This study highlighted several sulphide-rich horizon within the basal succession of the basin infill. The sulphides are either in relation with tectonic structures or with genuinely clay-rich deposits. The studied succession shows a progressive deepening of the basin through time with facies...

Sub-annual paleoenvironmental information evaluated from intensity variations of fluorescent annual layers in a stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan

Science.gov (United States)

Sasaki, Hana; Onishi, Yuri; Ishihara, Yoshiro; Yoshimura, Kazuhisa

2017-04-01

Stalagmites can provide various types of paleoenvironmental information such as information on vegetation and climate changes. Fluorescent annual layers formed by humic substances (mainly fulvic acids: FA) in these stalagmites can also provide a time proxy, and a time series on precipitation. Fluorescence intensity patterns in these annual layers can be classified into symmetric, gradually increasing and gradually decreasing types. Onishi et al. (EGU2016) demonstrated the existence of these fluorescence intensity patterns in the annual layers, and their stratigraphic changes, by numerical simulations, and suggested that the patterns could provide paleoenvironmental information at a sub-annual resolution. In this study, we carried out an analysis of fluorescence intensity patterns in the annual layers of a stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan, and also simulated the patterns in the stalagmite, to obtain paleoenvironmental information. Fluorescence intensity patterns in the annual layers are strongly affected by annual variations in FA concentration and precipitation rates of calcite. As the result of simulations of fluorescence intensity patterns, cumulative variations and various types of pattern are reproduced. These differences are depending on time lags between the variation of the FA concentration in the drip waters, and that of the growth rate of the stalagmite. Co-precipitation models of FA are divided into the "Hiatus model" in which FA are preferentially preserved in the stalagmite when its growth rate is relatively low, and the "Partition coefficient (PC) model" in which FA concentrations in the stalagmite increase when the calcite precipitation rate is relatively high. However, various fluorescence intensity patterns in the annual layers could be formed under a combination or either of both of the models. Fluorescence intensity patterns in an annual layer in the stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan

Contribution of the gravimetry to the structural study of the Haouz basin (Morocco)

International Nuclear Information System (INIS)

El Goumi, N.; Jaffal, M.; Kchikach, A.; Manar, A.

2010-01-01

The aim of the present study is to improve the knowledge of the Haouz basin structure using gravity data analysis. First of all, a residual anomaly map was computed from the Bouguer anomaly, greatly affected by an important regional gravity gradient. The calculated map provides information on the ground density variations mainly attributed to the top of the Paleozoic basement undulations under the sedimentary cover. However, in order to further study this map, it has been later analyzed with a method that allows evidencing different buried geological structures, combining the horizontal gradient and the upward continuations processing. The obtained results allows us to establish a structural map of the Haouz basin which confirms the existence of structures already recognized or assumed by the classic geological studies, and highlights accidents, as yet, unknown until the present time. This map shows that the fault system of the Haouz basin is organized in two families of directions NE-SW and NW-SE. (Author).

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.

Powder River Basin Coalbed Methane Development and Produced Water Management Study

International Nuclear Information System (INIS)

2002-01-01

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

Event review: Central Narmada Basin Paleoanthropology Fieldschool

Directory of Open Access Journals (Sweden)

Parth Chauhan

2016-03-01

Full Text Available In comparison to other subjects in Indian archaeology and Quaternary studies, paleoanthropology has declined significantly in recent decades as a prominent academic discipline in the Indian Subcontinent. Most archaeological research and teaching in South Asia are largely focused on younger time periods, primarily the protohistoric or Chalcolithic and historical phases. In addition to lack of general interest and lack of popularization, another major reason for this decline in paleoanthropology may be the methodological challenges in interpreting complex paleoanthropological records, e.g., landform assemblage, paleoenvironmental reconstructions, assessing contextual integrity of the archaeological evidence (compared to younger sites and so forth. Due to inadequate preserved evidence compared to younger archaeological sites, the study of human history during the Quaternary demands a multi-disciplinary approach with highly sophisticated and extensive field-based surveys and integrated scientific analyses from geological perspectives.

LIQUID EFFLUENT RETENTION FACILITY (LERF) BASIN 42 STUDIES

International Nuclear Information System (INIS)

DUNCAN JB

2004-01-01

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

LIQUID EFFLUENT RETENTION FACILITY (LERF) BASIN 42 STUDIES

Energy Technology Data Exchange (ETDEWEB)

DUNCAN JB

2004-10-29

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

Conjunctive Use of Surface and Groundwater with Inter-Basin Transfer Approach: Case Study Piranshahr Plain

Directory of Open Access Journals (Sweden)

Mahmoud Mohammad Rezapour Tabari

2012-01-01

Full Text Available In IRAN, inconsideration to water as a key sustainable development is the water crisis. This problem is the biggest factor for being marginalize planning and long-term management of water. The sustainable development policies in water resources management of IRAN require consideration of the different aspects of management that each of them required the scientific integrated programs. Optimal operation from inter-basin surface and groundwater resources and transfer surplus water to adjacent basins is important from different aspects. The purpose of this study is to develop an efficient optimization model based on inter-basin water resources and restoration of outer-basin water resources. In the proposed model the different three objective function such as inter-basin water supply demand, reduce the amount of water output of the boundary of IRAN and increase water transfer to adjacent basins are considered. In this model, water allocation is done based on consumption and resources priorities and groundwater table level constrain. In this research, the non-dominate sorting genetic algorithm is used for solution developed model because the objectives function and decision variables are complex and nonlinear. The optimal allocation of each water resources and Water transfer to adjacent basin are can be determined by using of proposed model. Based on optimal value and planning horizon, optimal allocation policy presented. The result as shown that applying the optimal operation policy can be transfer considerable volume of water resources within the basin for restoration the outside basin. Based on policy, can be prevented the great flow of water from river border.

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...

Radial ooids from Great Salt Lake (Utah) as paleoenvironmental archives: Insights from radiocarbon chronology and stable isotopes

Science.gov (United States)

Paradis, O. P.; Corsetti, F. A.; Bardsley, A.; Hammond, D. E.; Xu, X.; Walker, J. C.

2017-12-01

Ooids (laminated, carbonate coated grains) are ubiquitous in the geologic record in marine and lacustrine settings, and thus remain a common target for geochemical analysis to understand modern and ancient aqueous environments. However, the processes governing ooid formation remain unclear. Recently, radiocarbon dating has revealed that modern marine ooids grow slowly (Beaupre et al. 2015), and laboratory experiments have highlighted the importance of sediment transport and abrasion on net growth rates and ooid size (Trower et al. 2017). Ooid cortex structure includes micritic, tangential and/or radially oriented fabrics. Most modern marine ooids have tangential or micritic cortices, whereas many ancient ooids have radial cortices—thus, there is a need to understand how radial ooids in ancient rocks might inform us about their depositional environment. The Great Salt Lake (GSL), Utah, provides a unique environment to assess the growth rate of primary radial aragonitic ooids. Ooids collected near Antelope Island in the south arm of GSL were sieved, the 355-500 µm fraction was sequentially leached, and 14C of the evolved gas was analyzed to provide a time series of growth. The oldest inorganic carbon of this size fraction has an apparent 14C age of 6600 yr BP, with subsequent growth spanning over 6,000 years. Closed-basin lakes are particularly susceptible to a "reservoir effect" which results in anomalously old apparent radiocarbon ages. The 14C age of the modern dissolved inorganic carbon (DIC) of the south arm was measured to be 295 yr BP, a reservoir age comparable to estimates from lacustrine cave carbonates (McGee et al. 2012). Net growth rate of south arm ooids ranges between 0.01-0.025 µm per year. The δ13C of the outermost cortex suggests that the ooids resemble the modern DIC in the south arm water, suggesting ooids precipitate in equilibrium with lake water. Finer-scale structure in the δ13C of the ooid cortex through time suggests lake level changed

A late Eocene palynological record of climate change and Tibetan Plateau uplift (Xining Basin, China)

NARCIS (Netherlands)

Hoorn, C.; Straathof, J.; Abels, H.A.; Xu, Y.; Utescher, T.; Dupont-Nivet, G.

2012-01-01

Climate models suggest that Asian paleoenvironments, monsoons and continental aridification were primarily governed by tectonic uplift and sea retreat since the Eocene with potential contribution of global climate changes. However, the cause and timing of these paleoenvironmental changes remain

Organizing cross-sectoral collaboration in river basin management : Case studies from the Rhine and the Zhujiang (Pearl River) basins

NARCIS (Netherlands)

Silveira, André; Junier, S.J.; Hüesker, Frank; Qunfang, Fan; Rondorf, Andreas

2016-01-01

ABSTRACT: This paper analyses the drivers and constraints for effective cross-sectoral collaboration in river basin management and the extent to which factors identified in related literature determine success or failure of collaboration in selected case studies. Cases selected were from

Abyssal sediment erosion from the Central Indian Basin: Evidence from radiochemical and radiolarian studies

Digital Repository Service at National Institute of Oceanography (India)

Banakar, V.K.; Gupta, S.M.; Padmavati, V.K.

) 167-173 167 Elsevier Science Publishers B.V., Amsterdam Letter Section Abyssal sediment erosion in the Central Indian Basin: Evidence from radiochemical and radiolarian studies V.K. Banakar, S.M. Gupta and V.K. Padmavathi National Institute... of Oceanography, Dona-Paula, Goa-403 004, India (Revision accepted September 17, 1990) ABSTRACT Banakar, V.K., Gupta, S.M. and Padmavathi, V.K., 1991. Abyssal sediment erosion from the Central Indian Basin: Evi- dence from radiochemical and radiolarian studies...

Drowning unconformity of lacustrine rift basins: A case study from the Dongying Sag in Bohai Bay Basin, China

Science.gov (United States)

Chen, R.; Fan, J.

2015-12-01

The concept of drowning unconformity of lacustrine rift basins was proposed in this paper. This paper utilized 3D seismic data, well-log and the principles methods associated with structural geology, sedimentology and geochemistry, to analyze the drowning unconformity and discuss the origins of drowning unconformity in Dongying Sag in Bohai Bay Basin.Researching on it is not only important for a better understanding of tectonic evolution, palaeogeography and sedimentation of hydrocarbon source rocks, but also a vital guiding significance for the exploration of beach-bar sandstone reservoirs and shale oil.1. The concept of drowning unconformity of lacustrine rift basins is defined. With the consequences of rapid tectonic subsidence in basin, the sharp rise of lake-level and the increased rate of accommodation(A) in basin exceeded the rate of sediment supply(S),namely A>>S, the basin suddenly transformed into deep-water settings from shallow-water settings with sudden change of sediment transport and sediment dispersal patterns. 2.The sequence surface between Sha4 and Sha3 Member of Shahejie Formation is the drowning unconformity(43.5Ma). There are the sedimentary association of the reefs in shallow lacustrine, beach-bar sandstones and glutenite fan bodies under the surface. By contrast, there are the sedimentary association of deep-lake oil shales and shales over the surface. The drowning unconformity in Dongying Sag is a tectonic revolution surface which is changed from extensional tectonics to transtensional tectonics and it is also the surface of discontinuity from shallow lacustrine to deep lacustrine. The responses to sudden changes appeared in the parameters of geophysics, geochemistry and paleontology. 3. With the penetration of India into Asia plate in NNE trending,the subduction zones of Pacific Plate retreated. It caused the rapid downwelling of asthenospheric mantle, followed by the extensive drowning unconformity.

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)

Takaki, T.; Rodrigues, R.

1984-01-01

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 13 C 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 13 C 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 13 C between + 3,0 per mille and + 4,0 per mille. According to δ 18 O data, the surface waters were warm, with a tendency of becoming gradually cooler towards the top of the Tertiary. (Author) [pt

Late cenozoic evolution of Fortymile Wash: Major change in drainage pattern in the Yucca Mountain, Nevada region during late miocene volcanism

International Nuclear Information System (INIS)

Lundstrom, S.C.; Warren, R.G.

1994-01-01

The site characterization of Yucca Mountain, NV as a potential high level nuclear waste repository includes study of the surficial deposits as a record of the paleoenvironmental history of the Yucca Mountain region. An important aspect of this history is an understanding of the evolution of paleogeography leading to establishment of the present drainage pattern. Establishment of drainage basin evolution is needed before geomorphic response to paleoclimate and tectonics can be assessed, because a major change in drainage basin geometry can predominantly affect the sedimentary record. Because alluvial aquifers are significant to regional hydrology, a major change in surface drainage resulting in buried alluvium could have hydrogeologic significance. In this paper, we report on geologic evidence for a major modification in surface drainage pattern in the Yucca Mountain region, resulting in the probable establishment of the Fortymile Wash drainage basin by latest Miocene time

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

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......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...

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

International Nuclear Information System (INIS)

Minardi, P.S.P.

1982-10-01

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) [pt

Studies of the suitability of salt domes in east Texas basin for geologic isolation of nuclear wastes

International Nuclear Information System (INIS)

Kreitler, C.W.

1979-01-01

The suitability of salt domes in the east Texas basin (Tyler basin), Texas, for long-term isolation of nulear wastes is being evaluated. The major issues concern hydrogeologic and tectonic stability of the domes and potential natural resources in the basin. These issues are being approached by integration of dome-specific and regional hydrogeolgic, geologic, geomorphic, and remote-sensing investigations. Hydrogeologic studies are evaluating basinal hydrogeology and ground-water flow around the domes in order to determine the degree to which salt domes may be dissolving, their rates of solution, and the orientation of saline plumes in the fresh-water aquifers. Subsurface geologic studies are being conducted: (1) to determine the size and shape of specific salt domes, the geology of the strata immediately surrounding the domes, and the regional geology of the east Texas basin; (2) to understand the geologic history of dome growth and basin infilling; and (3) to evaluate potential natural resources. Geomorphic and surficial geology studies are determining whether there has been any dome growth or tectonic movement in the basin during the Quaternary. Remote-sensing studies are being conducted to determine: (1) if dome uplift has altered regional lineation patterns in Quaternary sediments; and (2) whether drainage density indicates Quaternary structural movement. On the basis of the screening criteria of Brunton et al (1978), Oakwood and Keechi domes have been chosen as possible candidate domes. Twenty-three domes have been eliminated because of insufficient size, too great a depth to salt, major hydrocarbon production, or previous use (such as liquid propane storage or salt mining or brining). Detailed geologic, hydrogeologic, and geomorphic investigations are now being conducted around Oakwood and Keechi salt domes

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

Directory of Open Access Journals (Sweden)

Asghar Roozpeykar

2016-01-01

Full Text Available 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 identification 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 Rupelian–Chattian 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.

An analytical study on groundwater flow in drainage basins with horizontal wells

Science.gov (United States)

Wang, Jun-Zhi; Jiang, Xiao-Wei; Wan, Li; Wang, Xu-Sheng; Li, Hailong

2014-06-01

Analytical studies on release/capture zones are often limited to a uniform background groundwater flow. In fact, for basin-scale problems, the undulating water table would lead to the development of hierarchically nested flow systems, which are more complex than a uniform flow. Under the premise that the water table is a replica of undulating topography and hardly influenced by wells, an analytical solution of hydraulic head is derived for a two-dimensional cross section of a drainage basin with horizontal injection/pumping wells. Based on the analytical solution, distributions of hydraulic head, stagnation points and flow systems (including release/capture zones) are explored. The superposition of injection/pumping wells onto the background flow field leads to the development of new internal stagnation points and new flow systems (including release/capture zones). Generally speaking, the existence of n injection/pumping wells would result in up to n new internal stagnation points and up to 2n new flow systems (including release/capture zones). The analytical study presented, which integrates traditional well hydraulics with the theory of regional groundwater flow, is useful in understanding basin-scale groundwater flow influenced by human activities.

Groundwater quality in the Northern Coast Ranges Basins, California

Science.gov (United States)

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

The Northern Coast Ranges (NOCO) study unit is 633 square miles and consists of 35 groundwater basins and subbasins (California Department of Water Resources, 2003; Mathany and Belitz, 2015). These basins and subbasins were grouped into two study areas based primarily on locality. The groundwater basins and subbasins located inland, not adjacent to the Pacific Ocean, were aggregated into the Interior Basins (NOCO-IN) study area. The groundwater basins and subbasins adjacent to the Pacific Ocean were aggregated into the Coastal Basins (NOCO-CO) study area (Mathany and others, 2011).

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

Science.gov (United States)

Wu, Ya; Wang, Yanxin

2014-05-01

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

Controlled Source Audio Magneto Telluric (CSAMT) studies for uranium exploration in Durgi area, Palnad sub-basin, Cuddapah basin, India

International Nuclear Information System (INIS)

Kumar, Indresh; Kumar, S. Vijaya; Ramesh Babu, V.; Kumar, B.V.L.; Dash, J.K.; Chaturvedi, A.K.

2017-01-01

Cuddapah basin is known for hosting unconformity proximal uranium deposits viz., Lambapur, Peddagattu, Chitirial and Koppunuru along the northern margin of the basin. It is well known that these deposits are mostly associated with basement granitoids in Srisailam Sub-basin, and with cover sediments in Palnad subbasin where basement topography and fault/fracture system influence the fluid flow causing basement alteration and ore deposition. Geological setup, surface manifestation of uranium anomalies and association of the hydro-uranium anomalies near Durgi area in southern part of the Palnad sub-basin, have prompted detail investigation by geophysical methods to probe greater depths. Controlled Source Audio Magneto Telluric (CSAMT) survey conducted over five decades of frequency (0.1-9600 Hz) delineated the various lithounits of Kurnool and Nallamalai Groups along with their thicknesses as there exist an appreciable resistivity contrast. Interpretation of CSAMT sounding data are constrained by resistivity logs and litholog data obtained from the boreholes drilled within the basin indicated three to four layered structure. Sub-surface 2-D and 3-D geo-electrical models are simulated by stitching 1-D layered inverted resistivity earth models. Stitched 1-D inverted resistivity sections revealed the unconformity between the Kurnool Group and Nallamalai Group along with basement undulations. The faults/fractures delineated from the CSAMT data corroborated well with the results of gravity data acquired over the same area. Simulated 3-D voxel resistivity model helped in visualising the faults/fractures, their depth extent, thickness of the Banganapalle quartzite and basement configuration. Integrated interpretation of CSAMT, gravity and borehole data facilitated in delineating the unconformity and the structural features favourable for uranium mineralisation in deeper parts of the Palnad sub-basin. (author)

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

Directory of Open Access Journals (Sweden)

A. Parhizkari

2016-03-01

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

A promising location in Patagonia for paleoclimate and paleoenvironmental reconstructions revealed by shallow firn core from Monte San Valentin (Northern patagonia Icefield, Chile)

DEFF Research Database (Denmark)

Vimeux, F.; de Angelis, M.; Ginot, P.

2008-01-01

temperature is -11.9°C at 10-m depth allowing to expect well preserved both chemical and isotopic signals, unperturbed by water percolation. The dating of the core, on the basis of a multi-proxy approach combining annual layer counting and radionuclide measurements, shows that past environment and climate can......The study of past climate variability from ice core investigations has been largely developed both in polar areas over the past decades and, more recently, in tropical regions, specifically along the South American Andes between 0° and 20°S. However a large gap still remains at mid......-latitudes in the Southern Hemisphere. In this framework, a 15.3-m long shallow firn core has been extracted in March 2005 from the summit plateau of Monte San Valentín (3747 m, 46°35'S, 73°19'W) in the Northern Patagonia Icefield to test its potential for paleoclimate and paleoenvironmental reconstructions. The firn...

Superposition of tectonic structures leading elongated intramontane basin: the Alhabia basin (Internal Zones, Betic Cordillera)

Science.gov (United States)

Martínez-Martos, Manuel; Galindo-Zaldivar, Jesús; Martínez-Moreno, Francisco José; Calvo-Rayo, Raquel; Sanz de Galdeano, Carlos

2017-10-01

The relief of the Betic Cordillera was formed since the late Serravallian inducing the development of intramontane basins. The Alhabia basin, situated in the central part of the Internal Zones, is located at the intersection of the Alpujarran Corridor, the Tabernas basin, both trending E-W, and the NW-SE oriented Gádor-Almería basin. The geometry of the basin has been constrained by new gravity data. The basin is limited to the North by the Sierra de Filabres and Sierra Nevada antiforms that started to develop in Serravallian times under N-S shortening and to the south by Sierra Alhamilla and Sierra de Gádor antiforms. Plate convergence in the region rotated counter-clockwise in Tortonian times favouring the formation of E-W dextral faults. In this setting, NE-SW extension, orthogonal to the shortening direction, was accommodated by normal faults on the SW edge of Sierra Alhamilla. The Alhabia basin shows a cross-shaped depocentre in the zone of synform and fault intersection. This field example serves to constrain recent counter-clockwise stress rotation during the latest stages of Neogene-Quaternary basin evolution in the Betic Cordillera Internal Zones and underlines the importance of studying the basins' deep structure and its relation with the tectonic structures interactions.

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

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

River water quality assessment using environmentric techniques: case study of Jakara River Basin.

Science.gov (United States)

Mustapha, Adamu; Aris, Ahmad Zaharin; Juahir, Hafizan; Ramli, Mohammad Firuz; Kura, Nura Umar

2013-08-01

Jakara River Basin has been extensively studied to assess the overall water quality and to identify the major variables responsible for water quality variations in the basin. A total of 27 sampling points were selected in the riverine network of the Upper Jakara River Basin. Water samples were collected in triplicate and analyzed for physicochemical variables. Pearson product-moment correlation analysis was conducted to evaluate the relationship of water quality parameters and revealed a significant relationship between salinity, conductivity with dissolved solids (DS) and 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and nitrogen in form of ammonia (NH4). Partial correlation analysis (r p) results showed that there is a strong relationship between salinity and turbidity (r p=0.930, p=0.001) and BOD5 and COD (r p=0.839, p=0.001) controlling for the linear effects of conductivity and NH4, respectively. Principal component analysis and or factor analysis was used to investigate the origin of each water quality parameter in the Jakara Basin and identified three major factors explaining 68.11 % of the total variance in water quality. The major variations are related to anthropogenic activities (irrigation agricultural, construction activities, clearing of land, and domestic waste disposal) and natural processes (erosion of river bank and runoff). Discriminant analysis (DA) was applied on the dataset to maximize the similarities between group relative to within-group variance of the parameters. DA provided better results with great discriminatory ability using eight variables (DO, BOD5, COD, SS, NH4, conductivity, salinity, and DS) as the most statistically significantly responsible for surface water quality variation in the area. The present study, however, makes several noteworthy contributions to the existing knowledge on the spatial variations of surface water quality and is believed to serve as a baseline data for further studies. Future

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)

1998-01-01

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

New tropical carcharhinids (chondrichthyes, carcharhiniformes) from the late Eocene early Oligocene of Balochistan, Pakistan: Paleoenvironmental and paleogeographic implications

Science.gov (United States)

Adnet, S.; Antoine, P.-O.; Hassan Baqri, S. R.; Crochet, J.-Y.; Marivaux, L.; Welcomme, J.-L.; Métais, G.

2007-04-01

New selachians (sharks and rays) have been collected from several late Eocene and early Oligocene marine localities in the Bugti Hills (Balochistan, Pakistan). Two new species of Requiem sharks (close to the Recent "Bull shark") are described : Carcharhinus balochensis and Carcharhinus perseus. The rest of the fauna is notable for the strong representation of Carcharhiniformes. These selachian faunas represent a unique tropical association for the Oligocene period and one of the first modern tropical selachian faunas, with modern taxa such as the two new species of "Bull sharks", Negaprion sp. and one of the first occurrences of Sphyrna sp. Moreover, these faunas permit paleoenvironmental interpretation of adjacent land masses. The relatively modern aspect of these faunas, compared with other contemporaneous and younger selachian associations from Atlantic and Mediterranean seas, suggests biogeographic isolation of selachian communities living in eastern and western parts of the Tethys before its final closure during the early-middle Miocene.

Preliminary results on quaternary studies from Bajestan Basin (Kavir-e Namak), Iran

Science.gov (United States)

Majid Padashi, Seyed; Büdel, Christian; Ullmann, Tobias; Tintrup, Angela; Baumhauer, Roland

2017-04-01

The increasing population and demand for developing infrastructures on the one hand, and the recent issues on water and air quality on the other hand, in addition to droughts and the shrinking of many wetlands and lakes, have encouraged Iran recently to invest more in palaeoenvironmental research - specifically on quaternary basins. Preliminary results of our study through field work, satellite imagery processing, SRTM data analysis and drilling, have created new insights on the Iranian playas and the history of the lakes. A combined geological and geomorphological approach for studying young lakes and playas of Iran has led to the identification of at least five major types of lakes and playas in different parts of Iran; for example the Bajestan basin which ranks the second biggest playa of Iran, is placed in the edge of the central Iranian microplate and Lut structural block. The Bajestan Playa (Kavir-e Namak) is surrounded by cretaceous limestones in the south and Paleozoic formations in the north. The basin comprises several kinds of quaternary deposits including sand dunes and Aeolian deposits, fluvial sediments, alluvial fans and lake sediments. The aeolian activity in the basin is primarily shaping landforms in the southwest and the north of the area. The major fluvial activity is considered to be driven from east and south of the playa. The integration of field observations and data derived from the analysis of SRTM digital elevation model (90m) and Landsat satellite imagery shows that the major part of the playa has flat slope. In addition, the morphometric assessment and the hydrological modelling showed that the major current alluvial channels have SW/NE trend with the highest density and intensity of activity in south west of the basin. The major alluvial deposits in the north and south of the playa represent a dissimilar geomorphology. While the northern part of the basin, from the rock unit outcrops to the edge of playa, is occupied by a narrow

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

Science.gov (United States)

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

2013-01-01

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

Regional study is the next important stage in evaluation of oil and gas industry potential of sedimentary basins of Western Kazakhstan

Directory of Open Access Journals (Sweden)

D.K. Azhgaliev

2018-03-01

Full Text Available The article presents the general state of exploration and regional geotectonic characteristics of the structure of the basins of Western Kazakhstan (the Caspian Basin, Ustyurt-Bozashi and Mangyshlak. Principal results of regional studies carried out on the «Comprehensive study of sedimentary basins of the Republic of Kazakhstan» project for 2009-2013 are given. Based on this, topical issues in the study of the deep structure of basins are emphasized, from the perspective of further assessment of the forecasted hydrocarbon potential. In accordance with the new deep drilling data (5.5-7.0 km and more in recent years, the importance and necessity of specifying the structure and high prospects of the Paleozoic deposits are substantiated. In this regard, it is stated that it is advisable to post a parametric well in the future with an anomalous projected depth (14-15 km in the central part of the Caspian Basin (Eurasia Project. Also, the program of regional studies (geotraverses and 2D seismic profiles on the most important geological «cuttings» from the sides of the Caspian basin to the center, the zones of its articulation with the other basins that apply in the south, was considered. The characteristic of the problems solved by the program of regional study of the basins of Western Kazakhstan is given.

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

International Nuclear Information System (INIS)

Zhang Zhenqiang; Li Guokuan; Zhao Zonghua; Zhang Jingxun

2001-01-01

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

A framework model for water-sharing among co-basin states of a river basin

Science.gov (United States)

Garg, N. K.; Azad, Shambhu

2018-05-01

A new framework model is presented in this study for sharing of water in a river basin using certain governing variables, in an effort to enhance the objectivity for a reasonable and equitable allocation of water among co-basin states. The governing variables were normalised to reduce the governing variables of different co-basin states of a river basin on same scale. In the absence of objective methods for evaluating the weights to be assigned to co-basin states for water allocation, a framework was conceptualised and formulated to determine the normalised weighting factors of different co-basin states as a function of the governing variables. The water allocation to any co-basin state had been assumed to be proportional to its struggle for equity, which in turn was assumed to be a function of the normalised discontent, satisfaction, and weighting factors of each co-basin state. System dynamics was used effectively to represent and solve the proposed model formulation. The proposed model was successfully applied to the Vamsadhara river basin located in the South-Eastern part of India, and a sensitivity analysis of the proposed model parameters was carried out to prove its robustness in terms of the proposed model convergence and validity over the broad spectrum values of the proposed model parameters. The solution converged quickly to a final allocation of 1444 million cubic metre (MCM) in the case of the Odisha co-basin state, and to 1067 MCM for the Andhra Pradesh co-basin state. The sensitivity analysis showed that the proposed model's allocation varied from 1584 MCM to 1336 MCM for Odisha state and from 927 to 1175 MCM for Andhra, depending upon the importance weights given to the governing variables for the calculation of the weighting factors. Thus, the proposed model was found to be very flexible to explore various policy options to arrive at a decision in a water sharing problem. It can therefore be effectively applied to any trans-boundary problem where

Towards a digital watershed, with a case study in the Heihe River Basin of northwest China

Science.gov (United States)

Li, X.; Cheng, G.-D.; Ma, M.-G.; Lu, L.; Ge, Y.-C.

2003-04-01

Integrated watershed study and river basin management needs integrated database and integrated hydrological and water resource models. We define digital watershed as a web-based information system that integrates data from different sources and in different scales through both information technology and hydrological modeling. In the last two years, a “digital basin” of the Heihe River Basin, which is a well-studied in-land catchment in China’s arid region was established. More than 6 Gb of in situ observation data, GIS maps, and remotely sensed data have been uploaded to the Heihe web site. Various database and dynamic web techniques such as PHP, ASP, XML, VRML are being used for data service. In addition, the DIAL (Data and Information Access Link), IMS (Internet Map Server) and other Web-GISs are used to make GIS and remote sensing datasets of the Heihe River Basin available and accessible on the Internet. We also have developed models for estimating the evapotranspiration, bio-physical parameters, and snow runoff. These methods can be considered as the elements to build up the integrated watershed model that can be used for integrated management of the Heihe River Basin. The official domain name of the digital Heihe River Basin is heihe.westgis.ac.cn

Hydrological Process Simulation of Inland River Watershed: A Case Study of the Heihe River Basin with Multiple Hydrological Models

OpenAIRE

Lili Wang; Zhonggen Wang; Jingjie Yu; Yichi Zhang; Suzhen Dang

2018-01-01

Simulating the hydrological processes of an inland river basin can help provide the scientific guidance to the policies of water allocation among different subbasins and water resource management groups within the subbasins. However, it is difficult to simulate the hydrological processes of an inland river basin with hydrological models due to the non-consistent hydrological characteristics of the entire basin. This study presents a solution to this problem with a case study about the hydrolo...

Basalt stratigraphy - Pasco Basin

International Nuclear Information System (INIS)

Waters, A.C.; Myers, C.W.; Brown, D.J.; Ledgerwood, R.K.

1979-10-01

The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

The Use of Isotope Techniques to Separate of Hydrography Components. Case Study: Ankara-Guvenc Basin

International Nuclear Information System (INIS)

Tekeli, Y.I.; Sorman, A.U.; Sayin, M.

2002-01-01

In this research, a stable environmental isotope study was carried out from analysis of water samples collected from rainfall, runoff (total discharge), springs (subsurface flows), and wells (ground waters)in Ankara-Guevenc basin having a drainage area of about 16.125 km 2 between 1996-2000. The aim of the study was to investigate the rainfall-runoff relationship for the basin. Recorded total ten discharge hydrographs are separated to their components using stable isotopes (Oxygen-18, Deuterium) contents. Among these samples, unit hydrographs from two one-peak storm hydrographs were derived using both isotope and graphical methods, and the derived unit hydrographs values including peaks were compared. Peak values of 10 and 20 minutes unit hydrographs of the basin derived by using isotope method (Q p = 1322 1/s and Q p = 1327 l/s) are compared with those of graphical method (Q p = 1656 1/s, and Q p = 1250 1/s) using Barnes semi-log approach. It was found out that, the contribution of subsurface flow which is component of total discharge hydrograph and originating from various sub layers are important in the total flow of basin using isotope method of approach

Western Gas Sands Project. Quarterly Basin Activities Report

Energy Technology Data Exchange (ETDEWEB)

Atkinson, C H

1979-01-31

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

Study of Mechanisms for Development and Strengthening of Water User Cooperatives (Case Study of Aras River Basin): Application of AHP Method

OpenAIRE

Rohallah maghabl

2014-01-01

Water user cooperatives were formed due to consideration to people's empowerment and participation in water investment and management. The purpose of this study was to investigate the mechanisms of development and strengthening of water user cooperatives in the Aras River Basin. The study population consisted of the management board members of the water user cooperatives in the Aras Basin in the year 2012. Respondents were selected by purposeful stratified sampling method. Having the data col...

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

International Nuclear Information System (INIS)

Senguji, F.H.

1999-01-01

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)

The Minorca Basin: a buffer zone between the Valencia and Liguro-Provençal Basins (NW Mediterranean Sea)

Science.gov (United States)

Pellen, Romain; Aslanian, Daniel; Rabineau, Marina; Leroux, Estelle; Gorini, Christian; Silenziario, Carmine; Blanpied, Christian; Rubino, Jean-Loup

2017-04-01

The present-day compartmented Mediterranean physiography is inherited from the last 250 Ma kinematic plate evolution (Eurasian, Africa, Iberic and Nubia plates) which implied the formation of orogenic chains, polyphased basins, and morphological - geodynamic thresholds. The interactions between these entities are strongly debated in the North-Western Mediterranean area. Several Neogene reconstructions have been proposed for the Valencia basin depending of the basin segmentation where each model imply a different subsidence, sedimentary, and palaeo-environmental evolution. Our study propose a new kinematic model for the Valencia Basin (VB) that encompasses the sedimentary infill, vertical movement and basin segmentation. Detailed analyses of seismic profiles and boreholes in the VB reveal a differentiated basin, the Minorca Basin (MB), lying between the old Mesozoic Valencia Basin sensu strico (VBss) and the young Oligocene Liguro-Provencal Basin (LPB) (Pellen et al., 2016). The relationship between these basins is shown through the correlation of four Miocene-to-present-day megasequences. The Central and North Balearic Fracture Zones (CFZ and NBFZ) that border the MB represent two morphological and geodynamical thresholds that created an accommodation in steps between the three domains. Little to no horizontal Neogene movements have been found for the Ibiza and Majorca Islands and imply a vertical "sag" subsidence. In contrast, the counterclockwise movement of the Corso-Sardinian blocks induced a counterclockwise movement of the Minorca block towards the SE along the CFZ and NBFZ, during the exhumation of lower continental crust in the LPB. The South-Eastward Minorca block translation stops when the first atypical oceanic crust occurs. The influence of the Neogene Betic compressional phase is thus limited to the VBss on the basis of a different MB origin. This new understanding places the AlKaPeCa blocks northeastward of the present-day Alboran Area. Both NW-SE and

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

Science.gov (United States)

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

2010-05-01

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

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

International Nuclear Information System (INIS)

Xia Yuliang; Zhu Jiechen; Zheng Maogong; Zhao Yunlong; Hu Zhenduo; Guo Xiuying; Gao Shangkui

1994-11-01

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.)

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

International Nuclear Information System (INIS)

Godarzi, M.

2000-01-01

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

Continental and Marine Environmental changes in Europe induced by Global Climate variability and Regional Paleogeography Changes

OpenAIRE

Popescu , Speranta - Maria

2008-01-01

version originale; My PhD and post-doctorate researches have focused on paleoclimatic, paleogeographical and paleoenvironmental reconstruction of the Mediterranean Basin and its adjacent seas (i.e. the residual former Paratethys) since 11 Ma. During this time-interval the Mediterranean marine and continental environments were affected by significant paleogeographic changes, forced by global climate and sea-level variability, plate tectonics and regional uplift of Alps s.l. and Carpathians. Tw...

Tsunami Induced Resonance in Enclosed Basins; Case Study of Haydarpasa Port In Istanbul

Science.gov (United States)

Kian, Rozita; Cevdet Yalciner, Ahmet; Zaytsev, Andrey; Aytore, Betul

2015-04-01

Coincidence of the frequency of forcing mechanisms and the natural frequency of free oscillations in the harbors or basins leads to formation of resonance oscillations and additional amplifications in the basins. This phenomenon becomes much more critical when it is caused by a tsunamis. In the cases of tsunami induced basin resonances, the wave amplifications may occur with more and unexpected damages. The harbor resilience against the marine hazards is important for the performance and success of recovery operations. Classifying the tsunami effects on the ports and harbors and on their functions is the main concern of this study. There are two types of impacts; direct impacts including structural damages due to strong currents, high water elevation and indirect ones because of basin resonance expose to seiche oscillations. The sea of Marmara has experienced numerous (more than 30) tsunamis in history where a highly populated metropolitan city Istanbul is located at North coast of Maramara sea. There are numerous ports and harbors located at Istanbul Coast. Haydarpasa port (41.0033 N, 29.0139 E) in Istanbul coast near Marmara sea, as a case study is selected to test its resilience under tsunami attack by numerical experiments. There are two breakwaters in Haydarpasa port with total length of three kilometers and the shape of basins are regular. Applying numerical model (NAMI DANCE) which solves nonlinear form of shallow water equations, the resonance oscillations in Haydarpasa Port is investigated by following the method given in Yalciner and Pelinovsky, (2006). In the applications, high resolution bathymetry and topography are used and an initial impulse is inputted to the study domain in the simulations. The computed time histories of water surface fluctuations at different locations inside the harbor are analyzed by using Fast Fourier Transform technique. The frequencies where the peaks of spectrum curves indicates the amplification of waves in the respective

The Central European Permian Basins; Rheological and structural controls on basin history and on inter-basin connectivity

NARCIS (Netherlands)

Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

2014-01-01

We analyse the relative importance of the major crustal-scale fault zones and crustal architecture in controlling basin formation, deformation and the structural connections between basins. The North and South Permian Basins of Central Europe are usually defined by the extend of Rotliegend

Overview of the regional geology of the Paradox Basin Study Region

International Nuclear Information System (INIS)

1983-03-01

The Geologic Project Manager for the Paradox Basin Salt Region (PBSR), Woodward-Clyde Consultants, has conducted geologic studies to characterize the region and evaluate selected geologic formations as potential repositories for the storage and disposal of nuclear waste. Evaluations have been made from the standpoint of engineering feasibility, safety, public health, and resource conflicts. The Regulatory Project Manager for the PBSR, Bechtel National, Inc., has performed environmental characterizations to ensure that data on ecological, socioeconomic, and other environmental factors required by the National Environmental Policy Act of 1969 are considered. This report characterizes, at a regional overview level of detail, the Paradox Basin Study Region Geology. Information sources include the published literature, field trip guidebooks, open file data of the US Geological Survey (USGC) and Utah Geologic and Mineral Survey, university theses, Geo-Ref Computer Search, and various unpublished sources of subsurface data such as well logs. Existing information has been synthesized and characterized. No field work was conducted as part of this study. Where possible, attempts were made to evaluate the data. All results of this study are subject to change as more data become available

Application of organic facies in sedimentological-stratigraphical model of the Oligo-Miocene and Miocene of the Campos Basin; Aplicacao da faciologia organica no modelo sedimentologico-estratigrafico do Oligo-Mioceno e Mioceno da Bacia de Campos

Energy Technology Data Exchange (ETDEWEB)

Mendonca Filho, Joao Graciano; Mendonca, Joalice de Oliveira; Oliveira, Antonio Donizeti de; Torres, Jaqueline [Universidade Federal do Rio de Janeiro (UFRJ). Centro de Ciencias Exatas e da Natureza. Inst. de Geociencias (Brazil)], e-mails: graciano@geologia.ufrj.br, donizeti@lafo.geologia.ufrj.br, joalice@lafo.geologia.ufrj.br, jaqueline@lafo.geologia.ufrj.br; Menezes, Taissa Rego [Centro de Pesquisas da Petrobras (CENPES), RJ (Brazil). P e D em Geociencias. Gerencia de Geoquimica], e-mail: taissamenezes@petrobras.com.br; Santos, Viviane Sampaio Santiago dos; Arienti, Luci Maria [Centro de Pesquisas da Petrobras (CENPES), RJ (Brazil). P e D em Geociencias. Gerencia de Sedimentologia e Estratigrafia], e-mails: vsss@petrobras.com.br, arienti@petrobras.com.br

2010-05-15

This study integrates palynofacies analyses and the sedimentological and stratigraphic model of the Oligo-Miocene/Miocene siliciclastic deposits from the stratigraphic interval of the shallow continental platform up to the slope/basin of the Oligo-Miocene/ Miocene of the Campos Basin proposed. The main objective of the palynofacies study was to characterize the particulate sedimentary organic matter to obtain information about the proximal-distal relationship and the sedimentary organic matter preservation and depositional environmental conditions. The 158 core samples collected in 29 wells of the 9 oil production fields (Albacora, Barracuda, Marlim Sul, Marlim, Voador, Marlim Leste, Moreia and Albacora Leste), were studied. This technique provides information about the proximal-distal relationship and the paleoenvironmental conditions of deposition and preservation of sedimentary organic matter, to facilitate the evaluation and comparisons between the associations of particulate organic components. Thus, the palynofacies technique can be used as another tool in the characterization of depositional systems, based on the spatial and temporal distribution of sedimentary intervals. In general the palynofacies assemblages showed the predominance of the Phytoclast Group (terrestrial derived organic matter) at various degradation stages due to the selective preservation process diagnosed in the studied samples. Some samples, revealed high dinocysts percentages indicative of transgressive depositional conditions. From the obtained data, it was possible to characterize the stratigraphic sequences according to the distribution of particulate organic content (e.g. influence of fluvio-deltaic systems, oxygen system, regressive-transgressive tendencies of each sequence). Additional analyses of Total Organic Carbon (% wt) showed the control of the particulate components from the Phytoclast Group on the TOC (% wt) content, suggesting that the relative sea-level variation curves

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

International Nuclear Information System (INIS)

Grant, T.A.

1984-03-01

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

BasinVis 1.0: A MATLAB®-based program for sedimentary basin subsidence analysis and visualization

Science.gov (United States)

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

2016-06-01

Stratigraphic and structural mapping is important to understand the internal structure of sedimentary basins. Subsidence analysis provides significant insights for basin evolution. We designed a new software package to process and visualize stratigraphic setting and subsidence evolution of sedimentary basins from well data. BasinVis 1.0 is implemented in MATLAB®, a multi-paradigm numerical computing environment, and employs two numerical methods: interpolation and subsidence analysis. Five different interpolation methods (linear, natural, cubic spline, Kriging, and thin-plate spline) are provided in this program for surface modeling. The subsidence analysis consists of decompaction and backstripping techniques. BasinVis 1.0 incorporates five main processing steps; (1) setup (study area and stratigraphic units), (2) loading well data, (3) stratigraphic setting visualization, (4) subsidence parameter input, and (5) subsidence analysis and visualization. For in-depth analysis, our software provides cross-section and dip-slip fault backstripping tools. The graphical user interface guides users through the workflow and provides tools to analyze and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the results using the full range of available plot options in MATLAB. We demonstrate all functions in a case study of Miocene sediment in the central Vienna Basin.

The role of Mesozoic sedimentary basin tapers on the formation of Cenozoic crustal shortening structures and foredeep in the western Sichuan Basin, China

Science.gov (United States)

Wang, M.

2017-12-01

The foreland basin records important clues of tectonic and sedimentary process of mountain-building, thus to explore its dynamic mechanism on the formation is an important issue of the mountain-basin interaction. The Longmen Shan fold-and-thrust belt and its adjacent Sichuan basin located in the eastern margin of Tibetan Plateau, are one of the most-concerned regions of studying modern mountain-building and seismic process, and are also a natural laboratory of studying the dynamics of the formation and development of foreland basin. However, it still need further explore on the mechanics of the development of the Cenozoic foreland basin and thrust-belts in the western Sichuan Basin. The Longmen Shan thrust belt has experienced multi-stages of tectonics evolution, foreland basin formation and topography growth since Late Triassic, and whether the early formed basin architecture and large Mesozoic sedimentary basin taper can influence the formation and development of the Cenozoic foreland basin and thrust belts? To solve these issues, this project aim to focus on the Cenozoic foreland basin and internal crustal shortening structures in the western Sichuan basin, on the basis of growth critical wedge taper theory. We will reconstruct the shape of multi-phases of sedimentary basin tapers, the temporal-spatial distribution of crustal shortening and thrusting sequences, and analyze the control mechanism of Mesozoic sedimentary basin taper on the formation of Cenozoic foreland basins, and final explore the interaction between the tectonics geomorphology, stress field and dynamic propagation of foreland basin.

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

International Nuclear Information System (INIS)

Smithson, G.

1993-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Smithson, G [Saskatchewan Research Council, Saskatoon, SK (Canada)

1993-12-01

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.

Model study of the impacts of future climate change on the hydrology of Ganges-Brahmaputra-Meghna (GBM) basin

Science.gov (United States)

Masood, M.; Yeh, P. J.-F.; Hanasaki, N.; Takeuchi, K.

2014-06-01

The intensity, duration, and geographic extent of floods in Bangladesh mostly depend on the combined influences of three river systems, Ganges, Brahmaputra and Meghna (GBM). In addition, climate change is likely to have significant effects on the hydrology and water resources of the GBM basins and might ultimately lead to more serious floods in Bangladesh. However, the assessment of climate change impacts on basin-scale hydrology by using well-constrained hydrologic modelling has rarely been conducted for GBM basins due to the lack of data for model calibration and validation. In this study, a macro-scale hydrologic model H08 has been applied regionally over the basin at a relatively fine grid resolution (10 km) by integrating the fine-resolution (~0.5 km) DEM data for accurate river networks delineation. The model has been calibrated via analyzing model parameter sensitivity and validated based on a long-term observed daily streamflow data. The impact of climate change on not only the runoff, but also the basin-scale hydrology including evapotranspiration, soil moisture and net radiation have been assessed in this study through three time-slice experiments; present-day (1979-2003), near-future (2015-2039) and far-future (2075-2099) periods. Results shows that, by the end of 21st century (a) the entire GBM basin is projected to be warmed by ~3°C (b) the changes of mean precipitation are projected to be +14.0, +10.4, and +15.2%, and the changes of mean runoff to be +14, +15, and +18% in the Brahmaputra, Ganges and Meghna basin respectively (c) evapotranspiration is predicted to increase significantly for the entire GBM basins (Brahmaputra: +14.4%, Ganges: +9.4%, Meghna: +8.8%) due to increased net radiation (Brahmaputra: +6%, Ganges: +5.9%, Meghna: +3.3%) as well as warmer air temperature. Changes of hydrologic variables will be larger in dry season (November-April) than that in wet season (May-October). Amongst three basins, Meghna shows the largest hydrological

Paleogeography of the Central Asian proto-Paratethys Sea in the Eocene: Controlling mechanisms and paleoenvironmental impacts

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

Basin Analysis and Petroleum System Characterisation of Western Bredasdorp Basin, Southern Offshore of South Africa: Insights from a 3d Crust-Scale Basin Model - (Phase 1)

Science.gov (United States)

Sonibare, W. A.; Scheck-Wenderoth, M.; Sippel, J.; Mikeš, D.

2012-04-01

In recent years, construction of 3D geological models and their subsequent upscaling for reservoir simulation has become an important tool within the oil industry for managing hydrocarbon reservoirs and increasing recovery rate. Incorporating petroleum system elements (i.e. source, reservoir and trap) into these models is a relatively new concept that seems very promising to play/prospect risk assessment and reservoir characterisation alike. However, yet to be fully integrated into this multi-disciplinary modelling approach are the qualitative and quantitative impacts of crust-scale basin dynamics on the observed basin-fill architecture and geometries. The focus of this study i.e. Western Bredasdorp Basin constitutes the extreme western section of the larger Bredasdorp sub-basin, which is the westernmost depocentre of the four southern Africa offshore sub-basins (others being Pletmos, Gamtoos and Algoa). These basins, which appear to be initiated by volcanically influenced continental rifting and break-up related to passive margin evolution (during the Mid-Late Jurassic to latest Valanginian), remain previously unstudied for crust-scale basin margin evolution, and particularly in terms of relating deep crustal processes to depo-system reconstruction and petroleum system evolution. Seismic interpretation of 42 2D seismic-reflection profiles forms the basis for maps of 6 stratigraphic horizons which record the syn-rift to post-rift (i.e. early drift and late drift to present-day seafloor) successions. In addition to this established seismic markers, high quality seismic profiles have shown evidence for a pre-rift sequence (i.e. older than Late Jurassic >130 Ma). The first goal of this study is the construction of a 3D gravity-constrained, crust-scale basin model from integration of seismics, well data and cores. This basin model is constructed using GMS (in-house GFZ Geo-Modelling Software) while testing its consistency with the gravity field is performed using IGMAS

Miocene block uplift and basin formation in the Patagonian foreland: The Gastre Basin, Argentina

Science.gov (United States)

Bilmes, A.; D'Elia, L.; Franzese, J. R.; Veiga, G. D.; Hernández, M.

2013-08-01

The intraplate fault-block mountains and intermontane deposits of the Gastre Basin, which are recorded more than 550 km east of the Andean trench in central Patagonia, Argentina, are analyzed. The Gastre Basin is one of the largest Patagonian intermontane basins, limited by uplifted blocks strongly oblique to the Andean chain. It was originated by reverse faulting and inversion of pre-existing normal faults associated with a Mesozoic rift basin and defined by older crustal heterogeneities. The deformational event occurred during the middle Miocene, related to a short contractional episode (16.1-14.86 Ma), probably in response to an eastward migration of the Andean fold and thrust belt. During Pliocene to Quaternary times, neither younger fault-block uplifts nor reconfigurations of the basin occurred. Similarities between the study area and other parts of the Patagonian foreland - such as the presence of Miocene reverse or inversion tectonics, as well as the accommodation of the Miocene sedimentary successions - suggest that the Gastre Basin is part of a major late early to middle Miocene broken foreland system (i.e. the Patagonian broken foreland) that exhumed discrete fault-block mountains and generated contemporary basins along more than 950 km parallel to the Andean trench (i.e. between 40°00' and 48°00' south latitude). Based on recent studies on the southern Andean Margin, this continental-scale contractional episode may be the result of a flat-slab subduction segment. Nevertheless, such a hypothesis is very difficult to support when analyzing such a large flat subduction segment along the entire Patagonian trench. This suggests the need to consider alternative flat-slab trigger mechanisms or other factors in the generation of broken foreland systems.

Spatial Preference Heterogeneity for Integrated River Basin Management: The Case of the Shiyang River Basin, China

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Fanus Asefaw Aregay

2016-09-01

Full Text Available Integrated river basin management (IRBM programs have been launched in most parts of China to ease escalating environmental degradation. Meanwhile, little is known about the benefits from and the support for these programs. This paper presents a case study of the preference heterogeneity for IRBM in the Shiyang River Basin, China, as measured by the Willingness to Pay (WTP, for a set of major restoration attributes. A discrete choice analysis of relevant restoration attributes was conducted. The results based on a sample of 1012 households in the whole basin show that, on average, there is significant support for integrated ecological restoration as indicated by significant WTP for all ecological attributes. However, residential location induced preference heterogeneities are prevalent. Generally, compared to upper-basin residents, middle sub-basin residents have lower mean WTP while lower sub-basin residents express higher mean WTP. The disparity in utility is partially explained by the difference in ecological and socio-economic status of the residents. In conclusion, estimating welfare benefit of IRBM projects based on sample responses from a specific sub-section of the basin only may either understate or overstate the welfare estimate.

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

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

International Nuclear Information System (INIS)

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

SimBasin: serious gaming for integrated decision-making in the Magdalena-Cauca basin

Science.gov (United States)

Craven, Joanne; Angarita, Hector; Corzo, Gerald

2016-04-01

discussed, such as using the game in planning processes and to engage local communities. The game has been beta tested at a modelling workshop in Bangkok and was then used as the basis of a national basin management forum in Bogotá. 42 high-level stakeholders attended and the session generated a great deal of interest in the decision support system, and served as a nucleus for different stakeholders to discuss ideas. The study discusses the development of the game and observations from these sessions. More information: http://simbasin.hilab.nl

Characteristic mega-basin water storage behavior using GRACE.

Science.gov (United States)

Reager, J T; Famiglietti, James S

2013-06-01

[1] A long-standing challenge for hydrologists has been a lack of observational data on global-scale basin hydrological behavior. With observations from NASA's Gravity Recovery and Climate Experiment (GRACE) mission, hydrologists are now able to study terrestrial water storage for large river basins (>200,000 km 2 ), with monthly time resolution. Here we provide results of a time series model of basin-averaged GRACE terrestrial water storage anomaly and Global Precipitation Climatology Project precipitation for the world's largest basins. We address the short (10 year) length of the GRACE record by adopting a parametric spectral method to calculate frequency-domain transfer functions of storage response to precipitation forcing and then generalize these transfer functions based on large-scale basin characteristics, such as percent forest cover and basin temperature. Among the parameters tested, results show that temperature, soil water-holding capacity, and percent forest cover are important controls on relative storage variability, while basin area and mean terrain slope are less important. The derived empirical relationships were accurate (0.54 ≤  E f  ≤ 0.84) in modeling global-scale water storage anomaly time series for the study basins using only precipitation, average basin temperature, and two land-surface variables, offering the potential for synthesis of basin storage time series beyond the GRACE observational period. Such an approach could be applied toward gap filling between current and future GRACE missions and for predicting basin storage given predictions of future precipitation.

Integrated studies of Azraq Basin in Jordan

Science.gov (United States)

Mohammed Shahbaz; B. Sunna

2000-01-01

Many historical indications of the eastern Mediterranean Basin exhibit climatic changes or alterations effecting the status of water resources, hence, effecting human-kind and the quality of life. It is essential to deeply understand the nature of climates and geological structures employing state of the art techniques to assess rainfall, runoff, and floods that...

PALEOENVIRONMENTAL RECONSTRUCTION FROM BENTHIC FORAMINIFERAL ASSEMBLAGES OF EARLY HOLOCENE, SHALLOW MARINE DEPOSITS IN GOMBONG, CENTRAL JAVA

Directory of Open Access Journals (Sweden)

Luli Gustiani

2017-07-01

Full Text Available A 30m-long sediment core covering the Holocene period was taken from the area of Gombong in the southern part of Central Java. The sediments were deposited in a shallow marine to lagoonal environment that was confirmed by the dominance of Ammonia beccarii along the core intervals. In addition, the species Quinqueloculina poeyana, Miliolinella lakemacquariensis, and Miliolinella subrotunda were also found in the sediments that are typical of normal shallow marine conditions. The decrease and increase in the abundance of these species throughout the core is an expression of sea level change in the area, which results the environmental changes. Low sea level is expressed by the dominance of Ammonia beccarii, and the low abundances or absence of the other three species. In contrast, high sea level stands are reflected by the presence of all four species. The high sea level would imply favorable conditions for benthic foraminifera because it would result in normal shallow marine conditions in the area. Finally, from this benthic assemblages study, it can be assumed that the environmental transformation from the originally shallow marine environment into land was occurred at level 5.5m depths of the sediment core, when all benthic foraminifera were terminated, including Ammonia beccarii. These new results from the shallow marine deposits in the Gombong area are a new contribution to the understanding of paleoenvironmental change in the region, which in turn is important for understanding sea level change as well as climate change in the region.

Active intra-basin faulting in the Northern Basin of Lake Malawi from seismic reflection data

Science.gov (United States)

Shillington, D. J.; Chindandali, P. R. N.; Scholz, C. A.; Ebinger, C. J.; Onyango, E. A.; Peterson, K.; Gaherty, J. B.; Nyblade, A.; Accardo, N. J.; McCartney, T.; Oliva, S. J.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

2016-12-01

Many questions remain about the development and evolution of fault systems in weakly extended rifts, including the relative roles of border faults and intra-basin faults, and segmentation at various scales. The northern Lake Malawi (Nyasa) rift in the East African Rift System is an early stage rift exhibiting pronounced tectonic segmentation, which is defined by 100-km-long border faults. The basins also contain a series of intrabasinal faults and associated synrift sediments. The occurrence of the 2009 Karonga Earthquake Sequence on one of these intrabasinal faults indicates that some of them are active. Here we present new multichannel seismic reflection data from the Northern Basin of the Malawi Rift collected in 2015 as a part of the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This rift basin is bound on its east side by the west-dipping Livingstone border fault. Over 650 km of seismic reflection profiles were acquired in the Northern Basin using a 500 to 1540 cu in air gun array and a 1200- to 1500-m seismic streamer. Dip lines image a series of north-south oriented west-dipping intra-basin faults and basement reflections up to 5 s twtt near the border fault. Cumulative offsets on intra-basin faults decrease to the west. The largest intra-basin fault has a vertical displacement of >2 s two-way travel time, indicating that it has accommodated significant total extension. Some of these intra-basin faults offset the lake bottom and the youngest sediments by up to 50 s twtt ( 37 m), demonstrating they are still active. The two largest intra-basin faults exhibit the largest offsets of young sediments and also correspond to the area of highest seismicity based on analysis of seismic data from the 89-station SEGMeNT onshore/offshore network (see Peterson et al, this session). Fault patterns in MCS profiles vary along the basin, suggesting a smaller scale of segmentation of faults within the basin; these variations in fault patterns

Study on the characteristics of future precipitation in response to external changes over arid and humid basins.

Science.gov (United States)

Xue, Lianqing; Zhu, Boli; Yang, Changbing; Wei, Guanghui; Meng, Xianyong; Long, Aihua; Yang, Guang

2017-11-09

The simulation abilities of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) models to the arid basin (the Tarim River Basin, TRB) and humid basin (the Yangtze River Basin, YRB) were evaluated, determining the response of precipitation to external changes over typical basins. Our study shows that the future temporal and spatial variation characteristics of precipitation are different in different regions with the CMIP5. The annual and seasonal changes in precipitation were analyzed for the RCP2.6, RCP4.5 and RCP8.5 during 2021~2100 compared to those during 1961~2005. Precipitation shows an increasing trend in the TRB, but which decreases and then increases in the YRB, with a turning point in the middle of twenty-first Century. The ranges in annual precipitation increase with the increase in the scenario emissions in the future. Note that the Tarim River Basin is more vulnerable to the impact of emissions, especially for annual or spring and winter precipitation. Based on the uncertainty of CMIP5 data, the links between future precipitation changes and the elevation and relief amplitude were evaluated. The change of precipitation decreases with elevation, relief amplitude in the TRB, while it increases with elevation but decreases with relief amplitude in the YRB.

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

Science.gov (United States)

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

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

A Basin Approach to a Hydrological Service Delivery System in the Amur River Basin

Directory of Open Access Journals (Sweden)

Sergei Borsch

2018-03-01

Full Text Available This paper presents the basin approach to the design, development, and operation of a hydrological forecasting and early warning system in a large transboundary river basin of high flood potential, where accurate, reliable, and timely available daily water-level and reservoir-inflow forecasts are essential for water-related economic and social activities (the Amur River basin case study. Key aspects of basin-scale system planning and implementation are considered, from choosing efficient forecast models and techniques, to developing and operating data-management procedures, to disseminating operational forecasts using web-GIS. The latter, making the relevant forecast data available in real time (via Internet, visual, and well interpretable, serves as a good tool for raising awareness of possible floods in a large region with transport and industrial hubs located alongside the Amur River (Khabarovsk, Komsomolsk-on-Amur.

Systematic impact assessment on inter-basin water transfer projects of the Hanjiang River Basin in China

Science.gov (United States)

Zhou, Yanlai; Guo, Shenglian; Hong, Xingjun; Chang, Fi-John

2017-10-01

China's inter-basin water transfer projects have gained increasing attention in recent years. This study proposes an intelligent water allocation methodology for establishing optimal inter-basin water allocation schemes and assessing the impacts of water transfer projects on water-demanding sectors in the Hanjiang River Basin of China. We first analyze water demands for water allocation purpose, and then search optimal water allocation strategies for maximizing the water supply to water-demanding sectors and mitigating the negative impacts by using the Standard Genetic Algorithm (SGA) and Adaptive Genetic Algorithm (AGA), respectively. Lastly, the performance indexes of the water supply system are evaluated under different scenarios of inter-basin water transfer projects. The results indicate that: the AGA with adaptive crossover and mutation operators could increase the average annual water transfer from the Hanjiang River by 0.79 billion m3 (8.8%), the average annual water transfer from the Changjiang River by 0.18 billion m3 (6.5%), and the average annual hydropower generation by 0.49 billion kW h (5.4%) as well as reduce the average annual unmet water demand by 0.40 billion m3 (9.7%), as compared with the those of the SGA. We demonstrate that the proposed intelligent water allocation schemes can significantly mitigate the negative impacts of inter-basin water transfer projects on the reliability, vulnerability and resilience of water supply to the demanding sectors in water-supplying basins. This study has a direct bearing on more intelligent and effectual water allocation management under various scenarios of inter-basin water transfer projects.

Challenging Futures Studies To Enhance Participatory River Basin Management

Science.gov (United States)

van der Helm, R.

Can the field of futures research help advance participatory management of river basins? This question is supposed to be answered by the present study of which this paper will mainly address the theoretical and conceptual point of view. The 2000 EU Framework directive on water emphasises at least two aspects that will mark the future management of river basins: the need for long-term planning, and a demand for participation. Neither the former nor the latter are new concepts as such, but its combination is in some sense revolutionary. Can long-term plans be made (and implemented) in a participative way, what tools could be useful in this respect, and does this lead to a satisfactory situation in terms of both reaching physical targets and enhancing social-institutional manageability? A possibly rich way to enter the discussion is to challenge futures research as a concept and a practice for enabling multiple stakeholders to design appropriate policies. Futures research is the overall field in which several methods and techniques (like scenario analysis) are mobilised to systematically think through and/or design the future. As such they have proven to be rich exercises to trigger ideas, stimulate debate and design desirable futures (and how to get there). More importantly these exercises have the capability to reconstitute actor relations, and by nature go beyond the institutional boundaries. Arguably the relation between futures research and the planning process is rather distant. Understandably commitments on the direct implementation of the results are hardly ever made, but its impact on changes in the capabilities of the network of actors involved may be large. As a hypothesis we consider that the distant link between an image of the future and the implementation in policy creates sufficient distance for actors to participate (in terms of responsibilities, legal constraints, etc.) and generate potentials, and enough degrees of freedom needed for a successful

Quantification and Postglacial evolution of an inner alpine sedimentary basin (Gradenmoos Basin, Hohe Tauern)

International Nuclear Information System (INIS)

Götz, J.

2012-01-01

The overall objective of this thesis is the quantification of sediment storage and the reconstruction of postglacial landscape evolution within the glacially overdeepened Gradenmoos Basin (subcatchment size: 4.1 km 2 ; basin floor elevation: 1920 m) in the central Gradenbach catchment (Schober Range, Hohe Tauern, Austrian Alps). Following the approach of denudation-accumulation-systems, most reliable results are obtained (1) if sediment output of a system can be neglected for an established period of time, (2) if sediment storage can be assessed with a high level of accuracy, (3) if the onset of sedimentation and amounts of initially stored sediments are known, and (4) if sediment contributing areas can be clearly delimited. Due to spatial scale and topographic characteristics, all mentioned aspects are fulfilled to a high degree within the studied basin. Applied methods include surface, subsurface and temporal investigations. Digital elevation data is derived from terrestrial laserscanning and geomorphologic mapping. The quantification of sediment storage is based on core drillings, geophysical methods (DC resistivity, refraction seismic, and ground penetrating radar), as well as GIS and 3D modelling. Radiocarbon dating and palynological analyses are additionally used to reconstruct the postglacial infilling progress of the basin. The study reveals that a continuous postglacial stratigraphic record is archived in the basin. As proposed by Lieb (1987) timing of basin deglaciation could be verified to late-Egesen times by means of radiocarbon ages (oldest sample just above basal till: 10.4 ka cal. BP) and first palynologic results. Lateglacial oscillations seem to have effectively scoured the basin, leaving only a shallow layer of basal till. The analysis of postglacial sedimentation in the basin is further improved by the existence of a former lake in the basin lasting for up to 7500 years until approx. 3.7 ka cal. BP. Both, the stratigraphic (fine, partly

Regionalization Study of Satellite based Hydrological Model (SHM) in Hydrologically Homogeneous River Basins of India

Science.gov (United States)

Kumari, Babita; Paul, Pranesh Kumar; Singh, Rajendra; Mishra, Ashok; Gupta, Praveen Kumar; Singh, Raghvendra P.

2017-04-01

A new semi-distributed conceptual hydrological model, namely Satellite based Hydrological Model (SHM), has been developed under 'PRACRITI-2' program of Space Application Centre (SAC), Ahmedabad for sustainable water resources management of India by using data from Indian Remote Sensing satellites. Entire India is divided into 5km x 5km grid cells and properties at the center of the cells are assumed to represent the property of the cells. SHM contains five modules namely surface water, forest, snow, groundwater and routing. Two empirical equations (SCS-CN and Hargreaves) and water balance method have been used in the surface water module; the forest module is based on the calculations of water balancing & dynamics of subsurface. 2-D Boussinesq equation is used for groundwater modelling which is solved using implicit finite-difference. The routing module follows a distributed routing approach which requires flow path and network with the key point of travel time estimation. The aim of this study is to evaluate the performance of SHM using regionalization technique which also checks the usefulness of a model in data scarce condition or for ungauged basins. However, homogeneity analysis is pre-requisite to regionalization. Similarity index (Φ) and hierarchical agglomerative cluster analysis are adopted to test the homogeneity in terms of physical attributes of three basins namely Brahmani (39,033 km km^2)), Baitarani (10,982 km km^2)) and Kangsabati (9,660 km km^2)) with respect to Subarnarekha (29,196 km km^2)) basin. The results of both homogeneity analysis show that Brahmani basin is the most homogeneous with respect to Subarnarekha river basin in terms of physical characteristics (land use land cover classes, soiltype and elevation). The calibration and validation of model parameters of Brahmani basin is in progress which are to be transferred into the SHM set up of Subarnarekha basin and results are to be compared with the results of calibrated and validated

Preliminary study of the uranium potential of the Wadesboro Triassic basin, North Carolina

International Nuclear Information System (INIS)

Thayer, P.A.; Harris, W.B.

1981-11-01

This report presents results of a four-channel spectrometric survey of the Wadesboro Triassic basin and adjacent Piedmont, North and South Carolina. A total of 216 gamma-ray spectrometric measurements was taken at 165 sites in the Wadesboro Basin and at 37 sites in the adjacent Piedmont. The normal sampling density in the Wadesboro Basin is one site per 4.5 km 2 . Surface radiometric surveys reveal no anomalous radioactivity. Estimated uranium concentrations (eU) from the area are from 0.1 to 4.9 ppM. Average eU content of Triassic sandstones is 1.5 ppM, which is nearly the average for adjacent metavolcanic rocks (1.6 ppM). Granitic intrusives of the Pageland and Lilesville plutons display the highest eU concentrations in the area, averaging 3.3 ppM. The uranium/thorium ratio is consistently low throughout the area, from 0.01 to 0.54; the log uranium/log thorium ratio is from -1.11 to a maximum of 0.66. Triassic sandstones have the highest values, averaging 0.25. Granites of the Pageland and Lilesville plutons have an average uranium/thorium ratio of 0.21, and Slate Belt metavolcanic rocks average 0.15. On the basis of surface radiometric surveys and geologic studies, it is believed that sedimentary strata of the Wadesboro Basin are poor targets for further uranium exploration. This conclusion is based on the lack of many favorable characteristics associated with fluvial uranium deposits

Preliminary study of the uranium potential of Tertiary rocks in the central San Juan Basin, New Mexico

International Nuclear Information System (INIS)

Vizcaino, H.P.; O'Neill, A.J.

1977-12-01

Three formations in the Tertiary of the San Juan Basin were investigated for their uranium favorability. They are the Ojo Alamo Sandstone, the Nacimiento Formation, and the San Jose Formation. The study comprised a literature survey and a basin analysis, which consisted of subsurface lithofacies, stratigraphic, and radiometric mapping. Field work in preparation for the subsurface analysis consisted of examination of outcrop and measured sections, surface radiometric traverses, and checking of reported surface radioactive anomalies. Interpretation of subsurface mapping provided the primary basis for favorability assessment. The sandstone trends depicted in lithofacies maps, and stratigraphic cross sections reflect large channel complexes and major fluvial systems originating in favorable source areas. Although surface radioactivity anomalies were found to be few, weak, and widespread, the San Juan Basin has abundant favorable host rocks. The subsurface anomalies, although weak, are widespread and sometimes persist throughout thickness intervals greater than 50 ft. Subsurface anomalies were mapped on a wide-spaced grid and are generalized. On the basis of apparent source, lithology, differential permeability, contents of carbonaceous detritus, and geometry, the Nacimiento Formation and the basal facies of the San Jose Formation in the north-central basin have the greatest potential. The Ojo Alamo Sandstone is less favorable, and the Nacimiento Formation in the southern part of the basin and the upper San Jose Formation are the least favorable of the units studied

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

OpenAIRE

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-01-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second...

Radioecological study of the interest zones in Somes river hydrographic basin

International Nuclear Information System (INIS)

Daraban, L.; Fiat, T.; Znamirovschi, V.; Cosma, C.; Bayer, Marta; Daraban, Laura

2000-01-01

Our research refers to the transfer of radioelements from water and mud to talophitae and unicellular algae organisms. The measurement of these elements was done for delimiting the radioactive zones of interest in the hydrographic basin of Somes. We demonstrated that the algae are biological indicators of the radioactivity in a river basin. A series of samples were examined by high-resolution gamma spectroscopy in our laboratory and at VUB Cyclotron Brussels with a Ge-Re detector for intercomparing. Uranium and its descendants were analyzed, as well as 137 Cs resulting from the Chernobyl fallout, which we found again accumulated in the mud of mountain lakes. A migration of the radionuclides from old barren gangue deposits of old polymetallic mines in the Somes river basin was noticed. (authors)

Paleoecological and paleoenvironmental changes during the continental Middle-Late Permian transition at the SE Iberian Ranges, Spain

Science.gov (United States)

De la Horra, R.; Galán-Abellán, A. B.; López-Gómez, J.; Sheldon, N. D.; Barrenechea, J. F.; Luque, F. J.; Arche, A.; Benito, M. I.

2012-08-01

The Middle and Late Permian are characterized by a pair of mass-extinction events that are recorded in both marine and continental environments. Here, we present the first continental western peri-Tethyan record of an extinction event located in the Middle-Late interval. In the SE Iberian Ranges, Central Spain, the transition between the Lower and Middle subunits of the Middle Permian Alcotas Formation indicates a significant paleoclimatic change from arid and semiarid conditions towards more humid conditions. Coincident with the onset of humid conditions there were changes in the sedimentology, mineralogy, and geochemistry that indicate significant environmental changes including a shift in weathering intensity and a change of fluvial style from braided to meandering systems. Near the top of the Middle Subunit, a local biotic crisis is recorded by palynomorph assemblages. Following this crisis, there is a total absence of coal beds, plant remains, and microflora that defines a barren zone in the uppermost part of the Alcotas Formation which is recorded throughout the basin. The barren zone is accompanied by a shift back to braided stream systems, but not by a return to carbonate-bearing paleosols indicative of arid or semi-arid conditions. This combination of features is consistent with other Middle-Late continental basins related with mass extinctions, so the barren zone is interpreted as the extinction interval. The regional character of the extinction interval and its proximity with the Middle-Late Permian transition could be related with the global mid-Capitanian biotic turnover described in this period of time in other marine basins. However, the common difficulties of dating with precision non-marine rocks make this relationship difficult to probe in the Iberian Basin and in other Middle-Late Permian basins. Further work, including high resolution carbon-isotope analyses and complete studies of the magnetostratigraphy, should be desirable in order to obtain

Eco policy: Environmental Stress and Conflicts in Africa. Case Study of Drainage Basins

International Nuclear Information System (INIS)

Okidi, C.O

1994-01-01

The main cause for African misery is limited supply of water which has a direct impact on agricultural production. The continent of Africa has a reticulation of 54 drainage basins including rivers which either traverse boundaries or form part of such boundaries. These basins cover approximately half of the continent but only 2% of the total water is utilized leaving 98% to replenish the oceans. In future Africa should focus attention on control, apportionment and utilization of the waters of it's drainage basins in order to ameliorate the the problems brought about by scarcity of rainfall and consequent drought and famine. After the drought in the late 1970s and mid-1980s, there has been efforts to control the promising rivers and transfer the water to to centres of agriculture and human settlements and this is likely to cause international conflicts. The author recommends that, in order to control such conflicts the basin states there should be systematic collaboration among the basin states in the management of such waters

Tectonic setting of Cretaceous basins on the NE Tibetan Plateau: Insights from the Jungong basin

Science.gov (United States)

Craddock, W.H.; Kirby, E.; Dewen, Z.; Jianhui, L.

2012-01-01

Quantifying the Cenozoic growth of high topography in the Indo-Asian collision zone remains challenging, due in part to significant shortening that occurred within Eurasia before collision. A growing body of evidence suggests that regions far removed from the suture zone experienced deformation before and during the early phases of Himalayan orogenesis. In the present-day north-eastern Tibetan Plateau, widespread deposits of Cretaceous sediment attest to significant basin formation; however, the tectonic setting of these basins remains enigmatic. We present a study of a regionally extensive network of sedimentary basins that are spatially associated with a system of SE-vergent thrust faults and are now exposed in the high ranges of the north-eastern corner of the Tibetan Plateau. We focus on a particularly well-exposed basin, located ~20km north of the Kunlun fault in the Anyemaqen Shan. The basin is filled by ~900m of alluvial sediments that become finer-grained away from the basin-bounding fault. Additionally, beds in the proximal footwall of the basin-bounding fault exhibit progressive, up-section shallowing and several intraformational unconformities which can be traced into correlative conformities in the distal part of the basin. The observations show sediment accumulated in the basin during fault motion. Regional constraints on the timing of sediment deposition are provided by both fossil assemblages from the Early Cretaceous, and by K-Ar dating of volcanic rocks that floor and cross-cut sedimentary fill. We argue that during the Cretaceous, the interior NE Tibetan Plateau experienced NW-SE contractional deformation similar to that documented throughout the Qinling-Dabie orogen to the east. The Songpan-Ganzi terrane apparently marked the southern limit of this deformation, such that it may have been a relatively rigid block in the Tibetan lithosphere, separating regions experiencing deformation north of the convergent Tethyan margin from regions deforming

Revised paleoenvironmental analysis of the Holocene portion of the Barbados sea-level record: Cobbler's Reef revisited

Science.gov (United States)

Toscano, Marguerite A.

2016-06-01

Sample elevations corrected for tectonic uplift and assessed relative to local modeled sea levels provide a new perspective on paleoenvironmental history at Cobbler's Reef, Barbados. Previously, 14C-dated surface samples of fragmented Acropora palmata plotted above paleo sea level based on their present (uplifted) elevations, suggesting supratidal rubble deposited during a period of extreme storms (4500-3000 cal BP), precipitating reef demise. At several sites, however, A. palmata persisted, existing until ~370 cal BP. Uplift-corrected A. palmata sample elevations lie below the western Atlantic sea-level curve, and ~2 m below ICE-6G-modeled paleo sea level, under slow rates of sea-level rise, negating the possibility that Cobbler's Reef is a supratidal storm ridge. Most sites show limited age ranges from corals likely damaged/killed on the reef crest, not the mixed ages of rubble ridges, strongly suggesting the reef framework died off in stages over 6500 yr. Reef crest death assemblages invoke multiple paleohistoric causes, from ubiquitous hurricanes to anthropogenic impacts. Comparison of death assemblage ages to dated regional paleotempestological sequences, proxy-based paleotemperatures, recorded hurricanes, tsunamis, European settlement, deforestation, and resulting turbidity, reveals many possible factors inimical to the survival of A. palmata along Cobbler's Reef.

A Permian methane seep system as a paleoenvironmental analogue for the pre-metazoan carbonate platforms

Directory of Open Access Journals (Sweden)

Lucas Veríssimo Warren

Full Text Available ABSTRACT: Following the rise of metazoans, the beginning of bioclasticity and substrate competition, the saga of microbial mats was in a fluctuating decline in the end of the Neoproterozoic era. Increases in diversity during the Phanerozoic and punctual upturns in the microbial carbonate production occured after the events of global mass extinctions. Gradually along the Phanerozoic, the microbial colonies occupied isolated niches and grazers-free environments, characterized by physically and/or geochemically stressful conditions, such as those found in saline bays, alkaline lakes and hydrothermal or cold seep vents. Here we report one of the oldest occurrences of a vent camp coupled with cold seepage of methane in the geologic record, associated with well-preserved microbialites and elephant skin structures. During the seep activity, oxygen depletion and high salinity conditions are prohibitive for complex animal life, clearing the way to microbial colonies to flourish. Due to the co-occurrence of high adaptability and low competitiveness of microbial forms, they became highly specialized in stressful conditions. We argue that the sporadic microbial mat upturns in Earth’s history are not restricted to geological periods, following massive death of metazoan species; they also may occur in response to punctual paleoenvironmental conditions that enable microbial colonies to growth. Indeed, the Phanerozoic geological record is punctuated of these examples, in a kind of hide-and-seek game of Precambrian times.

Evapotranspiration seasonality across the Amazon Basin

Science.gov (United States)

Eiji Maeda, Eduardo; Ma, Xuanlong; Wagner, Fabien Hubert; Kim, Hyungjun; Oki, Taikan; Eamus, Derek; Huete, Alfredo

2017-06-01

Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to analyse seasonal patterns in ET and their relationships with water and energy drivers over five sub-basins across the Amazon Basin. We used in situ measurements of river discharge, and remotely sensed estimates of terrestrial water storage, rainfall, and solar radiation. We show that the characteristics of ET seasonality in all sub-basins differ in timing and magnitude. The highest mean annual ET was found in the northern Rio Negro basin (˜ 1497 mm year-1) and the lowest values in the Solimões River basin (˜ 986 mm year-1). For the first time in a basin-scale study, using observational data, we show that factors limiting ET vary across climatic gradients in the Amazon, confirming local-scale eddy covariance studies. Both annual mean and seasonality in ET are driven by a combination of energy and water availability, as neither rainfall nor radiation alone could explain patterns in ET. In southern basins, despite seasonal rainfall deficits, deep root water uptake allows increasing rates of ET during the dry season, when radiation is usually higher than in the wet season. We demonstrate contrasting ET seasonality with satellite greenness across Amazon forests, with strong asynchronous relationships in ever-wet watersheds, and positive correlations observed in seasonally dry watersheds. Finally, we compared our results with estimates obtained by two ET models, and we conclude that neither of the two tested models could provide a consistent representation of ET seasonal patterns across the Amazon.

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)

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

International Nuclear Information System (INIS)

1983-12-01

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

Klamath River Basin water-quality data

Science.gov (United States)

Smith, Cassandra D.; Rounds, Stewart A.; Orzol, Leonard L.; Sobieszczyk, Steven

2018-05-29

The Klamath River Basin stretches from the mountains and inland basins of south-central Oregon and northern California to the Pacific Ocean, spanning multiple climatic regions and encompassing a variety of ecosystems. Water quantity and water quality are important topics in the basin, because water is a critical resource for farming and municipal use, power generation, and for the support of wildlife, aquatic ecosystems, and endangered species. Upper Klamath Lake is the largest freshwater lake in Oregon (112 square miles) and is known for its seasonal algal blooms. The Klamath River has dams for hydropower and the upper basin requires irrigation water to support agriculture and grazing. Multiple species of endangered fish inhabit the rivers and lakes, and the marshes are key stops on the Pacific flyway for migrating birds. For these and other reasons, the water resources in this basin have been studied and monitored to support their management distribution.

STRATIGRAPHIC EVOLUTION, PALEOENVIRONMENTS AND HYDROCARBON POTENTIALS OF THE BENUE/DAHOMEY BASINS, NIGERIAN AND POTIGUAR/CEARA BASINS, NE BRAZIL

International Nuclear Information System (INIS)

Akande, S.O; Adekeye, O.A.; Oj, O.J; Erdtmann, B.D.; Koutsokous, E.I.

2004-01-01

The stratigraphy, facies relationship and paleoenvironment of selected West African and the Brazillian rift basins permit the recognition of at least two major petroleum systems apart from the prolific Niger Delta petroleum system. The Lower Cretaceous fluivio-lacustrine petroleum system and Upper Cretaceous to Lower Tertiary, marine dominated petroleum system. Our combined studies of the stratigraphic, structural framework, paleoenvironment and time-space relationships of the petroleum systems in the Benue/Dahomey and the Potiguar/Ceara basins indicated that rifting and subsequent drifting during the opening of the South Atlantic controlled subsidence, sediment deposition and facies associations in individual basins. Whereas in the Potiguar/Ceara basins, the best developed source rocks are within the Neomacin-Aptian fluvio- lacustrine sequence of the Pendencia and Alagamar Formations which generated reserved hydrocarbon in the Acu Formation, empirical evidence for this petroleum system in the contiguous Benue/Dahomey basins are only based on the geochemical characteristics of the lower parts of the Bima Formation and the Abeokuta Group. In contrast, the Upper Cretaceous-Lower Tertiary marine petroleum system, which is constrained by poor development of reservoirs in the Potiguar/Ceara basin is productive in the Benue/Dahomey basins where source rocks, reservoir and sealing facies occur at this interval. Considering the recent hydrocarbon discoveries of the East Niger basin, the Doba (southern Chad), the Muglad basin (southern Sudan) sourced from the fluvio-lacustrine rift sequences, we suggest that this petroleum system needs more detailed exploration and has some potentials in the Benue/Dahomey frontier basins

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

Directory of Open Access Journals (Sweden)

Ilke Borowski

2008-06-01

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

Water and Benefit Sharing in Transboundary River Basins

Science.gov (United States)

Arjoon, D.; Tilmant, A.; Herrmann, M.

2015-12-01

Growing water scarcity underlies the importance of cooperation for the effective management of river basins, particularly in the context of international rivers in which unidirectional externalities can lead to asymmetric relationships between riparian countries. Studies have shown that significant economic benefits can be expected through basin-wide cooperation, however, the equitable partitioning of these benefits over the basin is less well studied and tends to overlook the importance of stakeholder input in the definition of equitability. In this study, an institutional arrangement to maximize welfare and then share the scarcity cost in a river basin is proposed. A river basin authority plays the role of a bulk water market operator, efficiently allocating bulk water to the users and collecting bulk water charges which are then equitably redistributed among water users. This highly regulated market restrains the behaviour of water users to control externalities and to ensure basin-wide coordination, enhanced efficiency, and the equitable redistribution of the scarcity cost. The institutional arrangement is implemented using the Eastern Nile River basin as a case study. The importance of this arrangement is that it can be adopted for application in negotiations to cooperate in trans-boundary river basins. The benefit sharing solution proposed is more likely to be perceived as equitable because water users help define the sharing rule. As a result, the definition of the sharing rule is not in question, as it would be if existing rules, such as bankruptcy rules or cooperative game theory solutions, are applied, with their inherent definitions of fairness. Results of the case study show that the sharing rule is predictable. Water users can expect to receive between 93.5% and 95% of their uncontested benefits (benefits that they expect to receive if water was not rationed), depending on the hydrologic scenario.

Groundwater quality studies: A Case study of the Densu Basin, Ghana

African Journals Online (AJOL)

Groundwater samples from 68 communities within the Densu basin were sampled and analysed over a period of 1 year for various physico-chemical water quality parameters using appropriate certified and acceptable international procedures, in order to assess the water types as well as the suitability of groundwater within ...

Hydrogeochemical studies of historical mining areas in the Humboldt River basin and adjacent areas, northern Nevada

Science.gov (United States)

Nash, J. Thomas

2005-01-01

The study area comprises the Humboldt River Basin and adjacent areas, with emphasis on mining areas relatively close to the Humboldt River. The basin comprises about 16,840 mi2 or 10,800,000 acres. The mineral resources of the Humboldt Basin have been investigated by many scientists over the past 100 years, but only recently has our knowledge of regional geology and mine geology been applied to the understanding and evaluation of mining effects on water and environmental quality. The investigations reported here apply some of the techniques and perspectives developed in the Abandoned Mine Lands Initiative (AMLI) of the U.S. Geological Survey (USGS), a program of integrated geological-hydrological-biological-chemical studies underway in the Upper Animas River watershed in Colorado and the Boulder River watershed in, Montana. The goal of my studies of sites and districts is to determine the character of mining-related contamination that is actively or potentially a threat to water quality and to estimate the potential for natural attenuation of that contamination. These geology-based studies and recommendations differ in matters of emphasis and data collection from the biology-based assessments that are the cornerstone of environmental regulations.

Application of nuclear logging to porosity studies in Itaborai basin

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Hydrological Process Simulation of Inland River Watershed: A Case Study of the Heihe River Basin with Multiple Hydrological Models

Directory of Open Access Journals (Sweden)

Lili Wang

2018-04-01

Full Text Available Simulating the hydrological processes of an inland river basin can help provide the scientific guidance to the policies of water allocation among different subbasins and water resource management groups within the subbasins. However, it is difficult to simulate the hydrological processes of an inland river basin with hydrological models due to the non-consistent hydrological characteristics of the entire basin. This study presents a solution to this problem with a case study about the hydrological process simulation in an inland river basin in China, Heihe River basin. It is divided into the upper, middle, and lower reaches based on the distinctive hydrological characteristics in the Heihe River basin, and three hydrological models are selected, applied, and tested to simulate the hydrological cycling processes for each reach. The upper reach is the contributing area with the complex runoff generation processes, therefore, the hydrological informatic modeling system (HIMS is utilized due to its combined runoff generation mechanisms. The middle reach has strong impacts of intensive human activities on the interactions of surface and subsurface flows, so a conceptual water balance model is applied to simulate the water balance process. For the lower reach, as the dissipative area with groundwater dominating the hydrological process, a groundwater modeling system with the embedment of MODFLOW model is applied to simulate the groundwater dynamics. Statistical parameters and water balance analysis prove that the three models have excellent performances in simulating the hydrological process of the three reaches. Therefore, it is an effective way to simulate the hydrological process of inland river basin with multiple hydrological models according to the characteristics of each subbasin.

The geologic history of Margaritifer basin, Mars

Science.gov (United States)

Salvatore, M. R.; Kraft, M. D.; Edwards, Christopher; Christensen, P.R.

2016-01-01

In this study, we investigate the fluvial, sedimentary, and volcanic history of Margaritifer basin and the Uzboi-Ladon-Morava (ULM) outflow channel system. This network of valleys and basins spans more than 8000 km in length, linking the fluvially dissected southern highlands and Argyre Basin with the northern lowlands via Ares Vallis. Compositionally, thermophysically, and morphologically distinct geologic units are identified and are used to place critical relative stratigraphic constraints on the timing of geologic processes in Margaritifer basin. Our analyses show that fluvial activity was separated in time by significant episodes of geologic activity, including the widespread volcanic resurfacing of Margaritifer basin and the formation of chaos terrain. The most recent fluvial activity within Margaritifer basin appears to terminate at a region of chaos terrain, suggesting possible communication between surface and subsurface water reservoirs. We conclude with a discussion of the implications of these observations on our current knowledge of Martian hydrologic evolution in this important region.

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

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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.

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

International Nuclear Information System (INIS)

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

Modeling the hydrologic effects of land and water development interventions: a case study of the upper Blue Nile river basin

Science.gov (United States)

Haregeweyn, Nigussie; Tsunekawa, Atsushi; Tsubo, Mitsuru; Meshesha, Derege; Adgo, Enyew; Poesen, Jean; Schütt, Brigitta

2014-05-01

Over 67% of the Ethiopian landmass has been identified as very vulnerable to climate variability and land degradation. These problems are more prevalent in the Upper Blue Nile (UBN, often called Abay) river basin covering a drainage area of about 199,800 km2. The UBN River runs from Lake Tana (NW Ethiopia) to the Ethiopia-Sudan border. To enhance the adaptive capacity to the high climate variability and land degradation in the basin, different land and water management measures (stone/soil bunds, runoff collector trenches, exclosures) have been extensively implemented, especially since recent years. Moreover, multipurpose water harvesting schemes including the Grand Ethiopian Renaissance Dam (GERD, reservoir area of ca. 4000 km2) and 17 other similar projects are being or to be implemented by 2025. However, impact studies on land and water management aspects rarely include detailed hydrological components especially at river basin scale, although it is generally regarded as a major determinant of hydrological processes. The main aim of this study is therefore to model the significance of land and water management interventions in surface runoff response at scale of UBN river basin and to suggest some recommendations. Spatially-distributed annual surface runoff was simulated for both present-day and future (2025) land and water management conditions using calibrated values of the proportional loss model in ArcGIS environment. Average annual rainfall map (1998-2012) was produced from calibrated TRMM satellite source and shows high spatial variability of rainfall ranging between ca. 1000 mm in the Eastern part of the basin to ca. 2000 mm in the southern part of the basin. Present-day land use day condition was obtained from Abay Basin Master Plan study. The future land use map was created taking into account the land and water development interventions to be implemented by 2025. Under present-day conditions, high spatial variability of annual runoff depth was observed

K-Basin gel formation studies

International Nuclear Information System (INIS)

Beck, M.A.

1998-01-01

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

Geochemical Modeling Of F Area Seepage Basin Composition And Variability

International Nuclear Information System (INIS)

Millings, M.; Denham, M.; Looney, B.

2012-01-01

From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin

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)

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

Fishes of the Taquari-Antas river basin (Patos Lagoon basin, southern Brazil

Directory of Open Access Journals (Sweden)

FG. Becker

Full Text Available The aquatic habitats of the Taquari-Antas river basin (in the Patos Lagoon basin, southern Brazil are under marked environmental transformation because of river damming for hydropower production. In order to provide an information baseline on the fish fauna of the Taquari-Antas basin, we provide a comprehensive survey of fish species based on primary and secondary data. We found 5,299 valid records of fish species in the basin, representing 119 species and 519 sampling sites. There are 13 non-native species, six of which are native to other Neotropical river basins. About 24% of the total native species are still lacking a taxonomic description at the species level. Three native long-distance migratory species were recorded (Leporinus obtusidens, Prochilodus lineatus, Salminus brasiliensis, as well as two potential mid-distance migrators (Parapimelodus nigribarbis and Pimelodus pintado. Although there is only one officially endangered species in the basin (S. brasiliensis, restricted range species (21.7% of total species should be considered in conservation efforts.

Use of hydrological modelling and isotope techniques in Guvenc basin

International Nuclear Information System (INIS)

Altinbilek, D.

1991-07-01

The study covers the work performed under Project No. 335-RC-TUR-5145 entitled ''Use of Hydrologic Modelling and Isotope Techniques in Guvenc Basin'' and is an initial part of a program for estimating runoff from Central Anatolia Watersheds. The study presented herein consists of mainly three parts: 1) the acquisition of a library of rainfall excess, direct runoff and isotope data for Guvenc basin; 2) the modification of SCS model to be applied to Guvenc basin first and then to other basins of Central Anatolia for predicting the surface runoff from gaged and ungaged watersheds; and 3) the use of environmental isotope technique in order to define the basin components of streamflow of Guvenc basin. 31 refs, figs and tabs

K-Basins design guidelines

International Nuclear Information System (INIS)

Roe, N.R.; Mills, W.C.

1995-06-01

The purpose of the design guidelines is to enable SNF and K Basin personnel to complete fuel and sludge removal, and basin water mitigation by providing engineering guidance for equipment design for the fuel basin, facility modifications (upgrades), remote tools, and new processes. It is not intended to be a purchase order reference for vendors. The document identifies materials, methods, and components that work at K Basins; it also Provides design input and a technical review process to facilitate project interfaces with operations in K Basins. This document is intended to compliment other engineering documentation used at K Basins and throughout the Spent Nuclear Fuel Project. Significant provisions, which are incorporated, include portions of the following: General Design Criteria (DOE 1989), Standard Engineering Practices (WHC-CM-6-1), Engineering Practices Guidelines (WHC 1994b), Hanford Plant Standards (DOE-RL 1989), Safety Analysis Manual (WHC-CM-4-46), and Radiological Design Guide (WHC 1994f). Documents (requirements) essential to the engineering design projects at K Basins are referenced in the guidelines

Evolution of sedimentary architecture in retro-foreland basin: Aquitaine basin example from Paleocene to lower Eocene.

Science.gov (United States)

Ortega, Carole; Lasseur, Eric; Guillocheau, François; Serrano, Olivier; Malet, David

2017-04-01

The Aquitaine basin located in south western Europe, is a Pyrenean retro-foreland basin. Two main phases of compression are recorded in this retro-foreland basin during the Pyrenean orogeny. A first upper Cretaceous phase corresponding to the early stage of the orogeny, and a second one usually related to a Pyrenean paroxysmal phase during the middle Eocene. During Paleocene to lower Eocene deformations are less pronounced, interpreted as a tectonically quiet period. The aim of the study is to better constrain the sedimentary system of the Aquitaine basin during this period of Paleocene-lower Eocene, in order to discuss the evolution of the sedimentary architecture in response of the Pyrenean compression. This work is based on a compilation of a large set of subsurface data (wells logs, seismic lines and cores logs) represented by isopachs and facies map. Three main cycles were identified during this structural quiet period: (1) The Danian cycle, is recorded by the aggradation of carbonate reef-rimmed platform. This platform is characterized by proximal facies (oncoid carbonate and mudstone with thalassinoides) to the north, which leads to distal deposit facies southern (pelagic carbonate with globigerina and slump facies) and present a significant thickness variation linked to the platform-slope-basin morphology. (2) The upper Selandian-Thanetian cycle follows a non-depositional/erosional surface associated with a Selandian hiatus. The base of this cycle marked the transition between the last reef rimmed platform and a carbonate ramp. The transgressive cycle is characterized by proximal lagoon facies to the north that leads southward to distal hemipelagic facies interfingered by turbiditic Lowstand System Tracks (LST). The location of these LST is strongly controlled by inherited Danian topography. The regressive cycle ends with a major regression associated with an erosional surface. This surface is linked with a network of canyons in the north, an important

Lithospheric-scale centrifuge models of pull-apart basins

Science.gov (United States)

Corti, Giacomo; Dooley, Tim P.

2015-11-01

We present here the results of the first lithospheric-scale centrifuge models of pull-apart basins. The experiments simulate relative displacement of two lithospheric blocks along two offset master faults, with the presence of a weak zone in the offset area localising deformation during strike-slip displacement. Reproducing the entire lithosphere-asthenosphere system provides boundary conditions that are more realistic than the horizontal detachment in traditional 1 g experiments and thus provide a better approximation of the dynamic evolution of natural pull-apart basins. Model results show that local extension in the pull-apart basins is accommodated through development of oblique-slip faulting at the basin margins and cross-basin faults obliquely cutting the rift depression. As observed in previous modelling studies, our centrifuge experiments suggest that the angle of offset between the master fault segments is one of the most important parameters controlling the architecture of pull-apart basins: the basins are lozenge shaped in the case of underlapping master faults, lazy-Z shaped in case of neutral offset and rhomboidal shaped for overlapping master faults. Model cross sections show significant along-strike variations in basin morphology, with transition from narrow V- and U-shaped grabens to a more symmetric, boxlike geometry passing from the basin terminations to the basin centre; a flip in the dominance of the sidewall faults from one end of the basin to the other is observed in all models. These geometries are also typical of 1 g models and characterise several pull-apart basins worldwide. Our models show that the complex faulting in the upper brittle layer corresponds at depth to strong thinning of the ductile layer in the weak zone; a rise of the base of the lithosphere occurs beneath the basin, and maximum lithospheric thinning roughly corresponds to the areas of maximum surface subsidence (i.e., the basin depocentre).

Tectono-sedimentary analysis using the anisotropy of magnetic susceptibility: a study of the terrestrial and freshwater Neogene of the Orava Basin

Science.gov (United States)

Łoziński, Maciej; Ziółkowski, Piotr; Wysocka, Anna

2017-10-01

The Orava Basin is an intramontane depression filled with presumably fine-grained sediments deposited in river, floodplain, swamp and lake settings. The basin infilling constitutes a crucial record of the neoalpine evolution of the Inner/Outer Carpathian boundary area since the Neogene, when the Jurassic-Paleogene basement became consolidated, uplifted and eroded. The combination of sedimentological and structural studies with anisotropy of magnetic susceptibility (AMS) measurements provided an effective tool for recognition of terrestrial environments and deformations of the basin infilling. The lithofacies-oriented sampling and statistical approach to the large dataset of AMS specimens were utilized to define 12 AMS facies based on anisotropy degree (P) and shape (T). The AMS facies allowed a distinction of sedimentary facies ambiguous for classical methods, especially floodplain and lacustrine sediments, as well as revealing their various vulnerabilities to tectonic modification of AMS. A spatial analysis of facies showed that tuffites along with lacustrine and swamp deposits were generally restricted to marginal and southern parts of the basin. Significant deformations were noticed at basin margins and within two intrabasinal tectonic zones, which indicated the tectonic activity of the Pieniny Klippen Belt after the Middle Miocene. The large southern area of the basin recorded consistent N-NE trending compression during basin inversion. This regional tectonic rearrangement resulted in a partial removal of the southernmost basin deposits and shaped the basin's present-day extent.

Observed changes in extremes of daily rainfall and temperature in Jemma Sub-Basin, Upper Blue Nile Basin, Ethiopia

Science.gov (United States)

Worku, Gebrekidan; Teferi, Ermias; Bantider, Amare; Dile, Yihun T.

2018-02-01

Climate variability has been a threat to the socio-economic development of Ethiopia. This paper examined the changes in rainfall, minimum, and maximum temperature extremes of Jemma Sub-Basin of the Upper Blue Nile Basin for the period of 1981 to 2014. The nonparametric Mann-Kendall, seasonal Mann-Kendall, and Sen's slope estimator were used to estimate annual trends. Ten rainfall and 12 temperature indices were used to study changes in rainfall and temperature extremes. The results showed an increasing trend of annual and summer rainfall in more than 78% of the stations and a decreasing trend of spring rainfall in most of the stations. An increase in rainfall extreme events was detected in the majority of the stations. Several rainfall extreme indices showed wetting trends in the sub-basin, whereas limited indices indicated dryness in most of the stations. Annual maximum and minimum temperature and extreme temperature indices showed warming trend in the sub-basin. Presence of extreme rainfall and a warming trend of extreme temperature indices may suggest signs of climate change in the Jemma Sub-Basin. This study, therefore, recommended the need for exploring climate induced risks and implementing appropriate climate change adaptation and mitigation strategies.

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

Science.gov (United States)

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

2010-01-01

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

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.

Riddled Basins of Attraction for Synchronized Type-I Intermittency

DEFF Research Database (Denmark)

Mancher, Martin; Nordahn, Morten; Mosekilde, Erik

1998-01-01

Chaotic mortion resticted to an invariant subspace of total phase space may be associated with basins of attraction that are riddled with holes belonging to the basin of another limiting state. We study the emergence of such basins of two coupled one-dimensional maps, each exhibiting type...

Satellite altimetry over large hydrological basins

Science.gov (United States)

Calmant, Stephane

2015-04-01

The use of satellite altimetry for hydrological applications, either it is basin management or hydrological modeling really started with the 21st century. Before, during two decades, the efforts were concentrated on the data processing until a precision of a few decimeters could be achieved. Today, several web sites distribute hundreds of series spread over hundeds of rivers runing in the major basins of the world. Among these, the Amazon basin has been the most widely studied. Satellite altimetry is now routinely used in this transboundary basin to predict discharges ranging over 4 orders of magnitude. In a few years, satellite altimetry should evolve dramatically. This year, we should see the launchs of Jason-3 and that of Sentinel-3A operating in SAR mode. With SAR, the accuracy and resolution of a growing number of measurements should be improved. In 2020, SWOT will provide a full coverage that will join in a unique framework all the previous and forthcoming missions. These technical and thematical evolutions will be illustrated by examples taken in the Amazon and Congo basin.

Study of southern CHAONAN sag lower continental slope basin deposition character in Northern South China Sea

Science.gov (United States)

Tang, Y.

2009-12-01

Northern South China Sea Margin locates in Eurasian plate,Indian-Australia plate,Pacific Plates.The South China Sea had underwent a complicated tectonic evolution in Cenozoic.During rifting,the continental shelf and slope forms a series of Cenozoic sedimentary basins,including Qiongdongnan basin,Pearl River Mouth basin,Taixinan basin.These basins fill in thick Cenozoic fluviolacustrine facies,transitional facies,marine facies,abyssal facies sediment,recording the evolution history of South China Sea Margin rifting and ocean basin extending.The studies of tectonics and deposition of depression in the Southern Chaonan Sag of lower continental slope in the Norther South China Sea were dealt with,based on the sequence stratigraphy and depositional facies interpretation of seismic profiles acquired by cruises of“China and Germany Joint Study on Marine Geosciences in the South China Sea”and“The formation,evolution and key issues of important resources in China marginal sea",and combining with ODP 1148 cole and LW33-1-1 well.The free-air gravity anomaly of the break up of the continental and ocean appears comparatively low negative anomaly traps which extended in EW,it is the reflection of passive margin gravitational effect.Bouguer gravity anomaly is comparatively low which is gradient zone extended NE-SW.Magnetic anomaly lies in Magnetic Quiet Zone at the Northern Continental Margin of the South China Sea.The Cenozoic sediments of lower continental slope in Southern Chaonan Sag can be divided into five stratum interface:SB5.5,SB10.5,SB16.5,SB23.8 and Hg,their ages are of Pliocene-Quaternary,late Miocene,middle Miocene,early Miocene,paleogene.The tectonic evolution of low continental slope depressions can be divided into rifting,rifting-depression transitional and depression stages,while their depositional environments change from river to shallow marine and abyssa1,which results in different topography in different stages.The topographic evolvement in the study

Penelitian Pendahuluan Angkutan Sedimen Melayang Sub-Das Citarik Hulu = (Suspended Sediment Transport in the Upper Citarik Sub-River Basin: A Preliminary Study

Directory of Open Access Journals (Sweden)

Soewarno .

2014-10-01

Full Text Available Apart from its function as a soil cover, forest also plays a positive role in preserving water and sediment in a river basin. Rain water which is abundant in the rainy season is caught and stored underground, so that the erosion and flood hazard can be eliminated. In the dry season groundwater becomes reservation to minimize and even eliminate the risk of water shortage. This preliminary study is to monitor suspended sediment transport with respect to the forest area of upper Citarum River Basin at upper Citarih Sub - River Basin. On the basis of the preliminary study results, it can be said that for a river basin where percentage of the forest area is smaller (i the suspended sediment concentration is higher and (ii the total sediment per area unit is greater. These indications were found during the study period, from September 1987 to February 1988. The preliminary study was conducted in a sub-river basin where the soil type is a mixture of andosol and brown regosol, and the terrain is undulating, hilly to mountainous with slope more than 15 percent.

Hydrograph sensitivity to estimates of map impervious cover: a WinHSPF BASINS case study

Science.gov (United States)

Endreny, Theodore A.; Somerlot, Christopher; Hassett, James M.

2003-04-01

The BASINS geographic information system hydrologic toolkit was designed to compute total maximum daily loads, which are often derived by combining water quantity estimates with pollutant concentration estimates. In this paper the BASINS toolkit PLOAD and WinHSPF sub-models are briefly described, and then a 0·45 km2 headwater watershed in the New York Croton River area is used for a case study illustrating a full WinHSPF implementation. The goal of the Croton study was to determine the sensitivity of WinHSPF hydrographs to changes in land cover map inputs. This scenario occurs when scaling the WinHSPF model from the smaller 0·45 km2 watershed to the larger 1000 km2 management basin of the entire Croton area. Methods used to test model sensitivity include first calibrating the WinHSPF hydrograph using research-monitored precipitation and discharge data together with high spatial resolution and accuracy land cover data of impervious and pervious areas, and then swapping three separate land cover files, known as GIRAS, MRLC, and DOQQ data, into the calibrated model. Research results indicated that the WinHSPF land cover swapping had peak flow sensitivity in December 2001 hydrographs between 35% underestimation and 20% overestimation, and that errors in land-cover-derived runoff ratios for storm totals and peak flows tracked with the land cover data estimates of impervious area.

Are calanco landforms similar to river basins?

Science.gov (United States)

Caraballo-Arias, N A; Ferro, V

2017-12-15

In the past badlands have been often considered as ideal field laboratories for studying landscape evolution because of their geometrical similarity to larger fluvial systems. For a given hydrological process, no scientific proof exists that badlands can be considered a model of river basin prototypes. In this paper the measurements carried out on 45 Sicilian calanchi, a type of badlands that appears as a small-scale hydrographic unit, are used to establish their morphological similarity with river systems whose data are available in the literature. At first the geomorphological similarity is studied by identifying the dimensionless groups, which can assume the same value or a scaled one in a fixed ratio, representing drainage basin shape, stream network and relief properties. Then, for each property, the dimensionless groups are calculated for the investigated calanchi and the river basins and their corresponding scale ratio is evaluated. The applicability of Hack's, Horton's and Melton's laws for establishing similarity criteria is also tested. The developed analysis allows to conclude that a quantitative morphological similarity between calanco landforms and river basins can be established using commonly applied dimensionless groups. In particular, the analysis showed that i) calanchi and river basins have a geometrically similar shape respect to the parameters Rf and Re with a scale factor close to 1, ii) calanchi and river basins are similar respect to the bifurcation and length ratios (λ=1), iii) for the investigated calanchi the Melton number assumes values less than that (0.694) corresponding to the river case and a scale ratio ranging from 0.52 and 0.78 can be used, iv) calanchi and river basins have similar mean relief ratio values (λ=1.13) and v) calanchi present active geomorphic processes and therefore fall in a more juvenile stage with respect to river basins. Copyright © 2017 Elsevier B.V. All rights reserved.

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)

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

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

Science.gov (United States)

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

2011-12-01

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

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

Regionalization of the Upper Tana Basin of Kenya Using Stream ...

African Journals Online (AJOL)

Regionalization of the Upper Tana Basin of Kenya Using Stream Flow Records. ... river gauge stations in the basin using the empirical orthogonal function analysis ... the study basin to be grouped into four homogenous hydrological zones that ...

Strategic planning for instream flow restoration: a case study of potential climate change impacts in the central Columbia River basin.

Science.gov (United States)

Donley, Erin E; Naiman, Robert J; Marineau, Mathieu D

2012-10-01

We provide a case study prioritizing instream flow restoration activities by sub-basin according to the habitat needs of Endangered Species Act (ESA)-listed salmonids relative to climate change in the central Columbia River basin in Washington State (USA). The objective is to employ scenario analysis to inform and improve existing instream flow restoration projects. We assess the sensitivity of late summer (July, August, and September) flows to the following scenario simulations - singly or in combination: climate change, changes in the quantity of water used for irrigation and possible changes to existing water resource policy. Flows for four sub-basins were modeled using the Water Evaluation and Planning system (WEAP) under historical and projected conditions of 2020 and 2040 for each scenario. Results indicate that Yakima will be the most flow-limited sub-basin with average reductions in streamflow of 41% under climate conditions of 2020 and 56% under 2040 conditions; 1.3-2.5 times greater than those of other sub-basins. In addition, irrigation plays a key role in the hydrology of the Yakima sub-basin - with flow reductions ranging from 78% to 90% under severe to extreme (i.e., 20-40%) increases in agricultural water use (2.0-4.4 times the reductions in the other sub-basins). The Yakima and Okanogan sub-basins are the most responsive to simulations of flow-bolstering policy change (providing salmon with first priority water allocation and at biologically relevant flows), as demonstrated by 91-100% target flows attained. The Wenatchee and Methow sub-basins do not exhibit similar responsiveness to simulated policy changes. Considering climate change only, we conclude that flow restoration should be prioritized first in the Yakima and Wenatchee sub-basins, and second in the Okanogan and Methow. Considering both climate change and possible policy changes, we recommend that the Yakima sub-basin receive the highest priority for flow restoration activities to sustain

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

Directory of Open Access Journals (Sweden)

Talchabhadel Rocky

2016-01-01

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

A Preliminary Study of Water Quality Index in Terengganu River Basin, Malaysia

International Nuclear Information System (INIS)

Suratman, S.; Mohd, S.M.I.; Hee, Y.Y.; Bedurus, E.A.; Latif, M.T.

2015-01-01

The Malaysian Department of Environment-Water Quality Index (DOE-WQI) was determined for the Terengganu River basin which is located at the coastal water of the southern South China Sea between July and October 2008. Monthly samplings were carried out at ten sampling stations within the basin. Six parameters listed in DOE-WQI were measured based on standard methods: pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) and ammonical nitrogen (AN). The results indicated the impact of various anthropogenic activities which contribute to high values of BOD, COD, TSS and AN at middle and downstream stations, as compared with the upstream of the basin. The reverses were true for the pH and DO values. The DOE-WQI ranged from 71.5-94.6 % (mean 86.9 %), which corresponded to a classification status range from slightly polluted to clean. With respect to the Malaysia National Water Quality Standards (NWQS), the level of most of the parameters measured remained at Class I which is suitable for the sustainable conservation of the natural environment, for water supply without treatment and as well as for very sensitive aquatic species. It is suggested that monitoring should be carried out continuously for proper management of this river basin. (author)

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

Science.gov (United States)

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-05-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

Directory of Open Access Journals (Sweden)

C. Liu

2015-05-01

Full Text Available Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

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

International Nuclear Information System (INIS)

Beary, M.M.; Honekemp, J.R.; Winters, N.

1995-01-01

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

K Basin spent fuel sludge treatment alternatives study. Volume 1, Regulatory options

International Nuclear Information System (INIS)

Beary, M.M.; Honekemp, J.R.; Winters, N.

1995-01-01

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. Volume 1 of this two-volume report describes the regulatory options for managing the sludges, including schedule and cost impacts, and assesses strategies for establishing a preferred path

Georeferenced historical forest maps of Bukovina (Northern Romania) - important tool for paleoenvironmental analyses

Science.gov (United States)

Popa, Ionel; Crǎciunescu, Vasile; Candrea, Bogdan; Timár, Gábor

2010-05-01

Austrian and Romanian forest surveyors, to correctly georeference the maps. A case study, demonstrating the usefulness of such old cartographic informations in understanding the forest landscape evolution is also included. The georeferenced map sheets provide an excellent basis of the paleo-environmental researches. Assessing the changes of the forest cover ratio is important for the analysis of the recent flash flood events at the eastern slopes of the Carpathian Mts.

Northern Rivers Basins ecological and human health studies : summary, relevance and recommendations

International Nuclear Information System (INIS)

1999-04-01

Residents in northern Alberta expressed concerns that the original Northern River Basins Study (NRBS) only examined the impacts of contaminants on ecological health and did not include impacts on human health. In response to these concerns, Alberta Health established the Northern River Basins Human Health Monitoring Program in 1994 to investigate the possible relationships between various environmental risk factors and the health of northern residents in the province. This document links the ecological information collected by the original NRBS program with the information provided by the health program. Issues regarding health impacts from pulp mills and oil sand mining were also discussed. The findings of the health program were summarized and recommendations were made for future studies. The contaminants of potential concern (COPC) arising from the original NRBS were described in terms of their sources and any known connections between exposure and human health. The COPCs included arsenic, dioxins, chlorinated furans, polycyclic aromatic hydrocarbons (PAH) polychlorinated biphenyls (PCB) mercury, chlorinated phenolics, toxaphene, carbon monoxide, nitrogen oxides, ozone, sulphur dioxide, acid sulphates and particulate matter. Examples of Canadian regulatory criteria for these contaminants were also presented. 41 refs., 1 tab

Effects of urbanization on agricultural lands and river basins: case study of Mersin (South of Turkey).

Science.gov (United States)

Duran, Celalettin; Gunek, Halil; Sandal, Ersin Kaya

2012-04-01

Largely, Turkey is a hilly and mountainous country. Many rivers rise from the mountains and flow into the seas surrounding the country. Mean while along fertile plains around the rivers and coastal floodplains of Turkey were densely populated than the other parts of the country. These characteristics show that there is a significant relationship between river basins and population or settlements. It is understood from this point of view, Mersin city and its vicinity (coastal floodplain and nearby river basins) show similar relationship. The city of Mersin was built on the southwest comer of Cukurova where Delicay and Efrenk creeks create narrow coastal floodplain. The plain has rich potential for agricultural practices with fertile alluvial soils and suitable climate. However, establishment of the port at the shore have increased commercial activity. Agricultural and commercial potential have attracted people to the area, and eventually has caused rapid spatial expansion of the city, and the urban sprawls over fertile agricultural lands along coastal floodplain and nearby river basins of the city. But unplanned, uncontrolled and illegal urbanization process has been causing degradation of agricultural areas and river basins, and also causing flooding in the city of Mersin and its vicinity. Especially in the basins, urbanization increases impervious surfaces throughout watersheds that increase erosion and runoff of surface water. In this study, the city of Mersin and its vicinity are examined in different ways, such as land use, urbanization, morphology and flows of the streams and given some directions for suitable urbanization.

Geochemical element mobility during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin (Saskatchewan, Canada)

International Nuclear Information System (INIS)

Kister, Philippe

2003-01-01

In order to understand the mechanisms of migration and deposition of ore elements, it is essential to determine the timing, source, and destination of the geochemical element mass transfers and/or transportation on a scale encompassing the great sedimentary basins. The purpose of this study is to trace and to date the element migrations that occurred during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin, which hosts the world's largest and richest uranium deposits. As this geological environment was proved to be efficient to preserve high grade ore deposits for over more than one billion years, it provides an opportunity to study some natural analogues of deep geological nuclear waste storage. Five research topics were studied: 3D modelling of the distribution of normative minerals and trace elements on a basin-wide scale; U-Pb and Rb-Sr systematics; average chemical age estimation; thermodynamic modelling of the major mineralogical assemblages; U-Pb geochronology of uranium oxides. Some elements have remained immobile (Zr) since their initial sedimentary deposition, or were transferred from one phase to another (Al, Th). Other elements have been transported during fluid flow events that occurred: (1) on a basin wide scale during diagenesis (REE, Y, Sr, Fe), (2) at the unconformity and in the vicinity of the fault zones that represent preferential fluid flow pathways between the basement and the sandstone cover (U, Ni, As, B, Mg, K, Fe, Sr, REE), (3) during the late fault reactivation events associated with the basin uplift (U, Pb, Ni, S, Sr, REE). The successive tectonic events related to the geodynamical context that lead to the formation of these high-grade U concentrations (1460 Ma, 1335 Ma and 1275 Ma in the McArthur River deposit), did not however systematically occur in the whole basin (1275 Ma only at Shea Creek). The exceptionally high grade and tonnages of some deposits seem to be related to a larger number of U

The Hachioji Experimental Basin Study — Storm runoff processes and the mechanism of its generation

Science.gov (United States)

Tanaka, T.; Yasuhara, M.; Sakai, H.; Marui, A.

1988-09-01

The study discusses storm runoff processes and the mechanism of its generation in relation to dynamic responses of subsurface water in a small forested drainage basin located in the western suburbs of Tokyo, Japan. Intensive field observations were carried out for the period 1980-1983. In the drainage basin overland flow occurred from restricted areas on the valley floor. No significant overland flow was produced on the steep hillside slopes even during a heavy storm event. The maximum extent of the saturated area occupied only 1-4% of the total basin area. The main source of storm runoff was groundwater flow. More than 90% of the total discharge was due to groundwater flow and the surface flow component contributed less than 10%. The rapid and large amounts of groundwater discharge during a storm event could not be explained solely by the traditional concept of Darcian matrix flow. These phenomena were mainly attributed to rapid flow such as pipe flow which has velocities about as high as those of surface flows. The pulsating flow phenomenon was observed as a characteristic of pipe flow.

Basins in ARC-continental collisions

Science.gov (United States)

Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio

2012-01-01

Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from

Attractors and basins of dynamical systems

Directory of Open Access Journals (Sweden)

Attila Dénes

2011-03-01

Full Text Available There are several programs for studying dynamical systems, but none of them is very useful for investigating basins and attractors of higher dimensional systems. Our goal in this paper is to show a new algorithm for finding even chaotic attractors and their basins for these systems. We present an implementation and examples for the use of this program.

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

NARCIS (Netherlands)

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

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Beary, M.M.; Honekemp, J.R.; Winters, N. [Science Applications International Corp., Richland, WA (United States)

1995-01-01

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.

Geology and salt deposits of the Michigan Basin

International Nuclear Information System (INIS)

Johnson, K.S.; Gonzales, S.

1976-07-01

The Silurian-age Salina salt, one of the greatest deposits of bedded rock salt in the world, underlies most of the Michigan basin and parts of the Appalachian basin in Ohio. Pennsylvania, New York, and West Virginia. Interest in this salt deposit has increased in recent years because there may be one or more areas where it could be used safely as a repository for the underground storage of high-level radioactive wastes. The general geology of the Michigan basin is summarized and the major salt deposits are described in the hope that these data will be useful in determining whether there are any areas in the basin that are sufficiently promising to warrant further detailed study. Distribution of the important salt deposits in the basin is limited to the Southern Peninsula of Michigan

Groundwater quality in the Colorado River basins, California

Science.gov (United States)

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Colorado River make up one of the study areas being evaluated. The Colorado River study area is approximately 884 square miles (2,290 square kilometers) and includes the Needles, Palo Verde Mesa, Palo Verde Valley, and Yuma groundwater basins (California Department of Water Resources, 2003). The Colorado River study area has an arid climate and is part of the Sonoran Desert. Average annual rainfall is about 3 inches (8 centimeters). Land use in the study area is approximately 47 percent (%) natural (mostly shrubland), 47% agricultural, and 6% urban. The primary crops are pasture and hay. The largest urban area is the city of Blythe (2010 population of 21,000). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay deposited by the Colorado River or derived from surrounding mountains. The primary aquifers in the Colorado River study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Colorado River basins are completed to depths between 230 and 460 feet (70 to 140 meters), consist of solid casing from the land surface to a depth of 130 of 390 feet (39 to 119 meters), and are screened or perforated below the solid casing. The main source of recharge to the groundwater systems in the Needles, Palo Verde Mesa, and Palo Verde Valley basins is the Colorado River; in the Yuma basin, the main source of recharge is from

Submarine landslides in Arctic sedimentation: Canada Basin

Science.gov (United States)

Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Lebedova-Ivanova, N; Chapman, C.

2016-01-01

Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of development, Canada Basin is geomorphologically confined with stable oceanographic structure, resulting in restricted depositional/reworking processes. The sedimentary record, therefore, underscores the significance of mass-transport processes in providing sediments to oceanic abyssal plains as few other basins are able to do.

A MATLAB®-based program for 3D visualization of stratigraphic setting and subsidence evolution of sedimentary basins: example application to the Vienna Basin

Science.gov (United States)

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

2015-04-01

In recent years, 3D visualization of sedimentary basins has become increasingly popular. Stratigraphic and structural mapping is highly important to understand the internal setting of sedimentary basins. And subsequent subsidence analysis provides significant insights for basin evolution. This study focused on developing a simple and user-friendly program which allows geologists to analyze and model sedimentary basin data. The developed program is aimed at stratigraphic and subsidence modelling of sedimentary basins from wells or stratigraphic profile data. This program is mainly based on two numerical methods; surface interpolation and subsidence analysis. For surface visualization four different interpolation techniques (Linear, Natural, Cubic Spline, and Thin-Plate Spline) are provided in this program. The subsidence analysis consists of decompaction and backstripping techniques. The numerical methods are computed in MATLAB® which is a multi-paradigm numerical computing environment used extensively in academic, research, and industrial fields. This program consists of five main processing steps; 1) setup (study area and stratigraphic units), 2) loading of well data, 3) stratigraphic modelling (depth distribution and isopach plots), 4) subsidence parameter input, and 5) subsidence modelling (subsided depth and subsidence rate plots). The graphical user interface intuitively guides users through all process stages and provides tools to analyse and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the visualization results using the full range of available plot options in MATLAB. All functions of this program are illustrated with a case study of Miocene sediments in the Vienna Basin. The basin is an ideal place to test this program, because sufficient data is

Study on integrated evaluation of sandstone-hosted uranium metallogenic potential in southern Yili basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Xu Jianguo; Zheng Enjiu; Li Shengxiang

2008-01-01

Plenty of geological data have been accumulated during mineral resource survey in China; under the guidance of new metallogenic theories, it is an important task of how to use these data most effectively for the new cycle uranium survey. In this paper, the flow of establishing the integrated mineral deposits prospecting model for sandstone-hosted uranium deposits is put forward. Based on studying geologic, hydrogeologic and regional geophysical field characteristics of representative uranium deposits No. 512 in southern Yili basin, its multi-source information descriptive model has been established, from which 512-type integrated prospecting models of sandstone-hosted uranium orefield and deposits are summarized. According to the established integrated prospecting models, the metallogenic information extraction of sandstone-hosted uranium deposits has completed in the study area. Finally, the integrated quantitative evaluation of sandstone-hosted uranium metallogenic potential is performed by using the evidence weighing method to integrate middle scale multi-source metallogenic information in the southern Yili basin, and good prediction effect is obtained. (authors)

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

International Nuclear Information System (INIS)

Minardi, P.S.P.

1982-10-01

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)

BASINs and WEPP Climate Assessment Tools (CAT): Case Study Guide to Potential Applications (Final Report)

Science.gov (United States)

EPA announced the release of the final report, BASINs and WEPP Climate Assessment Tools (CAT): Case Study Guide to Potential Applications. This report supports application of two recently developed water modeling tools, the Better Assessment Science Integrating point & ...

Regional summary and recommended study areas for the Texas panhandle portion of the Permian Basin. Technical report

International Nuclear Information System (INIS)

1979-10-01

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, proved 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

A Large Eddy Simulation Study of Heat Entrainment under Sea Ice in the Canadian Arctic Basin

Science.gov (United States)

Ramudu, E.; Yang, D.; Gelderloos, R.; Meneveau, C. V.; Gnanadesikan, A.

2016-12-01

Sea ice cover in the Arctic has declined rapidly in recent decades. The much faster than projected retreat suggests that climate models may be missing some key processes, or that these processes are not accurately represented. The entrainment of heat from the mixed layer by small-scale turbulence is one such process. In the Canadian Basin of the Arctic Ocean, relatively warm Pacific Summer Water (PSW) resides at the base of the mixed layer. With an increasing influx of PSW, the upper ocean in the Canadian Basin has been getting warmer and fresher since the early 2000s. While studies show a correlation between sea ice reduction and an increase in PSW temperature, others argue that PSW intrusions in the Canadian Basin cannot affect sea ice thickness because the strongly-stratified halocline prevents heat from the PSW layer from being entrained into the mixed layer and up to the basal ice surface. In this study, we try to resolve this conundrum by simulating the turbulent entrainment of heat from the PSW layer to a moving basal ice surface using large eddy simulation (LES). The LES model is based on a high-fidelity spectral approach on horizontal planes, and includes a Lagrangian dynamic subgrid model that reduces the need for empirical inputs for subgrid-scale viscosities and diffusivities. This LES tool allows us to investigate physical processes in the mixed layer at a very fine scale. We focus our study on summer conditions, when ice is melting, and show for a range of ice-drift velocities, halocline temperatures, and halocline salinity gradients characteristic of the Canadian Basin how much heat can be entrained from the PSW layer to the sea ice. Our results can be used to improve parameterizations of vertical heat flux under sea ice in coarse-grid ocean and climate models.

Study for recovery and utilization of coal mine gas in Russia (Kuznetsk coal basin)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of reducing greenhouse effect gas emissions in line with the Joint Implementation, a study was conducted on recovery/utilization of methane gas emitted from the Chertinskaya coal mine in the Kuznetsk coal basin area. According to the survey, the methane gas emitted from the Chertinskaya coal mine into the atmospheric air is 26 million to 36 million tons on the levels of the annual coal production between 0.7 million and 1 million tons. However, the monthly gas recovery amount and concentration largely fluctuate, and therefore, the use method to cope with this was studied. The study was now under way, and the electric power production using gas engine was regarded as the best. In this project, only the Chertinskaya mine can generate power of 34,721 MWh. In the whole Kuznetsk coal basin, approximately 200 million m{sup 3} of gas is needed to be removed for safety of the mine. The use of this will probably bring energy substitution of about 128,000 tons/year and CO2 reduction of 2.8 million tons/year. (NEDO)

The Agost Basin (Betic Cordillera, Alicante province, Spain): a pull-apart basin involving salt tectonics

Science.gov (United States)

Martín-Martín, Manuel; Estévez, Antonio; Martín-Rojas, Ivan; Guerrera, Francesco; Alcalá, Francisco J.; Serrano, Francisco; Tramontana, Mario

2018-03-01

The Agost Basin is characterized by a Miocene-Quaternary shallow marine and continental infilling controlled by the evolution of several curvilinear faults involving salt tectonics derived from Triassic rocks. From the Serravallian on, the area experienced a horizontal maximum compression with a rotation of the maximum stress axis from E-W to N-S. The resulting deformation gave rise to a strike-slip fault whose evolution is characterized progressively by three stages: (1) stepover/releasing bend with a dextral motion of blocks; (2) very close to pure horizontal compression; and (3) restraining bend with a sinistral movement of blocks. In particular, after an incipient fracturing stage, faults generated a pull-apart basin with terraced sidewall fault and graben subzones developed in the context of a dextral stepover during the lower part of late Miocene p.p. The occurrence of Triassic shales and evaporites played a fundamental role in the tectonic evolution of the study area. The salty material flowed along faults during this stage generating salt walls in root zones and salt push-up structures at the surface. During the purely compressive stage (middle part of late Miocene p.p.) the salt walls were squeezed to form extrusive mushroom-like structures. The large amount of clayish and salty material that surfaced was rapidly eroded and deposited into the basin, generating prograding fan clinoforms. The occurrence of shales and evaporites (both in the margins of the basin and in the proper infilling) favored folding of basin deposits, faulting, and the formation of rising blocks. Later, in the last stage (upper part of late Miocene p.p.), the area was affected by sinistral restraining conditions and faults must have bent to their current shape. The progressive folding of the basin and deformation of margins changed the supply points and finally caused the end of deposition and the beginning of the current erosive systems. On the basis of the interdisciplinary results

Mechanics of Formation of Forearc Basins of Indonesia and Alaska

Science.gov (United States)

Cassola, T.; Willett, S.; Kopp, H.

2010-12-01

In this study, the mechanics of forearc basins will be the object of a numerical investigation to understand the relationships between the wedge deformation and forearc basin formation. The aim of this work is to gain insight into the dynamics of the formation of the forearc basin on top of a deforming accretionary wedge, including the mechanism of formation of accommodation space and preservation of basin stratigraphy. Our tool is a two-dimensional numerical model that includes the rheological properties of the rock, including effective internal friction angle, effective basal friction angle, thermally-activated viscosity and strain softening. We also simulate different sedimentation rates in the basin, to study the influence of underfilled and overfilled basin conditions on wedge deformation. The stratigraphy in the basin is simulated, because, as noted in earlier studies, underfilled conditions incourage tectonic deformation in the inner wedge. We compare the numerical model to basins along the Sunda-Java Trench and the Alaskan margin. The Sunda-Java Trench shows a variety of structural and basin styles including underfilled and overfilled basins and different wedge geometries along the same trench. We interprete and document these structural styles, using depth migrated seismic sections of the Sunda Trench, obtained in three surveys, GINCO (11/98 - 01/99), MERAMEX (16/09/04 - 7/10/04) and SINDBAD (9/10/06 - 9/11/06) and made available by the IFM-GEOMAR group in Kiel and the Bundesanstalt für Geowissenschaften and Rohstoffe (BGR) in Hannover. On the Alaska margin we focus on the Kenai Peninsula, Kodiak Island plateau. This segment of the margin has one of the largest accretionary wedge - forearc basin systems in the world. It also exhibits a double forearc basin system with an interior basin (Cook inlet) and an outer basin, outboard of Kodiak Island, which is a prime candidate for a negative-alpha basin, as described by Fuller et al., (Geology, 2006). A number

Spent fuel consolidation in the 105KW Building fuel storage basin

International Nuclear Information System (INIS)

Johnson, B.H.

1994-01-01

This study is one element of a larger engineering study effort by WHC to examine the feasibility of irradiated fuel and sludge consolidation in the KW Basin in response to TPA Milestone (target date) M-34-00-T03. The study concludes that up to 11,500 fuel storage canisters could be accommodated in the KW Basin with modifications. These modifications would include provisions for multi-tiered canister storage involving the fabrication and installation of new storage racks and installation of additional decay heat removal systems for control of basin water temperature. The ability of existing systems to control radionuclide concentrations in the basin water is examined. The study discusses requirements for spent nuclear fuel inventory given the proposed multi-tiered storage arrangement, the impact of the consolidated mass on the KW Basin structure, and criticality issues associated with multi-tiered storage

Distribution, Statistics, and Resurfacing of Large Impact Basins on Mercury

Science.gov (United States)

Fassett, Caleb I.; Head, James W.; Baker, David M. H.; Chapman, Clark R.; Murchie, Scott L.; Neumann, Gregory A.; Oberst, Juergen; Prockter, Louise M.; Smith, David E.; Solomon, Sean C.;

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

Science.gov (United States)

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

2017-06-01

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

Cretaceous sedimentology of the Barmer Basin, Rajasthan, India

OpenAIRE

Beaumont, Hazel

2017-01-01

The Barmer Basin, western India, is a well-known and prospected petroleum system. However, the Lower Cretaceous Ghaggar-Hakra Formation has not been recognised as basin fill and not documented prior to this study. The formation outcrops in rotational fault blocks at the Sarnoo Hills and surrounding areas, on the eastern Barmer Basin margin. The thesis here describes and analyses the nature and evolution of the formation at both outcrop and within the subsurface, producing facies and depositio...

The Hack's law applied to young volcanic basin: the Tahiti case

Science.gov (United States)

Ye, F.; Sichoix, L.; Barriot, J.; Serafini, J.

2010-12-01

We study the channel morphology over the Tahiti island from the Hack’s law perspective. The Hack’s law is an empirical power relationship between basin drainage area and the length of its main channel. It had also been shown that drainage area becomes more elongate with increasing basin size. For typical continental basins, the exponent value lies between 0.47 for basins larger than 260,000 km2 and 0.7 for those spanning less than 20,720 km2 (Muller, 1973). In Tahiti, we extracted 27 principal basins ranging from 7 km2 to 90 km2 from a Digital Terrain Model of the island with a 5 m-resolution. We demonstrate that the Hack’s law still apply for such small basins (correlation coefficient R2=0.7) with an exponent value being approximately 0.5. It appears that the exponent value is influenced by the local geomorphic condition, and does not follow the previous study results (the exponent value decreases with increasing drainage area.) Our exponent value matches the result found w.r.t. debris-flow basins of China for drainage areas less than 100 km2 (Li et al., 2008). Otherwise, the young volcanic basins of Tahiti do not become longer and narrower with increasing basin size (R2=0.1). Besides, there is no correlation between the basin area and the basin convexity (R2=0). This means that there is no statistical change in basin shape with basin size. We present also the drainage area-slope relationship with respect to sediment or transport-limited processes. Key words: Hack’s law, channel morphology, DTM

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)

Hautevelle, Y.

2005-12-01

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)

Relating petroleum system and play development to basin evolution: West African South Atlantic basins

NARCIS (Netherlands)

Beglinger, S.E.; Doust, H.; Cloetingh, S.A.P.L.

2012-01-01

Sedimentary basins can be classified according to their structural genesis and evolutionary history and the latter can be linked to petroleumsystem and playdevelopment. We propose an approach in which we use the established concepts in a new way: breaking basins down into their natural basin cycle

Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361

Science.gov (United States)

Tauxe, L.; Sugisaki, S.; Jiménez-Espejo, F.; Escutia, C.; Cook, C. P.; van de Flierdt, T.; Iwai, M.

2015-02-01

IODP Expedition 318 drilled Site U1361 on the continental rise offshore of Adélie Land and the Wilkes subglacial basin. The objective was to reconstruct the stability of the East Antarctic Ice Sheet (EAIS) during Neogene warm periods, such as the late Miocene and the early Pliocene. The sedimentary record tells a complex story of compaction, and erosion (thus hiatuses). Teasing out the paleoenvironmental implications is essential for understanding the evolution of the EAIS. Anisotropy of magnetic susceptibility (AMS) is sensitive to differential compaction and other rock magnetic parameters like isothermal remanence and anhysteretic remanence are very sensitive to changes in the terrestrial source region. In general, highly anisotropic layers correspond with laminated clay-rich units, while more isotropic layers are bioturbated and have less clay. Layers enriched in diatoms are associated with the latter, which also have higher Ba/Al ratios consistent with higher productivity. Higher anisotropy layers have lower porosity and moisture contents and have fine grained magnetic mineralogy dominated by maghemite, the more oxidized form of iron oxide, while the lower anisotropy layers have magnetic mineralogies dominated by magnetite. The different magnetic mineralogies support the suggestion based on isotopic signatures by Cook et al. (2013) of different source regions during low productivity (cooler) and high productivity (warmer) times. These two facies were tied to the coastal outcrops of the Lower Paleozoic granitic terranes and the Ferrar Large Igneous Province in the more inland Wilkes Subglacial Basin respectively. Here we present evidence for a third geological unit, one eroded at the boundaries between the high and low clay zone with a "hard" (mostly hematite) dominated magnetic mineralogy. This unit likely outcrops in the Wilkes subglacial basin and could be hydrothermally altered Beacon sandstone similar to that detected by Craw and Findlay (1984) in Taylor

A study of tectonic activity in the Basin-Range Province and on the San Andreas Fault. No. 1: Kinematics of Basin-Range intraplate extension

Science.gov (United States)

Eddington, P. K.; Smith, R. B.; Renggli, C.

1986-01-01

Strain rates assessed from brittle fracture and total brittle-ductile deformation measured from geodetic data were compared to estimates of paleo-strain from Quaternary geology for the intraplate Great Basin part of the Basin-Range, western United States. These data provide an assessment of the kinematics and mode of lithospheric extension that the western U.S. Cordillera has experienced from the past few million years to the present. Strain and deformation rates were determined by the seismic moment tensor method using historic seismicity and fault plane solutions for sub-regions of homogeneous strain. Contemporary deformation in the Great Basin occurs principally along the active seismic zones. The integrated opening rate across the entire Great Basin is accommodated by E-E extension at 8 to 10 mm/a in the north that diminishes to NW-SE extension of 3.5 mm/a in the south. Zones of maximum lithospheric extension correspond to belts of thin crust, high heat flow, and Quaternary basaltic volcanism, suggesting that these parameters are related through mechanism of extension such as a stress relaxation, allowing bouyant uplift and ascension of magmas.

Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

Energy Technology Data Exchange (ETDEWEB)

Burillo, J. C.; Reyes C, M.; Montero C, M. E.; Renteria V, M.; Herrera P, E. F. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Reyes, I.; Espino, M. S., E-mail: elena.montero@cimav.edu.mx [Universidad Autonoma de Chihuahua, Facultad de Ingenieria, Nuevo Campus Universitario, Chihuahua (Mexico)

2012-06-15

The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m{sup 3}. The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

International Nuclear Information System (INIS)

Burillo, J. C.; Reyes C, M.; Montero C, M. E.; Renteria V, M.; Herrera P, E. F.; Reyes, I.; Espino, M. S.

2012-01-01

The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m 3 . The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

Geomorphological characterization of endorheic basins in northern Chile

Science.gov (United States)

Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

2011-12-01

Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1

Paleoenvironmental change as seen from a multiproxy perspective in the West Turkana Kaitio core (WTK13), Kenya

Science.gov (United States)

Beck, C. C.; Feibel, C. S.; Lupien, R.; Yost, C. L.; Rucina, S.; Russell, J. M.; Deino, A. L.; Sier, M.; Cohen, A. S.; Campisano, C. J.

2017-12-01

The Hominin Sites and Paleolakes Drilling Project's (HSPDP) primary goal is to provide high quality environmental records to test whether and how Earth system dynamics influenced the evolution of hominins in Africa. To this end, multiproxy records from individual basins are essential to understanding how paleoenvironments changed in relation to shifts in the climatic and/or tectonic regimes both locally on a basin-scale and regionally across East Africa. Because of its rich combination of paleoanthropologic and geologic data, the West Turkana Kaitio (WTK13) core is an important component of this synthesis. Using a combination of tephra chronology and paleomagnetic data, the core has been dated to 1.87-1.37 Ma. The sedimentology records deposition on a dynamic lacustrine margin becoming more influenced by channel and floodplain processes through time. Multiproxy records provide a window into paleoevironments of the Turkana Basin that operated on shorter time scales than this dominant first-order facies shift. Processional cycles (21 kyr) are picked up by indicator records where the preservation of the archive was good enough to allow for high-resolution analysis. However, interestingly, the biomarker record suggests that the hydroclimate of the Turkana Basin, while highly variable at the Milankovitch-scale, exhibits no directional trend in the mean values towards wetter or drier conditions. The combined phytolith and pollen records suggest that grasses, albeit with fluctuating abundances of C4 mesophytic and C4 xerophytic taxa, dominated the landscape throughout most of the core. This indicates that despite climatic variability, resource availability may have maintained some general consistency for hominins in the area. Ultimately, the time period spanned by the WTK13 record is significant for our understanding of hominin evolution as it covers an interval of increasing aridity on the African continent as observed in distal marine records. This synthesis

The study on the spatial-temporal changes of land use pattern in eastern Sichuan basin based on RS/GIS

Science.gov (United States)

Sun, Siqi; Xiao, Yi; Guo, Luo

2018-02-01

Eastern Sichuan Basin is one of the areas sensitive to global climate change. Due to impacts from human disturbance, the farmland in the study area has been degrading, and the desertification of land has been expanding rapidly. Based on the data of Landsat TM/ETM image in 1990, 1995, 2000, 2005 and 2010, this thesis analysed the spatial characteristics and dynamic trends of land use pattern in eastern Sichuan basin using software for remote sense and geographical information system. The driving factors of land-use change in study area were also discussed. The results indicated that: (i) the area of farmland has significantly decreased because of degradation and conversion from grassland into building land; (ii) farmland patches have changed into fragmented and isolated ones; (iii) the main landscapes in study area, are farmland and forests; (iv) land-use change is significantly associated with the human activities. This study provides a strong theoretical and technical basis for the policy-making of environmental protection and management in Eastern Sichuan Basin of Sichuan Province in china.

Morphometric analysis of the Marmara Sea river basins, Turkey

Science.gov (United States)

Elbaşı, Emre; Ozdemir, Hasan

2014-05-01

The drainage basin, the fundamental unit of the fluvial landscape, has been focus of research aimed at understanding the geometric characteristics of the master channel and its tributary network. This geometry is referred to as the basin morphometry and is nicely reviewed by Abrahams (1984). A great amount of research has focused on geometric characteristic of drainage basins, including the topology of the stream networks, and quantitative description of drainage texture, pattern, shape, and relief characteristics. Evaluation of morphometric parameters necessitates the analysis of various drainage parameters such as ordering of the various streams, measurement of basin area and perimeter, length of drainage channels, drainage density (Dd), stream frequency (Fs), bifurcation ratio (Rb), texture ratio (T), basin relief (Bh), Ruggedness number (Rn), time of concentration (Tc), hypsometric curve and integral (Hc and Hi) (Horton, 1932, Schumn, 1956, Strahler, 1957; Verstappen 1983; Keller and Pinter, 2002; Ozdemir and Bird, 2009). These morphometric parameters have generally been used to predict flood peaks, to assess sediment yield, and to estimate erosion rates in the basins. River basins of the Marmara Sea, has an area of approximately 40,000 sqkm, are the most important basins in Turkey based on their dense populations, industry and transportation systems. The primary aim of this study is to determine and analyse of morphometric characteristics of the Marmara Sea river basins using 10 m resolution Digital Elevation Model (DEM) and to evaluate of the results. For these purposes, digital 10 m contour maps scaled 1:25000 and geological maps scaled 1:100000 were used as the main data sources in the study. 10 m resolution DEM data were created using the contour maps and then drainage networks and their watersheds were extracted using D8 pour point model. Finally, linear, areal and relief morphometries were applied to the river basins using Geographic Information Systems

SOME ASPECTS OF HYDROLOGICAL RISK MANIFESTATION IN JIJIA BASIN

Directory of Open Access Journals (Sweden)

D. BURUIANĂ

2012-03-01

Full Text Available Jijia river basin surface geographically fits in Moldavian Plateau, Plain of Moldavia subunit. Being lowered by 200 to 300 m compared to adjacent subunits, it appears as a depression with altitudes between 270-300 m.Through its position in the extra-Carpathian region, away from the influence of oceanic air masses, but wide open to the action of air masses of eastern, north-eastern and northern continental origin, Jijia basin receives precipitations which vary according to the average altitude differing from the northern to the southern part of the basin (564 mm in north, 529.4 mm in Iasi. A characteristic phenomenon to the climate is represented by the torrential rains in the hot season, under the form of rain showers with great intensity, fact that influences the drainage of basin rivers. Jijia hydrographic basin is characterized by frequent and sharp variations of flow volumes and levels which lead to floods and flooding throughout the basin. The high waters generally occur between March and June, when approximately 70% of the annual stock is transported. The paper analyzes the main causes and consequences of flooding in the studied area, also identifying some structural and non-structural measures of flood protection applied by authorities in Jijia hydrographic basin. As a case study, the flood recorded in Dorohoi in June 28-29, 2010 is presented.

Structural Framework and Architecture of the Paleoproterozoic Bryah and Padbury Basins from Integrated Potential Field and Geological Datasets: Towards an Understanding of the Basin Evolution

Science.gov (United States)

Nigro R A Ramos, L.; Aitken, A.; Occhipinti, S.; Lindsay, M.

2017-12-01

The Bryah and Padbury Basins were developed along the northern margin of the Yilgarn Craton, in the southern portion of the Capricorn Orogen, which represents a Proterozoic tectonic zone that bounds the Yilgarn and Pilbara Cratons in Western Australia. These basins have been previously interpreted as developing in a rift, back-arc, and retro-arc foreland basins. Recent studies suggest that the Bryah Basin was deposited in a rift setting, while the overlying Padbury Basin evolved in a pro-foreland basin during the collision of the Yilgarn Craton and the Pilboyne block (formed by the Pilbara Craton and the Glenburgh Terrane), occurring in the Glenburgh Orogeny (2005-1960 Ma). This study focuses on characterizing the architecture and structural framework of the Bryah and Padbury Basins through analysis of geophysical and geological datasets, in order to better understand the different stages of the basins evolution. Gravity and magnetic data were used to define the main tectonic units and lithological boundaries, and to delineate major discontinuities in the upper and lower crust, as well as anomalies through a combination of map view interpretation and forward modelling. Geological mapping and drill core observations were linked with the geophysical interpretations. Fourteen magnetic domains are distinguished within the basins, while four main domains based on the Bouguer Anomaly are recognized. The highest gravity amplitude is related with an anomaly trending EW/NE-SW, which is coincident with the voluminous mafic rocks of the Bryah Basin, and may indicate the presence of an approximately 5km thick package of higher density mafic rocks. Magnetic depth estimations also indicate deep magnetic sources up to approximately 4,45km. These results can help to elucidate processes that occurred during the precursor rift of the early stages of the Bryah Basin, add information in relation to the basement control on sedimentation, allow the characterization of the varying

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

Energy Technology Data Exchange (ETDEWEB)

1993-10-01

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

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.

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

International Nuclear Information System (INIS)

Orphanopoulus Stehr, D.

1982-01-01

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.)

K Basin safety analysis

International Nuclear Information System (INIS)

Porten, D.R.; Crowe, R.D.

1994-01-01

The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall

Melo carboniferous basin

International Nuclear Information System (INIS)

Flossdarf, A.

1988-01-01

This report is about of the Melo carboniferous basin which limits are: in the South the large and high Tupambae hill, in the west the Paraiso hill and the river mountains, in the North Yaguaron river basin to Candidata in Rio Grande del Sur in Brazil.

Modeling effects of secondary tidal basins on estuarine morphodynamics

Science.gov (United States)

Nnafie, Abdel; Van Oyen, Tomas; De Maerschalck, Bart

2017-04-01

Many estuaries are situated in very densely populated areas with high economic activities that often conflict with their ecological values. For centuries, geometry and bathymetry of estuaries have been drastically modified trough engineering works such as embanking, sand extraction, channel deepening, land reclamations, etc. It is generally recognized that these works may increase the tidal range (e.g., Scheldt, Ems, Elbe) and turbidity (e.g., Loire, Ems) in estuaries [cf. Kerner, 2007; Wang et al., 2009; Winterwerp and Wang, 2013; Van Maren et al., 2015b,a]. In recent years, construction of secondary basins (also called retention basins) has gained increasing popularity among coastal managers to reduce tidal range and turbidity [Donner et al., 2012]. Previous studies have shown that location, geometry and number of secondary basins have a significant impact on tidal characteristics and sediment transport [Alebregtse and de Swart, 2014; Roos and Schuttelaars, 2015]. However, knowledge on how these secondary basins affect the morphodynamic development of estuaries on long time scales (order decades to centuries) is still lacking. The specific objectives of this study are twofold. First, to investigate effects of secondary basins on the long-term morphodynamic evolution of estuaries. In particular, effects of the presence of such a basin on the morphodynamic evolution of the main channel in the estuary and the physics underlying channel migration will be examined. For this, the Western Scheldt estuary (situated in the Netherlands) is used as a case study, which used to consist of multiple secondary tidal basins that were located at different positions in the estuary, and which have been gradually closed off between 1800 and 1968. Second, to systematically quantify sensitivity of model results to location, geometry, and to number of secondary basins. To this end, the state-of-the- art numerical model Delft3D is used, which has been successfully applied to

Geochemistry of the Late Paleozoic cherts in the Youjiang Basin: Implications for the basin evolution

Directory of Open Access Journals (Sweden)

Huang Hu

2013-10-01

Full Text Available We analyzed the major and rare earth element compositions of siliceous deposits from the Upper Devonian Liujiang Formation, Lower Carboniferous Luzhai Formation, Lower–Middle Permian Sidazhai Formation and Tapi Formation, which are widely distributed as bedded cherts in the interplatform basinal successions of the Youjiang Basin. The Liujiang Formation and Luzhai Formation cherts generally have high Al/(Al+Fe+Mn values (0.38–0.94 and are non-hydrothermal cherts. These cherts are generally characterized by moderately negative Ce anomalies and high Y/Ho values relatived to PAAS, indicating that the Youjiang Basin might have evolved into an open rift basin during the Late Devonian–Early Carboniferous. The Sidazhai Formation cherts from Ziyun generally have high Al/(Al+Fe+Mn values (0.60–0.78, suggesting negligible contribution from a hydrothermal component. The Sidazhai Formation cherts from Hechi and the Tapi Formation cherts from Malipo generally have low Al/(Al+Fe+Mn values (0.09–0.41, indicating an intense hydrothermal input. Relatived to the Sidazhai Formation cherts, the Tapi Formation cherts have higher Ce/Ce* values (0.68±0.19 and lower Y/Ho values (41.83±13.27, which may be affected by the terrigenous input from the Vietnam Block. The Sidazhai Formation cherts from Ziyun and Hechi exhibit negative Ce anomalies (0.43±0.12, 0.33±0.17, respectively with high Y/Ho values (57.44±16.20, 46.02±4.27, respectively, resembling the geochemical characteristics of open-ocean basin cherts. These cherts were deposited on a passive continental margin adjacent to the Babu branch ocean, which may have contributed to upwelling. Detailed spatial studies on geochemical characteristics of the Late Paleozoic cherts can unravel the evolution of the Youjiang Basin.

Quantification of water resources uncertainties in the Luvuvhu sub-basin of the Limpopo river basin

Science.gov (United States)

Oosthuizen, N.; Hughes, D.; Kapangaziwiri, E.; Mwenge Kahinda, J.; Mvandaba, V.

2018-06-01

In the absence of historical observed data, models are generally used to describe the different hydrological processes and generate data and information that will inform management and policy decision making. Ideally, any hydrological model should be based on a sound conceptual understanding of the processes in the basin and be backed by quantitative information for the parameterization of the model. However, these data are often inadequate in many sub-basins, necessitating the incorporation of the uncertainty related to the estimation process. This paper reports on the impact of the uncertainty related to the parameterization of the Pitman monthly model and water use data on the estimates of the water resources of the Luvuvhu, a sub-basin of the Limpopo river basin. The study reviews existing information sources associated with the quantification of water balance components and gives an update of water resources of the sub-basin. The flows generated by the model at the outlet of the basin were between 44.03 Mm3 and 45.48 Mm3 per month when incorporating +20% uncertainty to the main physical runoff generating parameters. The total predictive uncertainty of the model increased when water use data such as small farm and large reservoirs and irrigation were included. The dam capacity data was considered at an average of 62% uncertainty mainly as a result of the large differences between the available information in the national water resources database and that digitised from satellite imagery. Water used by irrigated crops was estimated with an average of about 50% uncertainty. The mean simulated monthly flows were between 38.57 Mm3 and 54.83 Mm3 after the water use uncertainty was added. However, it is expected that the uncertainty could be reduced by using higher resolution remote sensing imagery.

Environmental Setting of the Sugar Creek and Leary Weber Ditch Basins, Indiana, 2002-04

Science.gov (United States)

Lathrop, Timothy R.

2006-01-01

The Leary Weber Ditch Basin is nested within the Sugar Creek Basin in central Indiana. These basins make up one of the five study sites in the Nation selected for the Agricultural Chemicals: Sources, Transport, and Fate topical study, a part of the U.S. Geological Survey’s National Water-Quality Assessment Program. In this topical study, identifying the natural factors and human influences affecting water quality in the Leary Weber Ditch and Sugar Creek Basins are the focus of the assessment. A detailed comparison between the environmental settings of these basins is presented. Specifics of the topical study design as implemented in the Leary Weber Ditch and Sugar Creek Basins are described.

Basin Hopping Graph

DEFF Research Database (Denmark)

Kucharik, Marcel; Hofacker, Ivo; Stadler, Peter

2014-01-01

of the folding free energy landscape, however, can provide the relevant information. Results We introduce the basin hopping graph (BHG) as a novel coarse-grained model of folding landscapes. Each vertex of the BHG is a local minimum, which represents the corresponding basin in the landscape. Its edges connect...

Simulating Water Resource Disputes of Transboundary River: A Case Study of the Zhanghe River Basin, China

Science.gov (United States)

Yuan, Liang; He, Weijun; Liao, Zaiyi; Mulugeta Degefu, Dagmawi; An, Min; Zhang, Zhaofang

2018-01-01

Water resource disputes within transboundary river basin has been hindering the sustainable use of water resources and efficient management of environment. The problem is characterized by a complex information feedback loop that involves socio-economic and environmental systems. This paper presents a system dynamics based model that can simulate the dynamics of water demand, water supply, water adequacy and water allocation instability within a river basin. It was used for a case study in the Zhanghe River basin of China. The base scenario has been investigated for the time period between 2000 and 2050. The result shows that the Chinese national government should change the water allocation scheme of downstream Zhanghe River established in 1989, more water need to be allocated to the downstream cities and the actual allocation should be adjusted to reflect the need associated with the socio-economic and environmental changes within the region, and system dynamics improves the understanding of concepts and system interactions by offering a comprehensive and integrated view of the physical, social, economic, environmental, and political systems.

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

International Nuclear Information System (INIS)

Thackston, J.W.; Mangarella, P.A.; Preslo, L.M.

1986-05-01

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

Can Pallars i Llobateres: A new hominoid-bearing locality from the late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula).

Science.gov (United States)

Alba, David M; Casanovas-Vilar, Isaac; Furió, Marc; García-Paredes, Israel; Angelone, Chiara; Jovells-Vaqué, Sílvia; Luján, Àngel H; Almécija, Sergio; Moyà-Solà, Salvador

2018-05-18

In the Iberian Peninsula, Miocene apes (Hominoidea) are generally rare and mostly restricted to the Vallès-Penedès Basin. Here we report a new hominoid maxillary fragment with M 2 from this basin. It was surface-collected in March 2017 from the site of Can Pallars i Llobateres (CPL, Sant Quirze del Vallès), where fossil apes had not been previously recorded. The locality of provenance (CPL-M), which has delivered no further fossil remains, is located very close (ca. 50 m) to previously known CPL outcrops, and not very far (ca. 500 m in NW direction) from the classical hominoid-bearing locality of Can Poncic 1. Here we describe the new fossil and, based on the size and proportions of the M 2 , justify its taxonomic attribution to Hispanopithecus cf. laietanus, a species previously recorded from several Vallesian sites of the Vallès-Penedès Basin. Based on the associated mammalian fauna from CPL, we also provide a biochronological dating and a paleoenvironmental reconstruction for the site. The associated fauna enables an unambiguous correlation to the Cricetulodon hartenbergeri - Progonomys hispanicus interval local subzone, with an estimated age of 9.98-9.73 Ma (late Vallesian, MN10). Therefore, CPL-M is roughly coeval with the Hispanopithecus laietanus-bearing localities of Can Llobateres 1 and Can Feu 1, and minimally older than those of La Tarumba 1 and Can Llobateres 2. In contrast, CPL-M is younger than the early Vallesian (MN9) localities of Can Poncic 1 (the type locality of Hispanopithecus crusafonti) as well as Polinyà 2 (Gabarró) and Estació Depuradora d'Aigües Residuals-Riu Ripoll 13, where Hispanopithecus sp. is recorded. The associated fauna from CPL indicates a densely forested and humid paleoenvironment with nearby freshwater. This supports the view that Hispanopithecus might have been restricted to dense wetland forests soon before its extinction during the late Vallesian, due to progressive climatic deterioration. Coupled with the

State of stress in exhumed basins and implications for fluid flow: insights from the Illizi Basin, Algeria

KAUST Repository

English, Joseph M.

2017-05-31

The petroleum prospectivity of an exhumed basin is largely dependent on the ability of pre-existing traps to retain oil and gas volumes during and after the exhumation event. Although faults may act as lateral seals in petroleum traps, they may start to become hydraulically conductive again and enable fluid flow and hydrocarbon leakage during fault reactivation. We constrain the present day in situ stresses of the exhumed Illizi Basin in Algeria and demonstrate that the primary north–south and NW–SE (vertical strike-slip) fault systems in the study area are close to critical stress (i.e. an incipient state of shear failure). By contrast, the overpressured and unexhumed Berkine Basin and Hassi Messaoud areas to the north do not appear to be characterized by critical stress conditions. We present conceptual models of stress evolution and demonstrate that a sedimentary basin with benign in situ stresses at maximum burial may change to being characterized by critical stress conditions on existing fault systems during exhumation. These models are supportive of the idea that the breaching of a closed, overpressured system during exhumation of the Illizi Basin may have been a driving mechanism for the regional updip flow of high-salinity formation water within the Ordovician reservoirs during Eocene–Miocene time. This work also has implications for petroleum exploration in exhumed basins. Fault-bounded traps with faults oriented at a high angle to the maximum principal horizontal stress direction in strike-slip or normal faulting stress regimes are more likely to have retained hydrocarbons in exhumed basins than fault-bounded traps with faults that are more optimally oriented for shear failure and therefore have a greater propensity to become critically stressed during exhumation.

Terminal Fluvial Systems in a Semi-arid Endorheic Basin, Salar de Uyuni (Bolivia)

NARCIS (Netherlands)

Li, J.

2014-01-01

Many ancient sedimentary basins are interpreted as endorheic basins, internally drained basins with no direct hydrological connection to the marine environment. Some of these endorheic basins are economically important because of the abundance of hydrocarbon resources. To date, many studies have

Hydrochemical evolution and groundwater flow processes in the Galilee and Eromanga basins, Great Artesian Basin, Australia: a multivariate statistical approach.

Science.gov (United States)

Moya, Claudio E; Raiber, Matthias; Taulis, Mauricio; Cox, Malcolm E

2015-03-01

The Galilee and Eromanga basins are sub-basins of the Great Artesian Basin (GAB). In this study, a multivariate statistical approach (hierarchical cluster analysis, principal component analysis and factor analysis) is carried out to identify hydrochemical patterns and assess the processes that control hydrochemical evolution within key aquifers of the GAB in these basins. The results of the hydrochemical assessment are integrated into a 3D geological model (previously developed) to support the analysis of spatial patterns of hydrochemistry, and to identify the hydrochemical and hydrological processes that control hydrochemical variability. In this area of the GAB, the hydrochemical evolution of groundwater is dominated by evapotranspiration near the recharge area resulting in a dominance of the Na-Cl water types. This is shown conceptually using two selected cross-sections which represent discrete groundwater flow paths from the recharge areas to the deeper parts of the basins. With increasing distance from the recharge area, a shift towards a dominance of carbonate (e.g. Na-HCO3 water type) has been observed. The assessment of hydrochemical changes along groundwater flow paths highlights how aquifers are separated in some areas, and how mixing between groundwater from different aquifers occurs elsewhere controlled by geological structures, including between GAB aquifers and coal bearing strata of the Galilee Basin. The results of this study suggest that distinct hydrochemical differences can be observed within the previously defined Early Cretaceous-Jurassic aquifer sequence of the GAB. A revision of the two previously recognised hydrochemical sequences is being proposed, resulting in three hydrochemical sequences based on systematic differences in hydrochemistry, salinity and dominant hydrochemical processes. The integrated approach presented in this study which combines different complementary multivariate statistical techniques with a detailed assessment of the

Temporal evolution of fault systems in the Upper Jurassic of the Central German Molasse Basin: case study Unterhaching

Science.gov (United States)

Budach, Ingmar; Moeck, Inga; Lüschen, Ewald; Wolfgramm, Markus

2018-03-01

The structural evolution of faults in foreland basins is linked to a complex basin history ranging from extension to contraction and inversion tectonics. Faults in the Upper Jurassic of the German Molasse Basin, a Cenozoic Alpine foreland basin, play a significant role for geothermal exploration and are therefore imaged, interpreted and studied by 3D seismic reflection data. Beyond this applied aspect, the analysis of these seismic data help to better understand the temporal evolution of faults and respective stress fields. In 2009, a 27 km2 3D seismic reflection survey was conducted around the Unterhaching Gt 2 well, south of Munich. The main focus of this study is an in-depth analysis of a prominent v-shaped fault block structure located at the center of the 3D seismic survey. Two methods were used to study the periodic fault activity and its relative age of the detected faults: (1) horizon flattening and (2) analysis of incremental fault throws. Slip and dilation tendency analyses were conducted afterwards to determine the stresses resolved on the faults in the current stress field. Two possible kinematic models explain the structural evolution: One model assumes a left-lateral strike slip fault in a transpressional regime resulting in a positive flower structure. The other model incorporates crossing conjugate normal faults within a transtensional regime. The interpreted successive fault formation prefers the latter model. The episodic fault activity may enhance fault zone permeability hence reservoir productivity implying that the analysis of periodically active faults represents an important part in successfully targeting geothermal wells.

Classification of Prairie basins by their hysteretic connected functions

Science.gov (United States)

Shook, K.; Pomeroy, J. W.

2017-12-01

Diagnosing climate change impacts in the post-glacial landscapes of the North American Prairies through hydrological modelling is made difficult by drainage basin physiography. The region is cold, dry and flat with poorly developed stream networks, and so the basin area that is hydrologically connected to the stream outlet varies with basin depressional storage. The connected area controls the contributing area for runoff reaching the stream outlet. As depressional storage fills, ponds spill from one to another; the chain of spilling ponds allows water to flow over the landscape and increases the connected area of the basin. As depressional storage decreases, the connected fraction drops dramatically. Detailed, fine-scale models and remote sensing have shown that the relationship between connected area and the depressional storage is hysteretic in Prairie basins and that the nature of hysteresis varies with basin physiography. This hysteresis needs to be represented in hydrological models to calculate contributing area, and therefore streamflow hydrographs. Parameterisations of the hysteresis are needed for large-scale models used for climate change diagnosis. However, use of parameterisations of hysteresis requires guidance on how to represent them for a particular basin. This study shows that it is possible to relate the shape of hysteretic functions as determined by detailed models to the overall physiography of the basin, such as the fraction of the basin below the outlet, and remote sensing estimates of depressional storage, using the size distribution and location of maximum ponded water areas. By classifying basin physiography, the hysteresis of connected area - storage relationships can be estimated for basins that do not have high-resolution topographic data, and without computationally-expensive high-resolution modelling.

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)

Sediment-hosted micro-disseminated gold mineralization constrained by basin paleo-topographic highs in the Youjiang basin, South China

Science.gov (United States)

Liu, Jianming; Ye, Jie; Ying, Hanlong; Liu, Jiajun; Zheng, Minghua; Gu, Xuexiang

2002-06-01

The Youjiang basin is a Devonian-Triassic rift basin on the southern margin of the Yangtze Craton in South China. Strong syndepositional faulting defined the basin-and-range style paleo-topography that further developed into isolated carbonate platforms surrounded by siliciclastic filled depressions. Finally, thick Triassic siliciclastic deposits covered the platforms completely. In the Youjiang basin, numerous sediment-hosted, micro-disseminated gold (SMG) deposits occur mainly in Permian-Triassic chert and siliciclastic rocks. SMG ores are often auriferous sedimentary rocks with relatively low sulfide contents and moderate to weak alteration. Similar to Carlin-type gold ores in North America, SMG ores in the Youjiang basin are characterized by low-temperature mineral assemblages of pyrite, arsenopyrite, realgar, stibnite, cinnabar, marcasite, chalcedony and carbonate. Most of the SMG deposits are remarkably distributed around the carbonate platforms. Accordingly, there are platform-proximal and platform-distal SMG deposits. Platform-proximal SMG deposits often occur in the facies transition zone between the underlying platform carbonate rocks and the overlying siliciclastic rocks with an unconformity (often a paleo-karst surface) in between. In the ores and hostrocks there are abundant synsedimentary-syndiagenetic fabrics such as lamination, convolute bedding, slump texture, soft-sediment deformation etc. indicating submarine hydrothermal deposition and syndepositional faulting. Numerous fluid-escape and liquefaction fabrics imply strong fluid migration during sediment basin evolution. Such large-scale geological and fabric evidence implies that SMG ores were formed during basin evolution, probably in connection with basinal fluids. It is well known that basinal fluids (especially sediment-sourced fluids) will migrate generally (1) upwards, (2) towards basin margins or basin topographic highs, (3) and from thicker towards thinner deposits during basin evolution

Bibliography, geophysical data locations, and well core listings for the Mississippi Interior Salt Basin

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

To date, comprehensive basin analysis and petroleum system modeling studies have not been performed on any of the basins in the northeastern Gulf of Mexico. Of these basins, the Mississippi Interior Salt Basin has been selected for study because it is the most petroliferous basin in the northeastern Gulf of Mexico, small- and medium-size companies are drilling the majority of the exploration wells. These companies do not have the resources to perform basin analysis or petroleum system modeling research studies nor do they have the resources to undertake elaborate information searches through the volumes of publicly available data at the universities, geological surveys, and regulatory agencies in the region. The Advanced Geologic Basin Analysis Program of the US Department of Energy provides an avenue for studying and evaluating sedimentary basins. This program is designed to improve the efficiency of the discovery of the nation`s remaining undiscovered oil resources by providing improved access to information available in the public domain and by increasing the amount of public information on domestic basins. This report provides the information obtained from Year 1 of this study of the Mississippi Interior Salt Basin. The work during Year 1 focused on inventorying the data files and records of the major information repositories in the northeastern Gulf of Mexico and making these inventories easily accessible in an electronic format.

Rifting Thick Lithosphere - Canning Basin, Western Australia

Science.gov (United States)

Czarnota, Karol; White, Nicky

2016-04-01

The subsidence histories and architecture of most, but not all, rift basins are elegantly explained by extension of ~120 km thick lithosphere followed by thermal re-thickening of the lithospheric mantle to its pre-rift thickness. Although this well-established model underpins most basin analysis, it is unclear whether the model explains the subsidence of rift basins developed over substantially thick lithosphere (as imaged by seismic tomography beneath substantial portions of the continents). The Canning Basin of Western Australia is an example where a rift basin putatively overlies lithosphere ≥180 km thick, imaged using shear wave tomography. Subsidence modelling in this study shows that the entire subsidence history of the account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted in density by 50-70 kg m-3, which is in line with estimates derived from modelling rare-earth element concentrations of the ~20 Ma lamproites and global isostatic considerations. Together, these results suggest that thick lithosphere thinned to > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal re-thickening of the lithospheric mantle. Our results show that variations in lithospheric thickness place a fundamental control on basin architecture. The discrepancy between estimates of lithospheric thickness derived from subsidence data for the western Canning Basin and those derived from shear wave tomography suggests that the latter technique currently is limited in its ability to resolve lithospheric thickness variations at horizontal half-wavelength scales of <300 km.

Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists: an example from Tampere Schist Belt, Finland

DEFF Research Database (Denmark)

Kalliomäki, Henrik; Torvela, Taija; Moreau, Julien

, therefore, offers an excellent opportunity to examine the volcano-sedimentary evolution of an ancient marginal basin, and the mechanics of and strain distribution during its subsequent closure. The aim of this study is to investigate the structural development and the architecture of a part of the TSB...... in more detail, including the relationships between the volcano-sedimentary sequences, the tectonic structures, and the sulphide-bearing schist horizons. Important insights are gained into understanding the mechanisms of the basin closure and the localisation of the sulphide mineralisation within......, in order to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic relationship between the interpreted palaeothrusts and the sulphide-bearing schist horizons in the study area: early, gently dipping thrusts acted as both channels and traps...

Great Basin Experimental Range: Annotated bibliography

Science.gov (United States)

E. Durant McArthur; Bryce A. Richardson; Stanley G. Kitchen

2013-01-01

This annotated bibliography documents the research that has been conducted on the Great Basin Experimental Range (GBER, also known as the Utah Experiment Station, Great Basin Station, the Great Basin Branch Experiment Station, Great Basin Experimental Center, and other similar name variants) over the 102 years of its existence. Entries were drawn from the original...

Wave Energy Potential in the Eastern Mediterranean Levantine Basin. An Integrated 10-year Study

Science.gov (United States)

2014-01-01

SUBTITLE Wave energy potential in the Eastern Mediterranean Levantine Basin. An integrated 10-year study 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c... Cardone CV, Ewing JA, et al. The WAM model e a third generation ocean wave prediction model. J Phys Oceanogr 1988;18(12):1775e810. [70] Varinou M

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

International Nuclear Information System (INIS)

Kitcho, C.A.; Wong, I.G.; Turcotte, F.T.

1986-08-01

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

Frequency and sources of basin floor turbidites in alfonso basin, Gulf of California, Mexico: Products of slope failures

Science.gov (United States)

Gonzalez-Yajimovich, Oscar E.; Gorsline, Donn S.; Douglas, Robert G.

2007-07-01

Alfonso Basin is a small margin basin formed by extensional tectonics in the actively rifting, seismically active Gulf of California. The basin is centered at 24°40' N and 110° 38' W, and is a closed depression (maximum depth 420 m) with an effective sill depth of about 320 m (deepest sill), a width of 20 km and length of 25 km. Basin floor area below a depth of 350 m is about 260 km 2. The climate is arid to semiarid but was wetter during the early (ca. 10,000-7000 Calendar years Before Present [BP]) and middle Holocene (ca. 7000-4000 Cal. Years BP). Basin-wide turbidity currents reach the floor of Alfonso Basin at centennial to millennial intervals. The peninsular drainages tributary to the basin are small and have maximum flood discharges of the order of 10 4m 3. The basin-floor turbidites thicker than 1 cm have volumes of the order of 10 6m 3 to 10 8m 3 and require a much larger source. The largest turbidite seen in our cores is ca. 1 m thick in the central basin floor and was deposited 4900 Calendar Years Before Present (BP). Two smaller major events occurred about 1500 and 2800 Cal. Years BP. Seismicity over the past century of record shows a clustering of larger epicenters along faults forming the eastern Gulf side of Alfonso Basin. In that period there have been four earthquakes with magnitudes above 7.0 but all are distant from the basin. Frequency of such earthquakes in the basin vicinity is probably millennial. It is concluded that the basin-wide turbidites thicker than 1 cm must be generated by slope failures on the eastern side of the basin at roughly millennial intervals. The thin flood turbidites have a peninsular source at centennial frequencies.

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...

Geochemical and palynological records for the end-Triassic Mass-Extinction Event in the NE Paris Basin (Luxemburg)

Science.gov (United States)

Kuhlmann, Natascha; van de Schootbrugge, Bas; Thein, Jean; Fiebig, Jens; Franz, Sven-Oliver; Hanzo, Micheline; Colbach, Robert; Faber, Alain

2016-04-01

The End-Triassic mass-extinction event is one of the "big five" mass extinctions in Earth's history. Large scale flood basalt volcanism associated with the break-up of Pangaea, which resulted in the opening of the central Atlantic Ocean, is considered as the leading cause. In addition, an asteroid impact in Rochechouart (France; 201 ± 2 Ma) may have had a local influence on ecosystems and sedimentary settings. The Luxembourg Embayment, in the NE Paris Basin, offers a rare chance to study both effects in a range of settings from deltaic to lagoonal. A multidisciplinary study (sedimentology, geochemistry, palynology) has been carried out on a number of outcrops and cores that span from the Norian to lower Hettangian. Combined geochemical and palynological records from the Boust core drilled in the NE Paris Basin, provide evidence for paleoenvironmental changes associated with the end-Triassic mass-extinction event. The Triassic-Jurassic stratigraphy of the Boust core is well constrained by palynomorphs showing the disappaerance of typical Triassic pollen taxa (e.g. Ricciisporites tuberculates) and the occurrence of the marker species Polypodiisporites polymicroforatus within the uppermost Rhaetian, prior to the Hettangian dominance of Classopollis pollen. The organic carbon stable isotope record (δ13Corg) spanning the Norian to Hettangian, shows a series of prominent negative excursions within the middle Rhaetian, followed by a trend towards more positive values (approx -24 per mille) within the uppermost Rhaetian Argiles de Levallois Member. The lowermost Hettangian is characterized by a major negative excursion, reaching - 30 per mille that occurs in organic-rich sediments. This so-called "main negative excursion" is well-known from other locations, for example from Mariental in Northern Germany and from St Audrie's Bay in England, and Stenlille in Denmark. Based on redox-sensitive trace element records (V, Cr, Ni, Co, Th, U) the lowermost Hettangian in most of

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

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

An analytical study on nested flow systems in a Tóthian basin with a periodically changing water table

Science.gov (United States)

Zhao, Ke-Yu; Jiang, Xiao-Wei; Wang, Xu-Sheng; Wan, Li; Wang, Jun-Zhi; Wang, Heng; Li, Hailong

2018-01-01

Classical understanding on basin-scale groundwater flow patterns is based on Tóth's findings of a single flow system in a unit basin (Tóth, 1962) and nested flow systems in a complex basin (Tóth, 1963), both of which were based on steady state models. Vandenberg (1980) extended Tóth (1962) by deriving a transient solution under a periodically changing water table in a unit basin and examined the flow field distortion under different dimensionless response time, τ∗. Following Vandenberg's (1980) approach, we extended Tóth (1963) by deriving the transient solution under a periodically changing water table in a complex basin and examined the transient behavior of nested flow systems. Due to the effect of specific storage, the flow field is asymmetric with respect to the midline, and the trajectory of internal stagnation points constitutes a non-enclosed loop, whose width decreases when τ∗ decreases. The distribution of the relative magnitude of hydraulic head fluctuation, Δh∗ , is dependent on the horizontal distance away from a divide and the depth below the land surface. In the shallow part, Δh∗ decreases from 1 at the divide to 0 at its neighboring valley under all τ∗, while in the deep part, Δh∗ reaches a threshold, whose value decreases when τ∗ increases. The zones with flowing wells are also found to change periodically. As water table falls, there is a general trend of shrinkage in the area of zones with flowing wells, which has a lag to the declining water table under a large τ∗. Although fluxes have not been assigned in our model, the recharge/discharge flux across the top boundary can be obtained. This study is critical to understand a series of periodically changing hydrogeological phenomena in large-scale basins.

Paleoenvironmental evolution of the coastal plain of Southern Brazil: palynological data from a Holocene core in Santa Catarina State

Directory of Open Access Journals (Sweden)

LIDIA A. KUHN

2017-10-01

Full Text Available ABSTRACT This paper presents a paleoenvironmental reconstruction from palynological analyses of a sedimentary core of Holocene age, drilled at municipality of Garopaba (Santa Catarina, Southern Brazil. A total of 46 samples was collected for palynological analyses in the 450 cm-long core PCSC-3, as also three samples for radiocarbon dating and granulometric analyses. The palynological content includes 84 taxa related to pollen grains of angiosperms (38 and gimnosperm (3, spores of pteridophyta (16 and bryophyta (2, spores of fungi (8, algae (3, acritarchs (3, dinoflagellate cysts (2 and microforaminiferal linings (1. Three specimens of acritarchs are described and illustrated in detail. Three palynological phases were defined based on changes in assemblages: Phase I, Phase II and Phase III. The Phase I is characterized as a lagoonal paleoenvironment with marine influence from the beginning of the sedimentation (5390 cal yr BP, based on occurrences of acritarchs, dinoflagellate cysts and microforaminiferal linings. The Phase II (3032 yr BP until 858 cal yr BP also is characterized by a lagoonal paleoenvironment, however, presented decrease in percentage of marine elements and increase in freshwater algae record, suggesting less marine influence in the lagoonal body. In Phase III (last 856 years, underwater sedimentation prevailed, under swamp-like conditions.

Preliminary study of the uranium potential of the northern part of the Durham Triassic Basin, North Carolina

International Nuclear Information System (INIS)

Harris, W.B.; Thayer, P.A.

1981-09-01

This report presents results of a four-channel spectrometric survey of the northern part of the Durham Triassic basin and adjacent Piedmont, North Carolina. Gamma-ray spectrometric measurements were obtained at 112 localities from 136 different lithologies. The nominal sampling density in the Durham Basin is one site per 2 mi 2 . Surface radiometric surveys reveal no anomalous radioactivity in the northern part of the Durham Basin. Uranium concentrations in Triassic rocks are from 0.6 to 9.7 ppM and average 2.9 ppM. Mudrocks contain from 1.3 to 9.7 ppM, and the average is 4.5 ppM. Sandstones contain from 0.6 to 8.8 ppM, and the average is 2.5 ppM. Fanglomerates contain the lowest concentrations of uranium, from 1.4 to 2.0 ppM, for an average of 1.8 ppM. Uranium/thorium ratios average 0.27 for Triassic rocks and are from 0.04 to 1.85. The mean log uranium/log thorium for Triassic rocks is 0.37. Mudrock has the highest average uranium/thorium ratio (0.32), and the range is 0.09 to 0.66. Sandstones have an average uranium/thorium ratio of 0.26, and the range is 0.04 to 1.85. Fanglomerates have the lowest range uranium/thorium ratio (0.19), and the range is 0.12 to 0.19. On the basis of surface radiometric surveys and geologic studies, it is believed that sedimentary strata in the northern part of the Durham Basin are poor targets for further uranium exploration. This conclusion is based on the lack of favorable characteristics commonly present in fluvial uranium deposits. Among these are: (1) carbonaceous material is absent in Triassic rocks of the northern basin, (2) indicators of a reduzate facies in sandstones are not present, and (3) no tuffaceous beds are associated with sediments in the northern Durham Basin

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

Science.gov (United States)

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

2016-09-01

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

Constraining Basin Depth and Fault Displacement in the Malombe Basin Using Potential Field Methods

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Beresh, S. C. M.; Elifritz, E. A.; Méndez, K.; Johnson, S.; Mynatt, W. G.; Mayle, M.; Atekwana, E. A.; Laó-Dávila, D. A.; Chindandali, P. R. N.; Chisenga, C.; Gondwe, S.; Mkumbwa, M.; Kalaguluka, D.; Kalindekafe, L.; Salima, J.

2017-12-01

The Malombe Basin is part of the Malawi Rift which forms the southern part of the Western Branch of the East African Rift System. At its southern end, the Malawi Rift bifurcates into the Bilila-Mtakataka and Chirobwe-Ntcheu fault systems and the Lake Malombe Rift Basin around the Shire Horst, a competent block under the Nankumba Peninsula. The Malombe Basin is approximately 70km from north to south and 35km at its widest point from east to west, bounded by reversing-polarity border faults. We aim to constrain the depth of the basin to better understand displacement of each border fault. Our work utilizes two east-west gravity profiles across the basin coupled with Source Parameter Imaging (SPI) derived from a high-resolution aeromagnetic survey. The first gravity profile was done across the northern portion of the basin and the second across the southern portion. Gravity and magnetic data will be used to constrain basement depths and the thickness of the sedimentary cover. Additionally, Shuttle Radar Topography Mission (SRTM) data is used to understand the topographic expression of the fault scarps. Estimates for minimum displacement of the border faults on either side of the basin were made by adding the elevation of the scarps to the deepest SPI basement estimates at the basin borders. Our preliminary results using SPI and SRTM data show a minimum displacement of approximately 1.3km for the western border fault; the minimum displacement for the eastern border fault is 740m. However, SPI merely shows the depth to the first significantly magnetic layer in the subsurface, which may or may not be the actual basement layer. Gravimetric readings are based on subsurface density and thus circumvent issues arising from magnetic layers located above the basement; therefore expected results for our work will be to constrain more accurate basin depth by integrating the gravity profiles. Through more accurate basement depth estimates we also gain more accurate displacement

A NEW METHOD FOR ENVIRONMENTAL FLOW ASSESSMENT BASED ON BASIN GEOLOGY. APPLICATION TO EBRO BASIN.

Science.gov (United States)

2018-02-01

The determination of environmental flows is one of the commonest practical actions implemented on European rivers to promote their good ecological status. In Mediterranean rivers, groundwater inflows are a decisive factor in streamflow maintenance. This work examines the relationship between the lithological composition of the Ebro basin (Spain) and dry season flows in order to establish a model that can assist in the calculation of environmental flow rates.Due to the lack of information on the hydrogeological characteristics of the studied basin, the variable representing groundwater inflows has been estimated in a very simple way. The explanatory variable used in the proposed model is easy to calculate and is sufficiently powerful to take into account all the required characteristics.The model has a high coefficient of determination, indicating that it is accurate for the intended purpose. The advantage of this method compared to other methods is that it requires very little data and provides a simple estimate of environmental flow. It is also independent of the basin area and the river section order.The results of this research also contribute to knowledge of the variables that influence low flow periods and low flow rates on rivers in the Ebro basin.

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

International Nuclear Information System (INIS)

Cohen, Stewart J.

1996-01-01

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

Evolution of Xihulitu basin and its control to uranium ore-formation

International Nuclear Information System (INIS)

Guo Qingyin; Li Ziying; Dong Wenming

2003-01-01

There is a close relationship between basin filling succession and evolution of the basin. Characteristics of basin evolution can be studied by analyzing the basin filling succession. Two major periods are recognized according to the filling succession and subsequent alteration of the Xihulitu Basin. Evolutionary characteristics of each stage of the basin formation and alteration have been discussed in details. The types and special distribution of uranium metallization are controlled by the scale, connection degree and distribution of sandstone units and impermeable mudstone beds. The environment of uranium ore-formation became favorable as the faults modified the hydrodynamic condition. The basin had been uplifted for a long time after it was filled. Intergranular pores are not destroyed due to the weak mechanical compaction, which is beneficial to groundwater penetrating. Montmorillonitization and zeolitization in some sandstone units are strong because of the high content of volcanic fragments. The major uranium metallization is the phreatic oxidation type. The northern zone of the second sub-basin in the central section of the basin is regarded as the first perspective target for subsequent exploration. (authors)

Three-dimensional modeling of pull-apart basins: implications for the tectonics of the Dead Sea Basin

Science.gov (United States)

Katzman, Rafael; ten Brink, Uri S.; Lin, Jian

1995-01-01

We model the three-dimensional (3-D) crustal deformation in a deep pull-apart basin as a result of relative plate motion along a transform system and compare the results to the tectonics of the Dead Sea Basin. The brittle upper crust is modeled by a boundary element technique as an elastic block, broken by two en echelon semi-infinite vertical faults. The deformation is caused by a horizontal displacement that is imposed everywhere at the bottom of the block except in a stress-free “shear zone” in the vicinity of the fault zone. The bottom displacement represents the regional relative plate motion. Results show that the basin deformation depends critically on the width of the shear zone and on the amount of overlap between basin-bounding faults. As the width of the shear zone increases, the depth of the basin decreases, the rotation around a vertical axis near the fault tips decreases, and the basin shape (the distribution of subsidence normalized by the maximum subsidence) becomes broader. In contrast, two-dimensional plane stress modeling predicts a basin shape that is independent of the width of the shear zone. Our models also predict full-graben profiles within the overlapped region between bounding faults and half-graben shapes elsewhere. Increasing overlap also decreases uplift near the fault tips and rotation of blocks within the basin. We suggest that the observed structure of the Dead Sea Basin can be described by a 3-D model having a large overlap (more than 30 km) that probably increased as the basin evolved as a result of a stable shear motion that was distributed laterally over 20 to 40 km.

The influence of environmental variables on the functional structure of headwater stream fish assemblages: a study of two tropical basins in Central Brazil

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Rodrigo Assis Carvalho

Full Text Available We investigated functional patterns of fish assemblages of two adjacent basins (Araguaia and Tocantins to test whether their headwater stream fish assemblages are more functionally (dissimilar than expected by chance and whether these (dissimilarities are related to differences of environmental conditions between basins. We used an analysis of similarities (ANOSIM on a functional dissimilarity matrix to test for (dissimilarities between fish assemblages of both basins. We performed RLQ and fourth-corner analyses to determine fish species trait-environment relationship. Our results revealed functional dissimilarities between fish assemblages of both basins and significant species trait-environment relationships, suggesting that environmental conditions are driving such dissimilarities. Inter-basin dissimilarities are mainly driven by altitudinal and water temperature gradients, whereas dissimilarities among streams within the basins are influenced by channel depth, turbidity and conductivity. These five environmental variables mostly affected six fish species traits (body mass, water column position, substrate preference, parental care, foraging locality and migration in different manners. This study is an attempt to understand functional trends of fish assemblages in a tropical region that remains poorly known but severely threatened.

Retrodeforming the Sivas Basin (Turkey): Structural style of the central Anatolian basins and their integration in the geodynamic framework of Eastern Anatolia

Science.gov (United States)

Legeay, Etienne; Ringenbach, Jean-Claude; Callot, Jean-Paul; Mohn, Geoffroy; Kavak, Kaan

2017-04-01

Anatolia is the result of the amalgamation of Gondwandian microcontinents against Eurasia active margin. These were originally separated by several Neotethyan oceanic domains consumed by north-dipping subductions. Prior to the continental collision, regional convergence resulted in an obduction event, from north to south in Campanian time, which led to the emplacement of ophiolite nappes and ophiolitic mélanges onto the Tauride passive margin. Several sedimentary basins subsequently developed above the former sutures zones recorded the long-lasting geological evolution of the Anatolian domain from Late Cretaceous to Present The Sivas Basin is all together the richest, the most studied and also most complex of the group of Tertiary basins. The Sivas Basin formed above the northern leading edge of the Tauride platform, the Kırşehir micro-continent, the edge of the Pontide arc and the related sutures. Its complex structure is that of a fold-and-thrust belt with syn-orogenic salt tectonics. After the obduction, the Sivas basin recorded a relative quiet tectonic phase from Maastrichtian to Paleocene with basinal pelagic sedimentation and carbonate platform emplacement on its southern edge. Then shortening resumed in the Early Eocene with the development of north-verging thrusts. It is recorded by a coarse clastic input, with conglomeratic deltas fans grading up to basinal turbidites until the Late Eocene. Then the basin is progressively isolated and becomes an isolated foreland in which a thick evaporite formation deposited. Oligocene to Miocene continental clastics deposition was then mainly controlled by halokinesis: minibasin, salt ridges and salt sheets development. A first canopy is attributed to the second pulse of contraction from Late-Oligocene to Middle Miocene. This second stage end with the formation of back-thrust within the Sivas Basin and southward as a passive roof above a pre-salt triangle zone. This study relies both on extensive fieldwork (4 Ph

Colorado Basin Structure and Rifting, Argentine passive margin

Science.gov (United States)

Autin, Julia; Scheck-Wenderoth, Magdalena; Loegering, Markus; Anka, Zahie; Vallejo, Eduardo; Rodriguez, Jorge; Marchal, Denis; Reichert, Christian; di Primio, Rolando

2010-05-01

The Argentine margin presents a strong segmentation with considerable strike-slip movements along the fracture zones. We focus on the volcanic segment (between the Salado and Colorado transfer zones), which is characterized by seaward dipping reflectors (SDR) all along the ocean-continent transition [e.g. Franke et al., 2006; Gladczenko et al., 1997; Hinz et al., 1999]. The segment is structured by E-W trending basins, which differs from the South African margin basins and cannot be explained by classical models of rifting. Thus the study of the relationship between the basins and the Argentine margin itself will allow the understanding of their contemporary development. Moreover the comparison of the conjugate margins suggests a particular evolution of rifting and break-up. We firstly focus on the Colorado Basin, which is thought to be the conjugate of the well studied Orange Basin [Hirsch et al., 2009] at the South African margin [e.g. Franke et al., 2006]. This work presents results of a combined approach using seismic interpretation and structural, isostatic and thermal modelling highlighting the structure of the crust. The seismic interpretation shows two rift-related discordances: one intra syn-rift and the break-up unconformity. The overlying sediments of the sag phase are less deformed (no sedimentary wedges) and accumulated before the generation of oceanic crust. The axis of the Colorado Basin trends E-W in the western part, where the deepest pre-rift series are preserved. In contrast, the basin axis turns to a NW-SE direction in its eastern part, where mainly post-rift sediments accumulated. The most distal part reaches the margin slope and opens into the oceanic basin. The general basin direction is almost orthogonal to the present-day margin trend. The most frequent hypothesis explaining this geometry is that the Colorado Basin is an aborted rift resulting from a previous RRR triple junction [e.g. Franke et al., 2002]. The structural interpretation

Middle to Late Eocene paleoenvironmental changes in a marine transgressive sequence from the northern Tethyan margin (Adelholzen, Germany)

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GEBHARDT, Holger; ĆORIĆ, Stjepan; DARGA, Robert; BRIGUGLIO, Antonino; SCHENK, Bettina; WERNER, Winfried; ANDERSEN, Nils; SAMES, Benjamin

2015-01-01

The northern Tethyan margin is a key region for determining environmental changes associated with the collision of continental and oceanic tectonic plates and Alpine orogeny. Herein we investigated Middle to Late Eocene neritic to bathyal sediments deposited during an interval of unstable climatic conditions. In order to quantify paleoenvironmental changes, we developed a detailed age model based on biozonations of planktic foraminifera, calcareous nannoplankton, and larger benthic foraminifera. The section at Adelholzen covers the almost complete Lutetian Stage (calcareous nannoplankton zones NP15a-16, planktic foraminifera zones E8-11, shallow benthic (foraminifera) zones SBZ13-15) and large parts of the Priabonian Stage (NP18-20, E14/15), while the intermediate Bartonian Stage (NP17) is completely missing. Foraminiferal, calcareous nannoplankton, and macrofossil assemblages were analyzed for changes in paleo-water depth, mixing and stratification, paleo-primary productivity (pPP), food supply, and bottom water oxygenation. Paleo-water depth estimates range from 50 m (middle neritic, early Lutetian) to nearly 500 m (upper bathyal, late Priabonian). The combination of assemblage composition, planktic and benthic foraminiferal accumulation rates, and derived parameters (carbon-flux to sea floor, pPP) enabled us to identify a series of distinct paleoceanographic events of at least regional significance. Such events are characterized by considerable changes in primary productivity or reduced bottom water ventilation. Calculated pPP-values indicate oligotrophic conditions throughout. PMID:26346423

Hydrochemical and isotopic studies of ground water from Botucatu Aquifer - Partial results for North region of Parana Basin

International Nuclear Information System (INIS)

Silva, R.B.G. da; Kimmelmann, A.A.; Cunha Reboucas, A. da

1985-01-01

The first results of an investigation, to study the flow path, the processes controlling the chemical composition, the recharge, as well as, the origin, apparent ages and dynamic of the groundwater of the Botucatu Aquifer in the Brazilian part of the Parana Basin (818.000 Km 2 ), using hydrochemical and environmental isotope technics ( 2 H, 18 O, 13 C, 3 H, 14 C), are presented. Samples of 20 deep wells, located in the northern part of the Basin (states of Sao Paulo, Mato Grosso do Sul and Goias), were analysed. (Author) [pt

Development of streamflow projections under changing climate conditions over Colorado River basin headwaters

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W. P. Miller

2011-07-01

Full Text Available The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by relatively short-term (3 to 7 month forecasts determined by the Colorado Basin River Forecast Center (CBRFC using the National Weather Service (NWS River Forecasting System (RFS hydrologic model. While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing climate conditions. In this study, a bias-corrected, statistically downscaled dataset of projected climate is used to force the NWS RFS utilized by the CBRFC to derive projections of streamflow over the Green, Gunnison, and San Juan River headwater basins located within the Colorado River Basin. This study evaluates the impact of changing climate to evapotranspiration rates and contributes to a better understanding of how hydrologic processes change under varying climate conditions. The impact to evapotranspiration rates is taken into consideration and incorporated into the development of streamflow projections over Colorado River headwater basins in this study. Additionally, the NWS RFS is modified to account for impacts to evapotranspiration due to changing temperature over the basin. Adjusting evapotranspiration demands resulted in a 6 % to 13 % average decrease in runoff over the Gunnison River Basin when compared to static evapotranspiration rates. Streamflow projections derived using projections of future climate and the NWS RFS provided by the CBRFC resulted in decreased runoff in 2 of the 3 basins considered. Over the Gunnison and San Juan River basins, a 10 % to 15 % average decrease in basin runoff is projected through the year 2099. However, over the Green River basin, a 5 % to 8

Stratigraphy of the Caloris Basin, Mercury: Implications for Volcanic History and Basin Impact Melt

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Ernst, Carolyn M.; Denevi, Brett W.; Barnouin, Olivier S.; Klimczak, Christian; Chabot, Nancy L.; Head, James W.; Murchie, Scott L.; Neumann, Gregory A.; Prockter, Louis M.; Robinson, Mark S.;

Hydrochemistry of the Densu River Basin of Ghana

International Nuclear Information System (INIS)

Adomako, D.; Osae, S.; Fianko, J. R.

2007-01-01

Planned hydrochemical assessment of groundwater quality have been carried out to understand the sources of dissolved ions in the aquifers supporting groundwater systems in the Densu River basin. The basin is underlain mainly by the proterozoic basin type granitoids with associated gnesis, with dominant mineral such as plagioclase feldspars. The groundwater is Ca-HCO 3 and Na-HCO 3 facies, due to weathering and ion-exchange of minerals underlying the aquifers. The enrichment of the cation and anions are Na>Ca>Mg>K and HCO 3 >Cl>SO 4 >NO 3 respectively. Some of the elevated values of both cations and anions may be due to seawater intrusions, ion-exchange, oxidation and anthropogenic activities. Based on these studies, proper management would be recommended to address groundwater quality in the basin. (au)

Slope effects on SWAT modeling in a mountainous basin

OpenAIRE

Yacoub López, Cristina; Pérez Foguet, Agustí

2013-01-01

The soil and water assessment tool (SWAT) is a distributed basin model that includes the option of defining spatial discretization in terms of terrain slope. Influence of terrain slope in runoff results from mountain basins is a determining factor in its simulation results; however, its use as a criterion for basin discretization and for the parameter calibration has not yet been analyzed. In this study, this influence is analyzed for calibrations using two different cases. Ten discretization...

BASINS and WEPP Climate Assessment Tools (CAT): Case ...

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 of the potential future effects of climate change on water resources. This report presents a series of short, illustrative case studies using the BASINS and WEPP climate assessment tools.

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...

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

Deformation bands in porous sandstone: case study in basins of northeast Brazil; Bandas de deformacao em arenitos porosos: estudo de casos em bacias do nordeste do Brasil

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Talles Souza [PETROBRAS, RN (Brazil). Interpretacao e Avaliacao de bacias da Costa Leste do Brasil E and P. Gerencia de Interpretacao], e-mail: tallesferreira@petrobras.com.br; Silva, Fernando Cesar Alves da [Universidade Federal do Rio Grande do Norte (UFRN). Dept. de Geologia Programa de Pos-Graduacao em Geodinamica e Geofisica (Brazil)], e-mail: fernando@geologia.ufrn.br

2010-05-15

The meso and microscopic scale sandstone characterizations of the deformation bands of three sedimentary basins in northeastern Brazil; the Potiguar and Sergipe-Alagoas basins (Brazilian Atlantic Margin) and the Tucano Basin (aborted rift basin) were compared for their similarities and differences. Deformation bands are structures commonly developed in porous sandstones that make up the main reservoir-rock in siliciclastic petroleum systems. These structures influence the permo-porous properties and consequently the migration pathway into a sandstone reservoir. To understand their formation process and development has been the focus of a great number of articles in recent petroleum geology literature. This study highlights the similarities and the differences in the features and deformation mechanisms that provoked the development of deformation bands in the damage zones of major faults in three different sedimentary basins. In terms of basin tectonics, the deformation bands' formation and geometric arrangements are associated with major structures. In the case of the Acu Formation, a correlation was observed with the dextral Afonso Bezerra fault system, whereas in the Sergipe-Alagoas Basin the normal dextral strike-slip faults can be associated with the faulting of the boarder basin. In the Tucano Basin case, the deformation basins are related to the Jeremoabo transpressional fault, a major structure a few kilometers to the north. This study applies structural geology tools to better understand the geometric arrangement and growing mechanisms of deformation bands in different lithological and tectonic settings. Although the deformation bands present a similar aspect in a macroscopic view, the interplay between depositional and mineralogical parameters of the host rock, as well as the basin's burial and tectonic history resulted in the development of different sandstone deformation bands in three northeastern brazilian basins. (author)

New insights on the Marseille-Aubagne Oligocene basins (France)

Energy Technology Data Exchange (ETDEWEB)

Nury, D.; Villenueve, M.; Azrithac, P.; Gartner, A.; Linneann, U.; Chateauneuf, J. J.

2016-10-01

The Marseille-Aubagne Basins, which extend from Marseille to Roquevaire, occupy more than fifty per cent of the Marseille-Aubagne geological map, with approximately one million people living in this area. Despite this geological importance they are still poorly known. The first synthetic view was delivered in the 1935 geological map. Studied by Bonifay, the Quaternary deposits have been included in the 1969 geological map. Nevertheless, the Oligocene formations remained unmodified until Nury, who provided a lot of very detailed stratigraphic data. New studies have been carried out in the frame of the third issue of the 1:50,000 geological map. These studies allow us to distinguish between three different basins: the ''Jarret basin'' in the northern part, the ''Prado basin'' in the southwestern part and the ''Aubagne basin'' in the eastern part. Each of them contains its own stratigraphic succession, including several formations from the Rupelian to the Chattian. Globally, the Lower to Upper Rupelian formations are tectonically deformed, whilst deposits from the Latest Rupelian to the Latest Chattian show only slight deformation. Thus, two main geodynamic stages have been distinguished: the first beginning with the Early Oligocene extensive regime leading to the opening of NNE-SSW troughs all over the European platform and, the second, beginning with a NNW-SSE extensive regime coeval with the Western Mediterranean rifting. The key point that separates these two stages from each other is a possible Late Rupelian compressive regime. To sum up, this basin can be considered as a natural archive for the Oligocene events. Therefore, these basins should be considered as master pieces for the Oligocene palaeogeographic and geodynamic reconstructions. (Author)

A gravity study along a profile across the Sichuan Basin, the Qinling Mountains and the Ordos Basin (central China): Density, isostasy and dynamics

Science.gov (United States)

Zhang, Yongqian; Teng, Jiwen; Wang, Qianshen; Lü, Qingtian; Si, Xiang; Xu, Tao; Badal, José; Yan, Jiayong; Hao, Zhaobing

2017-10-01

In order to investigate the structure of the crust beneath the Middle Qinling Mountains (MQL) and neighboring areas in the North China Block and South China Block, a north-south gravity profile from Yuquan in the Sichuan Basin to Yulin in the Ordos Basin was conducted in 2011. The Bouguer gravity anomaly is determined from a high-quality gravity dataset collected between 31°N and 36°N of latitude, and varies between -200 and -110 mGal in the study region. Using accredited velocity density relationships, an initial crust-mantle density model is constructed for MQL and adjacent areas, which is later refined interactively to simulate the observed gravity anomaly. The present study reveals the features of the density and Bouguer gravity with respect to the tectonic units sampled by the profile. The lithosphere density model shows typical density values that depict a layered structure and allow differentiate the blocks that extend along the reference profile. The gravity field calculated by forward modeling from the final density distribution model correlates well with the measured gravity field within a standard deviation of 1.26 mGal. The density in the crystalline crust increases with depth from 2.65 g/cm3 up to the highest value of 2.95 g/cm3 near the bottom of the crust. The Conrad interface is identified as a density jump of about 0.05 g/cm3. The average density of the crust in MQL is clearly lower than the density in the formations on both sides. Starting from a combined Airy-Pratt isostatic compensation model, a partly compensated crust is found below MQL, suggesting future growth of the crust, unlike the Ordos and Sichuan basins that will remain stable. On the basis of the density and isostatic state of the crust and additional seismological research, such as the P-wave velocity model and Poisson's ratio, it is concluded that the lower crust delamination is a reasonable interpretation for the geophysical characteristics below the Qinling Orogen.

Predicting the ungauged basin : Model validation and realism assessment

NARCIS (Netherlands)

Van Emmerik, T.H.M.; Mulder, G.; Eilander, D.; Piet, M.; Savenije, H.H.G.

2015-01-01

The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

Predicting the ungauged basin: model validation and realism assessment

NARCIS (Netherlands)

van Emmerik, Tim; Mulder, Gert; Eilander, Dirk; Piet, Marijn; Savenije, Hubert

2015-01-01

The hydrological decade on Predictions in Ungauged Basins (PUB) led to many new insights in model development, calibration strategies, data acquisition and uncertainty analysis. Due to a limited amount of published studies on genuinely ungauged basins, model validation and realism assessment of

Sedimentary architecture of a Plio-Pleistocene proto-back-arc basin: Wanganui Basin, New Zealand

Science.gov (United States)

Proust, Jean-Noël; Lamarche, Geoffroy; Nodder, Scott; Kamp, Peter J. J.

2005-11-01

The sedimentary architecture of active margin basins, including back-arc basins, is known only from a few end-members that barely illustrate the natural diversity of such basins. Documenting more of these basins types is the key to refining our understanding of the tectonic evolution of continental margins. This paper documents the sedimentary architecture of an incipient back-arc basin 200 km behind the active Hikurangi subduction margin, North Island, New Zealand. The Wanganui Basin (WB) is a rapidly subsiding, Plio-Pleistocene sedimentary basin located at the southern termination of the extensional back-arc basin of the active Central Volcanic Region (TVZ). The WB is asymmetric with a steep, thrust-faulted, outer (arc-ward) margin and a gentle inner (craton-ward) margin. It contains a 4-km-thick succession of Plio-Pleistocene sediments, mostly lying offshore, composed of shelf platform sediments. It lacks the late molasse-like deposits derived from erosion of a subaerial volcanic arc and basement observed in classical back-arc basins. Detailed seismic stratigraphic interpretations from an extensive offshore seismic reflection data grid show that the sediment fill comprises two basin-scale mega-sequences: (1) a Pliocene (3.8 to 1.35 Ma), sub-parallel, regressive "pre-growth" sequence that overtops the uplifted craton-ward margin above the reverse Taranaki Fault, and (2) a Pleistocene (1.35 Ma to present), divergent, transgressive, "syn-growth" sequence that onlaps: (i) the craton-ward high to the west, and (ii) uplifted basement blocks associated with the high-angle reverse faults of the arc-ward margin to the east. Along strike, the sediments offlap first progressively southward (mega-sequence 1) and then southeastward (mega-sequence 2), with sediment transport funnelled between the craton- and arc-ward highs, towards the Hikurangi Trough through the Cook Strait. The change in offlap direction corresponds to the onset of arc-ward thrust faulting and the rise of

Misrepresenting the Jordan River Basin

Directory of Open Access Journals (Sweden)

Clemens Messerschmid

2015-06-01

Full Text Available This article advances a critique of the UN Economic and Social Commission for West Asia’s (ESCWA’s representation of the Jordan River Basin, as contained in its recently published Inventory of Shared Water Resources in Western Asia. We argue that ESCWA’s representation of the Jordan Basin is marked by serious technical errors and a systematic bias in favour of one riparian, Israel, and against the Jordan River’s four Arab riparians. We demonstrate this in relation to ESCWA’s account of the political geography of the Jordan River Basin, which foregrounds Israel and its perspectives and narratives; in relation to hydrology, where Israel’s contribution to the basin is overstated, whilst that of Arab riparians is understated; and in relation to development and abstraction, where Israel’s transformation and use of the basin are underplayed, while Arab impacts are exaggerated. Taken together, this bundle of misrepresentations conveys the impression that it is Israel which is the main contributor to the Jordan River Basin, Arab riparians its chief exploiters. This impression is, we argue, not just false but also surprising, given that the Inventory is in the name of an organisation of Arab states. The evidence discussed here provides a striking illustration of how hegemonic hydro-political narratives are reproduced, including by actors other than basin hegemons themselves.

Architecture of buried reverse fault zone in the sedimentary basin: A case study from the Hong-Che Fault Zone of the Junggar Basin

Science.gov (United States)

Liu, Yin; Wu, Kongyou; Wang, Xi; Liu, Bo; Guo, Jianxun; Du, Yannan

2017-12-01

It is widely accepted that the faults can act as the conduits or the barrier for oil and gas migration. Years of studies suggested that the internal architecture of a fault zone is complicated and composed of distinct components with different physical features, which can highly influence the migration of oil and gas along the fault. The field observation is the most useful methods of observing the fault zone architecture, however, in the petroleum exploration, what should be concerned is the buried faults in the sedimentary basin. Meanwhile, most of the studies put more attention on the strike-slip or normal faults, but the architecture of the reverse faults attracts less attention. In order to solve these questions, the Hong-Che Fault Zone in the northwest margin of the Junggar Basin, Xinjiang Province, is chosen for an example. Combining with the seismic data, well logs and drill core data, we put forward a comprehensive method to recognize the internal architectures of buried faults. High-precision seismic data reflect that the fault zone shows up as a disturbed seismic reflection belt. Four types of well logs, which are sensitive to the fractures, and a comprehensive discriminated parameter, named fault zone index are used in identifying the fault zone architecture. Drill core provides a direct way to identify different components of the fault zone, the fault core is composed of breccia, gouge, and serpentinized or foliated fault rocks and the damage zone develops multiphase of fractures, which are usually cemented. Based on the recognition results, we found that there is an obvious positive relationship between the width of the fault zone and the displacement, and the power-law relationship also exists between the width of the fault core and damage zone. The width of the damage zone in the hanging wall is not apparently larger than that in the footwall in the reverse fault, showing different characteristics with the normal fault. This study provides a

Validation studies on indexed sequential modeling for the Colorado River Basin

International Nuclear Information System (INIS)

Labadie, J.W.; Fontane, D.G.; Salas, J.D.; Ouarda, T.

1991-01-01

This paper reports on a method called indexed sequential modeling (ISM) that has been developed by the Western Area Power Administration to estimate reliable levels of project dependable power capacity (PDC) and applied to several federal hydro systems in the Western U.S. The validity of ISM in relation to more commonly accepted stochastic modeling approaches is analyzed by applying it to the Colorado River Basin using the Colorado River Simulation System (CRSS) developed by the U.S. Bureau of Reclamation. Performance of ISM is compared with results from input of stochastically generated data using the LAST Applied Stochastic Techniques Package. Results indicate that output generated from ISM synthetically generated sequences display an acceptable correspondence with results obtained from final convergent stochastically generated hydrology for the Colorado River Basin

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume I. Dalhart Basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and highly variable prcipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Laboratory Evaluation of Underwater Grouting of CPP-603 Basins

International Nuclear Information System (INIS)

Johnson, V.J.; Pao, J.H.; Demmer, R.L.; Tripp, J.L.

2002-01-01

A project is underway to deactivate a Fuel Storage Basin. The project specifies the requirements and identifies the tasks that will be performed for deactivation of the CPP- 603 building at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory. The Fuel Receiving and Storage Building (CPP- 603) was originally used to receive and store spent nuclear fuel from various facilities. The area to undergo deactivation includes the three spent nuclear fuel storage basins and a transfer canal (1.5 million gallons of water storage). Deactivation operations at the task site include management of the hot storage boxes and generic fuel objects, removal of the fuel storage racks, basin sludge, water evaporation and basin grouting, and interior equipment, tanks, and associated components. This includes a study to develop a grout formulation and placement process for this deactivation project. Water will be allowed to passively evaporate to r educe the spread of contamination from the walls of the basin. The basins will be filled with grout, underwater, as the water evaporates to maintain the basin water at a safe level. The objective of the deactivation project is to eliminate potential exposure to hazardous and radioactive materials and eliminate potential safety hazards associated with the CPP-603 building

Comparative study of carbonic anhydrase activity in waters among different geological eco-environments of Yangtze River basin and its ecological significance.

Science.gov (United States)

Nzung'a, Sila Onesmus; Pan, Weizhi; Shen, Taiming; Li, Wei; Qin, Xiaoqun; Wang, Chenwei; Zhang, Liankai; Yu, Longjiang

2018-04-01

This study provides the presence of carbonic anhydrase (CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO 3 - concentration and CO 2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas (PP3 - concentration (r=0.672, P2 sink flux (r=0.602, P=0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO 2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies. Copyright © 2017. Published by Elsevier B.V.

Regionalization for uncertainty reduction in flows in ungauged basins

NARCIS (Netherlands)

Booij, Martijn J.; Deckers, Dave L.E.H.; Rientjes, Tom H.M.; Krol, Martinus S.; Boegh, Eva; Kunstmann, Harald; Wagener, Thorsten; Hall, Alan; Bastidas, Luis; Franks, Stewart; Gupta, Hoshin; Rosbjerg, Dan; Schaake, John

2007-01-01

The objective of this study is to contribute to the reduction of predictive uncertainty in flows in ungauged basins through application of a regionalization method to 56 well-gauged basins in the United Kingdom. The classical approach of regionalization is adopted, where regression relationships

The evolution and performance of river basin management in the Murray-Darling Basin

Directory of Open Access Journals (Sweden)

Andrew Ross

2016-09-01

Full Text Available We explore bioregional management in the Murray-Darling Basin (MDB in Australia through the institutional design characteristics of the MDB River Basin Organization (RBO, the actors and organizations who supported and resisted the establishment of the RBO, and the effectiveness of the RBO. During the last 25 years, there has been a major structural reform in the MDB RBO, which has changed from an interstate coordinating body to an Australian government agency. Responsibility for basin management has been centralized under the leadership of the Australian government, and a comprehensive integrated Basin plan has been adopted. The driving forces for this centralization include national policy to restore river basins to sustainable levels of extraction, state government difficulties in reversing overallocation of water entitlements, the millennium drought and its effects, political expediency on the part of the Australian government and state governments, and a major injection of Australian government funding. The increasing hierarchy and centralization of the MDB RBO does not follow a general trend toward multilevel participative governance of RBOs, but decentralization should not be overstated because of the special circumstances at the time of the centralization and the continuing existence of some decentralized elements, such as catchment water plans, land use planning, and water quality. Further swings in the centralization-decentralization pendulum could occur. The MDB reform has succeeded in rebalancing Basin water allocations, including an allocation for the environment and reduced diversion limits. There are some longer term risks to the implementation of reform, including lack of cooperation by state governments, vertical coordination difficulties, and perceived reductions in the accountability and legitimacy of reform at the local level. If implementation of the Basin plan is diverted or delayed, a new institution, the Commonwealth

Sustaining Exploration in Mature Basins

International Nuclear Information System (INIS)

Bayo, A.

2002-01-01

Exploration is a business like any other business driven by opportunity, resources and expectation of profit. Therefore, exploration will thrive anywhere the opportunities are significant, the resources are available and the outlook for profit (or value creation) is good. To sustain exploration activities anywhere, irrespective of the environment, there must be good understanding of the drivers of these key investment criteria. This paper will examine these investment criteria as they relate to exploration business and address the peculiarity of exploration in mature basin. Mature basins are unique environment that lends themselves a mix of fears, paradigms and realities, particularly with respect to the perception of value. To sustain exploration activities in a mature basin, we need to understand these perceptions relative to the true drivers of profitability. Exploration in the mature basins can be as profitable as exploration in emerging basins if the dynamics of value definition-strategic and fiscal values are understood by operators, regulators and co ventures alike. Some suggestions are made in this presentation on what needs to be done in addressing these dynamic investment parameters and sustaining exploration activities in mature basins

L-Reactor 186-basin cleaning alternatives

International Nuclear Information System (INIS)

Turcotte, M.D.S.

1983-01-01

Operation of L Reactor will necessitate annual cleaning of the L Area 186 basins. Alternatives are presented for sediment discharge due to 186-basin cleaning activities as a basis for choosing the optimal cleaning method. Current cleaning activities (i.e. removal of accumulated sediments) for the P, C and K-Area 186 basins result in suspended solids concentrations in the effluent waters above the NPDES limits, requiring an exemption from the NPDES permit for these short-term releases. The objective of mitigating the 186-basin cleaning activities is to decrease the suspended solids concentrations to within permit limits while continuing satisfactory operation of the basins

Crustal characteristic variation in the central Yamato Basin, Japan Sea back-arc basin, deduced from seismic survey results

Science.gov (United States)

Sato, Takeshi; No, Tetsuo; Miura, Seiichi; Kodaira, Shuichi

2018-02-01

The crustal structure of the Yamato Bank, the central Yamato Basin, and the continental shelf in the southern Japan Sea back-arc basin is obtained based on a seismic survey using ocean bottom seismographs and seismic shot to elucidate the back-arc basin formation processes. The central Yamato Basin can be divided into three domains based on the crustal structure: the deep basin, the seamount, and the transition domains. In the deep basin domain, the crust without the sedimentary layer is about 12-13 km thick. Very few units have P-wave velocity of 5.4-6.0 km/s, which corresponds to the continental upper crust. In the seamount and transition domains, the crust without the sedimentary layer is about 12-16 km thick. The P-wave velocities of the upper and lower crusts differs among the deep basin, the seamount, and the transition domains. These results indicate that the central Yamato Basin displays crustal variability in different domains. The crust of the deep basin domain is oceanic in nature and suggests advanced back-arc basin development. The seamount domain might have been affected by volcanic activity after basin opening. In the transition domain, the crust comprises mixed characters of continental and oceanic crust. This crustal variation might represent the influence of different processes in the central Yamato Basin, suggesting that crustal development was influenced not only by back-arc opening processes but also by later volcanic activity. In the Yamato Bank and continental shelf, the upper crust has thickness of about 17-18 km and P-wave velocities of 3.3-4.1 to 6.6 km/s. The Yamato Bank and the continental shelf suggest a continental crustal character.

Colorado River basin sensitivity to disturbance impacts

Science.gov (United States)

Bennett, K. E.; Urrego-Blanco, J. R.; Jonko, A. K.; Vano, J. A.; Newman, A. J.; Bohn, T. J.; Middleton, R. S.

2017-12-01

The Colorado River basin is an important river for the food-energy-water nexus in the United States and is projected to change under future scenarios of increased CO2emissions and warming. Streamflow estimates to consider climate impacts occurring as a result of this warming are often provided using modeling tools which rely on uncertain inputs—to fully understand impacts on streamflow sensitivity analysis can help determine how models respond under changing disturbances such as climate and vegetation. In this study, we conduct a global sensitivity analysis with a space-filling Latin Hypercube sampling of the model parameter space and statistical emulation of the Variable Infiltration Capacity (VIC) hydrologic model to relate changes in runoff, evapotranspiration, snow water equivalent and soil moisture to model parameters in VIC. Additionally, we examine sensitivities of basin-wide model simulations using an approach that incorporates changes in temperature, precipitation and vegetation to consider impact responses for snow-dominated headwater catchments, low elevation arid basins, and for the upper and lower river basins. We find that for the Colorado River basin, snow-dominated regions are more sensitive to uncertainties. New parameter sensitivities identified include runoff/evapotranspiration sensitivity to albedo, while changes in snow water equivalent are sensitive to canopy fraction and Leaf Area Index (LAI). Basin-wide streamflow sensitivities to precipitation, temperature and vegetation are variable seasonally and also between sub-basins; with the largest sensitivities for smaller, snow-driven headwater systems where forests are dense. For a major headwater basin, a 1ºC of warming equaled a 30% loss of forest cover, while a 10% precipitation loss equaled a 90% forest cover decline. Scenarios utilizing multiple disturbances led to unexpected results where changes could either magnify or diminish extremes, such as low and peak flows and streamflow timing

Linking Governance to Sustainable Management Outcomes: Applying Dynamic Indicator Profiles to River Basin Organization Case Studies around the World.

Science.gov (United States)

Wei, Y.; Bouckaert, F. W.

2017-12-01

Institutional best practice for integrated river basin management advocates the river basin organisation (RBO) model as pivotal to achieve sustainable management outcomes and stakeholder engagement. The model has been widely practiced in transboundary settings and is increasingly adopted at national scales, though its effectiveness remains poorly studied. A meta-analysis of four river basins has been conducted to assess governance models and linking it to evaluation of biophysical management outcomes. The analysis is based on a Theory of Change framework, and includes functional dynamic governance indicator profiles, coupled to sustainable ecosystem management outcome profiles. The governance and outcome profiles, informed by context specific indicators, demand that targets for setting objectives are required in multiple dimensions, and trajectory outlines are a useful tool to track progress along the journey mapped out by the Theory of Change framework. Priorities, trade-offs and objectives vary in each basin, but the diagnostics tool allows comparison between basins in their capacity to reach targets through successive evaluations. The distance between capacity and target scores determines how program planning should be prioritized and resources allocated for implementation; this is a dynamic process requiring regular evaluations and adaptive management. The findings of this study provide a conceptual framework for combining dimensions of integrated water management principles that bridge tensions between (i) stakeholder engagement and participatory management (bottom-up approach) using localized knowledge and (ii) decision-making, control-and-command, system-scale, accountable and equitable management (top-down approach).The notion of adaptive management is broadened to include whole-of-program learnings, rather than single hypothesis based learning adjustments. This triple loop learning combines exploitative methods refinement with explorative evaluation of

Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

Science.gov (United States)

Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

2017-12-01

The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

Hydrocarbon-Rich Groundwater above Shale-Gas Formations: A Karoo Basin Case Study.

Science.gov (United States)

Eymold, William K; Swana, Kelley; Moore, Myles T; Whyte, Colin J; Harkness, Jennifer S; Talma, Siep; Murray, Ricky; Moortgat, Joachim B; Miller, Jodie; Vengosh, Avner; Darrah, Thomas H

2018-03-01

Horizontal drilling and hydraulic fracturing have enhanced unconventional hydrocarbon recovery but raised environmental concerns related to water quality. Because most basins targeted for shale-gas development in the USA have histories of both active and legacy petroleum extraction, confusion about the hydrogeological context of naturally occurring methane in shallow aquifers overlying shales remains. The Karoo Basin, located in South Africa, provides a near-pristine setting to evaluate these processes, without a history of conventional or unconventional energy extraction. We conducted a comprehensive pre-industrial evaluation of water quality and gas geochemistry in 22 groundwater samples across the Karoo Basin, including dissolved ions, water isotopes, hydrocarbon molecular and isotopic composition, and noble gases. Methane-rich samples were associated with high-salinity, NaCl-type groundwater and elevated levels of ethane, 4 He, and other noble gases produced by radioactive decay. This endmember displayed less negative δ 13 C-CH 4 and evidence of mixing between thermogenic natural gases and hydrogenotrophic methane. Atmospheric noble gases in the methane-rich samples record a history of fractionation during gas-phase migration from source rocks to shallow aquifers. Conversely, methane-poor samples have a paucity of ethane and 4 He, near saturation levels of atmospheric noble gases, and more negative δ 13 C-CH 4 ; methane in these samples is biogenic and produced by a mixture of hydrogenotrophic and acetoclastic sources. These geochemical observations are consistent with other basins targeted for unconventional energy extraction in the USA and contribute to a growing data base of naturally occurring methane in shallow aquifers globally, which provide a framework for evaluating environmental concerns related to unconventional energy development (e.g., stray gas). © 2018, National Ground Water Association.

Spatio-temporal trends of rainfall across Indian river basins

Science.gov (United States)

Bisht, Deepak Singh; Chatterjee, Chandranath; Raghuwanshi, Narendra Singh; Sridhar, Venkataramana

2018-04-01

Daily gridded high-resolution rainfall data of India Meteorological Department at 0.25° spatial resolution (1901-2015) was analyzed to detect the trend in seasonal, annual, and maximum cumulative rainfall for 1, 2, 3, and 5 days. The present study was carried out for 85 river basins of India during 1901-2015 and pre- and post-urbanization era, i.e., 1901-1970 and 1971-2015, respectively. Mann-Kendall ( α = 0.05) and Theil-Sen's tests were employed for detecting the trend and percentage of change over the period of time, respectively. Daily extreme rainfall events, above 95 and 99 percentile threshold, were also analyzed to detect any trend in their magnitude and number of occurrences. The upward trend was found for the majority of the sub-basins for 1-, 2-, 3-, and 5-day maximum cumulative rainfall during the post-urbanization era. The magnitude of extreme threshold events is also found to be increasing in the majority of the river basins during the post-urbanization era. A 30-year moving window analysis further revealed a widespread upward trend in a number of extreme threshold rainfall events possibly due to urbanization and climatic factors. Overall trends studied against intra-basin trend across Ganga basin reveal the mixed pattern of trends due to inherent spatial heterogeneity of rainfall, therefore, highlighting the importance of scale for such studies.

Spent LWR fuel storage costs: reracking, AR basins, and AFR basins

International Nuclear Information System (INIS)

1980-01-01

Whenever possible, fuel storage requirements will be met by reracking existing reactor basins and/or transfer of fuel to available space in other reactor basins. These alternatives represent not only the lowest cost storage options but also the most timely. They are recognized to face environmental and regulatory obstacles. However, such obstacles should be less severe than those that would be encountered with AR or AFR basin storage. When storage requirements cannot be met by the first two options, the least costly alternative for most utilities will be use of a Federal AFR. Storage costs of $100,000 to $150,000 MTU at a AFR are less costly than charges of up to $320,000/MTU that could be incurred by the use of AR basins. AFR storage costs do not include transportation from the reactor to the AFR. This cost would be paid by the utility separately. Only when a utility requires annual storage capacity for 100 MTU of spent fuel can self-storage begin to compete with AFR costs. The large reactor complexes discharging these fuel quantities are not currently those that require relief from fuel storage problems

Geologic Basin Boundaries (Basins_GHGRP) GIS Layer

Data.gov (United States)

U.S. Environmental Protection Agency — This is a coverage shapefile of geologic basin boundaries which are used by EPA's Greenhouse Gas Reporting Program. For onshore production, the "facility" includes...

hydrological study of the basin of Tunja using isotopics technical

International Nuclear Information System (INIS)

Camacho R, Gloria; Hernandez Luis

1992-01-01

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

Material Exchange and Migration between Pore Fluids and Sandstones during Diagenetic Processes in Rift Basins: A Case Study Based on Analysis of Diagenetic Products in Dongying Sag, Bohai Bay Basin, East China

Directory of Open Access Journals (Sweden)

W. Meng

2018-01-01

Full Text Available The exchange and migration of basin materials that are carried by pore fluids are the essence of diagenesis, which can alter physical properties of clastic rocks as well as control formation and distribution of favorable reservoirs of petroliferous basins. Diagenetic products and pore fluids, resulting from migration and exchange of basin materials, can be used to deduce those processes. In this study, 300 core samples from 46 wells were collected for preparation of casting thin sections, SEM, BSE, EDS, inclusion analysis, and isotope analysis in Dongying Sag, Bohai Bay Basin, East China. Combined with geochemical characteristics of pore fluids and geological background of the study area, the source and exchange mechanisms of materials in the pore fluids of rift basins were discussed. It was revealed that the material exchange of pore fluids could be divided into five stages. The first stage was the evaporation concentration stage during which mainly Ca2+, Mg2+, and CO32- precipitated as high-Mg calcites. Then came the shale compaction stage, when mainly Ca2+ and CO32- from shale compaction water precipitated as calcites. The third stage was the carboxylic acid dissolution stage featured by predominant dissolution of plagioclases, during which Ca2+ and Na+ entered pore fluids, and Si and Al also entered pore fluids and then migrated as clathrates, ultimately precipitating as kaolinites. The fourth stage was the organic CO2 stage, mainly characterized by the kaolinization of K-feldspar as well as dissolution of metamorphic lithic fragments and carbon cements. During this stage, K+, Fe2+, Mg2+, Ca2+, HCO3-, and CO32- entered pore fluids. The fifth stage was the alkaline fluid stage, during which the cementation of ferro-carbonates and ankerites as well as illitization or chloritization of kaolinites prevailed, leading to the precipitation of K+, Fe2+, Mg2+, Ca2+, and CO32- from pore fluids.

Task 50 - deposition of lignites in the Fort Union Group and related strata of the northern Great Plains

Energy Technology Data Exchange (ETDEWEB)

Hartman, J.H.; Roth, B.; Kihm, A.J.

1997-08-11

Late Cretaceous, Paleocene, and early Eocene geologic and paleontologic studies were undertaken in western North Dakota, eastern and south-central Montana, and northwestern and northeastern Wyoming. These study areas comprise the Williston, Bighorn, and Powder River Basins, all of which contain significant lignite resources. Research was undertaken in these basins because they have the best geologic sections and fossil record for the development of a chronostratigraphic (time-rock) framework for the correlation of lignite beds and other economic resources. A thorough understanding of the precise geologic age of the deposition of sediments permits a powerful means of interpreting the record of geologic events across the northern Great Plains. Such an understanding allows for rigorous interpretation of paleoenviromnents and estimates of resource potential and quality in this area of economically significant deposits. This work is part of ongoing research to document change in the composition of molluscan fossil faunas to provide a paleoenvironmentally sensitive independent means of interpreting time intervals of brief duration during the Late Cretaceous, Paleocene, and Eocene. This study focuses on the record of mollusks and, to a lesser extent, mammals in the (1) Hell Creek-Tullock Formations, which include the Cretaceous-Paleocene boundary, in the western portion of the Williston Basin, Montana; (2) uppermost Cretaceous, Paleocene, and lowermost Eocene strata in western North Dakota, which -includes the last interior seaway in North Dakota; (3) upper Paleocene and lowermost Eocene of the northern portion of the Bighorn Basin of south-central Montana and northwestern Wyoming; and (4) Powder River Basin of northeastern Wyoming and southeastern Montana. The geologic record provides different physical and paleontological information to aid in interpreting the geologic record through the study interval.

Hydroclimatology of the Missouri River basin

Science.gov (United States)

Wise, Erika K.; Woodhouse, Connie A.; McCabe, Gregory; Pederson, Gregory T.; St. Jacques, Jeannine-Marie

2018-01-01

Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River basin (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, observed and modeled hydroclimatic data and estimated natural flow records in the MRB are used to 1) assess the major source regions of MRB flow, 2) describe the climatic controls on streamflow in the upper and lower basins , and 3) investigate trends over the instrumental period. Analyses indicate that 72% of MRB runoff is generated by the headwaters in the upper basin and by the lowest portion of the basin near the mouth. Spring precipitation and temperature and winter precipitation impacted by changes in zonal versus meridional flow from the Pacific Ocean play key roles in surface water supply variability in the upper basin. Lower basin flow is significantly correlated with precipitation in late spring and early summer, indicative of Atlantic-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. Although increases in precipitation in the lower basin are currently overriding the effects of warming temperatures on total MRB flow, the upper basin’s long-term trend toward decreasing flows, reduction in snow versus rain fraction, and warming spring temperatures suggest that the upper basin may less often provide important flow supplements to the lower basin in the future.

Geotemperature pattern and geothermal resources in North China Basin

Energy Technology Data Exchange (ETDEWEB)

Deng Xiao; Chen Moxing; Xiong Liangping; Zhang Juming [Inst. of Geology. Academis Sinica, Beijing (China)

1995-12-31

Geotemperature pattern of the North China Basin has been studied. Results indicate that the geotemperature pattern of the Basin is in close correlation with its geological structure, mainly controlled by the structural form or the relief of the basement rock. Generally, high heat flow and high geotemperature zone correspond to basement uplifts whereas low heat flow and low geotemperature zone, to basement depressions. As a consequence, a `high-low-high` geotemperature pattern with NE and EW trending was thus formed and is observed in the North China Basin. This pattern has been validated and revealed by mathematical simulation. In the North China Basin, two main thermal water reservoirs are identified: porous type water in the Neogene system and fissure type water in Lower Paleozoic to Mid-Upper Proterozoic limestone bedrocks. The reserve of thermal water and recoverable resource are estimated. Results show that the North China Basin is an area with abundant low-medium temperature thermal water resources. 9 figs., 5 tabs., 10 refs.

Uranium prospecting in the Iguatu and Frade basins (Brazil)

International Nuclear Information System (INIS)

Lemos, J.C.

The Mineral Exploration Department of CNEN studied the possibilities of uranium occurences in the Iguatu and Frade Basins in the preliminary research program designated 'Small Basins of the Northeast' which contitutes the object of this report. The two basins are located in the State of Ceara. The results of geologic and radiometric researches ahowed that the possibilities for uranium mineralizations were small, since the analyses of samples from the two main anomalies showed the radioactivity came from the remains of monazite. Further analysis of sedimentologic factors indicated favorable confitions for uranium concentration, taking into consideration the large variations of vertical and lateral granulometries, which permit spectulation about the flow of uraniferous solutions. radiometric measurements of surface samples were insignificant and no uranium mineral was found. The result of research of the sedimentary Frade Basin was negative for uranium mineralization. The basin was entirely eroded, remaining as an outcrop described in this report. (F.E.) [pt

Diverse stakeholders create collaborative, multilevel basin governance for groundwater sustainability

Directory of Open Access Journals (Sweden)

Esther Conrad

2018-01-01

Full Text Available The Sustainable Groundwater Management Act (SGMA is introducing significant changes in the way groundwater is governed for agricultural use. It requires the formation of groundwater sustainability agencies (GSAs to manage groundwater basins for sustainability with the engagement of all users. That presents opportunities for collaboration, as well as challenges, particularly in basins with large numbers of agricultural water users who have longstanding private pumping rights. The GSA formation process has resulted in the creation of multiple GSAs in many such basins, particularly in the Central Valley. In case studies of three basins, we examine agricultural stakeholders' concerns about SGMA, and how these are being addressed in collaborative approaches to groundwater basin governance. We find that many water districts and private pumpers share a strong interest in maintaining local autonomy, but they have distinct concerns and different options for forming and participating in GSAs. Multilevel collaborative governance structures may help meet SGMA's requirements for broad stakeholder engagement, our studies suggest, while also addressing concerns about autonomy and including agricultural water users in decision-making.

Glendonites as a paleoenvironmental tool: Implications for early Cretaceous high latitudinal climates in Australia

Science.gov (United States)

De Lurio, Jennifer L.; Frakes, L. A.

1999-04-01

Glendonites, calcite pseudomorphs after the metastable mineral ikaite (CaCO 3 · 6H 2O), occur in the Late Aptian interval of the Bulldog Shale in the Eromanga Basin, Australia and in other Early Cretaceous basins at high paleolatitudes. Ikaite precipitation in the marine environment requires near-freezing temperatures (not higher than 4°C), high alkalinity, increased levels of orthophosphate, and high P CO2. The rapid and complete transformation of ikaite to calcite at temperatures between 5 and 8°C provides an upper limit on the oxygen isotopic composition of the pore waters: -2.6 ikaite precipitation. Data previously reported as 11 to 16°C (assuming δ w = 0.0‰SMOW) yield paleotemperatures ranging from -1 to 5°C, squarely in the range of ikaite stability. The low δ w indicates hyposaline conditions, most likely caused by mixing high latitude meteoric waters with seawater. The 18O depleted, low temperature waters suggest that the region was at least seasonally colder than previously accepted.

Wind energy in Mediterranean Basin

International Nuclear Information System (INIS)

Gaudiosi, G.

1991-01-01

In its examination of wind energy potential in the Mediterranean Basin, this paper provides brief notes on the Basin's geography; indicates power production and demand; describes the area's wind characteristics and wind monitoring activities; illustrates wind velocity distributions; estimates local wind power production potential; reviews the Basin's wind energy marketing situation and each bordering country's wind energy programs; surveys installed wind energy farms; and assesses national research and commercialization efforts

Constraining drivers of basin exhumation in the Molasse Basin by combining low-temperature thermochronology, thermal history and kinematic modeling

Science.gov (United States)

Luijendijk, Elco; von Hagke, Christoph; Hindle, David

2017-04-01

Due to a wealth of geological and thermochronology data the northern foreland basin of the European Alps is an ideal natural laboratory for understanding the dynamics of foreland basins and their interaction with surface and geodynamic processes. The northern foreland basin of the Alps has been exhumed since the Miocene. The timing, rate and cause of this phase of exhumation are still enigmatic. We compile all available thermochronology and organic maturity data and use a new thermal history model, PyBasin, to quantify the rate and timing of exhumation that can explain these data. In addition we quantify the amount of tectonic exhumation using a new kinematic model for the part of the basin that is passively moved above the detachment of the Jura Mountains. Our results show that the vitrinite reflectance, apatite fission track data and cooling rates show no clear difference between the thrusted and folded part of the foreland basin and the undeformed part of the foreland basin. The undeformed plateau Molasse shows a high rate of cooling during the Neogene of 40 to 100 °C, which is equal to >1.0 km of exhumation. Calculated rates of exhumation suggest that drainage reorganization can only explain a small part of the observed exhumation and cooling. Similarly, tectonic transport over a detachment ramp cannot explain the magnitude, timing and wavelength of the observed cooling signal. We conclude that the observed cooling rates suggest large wavelength exhumation that is probably caused by lithospheric-scale processes. In contrast to previous studies we find that the timing of exhumation is poorly constrained. Uncertainty analysis shows that models with timing starting as early as 12 Ma or as late as 2 Ma can all explain the observed data.

Modeling discharge and water quality in a temporary river basin using SWAT model: A case-study on the Ardila river

OpenAIRE

Durão, Anabela; Serafim, António; Brito, David; Morais, Manuela

2012-01-01

Temporary rivers have a hydrologic variability, which are characterized by long drought periods and short floods events, that influences water quality. Analysis of river flow generated in the Ardila river basin (temporary regime) using precipitation data (from 1931 to 2003) from a weather station, located within the basin, at the Portuguese side (which represents only 22% of the study area) showed a discrepancy between the modeled and observed runoff since 1981. It was also revealed a satisfa...

Paleohydrogeology of the San Joaquin basin, California

Science.gov (United States)

Wilson, A.M.; Garven, G.; Boles, J.R.

1999-01-01

Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

Sharing water and benefits in transboundary river basins

Science.gov (United States)

Arjoon, Diane; Tilmant, Amaury; Herrmann, Markus

2016-06-01

The equitable sharing of benefits in transboundary river basins is necessary to solve disputes among riparian countries and to reach a consensus on basin-wide development and management activities. Benefit-sharing arrangements must be collaboratively developed to be perceived not only as efficient, but also as equitable in order to be considered acceptable to all riparian countries. The current literature mainly describes what is meant by the term benefit sharing in the context of transboundary river basins and discusses this from a conceptual point of view, but falls short of providing practical, institutional arrangements that ensure maximum economic welfare as well as collaboratively developed methods for encouraging the equitable sharing of benefits. In this study, we define an institutional arrangement that distributes welfare in a river basin by maximizing the economic benefits of water use and then sharing these benefits in an equitable manner using a method developed through stakeholder involvement. We describe a methodology in which (i) a hydrological model is used to allocate scarce water resources, in an economically efficient manner, to water users in a transboundary basin, (ii) water users are obliged to pay for water, and (iii) the total of these water charges is equitably redistributed as monetary compensation to users in an amount determined through the application of a sharing method developed by stakeholder input, thus based on a stakeholder vision of fairness, using an axiomatic approach. With the proposed benefit-sharing mechanism, the efficiency-equity trade-off still exists, but the extent of the imbalance is reduced because benefits are maximized and redistributed according to a key that has been collectively agreed upon by the participants. The whole system is overseen by a river basin authority. The methodology is applied to the Eastern Nile River basin as a case study. The described technique not only ensures economic efficiency, but may

A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

Science.gov (United States)

Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

2017-12-01

Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

Environmental Setting and Implications on Water Quality, Upper Colorado River Basin, Colorado and Utah

Science.gov (United States)

Apodaca, Lori E.; Driver, Nancy E.; Stephens, Verlin C.; Spahr, Norman E.

1995-01-01

The Upper Colorado River Basin in Colorado and Utah is 1 of 60 study units selected for water-quality assessment as part of the U.S. Geological Survey's National Water-Quality Assessment program, which began full implementation in 1991. Understanding the environmental setting of the Upper Colorado River Basin study unit is important in evaluating water-quality issues in the basin. Natural and human factors that affect water quality in the basin are presented, including an overview of the physiography, climatic conditions, general geology and soils, ecoregions, population, land use, water management and use, hydrologic characteristics, and to the extent possible aquatic biology. These factors have substantial implications on water-quality conditions in the basin. For example, high concentrations of dissolved solids and selenium are present in the natural background water conditions of surface and ground water in parts ofthe basin. In addition, mining, urban, and agricultural land and water uses result in the presence of certain constituents in the surface and ground water of the basin that can detrimentally affect water quality. The environmental setting of the study unit provides a framework of the basin characteristics, which is important in the design of integrated studies of surface water, ground water, and biology.

Advancements in understanding the aeromagnetic expressions of basin-margin faults—An example from San Luis Basin, Colorado

Science.gov (United States)

Grauch, V. J.; Bedrosian, Paul A.; Drenth, Benjamin J.

2013-01-01

Advancements in aeromagnetic acquisition technology over the past few decades have led to greater resolution of shallow geologic sources with low magnetization, such as intrasedimentary faults and paleochannels. Detection and mapping of intrasedimentary faults in particular can be important for understanding the overall structural setting of an area, even if exploration targets are much deeper. Aeromagnetic methods are especially useful for mapping structures in mountain-piedmont areas at the margins of structural basins, where mineral exploration and seismic-hazard studies may be focused, and where logistical or data-quality issues encumber seismic methods. Understanding if the sources of aeromagnetic anomalies in this context originate from sedimentary units or bedrock is important for evaluating basin structure and/or depth to shallow exploration targets. Advancements in aeromagnetic acquisition technology over the past few decades have led to greater resolution of shallow geologic sources with low magnetization, such as intrasedimentary faults and paleochannels. Detection and mapping of intrasedimentary faults in particular can be important for understanding the overall structural setting of an area, even if exploration targets are much deeper. Aeromagnetic methods are especially useful for mapping structures in mountain-piedmont areas at the margins of structural basins, where mineral exploration and seismic-hazard studies may be focused, and where logistical or data-quality issues encumber seismic methods. Understanding if the sources of aeromagnetic anomalies in this context originate from sedimentary units or bedrock is important for evaluating basin structure and/or depth to shallow exploration targets.

Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia

Science.gov (United States)

Mather, Caroline C.; Skrzypek, Grzegorz; Dogramaci, Shawan; Grierson, Pauline F.

2018-04-01

Groundwater dolocrete occurring within the Fortescue Marsh, a large inland wetland in the Pilbara region of northwest Australia, has been investigated to provide paleoenvironmental and paleohydrological records and further the understanding of low temperature dolomite formation in terrestrial settings over the Quaternary Period. Two major phases of groundwater dolocrete formation are apparent from the presence of two distinct units of dolocrete, based on differences in depth, δ18O values and mineral composition. Group 1 (G1) occurs at depth 20-65 m b.g.l. (below ground level) and contains stoichiometric dolomite with δ18O values of -4.02-0.71‰. Group 2 (G2) is shallower (0-23 m b.g.l.), occurring close to the current groundwater level, and contains Ca-rich dolomite ± secondary calcite with a comparatively lower range of δ18O values (-7.74 and -6.03‰). Modelled δ18O values of paleogroundwater from which older G1 dolomite precipitated indicated highly saline source water, which had similar stable oxygen isotope compositions to relatively old brine groundwater within the Marsh, developed under a different hydroclimatic regime. The higher δ18O values suggest highly evaporitic conditions occurred at the Marsh, which may have been a playa lake to saline mud flat environment. In contrast, G2 dolomite precipitated from comparatively fresher water, and modelled δ18O values suggested formation from mixing between inflowing fresher groundwater with saline-brine groundwater within the Marsh. The δ18O values of the calcite indicates formation from brackish to saline groundwater, which suggests this process may be associated with coeval gypsum dissolution. In contrast to the modern hydrology of the Marsh, which is surface water dependent and driven by a flood and drought regime, past conditions conducive to dolomite precipitation suggest a groundwater dependent system, where shallow groundwaters were influenced by intensive evaporation.

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume II. Palo Duro basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and high variable precipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Utilization of Neutron Activation Analysis for geochemical study of major and trace elements in Bouregreg river basin (Morocco)

International Nuclear Information System (INIS)

Bounouira, H.; Bounakhla, M.; Embarch, K.; Choukri, A.; Cherkaoui, R.; Gaudry, A.; Treuil, M.; Chakiri, S.

2010-01-01

The Bouregreg river basin is located in the moroccan central massif which consists mainly of palaeozoic formations that were subject to the Hercynian orogeny. This study documents the backround geochemistry and hydrochemistry of the Bouregreg river basin, focusing on the distribution of major and trace elements, Rock samples were collected at 9 locations along the bouregreg river and its tributaries in the winter of 2005. Major (Al, fe, Mn, Na, K and Ti) and trace (Rb, Cs, Sr, Sc, Ba, Cr, V, Co, Ni, Zn, As, Sb, La, Ce, Nd, Sm, Tb, Dy, Yb, Lu, Hf, Ta, Mo, Th and U) elements were anlysed using instrumental Neutron Activation Analysis (INAA). Data show that most of the geochemistry and hydrochemistry are related to regional and local geology. the geochemical heritage of geological environment in the Bouregreg river basin is very important, that results from the more compatible behaviour and the inertia of some elements during the weathering (3d transition elements (Co, Ni, Cr,...), interne transition elements f (lanthanides, Zr, Hf, Nb, Ta,...)). The geochemical homogeneity of the basin shows also heritage during the crustal accretion (magmatism-metamorphism-sedimention) and the typology of this continental area is the same that the Upper Continental Crust (UCC). Some anomalously high heavy metal analyses, particulary for As and Sb, may be related to anthropogenic activities

Detrital fission-track-compositional signature of an orogenic chain-hinterland basin system: The case of the late Neogene Quaternary Valdelsa basin (Northern Apennines, Italy)

Science.gov (United States)

Balestrieri, M. L.; Benvenuti, M.; Tangocci, F.

2013-05-01

Detrital thermochronological data collected in syn-tectonic basin deposits are a promising tool for deciphering time and processes of the evolution of orogenic belts. Our study deals with the Valdelsa basin, one of the wider basins of central Tuscany, Italy. The Valdelsa basin is located at the rear of the Northern Apennines, a collisional orogen whose late Neogene Quaternary development is alternatively attributed to extensional and compressional regimes. These contrasting interpretations mostly rely on different reconstructions of the tectono-sedimentary evolution of several basins formed at the rear of the chain since the late Tortonian. Here, we explore the detrital thermochronological-compositional signature of tectonic and surface processes during the Valdelsa basin development. For this aim, detrital apatite fission-track analysis of 21 sand samples from the latest Messinian Gelasian fluvial to shallow marine basin deposits, has been accompanied by a clast composition analysis of 7 representative outcrops of the conglomerate facies. The grain-age distributions of the sediment samples are generally characterized by two distinct components, one younger peak (P1) varying between 5.5 ± 2.8 and 9.5 ± 1.0 Ma and one older peak (P2) varying from 15.0 ± 8.0 to 41.0 ± 10 Ma. By comparison with some bedrock ages obtained from the E-NE basin shoulder, we attributed the P2 peak to the Ligurian Units and the P1 peak to the Macigno Formation (Tuscan Units). These units are arranged one upon the other in the complex nappe pile forming the Northern Apennines orogen. While the gravel composition indicates a predominant feeding from the Ligurian units all along the sedimentary succession with a subordinate occurrence of Macigno pebbles slightly increasing upsection, the P1 peak is present even in the oldest collected sandy sediments. The early P1 occurrence reveals that the Macigno was exposed in the E-NE basin shoulder since at least the latest Messinian-early Zanclean

A comparison of integrated river basin management strategies: A global perspective

Science.gov (United States)

Zhao, Chunhong; Wang, Pei; Zhang, Guanghong

In order to achieve the integrated river basin management in the arid and rapid developing region, the Heihe River Basin (HRB) in Northwestern China, one of critical river basins were selected as a representative example, while the Murray-Darling Basin (MDB) in Australia and the Colorado River Basin (CRB) in the USA were selected for comparative analysis in this paper. Firstly, the comparable characters and hydrological contexts of these three watersheds were introduced in this paper. Then, based on comparative studies on the river basin challenges in terms of the drought, intensive irrigation, and rapid industrialization, the hydrological background of the MDB, the CRB and the HRB was presented. Subsequently, the river management strategies were compared in three aspects: water allocation, water organizations, and water act and scientific projects. Finally, we proposed recommendations for integrated river basin management for the HRB: (1) Water allocation strategies should be based on laws and markets on the whole basin; (2) Public participation should be stressed by the channels between governance organizations and local communities; (3) Scientific research should be integrated into river management to understand the interactions between the human and nature.

Hydrologic Sub-basins of Greenland

Data.gov (United States)

National Aeronautics and Space Administration — The Hydrologic Sub-basins of Greenland data set contains Geographic Information System (GIS) polygon shapefiles that include 293 hydrologic sub-basins of the...

Paleo-environment in the upper amazon basin during early to middle Miocene times

Science.gov (United States)

van Soelen, Els; Hoorn, Carina; Santos, Roberto V.; Dantas, Elton L.; Sinninghe Damsté, Jaap S.; Kim, Jung-Hyun

2014-05-01

The Amazon River has the largest catchment in the world and is responsible for the largest water discharge from land to the ocean. The river system that flows from the Andes to the Atlantic Equatorial Margin exists since the late Miocene, and results from Andean uplift which strongly affected erosion/deposition and major flow patterns in northern South-America. Two outcrop sites from the Solimões basin, Mariñame (17.7-16.1 Ma) and Los Chorros (14.2-12.7 Ma), may shed light on the inland paleo-environmental conditions during a period of active Andean uplift in the early to middle Miocene. Earlier works revealed the Mariñame outcrops to represent a river born in Amazonia. Instead the Los Chorros outcrops are relics of the Amazon River system, characterized by extensive wetlands consisting of swamps, shallow lakes, crevasse splays channels and crevasse-delta lakes (e.g. Hoorn et al., 2010). The freshwater ecosystems alternate with some intervals that are rich in marine palynomorphs (such as dinocysts), mangrove pollen, brackish tolerant molluscs and ostracods, which indicate brackish conditions and a marine influence. It is thought that these marine incursion are related to phases of global sea-level rise and rapid subsidence in the Andean foreland (Marshall & Lundberg, 1996). Still, much remains unknown about the Miocene river systems, like the extent and diversity of the wetland system and the nature of the marine incursions. To get a better understanding of the sources of the (in)organic material, geochemical methods were used. Strontium (Sr) and Neodymium (Nd) isotopes were analyzed on bulk sediments, and used for a paleo-provenance study. The Sr and Nd isotopic signature in the older section (Mariñame) is in general more radiogenic compared to the Los Chorros section. The most radiogenic values are comparable to those found nowadays in the the Precambrian Guyana shield. A Guyana sediment source would suggest a distinctly different flow direction of the major

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

Science.gov (United States)

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

2016-03-01

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

Petroleum geology of the Palo Duro Basin, Texas Panhandle

International Nuclear Information System (INIS)

Rose, P.R.

1986-03-01

The Palo Duro Basin, Permian Basin, Texas is an asymmetric, relatively shallow, intracratonic basin in the southern Texas Panhandle filled mostly by Mississippian, Pennsylvanian, and Permian sedimentary rocks. Although deeper and prolific prolific petroleum-producing basins adjoin it on the north (Anadarko Basin), south (Midland Basin), and east (Hardeman Basin), the Palo Duro Basin has produced remarkably small amounts of oil and gas to date. This is all the more noteworthy because the sedimentary sequence and rock types of the basin are similar to those of the adjacent basins. Analyses of the stratigraphic succession and structural configuration of the Palo Duro Basin suggest that adequate reservoir rocks, top-seals, and geologic structures are present. Most of the structures formed early enough to have trapped hydrocarbons if they were migrating in the rock column. Although additional work is under way to properly address the question of the petroleum source rocks, generation, and migration, the general absence of production in the basin may relate to an overall deficiency in hydrocarbon generation within the basin. Geologic information in this report will form part of the basis for further analysis and conclusions on hydrocarbon potential in the Palo Duro Basin

Lacustrine sedimentation and facies model for the last 45,000 yr in Chalco basin. Central Mexico

Science.gov (United States)

Ortega, B.; Lozano, S.; Caballero, M.; Herrera, D.

2013-05-01

Chalco basin in central Mexico (19° 15' N, 98° 58' W, 2200 m asl) is one of the most detailed lake sediment sequence analyzed in Mexico for paleoclimatic and paleoenvironmental studies. In this former lake, five drill cores up to 27 m depth were recovered in 1987-1989 by the UNAM team, and three cores covering most of the former sequence were obtained in 2008 and 2011. The upper 27 m of the Chalco lacustrine sequence contains the record of the last 45 kyr climate history in the northern American tropics. The active tectonic and volcanic setting of Chalco Lake in the Trans-Mexican Volcanic Belt, provides an opportunity to evaluate environmental (volcanic + tectonic vs. climatic) controls on lacustrine sedimentation. The establishment of a detailed time scale by 14C in pollen extracts provides an accurate chronological control. The stratigraphical and sedimentological analyses presented here provided the recognition of depositional environments and the architecture of the upper lacustrine succession. Sedimentary facies were defined on the basis of sedimentological descriptions, microscopic observation and compositional analyses. According to compositional criteria, facies were identified and groped into two main categories according to compositional criteria: 1) detrital and volcaniclastic, and 2) biogenic facies. The clastic facies includes massive to laminated, silty and clayey sediments composed of clay minerals, feldspars, amphiboles with minor amounts of quartz, opaque minerals and calcite. Diatoms are the most common biological remains in all the clastic facies. Most of the volcaniclastic deposits correspond to fall-out deposits, some of them of well documented eruptions of the nearby large stratovolcanoes Popocatepetl and Nevado de Toluca, which in turn serve as stratigraphical markers. The biogenic facies are massive to finely laminated diatom ooze and ostracod ooze layers. The sedimentary architecture of the lacustrine succession has been controlled by

Insights on the evolution of mid-ocean basins: the Atlantis Basin of southern Azores

Science.gov (United States)

Alves, T.; Bouriak, S.; Volkonskaya, A.; Monteiro, J.; Ivanov, M.

2003-04-01

Single-channel seismic reflection and sidescan (OKEAN) data acquired in an unstudied region of the North Atlantic give important insights on the evolution of mid-ocean basins. Located on the eastern flank of the Mid-Atlantic Ridge, south of the Azores Islands, the study area contains more than 1,000 ms two-way travel-time of sediments with a similar seismic stratigraphy to that of ODP sites 950-952 in the Madeira Abyssal Plain. Processed thickness values correspond to a maximum thickness of about 1450 m and an average thickness of more than 500 m based on velocity data from ODP sites 950-952. The structure of the surveyed area and its location in relation to the Madeira Abyssal Plain and Mid-Atlantic Ridge indicate the existence, south of Azores, of two distinct sedimentary basins separated by major structural lineaments (Azores-Gibraltar and Atlantis Fracture Zones) and by seamount chains (Cruiser-Great Meteor Chain, Plato-Atlantis Chain). The basement of the sedimentary basins is irregular, showing multiple dome-shaped volcanic structures identical to those in the Norwegian-Greenland Sea and Madeira Abyssal Plain. However, half-graben/graben basement blocks predominate east of 30ºW underneath a moderately deformed overburden. The complex structure observed most likely reflects changes in the direction and velocity of ocean spreading plus variations in the regional thermal gradients induced by local hot spots. In parallel, some of the sub-surface structures identified next to basin-bounding Fracture Zones may have resulted from transtensional and transpressional tectonism.

Evolution of the Rembrandt impact basin on Mercury.

Science.gov (United States)

Watters, Thomas R; Head, James W; Solomon, Sean C; Robinson, Mark S; Chapman, Clark R; Denevi, Brett W; Fassett, Caleb I; Murchie, Scott L; Strom, Robert G

2009-05-01

MESSENGER's second Mercury flyby revealed a ~715-kilometer-diameter impact basin, the second-largest well-preserved basin-scale impact structure known on the planet. The Rembrandt basin is comparable in age to the Caloris basin, is partially flooded by volcanic plains, and displays a unique wheel-and-spoke-like pattern of basin-radial and basin-concentric wrinkle ridges and graben. Stratigraphic relations indicate a multistaged infilling and deformational history involving successive or overlapping phases of contractional and extensional deformation. The youngest deformation of the basin involved the formation of a approximately 1000-kilometer-long lobate scarp, a product of the global cooling and contraction of Mercury.

Mechanism of crustal extension in the Laxmi Basin, Arabian Sea

Directory of Open Access Journals (Sweden)

Anju Pandey

2015-11-01

Full Text Available Continental rifting and magmatism has been extensively studied worldwide as it is believed that continental rifting, break up of continents and associated magmatism lead to genesis of new oceanic crust. However, various regions of the world show that these processes may lead to genesis of other types of crust than the oceanic crust. Laxmi Basin in the western continental margin of the India is one such region with an enigmatic crust. Due to its extreme strategic significance for the palaeogeographic reconstruction of continents during Cretaceous continental breakup of India, this basin has attracted various workers for more than two decades. However, still the issue of nature of crust in the basin remains controversial. In this contribution, in order to identify nature of crust, mechanism of continental extension in the Laxmi Basin has been studied for the first time through newly acquired seismic data from the basin. Here, we propose a plausible mechanism of crustal extension in the Laxmi Basin which eventually constrains the nature of crust of the Laxmi Basin. We have demonstrated that the crust in the Laxmi Basin can be categorised in two zones of stretched and transitional crust. In the stretched zone several fault bounded horst and graben structures are identified which preserve syn- and post-rift sediments along with different periods of hiatus in sedimentations as unconformities. These faults are identified as listric faults in the upper crust which sole out in the detachment faults. Detachment faults decouples the upper brittle and lower ductile crust. The transitional crust is identified as heavily intruded by sills and basaltic volcanic which were emplaced due to melting of subcontinental mantle (SCM after hyper-stretching of crust and serpentinisation of the SCM. Panikkar Ridge is proposed to be one such basaltic volcanic body derived from melting of lower part of the SCM.

Basin-wide impacts of climate change on ecosystem services in the Lower Mekong Basin

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Water resources support more than 60 million people in the Lower Mekong Basin (LMB) and are important for food security—especially rice production—and economic security. This study aims to quantify water yield under near- and long-term climate scenarios and assess the...

A multidisciplinary study of Holocene sediment records from Hjort Sø on Store Koldewey, Northeast Greenland

NARCIS (Netherlands)

Wagner, B.; Bennike, O.; Bos, J.A.A.; Cremer, H.; Lotter, A.F.; Melles, M.

2008-01-01

Two sediment cores of 70 and 252 cm length were recovered from Hjort Sø, a small lake on Store Koldewey, Northeast Greenland, and studied with a multidisciplinary approach in order to reconstruct the local environmental history and to test the relevance of proxies for paleoenvironmental information.

5. Basin assessment and watershed analysis

Science.gov (United States)

Leslie M. Reid; Robert R. Ziemer

1994-01-01

Abstract - Basin assessment is an important component of the President's Forest Plan, yet it has received little attention. Basin assessments are intended both to guide watershed analyses by specifying types of issues and interactions that need to be understood, and, eventually, to integrate the results of watershed analyses occurring within a river basin....

Upper Illinois River basin

Science.gov (United States)

Friedel, Michael J.

1998-01-01

During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

Hydrology of the Johnson Creek Basin, Oregon

Science.gov (United States)

Lee, Karl K.; Snyder, Daniel T.

2009-01-01

The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn

On the origin of the southern Permian Basin, Central Europe.

NARCIS (Netherlands)

van Wees, J.D.A.M.; Stephenson, R.A.; Ziegler, P.A.; Bayer, U.; McCann, T.; Dadlez, R.; Gaupp, R.; Narkiewicz, M.; Bitzer, F.; Scheck, M.

2000-01-01

A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the

Range extension of Moenkhausia oligolepis (Günther,1864 to the Pindaré river drainage, of Mearim river basin, and Itapecuru river basin of northeastern Brazil (Characiformes: Characidae

Directory of Open Access Journals (Sweden)

Erick Cristofore Guimarães

2016-08-01

Full Text Available The present study reports range extansion of Moenkhausia oligolepis to the Pindaré river drainage, of the Mearim river basin, and Itapecuru river basin, Maranhão state, northeastern Brazil. This species was previously known only from Venezuela, Guianas, and the Amazon River basins. In addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its diagnostic characters.

Identification of Critical Erosion Prone Areas and Computation of Sediment Yield Using Remote Sensing and GIS: A Case Study on Sarada River Basin

Science.gov (United States)

Sundara Kumar, P.; Venkata Praveen, T.; Anjanaya Prasad, M.; Santha Rao, P.

2018-06-01

The two most important resources blessed by nature to the mankind are land and water. Undoubtedly, these gifts have to be conserved and maintained with unflinching efforts from every one of us for an effective environmental and ecological balance. The efforts and energy of water resources engineers and conservationists are going in this direction to conserve these precious resources of nature. The present study is an attempt to develop suitable methodology to facilitate decision makers to conserve the resources and also reflects the cause mentioned above has been presented here. The main focus of this study is to identify the critical prone areas for soil erosion and computation of sediment yield in a small basin using Universal Soil Loss Equation and Modified Universal Soil Loss Equation (MUSLE) respectively. The developed model has been applied on Sarada river basin which has a drainage area of 1252.99 km2. This river is located in Andhra Pradesh State (AP), India. The basin has been divided into micro basins for effective estimation and also for precise identification of the areas that are prone to soil erosion. Remote Sensing and Geographic Information Systems tools were used to generate and spatially organize the data that is required for soil erosion modeling. It was found that the micro basins with very severe soil erosion are consisting of hilly areas with high topographic factor and 38.01% of the study area has the rate erosion more than 20 t/ha/year and hence requires an immediate attention from the soil conservation point of view. In this study region, though there is one discharge measuring gauge station available at Anakapalli but there is no sediment yield gauging means available to compute the sediment yield. Therefore, to arrive at the suspended-sediment concentration was a challenge task. In the present study the sediment measurement has been carried out with an instrument (DH-48), sediment sampling equipment as per IS: 4890-1968, has been used

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

International Nuclear Information System (INIS)

Leontiadis, J.L.

1980-10-01

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 m 3 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.)

Geology and Assessment of Undiscovered Oil and Gas Resources of the East Barents Basins Province and the Novaya Zemlya Basins and Admiralty Arch Province, 2008

Science.gov (United States)

Klett, Timothy R.; Moore, Thomas E.; Gautier, D.L.

2017-11-15

The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered petroleum resources of the East Barents Basins Province and the Novaya Zemlya Basins and Admiralty Arch Province as part of its Circum-Arctic Resource Appraisal. These two provinces are situated northeast of Scandinavia and the northwestern Russian Federation, on the Barents Sea Shelf between Novaya Zemlya to the east and the Barents Platform to the west. Three assessment units (AUs) were defined in the East Barents Basins Province for this study: the Kolguyev Terrace AU, the South Barents and Ludlov Saddle AU, and the North Barents Basin AU. A fourth AU, defined as the Novaya Zemlya Basins and Admiralty Arch AU, coincides with the Novaya Zemlya Basins and Admiralty Arch Province. These four AUs, all lying north of the Arctic Circle, were assessed for undiscovered, technically recoverable resources, resulting in total estimated mean volumes of ~7.4 billion barrels of crude oil, 318 trillion cubic feet (TCF) of natural gas, and 1.4 billion barrels of natural-gas liquids.

Bottom water circulation in Cascadia Basin

Science.gov (United States)

Hautala, Susan L.; Paul Johnson, H.; Hammond, Douglas E.

2009-10-01

A combination of beta spiral and minimum length inverse methods, along with a compilation of historical and recent high-resolution CTD data, are used to produce a quantitative estimate of the subthermocline circulation in Cascadia Basin. Flow in the North Pacific Deep Water, from 900-1900 m, is characterized by a basin-scale anticyclonic gyre. Below 2000 m, two water masses are present within the basin interior, distinguished by different potential temperature-salinity lines. These water masses, referred to as Cascadia Basin Bottom Water (CBBW) and Cascadia Basin Deep Water (CBDW), are separated by a transition zone at about 2400 m depth. Below the depth where it freely communicates with the broader North Pacific, Cascadia Basin is renewed by northward flow through deep gaps in the Blanco Fracture Zone that feeds the lower limb of a vertical circulation cell within the CBBW. Lower CBBW gradually warms and returns to the south at lighter density. Isopycnal layer renewal times, based on combined lateral and diapycnal advective fluxes, increase upwards from the bottom. The densest layer, existing in the southeast quadrant of the basin below ˜2850 m, has an advective flushing time of 0.6 years. The total volume flushing time for the entire CBBW is 2.4 years, corresponding to an average water parcel residence time of 4.7 years. Geothermal heating at the Cascadia Basin seafloor produces a characteristic bottom-intensified temperature anomaly and plays an important role in the conversion of cold bottom water to lighter density within the CBBW. Although covering only about 0.05% of the global seafloor, the combined effects of bottom heat flux and diapycnal mixing within Cascadia Basin provide about 2-3% of the total required global input to the upward branch of the global thermohaline circulation.

Large-scale coastal and fluvial models constrain the late Holocene evolution of the Ebro Delta